From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-244118.protonmail.ch (mail-244118.protonmail.ch [109.224.244.118]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 95E685038ED for ; Mon, 28 Sep 2026 22:21:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=109.224.244.118 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790634111; cv=none; b=j+LnOT6GEXS1ZL2TwSmLlHMrN1YPtATRrLl9Vicyfm6xnda/ERn8e1ywOdaRiZJrbAvTzK62vaxT5m1CpJyvl1BfLuRWD/kKeVYbSGcZ+XGL3lJoLUK3rL0kZBCxMLtvztL3vkhywSaNJ2uZy0IT233gpyXADhon22LdmRMcB8g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790634111; c=relaxed/simple; bh=HyfgMMIfZoKi0Hwdy4r8VkovR2N1sThBispmZp1iODc=; h=Date:To:From:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=mhuTNtrDroY2MtFv7Ma+oAXxbZs5UgNGjTeJyGsni9+23MlIqmLR/OcdLg7czex7lL1WeK24qzeBxIiUohpGi002Cttfy/tRmjvVbgxXPiXbFfeBojERfq/Np34NQXqC46OgpqYpRPlsGHoFKWIciNM/rw1QwJidUiYMuPgfprk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ironrobin.net; spf=pass smtp.mailfrom=ironrobin.net; dkim=pass (2048-bit key) header.d=ironrobin.net header.i=@ironrobin.net header.b=eRVdV4fi; arc=none smtp.client-ip=109.224.244.118 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ironrobin.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ironrobin.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ironrobin.net header.i=@ironrobin.net header.b="eRVdV4fi" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ironrobin.net; s=protonmail3; t=1790634098; x=1790893298; bh=vYkeSQJV2fQxgeu1Chw4mDgpE0JUyZ86r+y6g/YrNG8=; h=Date:To:From:Cc:Subject:Message-ID:In-Reply-To:References: Feedback-ID:From:To:Cc:Date:Subject:Reply-To:Feedback-ID: Message-ID:BIMI-Selector; b=eRVdV4fiVqDFFfWfMqWvhYdJkeaPgmmFRZMUQMOXiNbDPRD1+HVwSyD80vTpIriRo wDbs7yvWTxrN9YEc3NDg7JYINrUaRipMh22xCeHUurR9KaoC4Rvy0WahmoCnbBFgys 6a95RI5cInlkF1jEZEM5vGx1Ma3stq1DGtBRTSjWXB0OWWZBYBNWao1TaTUz89KxGq Aw7xjKrhUD0MevxtNAmUAGiErWPpxD9eda9IEBNfyp+zeCLVM9vb0xqr4A2LbxQyJD 74KmJaP3/E+fKuKMAx4K3AXO82MeXejC1YWNPNp6WF3s0H7JAGev7MJXUjaHwqbIV1 X/veSWoBY5mgw== Date: Mon, 28 Sep 2026 22:21:35 +0000 To: Hans de Goede , =?utf-8?Q?Ilpo_J=C3=A4rvinen?= From: Alex Robinson Cc: Bryan O'Donoghue , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Bjorn Andersson , Konrad Dybcio , Steev Klimaszewski , platform-driver-x86@vger.kernel.org, linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 2/3] platform: arm64: Add Lenovo ThinkPad X13s EC driver Message-ID: <20260928222056.10044-3-alex@ironrobin.net> In-Reply-To: <20260928222056.10044-1-alex@ironrobin.net> References: <20260928222056.10044-1-alex@ironrobin.net> Feedback-ID: 54785507:user:proton X-Pm-Message-ID: 9780ac56e7ebd892f7bc43193185aaea39c9fb80 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Add a standalone driver for the Lenovo ThinkPad X13s embedded controller, providing keyboard-backlight control and notifications of firmware-driven brightness changes. Keep the X13s-specific backlight, event and power-management handling separate from the T14s driver. Use STOP-separated command and response transfers and serialize EC access, including keyboard-backlight read-modify-write operations. Follow the EC command and power-state GPIO sequence described by the X13s ACPI DSDT when entering and leaving low power. Save the firmware-updated brightness