Re: [PATCH v4 1/4] HID: wiimote: turn on the LEDs indicating the controller id

["David Rheinsberg" <david@readahead.eu>]

Hi

On Mon, Aug 17, 2026, at 11:38 PM, Rafael Passos wrote:
> The behavior in a Wii/Wii U console is to have each controller turn on
> a different LED indicating the controller id.
> This commit implements the same behavior using the ida struct.
> Unlike switch controllers, each ID only turns one LED (from 1 to 4).
>
> Signed-off-by: Rafael Passos <rafael@rcpassos.me>
> ---
>  drivers/hid/hid-wiimote-core.c  | 52 +++++++++++++++++++++++++++++----
>  drivers/hid/hid-wiimote-debug.c |  5 +++-
>  drivers/hid/hid-wiimote.h       |  1 +
>  3 files changed, 51 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/hid/hid-wiimote-core.c 
> b/drivers/hid/hid-wiimote-core.c
> index 63c4fa8fbb9b..acf31d8b6991 100644
> --- a/drivers/hid/hid-wiimote-core.c
> +++ b/drivers/hid/hid-wiimote-core.c
> @@ -621,6 +621,13 @@ static const __u8 * const 
> wiimote_devtype_mods[WIIMOTE_DEV_NUM] = {
>  	},
>  };
> 
> +static const __u8 player_leds[] = {
> +	WIIPROTO_FLAG_LED1,
> +	WIIPROTO_FLAG_LED2,
> +	WIIPROTO_FLAG_LED3,
> +	WIIPROTO_FLAG_LED4
> +};
> +
>  static void wiimote_modules_load(struct wiimote_data *wdata,
>  				 unsigned int devtype)
>  {
> @@ -671,6 +678,12 @@ static void wiimote_modules_load(struct 
> wiimote_data *wdata,
>  	spin_lock_irq(&wdata->state.lock);
>  	wdata->state.devtype = devtype;
>  	spin_unlock_irq(&wdata->state.lock);
> +
> +	scoped_guard(spinlock_irqsave, &wdata->state.lock) {
> +		/* after loading modules, set the Player ID LED cycling from 1 to 4*/
> +		wiiproto_req_leds(wdata, player_leds[(wdata->player_id - 1) % 4]);
> +	}
> +

Sorry, I unintentionally sent the previous review in private. Anyway, I also noticed that if you set LEDs unconditionally, you can drop the same call from `wiimod_led_probe()` (the entire block guarded by `ops->arg == 0`).

Not all wiimote devices have LEDs, but I think it is safe to always send the LED request, given that those are embedded in all data requests, IIRC.

