3 files changed, 70 insertions, 15 deletions

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index a1ab22415883..07cca557c4b5 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1013,8 +1013,8 @@ static void sdhci_finish_command(struct sdhci_host *host)
 
 static void sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
 {
-        int div;
-        u16 clk;
+        int div = 0; /* Initialized for compiler warning */
+        u16 clk = 0;
         unsigned long timeout;
 
         if (clock == host->clock)
@@ -1032,14 +1032,45 @@ static void sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
                 goto out;
 
         if (host->version >= SDHCI_SPEC_300) {
-                /* Version 3.00 divisors must be a multiple of 2. */
-                if (host->max_clk <= clock)
-                        div = 1;
-                else {
-                        for (div = 2; div < SDHCI_MAX_DIV_SPEC_300; div += 2) {
-                                if ((host->max_clk / div) <= clock)
-                                        break;
+                /*
+                 * Check if the Host Controller supports Programmable Clock
+                 * Mode.
+                 */
+                if (host->clk_mul) {
+                        u16 ctrl;
+
+                        /*
+                         * We need to figure out whether the Host Driver needs
+                         * to select Programmable Clock Mode, or the value can
+                         * be set automatically by the Host Controller based on
+                         * the Preset Value registers.
+                         */
+                        ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
+                        if (!(ctrl & SDHCI_CTRL_PRESET_VAL_ENABLE)) {
+                                for (div = 1; div <= 1024; div++) {
+                                        if (((host->max_clk * host->clk_mul) /
+                                              div) <= clock)
+                                                break;
+                                }
+                                /*
+                                 * Set Programmable Clock Mode in the Clock
+                                 * Control register.
+                                 */
+                                clk = SDHCI_PROG_CLOCK_MODE;
+                                div--;
+                        }
+                } else {
+                        /* Version 3.00 divisors must be a multiple of 2. */
+                        if (host->max_clk <= clock)
+                                div = 1;
+                        else {
+                                for (div = 2; div < SDHCI_MAX_DIV_SPEC_300;
+                                     div += 2) {
+                                        if ((host->max_clk / div) <= clock)
+                                                break;
+                                }
                         }
+                        div >>= 1;
                 }
         } else {
                 /* Version 2.00 divisors must be a power of 2. */
@@ -1047,10 +1078,10 @@ static void sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
                         if ((host->max_clk / div) <= clock)
                                 break;
                 }
+                div >>= 1;
         }
-        div >>= 1;
 
-        clk = (div & SDHCI_DIV_MASK) << SDHCI_DIVIDER_SHIFT;
+        clk |= (div & SDHCI_DIV_MASK) << SDHCI_DIVIDER_SHIFT;
         clk |= ((div & SDHCI_DIV_HI_MASK) >> SDHCI_DIV_MASK_LEN)
                 << SDHCI_DIVIDER_HI_SHIFT;
         clk |= SDHCI_CLOCK_INT_EN;
@@ -2308,17 +2339,37 @@ int sdhci_add_host(struct sdhci_host *host)
                 host->timeout_clk *= 1000;
 
         /*
+         * In case of Host Controller v3.00, find out whether clock
+         * multiplier is supported.
+         */
+        host->clk_mul = (caps[1] & SDHCI_CLOCK_MUL_MASK) >>
+                        SDHCI_CLOCK_MUL_SHIFT;
+
+        /*
+         * In case the value in Clock Multiplier is 0, then programmable
+         * clock mode is not supported, otherwise the actual clock
+         * multiplier is one more than the value of Clock Multiplier
+         * in the Capabilities Register.
+         */
+        if (host->clk_mul)
+                host->clk_mul += 1;
+
+        /*
          * Set host parameters.
          */
         mmc->ops = &sdhci_ops;
+        mmc->f_max = host->max_clk;
         if (host->ops->get_min_clock)
                 mmc->f_min = host->ops->get_min_clock(host);
-        else if (host->version >= SDHCI_SPEC_300)
-                mmc->f_min = host->max_clk / SDHCI_MAX_DIV_SPEC_300;
-        else
+        else if (host->version >= SDHCI_SPEC_300) {
+                if (host->clk_mul) {
+                        mmc->f_min = (host->max_clk * host->clk_mul) / 1024;
+                        mmc->f_max = host->max_clk * host->clk_mul;
+                } else
+                        mmc->f_min = host->max_clk / SDHCI_MAX_DIV_SPEC_300;
+        } else
                 mmc->f_min = host->max_clk / SDHCI_MAX_DIV_SPEC_200;
 
-        mmc->f_max = host->max_clk;
         mmc->caps |= MMC_CAP_SDIO_IRQ | MMC_CAP_ERASE;
 
         /*
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index e62367491eee..6b0a0ee9ac6e 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -101,6 +101,7 @@
 #define  SDHCI_DIV_MASK 0xFF
 #define  SDHCI_DIV_MASK_LEN     8
 #define  SDHCI_DIV_HI_MASK      0x300
+#define  SDHCI_PROG_CLOCK_MODE  0x0020
 #define  SDHCI_CLOCK_CARD_EN    0x0004
 #define  SDHCI_CLOCK_INT_STABLE 0x0002
 #define  SDHCI_CLOCK_INT_EN     0x0001
@@ -191,6 +192,8 @@
 #define  SDHCI_DRIVER_TYPE_C    0x00000020
 #define  SDHCI_DRIVER_TYPE_D    0x00000040
 #define  SDHCI_USE_SDR50_TUNING 0x00002000
+#define  SDHCI_CLOCK_MUL_MASK   0x00FF0000
+#define  SDHCI_CLOCK_MUL_SHIFT  16
 
 #define SDHCI_CAPABILITIES_1    0x44
 
diff --git a/include/linux/mmc/sdhci.h b/include/linux/mmc/sdhci.h
index b74c8530e959..a88a799ed7c3 100644
--- a/include/linux/mmc/sdhci.h
+++ b/include/linux/mmc/sdhci.h
@@ -117,6 +117,7 @@ struct sdhci_host {
 
         unsigned int max_clk;   /* Max possible freq (MHz) */
         unsigned int timeout_clk;       /* Timeout freq (KHz) */
+        unsigned int clk_mul;   /* Clock Muliplier value */
 
         unsigned int clock;     /* Current clock (MHz) */
         u8 pwr;                 /* Current voltage */