diff mbox

[Resend,v5,02/16] spi/spi-atmel: detect the capabilities of SPI core by reading the VERSION register.

Message ID 1361925520-11981-1-git-send-email-wenyou.yang@atmel.com (mailing list archive)
State Superseded, archived
Headers show

Commit Message

Wenyou Yang Feb. 27, 2013, 12:38 a.m. UTC
The "has_dma_support" needed for future use with dmaengine driver.

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Cc: spi-devel-general@lists.sourceforge.net
Cc: linux-kernel@vger.kernel.org
---
 drivers/spi/spi-atmel.c |   70 ++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 57 insertions(+), 13 deletions(-)

Comments

Joachim Eastwood Feb. 27, 2013, 7:41 p.m. UTC | #1
On 27 February 2013 01:38, Wenyou Yang <wenyou.yang@atmel.com> wrote:
> The "has_dma_support" needed for future use with dmaengine driver.
>
> Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
> Cc: spi-devel-general@lists.sourceforge.net
> Cc: linux-kernel@vger.kernel.org
> ---
>  drivers/spi/spi-atmel.c |   70 ++++++++++++++++++++++++++++++++++++++---------
>  1 file changed, 57 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c
> index 5bf3786..a8e091b 100644
> --- a/drivers/spi/spi-atmel.c
> +++ b/drivers/spi/spi-atmel.c
> @@ -39,6 +39,7 @@
>  #define SPI_CSR1                               0x0034
>  #define SPI_CSR2                               0x0038
>  #define SPI_CSR3                               0x003c
> +#define SPI_VERSION                            0x00fc
>  #define SPI_RPR                                        0x0100
>  #define SPI_RCR                                        0x0104
>  #define SPI_TPR                                        0x0108
> @@ -71,6 +72,8 @@
>  #define SPI_FDIV_SIZE                          1
>  #define SPI_MODFDIS_OFFSET                     4
>  #define SPI_MODFDIS_SIZE                       1
> +#define SPI_WDRBT_OFFSET                       5
> +#define SPI_WDRBT_SIZE                         1
>  #define SPI_LLB_OFFSET                         7
>  #define SPI_LLB_SIZE                           1
>  #define SPI_PCS_OFFSET                         16
> @@ -180,6 +183,11 @@
>  #define spi_writel(port,reg,value) \
>         __raw_writel((value), (port)->regs + SPI_##reg)
>
> +struct atmel_spi_caps {
> +       bool    is_spi2;
> +       bool    has_wdrbt;
> +       bool    has_dma_support;
> +};
>
>  /*
>   * The core SPI transfer engine just talks to a register bank to set up
> @@ -204,6 +212,8 @@ struct atmel_spi {
>
>         void                    *buffer;
>         dma_addr_t              buffer_dma;
> +
> +       struct atmel_spi_caps   caps;
>  };
>
>  /* Controller-specific per-slave state */
> @@ -222,14 +232,10 @@ struct atmel_spi_device {
>   *  - SPI_SR.TXEMPTY, SPI_SR.NSSR (and corresponding irqs)
>   *  - SPI_CSRx.CSAAT
>   *  - SPI_CSRx.SBCR allows faster clocking
> - *
> - * We can determine the controller version by reading the VERSION
> - * register, but I haven't checked that it exists on all chips, and
> - * this is cheaper anyway.
>   */
> -static bool atmel_spi_is_v2(void)
> +static bool atmel_spi_is_v2(struct atmel_spi *as)
>  {
> -       return !cpu_is_at91rm9200();
> +       return as->caps.is_spi2;
>  }

Since you are removing cpu_is_at91rm9200() you might want to remove
the mach/cpu.h include as well.

Regarding the includes. I think asm/{io.h, gpio.h} should be converted
to linux/{io.h, gpio.h}. In it's own patch, though.

<snip>

> @@ -910,6 +921,32 @@ static void atmel_spi_cleanup(struct spi_device *spi)
>         kfree(asd);
>  }
>
> +static inline unsigned int atmel_get_version(struct atmel_spi *as)
> +{
> +       return spi_readl(as, VERSION) & 0x00000fff;
> +}
> +
> +static void __init atmel_get_caps(struct atmel_spi *as)
> +{
> +       unsigned int version;
> +
> +       version = atmel_get_version(as);
> +       dev_info(&as->pdev->dev, "version: 0x%x\n", version);
> +
> +       as->caps.is_spi2 = false;
> +       as->caps.has_wdrbt = false;
> +       as->caps.has_dma_support = false;
> +
> +       if (version > 0x121)
> +               as->caps.is_spi2 = true;
> +
> +       if (version >= 0x210)
> +               as->caps.has_wdrbt = true;
> +
> +       if (version >= 0x212)
> +               as->caps.has_dma_support = true;
> +}

This could be just written as: as->caps.has_dma_support = (version >= 0x212);
or using a conditional.

