RE: [PATCH v4 3/3] sdhci-s3c: Add SDHCI_QUIRK_NO_WP_BIT quirk for Samsung SoC

[Marek Szyprowski <m.szyprowski@samsung.com>]

Hello,

On Tuesday, July 27, 2010 2:44 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 |   36 ++++++++++++++++++++++++++++++++++++
>  drivers/mmc/host/sdhci.c     |    3 +++
>  drivers/mmc/host/sdhci.h     |    3 +++
>  3 files changed, 42 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci-s3c.c b/drivers/mmc/host/sdhci-s3c.c
> index 0d25285..98a8ec8 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 +214,32 @@ 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 *ourhost = to_s3c(mmc_priv(mmc));
> +
> +	return gpio_get_value(ourhost->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
>   *
> @@ -408,6 +435,15 @@ static int __devinit sdhci_s3c_probe(struct
> platform_device *pdev)
>  	host->quirks |= (SDHCI_QUIRK_32BIT_DMA_ADDR |
>  			 SDHCI_QUIRK_32BIT_DMA_SIZE);
> 
> +	/* Controller's WP pin doesn't connected with SD card and there is an
> +	 * allocated GPIO for getting WP data form SD card, use this quirk
> and
> +	 * send the GPIO number in pdata->wp_gpio. */
> +	if (gpio_is_valid(pdata->wp_gpio) && pdata->has_wp_gpio) {

IMHO the opposite order would make much more sense:
if (pdata->has_wp_gpio && gpio_is_valid(pdata->wp_gpio))

> +		sdhci_s3c_ops.get_ro = sdhci_s3c_get_ro;
> +		host->quirks |= SDHCI_QUIRK_NO_WP_BIT;
> +		sdhci_s3c_cfg_wp(pdata->wp_gpio);
> +	}
> +
>  	ret = sdhci_add_host(host);
>  	if (ret) {
>  		dev_err(dev, "sdhci_add_host() failed\n");
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index f9ca4c6..7fba401 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -1198,6 +1198,9 @@ static int sdhci_get_ro(struct mmc_host *mmc)
> 
>  	host = mmc_priv(mmc);
> 
> +	if ((host->quirks & SDHCI_QUIRK_NO_WP_BIT) && host->ops->get_ro)
> +		return host->ops->get_ro(mmc);
> +
>  	spin_lock_irqsave(&host->lock, flags);
> 
>  	if (host->flags & SDHCI_DEVICE_DEAD)
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index 0de8b38..dd9a233 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -247,6 +247,8 @@ struct sdhci_host {
>  #define SDHCI_QUIRK_MISSING_CAPS			(1<<28)
>  /* Controller has nonstandard clock management */
>  #define SDHCI_QUIRK_NONSTANDARD_MINCLOCK		(1<<29)
> +/* Controller has no write-protect pin connected with SD card */
> +#define SDHCI_QUIRK_NO_WP_BIT				(1<<30)
> 
>  	int			irq;		/* Device IRQ */
>  	void __iomem *		ioaddr;		/* Mapped address */
> @@ -321,6 +323,7 @@ struct sdhci_ops {
>  	unsigned int	(*get_max_clock)(struct sdhci_host *host);
>  	unsigned int	(*get_min_clock)(struct sdhci_host *host);
>  	unsigned int	(*get_timeout_clock)(struct sdhci_host *host);
> +	int		(*get_ro)(struct mmc_host *mmc);
>  };
> 
>  #ifdef CONFIG_MMC_SDHCI_IO_ACCESSORS

Otherwise looks fine.

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