diff mbox series

[v2,04/10] iio: adc: at91-sama5d2_adc: convert to platform specific data structures

Message ID 20210824115441.681253-5-eugen.hristev@microchip.com (mailing list archive)
State Accepted
Headers show
Series iio: adc: at91-sama5d2_adc: add support for sama7g5 | expand

Commit Message

Eugen Hristev Aug. 24, 2021, 11:54 a.m. UTC
Convert the driver to platform specific structures. This means:
- create a register layout struct that will hold offsets for registers
- create a platform struct that will hold platform information (number of
channels, indexes for different channels and pointer to layout struct)
- convert specific macros that are platform dependent into platform variables

This step is in fact a no-op, but allows the driver to be more flexible
and for future enhancement including adding new platforms that are partly
compatible with the current driver and differ slightly in register layout
or capabilities for example.

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
---
 drivers/iio/adc/at91-sama5d2_adc.c | 410 +++++++++++++++++------------
 1 file changed, 247 insertions(+), 163 deletions(-)

Comments

Jonathan Cameron Aug. 30, 2021, 12:21 p.m. UTC | #1
On Tue, 24 Aug 2021 14:54:35 +0300
Eugen Hristev <eugen.hristev@microchip.com> wrote:

> Convert the driver to platform specific structures. This means:
> - create a register layout struct that will hold offsets for registers
> - create a platform struct that will hold platform information (number of
> channels, indexes for different channels and pointer to layout struct)
> - convert specific macros that are platform dependent into platform variables
> 
> This step is in fact a no-op, but allows the driver to be more flexible
> and for future enhancement including adding new platforms that are partly
> compatible with the current driver and differ slightly in register layout
> or capabilities for example.
> 
> Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
> ---
>  drivers/iio/adc/at91-sama5d2_adc.c | 410 +++++++++++++++++------------
>  1 file changed, 247 insertions(+), 163 deletions(-)
> 
> diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c
> index 9d71dcffcf93..8ede18b8d789 100644
> --- a/drivers/iio/adc/at91-sama5d2_adc.c
> +++ b/drivers/iio/adc/at91-sama5d2_adc.c
> @@ -27,8 +27,9 @@
>  #include <linux/pinctrl/consumer.h>
>  #include <linux/regulator/consumer.h>
>  
> +struct at91_adc_reg_layout {
>  /* Control Register */
> -#define AT91_SAMA5D2_CR		0x00
> +	u16				CR;
>  /* Software Reset */
>  #define	AT91_SAMA5D2_CR_SWRST		BIT(0)
>  /* Start Conversion */
> @@ -39,7 +40,7 @@
>  #define	AT91_SAMA5D2_CR_CMPRST		BIT(4)
>  
>  /* Mode Register */
> -#define AT91_SAMA5D2_MR		0x04
> +	u16				MR;
>  /* Trigger Selection */
>  #define	AT91_SAMA5D2_MR_TRGSEL(v)	((v) << 1)
>  /* ADTRG */
> @@ -82,19 +83,19 @@
>  #define	AT91_SAMA5D2_MR_USEQ		BIT(31)
>  
>  /* Channel Sequence Register 1 */
> -#define AT91_SAMA5D2_SEQR1	0x08
> +	u16				SEQR1;
>  /* Channel Sequence Register 2 */
> -#define AT91_SAMA5D2_SEQR2	0x0c
> +	u16				SEQR2;
>  /* Channel Enable Register */
> -#define AT91_SAMA5D2_CHER	0x10
> +	u16				CHER;
>  /* Channel Disable Register */
> -#define AT91_SAMA5D2_CHDR	0x14
> +	u16				CHDR;
>  /* Channel Status Register */
> -#define AT91_SAMA5D2_CHSR	0x18
> +	u16				CHSR;
>  /* Last Converted Data Register */
> -#define AT91_SAMA5D2_LCDR	0x20
> +	u16				LCDR;
>  /* Interrupt Enable Register */
> -#define AT91_SAMA5D2_IER	0x24
> +	u16				IER;
>  /* Interrupt Enable Register - TS X measurement ready */
>  #define AT91_SAMA5D2_IER_XRDY   BIT(20)
>  /* Interrupt Enable Register - TS Y measurement ready */
> @@ -109,22 +110,23 @@
>  #define AT91_SAMA5D2_IER_PEN    BIT(29)
>  /* Interrupt Enable Register - No pen detect */
>  #define AT91_SAMA5D2_IER_NOPEN  BIT(30)
> +
>  /* Interrupt Disable Register */
> -#define AT91_SAMA5D2_IDR	0x28
> +	u16				IDR;
>  /* Interrupt Mask Register */
> -#define AT91_SAMA5D2_IMR	0x2c
> +	u16				IMR;
>  /* Interrupt Status Register */
> -#define AT91_SAMA5D2_ISR	0x30
> +	u16				ISR;
>  /* Interrupt Status Register - Pen touching sense status */
>  #define AT91_SAMA5D2_ISR_PENS   BIT(31)
>  /* Last Channel Trigger Mode Register */
> -#define AT91_SAMA5D2_LCTMR	0x34
> +	u16				LCTMR;
>  /* Last Channel Compare Window Register */
> -#define AT91_SAMA5D2_LCCWR	0x38
> +	u16				LCCWR;
>  /* Overrun Status Register */
> -#define AT91_SAMA5D2_OVER	0x3c
> +	u16				OVER;
>  /* Extended Mode Register */
> -#define AT91_SAMA5D2_EMR	0x40
> +	u16				EMR;
>  /* Extended Mode Register - Oversampling rate */
>  #define AT91_SAMA5D2_EMR_OSR(V)			((V) << 16)
>  #define AT91_SAMA5D2_EMR_OSR_MASK		GENMASK(17, 16)
> @@ -134,22 +136,22 @@
>  
>  /* Extended Mode Register - Averaging on single trigger event */
>  #define AT91_SAMA5D2_EMR_ASTE(V)		((V) << 20)
> +
>  /* Compare Window Register */
> -#define AT91_SAMA5D2_CWR	0x44
> +	u16				CWR;
>  /* Channel Gain Register */
> -#define AT91_SAMA5D2_CGR	0x48
> -
> +	u16				CGR;
>  /* Channel Offset Register */
> -#define AT91_SAMA5D2_COR	0x4c
> +	u16				COR;
>  #define AT91_SAMA5D2_COR_DIFF_OFFSET	16
>  
>  /* Analog Control Register */
> -#define AT91_SAMA5D2_ACR	0x94
> +	u16				ACR;
>  /* Analog Control Register - Pen detect sensitivity mask */
>  #define AT91_SAMA5D2_ACR_PENDETSENS_MASK        GENMASK(1, 0)
>  
>  /* Touchscreen Mode Register */
> -#define AT91_SAMA5D2_TSMR	0xb0
> +	u16				TSMR;
>  /* Touchscreen Mode Register - No touch mode */
>  #define AT91_SAMA5D2_TSMR_TSMODE_NONE           0
>  /* Touchscreen Mode Register - 4 wire screen, no pressure measurement */
> @@ -178,13 +180,13 @@
>  #define AT91_SAMA5D2_TSMR_PENDET_ENA            BIT(24)
>  
>  /* Touchscreen X Position Register */
> -#define AT91_SAMA5D2_XPOSR	0xb4
> +	u16				XPOSR;
>  /* Touchscreen Y Position Register */
> -#define AT91_SAMA5D2_YPOSR	0xb8
> +	u16				YPOSR;
>  /* Touchscreen Pressure Register */
> -#define AT91_SAMA5D2_PRESSR	0xbc
> +	u16				PRESSR;
>  /* Trigger Register */
> -#define AT91_SAMA5D2_TRGR	0xc0
> +	u16				TRGR;
>  /* Mask for TRGMOD field of TRGR register */
>  #define AT91_SAMA5D2_TRGR_TRGMOD_MASK GENMASK(2, 0)
>  /* No trigger, only software trigger can start conversions */
> @@ -203,30 +205,52 @@
>  #define AT91_SAMA5D2_TRGR_TRGPER(x)             ((x) << 16)
>  
>  /* Correction Select Register */
> -#define AT91_SAMA5D2_COSR	0xd0
> +	u16				COSR;
>  /* Correction Value Register */
> -#define AT91_SAMA5D2_CVR	0xd4
> +	u16				CVR;
>  /* Channel Error Correction Register */
> -#define AT91_SAMA5D2_CECR	0xd8
> +	u16				CECR;
>  /* Write Protection Mode Register */
> -#define AT91_SAMA5D2_WPMR	0xe4
> +	u16				WPMR;
>  /* Write Protection Status Register */
> -#define AT91_SAMA5D2_WPSR	0xe8
> +	u16				WPSR;
>  /* Version Register */
> -#define AT91_SAMA5D2_VERSION	0xfc
> -
> -#define AT91_SAMA5D2_HW_TRIG_CNT 3
> -#define AT91_SAMA5D2_SINGLE_CHAN_CNT 12
> -#define AT91_SAMA5D2_DIFF_CHAN_CNT 6
> -
> -#define AT91_SAMA5D2_TIMESTAMP_CHAN_IDX (AT91_SAMA5D2_SINGLE_CHAN_CNT + \
> -					 AT91_SAMA5D2_DIFF_CHAN_CNT + 1)
> +	u16				VERSION;
> +};
>  
> -#define AT91_SAMA5D2_TOUCH_X_CHAN_IDX (AT91_SAMA5D2_SINGLE_CHAN_CNT + \
> -					 AT91_SAMA5D2_DIFF_CHAN_CNT * 2)
> -#define AT91_SAMA5D2_TOUCH_Y_CHAN_IDX   (AT91_SAMA5D2_TOUCH_X_CHAN_IDX + 1)
> -#define AT91_SAMA5D2_TOUCH_P_CHAN_IDX   (AT91_SAMA5D2_TOUCH_Y_CHAN_IDX + 1)
> -#define AT91_SAMA5D2_MAX_CHAN_IDX	AT91_SAMA5D2_TOUCH_P_CHAN_IDX
> +static const struct at91_adc_reg_layout sama5d2_layout = {
> +	.CR =			0x00,
> +	.MR =			0x04,
> +	.SEQR1 =		0x08,
> +	.SEQR2 =		0x0c,
> +	.CHER =			0x10,
> +	.CHDR =			0x14,
> +	.CHSR =			0x18,
> +	.LCDR =			0x20,
> +	.IER =			0x24,
> +	.IDR =			0x28,
> +	.IMR =			0x2c,
> +	.ISR =			0x30,
> +	.LCTMR =		0x34,
> +	.LCCWR =		0x38,
> +	.OVER =			0x3c,
> +	.EMR =			0x40,
> +	.CWR =			0x44,
> +	.CGR =			0x48,
> +	.COR =			0x4c,
> +	.ACR =			0x94,
> +	.TSMR =			0xb0,
> +	.XPOSR =		0xb4,
> +	.YPOSR =		0xb8,
> +	.PRESSR =		0xbc,
> +	.TRGR =			0xc0,
> +	.COSR =			0xd0,
> +	.CVR =			0xd4,
> +	.CECR =			0xd8,
> +	.WPMR =			0xe4,
> +	.WPSR =			0xe8,
> +	.VERSION =		0xfc,
> +};
>  
>  #define AT91_SAMA5D2_TOUCH_SAMPLE_PERIOD_US          2000    /* 2ms */
>  #define AT91_SAMA5D2_TOUCH_PEN_DETECT_DEBOUNCE_US    200
> @@ -235,18 +259,6 @@
>  
>  #define AT91_SAMA5D2_MAX_POS_BITS			12
>  
> -/*
> - * Maximum number of bytes to hold conversion from all channels
> - * without the timestamp.
> - */
> -#define AT91_BUFFER_MAX_CONVERSION_BYTES ((AT91_SAMA5D2_SINGLE_CHAN_CNT + \
> -					 AT91_SAMA5D2_DIFF_CHAN_CNT) * 2)
> -
> -/* This total must also include the timestamp */
> -#define AT91_BUFFER_MAX_BYTES (AT91_BUFFER_MAX_CONVERSION_BYTES + 8)
> -
> -#define AT91_BUFFER_MAX_HWORDS (AT91_BUFFER_MAX_BYTES / 2)
> -
>  #define AT91_HWFIFO_MAX_SIZE_STR	"128"
>  #define AT91_HWFIFO_MAX_SIZE		128
>  
> @@ -255,12 +267,12 @@
>  #define AT91_OSR_4SAMPLES		4
>  #define AT91_OSR_16SAMPLES		16
>  
> -#define AT91_SAMA5D2_CHAN_SINGLE(num, addr)				\
> +#define AT91_SAMA5D2_CHAN_SINGLE(index, num, addr)			\
>  	{								\
>  		.type = IIO_VOLTAGE,					\
>  		.channel = num,						\
>  		.address = addr,					\
> -		.scan_index = num,					\
> +		.scan_index = index,					\
>  		.scan_type = {						\
>  			.sign = 'u',					\
>  			.realbits = 14,					\
> @@ -274,14 +286,14 @@
>  		.indexed = 1,						\
>  	}
>  
> -#define AT91_SAMA5D2_CHAN_DIFF(num, num2, addr)				\
> +#define AT91_SAMA5D2_CHAN_DIFF(index, num, num2, addr)			\
>  	{								\
>  		.type = IIO_VOLTAGE,					\
>  		.differential = 1,					\
>  		.channel = num,						\
>  		.channel2 = num2,					\
>  		.address = addr,					\
> -		.scan_index = num + AT91_SAMA5D2_SINGLE_CHAN_CNT,	\
> +		.scan_index = index,					\
>  		.scan_type = {						\
>  			.sign = 's',					\
>  			.realbits = 14,					\
> @@ -328,13 +340,48 @@
>  		.datasheet_name = name,					\
>  	}
>  
> -#define at91_adc_readl(st, reg)		readl_relaxed(st->base + reg)
> -#define at91_adc_writel(st, reg, val)	writel_relaxed(val, st->base + reg)
> +#define at91_adc_readl(st, reg)						\
> +	readl_relaxed((st)->base + (st)->soc_info.platform->layout->reg)
I was a bit in two minds about whether this should be in capitals to make it clear
macro magic is going on, or whether lowercase is fine.  In the end I couldn't make
up my mind so will accept it like this! :)


Jonathan
Eugen Hristev Aug. 30, 2021, 12:28 p.m. UTC | #2
On 8/30/21 3:21 PM, Jonathan Cameron wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> 
> On Tue, 24 Aug 2021 14:54:35 +0300
> Eugen Hristev <eugen.hristev@microchip.com> wrote:
> 
>> Convert the driver to platform specific structures. This means:
>> - create a register layout struct that will hold offsets for registers
>> - create a platform struct that will hold platform information (number of
>> channels, indexes for different channels and pointer to layout struct)
>> - convert specific macros that are platform dependent into platform variables
>>
>> This step is in fact a no-op, but allows the driver to be more flexible
>> and for future enhancement including adding new platforms that are partly
>> compatible with the current driver and differ slightly in register layout
>> or capabilities for example.
>>
>> Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
>> ---
>>   drivers/iio/adc/at91-sama5d2_adc.c | 410 +++++++++++++++++------------
>>   1 file changed, 247 insertions(+), 163 deletions(-)
>>
>> diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c
>> index 9d71dcffcf93..8ede18b8d789 100644
>> --- a/drivers/iio/adc/at91-sama5d2_adc.c
>> +++ b/drivers/iio/adc/at91-sama5d2_adc.c
>> @@ -27,8 +27,9 @@
>>   #include <linux/pinctrl/consumer.h>
>>   #include <linux/regulator/consumer.h>
>>
>> +struct at91_adc_reg_layout {
>>   /* Control Register */
>> -#define AT91_SAMA5D2_CR              0x00
>> +     u16                             CR;
>>   /* Software Reset */
>>   #define      AT91_SAMA5D2_CR_SWRST           BIT(0)
>>   /* Start Conversion */
>> @@ -39,7 +40,7 @@
>>   #define      AT91_SAMA5D2_CR_CMPRST          BIT(4)
>>
>>   /* Mode Register */
>> -#define AT91_SAMA5D2_MR              0x04
>> +     u16                             MR;
>>   /* Trigger Selection */
>>   #define      AT91_SAMA5D2_MR_TRGSEL(v)       ((v) << 1)
>>   /* ADTRG */
>> @@ -82,19 +83,19 @@
>>   #define      AT91_SAMA5D2_MR_USEQ            BIT(31)
>>
>>   /* Channel Sequence Register 1 */
>> -#define AT91_SAMA5D2_SEQR1   0x08
>> +     u16                             SEQR1;
>>   /* Channel Sequence Register 2 */
>> -#define AT91_SAMA5D2_SEQR2   0x0c
>> +     u16                             SEQR2;
>>   /* Channel Enable Register */
>> -#define AT91_SAMA5D2_CHER    0x10
>> +     u16                             CHER;
>>   /* Channel Disable Register */
>> -#define AT91_SAMA5D2_CHDR    0x14
>> +     u16                             CHDR;
>>   /* Channel Status Register */
>> -#define AT91_SAMA5D2_CHSR    0x18
>> +     u16                             CHSR;
>>   /* Last Converted Data Register */
>> -#define AT91_SAMA5D2_LCDR    0x20
>> +     u16                             LCDR;
>>   /* Interrupt Enable Register */
>> -#define AT91_SAMA5D2_IER     0x24
>> +     u16                             IER;
>>   /* Interrupt Enable Register - TS X measurement ready */
>>   #define AT91_SAMA5D2_IER_XRDY   BIT(20)
>>   /* Interrupt Enable Register - TS Y measurement ready */
>> @@ -109,22 +110,23 @@
>>   #define AT91_SAMA5D2_IER_PEN    BIT(29)
>>   /* Interrupt Enable Register - No pen detect */
>>   #define AT91_SAMA5D2_IER_NOPEN  BIT(30)
>> +
>>   /* Interrupt Disable Register */
>> -#define AT91_SAMA5D2_IDR     0x28
>> +     u16                             IDR;
>>   /* Interrupt Mask Register */
>> -#define AT91_SAMA5D2_IMR     0x2c
>> +     u16                             IMR;
>>   /* Interrupt Status Register */
>> -#define AT91_SAMA5D2_ISR     0x30
>> +     u16                             ISR;
>>   /* Interrupt Status Register - Pen touching sense status */
>>   #define AT91_SAMA5D2_ISR_PENS   BIT(31)
>>   /* Last Channel Trigger Mode Register */
>> -#define AT91_SAMA5D2_LCTMR   0x34
>> +     u16                             LCTMR;
>>   /* Last Channel Compare Window Register */
>> -#define AT91_SAMA5D2_LCCWR   0x38
>> +     u16                             LCCWR;
>>   /* Overrun Status Register */
>> -#define AT91_SAMA5D2_OVER    0x3c
>> +     u16                             OVER;
>>   /* Extended Mode Register */
>> -#define AT91_SAMA5D2_EMR     0x40
>> +     u16                             EMR;
>>   /* Extended Mode Register - Oversampling rate */
>>   #define AT91_SAMA5D2_EMR_OSR(V)                      ((V) << 16)
>>   #define AT91_SAMA5D2_EMR_OSR_MASK            GENMASK(17, 16)
>> @@ -134,22 +136,22 @@
>>
>>   /* Extended Mode Register - Averaging on single trigger event */
>>   #define AT91_SAMA5D2_EMR_ASTE(V)             ((V) << 20)
>> +
>>   /* Compare Window Register */
>> -#define AT91_SAMA5D2_CWR     0x44
>> +     u16                             CWR;
>>   /* Channel Gain Register */
>> -#define AT91_SAMA5D2_CGR     0x48
>> -
>> +     u16                             CGR;
>>   /* Channel Offset Register */
>> -#define AT91_SAMA5D2_COR     0x4c
>> +     u16                             COR;
>>   #define AT91_SAMA5D2_COR_DIFF_OFFSET 16
>>
>>   /* Analog Control Register */
>> -#define AT91_SAMA5D2_ACR     0x94
>> +     u16                             ACR;
>>   /* Analog Control Register - Pen detect sensitivity mask */
>>   #define AT91_SAMA5D2_ACR_PENDETSENS_MASK        GENMASK(1, 0)
>>
>>   /* Touchscreen Mode Register */
>> -#define AT91_SAMA5D2_TSMR    0xb0
>> +     u16                             TSMR;
>>   /* Touchscreen Mode Register - No touch mode */
>>   #define AT91_SAMA5D2_TSMR_TSMODE_NONE           0
>>   /* Touchscreen Mode Register - 4 wire screen, no pressure measurement */
>> @@ -178,13 +180,13 @@
>>   #define AT91_SAMA5D2_TSMR_PENDET_ENA            BIT(24)
>>
>>   /* Touchscreen X Position Register */
>> -#define AT91_SAMA5D2_XPOSR   0xb4
>> +     u16                             XPOSR;
>>   /* Touchscreen Y Position Register */
>> -#define AT91_SAMA5D2_YPOSR   0xb8
>> +     u16                             YPOSR;
>>   /* Touchscreen Pressure Register */
>> -#define AT91_SAMA5D2_PRESSR  0xbc
>> +     u16                             PRESSR;
>>   /* Trigger Register */
>> -#define AT91_SAMA5D2_TRGR    0xc0
>> +     u16                             TRGR;
>>   /* Mask for TRGMOD field of TRGR register */
>>   #define AT91_SAMA5D2_TRGR_TRGMOD_MASK GENMASK(2, 0)
>>   /* No trigger, only software trigger can start conversions */
>> @@ -203,30 +205,52 @@
>>   #define AT91_SAMA5D2_TRGR_TRGPER(x)             ((x) << 16)
>>
>>   /* Correction Select Register */
>> -#define AT91_SAMA5D2_COSR    0xd0
>> +     u16                             COSR;
>>   /* Correction Value Register */
>> -#define AT91_SAMA5D2_CVR     0xd4
>> +     u16                             CVR;
>>   /* Channel Error Correction Register */
>> -#define AT91_SAMA5D2_CECR    0xd8
>> +     u16                             CECR;
>>   /* Write Protection Mode Register */
>> -#define AT91_SAMA5D2_WPMR    0xe4
>> +     u16                             WPMR;
>>   /* Write Protection Status Register */
>> -#define AT91_SAMA5D2_WPSR    0xe8
>> +     u16                             WPSR;
>>   /* Version Register */
>> -#define AT91_SAMA5D2_VERSION 0xfc
>> -
>> -#define AT91_SAMA5D2_HW_TRIG_CNT 3
>> -#define AT91_SAMA5D2_SINGLE_CHAN_CNT 12
>> -#define AT91_SAMA5D2_DIFF_CHAN_CNT 6
>> -
>> -#define AT91_SAMA5D2_TIMESTAMP_CHAN_IDX (AT91_SAMA5D2_SINGLE_CHAN_CNT + \
>> -                                      AT91_SAMA5D2_DIFF_CHAN_CNT + 1)
>> +     u16                             VERSION;
>> +};
>>
>> -#define AT91_SAMA5D2_TOUCH_X_CHAN_IDX (AT91_SAMA5D2_SINGLE_CHAN_CNT + \
>> -                                      AT91_SAMA5D2_DIFF_CHAN_CNT * 2)
>> -#define AT91_SAMA5D2_TOUCH_Y_CHAN_IDX   (AT91_SAMA5D2_TOUCH_X_CHAN_IDX + 1)
>> -#define AT91_SAMA5D2_TOUCH_P_CHAN_IDX   (AT91_SAMA5D2_TOUCH_Y_CHAN_IDX + 1)
>> -#define AT91_SAMA5D2_MAX_CHAN_IDX    AT91_SAMA5D2_TOUCH_P_CHAN_IDX
>> +static const struct at91_adc_reg_layout sama5d2_layout = {
>> +     .CR =                   0x00,
>> +     .MR =                   0x04,
>> +     .SEQR1 =                0x08,
>> +     .SEQR2 =                0x0c,
>> +     .CHER =                 0x10,
>> +     .CHDR =                 0x14,
>> +     .CHSR =                 0x18,
>> +     .LCDR =                 0x20,
>> +     .IER =                  0x24,
>> +     .IDR =                  0x28,
>> +     .IMR =                  0x2c,
>> +     .ISR =                  0x30,
>> +     .LCTMR =                0x34,
>> +     .LCCWR =                0x38,
>> +     .OVER =                 0x3c,
>> +     .EMR =                  0x40,
>> +     .CWR =                  0x44,
>> +     .CGR =                  0x48,
>> +     .COR =                  0x4c,
>> +     .ACR =                  0x94,
>> +     .TSMR =                 0xb0,
>> +     .XPOSR =                0xb4,
>> +     .YPOSR =                0xb8,
>> +     .PRESSR =               0xbc,
>> +     .TRGR =                 0xc0,
>> +     .COSR =                 0xd0,
>> +     .CVR =                  0xd4,
>> +     .CECR =                 0xd8,
>> +     .WPMR =                 0xe4,
>> +     .WPSR =                 0xe8,
>> +     .VERSION =              0xfc,
>> +};
>>
>>   #define AT91_SAMA5D2_TOUCH_SAMPLE_PERIOD_US          2000    /* 2ms */
>>   #define AT91_SAMA5D2_TOUCH_PEN_DETECT_DEBOUNCE_US    200
>> @@ -235,18 +259,6 @@
>>
>>   #define AT91_SAMA5D2_MAX_POS_BITS                    12
>>
>> -/*
>> - * Maximum number of bytes to hold conversion from all channels
>> - * without the timestamp.
>> - */
>> -#define AT91_BUFFER_MAX_CONVERSION_BYTES ((AT91_SAMA5D2_SINGLE_CHAN_CNT + \
>> -                                      AT91_SAMA5D2_DIFF_CHAN_CNT) * 2)
>> -
>> -/* This total must also include the timestamp */
>> -#define AT91_BUFFER_MAX_BYTES (AT91_BUFFER_MAX_CONVERSION_BYTES + 8)
>> -
>> -#define AT91_BUFFER_MAX_HWORDS (AT91_BUFFER_MAX_BYTES / 2)
>> -
>>   #define AT91_HWFIFO_MAX_SIZE_STR     "128"
>>   #define AT91_HWFIFO_MAX_SIZE         128
>>
>> @@ -255,12 +267,12 @@
>>   #define AT91_OSR_4SAMPLES            4
>>   #define AT91_OSR_16SAMPLES           16
>>
>> -#define AT91_SAMA5D2_CHAN_SINGLE(num, addr)                          \
>> +#define AT91_SAMA5D2_CHAN_SINGLE(index, num, addr)                   \
>>        {                                                               \
>>                .type = IIO_VOLTAGE,                                    \
>>                .channel = num,                                         \
>>                .address = addr,                                        \
>> -             .scan_index = num,                                      \
>> +             .scan_index = index,                                    \
>>                .scan_type = {                                          \
>>                        .sign = 'u',                                    \
>>                        .realbits = 14,                                 \
>> @@ -274,14 +286,14 @@
>>                .indexed = 1,                                           \
>>        }
>>
>> -#define AT91_SAMA5D2_CHAN_DIFF(num, num2, addr)                              \
>> +#define AT91_SAMA5D2_CHAN_DIFF(index, num, num2, addr)                       \
>>        {                                                               \
>>                .type = IIO_VOLTAGE,                                    \
>>                .differential = 1,                                      \
>>                .channel = num,                                         \
>>                .channel2 = num2,                                       \
>>                .address = addr,                                        \
>> -             .scan_index = num + AT91_SAMA5D2_SINGLE_CHAN_CNT,       \
>> +             .scan_index = index,                                    \
>>                .scan_type = {                                          \
>>                        .sign = 's',                                    \
>>                        .realbits = 14,                                 \
>> @@ -328,13 +340,48 @@
>>                .datasheet_name = name,                                 \
>>        }
>>
>> -#define at91_adc_readl(st, reg)              readl_relaxed(st->base + reg)
>> -#define at91_adc_writel(st, reg, val)        writel_relaxed(val, st->base + reg)
>> +#define at91_adc_readl(st, reg)                                              \
>> +     readl_relaxed((st)->base + (st)->soc_info.platform->layout->reg)
> I was a bit in two minds about whether this should be in capitals to make it clear
> macro magic is going on, or whether lowercase is fine.  In the end I couldn't make
> up my mind so will accept it like this! :)
> 
> 
> Jonathan
> 


I was doubting as well when I wrote this... but what convinced me was 
the much cleaner calls to the reg read and writes.
Has some drawbacks sometimes (like the XPOSR and YPOSR writes), but they 
are not all over the code, so I guess it's fine.

