mmc: sdhci-esdhc: calculate sdclk divider from controller clock

The SDCLK is divided down from the host controller clock. Host
controller clock may be different from the maximum SDCLK, so
get it from the platform, instead of just using the max SDCLK.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
index 98f4670..eb1310c 100644
--- a/drivers/mmc/host/sdhci-esdhc-imx.c
+++ b/drivers/mmc/host/sdhci-esdhc-imx.c
@@ -391,6 +391,14 @@
 	return clk_get_rate(pltfm_host->clk) / 256 / 16;
 }
 
+static inline void esdhc_pltfm_set_clock(struct sdhci_host *host,
+					 unsigned int clock)
+{
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+
+	esdhc_set_clock(host, clock, clk_get_rate(pltfm_host->clk));
+}
+
 static unsigned int esdhc_pltfm_get_ro(struct sdhci_host *host)
 {
 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
@@ -438,7 +446,7 @@
 	.write_l = esdhc_writel_le,
 	.write_w = esdhc_writew_le,
 	.write_b = esdhc_writeb_le,
-	.set_clock = esdhc_set_clock,
+	.set_clock = esdhc_pltfm_set_clock,
 	.get_max_clock = sdhci_pltfm_clk_get_max_clock,
 	.get_min_clock = esdhc_pltfm_get_min_clock,
 	.get_ro = esdhc_pltfm_get_ro,