It would save some lines.

regards
Joachim Eastwood

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Wenyou Yang Feb. 28, 2013, 2:29 a.m. UTC | #2
Hi, Joachim,

> -----Original Message-----

> From: Joachim Eastwood [mailto:manabian@gmail.com]

> Sent: 2013?2?28? 3:41

> To: Yang, Wenyou

> Cc: linux-arm-kernel@lists.infradead.org; grant.likely@secretlab.ca; Ferre,

> Nicolas; plagnioj@jcrosoft.com; richard.genoud@gmail.com; Lin, JM;

> spi-devel-general@lists.sourceforge.net

> Subject: Re: [PATCH Resend v5 02/16] spi/spi-atmel: detect the capabilities of

> SPI core by reading the VERSION register.

> 

> On 27 February 2013 01:38, Wenyou Yang <wenyou.yang@atmel.com> wrote:

> > The "has_dma_support" needed for future use with dmaengine driver.

> >

> > Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>

> > Cc: spi-devel-general@lists.sourceforge.net

> > Cc: linux-kernel@vger.kernel.org

> > ---

> >  drivers/spi/spi-atmel.c |   70

> ++++++++++++++++++++++++++++++++++++++---------

> >  1 file changed, 57 insertions(+), 13 deletions(-)

> >

> > diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c

> > index 5bf3786..a8e091b 100644

> > --- a/drivers/spi/spi-atmel.c

> > +++ b/drivers/spi/spi-atmel.c

> > @@ -39,6 +39,7 @@

> >  #define SPI_CSR1                               0x0034

> >  #define SPI_CSR2                               0x0038

> >  #define SPI_CSR3                               0x003c

> > +#define SPI_VERSION                            0x00fc

> >  #define SPI_RPR                                        0x0100

> >  #define SPI_RCR                                        0x0104

> >  #define SPI_TPR                                        0x0108

> > @@ -71,6 +72,8 @@

> >  #define SPI_FDIV_SIZE                          1

> >  #define SPI_MODFDIS_OFFSET                     4

> >  #define SPI_MODFDIS_SIZE                       1

> > +#define SPI_WDRBT_OFFSET                       5

> > +#define SPI_WDRBT_SIZE                         1

> >  #define SPI_LLB_OFFSET                         7

> >  #define SPI_LLB_SIZE                           1

> >  #define SPI_PCS_OFFSET                         16

> > @@ -180,6 +183,11 @@

> >  #define spi_writel(port,reg,value) \

> >         __raw_writel((value), (port)->regs + SPI_##reg)

> >

> > +struct atmel_spi_caps {

> > +       bool    is_spi2;

> > +       bool    has_wdrbt;

> > +       bool    has_dma_support;

> > +};

> >

> >  /*

> >   * The core SPI transfer engine just talks to a register bank to set up

> > @@ -204,6 +212,8 @@ struct atmel_spi {

> >

> >         void                    *buffer;

> >         dma_addr_t              buffer_dma;

> > +

> > +       struct atmel_spi_caps   caps;

> >  };

> >

> >  /* Controller-specific per-slave state */

> > @@ -222,14 +232,10 @@ struct atmel_spi_device {

> >   *  - SPI_SR.TXEMPTY, SPI_SR.NSSR (and corresponding irqs)

> >   *  - SPI_CSRx.CSAAT

> >   *  - SPI_CSRx.SBCR allows faster clocking

> > - *

> > - * We can determine the controller version by reading the VERSION

> > - * register, but I haven't checked that it exists on all chips, and

> > - * this is cheaper anyway.

> >   */

> > -static bool atmel_spi_is_v2(void)

> > +static bool atmel_spi_is_v2(struct atmel_spi *as)

> >  {

> > -       return !cpu_is_at91rm9200();

> > +       return as->caps.is_spi2;

> >  }

> 

> Since you are removing cpu_is_at91rm9200() you might want to remove

> the mach/cpu.h include as well.