Thanks
David

>  	return;
> 
>  error:
> @@ -855,11 +868,11 @@ static void wiimote_init_set_type(struct 
> wiimote_data *wdata,
> 
>  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);
> +		hid_info(wdata->hdev, "cannot detect device; NAME: %s VID: %04x PID: 
> %04x EXT: %04x (%d)\n",
> +			name, vendor, product, exttype, wdata->player_id);
>  	else
> -		hid_info(wdata->hdev, "detected device: %s\n",
> -			 wiimote_devtype_names[devtype]);
> +		hid_info(wdata->hdev, "detected device: %s (%d)\n",
> +			 wiimote_devtype_names[devtype], wdata->player_id);
> 
>  	wiimote_modules_load(wdata, devtype);
>  }
> @@ -1752,6 +1765,7 @@ static struct wiimote_data *wiimote_create(struct 
> hid_device *hdev)
>  	mutex_init(&wdata->state.sync);
>  	wdata->state.drm = WIIPROTO_REQ_DRM_K;
>  	wdata->state.cmd_battery = 0xff;
> +	wdata->player_id = 0; // min 1, u8 0 is unasigned id
> 
>  	INIT_WORK(&wdata->init_worker, wiimote_init_worker);
>  	timer_setup(&wdata->timer, wiimote_init_timeout, 0);
> @@ -1759,12 +1773,17 @@ static struct wiimote_data 
> *wiimote_create(struct hid_device *hdev)
>  	return wdata;
>  }
> 
> +/* Global id allocator for wii remotes */
> +static DEFINE_IDA(wiimote_ida);
> +
>  static void wiimote_destroy(struct wiimote_data *wdata)
>  {
>  	unsigned long flags;
> 
>  	wiidebug_deinit(wdata);
> 
> +	ida_free(&wiimote_ida, wdata->player_id);
> +
>  	/* prevent init_worker from being scheduled again */
>  	spin_lock_irqsave(&wdata->state.lock, flags);
>  	wdata->state.flags |= WIIPROTO_FLAG_EXITING;
> @@ -1834,7 +1853,14 @@ static int wiimote_hid_probe(struct hid_device *hdev,
>  	if (ret)
>  		goto err_free;
> 
> -	hid_info(hdev, "New device registered\n");
> +	ret = ida_alloc_min(&wiimote_ida, 1, GFP_KERNEL);
> +	if (ret < 1) {
> +		hid_err(hdev, "cannot allocate controller id\n");
> +		goto err_free;
> +	}
> +
> +	wdata->player_id = ret;
> +	hid_info(hdev, "New device registered (Wiimote %d)\n", ret);
> 
>  	/* schedule device detection */
>  	wiimote_schedule(wdata);
> @@ -1887,7 +1913,21 @@ static struct hid_driver wiimote_hid_driver = {
>  	.remove = wiimote_hid_remove,
>  	.raw_event = wiimote_hid_event,
>  };
> -module_hid_driver(wiimote_hid_driver);
> +
> +
> +static int __init wiimote_init(void)
> +{
> +	return hid_register_driver(&wiimote_hid_driver);
> +}
> +
> +static void __exit wiimote_exit(void)
> +{
> +	hid_unregister_driver(&wiimote_hid_driver);
> +	ida_destroy(&wiimote_ida);
> +}
> +
> +module_init(wiimote_init);
> +module_exit(wiimote_exit);
> 
>  MODULE_LICENSE("GPL");
>  MODULE_AUTHOR("David Herrmann <dh.herrmann@gmail.com>");
> diff --git a/drivers/hid/hid-wiimote-debug.c b/drivers/hid/hid-wiimote-debug.c
> index 5f74917781f2..fc847c2a1c1f 100644
> --- a/drivers/hid/hid-wiimote-debug.c
> +++ b/drivers/hid/hid-wiimote-debug.c
> @@ -186,12 +186,14 @@ int wiidebug_init(struct wiimote_data *wdata)
>  	dbg->drm = debugfs_create_file("drm", S_IRUSR,
>  			dbg->wdata->hdev->debug_dir, dbg, &wiidebug_drm_fops);
> 
> +	debugfs_create_u8("player_id", S_IRUSR,
> +		   dbg->wdata->hdev->debug_dir, &wdata->player_id);
> +
>  	spin_lock_irqsave(&wdata->state.lock, flags);
>  	wdata->debug = dbg;
>  	spin_unlock_irqrestore(&wdata->state.lock, flags);
> 
>  	return 0;
> -
>  }
> 
>  void wiidebug_deinit(struct wiimote_data *wdata)
> @@ -208,5 +210,6 @@ void wiidebug_deinit(struct wiimote_data *wdata)
> 
>  	debugfs_remove(dbg->drm);
>  	debugfs_remove(dbg->eeprom);
> +	debugfs_lookup_and_remove("player_id", dbg->wdata->hdev->debug_dir);
>  	kfree(dbg);
>  }
> diff --git a/drivers/hid/hid-wiimote.h b/drivers/hid/hid-wiimote.h
> index 9c12f63f6dd2..8e5002f515e2 100644
> --- a/drivers/hid/hid-wiimote.h
> +++ b/drivers/hid/hid-wiimote.h
> @@ -153,6 +153,7 @@ struct wiimote_data {
>  	struct input_dev *mp;
>  	struct timer_list timer;
>  	struct wiimote_debug *debug;
> +	u8 player_id;
> 
>  	union {
>  		struct input_dev *input;
> -- 
> 2.55.0