mmc: meson-gx: include tx phase in the tuning process

It has been reported that some platforms (odroid-c2) may require
a different tx phase setting to operate at high speed (hs200 and hs400)

To improve the situation, this patch includes tx phase in the tuning
process.

Fixes: d341ca88eead ("mmc: meson-gx: rework tuning function")
Reported-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
index 08a55c2e96e1b409db9c6f7f99997e05666f02b6..85745ef179e22b2e49e4b23e15df311891f192dc 100644 (file)
--- a/drivers/mmc/host/meson-gx-mmc.c
+++ b/drivers/mmc/host/meson-gx-mmc.c
@@ -716,6 +716,22 @@ static int meson_mmc_clk_phase_tuning(struct mmc_host *mmc, u32 opcode,
 static int meson_mmc_execute_tuning(struct mmc_host *mmc, u32 opcode)
 {
        struct meson_host *host = mmc_priv(mmc);
+       int ret;
+
+       /*
+        * If this is the initial tuning, try to get a sane Rx starting
+        * phase before doing the actual tuning.
+        */
+       if (!mmc->doing_retune) {
+               ret = meson_mmc_clk_phase_tuning(mmc, opcode, host->rx_clk);
+
+               if (ret)
+                       return ret;
+       }
+
+       ret = meson_mmc_clk_phase_tuning(mmc, opcode, host->tx_clk);
+       if (ret)
+               return ret;
 
        return meson_mmc_clk_phase_tuning(mmc, opcode, host->rx_clk);
 }
@@ -746,8 +762,9 @@ static void meson_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
                if (!IS_ERR(mmc->supply.vmmc))
                        mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, ios->vdd);
 
-               /* Reset rx phase */
+               /* Reset phases */
                clk_set_phase(host->rx_clk, 0);
+               clk_set_phase(host->tx_clk, 270);
 
                break;