[PATCH 2/2] platform/x86: ideapad-laptop: add CapsLock/NumLock LED via EC
From: Rodnei Cilto
Date: Sat Jun 27 2026 - 21:58:00 EST
Some Lenovo IdeaPad laptops (e.g. 83RR/83SR, Wildcat Lake) have
physical CapsLock and NumLock LEDs controlled via the EC.
The EC exposes CAPL (bit 5) and NUML (bit 4) at offset 0xA1.
Writing these bits via ec_write() and evaluating _QDF via
acpi_evaluate_object() causes the firmware to sync EC state to the
GPIO lines that drive the physical LEDs.
Discovery via DSDT analysis on Lenovo IdeaPad 83RR (Wildcat Lake):
- CAPL/NUML at EC offset 0xA1 (bits 5 and 4)
- _QDF (_SB.PC00.LPCB.EC0._QDF) reads CAPL/NUML -> SGOV()
- GPIO 0x001A1087 -> CapsLock LED physical pin
- GPIO 0x001A0485 -> NumLock LED physical pin
- ec_read/ec_write exported via EXPORT_SYMBOL in drivers/acpi/ec.c
and declared in <linux/acpi.h>
Add two led_classdev entries (input::capslock, input::numlock)
guarded by DMI match (features.kbd_leds) for 83RR and its Brazil
regional variant 83SR.
Signed-off-by: Rodnei Cilto <rodnei.cilto@xxxxxxxxx>
---
drivers/platform/x86/lenovo/ideapad-laptop.c | 143 +++++++++++++++++++++++++++
1 file changed, 143 insertions(+)
diff --git a/drivers/platform/x86/lenovo/ideapad-laptop.c b/drivers/platform/x86/lenovo/ideapad-laptop.c
index 4fbc904f1fc3..03e3f234067c 100644
--- a/drivers/platform/x86/lenovo/ideapad-laptop.c
+++ b/drivers/platform/x86/lenovo/ideapad-laptop.c
@@ -42,6 +42,17 @@
#include <dt-bindings/leds/common.h>
+/* EC keyboard LED control (IdeaPad EC PS/2 emulation).
+ * Validated on Lenovo IdeaPad 83RR (Wildcat Lake):
+ * EC offset 0xA1 bit4=NUML, bit5=CAPL
+ * _QDF syncs EC state to GPIO -> physical LED
+ * ec_read/ec_write declared in <linux/acpi.h>
+ */
+#define IDEAPAD_EC_KBD_LED_OFFSET 0xA1
+#define IDEAPAD_EC_KBD_LED_NUML_BIT BIT(4)
+#define IDEAPAD_EC_KBD_LED_CAPL_BIT BIT(5)
+#define IDEAPAD_ACPI_EC0_QDF_PATH "\\_SB.PC00.LPCB.EC0._QDF"
+
#define IDEAPAD_RFKILL_DEV_NUM 3
enum {
@@ -198,6 +209,7 @@ struct ideapad_private {
bool ctrl_ps2_aux_port : 1;
bool usb_charging : 1;
bool ymc_ec_trigger : 1;
+ bool kbd_leds : 1;
} features;
struct {
bool initialized;
@@ -210,6 +222,11 @@ struct ideapad_private {
struct led_classdev led;
unsigned int last_brightness;
} fn_lock;
+ struct {
+ bool initialized;
+ struct led_classdev capslock;
+ struct led_classdev numlock;
+ } kbd_leds;
};
static bool no_bt_rfkill;
@@ -1587,6 +1604,99 @@ static void ideapad_backlight_notify_brightness(struct ideapad_private *priv)
/*
* keyboard backlight
*/
+static int ideapad_kbd_led_ec_set(u8 bit, bool on)
+{
+ u8 val;
+ int err;
+
+ err = ec_read(IDEAPAD_EC_KBD_LED_OFFSET, &val);
+ if (err)
+ return err;
+ if (on)
+ val |= bit;
+ else
+ val &= ~bit;
+ err = ec_write(IDEAPAD_EC_KBD_LED_OFFSET, val);
+ if (err)
+ return err;
+ acpi_evaluate_object(NULL, IDEAPAD_ACPI_EC0_QDF_PATH, NULL, NULL);
+ return 0;
+}
+
+static void ideapad_capslock_led_set(struct led_classdev *led_cdev,
+ enum led_brightness brightness)
+{
+ ideapad_kbd_led_ec_set(IDEAPAD_EC_KBD_LED_CAPL_BIT, brightness != LED_OFF);
+}
+
+static enum led_brightness ideapad_capslock_led_get(struct led_classdev *led_cdev)
+{
+ u8 val;
+
+ if (ec_read(IDEAPAD_EC_KBD_LED_OFFSET, &val))
+ return LED_OFF;
+ return (val & IDEAPAD_EC_KBD_LED_CAPL_BIT) ? LED_ON : LED_OFF;
+}
+
+static void ideapad_numlock_led_set(struct led_classdev *led_cdev,
+ enum led_brightness brightness)
+{
+ ideapad_kbd_led_ec_set(IDEAPAD_EC_KBD_LED_NUML_BIT, brightness != LED_OFF);
+}
+
+static enum led_brightness ideapad_numlock_led_get(struct led_classdev *led_cdev)
+{
+ u8 val;
+
+ if (ec_read(IDEAPAD_EC_KBD_LED_OFFSET, &val))
+ return LED_OFF;
