lkml.org 
[lkml]   [2018]   [Jan]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v3 1/2] phy: rockchip-emmc: retry calpad busy trimming
Date
From: Shawn Lin <shawn.lin@rock-chips.com>

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>
---

Changes in v3:
- As Doug commented on both upstream and gerrit.
Change "5, 50" to "0, 50", and the message of print.

Changes in v2:
- print the return valut with regmap_read_poll_timeout failing.

drivers/phy/rockchip/phy-rockchip-emmc.c | 27 +++++++++++++++++----------
1 file changed, 17 insertions(+), 10 deletions(-)

diff --git a/drivers/phy/rockchip/phy-rockchip-emmc.c b/drivers/phy/rockchip/phy-rockchip-emmc.c
index f1b24f1..b0d1093 100644
--- 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 */
--
2.7.4
\
 
 \ /
  Last update: 2018-01-14 23:22    [W:0.070 / U:6.380 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site