in the EC on Fn+Space and restore it on lid open, following the DSDT's SCMS(0x20) and SCMS(0x21) operations. Also save software-selected brightness so lid opening does not reinstate an older setting; this extends the DSDT's MLCS path, which does not explicitly save it. Defer event queries while suspended until normal resume, when the I2C controller is usable again. Save the hardware backlight brightness before entering low power and attempt to restore it on resume because the transition can reset it. Process deferred events afterwards so a lid-open restore takes precedence over a snapshot taken after lid closure blanked the light. Disable EC wakeup by default, following the upstream ThinkPad T14s EC driver's policy. The interrupt multiplexes events and no selective X13s EC wake-event mask is currently known. In particular, lid-close event 0x53 can wake the system, but identifying the event requires querying the EC over QUP8/I2C after the system has resumed far enough to use the bus. Disable wake broadly rather than trying to filter an already-triggered wakeup. This also prevents other EC events from waking the system by default; normal runtime interrupt handling remains enabled. Keep wakeup-source in DT to describe hardware capability. The I2C core sets up the wake IRQ before probe, and the driver disables wakeup policy without removing that capability. Userspace can explicitly re-enable it. Feedback on a selective X13s EC event-mask mechanism would be welcome. This follows earlier X13s EC work by Konrad Dybcio and Steev Klimaszewski. Assisted-by: LLM Signed-off-by: Alex Robinson --- diff --git a/MAINTAINERS b/MAINTAINERS --- a/MAINTAINERS +++ b/MAINTAINERS @@ -27177,6 +27177,12 @@ THINKPAD T14S EMBEDDED CONTROLLER DRIVER F:=09Documentation/devicetree/bindings/embedded-controller/lenovo,thinkpad= -t14s-ec.yaml F:=09drivers/platform/arm64/lenovo-thinkpad-t14s.c =20 +THINKPAD X13S EMBEDDED CONTROLLER DRIVER +M:=09Alex Robinson +S:=09Maintained +F:=09Documentation/devicetree/bindings/embedded-controller/lenovo,thinkpad= -x13s-ec.yaml +F:=09drivers/platform/arm64/lenovo-thinkpad-x13s.c + THINKPAD LMI DRIVER M:=09Mark Pearson L:=09platform-driver-x86@vger.kernel.org diff --git a/drivers/platform/arm64/Kconfig b/drivers/platform/arm64/Kconfi= g index e32e01b2a9bdd970d6f2b2bf6b051472c9a16103..c20b2fb40962f1d46e896ea7f7d= 0b16028f92f96 100644 --- a/drivers/platform/arm64/Kconfig +++ b/drivers/platform/arm64/Kconfig @@ -90,6 +90,22 @@ config EC_LENOVO_THINKPAD_T14S =20 =09 Say M or Y here to include this support. =20 +config EC_LENOVO_THINKPAD_X13S +=09tristate "Lenovo ThinkPad X13s Embedded Controller driver" +=09depends on ARCH_QCOM || COMPILE_TEST +=09depends on I2C +=09depends on GPIOLIB +=09select NEW_LEDS +=09select LEDS_CLASS +=09select LEDS_BRIGHTNESS_HW_CHANGED +=09help +=09 Driver for the embedded controller in the Lenovo ThinkPad X13s. +=09 Provides keyboard backlight control, hardware brightness change +=09 notifications and system sleep power sequencing. + +=09 To compile this driver as a module, choose M here: the module will +=09 be called lenovo-thinkpad-x13s. + config EC_QCOM_HAMOA =09tristate "Embedded Controller driver for Qualcomm Hamoa/Glymur referenc= e devices" =09depends on ARCH_QCOM || COMPILE_TEST diff --git