| Message ID | 1373789069-11604-6-git-send-email-josh.wu@atmel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Josh, On Sun, Jul 14, 2013 at 04:04:29PM +0800, Josh Wu wrote: > AT91 ADC hardware integrate touch screen support. So this patch add touch > screen support for at91 adc iio driver. > To enable touch screen support in adc, you need to add the dt parameters: > which type of touch are used? (4 or 5 wires), sample period time, > pen detect debounce time, average samples and pen detect resistor. > > In the meantime, since touch screen will use a interal period trigger of adc, > so it is conflict to other hardware triggers. Driver will disable the hardware > trigger support if touch screen is enabled. > > This driver has been tested in AT91SAM9X5-EK and SAMA5D3x-EK. > > Signed-off-by: Josh Wu <josh.wu@atmel.com> > Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> > --- > .../devicetree/bindings/arm/atmel-adc.txt | 13 + > arch/arm/mach-at91/include/mach/at91_adc.h | 34 ++ > drivers/iio/adc/at91_adc.c | 389 ++++++++++++++++++-- > 3 files changed, 412 insertions(+), 24 deletions(-) > > diff --git a/Documentation/devicetree/bindings/arm/atmel-adc.txt b/Documentation/devicetree/bindings/arm/atmel-adc.txt > index 0db2945..925d656 100644 > --- a/Documentation/devicetree/bindings/arm/atmel-adc.txt > +++ b/Documentation/devicetree/bindings/arm/atmel-adc.txt > @@ -29,6 +29,19 @@ Optional properties: > - atmel,adc-sample-hold-time: Sample and Hold Time in microseconds > - atmel,adc-clock-rate: ADC clock rate. If not specified, use the default > adc_op_clk. > + - atmel,adc-touchscreen-wires: Number of touch screen wires. Only support > + 4 and 5 wires touch screen. > + NOTE: when adc touch screen enabled, the adc hardware trigger will be > + disabled. Since touch screen will occupied the trigger register. > + - atmel,adc-ts-pendet-debounce: Debounce time in microsecond for touch pen > + detect. > + - atmel,adc-ts-sample-period-time: Sample Period Time in microsecond for > + touch screen > + - atmel,adc-ts-filter-average: Numbers of sampling data will be averaged. > + 0 means no average. 1 means average two samples. 2 means average four > + samples. 3 means average eight samples. > + - atmel,adc-ts-pendet-sensitivity: Pen Detection input pull-up resistor. > + It can be 0, 1, 2, 3. Could you expand a bit on what are these properties for? Are they board-specific? IP-specific? [...] > +#define DRIVER_NAME "at91_adc" This looks like this part doesn't belong to another cleanup patch. > +#define MAX_POS_BITS 12 > + > +#define ZTHRESHOLD 9000 > + > struct at91_adc_caps { > + bool has_12bits_xy; /* true means use 12 bits. Otherwise 10 bits */ Isn't that redundant with the low_res boolean? > bool has_tsmr; /* only at91sam9x5, sama5d3 have TSMR reg */ > u32 mr_prescal_mask; > u32 mr_startup_mask; > }; > > +enum atmel_adc_ts_type { > + ATMEL_ADC_TOUCHSCREEN_NONE = 0, > + ATMEL_ADC_TOUCHSCREEN_4WIRE, > + ATMEL_ADC_TOUCHSCREEN_5WIRE, > +}; > + > struct at91_adc_state { > struct clk *adc_clk; > u32 adc_clk_rate; > @@ -70,6 +83,29 @@ struct at91_adc_state { > bool low_res; /* the resolution corresponds to the lowest one */ > wait_queue_head_t wq_data_avail; > struct at91_adc_caps caps; > + > + /* > + * Following ADC channels are shared by touchscreen: > + * > + * CH0 -- Touch screen XP/UL > + * CH1 -- Touch screen XM/UR > + * CH2 -- Touch screen YP/LL > + * CH3 -- Touch screen YM/Sense > + * CH4 -- Touch screen LR(5-wire only) > + * > + * The bitfields below represents the reserved channel in the > + * touchscreen mode. > + */ > +#define CHAN_MASK_TOUCHSCREEN_4WIRE (0xf << 0) > +#define CHAN_MASK_TOUCHSCREEN_5WIRE (0x1f << 0) > + enum atmel_adc_ts_type touchscreen_type; > + struct input_dev *ts_input; > + > + u8 ts_filter_average; > + u16 ts_pen_detect_debounce; > + u8 ts_pen_detect_sensitivity; > + u16 ts_sample_period_time; > + u16 ts_sample_period_val; > }; > > static irqreturn_t at91_adc_trigger_handler(int irq, void *p) > @@ -104,14 +140,10 @@ static irqreturn_t at91_adc_trigger_handler(int irq, void *p) > return IRQ_HANDLED; > } > > -static irqreturn_t at91_adc_eoc_trigger(int irq, void *private) > +/* Handler for classic adc channel eoc trigger */ > +void handle_adc_eoc_trigger(int irq, struct iio_dev *idev) > { > - struct iio_dev *idev = private; > struct at91_adc_state *st = iio_priv(idev); > - u32 status = at91_adc_readl(st, st->registers->status_register); > - > - if (!(status & st->registers->drdy_mask)) > - return IRQ_HANDLED; Why are you changing the prototype and remove most of the useful part out of the handler? Maxime
Hi, Maxime On 7/15/2013 9:15 PM, Maxime Ripard wrote: > Hi Josh, > > On Sun, Jul 14, 2013 at 04:04:29PM +0800, Josh Wu wrote: >> AT91 ADC hardware integrate touch screen support. So this patch add touch >> screen support for at91 adc iio driver. >> To enable touch screen support in adc, you need to add the dt parameters: >> which type of touch are used? (4 or 5 wires), sample period time, >> pen detect debounce time, average samples and pen detect resistor. >> >> In the meantime, since touch screen will use a interal period trigger of adc, >> so it is conflict to other hardware triggers. Driver will disable the hardware >> trigger support if touch screen is enabled. >> >> This driver has been tested in AT91SAM9X5-EK and SAMA5D3x-EK. >> >> Signed-off-by: Josh Wu <josh.wu@atmel.com> >> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> >> --- >> .../devicetree/bindings/arm/atmel-adc.txt | 13 + >> arch/arm/mach-at91/include/mach/at91_adc.h | 34 ++ >> drivers/iio/adc/at91_adc.c | 389 ++++++++++++++++++-- >> 3 files changed, 412 insertions(+), 24 deletions(-) >> >> diff --git a/Documentation/devicetree/bindings/arm/atmel-adc.txt b/Documentation/devicetree/bindings/arm/atmel-adc.txt >> index 0db2945..925d656 100644 >> --- a/Documentation/devicetree/bindings/arm/atmel-adc.txt >> +++ b/Documentation/devicetree/bindings/arm/atmel-adc.txt >> @@ -29,6 +29,19 @@ Optional properties: >> - atmel,adc-sample-hold-time: Sample and Hold Time in microseconds >> - atmel,adc-clock-rate: ADC clock rate. If not specified, use the default >> adc_op_clk. >> + - atmel,adc-touchscreen-wires: Number of touch screen wires. Only support >> + 4 and 5 wires touch screen. >> + NOTE: when adc touch screen enabled, the adc hardware trigger will be >> + disabled. Since touch screen will occupied the trigger register. >> + - atmel,adc-ts-pendet-debounce: Debounce time in microsecond for touch pen >> + detect. >> + - atmel,adc-ts-sample-period-time: Sample Period Time in microsecond for >> + touch screen >> + - atmel,adc-ts-filter-average: Numbers of sampling data will be averaged. >> + 0 means no average. 1 means average two samples. 2 means average four >> + samples. 3 means average eight samples. >> + - atmel,adc-ts-pendet-sensitivity: Pen Detection input pull-up resistor. >> + It can be 0, 1, 2, 3. > Could you expand a bit on what are these properties for? Are they > board-specific? IP-specific? + - atmel,adc-touchscreen-wires: Number of touch screen wires. Only support + 4 and 5 wires touch screen. + NOTE: when adc touch screen enabled, the adc hardware trigger will be + disabled. Since touch screen will occupied the trigger register. It is board specific. Currently in AT91SAM9M10G45EK, AT91SAM9X5-EK, SAMA5D3x-EK all use 4 wire touch. Now the driver not support 5 wire yet. + - atmel,adc-ts-pendet-debounce: Debounce time in microsecond for touch pen + detect. de-glitch time for pen detect. Board specific. + - atmel,adc-ts-sample-period-time: Sample Period Time in microsecond for + touch screen The period to sample a touch data after pen is touched. Board specific. + - atmel,adc-ts-filter-average: Numbers of sampling data will be averaged. + 0 means no average. 1 means average two samples. 2 means average four + samples. 3 means average eight samples. + - atmel,adc-ts-pendet-sensitivity: Pen Detection input pull-up resistor. + It can be 0, 1, 2, 3. Above two properties only supported in SAM9X5, SAMA5D3 IP. > > [...] > >> +#define DRIVER_NAME "at91_adc" > This looks like this part doesn't belong to another cleanup patch. it is part of this patch. As it's a little cleanup, I integrate it as add touch feature. > >> +#define MAX_POS_BITS 12 >> + >> +#define ZTHRESHOLD 9000 >> + >> struct at91_adc_caps { >> + bool has_12bits_xy; /* true means use 12 bits. Otherwise 10 bits */ > Isn't that redundant with the low_res boolean? yes, right. I will remove it. > >> bool has_tsmr; /* only at91sam9x5, sama5d3 have TSMR reg */ >> u32 mr_prescal_mask; >> u32 mr_startup_mask; >> }; >> >> +enum atmel_adc_ts_type { >> + ATMEL_ADC_TOUCHSCREEN_NONE = 0, >> + ATMEL_ADC_TOUCHSCREEN_4WIRE, >> + ATMEL_ADC_TOUCHSCREEN_5WIRE, >> +}; >> + >> struct at91_adc_state { >> struct clk *adc_clk; >> u32 adc_clk_rate; >> @@ -70,6 +83,29 @@ struct at91_adc_state { >> bool low_res; /* the resolution corresponds to the lowest one */ >> wait_queue_head_t wq_data_avail; >> struct at91_adc_caps caps; >> + >> + /* >> + * Following ADC channels are shared by touchscreen: >> + * >> + * CH0 -- Touch screen XP/UL >> + * CH1 -- Touch screen XM/UR >> + * CH2 -- Touch screen YP/LL >> + * CH3 -- Touch screen YM/Sense >> + * CH4 -- Touch screen LR(5-wire only) >> + * >> + * The bitfields below represents the reserved channel in the >> + * touchscreen mode. >> + */ >> +#define CHAN_MASK_TOUCHSCREEN_4WIRE (0xf << 0) >> +#define CHAN_MASK_TOUCHSCREEN_5WIRE (0x1f << 0) >> + enum atmel_adc_ts_type touchscreen_type; >> + struct input_dev *ts_input; >> + >> + u8 ts_filter_average; >> + u16 ts_pen_detect_debounce; >> + u8 ts_pen_detect_sensitivity; >> + u16 ts_sample_period_time; >> + u16 ts_sample_period_val; >> }; >> >> static irqreturn_t at91_adc_trigger_handler(int irq, void *p) >> @@ -104,14 +140,10 @@ static irqreturn_t at91_adc_trigger_handler(int irq, void *p) >> return IRQ_HANDLED; >> } >> >> -static irqreturn_t at91_adc_eoc_trigger(int irq, void *private) >> +/* Handler for classic adc channel eoc trigger */ >> +void handle_adc_eoc_trigger(int irq, struct iio_dev *idev) >> { >> - struct iio_dev *idev = private; >> struct at91_adc_state *st = iio_priv(idev); >> - u32 status = at91_adc_readl(st, st->registers->status_register); >> - >> - if (!(status & st->registers->drdy_mask)) >> - return IRQ_HANDLED; > Why are you changing the prototype and remove most of the useful part > out of the handler? I change the protype because I make it as a sub interrupt handler. Since I just add a new interrupt handler which will check the interrupt type, if DRDY interrupt is coming, it will call your original handler. Otherwise use touch screen interrupt handler code. Following is the new interrupt handler code in this patch: +static irqreturn_t at91_adc_interrupt(int irq, void *private) +{ + struct iio_dev *idev = private; + struct at91_adc_state *st = iio_priv(idev); + u32 status = at91_adc_readl(st, st->registers->status_register); + const uint32_t ts_data_irq_mask = + AT91_ADC_IER_XRDY | + AT91_ADC_IER_YRDY | + AT91_ADC_IER_PRDY; + + if (status & st->registers->drdy_mask) + handle_adc_eoc_trigger(irq, idev); ^ | here we call original trigger handler. + + if (status & AT91_ADC_IER_PEN) { + at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN); + at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_NOPEN | + ts_data_irq_mask); + /* Set up period trigger for sampling */ + at91_adc_writel(st, st->registers->trigger_register, + AT91_ADC_TRGR_MOD_PERIOD_TRIG | + AT91_ADC_TRGR_TRGPER_(st->ts_sample_period_val)); + } else if (status & AT91_ADC_IER_NOPEN) { + at91_adc_writel(st, st->registers->trigger_register, 0); + at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_NOPEN | + ts_data_irq_mask); + at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN); + + input_report_key(st->ts_input, BTN_TOUCH, 0); + input_sync(st->ts_input); + } else if ((status & ts_data_irq_mask) == ts_data_irq_mask) { Those code will handle for the Touch screen interrupt. > > Maxime > Thanks. Best Regards, Josh Wu
Hi Josh, On Tue, Jul 16, 2013 at 05:09:32PM +0800, Josh Wu wrote: > On 7/15/2013 9:15 PM, Maxime Ripard wrote: > >Hi Josh, > > > >On Sun, Jul 14, 2013 at 04:04:29PM +0800, Josh Wu wrote: > >>AT91 ADC hardware integrate touch screen support. So this patch add touch > >>screen support for at91 adc iio driver. > >>To enable touch screen support in adc, you need to add the dt parameters: > >> which type of touch are used? (4 or 5 wires), sample period time, > >> pen detect debounce time, average samples and pen detect resistor. > >> > >>In the meantime, since touch screen will use a interal period trigger of adc, > >>so it is conflict to other hardware triggers. Driver will disable the hardware > >>trigger support if touch screen is enabled. > >> > >>This driver has been tested in AT91SAM9X5-EK and SAMA5D3x-EK. > >> > >>Signed-off-by: Josh Wu <josh.wu@atmel.com> > >>Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> > >>--- > >> .../devicetree/bindings/arm/atmel-adc.txt | 13 + > >> arch/arm/mach-at91/include/mach/at91_adc.h | 34 ++ > >> drivers/iio/adc/at91_adc.c | 389 ++++++++++++++++++-- > >> 3 files changed, 412 insertions(+), 24 deletions(-) > >> > >>diff --git a/Documentation/devicetree/bindings/arm/atmel-adc.txt b/Documentation/devicetree/bindings/arm/atmel-adc.txt > >>index 0db2945..925d656 100644 > >>--- a/Documentation/devicetree/bindings/arm/atmel-adc.txt > >>+++ b/Documentation/devicetree/bindings/arm/atmel-adc.txt > >>@@ -29,6 +29,19 @@ Optional properties: > >> - atmel,adc-sample-hold-time: Sample and Hold Time in microseconds > >> - atmel,adc-clock-rate: ADC clock rate. If not specified, use the default > >> adc_op_clk. > >>+ - atmel,adc-touchscreen-wires: Number of touch screen wires. Only support > >>+ 4 and 5 wires touch screen. > >>+ NOTE: when adc touch screen enabled, the adc hardware trigger will be > >>+ disabled. Since touch screen will occupied the trigger register. > >>+ - atmel,adc-ts-pendet-debounce: Debounce time in microsecond for touch pen > >>+ detect. > >>+ - atmel,adc-ts-sample-period-time: Sample Period Time in microsecond for > >>+ touch screen > >>+ - atmel,adc-ts-filter-average: Numbers of sampling data will be averaged. > >>+ 0 means no average. 1 means average two samples. 2 means average four > >>+ samples. 3 means average eight samples. > >>+ - atmel,adc-ts-pendet-sensitivity: Pen Detection input pull-up resistor. > >>+ It can be 0, 1, 2, 3. > >Could you expand a bit on what are these properties for? Are they > >board-specific? IP-specific? > > + - atmel,adc-touchscreen-wires: Number of touch screen wires. Only support > + 4 and 5 wires touch screen. > + NOTE: when adc touch screen enabled, the adc hardware trigger will be > + disabled. Since touch screen will occupied the trigger register. > > It is board specific. Currently in AT91SAM9M10G45EK, AT91SAM9X5-EK, > SAMA5D3x-EK all use 4 wire touch. > Now the driver not support 5 wire yet. I see, maybe you should add this in the documentation then > + - atmel,adc-ts-pendet-debounce: Debounce time in microsecond for > touch pen > + detect. > > de-glitch time for pen detect. Board specific. > > + - atmel,adc-ts-sample-period-time: Sample Period Time in microsecond for > + touch screen > > The period to sample a touch data after pen is touched. Board specific. > > + - atmel,adc-ts-filter-average: Numbers of sampling data will be averaged. > + 0 means no average. 1 means average two samples. 2 means average four > + samples. 3 means average eight samples. > + - atmel,adc-ts-pendet-sensitivity: Pen Detection input pull-up resistor. > + It can be 0, 1, 2, 3. > > Above two properties only supported in SAM9X5, SAMA5D3 IP. Ok, that should go to the documentation as well. What do the values of atmel,adc-ts-pendet-sensitivity correspond to? > >>@@ -104,14 +140,10 @@ static irqreturn_t at91_adc_trigger_handler(int irq, void *p) > >> return IRQ_HANDLED; > >> } > >>-static irqreturn_t at91_adc_eoc_trigger(int irq, void *private) > >>+/* Handler for classic adc channel eoc trigger */ > >>+void handle_adc_eoc_trigger(int irq, struct iio_dev *idev) > >> { > >>- struct iio_dev *idev = private; > >> struct at91_adc_state *st = iio_priv(idev); > >>- u32 status = at91_adc_readl(st, st->registers->status_register); > >>- > >>- if (!(status & st->registers->drdy_mask)) > >>- return IRQ_HANDLED; > >Why are you changing the prototype and remove most of the useful part > >out of the handler? > > I change the protype because I make it as a sub interrupt handler. > Since I just add a new interrupt handler which will check the > interrupt type, if DRDY interrupt is coming, it will call your > original handler. > Otherwise use touch screen interrupt handler code. > > Following is the new interrupt handler code in this patch: > > +static irqreturn_t at91_adc_interrupt(int irq, void *private) > +{ > + struct iio_dev *idev = private; > + struct at91_adc_state *st = iio_priv(idev); > + u32 status = at91_adc_readl(st, st->registers->status_register); > + const uint32_t ts_data_irq_mask = > + AT91_ADC_IER_XRDY | > + AT91_ADC_IER_YRDY | > + AT91_ADC_IER_PRDY; > + > + if (status & st->registers->drdy_mask) > + handle_adc_eoc_trigger(irq, idev); > > ^ > | > here we call original trigger handler. > > + > + if (status & AT91_ADC_IER_PEN) { > + at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN); > + at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_NOPEN | > + ts_data_irq_mask); > + /* Set up period trigger for sampling */ > + at91_adc_writel(st, st->registers->trigger_register, > + AT91_ADC_TRGR_MOD_PERIOD_TRIG | > + AT91_ADC_TRGR_TRGPER_(st->ts_sample_period_val)); > + } else if (status & AT91_ADC_IER_NOPEN) { > + at91_adc_writel(st, st->registers->trigger_register, 0); > + at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_NOPEN | > + ts_data_irq_mask); > + at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN); > + > + input_report_key(st->ts_input, BTN_TOUCH, 0); > + input_sync(st->ts_input); > + } else if ((status & ts_data_irq_mask) == ts_data_irq_mask) { > > Those code will handle for the Touch screen interrupt. Ah, right. Thanks! Maxime
