[PATCH] mmc: dw_mmc: fix dw_mci_get_cd
From: Seungwon Jeon <hidden>
Date: 2014-01-15 14:38:06
Also in:
linux-mmc
On Wed, January 15, 2014, Zhangfei wrote:
On 01/15/2014 08:26 PM, Seungwon Jeon wrote:quoted
quoted
quoted
quoted
@@ -1033,7 +1033,8 @@ static int dw_mci_get_cd(struct mmc_host *mmc) int present; struct dw_mci_slot *slot = mmc_priv(mmc); struct dw_mci_board *brd = slot->host->pdata; - int gpio_cd = !mmc_gpio_get_cd(mmc); + struct dw_mci *host = slot->host; + int gpio_cd = mmc_gpio_get_cd(mmc); /* Use platform get_cd function, else try onboard card detect */ if (brd->quirks & DW_MCI_QUIRK_BROKEN_CARD_DETECTION)@@ -1041,11 +1042,12 @@ 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;!!gpio_cd or gpio_cd is correct, isn't it?No, mmc_gpio_get_cd(mmc) has to revert.I'm missing something? If card is detected, mmc_gpio_get_cd() returns non-zero, right? I guess gpio_cd should be kept.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.
quoted hunk ↗ jump to hunk
--- a/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc.txt +++ b/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc.txt@@ -73,6 +73,8 @@ Optional properties: +* caps2-mmc-cd-active-low: cd pin is low when card active +diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c + if (of_find_property(np, "caps2-mmc-cd-active-low", NULL)) + pdata->caps2 |= MMC_CAP2_CD_ACTIVE_HIGH; +But it looks strange "cd-active-low" describing "CD_ACTIVE_HIGH" flag. When card active, cd = 0, and ACTIVE_HIGH is required to make mmc_gpio_get_cd return 1.
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. Thanks, Seungwon Jeon
int mmc_gpio_get_cd(struct mmc_host *host)
{
return !gpio_get_value_cansleep(ctx->cd_gpio) ^
!!(host->caps2 & MMC_CAP2_CD_ACTIVE_HIGH);
}
Thanks
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