usb: gadget: fastboot: Add fastboot erase

Adds the fastboot erase functionality, to erase a partition
specified by name. The erase is performed based on erase group size,
to avoid erasing other partitions. The start address and the size
is aligned to the erase group size for this.

Currently only supports erasing from eMMC.

Signed-off-by: Dileep Katta <dileep.katta@linaro.org>
Reviewed-by: Lukasz Majewski <l.majewski@samsung.com>

1 files changed, 56 insertions, 0 deletions

diff --git a/common/fb_mmc.c b/common/fb_mmc.c
index 6ea3938..513b7ab 100644
--- a/common/fb_mmc.c
+++ b/common/fb_mmc.c
@@ -10,6 +10,7 @@
 #include <part.h>
 #include <aboot.h>
 #include <sparse_format.h>
+#include <mmc.h>
 
 #ifndef CONFIG_FASTBOOT_GPT_NAME
 #define CONFIG_FASTBOOT_GPT_NAME GPT_ENTRY_NAME
@@ -110,3 +111,58 @@ void fb_mmc_flash_write(const char *cmd, void *download_buffer,
 		write_raw_image(dev_desc, &info, cmd, download_buffer,
 				download_bytes);
 }
+
+void fb_mmc_erase(const char *cmd, char *response)
+{
+	int ret;
+	block_dev_desc_t *dev_desc;
+	disk_partition_t info;
+	lbaint_t blks, blks_start, blks_size, grp_size;
+	struct mmc *mmc = find_mmc_device(CONFIG_FASTBOOT_FLASH_MMC_DEV);
+
+	if (mmc == NULL) {
+		error("invalid mmc device");
+		fastboot_fail("invalid mmc device");
+		return;
+	}
+
+	/* initialize the response buffer */
+	response_str = response;
+
+	dev_desc = get_dev("mmc", CONFIG_FASTBOOT_FLASH_MMC_DEV);
+	if (!dev_desc || dev_desc->type == DEV_TYPE_UNKNOWN) {
+		error("invalid mmc device");
+		fastboot_fail("invalid mmc device");
+		return;
+	}
+
+	ret = get_partition_info_efi_by_name(dev_desc, cmd, &info);
+	if (ret) {
+		error("cannot find partition: '%s'", cmd);
+		fastboot_fail("cannot find partition");
+		return;
+	}
+
+	/* Align blocks to erase group size to avoid erasing other partitions */
+	grp_size = mmc->erase_grp_size;
+	blks_start = (info.start + grp_size - 1) & ~(grp_size - 1);
+	if (info.size >= grp_size)
+		blks_size = (info.size - (blks_start - info.start)) &
+				(~(grp_size - 1));
+	else
+		blks_size = 0;
+
+	printf("Erasing blocks " LBAFU " to " LBAFU " due to alignment\n",
+	       blks_start, blks_start + blks_size);
+
+	blks = dev_desc->block_erase(dev_desc->dev, blks_start, blks_size);
+	if (blks != blks_size) {
+		error("failed erasing from device %d", dev_desc->dev);
+		fastboot_fail("failed erasing from device");
+		return;
+	}
+
+	printf("........ erased " LBAFU " bytes from '%s'\n",
+	       blks_size * info.blksz, cmd);
+	fastboot_okay("");
+}