[PATCH v2 0/3] platform: arm64: thinkpad-t14s-ec: new driver

[PATCH v2 0/3] platform: arm64: thinkpad-t14s-ec: new driver

[Sebastian Reichel]

Introduce driver for the ThinkPad T14s Gen6 Snapdragon EC. In theory
it seems to be compatible with the ThinkPad ACPI driver, but these
devices are booted with device tree. As the name implies, the existing
ThinkPad ACPI driver only supports the ACPI interface. Looking at
the implementation, the ACPI DSDT contains many mapping functions
to translate the low level I2C messages into the interface used by
the ThinkPad ACPI driver. Adding DT support to the ThinkPad ACPI driver
would require adding all those translation functions, which would add
more or less the same amount of code as writing a separate driver using
the low level interface directly. I don't think it's sensible to make
the existing ACPI driver even more complicated, so I went for a separate
driver.

I managed to get system LEDs, audio LEDs, extra keys and the keyboard
backlight control working. The EC also seems to be used for some thermal
bits, which I haven't looked into deeply. As far as I understand most
thermal and fan control is handled by a different controller
(0x36@i2c5) anyways.

Apart from that the EC is involved in proper system suspend, which
is something I do not yet understand (I don't have any documentation
apart from the dis-assembled DSDT and existing ACPI driver). Right
now I disabled wake capabilities for the IRQ, since it would wake
up the system when closing the LID. Hopefully a way to mask specific
events will be found in the future.

Changes in v2:
- Link to v1: https://lore.kernel.org/r/20250831-thinkpad-t14s-ec-v1-0-6e06a07afe0f@collabora.com
- Apply Reviewed-by tags from Bryan O'Donoghue
- Apply Tested-by tags from Neil Armstrong
- Update DT binding description, location and examples (Krzysztof Kozlowski)
- Add missing wakeup-source to DT binding (Rob Herring Bot)
- Update DTS newlines, pinctrl order, nodename (Konrad Dybcio)
- Updates to EC driver
  - Add bits.h and bitfield.h include (Ilpo Järvinen)
  - Drop mutex.h (myself, leftover from development)
  - Drop DEBUG define (Ilpo Järvinen)
  - Add THINKPAD_T14S_EC_BLINK_RATE_ON_OFF_MS (Bryan O'Donoghue, Ilpo Järvinen)
  - Add THINKPAD_T14S_EC_KEY_EVT_OFFSET (Ilpo Järvinen)
  - Add THINKPAD_T14S_EC_KEY_ENTRY (myself, to keep line length sane
    after THINKPAD_T14S_EC_KEY_EVT_OFFSET)
  - Align values of thinkpad_t14s_ec_led_status_t (Ilpo Järvinen)
  - Use u8 instead of char for I2C command buffers (Ilpo Järvinen)
  - Add some more newlines after goto/return (Bryan O'Donoghue)
  - Use FIELD_PREP/FIELD_GET instead of _SHIFT (Ilpo Järvinen)
  - Explicitly map to LED_ON/LED_OFF in audio_led_get (Ilpo Järvinen)
  - Add missing , after .driver.of_match_table (Ilpo Järvinen)
  - Change from KEY_MODE to KEY_PERFORMANCE (myself after seeing a patch
    for HID lenovo being sent to the list)

Signed-off-by: Sebastian Reichel <sre@kernel.org>
---
Sebastian Reichel (3):
      dt-bindings: platform: Add Lenovo Thinkpad T14s EC
      platform: arm64: thinkpad-t14s-ec: new driver
      arm64: dts: qcom: x1e80100-t14s: add EC

 .../lenovo,thinkpad-t14s-ec.yaml                   |  50 ++
 MAINTAINERS                                        |   6 +
 .../dts/qcom/x1e78100-lenovo-thinkpad-t14s.dtsi    |  24 +
 drivers/platform/arm64/Kconfig                     |  20 +
 drivers/platform/arm64/Makefile                    |   1 +
 drivers/platform/arm64/lenovo-thinkpad-t14s.c      | 610 +++++++++++++++++++++
 6 files changed, 711 insertions(+)
---
base-commit: b320789d6883cc00ac78ce83bccbfe7ed58afcf0
change-id: 20250831-thinkpad-t14s-ec-ddeb23dbdafb

Best regards,
-- 
Sebastian Reichel <sebastian.reichel@collabora.com>

[PATCH v2 1/3] dt-bindings: platform: Add Lenovo Thinkpad T14s EC

[Sebastian Reichel]

Add binding for the EC found in the Thinkpad T14s Gen6 Snapdragon,
which is based on the Qualcomm X1 Elite. Some of the system LEDs
and extra keys are only accessible via the EC.

Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
---
 .../lenovo,thinkpad-t14s-ec.yaml                   | 50 ++++++++++++++++++++++
 1 file changed, 50 insertions(+)

diff --git a/Documentation/devicetree/bindings/embedded-controller/lenovo,thinkpad-t14s-ec.yaml b/Documentation/devicetree/bindings/embedded-controller/lenovo,thinkpad-t14s-ec.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..c87ccb5b30868c7a616ec08b869286d627dd7406
--- /dev/null
+++ b/Documentation/devicetree/bindings/embedded-controller/lenovo,thinkpad-t14s-ec.yaml
@@ -0,0 +1,50 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/embedded-controller/lenovo,thinkpad-t14s-ec.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Lenovo Thinkpad T14s Embedded Controller
+
+maintainers:
+  - Sebastian Reichel <sre@kernel.org>
+
+description:
+  The Qualcomm Snapdragon-based Lenovo Thinkpad T14s has an Embedded Controller
+  (EC) which handles things such as keyboard backlight, LEDs or non-standard
+  keys.
+
+properties:
+  compatible:
+    const: lenovo,thinkpad-t14s-ec
+
+  reg:
+    const: 0x28
+
+  interrupts:
+    maxItems: 1
+
+  wakeup-source: true
+
+required:
+  - compatible
+  - reg
+  - interrupts
+
+additionalProperties: false
+
+examples:
+  - |+
+    #include <dt-bindings/interrupt-controller/irq.h>
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        embedded-controller@28 {
+            compatible = "lenovo,thinkpad-t14s-ec";
+            reg = <0x28>;
+            interrupts-extended = <&tlmm 66 IRQ_TYPE_LEVEL_LOW>;
+            wakeup-source;
+        };
+    };
+...

-- 
2.50.1

Re: [PATCH v2 1/3] dt-bindings: platform: Add Lenovo Thinkpad T14s EC

[Krzysztof Kozlowski]

On Fri, Sep 05, 2025 at 03:09:31AM +0200, Sebastian Reichel wrote:
> Add binding for the EC found in the Thinkpad T14s Gen6 Snapdragon,
> which is based on the Qualcomm X1 Elite. Some of the system LEDs
> and extra keys are only accessible via the EC.
> 
> Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
> Signed-off-by: Sebastian Reichel <sre@kernel.org>
> ---
>  .../lenovo,thinkpad-t14s-ec.yaml                   | 50 ++++++++++++++++++++++
>  1 file changed, 50 insertions(+)

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Best regards,
Krzysztof

[PATCH v2 2/3] platform: arm64: thinkpad-t14s-ec: new driver

[Sebastian Reichel]

Introduce EC driver for the ThinkPad T14s Gen6 Snapdragon, which is in
theory compatible with ThinkPad ACPI. On Linux the system is booted with
device tree, which is not supported by the ThinkPad ACPI driver
(drivers/platform/x86/lenovo/thinkpad_acpi.c). Also most of the hardware
compatibility is handled via ACPI tables, which are obviously not used
when booting via device tree. Thus adding DT compatibility to the
existing driver is not worth it as there is almost no code sharing.

The driver currently exposes features, which are not available
via other means:

 * Extra Keys
 * System LEDs
 * Keyboard Backlight Control

The driver has been developed by reading the ACPI DSDT. There
are some more features around thermal control, which are not
yet supported by the driver.

The speaker mute and mic mute LEDs need some additional changes
in the ALSA UCM to be set automatically.

Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on Thinkpad T14S OLED
Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
---
 MAINTAINERS                                   |   6 +
 drivers/platform/arm64/Kconfig                |  20 +
 drivers/platform/arm64/Makefile               |   1 +
 drivers/platform/arm64/lenovo-thinkpad-t14s.c | 610 ++++++++++++++++++++++++++
 4 files changed, 637 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 6dcfbd11efef87927041f5cf58d70633dbb4b18d..83375e4e6e8c6ddd82e71503416ad655c25684f0 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -25092,6 +25092,12 @@ W:	http://thinkwiki.org/wiki/Ibm-acpi
 T:	git git://repo.or.cz/linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git
 F:	drivers/platform/x86/lenovo/thinkpad_acpi.c
 
+THINKPAD T14S EMBEDDED CONTROLLER DRIVER
+M:	Sebastian Reichel <sre@kernel.org>
+S:	Maintained
+F:	Documentation/devicetree/bindings/platform/lenovo,thinkpad-t14s-ec.yaml
+F:	drivers/platform/arm64/lenovo-thinkpad-t14s.c
+
 THINKPAD LMI DRIVER
 M:	Mark Pearson <mpearson-lenovo@squebb.ca>
 L:	platform-driver-x86@vger.kernel.org
diff --git a/drivers/platform/arm64/Kconfig b/drivers/platform/arm64/Kconfig
index 06288aebc5599435065a37f8dacd046b5def80bd..10f905d7d6bfa5fad30a0689d3a20481268c781e 100644
--- a/drivers/platform/arm64/Kconfig
+++ b/drivers/platform/arm64/Kconfig
@@ -70,4 +70,24 @@ config EC_LENOVO_YOGA_C630
 
 	  Say M or Y here to include this support.
 
