Input: ALPS - do not mix trackstick and external PS/2 mouse data

Previously dev2 device was used for both external PS/2 mouse and internal
trackstick device (if available). This change introduces dev3 device which
is used for external PS/2 mouse data and dev2 is now used only for
trackstick.

In case that trackstick is not present dev2 is not created, so userspace
does not see non existent device in system.

Because laptops with ALPS devices often do not use i8042 active
multiplexing all data (from touchpad, trackstick and external PS/2 mouse)
come to one port.  So it is not possible to know if external PS/2 mouse is
connected or not. In most cases external PS/2 mouse is not connected so
driver will create dev3 input device after first bare PS/2 packet will be
received. So there will not be "ghost" input device.

This change also helps in identifying possible problems in future if driver
decides to report 6-bytes trackstick packets as 3-bytes bare PS/2 (data
will be reported to dev3 instead dev2).
Signed-off-by: NPali Rohár <pali.rohar@gmail.com>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/mouse/alps.c

@@ -165,8 +165,7 @@ static bool alps_is_valid_first_byte(struct alps_data *priv,
 	return (data & priv->mask0) == priv->byte0;
 }
 
-static void alps_report_buttons(struct psmouse *psmouse,
-				struct input_dev *dev1, struct input_dev *dev2,
+static void alps_report_buttons(struct input_dev *dev1, struct input_dev *dev2,
 				int left, int right, int middle)
 {
 	struct input_dev *dev;
@@ -176,20 +175,21 @@ static void alps_report_buttons(struct psmouse *psmouse,
 	 * other device (dev2) then this event should be also
 	 * sent through that device.
 	 */
-	dev = test_bit(BTN_LEFT, dev2->key) ? dev2 : dev1;
+	dev = (dev2 && test_bit(BTN_LEFT, dev2->key)) ? dev2 : dev1;
 	input_report_key(dev, BTN_LEFT, left);
 
-	dev = test_bit(BTN_RIGHT, dev2->key) ? dev2 : dev1;
+	dev = (dev2 && test_bit(BTN_RIGHT, dev2->key)) ? dev2 : dev1;
 	input_report_key(dev, BTN_RIGHT, right);
 
-	dev = test_bit(BTN_MIDDLE, dev2->key) ? dev2 : dev1;
+	dev = (dev2 && test_bit(BTN_MIDDLE, dev2->key)) ? dev2 : dev1;
 	input_report_key(dev, BTN_MIDDLE, middle);
 
 	/*
 	 * Sync the _other_ device now, we'll do the first
 	 * device later once we report the rest of the events.
 	 */
-	input_sync(dev2);
+	if (dev2)
+		input_sync(dev2);
 }
 
 static void alps_process_packet_v1_v2(struct psmouse *psmouse)
@@ -236,13 +236,13 @@ static void alps_process_packet_v1_v2(struct psmouse *psmouse)
 		input_report_rel(dev2, REL_X,  (x > 383 ? (x - 768) : x));
 		input_report_rel(dev2, REL_Y, -(y > 255 ? (y - 512) : y));
 
-		alps_report_buttons(psmouse, dev2, dev, left, right, middle);
+		alps_report_buttons(dev2, dev, left, right, middle);
 
 		input_sync(dev2);
 		return;
 	}
 
-	alps_report_buttons(psmouse, dev, dev2, left, right, middle);
+	alps_report_buttons(dev, dev2, left, right, middle);
 
 	/* Convert hardware tap to a reasonable Z value */
 	if (ges && !fin)
@@ -1123,23 +1123,89 @@ static void alps_process_packet_v7(struct psmouse *psmouse)
 		alps_process_touchpad_packet_v7(psmouse);
 }
 