On 07/14/2013 09:04 AM, Josh Wu wrote: > AT91 ADC hardware integrate touch screen support. So this patch add touch > screen support for at91 adc iio driver. > To enable touch screen support in adc, you need to add the dt parameters: > which type of touch are used? (4 or 5 wires), sample period time, > pen detect debounce time, average samples and pen detect resistor. > > In the meantime, since touch screen will use a interal period trigger of adc, > so it is conflict to other hardware triggers. Driver will disable the hardware > trigger support if touch screen is enabled. > > This driver has been tested in AT91SAM9X5-EK and SAMA5D3x-EK. Firstly, this is adding input subsystem stuff inside an iio driver. Generally we are very anti this sort of combination, but I agree that right now the support for doing it any other way is not really present. The next bit of text is actually largely irrelevant here as I actually read the driver after I wrote it and discovered the hardware handles all the nastiness of touch screen processing here. I'll leave it here for reference of anyone working on parts where it is relevant ;) When I had more time to work on IIO I was working on an iio to input bridge driver (similar to iio-hwmon, but using the buffered interface hooks instead). It was fundamentally working, but I never quite got around to cleaning it up for submission. I'd appreciate any comments on what is missing or does not work for this case. http://marc.info/?l=linux-iio&m=135167944813803&w=2 Ulitimately what I would love to see is a generic touch screen consumer driver for IIO adc's but appreciate that is a big and complex job given all the different varieties of touch screen and trying to abstract the control of the various channels. So back to this part. My immediate thought is that this really ought to have an mfd underneath separate IIO and input drivers. Dmitry, what do you think? > > Signed-off-by: Josh Wu <josh.wu@atmel.com> > Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> > --- > .../devicetree/bindings/arm/atmel-adc.txt | 13 + > arch/arm/mach-at91/include/mach/at91_adc.h | 34 ++ > drivers/iio/adc/at91_adc.c | 389 ++++++++++++++++++-- > 3 files changed, 412 insertions(+), 24 deletions(-) > > diff --git a/Documentation/devicetree/bindings/arm/atmel-adc.txt b/Documentation/devicetree/bindings/arm/atmel-adc.txt > index 0db2945..925d656 100644 > --- a/Documentation/devicetree/bindings/arm/atmel-adc.txt > +++ b/Documentation/devicetree/bindings/arm/atmel-adc.txt > @@ -29,6 +29,19 @@ Optional properties: > - atmel,adc-sample-hold-time: Sample and Hold Time in microseconds > - atmel,adc-clock-rate: ADC clock rate. If not specified, use the default > adc_op_clk. > + - atmel,adc-touchscreen-wires: Number of touch screen wires. Only support > + 4 and 5 wires touch screen. > + NOTE: when adc touch screen enabled, the adc hardware trigger will be > + disabled. Since touch screen will occupied the trigger register. > + - atmel,adc-ts-pendet-debounce: Debounce time in microsecond for touch pen > + detect. > + - atmel,adc-ts-sample-period-time: Sample Period Time in microsecond for > + touch screen > + - atmel,adc-ts-filter-average: Numbers of sampling data will be averaged. > + 0 means no average. 1 means average two samples. 2 means average four > + samples. 3 means average eight samples. > + - atmel,adc-ts-pendet-sensitivity: Pen Detection input pull-up resistor. > + It can be 0, 1, 2, 3. > > Optional trigger Nodes: > - Required properties: > diff --git a/arch/arm/mach-at91/include/mach/at91_adc.h b/arch/arm/mach-at91/include/mach/at91_adc.h > index ab273ee..6d6cc14 100644 > --- a/arch/arm/mach-at91/include/mach/at91_adc.h > +++ b/arch/arm/mach-at91/include/mach/at91_adc.h > @@ -57,10 +57,44 @@ > #define AT91_ADC_IER 0x24 /* Interrupt Enable Register */ > #define AT91_ADC_IDR 0x28 /* Interrupt Disable Register */ > #define AT91_ADC_IMR 0x2C /* Interrupt Mask Register */ > +#define AT91_ADC_IER_PEN (1 << 29) > +#define AT91_ADC_IER_NOPEN (1 << 30) > +#define AT91_ADC_IER_XRDY (1 << 20) > +#define AT91_ADC_IER_YRDY (1 << 21) > +#define AT91_ADC_IER_PRDY (1 << 22) > +#define AT91_ADC_ISR_PENS (1 << 31) > > #define AT91_ADC_CHR(n) (0x30 + ((n) * 4)) /* Channel Data Register N */ > #define AT91_ADC_DATA (0x3ff) > > +#define AT91_ADC_ACR 0x94 /* Analog Control Register */ > +#define AT91_ADC_ACR_PENDETSENS (0x3 << 0) /* pull-up resistor */ > + > +#define AT91_ADC_TSMR 0xB0 > +#define AT91_ADC_TSMR_TSMODE (3 << 0) /* Touch Screen Mode */ > +#define AT91_ADC_TSMR_TSMODE_NONE (0 << 0) > +#define AT91_ADC_TSMR_TSMODE_4WIRE_NO_PRESS (1 << 0) > +#define AT91_ADC_TSMR_TSMODE_4WIRE_PRESS (2 << 0) > +#define AT91_ADC_TSMR_TSMODE_5WIRE (3 << 0) > +#define AT91_ADC_TSMR_TSAV (3 << 4) /* Averages samples */ > +#define AT91_ADC_TSMR_TSAV_(x) ((x) << 4) > +#define AT91_ADC_TSMR_SCTIM (0x0f << 16) /* Switch closure time */ > +#define AT91_ADC_TSMR_PENDBC (0x0f << 28) /* Pen Debounce time */ > +#define AT91_ADC_TSMR_PENDBC_(x) ((x) << 28) > +#define AT91_ADC_TSMR_NOTSDMA (1 << 22) /* No Touchscreen DMA */ > +#define AT91_ADC_TSMR_PENDET_DIS (0 << 24) /* Pen contact detection disable */ > +#define AT91_ADC_TSMR_PENDET_ENA (1 << 24) /* Pen contact detection enable */ > + > +#define AT91_ADC_TSXPOSR 0xB4 > +#define AT91_ADC_TSYPOSR 0xB8 > +#define AT91_ADC_TSPRESSR 0xBC > + > #define AT91_ADC_VERSION 0xFC > > +/* Trigger Register bit field */ > +#define AT91_ADC_TRGR_TRGPER (0xffff << 16) > +#define AT91_ADC_TRGR_TRGPER_(x) ((x) << 16) > +#define AT91_ADC_TRGR_TRGMOD (0x7 << 0) > +#define AT91_ADC_TRGR_MOD_PERIOD_TRIG (5 << 0) > + > #endif > diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c > index 8f1386f..ffc0e42 100644 > --- a/drivers/iio/adc/at91_adc.c > +++ b/drivers/iio/adc/at91_adc.c > @@ -11,6 +11,7 @@ > #include <linux/clk.h> > #include <linux/err.h> > #include <linux/io.h> > +#include <linux/input.h> > #include <linux/interrupt.h> > #include <linux/jiffies.h> > #include <linux/kernel.h> > @@ -39,12 +40,24 @@ > #define at91_adc_writel(st, reg, val) \ > (writel_relaxed(val, st->reg_base + reg)) > > +#define DRIVER_NAME "at91_adc" > +#define MAX_POS_BITS 12 > + > +#define ZTHRESHOLD 9000 > + > struct at91_adc_caps { > + bool has_12bits_xy; /* true means use 12 bits. Otherwise 10 bits */ > bool has_tsmr; /* only at91sam9x5, sama5d3 have TSMR reg */ > u32 mr_prescal_mask; > u32 mr_startup_mask; > }; > > +enum atmel_adc_ts_type { > + ATMEL_ADC_TOUCHSCREEN_NONE = 0, > + ATMEL_ADC_TOUCHSCREEN_4WIRE, > + ATMEL_ADC_TOUCHSCREEN_5WIRE, > +}; > + > struct at91_adc_state { > struct clk *adc_clk; > u32 adc_clk_rate; > @@ -70,6 +83,29 @@ struct at91_adc_state { > bool low_res; /* the resolution corresponds to the lowest one */ > wait_queue_head_t wq_data_avail; > struct at91_adc_caps caps; > + > + /* > + * Following ADC channels are shared by touchscreen: > + * > + * CH0 -- Touch screen XP/UL > + * CH1 -- Touch screen XM/UR > + * CH2 -- Touch screen YP/LL > + * CH3 -- Touch screen YM/Sense > + * CH4 -- Touch screen LR(5-wire only) > + * > + * The bitfields below represents the reserved channel in the > + * touchscreen mode. > + */ > +#define CHAN_MASK_TOUCHSCREEN_4WIRE (0xf << 0) > +#define CHAN_MASK_TOUCHSCREEN_5WIRE (0x1f << 0) > + enum atmel_adc_ts_type touchscreen_type; > + struct input_dev *ts_input; > + > + u8 ts_filter_average; > + u16 ts_pen_detect_debounce; > + u8 ts_pen_detect_sensitivity; > + u16 ts_sample_period_time; > + u16 ts_sample_period_val; > }; > > static irqreturn_t at91_adc_trigger_handler(int irq, void *p) > @@ -104,14 +140,10 @@ static irqreturn_t at91_adc_trigger_handler(int irq, void *p) > return IRQ_HANDLED; > } > > -static irqreturn_t at91_adc_eoc_trigger(int irq, void *private) > +/* Handler for classic adc channel eoc trigger */ > +void handle_adc_eoc_trigger(int irq, struct iio_dev *idev) > { > - struct iio_dev *idev = private; > struct at91_adc_state *st = iio_priv(idev); > - u32 status = at91_adc_readl(st, st->registers->status_register); > - > - if (!(status & st->registers->drdy_mask)) > - return IRQ_HANDLED; > > if (iio_buffer_enabled(idev)) { > disable_irq_nosync(irq); > @@ -121,6 +153,115 @@ static irqreturn_t at91_adc_eoc_trigger(int irq, void *private) > st->done = true; > wake_up_interruptible(&st->wq_data_avail); > } > +} > + > +static int at91_ts_sample(struct at91_adc_state *st) > +{ > + unsigned int xscale, yscale, reg, z1, z2; > + unsigned int x, y, pres, xpos, ypos; > + unsigned int rxp = 1; > + unsigned int factor = 1000; > + struct iio_dev *idev = iio_priv_to_dev(st); > + > + unsigned int xyz_mask_bits = st->caps.has_12bits_xy ? 12 : 10; > + unsigned int xyz_mask = (1 << xyz_mask_bits) - 1; > + > + /* calculate position */ > + /* x position = (x / xscale) * max, max = 2^MAX_POS_BITS - 1 */ > + reg = at91_adc_readl(st, AT91_ADC_TSXPOSR); > + xpos = reg & xyz_mask; > + x = (xpos << MAX_POS_BITS) - xpos; > + xscale = (reg >> 16) & xyz_mask; > + if (xscale != 0) > + x /= xscale; > + else > + dev_err(&idev->dev, "xscale == 0!!!\n"); > + > + /* y position = (y / yscale) * max, max = 2^MAX_POS_BITS - 1 */ > + reg = at91_adc_readl(st, AT91_ADC_TSYPOSR); > + ypos = reg & xyz_mask; > + y = (ypos << MAX_POS_BITS) - ypos; > + yscale = (reg >> 16) & xyz_mask; > + if (yscale != 0) > + y /= yscale; > + else > + dev_err(&idev->dev, "yscale == 0!!!\n"); > + > + /* calculate the pressure */ > + reg = at91_adc_readl(st, AT91_ADC_TSPRESSR); > + z1 = reg & xyz_mask; > + z2 = (reg >> 16) & xyz_mask; > + > + if (z1 != 0) > + pres = rxp * (x * factor / 1024) * (z2 * factor / z1 - factor) > + / factor; > + else > + pres = ZTHRESHOLD; /* no pen contacted */ > + > + dev_dbg(&idev->dev, "xpos = %d, xscale = %d, ypos = %d, yscale = %d, z1 = %d, z2 = %d, press = %d\n", > + xpos, xscale, ypos, yscale, z1, z2, pres); > + > + if (pres < ZTHRESHOLD) { > + dev_dbg(&idev->dev, "x = %d, y = %d, pressure = %d\n", > + x, y, pres / factor); > + input_report_abs(st->ts_input, ABS_X, x); > + input_report_abs(st->ts_input, ABS_Y, y); > + input_report_abs(st->ts_input, ABS_PRESSURE, pres); > + input_report_key(st->ts_input, BTN_TOUCH, 1); > + input_sync(st->ts_input); > + } else { > + dev_dbg(&idev->dev, > + "pressure too low: not reporting\n"); > + } > + > + return 0; > +} > + > + > +static irqreturn_t at91_adc_interrupt(int irq, void *private) > +{ > + struct iio_dev *idev = private; > + struct at91_adc_state *st = iio_priv(idev); > + u32 status = at91_adc_readl(st, st->registers->status_register); > + const uint32_t ts_data_irq_mask = > + AT91_ADC_IER_XRDY | > + AT91_ADC_IER_YRDY | > + AT91_ADC_IER_PRDY; > + > + if (status & st->registers->drdy_mask) > + handle_adc_eoc_trigger(irq, idev); > + > + if (status & AT91_ADC_IER_PEN) { > + at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN); > + at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_NOPEN | > + ts_data_irq_mask); > + /* Set up period trigger for sampling */ > + at91_adc_writel(st, st->registers->trigger_register, > + AT91_ADC_TRGR_MOD_PERIOD_TRIG | > + AT91_ADC_TRGR_TRGPER_(st->ts_sample_period_val)); > + } else if (status & AT91_ADC_IER_NOPEN) { > + at91_adc_writel(st, st->registers->trigger_register, 0); > + at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_NOPEN | > + ts_data_irq_mask); > + at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN); > + > + input_report_key(st->ts_input, BTN_TOUCH, 0); > + input_sync(st->ts_input); > + } else if ((status & ts_data_irq_mask) == ts_data_irq_mask) { > + /* Now all touchscreen data is ready */ > + > + if (status & AT91_ADC_ISR_PENS) { > + /* validate data by pen contact */ > + at91_ts_sample(st); > + } else { > + /* triggered by event that is no pen contact, just read > + * them to clean the interrupt and discard all. > + */ > + at91_adc_readl(st, AT91_ADC_TSXPOSR); > + at91_adc_readl(st, AT91_ADC_TSYPOSR); > + at91_adc_readl(st, AT91_ADC_TSPRESSR); > + } > + } > > return IRQ_HANDLED; > } > @@ -130,6 +271,16 @@ static int at91_adc_channel_init(struct iio_dev *idev) > struct at91_adc_state *st = iio_priv(idev); > struct iio_chan_spec *chan_array, *timestamp; > int bit, idx = 0; > + unsigned long rsvd_mask = 0; > + > + /* If touchscreen is enable, then reserve the adc channels */ > + if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_4WIRE) > + rsvd_mask = CHAN_MASK_TOUCHSCREEN_4WIRE; > + else if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_5WIRE) > + rsvd_mask = CHAN_MASK_TOUCHSCREEN_5WIRE; > + > + /* set up the channel mask to reserve touchscreen channels */ > + st->channels_mask &= ~rsvd_mask; > > idev->num_channels = bitmap_weight(&st->channels_mask, > st->num_channels) + 1; > @@ -561,6 +712,57 @@ static int at91_adc_probe_dt(struct at91_adc_state *st, > i++; > } > > + /* Check if touchscreen is enabled in DT. */ > + ret = of_property_read_u32(node, "atmel,adc-touchscreen-wires", &prop); > + if (ret) > + dev_info(&idev->dev, "Touchscreen not enabled.\n"); > + else if (prop == 4) > + st->touchscreen_type = ATMEL_ADC_TOUCHSCREEN_4WIRE; > + else if (prop == 5) > + st->touchscreen_type = ATMEL_ADC_TOUCHSCREEN_5WIRE; > + else > + dev_warn(&idev->dev, "Unsupported number of touchscreen wires (%d)\n", > + prop); > + > + if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_NONE) > + return 0; > + > + /* Touch screen is enabled, so check touch screen dt parameters */ > + if (of_property_read_u32(node, "atmel,adc-ts-filter-average", &prop)) { > + dev_err(&idev->dev, "Missing atmel,adc-ts-filtering-average property in the DT.\n"); > + ret = -EINVAL; > + goto error_ret; > + } > + st->ts_filter_average = prop; > + if (st->ts_filter_average > 3) { > + dev_err(&idev->dev, "Invalid atmel,adc-ts-filtering-average property in the DT.\n"); > + ret = -EINVAL; > + goto error_ret; > + } > + > + prop = 0; > + of_property_read_u32(node, "atmel,adc-ts-pendet-debounce", &prop); > + st->ts_pen_detect_debounce = prop; > + > + /* default sample period is 2ms. The real touch sample period should be > + * this period * TSFREQ. > + */ > + prop = 2000; > + of_property_read_u32(node, "atmel,adc-ts-sample-period-time", &prop); > + st->ts_sample_period_time = prop; > + > + if (of_property_read_u32(node, "atmel,adc-ts-pendet-sensitivity", &prop)) { > + dev_err(&idev->dev, "Missing atmel,adc-ts-pendet-sensitivity property in the DT.\n"); > + ret = -EINVAL; > + goto error_ret; > + } > + st->ts_pen_detect_sensitivity = prop; > + if (st->ts_pen_detect_sensitivity > 3) { > + dev_err(&idev->dev, "Invalid atmel,adc-ts-pendet-sensitivity property in the DT.\n"); > + ret = -EINVAL; > + goto error_ret; > + } > + > return 0; > > error_ret: > @@ -592,6 +794,114 @@ static const struct iio_info at91_adc_info = { > .read_raw = &at91_adc_read_raw, > }; > > +/* Touchscreen related functions */ > +static int atmel_ts_open(struct input_dev *dev) > +{ > + struct at91_adc_state *st = input_get_drvdata(dev); > + > + at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN); > + return 0; > +} > + > +static void atmel_ts_close(struct input_dev *dev) > +{ > + struct at91_adc_state *st = input_get_drvdata(dev); > + > + at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN); > +} > + > +static int at91_ts_hw_init(struct at91_adc_state *st, u32 adc_clk_khz) > +{ > + u32 reg = 0, pendbc; > + int i = 0; > + > + if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_4WIRE) > + reg = AT91_ADC_TSMR_TSMODE_4WIRE_PRESS; > + else > + reg = AT91_ADC_TSMR_TSMODE_5WIRE; > + > + /* a Pen Detect Debounce Time is necessary for the ADC Touch to avoid > + * pen detect noise. > + * The formula is : Pen Detect Debounce Time = (2 ^ pendbc) / ADCClock > + */ > + pendbc = round_up(st->ts_pen_detect_debounce * adc_clk_khz / 1000, 1); > + > + while (pendbc >> ++i) > + ; /* Empty! Find the shift offset */ > + if (abs(pendbc - (1 << i)) < abs(pendbc - (1 << (i - 1)))) > + pendbc = i; > + else > + pendbc = i - 1; > + > + if (st->caps.has_tsmr) { > + reg |= AT91_ADC_TSMR_TSAV_(st->ts_filter_average) > + & AT91_ADC_TSMR_TSAV; > + reg |= AT91_ADC_TSMR_PENDBC_(pendbc) & AT91_ADC_TSMR_PENDBC; > + reg |= AT91_ADC_TSMR_NOTSDMA; > + reg |= AT91_ADC_TSMR_PENDET_ENA; > + reg |= 0x03 << 8; /* TSFREQ, need bigger than TSAV */ > + > + at91_adc_writel(st, AT91_ADC_TSMR, reg); > + } else { > + /* TODO: for 9g45 which has no TSMR */ > + } > + > + /* Change adc internal resistor value for better pen detection, > + * default value is 100 kOhm. > + * 0 = 200 kOhm, 1 = 150 kOhm, 2 = 100 kOhm, 3 = 50 kOhm > + * option only available on ES2 and higher > + */ > + at91_adc_writel(st, AT91_ADC_ACR, st->ts_pen_detect_sensitivity > + & AT91_ADC_ACR_PENDETSENS); > + > + /* Sample Peroid Time = (TRGPER + 1) / ADCClock */ > + st->ts_sample_period_val = round_up((st->ts_sample_period_time * > + adc_clk_khz / 1000) - 1, 1); > + > + return 0; > +} > + > +static int at91_ts_register(struct at91_adc_state *st) > +{ > + struct input_dev *input; > + struct iio_dev *idev = iio_priv_to_dev(st); > + int ret; > + > + input = input_allocate_device(); > + if (!input) { > + dev_err(&idev->dev, "Failed to allocate TS device!