mmc: support writing sparse images

Provide an alternate path for sparse-images to be
written to MMC. For example, via tftp on platforms
that don't support fastboot protocol. Or when an
image is to written at some offset, rather than the
start of a partition.

Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
[trini: Guard with CONFIG_FASTBOOT_FLASH tests, use LBAF for lbaint_t
        printing]
Signed-off-by: Tom Rini <trini@konsulko.com>

cmd/mmc.c

@@ -8,6 +8,8 @@
 #include <command.h>
 #include <console.h>
 #include <mmc.h>
+#include <sparse_format.h>
+#include <image-sparse.h>
 
 static int curr_device = -1;
 
@@ -307,6 +309,71 @@ static int do_mmc_read(cmd_tbl_t *cmdtp, int flag,
 }
 
 #if CONFIG_IS_ENABLED(MMC_WRITE)
+#if defined(CONFIG_FASTBOOT_FLASH)
+static lbaint_t mmc_sparse_write(struct sparse_storage *info, lbaint_t blk,
+				 lbaint_t blkcnt, const void *buffer)
+{
+	struct blk_desc *dev_desc = info->priv;
+
+	return blk_dwrite(dev_desc, blk, blkcnt, buffer);
+}
+
+static lbaint_t mmc_sparse_reserve(struct sparse_storage *info,
+				   lbaint_t blk, lbaint_t blkcnt)
+{
+	return blkcnt;
+}
+
+static int do_mmc_sparse_write(cmd_tbl_t *cmdtp, int flag,
+			       int argc, char * const argv[])
+{
+	struct sparse_storage sparse;
+	struct blk_desc *dev_desc;
+	struct mmc *mmc;
+	char dest[11];
+	void *addr;
+	u32 blk;
+
+	if (argc != 3)
+		return CMD_RET_USAGE;
+
+	addr = (void *)simple_strtoul(argv[1], NULL, 16);
+	blk = simple_strtoul(argv[2], NULL, 16);
+
+	if (!is_sparse_image(addr)) {
+		printf("Not a sparse image\n");
+		return CMD_RET_FAILURE;
+	}
+
+	mmc = init_mmc_device(curr_device, false);
+	if (!mmc)
+		return CMD_RET_FAILURE;
+
+	printf("\nMMC Sparse write: dev # %d, block # %d ... ",
+	       curr_device, blk);
+
+	if (mmc_getwp(mmc) == 1) {
+		printf("Error: card is write protected!\n");
+		return CMD_RET_FAILURE;
+	}
+
+	dev_desc = mmc_get_blk_desc(mmc);
+	sparse.priv = dev_desc;
+	sparse.blksz = 512;
+	sparse.start = blk;
+	sparse.size = dev_desc->lba - blk;
+	sparse.write = mmc_sparse_write;
+	sparse.reserve = mmc_sparse_reserve;
+	sparse.mssg = NULL;
+	sprintf(dest, "0x" LBAF, sparse.start * sparse.blksz);
+
+	if (write_sparse_image(&sparse, dest, addr))
+		return CMD_RET_FAILURE;
+	else
+		return CMD_RET_SUCCESS;
+}
+#endif
+
 static int do_mmc_write(cmd_tbl_t *cmdtp, int flag,
 			int argc, char * const argv[])
 {
@@ -801,6 +868,9 @@ static cmd_tbl_t cmd_mmc[] = {
 	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, "", ""),
+#if defined(CONFIG_FASTBOOT_FLASH)
+	U_BOOT_CMD_MKENT(swrite, 3, 0, do_mmc_sparse_write, "", ""),
+#endif
 	U_BOOT_CMD_MKENT(erase, 3, 0, do_mmc_erase, "", ""),
 #endif
 	U_BOOT_CMD_MKENT(rescan, 1, 1, do_mmc_rescan, "", ""),
@@ -857,6 +927,9 @@ U_BOOT_CMD(
 	"info - display info of the current MMC device\n"
 	"mmc read addr blk# cnt\n"
 	"mmc write addr blk# cnt\n"
+#if defined(CONFIG_FASTBOOT_FLASH)
+	"mmc swrite addr blk#\n"
+#endif
 	"mmc erase blk# cnt\n"
 	"mmc rescan\n"
 	"mmc part - lists available partition on current mmc device\n"