mmc: mmc: Read card's valid driver strength mask

In preparation for supporing drive strength selection
for eMMC, read the card's valid driver strengths.

Note that though the SD spec uses the term "drive strength",
the JEDEC eMMC spec uses the term "driver strength".

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 03c94c2..9b808d1 100644 (file)
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -437,6 +437,7 @@ static int mmc_decode_ext_csd(struct mmc_card *card, u8 *ext_csd)
        card->ext_csd.raw_trim_mult =
                ext_csd[EXT_CSD_TRIM_MULT];
        card->ext_csd.raw_partition_support = ext_csd[EXT_CSD_PARTITION_SUPPORT];
+       card->ext_csd.raw_driver_strength = ext_csd[EXT_CSD_DRIVER_STRENGTH];
        if (card->ext_csd.rev >= 4) {
                if (ext_csd[EXT_CSD_PARTITION_SETTING_COMPLETED] &
                    EXT_CSD_PART_SETTING_COMPLETED)

diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 2f073d5..4d3776d 100644 (file)
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -97,6 +97,7 @@ struct mmc_ext_csd {
        u8                      raw_erased_mem_count;   /* 181 */
        u8                      raw_ext_csd_structure;  /* 194 */
        u8                      raw_card_type;          /* 196 */
+       u8                      raw_driver_strength;    /* 197 */
        u8                      out_of_int_time;        /* 198 */
        u8                      raw_pwr_cl_52_195;      /* 200 */
        u8                      raw_pwr_cl_26_195;      /* 201 */

diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
index 124f562..4819cfb 100644 (file)
--- a/include/linux/mmc/mmc.h
+++ b/include/linux/mmc/mmc.h
@@ -302,6 +302,7 @@ struct _mmc_csd {
 #define EXT_CSD_REV                    192     /* RO */
 #define EXT_CSD_STRUCTURE              194     /* RO */
 #define EXT_CSD_CARD_TYPE              196     /* RO */
+#define EXT_CSD_DRIVER_STRENGTH                197     /* RO */
 #define EXT_CSD_OUT_OF_INTERRUPT_TIME  198     /* RO */
 #define EXT_CSD_PART_SWITCH_TIME        199     /* RO */
 #define EXT_CSD_PWR_CL_52_195          200     /* RO */