+config EC_LENOVO_THINKPAD_T14S
+	tristate "Lenovo Thinkpad T14s Embedded Controller driver"
+	depends on ARCH_QCOM || COMPILE_TEST
+	depends on I2C
+	depends on INPUT
+	select INPUT_SPARSEKMAP
+	select LEDS_CLASS
+	select NEW_LEDS
+	select SND_CTL_LED if SND
+	help
+	  Driver for the Embedded Controller in the Qualcomm Snapdragon-based
+	  Lenovo Thinkpad T14s, which provides access to keyboard backlight
+	  and status LEDs.
+
+	  This driver provides support for the mentioned laptop where this
+	  information is not properly exposed via the standard Qualcomm
+	  devices.
+
+	  Say M or Y here to include this support.
+
 endif # ARM64_PLATFORM_DEVICES
diff --git a/drivers/platform/arm64/Makefile b/drivers/platform/arm64/Makefile
index 46a99eba3264cc40e812567d1533bb86031a6af3..60c131cff6a15bb51a49c9edab95badf513ee0f6 100644
--- a/drivers/platform/arm64/Makefile
+++ b/drivers/platform/arm64/Makefile
@@ -8,3 +8,4 @@
 obj-$(CONFIG_EC_ACER_ASPIRE1)	+= acer-aspire1-ec.o
 obj-$(CONFIG_EC_HUAWEI_GAOKUN)	+= huawei-gaokun-ec.o
 obj-$(CONFIG_EC_LENOVO_YOGA_C630) += lenovo-yoga-c630.o
+obj-$(CONFIG_EC_LENOVO_THINKPAD_T14S) += lenovo-thinkpad-t14s.o
diff --git a/drivers/platform/arm64/lenovo-thinkpad-t14s.c b/drivers/platform/arm64/lenovo-thinkpad-t14s.c
new file mode 100644
index 0000000000000000000000000000000000000000..ee7d6343a0ff50e64b08d7e507486c91d4b41735
--- /dev/null
+++ b/drivers/platform/arm64/lenovo-thinkpad-t14s.c
@@ -0,0 +1,610 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2025, Sebastian Reichel
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/cleanup.h>
+#include <linux/device.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/input.h>
+#include <linux/input/sparse-keymap.h>
+#include <linux/leds.h>
+#include <linux/lockdep.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#define THINKPAD_T14S_EC_CMD_ECRD 0x02
+#define THINKPAD_T14S_EC_CMD_ECWR 0x03
+#define THINKPAD_T14S_EC_CMD_EVT 0xf0
+
+#define THINKPAD_T14S_EC_REG_LED	0x0c
+#define THINKPAD_T14S_EC_REG_KBD_BL1	0x0d
+#define THINKPAD_T14S_EC_REG_KBD_BL2	0xe1
+#define THINKPAD_T14S_EC_KBD_BL1_MASK	GENMASK_U8(7, 6)
+#define THINKPAD_T14S_EC_KBD_BL2_MASK	GENMASK_U8(3, 2)
+#define THINKPAD_T14S_EC_REG_AUD	0x30
+#define THINKPAD_T14S_EC_MIC_MUTE_LED	BIT(5)
+#define THINKPAD_T14S_EC_SPK_MUTE_LED	BIT(6)
+
+#define THINKPAD_T14S_EC_EVT_NONE			0x00
+#define THINKPAD_T14S_EC_EVT_KEY_FN_4			0x13
+#define THINKPAD_T14S_EC_EVT_KEY_FN_F7			0x16
+#define THINKPAD_T14S_EC_EVT_KEY_FN_SPACE		0x1F
+#define THINKPAD_T14S_EC_EVT_KEY_TP_DOUBLE_TAP		0x20
+#define THINKPAD_T14S_EC_EVT_AC_CONNECTED		0x26
+#define THINKPAD_T14S_EC_EVT_AC_DISCONNECTED		0x27
+#define THINKPAD_T14S_EC_EVT_KEY_POWER			0x28
+#define THINKPAD_T14S_EC_EVT_LID_OPEN			0x2A
+#define THINKPAD_T14S_EC_EVT_LID_CLOSED			0x2B
+#define THINKPAD_T14S_EC_EVT_KEY_FN_F12			0x62
+#define THINKPAD_T14S_EC_EVT_KEY_FN_TAB			0x63
+#define THINKPAD_T14S_EC_EVT_KEY_FN_F8			0x64
+#define THINKPAD_T14S_EC_EVT_KEY_FN_F10			0x65
+#define THINKPAD_T14S_EC_EVT_KEY_FN_F4			0x6A
+#define THINKPAD_T14S_EC_EVT_KEY_FN_D			0x6B
+#define THINKPAD_T14S_EC_EVT_KEY_FN_T			0x6C
+#define THINKPAD_T14S_EC_EVT_KEY_FN_H			0x6D
+#define THINKPAD_T14S_EC_EVT_KEY_FN_M			0x6E
+#define THINKPAD_T14S_EC_EVT_KEY_FN_L			0x6F
+#define THINKPAD_T14S_EC_EVT_KEY_FN_RIGHT_SHIFT		0x71
+#define THINKPAD_T14S_EC_EVT_KEY_FN_ESC			0x74
+#define THINKPAD_T14S_EC_EVT_KEY_FN_N			0x79
+#define THINKPAD_T14S_EC_EVT_KEY_FN_F11			0x7A
+#define THINKPAD_T14S_EC_EVT_KEY_FN_G			0x7E
+
+/* Hardware LED blink rate is 1 Hz (500ms off, 500ms on) */
+#define THINKPAD_T14S_EC_BLINK_RATE_ON_OFF_MS		500
+
+/*
+ * Add a virtual offset on all key event codes for sparse keymap handling,
+ * since the sparse keymap infrastructure does not map some raw key event codes
+ * used by the EC. For example 0x16 (THINKPAD_T14S_EC_EVT_KEY_FN_F7) is mapped
+ * to KEY_MUTE if no offset is applied.
+ */
+#define THINKPAD_T14S_EC_KEY_EVT_OFFSET			0x1000
+#define THINKPAD_T14S_EC_KEY_ENTRY(key, value) \
+	{ KE_KEY, THINKPAD_T14S_EC_KEY_EVT_OFFSET + THINKPAD_T14S_EC_EVT_KEY_##key, { value } }
+
+enum thinkpad_t14s_ec_led_status_t {
+	THINKPAD_EC_LED_OFF =	0x00,
+	THINKPAD_EC_LED_ON =	0x80,
+	THINKPAD_EC_LED_BLINK =	0xc0,
+};
+
+struct thinkpad_t14s_ec_led_classdev {
+	struct led_classdev led_classdev;
+	int led;
+	enum thinkpad_t14s_ec_led_status_t cache;
+	struct thinkpad_t14s_ec *ec;
+};
+
+struct thinkpad_t14s_ec {
+	struct regmap *regmap;
+	struct device *dev;
+	struct thinkpad_t14s_ec_led_classdev led_pwr_btn;
+	struct thinkpad_t14s_ec_led_classdev led_chrg_orange;
+	struct thinkpad_t14s_ec_led_classdev led_chrg_white;
+	struct thinkpad_t14s_ec_led_classdev led_lid_logo_dot;
+	struct led_classdev kbd_backlight;
+	struct led_classdev led_mic_mute;
+	struct led_classdev led_spk_mute;
+	struct input_dev *inputdev;
+};
+
+static const struct regmap_config thinkpad_t14s_ec_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = 0xff,
+};
+
+static int thinkpad_t14s_ec_write(void *context, unsigned int reg,
+				  unsigned int val)
+{
+	u8 buf[5] = {THINKPAD_T14S_EC_CMD_ECWR, reg, 0x00, 0x01, val};
+	struct thinkpad_t14s_ec *ec = context;
+	struct i2c_client *client = to_i2c_client(ec->dev);
+	int ret;
+
+	ret = i2c_master_send(client, buf, sizeof(buf));
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static int thinkpad_t14s_ec_read(void *context, unsigned int reg,
+				 unsigned int *val)
+{
+	u8 buf[4] = {THINKPAD_T14S_EC_CMD_ECRD, reg, 0x00, 0x01};
+	struct thinkpad_t14s_ec *ec = context;
+	struct i2c_client *client = to_i2c_client(ec->dev);
+	struct i2c_msg request, response;
+	u8 result;
+	int ret;
+
+	request.addr = client->addr;
+	request.flags = I2C_M_STOP;
+	request.len = sizeof(buf);
+	request.buf = buf;
+	response.addr = client->addr;
+	response.flags = I2C_M_RD;
+	response.len = 1;
+	response.buf = &result;
+
+	i2c_lock_bus(client->adapter, I2C_LOCK_SEGMENT);
+
+	ret = __i2c_transfer(client->adapter, &request, 1);
+	if (ret < 0)
+		goto out;
+
+	ret = __i2c_transfer(client->adapter, &response, 1);
+	if (ret < 0)
+		goto out;
+
+	*val = result;
+	ret = 0;
+
+out:
+	i2c_unlock_bus(client->adapter, I2C_LOCK_SEGMENT);
+	return ret;
+}
+
+static const struct regmap_bus thinkpad_t14s_ec_regmap_bus = {
+	.reg_write = thinkpad_t14s_ec_write,
+	.reg_read = thinkpad_t14s_ec_read,
+};
+
+static int thinkpad_t14s_ec_read_evt(struct thinkpad_t14s_ec *ec, u8 *val)
+{
+	u8 buf[4] = {THINKPAD_T14S_EC_CMD_EVT, 0x00, 0x00, 0x01};
+	struct i2c_client *client = to_i2c_client(ec->dev);
+	struct i2c_msg request, response;
