Re: [PATCH 16/24] omap4: Add i2c support on omap4 platform

[Tony Lindgren <tony@atomide.com>]

* Santosh Shilimkar <santosh.shilimkar@ti.com> [100216 07:55]:
> This patch is rebased version of earlier post to add I2C
> driver support to OMAP4 platform. On OMAP4, all
> I2C register address offsets are changed from OMAP1/2/3 I2C.
> In order to not have #ifdef's at various places in code,
> as well as to support multi-OMAP build, an array is created
> to hold the register addresses with it's offset.
> 
> This patch was submitted, reviewed and acked on mailing list
> already. For more details refer below link
> http://www.mail-archive.com/linux-i2c@vger.kernel.org/msg02281.html
> 
> This version updated on top of 16 bit support added as part of
> the commit "8bb209278e555a626f9637e844fe4c1b90e849f6"
> 
> Signed-off-by: Syed Rafiuddin <rafiuddin.syed@ti.com>
> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
> Acked-by: Kevin Hilman <khilman@deeprootsystems.com>
> CC: Tony Lindgren <tony@atomide.com>
> CC: Ben Dooks <ben-linux@fluff.org>
> ---
>  arch/arm/plat-omap/i2c.c      |   17 ++++-
>  drivers/i2c/busses/i2c-omap.c |  148 ++++++++++++++++++++++++++++++++---------
>  2 files changed, 131 insertions(+), 34 deletions(-)
> 
> diff --git a/arch/arm/plat-omap/i2c.c b/arch/arm/plat-omap/i2c.c
> index 96d2781..f18d757 100644
> --- a/arch/arm/plat-omap/i2c.c
> +++ b/arch/arm/plat-omap/i2c.c
> @@ -53,9 +53,15 @@ static struct resource i2c_resources[][2] = {
>  #if	defined(CONFIG_ARCH_OMAP2) || defined(CONFIG_ARCH_OMAP3)
>  	{ I2C_RESOURCE_BUILDER(OMAP2_I2C_BASE2, INT_24XX_I2C2_IRQ) },
>  #endif
> +#if	defined(CONFIG_ARCH_OMAP4)
> +	{ I2C_RESOURCE_BUILDER(OMAP2_I2C_BASE2, INT_44XX_I2C2_IRQ) },
> +#endif
>  #if	defined(CONFIG_ARCH_OMAP3)
>  	{ I2C_RESOURCE_BUILDER(OMAP2_I2C_BASE3, INT_34XX_I2C3_IRQ) },
>  #endif
> +#if	defined(CONFIG_ARCH_OMAP4)
> +	{ I2C_RESOURCE_BUILDER(OMAP2_I2C_BASE3, INT_44XX_I2C3_IRQ) },
> +#endif
>  };

This is OK, but..
  
>  #define I2C_DEV_BUILDER(bus_id, res, data)		\
> @@ -72,10 +78,11 @@ static struct resource i2c_resources[][2] = {
>  static u32 i2c_rate[ARRAY_SIZE(i2c_resources)];
>  static struct platform_device omap_i2c_devices[] = {
>  	I2C_DEV_BUILDER(1, i2c_resources[0], &i2c_rate[0]),
> -#if	defined(CONFIG_ARCH_OMAP2) || defined(CONFIG_ARCH_OMAP3)
> +#if	defined(CONFIG_ARCH_OMAP2) || defined(CONFIG_ARCH_OMAP3) || \
> +	defined(CONFIG_ARCH_OMAP4)
>  	I2C_DEV_BUILDER(2, i2c_resources[1], &i2c_rate[1]),
>  #endif
> -#if	defined(CONFIG_ARCH_OMAP3)
> +#if	defined(CONFIG_ARCH_OMAP3) || defined(CONFIG_ARCH_OMAP4)
>  	I2C_DEV_BUILDER(3, i2c_resources[2], &i2c_rate[2]),
>  #endif
>  };

.. the ifdefs above can be simplified to ifdef CONFIG_ARCH_OMAP2PLUS.
That is, with the patches already queued into omap for-next.


> @@ -370,7 +434,11 @@ static int omap_i2c_init(struct omap_i2c_dev *dev)
>  			internal_clk = 9600;
>  		else
>  			internal_clk = 4000;
> -		fclk_rate = clk_get_rate(dev->fclk) / 1000;
> +		/* FIXME: Remove this once clock framework is available*/
> +		if (dev->rev >= OMAP_I2C_REV_ON_4430)
> +			fclk_rate = 96000;
> +		else
> +			fclk_rate = clk_get_rate(dev->fclk) / 1000;
>  
>  		/* Compute prescaler divisor */
>  		psc = fclk_rate / internal_clk;

Sounds like this part should no longer be needed?

>  					*dev->buf++ = w;
>  					dev->buf_len--;
> -					/* Data reg from 2430 is 8 bit wide */
> +					/* Data reg in 2430, omap3 and
> +					 * omap4 is 8 bit wide
> +					 */
>  					if (!cpu_is_omap2430() &&
> -							!cpu_is_omap34xx()) {
> +							!cpu_is_omap34xx() &&
> +							!cpu_is_omap44xx()) {
>  						if (dev->buf_len) {
>  							*dev->buf++ = w >> 8;
>  							dev->buf_len--;

How about change this to if (cpu_class_is_omap1() || cpu_is_omap2420())?
That way it does not need to be patched for new omaps.

> @@ -786,9 +857,12 @@ complete:
>  				if (dev->buf_len) {
>  					w = *dev->buf++;
>  					dev->buf_len--;
> -					/* Data reg from  2430 is 8 bit wide */
> +					/* Data reg in 2430, omap3 and
> +					 * omap4 is 8 bit wide
> +					 */
>  					if (!cpu_is_omap2430() &&
> -							!cpu_is_omap34xx()) {
> +							!cpu_is_omap34xx() &&
> +							!cpu_is_omap44xx()) {
>  						if (dev->buf_len) {
>  							w |= *dev->buf++ << 8;
>  							dev->buf_len--;

Here too.

>  	dev->rev = omap_i2c_read_reg(dev, OMAP_I2C_REV_REG) & 0xff;
>  
> -	if (cpu_is_omap2430() || cpu_is_omap34xx()) {
> +	if (cpu_is_omap2430() || cpu_is_omap34xx() || cpu_is_omap44xx()) {
>  		u16 s;
>  
>  		/* Set up the fifo size - Get total size */

And here too.

Regards,

Tony