MMC: Fix for capacity calculation on eMMC

  The current mmc driver returns erroneous capacity information for
  eMMC.  The capacity of eMMC devices is available only in the ext-CSD
  register.  This patch add code to read the ext-CDSD register and
  correctly calculate eMMC capacity.

Signed-off-by: Sukumar Ghorai <s-ghorai@ti.com>
Acked-by: Steve Sakoman <steve@sakoman.com>

diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index 80cd9bff9bb8e23ed2fd08976d71cea56fb357fc..c543d837dc7e286dff1b28546e3ba7af7fd58dd0 100644 (file)
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -627,6 +627,7 @@ int mmc_startup(struct mmc *mmc)
        uint mult, freq;
        u64 cmult, csize;
        struct mmc_cmd cmd;
+       char ext_csd[512];
 
        /* Put the Card in Identify Mode */
        cmd.cmdidx = MMC_CMD_ALL_SEND_CID;
@@ -742,6 +743,16 @@ int mmc_startup(struct mmc *mmc)
        if (err)
                return err;
 
+       if (!IS_SD(mmc) && (mmc->version >= MMC_VERSION_4)) {
+               /* check  ext_csd version and capacity */
+               err = mmc_send_ext_csd(mmc, ext_csd);
+               if (!err & (ext_csd[192] >= 2)) {
+                       mmc->capacity = ext_csd[212] << 0 | ext_csd[213] << 8 |
+                                       ext_csd[214] << 16 | ext_csd[215] << 24;
+                       mmc->capacity *= 512;
+               }
+       }
+
        if (IS_SD(mmc))
                err = sd_change_freq(mmc);
        else