\n"); > + return -ENOMEM; > + } > + > + input->name = DRIVER_NAME; > + input->id.bustype = BUS_HOST; > + input->dev.parent = idev->dev.parent; > + input->open = atmel_ts_open; > + input->close = atmel_ts_close; > + > + __set_bit(EV_ABS, input->evbit); > + __set_bit(EV_KEY, input->evbit); > + __set_bit(BTN_TOUCH, input->keybit); > + input_set_abs_params(input, ABS_X, 0, (1 << MAX_POS_BITS) - 1, 0, 0); > + input_set_abs_params(input, ABS_Y, 0, (1 << MAX_POS_BITS) - 1, 0, 0); > + input_set_abs_params(input, ABS_PRESSURE, 0, 0xffffff, 0, 0); > + > + st->ts_input = input; > + input_set_drvdata(input, st); > + > + ret = input_register_device(input); > + if (ret) > + input_free_device(st->ts_input); > + > + return ret; > +} > + > +static void at91_ts_unregister(struct at91_adc_state *st) > +{ > + input_unregister_device(st->ts_input); > + input_free_device(st->ts_input); > +} > + > /* > * Since atmel adc support different ip for touchscreen mode. Through the > * IP check, we will know the touchscreen capbilities. > @@ -610,6 +920,7 @@ static void atmel_adc_get_cap(struct at91_adc_state *st) > /* keep only major version number */ > switch (version & 0xf00) { > case 0x500: /* SAMA5D3 */ > + st->caps.has_12bits_xy = 1; > case 0x400: /* AT91SAM9X5/9N12 */ > st->caps.has_tsmr = 1; > st->caps.mr_startup_mask = AT91_ADC_STARTUP; > @@ -683,7 +994,7 @@ static int at91_adc_probe(struct platform_device *pdev) > at91_adc_writel(st, AT91_ADC_CR, AT91_ADC_SWRST); > at91_adc_writel(st, AT91_ADC_IDR, 0xFFFFFFFF); > ret = request_irq(st->irq, > - at91_adc_eoc_trigger, > + at91_adc_interrupt, > 0, > pdev->dev.driver->name, > idev); > @@ -731,6 +1042,10 @@ static int at91_adc_probe(struct platform_device *pdev) > adc_clk = st->adc_clk_rate ? > st->adc_clk_rate : clk_get_rate(st->adc_clk); > adc_clk_khz = adc_clk / 1000; > + > + dev_dbg(&pdev->dev, "Master clock is set as: %d Hz, adc_clk should set as: %d Hz\n", > + mstrclk, adc_clk); > + > prsc = (mstrclk / (2 * adc_clk)) - 1; > > if (!st->startup_time) { > @@ -799,30 +1114,52 @@ static int at91_adc_probe(struct platform_device *pdev) > init_waitqueue_head(&st->wq_data_avail); > mutex_init(&st->lock); > > - ret = at91_adc_buffer_init(idev); > - if (ret < 0) { > - dev_err(&pdev->dev, "Couldn't initialize the buffer.\n"); > - goto error_disable_adc_clk; > - } > + /* > + * Since touch screen will set trigger register as period trigger. So > + * when touch screen is enabled, then we have to disable hardware > + * trigger for classic adc. > + */ > + if (!st->touchscreen_type) { > + ret = at91_adc_buffer_init(idev); > + if (ret < 0) { > + dev_err(&pdev->dev, "Couldn't initialize the buffer.\n"); > + goto error_disable_adc_clk; > + } > > - ret = at91_adc_trigger_init(idev); > - if (ret < 0) { > - dev_err(&pdev->dev, "Couldn't setup the triggers.\n"); > - goto error_unregister_buffer; > + ret = at91_adc_trigger_init(idev); > + if (ret < 0) { > + dev_err(&pdev->dev, "Couldn't setup the triggers.\n"); > + at91_adc_buffer_remove(idev); > + goto error_disable_adc_clk; > + } > + } else { > + if (!st->caps.has_tsmr) { > + dev_err(&pdev->dev, "We don't support non-TSMR adc\n"); > + goto error_disable_adc_clk; > + } > + > + ret = at91_ts_register(st); > + if (ret) > + goto error_disable_adc_clk; > + > + at91_ts_hw_init(st, adc_clk_khz); > } > > ret = iio_device_register(idev); > if (ret < 0) { > dev_err(&pdev->dev, "Couldn't register the device.\n"); > - goto error_remove_triggers; > + goto error_iio_device_register; > } > > return 0; > > -error_remove_triggers: > - at91_adc_trigger_remove(idev); > -error_unregister_buffer: > - at91_adc_buffer_remove(idev); > +error_iio_device_register: > + if (!st->touchscreen_type) { > + at91_adc_trigger_remove(idev); > + at91_adc_buffer_remove(idev); > + } else { > + at91_ts_unregister(st); > + } > error_disable_adc_clk: > clk_disable_unprepare(st->adc_clk); > error_disable_clk: > @@ -841,8 +1178,12 @@ static int at91_adc_remove(struct platform_device *pdev) > struct at91_adc_state *st = iio_priv(idev); > > iio_device_unregister(idev); > - at91_adc_trigger_remove(idev); > - at91_adc_buffer_remove(idev); > + if (!st->touchscreen_type) { > + at91_adc_trigger_remove(idev); > + at91_adc_buffer_remove(idev); > + } else { > + at91_ts_unregister(st); > + } > clk_disable_unprepare(st->adc_clk); > clk_disable_unprepare(st->clk); > free_irq(st->irq, idev); > @@ -861,7 +1202,7 @@ static struct platform_driver at91_adc_driver = { > .probe = at91_adc_probe, > .remove = at91_adc_remove, > .driver = { > - .name = "at91_adc", > + .name = DRIVER_NAME, > .of_match_table = of_match_ptr(at91_adc_dt_ids), > }, > }; >
On Sun, Jul 14, 2013 at 09:04:29AM +0100, Josh Wu wrote: > AT91 ADC hardware integrate touch screen support. So this patch add touch > screen support for at91 adc iio driver. > To enable touch screen support in adc, you need to add the dt parameters: > which type of touch are used? (4 or 5 wires), sample period time, > pen detect debounce time, average samples and pen detect resistor. > > In the meantime, since touch screen will use a interal period trigger of adc, > so it is conflict to other hardware triggers. Driver will disable the hardware > trigger support if touch screen is enabled. > > This driver has been tested in AT91SAM9X5-EK and SAMA5D3x-EK. > > Signed-off-by: Josh Wu <josh.wu@atmel.com> > Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> > --- > .../devicetree/bindings/arm/atmel-adc.txt | 13 + > arch/arm/mach-at91/include/mach/at91_adc.h | 34 ++ > drivers/iio/adc/at91_adc.c | 389 ++++++++++++++++++-- > 3 files changed, 412 insertions(+), 24 deletions(-) > > diff --git a/Documentation/devicetree/bindings/arm/atmel-adc.txt b/Documentation/devicetree/bindings/arm/atmel-adc.txt > index 0db2945..925d656 100644 > --- a/Documentation/devicetree/bindings/arm/atmel-adc.txt > +++ b/Documentation/devicetree/bindings/arm/atmel-adc.txt > @@ -29,6 +29,19 @@ Optional properties: > - atmel,adc-sample-hold-time: Sample and Hold Time in microseconds > - atmel,adc-clock-rate: ADC clock rate. If not specified, use the default > adc_op_clk. > + - atmel,adc-touchscreen-wires: Number of touch screen wires. Only support > + 4 and 5 wires touch screen. Are 4 and 5 wire configurations that can exist, or the only ones supported by the driver? > + NOTE: when adc touch screen enabled, the adc hardware trigger will be > + disabled. Since touch screen will occupied the trigger register. > + - atmel,adc-ts-pendet-debounce: Debounce time in microsecond for touch pen > + detect. For consistency with the adc-touchscreen-wires property, and other properties with timing information, how about atmel,adc-touchscreen-debounce-delay-us ? > + - atmel,adc-ts-sample-period-time: Sample Period Time in microsecond for > + touch screen Again, please be consistent with ts or touchscreen. It may also be good to have -us to make the units explicit (though it does leave the property name being quite a mothful): atmel,adc-touchscreen-sample-period-us ? > + - atmel,adc-ts-filter-average: Numbers of sampling data will be averaged. > + 0 means no average. 1 means average two samples. 2 means average four > + samples. 3 means average eight samples. Is this averaging done in the hardware, or the kernel driver? If it's the latter, this can be left for the kernel to decide. > + - atmel,adc-ts-pendet-sensitivity: Pen Detection input pull-up resistor. > + It can be 0, 1, 2, 3. I think "pendet" is a bit opaque. "pen-detect" may be better. What physical property does this represent (are these discrete values, or an enumeration)? Thanks, Mark. > > Optional trigger Nodes: > - Required properties: > diff --git a/arch/arm/mach-at91/include/mach/at91_adc.h b/arch/arm/mach-at91/include/mach/at91_adc.h > index ab273ee..6d6cc14 100644 > --- a/arch/arm/mach-at91/include/mach/at91_adc.h > +++ b/arch/arm/mach-at91/include/mach/at91_adc.h > @@ -57,10 +57,44 @@ > #define AT91_ADC_IER 0x24 /* Interrupt Enable Register */ > #define AT91_ADC_IDR 0x28 /* Interrupt Disable Register */ > #define AT91_ADC_IMR 0x2C /* Interrupt Mask Register */ > +#define AT91_ADC_IER_PEN (1 << 29) > +#define AT91_ADC_IER_NOPEN (1 << 30) > +#define AT91_ADC_IER_XRDY (1 << 20) > +#define AT91_ADC_IER_YRDY (1 << 21) > +#define AT91_ADC_IER_PRDY (1 << 22) > +#define AT91_ADC_ISR_PENS (1 << 31) > > #define AT91_ADC_CHR(n) (0x30 + ((n) * 4)) /* Channel Data Register N */ > #define AT91_ADC_DATA (0x3ff) > > +#define AT91_ADC_ACR 0x94 /* Analog Control Register */ > +#define AT91_ADC_ACR_PENDETSENS (0x3 << 0) /* pull-up resistor */ > + > +#define AT91_ADC_TSMR 0xB0 > +#define AT91_ADC_TSMR_TSMODE (3 << 0) /* Touch Screen Mode */ > +#define AT91_ADC_TSMR_TSMODE_NONE (0 << 0) > +#define AT91_ADC_TSMR_TSMODE_4WIRE_NO_PRESS (1 << 0) > +#define AT91_ADC_TSMR_TSMODE_4WIRE_PRESS (2 << 0) > +#define AT91_ADC_TSMR_TSMODE_5WIRE (3 << 0) > +#define AT91_ADC_TSMR_TSAV (3 << 4) /* Averages samples */ > +#define AT91_ADC_TSMR_TSAV_(x) ((x) << 4) > +#define AT91_ADC_TSMR_SCTIM (0x0f << 16) /* Switch closure time */ > +#define AT91_ADC_TSMR_PENDBC (0x0f << 28) /* Pen Debounce time */ > +#define AT91_ADC_TSMR_PENDBC_(x) ((x) << 28) > +#define AT91_ADC_TSMR_NOTSDMA (1 << 22) /* No Touchscreen DMA */ > +#define AT91_ADC_TSMR_PENDET_DIS (0 << 24) /* Pen contact detection disable */ > +#define AT91_ADC_TSMR_PENDET_ENA (1 << 24) /* Pen contact detection enable */ > + > +#define AT91_ADC_TSXPOSR 0xB4 > +#define AT91_ADC_TSYPOSR 0xB8 > +#define AT91_ADC_TSPRESSR 0xBC > + > #define AT91_ADC_VERSION 0xFC > > +/* Trigger Register bit field */ > +#define AT91_ADC_TRGR_TRGPER (0xffff << 16) > +#define AT91_ADC_TRGR_TRGPER_(x) ((x) << 16) > +#define AT91_ADC_TRGR_TRGMOD (0x7 << 0) > +#define AT91_ADC_TRGR_MOD_PERIOD_TRIG (5 << 0) > + > #endif > diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c > index 8f1386f..ffc0e42 100644 > --- a/drivers/iio/adc/at91_adc.c > +++ b/drivers/iio/adc/at91_adc.c > @@ -11,6 +11,7 @@ > #include <linux/clk.h> > #include <linux/err.h> > #include <linux/io.h> > +#include <linux/input.h> > #include <linux/interrupt.h> > #include <linux/jiffies.h> > #include <linux/kernel.h> > @@ -39,12 +40,24 @@ > #define at91_adc_writel(st, reg, val) \ > (writel_relaxed(val, st->reg_base + reg)) > > +#define DRIVER_NAME "at91_adc" > +#define MAX_POS_BITS 12 > + > +#define ZTHRESHOLD 9000 > + > struct at91_adc_caps { > + bool has_12bits_xy; /* true means use 12 bits. Otherwise 10 bits */ > bool has_tsmr; /* only at91sam9x5, sama5d3 have TSMR reg */ > u32 mr_prescal_mask; > u32 mr_startup_mask; > }; > > +enum atmel_adc_ts_type { > + ATMEL_ADC_TOUCHSCREEN_NONE = 0, > + ATMEL_ADC_TOUCHSCREEN_4WIRE, > + ATMEL_ADC_TOUCHSCREEN_5WIRE, > +}; > + > struct at91_adc_state { > struct clk *adc_clk; > u32 adc_clk_rate; > @@ -70,6 +83,29 @@ struct at91_adc_state { > bool low_res; /* the resolution corresponds to the lowest one */ > wait_queue_head_t wq_data_avail; > struct at91_adc_caps caps; > + > + /* > + * Following ADC channels are shared by touchscreen: > + * > + * CH0 -- Touch screen XP/UL > + * CH1 -- Touch screen XM/UR > + * CH2 -- Touch screen YP/LL > + * CH3 -- Touch screen YM/Sense > + * CH4 -- Touch screen LR(5-wire only) > + * > + * The bitfields below represents the reserved channel in the > + * touchscreen mode. > + */ > +#define CHAN_MASK_TOUCHSCREEN_4WIRE (0xf << 0) > +#define CHAN_MASK_TOUCHSCREEN_5WIRE (0x1f << 0) > + enum atmel_adc_ts_type touchscreen_type; > + struct input_dev *ts_input; > + > + u8 ts_filter_average; > + u16 ts_pen_detect_debounce; > + u8 ts_pen_detect_sensitivity; > + u16 ts_sample_period_time; > + u16 ts_sample_period_val; > }; > > static irqreturn_t at91_adc_trigger_handler(int irq, void *p) > @@ -104,14 +140,10 @@ static irqreturn_t at91_adc_trigger_handler(int irq, void *p) > return IRQ_HANDLED; > } > > -static irqreturn_t at91_adc_eoc_trigger(int irq, void *private) > +/* Handler for classic adc channel eoc trigger */ > +void handle_adc_eoc_trigger(int irq, struct iio_dev *idev) > { > - struct iio_dev *idev = private; > struct at91_adc_state *st = iio_priv(idev); > - u32 status = at91_adc_readl(st, st->registers->status_register); > - > - if (!(status & st->registers->drdy_mask)) > - return IRQ_HANDLED; > > if (iio_buffer_enabled(idev)) { > disable_irq_nosync(irq); > @@ -121,6 +153,115 @@ static irqreturn_t at91_adc_eoc_trigger(int irq, void *private) > st->done = true; > wake_up_interruptible(&st->wq_data_avail); > } > +} > + > +static int at91_ts_sample(struct at91_adc_state *st) > +{ > + unsigned int xscale, yscale, reg, z1, z2; > + unsigned int x, y, pres, xpos, ypos; > + unsigned int rxp = 1; > + unsigned int factor = 1000; > + struct iio_dev *idev = iio_priv_to_dev(st); > + > + unsigned int xyz_mask_bits = st->caps.has_12bits_xy ? 12 : 10; > + unsigned int xyz_mask = (1 << xyz_mask_bits) - 1; > + > + /* calculate position */ > + /* x position = (x / xscale) * max, max = 2^MAX_POS_BITS - 1 */ > + reg = at91_adc_readl(st, AT91_ADC_TSXPOSR); > + xpos = reg & xyz_mask; > + x = (xpos << MAX_POS_BITS) - xpos; > + xscale = (reg >> 16) & xyz_mask; > + if (xscale != 0) > + x /= xscale; > + else > + dev_err(&idev->dev, "xscale == 0!!!\n"); > + > + /* y position = (y / yscale) * max, max = 2^MAX_POS_BITS - 1 */ > + reg = at91_adc_readl(st, AT91_ADC_TSYPOSR); > + ypos = reg & xyz_mask; > + y = (ypos << MAX_POS_BITS) - ypos; > + yscale = (reg >> 16) & xyz_mask; > + if (yscale != 0) > + y /= yscale; > + else > + dev_err(&idev->dev, "yscale == 0!!!\n"); > + > + /* calculate the pressure */ > + reg = at91_adc_readl(st, AT91_ADC_TSPRESSR); > + z1 = reg & xyz_mask; > + z2 = (reg >> 16) & xyz_mask; > + > + if (z1 != 0) > + pres = rxp * (x * factor / 1024) * (z2 * factor / z1 - factor) > + / factor; > + else > + pres = ZTHRESHOLD; /* no pen contacted */ > + > + dev_dbg(&idev->dev, "xpos = %d, xscale = %d, ypos = %d, yscale = %d, z1 = %d, z2 = %d, press = %d\n", > + xpos, xscale, ypos, yscale, z1, z2, pres); > + > + if (pres < ZTHRESHOLD) { > + dev_dbg(&idev->dev, "x = %d, y = %d, pressure = %d\n", > + x, y, pres / factor); > + input_report_abs(st->ts_input, ABS_X, x); > + input_report_abs(st->ts_input, ABS_Y, y); > + input_report_abs(st->ts_input, ABS_PRESSURE, pres); > + input_report_key(st->ts_input, BTN_TOUCH, 1); > + input_sync(st->ts_input); > + } else { > + dev_dbg(&idev->dev, > + "pressure too low: not reporting\n"); > + } > + > + return 0; > +} > + > + > +static irqreturn_t at91_adc_interrupt(int irq, void *private) > +{ > + struct iio_dev *idev = private; > + struct at91_adc_state *st = iio_priv(idev); > + u32 status = at91_adc_readl(st, st->registers->status_register); > + const uint32_t ts_data_irq_mask = > + AT91_ADC_IER_XRDY | > + AT91_ADC_IER_YRDY | > + AT91_ADC_IER_PRDY; > + > + if (status & st->registers->drdy_mask) > + handle_adc_eoc_trigger(irq, idev); > + > + if (status & AT91_ADC_IER_PEN) { > + at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN); > + at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_NOPEN | > + ts_data_irq_mask); > + /* Set up period trigger for sampling */ > + at91_adc_writel(st, st->registers->trigger_register, > + AT91_ADC_TRGR_MOD_PERIOD_TRIG | > + AT91_ADC_TRGR_TRGPER_(st->ts_sample_period_val)); > + } else if (status & AT91_ADC_IER_NOPEN) { > + at91_adc_writel(st, st->registers->trigger_register, 0); > + at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_NOPEN | > + ts_data_irq_mask); > + at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN); > + > + input_report_key(st->ts_input, BTN_TOUCH, 0); > + input_sync(st->ts_input); > + } else if ((status & ts_data_irq_mask) == ts_data_irq_mask) { > + /* Now all touchscreen data is ready */ > + > + if (status & AT91_ADC_ISR_PENS) { > + /* validate data by pen contact */ > + at91_ts_sample(st); > + } else { > + /* triggered by event that is no pen contact, just read > + * them to clean the interrupt and discard all. > + */ > + at91_adc_readl(st, AT91_ADC_TSXPOSR); > + at91_adc_readl(st, AT91_ADC_TSYPOSR); > + at91_adc_readl(st, AT91_ADC_TSPRESSR); > + } > + } > > return IRQ_HANDLED; > } > @@ -130,6 +271,16 @@ static int at91_adc_channel_init(struct iio_dev *idev) > struct at91_adc_state *st = iio_priv(idev); > struct iio_chan_spec *chan_array, *timestamp; > int bit, idx = 0; > + unsigned long rsvd_mask = 0; > + > + /* If touchscreen is enable, then reserve the adc channels */ > + if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_4WIRE) > + rsvd_mask = CHAN_MASK_TOUCHSCREEN_4WIRE; > + else if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_5WIRE) > + rsvd_mask = CHAN_MASK_TOUCHSCREEN_5WIRE; > + > + /* set up the channel mask to reserve touchscreen channels */ > + st->channels_mask &= ~rsvd_mask; > > idev->num_channels = bitmap_weight(&st->channels_mask, > st->num_channels) + 1; > @@ -561,6 +712,57 @@ static int at91_adc_probe_dt(struct at91_adc_state *st, > i++; > } > > + /* Check if touchscreen is enabled in DT. */ > + ret = of_property_read_u32(node, "atmel,adc-touchscreen-wires", &prop); > + if (ret) > + dev_info(&idev->dev, "Touchscreen not enabled.\n"); > + else if (prop == 4) > + st->touchscreen_type = ATMEL_ADC_TOUCHSCREEN_4WIRE; > + else if (prop == 5) > + st->touchscreen_type = ATMEL_ADC_TOUCHSCREEN_5WIRE; > + else > + dev_warn(&idev->dev, "Unsupported number of touchscreen wires (%d)\n", > + prop); > + > + if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_NONE) > + return 0; > + > + /* Touch screen is enabled, so check touch screen dt parameters */ > + if (of_property_read_u32(node, "atmel,adc-ts-filter-average", &prop)) { > + dev_err(&idev->dev, "Missing atmel,adc-ts-filtering-average property in the DT.