mmc: dw_mmc: fix dw_mci_get_cd

Commit Message

Zhangfei Gao Jan. 15, 2014, 3:32 p.m. UTC

On 01/15/2014 10:38 PM, Seungwon Jeon wrote:
>> Hmm, looks you are right.
>> Though not see clearly mmc_gpio_get_cd declaratoin, other drivers
>> directly set get_cd as mmc_gpio_get_cd.
>> .get_cd	= mmc_gpio_get_cd
>>
>> However, in our board cd =0 when card is deteced while cd=1 when card is
>> removed.
>> In order to mmc_gpio_get_cd return 1, MMC_CAP2_CD_ACTIVE_HIGH has to be
>> set, as well as new property "caps2-mmc-cd-active-low".
> 
> Ok, you could do more.
> mmc_gpio_get_cd() is expected to return non-zero if card is detection.

> I think your board seems not to use pull-up on GPIO line for card detection.
> So, MMC_CAP2_CD_ACTIVE_HIGH would be needed.

Unfortunately, the specific cd pin can not be configured.
Suspect on our board the cd =1 when card is inserted, can not measure as
no clear resister and need check with hardware guy tomorrow.

"cd-inverted" may be required as mentioned by Arnd.
Will update the patch as following if no problem.

[e-mail]
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Comments

Arnd Bergmann Jan. 15, 2014, 3:54 p.m. UTC | #1

On Wednesday 15 January 2014, zhangfei wrote:
> 
> On 01/15/2014 10:38 PM, Seungwon Jeon wrote:
> >> Hmm, looks you are right.
> >> Though not see clearly mmc_gpio_get_cd declaratoin, other drivers
> >> directly set get_cd as mmc_gpio_get_cd.
> >> .get_cd	= mmc_gpio_get_cd
> >>
> >> However, in our board cd =0 when card is deteced while cd=1 when card is
> >> removed.
> >> In order to mmc_gpio_get_cd return 1, MMC_CAP2_CD_ACTIVE_HIGH has to be
> >> set, as well as new property "caps2-mmc-cd-active-low".
> > 
> > Ok, you could do more.
> > mmc_gpio_get_cd() is expected to return non-zero if card is detection.
> 
> > I think your board seems not to use pull-up on GPIO line for card detection.
> > So, MMC_CAP2_CD_ACTIVE_HIGH would be needed.
> 
> Unfortunately, the specific cd pin can not be configured.
> Suspect on our board the cd =1 when card is inserted, can not measure as
> no clear resister and need check with hardware guy tomorrow.
> 
> "cd-inverted" may be required as mentioned by Arnd.
> Will update the patch as following if no problem.

The patch looks right, but I wonder if a better longer-term
solution would be to just the common mmc_of_parse() function
rather than duplicating it in dw_mmc.

	Arnd

Patch

diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 9ded62c8225e..8326e54b96a8 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -1042,7 +1042,7 @@  static int dw_mci_get_cd(struct mmc_host *mmc)
        else if (brd->get_cd)
                present = !brd->get_cd(slot->id);
        else if (!IS_ERR_VALUE(gpio_cd))
-               present = !gpio_cd;
+               present = gpio_cd ^ brd->cd_inverted;
        else
                present = (mci_readl(slot->host, CDETECT) & (1 << slot->id))
                        == 0 ? 1 : 0;
@@ -2414,6 +2414,9 @@  static struct dw_mci_board *dw_mci_parse_dt(struct
dw_mci *host)
        if (of_find_property(np, "caps2-mmc-hs200-1_2v", NULL))
                pdata->caps2 |= MMC_CAP2_HS200_1_2V_SDR;

+       if (of_get_property(np, "cd-inverted", NULL))
+               pdata->cd_inverted = 1;
+
        return pdata;
 }

diff --git a/include/linux/mmc/dw_mmc.h b/include/linux/mmc/dw_mmc.h
index 6ce7d2cd3c7a..4535282589ab 100644
--- a/include/linux/mmc/dw_mmc.h
+++ b/include/linux/mmc/dw_mmc.h
@@ -238,6 +238,7 @@  struct dw_mci_board {
        u32 caps;       /* Capabilities */
        u32 caps2;      /* More capabilities */
        u32 pm_caps;    /* PM capabilities */
+       u8 cd_inverted;

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