dm: block: Adjust device calls to go through helpers function

To ease conversion to driver model, add helper functions which deal with
calling each block device method. With driver model we can reimplement these
functions with the same arguments.

Use inline functions to avoid increasing code size on some boards.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Stephen Warren <swarren@nvidia.com>

16 files changed, 94 insertions, 87 deletions

diff --git a/cmd/disk.c b/cmd/disk.c
index 27ed115d2f..e0219f810e 100644
--- a/cmd/disk.c
+++ b/cmd/disk.c
@@ -56,7 +56,7 @@ int common_diskboot(cmd_tbl_t *cmdtp, const char *intf, int argc,
 	      ", Block Size: %ld\n",
 	      info.start, info.size, info.blksz);
 
-	if (dev_desc->block_read(dev_desc, info.start, 1, (ulong *)addr) != 1) {
+	if (blk_dread(dev_desc, info.start, 1, (ulong *)addr) != 1) {
 		printf("** Read error on %d:%d\n", dev, part);
 		bootstage_error(BOOTSTAGE_ID_IDE_PART_READ);
 		return 1;
@@ -100,8 +100,8 @@ int common_diskboot(cmd_tbl_t *cmdtp, const char *intf, int argc,
 	cnt /= info.blksz;
 	cnt -= 1;
 
-	if (dev_desc->block_read(dev_desc, info.start + 1, cnt,
-				 (ulong *)(addr + info.blksz)) != cnt) {
+	if (blk_dread(dev_desc, info.start + 1, cnt,
+		      (ulong *)(addr + info.blksz)) != cnt) {
 		printf("** Read error on %d:%d\n", dev, part);
 		bootstage_error(BOOTSTAGE_ID_IDE_READ);
 		return 1;
diff --git a/cmd/ide.c b/cmd/ide.c
index dfd55480b7..c4c08c8855 100644
--- a/cmd/ide.c
+++ b/cmd/ide.c
@@ -10,6 +10,7 @@
  */
 
 #include <common.h>
+#include <blk.h>
 #include <config.h>
 #include <watchdog.h>
 #include <command.h>
@@ -203,8 +204,7 @@ int do_ide(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
 #endif
 
 			dev_desc = &ide_dev_desc[curr_device];
-			n = dev_desc->block_read(dev_desc, blk, cnt,
-						 (ulong *)addr);
+			n = blk_dread(dev_desc, blk, cnt, (ulong *)addr);
 			/* flush cache after read */
 			flush_cache(addr,
 				    cnt * ide_dev_desc[curr_device].blksz);
diff --git a/cmd/read.c b/cmd/read.c
index f8d766a713..61d8ce73e4 100644
--- a/cmd/read.c
+++ b/cmd/read.c
@@ -66,7 +66,7 @@ int do_read(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 		return 1;
 	}
 
-	if (dev_desc->block_read(dev_desc, offset + blk, cnt, addr) < 0) {
+	if (blk_read(dev_desc, offset + blk, cnt, addr) < 0) {
 		printf("Error reading blocks\n");
 		return 1;
 	}
diff --git a/cmd/usb.c b/cmd/usb.c
index 53fd6adb00..9ed5dc61ea 100644
--- a/cmd/usb.c
+++ b/cmd/usb.c
@@ -759,8 +759,7 @@ static int do_usb(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 			printf("\nUSB read: device %d block # %ld, count %ld"
 				" ... ", usb_stor_curr_dev, blk, cnt);
 			stor_dev = usb_stor_get_dev(usb_stor_curr_dev);
-			n = stor_dev->block_read(stor_dev, blk, cnt,
-						 (ulong *)addr);
+			n = blk_dread(stor_dev, blk, cnt, (ulong *)addr);
 			printf("%ld blocks read: %s\n", n,
 				(n == cnt) ? "OK" : "ERROR");
 			if (n == cnt)
@@ -781,8 +780,7 @@ static int do_usb(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 			printf("\nUSB write: device %d block # %ld, count %ld"
 				" ... ", usb_stor_curr_dev, blk, cnt);
 			stor_dev = usb_stor_get_dev(usb_stor_curr_dev);
-			n = stor_dev->block_write(stor_dev, blk, cnt,
-						(ulong *)addr);
+			n = blk_dwrite(stor_dev, blk, cnt, (ulong *)addr);
 			printf("%ld blocks write: %s\n", n,
 				(n == cnt) ? "OK" : "ERROR");
 			if (n == cnt)
diff --git a/common/fb_mmc.c b/common/fb_mmc.c
index da7949f6f0..e3abcc85be 100644
--- a/common/fb_mmc.c
+++ b/common/fb_mmc.c
@@ -6,6 +6,7 @@
 
