From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.21]) (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 A98F53CBE6C; Wed, 1 Apr 2026 10:42:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.21 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775040133; cv=none; b=AzyFwvRws2n0WSgWkfiVIqvhBwyMF1xa0mbgxpfgiVfXzqOqJRH68IlZEY0WOTVX+bzZi9TidSgBVI9RVNFQMt8lYlKcDEMehmKN4AikCw9oWMRZm92TMBFJWUyv66N/lr+DRVmaq7CAqDnRI60AwHGFJlV/b5zR/ssgJaESrcI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775040133; c=relaxed/simple; bh=td5Zyn2cZ1HcsQZzinWnxhcyLl4JZqmQyOAiTjFP8kI=; h=From:Date:To:cc:Subject:In-Reply-To:Message-ID:References: MIME-Version:Content-Type; b=ZHndYafOBB3WTES0aDjHxt+iuvxyMrtsUArZ74a4wXkXfqwKkP42xnuiBSuavSMDBkmfHKbxYgqNSsJ+clUXuK9krPS4/J+rGa5Ob5V0yJd+lHSLM53MV73u6fZA2bU2l5lxuYTG/r/WklJunCvcdEskXS9pZkFRAca+eYdCnLI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=pass smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=A/jwtqm+; arc=none smtp.client-ip=198.175.65.21 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="A/jwtqm+" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1775040130; x=1806576130; h=from:date:to:cc:subject:in-reply-to:message-id: references:mime-version; bh=td5Zyn2cZ1HcsQZzinWnxhcyLl4JZqmQyOAiTjFP8kI=; b=A/jwtqm+++xTdfho32+0DdUpeqe1dCdFvfTfqSkdx4cN3tBUdeUTDY3V t3acpCLRRsGTZghtDsD6XSBufDL+TnCvuXFuoSFgbN+qi29sEkBRyglNX sZW6Nk9TVgYdeXmWRgHWW2Dsq2IR0kOgGYKjtApqgmIkFxOx+UCbOC5Cv uYt6vuAbQKOS1G4kiUNR0ha6Oshtk67sJHjJyMXj8OZ38Dbk5DIb2vd58 FQw4utjR7+2eIYHQaSBcD0xLWMUrKDDbBEn7K3jF4A+fQlfiSP+0MdxTf N81Cv0SvX+IK+nbpwYYyCfV/WC5d2/wAD89KmdHJOFKy5GFhu5n1b07AA w==; X-CSE-ConnectionGUID: BGUn3WM+R3Wu1v5q8TkD8Q== X-CSE-MsgGUID: VRc57v7TRjmhL12k+HRAQg== X-IronPort-AV: E=McAfee;i="6800,10657,11745"; a="75958280" X-IronPort-AV: E=Sophos;i="6.23,153,1770624000"; d="scan'208";a="75958280" Received: from orviesa006.jf.intel.com ([10.64.159.146]) by orvoesa113.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Apr 2026 03:42:09 -0700 X-CSE-ConnectionGUID: gw37JFDZRWSeHrcIocS7nw== X-CSE-MsgGUID: njZXfq+8RP+NC7F/+l+7Jw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.23,153,1770624000"; d="scan'208";a="225635111" Received: from ijarvine-mobl1.ger.corp.intel.com (HELO localhost) ([10.245.244.192]) by orviesa006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Apr 2026 03:42:01 -0700 From: =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= Date: Wed, 1 Apr 2026 13:41:56 +0300 (EEST) To: Aleksandrs Vinarskis cc: Bjorn Andersson , Konrad Dybcio , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Hans de Goede , Bryan O'Donoghue , linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org, LKML , platform-driver-x86@vger.kernel.org, laurentiu.tudor1@dell.com, Abel Vesa , Tobias Heider , Val Packett Subject: Re: [PATCH 2/4] platform: arm64: dell-xps-ec: new driver In-Reply-To: <20260401-dell-xps-9345-ec-v1-2-afa5cacd49be@vinarskis.com> Message-ID: References: <20260401-dell-xps-9345-ec-v1-0-afa5cacd49be@vinarskis.com> <20260401-dell-xps-9345-ec-v1-2-afa5cacd49be@vinarskis.com> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII On Wed, 1 Apr 2026, Aleksandrs Vinarskis wrote: > Introduce EC driver for Dell XPS 13 9345 (codename 'tributo') which may > partially of fully compatible with Snapdragon-based Dell Latitude, > Inspiron ('thena'). Primary function of this driver is unblock EC's > thermal management, specifically to provide it with necessary > information to control device fans, peripherals power. > > The driver was developed primarily by analyzing ACPI DSDT's _DSM and > i2c dumps of