mmc: SDHC 3.0: support 10-bit divided clock mode

Signed-off-by: Zhangfei Gao <zgao6@marvell.com>
Cc: Michał Mirosław <mirqus@gmail.com>
Cc: David Vrabel <david.vrabel@csr.com>
Reviewed-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Chris Ball <cjb@laptop.org>

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index e0536175185a00df4648491a4abc854321313140..4432fec7467a2cdda56049411aec973f17004f01 100644 (file)
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1001,13 +1001,28 @@ static void sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
        if (clock == 0)
                goto out;
 
-       for (div = 1;div < 256;div *= 2) {
-               if ((host->max_clk / div) <= clock)
-                       break;
+       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 < 2046; div += 2) {
+                               if ((host->max_clk / div) <= clock)
+                                       break;
+                       }
+               }
+       } else {
+               /* Version 2.00 divisors must be a power of 2. */
+               for (div = 1; div < 256; div *= 2) {
+                       if ((host->max_clk / div) <= clock)
+                               break;
+               }
        }
        div >>= 1;
 
-       clk = div << 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;
        sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
 
@@ -1708,7 +1723,7 @@ int sdhci_add_host(struct sdhci_host *host)
        host->version = sdhci_readw(host, SDHCI_HOST_VERSION);
        host->version = (host->version & SDHCI_SPEC_VER_MASK)
                                >> SDHCI_SPEC_VER_SHIFT;
-       if (host->version > SDHCI_SPEC_200) {
+       if (host->version > SDHCI_SPEC_300) {
                printk(KERN_ERR "%s: Unknown controller version (%d). "
                        "You may experience problems.\n", mmc_hostname(mmc),
                        host->version);

diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index d316bc79b63689048c751daff28b806a7ebdfb0f..950d4fd90072e827b56c2027ae145cbf2eefa26b 100644 (file)
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -86,6 +86,10 @@
 
 #define SDHCI_CLOCK_CONTROL    0x2C
 #define  SDHCI_DIVIDER_SHIFT   8
+#define  SDHCI_DIVIDER_HI_SHIFT        6
+#define  SDHCI_DIV_MASK        0xFF
+#define  SDHCI_DIV_MASK_LEN    8
+#define  SDHCI_DIV_HI_MASK     0x300
 #define  SDHCI_CLOCK_CARD_EN   0x0004
 #define  SDHCI_CLOCK_INT_STABLE        0x0002
 #define  SDHCI_CLOCK_INT_EN    0x0001
@@ -178,6 +182,7 @@
 #define  SDHCI_SPEC_VER_SHIFT  0
 #define   SDHCI_SPEC_100       0
 #define   SDHCI_SPEC_200       1
+#define   SDHCI_SPEC_300       2
 
 struct sdhci_ops;