usb: ums - expose selected partition/s

By applying this patch, it will give us some flexibility to expose
a selected partition/s.

e.g:
1. To expose several partitions
ums 0 mmc 0:1,0:6

2. To expose the all partitions
ums 0 mmc 0:0

3. To expose multiple partititions on several devices
ums 0 mmc 0:1,1:6

4. It support legacy format
ums 0 mmc 0

Signed-off-by: John Tobias <john.tobias.ph@gmail.com>

diff --git a/cmd/usb_mass_storage.c b/cmd/usb_mass_storage.c
index 14eed980df90ca0d931a9b83493c0b56d9024335..ac53a73310bb9dd0d95217921d838201cc4987bf 100644 (file)
--- a/cmd/usb_mass_storage.c
+++ b/cmd/usb_mass_storage.c
@@ -50,14 +50,16 @@ static void ums_fini(void)
 
 #define UMS_NAME_LEN 16
 
-static int ums_init(const char *devtype, const char *devnums)
+static int ums_init(const char *devtype, const char *devnums_part_str)
 {
-       char *s, *t, *devnum, *name;
+       char *s, *t, *devnum_part_str, *name;
        struct blk_desc *block_dev;
+       disk_partition_t info;
+       int partnum;
        int ret;
        struct ums *ums_new;
 
-       s = strdup(devnums);
+       s = strdup(devnums_part_str);
        if (!s)
                return -1;
 
@@ -65,14 +67,23 @@ static int ums_init(const char *devtype, const char *devnums)
        ums_count = 0;
 
        for (;;) {
-               devnum = strsep(&t, ",");
-               if (!devnum)
+               devnum_part_str = strsep(&t, ",");
+               if (!devnum_part_str)
                        break;
 
-               ret = blk_get_device_by_str(devtype, devnum, &block_dev);
-               if (ret < 0)
+               partnum = blk_get_device_part_str(devtype, devnum_part_str,
+                                       &block_dev, &info, 1);
+
+               if (partnum < 0)
                        goto cleanup;
 
+               /* Check if the argument is in legacy format. If yes,
+                * expose all partitions by setting the partnum = 0
+                * e.g. ums 0 mmc 0
+                */
+               if (!strchr(devnum_part_str, ':'))
+                       partnum = 0;
+
                /* f_mass_storage.c assumes SECTOR_SIZE sectors */
                if (block_dev->blksz != SECTOR_SIZE) {
                        ret = -1;
@@ -86,10 +97,18 @@ static int ums_init(const char *devtype, const char *devnums)
                }
                ums = ums_new;
 
+               /* if partnum = 0, expose all partitions */
+               if (partnum == 0) {
+                       ums[ums_count].start_sector = 0;
+                       ums[ums_count].num_sectors = block_dev->lba;
+               } else {
+                       ums[ums_count].start_sector = info.start;
+                       ums[ums_count].num_sectors = info.size;
+               }
+
                ums[ums_count].read_sector = ums_read_sector;
                ums[ums_count].write_sector = ums_write_sector;
-               ums[ums_count].start_sector = 0;
-               ums[ums_count].num_sectors = block_dev->lba;
+
                name = malloc(UMS_NAME_LEN);
                if (!name) {
                        ret = -1;
@@ -230,6 +249,6 @@ cleanup_ums_init:
 
 U_BOOT_CMD(ums, 4, 1, do_usb_mass_storage,
        "Use the UMS [USB Mass Storage]",
-       "<USB_controller> [<devtype>] <devnum>  e.g. ums 0 mmc 0\n"
+       "<USB_controller> [<devtype>] <dev[:part]>  e.g. ums 0 mmc 0\n"
        "    devtype defaults to mmc"
 );