[PATCH v5 1/1] platform/x86: asus-wmi: add support for ASUS screenpad
From: Luke D. Jones
Date: Sun Aug 27 2023 - 19:25:27 EST
Add support for the WMI methods used to turn off and adjust the
brightness of the secondary "screenpad" device found on some high-end
ASUS laptops like the GX650P series and others.
These methods are utilised in a new backlight device named asus_screenpad.
Signed-off-by: Luke D. Jones <luke@xxxxxxxxxx>
---
drivers/platform/x86/asus-wmi.c | 131 +++++++++++++++++++++
drivers/platform/x86/asus-wmi.h | 1 +
include/linux/platform_data/x86/asus-wmi.h | 4 +
3 files changed, 136 insertions(+)
diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
index 13547e55ae82..2801c691133a 100644
--- a/drivers/platform/x86/asus-wmi.c
+++ b/drivers/platform/x86/asus-wmi.c
@@ -25,6 +25,7 @@
#include <linux/input/sparse-keymap.h>
#include <linux/kernel.h>
#include <linux/leds.h>
+#include <linux/minmax.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/pci_hotplug.h>
@@ -127,6 +128,9 @@ module_param(fnlock_default, bool, 0444);
#define NVIDIA_TEMP_MIN 75
#define NVIDIA_TEMP_MAX 87
+#define ASUS_SCREENPAD_BRIGHT_MIN 20
+#define ASUS_SCREENPAD_BRIGHT_MAX 255
+
static const char * const ashs_ids[] = { "ATK4001", "ATK4002", NULL };
static int throttle_thermal_policy_write(struct asus_wmi *);
@@ -212,6 +216,7 @@ struct asus_wmi {
struct input_dev *inputdev;
struct backlight_device *backlight_device;
+ struct backlight_device *screenpad_backlight_device;
struct platform_device *platform_device;
struct led_classdev wlan_led;
@@ -3776,6 +3781,123 @@ static int is_display_toggle(int code)
return 0;
}
+/* Screenpad backlight *******************************************************/
+
+static int read_screenpad_backlight_power(struct asus_wmi *asus)
+{
+ int ret;
+
+ ret = asus_wmi_get_devstate_simple(asus, ASUS_WMI_DEVID_SCREENPAD_POWER);
+ if (ret < 0)
+ return ret;
+ /* 1 == powered */
+ return ret ? FB_BLANK_UNBLANK : FB_BLANK_POWERDOWN;
+}
+
+static int read_screenpad_brightness(struct backlight_device *bd)
+{
+ struct asus_wmi *asus = bl_get_data(bd);
+ u32 retval;
+ int err;
+
+ err = read_screenpad_backlight_power(asus);
+ if (err < 0)
+ return err;
+ /* The device brightness can only be read if powered, so return stored */
+ if (err == FB_BLANK_POWERDOWN)
+ return asus->driver->screenpad_brightness;
+
+ err = asus_wmi_get_devstate(asus, ASUS_WMI_DEVID_SCREENPAD_LIGHT, &retval);
+ if (err < 0)
+ return err;
+
+ return (retval & ASUS_WMI_DSTS_BRIGHTNESS_MASK) - ASUS_SCREENPAD_BRIGHT_MIN;
+}
+
+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;
+
+ power = read_screenpad_backlight_power(asus);
+ if (power < 0)
+ return power;
+
+ if (bd->props.power != power) {
+ if (power != FB_BLANK_UNBLANK) {
+ /* Only brightness > 0 can power it back on */
+ ctrl_param = max(ASUS_SCREENPAD_BRIGHT_MIN, asus->driver->screenpad_brightness);
+ 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 == FB_BLANK_UNBLANK) {
+ /* 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);
+ }
+
+ /* Ensure brightness is stored to turn back on with */
+ asus->driver->screenpad_brightness = bd->props.brightness + ASUS_SCREENPAD_BRIGHT_MIN;
+
+ return err;
+}
+
+static const struct backlight_ops asus_screenpad_bl_ops = {
+ .get_brightness = read_screenpad_brightness,
+ .update_status = update_screenpad_bl_status,
+ .options = BL_CORE_SUSPENDRESUME,
+};
+
+static int asus_screenpad_init(struct asus_wmi *asus)
+{
+ struct backlight_device *bd;
+ struct backlight_properties props;
