3 files changed, 125 insertions, 29 deletions

diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index e6d586a22bbd..7297b1d1300c 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -830,31 +830,6 @@ static int hid_scan_report(struct hid_device *hid)
                 break;
         }
 
-        /* fall back to generic driver in case specific driver doesn't exist */
-        switch (hid->group) {
-        case HID_GROUP_MULTITOUCH_WIN_8:
-                /* fall-through */
-        case HID_GROUP_MULTITOUCH:
-                if (!IS_ENABLED(CONFIG_HID_MULTITOUCH))
-                        hid->group = HID_GROUP_GENERIC;
-                break;
-        case HID_GROUP_SENSOR_HUB:
-                if (!IS_ENABLED(CONFIG_HID_SENSOR_HUB))
-                        hid->group = HID_GROUP_GENERIC;
-                break;
-        case HID_GROUP_RMI:
-                if (!IS_ENABLED(CONFIG_HID_RMI))
-                        hid->group = HID_GROUP_GENERIC;
-                break;
-        case HID_GROUP_WACOM:
-                if (!IS_ENABLED(CONFIG_HID_WACOM))
-                        hid->group = HID_GROUP_GENERIC;
-                break;
-        case HID_GROUP_LOGITECH_DJ_DEVICE:
-                if (!IS_ENABLED(CONFIG_HID_LOGITECH_DJ))
-                        hid->group = HID_GROUP_GENERIC;
-                break;
-        }
         vfree(parser);
         return 0;
 }
@@ -1928,8 +1903,8 @@ static void hid_free_dynids(struct hid_driver *hdrv)
         spin_unlock(&hdrv->dyn_lock);
 }
 
-static const struct hid_device_id *hid_match_device(struct hid_device *hdev,
-                struct hid_driver *hdrv)
+const struct hid_device_id *hid_match_device(struct hid_device *hdev,
+                                             struct hid_driver *hdrv)
 {
         struct hid_dynid *dynid;
 
@@ -1944,6 +1919,7 @@ static const struct hid_device_id *hid_match_device(struct hid_device *hdev,
 
         return hid_match_id(hdev, hdrv->id_table);
 }
+EXPORT_SYMBOL_GPL(hid_match_device);
 
 static int hid_bus_match(struct device *dev, struct device_driver *drv)
 {
@@ -1973,6 +1949,23 @@ static int hid_device_probe(struct device *dev)
                         goto unlock;
                 }
 
+                if (hdrv->match) {
+                        if (!hdrv->match(hdev, hid_ignore_special_drivers)) {
+                                ret = -ENODEV;
+                                goto unlock;
+                        }
+                } else {
+                        /*
+                         * hid-generic implements .match(), so if
+                         * hid_ignore_special_drivers is set, we can safely
+                         * return.
+                         */
+                        if (hid_ignore_special_drivers) {
+                                ret = -ENODEV;
+                                goto unlock;
+                        }
+                }
+
                 hdev->driver = hdrv;
                 if (hdrv->probe) {
                         ret = hdrv->probe(hdev, id);
@@ -2069,7 +2062,7 @@ static int hid_uevent(struct device *dev, struct kobj_uevent_env *env)
         return 0;
 }
 
-static struct bus_type hid_bus_type = {
+struct bus_type hid_bus_type = {
         .name           = "hid",
         .dev_groups     = hid_dev_groups,
         .drv_groups     = hid_drv_groups,
@@ -2203,6 +2196,29 @@ void hid_destroy_device(struct hid_device *hdev)
 }
 EXPORT_SYMBOL_GPL(hid_destroy_device);
 
+
+static int __bus_add_driver(struct device_driver *drv, void *data)
+{
+        struct hid_driver *added_hdrv = data;
+        struct hid_driver *hdrv = to_hid_driver(drv);
+
+        if (hdrv->bus_add_driver)
+                hdrv->bus_add_driver(added_hdrv);
+
+        return 0;
+}
+
+static int __bus_removed_driver(struct device_driver *drv, void *data)
+{
+        struct hid_driver *removed_hdrv = data;
+        struct hid_driver *hdrv = to_hid_driver(drv);
+
+        if (hdrv->bus_removed_driver)
+                hdrv->bus_removed_driver(removed_hdrv);
+
+        return 0;
+}
+
 int __hid_register_driver(struct hid_driver *hdrv, struct module *owner,
                 const char *mod_name)
 {
@@ -2214,6 +2230,8 @@ int __hid_register_driver(struct hid_driver *hdrv, struct module *owner,
         INIT_LIST_HEAD(&hdrv->dyn_list);
         spin_lock_init(&hdrv->dyn_lock);
 
+        bus_for_each_drv(&hid_bus_type, NULL, hdrv, __bus_add_driver);
+
         return driver_register(&hdrv->driver);
 }
 EXPORT_SYMBOL_GPL(__hid_register_driver);
@@ -2222,6 +2240,8 @@ void hid_unregister_driver(struct hid_driver *hdrv)
 {
         driver_unregister(&hdrv->driver);
         hid_free_dynids(hdrv);
+
+        bus_for_each_drv(&hid_bus_type, NULL, hdrv, __bus_removed_driver);
 }
 EXPORT_SYMBOL_GPL(hid_unregister_driver);
 
diff --git a/drivers/hid/hid-generic.c b/drivers/hid/hid-generic.c
index e288a4a06fe8..3c0a1bf433d7 100644
--- a/drivers/hid/hid-generic.c
+++ b/drivers/hid/hid-generic.c
@@ -24,8 +24,71 @@
 
