mmc: sdhci-of-esdhc: limit SD clock for ls1012a/ls1046a

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 <[email protected]> Acked-by: Adrian Hunter <[email protected]> Signed-off-by: Ulf Hansson <[email protected]>
josf · Apr 28, 2017 · a627f02 · a627f02
1 parent e145ac4
commit a627f02
Showing 1 changed file with 14 additions and 0 deletions.
diff --git a/drivers/mmc/host/sdhci-of-esdhc.c b/drivers/mmc/host/sdhci-of-esdhc.c
@@ -457,6 +457,20 @@ 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)