+	int ret;
+
+	request.addr = client->addr;
+	request.flags = I2C_M_STOP;
+	request.len = sizeof(buf);
+	request.buf = buf;
+	response.addr = client->addr;
+	response.flags = I2C_M_RD;
+	response.len = 1;
+	response.buf = val;
+
+	i2c_lock_bus(client->adapter, I2C_LOCK_SEGMENT);
+
+	ret = __i2c_transfer(client->adapter, &request, 1);
+	if (ret < 0)
+		goto out;
+
+	ret = __i2c_transfer(client->adapter, &response, 1);
+	if (ret < 0)
+		goto out;
+
+	ret = 0;
+
+out:
+	i2c_unlock_bus(client->adapter, I2C_LOCK_SEGMENT);
+	return ret;
+}
+
+static int thinkpad_t14s_led_set_status(struct thinkpad_t14s_ec *ec,
+			struct thinkpad_t14s_ec_led_classdev *led,
+			const enum thinkpad_t14s_ec_led_status_t ledstatus)
+{
+	int ret;
+
+	ret = regmap_write(ec->regmap, THINKPAD_T14S_EC_REG_LED,
+			   led->led | ledstatus);
+	if (ret < 0)
+		return ret;
+
+	led->cache = ledstatus;
+	return 0;
+}
+
+static int thinkpad_t14s_led_set(struct led_classdev *led_cdev,
+				 enum led_brightness brightness)
+{
+	struct thinkpad_t14s_ec_led_classdev *led = container_of(led_cdev,
+			struct thinkpad_t14s_ec_led_classdev, led_classdev);
+	enum thinkpad_t14s_ec_led_status_t new_state;
+
+	if (brightness == LED_OFF)
+		new_state = THINKPAD_EC_LED_OFF;
+	else if (led->cache != THINKPAD_EC_LED_BLINK)
+		new_state = THINKPAD_EC_LED_ON;
+	else
+		new_state = THINKPAD_EC_LED_BLINK;
+
+	return thinkpad_t14s_led_set_status(led->ec, led, new_state);
+}
+
+static int thinkpad_t14s_led_blink_set(struct led_classdev *led_cdev,
+				       unsigned long *delay_on,
+				       unsigned long *delay_off)
+{
+	struct thinkpad_t14s_ec_led_classdev *led = container_of(led_cdev,
+			struct thinkpad_t14s_ec_led_classdev, led_classdev);
+
+	if (*delay_on == 0 && *delay_off == 0) {
+		/* We can choose the blink rate */
+		*delay_on = THINKPAD_T14S_EC_BLINK_RATE_ON_OFF_MS;
+		*delay_off = THINKPAD_T14S_EC_BLINK_RATE_ON_OFF_MS;
+	} else if ((*delay_on != THINKPAD_T14S_EC_BLINK_RATE_ON_OFF_MS) ||
+		   (*delay_off != THINKPAD_T14S_EC_BLINK_RATE_ON_OFF_MS))
+		return -EINVAL;
+
+	return thinkpad_t14s_led_set_status(led->ec, led, THINKPAD_EC_LED_BLINK);
+}
+
+static int thinkpad_t14s_init_led(struct thinkpad_t14s_ec *ec,
+				  struct thinkpad_t14s_ec_led_classdev *led,
+				  u8 id, const char *name)
+{
+	led->led_classdev.name = name;
+	led->led_classdev.flags = LED_RETAIN_AT_SHUTDOWN;
+	led->led_classdev.max_brightness = 1;
+	led->led_classdev.brightness_set_blocking = thinkpad_t14s_led_set;
+	led->led_classdev.blink_set = thinkpad_t14s_led_blink_set;
+	led->ec = ec;
+	led->led = id;
+
+	return devm_led_classdev_register(ec->dev, &led->led_classdev);
+}
+
+static int thinkpad_t14s_leds_probe(struct thinkpad_t14s_ec *ec)
+{
+	int ret;
+
+	ret = thinkpad_t14s_init_led(ec, &ec->led_pwr_btn, 0,
+				     "platform::power");
+	if (ret)
+		return ret;
+
+	ret = thinkpad_t14s_init_led(ec, &ec->led_chrg_orange, 1,
+				     "platform:amber:battery-charging");
+	if (ret)
+		return ret;
+
+	ret = thinkpad_t14s_init_led(ec, &ec->led_chrg_white, 2,
+				     "platform:white:battery-full");
+	if (ret)
+		return ret;
+
+	ret = thinkpad_t14s_init_led(ec, &ec->led_lid_logo_dot, 10,
+				     "platform::lid_logo_dot");
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int thinkpad_t14s_kbd_bl_set(struct led_classdev *led_cdev,
+				    enum led_brightness brightness)
+{
+	struct thinkpad_t14s_ec *ec = container_of(led_cdev,
+					struct thinkpad_t14s_ec, kbd_backlight);
+	int ret;
+	u8 val;
+
+	val = FIELD_PREP(THINKPAD_T14S_EC_KBD_BL1_MASK, brightness);
+	ret = regmap_update_bits(ec->regmap, THINKPAD_T14S_EC_REG_KBD_BL1,
+				 THINKPAD_T14S_EC_KBD_BL1_MASK, val);
+	if (ret < 0)
+		return ret;
+
+	val = FIELD_PREP(THINKPAD_T14S_EC_KBD_BL2_MASK, brightness);
+	ret = regmap_update_bits(ec->regmap, THINKPAD_T14S_EC_REG_KBD_BL2,
+				 THINKPAD_T14S_EC_KBD_BL2_MASK, val);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static enum led_brightness thinkpad_t14s_kbd_bl_get(struct led_classdev *led_cdev)
+{
+	struct thinkpad_t14s_ec *ec = container_of(led_cdev,
+					struct thinkpad_t14s_ec, kbd_backlight);
+	unsigned int val;
+	int ret;
+
+	ret = regmap_read(ec->regmap, THINKPAD_T14S_EC_REG_KBD_BL1, &val);
+	if (ret < 0)
+		return ret;
+
+	return FIELD_GET(THINKPAD_T14S_EC_KBD_BL1_MASK, val);
+}
+
+static void thinkpad_t14s_kbd_bl_update(struct thinkpad_t14s_ec *ec)
+{
+	enum led_brightness brightness = thinkpad_t14s_kbd_bl_get(&ec->kbd_backlight);
+
+	led_classdev_notify_brightness_hw_changed(&ec->kbd_backlight, brightness);
+}
+
+static int thinkpad_t14s_kbd_backlight_probe(struct thinkpad_t14s_ec *ec)
+{
+	ec->kbd_backlight.name = "platform::kbd_backlight";
+	ec->kbd_backlight.flags = LED_BRIGHT_HW_CHANGED;
+	ec->kbd_backlight.max_brightness = 2;
+	ec->kbd_backlight.brightness_set_blocking = thinkpad_t14s_kbd_bl_set;
+	ec->kbd_backlight.brightness_get = thinkpad_t14s_kbd_bl_get;
+
+	return devm_led_classdev_register(ec->dev, &ec->kbd_backlight);
+}
+
+static enum led_brightness thinkpad_t14s_audio_led_get(struct thinkpad_t14s_ec *ec,
+						       u8 led_bit)
+{
+	unsigned int val;
+	int ret;
+
+	ret = regmap_read(ec->regmap, THINKPAD_T14S_EC_REG_AUD, &val);
+	if (ret < 0)
+		return ret;
+
+	return !!(val && led_bit) ? LED_ON : LED_OFF;
+}
+
+static enum led_brightness thinkpad_t14s_audio_led_set(struct thinkpad_t14s_ec *ec,
+						       u8 led_bit,
+						       enum led_brightness brightness)
+{
+	u8 val = brightness ? led_bit : 0;
+
+	return regmap_update_bits(ec->regmap, THINKPAD_T14S_EC_REG_AUD, led_bit, val);
+}
+
+static enum led_brightness thinkpad_t14s_mic_mute_led_get(struct led_classdev *led_cdev)
+{
+	struct thinkpad_t14s_ec *ec = container_of(led_cdev,
+					struct thinkpad_t14s_ec, led_mic_mute);
+
+	return thinkpad_t14s_audio_led_get(ec, THINKPAD_T14S_EC_MIC_MUTE_LED);
+}
+
+static int thinkpad_t14s_mic_mute_led_set(struct led_classdev *led_cdev,
+					  enum led_brightness brightness)
+{
+	struct thinkpad_t14s_ec *ec = container_of(led_cdev,
+					struct thinkpad_t14s_ec, led_mic_mute);
+
+	return thinkpad_t14s_audio_led_set(ec, THINKPAD_T14S_EC_MIC_MUTE_LED, brightness);
+}
+
+static enum led_brightness thinkpad_t14s_spk_mute_led_get(struct led_classdev *led_cdev)
+{
+	struct thinkpad_t14s_ec *ec = container_of(led_cdev,
+					struct thinkpad_t14s_ec, led_spk_mute);
+
+	return thinkpad_t14s_audio_led_get(ec, THINKPAD_T14S_EC_SPK_MUTE_LED);
+}
+
+static int thinkpad_t14s_spk_mute_led_set(struct led_classdev *led_cdev,
+					  enum led_brightness brightness)
+{
