[PATCH] sdhci: Fix SD card detection issue

[Richard Clark <richard.xnu.clark@gmail.com>]

The mmc_gpio_get_cd(...) will return 0 called from sdhci_get_cd(...), which means
the card is not present. Actually, the card detection pin is active low by default
according to the SDHCI psec, thus the card detection result is not correct, more
specificly below if condition is true in mmc_rescan(...):
	...
	if (mmc_card_is_removable(host) && host->ops->get_cd &&
		host->ops->get_cd(host) == 0) {
		...
		goto out;
	}
The SD card device will have no chance to be created.

This commit fixes this detection issue via the MMC_CAP2_CD_ACTIVE_HIGH cap2 flag,
parsed from the 'cd-inverted' property of DT.

Signed-off-by: Richard Clark <richard.xnu.clark@gmail.com>
---
 drivers/mmc/host/sdhci.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index c79f73459915..79f33a161ca8 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -2483,6 +2483,9 @@ static int sdhci_get_cd(struct mmc_host *mmc)
 	 * Try slot gpio detect, if defined it take precedence
 	 * over build in controller functionality
 	 */
+	if (!(mmc->caps2 & MMC_CAP2_CD_ACTIVE_HIGH))
+		gpio_cd = !gpio_cd;
+
 	if (gpio_cd >= 0)
 		return !!gpio_cd;
 
-- 
2.34.1