[PATCH 1/2] usb: gadget: aspeed: allow to customize vhub device IDs/strings

[rentao . bupt]

From: Tao Ren <rentao.bupt@xxxxxxxxx>

This patch allows people to customize vendor/product/device IDs and
manufacture/product/serial strings in vhub's device descriptor through
device tree properties.

Signed-off-by: Tao Ren <rentao.bupt@xxxxxxxxx>
---
 drivers/usb/gadget/udc/aspeed-vhub/hub.c | 73 +++++++++++++++++++-----
 1 file changed, 59 insertions(+), 14 deletions(-)

diff --git a/drivers/usb/gadget/udc/aspeed-vhub/hub.c b/drivers/usb/gadget/udc/aspeed-vhub/hub.c
index 9c7e57fbd8ef..4e3ef83283a6 100644
--- a/drivers/usb/gadget/udc/aspeed-vhub/hub.c
+++ b/drivers/usb/gadget/udc/aspeed-vhub/hub.c
@@ -43,19 +43,23 @@
  *    - We may need to indicate TT support
  *    - We may need a device qualifier descriptor
  *	as devices can pretend to be usb1 or 2
- *    - Make vid/did overridable
  *    - make it look like usb1 if usb1 mode forced
  */
 #define KERNEL_REL	bin2bcd(((LINUX_VERSION_CODE >> 16) & 0x0ff))
 #define KERNEL_VER	bin2bcd(((LINUX_VERSION_CODE >> 8) & 0x0ff))
 
 enum {
+	AST_VHUB_STR_INDEX_MAX = 4,
 	AST_VHUB_STR_MANUF = 3,
 	AST_VHUB_STR_PRODUCT = 2,
 	AST_VHUB_STR_SERIAL = 1,
 };
 
-static const struct usb_device_descriptor ast_vhub_dev_desc = {
+/*
+ * Below is the default Device Descriptor of the vhub device. Some fields
+ * may be updated in "ast_vhub_fixup_dev_desc" function.
+ */
+static struct usb_device_descriptor ast_vhub_dev_desc = {
 	.bLength		= USB_DT_DEVICE_SIZE,
 	.bDescriptorType	= USB_DT_DEVICE,
 	.bcdUSB			= cpu_to_le16(0x0200),
@@ -148,10 +152,14 @@ static struct usb_hub_descriptor ast_vhub_hub_desc = {
 };
 
 /*
- * These strings converted to UTF-16 must be smaller than
- * our EP0 buffer.
+ * Below tables define the default Language ID and String Descriptors of
+ * the vhub. Language ID and strings may be overridden if according device
+ * tree properties are defined. Refer to "ast_vhub_fixup_dev_desc" function
+ * for details.
+ * Note: these strings converted to UTF-16 must be smaller than vhub EP0
+ * buffer size.
  */
-static const struct usb_string ast_vhub_str_array[] = {
+static struct usb_string ast_vhub_str_array[] = {
 	{
 		.id = AST_VHUB_STR_SERIAL,
 		.s = "00000000"
@@ -167,7 +175,7 @@ static const struct usb_string ast_vhub_str_array[] = {
 	{ }
 };
 
-static const struct usb_gadget_strings ast_vhub_strings = {
+static struct usb_gadget_strings ast_vhub_strings = {
 	.language = 0x0409,
 	.strings = (struct usb_string *)ast_vhub_str_array
 };
@@ -320,18 +328,15 @@ static int ast_vhub_rep_string(struct ast_vhub_ep *ep,
 			       u8 string_id, u16 lang_id,
 			       u16 len)
 {
-	int rc = usb_gadget_get_string (&ast_vhub_strings, string_id, ep->buf);
-
-	/*
-	 * This should never happen unless we put too big strings in
-	 * the array above
-	 */
-	BUG_ON(rc >= AST_VHUB_EP0_MAX_PACKET);
+	int rc;
+	u8 buf[256]; /* buffer size required by usb_gadget_get_string */
 
-	if (rc < 0)
+	rc = usb_gadget_get_string(&ast_vhub_strings, string_id, buf);
+	if (rc < 0 || rc >= AST_VHUB_EP0_MAX_PACKET)
 		return std_req_stall;
 
 	/* Shoot it from the EP buffer */
+	memcpy(ep->buf, buf, rc);
 	return ast_vhub_reply(ep, NULL, min_t(u16, rc, len));
 }
 
@@ -837,11 +842,51 @@ void ast_vhub_hub_reset(struct ast_vhub *vhub)
 	writel(0, vhub->regs + AST_VHUB_EP1_STS_CHG);
 }
 
+static void ast_vhub_fixup_dev_desc(struct ast_vhub *vhub)
+{
+	int i;
+	u8 id;
+	u16 of_id;
+	const char *of_str[AST_VHUB_STR_INDEX_MAX] = {NULL};
+	struct device_node *np = vhub->pdev->dev.of_node;
+
+	/*
+	 * Update IDs in device descriptor if according properties are
+	 * defined in device tree.
+	 */
+	if (!of_property_read_u16(np, "vendor-id", &of_id))
+		ast_vhub_dev_desc.idVendor = cpu_to_le16(of_id);
+	if (!of_property_read_u16(np, "product-id", &of_id))
+		ast_vhub_dev_desc.idProduct = cpu_to_le16(of_id);
+	if (!of_property_read_u16(np, "device-id", &of_id))
+		ast_vhub_dev_desc.bcdDevice = cpu_to_le16(of_id);
+
+	/*
+	 * Update string descriptors if according properties are defined
+	 * in device tree.
+	 */
+	if (!of_property_read_u16(np, "language-id", &of_id))
+		ast_vhub_strings.language = of_id;
+
+	of_str[AST_VHUB_STR_MANUF] = of_get_property(np, "manufacturer", NULL);
+	of_str[AST_VHUB_STR_PRODUCT] = of_get_property(np, "product", NULL);
+	of_str[AST_VHUB_STR_SERIAL] = of_get_property(np, "serial-number",
+						      NULL);
+
+	for (i = 0; ast_vhub_str_array[i].s != NULL; i++) {
+		id = ast_vhub_str_array[i].id;
+		if (of_str[id])
+			ast_vhub_str_array[i].s = of_str[id];
+	}
+}
+
 void ast_vhub_init_hub(struct ast_vhub *vhub)
 {
 	vhub->speed = USB_SPEED_UNKNOWN;
 	INIT_WORK(&vhub->wake_work, ast_vhub_wake_work);
 
+	ast_vhub_fixup_dev_desc(vhub);
+
 	/*
 	 * Fixup number of ports in hub descriptor.
 	 */
-- 
2.17.1