+	struct thinkpad_t14s_ec *ec = container_of(led_cdev,
+					struct thinkpad_t14s_ec, led_spk_mute);
+
+	return thinkpad_t14s_audio_led_set(ec, THINKPAD_T14S_EC_SPK_MUTE_LED, brightness);
+}
+
+static int thinkpad_t14s_kbd_audio_led_probe(struct thinkpad_t14s_ec *ec)
+{
+	int ret;
+
+	ec->led_mic_mute.name = "platform::micmute";
+	ec->led_mic_mute.max_brightness = 1,
+	ec->led_mic_mute.default_trigger = "audio-micmute",
+	ec->led_mic_mute.brightness_set_blocking = thinkpad_t14s_mic_mute_led_set;
+	ec->led_mic_mute.brightness_get = thinkpad_t14s_mic_mute_led_get;
+
+	ec->led_spk_mute.name = "platform::mute";
+	ec->led_spk_mute.max_brightness = 1,
+	ec->led_spk_mute.default_trigger = "audio-mute",
+	ec->led_spk_mute.brightness_set_blocking = thinkpad_t14s_spk_mute_led_set;
+	ec->led_spk_mute.brightness_get = thinkpad_t14s_spk_mute_led_get;
+
+	ret = devm_led_classdev_register(ec->dev, &ec->led_mic_mute);
+	if (ret)
+		return ret;
+
+	return devm_led_classdev_register(ec->dev, &ec->led_spk_mute);
+}
+
+static const struct key_entry thinkpad_t14s_keymap[] = {
+	THINKPAD_T14S_EC_KEY_ENTRY(FN_4, KEY_SLEEP),
+	THINKPAD_T14S_EC_KEY_ENTRY(FN_N, KEY_VENDOR),
+	THINKPAD_T14S_EC_KEY_ENTRY(FN_F4, KEY_MICMUTE),
+	THINKPAD_T14S_EC_KEY_ENTRY(FN_F7, KEY_SWITCHVIDEOMODE),
+	THINKPAD_T14S_EC_KEY_ENTRY(FN_F8, KEY_PERFORMANCE),
+	THINKPAD_T14S_EC_KEY_ENTRY(FN_F10, KEY_SELECTIVE_SCREENSHOT),
+	THINKPAD_T14S_EC_KEY_ENTRY(FN_F11, KEY_LINK_PHONE),
+	THINKPAD_T14S_EC_KEY_ENTRY(FN_F12, KEY_BOOKMARKS),
+	THINKPAD_T14S_EC_KEY_ENTRY(FN_SPACE, KEY_KBDILLUMTOGGLE),
+	THINKPAD_T14S_EC_KEY_ENTRY(FN_ESC, KEY_FN_ESC),
+	THINKPAD_T14S_EC_KEY_ENTRY(FN_TAB, KEY_ZOOM),
+	THINKPAD_T14S_EC_KEY_ENTRY(FN_RIGHT_SHIFT, KEY_FN_RIGHT_SHIFT),
+	THINKPAD_T14S_EC_KEY_ENTRY(TP_DOUBLE_TAP, KEY_PROG4),
+	{ KE_END }
+};
+
+static int thinkpad_t14s_input_probe(struct thinkpad_t14s_ec *ec)
+{
+	int ret;
+
+	ec->inputdev = devm_input_allocate_device(ec->dev);
+	if (!ec->inputdev)
+		return -ENOMEM;
+
+	ec->inputdev->name = "ThinkPad Extra Buttons";
+	ec->inputdev->phys = "thinkpad/input0";
+	ec->inputdev->id.bustype = BUS_HOST;
+	ec->inputdev->dev.parent = ec->dev;
+
+	ret = sparse_keymap_setup(ec->inputdev, thinkpad_t14s_keymap, NULL);
+	if (ret)
+		return ret;
+
+	ret = input_register_device(ec->inputdev);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static irqreturn_t thinkpad_t14s_ec_irq_handler(int irq, void *data)
+{
+	struct thinkpad_t14s_ec *ec = data;
+	int ret;
+	u8 val;
+
+	ret = thinkpad_t14s_ec_read_evt(ec, &val);
+	if (ret < 0) {
+		dev_err(ec->dev, "Failed to read event\n");
+		return IRQ_HANDLED;
+	}
+
+	switch (val) {
+	case THINKPAD_T14S_EC_EVT_NONE:
+		break;
+	case THINKPAD_T14S_EC_EVT_KEY_FN_SPACE:
+		thinkpad_t14s_kbd_bl_update(ec);
+		fallthrough;
+	case THINKPAD_T14S_EC_EVT_KEY_FN_F4:
+	case THINKPAD_T14S_EC_EVT_KEY_FN_F7:
+	case THINKPAD_T14S_EC_EVT_KEY_FN_4:
+	case THINKPAD_T14S_EC_EVT_KEY_FN_F8:
+	case THINKPAD_T14S_EC_EVT_KEY_FN_F12:
+	case THINKPAD_T14S_EC_EVT_KEY_FN_TAB:
+	case THINKPAD_T14S_EC_EVT_KEY_FN_F10:
+	case THINKPAD_T14S_EC_EVT_KEY_FN_N:
+	case THINKPAD_T14S_EC_EVT_KEY_FN_F11:
+	case THINKPAD_T14S_EC_EVT_KEY_FN_ESC:
+	case THINKPAD_T14S_EC_EVT_KEY_FN_RIGHT_SHIFT:
+	case THINKPAD_T14S_EC_EVT_KEY_TP_DOUBLE_TAP:
+		sparse_keymap_report_event(ec->inputdev,
+				THINKPAD_T14S_EC_KEY_EVT_OFFSET + val, 1, true);
+		break;
+	case THINKPAD_T14S_EC_EVT_AC_CONNECTED:
+		dev_dbg(ec->dev, "AC connected\n");
+		break;
+	case THINKPAD_T14S_EC_EVT_AC_DISCONNECTED:
+		dev_dbg(ec->dev, "AC disconnected\n");
+		break;
+	case THINKPAD_T14S_EC_EVT_KEY_POWER:
+		dev_dbg(ec->dev, "power button\n");
+		break;
+	case THINKPAD_T14S_EC_EVT_LID_OPEN:
+		dev_dbg(ec->dev, "LID open\n");
+		break;
+	case THINKPAD_T14S_EC_EVT_LID_CLOSED:
+		dev_dbg(ec->dev, "LID closed\n");
+		break;
+	case THINKPAD_T14S_EC_EVT_KEY_FN_G:
+		dev_dbg(ec->dev, "FN + G - toggle double-tapping\n");
+		break;
+	case THINKPAD_T14S_EC_EVT_KEY_FN_L:
+		dev_dbg(ec->dev, "FN + L - low performance mode\n");
+		break;
+	case THINKPAD_T14S_EC_EVT_KEY_FN_M:
+		dev_dbg(ec->dev, "FN + M - medium performance mode\n");
+		break;
+	case THINKPAD_T14S_EC_EVT_KEY_FN_H:
+		dev_dbg(ec->dev, "FN + H - high performance mode\n");
+		break;
+	case THINKPAD_T14S_EC_EVT_KEY_FN_T:
+		dev_dbg(ec->dev, "FN + T - toggle intelligent cooling mode\n");
+		break;
+	case THINKPAD_T14S_EC_EVT_KEY_FN_D:
+		dev_dbg(ec->dev, "FN + D - toggle privacy guard mode\n");
+		break;
+	default:
+		dev_info(ec->dev, "Unknown EC event: 0x%02x\n", val);
+		break;
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int thinkpad_t14s_ec_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct thinkpad_t14s_ec *ec;
+	int ret;
+
+	ec = devm_kzalloc(dev, sizeof(*ec), GFP_KERNEL);
+	if (!ec)
+		return -ENOMEM;
+
+	ec->dev = dev;
+
+	ec->regmap = devm_regmap_init(dev, &thinkpad_t14s_ec_regmap_bus,
+				      ec, &thinkpad_t14s_ec_regmap_config);
+	if (IS_ERR(ec->regmap))
+		return dev_err_probe(dev, PTR_ERR(ec->regmap),
+				     "Failed to init regmap\n");
+
+	ret = devm_request_threaded_irq(dev, client->irq, NULL,
+					thinkpad_t14s_ec_irq_handler,
+					IRQF_ONESHOT, dev_name(dev), ec);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "Failed to get IRQ\n");
+
+	ret = thinkpad_t14s_leds_probe(ec);
+	if (ret < 0)
+		return ret;
+
+	ret = thinkpad_t14s_kbd_backlight_probe(ec);
+	if (ret < 0)
+		return ret;
+
+	ret = thinkpad_t14s_kbd_audio_led_probe(ec);
+	if (ret < 0)
+		return ret;
+
+	ret = thinkpad_t14s_input_probe(ec);
+	if (ret < 0)
+		return ret;
+
+	/*
+	 * Disable wakeup support by default, because the driver currently does
+	 * not support masking any events and the laptop should not wake up when
+	 * the LID is closed.
+	 */
+	device_wakeup_disable(dev);
+
+	return 0;
+}
+
+static const struct of_device_id thinkpad_t14s_ec_of_match[] = {
+	{ .compatible = "lenovo,thinkpad-t14s-ec" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, thinkpad_t14s_ec_of_match);
+
+static const struct i2c_device_id thinkpad_t14s_ec_i2c_id_table[] = {
+	{ "thinkpad-t14s-ec", },
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, thinkpad_t14s_ec_i2c_id_table);
+
+static struct i2c_driver thinkpad_t14s_ec_i2c_driver = {
+	.driver = {
+		.name = "thinkpad-t14s-ec",
+		.of_match_table = thinkpad_t14s_ec_of_match,
+	},
+	.probe = thinkpad_t14s_ec_probe,
+	.id_table = thinkpad_t14s_ec_i2c_id_table,
+};
+module_i2c_driver(thinkpad_t14s_ec_i2c_driver);
+
+MODULE_AUTHOR("Sebastian Reichel <sre@kernel.org>");
+MODULE_DESCRIPTION("Lenovo Thinkpad T14s Embedded Controller");
+MODULE_LICENSE("GPL");