 #include <config.h>
 #include <common.h>
+#include <blk.h>
 #include <errno.h>
 #include <fastboot.h>
 #include <fb_mmc.h>
@@ -58,7 +59,7 @@ static int fb_mmc_sparse_write(struct sparse_storage *storage,
 	struct blk_desc *dev_desc = sparse->dev_desc;
 	int ret;
 
-	ret = dev_desc->block_write(dev_desc, offset, size, data);
+	ret = blk_dwrite(dev_desc, offset, size, data);
 	if (!ret)
 		return -EIO;
 
@@ -84,7 +85,7 @@ static void write_raw_image(struct blk_desc *dev_desc, disk_partition_t *info,
 
 	puts("Flashing Raw Image\n");
 
-	blks = dev_desc->block_write(dev_desc, info->start, blkcnt, buffer);
+	blks = blk_dwrite(dev_desc, info->start, blkcnt, buffer);
 	if (blks != blkcnt) {
 		error("failed writing to device %d\n", dev_desc->devnum);
 		fastboot_fail(response_str, "failed writing to device");
diff --git a/disk/part_amiga.c b/disk/part_amiga.c
index d323b4bc1e..4a67689c75 100644
--- a/disk/part_amiga.c
+++ b/disk/part_amiga.c
@@ -140,7 +140,7 @@ struct rigid_disk_block *get_rdisk(struct blk_desc *dev_desc)
 
     for (i=0; i<limit; i++)
     {
-	ulong res = dev_desc->block_read(dev_desc, i, 1, (ulong *)block_buffer);
+	ulong res = blk_dread(dev_desc, i, 1, (ulong *)block_buffer);
 	if (res == 1)
 	{
 	    struct rigid_disk_block *trdb = (struct rigid_disk_block *)block_buffer;
@@ -182,7 +182,7 @@ struct bootcode_block *get_bootcode(struct blk_desc *dev_desc)
 
     for (i = 0; i < limit; i++)
     {
-	ulong res = dev_desc->block_read(dev_desc, i, 1, (ulong *)block_buffer);
+	ulong res = blk_dread(dev_desc, i, 1, (ulong *)block_buffer);
 	if (res == 1)
 	{
 	    struct bootcode_block *boot = (struct bootcode_block *)block_buffer;
@@ -258,8 +258,7 @@ static struct partition_block *find_partition(struct blk_desc *dev_desc,
 
     while (block != 0xFFFFFFFF)
     {
-	ulong res = dev_desc->block_read(dev_desc, block, 1,
-					 (ulong *)block_buffer);
+	ulong res = blk_dread(dev_desc, block, 1, (ulong *)block_buffer);
 	if (res == 1)
 	{
 	    p = (struct partition_block *)block_buffer;
@@ -355,7 +354,7 @@ static void print_part_amiga(struct blk_desc *dev_desc)
 
 	PRINTF("Trying to load block #0x%X\n", block);
 
-	res = dev_desc->block_read(dev_desc, block, 1, (ulong *)block_buffer);
+	res = blk_dread(dev_desc, block, 1, (ulong *)block_buffer);
 	if (res == 1)
 	{
 	    p = (struct partition_block *)block_buffer;
diff --git a/disk/part_dos.c b/disk/part_dos.c
index 5f8d949b84..0ed1374ab7 100644
--- a/disk/part_dos.c
+++ b/disk/part_dos.c
@@ -91,7 +91,7 @@ static int test_part_dos(struct blk_desc *dev_desc)
 {
 	ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, dev_desc->blksz);
 
-	if (dev_desc->block_read(dev_desc, 0, 1, (ulong *)buffer) != 1)
+	if (blk_dread(dev_desc, 0, 1, (ulong *)buffer) != 1)
 		return -1;
 
 	if (test_block_type(buffer) != DOS_MBR)
@@ -111,8 +111,7 @@ static void print_partition_extended(struct blk_desc *dev_desc,
 	dos_partition_t *pt;
 	int i;
 
