Implement polling with 10 ms timeout for automatic pad drive strength
calibration.

Signed-off-by: Aapo Vienamo <avien...@nvidia.com>
---
 drivers/mmc/host/sdhci-tegra.c | 24 +++++++++++++++++++-----
 1 file changed, 19 insertions(+), 5 deletions(-)

diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c
index f108c48..e40ca43 100644
--- a/drivers/mmc/host/sdhci-tegra.c
+++ b/drivers/mmc/host/sdhci-tegra.c
@@ -49,6 +49,9 @@
 #define SDHCI_AUTO_CAL_START                   BIT(31)
 #define SDHCI_AUTO_CAL_ENABLE                  BIT(29)
 
+#define SDHCI_TEGRA_AUTO_CAL_STATUS     0x1ec
+#define SDHCI_TEGRA_AUTO_CAL_ACTIVE     BIT(31)
+
 #define NVQUIRK_FORCE_SDHCI_SPEC_200   BIT(0)
 #define NVQUIRK_ENABLE_BLOCK_GAP_DET   BIT(1)
 #define NVQUIRK_ENABLE_SDHCI_SPEC_300  BIT(2)
@@ -198,13 +201,24 @@ static void tegra_sdhci_reset(struct sdhci_host *host, u8 
mask)
 
 static void tegra_sdhci_pad_autocalib(struct sdhci_host *host)
 {
-       u32 val;
+       unsigned timeout = 10;
+       u32 reg;
 
-       mdelay(1);
+       reg = sdhci_readl(host, SDHCI_TEGRA_AUTO_CAL_CONFIG);
+       reg |= SDHCI_AUTO_CAL_ENABLE | SDHCI_AUTO_CAL_START;
+       sdhci_writel(host, reg, SDHCI_TEGRA_AUTO_CAL_CONFIG);
+       udelay(1);
+
+       do {
+               reg = sdhci_readl(host, SDHCI_TEGRA_AUTO_CAL_STATUS);
+               if (!(reg & SDHCI_TEGRA_AUTO_CAL_ACTIVE))
+                       break;
+               mdelay(1);
+               timeout--;
+       } while (timeout);
 
-       val = sdhci_readl(host, SDHCI_TEGRA_AUTO_CAL_CONFIG);
-       val |= SDHCI_AUTO_CAL_ENABLE | SDHCI_AUTO_CAL_START;
-       sdhci_writel(host,val, SDHCI_TEGRA_AUTO_CAL_CONFIG);
+       if (timeout == 0)
+               dev_err(mmc_dev(host->mmc), "Pad autocal timed out\n");
 }
 
 static void tegra_sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
-- 
2.7.4

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