a/drivers/platform/arm64/Makefile b/drivers/platform/arm64/Makef= ile index 7681be4a46e94e7cb80e50bcc5b724cb0961357b..23ed6eef7ce41a5f45d48f5f83b= 281ebbca94cbb 100644 --- a/drivers/platform/arm64/Makefile +++ b/drivers/platform/arm64/Makefile @@ -9,4 +9,5 @@ obj-$(CONFIG_EC_ACER_ASPIRE1)=09+=3D acer-aspire1-ec.o obj-$(CONFIG_EC_HUAWEI_GAOKUN)=09+=3D huawei-gaokun-ec.o obj-$(CONFIG_EC_LENOVO_YOGA_C630) +=3D lenovo-yoga-c630.o obj-$(CONFIG_EC_LENOVO_THINKPAD_T14S) +=3D lenovo-thinkpad-t14s.o +obj-$(CONFIG_EC_LENOVO_THINKPAD_X13S) +=3D lenovo-thinkpad-x13s.o obj-$(CONFIG_EC_QCOM_HAMOA) +=3D qcom-hamoa-ec.o diff --git a/drivers/platform/arm64/lenovo-thinkpad-x13s.c b/drivers/platfo= rm/arm64/lenovo-thinkpad-x13s.c new file mode 100644 index 0000000000000000000000000000000000000000..c600a616c9b6e8f4259caf61fd5= c16d129547c90 --- /dev/null +++ b/drivers/platform/arm64/lenovo-thinkpad-x13s.c @@ -0,0 +1,416 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Lenovo ThinkPad X13s embedded controller */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define X13S_EC_CMD_READ=09=090x02 +#define X13S_EC_CMD_WRITE=09=090x03 +#define X13S_EC_CMD_EVENT=09=090xf0 +#define X13S_EC_REG_POWER_STATE=090x80 +#define X13S_EC_POWER_STATE_ENTER=090x55 +#define X13S_EC_POWER_STATE_EXIT=090xaa +#define X13S_EC_REG_KBD_BACKLIGHT=090xc0 +#define X13S_EC_BACKLIGHT_MASK=09GENMASK(5, 4) +#define X13S_EC_REG_KBD_BACKLIGHT_SAVED=090x15 +#define X13S_EC_BACKLIGHT_SAVED_MASK=09GENMASK(2, 1) +#define X13S_EC_EVENT_FN_SPACE=090x1f +#define X13S_EC_EVENT_LID_OPEN=090x52 + +struct x13s_ec { +=09struct i2c_client *client; +=09struct gpio_desc *power_state; +=09/* Serializes EC transactions, backlight RMW and suspend/event state. *= / +=09struct mutex lock; +=09struct led_classdev led; +=09enum led_brightness saved_brightness; +=09bool suspended; +=09bool event_pending; +}; + +/* + * Each single-message transfer ends in STOP. Hold the bus segment across + * both halves so another client cannot interleave them. Keep the 10 ms + * post-command settling delay, including on failure. + */ +static int x13s_read(struct x13s_ec *ec, u8 cmd, u8 reg, u8 *value) +{ +=09struct i2c_client *client =3D ec->client; +=09u8 buf[] =3D { cmd, reg, 0, 1 }; +=09struct i2c_msg request =3D { +=09=09.addr =3D client->addr, +=09=09.flags =3D I2C_M_STOP, +=09=09.len =3D sizeof(buf), +=09=09.buf =3D buf, +=09}; +=09struct i2c_msg response =3D { +=09=09.addr =3D client->addr, +=09=09.flags =3D I2C_M_RD, +=09=09.len =3D 1, +=09=09.buf =3D value, +=09}; +=09int ret; + +=09lockdep_assert_held(&ec->lock); +=09if (ec->suspended) +=09=09return -EBUSY; + +=09i2c_lock_bus(client->adapter, I2C_LOCK_SEGMENT); +=09ret =3D __i2c_transfer(client->adapter, &request, 1); +=09if (ret =3D=3D 1) +=09=09ret =3D __i2c_transfer(client->adapter, &response, 1); +=09ret =3D ret =3D=3D 1 ? 0 : (ret < 0 ? ret : -EIO); +=09i2c_unlock_bus(client->adapter, I2C_LOCK_SEGMENT); +=09fsleep(10000); +=09return ret; +} + +/* Also used by normal PM callbacks while ordinary EC access is blocked. *= / +static int x13s_write(struct x13s_ec *ec, u8 reg, u8 value) +{ +=09u8 buf[] =3D { X13S_EC_CMD_WRITE, reg, 0, 1, value }; +=09int ret; + +=09lockdep_assert_held(&ec->lock); + +=09ret =3D i2c_master_send(ec->client, buf, sizeof(buf)); +=09ret =3D ret =3D=3D sizeof(buf) ? 