-	if (dev_desc->block_read(dev_desc, ext_part_sector, 1,
-				 (ulong *)buffer) != 1) {
+	if (blk_dread(dev_desc, ext_part_sector, 1, (ulong *)buffer) != 1) {
 		printf ("** Can't read partition table on %d:" LBAFU " **\n",
 			dev_desc->devnum, ext_part_sector);
 		return;
@@ -177,8 +176,7 @@ static int part_get_info_extended(struct blk_desc *dev_desc,
 	int i;
 	int dos_type;
 
-	if (dev_desc->block_read(dev_desc, ext_part_sector, 1,
-				 (ulong *)buffer) != 1) {
+	if (blk_dread(dev_desc, ext_part_sector, 1, (ulong *)buffer) != 1) {
 		printf ("** Can't read partition table on %d:" LBAFU " **\n",
 			dev_desc->devnum, ext_part_sector);
 		return -1;
diff --git a/disk/part_efi.c b/disk/part_efi.c
index ae8cd7ea58..b20907b377 100644
--- a/disk/part_efi.c
+++ b/disk/part_efi.c
@@ -324,7 +324,7 @@ static int test_part_efi(struct blk_desc *dev_desc)
 	ALLOC_CACHE_ALIGN_BUFFER_PAD(legacy_mbr, legacymbr, 1, dev_desc->blksz);
 
 	/* Read legacy MBR from block 0 and validate it */
-	if ((dev_desc->block_read(dev_desc, 0, 1, (ulong *)legacymbr) != 1)
+	if ((blk_dread(dev_desc, 0, 1, (ulong *)legacymbr) != 1)
 		|| (is_pmbr_valid(legacymbr) != 1)) {
 		return -1;
 	}
@@ -354,7 +354,7 @@ static int set_protective_mbr(struct blk_desc *dev_desc)
 	p_mbr->partition_record[0].nr_sects = (u32) dev_desc->lba - 1;
 
 	/* Write MBR sector to the MMC device */
-	if (dev_desc->block_write(dev_desc, 0, 1, p_mbr) != 1) {
+	if (blk_dwrite(dev_desc, 0, 1, p_mbr) != 1) {
 		printf("** Can't write to device %d **\n",
 			dev_desc->devnum);
 		return -1;
@@ -386,24 +386,21 @@ int write_gpt_table(struct blk_desc *dev_desc,
 	gpt_h->header_crc32 = cpu_to_le32(calc_crc32);
 
 	/* Write the First GPT to the block right after the Legacy MBR */
-	if (dev_desc->block_write(dev_desc, 1, 1, gpt_h) != 1)
+	if (blk_dwrite(dev_desc, 1, 1, gpt_h) != 1)
 		goto err;
 
-	if (dev_desc->block_write(dev_desc, 2, pte_blk_cnt, gpt_e)
+	if (blk_dwrite(dev_desc, 2, pte_blk_cnt, gpt_e)
 	    != pte_blk_cnt)
 		goto err;
 
 	prepare_backup_gpt_header(gpt_h);
 
-	if (dev_desc->block_write(dev_desc,
-				  (lbaint_t)le64_to_cpu(gpt_h->last_usable_lba)
-				  + 1,
-				  pte_blk_cnt, gpt_e) != pte_blk_cnt)
+	if (blk_dwrite(dev_desc, (lbaint_t)le64_to_cpu(gpt_h->last_usable_lba)
+		       + 1, pte_blk_cnt, gpt_e) != pte_blk_cnt)
 		goto err;
 
-	if (dev_desc->block_write(dev_desc,
-				  (lbaint_t)le64_to_cpu(gpt_h->my_lba), 1,
-				  gpt_h) != 1)
+	if (blk_dwrite(dev_desc, (lbaint_t)le64_to_cpu(gpt_h->my_lba), 1,
+		       gpt_h) != 1)
 		goto err;
 
