mmc: msm_sdcc: set DDR timing mode before setting the clock rate
Setting DDR timing mode in controller before setting the clock
rate will make sure that card don't see the double clock rate
even for very small amount duration. Some eMMC cards seems to lock
up if they see clock frequency > 52MHz.
(cherry picked from commit 2877d919135791d5223a9ba94b2cfc9ba50bc3df)
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
Change-Id: I7a4ace461e2def6d53863db4b768ec7e497b3095
Signed-off-by: Neha Pandey <nehap@codeaurora.org>
diff --git a/drivers/mmc/host/msm_sdcc.c b/drivers/mmc/host/msm_sdcc.c
index 8bac4ef..353b439 100644
--- a/drivers/mmc/host/msm_sdcc.c
+++ b/drivers/mmc/host/msm_sdcc.c
@@ -3156,8 +3156,21 @@
/*
* For DDR50 mode, controller needs clock rate to be
* double than what is required on the SD card CLK pin.
+ *
+ * Setting DDR timing mode in controller before setting the
+ * clock rate will make sure that card don't see the double
+ * clock rate even for very small duration. Some eMMC
+ * cards seems to lock up if they see clock frequency > 52MHz.
*/
if (ios->timing == MMC_TIMING_UHS_DDR50) {
+ u32 clk;
+
+ clk = readl_relaxed(host->base + MMCICLOCK);
+ clk &= ~(0x7 << 14); /* clear SELECT_IN field */
+ clk |= (3 << 14); /* set DDR timing mode */
+ writel_relaxed(clk, host->base + MMCICLOCK);
+ msmsdcc_sync_reg_wr(host);
+
/*
* Make sure that we don't double the clock if
* doubled clock rate is already set