I ignored it , you are right.
> 

> Regarding the includes. I think asm/{io.h, gpio.h} should be converted

> to linux/{io.h, gpio.h}. In it's own patch, though.

> 

I tried it, it is OK
> <snip>

> 

> > @@ -910,6 +921,32 @@ static void atmel_spi_cleanup(struct spi_device

> *spi)

> >         kfree(asd);

> >  }

> >

> > +static inline unsigned int atmel_get_version(struct atmel_spi *as)

> > +{

> > +       return spi_readl(as, VERSION) & 0x00000fff;

> > +}

> > +

> > +static void __init atmel_get_caps(struct atmel_spi *as)

> > +{

> > +       unsigned int version;

> > +

> > +       version = atmel_get_version(as);

> > +       dev_info(&as->pdev->dev, "version: 0x%x\n", version);

> > +

> > +       as->caps.is_spi2 = false;

> > +       as->caps.has_wdrbt = false;

> > +       as->caps.has_dma_support = false;

> > +

> > +       if (version > 0x121)

> > +               as->caps.is_spi2 = true;

> > +

> > +       if (version >= 0x210)

> > +               as->caps.has_wdrbt = true;

> > +

> > +       if (version >= 0x212)

> > +               as->caps.has_dma_support = true;

> > +}

> 

> This could be just written as: as->caps.has_dma_support = (version >= 0x212);

> or using a conditional.

> 

> It would save some lines.

> 

You are right.
> regards

> Joachim Eastwood

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diff mbox

Patch

diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c
index 5bf3786..a8e091b 100644
--- a/drivers/spi/spi-atmel.c
+++ b/drivers/spi/spi-atmel.c
@@ -39,6 +39,7 @@ 
 #define SPI_CSR1				0x0034
 #define SPI_CSR2				0x0038
 #define SPI_CSR3				0x003c
+#define SPI_VERSION				0x00fc
 #define SPI_RPR					0x0100
 #define SPI_RCR					0x0104
 #define SPI_TPR					0x0108
@@ -71,6 +72,8 @@ 
 #define SPI_FDIV_SIZE				1
 #define SPI_MODFDIS_OFFSET			4
 #define SPI_MODFDIS_SIZE			1
+#define SPI_WDRBT_OFFSET			5
+#define SPI_WDRBT_SIZE				1
 #define SPI_LLB_OFFSET				7
 #define SPI_LLB_SIZE				1
 #define SPI_PCS_OFFSET				16
@@ -180,6 +183,11 @@ 
 #define spi_writel(port,reg,value) \
 	__raw_writel((value), (port)->regs + SPI_##reg)
 
+struct atmel_spi_caps {
+	bool	is_spi2;
+	bool	has_wdrbt;
+	bool	has_dma_support;
+};
 
 /*
  * The core SPI transfer engine just talks to a register bank to set up
@@ -204,6 +212,8 @@  struct atmel_spi {
 
 	void			*buffer;
 	dma_addr_t		buffer_dma;
+
+	struct atmel_spi_caps	caps;
 };
 
 /* Controller-specific per-slave state */
@@ -222,14 +232,10 @@  struct atmel_spi_device {
  *  - SPI_SR.TXEMPTY, SPI_SR.NSSR (and corresponding irqs)
  *  - SPI_CSRx.CSAAT
  *  - SPI_CSRx.SBCR allows faster clocking
- *
- * We can determine the controller version by reading the VERSION
- * register, but I haven't checked that it exists on all chips, and
- * this is cheaper anyway.
  */
-static bool atmel_spi_is_v2(void)
+static bool atmel_spi_is_v2(struct atmel_spi *as)
 {
-	return !cpu_is_at91rm9200();
+	return as->caps.is_spi2;
 }
 
 /*
@@ -263,15 +269,20 @@  static void cs_activate(struct atmel_spi *as, struct spi_device *spi)
 	unsigned active = spi->mode & SPI_CS_HIGH;
 	u32 mr;
 
