spl: dfu: adding dfu support functions for SPL-DFU

Adding support functions to run dfu spl commands.

Signed-off-by: Ravi Babu <ravibabu@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/common/spl/spl_dfu.c b/common/spl/spl_dfu.c
new file mode 100644
index 0000000..e8d0ba1
--- /dev/null
+++ b/common/spl/spl_dfu.c
@@ -0,0 +1,57 @@
+/*
+ * (C) Copyright 2016
+ * Texas Instruments, <www.ti.com>
+ *
+ * Ravi B <ravibabu@ti.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+#include <common.h>
+#include <spl.h>
+#include <linux/compiler.h>
+#include <errno.h>
+#include <watchdog.h>
+#include <console.h>
+#include <g_dnl.h>
+#include <usb.h>
+#include <dfu.h>
+#include <environment.h>
+
+static int run_dfu(int usb_index, char *interface, char *devstring)
+{
+	int ret;
+
+	ret = dfu_init_env_entities(interface, devstring);
+	if (ret) {
+		dfu_free_entities();
+		goto exit;
+	}
+
+	run_usb_dnl_gadget(usb_index, "usb_dnl_dfu");
+exit:
+	dfu_free_entities();
+	return ret;
+}
+
+int spl_dfu_cmd(int usbctrl, char *dfu_alt_info, char *interface, char *devstr)
+{
+	char *str_env;
+	int ret;
+
+	/* set default environment */
+	set_default_env(0);
+	str_env = getenv(dfu_alt_info);
+	if (!str_env) {
+		error("\"dfu_alt_info\" env variable not defined!\n");
+		return -EINVAL;
+	}
+
+	ret = setenv("dfu_alt_info", str_env);
+	if (ret) {
+		error("unable to set env variable \"dfu_alt_info\"!\n");
+		return -EINVAL;
+	}
+
+	/* invoke dfu command */
+	return run_dfu(usbctrl, interface, devstr);
+}