[PATCH v2 3/3] sdhci-s3c: Add SDHCI_QUIRK_NO_WP_BIT quirk

[Kukjin Kim]

Marek Szyprowski wrote:
> 
> Hello,
> 
Hello :-)

> On Saturday, July 03, 2010 3:01 AM Kukjin Kim wrote:
> 
> > From: Hyuk Lee <hyuk1.lee at 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 at samsung.com>
> > Signed-off-by: Kukjin Kim <kgene.kim at samsung.com>
> > ---
> >  drivers/mmc/host/sdhci-s3c.c |   44
> > ++++++++++++++++++++++++++++++++++++++++++
> >  drivers/mmc/host/sdhci.c     |    3 ++
> >  drivers/mmc/host/sdhci.h     |    3 ++
> >  3 files changed, 50 insertions(+), 0 deletions(-)
> >
> > diff --git a/drivers/mmc/host/sdhci-s3c.c b/drivers/mmc/host/sdhci-s3c.c
> > index af21792..ed9376d 100644
> > --- a/drivers/mmc/host/sdhci-s3c.c
> > +++ b/drivers/mmc/host/sdhci-s3c.c
> > @@ -18,11 +18,13 @@
> >  #include <linux/slab.h>
> >  #include <linux/clk.h>
> >  #include <linux/io.h>
> > +#include <linux/gpio.h>
> >
> >  #include <linux/mmc/host.h>
> >
> >  #include <plat/sdhci.h>
> >  #include <plat/regs-sdhci.h>
> > +#include <plat/gpio-cfg.h>
> >
> >  #include "sdhci.h"
> >
> > @@ -209,6 +211,36 @@ 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);
> > +}
> > +
> >  static struct sdhci_ops sdhci_s3c_ops = {
> >  	.get_max_clock		= sdhci_s3c_get_max_clk,
> >  	.get_timeout_clock	= sdhci_s3c_get_timeout_clk,
> > @@ -311,6 +343,9 @@ static int __devinit sdhci_s3c_probe(struct
> > platform_device *pdev)
> >  	if (pdata->cfg_gpio)
> >  		pdata->cfg_gpio(pdev, pdata->max_width);
> >
> > +	if (pdata->wp_gpio)
> > +		sdhci_s3c_ops.get_ro = sdhci_s3c_get_ro;
> > +
> >  	host->hw_name = "samsung-hsmmc";
> >  	host->ops = &sdhci_s3c_ops;
> >  	host->quirks = 0;
> > @@ -335,6 +370,15 @@ 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 donsn't connected with SD card. So we
allocate
> > +	 * a GPIO for getting WP data from SD card and use that data as
> > +	 * the return value of the get_ro function */
> > +	host->quirks |= SDHCI_QUIRK_NO_WP_BIT;
> > +
> > +	/* to configure gpio pin as a card write protection signal */
> > +	if (pdata->wp_gpio)
> > +		sdhci_s3c_cfg_wp(pdata->wp_gpio);
> > +
> 
> Assuming that pdata->wp_gpio == 0 means that the board has no additional
wp
> feature is wrong from the 'good and clean' API point of view. For example
> GPIO_A0(0) pin for S5PV210 is gpio number 0. This would mean that it
cannot
> be used for this feature at all.
> 
Oh, you're right. missed that point.

> I was told to use gpio_is_valid() macro and use -1 as 'invalid gpio' pin
> number for implementing similar checks.

OK..will fix it.

Thanks.

Best regards,
Kgene.
--
Kukjin Kim <kgene.kim at samsung.com>, Senior Engineer,
SW Solution Development Team, Samsung Electronics Co., Ltd.