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>

3 files changed, 15 insertions, 6 deletions

diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
index 98f46704baa6..eb1310ca021e 100644
--- a/drivers/mmc/host/sdhci-esdhc-imx.c
+++ b/drivers/mmc/host/sdhci-esdhc-imx.c
@@ -391,6 +391,14 @@ static unsigned int esdhc_pltfm_get_min_clock(struct sdhci_host *host)
         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 @@ static const struct sdhci_ops sdhci_esdhc_ops = {
         .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,
diff --git a/drivers/mmc/host/sdhci-esdhc.h b/drivers/mmc/host/sdhci-esdhc.h
index d25f9ab9a54d..6f16406c37cd 100644
--- a/drivers/mmc/host/sdhci-esdhc.h
+++ b/drivers/mmc/host/sdhci-esdhc.h
@@ -42,7 +42,8 @@
 
 #define ESDHC_HOST_CONTROL_RES  0x05
 
-static inline void esdhc_set_clock(struct sdhci_host *host, unsigned int clock)
+static inline void esdhc_set_clock(struct sdhci_host *host, unsigned int clock,
+                                   unsigned int host_clock)
 {
         int pre_div = 2;
         int div = 1;
@@ -56,14 +57,14 @@ static inline void esdhc_set_clock(struct sdhci_host *host, unsigned int clock)
                 | ESDHC_CLOCK_MASK);
         sdhci_writel(host, temp, ESDHC_SYSTEM_CONTROL);
 
-        while (host->max_clk / pre_div / 16 > clock && pre_div < 256)
+        while (host_clock / pre_div / 16 > clock && pre_div < 256)
                 pre_div *= 2;
 
-        while (host->max_clk / pre_div / div > clock && div < 16)
+        while (host_clock / pre_div / div > clock && div < 16)
                 div++;
 
         dev_dbg(mmc_dev(host->mmc), "desired SD clock: %d, actual: %d\n",
-                clock, host->max_clk / pre_div / div);
+                clock, host_clock / pre_div / div);
 
         pre_div >>= 1;
         div--;
diff --git a/drivers/mmc/host/sdhci-of-esdhc.c b/drivers/mmc/host/sdhci-of-esdhc.c
index 37e668f5b992..2b7369729f91 100644
--- a/drivers/mmc/host/sdhci-of-esdhc.c
+++ b/drivers/mmc/host/sdhci-of-esdhc.c
@@ -200,7 +200,7 @@ static void esdhc_of_set_clock(struct sdhci_host *host, unsigned int clock)
         }
 
         /* Set the clock */
-        esdhc_set_clock(host, clock);
+        esdhc_set_clock(host, clock, host->max_clk);
 }
 
 #ifdef CONFIG_PM