-	if (atmel_spi_is_v2()) {
+	if (atmel_spi_is_v2(as)) {
 		/*
 		 * Always use CSR0. This ensures that the clock
 		 * switches to the correct idle polarity before we
 		 * toggle the CS.
 		 */
 		spi_writel(as, CSR0, asd->csr);
-		spi_writel(as, MR, SPI_BF(PCS, 0x0e) | SPI_BIT(MODFDIS)
+		if (as->caps.has_wdrbt) {
+			spi_writel(as, MR, SPI_BF(PCS, 0x0e) | SPI_BIT(WDRBT)
+				| SPI_BIT(MODFDIS) | SPI_BIT(MSTR));
+		} else {
+			spi_writel(as, MR, SPI_BF(PCS, 0x0e) | SPI_BIT(MODFDIS)
 				| SPI_BIT(MSTR));
+		}
 		mr = spi_readl(as, MR);
 		gpio_set_value(asd->npcs_pin, active);
 	} else {
@@ -318,7 +329,7 @@  static void cs_deactivate(struct atmel_spi *as, struct spi_device *spi)
 			asd->npcs_pin, active ? " (low)" : "",
 			mr);
 
-	if (atmel_spi_is_v2() || spi->chip_select != 0)
+	if (atmel_spi_is_v2(as) || spi->chip_select != 0)
 		gpio_set_value(asd->npcs_pin, !active);
 }
 
@@ -719,7 +730,7 @@  static int atmel_spi_setup(struct spi_device *spi)
 	}
 
 	/* see notes above re chipselect */
-	if (!atmel_spi_is_v2()
+	if (!atmel_spi_is_v2(as)
 			&& spi->chip_select == 0
 			&& (spi->mode & SPI_CS_HIGH)) {
 		dev_dbg(&spi->dev, "setup: can't be active-high\n");
@@ -728,7 +739,7 @@  static int atmel_spi_setup(struct spi_device *spi)
 
 	/* v1 chips start out at half the peripheral bus speed. */
 	bus_hz = clk_get_rate(as->clk);
-	if (!atmel_spi_is_v2())
+	if (!atmel_spi_is_v2(as))
 		bus_hz /= 2;
 
 	if (spi->max_speed_hz) {
@@ -804,7 +815,7 @@  static int atmel_spi_setup(struct spi_device *spi)
 		"setup: %lu Hz bpw %u mode 0x%x -> csr%d %08x\n",
 		bus_hz / scbr, bits, spi->mode, spi->chip_select, csr);
 
-	if (!atmel_spi_is_v2())
+	if (!atmel_spi_is_v2(as))
 		spi_writel(as, CSR0 + 4 * spi->chip_select, csr);
 
 	return 0;
@@ -910,6 +921,32 @@  static void atmel_spi_cleanup(struct spi_device *spi)
 	kfree(asd);
 }
 
+static inline unsigned int atmel_get_version(struct atmel_spi *as)
+{
+	return spi_readl(as, VERSION) & 0x00000fff;
+}
+
+static void __init atmel_get_caps(struct atmel_spi *as)
+{
+	unsigned int version;
+
+	version = atmel_get_version(as);
+	dev_info(&as->pdev->dev, "version: 0x%x\n", version);
+
+	as->caps.is_spi2 = false;
+	as->caps.has_wdrbt = false;
+	as->caps.has_dma_support = false;
+
+	if (version > 0x121)
+		as->caps.is_spi2 = true;
+
+	if (version >= 0x210)
+		as->caps.has_wdrbt = true;
+
+	if (version >= 0x212)
+		as->caps.has_dma_support = true;
+}
+
 /*-------------------------------------------------------------------------*/
 
 static int atmel_spi_probe(struct platform_device *pdev)
@@ -970,6 +1007,8 @@  static int atmel_spi_probe(struct platform_device *pdev)
 	as->irq = irq;
 	as->clk = clk;
 
+	atmel_get_caps(as);
+
 	ret = request_irq(irq, atmel_spi_interrupt, 0,
 			dev_name(&pdev->dev), master);
 	if (ret)
@@ -979,7 +1018,12 @@  static int atmel_spi_probe(struct platform_device *pdev)
 	clk_enable(clk);
 	spi_writel(as, CR, SPI_BIT(SWRST));
 	spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */
-	spi_writel(as, MR, SPI_BIT(MSTR) | SPI_BIT(MODFDIS));
+	if (as->caps.has_wdrbt) {
+		spi_writel(as, MR, SPI_BIT(WDRBT) | SPI_BIT(MODFDIS)
+				| SPI_BIT(MSTR));
+	} else {
+		spi_writel(as, MR, SPI_BIT(MSTR) | SPI_BIT(MODFDIS));
+	}
 	spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS));
 	spi_writel(as, CR, SPI_BIT(SPIEN));