Thanks for reviewing !
Eugen Hristev Aug. 30, 2021, 12:31 p.m. UTC | #3
On 8/24/21 2:54 PM, Eugen Hristev wrote:
> Convert the driver to platform specific structures. This means:
> - create a register layout struct that will hold offsets for registers
> - create a platform struct that will hold platform information (number of
> channels, indexes for different channels and pointer to layout struct)
> - convert specific macros that are platform dependent into platform variables
> 
> This step is in fact a no-op, but allows the driver to be more flexible
> and for future enhancement including adding new platforms that are partly
> compatible with the current driver and differ slightly in register layout
> or capabilities for example.
> 
> Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
> ---
>   drivers/iio/adc/at91-sama5d2_adc.c | 410 +++++++++++++++++------------
>   1 file changed, 247 insertions(+), 163 deletions(-)
> 
> diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c
> index 9d71dcffcf93..8ede18b8d789 100644
> --- a/drivers/iio/adc/at91-sama5d2_adc.c
> +++ b/drivers/iio/adc/at91-sama5d2_adc.c
> @@ -27,8 +27,9 @@
>   #include <linux/pinctrl/consumer.h>
>   #include <linux/regulator/consumer.h>
>   
> +struct at91_adc_reg_layout {
>   /* Control Register */
> -#define AT91_SAMA5D2_CR		0x00
> +	u16				CR;
>   /* Software Reset */
>   #define	AT91_SAMA5D2_CR_SWRST		BIT(0)
>   /* Start Conversion */
> @@ -39,7 +40,7 @@
>   #define	AT91_SAMA5D2_CR_CMPRST		BIT(4)
>   
>   /* Mode Register */
> -#define AT91_SAMA5D2_MR		0x04
> +	u16				MR;
>   /* Trigger Selection */
>   #define	AT91_SAMA5D2_MR_TRGSEL(v)	((v) << 1)
>   /* ADTRG */
> @@ -82,19 +83,19 @@
>   #define	AT91_SAMA5D2_MR_USEQ		BIT(31)
>   
>   /* Channel Sequence Register 1 */
> -#define AT91_SAMA5D2_SEQR1	0x08
> +	u16				SEQR1;
>   /* Channel Sequence Register 2 */
> -#define AT91_SAMA5D2_SEQR2	0x0c
> +	u16				SEQR2;
>   /* Channel Enable Register */
> -#define AT91_SAMA5D2_CHER	0x10
> +	u16				CHER;
>   /* Channel Disable Register */
> -#define AT91_SAMA5D2_CHDR	0x14
> +	u16				CHDR;
>   /* Channel Status Register */
> -#define AT91_SAMA5D2_CHSR	0x18
> +	u16				CHSR;
>   /* Last Converted Data Register */
> -#define AT91_SAMA5D2_LCDR	0x20
> +	u16				LCDR;
>   /* Interrupt Enable Register */
> -#define AT91_SAMA5D2_IER	0x24
> +	u16				IER;
>   /* Interrupt Enable Register - TS X measurement ready */
>   #define AT91_SAMA5D2_IER_XRDY   BIT(20)
>   /* Interrupt Enable Register - TS Y measurement ready */
> @@ -109,22 +110,23 @@
>   #define AT91_SAMA5D2_IER_PEN    BIT(29)
>   /* Interrupt Enable Register - No pen detect */
>   #define AT91_SAMA5D2_IER_NOPEN  BIT(30)
> +
>   /* Interrupt Disable Register */
> -#define AT91_SAMA5D2_IDR	0x28
> +	u16				IDR;
>   /* Interrupt Mask Register */
> -#define AT91_SAMA5D2_IMR	0x2c
> +	u16				IMR;
>   /* Interrupt Status Register */
> -#define AT91_SAMA5D2_ISR	0x30
> +	u16				ISR;
>   /* Interrupt Status Register - Pen touching sense status */
>   #define AT91_SAMA5D2_ISR_PENS   BIT(31)
>   /* Last Channel Trigger Mode Register */
> -#define AT91_SAMA5D2_LCTMR	0x34
> +	u16				LCTMR;
>   /* Last Channel Compare Window Register */
> -#define AT91_SAMA5D2_LCCWR	0x38
> +	u16				LCCWR;
>   /* Overrun Status Register */
> -#define AT91_SAMA5D2_OVER	0x3c
> +	u16				OVER;
>   /* Extended Mode Register */
> -#define AT91_SAMA5D2_EMR	0x40
> +	u16				EMR;
>   /* Extended Mode Register - Oversampling rate */
>   #define AT91_SAMA5D2_EMR_OSR(V)			((V) << 16)
>   #define AT91_SAMA5D2_EMR_OSR_MASK		GENMASK(17, 16)
> @@ -134,22 +136,22 @@
>   
>   /* Extended Mode Register - Averaging on single trigger event */
>   #define AT91_SAMA5D2_EMR_ASTE(V)		((V) << 20)
> +
>   /* Compare Window Register */
> -#define AT91_SAMA5D2_CWR	0x44
> +	u16				CWR;
>   /* Channel Gain Register */
> -#define AT91_SAMA5D2_CGR	0x48
> -
> +	u16				CGR;
>   /* Channel Offset Register */
> -#define AT91_SAMA5D2_COR	0x4c
> +	u16				COR;
>   #define AT91_SAMA5D2_COR_DIFF_OFFSET	16
>   
>   /* Analog Control Register */
> -#define AT91_SAMA5D2_ACR	0x94
> +	u16				ACR;
>   /* Analog Control Register - Pen detect sensitivity mask */
>   #define AT91_SAMA5D2_ACR_PENDETSENS_MASK        GENMASK(1, 0)
>   
>   /* Touchscreen Mode Register */
> -#define AT91_SAMA5D2_TSMR	0xb0
> +	u16				TSMR;
>   /* Touchscreen Mode Register - No touch mode */
>   #define AT91_SAMA5D2_TSMR_TSMODE_NONE           0
>   /* Touchscreen Mode Register - 4 wire screen, no pressure measurement */
> @@ -178,13 +180,13 @@
>   #define AT91_SAMA5D2_TSMR_PENDET_ENA            BIT(24)
>   
>   /* Touchscreen X Position Register */
> -#define AT91_SAMA5D2_XPOSR	0xb4
> +	u16				XPOSR;
>   /* Touchscreen Y Position Register */
> -#define AT91_SAMA5D2_YPOSR	0xb8
> +	u16				YPOSR;
>   /* Touchscreen Pressure Register */
> -#define AT91_SAMA5D2_PRESSR	0xbc
> +	u16				PRESSR;
>   /* Trigger Register */
> -#define AT91_SAMA5D2_TRGR	0xc0
> +	u16				TRGR;
>   /* Mask for TRGMOD field of TRGR register */
>   #define AT91_SAMA5D2_TRGR_TRGMOD_MASK GENMASK(2, 0)
>   /* No trigger, only software trigger can start conversions */
> @@ -203,30 +205,52 @@
>   #define AT91_SAMA5D2_TRGR_TRGPER(x)             ((x) << 16)
>   
>   /* Correction Select Register */
> -#define AT91_SAMA5D2_COSR	0xd0
> +	u16				COSR;
>   /* Correction Value Register */
> -#define AT91_SAMA5D2_CVR	0xd4
> +	u16				CVR;
>   /* Channel Error Correction Register */
> -#define AT91_SAMA5D2_CECR	0xd8
> +	u16				CECR;
>   /* Write Protection Mode Register */
> -#define AT91_SAMA5D2_WPMR	0xe4
> +	u16				WPMR;
>   /* Write Protection Status Register */
> -#define AT91_SAMA5D2_WPSR	0xe8
> +	u16				WPSR;
>   /* Version Register */
> -#define AT91_SAMA5D2_VERSION	0xfc
> -
> -#define AT91_SAMA5D2_HW_TRIG_CNT 3
> -#define AT91_SAMA5D2_SINGLE_CHAN_CNT 12
> -#define AT91_SAMA5D2_DIFF_CHAN_CNT 6
> -
> -#define AT91_SAMA5D2_TIMESTAMP_CHAN_IDX (AT91_SAMA5D2_SINGLE_CHAN_CNT + \
> -					 AT91_SAMA5D2_DIFF_CHAN_CNT + 1)
> +	u16				VERSION;
> +};
>   
> -#define AT91_SAMA5D2_TOUCH_X_CHAN_IDX (AT91_SAMA5D2_SINGLE_CHAN_CNT + \
> -					 AT91_SAMA5D2_DIFF_CHAN_CNT * 2)

Hi Jonathan,

While we are here, regarding the above line, I cannot tell why did I 
multiply by two the differential channel count. This makes some gaps in 
the number of channels when we put them all in the same table.

I did not change this as it would break the ABI regarding the bindings 
for the touchscreen #adc-cells phandle references.

However, I am thinking if there was a reason for it or it was a slip 
when I initially wrote this.

Do you think there is any reason to change it and tighten the holes in 
the indexes list ?


