usb: gadget: push iSerialNumber into gadgets

This patch pushes the iSerialNumber module argument from composite into
each gadget. Once the user uses the module paramter, the string is
overwritten with the final value.

Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>

4 files changed, 41 insertions, 13 deletions

diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index 317a5ece3bd2..5642b2170541 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -40,10 +40,6 @@ static char *iProduct;
 module_param(iProduct, charp, S_IRUGO);
 MODULE_PARM_DESC(iProduct, "USB Product string");
 
-static char *iSerialNumber;
-module_param(iSerialNumber, charp, S_IRUGO);
-MODULE_PARM_DESC(iSerialNumber, "SerialNumber string");
-
 static char composite_manufacturer[50];
 
 /*-------------------------------------------------------------------------*/
@@ -925,7 +921,7 @@ static int get_string(struct usb_composite_dev *cdev,
 	else if (cdev->product_override == id)
 		str = iProduct ?: composite->iProduct;
 	else if (cdev->serial_override == id)
-		str = iSerialNumber ?: composite->iSerialNumber;
+		str = composite->iSerialNumber;
 	else
 		str = NULL;
 	if (str) {
@@ -1411,6 +1407,7 @@ static void update_unchanged_dev_desc(struct usb_device_descriptor *new,
 	__le16 idVendor;
 	__le16 idProduct;
 	__le16 bcdDevice;
+	u8 iSerialNumber;
 
 	/*
 	 * these variables may have been set in
@@ -1419,6 +1416,7 @@ static void update_unchanged_dev_desc(struct usb_device_descriptor *new,
 	idVendor = new->idVendor;
 	idProduct = new->idProduct;
 	bcdDevice = new->bcdDevice;
+	iSerialNumber = new->iSerialNumber;
 
 	*new = *old;
 	if (idVendor)
@@ -1427,6 +1425,8 @@ static void update_unchanged_dev_desc(struct usb_device_descriptor *new,
 		new->idProduct = idProduct;
 	if (bcdDevice)
 		new->bcdDevice = bcdDevice;
+	if (iSerialNumber)
+		new->iSerialNumber = iSerialNumber;
 }
 
 static struct usb_composite_driver *to_cdriver(struct usb_gadget_driver *gdrv)
@@ -1505,8 +1505,7 @@ static int composite_bind(struct usb_gadget *gadget,
 		cdev->product_override =
 			override_id(cdev, &cdev->desc.iProduct);
 
-	if (iSerialNumber ||
-	    (!cdev->desc.iSerialNumber && composite->iSerialNumber))
+	if (composite->iSerialNumber)
 		cdev->serial_override =
 			override_id(cdev, &cdev->desc.iSerialNumber);
 
@@ -1691,6 +1690,8 @@ void usb_composite_overwrite_options(struct usb_composite_dev *cdev,
 		struct usb_composite_overwrite *covr)
 {
 	struct usb_device_descriptor	*desc = &cdev->desc;
+	struct usb_gadget_strings	*gstr = cdev->driver->strings[0];
+	struct usb_string		*dev_str = gstr->strings;
 
 	if (covr->idVendor)
 		desc->idVendor = cpu_to_le16(covr->idVendor);
@@ -1700,4 +1701,9 @@ void usb_composite_overwrite_options(struct usb_composite_dev *cdev,
 
 	if (covr->bcdDevice)
 		desc->bcdDevice = cpu_to_le16(covr->bcdDevice);
+
+	if (covr->serial_number) {
+		desc->iSerialNumber = dev_str[USB_GADGET_SERIAL_IDX].id;
+		dev_str[USB_GADGET_SERIAL_IDX].s = covr->serial_number;
+	}
 }
diff --git a/drivers/usb/gadget/mass_storage.c b/drivers/usb/gadget/mass_storage.c
index 8ffbade383f2..6f5a3b232d81 100644
--- a/drivers/usb/gadget/mass_storage.c
+++ b/drivers/usb/gadget/mass_storage.c
@@ -83,6 +83,22 @@ static const struct usb_descriptor_header *otg_desc[] = {
 	NULL,
 };
 
