usb, g_dnl: make iSerialNumber board configurable

add the possibility to set the iSerialNumber board specific.
Default value for iSerialNumber is 0x0. This value can
changed board specific through the new function
g_dnl_set_serialnumber() which must be called from the
board specific function g_dnl_bind_fixup().

Signed-off-by: Heiko Schocher <hs@denx.de>
Cc: Marek Vasut <marek.vasut@gmail.com>
Cc: Lukasz Majewski <l.majewski@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Tested-by: Lukasz Majewski <l.majewski@samsung.com>

drivers/usb/gadget/g_dnl.c

@@ -33,6 +33,9 @@
 #define STRING_PRODUCT 2
 /* Index of String Descriptor describing this configuration */
 #define STRING_USBDOWN 2
+/* Index of String serial */
+#define STRING_SERIAL  3
+#define MAX_STRING_SERIAL	32
 /* Number of supported configurations */
 #define CONFIGURATION_NUMBER 1
 
@@ -40,8 +43,16 @@
 
 static const char shortname[] = "usb_dnl_";
 static const char product[] = "USB download gadget";
+static char g_dnl_serial[MAX_STRING_SERIAL];
 static const char manufacturer[] = CONFIG_G_DNL_MANUFACTURER;
 
+void g_dnl_set_serialnumber(char *s)
+{
+	memset(g_dnl_serial, 0, MAX_STRING_SERIAL);
+	if (strlen(s) < MAX_STRING_SERIAL)
+		strncpy(g_dnl_serial, s, strlen(s));
+}
+
 static struct usb_device_descriptor device_desc = {
 	.bLength = sizeof device_desc,
 	.bDescriptorType = USB_DT_DEVICE,
@@ -53,6 +64,7 @@ static struct usb_device_descriptor device_desc = {
 	.idVendor = __constant_cpu_to_le16(CONFIG_G_DNL_VENDOR_NUM),
 	.idProduct = __constant_cpu_to_le16(CONFIG_G_DNL_PRODUCT_NUM),
 	.iProduct = STRING_PRODUCT,
+	.iSerialNumber = STRING_SERIAL,
 	.bNumConfigurations = 1,
 };
 
@@ -63,6 +75,7 @@ static struct usb_device_descriptor device_desc = {
 static struct usb_string g_dnl_string_defs[] = {
 	{.s = manufacturer},
 	{.s = product},
+	{.s = g_dnl_serial},
 	{ }		/* end of list */
 };
 
@@ -156,6 +169,13 @@ static int g_dnl_bind(struct usb_composite_dev *cdev)
 	g_dnl_string_defs[1].id = id;
 	device_desc.iProduct = id;
 
+	id = usb_string_id(cdev);
+	if (id < 0)
+		return id;
+
+	g_dnl_string_defs[2].id = id;
+	device_desc.iSerialNumber = id;
+
 	g_dnl_bind_fixup(&device_desc, cdev->driver->name);
 	ret = g_dnl_config_register(cdev);
 	if (ret)

include/g_dnl.h

@@ -13,5 +13,6 @@
 int g_dnl_bind_fixup(struct usb_device_descriptor *, const char *);
 int g_dnl_register(const char *s);
 void g_dnl_unregister(void);
+void g_dnl_set_serialnumber(char *);
 
 #endif /* __G_DOWNLOAD_H_ */