mmc: SDHC 3.0: correct f_min calculation for SD 3.0 spec

While we're at it, add symbols for SDHCI_MAX_DIV_SPEC_{200,300}.

Signed-off-by: Zhangfei Gao <zhangfei.gao@marvell.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

2 files changed, 12 insertions, 3 deletions

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index ac8b12b18fa4..e3c9153a87e8 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1006,14 +1006,14 @@ static void sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
                 if (host->max_clk <= clock)
                         div = 1;
                 else {
-                        for (div = 2; div < 2046; div += 2) {
+                        for (div = 2; div < SDHCI_MAX_DIV_SPEC_300; 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) {
+                for (div = 1; div < SDHCI_MAX_DIV_SPEC_200; div *= 2) {
                         if ((host->max_clk / div) <= clock)
                                 break;
                 }
@@ -1835,8 +1835,10 @@ int sdhci_add_host(struct sdhci_host *host)
         mmc->ops = &sdhci_ops;
         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
-                mmc->f_min = host->max_clk / 256;
+                mmc->f_min = host->max_clk / SDHCI_MAX_DIV_SPEC_200;
         mmc->f_max = host->max_clk;
         mmc->caps |= MMC_CAP_SDIO_IRQ;
 
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index ae28a310a6a1..112543ae36c9 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -185,6 +185,13 @@
 #define   SDHCI_SPEC_200        1
 #define   SDHCI_SPEC_300        2
 
+/*
+ * End of controller registers.
+ */
+
+#define SDHCI_MAX_DIV_SPEC_200  256
+#define SDHCI_MAX_DIV_SPEC_300  2046
+
 struct sdhci_ops;
 
 struct sdhci_host {