mmc: compile out erase and write mmc commands if write operations are not enabled

Also remove erase_grp_size and write_bl_len from struct mmc as they are
not used anymore. On ARM, removing them saves about 100 bytes of code
space in SPL.

Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
diff --git a/cmd/mmc.c b/cmd/mmc.c
index 9a95293..65601d8 100644
--- a/cmd/mmc.c
+++ b/cmd/mmc.c
@@ -45,8 +45,10 @@
 	printf("Bus Width: %d-bit%s\n", mmc->bus_width,
 			mmc->ddr_mode ? " DDR" : "");
 
+#if CONFIG_IS_ENABLED(MMC_WRITE)
 	puts("Erase Group Size: ");
 	print_size(((u64)mmc->erase_grp_size) << 9, "\n");
+#endif
 
 	if (!IS_SD(mmc) && mmc->version >= MMC_VERSION_4_41) {
 		bool has_enh = (mmc->part_support & ENHNCD_SUPPORT) != 0;
@@ -302,6 +304,8 @@
 
 	return (n == cnt) ? CMD_RET_SUCCESS : CMD_RET_FAILURE;
 }
+
+#if CONFIG_IS_ENABLED(MMC_WRITE)
 static int do_mmc_write(cmd_tbl_t *cmdtp, int flag,
 			int argc, char * const argv[])
 {
@@ -360,6 +364,8 @@
 
 	return (n == cnt) ? CMD_RET_SUCCESS : CMD_RET_FAILURE;
 }
+#endif
+
 static int do_mmc_rescan(cmd_tbl_t *cmdtp, int flag,
 			 int argc, char * const argv[])
 {
@@ -792,8 +798,10 @@
 static cmd_tbl_t cmd_mmc[] = {
 	U_BOOT_CMD_MKENT(info, 1, 0, do_mmcinfo, "", ""),
 	U_BOOT_CMD_MKENT(read, 4, 1, do_mmc_read, "", ""),
+#if CONFIG_IS_ENABLED(MMC_WRITE)
 	U_BOOT_CMD_MKENT(write, 4, 0, do_mmc_write, "", ""),
 	U_BOOT_CMD_MKENT(erase, 3, 0, do_mmc_erase, "", ""),
+#endif
 	U_BOOT_CMD_MKENT(rescan, 1, 1, do_mmc_rescan, "", ""),
 	U_BOOT_CMD_MKENT(part, 1, 1, do_mmc_part, "", ""),
 	U_BOOT_CMD_MKENT(dev, 3, 0, do_mmc_dev, "", ""),
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index fd94987..3930aad 100644
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -2066,9 +2066,11 @@
 	}
 
 	if (ext_csd[EXT_CSD_ERASE_GROUP_DEF] & 0x01) {
+#if CONFIG_IS_ENABLED(MMC_WRITE)
 		/* Read out group size from ext_csd */
 		mmc->erase_grp_size =
 			ext_csd[EXT_CSD_HC_ERASE_GRP_SIZE] * 1024;
+#endif
 		/*
 		 * if high capacity and partition setting completed
 		 * SEC_COUNT is valid even if it is smaller than 2 GiB
@@ -2082,7 +2084,9 @@
 			capacity *= MMC_MAX_BLOCK_LEN;
 			mmc->capacity_user = capacity;
 		}
-	} else {
+	}
+#if CONFIG_IS_ENABLED(MMC_WRITE)
+	else {
 		/* Calculate the group size from the csd value. */
 		int erase_gsz, erase_gmul;
 
@@ -2091,7 +2095,7 @@
 		mmc->erase_grp_size = (erase_gsz + 1)
 			* (erase_gmul + 1);
 	}
-
+#endif
 	mmc->hc_wp_grp_size = 1024
 		* ext_csd[EXT_CSD_HC_ERASE_GRP_SIZE]
 		* ext_csd[EXT_CSD_HC_WP_GRP_SIZE];
@@ -2222,11 +2226,13 @@
 
 	mmc->dsr_imp = ((cmd.response[1] >> 12) & 0x1);
 	mmc->read_bl_len = 1 << ((cmd.response[1] >> 16) & 0xf);
+#if CONFIG_IS_ENABLED(MMC_WRITE)
 
 	if (IS_SD(mmc))
 		mmc->write_bl_len = mmc->read_bl_len;
 	else
 		mmc->write_bl_len = 1 << ((cmd.response[3] >> 22) & 0xf);
+#endif
 
 	if (mmc->high_capacity) {
 		csize = (mmc->csd[1] & 0x3f) << 16
@@ -2248,8 +2254,10 @@
 	if (mmc->read_bl_len > MMC_MAX_BLOCK_LEN)
 		mmc->read_bl_len = MMC_MAX_BLOCK_LEN;
 
+#if CONFIG_IS_ENABLED(MMC_WRITE)
 	if (mmc->write_bl_len > MMC_MAX_BLOCK_LEN)
 		mmc->write_bl_len = MMC_MAX_BLOCK_LEN;
+#endif
 
 	if ((mmc->dsr_imp) && (0xffffffff != mmc->dsr)) {
 		cmd.cmdidx = MMC_CMD_SET_DSR;
@@ -2273,7 +2281,9 @@
 	/*
 	 * For SD, its erase group is always one sector
 	 */
+#if CONFIG_IS_ENABLED(MMC_WRITE)
 	mmc->erase_grp_size = 1;
+#endif
 	mmc->part_config = MMCPART_NOAVAILABLE;
 
 	err = mmc_startup_v4(mmc);
@@ -2304,7 +2314,9 @@
 	/* Fix the block length for DDR mode */
 	if (mmc->ddr_mode) {
 		mmc->read_bl_len = MMC_MAX_BLOCK_LEN;
+#if CONFIG_IS_ENABLED(MMC_WRITE)
 		mmc->write_bl_len = MMC_MAX_BLOCK_LEN;
+#endif
 	}
 
 	/* fill in device description */
diff --git a/include/mmc.h b/include/mmc.h
index f50c714..3abeb58 100644
--- a/include/mmc.h
+++ b/include/mmc.h
@@ -585,8 +585,10 @@
 	uint tran_speed;
 	uint legacy_speed; /* speed for the legacy mode provided by the card */
 	uint read_bl_len;
+#if CONFIG_IS_ENABLED(MMC_WRITE)
 	uint write_bl_len;
 	uint erase_grp_size;	/* in 512-byte sectors */
+#endif
 	uint hc_wp_grp_size;	/* in 512-byte sectors */
 #if CONFIG_IS_ENABLED(MMC_WRITE)
 	struct sd_ssr	ssr;	/* SD status register */