 	debug("GPT successfully written to block device!\n");
@@ -739,7 +736,7 @@ int write_mbr_and_gpt_partitions(struct blk_desc *dev_desc, void *buf)
 	/* write MBR */
 	lba = 0;	/* MBR is always at 0 */
 	cnt = 1;	/* MBR (1 block) */
-	if (dev_desc->block_write(dev_desc, lba, cnt, buf) != cnt) {
+	if (blk_dwrite(dev_desc, lba, cnt, buf) != cnt) {
 		printf("%s: failed writing '%s' (%d blks at 0x" LBAF ")\n",
 		       __func__, "MBR", cnt, lba);
 		return 1;
@@ -748,7 +745,7 @@ int write_mbr_and_gpt_partitions(struct blk_desc *dev_desc, void *buf)
 	/* write Primary GPT */
 	lba = GPT_PRIMARY_PARTITION_TABLE_LBA;
 	cnt = 1;	/* GPT Header (1 block) */
-	if (dev_desc->block_write(dev_desc, lba, cnt, gpt_h) != cnt) {
+	if (blk_dwrite(dev_desc, lba, cnt, gpt_h) != cnt) {
 		printf("%s: failed writing '%s' (%d blks at 0x" LBAF ")\n",
 		       __func__, "Primary GPT Header", cnt, lba);
 		return 1;
@@ -756,7 +753,7 @@ int write_mbr_and_gpt_partitions(struct blk_desc *dev_desc, void *buf)
 
 	lba = le64_to_cpu(gpt_h->partition_entry_lba);
 	cnt = gpt_e_blk_cnt;
-	if (dev_desc->block_write(dev_desc, lba, cnt, gpt_e) != cnt) {
+	if (blk_dwrite(dev_desc, lba, cnt, gpt_e) != cnt) {
 		printf("%s: failed writing '%s' (%d blks at 0x" LBAF ")\n",
 		       __func__, "Primary GPT Entries", cnt, lba);
 		return 1;
@@ -767,7 +764,7 @@ int write_mbr_and_gpt_partitions(struct blk_desc *dev_desc, void *buf)
 	/* write Backup GPT */
 	lba = le64_to_cpu(gpt_h->partition_entry_lba);
 	cnt = gpt_e_blk_cnt;
-	if (dev_desc->block_write(dev_desc, lba, cnt, gpt_e) != cnt) {
+	if (blk_dwrite(dev_desc, lba, cnt, gpt_e) != cnt) {
 		printf("%s: failed writing '%s' (%d blks at 0x" LBAF ")\n",
 		       __func__, "Backup GPT Entries", cnt, lba);
 		return 1;
@@ -775,7 +772,7 @@ int write_mbr_and_gpt_partitions(struct blk_desc *dev_desc, void *buf)
 
 	lba = le64_to_cpu(gpt_h->my_lba);
 	cnt = 1;	/* GPT Header (1 block) */
-	if (dev_desc->block_write(dev_desc, lba, cnt, gpt_h) != cnt) {
+	if (blk_dwrite(dev_desc, lba, cnt, gpt_h) != cnt) {
 		printf("%s: failed writing '%s' (%d blks at 0x" LBAF ")\n",
 		       __func__, "Backup GPT Header", cnt, lba);
 		return 1;
@@ -845,7 +842,7 @@ static int is_gpt_valid(struct blk_desc *dev_desc, u64 lba,
 	}
 
 	/* Read GPT Header from device */
-	if (dev_desc->block_read(dev_desc, (lbaint_t)lba, 1, pgpt_head) != 1) {
+	if (blk_dread(dev_desc, (lbaint_t)lba, 1, pgpt_head) != 1) {
 		printf("*** ERROR: Can't read GPT header ***\n");
 		return 0;
 	}
@@ -913,8 +910,7 @@ static gpt_entry *alloc_read_gpt_entries(struct blk_desc *dev_desc,
 	/* Read GPT Entries from device */
 	blk = le64_to_cpu(pgpt_head->partition_entry_lba);
 	blk_cnt = BLOCK_CNT(count, dev_desc);
-	if (dev_desc->block_read(dev_desc, blk, (lbaint_t)blk_cnt, pte)
-	    != blk_cnt) {
+	if (blk_dread(dev_desc, blk, (lbaint_t)blk_cnt, pte) != blk_cnt) {
 		printf("*** ERROR: Can't read GPT Entries ***\n");
 		free(pte);
 		return NULL;
diff --git a/disk/part_iso.c b/disk/part_iso.c
index c78ae21bf3..76eab3915f 100644
--- a/disk/part_iso.c
+++ b/disk/part_iso.c
@@ -63,7 +63,7 @@ int part_get_info_iso_verb(struct blk_desc *dev_desc, int part_num,
 
