usb: rockchip: add rockusb command

this patch add rockusb command. the usage is
rockusb <USB_controller> <devtype> <dev[:part]>
e.g. rockusb 0 mmc 0

Signed-off-by: Eddie Cai <eddie.cai.linux@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/cmd/rockusb.c b/cmd/rockusb.c
new file mode 100644
index 0000000..af81cdc
--- /dev/null
+++ b/cmd/rockusb.c
@@ -0,0 +1,74 @@
+/*
+ * Copyright (C) 2017 Eddie Cai <eddie.cai.linux@gmail.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <command.h>
+#include <console.h>
+#include <g_dnl.h>
+#include <usb.h>
+#include <asm/arch/f_rockusb.h>
+
+static int do_rockusb(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
+{
+	int controller_index, dev_index;
+	char *usb_controller;
+	char *devtype;
+	char *devnum;
+	int ret;
+
+	if (argc < 2)
+		return CMD_RET_USAGE;
+
+	usb_controller = argv[1];
+	controller_index = simple_strtoul(usb_controller, NULL, 0);
+
+	if (argc >= 4) {
+		devtype = argv[2];
+		devnum  = argv[3];
+	} else {
+		return CMD_RET_USAGE;
+	}
+	dev_index = simple_strtoul(devnum, NULL, 0);
+	rockusb_dev_init(devtype, dev_index);
+
+	ret = board_usb_init(controller_index, USB_INIT_DEVICE);
+	if (ret) {
+		printf("USB init failed: %d\n", ret);
+		return CMD_RET_FAILURE;
+	}
+
+	g_dnl_clear_detach();
+	ret = g_dnl_register("usb_dnl_rockusb");
+	if (ret)
+		return CMD_RET_FAILURE;
+
+	if (!g_dnl_board_usb_cable_connected()) {
+		puts("\rUSB cable not detected, Command exit.\n");
+		ret = CMD_RET_FAILURE;
+		goto exit;
+	}
+
+	while (1) {
+		if (g_dnl_detach())
+			break;
+		if (ctrlc())
+			break;
+		usb_gadget_handle_interrupts(controller_index);
+	}
+	ret = CMD_RET_SUCCESS;
+
+exit:
+	g_dnl_unregister();
+	g_dnl_clear_detach();
+	board_usb_cleanup(controller_index, USB_INIT_DEVICE);
+
+	return ret;
+}
+
+U_BOOT_CMD(rockusb, 4, 1, do_rockusb,
+	   "use the rockusb protocol",
+	   "<USB_controller> <devtype> <dev[:part]>  e.g. rockusb 0 mmc 0\n"
+);