linux-kernel - Re: [PATCH v1 1/2] hid-asus: use hid for brightness control on keyboard

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Date: Wed, 29 May 2024 10:21:56 +0200
From: Hans de Goede <hdegoede@...hat.com>
To: "Luke D. Jones" <luke@...nes.dev>, jikos@...nel.org
Cc: ilpo.jarvinen@...ux.intel.com, corentin.chary@...il.com,
 platform-driver-x86@...r.kernel.org, linux-kernel@...r.kernel.org,
 linux-input@...r.kernel.org, bentiss@...nel.org
Subject: Re: [PATCH v1 1/2] hid-asus: use hid for brightness control on
 keyboard

Hi Luke,

Thank you for the new version, much better.

On 5/29/24 3:28 AM, Luke D. Jones wrote:
> On almost all ASUS ROG series laptops the MCU used for the USB keyboard
> also has a HID packet used for setting the brightness. This is usually
> the same as the WMI method. But in some laptops the WMI method either
> is missing or doesn't work, so we should default to the HID control.
> 
> Signed-off-by: Luke D. Jones <luke@...nes.dev>
> ---
>  drivers/hid/hid-asus.c                     |  6 ++++
>  drivers/platform/x86/asus-wmi.c            | 35 +++++++++++++++++++++-
>  include/linux/platform_data/x86/asus-wmi.h | 10 +++++++
>  3 files changed, 50 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/hid/hid-asus.c b/drivers/hid/hid-asus.c
> index 02de2bf4f790..4cba8e143031 100644
> --- a/drivers/hid/hid-asus.c
> +++ b/drivers/hid/hid-asus.c
> @@ -492,12 +492,18 @@ static void asus_kbd_backlight_work(struct work_struct *work)
>   */
>  static bool asus_kbd_wmi_led_control_present(struct hid_device *hdev)
>  {
> +	struct asus_drvdata *drvdata = hid_get_drvdata(hdev);
>  	u32 value;
>  	int ret;
>  
>  	if (!IS_ENABLED(CONFIG_ASUS_WMI))
>  		return false;
>  
> +	if (drvdata->quirks & QUIRK_ROG_NKEY_KEYBOARD && asus_use_hid_led()) {
> +		hid_info(hdev, "using HID for asus::kbd_backlight\n");
> +		return false;
> +	}
> +
>  	ret = asus_wmi_evaluate_method(ASUS_WMI_METHODID_DSTS,
>  				       ASUS_WMI_DEVID_KBD_BACKLIGHT, 0, &value);
>  	hid_dbg(hdev, "WMI backlight check: rc %d value %x", ret, value);
> diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
> index 3f9b6285c9a6..54cb07c79fcf 100644
> --- a/drivers/platform/x86/asus-wmi.c
> +++ b/drivers/platform/x86/asus-wmi.c
> @@ -144,6 +144,15 @@ module_param(fnlock_default, bool, 0444);
>  
>  static const char * const ashs_ids[] = { "ATK4001", "ATK4002", NULL };
>  
> +static const char * const use_hid_led_matches[] = {
> +	"ROG Zephyrus",
> +	"ROG Strix",
> +	"ROG Flow",
> +	"GA403",
> +	"GU605",
> +	"RC71L",
> +};
> +
>  static int throttle_thermal_policy_write(struct asus_wmi *);
>  
>  static bool ashs_present(void)
> @@ -1642,6 +1651,29 @@ static int micmute_led_set(struct led_classdev *led_cdev,
>  	return err < 0 ? err : 0;
>  }
>  
> +bool asus_use_hid_led(void)
> +{
> +	const char *product, *board;
> +	int i;
> +
> +	product = dmi_get_system_info(DMI_PRODUCT_FAMILY);
> +	if (!product)
> +		return false;
> +
> +	board = dmi_get_system_info(DMI_BOARD_NAME);
> +	if (!board)
> +		return false;
> +
> +	for (i = 0; i < ARRAY_SIZE(use_hid_led_matches); i++) {
> +		if (strstr(product, use_hid_led_matches[i]))
> +			return true;
> +		if (strstr(board, use_hid_led_matches[i]))
> +			return true;
> +	}
> +	return false;
> +}
> +EXPORT_SYMBOL_GPL(asus_use_hid_led);
> +

With the new helper in this form you are pretty much re-inventing
dmi_check_system().

So IMHO you should just replace use_hid_led_matches[] with
a dmi_system_id array and simplify asus_use_hid_led() to just
a single "dmi_check_system(asus_use_hid_led_dmi_ids)" call.

Using dmi_system_id-s also allows you to specify if the string
which is being matched should be matched against DMI_PRODUCT_FAMILY
or DMI_BOARD_NAME. Note the normal DMI_MATCH() macro to fill in
dmi_system_id array entries does non exact matching using strstr()
just like you do above.

Note you need to terminate the dmi_system_id array with an empty
{} entry.



>  static void asus_wmi_led_exit(struct asus_wmi *asus)
>  {
>  	led_classdev_unregister(&asus->kbd_led);
> @@ -1681,7 +1713,8 @@ static int asus_wmi_led_init(struct asus_wmi *asus)
>  			goto error;
>  	}
>  
> -	if (!kbd_led_read(asus, &led_val, NULL)) {
> +	if (!kbd_led_read(asus, &led_val, NULL) && !asus_use_hid_led()) {
> +		pr_info("using asus-wmi for asus::kbd_backlight\n");
>  		asus->kbd_led_wk = led_val;
>  		asus->kbd_led.name = "asus::kbd_backlight";
>  		asus->kbd_led.flags = LED_BRIGHT_HW_CHANGED;
> diff --git a/include/linux/platform_data/x86/asus-wmi.h b/include/linux/platform_data/x86/asus-wmi.h
> index 3eb5cd6773ad..6833035f7006 100644
> --- a/include/linux/platform_data/x86/asus-wmi.h
> +++ b/include/linux/platform_data/x86/asus-wmi.h
> @@ -160,4 +160,14 @@ static inline int asus_wmi_evaluate_method(u32 method_id, u32 arg0, u32 arg1,
>  }
>  #endif
>  
> +/* To be used by both hid-asus and asus-wmi to determine which controls kbd_brightness */
> +#if IS_ENABLED(CONFIG_ASUS_WMI)
> +bool asus_use_hid_led(void);
> +#else
> +static inline bool asus_use_hid_led(void)
> +{
> +	return true;
> +}
> +#endif
> +
>  #endif	/* __PLATFORM_DATA_X86_ASUS_WMI_H */

Regards,

Hans