On Fri, 25 Jun 2010 22:06:44 +0400
Anton Vorontsov <avoront...@mvista.com> wrote:

> There's nothing special, just SoC-specific ops and quirks.
> 
> ...
>
> +static void sdhci_cns3xxx_set_clock(struct sdhci_host *host, unsigned int 
> clock)
> +{
> +     struct device *dev = mmc_dev(host->mmc);
> +     int div = 1;
> +     u16 clk;
> +     unsigned long timeout;
> +
> +     if (clock == host->clock)
> +             return;

I assume that mmc core prevents this function from being exectued twice
at the same time?

> +     sdhci_writew(host, 0, SDHCI_CLOCK_CONTROL);
> +
> +     if (clock == 0)
> +             goto out;
> +
> +     while (host->max_clk / div > clock) {
> +             /*
> +              * On CNS3xxx divider grows linearly up to 4, and then
> +              * exponentially up to 256.
> +              */
> +             if (div < 4)
> +                     div += 1;
> +             else if (div < 256)
> +                     div *= 2;
> +             else
> +                     break;
> +     }
> +
> +     dev_dbg(dev, "desired SD clock: %d, actual: %d\n",
> +             clock, host->max_clk / div);
> +
> +     /* Divide by 3 is special. */
> +     if (div != 3)
> +             div >>= 1;
> +
> +     clk = div << SDHCI_DIVIDER_SHIFT;
> +     clk |= SDHCI_CLOCK_INT_EN;
> +     sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
> +
> +     timeout = 20;
> +     while (!((clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL))
> +                     & SDHCI_CLOCK_INT_STABLE)) {
> +             if (timeout == 0) {
> +                     dev_warn(dev, "clock is unstable");
> +                     break;
> +             }
> +             timeout--;
> +             mdelay(1);

Could we have used the more polite msleep() here?

> +     }
> +
> +     clk |= SDHCI_CLOCK_CARD_EN;
> +     sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
> +out:
> +     host->clock = clock;
> +}
> +
>
> ...
>
> --- a/drivers/mmc/host/sdhci-pltfm.c
> +++ b/drivers/mmc/host/sdhci-pltfm.c
> @@ -158,6 +158,9 @@ static int __devexit sdhci_pltfm_remove(struct 
> platform_device *pdev)
>  
>  static const struct platform_device_id sdhci_pltfm_ids[] = {
>       { "sdhci", },
> +#ifdef CONFIG_MMC_SDHCI_CNS3XXX
> +     { "sdhci-cns3xxx", (kernel_ulong_t)&sdhci_cns3xxx_pdata },
> +#endif

What the heck is this kernel_ulong_t thing and why did `struct
platform_device_id' see a need to invent it??


>       { },
>  };
>  MODULE_DEVICE_TABLE(platform, sdhci_pltfm_ids);
>
> ...
>
--
To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to