 	/* the first sector (sector 0x10) must be a primary volume desc */
 	blkaddr=PVD_OFFSET;
-	if (dev_desc->block_read(dev_desc, PVD_OFFSET, 1, (ulong *)tmpbuf) != 1)
+	if (blk_dread(dev_desc, PVD_OFFSET, 1, (ulong *)tmpbuf) != 1)
 		return -1;
 	if(ppr->desctype!=0x01) {
 		if(verb)
@@ -85,7 +85,7 @@ int part_get_info_iso_verb(struct blk_desc *dev_desc, int part_num,
 	PRINTF(" Lastsect:%08lx\n",lastsect);
 	for(i=blkaddr;i<lastsect;i++) {
 		PRINTF("Reading block %d\n", i);
-		if (dev_desc->block_read(dev_desc, i, 1, (ulong *)tmpbuf) != 1)
+		if (blk_dread(dev_desc, i, 1, (ulong *)tmpbuf) != 1)
 			return -1;
 		if(ppr->desctype==0x00)
 			break; /* boot entry found */
@@ -105,7 +105,7 @@ int part_get_info_iso_verb(struct blk_desc *dev_desc, int part_num,
 	}
 	bootaddr=le32_to_int(pbr->pointer);
 	PRINTF(" Boot Entry at: %08lX\n",bootaddr);
-	if (dev_desc->block_read(dev_desc, bootaddr, 1, (ulong *)tmpbuf) != 1) {
+	if (blk_dread(dev_desc, bootaddr, 1, (ulong *)tmpbuf) != 1) {
 		if(verb)
 			printf ("** Can't read Boot Entry at %lX on %d:%d **\n",
 				bootaddr, dev_desc->devnum, part_num);
diff --git a/disk/part_mac.c b/disk/part_mac.c
index 07bbc1988a..ce57b5739d 100644
--- a/disk/part_mac.c
+++ b/disk/part_mac.c
@@ -53,8 +53,7 @@ static int test_part_mac(struct blk_desc *dev_desc)
 
 	n = 1;	/* assuming at least one partition */
 	for (i=1; i<=n; ++i) {
-		if ((dev_desc->block_read(dev_desc, i, 1,
-					  (ulong *)mpart) != 1) ||
+		if ((blk_dread(dev_desc, i, 1, (ulong *)mpart) != 1) ||
 		    (mpart->signature != MAC_PARTITION_MAGIC) ) {
 			return (-1);
 		}
@@ -106,7 +105,7 @@ static void print_part_mac(struct blk_desc *dev_desc)
 		char c;
 
 		printf ("%4ld: ", i);
-		if (dev_desc->block_read(dev_desc, i, 1, (ulong *)mpart) != 1) {
+		if (blk_dread(dev_desc, i, 1, (ulong *)mpart) != 1) {
 			printf ("** Can't read Partition Map on %d:%ld **\n",
 				dev_desc->devnum, i);
 			return;
@@ -153,7 +152,7 @@ static void print_part_mac(struct blk_desc *dev_desc)
 static int part_mac_read_ddb(struct blk_desc *dev_desc,
 			     mac_driver_desc_t *ddb_p)
 {
-	if (dev_desc->block_read(dev_desc, 0, 1, (ulong *)ddb_p) != 1) {
+	if (blk_dread(dev_desc, 0, 1, (ulong *)ddb_p) != 1) {
 		printf ("** Can't read Driver Desriptor Block **\n");
 		return (-1);
 	}
@@ -182,7 +181,7 @@ static int part_mac_read_pdb(struct blk_desc *dev_desc, int part,
 		 * partition 1 first since this is the only way to
 		 * know how many partitions we have.
 		 */
-		if (dev_desc->block_read(dev_desc, n, 1, (ulong *)pdb_p) != 1) {
+		if (blk_dread(dev_desc, n, 1, (ulong *)pdb_p) != 1) {
 			printf ("** Can't read Partition Map on %d:%d **\n",
 				dev_desc->devnum, n);
 			return (-1);
diff --git a/fs/ext4/dev.c b/fs/ext4/dev.c
index 3eef66f847..ee84d3fbe1 100644
--- a/fs/ext4/dev.c
+++ b/fs/ext4/dev.c
@@ -24,6 +24,7 @@
  */
 