Eugen

> -#define AT91_SAMA5D2_TOUCH_Y_CHAN_IDX   (AT91_SAMA5D2_TOUCH_X_CHAN_IDX + 1)
> -#define AT91_SAMA5D2_TOUCH_P_CHAN_IDX   (AT91_SAMA5D2_TOUCH_Y_CHAN_IDX + 1)
> -#define AT91_SAMA5D2_MAX_CHAN_IDX	AT91_SAMA5D2_TOUCH_P_CHAN_IDX
> +static const struct at91_adc_reg_layout sama5d2_layout = {
> +	.CR =			0x00,
> +	.MR =			0x04,
> +	.SEQR1 =		0x08,
> +	.SEQR2 =		0x0c,
> +	.CHER =			0x10,
> +	.CHDR =			0x14,
> +	.CHSR =			0x18,
> +	.LCDR =			0x20,
> +	.IER =			0x24,
> +	.IDR =			0x28,
> +	.IMR =			0x2c,
> +	.ISR =			0x30,
> +	.LCTMR =		0x34,
> +	.LCCWR =		0x38,
> +	.OVER =			0x3c,
> +	.EMR =			0x40,
> +	.CWR =			0x44,
> +	.CGR =			0x48,
> +	.COR =			0x4c,
> +	.ACR =			0x94,
> +	.TSMR =			0xb0,
> +	.XPOSR =		0xb4,
> +	.YPOSR =		0xb8,
> +	.PRESSR =		0xbc,
> +	.TRGR =			0xc0,
> +	.COSR =			0xd0,
> +	.CVR =			0xd4,
> +	.CECR =			0xd8,
> +	.WPMR =			0xe4,
> +	.WPSR =			0xe8,
> +	.VERSION =		0xfc,
> +};
>   
>   #define AT91_SAMA5D2_TOUCH_SAMPLE_PERIOD_US          2000    /* 2ms */
>   #define AT91_SAMA5D2_TOUCH_PEN_DETECT_DEBOUNCE_US    200
> @@ -235,18 +259,6 @@
>   
>   #define AT91_SAMA5D2_MAX_POS_BITS			12
>   
> -/*
> - * Maximum number of bytes to hold conversion from all channels
> - * without the timestamp.
> - */
> -#define AT91_BUFFER_MAX_CONVERSION_BYTES ((AT91_SAMA5D2_SINGLE_CHAN_CNT + \
> -					 AT91_SAMA5D2_DIFF_CHAN_CNT) * 2)
> -
> -/* This total must also include the timestamp */
> -#define AT91_BUFFER_MAX_BYTES (AT91_BUFFER_MAX_CONVERSION_BYTES + 8)
> -
> -#define AT91_BUFFER_MAX_HWORDS (AT91_BUFFER_MAX_BYTES / 2)
> -
>   #define AT91_HWFIFO_MAX_SIZE_STR	"128"
>   #define AT91_HWFIFO_MAX_SIZE		128
>   
> @@ -255,12 +267,12 @@
>   #define AT91_OSR_4SAMPLES		4
>   #define AT91_OSR_16SAMPLES		16
>   
> -#define AT91_SAMA5D2_CHAN_SINGLE(num, addr)				\
> +#define AT91_SAMA5D2_CHAN_SINGLE(index, num, addr)			\
>   	{								\
>   		.type = IIO_VOLTAGE,					\
>   		.channel = num,						\
>   		.address = addr,					\
> -		.scan_index = num,					\
> +		.scan_index = index,					\
>   		.scan_type = {						\
>   			.sign = 'u',					\
>   			.realbits = 14,					\
> @@ -274,14 +286,14 @@
>   		.indexed = 1,						\
>   	}
>   
> -#define AT91_SAMA5D2_CHAN_DIFF(num, num2, addr)				\
> +#define AT91_SAMA5D2_CHAN_DIFF(index, num, num2, addr)			\
>   	{								\
>   		.type = IIO_VOLTAGE,					\
>   		.differential = 1,					\
>   		.channel = num,						\
>   		.channel2 = num2,					\
>   		.address = addr,					\
> -		.scan_index = num + AT91_SAMA5D2_SINGLE_CHAN_CNT,	\
> +		.scan_index = index,					\
>   		.scan_type = {						\
>   			.sign = 's',					\
>   			.realbits = 14,					\
> @@ -328,13 +340,48 @@
>   		.datasheet_name = name,					\
>   	}
>   
> -#define at91_adc_readl(st, reg)		readl_relaxed(st->base + reg)
> -#define at91_adc_writel(st, reg, val)	writel_relaxed(val, st->base + reg)
> +#define at91_adc_readl(st, reg)						\
> +	readl_relaxed((st)->base + (st)->soc_info.platform->layout->reg)
> +#define at91_adc_read_chan(st, reg)					\
> +	readl_relaxed((st)->base + reg)
> +#define at91_adc_writel(st, reg, val)					\
> +	writel_relaxed(val, (st)->base + (st)->soc_info.platform->layout->reg)
> +
> +/**
> + * struct at91_adc_platform - at91-sama5d2 platform information struct
> + * @layout:		pointer to the reg layout struct
> + * @adc_channels:	pointer to an array of channels for registering in
> + *			the iio subsystem
> + * @nr_channels:	number of physical channels available
> + * @touch_chan_x:	index of the touchscreen X channel
> + * @touch_chan_y:	index of the touchscreen Y channel
> + * @touch_chan_p:	index of the touchscreen P channel
> + * @max_channels:	number of total channels
> + * @hw_trig_cnt:	number of possible hardware triggers
> + */
> +struct at91_adc_platform {
> +	const struct at91_adc_reg_layout	*layout;
> +	const struct iio_chan_spec		(*adc_channels)[];
> +	unsigned int				nr_channels;
> +	unsigned int				touch_chan_x;
> +	unsigned int				touch_chan_y;
> +	unsigned int				touch_chan_p;
> +	unsigned int				max_channels;
> +	unsigned int				hw_trig_cnt;
> +};
>   
> +/**
> + * struct at91_adc_soc_info - at91-sama5d2 soc information struct
> + * @startup_time:	device startup time
> + * @min_sample_rate:	minimum sample rate in Hz
> + * @max_sample_rate:	maximum sample rate in Hz
> + * @platform:		pointer to the platform structure
> + */
>   struct at91_adc_soc_info {
>   	unsigned			startup_time;
>   	unsigned			min_sample_rate;
>   	unsigned			max_sample_rate;
> +	const struct at91_adc_platform	*platform;
>   };
>   
>   struct at91_adc_trigger {
> @@ -382,6 +429,15 @@ struct at91_adc_touch {
>   	struct work_struct		workq;
>   };
>   
> +/*
> + * Buffer size requirements:
> + * No channels * bytes_per_channel(2) + timestamp bytes (8)
> + * Divided by 2 because we need half words.
> + * We assume 32 channels for now, has to be increased if needed.
> + * Nobody minds a buffer being too big.
> + */
> +#define AT91_BUFFER_MAX_HWORDS ((32 * 2 + 8) / 2)
> +
>   struct at91_adc_state {
>   	void __iomem			*base;
>   	int				irq;
> @@ -437,29 +493,49 @@ static const struct at91_adc_trigger at91_adc_trigger_list[] = {
>   	},
>   };
>   
> -static const struct iio_chan_spec at91_adc_channels[] = {
> -	AT91_SAMA5D2_CHAN_SINGLE(0, 0x50),
> -	AT91_SAMA5D2_CHAN_SINGLE(1, 0x54),
> -	AT91_SAMA5D2_CHAN_SINGLE(2, 0x58),
> -	AT91_SAMA5D2_CHAN_SINGLE(3, 0x5c),
> -	AT91_SAMA5D2_CHAN_SINGLE(4, 0x60),
> -	AT91_SAMA5D2_CHAN_SINGLE(5, 0x64),
> -	AT91_SAMA5D2_CHAN_SINGLE(6, 0x68),
> -	AT91_SAMA5D2_CHAN_SINGLE(7, 0x6c),
> -	AT91_SAMA5D2_CHAN_SINGLE(8, 0x70),
> -	AT91_SAMA5D2_CHAN_SINGLE(9, 0x74),
> -	AT91_SAMA5D2_CHAN_SINGLE(10, 0x78),
> -	AT91_SAMA5D2_CHAN_SINGLE(11, 0x7c),
> -	AT91_SAMA5D2_CHAN_DIFF(0, 1, 0x50),
> -	AT91_SAMA5D2_CHAN_DIFF(2, 3, 0x58),
> -	AT91_SAMA5D2_CHAN_DIFF(4, 5, 0x60),
> -	AT91_SAMA5D2_CHAN_DIFF(6, 7, 0x68),
> -	AT91_SAMA5D2_CHAN_DIFF(8, 9, 0x70),
> -	AT91_SAMA5D2_CHAN_DIFF(10, 11, 0x78),
> -	IIO_CHAN_SOFT_TIMESTAMP(AT91_SAMA5D2_TIMESTAMP_CHAN_IDX),
> -	AT91_SAMA5D2_CHAN_TOUCH(AT91_SAMA5D2_TOUCH_X_CHAN_IDX, "x", IIO_MOD_X),
> -	AT91_SAMA5D2_CHAN_TOUCH(AT91_SAMA5D2_TOUCH_Y_CHAN_IDX, "y", IIO_MOD_Y),
> -	AT91_SAMA5D2_CHAN_PRESSURE(AT91_SAMA5D2_TOUCH_P_CHAN_IDX, "pressure"),
> +static const struct iio_chan_spec at91_sama5d2_adc_channels[] = {
> +	AT91_SAMA5D2_CHAN_SINGLE(0, 0, 0x50),
> +	AT91_SAMA5D2_CHAN_SINGLE(1, 1, 0x54),
> +	AT91_SAMA5D2_CHAN_SINGLE(2, 2, 0x58),
> +	AT91_SAMA5D2_CHAN_SINGLE(3, 3, 0x5c),
> +	AT91_SAMA5D2_CHAN_SINGLE(4, 4, 0x60),
> +	AT91_SAMA5D2_CHAN_SINGLE(5, 5, 0x64),
> +	AT91_SAMA5D2_CHAN_SINGLE(6, 6, 0x68),
> +	AT91_SAMA5D2_CHAN_SINGLE(7, 7, 0x6c),
> +	AT91_SAMA5D2_CHAN_SINGLE(8, 8, 0x70),
> +	AT91_SAMA5D2_CHAN_SINGLE(9, 9, 0x74),
> +	AT91_SAMA5D2_CHAN_SINGLE(10, 10, 0x78),
> +	AT91_SAMA5D2_CHAN_SINGLE(11, 11, 0x7c),
> +	AT91_SAMA5D2_CHAN_DIFF(12, 0, 1, 0x50),
> +	AT91_SAMA5D2_CHAN_DIFF(13, 2, 3, 0x58),
> +	AT91_SAMA5D2_CHAN_DIFF(14, 4, 5, 0x60),
> +	AT91_SAMA5D2_CHAN_DIFF(15, 6, 7, 0x68),
> +	AT91_SAMA5D2_CHAN_DIFF(16, 8, 9, 0x70),
> +	AT91_SAMA5D2_CHAN_DIFF(17, 10, 11, 0x78),
> +	IIO_CHAN_SOFT_TIMESTAMP(18),
> +	AT91_SAMA5D2_CHAN_TOUCH(19, "x", IIO_MOD_X),
> +	AT91_SAMA5D2_CHAN_TOUCH(20, "y", IIO_MOD_Y),
> +	AT91_SAMA5D2_CHAN_PRESSURE(21, "pressure"),
> +};
> +
> +static const struct at91_adc_platform sama5d2_platform = {
> +	.layout = &sama5d2_layout,
> +	.adc_channels = &at91_sama5d2_adc_channels,
> +#define AT91_SAMA5D2_SINGLE_CHAN_CNT 12
> +#define AT91_SAMA5D2_DIFF_CHAN_CNT 6
> +	.nr_channels = AT91_SAMA5D2_SINGLE_CHAN_CNT +
> +		       AT91_SAMA5D2_DIFF_CHAN_CNT,
> +#define AT91_SAMA5D2_TOUCH_X_CHAN_IDX	(AT91_SAMA5D2_SINGLE_CHAN_CNT + \
> +					AT91_SAMA5D2_DIFF_CHAN_CNT * 2)
> +	.touch_chan_x = AT91_SAMA5D2_TOUCH_X_CHAN_IDX,
> +#define AT91_SAMA5D2_TOUCH_Y_CHAN_IDX	(AT91_SAMA5D2_TOUCH_X_CHAN_IDX + 1)
> +	.touch_chan_y = AT91_SAMA5D2_TOUCH_Y_CHAN_IDX,
> +#define AT91_SAMA5D2_TOUCH_P_CHAN_IDX	(AT91_SAMA5D2_TOUCH_Y_CHAN_IDX + 1)
> +	.touch_chan_p = AT91_SAMA5D2_TOUCH_P_CHAN_IDX,
> +#define AT91_SAMA5D2_MAX_CHAN_IDX	AT91_SAMA5D2_TOUCH_P_CHAN_IDX
> +	.max_channels = ARRAY_SIZE(at91_sama5d2_adc_channels),
> +#define AT91_SAMA5D2_HW_TRIG_CNT	3
> +	.hw_trig_cnt = AT91_SAMA5D2_HW_TRIG_CNT,
>   };
>   
>   static int at91_adc_chan_xlate(struct iio_dev *indio_dev, int chan)
> @@ -493,6 +569,7 @@ static unsigned int at91_adc_active_scan_mask_to_reg(struct iio_dev *indio_dev)
>   {
>   	u32 mask = 0;
>   	u8 bit;
> +	struct at91_adc_state *st = iio_priv(indio_dev);
>   
>   	for_each_set_bit(bit, indio_dev->active_scan_mask,
>   			 indio_dev->num_channels) {
> @@ -501,13 +578,13 @@ static unsigned int at91_adc_active_scan_mask_to_reg(struct iio_dev *indio_dev)
>   		mask |= BIT(chan->channel);
>   	}
>   
> -	return mask & GENMASK(11, 0);
> +	return mask & GENMASK(st->soc_info.platform->nr_channels, 0);
>   }
>   
>   static void at91_adc_config_emr(struct at91_adc_state *st)
>   {
>   	/* configure the extended mode register */
> -	unsigned int emr = at91_adc_readl(st, AT91_SAMA5D2_EMR);
> +	unsigned int emr = at91_adc_readl(st, EMR);
>   
>   	/* select oversampling per single trigger event */
>   	emr |= AT91_SAMA5D2_EMR_ASTE(1);
> @@ -531,7 +608,7 @@ static void at91_adc_config_emr(struct at91_adc_state *st)
>   		break;
>   	}
>   
> -	at91_adc_writel(st, AT91_SAMA5D2_EMR, emr);
> +	at91_adc_writel(st, EMR, emr);
>   }
>   
>   static int at91_adc_adjust_val_osr(struct at91_adc_state *st, int *val)
> @@ -584,9 +661,9 @@ static int at91_adc_configure_touch(struct at91_adc_state *st, bool state)
>   
>   	if (!state) {
>   		/* disabling touch IRQs and setting mode to no touch enabled */
> -		at91_adc_writel(st, AT91_SAMA5D2_IDR,
> +		at91_adc_writel(st, IDR,
>   				AT91_SAMA5D2_IER_PEN | AT91_SAMA5D2_IER_NOPEN);
> -		at91_adc_writel(st, AT91_SAMA5D2_TSMR, 0);
> +		at91_adc_writel(st, TSMR, 0);
>   		return 0;
>   	}
>   	/*
> @@ -612,19 +689,19 @@ static int at91_adc_configure_touch(struct at91_adc_state *st, bool state)
>   	tsmr |= AT91_SAMA5D2_TSMR_PENDET_ENA;
>   	tsmr |= AT91_SAMA5D2_TSMR_TSFREQ(2) & AT91_SAMA5D2_TSMR_TSFREQ_MASK;
>   
> -	at91_adc_writel(st, AT91_SAMA5D2_TSMR, tsmr);
> +	at91_adc_writel(st, TSMR, tsmr);
>   
> -	acr =  at91_adc_readl(st, AT91_SAMA5D2_ACR);
> +	acr =  at91_adc_readl(st, ACR);
>   	acr &= ~AT91_SAMA5D2_ACR_PENDETSENS_MASK;
>   	acr |= 0x02 & AT91_SAMA5D2_ACR_PENDETSENS_MASK;
> -	at91_adc_writel(st, AT91_SAMA5D2_ACR, acr);
> +	at91_adc_writel(st, ACR, acr);
>   
>   	/* Sample Period Time = (TRGPER + 1) / ADCClock */
>   	st->touch_st.sample_period_val =
>   				 round_up((AT91_SAMA5D2_TOUCH_SAMPLE_PERIOD_US *
>   				 clk_khz / 1000) - 1, 1);
>   	/* enable pen detect IRQ */
> -	at91_adc_writel(st, AT91_SAMA5D2_IER, AT91_SAMA5D2_IER_PEN);
> +	at91_adc_writel(st, IER, AT91_SAMA5D2_IER_PEN);
>   
>   	return 0;
>   }
> @@ -640,7 +717,11 @@ static u16 at91_adc_touch_pos(struct at91_adc_state *st, int reg)
>   	 * max = 2^AT91_SAMA5D2_MAX_POS_BITS - 1
>   	 */
>   	/* first half of register is the x or y, second half is the scale */
> -	val = at91_adc_readl(st, reg);
> +	if (reg == st->soc_info.platform->layout->XPOSR)
> +		val = at91_adc_readl(st, XPOSR);
> +	else if (reg == st->soc_info.platform->layout->YPOSR)
> +		val = at91_adc_readl(st, YPOSR);
> +
>   	if (!val)
>   		dev_dbg(&st->indio_dev->dev, "pos is 0\n");
>   
> @@ -658,13 +739,13 @@ static u16 at91_adc_touch_pos(struct at91_adc_state *st, int reg)
>   
>   static u16 at91_adc_touch_x_pos(struct at91_adc_state *st)
>   {
> -	st->touch_st.x_pos = at91_adc_touch_pos(st, AT91_SAMA5D2_XPOSR);
> +	st->touch_st.x_pos = at91_adc_touch_pos(st, st->soc_info.platform->layout->XPOSR);
>   	return st->touch_st.x_pos;
>   }
>   
>   static u16 at91_adc_touch_y_pos(struct at91_adc_state *st)
>   {
> -	return at91_adc_touch_pos(st, AT91_SAMA5D2_YPOSR);
> +	return at91_adc_touch_pos(st, st->soc_info.platform->layout->YPOSR);
>   }
>   
>   static u16 at91_adc_touch_pressure(struct at91_adc_state *st)
> @@ -676,7 +757,7 @@ static u16 at91_adc_touch_pressure(struct at91_adc_state *st)
>   	u32 factor = 1000;
>   
>   	/* calculate the pressure */
> -	val = at91_adc_readl(st, AT91_SAMA5D2_PRESSR);
> +	val = at91_adc_readl(st, PRESSR);
>   	z1 = val & AT91_SAMA5D2_XYZ_MASK;
>   	z2 = (val >> 16) & AT91_SAMA5D2_XYZ_MASK;
>   
> @@ -700,9 +781,9 @@ static int at91_adc_read_position(struct at91_adc_state *st, int chan, u16 *val)
>   	*val = 0;
>   	if (!st->touch_st.touching)
>   		return -ENODATA;
> -	if (chan == AT91_SAMA5D2_TOUCH_X_CHAN_IDX)
> +	if (chan == st->soc_info.platform->touch_chan_x)
>   		*val = at91_adc_touch_x_pos(st);
> -	else if (chan == AT91_SAMA5D2_TOUCH_Y_CHAN_IDX)
> +	else if (chan == st->soc_info.platform->touch_chan_y)
>   		*val = at91_adc_touch_y_pos(st);
>   	else
>   		return -ENODATA;
> @@ -715,7 +796,7 @@ static int at91_adc_read_pressure(struct at91_adc_state *st, int chan, u16 *val)
>   	*val = 0;
>   	if (!st->touch_st.touching)
>   		return -ENODATA;
> -	if (chan == AT91_SAMA5D2_TOUCH_P_CHAN_IDX)
> +	if (chan == st->soc_info.platform->touch_chan_y)
>   		*val = at91_adc_touch_pressure(st);
>   	else
>   		return -ENODATA;
> @@ -727,7 +808,7 @@ static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state)
>   {
>   	struct iio_dev *indio = iio_trigger_get_drvdata(trig);
>   	struct at91_adc_state *st = iio_priv(indio);
> -	u32 status = at91_adc_readl(st, AT91_SAMA5D2_TRGR);
> +	u32 status = at91_adc_readl(st, TRGR);
>   
>   	/* clear TRGMOD */
>   	status &= ~AT91_SAMA5D2_TRGR_TRGMOD_MASK;
> @@ -736,7 +817,7 @@ static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state)
>   		status |= st->selected_trig->trgmod_value;
>   
>   	/* set/unset hw trigger */
> -	at91_adc_writel(st, AT91_SAMA5D2_TRGR, status);
> +	at91_adc_writel(st, TRGR, status);
>   
>   	return 0;
>   }
> @@ -753,7 +834,7 @@ static void at91_adc_reenable_trigger(struct iio_trigger *trig)
>   	enable_irq(st->irq);
>   
>   	/* Needed to ACK the DRDY interruption */
> -	at91_adc_readl(st, AT91_SAMA5D2_LCDR);
> +	at91_adc_readl(st, LCDR);
>   }
>   
>   static const struct iio_trigger_ops at91_adc_trigger_ops = {
> @@ -848,7 +929,7 @@ static int at91_adc_dma_start(struct iio_dev *indio_dev)
>   	}
>   
>   	/* enable general overrun error signaling */
> -	at91_adc_writel(st, AT91_SAMA5D2_IER, AT91_SAMA5D2_IER_GOVRE);
> +	at91_adc_writel(st, IER, AT91_SAMA5D2_IER_GOVRE);
>   	/* Issue pending DMA requests */
>   	dma_async_issue_pending(st->dma_st.dma_chan);
>   
> @@ -878,7 +959,7 @@ static bool at91_adc_current_chan_is_touch(struct iio_dev *indio_dev)
>   
>   	return !!bitmap_subset(indio_dev->active_scan_mask,
>   			       &st->touch_st.channels_bitmask,
> -			       AT91_SAMA5D2_MAX_CHAN_IDX + 1);
> +			       st->soc_info.platform->max_channels + 1);
>   }
>   
>   static int at91_adc_buffer_prepare(struct iio_dev *indio_dev)
> @@ -915,7 +996,7 @@ static int at91_adc_buffer_prepare(struct iio_dev *indio_dev)
>   		    chan->type == IIO_PRESSURE)
>   			continue;
>   
> -		cor = at91_adc_readl(st, AT91_SAMA5D2_COR);
> +		cor = at91_adc_readl(st, COR);
>   
>   		if (chan->differential)
>   			cor |= (BIT(chan->channel) | BIT(chan->channel2)) <<
> @@ -924,13 +1005,13 @@ static int at91_adc_buffer_prepare(struct iio_dev *indio_dev)
>   			cor &= ~(BIT(chan->channel) <<
>   			       AT91_SAMA5D2_COR_DIFF_OFFSET);
>   
> -		at91_adc_writel(st, AT91_SAMA5D2_COR, cor);
> +		at91_adc_writel(st, COR, cor);
>   
> -		at91_adc_writel(st, AT91_SAMA5D2_CHER, BIT(chan->channel));
> +		at91_adc_writel(st, CHER, BIT(chan->channel));
>   	}
>   
>   	if (at91_adc_buffer_check_use_irq(indio_dev, st))
> -		at91_adc_writel(st, AT91_SAMA5D2_IER, AT91_SAMA5D2_IER_DRDY);
> +		at91_adc_writel(st, IER, AT91_SAMA5D2_IER_DRDY);
>   
>   	return 0;
>   }
> @@ -966,17 +1047,17 @@ static int at91_adc_buffer_postdisable(struct iio_dev *indio_dev)
>   		    chan->type == IIO_PRESSURE)
>   			continue;
>   
> -		at91_adc_writel(st, AT91_SAMA5D2_CHDR, BIT(chan->channel));
> +		at91_adc_writel(st, CHDR, BIT(chan->channel));
>   
>   		if (st->dma_st.dma_chan)
> -			at91_adc_readl(st, chan->address);
> +			at91_adc_read_chan(st, chan->address);
>   	}
>   
>   	if (at91_adc_buffer_check_use_irq(indio_dev, st))
> -		at91_adc_writel(st, AT91_SAMA5D2_IDR, AT91_SAMA5D2_IER_DRDY);
> +		at91_adc_writel(st, IDR, AT91_SAMA5D2_IER_DRDY);
>   
>   	/* read overflow register to clear possible overflow status */
> -	at91_adc_readl(st, AT91_SAMA5D2_OVER);
> +	at91_adc_readl(st, OVER);
>   
>   	/* if we are using DMA we must clear registers and end DMA */
>   	if (st->dma_st.dma_chan)
> @@ -1024,7 +1105,7 @@ static void at91_adc_trigger_handler_nodma(struct iio_dev *indio_dev,
>   	 * Check if the conversion is ready. If not, wait a little bit, and
>   	 * in case of timeout exit with an error.
>   	 */
> -	while ((at91_adc_readl(st, AT91_SAMA5D2_ISR) & mask) != mask &&
> +	while ((at91_adc_readl(st, ISR) & mask) != mask &&
>   	       timeout) {
>   		usleep_range(50, 100);
>   		timeout--;
> @@ -1052,7 +1133,7 @@ static void at91_adc_trigger_handler_nodma(struct iio_dev *indio_dev,
>   		 * Thus, emit a warning.
>   		 */
>   		if (chan->type == IIO_VOLTAGE) {
> -			val = at91_adc_readl(st, chan->address);
> +			val = at91_adc_read_chan(st, chan->address);
>   			at91_adc_adjust_val_osr(st, &val);
>   			st->buffer[i] = val;
>   		} else {
> @@ -1073,7 +1154,7 @@ static void at91_adc_trigger_handler_dma(struct iio_dev *indio_dev)
>   	s64 interval;
>   	int sample_index = 0, sample_count, sample_size;
>   
> -	u32 status = at91_adc_readl(st, AT91_SAMA5D2_ISR);
> +	u32 status = at91_adc_readl(st, ISR);
>   	/* if we reached this point, we cannot sample faster */
>   	if (status & AT91_SAMA5D2_IER_GOVRE)
>   		pr_info_ratelimited("%s: conversion overrun detected\n",
> @@ -1125,7 +1206,7 @@ static irqreturn_t at91_adc_trigger_handler(int irq, void *p)
>   	 * actually polling the trigger now.
>   	 */
>   	if (iio_trigger_validate_own_device(indio_dev->trig, indio_dev))
> -		at91_adc_writel(st, AT91_SAMA5D2_CR, AT91_SAMA5D2_CR_START);
> +		at91_adc_writel(st, CR, AT91_SAMA5D2_CR_START);
>   
>   	if (st->dma_st.dma_chan)
>   		at91_adc_trigger_handler_dma(indio_dev);
> @@ -1172,11 +1253,11 @@ static void at91_adc_setup_samp_freq(struct iio_dev *indio_dev, unsigned freq)
>   	startup = at91_adc_startup_time(st->soc_info.startup_time,
>   					freq / 1000);
>   
> -	mr = at91_adc_readl(st, AT91_SAMA5D2_MR);
> +	mr = at91_adc_readl(st, MR);
>   	mr &= ~(AT91_SAMA5D2_MR_STARTUP_MASK | AT91_SAMA5D2_MR_PRESCAL_MASK);
>   	mr |= AT91_SAMA5D2_MR_STARTUP(startup);
>   	mr |= AT91_SAMA5D2_MR_PRESCAL(prescal);
> -	at91_adc_writel(st, AT91_SAMA5D2_MR, mr);
> +	at91_adc_writel(st, MR, mr);
>   
>   	dev_dbg(&indio_dev->dev, "freq: %u, startup: %u, prescal: %u\n",
>   		freq, startup, prescal);
> @@ -1196,7 +1277,7 @@ static void at91_adc_touch_data_handler(struct iio_dev *indio_dev)
>   	int i = 0;
>   
>   	for_each_set_bit(bit, indio_dev->active_scan_mask,
> -			 AT91_SAMA5D2_MAX_CHAN_IDX + 1) {
> +			 st->soc_info.platform->max_channels + 1) {
>   		struct iio_chan_spec const *chan =
>   					 at91_adc_chan_get(indio_dev, bit);
>   
> @@ -1222,12 +1303,11 @@ static void at91_adc_touch_data_handler(struct iio_dev *indio_dev)
>   
>   static void at91_adc_pen_detect_interrupt(struct at91_adc_state *st)
>   {
> -	at91_adc_writel(st, AT91_SAMA5D2_IDR, AT91_SAMA5D2_IER_PEN);
> -	at91_adc_writel(st, AT91_SAMA5D2_IER, AT91_SAMA5D2_IER_NOPEN |
> +	at91_adc_writel(st, IDR, AT91_SAMA5D2_IER_PEN);
> +	at91_adc_writel(st, IER, AT91_SAMA5D2_IER_NOPEN |
>   			AT91_SAMA5D2_IER_XRDY | AT91_SAMA5D2_IER_YRDY |
>   			AT91_SAMA5D2_IER_PRDY);
> -	at91_adc_writel(st, AT91_SAMA5D2_TRGR,
> -			AT91_SAMA5D2_TRGR_TRGMOD_PERIODIC |
> +	at91_adc_writel(st, TRGR, AT91_SAMA5D2_TRGR_TRGMOD_PERIODIC |
>   			AT91_SAMA5D2_TRGR_TRGPER(st->touch_st.sample_period_val));
>   	st->touch_st.touching = true;
>   }
> @@ -1236,16 +1316,15 @@ static void at91_adc_no_pen_detect_interrupt(struct iio_dev *indio_dev)
>   {
>   	struct at91_adc_state *st = iio_priv(indio_dev);
>   
> -	at91_adc_writel(st, AT91_SAMA5D2_TRGR,
> -			AT91_SAMA5D2_TRGR_TRGMOD_NO_TRIGGER);
> -	at91_adc_writel(st, AT91_SAMA5D2_IDR, AT91_SAMA5D2_IER_NOPEN |
> +	at91_adc_writel(st, TRGR, AT91_SAMA5D2_TRGR_TRGMOD_NO_TRIGGER);
> +	at91_adc_writel(st, IDR, AT91_SAMA5D2_IER_NOPEN |
>   			AT91_SAMA5D2_IER_XRDY | AT91_SAMA5D2_IER_YRDY |
>   			AT91_SAMA5D2_IER_PRDY);
>   	st->touch_st.touching = false;
>   
>   	at91_adc_touch_data_handler(indio_dev);
>   
> -	at91_adc_writel(st, AT91_SAMA5D2_IER, AT91_SAMA5D2_IER_PEN);
> +	at91_adc_writel(st, IER, AT91_SAMA5D2_IER_PEN);
>   }
>   
>   static void at91_adc_workq_handler(struct work_struct *workq)
> @@ -1263,8 +1342,8 @@ static irqreturn_t at91_adc_interrupt(int irq, void *private)
>   {
>   	struct iio_dev *indio = private;
>   	struct at91_adc_state *st = iio_priv(indio);
> -	u32 status = at91_adc_readl(st, AT91_SAMA5D2_ISR);
> -	u32 imr = at91_adc_readl(st, AT91_SAMA5D2_IMR);
> +	u32 status = at91_adc_readl(st, ISR);
> +	u32 imr = at91_adc_readl(st, IMR);
>   	u32 rdy_mask = AT91_SAMA5D2_IER_XRDY | AT91_SAMA5D2_IER_YRDY |
>   			AT91_SAMA5D2_IER_PRDY;
>   
> @@ -1285,9 +1364,9 @@ static irqreturn_t at91_adc_interrupt(int irq, void *private)
>   		 * touching, but the measurements are not ready yet.
>   		 * read and ignore.
>   		 */
> -		status = at91_adc_readl(st, AT91_SAMA5D2_XPOSR);
> -		status = at91_adc_readl(st, AT91_SAMA5D2_YPOSR);
> -		status = at91_adc_readl(st, AT91_SAMA5D2_PRESSR);
> +		status = at91_adc_readl(st, XPOSR);
> +		status = at91_adc_readl(st, YPOSR);
> +		status = at91_adc_readl(st, PRESSR);
>   	} else if (iio_buffer_enabled(indio) &&
>   		   (status & AT91_SAMA5D2_IER_DRDY)) {
>   		/* triggered buffer without DMA */
> @@ -1299,7 +1378,7 @@ static irqreturn_t at91_adc_interrupt(int irq, void *private)
>   		WARN(true, "Unexpected irq occurred\n");
>   	} else if (!iio_buffer_enabled(indio)) {
>   		/* software requested conversion */
> -		st->conversion_value = at91_adc_readl(st, st->chan->address);
> +		st->conversion_value = at91_adc_read_chan(st, st->chan->address);
>   		st->conversion_done = true;
>   		wake_up_interruptible(&st->wq_data_available);
>   	}
> @@ -1360,10 +1439,10 @@ static int at91_adc_read_info_raw(struct iio_dev *indio_dev,
>   		cor = (BIT(chan->channel) | BIT(chan->channel2)) <<
>   		      AT91_SAMA5D2_COR_DIFF_OFFSET;
>   
> -	at91_adc_writel(st, AT91_SAMA5D2_COR, cor);
> -	at91_adc_writel(st, AT91_SAMA5D2_CHER, BIT(chan->channel));
> -	at91_adc_writel(st, AT91_SAMA5D2_IER, BIT(chan->channel));
> -	at91_adc_writel(st, AT91_SAMA5D2_CR, AT91_SAMA5D2_CR_START);
> +	at91_adc_writel(st, COR, cor);
> +	at91_adc_writel(st, CHER, BIT(chan->channel));
> +	at91_adc_writel(st, IER, BIT(chan->channel));
> +	at91_adc_writel(st, CR, AT91_SAMA5D2_CR_START);
>   
>   	ret = wait_event_interruptible_timeout(st->wq_data_available,
>   					       st->conversion_done,
> @@ -1379,11 +1458,11 @@ static int at91_adc_read_info_raw(struct iio_dev *indio_dev,
>   		st->conversion_done = false;
>   	}
>   
> -	at91_adc_writel(st, AT91_SAMA5D2_IDR, BIT(chan->channel));
> -	at91_adc_writel(st, AT91_SAMA5D2_CHDR, BIT(chan->channel));
> +	at91_adc_writel(st, IDR, BIT(chan->channel));
> +	at91_adc_writel(st, CHDR, BIT(chan->channel));
>   
>   	/* Needed to ACK the DRDY interruption */
> -	at91_adc_readl(st, AT91_SAMA5D2_LCDR);
> +	at91_adc_readl(st, LCDR);
>   
>   	mutex_unlock(&st->lock);
>   
> @@ -1455,14 +1534,15 @@ static void at91_adc_dma_init(struct platform_device *pdev)
>   	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
>   	struct at91_adc_state *st = iio_priv(indio_dev);
>   	struct dma_slave_config config = {0};
> +	/* we have 2 bytes for each channel */
> +	unsigned int sample_size = st->soc_info.platform->nr_channels * 2;
>   	/*
>   	 * We make the buffer double the size of the fifo,
>   	 * such that DMA uses one half of the buffer (full fifo size)
>   	 * and the software uses the other half to read/write.
>   	 */
>   	unsigned int pages = DIV_ROUND_UP(AT91_HWFIFO_MAX_SIZE *
> -					  AT91_BUFFER_MAX_CONVERSION_BYTES * 2,
> -					  PAGE_SIZE);
> +					  sample_size * 2, PAGE_SIZE);
>   
>   	if (st->dma_st.dma_chan)
>   		return;
> @@ -1486,7 +1566,7 @@ static void at91_adc_dma_init(struct platform_device *pdev)
>   	/* Configure DMA channel to read data register */
>   	config.direction = DMA_DEV_TO_MEM;
>   	config.src_addr = (phys_addr_t)(st->dma_st.phys_addr
> -			  + AT91_SAMA5D2_LCDR);
> +			  + st->soc_info.platform->layout->LCDR);
>   	config.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
>   	config.src_maxburst = 1;
>   	config.dst_maxburst = 1;
> @@ -1515,9 +1595,10 @@ static void at91_adc_dma_disable(struct platform_device *pdev)
>   {
>   	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
>   	struct at91_adc_state *st = iio_priv(indio_dev);
> +	/* we have 2 bytes for each channel */
> +	unsigned int sample_size = st->soc_info.platform->nr_channels * 2;
>   	unsigned int pages = DIV_ROUND_UP(AT91_HWFIFO_MAX_SIZE *
> -					  AT91_BUFFER_MAX_CONVERSION_BYTES * 2,
> -					  PAGE_SIZE);
> +					  sample_size * 2, PAGE_SIZE);
>   
>   	/* if we are not using DMA, just return */
>   	if (!st->dma_st.dma_chan)
> @@ -1578,14 +1659,14 @@ static int at91_adc_update_scan_mode(struct iio_dev *indio_dev,
>   	struct at91_adc_state *st = iio_priv(indio_dev);
>   
>   	if (bitmap_subset(scan_mask, &st->touch_st.channels_bitmask,
> -			  AT91_SAMA5D2_MAX_CHAN_IDX + 1))
> +			  st->soc_info.platform->max_channels + 1))
>   		return 0;
>   	/*
>   	 * if the new bitmap is a combination of touchscreen and regular
>   	 * channels, then we are not fine
>   	 */
>   	if (bitmap_intersects(&st->touch_st.channels_bitmask, scan_mask,
> -			      AT91_SAMA5D2_MAX_CHAN_IDX + 1))
> +			      st->soc_info.platform->max_channels + 1))
>   		return -EINVAL;
>   	return 0;
>   }
> @@ -1594,13 +1675,13 @@ static void at91_adc_hw_init(struct iio_dev *indio_dev)
>   {
>   	struct at91_adc_state *st = iio_priv(indio_dev);
>   
> -	at91_adc_writel(st, AT91_SAMA5D2_CR, AT91_SAMA5D2_CR_SWRST);
> -	at91_adc_writel(st, AT91_SAMA5D2_IDR, 0xffffffff);
> +	at91_adc_writel(st, CR, AT91_SAMA5D2_CR_SWRST);
> +	at91_adc_writel(st, IDR, 0xffffffff);
>   	/*
>   	 * Transfer field must be set to 2 according to the datasheet and
>   	 * allows different analog settings for each channel.
>   	 */
> -	at91_adc_writel(st, AT91_SAMA5D2_MR,
> +	at91_adc_writel(st, MR,
>   			AT91_SAMA5D2_MR_TRANSFER(2) | AT91_SAMA5D2_MR_ANACH);
>   
>   	at91_adc_setup_samp_freq(indio_dev, st->soc_info.min_sample_rate);
> @@ -1716,21 +1797,23 @@ static int at91_adc_probe(struct platform_device *pdev)
>   	if (!indio_dev)
>   		return -ENOMEM;
>   
> +	st = iio_priv(indio_dev);
> +	st->indio_dev = indio_dev;
> +
> +	st->soc_info.platform = of_device_get_match_data(&pdev->dev);
> +
>   	indio_dev->name = dev_name(&pdev->dev);
>   	indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE;
>   	indio_dev->info = &at91_adc_info;
> -	indio_dev->channels = at91_adc_channels;
> -	indio_dev->num_channels = ARRAY_SIZE(at91_adc_channels);
> -
> -	st = iio_priv(indio_dev);
> -	st->indio_dev = indio_dev;
> +	indio_dev->channels = *st->soc_info.platform->adc_channels;
> +	indio_dev->num_channels = st->soc_info.platform->max_channels;
>   
>   	bitmap_set(&st->touch_st.channels_bitmask,
> -		   AT91_SAMA5D2_TOUCH_X_CHAN_IDX, 1);
> +		   st->soc_info.platform->touch_chan_x, 1);
>   	bitmap_set(&st->touch_st.channels_bitmask,
> -		   AT91_SAMA5D2_TOUCH_Y_CHAN_IDX, 1);
> +		   st->soc_info.platform->touch_chan_y, 1);
>   	bitmap_set(&st->touch_st.channels_bitmask,
> -		   AT91_SAMA5D2_TOUCH_P_CHAN_IDX, 1);
> +		   st->soc_info.platform->touch_chan_p, 1);
>   
>   	st->oversampling_ratio = AT91_OSR_1SAMPLES;
>   
> @@ -1770,7 +1853,7 @@ static int at91_adc_probe(struct platform_device *pdev)
>   	st->selected_trig = NULL;
>   
>   	/* find the right trigger, or no trigger at all */
> -	for (i = 0; i < AT91_SAMA5D2_HW_TRIG_CNT + 1; i++)
> +	for (i = 0; i < st->soc_info.platform->hw_trig_cnt + 1; i++)
>   		if (at91_adc_trigger_list[i].edge_type == edge_type) {
>   			st->selected_trig = &at91_adc_trigger_list[i];
>   			break;
> @@ -1855,7 +1938,7 @@ static int at91_adc_probe(struct platform_device *pdev)
>   			 st->selected_trig->name);
>   
>   	dev_info(&pdev->dev, "version: %x\n",
> -		 readl_relaxed(st->base + AT91_SAMA5D2_VERSION));
> +		 readl_relaxed(st->base + st->soc_info.platform->layout->VERSION));
>   
>   	return 0;
>   
> @@ -1898,7 +1981,7 @@ static __maybe_unused int at91_adc_suspend(struct device *dev)
>   	 * and can be used by for other devices.
>   	 * Otherwise, ADC will hog them and we can't go to suspend mode.
>   	 */
> -	at91_adc_writel(st, AT91_SAMA5D2_CR, AT91_SAMA5D2_CR_SWRST);
> +	at91_adc_writel(st, CR, AT91_SAMA5D2_CR_SWRST);
>   
>   	clk_disable_unprepare(st->per_clk);
>   	regulator_disable(st->vref);
> @@ -1958,6 +2041,7 @@ static SIMPLE_DEV_PM_OPS(at91_adc_pm_ops, at91_adc_suspend, at91_adc_resume);
>   static const struct of_device_id at91_adc_dt_match[] = {
>   	{
>   		.compatible = "atmel,sama5d2-adc",
> +		.data = (const void *)&sama5d2_platform,
>   	}, {
>   		/* sentinel */
>   	}
>
Jonathan Cameron Aug. 30, 2021, 2:44 p.m. UTC | #4
On Mon, 30 Aug 2021 12:31:46 +0000
<Eugen.Hristev@microchip.com> wrote:

> On 8/24/21 2:54 PM, Eugen Hristev wrote:
> > Convert the driver to platform specific structures. This means:
> > - create a register layout struct that will hold offsets for registers
> > - create a platform struct that will hold platform information (number of
> > channels, indexes for different channels and pointer to layout struct)
> > - convert specific macros that are platform dependent into platform variables
> > 
> > This step is in fact a no-op, but allows the driver to be more flexible
> > and for future enhancement including adding new platforms that are partly
> > compatible with the current driver and differ slightly in register layout
> > or capabilities for example.
> > 
> > Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
> > ---
> >   drivers/iio/adc/at91-sama5d2_adc.c | 410 +++++++++++++++++------------
> >   1 file changed, 247 insertions(+), 163 deletions(-)
> > 
> > diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c
> > index 9d71dcffcf93..8ede18b8d789 100644
> > --- a/drivers/iio/adc/at91-sama5d2_adc.c
> > +++ b/drivers/iio/adc/at91-sama5d2_adc.c
> > @@ -27,8 +27,9 @@
> >   #include <linux/pinctrl/consumer.h>
> >   #include <linux/regulator/consumer.h>
> >   
> > +struct at91_adc_reg_layout {
> >   /* Control Register */
> > -#define AT91_SAMA5D2_CR		0x00
> > +	u16				CR;
> >   /* Software Reset */
> >   #define	AT91_SAMA5D2_CR_SWRST		BIT(0)
> >   /* Start Conversion */
> > @@ -39,7 +40,7 @@
> >   #define	AT91_SAMA5D2_CR_CMPRST		BIT(4)
> >   
> >   /* Mode Register */
> > -#define AT91_SAMA5D2_MR		0x04
> > +	u16				MR;
> >   /* Trigger Selection */
> >   #define	AT91_SAMA5D2_MR_TRGSEL(v)	((v) << 1)
> >   /* ADTRG */
> > @@ -82,19 +83,19 @@
> >   #define	AT91_SAMA5D2_MR_USEQ		BIT(31)
> >   
> >   /* Channel Sequence Register 1 */
> > -#define AT91_SAMA5D2_SEQR1	0x08
> > +	u16				SEQR1;
> >   /* Channel Sequence Register 2 */
> > -#define AT91_SAMA5D2_SEQR2	0x0c
> > +	u16				SEQR2;
> >   /* Channel Enable Register */
> > -#define AT91_SAMA5D2_CHER	0x10
> > +	u16				CHER;
> >   /* Channel Disable Register */
> > -#define AT91_SAMA5D2_CHDR	0x14
> > +	u16				CHDR;
> >   /* Channel Status Register */
> > -#define AT91_SAMA5D2_CHSR	0x18
> > +	u16				CHSR;
> >   /* Last Converted Data Register */
> > -#define AT91_SAMA5D2_LCDR	0x20
> > +	u16				LCDR;
> >   /* Interrupt Enable Register */
> > -#define AT91_SAMA5D2_IER	0x24
> > +	u16				IER;
> >   /* Interrupt Enable Register - TS X measurement ready */
> >   #define AT91_SAMA5D2_IER_XRDY   BIT(20)
> >   /* Interrupt Enable Register - TS Y measurement ready */
> > @@ -109,22 +110,23 @@
> >   #define AT91_SAMA5D2_IER_PEN    BIT(29)
> >   /* Interrupt Enable Register - No pen detect */
> >   #define AT91_SAMA5D2_IER_NOPEN  BIT(30)
> > +
> >   /* Interrupt Disable Register */
> > -#define AT91_SAMA5D2_IDR	0x28
> > +	u16				IDR;
> >   /* Interrupt Mask Register */
> > -#define AT91_SAMA5D2_IMR	0x2c
> > +	u16				IMR;
> >   /* Interrupt Status Register */
> > -#define AT91_SAMA5D2_ISR	0x30
> > +	u16				ISR;
> >   /* Interrupt Status Register - Pen touching sense status */
> >   #define AT91_SAMA5D2_ISR_PENS   BIT(31)
> >   /* Last Channel Trigger Mode Register */
> > -#define AT91_SAMA5D2_LCTMR	0x34
> > +	u16				LCTMR;
> >   /* Last Channel Compare Window Register */
> > -#define AT91_SAMA5D2_LCCWR	0x38
> > +	u16				LCCWR;
> >   /* Overrun Status Register */
> > -#define AT91_SAMA5D2_OVER	0x3c
> > +	u16				OVER;
> >   /* Extended Mode Register */
> > -#define AT91_SAMA5D2_EMR	0x40
> > +	u16				EMR;
> >   /* Extended Mode Register - Oversampling rate */
> >   #define AT91_SAMA5D2_EMR_OSR(V)			((V) << 16)
> >   #define AT91_SAMA5D2_EMR_OSR_MASK		GENMASK(17, 16)
> > @@ -134,22 +136,22 @@
> >   
> >   /* Extended Mode Register - Averaging on single trigger event */
> >   #define AT91_SAMA5D2_EMR_ASTE(V)		((V) << 20)
> > +
> >   /* Compare Window Register */
> > -#define AT91_SAMA5D2_CWR	0x44
> > +	u16				CWR;
> >   /* Channel Gain Register */
> > -#define AT91_SAMA5D2_CGR	0x48
> > -
> > +	u16				CGR;
> >   /* Channel Offset Register */
> > -#define AT91_SAMA5D2_COR	0x4c
> > +	u16				COR;
> >   #define AT91_SAMA5D2_COR_DIFF_OFFSET	16
> >   
> >   /* Analog Control Register */
> > -#define AT91_SAMA5D2_ACR	0x94
> > +	u16				ACR;
> >   /* Analog Control Register - Pen detect sensitivity mask */
> >   #define AT91_SAMA5D2_ACR_PENDETSENS_MASK        GENMASK(1, 0)
> >   
> >   /* Touchscreen Mode Register */
> > -#define AT91_SAMA5D2_TSMR	0xb0
> > +	u16				TSMR;
> >   /* Touchscreen Mode Register - No touch mode */
> >   #define AT91_SAMA5D2_TSMR_TSMODE_NONE           0
> >   /* Touchscreen Mode Register - 4 wire screen, no pressure measurement */
> > @@ -178,13 +180,13 @@
> >   #define AT91_SAMA5D2_TSMR_PENDET_ENA            BIT(24)
> >   
> >   /* Touchscreen X Position Register */
> > -#define AT91_SAMA5D2_XPOSR	0xb4
> > +	u16				XPOSR;
> >   /* Touchscreen Y Position Register */
> > -#define AT91_SAMA5D2_YPOSR	0xb8
> > +	u16				YPOSR;
> >   /* Touchscreen Pressure Register */
> > -#define AT91_SAMA5D2_PRESSR	0xbc
> > +	u16				PRESSR;
> >   /* Trigger Register */
> > -#define AT91_SAMA5D2_TRGR	0xc0
> > +	u16				TRGR;
> >   /* Mask for TRGMOD field of TRGR register */
> >   #define AT91_SAMA5D2_TRGR_TRGMOD_MASK GENMASK(2, 0)
> >   /* No trigger, only software trigger can start conversions */
> > @@ -203,30 +205,52 @@
> >   #define AT91_SAMA5D2_TRGR_TRGPER(x)             ((x) << 16)
> >   
> >   /* Correction Select Register */
> > -#define AT91_SAMA5D2_COSR	0xd0
> > +	u16				COSR;
> >   /* Correction Value Register */
> > -#define AT91_SAMA5D2_CVR	0xd4
> > +	u16				CVR;
> >   /* Channel Error Correction Register */
> > -#define AT91_SAMA5D2_CECR	0xd8
> > +	u16				CECR;
> >   /* Write Protection Mode Register */
> > -#define AT91_SAMA5D2_WPMR	0xe4
> > +	u16				WPMR;
> >   /* Write Protection Status Register */
> > -#define AT91_SAMA5D2_WPSR	0xe8
> > +	u16				WPSR;
> >   /* Version Register */
> > -#define AT91_SAMA5D2_VERSION	0xfc
> > -
> > -#define AT91_SAMA5D2_HW_TRIG_CNT 3
> > -#define AT91_SAMA5D2_SINGLE_CHAN_CNT 12
> > -#define AT91_SAMA5D2_DIFF_CHAN_CNT 6
> > -
> > -#define AT91_SAMA5D2_TIMESTAMP_CHAN_IDX (AT91_SAMA5D2_SINGLE_CHAN_CNT + \
> > -					 AT91_SAMA5D2_DIFF_CHAN_CNT + 1)
> > +	u16				VERSION;
> > +};
> >   
> > -#define AT91_SAMA5D2_TOUCH_X_CHAN_IDX (AT91_SAMA5D2_SINGLE_CHAN_CNT + \
> > -					 AT91_SAMA5D2_DIFF_CHAN_CNT * 2)  
> 
> Hi Jonathan,
> 
> While we are here, regarding the above line, I cannot tell why did I 
> multiply by two the differential channel count. This makes some gaps in 
> the number of channels when we put them all in the same table.
> 
> I did not change this as it would break the ABI regarding the bindings 
> for the touchscreen #adc-cells phandle references.