-- 
2.50.1

Re: [PATCH v2 2/3] platform: arm64: thinkpad-t14s-ec: new driver

[Ilpo Järvinen]

On Fri, 5 Sep 2025, Sebastian Reichel wrote:

> Introduce EC driver for the ThinkPad T14s Gen6 Snapdragon, which is in
> theory compatible with ThinkPad ACPI. On Linux the system is booted with
> device tree, which is not supported by the ThinkPad ACPI driver
> (drivers/platform/x86/lenovo/thinkpad_acpi.c). Also most of the hardware
> compatibility is handled via ACPI tables, which are obviously not used
> when booting via device tree. Thus adding DT compatibility to the
> existing driver is not worth it as there is almost no code sharing.
> 
> The driver currently exposes features, which are not available
> via other means:
> 
>  * Extra Keys
>  * System LEDs
>  * Keyboard Backlight Control
> 
> The driver has been developed by reading the ACPI DSDT. There
> are some more features around thermal control, which are not
> yet supported by the driver.
> 
> The speaker mute and mic mute LEDs need some additional changes
> in the ALSA UCM to be set automatically.
> 
> Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on Thinkpad T14S OLED
> Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
> Signed-off-by: Sebastian Reichel <sre@kernel.org>
> ---
>  MAINTAINERS                                   |   6 +
>  drivers/platform/arm64/Kconfig                |  20 +
>  drivers/platform/arm64/Makefile               |   1 +
>  drivers/platform/arm64/lenovo-thinkpad-t14s.c | 610 ++++++++++++++++++++++++++
>  4 files changed, 637 insertions(+)
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 6dcfbd11efef87927041f5cf58d70633dbb4b18d..83375e4e6e8c6ddd82e71503416ad655c25684f0 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -25092,6 +25092,12 @@ W:	http://thinkwiki.org/wiki/Ibm-acpi
>  T:	git git://repo.or.cz/linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git
>  F:	drivers/platform/x86/lenovo/thinkpad_acpi.c
>  
> +THINKPAD T14S EMBEDDED CONTROLLER DRIVER
> +M:	Sebastian Reichel <sre@kernel.org>
> +S:	Maintained
> +F:	Documentation/devicetree/bindings/platform/lenovo,thinkpad-t14s-ec.yaml
> +F:	drivers/platform/arm64/lenovo-thinkpad-t14s.c
> +
>  THINKPAD LMI DRIVER
>  M:	Mark Pearson <mpearson-lenovo@squebb.ca>
>  L:	platform-driver-x86@vger.kernel.org
> diff --git a/drivers/platform/arm64/Kconfig b/drivers/platform/arm64/Kconfig
> index 06288aebc5599435065a37f8dacd046b5def80bd..10f905d7d6bfa5fad30a0689d3a20481268c781e 100644
> --- a/drivers/platform/arm64/Kconfig
> +++ b/drivers/platform/arm64/Kconfig
> @@ -70,4 +70,24 @@ config EC_LENOVO_YOGA_C630
>  
>  	  Say M or Y here to include this support.
>  
> +config EC_LENOVO_THINKPAD_T14S
> +	tristate "Lenovo Thinkpad T14s Embedded Controller driver"
> +	depends on ARCH_QCOM || COMPILE_TEST
> +	depends on I2C
> +	depends on INPUT
> +	select INPUT_SPARSEKMAP
> +	select LEDS_CLASS
> +	select NEW_LEDS
> +	select SND_CTL_LED if SND
> +	help
> +	  Driver for the Embedded Controller in the Qualcomm Snapdragon-based
> +	  Lenovo Thinkpad T14s, which provides access to keyboard backlight
> +	  and status LEDs.
> +
> +	  This driver provides support for the mentioned laptop where this
> +	  information is not properly exposed via the standard Qualcomm
> +	  devices.
> +
> +	  Say M or Y here to include this support.
> +
>  endif # ARM64_PLATFORM_DEVICES
> diff --git a/drivers/platform/arm64/Makefile b/drivers/platform/arm64/Makefile
> index 46a99eba3264cc40e812567d1533bb86031a6af3..60c131cff6a15bb51a49c9edab95badf513ee0f6 100644
> --- a/drivers/platform/arm64/Makefile
> +++ b/drivers/platform/arm64/Makefile
> @@ -8,3 +8,4 @@
>  obj-$(CONFIG_EC_ACER_ASPIRE1)	+= acer-aspire1-ec.o
>  obj-$(CONFIG_EC_HUAWEI_GAOKUN)	+= huawei-gaokun-ec.o
>  obj-$(CONFIG_EC_LENOVO_YOGA_C630) += lenovo-yoga-c630.o
> +obj-$(CONFIG_EC_LENOVO_THINKPAD_T14S) += lenovo-thinkpad-t14s.o
> diff --git a/drivers/platform/arm64/lenovo-thinkpad-t14s.c b/drivers/platform/arm64/lenovo-thinkpad-t14s.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..ee7d6343a0ff50e64b08d7e507486c91d4b41735
> --- /dev/null
> +++ b/drivers/platform/arm64/lenovo-thinkpad-t14s.c
> @@ -0,0 +1,610 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2025, Sebastian Reichel
> + */
> +
> +#include <linux/bitfield.h>
> +#include <linux/bits.h>
> +#include <linux/cleanup.h>
> +#include <linux/device.h>
> +#include <linux/delay.h>
> +#include <linux/err.h>
> +#include <linux/i2c.h>
> +#include <linux/input.h>
> +#include <linux/input/sparse-keymap.h>
> +#include <linux/leds.h>
> +#include <linux/lockdep.h>
> +#include <linux/module.h>
> +#include <linux/regmap.h>
> +#include <linux/slab.h>
> +
> +#define THINKPAD_T14S_EC_CMD_ECRD 0x02
> +#define THINKPAD_T14S_EC_CMD_ECWR 0x03
> +#define THINKPAD_T14S_EC_CMD_EVT 0xf0

align.

> +
> +#define THINKPAD_T14S_EC_REG_LED	0x0c
> +#define THINKPAD_T14S_EC_REG_KBD_BL1	0x0d
> +#define THINKPAD_T14S_EC_REG_KBD_BL2	0xe1
> +#define THINKPAD_T14S_EC_KBD_BL1_MASK	GENMASK_U8(7, 6)
> +#define THINKPAD_T14S_EC_KBD_BL2_MASK	GENMASK_U8(3, 2)
> +#define THINKPAD_T14S_EC_REG_AUD	0x30
> +#define THINKPAD_T14S_EC_MIC_MUTE_LED	BIT(5)
> +#define THINKPAD_T14S_EC_SPK_MUTE_LED	BIT(6)
> +
> +#define THINKPAD_T14S_EC_EVT_NONE			0x00
> +#define THINKPAD_T14S_EC_EVT_KEY_FN_4			0x13
> +#define THINKPAD_T14S_EC_EVT_KEY_FN_F7			0x16
> +#define THINKPAD_T14S_EC_EVT_KEY_FN_SPACE		0x1F
> +#define THINKPAD_T14S_EC_EVT_KEY_TP_DOUBLE_TAP		0x20
> +#define THINKPAD_T14S_EC_EVT_AC_CONNECTED		0x26
> +#define THINKPAD_T14S_EC_EVT_AC_DISCONNECTED		0x27
> +#define THINKPAD_T14S_EC_EVT_KEY_POWER			0x28
> +#define THINKPAD_T14S_EC_EVT_LID_OPEN			0x2A
> +#define THINKPAD_T14S_EC_EVT_LID_CLOSED			0x2B
> +#define THINKPAD_T14S_EC_EVT_KEY_FN_F12			0x62
> +#define THINKPAD_T14S_EC_EVT_KEY_FN_TAB			0x63
> +#define THINKPAD_T14S_EC_EVT_KEY_FN_F8			0x64
> +#define THINKPAD_T14S_EC_EVT_KEY_FN_F10			0x65
> +#define THINKPAD_T14S_EC_EVT_KEY_FN_F4			0x6A
> +#define THINKPAD_T14S_EC_EVT_KEY_FN_D			0x6B
> +#define THINKPAD_T14S_EC_EVT_KEY_FN_T			0x6C
> +#define THINKPAD_T14S_EC_EVT_KEY_FN_H			0x6D
> +#define THINKPAD_T14S_EC_EVT_KEY_FN_M			0x6E
> +#define THINKPAD_T14S_EC_EVT_KEY_FN_L			0x6F
> +#define THINKPAD_T14S_EC_EVT_KEY_FN_RIGHT_SHIFT		0x71
> +#define THINKPAD_T14S_EC_EVT_KEY_FN_ESC			0x74
> +#define THINKPAD_T14S_EC_EVT_KEY_FN_N			0x79
> +#define THINKPAD_T14S_EC_EVT_KEY_FN_F11			0x7A
> +#define THINKPAD_T14S_EC_EVT_KEY_FN_G			0x7E
> +
> +/* Hardware LED blink rate is 1 Hz (500ms off, 500ms on) */
> +#define THINKPAD_T14S_EC_BLINK_RATE_ON_OFF_MS		500
> +
> +/*
> + * Add a virtual offset on all key event codes for sparse keymap handling,
> + * since the sparse keymap infrastructure does not map some raw key event codes
> + * used by the EC. For example 0x16 (THINKPAD_T14S_EC_EVT_KEY_FN_F7) is mapped
> + * to KEY_MUTE if no offset is applied.
> + */
> +#define THINKPAD_T14S_EC_KEY_EVT_OFFSET			0x1000
> +#define THINKPAD_T14S_EC_KEY_ENTRY(key, value) \
> +	{ KE_KEY, THINKPAD_T14S_EC_KEY_EVT_OFFSET + THINKPAD_T14S_EC_EVT_KEY_##key, { value } }
> +
> +enum thinkpad_t14s_ec_led_status_t {
> +	THINKPAD_EC_LED_OFF =	0x00,
> +	THINKPAD_EC_LED_ON =	0x80,
> +	THINKPAD_EC_LED_BLINK =	0xc0,
> +};
> +
> +struct thinkpad_t14s_ec_led_classdev {
> +	struct led_classdev led_classdev;
> +	int led;
> +	enum thinkpad_t14s_ec_led_status_t cache;
> +	struct thinkpad_t14s_ec *ec;
> +};
> +
> +struct thinkpad_t14s_ec {
> +	struct regmap *regmap;
> +	struct device *dev;
> +	struct thinkpad_t14s_ec_led_classdev led_pwr_btn;
> +	struct thinkpad_t14s_ec_led_classdev led_chrg_orange;
> +	struct thinkpad_t14s_ec_led_classdev led_chrg_white;
> +	struct thinkpad_t14s_ec_led_classdev led_lid_logo_dot;
> +	struct led_classdev kbd_backlight;
> +	struct led_classdev led_mic_mute;
> +	struct led_classdev led_spk_mute;
> +	struct input_dev *inputdev;
> +};
> +
> +static const struct regmap_config thinkpad_t14s_ec_regmap_config = {
> +	.reg_bits = 8,
> +	.val_bits = 8,
> +	.max_register = 0xff,
> +};
> +
> +static int thinkpad_t14s_ec_write(void *context, unsigned int reg,
> +				  unsigned int val)
> +{
> +	u8 buf[5] = {THINKPAD_T14S_EC_CMD_ECWR, reg, 0x00, 0x01, val};
> +	struct thinkpad_t14s_ec *ec = context;
> +	struct i2c_client *client = to_i2c_client(ec->dev);
> +	int ret;
> +
> +	ret = i2c_master_send(client, buf, sizeof(buf));
> +	if (ret < 0)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static int thinkpad_t14s_ec_read(void *context, unsigned int reg,
> +				 unsigned int *val)
> +{
> +	u8 buf[4] = {THINKPAD_T14S_EC_CMD_ECRD, reg, 0x00, 0x01};
> +	struct thinkpad_t14s_ec *ec = context;
> +	struct i2c_client *client = to_i2c_client(ec->dev);
> +	struct i2c_msg request, response;
> +	u8 result;
> +	int ret;
> +
> +	request.addr = client->addr;
> +	request.flags = I2C_M_STOP;
> +	request.len = sizeof(buf);
> +	request.buf = buf;
> +	response.addr = client->addr;
> +	response.flags = I2C_M_RD;
> +	response.len = 1;
> +	response.buf = &result;
> +
> +	i2c_lock_bus(client->adapter, I2C_LOCK_SEGMENT);
> +
> +	ret = __i2c_transfer(client->adapter, &request, 1);
> +	if (ret < 0)
> +		goto out;
> +
> +	ret = __i2c_transfer(client->adapter, &response, 1);
> +	if (ret < 0)
> +		goto out;
> +
> +	*val = result;
> +	ret = 0;
> +
> +out:
> +	i2c_unlock_bus(client->adapter, I2C_LOCK_SEGMENT);
> +	return ret;
> +}
> +
> +static const struct regmap_bus thinkpad_t14s_ec_regmap_bus = {
> +	.reg_write = thinkpad_t14s_ec_write,
> +	.reg_read = thinkpad_t14s_ec_read,
> +};
> +
> +static int thinkpad_t14s_ec_read_evt(struct thinkpad_t14s_ec *ec, u8 *val)
> +{
> +	u8 buf[4] = {THINKPAD_T14S_EC_CMD_EVT, 0x00, 0x00, 0x01};
> +	struct i2c_client *client = to_i2c_client(ec->dev);
> +	struct i2c_msg request, response;
> +	int ret;
> +
> +	request.addr = client->addr;
> +	request.flags = I2C_M_STOP;
> +	request.len = sizeof(buf);
> +	request.buf = buf;
> +	response.addr = client->addr;
> +	response.flags = I2C_M_RD;
> +	response.len = 1;
> +	response.buf = val;
> +
> +	i2c_lock_bus(client->adapter, I2C_LOCK_SEGMENT);
> +
> +	ret = __i2c_transfer(client->adapter, &request, 1);
> +	if (ret < 0)
> +		goto out;
> +
> +	ret = __i2c_transfer(client->adapter, &response, 1);
> +	if (ret < 0)
> +		goto out;
> +
> +	ret = 0;
> +
> +out:
> +	i2c_unlock_bus(client->adapter, I2C_LOCK_SEGMENT);
> +	return ret;
> +}
> +
> +static int thinkpad_t14s_led_set_status(struct thinkpad_t14s_ec *ec,
> +			struct thinkpad_t14s_ec_led_classdev *led,
> +			const enum thinkpad_t14s_ec_led_status_t ledstatus)
> +{
> +	int ret;
> +
> +	ret = regmap_write(ec->regmap, THINKPAD_T14S_EC_REG_LED,
> +			   led->led | ledstatus);
> +	if (ret < 0)
> +		return ret;
> +
> +	led->cache = ledstatus;
> +	return 0;
> +}
> +
> +static int thinkpad_t14s_led_set(struct led_classdev *led_cdev,
> +				 enum led_brightness brightness)