0 : (ret < 0 ? ret : -EIO); +=09fsleep(10000); +=09return ret; +} + +static int x13s_brightness(struct x13s_ec *ec) +{ +=09u8 value; +=09int ret; + +=09ret =3D x13s_read(ec, X13S_EC_CMD_READ, X13S_EC_REG_KBD_BACKLIGHT, &val= ue); +=09if (ret) +=09=09return ret; + +=09ret =3D FIELD_GET(X13S_EC_BACKLIGHT_MASK, value); +=09return ret =3D=3D 3 ? -EINVAL : ret; +} + +static enum led_brightness x13s_brightness_get(struct led_classdev *led) +{ +=09struct x13s_ec *ec =3D container_of(led, struct x13s_ec, led); +=09int ret; + +=09mutex_lock(&ec->lock); +=09ret =3D x13s_brightness(ec); +=09mutex_unlock(&ec->lock); +=09return ret; +} + +static int x13s_set_brightness_locked(struct x13s_ec *ec, +=09=09=09=09 enum led_brightness brightness) +{ +=09u8 old, new; +=09int ret; + +=09lockdep_assert_held(&ec->lock); +=09if (brightness > 2) +=09=09return -EINVAL; + +=09ret =3D x13s_read(ec, X13S_EC_CMD_READ, X13S_EC_REG_KBD_BACKLIGHT, &old= ); +=09if (ret) +=09=09return ret; +=09/* Never interpret or overwrite a reserved current brightness. */ +=09if (FIELD_GET(X13S_EC_BACKLIGHT_MASK, old) =3D=3D 3) +=09=09return -EINVAL; +=09new =3D (old & ~X13S_EC_BACKLIGHT_MASK) | +=09=09FIELD_PREP(X13S_EC_BACKLIGHT_MASK, brightness); +=09return x13s_write(ec, X13S_EC_REG_KBD_BACKLIGHT, new); +} + +/* SCMS(0x20): save the brightness obtained from C0 in the EC. */ +static int x13s_save_brightness_locked(struct x13s_ec *ec, +=09=09=09=09 enum led_brightness brightness) +{ +=09u8 value; +=09int ret; + +=09lockdep_assert_held(&ec->lock); +=09ret =3D x13s_read(ec, X13S_EC_CMD_READ, X13S_EC_REG_KBD_BACKLIGHT_SAVED= , +=09=09=09&value); +=09if (ret) +=09=09return ret; + +=09value &=3D ~X13S_EC_BACKLIGHT_SAVED_MASK; +=09value |=3D FIELD_PREP(X13S_EC_BACKLIGHT_SAVED_MASK, brightness); +=09return x13s_write(ec, X13S_EC_REG_KBD_BACKLIGHT_SAVED, value); +} + +/* SCMS(0x21): restore C0 from the EC's saved brightness. */ +static int x13s_restore_brightness_locked(struct x13s_ec *ec) +{ +=09u8 value; +=09int brightness, ret; + +=09lockdep_assert_held(&ec->lock); +=09ret =3D x13s_read(ec, X13S_EC_CMD_READ, X13S_EC_REG_KBD_BACKLIGHT_SAVED= , +=09=09=09&value); +=09if (ret) +=09=09return ret; + +=09brightness =3D FIELD_GET(X13S_EC_BACKLIGHT_SAVED_MASK, value); +=09ret =3D x13s_set_brightness_locked(ec, brightness); +=09return ret ? ret : brightness; +} + +static int x13s_brightness_set(struct led_classdev *led, +=09=09=09 enum led_brightness brightness) +{ +=09struct x13s_ec *ec =3D container_of(led, struct x13s_ec, led); +=09int ret; + +=09mutex_lock(&ec->lock); +=09ret =3D x13s_set_brightness_locked(ec, brightness); +=09/* Keep software selections across the EC's lid blank/restore cycle. */ +=09if (!ret) +=09=09ret =3D x13s_save_brightness_locked(ec, brightness); +=09mutex_unlock(&ec->lock); +=09return ret; +} + +static void x13s_refresh_brightness(struct x13s_ec *ec) +{ +=09int brightness, ret; + +=09lockdep_assert_held(&ec->lock); +=09/* Firmware owns the transition; save its result as _Q1F does. */ +=09brightness =3D x13s_brightness(ec); +=09if (brightness < 0) { +=09=09dev_err_ratelimited(&ec->client->dev, +=09=09=09=09 "Backlight refresh failed: %d\n", brightness); +=09=09return; +=09} +=09ret =3D x13s_save_brightness_locked(ec, brightness); +=09if (ret) +=09=09dev_err_ratelimited(&ec->client->dev, +=09=09=09=09 "Backlight save failed: %d\n", ret); +=09led_classdev_notify_brightness_hw_changed(&ec->led, brightness); +} + +static void x13s_query_event(struct x13s_ec *ec) +{ +=09u8 event; +=09int ret; + +=09lockdep_assert_held(&ec->lock); +=09/* One query per interrupt, with no event-draining loop or retry. */ +=09ret =3D x13s_read(ec, X13S_EC_CMD_EVENT, 0, &event); +=09if (ret) { +=09=09dev_err_ratelimited(&ec->client->dev, "Event query failed: %d\n", re= t); +=09=09return; +=09} +=09if (event =3D=3D X13S_EC_EVENT_FN_SPACE) { +=09=09x13s_refresh_brightness(ec); +=09} else if (event =3D=3D X13S_EC_EVENT_LID_OPEN) { +=09=09ret =3D x13s_restore_brightness_locked(ec); +=09=09if (ret < 0) { +=09=09=09dev_err_ratelimited(&ec->client->dev, +=09=09=09=09=09 "Backlight lid restore failed: %d\n", ret); +=09=09=09return; +=09=09} +=09=09ec->led.brightness =3D ret; +=09=09led_classdev_notify_brightness_hw_changed(&ec->led, ret); +=09} +} + +static void x13s_process_pending_event(struct x13s_ec *ec) +{ +=09lockdep_assert_held(&ec->lock); +=09if (ec->event_pending) { +=09=09ec->event_pending =3D false; +=09=09x13s_query_event(ec); +=09} +} + +static irqreturn_t x13s_irq(int irq, void *data) +{ +=09struct x13s_ec *ec =3D data; + +=09mutex_lock(&ec->lock); +=09/* Coalesce suspended IRQs into one query; never access I2C here. */ +=09if (ec->suspended) +=09=09ec->event_pending =3D true; +=09else +=09=09x13s_query_event(ec); +=09mutex_unlock(&ec->lock); +=09return IRQ_HANDLED; +} + +static int x13s_probe(struct i2c_client *client) +{ +=09struct device *dev =3D &client->dev; +=09struct x13s_ec *ec; +=09int ret; + +=09if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) +=09=09return -EOPNOTSUPP; +=09if (client->irq <=3D 0) +=09=09return dev_err_probe(dev, -EINVAL, "Missing event IRQ\n"); +=09if (irq_get_trigger_type(client->irq) !=3D IRQ_TYPE_EDGE_FALLING) +=09=09return dev_err_probe(dev, -EINVAL, "Expected falling-edge IRQ\n"); + +=09ec =3D devm_kzalloc(dev, sizeof(*ec), GFP_KERNEL); +=09if (!ec) +=09=09return -ENOMEM; +=09ec->client =3D client; +=09ret =3D devm_mutex_init(dev, &ec->lock); +=09if (ret) +=09=09return ret; +=09i2c_set_clientdata(client, ec); + +=09ec->power_state =3D devm_gpiod_get(dev, "power-state", GPIOD_OUT_HIGH); +=09if (IS_ERR(ec->power_state)) +=09=09return dev_err_probe(dev, PTR_ERR(ec->power_state), +=09=09=09=09 "Failed to acquire power-state GPIO high\n"); + +=09ec->led.name =3D "platform::kbd_backlight"; +=09ec->led.max_brightness =3D 2; +=09ec->led.flags =3D LED_BRIGHT_HW_CHANGED | LED_RETAIN_AT_SHUTDOWN; +=09ec->led.brightness_get =3D x13s_brightness_get; +=09ec->led.brightness_set_blocking =3D x13s_brightness_set; +=09ret =3D devm_led_classdev_register(dev, &ec->led); +=09if (ret) +=09=09return dev_err_probe(dev, ret, "Failed to register keyboard backligh= t\n"); + +=09/* Devres synchronizes the IRQ before unregistering the LED. */ +=09ret =3D devm_request_threaded_irq(dev, client->irq, NULL, x13s_irq, +=09=09=09=09=09IRQF_ONESHOT, dev_name(dev), ec); +=09if (ret) +=09=09return dev_err_probe(dev, ret, "Failed to request event IRQ\n"); + +=09/* +=09 * As on the T14s, disable wakeup by default since selective EC event +=09 * masking is not known. Keep runtime IRQ handling enabled. +=09 */ +=09device_wakeup_disable(dev); + +=09return 0; +} + +static int x13s_power_gpio(struct x13s_ec *ec, int value) +{ +=09int ret; + +=09lockdep_assert_held(&ec->lock); +=09ret =3D gpiod_set_value_cansleep(ec->power_state, value); +=09if (ret) +=09=09dev_err(&ec->client->dev, "Failed to set power-state GPIO to %d: %d\= n", +=09=09=09value, ret); +=09return ret; +} + +static void x13s_exit_low_power(struct x13s_ec *ec) +{ +=09int ret; + +=09lockdep_assert_held(&ec->lock); +=09x13s_power_gpio(ec, 1); +=09/* DSDT: GPIO176 high, Sleep(10), then register 0x80 <- 0xaa. */ +=09fsleep(10000); +=09ret =3D x13s_write(ec, X13S_EC_REG_POWER_STATE, X13S_EC_POWER_STATE_EXI= T); +=09if (ret) +=09=09dev_err(&ec->client->dev, "Failed to exit low power: %d\n", ret); + +=09/* Resume ordinary access even if the EC exit attempt failed. */ +=09ec->suspended =3D false; +} + +static int x13s_suspend(struct device *dev) +{ +=09struct x13s_ec *ec =3D dev_get_drvdata(dev); +=09int ret; + +=09/* Finish in-flight access while the GENI parent is still usable. */ +=09mutex_lock(&ec->lock); +=09if (ec->suspended) +=09=09goto out; +=09/* Keep the previous snapshot if reading the hardware fails. */ +=09ret =3D x13s_brightness(ec); +=09if (ret < 0) +=09=09dev_err(dev, "Failed to save backlight brightness: %d\n", ret); +=09else +=09=09ec->saved_brightness =3D ret; + +=09/* DSDT: register 0x80 <- 0x55, then GPIO176 low. */ +=09ret =3D x13s_write(ec, X13S_EC_REG_POWER_STATE, X13S_EC_POWER_STATE_ENT= ER); +=09if (ret) +=09=09dev_err(dev, "Failed to enter low power: %d\n", ret); +=09else +=09=09x13s_power_gpio(ec, 0); +=09/* Defer event queries throughout host suspend, even on EC failure. */ +=09ec->suspended =3D true; +out: +=09mutex_unlock(&ec->lock); +=09return 0; +} + +static int x13s_resume(struct device *dev) +{ +=09struct x13s_ec *ec =3D dev_get_drvdata(dev); +=09int ret; + +=09/* +=09 * Normal resume runs after the adapter and its GENI parent. In +=09 * particular, device_resume_early() has re-enabled runtime PM: +=09 * GENI's resume_noirq() alone is not sufficient for I2C transfers. +=09 * Consume the pending query under the IRQ thread's mutex, without +=09 * a worker that could race a new IRQ or the next suspend. +=09 */ +=09mutex_lock(&ec->lock); +=09x13s_exit_low_power(ec); +=09ret =3D x13s_set_brightness_locked(ec, ec->saved_brightness); +=09if (ret) +=09=09dev_err(dev, "Failed to restore backlight brightness: %d\n", ret); +=09else +=09=09/* A software restore is not a hardware brightness change. */ +=09=09ec->led.brightness =3D ec->saved_brightness; + +=09/* A deferred lid-open restore must supersede the PM snapshot. */ +=09x13s_process_pending_event(ec); +=09mutex_unlock(&ec->lock); +=09return 0; +} + +static DEFINE_SIMPLE_DEV_PM_OPS(x13s_pm_ops, x13s_suspend, x13s_resume); + +static const struct of_device_id x13s_of_match[] =3D { +=09{ .compatible =3D "lenovo,thinkpad-x13s-ec" }, +=09{ } +}; +MODULE_DEVICE_TABLE(of, x13s_of_match); + +static struct i2c_driver x13s_driver =3D { +=09.probe =3D x13s_probe, +=09.driver =3D { +=09=09.name =3D "thinkpad-x13s-ec", +=09=09.of_match_table =3D x13s_of_match, +=09=09.pm =3D pm_sleep_ptr(&x13s_pm_ops), +=09}, +}; +module_i2c_driver(x13s_driver); + +MODULE_DESCRIPTION("Lenovo ThinkPad X13s Embedded Controller"); +MODULE_LICENSE("GPL");