Really?  Xlate is based off scan_index, not these values I think...

> 
> However, I am thinking if there was a reason for it or it was a slip 
> when I initially wrote this.

I've no idea :)  I can't immediately see why we'd need the padding.

> 
> Do you think there is any reason to change it and tighten the holes in 
> the indexes list ?

I don't think it matters. As far as I can tell they are used mostly (possibly
entirely) for internal management and not exposed to any of the ABIs etc.

Jonathan

> 
> 
> Eugen
> 
> > -#define AT91_SAMA5D2_TOUCH_Y_CHAN_IDX   (AT91_SAMA5D2_TOUCH_X_CHAN_IDX + 1)
> > -#define AT91_SAMA5D2_TOUCH_P_CHAN_IDX   (AT91_SAMA5D2_TOUCH_Y_CHAN_IDX + 1)
> > -#define AT91_SAMA5D2_MAX_CHAN_IDX	AT91_SAMA5D2_TOUCH_P_CHAN_IDX
> > +static const struct at91_adc_reg_layout sama5d2_layout = {
> > +	.CR =			0x00,
> > +	.MR =			0x04,
> > +	.SEQR1 =		0x08,
> > +	.SEQR2 =		0x0c,
> > +	.CHER =			0x10,
> > +	.CHDR =			0x14,
> > +	.CHSR =			0x18,
> > +	.LCDR =			0x20,
> > +	.IER =			0x24,
> > +	.IDR =			0x28,
> > +	.IMR =			0x2c,
> > +	.ISR =			0x30,
> > +	.LCTMR =		0x34,
> > +	.LCCWR =		0x38,
> > +	.OVER =			0x3c,
> > +	.EMR =			0x40,
> > +	.CWR =			0x44,
> > +	.CGR =			0x48,
> > +	.COR =			0x4c,
> > +	.ACR =			0x94,
> > +	.TSMR =			0xb0,
> > +	.XPOSR =		0xb4,
> > +	.YPOSR =		0xb8,
> > +	.PRESSR =		0xbc,
> > +	.TRGR =			0xc0,
> > +	.COSR =			0xd0,
> > +	.CVR =			0xd4,
> > +	.CECR =			0xd8,
> > +	.WPMR =			0xe4,
> > +	.WPSR =			0xe8,
> > +	.VERSION =		0xfc,
> > +};
> >   
> >   #define AT91_SAMA5D2_TOUCH_SAMPLE_PERIOD_US          2000    /* 2ms */
> >   #define AT91_SAMA5D2_TOUCH_PEN_DETECT_DEBOUNCE_US    200
> > @@ -235,18 +259,6 @@
> >   
> >   #define AT91_SAMA5D2_MAX_POS_BITS			12
> >   
> > -/*
> > - * Maximum number of bytes to hold conversion from all channels
> > - * without the timestamp.
> > - */
> > -#define AT91_BUFFER_MAX_CONVERSION_BYTES ((AT91_SAMA5D2_SINGLE_CHAN_CNT + \
> > -					 AT91_SAMA5D2_DIFF_CHAN_CNT) * 2)
> > -
> > -/* This total must also include the timestamp */
> > -#define AT91_BUFFER_MAX_BYTES (AT91_BUFFER_MAX_CONVERSION_BYTES + 8)
> > -
> > -#define AT91_BUFFER_MAX_HWORDS (AT91_BUFFER_MAX_BYTES / 2)
> > -
> >   #define AT91_HWFIFO_MAX_SIZE_STR	"128"
> >   #define AT91_HWFIFO_MAX_SIZE		128
> >   
> > @@ -255,12 +267,12 @@
> >   #define AT91_OSR_4SAMPLES		4
> >   #define AT91_OSR_16SAMPLES		16
> >   
> > -#define AT91_SAMA5D2_CHAN_SINGLE(num, addr)				\
> > +#define AT91_SAMA5D2_CHAN_SINGLE(index, num, addr)			\
> >   	{								\
> >   		.type = IIO_VOLTAGE,					\
> >   		.channel = num,						\
> >   		.address = addr,					\
> > -		.scan_index = num,					\
> > +		.scan_index = index,					\
> >   		.scan_type = {						\
> >   			.sign = 'u',					\
> >   			.realbits = 14,					\
> > @@ -274,14 +286,14 @@
> >   		.indexed = 1,						\
> >   	}
> >   
> > -#define AT91_SAMA5D2_CHAN_DIFF(num, num2, addr)				\
> > +#define AT91_SAMA5D2_CHAN_DIFF(index, num, num2, addr)			\
> >   	{								\
> >   		.type = IIO_VOLTAGE,					\
> >   		.differential = 1,					\
> >   		.channel = num,						\
> >   		.channel2 = num2,					\
> >   		.address = addr,					\
> > -		.scan_index = num + AT91_SAMA5D2_SINGLE_CHAN_CNT,	\
> > +		.scan_index = index,					\
> >   		.scan_type = {						\
> >   			.sign = 's',					\
> >   			.realbits = 14,					\
> > @@ -328,13 +340,48 @@
> >   		.datasheet_name = name,					\
> >   	}
> >   
> > -#define at91_adc_readl(st, reg)		readl_relaxed(st->base + reg)
> > -#define at91_adc_writel(st, reg, val)	writel_relaxed(val, st->base + reg)
> > +#define at91_adc_readl(st, reg)						\
> > +	readl_relaxed((st)->base + (st)->soc_info.platform->layout->reg)
> > +#define at91_adc_read_chan(st, reg)					\
> > +	readl_relaxed((st)->base + reg)
> > +#define at91_adc_writel(st, reg, val)					\
> > +	writel_relaxed(val, (st)->base + (st)->soc_info.platform->layout->reg)
> > +
> > +/**
> > + * struct at91_adc_platform - at91-sama5d2 platform information struct
> > + * @layout:		pointer to the reg layout struct
> > + * @adc_channels:	pointer to an array of channels for registering in
> > + *			the iio subsystem
> > + * @nr_channels:	number of physical channels available
> > + * @touch_chan_x:	index of the touchscreen X channel
> > + * @touch_chan_y:	index of the touchscreen Y channel
> > + * @touch_chan_p:	index of the touchscreen P channel
> > + * @max_channels:	number of total channels
> > + * @hw_trig_cnt:	number of possible hardware triggers
> > + */
> > +struct at91_adc_platform {
> > +	const struct at91_adc_reg_layout	*layout;
> > +	const struct iio_chan_spec		(*adc_channels)[];
> > +	unsigned int				nr_channels;
> > +	unsigned int				touch_chan_x;
> > +	unsigned int				touch_chan_y;
> > +	unsigned int				touch_chan_p;
> > +	unsigned int				max_channels;
> > +	unsigned int				hw_trig_cnt;
> > +};
> >   
> > +/**
> > + * struct at91_adc_soc_info - at91-sama5d2 soc information struct
> > + * @startup_time:	device startup time
> > + * @min_sample_rate:	minimum sample rate in Hz
> > + * @max_sample_rate:	maximum sample rate in Hz
> > + * @platform:		pointer to the platform structure
> > + */
> >   struct at91_adc_soc_info {
> >   	unsigned			startup_time;
> >   	unsigned			min_sample_rate;
> >   	unsigned			max_sample_rate;
> > +	const struct at91_adc_platform	*platform;
> >   };
> >   
> >   struct at91_adc_trigger {
> > @@ -382,6 +429,15 @@ struct at91_adc_touch {
> >   	struct work_struct		workq;
> >   };
> >   
> > +/*
> > + * Buffer size requirements:
> > + * No channels * bytes_per_channel(2) + timestamp bytes (8)
> > + * Divided by 2 because we need half words.
> > + * We assume 32 channels for now, has to be increased if needed.
> > + * Nobody minds a buffer being too big.
> > + */
> > +#define AT91_BUFFER_MAX_HWORDS ((32 * 2 + 8) / 2)
> > +
> >   struct at91_adc_state {
> >   	void __iomem			*base;
> >   	int				irq;
> > @@ -437,29 +493,49 @@ static const struct at91_adc_trigger at91_adc_trigger_list[] = {
> >   	},
> >   };
> >   
> > -static const struct iio_chan_spec at91_adc_channels[] = {
> > -	AT91_SAMA5D2_CHAN_SINGLE(0, 0x50),
> > -	AT91_SAMA5D2_CHAN_SINGLE(1, 0x54),
> > -	AT91_SAMA5D2_CHAN_SINGLE(2, 0x58),
> > -	AT91_SAMA5D2_CHAN_SINGLE(3, 0x5c),
> > -	AT91_SAMA5D2_CHAN_SINGLE(4, 0x60),
> > -	AT91_SAMA5D2_CHAN_SINGLE(5, 0x64),
> > -	AT91_SAMA5D2_CHAN_SINGLE(6, 0x68),
> > -	AT91_SAMA5D2_CHAN_SINGLE(7, 0x6c),
> > -	AT91_SAMA5D2_CHAN_SINGLE(8, 0x70),
> > -	AT91_SAMA5D2_CHAN_SINGLE(9, 0x74),
> > -	AT91_SAMA5D2_CHAN_SINGLE(10, 0x78),
> > -	AT91_SAMA5D2_CHAN_SINGLE(11, 0x7c),
> > -	AT91_SAMA5D2_CHAN_DIFF(0, 1, 0x50),
> > -	AT91_SAMA5D2_CHAN_DIFF(2, 3, 0x58),
> > -	AT91_SAMA5D2_CHAN_DIFF(4, 5, 0x60),
> > -	AT91_SAMA5D2_CHAN_DIFF(6, 7, 0x68),
> > -	AT91_SAMA5D2_CHAN_DIFF(8, 9, 0x70),
> > -	AT91_SAMA5D2_CHAN_DIFF(10, 11, 0x78),
> > -	IIO_CHAN_SOFT_TIMESTAMP(AT91_SAMA5D2_TIMESTAMP_CHAN_IDX),
> > -	AT91_SAMA5D2_CHAN_TOUCH(AT91_SAMA5D2_TOUCH_X_CHAN_IDX, "x", IIO_MOD_X),
> > -	AT91_SAMA5D2_CHAN_TOUCH(AT91_SAMA5D2_TOUCH_Y_CHAN_IDX, "y", IIO_MOD_Y),
> > -	AT91_SAMA5D2_CHAN_PRESSURE(AT91_SAMA5D2_TOUCH_P_CHAN_IDX, "pressure"),
> > +static const struct iio_chan_spec at91_sama5d2_adc_channels[] = {
> > +	AT91_SAMA5D2_CHAN_SINGLE(0, 0, 0x50),
> > +	AT91_SAMA5D2_CHAN_SINGLE(1, 1, 0x54),
> > +	AT91_SAMA5D2_CHAN_SINGLE(2, 2, 0x58),
> > +	AT91_SAMA5D2_CHAN_SINGLE(3, 3, 0x5c),
> > +	AT91_SAMA5D2_CHAN_SINGLE(4, 4, 0x60),
> > +	AT91_SAMA5D2_CHAN_SINGLE(5, 5, 0x64),
> > +	AT91_SAMA5D2_CHAN_SINGLE(6, 6, 0x68),
> > +	AT91_SAMA5D2_CHAN_SINGLE(7, 7, 0x6c),
> > +	AT91_SAMA5D2_CHAN_SINGLE(8, 8, 0x70),
> > +	AT91_SAMA5D2_CHAN_SINGLE(9, 9, 0x74),
> > +	AT91_SAMA5D2_CHAN_SINGLE(10, 10, 0x78),
> > +	AT91_SAMA5D2_CHAN_SINGLE(11, 11, 0x7c),
> > +	AT91_SAMA5D2_CHAN_DIFF(12, 0, 1, 0x50),
> > +	AT91_SAMA5D2_CHAN_DIFF(13, 2, 3, 0x58),
> > +	AT91_SAMA5D2_CHAN_DIFF(14, 4, 5, 0x60),
> > +	AT91_SAMA5D2_CHAN_DIFF(15, 6, 7, 0x68),
> > +	AT91_SAMA5D2_CHAN_DIFF(16, 8, 9, 0x70),
> > +	AT91_SAMA5D2_CHAN_DIFF(17, 10, 11, 0x78),
> > +	IIO_CHAN_SOFT_TIMESTAMP(18),
> > +	AT91_SAMA5D2_CHAN_TOUCH(19, "x", IIO_MOD_X),
> > +	AT91_SAMA5D2_CHAN_TOUCH(20, "y", IIO_MOD_Y),
> > +	AT91_SAMA5D2_CHAN_PRESSURE(21, "pressure"),
> > +};
> > +
> > +static const struct at91_adc_platform sama5d2_platform = {
> > +	.layout = &sama5d2_layout,
> > +	.adc_channels = &at91_sama5d2_adc_channels,
> > +#define AT91_SAMA5D2_SINGLE_CHAN_CNT 12
> > +#define AT91_SAMA5D2_DIFF_CHAN_CNT 6
> > +	.nr_channels = AT91_SAMA5D2_SINGLE_CHAN_CNT +
> > +		       AT91_SAMA5D2_DIFF_CHAN_CNT,
> > +#define AT91_SAMA5D2_TOUCH_X_CHAN_IDX	(AT91_SAMA5D2_SINGLE_CHAN_CNT + \
> > +					AT91_SAMA5D2_DIFF_CHAN_CNT * 2)
> > +	.touch_chan_x = AT91_SAMA5D2_TOUCH_X_CHAN_IDX,
> > +#define AT91_SAMA5D2_TOUCH_Y_CHAN_IDX	(AT91_SAMA5D2_TOUCH_X_CHAN_IDX + 1)
> > +	.touch_chan_y = AT91_SAMA5D2_TOUCH_Y_CHAN_IDX,
> > +#define AT91_SAMA5D2_TOUCH_P_CHAN_IDX	(AT91_SAMA5D2_TOUCH_Y_CHAN_IDX + 1)
> > +	.touch_chan_p = AT91_SAMA5D2_TOUCH_P_CHAN_IDX,
> > +#define AT91_SAMA5D2_MAX_CHAN_IDX	AT91_SAMA5D2_TOUCH_P_CHAN_IDX
> > +	.max_channels = ARRAY_SIZE(at91_sama5d2_adc_channels),
> > +#define AT91_SAMA5D2_HW_TRIG_CNT	3
> > +	.hw_trig_cnt = AT91_SAMA5D2_HW_TRIG_CNT,
> >   };
> >   
> >   static int at91_adc_chan_xlate(struct iio_dev *indio_dev, int chan)
> > @@ -493,6 +569,7 @@ static unsigned int at91_adc_active_scan_mask_to_reg(struct iio_dev *indio_dev)
> >   {
> >   	u32 mask = 0;
> >   	u8 bit;
> > +	struct at91_adc_state *st = iio_priv(indio_dev);
> >   
> >   	for_each_set_bit(bit, indio_dev->active_scan_mask,
> >   			 indio_dev->num_channels) {
> > @@ -501,13 +578,13 @@ static unsigned int at91_adc_active_scan_mask_to_reg(struct iio_dev *indio_dev)
> >   		mask |= BIT(chan->channel);
> >   	}
> >   
> > -	return mask & GENMASK(11, 0);
> > +	return mask & GENMASK(st->soc_info.platform->nr_channels, 0);
> >   }
> >   
> >   static void at91_adc_config_emr(struct at91_adc_state *st)
> >   {
> >   	/* configure the extended mode register */
> > -	unsigned int emr = at91_adc_readl(st, AT91_SAMA5D2_EMR);
> > +	unsigned int emr = at91_adc_readl(st, EMR);
> >   
> >   	/* select oversampling per single trigger event */
> >   	emr |= AT91_SAMA5D2_EMR_ASTE(1);
> > @@ -531,7 +608,7 @@ static void at91_adc_config_emr(struct at91_adc_state *st)
> >   		break;
> >   	}
> >   
> > -	at91_adc_writel(st, AT91_SAMA5D2_EMR, emr);
> > +	at91_adc_writel(st, EMR, emr);
> >   }
> >   
> >   static int at91_adc_adjust_val_osr(struct at91_adc_state *st, int *val)
> > @@ -584,9 +661,9 @@ static int at91_adc_configure_touch(struct at91_adc_state *st, bool state)
> >   
> >   	if (!state) {
> >   		/* disabling touch IRQs and setting mode to no touch enabled */
> > -		at91_adc_writel(st, AT91_SAMA5D2_IDR,
> > +		at91_adc_writel(st, IDR,
> >   				AT91_SAMA5D2_IER_PEN | AT91_SAMA5D2_IER_NOPEN);
> > -		at91_adc_writel(st, AT91_SAMA5D2_TSMR, 0);
> > +		at91_adc_writel(st, TSMR, 0);
> >   		return 0;
> >   	}
> >   	/*
> > @@ -612,19 +689,19 @@ static int at91_adc_configure_touch(struct at91_adc_state *st, bool state)
> >   	tsmr |= AT91_SAMA5D2_TSMR_PENDET_ENA;
> >   	tsmr |= AT91_SAMA5D2_TSMR_TSFREQ(2) & AT91_SAMA5D2_TSMR_TSFREQ_MASK;
> >   
> > -	at91_adc_writel(st, AT91_SAMA5D2_TSMR, tsmr);
> > +	at91_adc_writel(st, TSMR, tsmr);
> >   
> > -	acr =  at91_adc_readl(st, AT91_SAMA5D2_ACR);
> > +	acr =  at91_adc_readl(st, ACR);
> >   	acr &= ~AT91_SAMA5D2_ACR_PENDETSENS_MASK;
> >   	acr |= 0x02 & AT91_SAMA5D2_ACR_PENDETSENS_MASK;
> > -	at91_adc_writel(st, AT91_SAMA5D2_ACR, acr);
> > +	at91_adc_writel(st, ACR, acr);
> >   
> >   	/* Sample Period Time = (TRGPER + 1) / ADCClock */
> >   	st->touch_st.sample_period_val =
> >   				 round_up((AT91_SAMA5D2_TOUCH_SAMPLE_PERIOD_US *
> >   				 clk_khz / 1000) - 1, 1);
> >   	/* enable pen detect IRQ */
> > -	at91_adc_writel(st, AT91_SAMA5D2_IER, AT91_SAMA5D2_IER_PEN);
> > +	at91_adc_writel(st, IER, AT91_SAMA5D2_IER_PEN);
> >   
> >   	return 0;
> >   }
> > @@ -640,7 +717,11 @@ static u16 at91_adc_touch_pos(struct at91_adc_state *st, int reg)
> >   	 * max = 2^AT91_SAMA5D2_MAX_POS_BITS - 1
> >   	 */
> >   	/* first half of register is the x or y, second half is the scale */
> > -	val = at91_adc_readl(st, reg);
> > +	if (reg == st->soc_info.platform->layout->XPOSR)
> > +		val = at91_adc_readl(st, XPOSR);
> > +	else if (reg == st->soc_info.platform->layout->YPOSR)
> > +		val = at91_adc_readl(st, YPOSR);
> > +
> >   	if (!val)
> >   		dev_dbg(&st->indio_dev->dev, "pos is 0\n");
> >   
> > @@ -658,13 +739,13 @@ static u16 at91_adc_touch_pos(struct at91_adc_state *st, int reg)
> >   
> >   static u16 at91_adc_touch_x_pos(struct at91_adc_state *st)
> >   {
> > -	st->touch_st.x_pos = at91_adc_touch_pos(st, AT91_SAMA5D2_XPOSR);
> > +	st->touch_st.x_pos = at91_adc_touch_pos(st, st->soc_info.platform->layout->XPOSR);
> >   	return st->touch_st.x_pos;
> >   }
> >   
> >   static u16 at91_adc_touch_y_pos(struct at91_adc_state *st)
> >   {
> > -	return at91_adc_touch_pos(st, AT91_SAMA5D2_YPOSR);
> > +	return at91_adc_touch_pos(st, st->soc_info.platform->layout->YPOSR);
> >   }
> >   
> >   static u16 at91_adc_touch_pressure(struct at91_adc_state *st)
> > @@ -676,7 +757,7 @@ static u16 at91_adc_touch_pressure(struct at91_adc_state *st)
> >   	u32 factor = 1000;
> >   
> >   	/* calculate the pressure */
> > -	val = at91_adc_readl(st, AT91_SAMA5D2_PRESSR);
> > +	val = at91_adc_readl(st, PRESSR);
> >   	z1 = val & AT91_SAMA5D2_XYZ_MASK;
> >   	z2 = (val >> 16) & AT91_SAMA5D2_XYZ_MASK;
> >   
> > @@ -700,9 +781,9 @@ static int at91_adc_read_position(struct at91_adc_state *st, int chan, u16 *val)
> >   	*val = 0;
> >   	if (!st->touch_st.touching)
> >   		return -ENODATA;
> > -	if (chan == AT91_SAMA5D2_TOUCH_X_CHAN_IDX)
> > +	if (chan == st->soc_info.platform->touch_chan_x)
> >   		*val = at91_adc_touch_x_pos(st);
> > -	else if (chan == AT91_SAMA5D2_TOUCH_Y_CHAN_IDX)
> > +	else if (chan == st->soc_info.platform->touch_chan_y)
> >   		*val = at91_adc_touch_y_pos(st);
> >   	else
> >   		return -ENODATA;
> > @@ -715,7 +796,7 @@ static int at91_adc_read_pressure(struct at91_adc_state *st, int chan, u16 *val)
> >   	*val = 0;
> >   	if (!st->touch_st.touching)
> >   		return -ENODATA;
> > -	if (chan == AT91_SAMA5D2_TOUCH_P_CHAN_IDX)
> > +	if (chan == st->soc_info.platform->touch_chan_y)
> >   		*val = at91_adc_touch_pressure(st);
> >   	else
> >   		return -ENODATA;
> > @@ -727,7 +808,7 @@ static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state)
> >   {
> >   	struct iio_dev *indio = iio_trigger_get_drvdata(trig);
> >   	struct at91_adc_state *st = iio_priv(indio);
> > -	u32 status = at91_adc_readl(st, AT91_SAMA5D2_TRGR);
> > +	u32 status = at91_adc_readl(st, TRGR);
> >   
> >   	/* clear TRGMOD */
> >   	status &= ~AT91_SAMA5D2_TRGR_TRGMOD_MASK;
> > @@ -736,7 +817,7 @@ static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state)
> >   		status |= st->selected_trig->trgmod_value;
> >   
> >   	/* set/unset hw trigger */
> > -	at91_adc_writel(st, AT91_SAMA5D2_TRGR, status);
> > +	at91_adc_writel(st, TRGR, status);
> >   
> >   	return 0;
> >   }
> > @@ -753,7 +834,7 @@ static void at91_adc_reenable_trigger(struct iio_trigger *trig)
> >   	enable_irq(st->irq);
> >   
> >   	/* Needed to ACK the DRDY interruption */
> > -	at91_adc_readl(st, AT91_SAMA5D2_LCDR);
> > +	at91_adc_readl(st, LCDR);
> >   }
> >   
> >   static const struct iio_trigger_ops at91_adc_trigger_ops = {
> > @@ -848,7 +929,7 @@ static int at91_adc_dma_start(struct iio_dev *indio_dev)
> >   	}
> >   
> >   	/* enable general overrun error signaling */
> > -	at91_adc_writel(st, AT91_SAMA5D2_IER, AT91_SAMA5D2_IER_GOVRE);
> > +	at91_adc_writel(st, IER, AT91_SAMA5D2_IER_GOVRE);
> >   	/* Issue pending DMA requests */
> >   	dma_async_issue_pending(st->dma_st.dma_chan);
> >   
> > @@ -878,7 +959,7 @@ static bool at91_adc_current_chan_is_touch(struct iio_dev *indio_dev)
> >   
> >   	return !!bitmap_subset(indio_dev->active_scan_mask,
> >   			       &st->touch_st.channels_bitmask,
> > -			       AT91_SAMA5D2_MAX_CHAN_IDX + 1);
> > +			       st->soc_info.platform->max_channels + 1);
> >   }
> >   
> >   static int at91_adc_buffer_prepare(struct iio_dev *indio_dev)
> > @@ -915,7 +996,7 @@ static int at91_adc_buffer_prepare(struct iio_dev *indio_dev)
> >   		    chan->type == IIO_PRESSURE)
> >   			continue;
> >   
> > -		cor = at91_adc_readl(st, AT91_SAMA5D2_COR);
> > +		cor = at91_adc_readl(st, COR);
> >   
> >   		if (chan->differential)
> >   			cor |= (BIT(chan->channel) | BIT(chan->channel2)) <<
> > @@ -924,13 +1005,13 @@ static int at91_adc_buffer_prepare(struct iio_dev *indio_dev)
> >   			cor &= ~(BIT(chan->channel) <<
> >   			       AT91_SAMA5D2_COR_DIFF_OFFSET);
> >   
> > -		at91_adc_writel(st, AT91_SAMA5D2_COR, cor);
> > +		at91_adc_writel(st, COR, cor);
> >   
> > -		at91_adc_writel(st, AT91_SAMA5D2_CHER, BIT(chan->channel));
> > +		at91_adc_writel(st, CHER, BIT(chan->channel));
> >   	}
> >   
> >   	if (at91_adc_buffer_check_use_irq(indio_dev, st))
> > -		at91_adc_writel(st, AT91_SAMA5D2_IER, AT91_SAMA5D2_IER_DRDY);
> > +		at91_adc_writel(st, IER, AT91_SAMA5D2_IER_DRDY);
> >   
> >   	return 0;
> >   }
> > @@ -966,17 +1047,17 @@ static int at91_adc_buffer_postdisable(struct iio_dev *indio_dev)
> >   		    chan->type == IIO_PRESSURE)
> >   			continue;
> >   
> > -		at91_adc_writel(st, AT91_SAMA5D2_CHDR, BIT(chan->channel));
> > +		at91_adc_writel(st, CHDR, BIT(chan->channel));
> >   
> >   		if (st->dma_st.dma_chan)
> > -			at91_adc_readl(st, chan->address);
> > +			at91_adc_read_chan(st, chan->address);
> >   	}
> >   
> >   	if (at91_adc_buffer_check_use_irq(indio_dev, st))
> > -		at91_adc_writel(st, AT91_SAMA5D2_IDR, AT91_SAMA5D2_IER_DRDY);
> > +		at91_adc_writel(st, IDR, AT91_SAMA5D2_IER_DRDY);
> >   
> >   	/* read overflow register to clear possible overflow status */
> > -	at91_adc_readl(st, AT91_SAMA5D2_OVER);
> > +	at91_adc_readl(st, OVER);
> >   
> >   	/* if we are using DMA we must clear registers and end DMA */
> >   	if (st->dma_st.dma_chan)
> > @@ -1024,7 +1105,7 @@ static void at91_adc_trigger_handler_nodma(struct iio_dev *indio_dev,
> >   	 * Check if the conversion is ready. If not, wait a little bit, and
> >   	 * in case of timeout exit with an error.
> >   	 */
> > -	while ((at91_adc_readl(st, AT91_SAMA5D2_ISR) & mask) != mask &&
> > +	while ((at91_adc_readl(st, ISR) & mask) != mask &&
> >   	       timeout) {
> >   		usleep_range(50, 100);
> >   		timeout--;
> > @@ -1052,7 +1133,7 @@ static void at91_adc_trigger_handler_nodma(struct iio_dev *indio_dev,
> >   		 * Thus, emit a warning.
> >   		 */
> >   		if (chan->type == IIO_VOLTAGE) {
> > -			val = at91_adc_readl(st, chan->address);
> > +			val = at91_adc_read_chan(st, chan->address);
> >   			at91_adc_adjust_val_osr(st, &val);
> >   			st->buffer[i] = val;
> >   		} else {
> > @@ -1073,7 +1154,7 @@ static void at91_adc_trigger_handler_dma(struct iio_dev *indio_dev)
> >   	s64 interval;
> >   	int sample_index = 0, sample_count, sample_size;
> >   
> > -	u32 status = at91_adc_readl(st, AT91_SAMA5D2_ISR);
> > +	u32 status = at91_adc_readl(st, ISR);
> >   	/* if we reached this point, we cannot sample faster */
> >   	if (status & AT91_SAMA5D2_IER_GOVRE)
> >   		pr_info_ratelimited("%s: conversion overrun detected\n",
> > @@ -1125,7 +1206,7 @@ static irqreturn_t at91_adc_trigger_handler(int irq, void *p)
> >   	 * actually polling the trigger now.
> >   	 */
> >   	if (iio_trigger_validate_own_device(indio_dev->trig, indio_dev))
> > -		at91_adc_writel(st, AT91_SAMA5D2_CR, AT91_SAMA5D2_CR_START);
> > +		at91_adc_writel(st, CR, AT91_SAMA5D2_CR_START);
> >   
> >   	if (st->dma_st.dma_chan)
> >   		at91_adc_trigger_handler_dma(indio_dev);
