platform/x86: asus-wmi: adjust screenpad power/brightness handling

Fix illogical screen off control by hardcoding 0 and 1 depending on the
requested brightness and also do not rely on the last screenpad power
state to issue screen brightness commands.

Fixes: 2c97d3e55b70 ("platform/x86: asus-wmi: add support for ASUS screenpad")
Signed-off-by: Denis Benato <denis.benato@linux.dev>
Signed-off-by: Luke Jones <luke@ljones.dev>
Link: https://patch.msgid.link/20260302174431.349816-2-denis.benato@linux.dev
Link: https://patch.msgid.link/20260326231154.856729-2-ethantidmore06@gmail.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
index dc330a8ee2f23a5241024989e68225c6eb48d39c..f4a5da5b1bb8716091584ab0df5d57099200d2d1 100644 (file)
--- a/drivers/platform/x86/asus-wmi.c
+++ b/drivers/platform/x86/asus-wmi.c
@@ -4422,32 +4422,24 @@ static int read_screenpad_brightness(struct backlight_device *bd)
 
 static int update_screenpad_bl_status(struct backlight_device *bd)
 {
-       struct asus_wmi *asus = bl_get_data(bd);
-       int power, err = 0;
-       u32 ctrl_param;
+       u32 ctrl_param = bd->props.brightness;
+       int err = 0;
 
-       power = read_screenpad_backlight_power(asus);
-       if (power < 0)
-               return power;
+       if (bd->props.power) {
+               err = asus_wmi_set_devstate(ASUS_WMI_DEVID_SCREENPAD_POWER, 1, NULL);
+               if (err < 0)
+                       return err;
 
-       if (bd->props.power != power) {
-               if (power != BACKLIGHT_POWER_ON) {
-                       /* Only brightness > 0 can power it back on */
-                       ctrl_param = asus->driver->screenpad_brightness - ASUS_SCREENPAD_BRIGHT_MIN;
-                       err = asus_wmi_set_devstate(ASUS_WMI_DEVID_SCREENPAD_LIGHT,
-                                                   ctrl_param, NULL);
-               } else {
-                       err = asus_wmi_set_devstate(ASUS_WMI_DEVID_SCREENPAD_POWER, 0, NULL);
-               }
-       } else if (power == BACKLIGHT_POWER_ON) {
-               /* Only set brightness if powered on or we get invalid/unsync state */
-               ctrl_param = bd->props.brightness + ASUS_SCREENPAD_BRIGHT_MIN;
                err = asus_wmi_set_devstate(ASUS_WMI_DEVID_SCREENPAD_LIGHT, ctrl_param, NULL);
+               if (err < 0)
+                       return err;
        }
 
-       /* Ensure brightness is stored to turn back on with */
-       if (err == 0)
-               asus->driver->screenpad_brightness = bd->props.brightness + ASUS_SCREENPAD_BRIGHT_MIN;
+       if (!bd->props.power) {
+               err = asus_wmi_set_devstate(ASUS_WMI_DEVID_SCREENPAD_POWER, 0, NULL);
+               if (err < 0)
+                       return err;
+       }
 
        return err;
 }