communication between SoC and EC. Changes to Windows > driver's behavior include increasing temperature feed loop from ~50ms > to 100ms here. > > While Xps's EC is rather complex and controls practically all device > peripherals including touch row's brightness and special keys such as > mic mute, these do not go over this particular i2c interface. > > Not yet implemented features: > - On lid-close IRQ event is registered. Windows performs what to > appears to be thermistor constants readout, though its not obvious > what it used for. > - According to ACPI's _DSM there is a method to readout fans' RPM. > - Initial thermistor constants were sniffed from Windows, these can be > likely fine tuned for better cooling performance. > - There is additional temperature reading that Windows sents to EC but > more rare than others, likely SoC T_j / TZ98 or TZ4. This is the only > thermal zone who's reading can exceed 115C without triggering thermal > shutdown. > - Given similarities between 'tributo' and 'thena' platforms, including > EC i2c address, driver can be potentially extended to support both. > > Signed-off-by: Aleksandrs Vinarskis > --- > MAINTAINERS | 1 + > drivers/platform/arm64/Kconfig | 12 ++ > drivers/platform/arm64/Makefile | 1 + > drivers/platform/arm64/dell-xps-ec.c | 269 +++++++++++++++++++++++++++++++++++ > 4 files changed, 283 insertions(+) > > diff --git a/MAINTAINERS b/MAINTAINERS > index fe3f2fc4fbc087d8041f97708fbb93722f7d1882..f82c7f6c7377d3f2ff0ae1be263d854749541f03 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -7240,6 +7240,7 @@ DELL XPS EMBEDDED CONTROLLER DRIVER > M: Aleksandrs Vinarskis > S: Maintained > F: Documentation/devicetree/bindings/embedded-controller/dell,xps13-9345-ec.yaml > +F: drivers/platform/arm64/dell-xps-ec.c > > DELTA AHE-50DC FAN CONTROL MODULE DRIVER > M: Zev Weiss > diff --git a/drivers/platform/arm64/Kconfig b/drivers/platform/arm64/Kconfig > index 10f905d7d6bfa5fad30a0689d3a20481268c781e..0bc8f016032bb05cb3a7cc50bdf1092da04153bc 100644 > --- a/drivers/platform/arm64/Kconfig > +++ b/drivers/platform/arm64/Kconfig > @@ -33,6 +33,18 @@ config EC_ACER_ASPIRE1 > laptop where this information is not properly exposed via the > standard ACPI devices. > > +config EC_DELL_XPS > + tristate "Dell XPS 9345 Embedded Controller driver" > + depends on ARCH_QCOM || COMPILE_TEST > + depends on I2C > + depends on IIO > + help > + Driver for the Embedded Controller in the Qualcomm Snapdragon-based > + Dell XPS 13 9345, which handles thermal management and fan speed > + control. > + > + Say M or Y here to include this support. > + > config EC_HUAWEI_GAOKUN > tristate "Huawei Matebook E Go Embedded Controller driver" > depends on ARCH_QCOM || COMPILE_TEST > diff --git a/drivers/platform/arm64/Makefile b/drivers/platform/arm64/Makefile > index 60c131cff6a15bb51a49c9edab95badf513ee0f6..6768dc6c2310837374e67381cfc729bed1fdaaef 100644 > --- a/drivers/platform/arm64/Makefile > +++ b/drivers/platform/arm64/Makefile > @@ -6,6 +6,7 @@ > # > > obj-$(CONFIG_EC_ACER_ASPIRE1) += acer-aspire1-ec.o > +obj-$(CONFIG_EC_DELL_XPS) += dell-xps-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/dell-xps-ec.c b/drivers/platform/arm64/dell-xps-ec.c > new file mode 100644 > index 0000000000000000000000000000000000000000..5ea8f30931d8b61acbb948d8617dde3681fb8de3 > --- /dev/null > +++ b/drivers/platform/arm64/dell-xps-ec.c > @@ -0,0 +1,269 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * Copyright (c) 2026, Aleksandrs Vinarskis > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#define DELL_XPS_EC_SUSPEND_CMD 0xb9 > +#define DELL_XPS_EC_SUSPEND_MSG_LEN 64 > + > +#define DELL_XPS_EC_TEMP_CMD0 0xfb > +#define DELL_XPS_EC_TEMP_CMD1 0x20 > +#define DELL_XPS_EC_TEMP_CMD3 0x02 > +#define DELL_XPS_EC_TEMP_MSG_LEN 6 > +#define DELL_XPS_EC_TEMP_INTERVAL_MS 100 > + > +/* > + * Format: > + * - header/unknown (2 bytes) > + * - per-thermistor entries (3 bytes): thermistor_id, param1, param2 > + */ > +static const u8 dell_xps_ec_thermistor_profile[] = { > + 0xff, 0x54, > + 0x01, 0x00, 0x2b, /* sys_therm0 */ > + 0x02, 0x44, 0x2a, /* sys_therm1 */ > + 0x03, 0x44, 0x2b, /* sys_therm2 */ > + 0x04, 0x44, 0x28, /* sys_therm3 */ > + 0x05, 0x55, 0x2a, /* sys_therm4 */ > + 0x06, 0x44, 0x26, /* sys_therm5 */ > + 0x07, 0x44, 0x2b, /* sys_therm6 */ > +}; > + > +/* > + * Mapping from IIO channel name to EC command byte > + */ > +static const struct { > + const char *name; > + u8 cmd; > +} dell_xps_ec_therms[] = { > + /* TODO: 0x01 is sent only occasionally, likely TZ98 or TZ4 */ > + { "sys_therm0", 0x02 }, > + { "sys_therm1", 0x03 }, > + { "sys_therm2", 0x04 }, > + { "sys_therm3", 0x05 }, > + { "sys_therm4", 0x06 }, > + { "sys_therm5", 0x07 }, > + { "sys_therm6", 0x08 }, > +}; > + > +struct dell_xps_ec { > + struct device *dev; > + struct i2c_client *client; > + struct iio_channel *therm_channels[ARRAY_SIZE(dell_xps_ec_therms)]; > + struct delayed_work temp_work; > +}; > + > +static int dell_xps_ec_suspend_cmd(struct dell_xps_ec *ec, bool suspend) > +{ > + u8 buf[DELL_XPS_EC_SUSPEND_MSG_LEN] = {}; > + int ret; > + > + buf[0] = DELL_XPS_EC_SUSPEND_CMD; > + buf[1] = suspend ? 0x01 : 0x00; > + /* bytes 2..63 remain zero */ > + > + ret = i2c_master_send(ec->client, buf, sizeof(buf)); > + if (ret < 0) > + return ret; > + > + return 0; > +} > + > +static int dell_xps_ec_send_temp(struct dell_xps_ec *ec, u8 cmd_byte, > + int milli_celsius) > +{ > + u8 buf[DELL_XPS_EC_TEMP_MSG_LEN]; > + u16 deci_celsius; > + int ret; > + > + /* Convert milli-Celsius to deci-Celsius (Celsius * 10) */ > + deci_celsius = milli_celsius / 100; > + > + buf[0] = DELL_XPS_EC_TEMP_CMD0; > + buf[1] = DELL_XPS_EC_TEMP_CMD1; > + buf[2] = cmd_byte; > + buf[3] = DELL_XPS_EC_TEMP_CMD3; > + buf[4] = deci_celsius & 0xff; /* LSB */ > + buf[5] = (deci_celsius >> 8) & 0xff; /* MSB */ This looks like a 16-bit field so it should be handled as such and with annotated endianness. One option would be to use a struct so you can use it as a field. > + ret = i2c_master_send(ec->client, buf, sizeof(buf)); > + if (ret < 0) > + return ret; > + > + return 0; > +} > + > +static void dell_xps_ec_temp_work_fn(struct work_struct *work) > +{ > + struct dell_xps_ec *ec = container_of(work, struct dell_xps_ec, > + temp_work.work); > + int val, ret, i; > + > + for (i = 0; i < ARRAY_SIZE(dell_xps_ec_therms); i++) { > + if (!ec->therm_channels[i]) > + continue; > + > + ret = iio_read_channel_processed(ec->therm_channels[i], &val); > + if (ret < 0) { > + dev_err_ratelimited(ec->dev, > + "Failed to read thermistor %s: %d\n", > + dell_xps_ec_therms[i].name, ret); Add include for dev_err_ratelimited(). > + continue; > + } > + > + ret = dell_xps_ec_send_temp(ec, dell_xps_ec_therms[i].cmd, val); > + if (ret < 0) { > + dev_err_ratelimited(ec->dev, > + "Failed to send temp for %s: %d\n", > + dell_xps_ec_therms[i].name, ret); > + } > + } > + > + schedule_delayed_work(&ec->temp_work, > + msecs_to_jiffies(DELL_XPS_EC_TEMP_INTERVAL_MS)); Add include for msecs_to_jiffies(). > +} > + > +static irqreturn_t dell_xps_ec_irq_handler(int irq, void *data) > +{ > + struct dell_xps_ec *ec = data; > + > + /* > + * TODO: IRQ is fired on lid-close. Follow