mmc: sdhci-of-at91: force card detect value for non removable devices

[sfrench/cifs-2.6.git] / drivers / mmc / host / sdhci-of-at91.c

diff --git a/drivers/mmc/host/sdhci-of-at91.c b/drivers/mmc/host/sdhci-of-at91.c
index 7611fd679f1ad83d7dee4052aebb6e9f6d3168cf..1485530c35921744a5fac79f53e2f35c05e1b51d 100644 (file)
--- a/drivers/mmc/host/sdhci-of-at91.c
+++ b/drivers/mmc/host/sdhci-of-at91.c
@@ -31,6 +31,7 @@
 
 #define SDMMC_MC1R     0x204
 #define                SDMMC_MC1R_DDR          BIT(3)
+#define                SDMMC_MC1R_FCD          BIT(7)
 #define SDMMC_CACR     0x230
 #define                SDMMC_CACR_CAPWREN      BIT(0)
 #define                SDMMC_CACR_KEY          (0x46 << 8)
@@ -43,6 +44,15 @@ struct sdhci_at91_priv {
        struct clk *mainck;
 };
 
+static void sdhci_at91_set_force_card_detect(struct sdhci_host *host)
+{
+       u8 mc1r;
+
+       mc1r = readb(host->ioaddr + SDMMC_MC1R);
+       mc1r |= SDMMC_MC1R_FCD;
+       writeb(mc1r, host->ioaddr + SDMMC_MC1R);
+}
+
 static void sdhci_at91_set_clock(struct sdhci_host *host, unsigned int clock)
 {
        u16 clk;
@@ -110,10 +120,18 @@ void sdhci_at91_set_uhs_signaling(struct sdhci_host *host, unsigned int timing)
        sdhci_set_uhs_signaling(host, timing);
 }
 
+static void sdhci_at91_reset(struct sdhci_host *host, u8 mask)
+{
+       sdhci_reset(host, mask);
+
+       if (host->mmc->caps & MMC_CAP_NONREMOVABLE)
+               sdhci_at91_set_force_card_detect(host);
+}
+
 static const struct sdhci_ops sdhci_at91_sama5d2_ops = {
        .set_clock              = sdhci_at91_set_clock,
        .set_bus_width          = sdhci_set_bus_width,
-       .reset                  = sdhci_reset,
+       .reset                  = sdhci_at91_reset,
        .set_uhs_signaling      = sdhci_at91_set_uhs_signaling,
        .set_power              = sdhci_at91_set_power,
 };
@@ -324,6 +342,21 @@ static int sdhci_at91_probe(struct platform_device *pdev)
                host->quirks &= ~SDHCI_QUIRK_BROKEN_CARD_DETECTION;
        }
 
+       /*
+        * If the device attached to the MMC bus is not removable, it is safer
+        * to set the Force Card Detect bit. People often don't connect the
+        * card detect signal and use this pin for another purpose. If the card
+        * detect pin is not muxed to SDHCI controller, a default value is
+        * used. This value can be different from a SoC revision to another
+        * one. Problems come when this default value is not card present. To
+        * avoid this case, if the device is non removable then the card
+        * detection procedure using the SDMCC_CD signal is bypassed.
+        * This bit is reset when a software reset for all command is performed
+        * so we need to implement our own reset function to set back this bit.
+        */
+       if (host->mmc->caps & MMC_CAP_NONREMOVABLE)
+               sdhci_at91_set_force_card_detect(host);
+
        pm_runtime_put_autosuspend(&pdev->dev);
 
        return 0;