\n"); > + ret = -EINVAL; > + goto error_ret; > + } > + st->ts_filter_average = prop; > + if (st->ts_filter_average > 3) { > + dev_err(&idev->dev, "Invalid atmel,adc-ts-filtering-average property in the DT.\n"); > + ret = -EINVAL; > + goto error_ret; > + } > + > + prop = 0; > + of_property_read_u32(node, "atmel,adc-ts-pendet-debounce", &prop); > + st->ts_pen_detect_debounce = prop; > + > + /* default sample period is 2ms. The real touch sample period should be > + * this period * TSFREQ. > + */ > + prop = 2000; > + of_property_read_u32(node, "atmel,adc-ts-sample-period-time", &prop); > + st->ts_sample_period_time = prop; > + > + if (of_property_read_u32(node, "atmel,adc-ts-pendet-sensitivity", &prop)) { > + dev_err(&idev->dev, "Missing atmel,adc-ts-pendet-sensitivity property in the DT.\n"); > + ret = -EINVAL; > + goto error_ret; > + } > + st->ts_pen_detect_sensitivity = prop; > + if (st->ts_pen_detect_sensitivity > 3) { > + dev_err(&idev->dev, "Invalid atmel,adc-ts-pendet-sensitivity property in the DT.\n"); > + ret = -EINVAL; > + goto error_ret; > + } > + > return 0; > > error_ret: > @@ -592,6 +794,114 @@ static const struct iio_info at91_adc_info = { > .read_raw = &at91_adc_read_raw, > }; > > +/* Touchscreen related functions */ > +static int atmel_ts_open(struct input_dev *dev) > +{ > + struct at91_adc_state *st = input_get_drvdata(dev); > + > + at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN); > + return 0; > +} > + > +static void atmel_ts_close(struct input_dev *dev) > +{ > + struct at91_adc_state *st = input_get_drvdata(dev); > + > + at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN); > +} > + > +static int at91_ts_hw_init(struct at91_adc_state *st, u32 adc_clk_khz) > +{ > + u32 reg = 0, pendbc; > + int i = 0; > + > + if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_4WIRE) > + reg = AT91_ADC_TSMR_TSMODE_4WIRE_PRESS; > + else > + reg = AT91_ADC_TSMR_TSMODE_5WIRE; > + > + /* a Pen Detect Debounce Time is necessary for the ADC Touch to avoid > + * pen detect noise. > + * The formula is : Pen Detect Debounce Time = (2 ^ pendbc) / ADCClock > + */ > + pendbc = round_up(st->ts_pen_detect_debounce * adc_clk_khz / 1000, 1); > + > + while (pendbc >> ++i) > + ; /* Empty! Find the shift offset */ > + if (abs(pendbc - (1 << i)) < abs(pendbc - (1 << (i - 1)))) > + pendbc = i; > + else > + pendbc = i - 1; > + > + if (st->caps.has_tsmr) { > + reg |= AT91_ADC_TSMR_TSAV_(st->ts_filter_average) > + & AT91_ADC_TSMR_TSAV; > + reg |= AT91_ADC_TSMR_PENDBC_(pendbc) & AT91_ADC_TSMR_PENDBC; > + reg |= AT91_ADC_TSMR_NOTSDMA; > + reg |= AT91_ADC_TSMR_PENDET_ENA; > + reg |= 0x03 << 8; /* TSFREQ, need bigger than TSAV */ > + > + at91_adc_writel(st, AT91_ADC_TSMR, reg); > + } else { > + /* TODO: for 9g45 which has no TSMR */ > + } > + > + /* Change adc internal resistor value for better pen detection, > + * default value is 100 kOhm. > + * 0 = 200 kOhm, 1 = 150 kOhm, 2 = 100 kOhm, 3 = 50 kOhm > + * option only available on ES2 and higher > + */ > + at91_adc_writel(st, AT91_ADC_ACR, st->ts_pen_detect_sensitivity > + & AT91_ADC_ACR_PENDETSENS); > + > + /* Sample Peroid Time = (TRGPER + 1) / ADCClock */ > + st->ts_sample_period_val = round_up((st->ts_sample_period_time * > + adc_clk_khz / 1000) - 1, 1); > + > + return 0; > +} > + > +static int at91_ts_register(struct at91_adc_state *st) > +{ > + struct input_dev *input; > + struct iio_dev *idev = iio_priv_to_dev(st); > + int ret; > + > + input = input_allocate_device(); > + if (!input) { > + dev_err(&idev->dev, "Failed to allocate TS device!\n"); > + return -ENOMEM; > + } > + > + input->name = DRIVER_NAME; > + input->id.bustype = BUS_HOST; > + input->dev.parent = idev->dev.parent; > + input->open = atmel_ts_open; > + input->close = atmel_ts_close; > + > + __set_bit(EV_ABS, input->evbit); > + __set_bit(EV_KEY, input->evbit); > + __set_bit(BTN_TOUCH, input->keybit); > + input_set_abs_params(input, ABS_X, 0, (1 << MAX_POS_BITS) - 1, 0, 0); > + input_set_abs_params(input, ABS_Y, 0, (1 << MAX_POS_BITS) - 1, 0, 0); > + input_set_abs_params(input, ABS_PRESSURE, 0, 0xffffff, 0, 0); > + > + st->ts_input = input; > + input_set_drvdata(input, st); > + > + ret = input_register_device(input); > + if (ret) > + input_free_device(st->ts_input); > + > + return ret; > +} > + > +static void at91_ts_unregister(struct at91_adc_state *st) > +{ > + input_unregister_device(st->ts_input); > + input_free_device(st->ts_input); > +} > + > /* > * Since atmel adc support different ip for touchscreen mode. Through the > * IP check, we will know the touchscreen capbilities. > @@ -610,6 +920,7 @@ static void atmel_adc_get_cap(struct at91_adc_state *st) > /* keep only major version number */ > switch (version & 0xf00) { > case 0x500: /* SAMA5D3 */ > + st->caps.has_12bits_xy = 1; > case 0x400: /* AT91SAM9X5/9N12 */ > st->caps.has_tsmr = 1; > st->caps.mr_startup_mask = AT91_ADC_STARTUP; > @@ -683,7 +994,7 @@ static int at91_adc_probe(struct platform_device *pdev) > at91_adc_writel(st, AT91_ADC_CR, AT91_ADC_SWRST); > at91_adc_writel(st, AT91_ADC_IDR, 0xFFFFFFFF); > ret = request_irq(st->irq, > - at91_adc_eoc_trigger, > + at91_adc_interrupt, > 0, > pdev->dev.driver->name, > idev); > @@ -731,6 +1042,10 @@ static int at91_adc_probe(struct platform_device *pdev) > adc_clk = st->adc_clk_rate ? > st->adc_clk_rate : clk_get_rate(st->adc_clk); > adc_clk_khz = adc_clk / 1000; > + > + dev_dbg(&pdev->dev, "Master clock is set as: %d Hz, adc_clk should set as: %d Hz\n", > + mstrclk, adc_clk); > + > prsc = (mstrclk / (2 * adc_clk)) - 1; > > if (!st->startup_time) { > @@ -799,30 +1114,52 @@ static int at91_adc_probe(struct platform_device *pdev) > init_waitqueue_head(&st->wq_data_avail); > mutex_init(&st->lock); > > - ret = at91_adc_buffer_init(idev); > - if (ret < 0) { > - dev_err(&pdev->dev, "Couldn't initialize the buffer.\n"); > - goto error_disable_adc_clk; > - } > + /* > + * Since touch screen will set trigger register as period trigger. So > + * when touch screen is enabled, then we have to disable hardware > + * trigger for classic adc. > + */ > + if (!st->touchscreen_type) { > + ret = at91_adc_buffer_init(idev); > + if (ret < 0) { > + dev_err(&pdev->dev, "Couldn't initialize the buffer.\n"); > + goto error_disable_adc_clk; > + } > > - ret = at91_adc_trigger_init(idev); > - if (ret < 0) { > - dev_err(&pdev->dev, "Couldn't setup the triggers.\n"); > - goto error_unregister_buffer; > + ret = at91_adc_trigger_init(idev); > + if (ret < 0) { > + dev_err(&pdev->dev, "Couldn't setup the triggers.\n"); > + at91_adc_buffer_remove(idev); > + goto error_disable_adc_clk; > + } > + } else { > + if (!st->caps.has_tsmr) { > + dev_err(&pdev->dev, "We don't support non-TSMR adc\n"); > + goto error_disable_adc_clk; > + } > + > + ret = at91_ts_register(st); > + if (ret) > + goto error_disable_adc_clk; > + > + at91_ts_hw_init(st, adc_clk_khz); > } > > ret = iio_device_register(idev); > if (ret < 0) { > dev_err(&pdev->dev, "Couldn't register the device.\n"); > - goto error_remove_triggers; > + goto error_iio_device_register; > } > > return 0; > > -error_remove_triggers: > - at91_adc_trigger_remove(idev); > -error_unregister_buffer: > - at91_adc_buffer_remove(idev); > +error_iio_device_register: > + if (!st->touchscreen_type) { > + at91_adc_trigger_remove(idev); > + at91_adc_buffer_remove(idev); > + } else { > + at91_ts_unregister(st); > + } > error_disable_adc_clk: > clk_disable_unprepare(st->adc_clk); > error_disable_clk: > @@ -841,8 +1178,12 @@ static int at91_adc_remove(struct platform_device *pdev) > struct at91_adc_state *st = iio_priv(idev); > > iio_device_unregister(idev); > - at91_adc_trigger_remove(idev); > - at91_adc_buffer_remove(idev); > + if (!st->touchscreen_type) { > + at91_adc_trigger_remove(idev); > + at91_adc_buffer_remove(idev); > + } else { > + at91_ts_unregister(st); > + } > clk_disable_unprepare(st->adc_clk); > clk_disable_unprepare(st->clk); > free_irq(st->irq, idev); > @@ -861,7 +1202,7 @@ static struct platform_driver at91_adc_driver = { > .probe = at91_adc_probe, > .remove = at91_adc_remove, > .driver = { > - .name = "at91_adc", > + .name = DRIVER_NAME, > .of_match_table = of_match_ptr(at91_adc_dt_ids), > }, > }; > -- > 1.7.10 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >
Hi, Dear Mark On 7/22/2013 9:17 PM, Mark Rutland wrote: > On Sun, Jul 14, 2013 at 09:04:29AM +0100, Josh Wu wrote: >> AT91 ADC hardware integrate touch screen support. So this patch add touch >> screen support for at91 adc iio driver. >> To enable touch screen support in adc, you need to add the dt parameters: >> which type of touch are used? (4 or 5 wires), sample period time, >> pen detect debounce time, average samples and pen detect resistor. >> >> In the meantime, since touch screen will use a interal period trigger of adc, >> so it is conflict to other hardware triggers. Driver will disable the hardware >> trigger support if touch screen is enabled. >> >> This driver has been tested in AT91SAM9X5-EK and SAMA5D3x-EK. >> >> Signed-off-by: Josh Wu <josh.wu@atmel.com> >> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> >> --- >> .../devicetree/bindings/arm/atmel-adc.txt | 13 + >> arch/arm/mach-at91/include/mach/at91_adc.h | 34 ++ >> drivers/iio/adc/at91_adc.c | 389 ++++++++++++++++++-- >> 3 files changed, 412 insertions(+), 24 deletions(-) >> >> diff --git a/Documentation/devicetree/bindings/arm/atmel-adc.txt b/Documentation/devicetree/bindings/arm/atmel-adc.txt >> index 0db2945..925d656 100644 >> --- a/Documentation/devicetree/bindings/arm/atmel-adc.txt >> +++ b/Documentation/devicetree/bindings/arm/atmel-adc.txt >> @@ -29,6 +29,19 @@ Optional properties: >> - atmel,adc-sample-hold-time: Sample and Hold Time in microseconds >> - atmel,adc-clock-rate: ADC clock rate. If not specified, use the default >> adc_op_clk. >> + - atmel,adc-touchscreen-wires: Number of touch screen wires. Only support >> + 4 and 5 wires touch screen. > Are 4 and 5 wire configurations that can exist, or the only ones > supported by the driver? It can be set: atmel,adc-touchscreen-wires = <4>; or atmel,adc-touchscreen-wires = <5>; according to your touch screen. > >> + NOTE: when adc touch screen enabled, the adc hardware trigger will be >> + disabled. Since touch screen will occupied the trigger register. >> + - atmel,adc-ts-pendet-debounce: Debounce time in microsecond for touch pen >> + detect. > For consistency with the adc-touchscreen-wires property, and other > properties with timing information, how about > atmel,adc-touchscreen-debounce-delay-us ? sound nice to me. > >> + - atmel,adc-ts-sample-period-time: Sample Period Time in microsecond for >> + touch screen > Again, please be consistent with ts or touchscreen. It may also be good > to have -us to make the units explicit (though it does leave the > property name being quite a mothful): > > atmel,adc-touchscreen-sample-period-us ? nice. I will use this one. > >> + - atmel,adc-ts-filter-average: Numbers of sampling data will be averaged. >> + 0 means no average. 1 means average two samples. 2 means average four >> + samples. 3 means average eight samples. > Is this averaging done in the hardware, or the kernel driver? It is done in the hardware. But for some soc, like AT91SAM9G45, hardware doesn't support hardware average. So I am wondering use it as for both hardware and softer average. BTW, you mentioned the kernel driver, do you mean a filter algorithm is already implemented in kernel library? > > If it's the latter, this can be left for the kernel to decide. > >> + - atmel,adc-ts-pendet-sensitivity: Pen Detection input pull-up resistor. >> + It can be 0, 1, 2, 3. > I think "pendet" is a bit opaque. "pen-detect" may be better. yes. I'll change this. > What > physical property does this represent (are these discrete values, or an > enumeration)? This property is supported by hardware, it can change the adc internal resistor value for better pen detection, * 0 = 200 kOhm, 1 = 150 kOhm, 2 = 100 kOhm, 3 = 50 kOhm In general, we just use default value 2 for 100kOhm. I think I need add more detail infomation in the dt document. Thanks again, Best Regards, Josh Wu > > Thanks, > Mark. > >> Optional trigger Nodes: >> - Required properties: >> diff --git a/arch/arm/mach-at91/include/mach/at91_adc.h b/arch/arm/mach-at91/include/mach/at91_adc.h >> index ab273ee..6d6cc14 100644 >> --- a/arch/arm/mach-at91/include/mach/at91_adc.h >> +++ b/arch/arm/mach-at91/include/mach/at91_adc.h >> @@ -57,10 +57,44 @@ >> #define AT91_ADC_IER 0x24 /* Interrupt Enable Register */ >> #define AT91_ADC_IDR 0x28 /* Interrupt Disable Register */ >> #define AT91_ADC_IMR 0x2C /* Interrupt Mask Register */ >> +#define AT91_ADC_IER_PEN (1 << 29) >> +#define AT91_ADC_IER_NOPEN (1 << 30) >> +#define AT91_ADC_IER_XRDY (1 << 20) >> +#define AT91_ADC_IER_YRDY (1 << 21) >> +#define AT91_ADC_IER_PRDY (1 << 22) >> +#define AT91_ADC_ISR_PENS (1 << 31) >> >> #define AT91_ADC_CHR(n) (0x30 + ((n) * 4)) /* Channel Data Register N */ >> #define AT91_ADC_DATA (0x3ff) >> >> +#define AT91_ADC_ACR 0x94 /* Analog Control Register */ >> +#define AT91_ADC_ACR_PENDETSENS (0x3 << 0) /* pull-up resistor */ >> + >> +#define AT91_ADC_TSMR 0xB0 >> +#define AT91_ADC_TSMR_TSMODE (3 << 0) /* Touch Screen Mode */ >> +#define AT91_ADC_TSMR_TSMODE_NONE (0 << 0) >> +#define AT91_ADC_TSMR_TSMODE_4WIRE_NO_PRESS (1 << 0) >> +#define AT91_ADC_TSMR_TSMODE_4WIRE_PRESS (2 << 0) >> +#define AT91_ADC_TSMR_TSMODE_5WIRE (3 << 0) >> +#define AT91_ADC_TSMR_TSAV (3 << 4) /* Averages samples */ >> +#define AT91_ADC_TSMR_TSAV_(x) ((x) << 4) >> +#define AT91_ADC_TSMR_SCTIM (0x0f << 16) /* Switch closure time */ >> +#define AT91_ADC_TSMR_PENDBC (0x0f << 28) /* Pen Debounce time */ >> +#define AT91_ADC_TSMR_PENDBC_(x) ((x) << 28) >> +#define AT91_ADC_TSMR_NOTSDMA (1 << 22) /* No Touchscreen DMA */ >> +#define AT91_ADC_TSMR_PENDET_DIS (0 << 24) /* Pen contact detection disable */ >> +#define AT91_ADC_TSMR_PENDET_ENA (1 << 24) /* Pen contact detection enable */ >> + >> +#define AT91_ADC_TSXPOSR 0xB4 >> +#define AT91_ADC_TSYPOSR 0xB8 >> +#define AT91_ADC_TSPRESSR 0xBC >> + >> #define AT91_ADC_VERSION 0xFC >> >> +/* Trigger Register bit field */ >> +#define AT91_ADC_TRGR_TRGPER (0xffff << 16) >> +#define AT91_ADC_TRGR_TRGPER_(x) ((x) << 16) >> +#define AT91_ADC_TRGR_TRGMOD (0x7 << 0) >> +#define AT91_ADC_TRGR_MOD_PERIOD_TRIG (5 << 0) >> + >> #endif >> diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c >> index 8f1386f..ffc0e42 100644 >> --- a/drivers/iio/adc/at91_adc.c >> +++ b/drivers/iio/adc/at91_adc.c >> @@ -11,6 +11,7 @@ >> #include <linux/clk.h> >> #include <linux/err.h> >> #include <linux/io.h> >> +#include <linux/input.h> >> #include <linux/interrupt.h> >> #include <linux/jiffies.h> >> #include <linux/kernel.h> >> @@ -39,12 +40,24 @@ >> #define at91_adc_writel(st, reg, val) \ >> (writel_relaxed(val, st->reg_base + reg)) >> >> +#define DRIVER_NAME "at91_adc" >> +#define MAX_POS_BITS 12 >> + >> +#define ZTHRESHOLD 9000 >> + >> struct at91_adc_caps { >> + bool has_12bits_xy; /* true means use 12 bits. Otherwise 10 bits */ >> bool has_tsmr; /* only at91sam9x5, sama5d3 have TSMR reg */ >> u32 mr_prescal_mask; >> u32 mr_startup_mask; >> }; >> >> +enum atmel_adc_ts_type { >> + ATMEL_ADC_TOUCHSCREEN_NONE = 0, >> + ATMEL_ADC_TOUCHSCREEN_4WIRE, >> + ATMEL_ADC_TOUCHSCREEN_5WIRE, >> +}; >> + >> struct at91_adc_state { >> struct clk *adc_clk; >> u32 adc_clk_rate; >> @@ -70,6 +83,29 @@ struct at91_adc_state { >> bool low_res; /* the resolution corresponds to the lowest one */ >> wait_queue_head_t wq_data_avail; >> struct at91_adc_caps caps; >> + >> + /* >> + * Following ADC channels are shared by touchscreen: >> + * >> + * CH0 -- Touch screen XP/UL >> + * CH1 -- Touch screen XM/UR >> + * CH2 -- Touch screen YP/LL >> + * CH3 -- Touch screen YM/Sense >> + * CH4 -- Touch screen LR(5-wire only) >> + * >> + * The bitfields below represents the reserved channel in the >> + * touchscreen mode. >> + */ >> +#define CHAN_MASK_TOUCHSCREEN_4WIRE (0xf << 0) >> +#define CHAN_MASK_TOUCHSCREEN_5WIRE (0x1f << 0) >> + enum atmel_adc_ts_type touchscreen_type; >> + struct input_dev *ts_input; >> + >> + u8 ts_filter_average; >> + u16 ts_pen_detect_debounce; >> + u8 ts_pen_detect_sensitivity; >> + u16 ts_sample_period_time; >> + u16 ts_sample_period_val; >> }; >> >> static irqreturn_t at91_adc_trigger_handler(int irq, void *p) >> @@ -104,14 +140,10 @@ static irqreturn_t at91_adc_trigger_handler(int irq, void *p) >> return IRQ_HANDLED; >> } >> >> -static irqreturn_t at91_adc_eoc_trigger(int irq, void *private) >> +/* Handler for classic adc channel eoc trigger */ >> +void handle_adc_eoc_trigger(int irq, struct iio_dev *idev) >> { >> - struct iio_dev *idev = private; >> struct at91_adc_state *st = iio_priv(idev); >> - u32 status = at91_adc_readl(st, st->registers->status_register); >> - >> - if (!(status & st->registers->drdy_mask)) >> - return IRQ_HANDLED; >> >> if (iio_buffer_enabled(idev)) { >> disable_irq_nosync(irq); >> @@ -121,6 +153,115 @@ static irqreturn_t at91_adc_eoc_trigger(int irq, void *private) >> st->done = true; >> wake_up_interruptible(&st->wq_data_avail); >> } >> +} >> + >> +static int at91_ts_sample(struct at91_adc_state *st) >> +{ >> + unsigned int xscale, yscale, reg, z1, z2; >> + unsigned int x, y, pres, xpos, ypos; >> + unsigned int rxp = 1; >> + unsigned int factor = 1000; >> + struct iio_dev *idev = iio_priv_to_dev(st); >> + >> + unsigned int xyz_mask_bits = st->caps.has_12bits_xy ? 