HID: wiimote: add device detection

Nintendo produced many different devices that are internally based on the
Wii Remote protocol but provide different peripherals. To support these
devices, we need to schedule a device detection during initialization.

Device detection includes requesting a status report, reading extension
information and then evaluating which device we may be dealing with.

We currently detect gen1 and gen2 Wii Remote devices. All other devices
are marked as generic devices. More detections will be added later.

In followup patches we will be using these device IDs to control which
peripherals to initialize. For instance if a device is known to have no IR
camera, there is no need to provide the IR input device nor trying to
access IR registers. In fact, there are 3rd party devices that break if we
try things like this (hurray!).

The init_worker will be scheduled whenever we get hotplug events. This
isn't implemented, yet and will be added later. However, we need to make
sure that this worker can be called multiple times.

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

1 files changed, 152 insertions, 1 deletions

diff --git a/drivers/hid/hid-wiimote-core.c b/drivers/hid/hid-wiimote-core.c
index 02656a8cc7d..76d2c73eb69 100644
--- a/drivers/hid/hid-wiimote-core.c
+++ b/drivers/hid/hid-wiimote-core.c
@@ -399,6 +399,45 @@ ssize_t wiimote_cmd_read(struct wiimote_data *wdata, __u32 offset, __u8 *rmem,
 	return ret;
 }
 
+/* requires the cmd-mutex to be held */
+static int wiimote_cmd_init_ext(struct wiimote_data *wdata)
+{
+	__u8 wmem;
+	int ret;
+
+	/* initialize extension */
+	wmem = 0x55;
+	ret = wiimote_cmd_write(wdata, 0xa400f0, &wmem, sizeof(wmem));
+	if (ret)
+		return ret;
+
+	/* disable default encryption */
+	wmem = 0x0;
+	ret = wiimote_cmd_write(wdata, 0xa400fb, &wmem, sizeof(wmem));
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+/* requires the cmd-mutex to be held */
+static __u8 wiimote_cmd_read_ext(struct wiimote_data *wdata)
+{
+	__u8 rmem[6];
+	int ret;
+
+	/* read extension ID */
+	ret = wiimote_cmd_read(wdata, 0xa400fa, rmem, 6);
+	if (ret != 6)
+		return WIIMOTE_EXT_NONE;
+
+	if (rmem[0] == 0xff && rmem[1] == 0xff && rmem[2] == 0xff &&
+	    rmem[3] == 0xff && rmem[4] == 0xff && rmem[5] == 0xff)
+		return WIIMOTE_EXT_NONE;
+
+	return WIIMOTE_EXT_UNKNOWN;
+}
+
 static int wiimote_battery_get_property(struct power_supply *psy,
 						enum power_supply_property psp,
 						union power_supply_propval *val)
@@ -662,6 +701,105 @@ static void wiimote_ir_close(struct input_dev *dev)
 	wiimote_init_ir(wdata, 0);
 }
 