Could you include brightness into the function name so that it's more 
obvious what callback this relates to.

> +{
> +	struct thinkpad_t14s_ec_led_classdev *led = container_of(led_cdev,
> +			struct thinkpad_t14s_ec_led_classdev, led_classdev);
> +	enum thinkpad_t14s_ec_led_status_t new_state;
> +
> +	if (brightness == LED_OFF)
> +		new_state = THINKPAD_EC_LED_OFF;
> +	else if (led->cache != THINKPAD_EC_LED_BLINK)
> +		new_state = THINKPAD_EC_LED_ON;
> +	else
> +		new_state = THINKPAD_EC_LED_BLINK;
> +
> +	return thinkpad_t14s_led_set_status(led->ec, led, new_state);
> +}
> +
> +static int thinkpad_t14s_led_blink_set(struct led_classdev *led_cdev,
> +				       unsigned long *delay_on,
> +				       unsigned long *delay_off)
> +{
> +	struct thinkpad_t14s_ec_led_classdev *led = container_of(led_cdev,
> +			struct thinkpad_t14s_ec_led_classdev, led_classdev);
> +
> +	if (*delay_on == 0 && *delay_off == 0) {
> +		/* We can choose the blink rate */
> +		*delay_on = THINKPAD_T14S_EC_BLINK_RATE_ON_OFF_MS;
> +		*delay_off = THINKPAD_T14S_EC_BLINK_RATE_ON_OFF_MS;
> +	} else if ((*delay_on != THINKPAD_T14S_EC_BLINK_RATE_ON_OFF_MS) ||
> +		   (*delay_off != THINKPAD_T14S_EC_BLINK_RATE_ON_OFF_MS))
> +		return -EINVAL;
> +
> +	return thinkpad_t14s_led_set_status(led->ec, led, THINKPAD_EC_LED_BLINK);
> +}
> +
> +static int thinkpad_t14s_init_led(struct thinkpad_t14s_ec *ec,
> +				  struct thinkpad_t14s_ec_led_classdev *led,
> +				  u8 id, const char *name)
> +{
> +	led->led_classdev.name = name;
> +	led->led_classdev.flags = LED_RETAIN_AT_SHUTDOWN;
> +	led->led_classdev.max_brightness = 1;
> +	led->led_classdev.brightness_set_blocking = thinkpad_t14s_led_set;
> +	led->led_classdev.blink_set = thinkpad_t14s_led_blink_set;
> +	led->ec = ec;
> +	led->led = id;
> +
> +	return devm_led_classdev_register(ec->dev, &led->led_classdev);
> +}
> +
> +static int thinkpad_t14s_leds_probe(struct thinkpad_t14s_ec *ec)
> +{
> +	int ret;
> +
> +	ret = thinkpad_t14s_init_led(ec, &ec->led_pwr_btn, 0,
> +				     "platform::power");
> +	if (ret)
> +		return ret;
> +
> +	ret = thinkpad_t14s_init_led(ec, &ec->led_chrg_orange, 1,
> +				     "platform:amber:battery-charging");
> +	if (ret)
> +		return ret;
> +
> +	ret = thinkpad_t14s_init_led(ec, &ec->led_chrg_white, 2,
> +				     "platform:white:battery-full");
> +	if (ret)
> +		return ret;
> +
> +	ret = thinkpad_t14s_init_led(ec, &ec->led_lid_logo_dot, 10,
> +				     "platform::lid_logo_dot");
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static int thinkpad_t14s_kbd_bl_set(struct led_classdev *led_cdev,
> +				    enum led_brightness brightness)
> +{
> +	struct thinkpad_t14s_ec *ec = container_of(led_cdev,
> +					struct thinkpad_t14s_ec, kbd_backlight);
> +	int ret;
> +	u8 val;
> +
> +	val = FIELD_PREP(THINKPAD_T14S_EC_KBD_BL1_MASK, brightness);
> +	ret = regmap_update_bits(ec->regmap, THINKPAD_T14S_EC_REG_KBD_BL1,
> +				 THINKPAD_T14S_EC_KBD_BL1_MASK, val);
> +	if (ret < 0)
> +		return ret;
> +
> +	val = FIELD_PREP(THINKPAD_T14S_EC_KBD_BL2_MASK, brightness);
> +	ret = regmap_update_bits(ec->regmap, THINKPAD_T14S_EC_REG_KBD_BL2,
> +				 THINKPAD_T14S_EC_KBD_BL2_MASK, val);
> +	if (ret < 0)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static enum led_brightness thinkpad_t14s_kbd_bl_get(struct led_classdev *led_cdev)
> +{
> +	struct thinkpad_t14s_ec *ec = container_of(led_cdev,

Add include.