12 : 10; >> + unsigned int xyz_mask = (1 << xyz_mask_bits) - 1; >> + >> + /* calculate position */ >> + /* x position = (x / xscale) * max, max = 2^MAX_POS_BITS - 1 */ >> + reg = at91_adc_readl(st, AT91_ADC_TSXPOSR); >> + xpos = reg & xyz_mask; >> + x = (xpos << MAX_POS_BITS) - xpos; >> + xscale = (reg >> 16) & xyz_mask; >> + if (xscale != 0) >> + x /= xscale; >> + else >> + dev_err(&idev->dev, "xscale == 0!!!\n"); >> + >> + /* y position = (y / yscale) * max, max = 2^MAX_POS_BITS - 1 */ >> + reg = at91_adc_readl(st, AT91_ADC_TSYPOSR); >> + ypos = reg & xyz_mask; >> + y = (ypos << MAX_POS_BITS) - ypos; >> + yscale = (reg >> 16) & xyz_mask; >> + if (yscale != 0) >> + y /= yscale; >> + else >> + dev_err(&idev->dev, "yscale == 0!!!\n"); >> + >> + /* calculate the pressure */ >> + reg = at91_adc_readl(st, AT91_ADC_TSPRESSR); >> + z1 = reg & xyz_mask; >> + z2 = (reg >> 16) & xyz_mask; >> + >> + if (z1 != 0) >> + pres = rxp * (x * factor / 1024) * (z2 * factor / z1 - factor) >> + / factor; >> + else >> + pres = ZTHRESHOLD; /* no pen contacted */ >> + >> + dev_dbg(&idev->dev, "xpos = %d, xscale = %d, ypos = %d, yscale = %d, z1 = %d, z2 = %d, press = %d\n", >> + xpos, xscale, ypos, yscale, z1, z2, pres); >> + >> + if (pres < ZTHRESHOLD) { >> + dev_dbg(&idev->dev, "x = %d, y = %d, pressure = %d\n", >> + x, y, pres / factor); >> + input_report_abs(st->ts_input, ABS_X, x); >> + input_report_abs(st->ts_input, ABS_Y, y); >> + input_report_abs(st->ts_input, ABS_PRESSURE, pres); >> + input_report_key(st->ts_input, BTN_TOUCH, 1); >> + input_sync(st->ts_input); >> + } else { >> + dev_dbg(&idev->dev, >> + "pressure too low: not reporting\n"); >> + } >> + >> + return 0; >> +} >> + >> + >> +static irqreturn_t at91_adc_interrupt(int irq, void *private) >> +{ >> + struct iio_dev *idev = private; >> + struct at91_adc_state *st = iio_priv(idev); >> + u32 status = at91_adc_readl(st, st->registers->status_register); >> + const uint32_t ts_data_irq_mask = >> + AT91_ADC_IER_XRDY | >> + AT91_ADC_IER_YRDY | >> + AT91_ADC_IER_PRDY; >> + >> + if (status & st->registers->drdy_mask) >> + handle_adc_eoc_trigger(irq, idev); >> + >> + if (status & AT91_ADC_IER_PEN) { >> + at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN); >> + at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_NOPEN | >> + ts_data_irq_mask); >> + /* Set up period trigger for sampling */ >> + at91_adc_writel(st, st->registers->trigger_register, >> + AT91_ADC_TRGR_MOD_PERIOD_TRIG | >> + AT91_ADC_TRGR_TRGPER_(st->ts_sample_period_val)); >> + } else if (status & AT91_ADC_IER_NOPEN) { >> + at91_adc_writel(st, st->registers->trigger_register, 0); >> + at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_NOPEN | >> + ts_data_irq_mask); >> + at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN); >> + >> + input_report_key(st->ts_input, BTN_TOUCH, 0); >> + input_sync(st->ts_input); >> + } else if ((status & ts_data_irq_mask) == ts_data_irq_mask) { >> + /* Now all touchscreen data is ready */ >> + >> + if (status & AT91_ADC_ISR_PENS) { >> + /* validate data by pen contact */ >> + at91_ts_sample(st); >> + } else { >> + /* triggered by event that is no pen contact, just read >> + * them to clean the interrupt and discard all. >> + */ >> + at91_adc_readl(st, AT91_ADC_TSXPOSR); >> + at91_adc_readl(st, AT91_ADC_TSYPOSR); >> + at91_adc_readl(st, AT91_ADC_TSPRESSR); >> + } >> + } >> >> return IRQ_HANDLED; >> } >> @@ -130,6 +271,16 @@ static int at91_adc_channel_init(struct iio_dev *idev) >> struct at91_adc_state *st = iio_priv(idev); >> struct iio_chan_spec *chan_array, *timestamp; >> int bit, idx = 0; >> + unsigned long rsvd_mask = 0; >> + >> + /* If touchscreen is enable, then reserve the adc channels */ >> + if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_4WIRE) >> + rsvd_mask = CHAN_MASK_TOUCHSCREEN_4WIRE; >> + else if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_5WIRE) >> + rsvd_mask = CHAN_MASK_TOUCHSCREEN_5WIRE; >> + >> + /* set up the channel mask to reserve touchscreen channels */ >> + st->channels_mask &= ~rsvd_mask; >> >> idev->num_channels = bitmap_weight(&st->channels_mask, >> st->num_channels) + 1; >> @@ -561,6 +712,57 @@ static int at91_adc_probe_dt(struct at91_adc_state *st, >> i++; >> } >> >> + /* Check if touchscreen is enabled in DT. */ >> + ret = of_property_read_u32(node, "atmel,adc-touchscreen-wires", &prop); >> + if (ret) >> + dev_info(&idev->dev, "Touchscreen not enabled.\n"); >> + else if (prop == 4) >> + st->touchscreen_type = ATMEL_ADC_TOUCHSCREEN_4WIRE; >> + else if (prop == 5) >> + st->touchscreen_type = ATMEL_ADC_TOUCHSCREEN_5WIRE; >> + else >> + dev_warn(&idev->dev, "Unsupported number of touchscreen wires (%d)\n", >> + prop); >> + >> + if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_NONE) >> + return 0; >> + >> + /* Touch screen is enabled, so check touch screen dt parameters */ >> + if (of_property_read_u32(node, "atmel,adc-ts-filter-average", &prop)) { >> + dev_err(&idev->dev, "Missing atmel,adc-ts-filtering-average property in the DT.\n"); >> + ret = -EINVAL; >> + goto error_ret; >> + } >> + st->ts_filter_average = prop; >> + if (st->ts_filter_average > 3) { >> + dev_err(&idev->dev, "Invalid atmel,adc-ts-filtering-average property in the DT.\n"); >> + ret = -EINVAL; >> + goto error_ret; >> + } >> + >> + prop = 0; >> + of_property_read_u32(node, "atmel,adc-ts-pendet-debounce", &prop); >> + st->ts_pen_detect_debounce = prop; >> + >> + /* default sample period is 2ms. The real touch sample period should be >> + * this period * TSFREQ. >> + */ >> + prop = 2000; >> + of_property_read_u32(node, "atmel,adc-ts-sample-period-time", &prop); >> + st->ts_sample_period_time = prop; >> + >> + if (of_property_read_u32(node, "atmel,adc-ts-pendet-sensitivity", &prop)) { >> + dev_err(&idev->dev, "Missing atmel,adc-ts-pendet-sensitivity property in the DT.\n"); >> + ret = -EINVAL; >> + goto error_ret; >> + } >> + st->ts_pen_detect_sensitivity = prop; >> + if (st->ts_pen_detect_sensitivity > 3) { >> + dev_err(&idev->dev, "Invalid atmel,adc-ts-pendet-sensitivity property in the DT.\n"); >> + ret = -EINVAL; >> + goto error_ret; >> + } >> + >> return 0; >> >> error_ret: >> @@ -592,6 +794,114 @@ static const struct iio_info at91_adc_info = { >> .read_raw = &at91_adc_read_raw, >> }; >> >> +/* Touchscreen related functions */ >> +static int atmel_ts_open(struct input_dev *dev) >> +{ >> + struct at91_adc_state *st = input_get_drvdata(dev); >> + >> + at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN); >> + return 0; >> +} >> + >> +static void atmel_ts_close(struct input_dev *dev) >> +{ >> + struct at91_adc_state *st = input_get_drvdata(dev); >> + >> + at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN); >> +} >> + >> +static int at91_ts_hw_init(struct at91_adc_state *st, u32 adc_clk_khz) >> +{ >> + u32 reg = 0, pendbc; >> + int i = 0; >> + >> + if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_4WIRE) >> + reg = AT91_ADC_TSMR_TSMODE_4WIRE_PRESS; >> + else >> + reg = AT91_ADC_TSMR_TSMODE_5WIRE; >> + >> + /* a Pen Detect Debounce Time is necessary for the ADC Touch to avoid >> + * pen detect noise. >> + * The formula is : Pen Detect Debounce Time = (2 ^ pendbc) / ADCClock >> + */ >> + pendbc = round_up(st->ts_pen_detect_debounce * adc_clk_khz / 1000, 1); >> + >> + while (pendbc >> ++i) >> + ; /* Empty! Find the shift offset */ >> + if (abs(pendbc - (1 << i)) < abs(pendbc - (1 << (i - 1)))) >> + pendbc = i; >> + else >> + pendbc = i - 1; >> + >> + if (st->caps.has_tsmr) { >> + reg |= AT91_ADC_TSMR_TSAV_(st->ts_filter_average) >> + & AT91_ADC_TSMR_TSAV; >> + reg |= AT91_ADC_TSMR_PENDBC_(pendbc) & AT91_ADC_TSMR_PENDBC; >> + reg |= AT91_ADC_TSMR_NOTSDMA; >> + reg |= AT91_ADC_TSMR_PENDET_ENA; >> + reg |= 0x03 << 8; /* TSFREQ, need bigger than TSAV */ >> + >> + at91_adc_writel(st, AT91_ADC_TSMR, reg); >> + } else { >> + /* TODO: for 9g45 which has no TSMR */ >> + } >> + >> + /* Change adc internal resistor value for better pen detection, >> + * default value is 100 kOhm. >> + * 0 = 200 kOhm, 1 = 150 kOhm, 2 = 100 kOhm, 3 = 50 kOhm >> + * option only available on ES2 and higher >> + */ >> + at91_adc_writel(st, AT91_ADC_ACR, st->ts_pen_detect_sensitivity >> + & AT91_ADC_ACR_PENDETSENS); >> + >> + /* Sample Peroid Time = (TRGPER + 1) / ADCClock */ >> + st->ts_sample_period_val = round_up((st->ts_sample_period_time * >> + adc_clk_khz / 1000) - 1, 1); >> + >> + return 0; >> +} >> + >> +static int at91_ts_register(struct at91_adc_state *st) >> +{ >> + struct input_dev *input; >> + struct iio_dev *idev = iio_priv_to_dev(st); >> + int ret; >> + >> + input = input_allocate_device(); >> + if (!input) { >> + dev_err(&idev->dev, "Failed to allocate TS device!\n"); >> + return -ENOMEM; >> + } >> + >> + input->name = DRIVER_NAME; >> + input->id.bustype = BUS_HOST; >> + input->dev.parent = idev->dev.parent; >> + input->open = atmel_ts_open; >> + input->close = atmel_ts_close; >> + >> + __set_bit(EV_ABS, input->evbit); >> + __set_bit(EV_KEY, input->evbit); >> + __set_bit(BTN_TOUCH, input->keybit); >> + input_set_abs_params(input, ABS_X, 0, (1 << MAX_POS_BITS) - 1, 0, 0); >> + input_set_abs_params(input, ABS_Y, 0, (1 << MAX_POS_BITS) - 1, 0, 0); >> + input_set_abs_params(input, ABS_PRESSURE, 0, 0xffffff, 0, 0); >> + >> + st->ts_input = input; >> + input_set_drvdata(input, st); >> + >> + ret = input_register_device(input); >> + if (ret) >> + input_free_device(st->ts_input); >> + >> + return ret; >> +} >> + >> +static void at91_ts_unregister(struct at91_adc_state *st) >> +{ >> + input_unregister_device(st->ts_input); >> + input_free_device(st->ts_input); >> +} >> + >> /* >> * Since atmel adc support different ip for touchscreen mode. Through the >> * IP check, we will know the touchscreen capbilities. >> @@ -610,6 +920,7 @@ static void atmel_adc_get_cap(struct at91_adc_state *st) >> /* keep only major version number */ >> switch (version & 0xf00) { >> case 0x500: /* SAMA5D3 */ >> + st->caps.has_12bits_xy = 1; >> case 0x400: /* AT91SAM9X5/9N12 */ >> st->caps.has_tsmr = 1; >> st->caps.mr_startup_mask = AT91_ADC_STARTUP; >> @@ -683,7 +994,7 @@ static int at91_adc_probe(struct platform_device *pdev) >> at91_adc_writel(st, AT91_ADC_CR, AT91_ADC_SWRST); >> at91_adc_writel(st, AT91_ADC_IDR, 0xFFFFFFFF); >> ret = request_irq(st->irq, >> - at91_adc_eoc_trigger, >> + at91_adc_interrupt, >> 0, >> pdev->dev.driver->name, >> idev); >> @@ -731,6 +1042,10 @@ static int at91_adc_probe(struct platform_device *pdev) >> adc_clk = st->adc_clk_rate ? >> st->adc_clk_rate : clk_get_rate(st->adc_clk); >> adc_clk_khz = adc_clk / 1000; >> + >> + dev_dbg(&pdev->dev, "Master clock is set as: %d Hz, adc_clk should set as: %d Hz\n", >> + mstrclk, adc_clk); >> + >> prsc = (mstrclk / (2 * adc_clk)) - 1; >> >> if (!st->startup_time) { >> @@ -799,30 +1114,52 @@ static int at91_adc_probe(struct platform_device *pdev) >> init_waitqueue_head(&st->wq_data_avail); >> mutex_init(&st->lock); >> >> - ret = at91_adc_buffer_init(idev); >> - if (ret < 0) { >> - dev_err(&pdev->dev, "Couldn't initialize the buffer.\n"); >> - goto error_disable_adc_clk; >> - } >> + /* >> + * Since touch screen will set trigger register as period trigger. So >> + * when touch screen is enabled, then we have to disable hardware >> + * trigger for classic adc. >> + */ >> + if (!st->touchscreen_type) { >> + ret = at91_adc_buffer_init(idev); >> + if (ret < 0) { >> + dev_err(&pdev->dev, "Couldn't initialize the buffer.\n"); >> + goto error_disable_adc_clk; >> + } >> >> - ret = at91_adc_trigger_init(idev); >> - if (ret < 0) { >> - dev_err(&pdev->dev, "Couldn't setup the triggers.\n"); >> - goto error_unregister_buffer; >> + ret = at91_adc_trigger_init(idev); >> + if (ret < 0) { >> + dev_err(&pdev->dev, "Couldn't setup the triggers.\n"); >> + at91_adc_buffer_remove(idev); >> + goto error_disable_adc_clk; >> + } >> + } else { >> + if (!st->caps.has_tsmr) { >> + dev_err(&pdev->dev, "We don't support non-TSMR adc\n"); >> + goto error_disable_adc_clk; >> + } >> + >> + ret = at91_ts_register(st); >> + if (ret) >> + goto error_disable_adc_clk; >> + >> + at91_ts_hw_init(st, adc_clk_khz); >> } >> >> ret = iio_device_register(idev); >> if (ret < 0) { >> dev_err(&pdev->dev, "Couldn't register the device.\n"); >> - goto error_remove_triggers; >> + goto error_iio_device_register; >> } >> >> return 0; >> >> -error_remove_triggers: >> - at91_adc_trigger_remove(idev); >> -error_unregister_buffer: >> - at91_adc_buffer_remove(idev); >> +error_iio_device_register: >> + if (!st->touchscreen_type) { >> + at91_adc_trigger_remove(idev); >> + at91_adc_buffer_remove(idev); >> + } else { >> + at91_ts_unregister(st); >> + } >> error_disable_adc_clk: >> clk_disable_unprepare(st->adc_clk); >> error_disable_clk: >> @@ -841,8 +1178,12 @@ static int at91_adc_remove(struct platform_device *pdev) >> struct at91_adc_state *st = iio_priv(idev); >> >> iio_device_unregister(idev); >> - at91_adc_trigger_remove(idev); >> - at91_adc_buffer_remove(idev); >> + if (!st->touchscreen_type) { >> + at91_adc_trigger_remove(idev); >> + at91_adc_buffer_remove(idev); >> + } else { >> + at91_ts_unregister(st); >> + } >> clk_disable_unprepare(st->adc_clk); >> clk_disable_unprepare(st->clk); >> free_irq(st->irq, idev); >> @@ -861,7 +1202,7 @@ static struct platform_driver at91_adc_driver = { >> .probe = at91_adc_probe, >> .remove = at91_adc_remove, >> .driver = { >> - .name = "at91_adc", >> + .name = DRIVER_NAME, >> .of_match_table = of_match_ptr(at91_adc_dt_ids), >> }, >> }; >> -- >> 1.7.10 >> >> >> _______________________________________________ >> linux-arm-kernel mailing list >> linux-arm-kernel@lists.infradead.org >> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >>
On Thu, Jul 25, 2013 at 08:56:38AM +0100, Josh Wu wrote: > Hi, Dear Mark > > On 7/22/2013 9:17 PM, Mark Rutland wrote: > > On Sun, Jul 14, 2013 at 09:04:29AM +0100, Josh Wu wrote: > >> AT91 ADC hardware integrate touch screen support. So this patch add touch > >> screen support for at91 adc iio driver. > >> To enable touch screen support in adc, you need to add the dt parameters: > >> which type of touch are used? (4 or 5 wires), sample period time, > >> pen detect debounce time, average samples and pen detect resistor. > >> > >> In the meantime, since touch screen will use a interal period trigger of adc, > >> so it is conflict to other hardware triggers. Driver will disable the hardware > >> trigger support if touch screen is enabled. > >> > >> This driver has been tested in AT91SAM9X5-EK and SAMA5D3x-EK. > >> > >> Signed-off-by: Josh Wu <josh.wu@atmel.com> > >> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> > >> --- > >> .../devicetree/bindings/arm/atmel-adc.txt | 13 + > >> arch/arm/mach-at91/include/mach/at91_adc.h | 34 ++ > >> drivers/iio/adc/at91_adc.c | 389 ++++++++++++++++++-- > >> 3 files changed, 412 insertions(+), 24 deletions(-) > >> > >> diff --git a/Documentation/devicetree/bindings/arm/atmel-adc.txt b/Documentation/devicetree/bindings/arm/atmel-adc.txt > >> index 0db2945..925d656 100644 > >> --- a/Documentation/devicetree/bindings/arm/atmel-adc.txt > >> +++ b/Documentation/devicetree/bindings/arm/atmel-adc.txt > >> @@ -29,6 +29,19 @@ Optional properties: > >> - atmel,adc-sample-hold-time: Sample and Hold Time in microseconds > >> - atmel,adc-clock-rate: ADC clock rate. If not specified, use the default > >> adc_op_clk. > >> + - atmel,adc-touchscreen-wires: Number of touch screen wires. Only support > >> + 4 and 5 wires touch screen. > > Are 4 and 5 wire configurations that can exist, or the only ones > > supported by the driver? > > It can be set: > > atmel,adc-touchscreen-wires = <4>; > or > atmel,adc-touchscreen-wires = <5>; > > according to your touch screen. That doesn't answer my question. Is it possible that 3 or 6 wire configurations might exist, for example, even if not supported by this driver? Or does the design of the adc prevent this? Is there any documentation that might make this clearer? > > > > >> + NOTE: when adc touch screen enabled, the adc hardware trigger will be > >> + disabled. Since touch screen will occupied the trigger register. > >> + - atmel,adc-ts-pendet-debounce: Debounce time in microsecond for touch pen > >> + detect. > > For consistency with the adc-touchscreen-wires property, and other > > properties with timing information, how about > > atmel,adc-touchscreen-debounce-delay-us ? > > sound nice to me. Additionally, is this likely to vary from board to board? This feels like configuration that could be done based on the compatible string... > > > > >> + - atmel,adc-ts-sample-period-time: Sample Period Time in microsecond for > >> + touch screen > > Again, please be consistent with ts or touchscreen. It may also be good > > to have -us to make the units explicit (though it does leave the > > property name being quite a mothful): > > > > atmel,adc-touchscreen-sample-period-us ? > > nice. I will use this one. Looking again at the driver code, it looks like a value derived from this eventually gets written to the hardware. Is this a fixed value at integration time, or is this a configuration value? If it's the latter, can the driver not derive a good value for this itself? > > > > >> + - atmel,adc-ts-filter-average: Numbers of sampling data will be averaged. > >> + 0 means no average. 1 means average two samples. 2 means average four > >> + samples. 3 means average eight samples. > > Is this averaging done in the hardware, or the kernel driver? > > It is done in the hardware. Similarly, this seems to eventually get written to hardware, and thus seems more like configuration than hardware description. Why does this need to be in the DT? As an aside, in general it's nicer to describe a property as a logical value rather than the raw value that gets programmed into hardware (e.g. this property could by 2, 4, or 8 rather than 1, 2, or 4). > But for some soc, like AT91SAM9G45, hardware doesn't support hardware > average. > So I am wondering use it as for both hardware and softer average. > > BTW, you mentioned the kernel driver, do you mean a filter algorithm is > already implemented in kernel library? I do not know of any such filter algorithm in the kernel, though there may be one. I was simply confused as to what this was used for. > > > > > If it's the latter, this can be left for the kernel to decide. > > > >> + - atmel,adc-ts-pendet-sensitivity: Pen Detection input pull-up resistor. > >> + It can be 0, 1, 2, 3. > > I think "pendet" is a bit opaque. "pen-detect" may be better. > > yes. I'll change this. > > > What > > physical property does this represent (are these discrete values, or an > > enumeration)? > > This property is supported by hardware, it can change the adc internal > resistor value for better pen detection, > * 0 = 200 kOhm, 1 = 150 kOhm, 2 = 100 kOhm, 3 = 50 kOhm > In general, we just use default value 2 for 100kOhm. This value eventually gets written to hardware, and seems more like configuration than hardware description. Why does this need to be in the DT? Thanks, Mark. > I think I need add more detail infomation in the dt document. > > Thanks again, > Best Regards, > Josh Wu > > > > > Thanks, > > Mark. > > > >> Optional trigger Nodes: > >> - Required properties: > >> diff --git a/arch/arm/mach-at91/include/mach/at91_adc.h b/arch/arm/mach-at91/include/mach/at91_adc.h > >> index ab273ee..6d6cc14 100644 > >> --- a/arch/arm/mach-at91/include/mach/at91_adc.h > >> +++ b/arch/arm/mach-at91/include/mach/at91_adc.h > >> @@ -57,10 +57,44 @@ > >> #define AT91_ADC_IER 0x24 /* Interrupt Enable Register */ > >> #define AT91_ADC_IDR 0x28 /* Interrupt Disable Register */ > >> #define AT91_ADC_IMR 0x2C /* Interrupt Mask Register */ > >> +#define AT91_ADC_IER_PEN (1 << 29) > >> +#define AT91_ADC_IER_NOPEN (1 << 30) > >> +#define AT91_ADC_IER_XRDY (1 << 20) > >> +#define AT91_ADC_IER_YRDY (1 << 21) > >> +#define AT91_ADC_IER_PRDY (1 << 22) > >> +#define AT91_ADC_ISR_PENS (1 << 31) > >> > >> #define AT91_ADC_CHR(n) (0x30 + ((n) * 4)) /* Channel Data Register N */ > >> #define AT91_ADC_DATA (0x3ff) > >> > >> +#define AT91_ADC_ACR 0x94 /* Analog Control Register */ > >> +#define AT91_ADC_ACR_PENDETSENS (0x3 << 0) /* pull-up resistor */ > >> + > >> +#define AT91_ADC_TSMR 0xB0 > >> +#define AT91_ADC_TSMR_TSMODE (3 << 0) /* Touch Screen Mode */ > >> +#define AT91_ADC_TSMR_TSMODE_NONE (0 << 0) > >> +#define AT91_ADC_TSMR_TSMODE_4WIRE_NO_PRESS (1 << 0) > >> +#define AT91_ADC_TSMR_TSMODE_4WIRE_PRESS (2 << 0) > >> +#define AT91_ADC_TSMR_TSMODE_5WIRE (3 << 0) > >> +#define AT91_ADC_TSMR_TSAV (3 << 4) /* Averages samples */ > >> +#define AT91_ADC_TSMR_TSAV_(x) ((x) << 4) > >> +#define AT91_ADC_TSMR_SCTIM (0x0f << 16) /* Switch closure time */ > >> +#define AT91_ADC_TSMR_PENDBC (0x0f << 28) /* Pen Debounce time */ > >> +#define AT91_ADC_TSMR_PENDBC_(x) ((x) << 28) > >> +#define AT91_ADC_TSMR_NOTSDMA (1 << 22) /* No Touchscreen DMA */ > >> +#define AT91_ADC_TSMR_PENDET_DIS (0 << 24) /* Pen contact detection disable */ > >> +#define AT91_ADC_TSMR_PENDET_ENA (1 << 24) /* Pen contact detection enable */ > >> + > >> +#define AT91_ADC_TSXPOSR 0xB4 > >> +#define AT91_ADC_TSYPOSR 0xB8 > >> +#define AT91_ADC_TSPRESSR 0xBC > >> + > >> #define AT91_ADC_VERSION 0xFC > >> > >> +/* Trigger Register bit field */ > >> +#define AT91_ADC_TRGR_TRGPER (0xffff << 16) > >> +#define AT91_ADC_TRGR_TRGPER_(x) ((x) << 16) > >> +#define AT91_ADC_TRGR_TRGMOD (0x7 << 0) > >> +#define AT91_ADC_TRGR_MOD_PERIOD_TRIG (5 << 0) > >> + > >> #endif > >> diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c > >> index 8f1386f..ffc0e42 100644 > >> --- a/drivers/iio/adc/at91_adc.c > >> +++ b/drivers/iio/adc/at91_adc.c > >> @@ -11,6 +11,7 @@ > >> #include <linux/clk.h> > >> #include <linux/err.h> > >> #include <linux/io.h> > >> +#include <linux/input.h> > >> #include <linux/interrupt.h> > >> #include <linux/jiffies.h> > >> #include <linux/kernel.h> > >> @@ -39,12 +40,24 @@ > >> #define at91_adc_writel(st, reg, val) \ > >> (writel_relaxed(val, st->reg_base + reg)) > >> > >> +#define DRIVER_NAME "at91_adc" > >> +#define MAX_POS_BITS 12 > >> + > >> +#define ZTHRESHOLD 9000 > >> + > >> struct at91_adc_caps { > >> + bool has_12bits_xy; /* true means use 12 bits. Otherwise 10 bits */ > >> bool has_tsmr; /* only at91sam9x5, sama5d3 have TSMR reg */ > >> u32 mr_prescal_mask; > >> u32 mr_startup_mask; > >> }; > >> > >> +enum atmel_adc_ts_type { > >> + ATMEL_ADC_TOUCHSCREEN_NONE = 0, > >> + ATMEL_ADC_TOUCHSCREEN_4WIRE, > >> + ATMEL_ADC_TOUCHSCREEN_5WIRE, > >> +}; > >> + > >> struct at91_adc_state { > >> struct clk *adc_clk; > >> u32 adc_clk_rate; > >> @@ -70,6 +83,29 @@ struct at91_adc_state { > >> bool low_res; /* the resolution corresponds to the lowest one */ > >> wait_queue_head_t wq_data_avail; > >> struct at91_adc_caps caps; > >> + > >> + /* > >> + * Following ADC channels are shared by touchscreen: > >> + * > >> + * CH0 -- Touch screen XP/UL > >> + * CH1 -- Touch screen XM/UR > >> + * CH2 -- Touch screen YP/LL > >> + * CH3 -- Touch screen YM/Sense > >> + * CH4 -- Touch screen LR(5-wire only) > >> + * > >> + * The bitfields below represents the reserved channel in the > >> + * touchscreen mode. > >> + */ > >> +#define CHAN_MASK_TOUCHSCREEN_4WIRE (0xf << 0) > >> +#define CHAN_MASK_TOUCHSCREEN_5WIRE (0x1f << 0) > >> + enum atmel_adc_ts_type touchscreen_type; > >> + struct input_dev *ts_input; > >> + > >> + u8 ts_filter_average; > >> + u16 ts_pen_detect_debounce; > >> + u8 ts_pen_detect_sensitivity; > >> + u16 ts_sample_period_time; > >> + u16 ts_sample_period_val; > >> }; > >> > >> static irqreturn_t at91_adc_trigger_handler(int irq, void *p) > >> @@ -104,14 +140,10 @@ static irqreturn_t at91_adc_trigger_handler(int irq, void *p) > >> return IRQ_HANDLED; > >> } > >> > >> -static irqreturn_t at91_adc_eoc_trigger(int irq, void *private) > >> +/* Handler for classic adc channel eoc trigger */ > >> +void handle_adc_eoc_trigger(int irq, struct iio_dev *idev) > >> { > >> - struct iio_dev *idev = private; > >> struct at91_adc_state *st = iio_priv(idev); > >> - u32 status = at91_adc_readl(st, st->registers->status_register); > >> - > >> - if (!(status & st->registers->drdy_mask)) > >> - return IRQ_HANDLED; > >> > >> if (iio_buffer_enabled(idev)) { > >> disable_irq_nosync(irq); > >> @@ -121,6 +153,115 @@ static irqreturn_t at91_adc_eoc_trigger(int irq, void *private) > >> st->done = true; > >> wake_up_interruptible(&st->wq_data_avail); > >> } > >> +} > >> + > >> +static int at91_ts_sample(struct at91_adc_state *st) > >> +{ > >> + unsigned int xscale, yscale, reg, z1, z2; > >> + unsigned int x, y, pres, xpos, ypos; > >> + unsigned int rxp = 1; > >> + unsigned int factor = 1000; > >> + struct iio_dev *idev = iio_priv_to_dev(st); > >> + > >> + unsigned int xyz_mask_bits = st->caps.has_12bits_xy ? 12 : 10; > >> + unsigned int xyz_mask = (1 << xyz_mask_bits) - 1; > >> + > >> + /* calculate position */ > >> + /* x position = (x / xscale) * max, max = 2^MAX_POS_BITS - 1 */ > >> + reg = at91_adc_readl(st, AT91_ADC_TSXPOSR); > >> + xpos = reg & xyz_mask; > >> + x = (xpos << MAX_POS_BITS) - xpos; > >> + xscale = (reg >> 16) & xyz_mask; > >> + if (xscale != 0) > >> + x /= xscale; > >> + else > >> + dev_err(&idev->dev, "xscale == 0!!!\n"); > >> + > >> + /* y position = (y / yscale) * max, max = 2^MAX_POS_BITS - 1 */ > >> + reg = at91_adc_readl(st, AT91_ADC_TSYPOSR); > >> + ypos = reg & xyz_mask; > >> + y = (ypos << MAX_POS_BITS) - ypos; > >> + yscale = (reg >> 16) & xyz_mask; > >> + if (yscale != 0) > >> + y /= yscale; > >> + else > >> + dev_err(&idev->dev, "yscale == 0!!!\n"); > >> + > >> + /* calculate the pressure */ > >> + reg = at91_adc_readl(st, AT91_ADC_TSPRESSR); > >> + z1 = reg & xyz_mask; > >> + z2 = (reg >> 16) & xyz_mask; > >> + > >> + if (z1 != 0) > >> + pres = rxp * (x * factor / 1024) * (z2 * factor / z1 - factor) > >> + / factor; > >> + else > >> + pres = ZTHRESHOLD; /* no pen contacted */ > >> + > >> + dev_dbg(&idev->dev, "xpos = %d, xscale = %d, ypos = %d, yscale = %d, z1 = %d, z2 = %d, press = %d\n", > >> + xpos, xscale, ypos, yscale, z1, z2, pres); > >> + > >> + if (pres < ZTHRESHOLD) { > >> + dev_dbg(&idev->dev, "x = %d, y = %d, pressure = %d\n", > >> + x, y, pres / factor); > >> + input_report_abs(st->ts_input, ABS_X, x); > >> + input_report_abs(st->ts_input, ABS_Y, y); > >> + input_report_abs(st->ts_input, ABS_PRESSURE, pres); > >> + input_report_key(st->ts_input, BTN_TOUCH, 1); > >> + input_sync(st->ts_input); > >> + } else { > >> + dev_dbg(&idev->dev, > >> + "pressure too low: not reporting\n"); > >> + } > >> + > >> + return 0; > >> +} > >> + > >> + > >> +static irqreturn_t at91_adc_interrupt(int irq, void *private) > >> +{ > >> + struct iio_dev *idev = private; > >> + struct at91_adc_state *st = iio_priv(idev); > >> + u32 status = at91_adc_readl(st, st->registers->status_register); > >> + const uint32_t ts_data_irq_mask = > >> + AT91_ADC_IER_XRDY | > >> + AT91_ADC_IER_YRDY | > >> + AT91_ADC_IER_PRDY; > >> + > >> + if (status & st->registers->drdy_mask) > >> + handle_adc_eoc_trigger(irq, idev); > >> + > >> + if (status & AT91_ADC_IER_PEN) { > >> + at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN); > >> + at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_NOPEN | > >> + ts_data_irq_mask); > >> + /* Set up period trigger for sampling */ > >> + at91_adc_writel(st, st->registers->trigger_register, > >> + AT91_ADC_TRGR_MOD_PERIOD_TRIG | > >> + AT91_ADC_TRGR_TRGPER_(st->ts_sample_period_val)); > >> + } else if (status & AT91_ADC_IER_NOPEN) { > >> + at91_adc_writel(st, st->registers->trigger_register, 0); > >> + at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_NOPEN | > >> + ts_data_irq_mask); > >> + at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN); > >> + > >> + input_report_key(st->ts_input, BTN_TOUCH, 0); > >> + input_sync(st->ts_input); > >> + } else if ((status & ts_data_irq_mask) == ts_data_irq_mask) { > >> + /* Now all touchscreen data is ready */ > >> + > >> + if (status & AT91_ADC_ISR_PENS) { > >> + /* validate data by pen contact */ > >> + at91_ts_sample(st); > >> + } else { > >> + /* triggered by event that is no pen contact, just read > >> + * them to clean the interrupt and discard all. > >> + */ > >> + at91_adc_readl(st, AT91_ADC_TSXPOSR); > >> + at91_adc_readl(st, AT91_ADC_TSYPOSR); > >> + at91_adc_readl(st, AT91_ADC_TSPRESSR); > >> + } > >> + } > >> > >> return IRQ_HANDLED; > >> } > >> @@ -130,6 +271,16 @@ static int at91_adc_channel_init(struct iio_dev *idev) > >> struct at91_adc_state *st = iio_priv(idev); > >> struct iio_chan_spec *chan_array, *timestamp; > >> int bit, idx = 0; > >> + unsigned long rsvd_mask = 0; > >> + > >> + /* If touchscreen is enable, then reserve the adc channels */ > >> + if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_4WIRE) > >> + rsvd_mask = CHAN_MASK_TOUCHSCREEN_4WIRE; > >> + else if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_5WIRE) > >> + rsvd_mask = CHAN_MASK_TOUCHSCREEN_5WIRE; > >> + > >> + /* set up the channel mask to reserve touchscreen channels */ > >> + st->channels_mask &= ~rsvd_mask; > >> > >> idev->num_channels = bitmap_weight(&st->channels_mask, > >> st->num_channels) + 1; > >> @@ -561,6 +712,57 @@ static int at91_adc_probe_dt(struct at91_adc_state *st, > >> i++; > >> } > >> > >> + /* Check if touchscreen is enabled in DT. */ > >> + ret = of_property_read_u32(node, "atmel,adc-touchscreen-wires", &prop); > >> + if (ret) > >> + dev_info(&idev->dev, "Touchscreen not enabled.\n"); > >> + else if (prop == 4) > >> + st->touchscreen_type = ATMEL_ADC_TOUCHSCREEN_4WIRE; > >> + else if (prop == 5) > >> + st->touchscreen_type = ATMEL_ADC_TOUCHSCREEN_5WIRE; > >> + else > >> + dev_warn(&idev->dev, "Unsupported number of touchscreen wires (%d)\n", > >> + prop); > >> + > >> + if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_NONE) > >> + return 0; > >> + > >> + /* Touch screen is enabled, so check touch screen dt parameters */ > >> + if (of_property_read_u32(node, "atmel,adc-ts-filter-average", &prop)) { > >> + dev_err(&idev->dev, "Missing atmel,adc-ts-filtering-average property in the DT.\n"); > >> + ret = -EINVAL; > >> + goto error_ret; > >> + } > >> + st->ts_filter_average = prop; > >> + if (st->ts_filter_average > 3) { > >> + dev_err(&idev->dev, "Invalid atmel,adc-ts-filtering-average property in the DT.\n"); > >> + ret = -EINVAL; > >> + goto error_ret; > >> + } > >> + > >> + prop = 0; > >> + of_property_read_u32(node, "atmel,adc-ts-pendet-debounce", &prop); > >> + st->ts_pen_detect_debounce = prop; > >> + > >> + /* default sample period is 2ms. The real touch sample period should be > >> + * this period * TSFREQ. > >> + */ > >> + prop = 2000; > >> + of_property_read_u32(node, "atmel,adc-ts-sample-period-time", &prop); > >> + st->ts_sample_period_time = prop; > >> + > >> + if (of_property_read_u32(node, "atmel,adc-ts-pendet-sensitivity", &prop)) { > >> + dev_err(&idev->dev, "Missing atmel,adc-ts-pendet-sensitivity property in the DT.\n"); > >> + ret = -EINVAL; > >> + goto error_ret; > >> + } > >> + st->ts_pen_detect_sensitivity = prop; > >> + if (st->ts_pen_detect_sensitivity > 3) { > >> + dev_err(&idev->dev, "Invalid atmel,adc-ts-pendet-sensitivity property in the DT.\n"); > >> + ret = -EINVAL; > >> + goto error_ret; > >> + } > >> + > >> return 0; > >> > >> error_ret: > >> @@ -592,6 +794,114 @@ static const struct iio_info at91_adc_info = { > >> .read_raw = &at91_adc_read_raw, > >> }; > >> > >> +/* Touchscreen related functions */ > >> +static int atmel_ts_open(struct input_dev *dev) > >> +{ > >> + struct at91_adc_state *st = input_get_drvdata(dev); > >> + > >> + at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN); > >> + return 0; > >> +} > >> + > >> +static void atmel_ts_close(struct input_dev *dev) > >> +{ > >> + struct at91_adc_state *st = input_get_drvdata(dev); > >> + > >> + at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN); > >> +} > >> + > >> +static int at91_ts_hw_init(struct at91_adc_state *st, u32 adc_clk_khz) > >> +{ > >> + u32 reg = 0, pendbc; > >> + int i = 0; > >> + > >> + if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_4WIRE) > >> + reg = AT91_ADC_TSMR_TSMODE_4WIRE_PRESS; > >> + else > >> + reg = AT91_ADC_TSMR_TSMODE_5WIRE; > >> + > >> + /* a Pen Detect Debounce Time is necessary for the ADC Touch to avoid > >> + * pen detect noise. > >> + * The formula is : Pen Detect Debounce Time = (2 ^ pendbc) / ADCClock > >> + */ > >> + pendbc = round_up(st->ts_pen_detect_debounce * adc_clk_khz / 1000, 1); > >> + > >> + while (pendbc >> ++i) > >> + ; /* Empty! Find the shift offset */ > >> + if (abs(pendbc - (1 << i)) < abs(pendbc - (1 << (i - 1)))) > >> + pendbc = i; > >> + else > >> + pendbc = i - 1; > >> + > >> + if (st->caps.has_tsmr) { > >> + reg |= AT91_ADC_TSMR_TSAV_(st->ts_filter_average) > >> + & AT91_ADC_TSMR_TSAV; > >> + reg |= AT91_ADC_TSMR_PENDBC_(pendbc) & AT91_ADC_TSMR_PENDBC; > >> + reg |= AT91_ADC_TSMR_NOTSDMA; > >> + reg |= AT91_ADC_TSMR_PENDET_ENA; > >> + reg |= 0x03 << 8; /* TSFREQ, need bigger than TSAV */ > >> + > >> + at91_adc_writel(st, AT91_ADC_TSMR, reg); > >> + } else { > >> + /* TODO: for 9g45 which has no TSMR */ > >> + } > >> + > >> + /* Change adc internal resistor value for better pen detection, > >> + * default value is 100 kOhm. > >> + * 0 = 200 kOhm, 1 = 150 kOhm, 2 = 100 kOhm, 3 = 50 kOhm > >> + * option only available on ES2 and higher > >> + */ > >> + at91_adc_writel(st, AT91_ADC_ACR, st->ts_pen_detect_sensitivity > >> + & AT91_ADC_ACR_PENDETSENS); > >> + > >> + /* Sample Peroid Time = (TRGPER + 1) / ADCClock */ > >> + st->ts_sample_period_val = round_up((st->ts_sample_period_time * > >> + adc_clk_khz / 1000) - 1, 1); > >> + > >> + return 0; > >> +} > >> + > >> +static int at91_ts_register(struct at91_adc_state *st) > >> +{ > >> + struct input_dev *input; > >> + struct iio_dev *idev = iio_priv_to_dev(st); > >> + int ret; > >> + > >> + input = input_allocate_device(); > >> + if (!input) { > >> + dev_err(&idev->dev, "Failed to allocate TS device!