+/* device (re-)initialization and detection */
+
+static const char *wiimote_devtype_names[WIIMOTE_DEV_NUM] = {
+	[WIIMOTE_DEV_PENDING] = "Pending",
+	[WIIMOTE_DEV_UNKNOWN] = "Unknown",
+	[WIIMOTE_DEV_GENERIC] = "Generic",
+	[WIIMOTE_DEV_GEN10] = "Nintendo Wii Remote (Gen 1)",
+	[WIIMOTE_DEV_GEN20] = "Nintendo Wii Remote Plus (Gen 2)",
+};
+
+/* Try to guess the device type based on all collected information. We
+ * first try to detect by static extension types, then VID/PID and the
+ * device name. If we cannot detect the device, we use
+ * WIIMOTE_DEV_GENERIC so all modules will get probed on the device. */
+static void wiimote_init_set_type(struct wiimote_data *wdata,
+				  __u8 exttype)
+{
+	__u8 devtype = WIIMOTE_DEV_GENERIC;
+	__u16 vendor, product;
+	const char *name;
+
+	vendor = wdata->hdev->vendor;
+	product = wdata->hdev->product;
+	name = wdata->hdev->name;
+
+	if (!strcmp(name, "Nintendo RVL-CNT-01")) {
+		devtype = WIIMOTE_DEV_GEN10;
+		goto done;
+	} else if (!strcmp(name, "Nintendo RVL-CNT-01-TR")) {
+		devtype = WIIMOTE_DEV_GEN20;
+		goto done;
+	}
+
+	if (vendor == USB_VENDOR_ID_NINTENDO) {
+		if (product == USB_DEVICE_ID_NINTENDO_WIIMOTE) {
+			devtype = WIIMOTE_DEV_GEN10;
+			goto done;
+		} else if (product == USB_DEVICE_ID_NINTENDO_WIIMOTE2) {
+			devtype = WIIMOTE_DEV_GEN20;
+			goto done;
+		}
+	}
+
+done:
+	if (devtype == WIIMOTE_DEV_GENERIC)
+		hid_info(wdata->hdev, "cannot detect device; NAME: %s VID: %04x PID: %04x EXT: %04x\n",
+			name, vendor, product, exttype);
+	else
+		hid_info(wdata->hdev, "detected device: %s\n",
+			 wiimote_devtype_names[devtype]);
+
+	spin_lock_irq(&wdata->state.lock);
+	wdata->state.devtype = devtype;
+	spin_unlock_irq(&wdata->state.lock);
+}
+
+static void wiimote_init_detect(struct wiimote_data *wdata)
+{
+	__u8 exttype = WIIMOTE_EXT_NONE;
+	bool ext;
+	int ret;
+
+	wiimote_cmd_acquire_noint(wdata);
+
+	spin_lock_irq(&wdata->state.lock);
+	wiimote_cmd_set(wdata, WIIPROTO_REQ_SREQ, 0);
+	wiiproto_req_status(wdata);
+	spin_unlock_irq(&wdata->state.lock);
+
+	ret = wiimote_cmd_wait_noint(wdata);
+	if (ret)
+		goto out_release;
+
+	spin_lock_irq(&wdata->state.lock);
+	ext = wdata->state.flags & WIIPROTO_FLAG_EXT_PLUGGED;
+	spin_unlock_irq(&wdata->state.lock);
+
+	if (!ext)
+		goto out_release;
+
+	wiimote_cmd_init_ext(wdata);
+	exttype = wiimote_cmd_read_ext(wdata);
+
+out_release:
+	wiimote_cmd_release(wdata);
+	wiimote_init_set_type(wdata, exttype);
+}
+
+static void wiimote_init_worker(struct work_struct *work)
+{
+	struct wiimote_data *wdata = container_of(work, struct wiimote_data,
+						  init_worker);
+
+	if (wdata->state.devtype == WIIMOTE_DEV_PENDING)
+		wiimote_init_detect(wdata);
+}
+
+/* protocol handlers */
+
 static void handler_keys(struct wiimote_data *wdata, const __u8 *payload)
 {
 	input_report_key(wdata->input, wiiproto_keymap[WIIPROTO_KEY_LEFT],
@@ -776,7 +914,14 @@ static void handler_status(struct wiimote_data *wdata, const __u8 *payload)
 {
 	handler_status_K(wdata, payload);
 
-	wiiext_event(wdata, payload[2] & 0x02);
+	/* update extension status */
+	if (payload[2] & 0x02) {
+		wdata->state.flags |= WIIPROTO_FLAG_EXT_PLUGGED;
+		wiiext_event(wdata, true);
+	} else {
+		wdata->state.flags &= ~WIIPROTO_FLAG_EXT_PLUGGED;
+		wiiext_event(wdata, false);
+	}
 
 	if (wiimote_cmd_pending(wdata, WIIPROTO_REQ_SREQ, 0)) {
 		wdata->state.cmd_battery = payload[5];
@@ -1135,6 +1280,8 @@ static struct wiimote_data *wiimote_create(struct hid_device *hdev)
 	mutex_init(&wdata->state.sync);
 	wdata->state.drm = WIIPROTO_REQ_DRM_K;
 
+	INIT_WORK(&wdata->init_worker, wiimote_init_worker);
+
 	return wdata;
 
 err_ir:
@@ -1157,6 +1304,7 @@ static void wiimote_destroy(struct wiimote_data *wdata)
 	input_unregister_device(wdata->accel);
 	input_unregister_device(wdata->ir);
 	input_unregister_device(wdata->input);
+	cancel_work_sync(&wdata->init_worker);
 	cancel_work_sync(&wdata->queue.worker);
 	hid_hw_close(wdata->hdev);
 	hid_hw_stop(wdata->hdev);
@@ -1253,6 +1401,9 @@ static int wiimote_hid_probe(struct hid_device *hdev,
 	wiiproto_req_leds(wdata, WIIPROTO_FLAG_LED1);
 	spin_unlock_irq(&wdata->state.lock);
 
+	/* schedule device detection */
+	schedule_work(&wdata->init_worker);
+
 	return 0;
 
 err_free: