local/mmc: dw_mmc: exynos: dynamically adjust the SAMPLE_CLK_TUNING

This is workaround patch.
Some board doesn't work fine, when send the tuning command.
It's related with CLK_TUNING bits.
But every board doesn't work fine with same values.
(In future, needs to analysis this problem.)

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>

diff --git a/drivers/mmc/host/dw_mmc-exynos.c b/drivers/mmc/host/dw_mmc-exynos.c
index 90cdafc..5c9c203 100644 (file)
--- a/drivers/mmc/host/dw_mmc-exynos.c
+++ b/drivers/mmc/host/dw_mmc-exynos.c
@@ -433,8 +433,9 @@ static inline void dw_mci_exynos_set_clksmpl(struct dw_mci *host, u8 sample)
 static inline u8 dw_mci_exynos_move_next_clksmpl(struct dw_mci *host)
 {
        struct dw_mci_exynos_priv_data *priv = host->priv;
+       const u8 clk_tuning[] = {3, 0};
        u32 clksel;
-       u8 sample;
+       u8 sample, idx;
 
        if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
                priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
@@ -443,14 +444,21 @@ static inline u8 dw_mci_exynos_move_next_clksmpl(struct dw_mci *host)
                clksel = mci_readl(host, CLKSEL);
 
        sample = (clksel + 1) & 0x7;
-       clksel = SDMMC_CLKSEL_UP_SAMPLE(clksel, sample) |
-               SDMMC_CLKSEL_SAMPLE_CLK_TUNING(0x3) |
-               SDMMC_CLKSEL_CORE_CLK_TUNING(0x1);
+       clksel = SDMMC_CLKSEL_UP_SAMPLE(clksel, sample);
 
        if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
-               priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
+               priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU) {
+               /*
+                * Workaround for Exynos5433 TM2 board.
+                * If other Exynos variants are not working,
+                * needs to set other value.
+                */
+               idx = sample / 7;
+               clksel |= SDMMC_CLKSEL_SAMPLE_CLK_TUNING(clk_tuning[idx]) |
+               SDMMC_CLKSEL_CORE_CLK_TUNING(0x1);
+
                mci_writel(host, CLKSEL64, clksel);
-       else
+       } else
                mci_writel(host, CLKSEL, clksel);
 
        return sample;