phy: rockchip-emmc: retry calpad busy trimming

It turns out that 5us isn't enough for all cases, so let's
retry some more times to wait for caldone.

Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Tested-by: Ziyuan Xu <xzy.xu@rock-chips.com>
Signed-off-by: Caesar Wang <wxt@rock-chips.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

diff --git a/drivers/phy/rockchip/phy-rockchip-emmc.c b/drivers/phy/rockchip/phy-rockchip-emmc.c
index f1b24f1..b0d1093 100644 (file)
--- a/drivers/phy/rockchip/phy-rockchip-emmc.c
+++ b/drivers/phy/rockchip/phy-rockchip-emmc.c
@@ -76,6 +76,10 @@
 #define PHYCTRL_OTAPDLYSEL_MASK                0xf
 #define PHYCTRL_OTAPDLYSEL_SHIFT       0x7
 
+#define PHYCTRL_IS_CALDONE(x) \
+       ((((x) >> PHYCTRL_CALDONE_SHIFT) & \
+         PHYCTRL_CALDONE_MASK) == PHYCTRL_CALDONE_DONE)
+
 struct rockchip_emmc_phy {
        unsigned int    reg_offset;
        struct regmap   *reg_base;
@@ -90,6 +94,7 @@ static int rockchip_emmc_phy_power(struct phy *phy, bool on_off)
        unsigned int freqsel = PHYCTRL_FREQSEL_200M;
        unsigned long rate;
        unsigned long timeout;
+       int ret;
 
        /*
         * Keep phyctrl_pdb and phyctrl_endll low to allow
@@ -160,17 +165,19 @@ static int rockchip_emmc_phy_power(struct phy *phy, bool on_off)
                                   PHYCTRL_PDB_SHIFT));
 
        /*
-        * According to the user manual, it asks driver to
-        * wait 5us for calpad busy trimming
+        * According to the user manual, it asks driver to wait 5us for
+        * calpad busy trimming. However it is documented that this value is
+        * PVT(A.K.A process,voltage and temperature) relevant, so some
+        * failure cases are found which indicates we should be more tolerant
+        * to calpad busy trimming.
         */
-       udelay(5);
-       regmap_read(rk_phy->reg_base,
-                   rk_phy->reg_offset + GRF_EMMCPHY_STATUS,
-                   &caldone);
-       caldone = (caldone >> PHYCTRL_CALDONE_SHIFT) & PHYCTRL_CALDONE_MASK;
-       if (caldone != PHYCTRL_CALDONE_DONE) {
-               pr_err("rockchip_emmc_phy_power: caldone timeout.\n");
-               return -ETIMEDOUT;
+       ret = regmap_read_poll_timeout(rk_phy->reg_base,
+                                      rk_phy->reg_offset + GRF_EMMCPHY_STATUS,
+                                      caldone, PHYCTRL_IS_CALDONE(caldone),
+                                      0, 50);
+       if (ret) {
+               pr_err("%s: caldone failed, ret=%d\n", __func__, ret);
+               return ret;
        }
 
        /* Set the frequency of the DLL operation */