mmc: sdhci-omap: Add special reset capability

Some omap controllers need software to monitor a 0->1->0 for software
reset. Add a SDHCI_OMAP_SPECIAL_RESET flag to indicate this.

Signed-off-by: Faiz Abbas <faiz_abbas@ti.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/20200116105154.7685-11-faiz_abbas@ti.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/mmc/host/sdhci-omap.c b/drivers/mmc/host/sdhci-omap.c
index 5433c9e..8820531 100644 (file)
--- a/drivers/mmc/host/sdhci-omap.c
+++ b/drivers/mmc/host/sdhci-omap.c
@@ -86,6 +86,7 @@
 
 /* sdhci-omap controller flags */
 #define SDHCI_OMAP_REQUIRE_IODELAY     BIT(0)
+#define SDHCI_OMAP_SPECIAL_RESET       BIT(1)
 
 struct sdhci_omap_data {
        u32 offset;
@@ -779,15 +780,35 @@ static void sdhci_omap_set_uhs_signaling(struct sdhci_host *host,
        sdhci_omap_start_clock(omap_host);
 }
 
+#define MMC_TIMEOUT_US         20000           /* 20000 micro Sec */
 static void sdhci_omap_reset(struct sdhci_host *host, u8 mask)
 {
        struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
        struct sdhci_omap_host *omap_host = sdhci_pltfm_priv(pltfm_host);
+       unsigned long limit = MMC_TIMEOUT_US;
+       unsigned long i = 0;
 
        /* Don't reset data lines during tuning operation */
        if (omap_host->is_tuning)
                mask &= ~SDHCI_RESET_DATA;
 
+       if (omap_host->flags & SDHCI_OMAP_SPECIAL_RESET) {
+               sdhci_writeb(host, mask, SDHCI_SOFTWARE_RESET);
+               while ((!(sdhci_readb(host, SDHCI_SOFTWARE_RESET) & mask)) &&
+                      (i++ < limit))
+                       udelay(1);
+               i = 0;
+               while ((sdhci_readb(host, SDHCI_SOFTWARE_RESET) & mask) &&
+                      (i++ < limit))
+                       udelay(1);
+
+               if (sdhci_readb(host, SDHCI_SOFTWARE_RESET) & mask)
+                       dev_err(mmc_dev(host->mmc),
+                               "Timeout waiting on controller reset in %s\n",
+                               __func__);
+               return;
+       }
+
        sdhci_reset(host, mask);
 }
 
@@ -900,10 +921,12 @@ static const struct sdhci_omap_data k2g_data = {
 
 static const struct sdhci_omap_data am335_data = {
        .offset = 0x200,
+       .flags = SDHCI_OMAP_SPECIAL_RESET,
 };
 
 static const struct sdhci_omap_data am437_data = {
        .offset = 0x200,
+       .flags = SDHCI_OMAP_SPECIAL_RESET,
 };
 
 static const struct sdhci_omap_data dra7_data = {