[PATCH] pxa/hx4700: Set DS1WM clock_rate

[Eric Miao]

On Wed, Aug 10, 2011 at 12:23 AM, Paul Parsons <lost.distance at yahoo.com> wrote:
> The mfd/asic3 driver did not set the ds1wm_driver_data.clock_rate field before
> passing the structure to the ds1wm cell driver. By chance, ds1wm_find_divisor()
> returned the correct divisor when this zero clock_rate was passed in. However
> a recent change to ds1wm_find_divisor() removed this unintended behaviour. This
> patch explicitly sets the ds1wm_driver_data.clock_rate field.
>
> Signed-off-by: Paul Parsons <lost.distance at yahoo.com>
> ---
>
> diff -uprN clean-3.0.1/arch/arm/mach-pxa/hx4700.c linux-3.0.1/arch/arm/mach-pxa/hx4700.c
> --- clean-3.0.1/arch/arm/mach-pxa/hx4700.c      2011-08-05 05:59:21.000000000 +0100
> +++ linux-3.0.1/arch/arm/mach-pxa/hx4700.c      2011-08-07 23:02:18.653447085 +0100
> @@ -310,6 +310,7 @@ static struct asic3_platform_data asic3_
>        .gpio_config_num = ARRAY_SIZE(asic3_gpio_config),
>        .irq_base        = IRQ_BOARD_START,
>        .gpio_base       = HX4700_ASIC3_GPIO_BASE,
> +       .clock_rate      = 4000000,
>  };
>
>  static struct platform_device asic3 = {
> diff -uprN clean-3.0.1/drivers/mfd/asic3.c linux-3.0.1/drivers/mfd/asic3.c
> --- clean-3.0.1/drivers/mfd/asic3.c     2011-08-05 05:59:21.000000000 +0100
> +++ linux-3.0.1/drivers/mfd/asic3.c     2011-08-07 23:02:18.653447085 +0100
> @@ -867,10 +867,13 @@ static int __init asic3_mfd_probe(struct
>        asic3_mmc_resources[0].start >>= asic->bus_shift;
>        asic3_mmc_resources[0].end   >>= asic->bus_shift;
>
> -       ret = mfd_add_devices(&pdev->dev, pdev->id,
> +       if (pdata->clock_rate) {
> +               ds1wm_pdata.clock_rate = pdata->clock_rate;
> +               ret = mfd_add_devices(&pdev->dev, pdev->id,
>                        &asic3_cell_ds1wm, 1, mem, asic->irq_base);
> -       if (ret < 0)
> -               goto out;
> +               if (ret < 0)
> +                       goto out;
> +       }

Or this parent driver can silently pass the clock_rate to ds1wm sub-driver
without the if () condition, as it leaves to the sub-driver to decide whether
it's a valid value, unless you want to use 'clock_rate' to explicitly control
the registration of the sub-device.

>
>        if (mem_sdio && (irq >= 0)) {
>                ret = mfd_add_devices(&pdev->dev, pdev->id,
> diff -uprN clean-3.0.1/include/linux/mfd/asic3.h linux-3.0.1/include/linux/mfd/asic3.h
> --- clean-3.0.1/include/linux/mfd/asic3.h       2011-08-05 05:59:21.000000000 +0100
> +++ linux-3.0.1/include/linux/mfd/asic3.h       2011-08-07 23:02:18.653447085 +0100
> @@ -31,6 +31,8 @@ struct asic3_platform_data {
>
>        unsigned int gpio_base;
>
> +       unsigned int clock_rate;
> +
>        struct asic3_led *leds;
>  };
>
>
>