[PATCH AUTOSEL for 4.4 060/101] mmc: sdhci-of-esdhc: limit SD clock for ls1012a/ls1046a

Sasha Levin
2018-03-08T05:31:40Z

From: yangbo lu <yangbo.lu@nxp.com>

[ Upstream commit a627f025eb0534052ff451427c16750b3530634c ]

The ls1046a datasheet specified that the max SD clock frequency
for eSDHC SDR104/HS200 was 167MHz, and the ls1012a datasheet
specified it's 125MHz for ls1012a. So this patch is to add the
limitation.

Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
drivers/mmc/host/sdhci-of-esdhc.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)

diff --git a/drivers/mmc/host/sdhci-of-esdhc.c b/drivers/mmc/host/sdhci-of-esdhc.c
index 83b1226471c1..ac66c61d9433 100644
--- a/drivers/mmc/host/sdhci-of-esdhc.c
+++ b/drivers/mmc/host/sdhci-of-esdhc.c
@@ -418,6 +418,20 @@ static void esdhc_of_set_clock(struct sdhci_host *host, unsigned int clock)
if (esdhc->vendor_ver < VENDOR_V_23)
pre_div = 2;

+ /*
+ * Limit SD clock to 167MHz for ls1046a according to its datasheet
+ */
+ if (clock > 167000000 &&
+ of_find_compatible_node(NULL, NULL, "fsl,ls1046a-esdhc"))
+ clock = 167000000;
+
+ /*
+ * Limit SD clock to 125MHz for ls1012a according to its datasheet
+ */
+ if (clock > 125000000 &&
+ of_find_compatible_node(NULL, NULL, "fsl,ls1012a-esdhc"))
+ clock = 125000000;
+
/* Workaround to reduce the clock frequency for p1010 esdhc */
if (of_find_compatible_node(NULL, NULL, "fsl,p1010-esdhc")) {
if (clock > 20000000)
--
2.14.1