-static void alps_report_bare_ps2_packet(struct psmouse *psmouse,
+static DEFINE_MUTEX(alps_mutex);
+
+static void alps_register_bare_ps2_mouse(struct work_struct *work)
+{
+	struct alps_data *priv =
+		container_of(work, struct alps_data, dev3_register_work.work);
+	struct psmouse *psmouse = priv->psmouse;
+	struct input_dev *dev3;
+	int error = 0;
+
+	mutex_lock(&alps_mutex);
+
+	if (priv->dev3)
+		goto out;
+
+	dev3 = input_allocate_device();
+	if (!dev3) {
+		psmouse_err(psmouse, "failed to allocate secondary device\n");
+		error = -ENOMEM;
+		goto out;
+	}
+
+	snprintf(priv->phys3, sizeof(priv->phys3), "%s/%s",
+		 psmouse->ps2dev.serio->phys,
+		 (priv->dev2 ? "input2" : "input1"));
+	dev3->phys = priv->phys3;
+
+	/*
+	 * format of input device name is: "protocol vendor name"
+	 * see function psmouse_switch_protocol() in psmouse-base.c
+	 */
+	dev3->name = "PS/2 ALPS Mouse";
+
+	dev3->id.bustype = BUS_I8042;
+	dev3->id.vendor  = 0x0002;
+	dev3->id.product = PSMOUSE_PS2;
+	dev3->id.version = 0x0000;
+	dev3->dev.parent = &psmouse->ps2dev.serio->dev;
+
+	input_set_capability(dev3, EV_REL, REL_X);
+	input_set_capability(dev3, EV_REL, REL_Y);
+	input_set_capability(dev3, EV_KEY, BTN_LEFT);
+	input_set_capability(dev3, EV_KEY, BTN_RIGHT);
+	input_set_capability(dev3, EV_KEY, BTN_MIDDLE);
+
+	__set_bit(INPUT_PROP_POINTER, dev3->propbit);
+
+	error = input_register_device(dev3);
+	if (error) {
+		psmouse_err(psmouse,
+			    "failed to register secondary device: %d\n",
+			    error);
+		input_free_device(dev3);
+		goto out;
+	}
+
+	priv->dev3 = dev3;
+
+out:
+	/*
+	 * Save the error code so that we can detect that we
+	 * already tried to create the device.
+	 */
+	if (error)
+		priv->dev3 = ERR_PTR(error);
+
+	mutex_unlock(&alps_mutex);
+}
+
+static void alps_report_bare_ps2_packet(struct input_dev *dev,
 					unsigned char packet[],
 					bool report_buttons)
 {
-	struct alps_data *priv = psmouse->private;
-	struct input_dev *dev2 = priv->dev2;
-
 	if (report_buttons)
-		alps_report_buttons(psmouse, dev2, psmouse->dev,
+		alps_report_buttons(dev, NULL,
 				packet[0] & 1, packet[0] & 2, packet[0] & 4);
 
-	input_report_rel(dev2, REL_X,
+	input_report_rel(dev, REL_X,
 		packet[1] ? packet[1] - ((packet[0] << 4) & 0x100) : 0);
-	input_report_rel(dev2, REL_Y,
+	input_report_rel(dev, REL_Y,
 		packet[2] ? ((packet[0] << 3) & 0x100) - packet[2] : 0);
 
-	input_sync(dev2);
+	input_sync(dev);
 }
 
 static psmouse_ret_t alps_handle_interleaved_ps2(struct psmouse *psmouse)
@@ -1204,8 +1270,8 @@ static psmouse_ret_t alps_handle_interleaved_ps2(struct psmouse *psmouse)
 		 * de-synchronization.
 		 */
 
-		alps_report_bare_ps2_packet(psmouse, &psmouse->packet[3],
-					    false);
+		alps_report_bare_ps2_packet(priv->dev2,
+					    &psmouse->packet[3], false);
 
 		/*
 		 * Continue with the standard ALPS protocol handling,
@@ -1261,9 +1327,18 @@ static psmouse_ret_t alps_process_byte(struct psmouse *psmouse)
 	 * properly we only do this if the device is fully synchronized.
 	 */
 	if (!psmouse->out_of_sync_cnt && (psmouse->packet[0] & 0xc8) == 0x08) {
+
+		/* Register dev3 mouse if we received PS/2 packet first time */
+		if (unlikely(!priv->dev3))
+			psmouse_queue_work(psmouse,
+					   &priv->dev3_register_work, 0);
+
 		if (psmouse->pktcnt == 3) {
-			alps_report_bare_ps2_packet(psmouse, psmouse->packet,
-						    true);
+			/* Once dev3 mouse device is registered report data */
+			if (likely(!IS_ERR_OR_NULL(priv->dev3)))
+				alps_report_bare_ps2_packet(priv->dev3,
+							    psmouse->packet,
+							    true);
 			return PSMOUSE_FULL_PACKET;
 		}
 		return PSMOUSE_GOOD_DATA;
@@ -2378,7 +2453,10 @@ static void alps_disconnect(struct psmouse *psmouse)
 
 	psmouse_reset(psmouse);
 	del_timer_sync(&priv->timer);
-	input_unregister_device(priv->dev2);
+	if (priv->dev2)
+		input_unregister_device(priv->dev2);
+	if (!IS_ERR_OR_NULL(priv->dev3))
+		input_unregister_device(priv->dev3);
 	kfree(priv);
 }
 
@@ -2412,17 +2490,9 @@ static void alps_set_abs_params_mt(struct alps_data *priv,
 int alps_init(struct psmouse *psmouse)
 {
 	struct alps_data *priv = psmouse->private;
-	struct input_dev *dev1 = psmouse->dev, *dev2;
+	struct input_dev *dev1 = psmouse->dev;
 	int error;
 
-	dev2 = input_allocate_device();
-	if (!dev2) {
-		error = -ENOMEM;
-		goto init_fail;
-	}
-
-	priv->dev2 = dev2;
-
 	error = priv->hw_init(psmouse);
 	if (error)
 		goto init_fail;
@@ -2474,36 +2544,57 @@ int alps_init(struct psmouse *psmouse)
 	}
 
 	if (priv->flags & ALPS_DUALPOINT) {
+		struct input_dev *dev2;
+
+		dev2 = input_allocate_device();
+		if (!dev2) {
+			psmouse_err(psmouse,
+				    "failed to allocate trackstick device\n");
+			error = -ENOMEM;
+			goto init_fail;
+		}
+
+		snprintf(priv->phys2, sizeof(priv->phys2), "%s/input1",
+			 psmouse->ps2dev.serio->phys);
+		dev2->phys = priv->phys2;
+
 		/*
 		 * format of input device name is: "protocol vendor name"
 		 * see function psmouse_switch_protocol() in psmouse-base.c
 		 */
 		dev2->name = "AlpsPS/2 ALPS DualPoint Stick";
+
+		dev2->id.bustype = BUS_I8042;
+		dev2->id.vendor  = 0x0002;
 		dev2->id.product = PSMOUSE_ALPS;
 		dev2->id.version = priv->proto_version;
-	} else {
-		dev2->name = "PS/2 ALPS Mouse";
-		dev2->id.product = PSMOUSE_PS2;
-		dev2->id.version = 0x0000;
-	}
-
-	snprintf(priv->phys, sizeof(priv->phys), "%s/input1", psmouse->ps2dev.serio->phys);
-	dev2->phys = priv->phys;
-	dev2->id.bustype = BUS_I8042;
-	dev2->id.vendor  = 0x0002;
-	dev2->dev.parent = &psmouse->ps2dev.serio->dev;
+		dev2->dev.parent = &psmouse->ps2dev.serio->dev;
 
-	dev2->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REL);
-	dev2->relbit[BIT_WORD(REL_X)] = BIT_MASK(REL_X) | BIT_MASK(REL_Y);
-	dev2->keybit[BIT_WORD(BTN_LEFT)] =
-		BIT_MASK(BTN_LEFT) | BIT_MASK(BTN_MIDDLE) | BIT_MASK(BTN_RIGHT);
+		input_set_capability(dev2, EV_REL, REL_X);
+		input_set_capability(dev2, EV_REL, REL_Y);
+		input_set_capability(dev2, EV_KEY, BTN_LEFT);
+		input_set_capability(dev2, EV_KEY, BTN_RIGHT);
+		input_set_capability(dev2, EV_KEY, BTN_MIDDLE);
 
-	__set_bit(INPUT_PROP_POINTER, dev2->propbit);
-	if (priv->flags & ALPS_DUALPOINT)
+		__set_bit(INPUT_PROP_POINTER, dev2->propbit);
 		__set_bit(INPUT_PROP_POINTING_STICK, dev2->propbit);
 
-	if (input_register_device(priv->dev2))
-		goto init_fail;
+		error = input_register_device(dev2);
+		if (error) {
+			psmouse_err(psmouse,
+				    "failed to register trackstick device: %d\n",
+				    error);
+			input_free_device(dev2);
+			goto init_fail;
+		}
+
+		priv->dev2 = dev2;
+	}
+
+	priv->psmouse = psmouse;
+
+	INIT_DELAYED_WORK(&priv->dev3_register_work,
+			  alps_register_bare_ps2_mouse);
 
 	psmouse->protocol_handler = alps_process_byte;
 	psmouse->poll = alps_poll;
@@ -2521,7 +2612,6 @@ int alps_init(struct psmouse *psmouse)
 
 init_fail:
 	psmouse_reset(psmouse);
-	input_free_device(dev2);
 	/*
 	 * Even though we did not allocate psmouse->private we do free
 	 * it here.

drivers/input/mouse/alps.h

@@ -141,8 +141,12 @@ struct alps_fields {
 
 /**
  * struct alps_data - private data structure for the ALPS driver
- * @dev2: "Relative" device used to report trackstick or mouse activity.
- * @phys: Physical path for the relative device.
+ * @psmouse: Pointer to parent psmouse device
+ * @dev2: Trackstick device (can be NULL).
+ * @dev3: Generic PS/2 mouse (can be NULL, delayed registering).
+ * @phys2: Physical path for the trackstick device.
+ * @phys3: Physical path for the generic PS/2 mouse.
+ * @dev3_register_work: Delayed work for registering PS/2 mouse.
  * @nibble_commands: Command mapping used for touchpad register accesses.
  * @addr_command: Command used to tell the touchpad that a register address
  *   follows.
@@ -169,8 +173,12 @@ struct alps_fields {
  * @timer: Timer for flushing out the final report packet in the stream.
  */
 struct alps_data {
+	struct psmouse *psmouse;
 	struct input_dev *dev2;
-	char phys[32];
+	struct input_dev *dev3;
+	char phys2[32];
+	char phys3[32];
+	struct delayed_work dev3_register_work;
 
 	/* these are autodetected when the device is identified */
 	const struct alps_nibble_commands *nibble_commands;