> +					struct thinkpad_t14s_ec, kbd_backlight);
> +	unsigned int val;
> +	int ret;
> +
> +	ret = regmap_read(ec->regmap, THINKPAD_T14S_EC_REG_KBD_BL1, &val);
> +	if (ret < 0)
> +		return ret;
> +
> +	return FIELD_GET(THINKPAD_T14S_EC_KBD_BL1_MASK, val);
> +}
> +
> +static void thinkpad_t14s_kbd_bl_update(struct thinkpad_t14s_ec *ec)
> +{
> +	enum led_brightness brightness = thinkpad_t14s_kbd_bl_get(&ec->kbd_backlight);
> +
> +	led_classdev_notify_brightness_hw_changed(&ec->kbd_backlight, brightness);
> +}
> +
> +static int thinkpad_t14s_kbd_backlight_probe(struct thinkpad_t14s_ec *ec)
> +{
> +	ec->kbd_backlight.name = "platform::kbd_backlight";
> +	ec->kbd_backlight.flags = LED_BRIGHT_HW_CHANGED;
> +	ec->kbd_backlight.max_brightness = 2;
> +	ec->kbd_backlight.brightness_set_blocking = thinkpad_t14s_kbd_bl_set;
> +	ec->kbd_backlight.brightness_get = thinkpad_t14s_kbd_bl_get;
> +
> +	return devm_led_classdev_register(ec->dev, &ec->kbd_backlight);
> +}
> +
> +static enum led_brightness thinkpad_t14s_audio_led_get(struct thinkpad_t14s_ec *ec,
> +						       u8 led_bit)
> +{
> +	unsigned int val;
> +	int ret;
> +
> +	ret = regmap_read(ec->regmap, THINKPAD_T14S_EC_REG_AUD, &val);
> +	if (ret < 0)
> +		return ret;
> +
> +	return !!(val && led_bit) ? LED_ON : LED_OFF;
> +}
> +
> +static enum led_brightness thinkpad_t14s_audio_led_set(struct thinkpad_t14s_ec *ec,
> +						       u8 led_bit,
> +						       enum led_brightness brightness)
> +{
> +	u8 val = brightness ? led_bit : 0;
> +
> +	return regmap_update_bits(ec->regmap, THINKPAD_T14S_EC_REG_AUD, led_bit, val);
> +}
> +
> +static enum led_brightness thinkpad_t14s_mic_mute_led_get(struct led_classdev *led_cdev)
> +{
> +	struct thinkpad_t14s_ec *ec = container_of(led_cdev,
> +					struct thinkpad_t14s_ec, led_mic_mute);
> +
> +	return thinkpad_t14s_audio_led_get(ec, THINKPAD_T14S_EC_MIC_MUTE_LED);
> +}
> +
> +static int thinkpad_t14s_mic_mute_led_set(struct led_classdev *led_cdev,
> +					  enum led_brightness brightness)
> +{
> +	struct thinkpad_t14s_ec *ec = container_of(led_cdev,
> +					struct thinkpad_t14s_ec, led_mic_mute);
> +
> +	return thinkpad_t14s_audio_led_set(ec, THINKPAD_T14S_EC_MIC_MUTE_LED, brightness);
> +}
> +
> +static enum led_brightness thinkpad_t14s_spk_mute_led_get(struct led_classdev *led_cdev)
> +{
> +	struct thinkpad_t14s_ec *ec = container_of(led_cdev,
> +					struct thinkpad_t14s_ec, led_spk_mute);
> +
> +	return thinkpad_t14s_audio_led_get(ec, THINKPAD_T14S_EC_SPK_MUTE_LED);
> +}
> +
> +static int thinkpad_t14s_spk_mute_led_set(struct led_classdev *led_cdev,
> +					  enum led_brightness brightness)
> +{
> +	struct thinkpad_t14s_ec *ec = container_of(led_cdev,
> +					struct thinkpad_t14s_ec, led_spk_mute);
> +
> +	return thinkpad_t14s_audio_led_set(ec, THINKPAD_T14S_EC_SPK_MUTE_LED, brightness);
> +}
> +
> +static int thinkpad_t14s_kbd_audio_led_probe(struct thinkpad_t14s_ec *ec)
> +{
> +	int ret;
> +
> +	ec->led_mic_mute.name = "platform::micmute";
> +	ec->led_mic_mute.max_brightness = 1,
> +	ec->led_mic_mute.default_trigger = "audio-micmute",
> +	ec->led_mic_mute.brightness_set_blocking = thinkpad_t14s_mic_mute_led_set;
> +	ec->led_mic_mute.brightness_get = thinkpad_t14s_mic_mute_led_get;
> +
> +	ec->led_spk_mute.name = "platform::mute";
> +	ec->led_spk_mute.max_brightness = 1,
> +	ec->led_spk_mute.default_trigger = "audio-mute",
> +	ec->led_spk_mute.brightness_set_blocking = thinkpad_t14s_spk_mute_led_set;
> +	ec->led_spk_mute.brightness_get = thinkpad_t14s_spk_mute_led_get;
> +
> +	ret = devm_led_classdev_register(ec->dev, &ec->led_mic_mute);
> +	if (ret)
> +		return ret;
> +
> +	return devm_led_classdev_register(ec->dev, &ec->led_spk_mute);
> +}
> +
> +static const struct key_entry thinkpad_t14s_keymap[] = {
> +	THINKPAD_T14S_EC_KEY_ENTRY(FN_4, KEY_SLEEP),
> +	THINKPAD_T14S_EC_KEY_ENTRY(FN_N, KEY_VENDOR),
> +	THINKPAD_T14S_EC_KEY_ENTRY(FN_F4, KEY_MICMUTE),
> +	THINKPAD_T14S_EC_KEY_ENTRY(FN_F7, KEY_SWITCHVIDEOMODE),
> +	THINKPAD_T14S_EC_KEY_ENTRY(FN_F8, KEY_PERFORMANCE),
> +	THINKPAD_T14S_EC_KEY_ENTRY(FN_F10, KEY_SELECTIVE_SCREENSHOT),
> +	THINKPAD_T14S_EC_KEY_ENTRY(FN_F11, KEY_LINK_PHONE),
> +	THINKPAD_T14S_EC_KEY_ENTRY(FN_F12, KEY_BOOKMARKS),
> +	THINKPAD_T14S_EC_KEY_ENTRY(FN_SPACE, KEY_KBDILLUMTOGGLE),
> +	THINKPAD_T14S_EC_KEY_ENTRY(FN_ESC, KEY_FN_ESC),
> +	THINKPAD_T14S_EC_KEY_ENTRY(FN_TAB, KEY_ZOOM),
> +	THINKPAD_T14S_EC_KEY_ENTRY(FN_RIGHT_SHIFT, KEY_FN_RIGHT_SHIFT),
> +	THINKPAD_T14S_EC_KEY_ENTRY(TP_DOUBLE_TAP, KEY_PROG4),
> +	{ KE_END }
> +};
> +
> +static int thinkpad_t14s_input_probe(struct thinkpad_t14s_ec *ec)
> +{
> +	int ret;
> +
> +	ec->inputdev = devm_input_allocate_device(ec->dev);
> +	if (!ec->inputdev)
> +		return -ENOMEM;
> +
> +	ec->inputdev->name = "ThinkPad Extra Buttons";
> +	ec->inputdev->phys = "thinkpad/input0";
> +	ec->inputdev->id.bustype = BUS_HOST;
> +	ec->inputdev->dev.parent = ec->dev;
> +
> +	ret = sparse_keymap_setup(ec->inputdev, thinkpad_t14s_keymap, NULL);
> +	if (ret)
> +		return ret;
> +
> +	ret = input_register_device(ec->inputdev);
> +	if (ret < 0)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static irqreturn_t thinkpad_t14s_ec_irq_handler(int irq, void *data)
> +{
> +	struct thinkpad_t14s_ec *ec = data;
> +	int ret;
> +	u8 val;
> +
> +	ret = thinkpad_t14s_ec_read_evt(ec, &val);
> +	if (ret < 0) {
> +		dev_err(ec->dev, "Failed to read event\n");
> +		return IRQ_HANDLED;
> +	}
> +
> +	switch (val) {
> +	case THINKPAD_T14S_EC_EVT_NONE:
> +		break;
> +	case THINKPAD_T14S_EC_EVT_KEY_FN_SPACE:
> +		thinkpad_t14s_kbd_bl_update(ec);
> +		fallthrough;
> +	case THINKPAD_T14S_EC_EVT_KEY_FN_F4:
> +	case THINKPAD_T14S_EC_EVT_KEY_FN_F7:
> +	case THINKPAD_T14S_EC_EVT_KEY_FN_4:
> +	case THINKPAD_T14S_EC_EVT_KEY_FN_F8:
> +	case THINKPAD_T14S_EC_EVT_KEY_FN_F12:
> +	case THINKPAD_T14S_EC_EVT_KEY_FN_TAB:
> +	case THINKPAD_T14S_EC_EVT_KEY_FN_F10:
> +	case THINKPAD_T14S_EC_EVT_KEY_FN_N:
> +	case THINKPAD_T14S_EC_EVT_KEY_FN_F11:
> +	case THINKPAD_T14S_EC_EVT_KEY_FN_ESC:
> +	case THINKPAD_T14S_EC_EVT_KEY_FN_RIGHT_SHIFT:
> +	case THINKPAD_T14S_EC_EVT_KEY_TP_DOUBLE_TAP:
> +		sparse_keymap_report_event(ec->inputdev,
> +				THINKPAD_T14S_EC_KEY_EVT_OFFSET + val, 1, true);
> +		break;
> +	case THINKPAD_T14S_EC_EVT_AC_CONNECTED:
> +		dev_dbg(ec->dev, "AC connected\n");
> +		break;
> +	case THINKPAD_T14S_EC_EVT_AC_DISCONNECTED:
> +		dev_dbg(ec->dev, "AC disconnected\n");
> +		break;
> +	case THINKPAD_T14S_EC_EVT_KEY_POWER:
> +		dev_dbg(ec->dev, "power button\n");
> +		break;
> +	case THINKPAD_T14S_EC_EVT_LID_OPEN:
> +		dev_dbg(ec->dev, "LID open\n");
> +		break;
> +	case THINKPAD_T14S_EC_EVT_LID_CLOSED:
> +		dev_dbg(ec->dev, "LID closed\n");
> +		break;
> +	case THINKPAD_T14S_EC_EVT_KEY_FN_G:
> +		dev_dbg(ec->dev, "FN + G - toggle double-tapping\n");
> +		break;
> +	case THINKPAD_T14S_EC_EVT_KEY_FN_L:
> +		dev_dbg(ec->dev, "FN + L - low performance mode\n");
> +		break;
> +	case THINKPAD_T14S_EC_EVT_KEY_FN_M:
> +		dev_dbg(ec->dev, "FN + M - medium performance mode\n");
> +		break;
> +	case THINKPAD_T14S_EC_EVT_KEY_FN_H:
> +		dev_dbg(ec->dev, "FN + H - high performance mode\n");
> +		break;
> +	case THINKPAD_T14S_EC_EVT_KEY_FN_T:
> +		dev_dbg(ec->dev, "FN + T - toggle intelligent cooling mode\n");
> +		break;
> +	case THINKPAD_T14S_EC_EVT_KEY_FN_D:
> +		dev_dbg(ec->dev, "FN + D - toggle privacy guard mode\n");
> +		break;
> +	default:
> +		dev_info(ec->dev, "Unknown EC event: 0x%02x\n", val);

Add include.

> +		break;
> +	}
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int thinkpad_t14s_ec_probe(struct i2c_client *client)
> +{
> +	struct device *dev = &client->dev;
> +	struct thinkpad_t14s_ec *ec;
> +	int ret;
> +
> +	ec = devm_kzalloc(dev, sizeof(*ec), GFP_KERNEL);
> +	if (!ec)
> +		return -ENOMEM;
> +
> +	ec->dev = dev;
> +
> +	ec->regmap = devm_regmap_init(dev, &thinkpad_t14s_ec_regmap_bus,
> +				      ec, &thinkpad_t14s_ec_regmap_config);
> +	if (IS_ERR(ec->regmap))
> +		return dev_err_probe(dev, PTR_ERR(ec->regmap),
> +				     "Failed to init regmap\n");
> +
> +	ret = devm_request_threaded_irq(dev, client->irq, NULL,
> +					thinkpad_t14s_ec_irq_handler,
> +					IRQF_ONESHOT, dev_name(dev), ec);

Add include for IRQF_ONESHOT.

Thanks for the update, except for the nits noted above, this seemed 
otherwise fine for me.

-- 
 i.


