[U-Boot] [PATCH v1 1/1] usb: gadget: fastboot: Add fastboot erase

[Dileep Katta]

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 at linaro.org>
---
Note: The changes are on top of oem command support added by robh at kernel.org

 common/fb_mmc.c                 | 58 +++++++++++++++++++++++++++++++++++++++++
 drivers/usb/gadget/f_fastboot.c | 23 ++++++++++++++++
 include/fb_mmc.h                |  1 +
 3 files changed, 82 insertions(+)

diff --git a/common/fb_mmc.c b/common/fb_mmc.c
index 6ea3938..3911989 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 +111,60 @@ 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\n");
+		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\n");
+		fastboot_fail("invalid mmc device");
+		return;
+	}
+
+	ret = get_partition_info_efi_by_name(dev_desc, cmd, &info);
+	if (ret) {
+		error("cannot find partition: '%s'\n", cmd);
+		fastboot_fail("cannot find partition");
+		return;
+	}
+
+	puts("Erasing partition\n");
+
+	/* 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\n", dev_desc->dev);
+		fastboot_fail("failed erasing from device");
+		return;
+	}
+
+	printf("........ erased " LBAFU " bytes from '%s'\n",
+	       blks_size * info.blksz, cmd);
+	fastboot_okay("");
+}
diff --git a/drivers/usb/gadget/f_fastboot.c b/drivers/usb/gadget/f_fastboot.c
index f7d84bf..a8d8205 100644
--- a/drivers/usb/gadget/f_fastboot.c
+++ b/drivers/usb/gadget/f_fastboot.c
@@ -535,6 +535,26 @@ static void cb_oem(struct usb_ep *ep, struct usb_request *req)
 	}
 }
 
+static void cb_erase(struct usb_ep *ep, struct usb_request *req)
+{
+	char *cmd = req->buf;
+	char response[RESPONSE_LEN];
+
+	strsep(&cmd, ":");
+	if (!cmd) {
+		error("missing partition name\n");
+		fastboot_tx_write_str("FAILmissing partition name");
+		return;
+	}
+
+	strcpy(response, "FAILno flash device defined");
+
+#ifdef CONFIG_FASTBOOT_FLASH_MMC_DEV
+	fb_mmc_erase(cmd, response);
+#endif
+	fastboot_tx_write_str(response);
+}
+
 struct cmd_dispatch_info {
 	char *cmd;
 	void (*cb)(struct usb_ep *ep, struct usb_request *req);
@@ -566,6 +586,9 @@ static const struct cmd_dispatch_info cmd_dispatch_info[] = {
 	{
 		.cmd = "oem",
 		.cb = cb_oem,
+	}, {
+		.cmd = "erase",
+		.cb = cb_erase,
 	},
 };
 
diff --git a/include/fb_mmc.h b/include/fb_mmc.h
index 1ad1d13..402ba9b 100644
--- a/include/fb_mmc.h
+++ b/include/fb_mmc.h
@@ -6,3 +6,4 @@
 
 void fb_mmc_flash_write(const char *cmd, void *download_buffer,
 			unsigned int download_bytes, char *response);
+void fb_mmc_erase(const char *cmd, char *response);
-- 
1.8.3.2