usb: core: allow a reference device for new_id

Often, usb drivers need some driver_info to get a device to work. To
have access to driver_info when using new_id, allow to pass a reference
vendor:product tuple from which new_id will inherit driver_info.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 15 insertions, 3 deletions

diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c
index 574f5a04c92d..9b29e5c94be7 100644
--- a/drivers/usb/core/driver.c
+++ b/drivers/usb/core/driver.c
@@ -37,6 +37,7 @@
  * and cause the driver to probe for all devices again.
  */
 ssize_t usb_store_new_id(struct usb_dynids *dynids,
+                         const struct usb_device_id *id_table,
                          struct device_driver *driver,
                          const char *buf, size_t count)
 {
@@ -44,11 +45,12 @@ ssize_t usb_store_new_id(struct usb_dynids *dynids,
         u32 idVendor = 0;
         u32 idProduct = 0;
         unsigned int bInterfaceClass = 0;
+        u32 refVendor, refProduct;
         int fields = 0;
         int retval = 0;
 
-        fields = sscanf(buf, "%x %x %x", &idVendor, &idProduct,
-                                        &bInterfaceClass);
+        fields = sscanf(buf, "%x %x %x %x %x", &idVendor, &idProduct,
+                        &bInterfaceClass, &refVendor, &refProduct);
         if (fields < 2)
                 return -EINVAL;
 
@@ -68,6 +70,16 @@ ssize_t usb_store_new_id(struct usb_dynids *dynids,
                 dynid->id.match_flags |= USB_DEVICE_ID_MATCH_INT_CLASS;
         }
 
+        if (fields > 4) {
+                const struct usb_device_id *id = id_table;
+
+                for (; id->match_flags; id++)
+                        if (id->idVendor == refVendor && id->idProduct == refProduct) {
+                                dynid->id.driver_info = id->driver_info;
+                                break;
+                        }
+        }
+
         spin_lock(&dynids->lock);
         list_add_tail(&dynid->node, &dynids->list);
         spin_unlock(&dynids->lock);
@@ -109,7 +121,7 @@ static ssize_t new_id_store(struct device_driver *driver,
 {
         struct usb_driver *usb_drv = to_usb_driver(driver);
 
-        return usb_store_new_id(&usb_drv->dynids, driver, buf, count);
+        return usb_store_new_id(&usb_drv->dynids, usb_drv->id_table, driver, buf, count);
 }
 static DRIVER_ATTR_RW(new_id);