> > @@ -1172,11 +1253,11 @@ static void at91_adc_setup_samp_freq(struct iio_dev *indio_dev, unsigned freq)
> >   	startup = at91_adc_startup_time(st->soc_info.startup_time,
> >   					freq / 1000);
> >   
> > -	mr = at91_adc_readl(st, AT91_SAMA5D2_MR);
> > +	mr = at91_adc_readl(st, MR);
> >   	mr &= ~(AT91_SAMA5D2_MR_STARTUP_MASK | AT91_SAMA5D2_MR_PRESCAL_MASK);
> >   	mr |= AT91_SAMA5D2_MR_STARTUP(startup);
> >   	mr |= AT91_SAMA5D2_MR_PRESCAL(prescal);
> > -	at91_adc_writel(st, AT91_SAMA5D2_MR, mr);
> > +	at91_adc_writel(st, MR, mr);
> >   
> >   	dev_dbg(&indio_dev->dev, "freq: %u, startup: %u, prescal: %u\n",
> >   		freq, startup, prescal);
> > @@ -1196,7 +1277,7 @@ static void at91_adc_touch_data_handler(struct iio_dev *indio_dev)
> >   	int i = 0;
> >   
> >   	for_each_set_bit(bit, indio_dev->active_scan_mask,
> > -			 AT91_SAMA5D2_MAX_CHAN_IDX + 1) {
> > +			 st->soc_info.platform->max_channels + 1) {
> >   		struct iio_chan_spec const *chan =
> >   					 at91_adc_chan_get(indio_dev, bit);
> >   
> > @@ -1222,12 +1303,11 @@ static void at91_adc_touch_data_handler(struct iio_dev *indio_dev)
> >   
> >   static void at91_adc_pen_detect_interrupt(struct at91_adc_state *st)
> >   {
> > -	at91_adc_writel(st, AT91_SAMA5D2_IDR, AT91_SAMA5D2_IER_PEN);
> > -	at91_adc_writel(st, AT91_SAMA5D2_IER, AT91_SAMA5D2_IER_NOPEN |
> > +	at91_adc_writel(st, IDR, AT91_SAMA5D2_IER_PEN);
> > +	at91_adc_writel(st, IER, AT91_SAMA5D2_IER_NOPEN |
> >   			AT91_SAMA5D2_IER_XRDY | AT91_SAMA5D2_IER_YRDY |
> >   			AT91_SAMA5D2_IER_PRDY);
> > -	at91_adc_writel(st, AT91_SAMA5D2_TRGR,
> > -			AT91_SAMA5D2_TRGR_TRGMOD_PERIODIC |
> > +	at91_adc_writel(st, TRGR, AT91_SAMA5D2_TRGR_TRGMOD_PERIODIC |
> >   			AT91_SAMA5D2_TRGR_TRGPER(st->touch_st.sample_period_val));
> >   	st->touch_st.touching = true;
> >   }
> > @@ -1236,16 +1316,15 @@ static void at91_adc_no_pen_detect_interrupt(struct iio_dev *indio_dev)
> >   {
> >   	struct at91_adc_state *st = iio_priv(indio_dev);
> >   
> > -	at91_adc_writel(st, AT91_SAMA5D2_TRGR,
> > -			AT91_SAMA5D2_TRGR_TRGMOD_NO_TRIGGER);
> > -	at91_adc_writel(st, AT91_SAMA5D2_IDR, AT91_SAMA5D2_IER_NOPEN |
> > +	at91_adc_writel(st, TRGR, AT91_SAMA5D2_TRGR_TRGMOD_NO_TRIGGER);
> > +	at91_adc_writel(st, IDR, AT91_SAMA5D2_IER_NOPEN |
> >   			AT91_SAMA5D2_IER_XRDY | AT91_SAMA5D2_IER_YRDY |
> >   			AT91_SAMA5D2_IER_PRDY);
> >   	st->touch_st.touching = false;
> >   
> >   	at91_adc_touch_data_handler(indio_dev);
> >   
> > -	at91_adc_writel(st, AT91_SAMA5D2_IER, AT91_SAMA5D2_IER_PEN);
> > +	at91_adc_writel(st, IER, AT91_SAMA5D2_IER_PEN);
> >   }
> >   
> >   static void at91_adc_workq_handler(struct work_struct *workq)
> > @@ -1263,8 +1342,8 @@ static irqreturn_t at91_adc_interrupt(int irq, void *private)
> >   {
> >   	struct iio_dev *indio = private;
> >   	struct at91_adc_state *st = iio_priv(indio);
> > -	u32 status = at91_adc_readl(st, AT91_SAMA5D2_ISR);
> > -	u32 imr = at91_adc_readl(st, AT91_SAMA5D2_IMR);
> > +	u32 status = at91_adc_readl(st, ISR);
> > +	u32 imr = at91_adc_readl(st, IMR);
> >   	u32 rdy_mask = AT91_SAMA5D2_IER_XRDY | AT91_SAMA5D2_IER_YRDY |
> >   			AT91_SAMA5D2_IER_PRDY;
> >   
> > @@ -1285,9 +1364,9 @@ static irqreturn_t at91_adc_interrupt(int irq, void *private)
> >   		 * touching, but the measurements are not ready yet.
> >   		 * read and ignore.
> >   		 */
> > -		status = at91_adc_readl(st, AT91_SAMA5D2_XPOSR);
> > -		status = at91_adc_readl(st, AT91_SAMA5D2_YPOSR);
> > -		status = at91_adc_readl(st, AT91_SAMA5D2_PRESSR);
> > +		status = at91_adc_readl(st, XPOSR);
> > +		status = at91_adc_readl(st, YPOSR);
> > +		status = at91_adc_readl(st, PRESSR);
> >   	} else if (iio_buffer_enabled(indio) &&
> >   		   (status & AT91_SAMA5D2_IER_DRDY)) {
> >   		/* triggered buffer without DMA */
> > @@ -1299,7 +1378,7 @@ static irqreturn_t at91_adc_interrupt(int irq, void *private)
> >   		WARN(true, "Unexpected irq occurred\n");
> >   	} else if (!iio_buffer_enabled(indio)) {
> >   		/* software requested conversion */
> > -		st->conversion_value = at91_adc_readl(st, st->chan->address);
> > +		st->conversion_value = at91_adc_read_chan(st, st->chan->address);
> >   		st->conversion_done = true;
> >   		wake_up_interruptible(&st->wq_data_available);
> >   	}
> > @@ -1360,10 +1439,10 @@ static int at91_adc_read_info_raw(struct iio_dev *indio_dev,
> >   		cor = (BIT(chan->channel) | BIT(chan->channel2)) <<
> >   		      AT91_SAMA5D2_COR_DIFF_OFFSET;
> >   
> > -	at91_adc_writel(st, AT91_SAMA5D2_COR, cor);
> > -	at91_adc_writel(st, AT91_SAMA5D2_CHER, BIT(chan->channel));
> > -	at91_adc_writel(st, AT91_SAMA5D2_IER, BIT(chan->channel));
> > -	at91_adc_writel(st, AT91_SAMA5D2_CR, AT91_SAMA5D2_CR_START);
> > +	at91_adc_writel(st, COR, cor);
> > +	at91_adc_writel(st, CHER, BIT(chan->channel));
> > +	at91_adc_writel(st, IER, BIT(chan->channel));
> > +	at91_adc_writel(st, CR, AT91_SAMA5D2_CR_START);
> >   
> >   	ret = wait_event_interruptible_timeout(st->wq_data_available,
> >   					       st->conversion_done,
> > @@ -1379,11 +1458,11 @@ static int at91_adc_read_info_raw(struct iio_dev *indio_dev,
> >   		st->conversion_done = false;
> >   	}
> >   
> > -	at91_adc_writel(st, AT91_SAMA5D2_IDR, BIT(chan->channel));
> > -	at91_adc_writel(st, AT91_SAMA5D2_CHDR, BIT(chan->channel));
> > +	at91_adc_writel(st, IDR, BIT(chan->channel));
> > +	at91_adc_writel(st, CHDR, BIT(chan->channel));
> >   
> >   	/* Needed to ACK the DRDY interruption */
> > -	at91_adc_readl(st, AT91_SAMA5D2_LCDR);
> > +	at91_adc_readl(st, LCDR);
> >   
> >   	mutex_unlock(&st->lock);
> >   
> > @@ -1455,14 +1534,15 @@ static void at91_adc_dma_init(struct platform_device *pdev)
> >   	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
> >   	struct at91_adc_state *st = iio_priv(indio_dev);
> >   	struct dma_slave_config config = {0};
> > +	/* we have 2 bytes for each channel */
> > +	unsigned int sample_size = st->soc_info.platform->nr_channels * 2;
> >   	/*
> >   	 * We make the buffer double the size of the fifo,
> >   	 * such that DMA uses one half of the buffer (full fifo size)
> >   	 * and the software uses the other half to read/write.
> >   	 */
> >   	unsigned int pages = DIV_ROUND_UP(AT91_HWFIFO_MAX_SIZE *
> > -					  AT91_BUFFER_MAX_CONVERSION_BYTES * 2,
> > -					  PAGE_SIZE);
> > +					  sample_size * 2, PAGE_SIZE);
> >   
> >   	if (st->dma_st.dma_chan)
> >   		return;
> > @@ -1486,7 +1566,7 @@ static void at91_adc_dma_init(struct platform_device *pdev)
> >   	/* Configure DMA channel to read data register */
> >   	config.direction = DMA_DEV_TO_MEM;
> >   	config.src_addr = (phys_addr_t)(st->dma_st.phys_addr
> > -			  + AT91_SAMA5D2_LCDR);
> > +			  + st->soc_info.platform->layout->LCDR);
> >   	config.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
> >   	config.src_maxburst = 1;
> >   	config.dst_maxburst = 1;
> > @@ -1515,9 +1595,10 @@ static void at91_adc_dma_disable(struct platform_device *pdev)
> >   {
> >   	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
> >   	struct at91_adc_state *st = iio_priv(indio_dev);
> > +	/* we have 2 bytes for each channel */
> > +	unsigned int sample_size = st->soc_info.platform->nr_channels * 2;
> >   	unsigned int pages = DIV_ROUND_UP(AT91_HWFIFO_MAX_SIZE *
> > -					  AT91_BUFFER_MAX_CONVERSION_BYTES * 2,
> > -					  PAGE_SIZE);
> > +					  sample_size * 2, PAGE_SIZE);
> >   
> >   	/* if we are not using DMA, just return */
> >   	if (!st->dma_st.dma_chan)
> > @@ -1578,14 +1659,14 @@ static int at91_adc_update_scan_mode(struct iio_dev *indio_dev,
> >   	struct at91_adc_state *st = iio_priv(indio_dev);
> >   
> >   	if (bitmap_subset(scan_mask, &st->touch_st.channels_bitmask,
> > -			  AT91_SAMA5D2_MAX_CHAN_IDX + 1))
> > +			  st->soc_info.platform->max_channels + 1))
> >   		return 0;
> >   	/*
> >   	 * if the new bitmap is a combination of touchscreen and regular
> >   	 * channels, then we are not fine
> >   	 */
> >   	if (bitmap_intersects(&st->touch_st.channels_bitmask, scan_mask,
> > -			      AT91_SAMA5D2_MAX_CHAN_IDX + 1))
> > +			      st->soc_info.platform->max_channels + 1))
> >   		return -EINVAL;
> >   	return 0;
> >   }
> > @@ -1594,13 +1675,13 @@ static void at91_adc_hw_init(struct iio_dev *indio_dev)
> >   {
> >   	struct at91_adc_state *st = iio_priv(indio_dev);
> >   
> > -	at91_adc_writel(st, AT91_SAMA5D2_CR, AT91_SAMA5D2_CR_SWRST);
> > -	at91_adc_writel(st, AT91_SAMA5D2_IDR, 0xffffffff);
> > +	at91_adc_writel(st, CR, AT91_SAMA5D2_CR_SWRST);
> > +	at91_adc_writel(st, IDR, 0xffffffff);
> >   	/*
> >   	 * Transfer field must be set to 2 according to the datasheet and
> >   	 * allows different analog settings for each channel.
> >   	 */
> > -	at91_adc_writel(st, AT91_SAMA5D2_MR,
> > +	at91_adc_writel(st, MR,
> >   			AT91_SAMA5D2_MR_TRANSFER(2) | AT91_SAMA5D2_MR_ANACH);
> >   
> >   	at91_adc_setup_samp_freq(indio_dev, st->soc_info.min_sample_rate);
> > @@ -1716,21 +1797,23 @@ static int at91_adc_probe(struct platform_device *pdev)
> >   	if (!indio_dev)
> >   		return -ENOMEM;
> >   
> > +	st = iio_priv(indio_dev);
> > +	st->indio_dev = indio_dev;
> > +
> > +	st->soc_info.platform = of_device_get_match_data(&pdev->dev);
> > +
> >   	indio_dev->name = dev_name(&pdev->dev);
> >   	indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE;
> >   	indio_dev->info = &at91_adc_info;
> > -	indio_dev->channels = at91_adc_channels;
> > -	indio_dev->num_channels = ARRAY_SIZE(at91_adc_channels);
> > -
> > -	st = iio_priv(indio_dev);
> > -	st->indio_dev = indio_dev;
> > +	indio_dev->channels = *st->soc_info.platform->adc_channels;
> > +	indio_dev->num_channels = st->soc_info.platform->max_channels;
> >   
> >   	bitmap_set(&st->touch_st.channels_bitmask,
> > -		   AT91_SAMA5D2_TOUCH_X_CHAN_IDX, 1);
> > +		   st->soc_info.platform->touch_chan_x, 1);
> >   	bitmap_set(&st->touch_st.channels_bitmask,
> > -		   AT91_SAMA5D2_TOUCH_Y_CHAN_IDX, 1);
> > +		   st->soc_info.platform->touch_chan_y, 1);
> >   	bitmap_set(&st->touch_st.channels_bitmask,
> > -		   AT91_SAMA5D2_TOUCH_P_CHAN_IDX, 1);
> > +		   st->soc_info.platform->touch_chan_p, 1);
> >   
> >   	st->oversampling_ratio = AT91_OSR_1SAMPLES;
> >   
> > @@ -1770,7 +1853,7 @@ static int at91_adc_probe(struct platform_device *pdev)
> >   	st->selected_trig = NULL;
> >   
> >   	/* find the right trigger, or no trigger at all */
> > -	for (i = 0; i < AT91_SAMA5D2_HW_TRIG_CNT + 1; i++)
> > +	for (i = 0; i < st->soc_info.platform->hw_trig_cnt + 1; i++)
> >   		if (at91_adc_trigger_list[i].edge_type == edge_type) {
> >   			st->selected_trig = &at91_adc_trigger_list[i];
> >   			break;
> > @@ -1855,7 +1938,7 @@ static int at91_adc_probe(struct platform_device *pdev)
> >   			 st->selected_trig->name);
> >   
> >   	dev_info(&pdev->dev, "version: %x\n",
> > -		 readl_relaxed(st->base + AT91_SAMA5D2_VERSION));
> > +		 readl_relaxed(st->base + st->soc_info.platform->layout->VERSION));
> >   
> >   	return 0;
> >   
> > @@ -1898,7 +1981,7 @@ static __maybe_unused int at91_adc_suspend(struct device *dev)
> >   	 * and can be used by for other devices.
> >   	 * Otherwise, ADC will hog them and we can't go to suspend mode.
> >   	 */
> > -	at91_adc_writel(st, AT91_SAMA5D2_CR, AT91_SAMA5D2_CR_SWRST);
> > +	at91_adc_writel(st, CR, AT91_SAMA5D2_CR_SWRST);
> >   
> >   	clk_disable_unprepare(st->per_clk);
> >   	regulator_disable(st->vref);
> > @@ -1958,6 +2041,7 @@ static SIMPLE_DEV_PM_OPS(at91_adc_pm_ops, at91_adc_suspend, at91_adc_resume);
> >   static const struct of_device_id at91_adc_dt_match[] = {
> >   	{
> >   		.compatible = "atmel,sama5d2-adc",
> > +		.data = (const void *)&sama5d2_platform,
> >   	}, {
> >   		/* sentinel */
> >   	}
> >   
>
Eugen Hristev Aug. 31, 2021, 11:50 a.m. UTC | #5
On 8/30/21 5:44 PM, Jonathan Cameron wrote:
> On Mon, 30 Aug 2021 12:31:46 +0000
> <Eugen.Hristev@microchip.com> wrote:
> 
>> On 8/24/21 2:54 PM, Eugen Hristev wrote:
>>> Convert the driver to platform specific structures. This means:
>>> - create a register layout struct that will hold offsets for registers
>>> - create a platform struct that will hold platform information (number of
>>> channels, indexes for different channels and pointer to layout struct)
>>> - convert specific macros that are platform dependent into platform variables
>>>
>>> This step is in fact a no-op, but allows the driver to be more flexible
>>> and for future enhancement including adding new platforms that are partly
>>> compatible with the current driver and differ slightly in register layout
>>> or capabilities for example.
>>>
>>> Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
>>> ---
>>>    drivers/iio/adc/at91-sama5d2_adc.c | 410 +++++++++++++++++------------
>>>    1 file changed, 247 insertions(+), 163 deletions(-)
>>>
>>> diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c
>>> index 9d71dcffcf93..8ede18b8d789 100644
>>> --- a/drivers/iio/adc/at91-sama5d2_adc.c
>>> +++ b/drivers/iio/adc/at91-sama5d2_adc.c
>>> @@ -27,8 +27,9 @@
>>>    #include <linux/pinctrl/consumer.h>
>>>    #include <linux/regulator/consumer.h>
>>>
>>> +struct at91_adc_reg_layout {
>>>    /* Control Register */
>>> -#define AT91_SAMA5D2_CR            0x00
>>> +   u16                             CR;
>>>    /* Software Reset */
>>>    #define   AT91_SAMA5D2_CR_SWRST           BIT(0)
>>>    /* Start Conversion */
>>> @@ -39,7 +40,7 @@
>>>    #define   AT91_SAMA5D2_CR_CMPRST          BIT(4)
>>>
>>>    /* Mode Register */
>>> -#define AT91_SAMA5D2_MR            0x04
>>> +   u16                             MR;
>>>    /* Trigger Selection */
>>>    #define   AT91_SAMA5D2_MR_TRGSEL(v)       ((v) << 1)
>>>    /* ADTRG */
>>> @@ -82,19 +83,19 @@
>>>    #define   AT91_SAMA5D2_MR_USEQ            BIT(31)
>>>
>>>    /* Channel Sequence Register 1 */
>>> -#define AT91_SAMA5D2_SEQR1 0x08
>>> +   u16                             SEQR1;
>>>    /* Channel Sequence Register 2 */
>>> -#define AT91_SAMA5D2_SEQR2 0x0c
>>> +   u16                             SEQR2;
>>>    /* Channel Enable Register */
>>> -#define AT91_SAMA5D2_CHER  0x10
>>> +   u16                             CHER;
>>>    /* Channel Disable Register */
>>> -#define AT91_SAMA5D2_CHDR  0x14
>>> +   u16                             CHDR;
>>>    /* Channel Status Register */
>>> -#define AT91_SAMA5D2_CHSR  0x18
>>> +   u16                             CHSR;
>>>    /* Last Converted Data Register */
>>> -#define AT91_SAMA5D2_LCDR  0x20
>>> +   u16                             LCDR;
>>>    /* Interrupt Enable Register */
>>> -#define AT91_SAMA5D2_IER   0x24
>>> +   u16                             IER;
>>>    /* Interrupt Enable Register - TS X measurement ready */
>>>    #define AT91_SAMA5D2_IER_XRDY   BIT(20)
>>>    /* Interrupt Enable Register - TS Y measurement ready */
>>> @@ -109,22 +110,23 @@
>>>    #define AT91_SAMA5D2_IER_PEN    BIT(29)
>>>    /* Interrupt Enable Register - No pen detect */
>>>    #define AT91_SAMA5D2_IER_NOPEN  BIT(30)
>>> +
>>>    /* Interrupt Disable Register */
>>> -#define AT91_SAMA5D2_IDR   0x28
>>> +   u16                             IDR;
>>>    /* Interrupt Mask Register */
>>> -#define AT91_SAMA5D2_IMR   0x2c
>>> +   u16                             IMR;
>>>    /* Interrupt Status Register */
>>> -#define AT91_SAMA5D2_ISR   0x30
>>> +   u16                             ISR;
>>>    /* Interrupt Status Register - Pen touching sense status */
>>>    #define AT91_SAMA5D2_ISR_PENS   BIT(31)
>>>    /* Last Channel Trigger Mode Register */
>>> -#define AT91_SAMA5D2_LCTMR 0x34
>>> +   u16                             LCTMR;
>>>    /* Last Channel Compare Window Register */
>>> -#define AT91_SAMA5D2_LCCWR 0x38
>>> +   u16                             LCCWR;
>>>    /* Overrun Status Register */
>>> -#define AT91_SAMA5D2_OVER  0x3c
>>> +   u16                             OVER;
>>>    /* Extended Mode Register */
>>> -#define AT91_SAMA5D2_EMR   0x40
>>> +   u16                             EMR;
>>>    /* Extended Mode Register - Oversampling rate */
>>>    #define AT91_SAMA5D2_EMR_OSR(V)                   ((V) << 16)
>>>    #define AT91_SAMA5D2_EMR_OSR_MASK         GENMASK(17, 16)
>>> @@ -134,22 +136,22 @@
>>>
>>>    /* Extended Mode Register - Averaging on single trigger event */
>>>    #define AT91_SAMA5D2_EMR_ASTE(V)          ((V) << 20)
>>> +
>>>    /* Compare Window Register */
>>> -#define AT91_SAMA5D2_CWR   0x44
>>> +   u16                             CWR;
>>>    /* Channel Gain Register */
>>> -#define AT91_SAMA5D2_CGR   0x48
>>> -
>>> +   u16                             CGR;
>>>    /* Channel Offset Register */
>>> -#define AT91_SAMA5D2_COR   0x4c
>>> +   u16                             COR;
>>>    #define AT91_SAMA5D2_COR_DIFF_OFFSET      16
>>>
>>>    /* Analog Control Register */
>>> -#define AT91_SAMA5D2_ACR   0x94
>>> +   u16                             ACR;
>>>    /* Analog Control Register - Pen detect sensitivity mask */
>>>    #define AT91_SAMA5D2_ACR_PENDETSENS_MASK        GENMASK(1, 0)
>>>
>>>    /* Touchscreen Mode Register */
>>> -#define AT91_SAMA5D2_TSMR  0xb0
>>> +   u16                             TSMR;
>>>    /* Touchscreen Mode Register - No touch mode */
>>>    #define AT91_SAMA5D2_TSMR_TSMODE_NONE           0
>>>    /* Touchscreen Mode Register - 4 wire screen, no pressure measurement */
>>> @@ -178,13 +180,13 @@
>>>    #define AT91_SAMA5D2_TSMR_PENDET_ENA            BIT(24)
>>>
>>>    /* Touchscreen X Position Register */
>>> -#define AT91_SAMA5D2_XPOSR 0xb4
>>> +   u16                             XPOSR;
>>>    /* Touchscreen Y Position Register */
>>> -#define AT91_SAMA5D2_YPOSR 0xb8
>>> +   u16                             YPOSR;
>>>    /* Touchscreen Pressure Register */
>>> -#define AT91_SAMA5D2_PRESSR        0xbc
>>> +   u16                             PRESSR;
>>>    /* Trigger Register */
>>> -#define AT91_SAMA5D2_TRGR  0xc0
>>> +   u16                             TRGR;
>>>    /* Mask for TRGMOD field of TRGR register */
>>>    #define AT91_SAMA5D2_TRGR_TRGMOD_MASK GENMASK(2, 0)
>>>    /* No trigger, only software trigger can start conversions */
>>> @@ -203,30 +205,52 @@
>>>    #define AT91_SAMA5D2_TRGR_TRGPER(x)             ((x) << 16)
>>>
>>>    /* Correction Select Register */
>>> -#define AT91_SAMA5D2_COSR  0xd0
>>> +   u16                             COSR;
>>>    /* Correction Value Register */
>>> -#define AT91_SAMA5D2_CVR   0xd4
>>> +   u16                             CVR;
>>>    /* Channel Error Correction Register */
>>> -#define AT91_SAMA5D2_CECR  0xd8
>>> +   u16                             CECR;
>>>    /* Write Protection Mode Register */
>>> -#define AT91_SAMA5D2_WPMR  0xe4
>>> +   u16                             WPMR;
>>>    /* Write Protection Status Register */
>>> -#define AT91_SAMA5D2_WPSR  0xe8
>>> +   u16                             WPSR;
>>>    /* Version Register */
>>> -#define AT91_SAMA5D2_VERSION       0xfc
>>> -
>>> -#define AT91_SAMA5D2_HW_TRIG_CNT 3
>>> -#define AT91_SAMA5D2_SINGLE_CHAN_CNT 12
>>> -#define AT91_SAMA5D2_DIFF_CHAN_CNT 6
>>> -
>>> -#define AT91_SAMA5D2_TIMESTAMP_CHAN_IDX (AT91_SAMA5D2_SINGLE_CHAN_CNT + \
>>> -                                    AT91_SAMA5D2_DIFF_CHAN_CNT + 1)
>>> +   u16                             VERSION;
>>> +};
>>>
>>> -#define AT91_SAMA5D2_TOUCH_X_CHAN_IDX (AT91_SAMA5D2_SINGLE_CHAN_CNT + \
>>> -                                    AT91_SAMA5D2_DIFF_CHAN_CNT * 2)
>>
>> Hi Jonathan,
>>
>> While we are here, regarding the above line, I cannot tell why did I
>> multiply by two the differential channel count. This makes some gaps in
>> the number of channels when we put them all in the same table.
>>
>> I did not change this as it would break the ABI regarding the bindings
>> for the touchscreen #adc-cells phandle references.
> 
> Really?  Xlate is based off scan_index, not these values I think...