+ int err, power;
+ int brightness = 0;
+
+ power = read_screenpad_backlight_power(asus);
+ if (power < 0)
+ return power;
+
+ if (power != FB_BLANK_POWERDOWN) {
+ err = asus_wmi_get_devstate(asus, ASUS_WMI_DEVID_SCREENPAD_LIGHT, &brightness);
+ if (err < 0)
+ return err;
+ }
+ /* default to an acceptable min brightness on boot if too low */
+ if (brightness < ASUS_SCREENPAD_BRIGHT_MIN)
+ brightness = ASUS_SCREENPAD_BRIGHT_MIN;
+
+ memset(&props, 0, sizeof(struct backlight_properties));
+ props.type = BACKLIGHT_RAW; /* ensure this bd is last to be picked */
+ props.max_brightness = ASUS_SCREENPAD_BRIGHT_MAX - ASUS_SCREENPAD_BRIGHT_MIN;
+ bd = backlight_device_register("asus_screenpad",
+ &asus->platform_device->dev, asus,
+ &asus_screenpad_bl_ops, &props);
+ if (IS_ERR(bd)) {
+ pr_err("Could not register backlight device\n");
+ return PTR_ERR(bd);
+ }
+
+ asus->screenpad_backlight_device = bd;
+ asus->driver->screenpad_brightness = brightness;
+ bd->props.brightness = brightness;
+ bd->props.power = power;
+ backlight_update_status(bd);
+
+ return 0;
+}
+
+static void asus_screenpad_exit(struct asus_wmi *asus)
+{
+ backlight_device_unregister(asus->screenpad_backlight_device);
+
+ asus->screenpad_backlight_device = NULL;
+}
+
/* Fn-lock ********************************************************************/
static bool asus_wmi_has_fnlock_key(struct asus_wmi *asus)
@@ -4431,6 +4553,12 @@ static int asus_wmi_add(struct platform_device *pdev)
} else if (asus->driver->quirks->wmi_backlight_set_devstate)
err = asus_wmi_set_devstate(ASUS_WMI_DEVID_BACKLIGHT, 2, NULL);
+ if (asus_wmi_dev_is_present(asus, ASUS_WMI_DEVID_SCREENPAD_LIGHT)) {
+ err = asus_screenpad_init(asus);
+ if (err && err != -ENODEV)
+ goto fail_screenpad;
+ }
+
if (asus_wmi_has_fnlock_key(asus)) {
asus->fnlock_locked = fnlock_default;
asus_wmi_fnlock_update(asus);
@@ -4454,6 +4582,8 @@ static int asus_wmi_add(struct platform_device *pdev)
asus_wmi_backlight_exit(asus);
fail_backlight:
asus_wmi_rfkill_exit(asus);
+fail_screenpad:
+ asus_screenpad_exit(asus);
fail_rfkill:
asus_wmi_led_exit(asus);
fail_leds:
@@ -4480,6 +4610,7 @@ static int asus_wmi_remove(struct platform_device *device)
asus = platform_get_drvdata(device);
wmi_remove_notify_handler(asus->driver->event_guid);
asus_wmi_backlight_exit(asus);
+ asus_screenpad_exit(asus);
asus_wmi_input_exit(asus);
asus_wmi_led_exit(asus);
asus_wmi_rfkill_exit(asus);
diff --git a/drivers/platform/x86/asus-wmi.h b/drivers/platform/x86/asus-wmi.h
index a478ebfd34df..5fbdd0eafa02 100644
--- a/drivers/platform/x86/asus-wmi.h
+++ b/drivers/platform/x86/asus-wmi.h
@@ -57,6 +57,7 @@ struct quirk_entry {
struct asus_wmi_driver {
int brightness;
int panel_power;
+ int screenpad_brightness;
int wlan_ctrl_by_user;
const char *name;
diff --git a/include/linux/platform_data/x86/asus-wmi.h b/include/linux/platform_data/x86/asus-wmi.h
index 16e99a1c37fc..63e630276499 100644
--- a/include/linux/platform_data/x86/asus-wmi.h
+++ b/include/linux/platform_data/x86/asus-wmi.h
@@ -58,6 +58,10 @@
#define ASUS_WMI_DEVID_KBD_BACKLIGHT 0x00050021
#define ASUS_WMI_DEVID_LIGHT_SENSOR 0x00050022 /* ?? */
#define ASUS_WMI_DEVID_LIGHTBAR 0x00050025
+/* This can only be used to disable the screen, not re-enable */
+#define ASUS_WMI_DEVID_SCREENPAD_POWER 0x00050031
+/* Writing a brightness re-enables the screen if disabled */
+#define ASUS_WMI_DEVID_SCREENPAD_LIGHT 0x00050032
#define ASUS_WMI_DEVID_FAN_BOOST_MODE 0x00110018
#define ASUS_WMI_DEVID_THROTTLE_THERMAL_POLICY 0x00120075
--
2.41.0