 #include <common.h>
+#include <blk.h>
 #include <config.h>
 #include <memalign.h>
 #include <ext4fs.h>
@@ -76,9 +77,8 @@ int ext4fs_devread(lbaint_t sector, int byte_offset, int byte_len, char *buf)
 	if (byte_offset != 0) {
 		int readlen;
 		/* read first part which isn't aligned with start of sector */
-		if (ext4fs_blk_desc->block_read(ext4fs_blk_desc,
-						part_info->start + sector,
-						1, (void *)sec_buf) != 1) {
+		if (blk_dread(ext4fs_blk_desc, part_info->start + sector, 1,
+			      (void *)sec_buf) != 1) {
 			printf(" ** ext2fs_devread() read error **\n");
 			return 0;
 		}
@@ -100,17 +100,15 @@ int ext4fs_devread(lbaint_t sector, int byte_offset, int byte_len, char *buf)
 		ALLOC_CACHE_ALIGN_BUFFER(u8, p, ext4fs_blk_desc->blksz);
 
 		block_len = ext4fs_blk_desc->blksz;
-		ext4fs_blk_desc->block_read(ext4fs_blk_desc,
-						  part_info->start + sector,
-						  1, (void *)p);
+		blk_dread(ext4fs_blk_desc, part_info->start + sector, 1,
+			  (void *)p);
 		memcpy(buf, p, byte_len);
 		return 1;
 	}
 
-	if (ext4fs_blk_desc->block_read(ext4fs_blk_desc,
-					part_info->start + sector,
-					block_len >> log2blksz, (void *)buf)
-				!= block_len >> log2blksz) {
+	if (blk_dread(ext4fs_blk_desc, part_info->start + sector,
+		      block_len >> log2blksz, (void *)buf) !=
+			block_len >> log2blksz) {
 		printf(" ** %s read error - block\n", __func__);
 		return 0;
 	}
@@ -121,9 +119,8 @@ int ext4fs_devread(lbaint_t sector, int byte_offset, int byte_len, char *buf)
 
 	if (byte_len != 0) {
 		/* read rest of data which are not in whole sector */
-		if (ext4fs_blk_desc->block_read(ext4fs_blk_desc,
-						part_info->start + sector,
-						1, (void *)sec_buf) != 1) {
+		if (blk_dread(ext4fs_blk_desc, part_info->start + sector, 1,
+			      (void *)sec_buf) != 1) {
 			printf("* %s read error - last part\n", __func__);
 			return 0;
 		}
diff --git a/fs/ext4/ext4_common.c b/fs/ext4/ext4_common.c
index 294a46eadf..84fba767c1 100644
--- a/fs/ext4/ext4_common.c
+++ b/fs/ext4/ext4_common.c
@@ -81,29 +81,20 @@ void put_ext4(uint64_t off, void *buf, uint32_t size)
 	}
 
 	if (remainder) {
-		if (fs->dev_desc->block_read) {
-			fs->dev_desc->block_read(fs->dev_desc,
-						 startblock, 1, sec_buf);
-			temp_ptr = sec_buf;
-			memcpy((temp_ptr + remainder),
-			       (unsigned char *)buf, size);
-			fs->dev_desc->block_write(fs->dev_desc,
-						  startblock, 1, sec_buf);
-		}
+		blk_dread(fs->dev_desc, startblock, 1, sec_buf);
+		temp_ptr = sec_buf;
+		memcpy((temp_ptr + remainder), (unsigned char *)buf, size);
+		blk_dwrite(fs->dev_desc, startblock, 1, sec_buf);
 	} else {
 		if (size >> log2blksz != 0) {
-			fs->dev_desc->block_write(fs->dev_desc,
-						  startblock,
-						  size >> log2blksz,
-						  (unsigned long *)buf);
+			blk_dwrite(fs->dev_desc, startblock, size >> log2blksz,
+				   (unsigned long *)buf);
 		} else {
-			fs->dev_desc->block_read(fs->dev_desc,
-						 startblock, 1, sec_buf);
+			blk_dread(fs->dev_desc, startblock, 1, sec_buf);
 			temp_ptr = sec_buf;
 			memcpy(temp_ptr, buf, size);
-			fs->dev_desc->block_write(fs->dev_desc,
-						  startblock, 1,
-						  (unsigned long *)sec_buf);
+			blk_dwrite(fs->dev_desc, startblock, 1,
+				   (unsigned long *)sec_buf);
 		}
 	}
 }
diff --git a/fs/fat/fat.c b/fs/fat/fat.c
index f87ddd7630..600a90e309 100644
--- a/fs/fat/fat.c
+++ b/fs/fat/fat.c
@@ -10,6 +10,7 @@
  */
 