I figured it out.

We have 12 single channels [0..11] then 6 differential [12, 14, 16, 18, 
20, 22] spaced by two, a timestamp [23], then we have the X channel 
index at 24, Y at 25 and pressure are 26.

These are reflected in this file :

https://elixir.bootlin.com/linux/latest/source/include/dt-bindings/iio/adc/at91-sama5d2_adc.h

And the resistive touchscreen connects to the adc with these indexes.

And I realised why we have the padding/spaces.
It was the original design of the driver, in the line which I 
highlighted now below in the patch : (and I never changed this since 
working on this driver, because it was a break of the ABI in channel 
numbers ...)


> 
>>
>> However, I am thinking if there was a reason for it or it was a slip
>> when I initially wrote this.
> 
> I've no idea :)  I can't immediately see why we'd need the padding.
> 
>>
>> Do you think there is any reason to change it and tighten the holes in
>> the indexes list ?
> 
> I don't think it matters. As far as I can tell they are used mostly (possibly
> entirely) for internal management and not exposed to any of the ABIs etc.
> 
> Jonathan
> 
>>
>>
>> Eugen
>>
>>> -#define AT91_SAMA5D2_TOUCH_Y_CHAN_IDX   (AT91_SAMA5D2_TOUCH_X_CHAN_IDX + 1)
>>> -#define AT91_SAMA5D2_TOUCH_P_CHAN_IDX   (AT91_SAMA5D2_TOUCH_Y_CHAN_IDX + 1)
>>> -#define AT91_SAMA5D2_MAX_CHAN_IDX  AT91_SAMA5D2_TOUCH_P_CHAN_IDX
>>> +static const struct at91_adc_reg_layout sama5d2_layout = {
>>> +   .CR =                   0x00,
>>> +   .MR =                   0x04,
>>> +   .SEQR1 =                0x08,
>>> +   .SEQR2 =                0x0c,
>>> +   .CHER =                 0x10,
>>> +   .CHDR =                 0x14,
>>> +   .CHSR =                 0x18,
>>> +   .LCDR =                 0x20,
>>> +   .IER =                  0x24,
>>> +   .IDR =                  0x28,
>>> +   .IMR =                  0x2c,
>>> +   .ISR =                  0x30,
>>> +   .LCTMR =                0x34,
>>> +   .LCCWR =                0x38,
>>> +   .OVER =                 0x3c,
>>> +   .EMR =                  0x40,
>>> +   .CWR =                  0x44,
>>> +   .CGR =                  0x48,
>>> +   .COR =                  0x4c,
>>> +   .ACR =                  0x94,
>>> +   .TSMR =                 0xb0,
>>> +   .XPOSR =                0xb4,
>>> +   .YPOSR =                0xb8,
>>> +   .PRESSR =               0xbc,
>>> +   .TRGR =                 0xc0,
>>> +   .COSR =                 0xd0,
>>> +   .CVR =                  0xd4,
>>> +   .CECR =                 0xd8,
>>> +   .WPMR =                 0xe4,
>>> +   .WPSR =                 0xe8,
>>> +   .VERSION =              0xfc,
>>> +};
>>>
>>>    #define AT91_SAMA5D2_TOUCH_SAMPLE_PERIOD_US          2000    /* 2ms */
>>>    #define AT91_SAMA5D2_TOUCH_PEN_DETECT_DEBOUNCE_US    200
>>> @@ -235,18 +259,6 @@
>>>
>>>    #define AT91_SAMA5D2_MAX_POS_BITS                 12
>>>
>>> -/*
>>> - * Maximum number of bytes to hold conversion from all channels
>>> - * without the timestamp.
>>> - */
>>> -#define AT91_BUFFER_MAX_CONVERSION_BYTES ((AT91_SAMA5D2_SINGLE_CHAN_CNT + \
>>> -                                    AT91_SAMA5D2_DIFF_CHAN_CNT) * 2)
>>> -
>>> -/* This total must also include the timestamp */
>>> -#define AT91_BUFFER_MAX_BYTES (AT91_BUFFER_MAX_CONVERSION_BYTES + 8)
>>> -
>>> -#define AT91_BUFFER_MAX_HWORDS (AT91_BUFFER_MAX_BYTES / 2)
>>> -
>>>    #define AT91_HWFIFO_MAX_SIZE_STR  "128"
>>>    #define AT91_HWFIFO_MAX_SIZE              128
>>>
>>> @@ -255,12 +267,12 @@
>>>    #define AT91_OSR_4SAMPLES         4
>>>    #define AT91_OSR_16SAMPLES                16
>>>
>>> -#define AT91_SAMA5D2_CHAN_SINGLE(num, addr)                                \
>>> +#define AT91_SAMA5D2_CHAN_SINGLE(index, num, addr)                 \
>>>      {                                                               \
>>>              .type = IIO_VOLTAGE,                                    \
>>>              .channel = num,                                         \
>>>              .address = addr,                                        \
>>> -           .scan_index = num,                                      \
>>> +           .scan_index = index,                                    \
>>>              .scan_type = {                                          \
>>>                      .sign = 'u',                                    \
>>>                      .realbits = 14,                                 \
>>> @@ -274,14 +286,14 @@
>>>              .indexed = 1,                                           \
>>>      }
>>>
>>> -#define AT91_SAMA5D2_CHAN_DIFF(num, num2, addr)                            \
>>> +#define AT91_SAMA5D2_CHAN_DIFF(index, num, num2, addr)                     \
>>>      {                                                               \
>>>              .type = IIO_VOLTAGE,                                    \
>>>              .differential = 1,                                      \
>>>              .channel = num,                                         \
>>>              .channel2 = num2,                                       \
>>>              .address = addr,                                        \
>>> -           .scan_index = num + AT91_SAMA5D2_SINGLE_CHAN_CNT,       \

Here it is: we always added num to the single channel count, but num 
goes incrementally in steps of two : 0, 2, 4, 6, 8, 10

>>> +           .scan_index = index,                                    \
>>>              .scan_type = {                                          \
>>>                      .sign = 's',                                    \
>>>                      .realbits = 14,                                 \
>>> @@ -328,13 +340,48 @@
>>>              .datasheet_name = name,                                 \
>>>      }
>>>
>>> -#define at91_adc_readl(st, reg)            readl_relaxed(st->base + reg)
>>> -#define at91_adc_writel(st, reg, val)      writel_relaxed(val, st->base + reg)
>>> +#define at91_adc_readl(st, reg)                                            \
>>> +   readl_relaxed((st)->base + (st)->soc_info.platform->layout->reg)
>>> +#define at91_adc_read_chan(st, reg)                                        \
>>> +   readl_relaxed((st)->base + reg)
>>> +#define at91_adc_writel(st, reg, val)                                      \
>>> +   writel_relaxed(val, (st)->base + (st)->soc_info.platform->layout->reg)
>>> +
>>> +/**
>>> + * struct at91_adc_platform - at91-sama5d2 platform information struct
>>> + * @layout:                pointer to the reg layout struct
>>> + * @adc_channels:  pointer to an array of channels for registering in
>>> + *                 the iio subsystem
>>> + * @nr_channels:   number of physical channels available
>>> + * @touch_chan_x:  index of the touchscreen X channel
>>> + * @touch_chan_y:  index of the touchscreen Y channel
>>> + * @touch_chan_p:  index of the touchscreen P channel
>>> + * @max_channels:  number of total channels
>>> + * @hw_trig_cnt:   number of possible hardware triggers
>>> + */
>>> +struct at91_adc_platform {
>>> +   const struct at91_adc_reg_layout        *layout;
>>> +   const struct iio_chan_spec              (*adc_channels)[];
>>> +   unsigned int                            nr_channels;
>>> +   unsigned int                            touch_chan_x;
>>> +   unsigned int                            touch_chan_y;
>>> +   unsigned int                            touch_chan_p;
>>> +   unsigned int                            max_channels;
>>> +   unsigned int                            hw_trig_cnt;
>>> +};
>>>
>>> +/**
>>> + * struct at91_adc_soc_info - at91-sama5d2 soc information struct
>>> + * @startup_time:  device startup time
>>> + * @min_sample_rate:       minimum sample rate in Hz
>>> + * @max_sample_rate:       maximum sample rate in Hz
>>> + * @platform:              pointer to the platform structure
>>> + */
>>>    struct at91_adc_soc_info {
>>>      unsigned                        startup_time;
>>>      unsigned                        min_sample_rate;
>>>      unsigned                        max_sample_rate;
>>> +   const struct at91_adc_platform  *platform;
>>>    };
>>>
>>>    struct at91_adc_trigger {
>>> @@ -382,6 +429,15 @@ struct at91_adc_touch {
>>>      struct work_struct              workq;
>>>    };
>>>
>>> +/*
>>> + * Buffer size requirements:
>>> + * No channels * bytes_per_channel(2) + timestamp bytes (8)
>>> + * Divided by 2 because we need half words.
>>> + * We assume 32 channels for now, has to be increased if needed.
>>> + * Nobody minds a buffer being too big.
>>> + */
>>> +#define AT91_BUFFER_MAX_HWORDS ((32 * 2 + 8) / 2)
>>> +
>>>    struct at91_adc_state {
>>>      void __iomem                    *base;
>>>      int                             irq;
>>> @@ -437,29 +493,49 @@ static const struct at91_adc_trigger at91_adc_trigger_list[] = {
>>>      },
>>>    };
>>>
>>> -static const struct iio_chan_spec at91_adc_channels[] = {
>>> -   AT91_SAMA5D2_CHAN_SINGLE(0, 0x50),
>>> -   AT91_SAMA5D2_CHAN_SINGLE(1, 0x54),
>>> -   AT91_SAMA5D2_CHAN_SINGLE(2, 0x58),
>>> -   AT91_SAMA5D2_CHAN_SINGLE(3, 0x5c),
>>> -   AT91_SAMA5D2_CHAN_SINGLE(4, 0x60),
>>> -   AT91_SAMA5D2_CHAN_SINGLE(5, 0x64),
>>> -   AT91_SAMA5D2_CHAN_SINGLE(6, 0x68),
>>> -   AT91_SAMA5D2_CHAN_SINGLE(7, 0x6c),
>>> -   AT91_SAMA5D2_CHAN_SINGLE(8, 0x70),
>>> -   AT91_SAMA5D2_CHAN_SINGLE(9, 0x74),
>>> -   AT91_SAMA5D2_CHAN_SINGLE(10, 0x78),
>>> -   AT91_SAMA5D2_CHAN_SINGLE(11, 0x7c),
>>> -   AT91_SAMA5D2_CHAN_DIFF(0, 1, 0x50),
>>> -   AT91_SAMA5D2_CHAN_DIFF(2, 3, 0x58),
>>> -   AT91_SAMA5D2_CHAN_DIFF(4, 5, 0x60),
>>> -   AT91_SAMA5D2_CHAN_DIFF(6, 7, 0x68),
>>> -   AT91_SAMA5D2_CHAN_DIFF(8, 9, 0x70),
>>> -   AT91_SAMA5D2_CHAN_DIFF(10, 11, 0x78),

you can see it here,

>>> -   IIO_CHAN_SOFT_TIMESTAMP(AT91_SAMA5D2_TIMESTAMP_CHAN_IDX),
>>> -   AT91_SAMA5D2_CHAN_TOUCH(AT91_SAMA5D2_TOUCH_X_CHAN_IDX, "x", IIO_MOD_X),
>>> -   AT91_SAMA5D2_CHAN_TOUCH(AT91_SAMA5D2_TOUCH_Y_CHAN_IDX, "y", IIO_MOD_Y),
>>> -   AT91_SAMA5D2_CHAN_PRESSURE(AT91_SAMA5D2_TOUCH_P_CHAN_IDX, "pressure"),
>>> +static const struct iio_chan_spec at91_sama5d2_adc_channels[] = {
>>> +   AT91_SAMA5D2_CHAN_SINGLE(0, 0, 0x50),
>>> +   AT91_SAMA5D2_CHAN_SINGLE(1, 1, 0x54),
>>> +   AT91_SAMA5D2_CHAN_SINGLE(2, 2, 0x58),
>>> +   AT91_SAMA5D2_CHAN_SINGLE(3, 3, 0x5c),
>>> +   AT91_SAMA5D2_CHAN_SINGLE(4, 4, 0x60),
>>> +   AT91_SAMA5D2_CHAN_SINGLE(5, 5, 0x64),
>>> +   AT91_SAMA5D2_CHAN_SINGLE(6, 6, 0x68),
>>> +   AT91_SAMA5D2_CHAN_SINGLE(7, 7, 0x6c),
>>> +   AT91_SAMA5D2_CHAN_SINGLE(8, 8, 0x70),
>>> +   AT91_SAMA5D2_CHAN_SINGLE(9, 9, 0x74),
>>> +   AT91_SAMA5D2_CHAN_SINGLE(10, 10, 0x78),
>>> +   AT91_SAMA5D2_CHAN_SINGLE(11, 11, 0x7c),
>>> +   AT91_SAMA5D2_CHAN_DIFF(12, 0, 1, 0x50),
>>> +   AT91_SAMA5D2_CHAN_DIFF(13, 2, 3, 0x58),
>>> +   AT91_SAMA5D2_CHAN_DIFF(14, 4, 5, 0x60),
>>> +   AT91_SAMA5D2_CHAN_DIFF(15, 6, 7, 0x68),
>>> +   AT91_SAMA5D2_CHAN_DIFF(16, 8, 9, 0x70),
>>> +   AT91_SAMA5D2_CHAN_DIFF(17, 10, 11, 0x78),
>>> +   IIO_CHAN_SOFT_TIMESTAMP(18),
>>> +   AT91_SAMA5D2_CHAN_TOUCH(19, "x", IIO_MOD_X),
>>> +   AT91_SAMA5D2_CHAN_TOUCH(20, "y", IIO_MOD_Y),
>>> +   AT91_SAMA5D2_CHAN_PRESSURE(21, "pressure"),

And I have to come up with a new version of the patch to fix this.

It should be like this:


 >>> +   AT91_SAMA5D2_CHAN_SINGLE(11, 11, 0x7c),
 >>> +   AT91_SAMA5D2_CHAN_DIFF(12, 0, 1, 0x50),
 >>> +   AT91_SAMA5D2_CHAN_DIFF(14, 2, 3, 0x58),
 >>> +   AT91_SAMA5D2_CHAN_DIFF(16, 4, 5, 0x60),
 >>> +   AT91_SAMA5D2_CHAN_DIFF(18, 6, 7, 0x68),
 >>> +   AT91_SAMA5D2_CHAN_DIFF(20, 8, 9, 0x70),
 >>> +   AT91_SAMA5D2_CHAN_DIFF(22, 10, 11, 0x78),
 >>> +   IIO_CHAN_SOFT_TIMESTAMP(23),
 >>> +   AT91_SAMA5D2_CHAN_TOUCH(24, "x", IIO_MOD_X),
 >>> +   AT91_SAMA5D2_CHAN_TOUCH(25, "y", IIO_MOD_Y),
 >>> +   AT91_SAMA5D2_CHAN_PRESSURE(26, "pressure"),


Sorry about this. Do you want me to resend the whole series together 
with the fixes found by robots ?

I can redo the series, retest it, and send it tomorrow as a v3.


Thanks,
Eugen

>>> +};
>>> +
[snip]
Jonathan Cameron Sept. 5, 2021, 10:08 a.m. UTC | #6
On Tue, 31 Aug 2021 11:50:00 +0000
<Eugen.Hristev@microchip.com> wrote:

> On 8/30/21 5:44 PM, Jonathan Cameron wrote:
> > On Mon, 30 Aug 2021 12:31:46 +0000
> > <Eugen.Hristev@microchip.com> wrote:
> >   
> >> On 8/24/21 2:54 PM, Eugen Hristev wrote:  
> >>> Convert the driver to platform specific structures. This means:
> >>> - create a register layout struct that will hold offsets for registers
> >>> - create a platform struct that will hold platform information (number of
> >>> channels, indexes for different channels and pointer to layout struct)
> >>> - convert specific macros that are platform dependent into platform variables
> >>>
> >>> This step is in fact a no-op, but allows the driver to be more flexible
> >>> and for future enhancement including adding new platforms that are partly
> >>> compatible with the current driver and differ slightly in register layout
> >>> or capabilities for example.
> >>>
> >>> Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
> >>> ---
> >>>    drivers/iio/adc/at91-sama5d2_adc.c | 410 +++++++++++++++++------------
> >>>    1 file changed, 247 insertions(+), 163 deletions(-)
> >>>
> >>> diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c
> >>> index 9d71dcffcf93..8ede18b8d789 100644
> >>> --- a/drivers/iio/adc/at91-sama5d2_adc.c
> >>> +++ b/drivers/iio/adc/at91-sama5d2_adc.c
> >>> @@ -27,8 +27,9 @@
> >>>    #include <linux/pinctrl/consumer.h>
> >>>    #include <linux/regulator/consumer.h>
> >>>
> >>> +struct at91_adc_reg_layout {
> >>>    /* Control Register */
> >>> -#define AT91_SAMA5D2_CR            0x00
> >>> +   u16                             CR;
> >>>    /* Software Reset */
> >>>    #define   AT91_SAMA5D2_CR_SWRST           BIT(0)
> >>>    /* Start Conversion */
> >>> @@ -39,7 +40,7 @@
> >>>    #define   AT91_SAMA5D2_CR_CMPRST          BIT(4)
> >>>
> >>>    /* Mode Register */
> >>> -#define AT91_SAMA5D2_MR            0x04
> >>> +   u16                             MR;
> >>>    /* Trigger Selection */
> >>>    #define   AT91_SAMA5D2_MR_TRGSEL(v)       ((v) << 1)
> >>>    /* ADTRG */
> >>> @@ -82,19 +83,19 @@
> >>>    #define   AT91_SAMA5D2_MR_USEQ            BIT(31)
> >>>
> >>>    /* Channel Sequence Register 1 */
> >>> -#define AT91_SAMA5D2_SEQR1 0x08
> >>> +   u16                             SEQR1;
> >>>    /* Channel Sequence Register 2 */
> >>> -#define AT91_SAMA5D2_SEQR2 0x0c
> >>> +   u16                             SEQR2;
> >>>    /* Channel Enable Register */
> >>> -#define AT91_SAMA5D2_CHER  0x10
> >>> +   u16                             CHER;
> >>>    /* Channel Disable Register */
> >>> -#define AT91_SAMA5D2_CHDR  0x14
> >>> +   u16                             CHDR;
> >>>    /* Channel Status Register */
> >>> -#define AT91_SAMA5D2_CHSR  0x18
> >>> +   u16                             CHSR;
> >>>    /* Last Converted Data Register */
> >>> -#define AT91_SAMA5D2_LCDR  0x20
> >>> +   u16                             LCDR;
> >>>    /* Interrupt Enable Register */
> >>> -#define AT91_SAMA5D2_IER   0x24
> >>> +   u16                             IER;
> >>>    /* Interrupt Enable Register - TS X measurement ready */
> >>>    #define AT91_SAMA5D2_IER_XRDY   BIT(20)
> >>>    /* Interrupt Enable Register - TS Y measurement ready */
> >>> @@ -109,22 +110,23 @@
> >>>    #define AT91_SAMA5D2_IER_PEN    BIT(29)
> >>>    /* Interrupt Enable Register - No pen detect */
> >>>    #define AT91_SAMA5D2_IER_NOPEN  BIT(30)
> >>> +
> >>>    /* Interrupt Disable Register */
> >>> -#define AT91_SAMA5D2_IDR   0x28
> >>> +   u16                             IDR;
> >>>    /* Interrupt Mask Register */
> >>> -#define AT91_SAMA5D2_IMR   0x2c
> >>> +   u16                             IMR;
> >>>    /* Interrupt Status Register */
> >>> -#define AT91_SAMA5D2_ISR   0x30
> >>> +   u16                             ISR;
> >>>    /* Interrupt Status Register - Pen touching sense status */
> >>>    #define AT91_SAMA5D2_ISR_PENS   BIT(31)
> >>>    /* Last Channel Trigger Mode Register */
> >>> -#define AT91_SAMA5D2_LCTMR 0x34
> >>> +   u16                             LCTMR;
> >>>    /* Last Channel Compare Window Register */
> >>> -#define AT91_SAMA5D2_LCCWR 0x38
> >>> +   u16                             LCCWR;
> >>>    /* Overrun Status Register */
> >>> -#define AT91_SAMA5D2_OVER  0x3c
> >>> +   u16                             OVER;
> >>>    /* Extended Mode Register */
> >>> -#define AT91_SAMA5D2_EMR   0x40
> >>> +   u16                             EMR;
> >>>    /* Extended Mode Register - Oversampling rate */
> >>>    #define AT91_SAMA5D2_EMR_OSR(V)                   ((V) << 16)
> >>>    #define AT91_SAMA5D2_EMR_OSR_MASK         GENMASK(17, 16)
> >>> @@ -134,22 +136,22 @@
> >>>
> >>>    /* Extended Mode Register - Averaging on single trigger event */
> >>>    #define AT91_SAMA5D2_EMR_ASTE(V)          ((V) << 20)
> >>> +
> >>>    /* Compare Window Register */
> >>> -#define AT91_SAMA5D2_CWR   0x44
> >>> +   u16                             CWR;
> >>>    /* Channel Gain Register */
> >>> -#define AT91_SAMA5D2_CGR   0x48
> >>> -
> >>> +   u16                             CGR;
> >>>    /* Channel Offset Register */
> >>> -#define AT91_SAMA5D2_COR   0x4c
> >>> +   u16                             COR;
> >>>    #define AT91_SAMA5D2_COR_DIFF_OFFSET      16
> >>>
> >>>    /* Analog Control Register */
> >>> -#define AT91_SAMA5D2_ACR   0x94
> >>> +   u16                             ACR;
> >>>    /* Analog Control Register - Pen detect sensitivity mask */
> >>>    #define AT91_SAMA5D2_ACR_PENDETSENS_MASK        GENMASK(1, 0)
> >>>
> >>>    /* Touchscreen Mode Register */
> >>> -#define AT91_SAMA5D2_TSMR  0xb0
> >>> +   u16                             TSMR;
> >>>    /* Touchscreen Mode Register - No touch mode */
> >>>    #define AT91_SAMA5D2_TSMR_TSMODE_NONE           0
> >>>    /* Touchscreen Mode Register - 4 wire screen, no pressure measurement */
> >>> @@ -178,13 +180,13 @@
> >>>    #define AT91_SAMA5D2_TSMR_PENDET_ENA            BIT(24)
> >>>
> >>>    /* Touchscreen X Position Register */
> >>> -#define AT91_SAMA5D2_XPOSR 0xb4
> >>> +   u16                             XPOSR;
> >>>    /* Touchscreen Y Position Register */
> >>> -#define AT91_SAMA5D2_YPOSR 0xb8
> >>> +   u16                             YPOSR;
> >>>    /* Touchscreen Pressure Register */
> >>> -#define AT91_SAMA5D2_PRESSR        0xbc
> >>> +   u16                             PRESSR;
> >>>    /* Trigger Register */
> >>> -#define AT91_SAMA5D2_TRGR  0xc0
> >>> +   u16                             TRGR;
> >>>    /* Mask for TRGMOD field of TRGR register */
> >>>    #define AT91_SAMA5D2_TRGR_TRGMOD_MASK GENMASK(2, 0)
> >>>    /* No trigger, only software trigger can start conversions */
> >>> @@ -203,30 +205,52 @@
> >>>    #define AT91_SAMA5D2_TRGR_TRGPER(x)             ((x) << 16)
> >>>
> >>>    /* Correction Select Register */
> >>> -#define AT91_SAMA5D2_COSR  0xd0
> >>> +   u16                             COSR;
> >>>    /* Correction Value Register */
> >>> -#define AT91_SAMA5D2_CVR   0xd4
> >>> +   u16                             CVR;
> >>>    /* Channel Error Correction Register */
> >>> -#define AT91_SAMA5D2_CECR  0xd8
> >>> +   u16                             CECR;
> >>>    /* Write Protection Mode Register */
> >>> -#define AT91_SAMA5D2_WPMR  0xe4
> >>> +   u16                             WPMR;
> >>>    /* Write Protection Status Register */
> >>> -#define AT91_SAMA5D2_WPSR  0xe8
> >>> +   u16                             WPSR;
> >>>    /* Version Register */
> >>> -#define AT91_SAMA5D2_VERSION       0xfc
> >>> -
> >>> -#define AT91_SAMA5D2_HW_TRIG_CNT 3
> >>> -#define AT91_SAMA5D2_SINGLE_CHAN_CNT 12
> >>> -#define AT91_SAMA5D2_DIFF_CHAN_CNT 6
> >>> -
> >>> -#define AT91_SAMA5D2_TIMESTAMP_CHAN_IDX (AT91_SAMA5D2_SINGLE_CHAN_CNT + \
> >>> -                                    AT91_SAMA5D2_DIFF_CHAN_CNT + 1)
> >>> +   u16                             VERSION;
> >>> +};
> >>>
> >>> -#define AT91_SAMA5D2_TOUCH_X_CHAN_IDX (AT91_SAMA5D2_SINGLE_CHAN_CNT + \
> >>> -                                    AT91_SAMA5D2_DIFF_CHAN_CNT * 2)  
> >>
> >> Hi Jonathan,
> >>
> >> While we are here, regarding the above line, I cannot tell why did I
> >> multiply by two the differential channel count. This makes some gaps in
> >> the number of channels when we put them all in the same table.
> >>
> >> I did not change this as it would break the ABI regarding the bindings
> >> for the touchscreen #adc-cells phandle references.  
> > 
> > Really?  Xlate is based off scan_index, not these values I think...  
> 
> I figured it out.
> 
> We have 12 single channels [0..11] then 6 differential [12, 14, 16, 18, 
> 20, 22] spaced by two, a timestamp [23], then we have the X channel 
> index at 24, Y at 25 and pressure are 26.
> 
> These are reflected in this file :
> 
> https://elixir.bootlin.com/linux/latest/source/include/dt-bindings/iio/adc/at91-sama5d2_adc.h
> 
> And the resistive touchscreen connects to the adc with these indexes.
> 
> And I realised why we have the padding/spaces.
> It was the original design of the driver, in the line which I 
> highlighted now below in the patch : (and I never changed this since 
> working on this driver, because it was a break of the ABI in channel 
> numbers ...)
> 
> 
> >   
> >>
> >> However, I am thinking if there was a reason for it or it was a slip
> >> when I initially wrote this.  
> > 
> > I've no idea :)  I can't immediately see why we'd need the padding.
> >   
> >>
> >> Do you think there is any reason to change it and tighten the holes in
> >> the indexes list ?  
> > 
> > I don't think it matters. As far as I can tell they are used mostly (possibly
> > entirely) for internal management and not exposed to any of the ABIs etc.
> > 
> > Jonathan
> >   
> >>
> >>
> >> Eugen
> >>  
> >>> -#define AT91_SAMA5D2_TOUCH_Y_CHAN_IDX   (AT91_SAMA5D2_TOUCH_X_CHAN_IDX + 1)
> >>> -#define AT91_SAMA5D2_TOUCH_P_CHAN_IDX   (AT91_SAMA5D2_TOUCH_Y_CHAN_IDX + 1)
> >>> -#define AT91_SAMA5D2_MAX_CHAN_IDX  AT91_SAMA5D2_TOUCH_P_CHAN_IDX
> >>> +static const struct at91_adc_reg_layout sama5d2_layout = {
> >>> +   .CR =                   0x00,
> >>> +   .MR =                   0x04,
> >>> +   .SEQR1 =                0x08,
> >>> +   .SEQR2 =                0x0c,
> >>> +   .CHER =                 0x10,
> >>> +   .CHDR =                 0x14,
> >>> +   .CHSR =                 0x18,
> >>> +   .LCDR =                 0x20,
> >>> +   .IER =                  0x24,
> >>> +   .IDR =                  0x28,
> >>> +   .IMR =                  0x2c,
> >>> +   .ISR =                  0x30,
> >>> +   .LCTMR =                0x34,
> >>> +   .LCCWR =                0x38,
> >>> +   .OVER =                 0x3c,
> >>> +   .EMR =                  0x40,
> >>> +   .CWR =                  0x44,
> >>> +   .CGR =                  0x48,
> >>> +   .COR =                  0x4c,
> >>> +   .ACR =                  0x94,
> >>> +   .TSMR =                 0xb0,
> >>> +   .XPOSR =                0xb4,
> >>> +   .YPOSR =                0xb8,
> >>> +   .PRESSR =               0xbc,
> >>> +   .TRGR =                 0xc0,
> >>> +   .COSR =                 0xd0,
> >>> +   .CVR =                  0xd4,
> >>> +   .CECR =                 0xd8,
> >>> +   .WPMR =                 0xe4,
> >>> +   .WPSR =                 0xe8,
> >>> +   .VERSION =              0xfc,
> >>> +};
> >>>
> >>>    #define AT91_SAMA5D2_TOUCH_SAMPLE_PERIOD_US          2000    /* 2ms */
> >>>    #define AT91_SAMA5D2_TOUCH_PEN_DETECT_DEBOUNCE_US    200
> >>> @@ -235,18 +259,6 @@
> >>>
> >>>    #define AT91_SAMA5D2_MAX_POS_BITS                 12
> >>>
> >>> -/*
> >>> - * Maximum number of bytes to hold conversion from all channels
> >>> - * without the timestamp.
> >>> - */
> >>> -#define AT91_BUFFER_MAX_CONVERSION_BYTES ((AT91_SAMA5D2_SINGLE_CHAN_CNT + \
> >>> -                                    AT91_SAMA5D2_DIFF_CHAN_CNT) * 2)
> >>> -
> >>> -/* This total must also include the timestamp */
> >>> -#define AT91_BUFFER_MAX_BYTES (AT91_BUFFER_MAX_CONVERSION_BYTES + 8)
> >>> -
> >>> -#define AT91_BUFFER_MAX_HWORDS (AT91_BUFFER_MAX_BYTES / 2)
> >>> -
> >>>    #define AT91_HWFIFO_MAX_SIZE_STR  "128"
> >>>    #define AT91_HWFIFO_MAX_SIZE              128
> >>>
> >>> @@ -255,12 +267,12 @@
> >>>    #define AT91_OSR_4SAMPLES         4
> >>>    #define AT91_OSR_16SAMPLES                16
> >>>
> >>> -#define AT91_SAMA5D2_CHAN_SINGLE(num, addr)                                \
> >>> +#define AT91_SAMA5D2_CHAN_SINGLE(index, num, addr)                 \
> >>>      {                                                               \
> >>>              .type = IIO_VOLTAGE,                                    \
> >>>              .channel = num,                                         \
> >>>              .address = addr,                                        \
> >>> -           .scan_index = num,                                      \
> >>> +           .scan_index = index,                                    \
> >>>              .scan_type = {                                          \
> >>>                      .sign = 'u',                                    \
> >>>                      .realbits = 14,                                 \
> >>> @@ -274,14 +286,14 @@
> >>>              .indexed = 1,                                           \
> >>>      }
> >>>
> >>> -#define AT91_SAMA5D2_CHAN_DIFF(num, num2, addr)                            \
> >>> +#define AT91_SAMA5D2_CHAN_DIFF(index, num, num2, addr)                     \
> >>>      {                                                               \
> >>>              .type = IIO_VOLTAGE,                                    \
> >>>              .differential = 1,                                      \
> >>>              .channel = num,                                         \
> >>>              .channel2 = num2,                                       \
> >>>              .address = addr,                                        \
> >>> -           .scan_index = num + AT91_SAMA5D2_SINGLE_CHAN_CNT,       \  
> 
> Here it is: we always added num to the single channel count, but num 
> goes incrementally in steps of two : 0, 2, 4, 6, 8, 10

Ah. That makes sense.  Of course with a separate index value passed in we could
have broken that connection but meh it doesn't matter.  The ABI has always
allowed holes in scan_index so everything should just work even it if seems
a bit inelegant!

