[PATCH v3 3/3] sdhci-s3c: Add SDHCI_QUIRK_NO_WP_BIT quirk for Samsung SoC

[m.szyprowski@samsung.com (Marek Szyprowski)]

Hello,

On Friday, July 23, 2010 1:57 PM Kukjin Kim wrote:

> From: Hyuk Lee <hyuk1.lee@samsung.com>
> 
> If host controller doesn't have WP pin which should be connnected with
> SDMMC
> card WP pin, can implement get_ro function with using the allocated gpio.
> In order to use this quirk wp_gpio in the platform data must be set.
> 
> Signed-off-by: Hyuk Lee <hyuk1.lee@samsung.com>
> Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
> ---
>  drivers/mmc/host/sdhci-s3c.c |   43
> ++++++++++++++++++++++++++++++++++++++++++
>  drivers/mmc/host/sdhci.c     |    3 ++
>  drivers/mmc/host/sdhci.h     |    3 ++
>  3 files changed, 49 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci-s3c.c b/drivers/mmc/host/sdhci-s3c.c
> index 0d25285..0b75e57 100644
> --- a/drivers/mmc/host/sdhci-s3c.c
> +++ b/drivers/mmc/host/sdhci-s3c.c
> @@ -22,6 +22,7 @@
> 
>  #include <linux/mmc/host.h>
> 
> +#include <plat/gpio-cfg.h>
>  #include <plat/sdhci.h>
>  #include <plat/regs-sdhci.h>
> 
> @@ -213,6 +214,36 @@ static void sdhci_s3c_set_clock(struct sdhci_host
> *host, unsigned int clock)
>  }
> 
>  /**
> + * sdhci_s3c_get_ro - callback for get_ro
> + * @host: The SDHCI host being changed
> + *
> + * If the WP pin is connected with GPIO, can get the value which indicates
> + * the card is locked or not.
> +*/
> +static int sdhci_s3c_get_ro(struct mmc_host *mmc)
> +{
> +	struct sdhci_s3c *sc;
> +	struct sdhci_host *host;
> +
> +	host = mmc_priv(mmc);
> +	sc = sdhci_priv(host);
> +
> +	return gpio_get_value(sc->pdata->wp_gpio);
> +}
> +
> +/**
> + * sdhci_s3c_cfg_wp - configure GPIO for WP pin
> + * @gpio_num: GPIO number which connected with WP line from SD/MMC slot
> + *
> + * Configure GPIO for using WP line
> +*/
> +static void sdhci_s3c_cfg_wp(unsigned int gpio_num)
> +{
> +	s3c_gpio_cfgpin(gpio_num, S3C_GPIO_INPUT);
> +	s3c_gpio_setpull(gpio_num, S3C_GPIO_PULL_UP);
> +}
> +
> +/**
>   * sdhci_s3c_get_min_clock - callback to get minimal supported clock value
>   * @host: The SDHCI host being queried
>   *
> @@ -375,6 +406,9 @@ static int __devinit sdhci_s3c_probe(struct
> platform_device *pdev)
>  	if (pdata->cfg_gpio)
>  		pdata->cfg_gpio(pdev, pdata->max_width);
> 
> +	if (gpio_is_valid(pdata->wp_gpio))
> +		sdhci_s3c_ops.get_ro = sdhci_s3c_get_ro;
> +

There is still a problem here, but the opposite to the issue from V1 of this
patch.
If one apply the current version, he would need to set pdata->wp_gpio to -1 on
all
existing platforms to get old behavior of the driver. Leaving it as zero means
that
the driver will try to use GPA(0) for write protection.

Adding one more field to pdata (like "bool has_gpio_wp") seems to be unavoidable
in this case imho.

> (snip)

Best regards
--
Marek Szyprowski
Samsung Poland R&D Center