\n"); > >> + return -ENOMEM; > >> + } > >> + > >> + input->name = DRIVER_NAME; > >> + input->id.bustype = BUS_HOST; > >> + input->dev.parent = idev->dev.parent; > >> + input->open = atmel_ts_open; > >> + input->close = atmel_ts_close; > >> + > >> + __set_bit(EV_ABS, input->evbit); > >> + __set_bit(EV_KEY, input->evbit); > >> + __set_bit(BTN_TOUCH, input->keybit); > >> + input_set_abs_params(input, ABS_X, 0, (1 << MAX_POS_BITS) - 1, 0, 0); > >> + input_set_abs_params(input, ABS_Y, 0, (1 << MAX_POS_BITS) - 1, 0, 0); > >> + input_set_abs_params(input, ABS_PRESSURE, 0, 0xffffff, 0, 0); > >> + > >> + st->ts_input = input; > >> + input_set_drvdata(input, st); > >> + > >> + ret = input_register_device(input); > >> + if (ret) > >> + input_free_device(st->ts_input); > >> + > >> + return ret; > >> +} > >> + > >> +static void at91_ts_unregister(struct at91_adc_state *st) > >> +{ > >> + input_unregister_device(st->ts_input); > >> + input_free_device(st->ts_input); > >> +} > >> + > >> /* > >> * Since atmel adc support different ip for touchscreen mode. Through the > >> * IP check, we will know the touchscreen capbilities. > >> @@ -610,6 +920,7 @@ static void atmel_adc_get_cap(struct at91_adc_state *st) > >> /* keep only major version number */ > >> switch (version & 0xf00) { > >> case 0x500: /* SAMA5D3 */ > >> + st->caps.has_12bits_xy = 1; > >> case 0x400: /* AT91SAM9X5/9N12 */ > >> st->caps.has_tsmr = 1; > >> st->caps.mr_startup_mask = AT91_ADC_STARTUP; > >> @@ -683,7 +994,7 @@ static int at91_adc_probe(struct platform_device *pdev) > >> at91_adc_writel(st, AT91_ADC_CR, AT91_ADC_SWRST); > >> at91_adc_writel(st, AT91_ADC_IDR, 0xFFFFFFFF); > >> ret = request_irq(st->irq, > >> - at91_adc_eoc_trigger, > >> + at91_adc_interrupt, > >> 0, > >> pdev->dev.driver->name, > >> idev); > >> @@ -731,6 +1042,10 @@ static int at91_adc_probe(struct platform_device *pdev) > >> adc_clk = st->adc_clk_rate ? > >> st->adc_clk_rate : clk_get_rate(st->adc_clk); > >> adc_clk_khz = adc_clk / 1000; > >> + > >> + dev_dbg(&pdev->dev, "Master clock is set as: %d Hz, adc_clk should set as: %d Hz\n", > >> + mstrclk, adc_clk); > >> + > >> prsc = (mstrclk / (2 * adc_clk)) - 1; > >> > >> if (!st->startup_time) { > >> @@ -799,30 +1114,52 @@ static int at91_adc_probe(struct platform_device *pdev) > >> init_waitqueue_head(&st->wq_data_avail); > >> mutex_init(&st->lock); > >> > >> - ret = at91_adc_buffer_init(idev); > >> - if (ret < 0) { > >> - dev_err(&pdev->dev, "Couldn't initialize the buffer.\n"); > >> - goto error_disable_adc_clk; > >> - } > >> + /* > >> + * Since touch screen will set trigger register as period trigger. So > >> + * when touch screen is enabled, then we have to disable hardware > >> + * trigger for classic adc. > >> + */ > >> + if (!st->touchscreen_type) { > >> + ret = at91_adc_buffer_init(idev); > >> + if (ret < 0) { > >> + dev_err(&pdev->dev, "Couldn't initialize the buffer.\n"); > >> + goto error_disable_adc_clk; > >> + } > >> > >> - ret = at91_adc_trigger_init(idev); > >> - if (ret < 0) { > >> - dev_err(&pdev->dev, "Couldn't setup the triggers.\n"); > >> - goto error_unregister_buffer; > >> + ret = at91_adc_trigger_init(idev); > >> + if (ret < 0) { > >> + dev_err(&pdev->dev, "Couldn't setup the triggers.\n"); > >> + at91_adc_buffer_remove(idev); > >> + goto error_disable_adc_clk; > >> + } > >> + } else { > >> + if (!st->caps.has_tsmr) { > >> + dev_err(&pdev->dev, "We don't support non-TSMR adc\n"); > >> + goto error_disable_adc_clk; > >> + } > >> + > >> + ret = at91_ts_register(st); > >> + if (ret) > >> + goto error_disable_adc_clk; > >> + > >> + at91_ts_hw_init(st, adc_clk_khz); > >> } > >> > >> ret = iio_device_register(idev); > >> if (ret < 0) { > >> dev_err(&pdev->dev, "Couldn't register the device.\n"); > >> - goto error_remove_triggers; > >> + goto error_iio_device_register; > >> } > >> > >> return 0; > >> > >> -error_remove_triggers: > >> - at91_adc_trigger_remove(idev); > >> -error_unregister_buffer: > >> - at91_adc_buffer_remove(idev); > >> +error_iio_device_register: > >> + if (!st->touchscreen_type) { > >> + at91_adc_trigger_remove(idev); > >> + at91_adc_buffer_remove(idev); > >> + } else { > >> + at91_ts_unregister(st); > >> + } > >> error_disable_adc_clk: > >> clk_disable_unprepare(st->adc_clk); > >> error_disable_clk: > >> @@ -841,8 +1178,12 @@ static int at91_adc_remove(struct platform_device *pdev) > >> struct at91_adc_state *st = iio_priv(idev); > >> > >> iio_device_unregister(idev); > >> - at91_adc_trigger_remove(idev); > >> - at91_adc_buffer_remove(idev); > >> + if (!st->touchscreen_type) { > >> + at91_adc_trigger_remove(idev); > >> + at91_adc_buffer_remove(idev); > >> + } else { > >> + at91_ts_unregister(st); > >> + } > >> clk_disable_unprepare(st->adc_clk); > >> clk_disable_unprepare(st->clk); > >> free_irq(st->irq, idev); > >> @@ -861,7 +1202,7 @@ static struct platform_driver at91_adc_driver = { > >> .probe = at91_adc_probe, > >> .remove = at91_adc_remove, > >> .driver = { > >> - .name = "at91_adc", > >> + .name = DRIVER_NAME, > >> .of_match_table = of_match_ptr(at91_adc_dt_ids), > >> }, > >> }; > >> -- > >> 1.7.10 > >> > >> > >> _______________________________________________ > >> linux-arm-kernel mailing list > >> linux-arm-kernel@lists.infradead.org > >> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel > >> > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >
Dear Mark Thanks for the detailed comment. Check mine in below: On 7/26/2013 12:45 AM, Mark Rutland wrote: > On Thu, Jul 25, 2013 at 08:56:38AM +0100, Josh Wu wrote: >> Hi, Dear Mark >> >> On 7/22/2013 9:17 PM, Mark Rutland wrote: >>> On Sun, Jul 14, 2013 at 09:04:29AM +0100, Josh Wu wrote: >>>> AT91 ADC hardware integrate touch screen support. So this patch add touch >>>> screen support for at91 adc iio driver. >>>> To enable touch screen support in adc, you need to add the dt parameters: >>>> which type of touch are used? (4 or 5 wires), sample period time, >>>> pen detect debounce time, average samples and pen detect resistor. >>>> >>>> In the meantime, since touch screen will use a interal period trigger of adc, >>>> so it is conflict to other hardware triggers. Driver will disable the hardware >>>> trigger support if touch screen is enabled. >>>> >>>> This driver has been tested in AT91SAM9X5-EK and SAMA5D3x-EK. >>>> >>>> Signed-off-by: Josh Wu <josh.wu@atmel.com> >>>> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> >>>> --- >>>> .../devicetree/bindings/arm/atmel-adc.txt | 13 + >>>> arch/arm/mach-at91/include/mach/at91_adc.h | 34 ++ >>>> drivers/iio/adc/at91_adc.c | 389 ++++++++++++++++++-- >>>> 3 files changed, 412 insertions(+), 24 deletions(-) >>>> >>>> diff --git a/Documentation/devicetree/bindings/arm/atmel-adc.txt b/Documentation/devicetree/bindings/arm/atmel-adc.txt >>>> index 0db2945..925d656 100644 >>>> --- a/Documentation/devicetree/bindings/arm/atmel-adc.txt >>>> +++ b/Documentation/devicetree/bindings/arm/atmel-adc.txt >>>> @@ -29,6 +29,19 @@ Optional properties: >>>> - atmel,adc-sample-hold-time: Sample and Hold Time in microseconds >>>> - atmel,adc-clock-rate: ADC clock rate. If not specified, use the default >>>> adc_op_clk. >>>> + - atmel,adc-touchscreen-wires: Number of touch screen wires. Only support >>>> + 4 and 5 wires touch screen. >>> Are 4 and 5 wire configurations that can exist, or the only ones >>> supported by the driver? >> It can be set: >> >> atmel,adc-touchscreen-wires = <4>; >> or >> atmel,adc-touchscreen-wires = <5>; >> >> according to your touch screen. > That doesn't answer my question. > > Is it possible that 3 or 6 wire configurations might exist, for example, > even if not supported by this driver? Or does the design of the adc > prevent this? No, only 4-wire or 5-wire touch screen support in market so far. > > Is there any documentation that might make this clearer? > >>>> + NOTE: when adc touch screen enabled, the adc hardware trigger will be >>>> + disabled. Since touch screen will occupied the trigger register. >>>> + - atmel,adc-ts-pendet-debounce: Debounce time in microsecond for touch pen >>>> + detect. >>> For consistency with the adc-touchscreen-wires property, and other >>> properties with timing information, how about >>> atmel,adc-touchscreen-debounce-delay-us ? >> sound nice to me. > Additionally, is this likely to vary from board to board? This feels > like configuration that could be done based on the compatible string... > >>>> + - atmel,adc-ts-sample-period-time: Sample Period Time in microsecond for >>>> + touch screen >>> Again, please be consistent with ts or touchscreen. It may also be good >>> to have -us to make the units explicit (though it does leave the >>> property name being quite a mothful): >>> >>> atmel,adc-touchscreen-sample-period-us ? >> nice. I will use this one. > Looking again at the driver code, it looks like a value derived from > this eventually gets written to the hardware. Is this a fixed value at > integration time, or is this a configuration value? If it's the latter, > can the driver not derive a good value for this itself? After a further thinking, I think it is better to remove this sample period us & pen detect debouce us. Since it is a fixed value and no need to change it so far (in at91sam9x5ek, sama5d3xek). > >>>> + - atmel,adc-ts-filter-average: Numbers of sampling data will be averaged. >>>> + 0 means no average. 1 means average two samples. 2 means average four >>>> + samples. 3 means average eight samples. >>> Is this averaging done in the hardware, or the kernel driver? >> It is done in the hardware. > Similarly, this seems to eventually get written to hardware, and thus > seems more like configuration than hardware description. Why does this > need to be in the DT? > > As an aside, in general it's nicer to describe a property as a logical > value rather than the raw value that gets programmed into hardware (e.g. > this property could by 2, 4, or 8 rather than 1, 2, or 4). > >> But for some soc, like AT91SAM9G45, hardware doesn't support hardware >> average. >> So I am wondering use it as for both hardware and softer average. >> >> BTW, you mentioned the kernel driver, do you mean a filter algorithm is >> already implemented in kernel library? > I do not know of any such filter algorithm in the kernel, though there > may be one. I was simply confused as to what this was used for. > >>> If it's the latter, this can be left for the kernel to decide. >>> >>>> + - atmel,adc-ts-pendet-sensitivity: Pen Detection input pull-up resistor. >>>> + It can be 0, 1, 2, 3. >>> I think "pendet" is a bit opaque. "pen-detect" may be better. >> yes. I'll change this. >> >>> What >>> physical property does this represent (are these discrete values, or an >>> enumeration)? >> This property is supported by hardware, it can change the adc internal >> resistor value for better pen detection, >> * 0 = 200 kOhm, 1 = 150 kOhm, 2 = 100 kOhm, 3 = 50 kOhm >> In general, we just use default value 2 for 100kOhm. > This value eventually gets written to hardware, and seems more like > configuration than hardware description. Why does this need to be in the > DT? I am a little bit confused by the hardware configuration and hardware description. It seems I prefer to put all the hardware configurable value to DT. Since I think this can be changed in DT. But as you mentioned above, only the hardware description can be in DT. Could you give me a more detail about the difference between hardware configuration and hardware description? Thanks in advance. > > Thanks, > Mark. [... ...] Best Regards, Josh Wu
On Tue, Aug 06, 2013 at 11:24:14AM +0100, Josh Wu wrote: > Dear Mark > > Thanks for the detailed comment. Check mine in below: > > On 7/26/2013 12:45 AM, Mark Rutland wrote: > > On Thu, Jul 25, 2013 at 08:56:38AM +0100, Josh Wu wrote: > >> Hi, Dear Mark > >> > >> On 7/22/2013 9:17 PM, Mark Rutland wrote: > >>> On Sun, Jul 14, 2013 at 09:04:29AM +0100, Josh Wu wrote: > >>>> AT91 ADC hardware integrate touch screen support. So this patch add touch > >>>> screen support for at91 adc iio driver. > >>>> To enable touch screen support in adc, you need to add the dt parameters: > >>>> which type of touch are used? (4 or 5 wires), sample period time, > >>>> pen detect debounce time, average samples and pen detect resistor. > >>>> > >>>> In the meantime, since touch screen will use a interal period trigger of adc, > >>>> so it is conflict to other hardware triggers. Driver will disable the hardware > >>>> trigger support if touch screen is enabled. > >>>> > >>>> This driver has been tested in AT91SAM9X5-EK and SAMA5D3x-EK. > >>>> > >>>> Signed-off-by: Josh Wu <josh.wu@atmel.com> > >>>> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> > >>>> --- > >>>> .../devicetree/bindings/arm/atmel-adc.txt | 13 + > >>>> arch/arm/mach-at91/include/mach/at91_adc.h | 34 ++ > >>>> drivers/iio/adc/at91_adc.c | 389 ++++++++++++++++++-- > >>>> 3 files changed, 412 insertions(+), 24 deletions(-) > >>>> > >>>> diff --git a/Documentation/devicetree/bindings/arm/atmel-adc.txt b/Documentation/devicetree/bindings/arm/atmel-adc.txt > >>>> index 0db2945..925d656 100644 > >>>> --- a/Documentation/devicetree/bindings/arm/atmel-adc.txt > >>>> +++ b/Documentation/devicetree/bindings/arm/atmel-adc.txt > >>>> @@ -29,6 +29,19 @@ Optional properties: > >>>> - atmel,adc-sample-hold-time: Sample and Hold Time in microseconds > >>>> - atmel,adc-clock-rate: ADC clock rate. If not specified, use the default > >>>> adc_op_clk. > >>>> + - atmel,adc-touchscreen-wires: Number of touch screen wires. Only support > >>>> + 4 and 5 wires touch screen. > >>> Are 4 and 5 wire configurations that can exist, or the only ones > >>> supported by the driver? > >> It can be set: > >> > >> atmel,adc-touchscreen-wires = <4>; > >> or > >> atmel,adc-touchscreen-wires = <5>; > >> > >> according to your touch screen. > > That doesn't answer my question. > > > > Is it possible that 3 or 6 wire configurations might exist, for example, > > even if not supported by this driver? Or does the design of the adc > > prevent this? > > No, only 4-wire or 5-wire touch screen support in market so far. Ok. The point that I was trying to get at was that "Only support 4 and 5 wires touch screen" seems to be a description of the driver rather than a physical limitation that should limit what we can describe in dt. > > > > > Is there any documentation that might make this clearer? > > > >>>> + NOTE: when adc touch screen enabled, the adc hardware trigger will be > >>>> + disabled. Since touch screen will occupied the trigger register. > >>>> + - atmel,adc-ts-pendet-debounce: Debounce time in microsecond for touch pen > >>>> + detect. > >>> For consistency with the adc-touchscreen-wires property, and other > >>> properties with timing information, how about > >>> atmel,adc-touchscreen-debounce-delay-us ? > >> sound nice to me. > > Additionally, is this likely to vary from board to board? This feels > > like configuration that could be done based on the compatible string... > > > >>>> + - atmel,adc-ts-sample-period-time: Sample Period Time in microsecond for > >>>> + touch screen > >>> Again, please be consistent with ts or touchscreen. It may also be good > >>> to have -us to make the units explicit (though it does leave the > >>> property name being quite a mothful): > >>> > >>> atmel,adc-touchscreen-sample-period-us ? > >> nice. I will use this one. > > Looking again at the driver code, it looks like a value derived from > > this eventually gets written to the hardware. Is this a fixed value at > > integration time, or is this a configuration value? If it's the latter, > > can the driver not derive a good value for this itself? > > After a further thinking, I think it is better to remove this sample > period us & pen detect debouce us. > Since it is a fixed value and no need to change it so far (in > at91sam9x5ek, sama5d3xek). Ok. > > > > >>>> + - atmel,adc-ts-filter-average: Numbers of sampling data will be averaged. > >>>> + 0 means no average. 1 means average two samples. 2 means average four > >>>> + samples. 3 means average eight samples. > >>> Is this averaging done in the hardware, or the kernel driver? > >> It is done in the hardware. > > Similarly, this seems to eventually get written to hardware, and thus > > seems more like configuration than hardware description. Why does this > > need to be in the DT? > > > > As an aside, in general it's nicer to describe a property as a logical > > value rather than the raw value that gets programmed into hardware (e.g. > > this property could by 2, 4, or 8 rather than 1, 2, or 4). > > > >> But for some soc, like AT91SAM9G45, hardware doesn't support hardware > >> average. > >> So I am wondering use it as for both hardware and softer average. > >> > >> BTW, you mentioned the kernel driver, do you mean a filter algorithm is > >> already implemented in kernel library? > > I do not know of any such filter algorithm in the kernel, though there > > may be one. I was simply confused as to what this was used for. > > > >>> If it's the latter, this can be left for the kernel to decide. > >>> > >>>> + - atmel,adc-ts-pendet-sensitivity: Pen Detection input pull-up resistor. > >>>> + It can be 0, 1, 2, 3. > >>> I think "pendet" is a bit opaque. "pen-detect" may be better. > >> yes. I'll change this. > >> > >>> What > >>> physical property does this represent (are these discrete values, or an > >>> enumeration)? > >> This property is supported by hardware, it can change the adc internal > >> resistor value for better pen detection, > >> * 0 = 200 kOhm, 1 = 150 kOhm, 2 = 100 kOhm, 3 = 50 kOhm > >> In general, we just use default value 2 for 100kOhm. > > This value eventually gets written to hardware, and seems more like > > configuration than hardware description. Why does this need to be in the > > DT? > > I am a little bit confused by the hardware configuration and hardware > description. > It seems I prefer to put all the hardware configurable value to DT. > Since I think this can be changed in DT. > But as you mentioned above, only the hardware description can be in DT. > Could you give me a more detail about the difference between hardware > configuration and hardware description? It's admittedly a gray area, but the basic idea would be that anything we might feasibly want to change the value of later shouldn't go into the DT, while properties of the hardware that might influence those decisions should be in the DT. It seems to me that the pen detect resistor value is something we might want to change later, if people found a particular touchscreen were too sensitive, for instance. However, maybe not. Thanks, Mark.