> 
> >>> +           .scan_index = index,                                    \
> >>>              .scan_type = {                                          \
> >>>                      .sign = 's',                                    \
> >>>                      .realbits = 14,                                 \
> >>> @@ -328,13 +340,48 @@
> >>>              .datasheet_name = name,                                 \
> >>>      }
> >>>
> >>> -#define at91_adc_readl(st, reg)            readl_relaxed(st->base + reg)
> >>> -#define at91_adc_writel(st, reg, val)      writel_relaxed(val, st->base + reg)
> >>> +#define at91_adc_readl(st, reg)                                            \
> >>> +   readl_relaxed((st)->base + (st)->soc_info.platform->layout->reg)
> >>> +#define at91_adc_read_chan(st, reg)                                        \
> >>> +   readl_relaxed((st)->base + reg)
> >>> +#define at91_adc_writel(st, reg, val)                                      \
> >>> +   writel_relaxed(val, (st)->base + (st)->soc_info.platform->layout->reg)
> >>> +
> >>> +/**
> >>> + * struct at91_adc_platform - at91-sama5d2 platform information struct
> >>> + * @layout:                pointer to the reg layout struct
> >>> + * @adc_channels:  pointer to an array of channels for registering in
> >>> + *                 the iio subsystem
> >>> + * @nr_channels:   number of physical channels available
> >>> + * @touch_chan_x:  index of the touchscreen X channel
> >>> + * @touch_chan_y:  index of the touchscreen Y channel
> >>> + * @touch_chan_p:  index of the touchscreen P channel
> >>> + * @max_channels:  number of total channels
> >>> + * @hw_trig_cnt:   number of possible hardware triggers
> >>> + */
> >>> +struct at91_adc_platform {
> >>> +   const struct at91_adc_reg_layout        *layout;
> >>> +   const struct iio_chan_spec              (*adc_channels)[];
> >>> +   unsigned int                            nr_channels;
> >>> +   unsigned int                            touch_chan_x;
> >>> +   unsigned int                            touch_chan_y;
> >>> +   unsigned int                            touch_chan_p;
> >>> +   unsigned int                            max_channels;
> >>> +   unsigned int                            hw_trig_cnt;
> >>> +};
> >>>
> >>> +/**
> >>> + * struct at91_adc_soc_info - at91-sama5d2 soc information struct
> >>> + * @startup_time:  device startup time
> >>> + * @min_sample_rate:       minimum sample rate in Hz
> >>> + * @max_sample_rate:       maximum sample rate in Hz
> >>> + * @platform:              pointer to the platform structure
> >>> + */
> >>>    struct at91_adc_soc_info {
> >>>      unsigned                        startup_time;
> >>>      unsigned                        min_sample_rate;
> >>>      unsigned                        max_sample_rate;
> >>> +   const struct at91_adc_platform  *platform;
> >>>    };
> >>>
> >>>    struct at91_adc_trigger {
> >>> @@ -382,6 +429,15 @@ struct at91_adc_touch {
> >>>      struct work_struct              workq;
> >>>    };
> >>>
> >>> +/*
> >>> + * Buffer size requirements:
> >>> + * No channels * bytes_per_channel(2) + timestamp bytes (8)
> >>> + * Divided by 2 because we need half words.
> >>> + * We assume 32 channels for now, has to be increased if needed.
> >>> + * Nobody minds a buffer being too big.
> >>> + */
> >>> +#define AT91_BUFFER_MAX_HWORDS ((32 * 2 + 8) / 2)
> >>> +
> >>>    struct at91_adc_state {
> >>>      void __iomem                    *base;
> >>>      int                             irq;
> >>> @@ -437,29 +493,49 @@ static const struct at91_adc_trigger at91_adc_trigger_list[] = {
> >>>      },
> >>>    };
> >>>
> >>> -static const struct iio_chan_spec at91_adc_channels[] = {
> >>> -   AT91_SAMA5D2_CHAN_SINGLE(0, 0x50),
> >>> -   AT91_SAMA5D2_CHAN_SINGLE(1, 0x54),
> >>> -   AT91_SAMA5D2_CHAN_SINGLE(2, 0x58),
> >>> -   AT91_SAMA5D2_CHAN_SINGLE(3, 0x5c),
> >>> -   AT91_SAMA5D2_CHAN_SINGLE(4, 0x60),
> >>> -   AT91_SAMA5D2_CHAN_SINGLE(5, 0x64),
> >>> -   AT91_SAMA5D2_CHAN_SINGLE(6, 0x68),
> >>> -   AT91_SAMA5D2_CHAN_SINGLE(7, 0x6c),
> >>> -   AT91_SAMA5D2_CHAN_SINGLE(8, 0x70),
> >>> -   AT91_SAMA5D2_CHAN_SINGLE(9, 0x74),
> >>> -   AT91_SAMA5D2_CHAN_SINGLE(10, 0x78),
> >>> -   AT91_SAMA5D2_CHAN_SINGLE(11, 0x7c),
> >>> -   AT91_SAMA5D2_CHAN_DIFF(0, 1, 0x50),
> >>> -   AT91_SAMA5D2_CHAN_DIFF(2, 3, 0x58),
> >>> -   AT91_SAMA5D2_CHAN_DIFF(4, 5, 0x60),
> >>> -   AT91_SAMA5D2_CHAN_DIFF(6, 7, 0x68),
> >>> -   AT91_SAMA5D2_CHAN_DIFF(8, 9, 0x70),
> >>> -   AT91_SAMA5D2_CHAN_DIFF(10, 11, 0x78),  
> 
> you can see it here,
> 
> >>> -   IIO_CHAN_SOFT_TIMESTAMP(AT91_SAMA5D2_TIMESTAMP_CHAN_IDX),
> >>> -   AT91_SAMA5D2_CHAN_TOUCH(AT91_SAMA5D2_TOUCH_X_CHAN_IDX, "x", IIO_MOD_X),
> >>> -   AT91_SAMA5D2_CHAN_TOUCH(AT91_SAMA5D2_TOUCH_Y_CHAN_IDX, "y", IIO_MOD_Y),
> >>> -   AT91_SAMA5D2_CHAN_PRESSURE(AT91_SAMA5D2_TOUCH_P_CHAN_IDX, "pressure"),
> >>> +static const struct iio_chan_spec at91_sama5d2_adc_channels[] = {
> >>> +   AT91_SAMA5D2_CHAN_SINGLE(0, 0, 0x50),
> >>> +   AT91_SAMA5D2_CHAN_SINGLE(1, 1, 0x54),
> >>> +   AT91_SAMA5D2_CHAN_SINGLE(2, 2, 0x58),
> >>> +   AT91_SAMA5D2_CHAN_SINGLE(3, 3, 0x5c),
> >>> +   AT91_SAMA5D2_CHAN_SINGLE(4, 4, 0x60),
> >>> +   AT91_SAMA5D2_CHAN_SINGLE(5, 5, 0x64),
> >>> +   AT91_SAMA5D2_CHAN_SINGLE(6, 6, 0x68),
> >>> +   AT91_SAMA5D2_CHAN_SINGLE(7, 7, 0x6c),
> >>> +   AT91_SAMA5D2_CHAN_SINGLE(8, 8, 0x70),
> >>> +   AT91_SAMA5D2_CHAN_SINGLE(9, 9, 0x74),
> >>> +   AT91_SAMA5D2_CHAN_SINGLE(10, 10, 0x78),
> >>> +   AT91_SAMA5D2_CHAN_SINGLE(11, 11, 0x7c),
> >>> +   AT91_SAMA5D2_CHAN_DIFF(12, 0, 1, 0x50),
> >>> +   AT91_SAMA5D2_CHAN_DIFF(13, 2, 3, 0x58),
> >>> +   AT91_SAMA5D2_CHAN_DIFF(14, 4, 5, 0x60),
> >>> +   AT91_SAMA5D2_CHAN_DIFF(15, 6, 7, 0x68),
> >>> +   AT91_SAMA5D2_CHAN_DIFF(16, 8, 9, 0x70),
> >>> +   AT91_SAMA5D2_CHAN_DIFF(17, 10, 11, 0x78),
> >>> +   IIO_CHAN_SOFT_TIMESTAMP(18),
> >>> +   AT91_SAMA5D2_CHAN_TOUCH(19, "x", IIO_MOD_X),
> >>> +   AT91_SAMA5D2_CHAN_TOUCH(20, "y", IIO_MOD_Y),
> >>> +   AT91_SAMA5D2_CHAN_PRESSURE(21, "pressure"),  
> 
> And I have to come up with a new version of the patch to fix this.
> 
> It should be like this:
> 
> 
>  >>> +   AT91_SAMA5D2_CHAN_SINGLE(11, 11, 0x7c),
>  >>> +   AT91_SAMA5D2_CHAN_DIFF(12, 0, 1, 0x50),
>  >>> +   AT91_SAMA5D2_CHAN_DIFF(14, 2, 3, 0x58),
>  >>> +   AT91_SAMA5D2_CHAN_DIFF(16, 4, 5, 0x60),
>  >>> +   AT91_SAMA5D2_CHAN_DIFF(18, 6, 7, 0x68),
>  >>> +   AT91_SAMA5D2_CHAN_DIFF(20, 8, 9, 0x70),
>  >>> +   AT91_SAMA5D2_CHAN_DIFF(22, 10, 11, 0x78),
>  >>> +   IIO_CHAN_SOFT_TIMESTAMP(23),
>  >>> +   AT91_SAMA5D2_CHAN_TOUCH(24, "x", IIO_MOD_X),
>  >>> +   AT91_SAMA5D2_CHAN_TOUCH(25, "y", IIO_MOD_Y),
>  >>> +   AT91_SAMA5D2_CHAN_PRESSURE(26, "pressure"),  
> 
> 
> Sorry about this. Do you want me to resend the whole series together 
> with the fixes found by robots ?
> 
> I can redo the series, retest it, and send it tomorrow as a v3.

Please do (looks like you already did ;) 
> 
> 
> Thanks,
> Eugen
> 
> >>> +};
> >>> +  
> [snip]
diff mbox series

Patch

diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c
index 9d71dcffcf93..8ede18b8d789 100644
--- a/drivers/iio/adc/at91-sama5d2_adc.c
+++ b/drivers/iio/adc/at91-sama5d2_adc.c
@@ -27,8 +27,9 @@ 
 #include <linux/pinctrl/consumer.h>
 #include <linux/regulator/consumer.h>
 
+struct at91_adc_reg_layout {
 /* Control Register */
-#define AT91_SAMA5D2_CR		0x00
+	u16				CR;
 /* Software Reset */
 #define	AT91_SAMA5D2_CR_SWRST		BIT(0)
 /* Start Conversion */
@@ -39,7 +40,7 @@ 
 #define	AT91_SAMA5D2_CR_CMPRST		BIT(4)
 
 /* Mode Register */
-#define AT91_SAMA5D2_MR		0x04
+	u16				MR;
 /* Trigger Selection */
 #define	AT91_SAMA5D2_MR_TRGSEL(v)	((v) << 1)
 /* ADTRG */
@@ -82,19 +83,19 @@ 
 #define	AT91_SAMA5D2_MR_USEQ		BIT(31)
 
 /* Channel Sequence Register 1 */
-#define AT91_SAMA5D2_SEQR1	0x08
+	u16				SEQR1;
 /* Channel Sequence Register 2 */
-#define AT91_SAMA5D2_SEQR2	0x0c
+	u16				SEQR2;
 /* Channel Enable Register */
-#define AT91_SAMA5D2_CHER	0x10
+	u16				CHER;
 /* Channel Disable Register */
-#define AT91_SAMA5D2_CHDR	0x14
+	u16				CHDR;
 /* Channel Status Register */
-#define AT91_SAMA5D2_CHSR	0x18
+	u16				CHSR;
 /* Last Converted Data Register */
-#define AT91_SAMA5D2_LCDR	0x20
+	u16				LCDR;
 /* Interrupt Enable Register */
-#define AT91_SAMA5D2_IER	0x24
+	u16				IER;
 /* Interrupt Enable Register - TS X measurement ready */
 #define AT91_SAMA5D2_IER_XRDY   BIT(20)
 /* Interrupt Enable Register - TS Y measurement ready */
@@ -109,22 +110,23 @@ 
 #define AT91_SAMA5D2_IER_PEN    BIT(29)
 /* Interrupt Enable Register - No pen detect */
 #define AT91_SAMA5D2_IER_NOPEN  BIT(30)
+
 /* Interrupt Disable Register */
-#define AT91_SAMA5D2_IDR	0x28
+	u16				IDR;
 /* Interrupt Mask Register */
-#define AT91_SAMA5D2_IMR	0x2c
+	u16				IMR;
 /* Interrupt Status Register */
-#define AT91_SAMA5D2_ISR	0x30
+	u16				ISR;
 /* Interrupt Status Register - Pen touching sense status */
 #define AT91_SAMA5D2_ISR_PENS   BIT(31)
 /* Last Channel Trigger Mode Register */
-#define AT91_SAMA5D2_LCTMR	0x34
+	u16				LCTMR;
 /* Last Channel Compare Window Register */
-#define AT91_SAMA5D2_LCCWR	0x38
+	u16				LCCWR;
 /* Overrun Status Register */
-#define AT91_SAMA5D2_OVER	0x3c
+	u16				OVER;
 /* Extended Mode Register */
-#define AT91_SAMA5D2_EMR	0x40
+	u16				EMR;
 /* Extended Mode Register - Oversampling rate */
 #define AT91_SAMA5D2_EMR_OSR(V)			((V) << 16)
 #define AT91_SAMA5D2_EMR_OSR_MASK		GENMASK(17, 16)
@@ -134,22 +136,22 @@ 
 
 /* Extended Mode Register - Averaging on single trigger event */
 #define AT91_SAMA5D2_EMR_ASTE(V)		((V) << 20)
+
 /* Compare Window Register */
-#define AT91_SAMA5D2_CWR	0x44
+	u16				CWR;
 /* Channel Gain Register */
-#define AT91_SAMA5D2_CGR	0x48
-
+	u16				CGR;
 /* Channel Offset Register */
-#define AT91_SAMA5D2_COR	0x4c
+	u16				COR;
 #define AT91_SAMA5D2_COR_DIFF_OFFSET	16
 
 /* Analog Control Register */
-#define AT91_SAMA5D2_ACR	0x94
+	u16				ACR;
 /* Analog Control Register - Pen detect sensitivity mask */
 #define AT91_SAMA5D2_ACR_PENDETSENS_MASK        GENMASK(1, 0)
 
 /* Touchscreen Mode Register */
-#define AT91_SAMA5D2_TSMR	0xb0
+	u16				TSMR;
 /* Touchscreen Mode Register - No touch mode */
 #define AT91_SAMA5D2_TSMR_TSMODE_NONE           0
 /* Touchscreen Mode Register - 4 wire screen, no pressure measurement */
@@ -178,13 +180,13 @@ 
 #define AT91_SAMA5D2_TSMR_PENDET_ENA            BIT(24)
 
 /* Touchscreen X Position Register */
-#define AT91_SAMA5D2_XPOSR	0xb4
+	u16				XPOSR;
 /* Touchscreen Y Position Register */
-#define AT91_SAMA5D2_YPOSR	0xb8
+	u16				YPOSR;
 /* Touchscreen Pressure Register */
-#define AT91_SAMA5D2_PRESSR	0xbc
+	u16				PRESSR;
 /* Trigger Register */
-#define AT91_SAMA5D2_TRGR	0xc0
+	u16				TRGR;
 /* Mask for TRGMOD field of TRGR register */
 #define AT91_SAMA5D2_TRGR_TRGMOD_MASK GENMASK(2, 0)
 /* No trigger, only software trigger can start conversions */
@@ -203,30 +205,52 @@ 
 #define AT91_SAMA5D2_TRGR_TRGPER(x)             ((x) << 16)
 
 /* Correction Select Register */
-#define AT91_SAMA5D2_COSR	0xd0
+	u16				COSR;
 /* Correction Value Register */
-#define AT91_SAMA5D2_CVR	0xd4
+	u16				CVR;
 /* Channel Error Correction Register */
-#define AT91_SAMA5D2_CECR	0xd8
+	u16				CECR;
 /* Write Protection Mode Register */
-#define AT91_SAMA5D2_WPMR	0xe4
+	u16				WPMR;
 /* Write Protection Status Register */
-#define AT91_SAMA5D2_WPSR	0xe8
+	u16				WPSR;
 /* Version Register */
-#define AT91_SAMA5D2_VERSION	0xfc
-
-#define AT91_SAMA5D2_HW_TRIG_CNT 3
-#define AT91_SAMA5D2_SINGLE_CHAN_CNT 12
-#define AT91_SAMA5D2_DIFF_CHAN_CNT 6
-
-#define AT91_SAMA5D2_TIMESTAMP_CHAN_IDX (AT91_SAMA5D2_SINGLE_CHAN_CNT + \
-					 AT91_SAMA5D2_DIFF_CHAN_CNT + 1)
+	u16				VERSION;
+};
 
-#define AT91_SAMA5D2_TOUCH_X_CHAN_IDX (AT91_SAMA5D2_SINGLE_CHAN_CNT + \
-					 AT91_SAMA5D2_DIFF_CHAN_CNT * 2)
-#define AT91_SAMA5D2_TOUCH_Y_CHAN_IDX   (AT91_SAMA5D2_TOUCH_X_CHAN_IDX + 1)
-#define AT91_SAMA5D2_TOUCH_P_CHAN_IDX   (AT91_SAMA5D2_TOUCH_Y_CHAN_IDX + 1)
-#define AT91_SAMA5D2_MAX_CHAN_IDX	AT91_SAMA5D2_TOUCH_P_CHAN_IDX
+static const struct at91_adc_reg_layout sama5d2_layout = {
+	.CR =			0x00,
+	.MR =			0x04,
+	.SEQR1 =		0x08,
+	.SEQR2 =		0x0c,
+	.CHER =			0x10,
+	.CHDR =			0x14,
+	.CHSR =			0x18,
+	.LCDR =			0x20,
+	.IER =			0x24,
+	.IDR =			0x28,
+	.IMR =			0x2c,
+	.ISR =			0x30,
+	.LCTMR =		0x34,
+	.LCCWR =		0x38,
+	.OVER =			0x3c,
+	.EMR =			0x40,
+	.CWR =			0x44,
+	.CGR =			0x48,
+	.COR =			0x4c,
+	.ACR =			0x94,
+	.TSMR =			0xb0,
+	.XPOSR =		0xb4,
+	.YPOSR =		0xb8,
+	.PRESSR =		0xbc,
+	.TRGR =			0xc0,
+	.COSR =			0xd0,
+	.CVR =			0xd4,
+	.CECR =			0xd8,
+	.WPMR =			0xe4,
+	.WPSR =			0xe8,
+	.VERSION =		0xfc,
+};
 
 #define AT91_SAMA5D2_TOUCH_SAMPLE_PERIOD_US          2000    /* 2ms */
 #define AT91_SAMA5D2_TOUCH_PEN_DETECT_DEBOUNCE_US    200
@@ -235,18 +259,6 @@ 
 
 #define AT91_SAMA5D2_MAX_POS_BITS			12
 
-/*
- * Maximum number of bytes to hold conversion from all channels
- * without the timestamp.
- */
-#define AT91_BUFFER_MAX_CONVERSION_BYTES ((AT91_SAMA5D2_SINGLE_CHAN_CNT + \
-					 AT91_SAMA5D2_DIFF_CHAN_CNT) * 2)
-
-/* This total must also include the timestamp */
-#define AT91_BUFFER_MAX_BYTES (AT91_BUFFER_MAX_CONVERSION_BYTES + 8)
-
-#define AT91_BUFFER_MAX_HWORDS (AT91_BUFFER_MAX_BYTES / 2)
-
 #define AT91_HWFIFO_MAX_SIZE_STR	"128"
 #define AT91_HWFIFO_MAX_SIZE		128
 
@@ -255,12 +267,12 @@ 
 #define AT91_OSR_4SAMPLES		4
 #define AT91_OSR_16SAMPLES		16
 
-#define AT91_SAMA5D2_CHAN_SINGLE(num, addr)				\
+#define AT91_SAMA5D2_CHAN_SINGLE(index, num, addr)			\
 	{								\
 		.type = IIO_VOLTAGE,					\
 		.channel = num,						\
 		.address = addr,					\
-		.scan_index = num,					\
+		.scan_index = index,					\
 		.scan_type = {						\
 			.sign = 'u',					\
 			.realbits = 14,					\
@@ -274,14 +286,14 @@ 
 		.indexed = 1,						\
 	}
 
-#define AT91_SAMA5D2_CHAN_DIFF(num, num2, addr)				\
+#define AT91_SAMA5D2_CHAN_DIFF(index, num, num2, addr)			\
 	{								\
 		.type = IIO_VOLTAGE,					\
 		.differential = 1,					\
 		.channel = num,						\
 		.channel2 = num2,					\
 		.address = addr,					\
-		.scan_index = num + AT91_SAMA5D2_SINGLE_CHAN_CNT,	\
+		.scan_index = index,					\
 		.scan_type = {						\
 			.sign = 's',					\
 			.realbits = 14,					\
@@ -328,13 +340,48 @@ 
 		.datasheet_name = name,					\
 	}
 
-#define at91_adc_readl(st, reg)		readl_relaxed(st->base + reg)
-#define at91_adc_writel(st, reg, val)	writel_relaxed(val, st->base + reg)
+#define at91_adc_readl(st, reg)						\
+	readl_relaxed((st)->base + (st)->soc_info.platform->layout->reg)
+#define at91_adc_read_chan(st, reg)					\
+	readl_relaxed((st)->base + reg)
+#define at91_adc_writel(st, reg, val)					\
+	writel_relaxed(val, (st)->base + (st)->soc_info.platform->layout->reg)
+
+/**
+ * struct at91_adc_platform - at91-sama5d2 platform information struct
+ * @layout:		pointer to the reg layout struct
+ * @adc_channels:	pointer to an array of channels for registering in
+ *			the iio subsystem
+ * @nr_channels:	number of physical channels available
+ * @touch_chan_x:	index of the touchscreen X channel
+ * @touch_chan_y:	index of the touchscreen Y channel
+ * @touch_chan_p:	index of the touchscreen P channel
+ * @max_channels:	number of total channels
+ * @hw_trig_cnt:	number of possible hardware triggers
+ */
+struct at91_adc_platform {
+	const struct at91_adc_reg_layout	*layout;
+	const struct iio_chan_spec		(*adc_channels)[];
+	unsigned int				nr_channels;
+	unsigned int				touch_chan_x;
+	unsigned int				touch_chan_y;
+	unsigned int				touch_chan_p;
+	unsigned int				max_channels;
+	unsigned int				hw_trig_cnt;
+};
 
+/**
+ * struct at91_adc_soc_info - at91-sama5d2 soc information struct
+ * @startup_time:	device startup time
+ * @min_sample_rate:	minimum sample rate in Hz
+ * @max_sample_rate:	maximum sample rate in Hz
+ * @platform:		pointer to the platform structure
+ */
 struct at91_adc_soc_info {
 	unsigned			startup_time;
 	unsigned			min_sample_rate;
 	unsigned			max_sample_rate;
+	const struct at91_adc_platform	*platform;
 };
 
 struct at91_adc_trigger {
@@ -382,6 +429,15 @@  struct at91_adc_touch {
 	struct work_struct		workq;
 };
 
+/*
+ * Buffer size requirements:
+ * No channels * bytes_per_channel(2) + timestamp bytes (8)
+ * Divided by 2 because we need half words.
+ * We assume 32 channels for now, has to be increased if needed.
+ * Nobody minds a buffer being too big.
+ */
+#define AT91_BUFFER_MAX_HWORDS ((32 * 2 + 8) / 2)
+
 struct at91_adc_state {
 	void __iomem			*base;
 	int				irq;
@@ -437,29 +493,49 @@  static const struct at91_adc_trigger at91_adc_trigger_list[] = {
 	},
 };
 
-static const struct iio_chan_spec at91_adc_channels[] = {
-	AT91_SAMA5D2_CHAN_SINGLE(0, 0x50),
-	AT91_SAMA5D2_CHAN_SINGLE(1, 0x54),
-	AT91_SAMA5D2_CHAN_SINGLE(2, 0x58),
-	AT91_SAMA5D2_CHAN_SINGLE(3, 0x5c),
-	AT91_SAMA5D2_CHAN_SINGLE(4, 0x60),
-	AT91_SAMA5D2_CHAN_SINGLE(5, 0x64),
-	AT91_SAMA5D2_CHAN_SINGLE(6, 0x68),
-	AT91_SAMA5D2_CHAN_SINGLE(7, 0x6c),
-	AT91_SAMA5D2_CHAN_SINGLE(8, 0x70),
-	AT91_SAMA5D2_CHAN_SINGLE(9, 0x74),
-	AT91_SAMA5D2_CHAN_SINGLE(10, 0x78),
-	AT91_SAMA5D2_CHAN_SINGLE(11, 0x7c),
-	AT91_SAMA5D2_CHAN_DIFF(0, 1, 0x50),
-	AT91_SAMA5D2_CHAN_DIFF(2, 3, 0x58),
-	AT91_SAMA5D2_CHAN_DIFF(4, 5, 0x60),
-	AT91_SAMA5D2_CHAN_DIFF(6, 7, 0x68),
-	AT91_SAMA5D2_CHAN_DIFF(8, 9, 0x70),
-	AT91_SAMA5D2_CHAN_DIFF(10, 11, 0x78),
-	IIO_CHAN_SOFT_TIMESTAMP(AT91_SAMA5D2_TIMESTAMP_CHAN_IDX),
-	AT91_SAMA5D2_CHAN_TOUCH(AT91_SAMA5D2_TOUCH_X_CHAN_IDX, "x", IIO_MOD_X),
-	AT91_SAMA5D2_CHAN_TOUCH(AT91_SAMA5D2_TOUCH_Y_CHAN_IDX, "y", IIO_MOD_Y),
-	AT91_SAMA5D2_CHAN_PRESSURE(AT91_SAMA5D2_TOUCH_P_CHAN_IDX, "pressure"),
+static const struct iio_chan_spec at91_sama5d2_adc_channels[] = {
+	AT91_SAMA5D2_CHAN_SINGLE(0, 0, 0x50),
+	AT91_SAMA5D2_CHAN_SINGLE(1, 1, 0x54),
+	AT91_SAMA5D2_CHAN_SINGLE(2, 2, 0x58),
+	AT91_SAMA5D2_CHAN_SINGLE(3, 3, 0x5c),
+	AT91_SAMA5D2_CHAN_SINGLE(4, 4, 0x60),
+	AT91_SAMA5D2_CHAN_SINGLE(5, 5, 0x64),
+	AT91_SAMA5D2_CHAN_SINGLE(6, 6, 0x68),
+	AT91_SAMA5D2_CHAN_SINGLE(7, 7, 0x6c),
+	AT91_SAMA5D2_CHAN_SINGLE(8, 8, 0x70),
+	AT91_SAMA5D2_CHAN_SINGLE(9, 9, 0x74),
+	AT91_SAMA5D2_CHAN_SINGLE(10, 10, 0x78),
+	AT91_SAMA5D2_CHAN_SINGLE(11, 11, 0x7c),
+	AT91_SAMA5D2_CHAN_DIFF(12, 0, 1, 0x50),
+	AT91_SAMA5D2_CHAN_DIFF(13, 2, 3, 0x58),
+	AT91_SAMA5D2_CHAN_DIFF(14, 4, 5, 0x60),
+	AT91_SAMA5D2_CHAN_DIFF(15, 6, 7, 0x68),
+	AT91_SAMA5D2_CHAN_DIFF(16, 8, 9, 0x70),
+	AT91_SAMA5D2_CHAN_DIFF(17, 10, 11, 0x78),
+	IIO_CHAN_SOFT_TIMESTAMP(18),
+	AT91_SAMA5D2_CHAN_TOUCH(19, "x", IIO_MOD_X),
+	AT91_SAMA5D2_CHAN_TOUCH(20, "y", IIO_MOD_Y),
+	AT91_SAMA5D2_CHAN_PRESSURE(21, "pressure"),
+};
+
+static const struct at91_adc_platform sama5d2_platform = {
+	.layout = &sama5d2_layout,
+	.adc_channels = &at91_sama5d2_adc_channels,
+#define AT91_SAMA5D2_SINGLE_CHAN_CNT 12
+#define AT91_SAMA5D2_DIFF_CHAN_CNT 6
+	.nr_channels = AT91_SAMA5D2_SINGLE_CHAN_CNT +
+		       AT91_SAMA5D2_DIFF_CHAN_CNT,
+#define AT91_SAMA5D2_TOUCH_X_CHAN_IDX	(AT91_SAMA5D2_SINGLE_CHAN_CNT + \
+					AT91_SAMA5D2_DIFF_CHAN_CNT * 2)
+	.touch_chan_x = AT91_SAMA5D2_TOUCH_X_CHAN_IDX,
+#define AT91_SAMA5D2_TOUCH_Y_CHAN_IDX	(AT91_SAMA5D2_TOUCH_X_CHAN_IDX + 1)
+	.touch_chan_y = AT91_SAMA5D2_TOUCH_Y_CHAN_IDX,
+#define AT91_SAMA5D2_TOUCH_P_CHAN_IDX	(AT91_SAMA5D2_TOUCH_Y_CHAN_IDX + 1)
+	.touch_chan_p = AT91_SAMA5D2_TOUCH_P_CHAN_IDX,
+#define AT91_SAMA5D2_MAX_CHAN_IDX	AT91_SAMA5D2_TOUCH_P_CHAN_IDX
+	.max_channels = ARRAY_SIZE(at91_sama5d2_adc_channels),
+#define AT91_SAMA5D2_HW_TRIG_CNT	3
+	.hw_trig_cnt = AT91_SAMA5D2_HW_TRIG_CNT,
 };
 
 static int at91_adc_chan_xlate(struct iio_dev *indio_dev, int chan)
@@ -493,6 +569,7 @@  static unsigned int at91_adc_active_scan_mask_to_reg(struct iio_dev *indio_dev)
 {
 	u32 mask = 0;
 	u8 bit;
+	struct at91_adc_state *st = iio_priv(indio_dev);
 
 	for_each_set_bit(bit, indio_dev->active_scan_mask,
 			 indio_dev->num_channels) {
@@ -501,13 +578,13 @@  static unsigned int at91_adc_active_scan_mask_to_reg(struct iio_dev *indio_dev)
 		mask |= BIT(chan->channel);
 	}
 
