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>

1 files changed, 18 insertions, 1 deletions

diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
index 08a55c2e96e1..85745ef179e2 100644
--- 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;