+static struct usb_string strings_dev[] = {
+	[USB_GADGET_MANUFACTURER_IDX].s = "",
+	[USB_GADGET_PRODUCT_IDX].s = "",
+	[USB_GADGET_SERIAL_IDX].s = "",
+	{  } /* end of list */
+};
+
+static struct usb_gadget_strings stringtab_dev = {
+	.language       = 0x0409,       /* en-us */
+	.strings        = strings_dev,
+};
+
+static struct usb_gadget_strings *dev_strings[] = {
+	&stringtab_dev,
+	NULL,
+};
 
 /****************************** Configurations ******************************/
 
@@ -141,6 +157,10 @@ static int __init msg_bind(struct usb_composite_dev *cdev)
 {
 	int status;
 
+	status = usb_string_ids_tab(cdev, strings_dev);
+	if (status < 0)
+		return status;
+
 	status = usb_add_config(cdev, &msg_config_driver, msg_do_config);
 	if (status < 0)
 		return status;
@@ -160,6 +180,7 @@ static __refdata struct usb_composite_driver msg_driver = {
 	.iProduct	= DRIVER_DESC,
 	.max_speed	= USB_SPEED_SUPER,
 	.needs_serial	= 1,
+	.strings	= dev_strings,
 	.bind		= msg_bind,
 };
 
diff --git a/drivers/usb/gadget/printer.c b/drivers/usb/gadget/printer.c
index f02434a10dec..3321a9df4862 100644
--- a/drivers/usb/gadget/printer.c
+++ b/drivers/usb/gadget/printer.c
@@ -118,8 +118,7 @@ static struct printer_dev usb_printer_gadget;
  * parameters are in UTF-8 (superset of ASCII's 7 bit characters).
  */
 
-static char *iSerialNum;
-module_param(iSerialNum, charp, S_IRUGO);
+module_param_named(iSerialNum, coverwrite.serial_number, charp, S_IRUGO);
 MODULE_PARM_DESC(iSerialNum, "1");
 
 static char *iPNPstring;
@@ -1170,9 +1169,6 @@ static int __init printer_bind_config(struct usb_configuration *c)
 		init_utsname()->sysname, init_utsname()->release,
 		gadget->name);
 
-	if (iSerialNum)
-		strlcpy(serial_num, iSerialNum, sizeof serial_num);
-
 	if (iPNPstring)
 		strlcpy(&pnp_string[2], iPNPstring, (sizeof pnp_string)-2);
 
diff --git a/include/linux/usb/composite.h b/include/linux/usb/composite.h
index f821a3ad475d..9d068a4be778 100644
--- a/include/linux/usb/composite.h
+++ b/include/linux/usb/composite.h
@@ -400,6 +400,7 @@ struct usb_composite_overwrite {
 	u16	idVendor;
 	u16	idProduct;
 	u16	bcdDevice;
+	char	*serial_number;
 };
 #define USB_GADGET_COMPOSITE_OPTIONS()					\
 	static struct usb_composite_overwrite coverwrite;		\
@@ -411,7 +412,11 @@ struct usb_composite_overwrite {
 	MODULE_PARM_DESC(idProduct, "USB Product ID");			\
 									\
 	module_param_named(bcdDevice, coverwrite.bcdDevice, ushort, S_IRUGO); \
-	MODULE_PARM_DESC(bcdDevice, "USB Device version (BCD)")
+	MODULE_PARM_DESC(bcdDevice, "USB Device version (BCD)");	\
+									\
+	module_param_named(iSerialNumber, coverwrite.serial_number, charp, \
+			S_IRUGO); \
+	MODULE_PARM_DESC(iSerialNumber, "SerialNumber string")
 
 void usb_composite_overwrite_options(struct usb_composite_dev *cdev,
 		struct usb_composite_overwrite *covr);