 #include <common.h>
+#include <blk.h>
 #include <config.h>
 #include <exports.h>
 #include <fat.h>
@@ -48,11 +49,10 @@ static int disk_read(__u32 block, __u32 nr_blocks, void *buf)
 {
 	ulong ret;
 
-	if (!cur_dev || !cur_dev->block_read)
+	if (!cur_dev)
 		return -1;
 
-	ret = cur_dev->block_read(cur_dev, cur_part_info.start + block,
-				  nr_blocks, buf);
+	ret = blk_dread(cur_dev, cur_part_info.start + block, nr_blocks, buf);
 
 	if (nr_blocks && ret == 0)
 		return -1;
diff --git a/fs/fat/fat_write.c b/fs/fat/fat_write.c
index 5ed324ce1a..baa85ec3b4 100644
--- a/fs/fat/fat_write.c
+++ b/fs/fat/fat_write.c
@@ -32,7 +32,7 @@ static int disk_write(__u32 block, __u32 nr_blocks, void *buf)
 {
 	ulong ret;
 
-	if (!cur_dev || !cur_dev->block_write)
+	if (!cur_dev)
 		return -1;
 
 	if (cur_part_info.start + block + nr_blocks >
@@ -41,8 +41,7 @@ static int disk_write(__u32 block, __u32 nr_blocks, void *buf)
 		return -1;
 	}
 
-	ret = cur_dev->block_write(cur_dev, cur_part_info.start + block,
-				   nr_blocks, buf);
+	ret = blk_dwrite(cur_dev, cur_part_info.start + block, nr_blocks, buf);
 	if (nr_blocks && ret == 0)
 		return -1;
 
diff --git a/include/blk.h b/include/blk.h
index 9c54842961..7b2e5e286f 100644
--- a/include/blk.h
+++ b/include/blk.h
@@ -71,4 +71,33 @@ struct blk_desc {
 #define PAD_TO_BLOCKSIZE(size, blk_desc) \
 	(PAD_SIZE(size, blk_desc->blksz))
 
+/*
+ * These functions should take struct udevice instead of struct blk_desc,
+ * but this is convenient for migration to driver model. Add a 'd' prefix
+ * to the function operations, so that blk_read(), etc. can be reserved for
+ * functions with the correct arguments.
+ */
+static inline ulong blk_dread(struct blk_desc *block_dev, lbaint_t start,
+			      lbaint_t blkcnt, void *buffer)
+{
+	/*
+	 * We could check if block_read is NULL and return -ENOSYS. But this
+	 * bloats the code slightly (cause some board to fail to build), and
+	 * it would be an error to try an operation that does not exist.
+	 */
+	return block_dev->block_read(block_dev, start, blkcnt, buffer);
+}
+
+static inline ulong blk_dwrite(struct blk_desc *block_dev, lbaint_t start,
+			       lbaint_t blkcnt, const void *buffer)
+{
+	return block_dev->block_write(block_dev, start, blkcnt, buffer);
+}
+
+static inline ulong blk_derase(struct blk_desc *block_dev, lbaint_t start,
+			       lbaint_t blkcnt)
+{
+	return block_dev->block_erase(block_dev, start, blkcnt);
+}
+
 #endif
diff --git a/test/dm/usb.c b/test/dm/usb.c
index 0996185049..2d20354178 100644
--- a/test/dm/usb.c
+++ b/test/dm/usb.c
@@ -50,7 +50,7 @@ static int dm_test_usb_flash(struct unit_test_state *uts)
 	/* Read a few blocks and look for the string we expect */
 	ut_asserteq(512, dev_desc->blksz);
 	memset(cmp, '\0', sizeof(cmp));
-	ut_asserteq(2, dev_desc->block_read(dev_desc, 0, 2, cmp));
+	ut_asserteq(2, blk_dread(dev_desc, 0, 2, cmp));
 	ut_assertok(strcmp(cmp, "this is a test"));
 
 	return 0;