diff --git a/Documentation/devicetree/bindings/arm/atmel-adc.txt b/Documentation/devicetree/bindings/arm/atmel-adc.txt index 0db2945..925d656 100644 --- a/Documentation/devicetree/bindings/arm/atmel-adc.txt +++ b/Documentation/devicetree/bindings/arm/atmel-adc.txt @@ -29,6 +29,19 @@ Optional properties: - atmel,adc-sample-hold-time: Sample and Hold Time in microseconds - atmel,adc-clock-rate: ADC clock rate. If not specified, use the default adc_op_clk. + - atmel,adc-touchscreen-wires: Number of touch screen wires. Only support + 4 and 5 wires touch screen. + NOTE: when adc touch screen enabled, the adc hardware trigger will be + disabled. Since touch screen will occupied the trigger register. + - atmel,adc-ts-pendet-debounce: Debounce time in microsecond for touch pen + detect. + - atmel,adc-ts-sample-period-time: Sample Period Time in microsecond for + touch screen + - atmel,adc-ts-filter-average: Numbers of sampling data will be averaged. + 0 means no average. 1 means average two samples. 2 means average four + samples. 3 means average eight samples. + - atmel,adc-ts-pendet-sensitivity: Pen Detection input pull-up resistor. + It can be 0, 1, 2, 3. Optional trigger Nodes: - Required properties: diff --git a/arch/arm/mach-at91/include/mach/at91_adc.h b/arch/arm/mach-at91/include/mach/at91_adc.h index ab273ee..6d6cc14 100644 --- a/arch/arm/mach-at91/include/mach/at91_adc.h +++ b/arch/arm/mach-at91/include/mach/at91_adc.h @@ -57,10 +57,44 @@ #define AT91_ADC_IER 0x24 /* Interrupt Enable Register */ #define AT91_ADC_IDR 0x28 /* Interrupt Disable Register */ #define AT91_ADC_IMR 0x2C /* Interrupt Mask Register */ +#define AT91_ADC_IER_PEN (1 << 29) +#define AT91_ADC_IER_NOPEN (1 << 30) +#define AT91_ADC_IER_XRDY (1 << 20) +#define AT91_ADC_IER_YRDY (1 << 21) +#define AT91_ADC_IER_PRDY (1 << 22) +#define AT91_ADC_ISR_PENS (1 << 31) #define AT91_ADC_CHR(n) (0x30 + ((n) * 4)) /* Channel Data Register N */ #define AT91_ADC_DATA (0x3ff) +#define AT91_ADC_ACR 0x94 /* Analog Control Register */ +#define AT91_ADC_ACR_PENDETSENS (0x3 << 0) /* pull-up resistor */ + +#define AT91_ADC_TSMR 0xB0 +#define AT91_ADC_TSMR_TSMODE (3 << 0) /* Touch Screen Mode */ +#define AT91_ADC_TSMR_TSMODE_NONE (0 << 0) +#define AT91_ADC_TSMR_TSMODE_4WIRE_NO_PRESS (1 << 0) +#define AT91_ADC_TSMR_TSMODE_4WIRE_PRESS (2 << 0) +#define AT91_ADC_TSMR_TSMODE_5WIRE (3 << 0) +#define AT91_ADC_TSMR_TSAV (3 << 4) /* Averages samples */ +#define AT91_ADC_TSMR_TSAV_(x) ((x) << 4) +#define AT91_ADC_TSMR_SCTIM (0x0f << 16) /* Switch closure time */ +#define AT91_ADC_TSMR_PENDBC (0x0f << 28) /* Pen Debounce time */ +#define AT91_ADC_TSMR_PENDBC_(x) ((x) << 28) +#define AT91_ADC_TSMR_NOTSDMA (1 << 22) /* No Touchscreen DMA */ +#define AT91_ADC_TSMR_PENDET_DIS (0 << 24) /* Pen contact detection disable */ +#define AT91_ADC_TSMR_PENDET_ENA (1 << 24) /* Pen contact detection enable */ + +#define AT91_ADC_TSXPOSR 0xB4 +#define AT91_ADC_TSYPOSR 0xB8 +#define AT91_ADC_TSPRESSR 0xBC + #define AT91_ADC_VERSION 0xFC +/* Trigger Register bit field */ +#define AT91_ADC_TRGR_TRGPER (0xffff << 16) +#define AT91_ADC_TRGR_TRGPER_(x) ((x) << 16) +#define AT91_ADC_TRGR_TRGMOD (0x7 << 0) +#define AT91_ADC_TRGR_MOD_PERIOD_TRIG (5 << 0) + #endif diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c index 8f1386f..ffc0e42 100644 --- a/drivers/iio/adc/at91_adc.c +++ b/drivers/iio/adc/at91_adc.c @@ -11,6 +11,7 @@ #include <linux/clk.h> #include <linux/err.h> #include <linux/io.h> +#include <linux/input.h> #include <linux/interrupt.h> #include <linux/jiffies.h> #include <linux/kernel.h> @@ -39,12 +40,24 @@ #define at91_adc_writel(st, reg, val) \ (writel_relaxed(val, st->reg_base + reg)) +#define DRIVER_NAME "at91_adc" +#define MAX_POS_BITS 12 + +#define ZTHRESHOLD 9000 + struct at91_adc_caps { + bool has_12bits_xy; /* true means use 12 bits. Otherwise 10 bits */ bool has_tsmr; /* only at91sam9x5, sama5d3 have TSMR reg */ u32 mr_prescal_mask; u32 mr_startup_mask; }; +enum atmel_adc_ts_type { + ATMEL_ADC_TOUCHSCREEN_NONE = 0, + ATMEL_ADC_TOUCHSCREEN_4WIRE, + ATMEL_ADC_TOUCHSCREEN_5WIRE, +}; + struct at91_adc_state { struct clk *adc_clk; u32 adc_clk_rate; @@ -70,6 +83,29 @@ struct at91_adc_state { bool low_res; /* the resolution corresponds to the lowest one */ wait_queue_head_t wq_data_avail; struct at91_adc_caps caps; + + /* + * Following ADC channels are shared by touchscreen: + * + * CH0 -- Touch screen XP/UL + * CH1 -- Touch screen XM/UR + * CH2 -- Touch screen YP/LL + * CH3 -- Touch screen YM/Sense + * CH4 -- Touch screen LR(5-wire only) + * + * The bitfields below represents the reserved channel in the + * touchscreen mode. + */ +#define CHAN_MASK_TOUCHSCREEN_4WIRE (0xf << 0) +#define CHAN_MASK_TOUCHSCREEN_5WIRE (0x1f << 0) + enum atmel_adc_ts_type touchscreen_type; + struct input_dev *ts_input; + + u8 ts_filter_average; + u16 ts_pen_detect_debounce; + u8 ts_pen_detect_sensitivity; + u16 ts_sample_period_time; + u16 ts_sample_period_val; }; static irqreturn_t at91_adc_trigger_handler(int irq, void *p) @@ -104,14 +140,10 @@ static irqreturn_t at91_adc_trigger_handler(int irq, void *p) return IRQ_HANDLED; } -static irqreturn_t at91_adc_eoc_trigger(int irq, void *private) +/* Handler for classic adc channel eoc trigger */ +void handle_adc_eoc_trigger(int irq, struct iio_dev *idev) { - struct iio_dev *idev = private; struct at91_adc_state *st = iio_priv(idev); - u32 status = at91_adc_readl(st, st->registers->status_register); - - if (!(status & st->registers->drdy_mask)) - return IRQ_HANDLED; if (iio_buffer_enabled(idev)) { disable_irq_nosync(irq); @@ -121,6 +153,115 @@ static irqreturn_t at91_adc_eoc_trigger(int irq, void *private) st->done = true; wake_up_interruptible(&st->wq_data_avail); } +} + +static int at91_ts_sample(struct at91_adc_state *st) +{ + unsigned int xscale, yscale, reg, z1, z2; + unsigned int x, y, pres, xpos, ypos; + unsigned int rxp = 1; + unsigned int factor = 1000; + struct iio_dev *idev = iio_priv_to_dev(st); + + unsigned int xyz_mask_bits = st->caps.has_12bits_xy ? 12 : 10; + unsigned int xyz_mask = (1 << xyz_mask_bits) - 1; + + /* calculate position */ + /* x position = (x / xscale) * max, max = 2^MAX_POS_BITS - 1 */ + reg = at91_adc_readl(st, AT91_ADC_TSXPOSR); + xpos = reg & xyz_mask; + x = (xpos << MAX_POS_BITS) - xpos; + xscale = (reg >> 16) & xyz_mask; + if (xscale != 0) + x /= xscale; + else + dev_err(&idev->dev, "xscale == 0!!!\n"); + + /* y position = (y / yscale) * max, max = 2^MAX_POS_BITS - 1 */ + reg = at91_adc_readl(st, AT91_ADC_TSYPOSR); + ypos = reg & xyz_mask; + y = (ypos << MAX_POS_BITS) - ypos; + yscale = (reg >> 16) & xyz_mask; + if (yscale != 0) + y /= yscale; + else + dev_err(&idev->dev, "yscale == 0!!!\n"); + + /* calculate the pressure */ + reg = at91_adc_readl(st, AT91_ADC_TSPRESSR); + z1 = reg & xyz_mask; + z2 = (reg >> 16) & xyz_mask; + + if (z1 != 0) + pres = rxp * (x * factor / 1024) * (z2 * factor / z1 - factor) + / factor; + else + pres = ZTHRESHOLD; /* no pen contacted */ + + dev_dbg(&idev->dev, "xpos = %d, xscale = %d, ypos = %d, yscale = %d, z1 = %d, z2 = %d, press = %d\n", + xpos, xscale, ypos, yscale, z1, z2, pres); + + if (pres < ZTHRESHOLD) { + dev_dbg(&idev->dev, "x = %d, y = %d, pressure = %d\n", + x, y, pres / factor); + input_report_abs(st->ts_input, ABS_X, x); + input_report_abs(st->ts_input, ABS_Y, y); + input_report_abs(st->ts_input, ABS_PRESSURE, pres); + input_report_key(st->ts_input, BTN_TOUCH, 1); + input_sync(st->ts_input); + } else { + dev_dbg(&idev->dev, + "pressure too low: not reporting\n"); + } + + return 0; +} + + +static irqreturn_t at91_adc_interrupt(int irq, void *private) +{ + struct iio_dev *idev = private; + struct at91_adc_state *st = iio_priv(idev); + u32 status = at91_adc_readl(st, st->registers->status_register); + const uint32_t ts_data_irq_mask = + AT91_ADC_IER_XRDY | + AT91_ADC_IER_YRDY | + AT91_ADC_IER_PRDY; + + if (status & st->registers->drdy_mask) + handle_adc_eoc_trigger(irq, idev); + + if (status & AT91_ADC_IER_PEN) { + at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN); + at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_NOPEN | + ts_data_irq_mask); + /* Set up period trigger for sampling */ + at91_adc_writel(st, st->registers->trigger_register, + AT91_ADC_TRGR_MOD_PERIOD_TRIG | + AT91_ADC_TRGR_TRGPER_(st->ts_sample_period_val)); + } else if (status & AT91_ADC_IER_NOPEN) { + at91_adc_writel(st, st->registers->trigger_register, 0); + at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_NOPEN | + ts_data_irq_mask); + at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN); + + input_report_key(st->ts_input, BTN_TOUCH, 0); + input_sync(st->ts_input); + } else if ((status & ts_data_irq_mask) == ts_data_irq_mask) { + /* Now all touchscreen data is ready */ + + if (status & AT91_ADC_ISR_PENS) { + /* validate data by pen contact */ + at91_ts_sample(st); + } else { + /* triggered by event that is no pen contact, just read + * them to clean the interrupt and discard all. + */ + at91_adc_readl(st, AT91_ADC_TSXPOSR); + at91_adc_readl(st, AT91_ADC_TSYPOSR); + at91_adc_readl(st, AT91_ADC_TSPRESSR); + } + } return IRQ_HANDLED; } @@ -130,6 +271,16 @@ static int at91_adc_channel_init(struct iio_dev *idev) struct at91_adc_state *st = iio_priv(idev); struct iio_chan_spec *chan_array, *timestamp; int bit, idx = 0; + unsigned long rsvd_mask = 0; + + /* If touchscreen is enable, then reserve the adc channels */ + if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_4WIRE) + rsvd_mask = CHAN_MASK_TOUCHSCREEN_4WIRE; + else if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_5WIRE) + rsvd_mask = CHAN_MASK_TOUCHSCREEN_5WIRE; + + /* set up the channel mask to reserve touchscreen channels */ + st->channels_mask &= ~rsvd_mask; idev->num_channels = bitmap_weight(&st->channels_mask, st->num_channels) + 1; @@ -561,6 +712,57 @@ static int at91_adc_probe_dt(struct at91_adc_state *st, i++; } + /* Check if touchscreen is enabled in DT. */ + ret = of_property_read_u32(node, "atmel,adc-touchscreen-wires", &prop); + if (ret) + dev_info(&idev->dev, "Touchscreen not enabled.\n"); + else if (prop == 4) + st->touchscreen_type = ATMEL_ADC_TOUCHSCREEN_4WIRE; + else if (prop == 5) + st->touchscreen_type = ATMEL_ADC_TOUCHSCREEN_5WIRE; + else + dev_warn(&idev->dev, "Unsupported number of touchscreen wires (%d)\n", + prop); + + if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_NONE) + return 0; + + /* Touch screen is enabled, so check touch screen dt parameters */ + if (of_property_read_u32(node, "atmel,adc-ts-filter-average", &prop)) { + dev_err(&idev->dev, "Missing atmel,adc-ts-filtering-average property in the DT.\n"); + ret = -EINVAL; + goto error_ret; + } + st->ts_filter_average = prop; + if (st->ts_filter_average > 3) { + dev_err(&idev->dev, "Invalid atmel,adc-ts-filtering-average property in the DT.\n"); + ret = -EINVAL; + goto error_ret; + } + + prop = 0; + of_property_read_u32(node, "atmel,adc-ts-pendet-debounce", &prop); + st->ts_pen_detect_debounce = prop; + + /* default sample period is 2ms. The real touch sample period should be + * this period * TSFREQ. + */ + prop = 2000; + of_property_read_u32(node, "atmel,adc-ts-sample-period-time", &prop); + st->ts_sample_period_time = prop; + + if (of_property_read_u32(node, "atmel,adc-ts-pendet-sensitivity", &prop)) { + dev_err(&idev->dev, "Missing atmel,adc-ts-pendet-sensitivity property in the DT.\n"); + ret = -EINVAL; + goto error_ret; + } + st->ts_pen_detect_sensitivity = prop; + if (st->ts_pen_detect_sensitivity > 3) { + dev_err(&idev->dev, "Invalid atmel,adc-ts-pendet-sensitivity property in the DT.\n"); + ret = -EINVAL; + goto error_ret; + } + return 0; error_ret: @@ -592,6 +794,114 @@ static const struct iio_info at91_adc_info = { .read_raw = &at91_adc_read_raw, }; +/* Touchscreen related functions */ +static int atmel_ts_open(struct input_dev *dev) +{ + struct at91_adc_state *st = input_get_drvdata(dev); + + at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN); + return 0; +} + +static void atmel_ts_close(struct input_dev *dev) +{ + struct at91_adc_state *st = input_get_drvdata(dev); + + at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN); +} + +static int at91_ts_hw_init(struct at91_adc_state *st, u32 adc_clk_khz) +{ + u32 reg = 0, pendbc; + int i = 0; + + if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_4WIRE) + reg = AT91_ADC_TSMR_TSMODE_4WIRE_PRESS; + else + reg = AT91_ADC_TSMR_TSMODE_5WIRE; + + /* a Pen Detect Debounce Time is necessary for the ADC Touch to avoid + * pen detect noise. + * The formula is : Pen Detect Debounce Time = (2 ^ pendbc) / ADCClock + */ + pendbc = round_up(st->ts_pen_detect_debounce * adc_clk_khz / 1000, 1); + + while (pendbc >> ++i) + ; /* Empty! Find the shift offset */ + if (abs(pendbc - (1 << i)) < abs(pendbc - (1 << (i - 1)))) + pendbc = i; + else + pendbc = i - 1; + + if (st->caps.has_tsmr) { + reg |= AT91_ADC_TSMR_TSAV_(st->ts_filter_average) + & AT91_ADC_TSMR_TSAV; + reg |= AT91_ADC_TSMR_PENDBC_(pendbc) & AT91_ADC_TSMR_PENDBC; + reg |= AT91_ADC_TSMR_NOTSDMA; + reg |= AT91_ADC_TSMR_PENDET_ENA; + reg |= 0x03 << 8; /* TSFREQ, need bigger than TSAV */ + + at91_adc_writel(st, AT91_ADC_TSMR, reg); + } else { + /* TODO: for 9g45 which has no TSMR */ + } + + /* Change adc internal resistor value for better pen detection, + * default value is 100 kOhm. + * 0 = 200 kOhm, 1 = 150 kOhm, 2 = 100 kOhm, 3 = 50 kOhm + * option only available on ES2 and higher + */ + at91_adc_writel(st, AT91_ADC_ACR, st->ts_pen_detect_sensitivity + & AT91_ADC_ACR_PENDETSENS); + + /* Sample Peroid Time = (TRGPER + 1) / ADCClock */ + st->ts_sample_period_val = round_up((st->ts_sample_period_time * + adc_clk_khz / 1000) - 1, 1); + + return 0; +} + +static int at91_ts_register(struct at91_adc_state *st) +{ + struct input_dev *input; + struct iio_dev *idev = iio_priv_to_dev(st); + int ret; + + input = input_allocate_device(); + if (!input) { + dev_err(&idev->dev, "Failed to allocate TS device!\n"); + return -ENOMEM; + } + + input->name = DRIVER_NAME; + input->id.bustype = BUS_HOST; + input->dev.parent = idev->dev.parent; + input->open = atmel_ts_open; + input->close = atmel_ts_close; + + __set_bit(EV_ABS, input->evbit); + __set_bit(EV_KEY, input->evbit); + __set_bit(BTN_TOUCH, input->keybit); + input_set_abs_params(input, ABS_X, 0, (1 << MAX_POS_BITS) - 1, 0, 0); + input_set_abs_params(input, ABS_Y, 0, (1 << MAX_POS_BITS) - 1, 0, 0); + input_set_abs_params(input, ABS_PRESSURE, 0, 0xffffff, 0, 0); + + st->ts_input = input; + input_set_drvdata(input, st); + + ret = input_register_device(input); + if (ret) + input_free_device(st->ts_input); + + return ret; +} + +static void at91_ts_unregister(struct at91_adc_state *st) +{ + input_unregister_device(st->ts_input); + input_free_device(st->ts_input); +} + /* * Since atmel adc support different ip for touchscreen mode. Through the * IP check, we will know the touchscreen capbilities. @@ -610,6 +920,7 @@ static void atmel_adc_get_cap(struct at91_adc_state *st) /* keep only major version number */ switch (version & 0xf00) { case 0x500: /* SAMA5D3 */ + st->caps.has_12bits_xy = 1; case 0x400: /* AT91SAM9X5/9N12 */ st->caps.has_tsmr = 1; st->caps.mr_startup_mask = AT91_ADC_STARTUP; @@ -683,7 +994,7 @@ static int at91_adc_probe(struct platform_device *pdev) at91_adc_writel(st, AT91_ADC_CR, AT91_ADC_SWRST); at91_adc_writel(st, AT91_ADC_IDR, 0xFFFFFFFF); ret = request_irq(st->irq, - at91_adc_eoc_trigger, + at91_adc_interrupt, 0, pdev->dev.driver->name, idev); @@ -731,6 +1042,10 @@ static int at91_adc_probe(struct platform_device *pdev) adc_clk = st->adc_clk_rate ? st->adc_clk_rate : clk_get_rate(st->adc_clk); adc_clk_khz = adc_clk / 1000; + + dev_dbg(&pdev->dev, "Master clock is set as: %d Hz, adc_clk should set as: %d Hz\n", + mstrclk, adc_clk); + prsc = (mstrclk / (2 * adc_clk)) - 1; if (!st->startup_time) { @@ -799,30 +1114,52 @@ static int at91_adc_probe(struct platform_device *pdev) init_waitqueue_head(&st->wq_data_avail); mutex_init(&st->lock); - ret = at91_adc_buffer_init(idev); - if (ret < 0) { - dev_err(&pdev->dev, "Couldn't initialize the buffer.\n"); - goto error_disable_adc_clk; - } + /* + * Since touch screen will set trigger register as period trigger. So + * when touch screen is enabled, then we have to disable hardware + * trigger for classic adc. + */ + if (!st->touchscreen_type) { + ret = at91_adc_buffer_init(idev); + if (ret < 0) { + dev_err(&pdev->dev, "Couldn't initialize the buffer.\n"); + goto error_disable_adc_clk; + } - ret = at91_adc_trigger_init(idev); - if (ret < 0) { - dev_err(&pdev->dev, "Couldn't setup the triggers.\n"); - goto error_unregister_buffer; + ret = at91_adc_trigger_init(idev); + if (ret < 0) { + dev_err(&pdev->dev, "Couldn't setup the triggers.\n"); + at91_adc_buffer_remove(idev); + goto error_disable_adc_clk; + } + } else { + if (!st->caps.has_tsmr) { + dev_err(&pdev->dev, "We don't support non-TSMR adc\n"); + goto error_disable_adc_clk; + } + + ret = at91_ts_register(st); + if (ret) + goto error_disable_adc_clk; + + at91_ts_hw_init(st, adc_clk_khz); } ret = iio_device_register(idev); if (ret < 0) { dev_err(&pdev->dev, "Couldn't register the device.\n"); - goto error_remove_triggers; + goto error_iio_device_register; } return 0; -error_remove_triggers: - at91_adc_trigger_remove(idev); -error_unregister_buffer: - at91_adc_buffer_remove(idev); +error_iio_device_register: + if (!st->touchscreen_type) { + at91_adc_trigger_remove(idev); + at91_adc_buffer_remove(idev); + } else { + at91_ts_unregister(st); + } error_disable_adc_clk: clk_disable_unprepare(st->adc_clk); error_disable_clk: @@ -841,8 +1178,12 @@ static int at91_adc_remove(struct platform_device *pdev) struct at91_adc_state *st = iio_priv(idev); iio_device_unregister(idev); - at91_adc_trigger_remove(idev); - at91_adc_buffer_remove(idev); + if (!st->touchscreen_type) { + at91_adc_trigger_remove(idev); + at91_adc_buffer_remove(idev); + } else { + at91_ts_unregister(st); + } clk_disable_unprepare(st->adc_clk); clk_disable_unprepare(st->clk); free_irq(st->irq, idev); @@ -861,7 +1202,7 @@ static struct platform_driver at91_adc_driver = { .probe = at91_adc_probe, .remove = at91_adc_remove, .driver = { - .name = "at91_adc", + .name = DRIVER_NAME, .of_match_table = of_match_ptr(at91_adc_dt_ids), }, };
AT91 ADC hardware integrate touch screen support. So this patch add touch screen support for at91 adc iio driver. To enable touch screen support in adc, you need to add the dt parameters: which type of touch are used? (4 or 5 wires), sample period time, pen detect debounce time, average samples and pen detect resistor. In the meantime, since touch screen will use a interal period trigger of adc, so it is conflict to other hardware triggers. Driver will disable the hardware trigger support if touch screen is enabled. This driver has been tested in AT91SAM9X5-EK and SAMA5D3x-EK. Signed-off-by: Josh Wu <josh.wu@atmel.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> --- .../devicetree/bindings/arm/atmel-adc.txt | 13 + arch/arm/mach-at91/include/mach/at91_adc.h | 34 ++ drivers/iio/adc/at91_adc.c | 389 ++++++++++++++++++-- 3 files changed, 412 insertions(+), 24 deletions(-)