Input: add match() method to input hanlders

Get rid of blacklist in input handler structure and instead allow
handlers to define their own match() method to perform fine-grained
filtering of supported devices.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

drivers/char/keyboard.c

@@ -1323,6 +1323,21 @@ static void kbd_event(struct input_handle *handle, unsigned int event_type,
 	schedule_console_callback();
 }
 
+static bool kbd_match(struct input_handler *handler, struct input_dev *dev)
+{
+	int i;
+
+	if (test_bit(EV_SND, dev->evbit))
+		return true;
+
+	if (test_bit(EV_KEY, dev->evbit))
+		for (i = KEY_RESERVED; i < BTN_MISC; i++)
+			if (test_bit(i, dev->keybit))
+				return true;
+
+	return false;
+}
+
 /*
  * When a keyboard (or other input device) is found, the kbd_connect
  * function is called. The function then looks at the device, and if it
@@ -1334,14 +1349,6 @@ static int kbd_connect(struct input_handler *handler, struct input_dev *dev,
 {
 	struct input_handle *handle;
 	int error;
-	int i;
-
-	for (i = KEY_RESERVED; i < BTN_MISC; i++)
-		if (test_bit(i, dev->keybit))
-			break;
-
-	if (i == BTN_MISC && !test_bit(EV_SND, dev->evbit))
-		return -ENODEV;
 
 	handle = kzalloc(sizeof(struct input_handle), GFP_KERNEL);
 	if (!handle)
@@ -1407,6 +1414,7 @@ MODULE_DEVICE_TABLE(input, kbd_ids);
 
 static struct input_handler kbd_handler = {
 	.event		= kbd_event,
+	.match		= kbd_match,
 	.connect	= kbd_connect,
 	.disconnect	= kbd_disconnect,
 	.start		= kbd_start,

drivers/input/input.c

@@ -723,12 +723,13 @@ EXPORT_SYMBOL(input_set_keycode);
 		if (i != BITS_TO_LONGS(max)) \
 			continue;
 
-static const struct input_device_id *input_match_device(const struct input_device_id *id,
+static const struct input_device_id *input_match_device(struct input_handler *handler,
 							struct input_dev *dev)
 {
+	const struct input_device_id *id;
 	int i;
 
-	for (; id->flags || id->driver_info; id++) {
+	for (id = handler->id_table; id->flags || id->driver_info; id++) {
 
 		if (id->flags & INPUT_DEVICE_ID_MATCH_BUS)
 			if (id->bustype != dev->id.bustype)
@@ -756,7 +757,8 @@ static const struct input_device_id *input_match_device(const struct input_devic
 		MATCH_BIT(ffbit,  FF_MAX);
 		MATCH_BIT(swbit,  SW_MAX);
 
-		return id;
+		if (!handler->match || handler->match(handler, dev))
+			return id;
 	}
 
 	return NULL;
@@ -767,10 +769,7 @@ static int input_attach_handler(struct input_dev *dev, struct input_handler *han
 	const struct input_device_id *id;
 	int error;
 
-	if (handler->blacklist && input_match_device(handler->blacklist, dev))
+	id = input_match_device(handler, dev);
-		return -ENODEV;
-
-	id = input_match_device(handler->id_table, dev);
 	if (!id)
 		return -ENODEV;
 

drivers/input/joydev.c

@@ -775,6 +775,20 @@ static void joydev_cleanup(struct joydev *joydev)
 		input_close_device(handle);
 }
 
+
+static bool joydev_match(struct input_handler *handler, struct input_dev *dev)
+{
+	/* Avoid touchpads and touchscreens */
+	if (test_bit(EV_KEY, dev->evbit) && test_bit(BTN_TOUCH, dev->keybit))
+		return false;
+
+	/* Avoid tablets, digitisers and similar devices */
+	if (test_bit(EV_KEY, dev->evbit) && test_bit(BTN_DIGI, dev->keybit))
+		return false;
+
+	return true;
+}
+
 static int joydev_connect(struct input_handler *handler, struct input_dev *dev,
 			  const struct input_device_id *id)
 {
@@ -894,22 +908,6 @@ static void joydev_disconnect(struct input_handle *handle)
 	put_device(&joydev->dev);
 }
 
-static const struct input_device_id joydev_blacklist[] = {
-	{
-		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
-				INPUT_DEVICE_ID_MATCH_KEYBIT,
-		.evbit = { BIT_MASK(EV_KEY) },
-		.keybit = { [BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH) },
-	},	/* Avoid itouchpads and touchscreens */
-	{
-		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
-				INPUT_DEVICE_ID_MATCH_KEYBIT,
-		.evbit = { BIT_MASK(EV_KEY) },
-		.keybit = { [BIT_WORD(BTN_DIGI)] = BIT_MASK(BTN_DIGI) },
-	},	/* Avoid tablets, digitisers and similar devices */
-	{ }	/* Terminating entry */
-};
-
 static const struct input_device_id joydev_ids[] = {
 	{
 		.flags = INPUT_DEVICE_ID_MATCH_EVBIT |
@@ -936,13 +934,13 @@ MODULE_DEVICE_TABLE(input, joydev_ids);
 
 static struct input_handler joydev_handler = {
 	.event		= joydev_event,
+	.match		= joydev_match,
 	.connect	= joydev_connect,
 	.disconnect	= joydev_disconnect,
 	.fops		= &joydev_fops,
 	.minor		= JOYDEV_MINOR_BASE,
 	.name		= "joydev",
 	.id_table	= joydev_ids,
-	.blacklist	= joydev_blacklist,
 };
 
 static int __init joydev_init(void)

include/linux/input.h

@@ -1200,6 +1200,8 @@ struct input_handle;
  *	it may not sleep
  * @filter: similar to @event; separates normal event handlers from
  *	"filters".
+ * @match: called after comparing device's id with handler's id_table
+ *	to perform fine-grained matching between device and handler
  * @connect: called when attaching a handler to an input device
  * @disconnect: disconnects a handler from input device
  * @start: starts handler for given handle. This function is called by
@@ -1211,8 +1213,6 @@ struct input_handle;
  * @name: name of the handler, to be shown in /proc/bus/input/handlers
  * @id_table: pointer to a table of input_device_ids this driver can
  *	handle
- * @blacklist: pointer to a table of input_device_ids this driver should
- *	ignore even if they match @id_table
  * @h_list: list of input handles associated with the handler
  * @node: for placing the driver onto input_handler_list
  *
@@ -1235,6 +1235,7 @@ struct input_handler {
 
 	void (*event)(struct input_handle *handle, unsigned int type, unsigned int code, int value);
 	bool (*filter)(struct input_handle *handle, unsigned int type, unsigned int code, int value);
+	bool (*match)(struct input_handler *handler, struct input_dev *dev);
 	int (*connect)(struct input_handler *handler, struct input_dev *dev, const struct input_device_id *id);
 	void (*disconnect)(struct input_handle *handle);
 	void (*start)(struct input_handle *handle);
@@ -1244,7 +1245,6 @@ struct input_handler {
 	const char *name;
 
 	const struct input_device_id *id_table;
-	const struct input_device_id *blacklist;
 
 	struct list_head	h_list;
 	struct list_head	node;