[PATCH 4.16 199/272] phy: rockchip-emmc: retry calpad busy trimming

Greg Kroah-Hartman
2018-05-28T11:13:11Z

From: Shawn Lin <shawn.lin@rock-chips.com>

[ Upstream commit a4781c2a74b249cad814ceea7272997bbd20051e ]

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>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/phy/rockchip/phy-rockchip-emmc.c | 27 +++++++++++++++++----------
1 file changed, 17 insertions(+), 10 deletions(-)

--- 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(struc
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(struc
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 */