-	return mask & GENMASK(11, 0);
+	return mask & GENMASK(st->soc_info.platform->nr_channels, 0);
 }
 
 static void at91_adc_config_emr(struct at91_adc_state *st)
 {
 	/* configure the extended mode register */
-	unsigned int emr = at91_adc_readl(st, AT91_SAMA5D2_EMR);
+	unsigned int emr = at91_adc_readl(st, EMR);
 
 	/* select oversampling per single trigger event */
 	emr |= AT91_SAMA5D2_EMR_ASTE(1);
@@ -531,7 +608,7 @@  static void at91_adc_config_emr(struct at91_adc_state *st)
 		break;
 	}
 
-	at91_adc_writel(st, AT91_SAMA5D2_EMR, emr);
+	at91_adc_writel(st, EMR, emr);
 }
 
 static int at91_adc_adjust_val_osr(struct at91_adc_state *st, int *val)
@@ -584,9 +661,9 @@  static int at91_adc_configure_touch(struct at91_adc_state *st, bool state)
 
 	if (!state) {
 		/* disabling touch IRQs and setting mode to no touch enabled */
-		at91_adc_writel(st, AT91_SAMA5D2_IDR,
+		at91_adc_writel(st, IDR,
 				AT91_SAMA5D2_IER_PEN | AT91_SAMA5D2_IER_NOPEN);
-		at91_adc_writel(st, AT91_SAMA5D2_TSMR, 0);
+		at91_adc_writel(st, TSMR, 0);
 		return 0;
 	}
 	/*
@@ -612,19 +689,19 @@  static int at91_adc_configure_touch(struct at91_adc_state *st, bool state)
 	tsmr |= AT91_SAMA5D2_TSMR_PENDET_ENA;
 	tsmr |= AT91_SAMA5D2_TSMR_TSFREQ(2) & AT91_SAMA5D2_TSMR_TSFREQ_MASK;
 
-	at91_adc_writel(st, AT91_SAMA5D2_TSMR, tsmr);
+	at91_adc_writel(st, TSMR, tsmr);
 
-	acr =  at91_adc_readl(st, AT91_SAMA5D2_ACR);
+	acr =  at91_adc_readl(st, ACR);
 	acr &= ~AT91_SAMA5D2_ACR_PENDETSENS_MASK;
 	acr |= 0x02 & AT91_SAMA5D2_ACR_PENDETSENS_MASK;
-	at91_adc_writel(st, AT91_SAMA5D2_ACR, acr);
+	at91_adc_writel(st, ACR, acr);
 
 	/* Sample Period Time = (TRGPER + 1) / ADCClock */
 	st->touch_st.sample_period_val =
 				 round_up((AT91_SAMA5D2_TOUCH_SAMPLE_PERIOD_US *
 				 clk_khz / 1000) - 1, 1);
 	/* enable pen detect IRQ */
-	at91_adc_writel(st, AT91_SAMA5D2_IER, AT91_SAMA5D2_IER_PEN);
+	at91_adc_writel(st, IER, AT91_SAMA5D2_IER_PEN);
 
 	return 0;
 }
@@ -640,7 +717,11 @@  static u16 at91_adc_touch_pos(struct at91_adc_state *st, int reg)
 	 * max = 2^AT91_SAMA5D2_MAX_POS_BITS - 1
 	 */
 	/* first half of register is the x or y, second half is the scale */
-	val = at91_adc_readl(st, reg);
+	if (reg == st->soc_info.platform->layout->XPOSR)
+		val = at91_adc_readl(st, XPOSR);
+	else if (reg == st->soc_info.platform->layout->YPOSR)
+		val = at91_adc_readl(st, YPOSR);
+
 	if (!val)
 		dev_dbg(&st->indio_dev->dev, "pos is 0\n");
 
@@ -658,13 +739,13 @@  static u16 at91_adc_touch_pos(struct at91_adc_state *st, int reg)
 
 static u16 at91_adc_touch_x_pos(struct at91_adc_state *st)
 {
-	st->touch_st.x_pos = at91_adc_touch_pos(st, AT91_SAMA5D2_XPOSR);
+	st->touch_st.x_pos = at91_adc_touch_pos(st, st->soc_info.platform->layout->XPOSR);
 	return st->touch_st.x_pos;
 }
 
 static u16 at91_adc_touch_y_pos(struct at91_adc_state *st)
 {
-	return at91_adc_touch_pos(st, AT91_SAMA5D2_YPOSR);
+	return at91_adc_touch_pos(st, st->soc_info.platform->layout->YPOSR);
 }
 
 static u16 at91_adc_touch_pressure(struct at91_adc_state *st)
@@ -676,7 +757,7 @@  static u16 at91_adc_touch_pressure(struct at91_adc_state *st)
 	u32 factor = 1000;
 
 	/* calculate the pressure */
-	val = at91_adc_readl(st, AT91_SAMA5D2_PRESSR);
+	val = at91_adc_readl(st, PRESSR);
 	z1 = val & AT91_SAMA5D2_XYZ_MASK;
 	z2 = (val >> 16) & AT91_SAMA5D2_XYZ_MASK;
 
@@ -700,9 +781,9 @@  static int at91_adc_read_position(struct at91_adc_state *st, int chan, u16 *val)
 	*val = 0;
 	if (!st->touch_st.touching)
 		return -ENODATA;
-	if (chan == AT91_SAMA5D2_TOUCH_X_CHAN_IDX)
+	if (chan == st->soc_info.platform->touch_chan_x)
 		*val = at91_adc_touch_x_pos(st);
-	else if (chan == AT91_SAMA5D2_TOUCH_Y_CHAN_IDX)
+	else if (chan == st->soc_info.platform->touch_chan_y)
 		*val = at91_adc_touch_y_pos(st);
 	else
 		return -ENODATA;
@@ -715,7 +796,7 @@  static int at91_adc_read_pressure(struct at91_adc_state *st, int chan, u16 *val)
 	*val = 0;
 	if (!st->touch_st.touching)
 		return -ENODATA;
-	if (chan == AT91_SAMA5D2_TOUCH_P_CHAN_IDX)
+	if (chan == st->soc_info.platform->touch_chan_y)
 		*val = at91_adc_touch_pressure(st);
 	else
 		return -ENODATA;
@@ -727,7 +808,7 @@  static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state)
 {
 	struct iio_dev *indio = iio_trigger_get_drvdata(trig);
 	struct at91_adc_state *st = iio_priv(indio);
-	u32 status = at91_adc_readl(st, AT91_SAMA5D2_TRGR);
+	u32 status = at91_adc_readl(st, TRGR);
 
 	/* clear TRGMOD */
 	status &= ~AT91_SAMA5D2_TRGR_TRGMOD_MASK;
@@ -736,7 +817,7 @@  static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state)
 		status |= st->selected_trig->trgmod_value;
 
 	/* set/unset hw trigger */
-	at91_adc_writel(st, AT91_SAMA5D2_TRGR, status);
+	at91_adc_writel(st, TRGR, status);
 
 	return 0;
 }
@@ -753,7 +834,7 @@  static void at91_adc_reenable_trigger(struct iio_trigger *trig)
 	enable_irq(st->irq);
 
 	/* Needed to ACK the DRDY interruption */
-	at91_adc_readl(st, AT91_SAMA5D2_LCDR);
+	at91_adc_readl(st, LCDR);
 }
 
 static const struct iio_trigger_ops at91_adc_trigger_ops = {
@@ -848,7 +929,7 @@  static int at91_adc_dma_start(struct iio_dev *indio_dev)
 	}
 
 	/* enable general overrun error signaling */
-	at91_adc_writel(st, AT91_SAMA5D2_IER, AT91_SAMA5D2_IER_GOVRE);
+	at91_adc_writel(st, IER, AT91_SAMA5D2_IER_GOVRE);
 	/* Issue pending DMA requests */
 	dma_async_issue_pending(st->dma_st.dma_chan);
 
@@ -878,7 +959,7 @@  static bool at91_adc_current_chan_is_touch(struct iio_dev *indio_dev)
 
 	return !!bitmap_subset(indio_dev->active_scan_mask,
 			       &st->touch_st.channels_bitmask,
-			       AT91_SAMA5D2_MAX_CHAN_IDX + 1);
+			       st->soc_info.platform->max_channels + 1);
 }
 
 static int at91_adc_buffer_prepare(struct iio_dev *indio_dev)
@@ -915,7 +996,7 @@  static int at91_adc_buffer_prepare(struct iio_dev *indio_dev)
 		    chan->type == IIO_PRESSURE)
 			continue;
 
-		cor = at91_adc_readl(st, AT91_SAMA5D2_COR);
+		cor = at91_adc_readl(st, COR);
 
 		if (chan->differential)
 			cor |= (BIT(chan->channel) | BIT(chan->channel2)) <<
@@ -924,13 +1005,13 @@  static int at91_adc_buffer_prepare(struct iio_dev *indio_dev)
 			cor &= ~(BIT(chan->channel) <<
 			       AT91_SAMA5D2_COR_DIFF_OFFSET);
 
-		at91_adc_writel(st, AT91_SAMA5D2_COR, cor);
+		at91_adc_writel(st, COR, cor);
 
-		at91_adc_writel(st, AT91_SAMA5D2_CHER, BIT(chan->channel));
+		at91_adc_writel(st, CHER, BIT(chan->channel));
 	}
 
 	if (at91_adc_buffer_check_use_irq(indio_dev, st))
-		at91_adc_writel(st, AT91_SAMA5D2_IER, AT91_SAMA5D2_IER_DRDY);
+		at91_adc_writel(st, IER, AT91_SAMA5D2_IER_DRDY);
 
 	return 0;
 }
@@ -966,17 +1047,17 @@  static int at91_adc_buffer_postdisable(struct iio_dev *indio_dev)
 		    chan->type == IIO_PRESSURE)
 			continue;
 
-		at91_adc_writel(st, AT91_SAMA5D2_CHDR, BIT(chan->channel));
+		at91_adc_writel(st, CHDR, BIT(chan->channel));
 
 		if (st->dma_st.dma_chan)
-			at91_adc_readl(st, chan->address);
+			at91_adc_read_chan(st, chan->address);
 	}
 
 	if (at91_adc_buffer_check_use_irq(indio_dev, st))
-		at91_adc_writel(st, AT91_SAMA5D2_IDR, AT91_SAMA5D2_IER_DRDY);
+		at91_adc_writel(st, IDR, AT91_SAMA5D2_IER_DRDY);
 
 	/* read overflow register to clear possible overflow status */
-	at91_adc_readl(st, AT91_SAMA5D2_OVER);
+	at91_adc_readl(st, OVER);
 
 	/* if we are using DMA we must clear registers and end DMA */
 	if (st->dma_st.dma_chan)
@@ -1024,7 +1105,7 @@  static void at91_adc_trigger_handler_nodma(struct iio_dev *indio_dev,
 	 * Check if the conversion is ready. If not, wait a little bit, and
 	 * in case of timeout exit with an error.
 	 */
-	while ((at91_adc_readl(st, AT91_SAMA5D2_ISR) & mask) != mask &&
+	while ((at91_adc_readl(st, ISR) & mask) != mask &&
 	       timeout) {
 		usleep_range(50, 100);
 		timeout--;
@@ -1052,7 +1133,7 @@  static void at91_adc_trigger_handler_nodma(struct iio_dev *indio_dev,
 		 * Thus, emit a warning.
 		 */
 		if (chan->type == IIO_VOLTAGE) {
-			val = at91_adc_readl(st, chan->address);
+			val = at91_adc_read_chan(st, chan->address);
 			at91_adc_adjust_val_osr(st, &val);
 			st->buffer[i] = val;
 		} else {
@@ -1073,7 +1154,7 @@  static void at91_adc_trigger_handler_dma(struct iio_dev *indio_dev)
 	s64 interval;
 	int sample_index = 0, sample_count, sample_size;
 
-	u32 status = at91_adc_readl(st, AT91_SAMA5D2_ISR);
+	u32 status = at91_adc_readl(st, ISR);
 	/* if we reached this point, we cannot sample faster */
 	if (status & AT91_SAMA5D2_IER_GOVRE)
 		pr_info_ratelimited("%s: conversion overrun detected\n",
@@ -1125,7 +1206,7 @@  static irqreturn_t at91_adc_trigger_handler(int irq, void *p)
 	 * actually polling the trigger now.
 	 */
 	if (iio_trigger_validate_own_device(indio_dev->trig, indio_dev))
-		at91_adc_writel(st, AT91_SAMA5D2_CR, AT91_SAMA5D2_CR_START);
+		at91_adc_writel(st, CR, AT91_SAMA5D2_CR_START);
 
 	if (st->dma_st.dma_chan)
 		at91_adc_trigger_handler_dma(indio_dev);
@@ -1172,11 +1253,11 @@  static void at91_adc_setup_samp_freq(struct iio_dev *indio_dev, unsigned freq)
 	startup = at91_adc_startup_time(st->soc_info.startup_time,
 					freq / 1000);
 
-	mr = at91_adc_readl(st, AT91_SAMA5D2_MR);
+	mr = at91_adc_readl(st, MR);
 	mr &= ~(AT91_SAMA5D2_MR_STARTUP_MASK | AT91_SAMA5D2_MR_PRESCAL_MASK);
 	mr |= AT91_SAMA5D2_MR_STARTUP(startup);
 	mr |= AT91_SAMA5D2_MR_PRESCAL(prescal);
-	at91_adc_writel(st, AT91_SAMA5D2_MR, mr);
+	at91_adc_writel(st, MR, mr);
 
 	dev_dbg(&indio_dev->dev, "freq: %u, startup: %u, prescal: %u\n",
 		freq, startup, prescal);
@@ -1196,7 +1277,7 @@  static void at91_adc_touch_data_handler(struct iio_dev *indio_dev)
 	int i = 0;
 
 	for_each_set_bit(bit, indio_dev->active_scan_mask,
-			 AT91_SAMA5D2_MAX_CHAN_IDX + 1) {
+			 st->soc_info.platform->max_channels + 1) {
 		struct iio_chan_spec const *chan =
 					 at91_adc_chan_get(indio_dev, bit);
 
@@ -1222,12 +1303,11 @@  static void at91_adc_touch_data_handler(struct iio_dev *indio_dev)
 
 static void at91_adc_pen_detect_interrupt(struct at91_adc_state *st)
 {
-	at91_adc_writel(st, AT91_SAMA5D2_IDR, AT91_SAMA5D2_IER_PEN);
-	at91_adc_writel(st, AT91_SAMA5D2_IER, AT91_SAMA5D2_IER_NOPEN |
+	at91_adc_writel(st, IDR, AT91_SAMA5D2_IER_PEN);
+	at91_adc_writel(st, IER, AT91_SAMA5D2_IER_NOPEN |
 			AT91_SAMA5D2_IER_XRDY | AT91_SAMA5D2_IER_YRDY |
 			AT91_SAMA5D2_IER_PRDY);
-	at91_adc_writel(st, AT91_SAMA5D2_TRGR,
-			AT91_SAMA5D2_TRGR_TRGMOD_PERIODIC |
+	at91_adc_writel(st, TRGR, AT91_SAMA5D2_TRGR_TRGMOD_PERIODIC |
 			AT91_SAMA5D2_TRGR_TRGPER(st->touch_st.sample_period_val));
 	st->touch_st.touching = true;
 }
@@ -1236,16 +1316,15 @@  static void at91_adc_no_pen_detect_interrupt(struct iio_dev *indio_dev)
 {
 	struct at91_adc_state *st = iio_priv(indio_dev);
 
-	at91_adc_writel(st, AT91_SAMA5D2_TRGR,
-			AT91_SAMA5D2_TRGR_TRGMOD_NO_TRIGGER);
-	at91_adc_writel(st, AT91_SAMA5D2_IDR, AT91_SAMA5D2_IER_NOPEN |
+	at91_adc_writel(st, TRGR, AT91_SAMA5D2_TRGR_TRGMOD_NO_TRIGGER);
+	at91_adc_writel(st, IDR, AT91_SAMA5D2_IER_NOPEN |
 			AT91_SAMA5D2_IER_XRDY | AT91_SAMA5D2_IER_YRDY |
 			AT91_SAMA5D2_IER_PRDY);
 	st->touch_st.touching = false;
 
 	at91_adc_touch_data_handler(indio_dev);
 
-	at91_adc_writel(st, AT91_SAMA5D2_IER, AT91_SAMA5D2_IER_PEN);
+	at91_adc_writel(st, IER, AT91_SAMA5D2_IER_PEN);
 }
 
 static void at91_adc_workq_handler(struct work_struct *workq)
@@ -1263,8 +1342,8 @@  static irqreturn_t at91_adc_interrupt(int irq, void *private)
 {
 	struct iio_dev *indio = private;
 	struct at91_adc_state *st = iio_priv(indio);
-	u32 status = at91_adc_readl(st, AT91_SAMA5D2_ISR);
-	u32 imr = at91_adc_readl(st, AT91_SAMA5D2_IMR);
+	u32 status = at91_adc_readl(st, ISR);
+	u32 imr = at91_adc_readl(st, IMR);
 	u32 rdy_mask = AT91_SAMA5D2_IER_XRDY | AT91_SAMA5D2_IER_YRDY |
 			AT91_SAMA5D2_IER_PRDY;
 
@@ -1285,9 +1364,9 @@  static irqreturn_t at91_adc_interrupt(int irq, void *private)
 		 * touching, but the measurements are not ready yet.
 		 * read and ignore.
 		 */
-		status = at91_adc_readl(st, AT91_SAMA5D2_XPOSR);
-		status = at91_adc_readl(st, AT91_SAMA5D2_YPOSR);
-		status = at91_adc_readl(st, AT91_SAMA5D2_PRESSR);
+		status = at91_adc_readl(st, XPOSR);
+		status = at91_adc_readl(st, YPOSR);
+		status = at91_adc_readl(st, PRESSR);
 	} else if (iio_buffer_enabled(indio) &&
 		   (status & AT91_SAMA5D2_IER_DRDY)) {
 		/* triggered buffer without DMA */
@@ -1299,7 +1378,7 @@  static irqreturn_t at91_adc_interrupt(int irq, void *private)
 		WARN(true, "Unexpected irq occurred\n");
 	} else if (!iio_buffer_enabled(indio)) {
 		/* software requested conversion */
-		st->conversion_value = at91_adc_readl(st, st->chan->address);
+		st->conversion_value = at91_adc_read_chan(st, st->chan->address);
 		st->conversion_done = true;
 		wake_up_interruptible(&st->wq_data_available);
 	}
@@ -1360,10 +1439,10 @@  static int at91_adc_read_info_raw(struct iio_dev *indio_dev,
 		cor = (BIT(chan->channel) | BIT(chan->channel2)) <<
 		      AT91_SAMA5D2_COR_DIFF_OFFSET;
 
-	at91_adc_writel(st, AT91_SAMA5D2_COR, cor);
-	at91_adc_writel(st, AT91_SAMA5D2_CHER, BIT(chan->channel));
-	at91_adc_writel(st, AT91_SAMA5D2_IER, BIT(chan->channel));
-	at91_adc_writel(st, AT91_SAMA5D2_CR, AT91_SAMA5D2_CR_START);
+	at91_adc_writel(st, COR, cor);
+	at91_adc_writel(st, CHER, BIT(chan->channel));
+	at91_adc_writel(st, IER, BIT(chan->channel));
+	at91_adc_writel(st, CR, AT91_SAMA5D2_CR_START);
 
 	ret = wait_event_interruptible_timeout(st->wq_data_available,
 					       st->conversion_done,
@@ -1379,11 +1458,11 @@  static int at91_adc_read_info_raw(struct iio_dev *indio_dev,
 		st->conversion_done = false;
 	}
 
-	at91_adc_writel(st, AT91_SAMA5D2_IDR, BIT(chan->channel));
-	at91_adc_writel(st, AT91_SAMA5D2_CHDR, BIT(chan->channel));
+	at91_adc_writel(st, IDR, BIT(chan->channel));
+	at91_adc_writel(st, CHDR, BIT(chan->channel));
 
 	/* Needed to ACK the DRDY interruption */
-	at91_adc_readl(st, AT91_SAMA5D2_LCDR);
+	at91_adc_readl(st, LCDR);
 
 	mutex_unlock(&st->lock);
 
@@ -1455,14 +1534,15 @@  static void at91_adc_dma_init(struct platform_device *pdev)
 	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
 	struct at91_adc_state *st = iio_priv(indio_dev);
 	struct dma_slave_config config = {0};
+	/* we have 2 bytes for each channel */
+	unsigned int sample_size = st->soc_info.platform->nr_channels * 2;
 	/*
 	 * We make the buffer double the size of the fifo,
 	 * such that DMA uses one half of the buffer (full fifo size)
 	 * and the software uses the other half to read/write.
 	 */
 	unsigned int pages = DIV_ROUND_UP(AT91_HWFIFO_MAX_SIZE *
-					  AT91_BUFFER_MAX_CONVERSION_BYTES * 2,
-					  PAGE_SIZE);
+					  sample_size * 2, PAGE_SIZE);
 
 	if (st->dma_st.dma_chan)
 		return;
@@ -1486,7 +1566,7 @@  static void at91_adc_dma_init(struct platform_device *pdev)
 	/* Configure DMA channel to read data register */
 	config.direction = DMA_DEV_TO_MEM;
 	config.src_addr = (phys_addr_t)(st->dma_st.phys_addr
-			  + AT91_SAMA5D2_LCDR);
+			  + st->soc_info.platform->layout->LCDR);
 	config.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
 	config.src_maxburst = 1;
 	config.dst_maxburst = 1;
@@ -1515,9 +1595,10 @@  static void at91_adc_dma_disable(struct platform_device *pdev)
 {
 	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
 	struct at91_adc_state *st = iio_priv(indio_dev);
+	/* we have 2 bytes for each channel */
+	unsigned int sample_size = st->soc_info.platform->nr_channels * 2;
 	unsigned int pages = DIV_ROUND_UP(AT91_HWFIFO_MAX_SIZE *
-					  AT91_BUFFER_MAX_CONVERSION_BYTES * 2,
-					  PAGE_SIZE);
+					  sample_size * 2, PAGE_SIZE);
 
 	/* if we are not using DMA, just return */
 	if (!st->dma_st.dma_chan)
@@ -1578,14 +1659,14 @@  static int at91_adc_update_scan_mode(struct iio_dev *indio_dev,
 	struct at91_adc_state *st = iio_priv(indio_dev);
 
 	if (bitmap_subset(scan_mask, &st->touch_st.channels_bitmask,
-			  AT91_SAMA5D2_MAX_CHAN_IDX + 1))
+			  st->soc_info.platform->max_channels + 1))
 		return 0;
 	/*
 	 * if the new bitmap is a combination of touchscreen and regular
 	 * channels, then we are not fine
 	 */
 	if (bitmap_intersects(&st->touch_st.channels_bitmask, scan_mask,
-			      AT91_SAMA5D2_MAX_CHAN_IDX + 1))
+			      st->soc_info.platform->max_channels + 1))
 		return -EINVAL;
 	return 0;
 }
@@ -1594,13 +1675,13 @@  static void at91_adc_hw_init(struct iio_dev *indio_dev)
 {
 	struct at91_adc_state *st = iio_priv(indio_dev);
 
-	at91_adc_writel(st, AT91_SAMA5D2_CR, AT91_SAMA5D2_CR_SWRST);
-	at91_adc_writel(st, AT91_SAMA5D2_IDR, 0xffffffff);
+	at91_adc_writel(st, CR, AT91_SAMA5D2_CR_SWRST);
+	at91_adc_writel(st, IDR, 0xffffffff);
 	/*
 	 * Transfer field must be set to 2 according to the datasheet and
 	 * allows different analog settings for each channel.
 	 */
-	at91_adc_writel(st, AT91_SAMA5D2_MR,
+	at91_adc_writel(st, MR,
 			AT91_SAMA5D2_MR_TRANSFER(2) | AT91_SAMA5D2_MR_ANACH);
 
 	at91_adc_setup_samp_freq(indio_dev, st->soc_info.min_sample_rate);
@@ -1716,21 +1797,23 @@  static int at91_adc_probe(struct platform_device *pdev)
 	if (!indio_dev)
 		return -ENOMEM;
 
+	st = iio_priv(indio_dev);
+	st->indio_dev = indio_dev;
+
+	st->soc_info.platform = of_device_get_match_data(&pdev->dev);
+
 	indio_dev->name = dev_name(&pdev->dev);
 	indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE;
 	indio_dev->info = &at91_adc_info;
-	indio_dev->channels = at91_adc_channels;
-	indio_dev->num_channels = ARRAY_SIZE(at91_adc_channels);
-
-	st = iio_priv(indio_dev);
-	st->indio_dev = indio_dev;
+	indio_dev->channels = *st->soc_info.platform->adc_channels;
+	indio_dev->num_channels = st->soc_info.platform->max_channels;
 
 	bitmap_set(&st->touch_st.channels_bitmask,
-		   AT91_SAMA5D2_TOUCH_X_CHAN_IDX, 1);
+		   st->soc_info.platform->touch_chan_x, 1);
 	bitmap_set(&st->touch_st.channels_bitmask,
-		   AT91_SAMA5D2_TOUCH_Y_CHAN_IDX, 1);
+		   st->soc_info.platform->touch_chan_y, 1);
 	bitmap_set(&st->touch_st.channels_bitmask,
-		   AT91_SAMA5D2_TOUCH_P_CHAN_IDX, 1);
+		   st->soc_info.platform->touch_chan_p, 1);
 
 	st->oversampling_ratio = AT91_OSR_1SAMPLES;
 
@@ -1770,7 +1853,7 @@  static int at91_adc_probe(struct platform_device *pdev)
 	st->selected_trig = NULL;
 
 	/* find the right trigger, or no trigger at all */
-	for (i = 0; i < AT91_SAMA5D2_HW_TRIG_CNT + 1; i++)
+	for (i = 0; i < st->soc_info.platform->hw_trig_cnt + 1; i++)
 		if (at91_adc_trigger_list[i].edge_type == edge_type) {
 			st->selected_trig = &at91_adc_trigger_list[i];
 			break;
@@ -1855,7 +1938,7 @@  static int at91_adc_probe(struct platform_device *pdev)
 			 st->selected_trig->name);
 
 	dev_info(&pdev->dev, "version: %x\n",
-		 readl_relaxed(st->base + AT91_SAMA5D2_VERSION));
+		 readl_relaxed(st->base + st->soc_info.platform->layout->VERSION));
 
 	return 0;
 
@@ -1898,7 +1981,7 @@  static __maybe_unused int at91_adc_suspend(struct device *dev)
 	 * and can be used by for other devices.
 	 * Otherwise, ADC will hog them and we can't go to suspend mode.
 	 */
-	at91_adc_writel(st, AT91_SAMA5D2_CR, AT91_SAMA5D2_CR_SWRST);
+	at91_adc_writel(st, CR, AT91_SAMA5D2_CR_SWRST);
 
 	clk_disable_unprepare(st->per_clk);
 	regulator_disable(st->vref);
@@ -1958,6 +2041,7 @@  static SIMPLE_DEV_PM_OPS(at91_adc_pm_ops, at91_adc_suspend, at91_adc_resume);
 static const struct of_device_id at91_adc_dt_match[] = {
 	{
 		.compatible = "atmel,sama5d2-adc",
+		.data = (const void *)&sama5d2_platform,
 	}, {
 		/* sentinel */
 	}