mmc: read the high capacity WP group size for eMMC

Read the eMMC high capacity write protect group size at mmc device
initialization. This is useful to correctly partition an eMMC device,
as partitions need to be aligned to this size.

Signed-off-by: Diego Santa Cruz <Diego.SantaCruz@spinetix.com>

drivers/mmc/mmc.c

@@ -1065,7 +1065,9 @@ static int mmc_startup(struct mmc *mmc)
 				return err;
 			else
 				ext_csd[EXT_CSD_ERASE_GROUP_DEF] = 1;
+		}
 
+		if (ext_csd[EXT_CSD_ERASE_GROUP_DEF] & 0x01) {
 			/* Read out group size from ext_csd */
 			mmc->erase_grp_size =
 				ext_csd[EXT_CSD_HC_ERASE_GRP_SIZE] * 1024;
@@ -1092,6 +1094,10 @@ static int mmc_startup(struct mmc *mmc)
 			mmc->erase_grp_size = (erase_gsz + 1)
 				* (erase_gmul + 1);
 		}
+
+		mmc->hc_wp_grp_size = 1024
+			* ext_csd[EXT_CSD_HC_ERASE_GRP_SIZE]
+			* ext_csd[EXT_CSD_HC_WP_GRP_SIZE];
 	}
 
 	err = mmc_set_capacity(mmc, mmc->part_num);

include/mmc.h

@@ -316,6 +316,7 @@ struct mmc {
 	uint read_bl_len;
 	uint write_bl_len;
 	uint erase_grp_size;	/* in 512-byte sectors */
+	uint hc_wp_grp_size;	/* in 512-byte sectors */
 	u64 capacity;
 	u64 capacity_user;
 	u64 capacity_boot;