ums: allow the user to specify the device type

Allow an optional devtype parameter to the ums command, which specifies
the type of the device to be exported. This could allow exporting a SATA
or even another USB device.

Cc: Lukasz Majewski <l.majewski@samsung.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Przemyslaw Marczak <p.marczak@samsung.com>

common/cmd_usb_mass_storage.c

@@ -77,8 +77,13 @@ int do_usb_mass_storage(cmd_tbl_t *cmdtp, int flag,
 		return CMD_RET_USAGE;
 
 	usb_controller = argv[1];
-	devtype = "mmc";
-	devnum  = argv[2];
+	if (argc >= 4) {
+		devtype = argv[2];
+		devnum  = argv[3];
+	} else {
+		devtype = "mmc";
+		devnum  = argv[2];
+	}
 
 	ums = ums_init(devtype, devnum);
 	if (!ums)
@@ -152,7 +157,8 @@ exit:
 	return CMD_RET_SUCCESS;
 }
 
-U_BOOT_CMD(ums, CONFIG_SYS_MAXARGS, 1, do_usb_mass_storage,
+U_BOOT_CMD(ums, 4, 1, do_usb_mass_storage,
 	"Use the UMS [User Mass Storage]",
-	"ums <USB_controller> <mmc_dev>  e.g. ums 0 0"
+	"ums <USB_controller> [<devtype>] <devnum>  e.g. ums 0 mmc 0\n"
+	"    devtype defaults to mmc"
 );