[PATCH] mmc: Fix force card detect in sdhci

From: mathieu
Date: Wed Aug 30 2023 - 15:14:54 EST


From: Mathieu Moneyron <mathieu.moneyron@xxxxxxxxx>

On the ATMEL at91 when using the non-removable flag in device tree and not
using the card-detect pin inside the device-tree pinctrl, the card detect
pin is physically still used which can cause unknown behaviour when this
pin is used for other purposes.

>From my interpretation this seems to be caused by a hardware design flaw
and the real hardware is not working as intended by the documentation.

Signed-off-by: Mathieu Moneyron <mathieu.moneyron@xxxxxxxxx>
---
drivers/mmc/host/sdhci-of-at91.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/drivers/mmc/host/sdhci-of-at91.c b/drivers/mmc/host/sdhci-of-at91.c
index 69fef88e7..4fd6bfbf6 100644
--- a/drivers/mmc/host/sdhci-of-at91.c
+++ b/drivers/mmc/host/sdhci-of-at91.c
@@ -51,10 +51,15 @@ struct sdhci_at91_priv {
static void sdhci_at91_set_force_card_detect(struct sdhci_host *host)
{
u8 mc1r;
+ u8 ctrl;

mc1r = readb(host->ioaddr + SDMMC_MC1R);
mc1r |= SDMMC_MC1R_FCD;
writeb(mc1r, host->ioaddr + SDMMC_MC1R);
+
+ ctrl = readb(host->ioaddr + SDHCI_HOST_CONTROL);
+ ctrl |= SDHCI_CTRL_CDTEST_INS | SDHCI_CTRL_CDTEST_EN;
+ writeb(ctrl, host->ioaddr + SDHCI_HOST_CONTROL);
}

static void sdhci_at91_set_clock(struct sdhci_host *host, unsigned int clock)
--
2.25.1