+ return (val & IDEAPAD_EC_KBD_LED_NUML_BIT) ? LED_ON : LED_OFF;
+}
+
+static int ideapad_kbd_leds_init(struct ideapad_private *priv)
+{
+ int err;
+
+ if (WARN_ON(priv->kbd_leds.initialized))
+ return -EEXIST;
+
+ priv->kbd_leds.capslock.name = "input::capslock";
+ priv->kbd_leds.capslock.max_brightness = 1;
+ priv->kbd_leds.capslock.brightness_set = ideapad_capslock_led_set;
+ priv->kbd_leds.capslock.brightness_get = ideapad_capslock_led_get;
+ priv->kbd_leds.capslock.flags = LED_RETAIN_AT_SHUTDOWN;
+
+ err = led_classdev_register(&priv->platform_device->dev,
+ &priv->kbd_leds.capslock);
+ if (err)
+ return err;
+
+ priv->kbd_leds.numlock.name = "input::numlock";
+ priv->kbd_leds.numlock.max_brightness = 1;
+ priv->kbd_leds.numlock.brightness_set = ideapad_numlock_led_set;
+ priv->kbd_leds.numlock.brightness_get = ideapad_numlock_led_get;
+ priv->kbd_leds.numlock.flags = LED_RETAIN_AT_SHUTDOWN;
+
+ err = led_classdev_register(&priv->platform_device->dev,
+ &priv->kbd_leds.numlock);
+ if (err) {
+ led_classdev_unregister(&priv->kbd_leds.capslock);
+ return err;
+ }
+
+ priv->kbd_leds.initialized = true;
+ return 0;
+}
+
+static void ideapad_kbd_leds_exit(struct ideapad_private *priv)
+{
+ if (!priv->kbd_leds.initialized)
+ return;
+ priv->kbd_leds.initialized = false;
+ led_classdev_unregister(&priv->kbd_leds.numlock);
+ led_classdev_unregister(&priv->kbd_leds.capslock);
+}
+
static int ideapad_kbd_bl_check_tristate(int type)
{
return (type == KBD_BL_TRISTATE) || (type == KBD_BL_TRISTATE_AUTO);
@@ -1832,6 +1942,29 @@ static void ideapad_sync_touchpad_state(struct ideapad_private *priv, bool send_
priv->r_touchpad_val = value;
}
+static const struct dmi_system_id ideapad_kbd_leds_dmi_table[] = {
+ {
+ /*
+ * Lenovo IdeaPad 83RR (Wildcat Lake) - EC PS/2 emulation
+ * controls CapsLock/NumLock LEDs via EC offset 0xA1 + _QDF.
+ * CAPL=bit5 (0x20), NUML=bit4 (0x10).
+ * _QDF drives GPIO via SGOV() to physical LED pins.
+ */
+ .matches = {
+ DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
+ DMI_MATCH(DMI_PRODUCT_NAME, "83RR"),
+ },
+ },
+ {
+ /* Lenovo IdeaPad 83SR (83RR Brazil regional variant) */
+ .matches = {
+ DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
+ DMI_MATCH(DMI_PRODUCT_NAME, "83SR"),
+ },
+ },
+ { }
+};
+
static const struct dmi_system_id ymc_ec_trigger_quirk_dmi_table[] = {
{
/* Lenovo Yoga 7 14ARB7 */
@@ -2178,6 +2311,8 @@ static int ideapad_check_features(struct ideapad_private *priv)
priv->features.touchpad_ctrl_via_ec = touchpad_ctrl_via_ec;
priv->features.ymc_ec_trigger =
ymc_ec_trigger || dmi_check_system(ymc_ec_trigger_quirk_dmi_table);
+ priv->features.kbd_leds =
+ dmi_check_system(ideapad_kbd_leds_dmi_table);
if (!read_ec_data(handle, VPCCMD_R_FAN, &val))
priv->features.fan_mode = true;
@@ -2418,6 +2553,12 @@ static int ideapad_acpi_add(struct platform_device *pdev)
dev_info(&pdev->dev, "FnLock control not available\n");
}
+ if (priv->features.kbd_leds) {
+ err = ideapad_kbd_leds_init(priv);
+ if (err)
+ dev_warn(&pdev->dev, "Could not set up kbd LEDs: %d\n", err);
+ }
+
/*
* On some models without a hw-switch (the yoga 2 13 at least)
* VPCCMD_W_RF must be explicitly set to 1 for the wifi to work.
@@ -2477,6 +2618,7 @@ static int ideapad_acpi_add(struct platform_device *pdev)
ideapad_unregister_rfkill(priv, i);
ideapad_fn_lock_led_exit(priv);
+ ideapad_kbd_leds_exit(priv);
ideapad_kbd_bl_exit(priv);
ideapad_input_exit(priv);
@@ -2506,6 +2648,7 @@ static void ideapad_acpi_remove(struct platform_device *pdev)
ideapad_unregister_rfkill(priv, i);
ideapad_fn_lock_led_exit(priv);
+ ideapad_kbd_leds_exit(priv);
ideapad_kbd_bl_exit(priv);
ideapad_input_exit(priv);
ideapad_debugfs_exit(priv);
--
2.51.0