> +	if (ret < 0)
> +		return dev_err_probe(dev, ret, "Failed to get IRQ\n");
> +
> +	ret = thinkpad_t14s_leds_probe(ec);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = thinkpad_t14s_kbd_backlight_probe(ec);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = thinkpad_t14s_kbd_audio_led_probe(ec);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = thinkpad_t14s_input_probe(ec);
> +	if (ret < 0)
> +		return ret;
> +
> +	/*
> +	 * Disable wakeup support by default, because the driver currently does
> +	 * not support masking any events and the laptop should not wake up when
> +	 * the LID is closed.
> +	 */
> +	device_wakeup_disable(dev);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id thinkpad_t14s_ec_of_match[] = {
> +	{ .compatible = "lenovo,thinkpad-t14s-ec" },
> +	{}
> +};
> +MODULE_DEVICE_TABLE(of, thinkpad_t14s_ec_of_match);
> +
> +static const struct i2c_device_id thinkpad_t14s_ec_i2c_id_table[] = {
> +	{ "thinkpad-t14s-ec", },
> +	{}
> +};
> +MODULE_DEVICE_TABLE(i2c, thinkpad_t14s_ec_i2c_id_table);
> +
> +static struct i2c_driver thinkpad_t14s_ec_i2c_driver = {
> +	.driver = {
> +		.name = "thinkpad-t14s-ec",
> +		.of_match_table = thinkpad_t14s_ec_of_match,
> +	},
> +	.probe = thinkpad_t14s_ec_probe,
> +	.id_table = thinkpad_t14s_ec_i2c_id_table,
> +};
> +module_i2c_driver(thinkpad_t14s_ec_i2c_driver);
> +
> +MODULE_AUTHOR("Sebastian Reichel <sre@kernel.org>");
> +MODULE_DESCRIPTION("Lenovo Thinkpad T14s Embedded Controller");
> +MODULE_LICENSE("GPL");
> 
> 

Re: [PATCH v2 2/3] platform: arm64: thinkpad-t14s-ec: new driver

[Konrad Dybcio]

On 9/5/25 3:09 AM, Sebastian Reichel wrote:
> Introduce EC driver for the ThinkPad T14s Gen6 Snapdragon, which is in
> theory compatible with ThinkPad ACPI. On Linux the system is booted with
> device tree, which is not supported by the ThinkPad ACPI driver
> (drivers/platform/x86/lenovo/thinkpad_acpi.c). Also most of the hardware
> compatibility is handled via ACPI tables, which are obviously not used
> when booting via device tree. Thus adding DT compatibility to the
> existing driver is not worth it as there is almost no code sharing.
> 
> The driver currently exposes features, which are not available
> via other means:
> 
>  * Extra Keys
>  * System LEDs
>  * Keyboard Backlight Control
> 
> The driver has been developed by reading the ACPI DSDT. There
> are some more features around thermal control, which are not
> yet supported by the driver.
> 
> The speaker mute and mic mute LEDs need some additional changes
> in the ALSA UCM to be set automatically.
> 
> Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on Thinkpad T14S OLED
> Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
> Signed-off-by: Sebastian Reichel <sre@kernel.org>
> ---

[...]

> +#define THINKPAD_T14S_EC_CMD_ECRD 0x02
> +#define THINKPAD_T14S_EC_CMD_ECWR 0x03
> +#define THINKPAD_T14S_EC_CMD_EVT 0xf0

T14S_EC_ is already a good prefix, imo

[...]

> +static enum led_brightness thinkpad_t14s_audio_led_get(struct thinkpad_t14s_ec *ec,
> +						       u8 led_bit)
> +{
> +	unsigned int val;
> +	int ret;
> +
> +	ret = regmap_read(ec->regmap, THINKPAD_T14S_EC_REG_AUD, &val);
> +	if (ret < 0)
> +		return ret;
> +
> +	return !!(val && led_bit) ? LED_ON : LED_OFF;

&& already returns a boolean

but I think you meant to use & here

> +}
> +
> +static enum led_brightness thinkpad_t14s_audio_led_set(struct thinkpad_t14s_ec *ec,
> +						       u8 led_bit,
> +						       enum led_brightness brightness)
> +{
> +	u8 val = brightness ? led_bit : 0;
> +
> +	return regmap_update_bits(ec->regmap, THINKPAD_T14S_EC_REG_AUD, led_bit, val);

regmap_assign_bits()

> +static int thinkpad_t14s_input_probe(struct thinkpad_t14s_ec *ec)
> +{
> +	int ret;
> +
> +	ec->inputdev = devm_input_allocate_device(ec->dev);
> +	if (!ec->inputdev)
> +		return -ENOMEM;
> +
> +	ec->inputdev->name = "ThinkPad Extra Buttons";
> +	ec->inputdev->phys = "thinkpad/input0";
> +	ec->inputdev->id.bustype = BUS_HOST;
> +	ec->inputdev->dev.parent = ec->dev;
> +
> +	ret = sparse_keymap_setup(ec->inputdev, thinkpad_t14s_keymap, NULL);
> +	if (ret)
> +		return ret;
> +
> +	ret = input_register_device(ec->inputdev);
> +	if (ret < 0)
> +		return ret;
> +
> +	return 0;

You can return input_register_device() directly 

Konrad

[PATCH v2 3/3] arm64: dts: qcom: x1e80100-t14s: add EC

[Sebastian Reichel]

Describe ThinkPad Embedded Controller in the T14s device tree,
which adds LED and special key support.

Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on Thinkpad T14S OLED
Signed-off-by: Sebastian Reichel <sre@kernel.org>
---
 .../dts/qcom/x1e78100-lenovo-thinkpad-t14s.dtsi    | 24 ++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/arch/arm64/boot/dts/qcom/x1e78100-lenovo-thinkpad-t14s.dtsi b/arch/arm64/boot/dts/qcom/x1e78100-lenovo-thinkpad-t14s.dtsi
index ac1dddf27da30e6a9f7e1d1ecbd5192bf2d0671e..f70489aba870289edbcf84ec22fdb004e010868b 100644
--- a/arch/arm64/boot/dts/qcom/x1e78100-lenovo-thinkpad-t14s.dtsi
+++ b/arch/arm64/boot/dts/qcom/x1e78100-lenovo-thinkpad-t14s.dtsi
@@ -887,6 +887,24 @@ eusb6_repeater: redriver@4f {
 	};
 };
 
+&i2c6 {
+	clock-frequency = <400000>;
+
+	status = "okay";
+
+	embedded-controller@28 {
+		compatible = "lenovo,thinkpad-t14s-ec";
+		reg = <0x28>;
+
+		interrupts-extended = <&tlmm 66 IRQ_TYPE_LEVEL_LOW>;
+
+		pinctrl-0 = <&ec_int_n_default>;
+		pinctrl-names = "default";
+
+		wakeup-source;
+	};
+};
+
 &i2c7 {
 	clock-frequency = <400000>;
 
@@ -1267,6 +1285,12 @@ &tlmm {
 			       <72 2>, /* Secure EC I2C connection (?) */
 			       <238 1>; /* UFS Reset */
 
+	ec_int_n_default: ec-int-n-state {
+		pins = "gpio66";
+		function = "gpio";
+		bias-disable;
+	};
+
 	eusb3_reset_n: eusb3-reset-n-state {
 		pins = "gpio6";
 		function = "gpio";

-- 
2.50.1

Re: [PATCH v2 3/3] arm64: dts: qcom: x1e80100-t14s: add EC

[Bryan O'Donoghue]

On 05/09/2025 02:09, Sebastian Reichel wrote:
> Describe ThinkPad Embedded Controller in the T14s device tree,
> which adds LED and special key support.
> 
> Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on Thinkpad T14S OLED
> Signed-off-by: Sebastian Reichel <sre@kernel.org>
> ---
>   .../dts/qcom/x1e78100-lenovo-thinkpad-t14s.dtsi    | 24 ++++++++++++++++++++++
>   1 file changed, 24 insertions(+)
> 
> diff --git a/arch/arm64/boot/dts/qcom/x1e78100-lenovo-thinkpad-t14s.dtsi b/arch/arm64/boot/dts/qcom/x1e78100-lenovo-thinkpad-t14s.dtsi
> index ac1dddf27da30e6a9f7e1d1ecbd5192bf2d0671e..f70489aba870289edbcf84ec22fdb004e010868b 100644
> --- a/arch/arm64/boot/dts/qcom/x1e78100-lenovo-thinkpad-t14s.dtsi
> +++ b/arch/arm64/boot/dts/qcom/x1e78100-lenovo-thinkpad-t14s.dtsi
> @@ -887,6 +887,24 @@ eusb6_repeater: redriver@4f {
>   	};
>   };
>   
> +&i2c6 {
> +	clock-frequency = <400000>;
> +
> +	status = "okay";
> +
> +	embedded-controller@28 {
> +		compatible = "lenovo,thinkpad-t14s-ec";
> +		reg = <0x28>;
> +
> +		interrupts-extended = <&tlmm 66 IRQ_TYPE_LEVEL_LOW>;
> +
> +		pinctrl-0 = <&ec_int_n_default>;
> +		pinctrl-names = "default";
> +
> +		wakeup-source;
> +	};
> +};
> +
>   &i2c7 {
>   	clock-frequency = <400000>;
>   
> @@ -1267,6 +1285,12 @@ &tlmm {
>   			       <72 2>, /* Secure EC I2C connection (?) */
>   			       <238 1>; /* UFS Reset */
>   
> +	ec_int_n_default: ec-int-n-state {
> +		pins = "gpio66";
> +		function = "gpio";
> +		bias-disable;
> +	};
> +
>   	eusb3_reset_n: eusb3-reset-n-state {
>   		pins = "gpio6";
>   		function = "gpio";
> 

Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>

Re: [PATCH v2 3/3] arm64: dts: qcom: x1e80100-t14s: add EC

[Konrad Dybcio]

On 9/5/25 3:09 AM, Sebastian Reichel wrote:
> Describe ThinkPad Embedded Controller in the T14s device tree,
> which adds LED and special key support.
> 
> Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on Thinkpad T14S OLED
> Signed-off-by: Sebastian Reichel <sre@kernel.org>
> ---

Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>

Konrad