 #include <linux/hid.h>
 
+static struct hid_driver hid_generic;
+
+static int __unmap_hid_generic(struct device *dev, void *data)
+{
+        struct hid_driver *hdrv = data;
+        struct hid_device *hdev = to_hid_device(dev);
+
+        /* only unbind matching devices already bound to hid-generic */
+        if (hdev->driver != &hid_generic ||
+            hid_match_device(hdev, hdrv) == NULL)
+                return 0;
+
+        if (dev->parent)        /* Needed for USB */
+                device_lock(dev->parent);
+        device_release_driver(dev);
+        if (dev->parent)
+                device_unlock(dev->parent);
+
+        return 0;
+}
+
+static void hid_generic_add_driver(struct hid_driver *hdrv)
+{
+        bus_for_each_dev(&hid_bus_type, NULL, hdrv, __unmap_hid_generic);
+}
+
+static void hid_generic_removed_driver(struct hid_driver *hdrv)
+{
+        int ret;
+
+        ret = driver_attach(&hid_generic.driver);
+}
+
+static int __check_hid_generic(struct device_driver *drv, void *data)
+{
+        struct hid_driver *hdrv = to_hid_driver(drv);
+        struct hid_device *hdev = data;
+
+        if (hdrv == &hid_generic)
+                return 0;
+
+        return hid_match_device(hdev, hdrv) != NULL;
+}
+
+static bool hid_generic_match(struct hid_device *hdev,
+                              bool ignore_special_driver)
+{
+        if (ignore_special_driver)
+                return true;
+
+        if (hdev->quirks & HID_QUIRK_HAVE_SPECIAL_DRIVER)
+                return false;
+
+        /*
+         * If any other driver wants the device, leave the device to this other
+         * driver.
+         */
+        if (bus_for_each_drv(&hid_bus_type, NULL, hdev, __check_hid_generic))
+                return false;
+
+        return true;
+}
+
 static const struct hid_device_id hid_table[] = {
-        { HID_DEVICE(HID_BUS_ANY, HID_GROUP_GENERIC, HID_ANY_ID, HID_ANY_ID) },
+        { HID_DEVICE(HID_BUS_ANY, HID_GROUP_ANY, HID_ANY_ID, HID_ANY_ID) },
         { }
 };
 MODULE_DEVICE_TABLE(hid, hid_table);
@@ -33,6 +96,9 @@ MODULE_DEVICE_TABLE(hid, hid_table);
 static struct hid_driver hid_generic = {
         .name = "hid-generic",
         .id_table = hid_table,
+        .match = hid_generic_match,
+        .bus_add_driver = hid_generic_add_driver,
+        .bus_removed_driver = hid_generic_removed_driver,
 };
 module_hid_driver(hid_generic);
 
diff --git a/include/linux/hid.h b/include/linux/hid.h
index 83df331576a5..39cdeb205caa 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -672,6 +672,7 @@ struct hid_usage_id {
  *            to be called)
  * @dyn_list: list of dynamically added device ids
  * @dyn_lock: lock protecting @dyn_list
+ * @match: check if the given device is handled by this driver
  * @probe: new device inserted
  * @remove: device removed (NULL if not a hot-plug capable driver)
  * @report_table: on which reports to call raw_event (NULL means all)
@@ -684,6 +685,8 @@ struct hid_usage_id {
  * @input_mapped: invoked on input registering after mapping an usage
  * @input_configured: invoked just before the device is registered
  * @feature_mapping: invoked on feature registering
+ * @bus_add_driver: invoked when a HID driver is about to be added
+ * @bus_removed_driver: invoked when a HID driver has been removed
  * @suspend: invoked on suspend (NULL means nop)
  * @resume: invoked on resume if device was not reset (NULL means nop)
  * @reset_resume: invoked on resume if device was reset (NULL means nop)
@@ -712,6 +715,7 @@ struct hid_driver {
         struct list_head dyn_list;
         spinlock_t dyn_lock;
 
+        bool (*match)(struct hid_device *dev, bool ignore_special_driver);
         int (*probe)(struct hid_device *dev, const struct hid_device_id *id);
         void (*remove)(struct hid_device *dev);
 
@@ -737,6 +741,8 @@ struct hid_driver {
         void (*feature_mapping)(struct hid_device *hdev,
                         struct hid_field *field,
                         struct hid_usage *usage);
+        void (*bus_add_driver)(struct hid_driver *driver);
+        void (*bus_removed_driver)(struct hid_driver *driver);
 #ifdef CONFIG_PM
         int (*suspend)(struct hid_device *hdev, pm_message_t message);
         int (*resume)(struct hid_device *hdev);
@@ -815,6 +821,8 @@ extern bool hid_ignore(struct hid_device *);
 extern int hid_add_device(struct hid_device *);
 extern void hid_destroy_device(struct hid_device *);
 
+extern struct bus_type hid_bus_type;
+
 extern int __must_check __hid_register_driver(struct hid_driver *,
                 struct module *, const char *mod_name);
 
@@ -865,6 +873,8 @@ bool hid_match_one_id(const struct hid_device *hdev,
                       const struct hid_device_id *id);
 const struct hid_device_id *hid_match_id(const struct hid_device *hdev,
                                          const struct hid_device_id *id);
+const struct hid_device_id *hid_match_device(struct hid_device *hdev,
+                                             struct hid_driver *hdrv);
 s32 hid_snto32(__u32 value, unsigned n);
 __u32 hid_field_extract(const struct hid_device *hid, __u8 *report,
                      unsigned offset, unsigned n);