Windows example to read out > + * the thermistor thresholds and potentially fan speeds. > + */ > + dev_info_ratelimited(ec->dev, "IRQ triggered! (irq=%d)\n", irq); > + > + return IRQ_HANDLED; > +} > + > +static int dell_xps_ec_probe(struct i2c_client *client) > +{ > + struct device *dev = &client->dev; > + struct dell_xps_ec *ec; > + int ret, i; > + > + ec = devm_kzalloc(dev, sizeof(*ec), GFP_KERNEL); > + if (!ec) > + return -ENOMEM; > + > + ec->dev = dev; > + ec->client = client; > + i2c_set_clientdata(client, ec); > + > + /* Set default thermistor profile */ > + ret = i2c_master_send(client, dell_xps_ec_thermistor_profile, > + sizeof(dell_xps_ec_thermistor_profile)); > + if (ret < 0) > + return dev_err_probe(dev, ret, "Failed to set thermistor profile\n"); > + > + /* Get IIO channels for thermistors */ > + for (i = 0; i < ARRAY_SIZE(dell_xps_ec_therms); i++) { > + ec->therm_channels[i] = devm_iio_channel_get(dev, > + dell_xps_ec_therms[i].name); > + if (IS_ERR(ec->therm_channels[i])) { Add include. > + ret = PTR_ERR(ec->therm_channels[i]); > + ec->therm_channels[i] = NULL; > + if (ret == -EPROBE_DEFER) > + return ret; > + dev_warn(dev, "Thermistor %s not available: %d\n", > + dell_xps_ec_therms[i].name, ret); > + } > + } > + > + /* Start periodic temperature reporting */ > + ret = devm_delayed_work_autocancel(dev, &ec->temp_work, > + dell_xps_ec_temp_work_fn); > + if (ret) > + return ret; > + schedule_delayed_work(&ec->temp_work, > + msecs_to_jiffies(DELL_XPS_EC_TEMP_INTERVAL_MS)); > + dev_info(dev, "Started periodic temperature reporting to EC every %d ms\n", > + DELL_XPS_EC_TEMP_INTERVAL_MS); > + > + /* Request IRQ for EC events */ > + ret = devm_request_threaded_irq(dev, client->irq, NULL, > + dell_xps_ec_irq_handler, > + IRQF_ONESHOT, dev_name(dev), ec); > + if (ret < 0) > + return dev_err_probe(dev, ret, "Failed to request IRQ\n"); > + > + return 0; > +} > + > +/* > + * Notify EC of suspend > + * > + * This will: > + * - Ramp down the fans > + * - Cut power to display/trackpad/keyboard/touch row > + * - Periodically (?) power them back, such that wake-up source still works > + */ > +static int dell_xps_ec_suspend(struct device *dev) > +{ > + struct dell_xps_ec *ec = dev_get_drvdata(dev); > + > + cancel_delayed_work_sync(&ec->temp_work); > + > + return dell_xps_ec_suspend_cmd(ec, true); > +} > + > +/* > + * Notify EC of resume > + * > + * This will undo the suspend actions > + * Without the resume signal, device would wake up but be forced back into > + * suspend by EC within seconds > + */ > +static int dell_xps_ec_resume(struct device *dev) > +{ > + struct dell_xps_ec *ec = dev_get_drvdata(dev); > + int ret; > + > + ret = dell_xps_ec_suspend_cmd(ec, false); > + if (ret) > + return ret; > + > + schedule_delayed_work(&ec->temp_work, > + msecs_to_jiffies(DELL_XPS_EC_TEMP_INTERVAL_MS)); > + return 0; > +} > + > +static const struct of_device_id dell_xps_ec_of_match[] = { > + { .compatible = "dell,xps13-9345-ec" }, > + {} > +}; > +MODULE_DEVICE_TABLE(of, dell_xps_ec_of_match); > + > +static const struct i2c_device_id dell_xps_ec_i2c_id[] = { > + { "dell-xps-ec" }, > + {} > +}; > +MODULE_DEVICE_TABLE(i2c, dell_xps_ec_i2c_id); > + > +static const struct dev_pm_ops dell_xps_ec_pm_ops = { > + SYSTEM_SLEEP_PM_OPS(dell_xps_ec_suspend, dell_xps_ec_resume) > +}; > + > +static struct i2c_driver dell_xps_ec_driver = { > + .driver = { > + .name = "dell-xps-ec", > + .of_match_table = dell_xps_ec_of_match, > + .pm = &dell_xps_ec_pm_ops, > + }, > + .probe = dell_xps_ec_probe, > + .id_table = dell_xps_ec_i2c_id, > +}; > +module_i2c_driver(dell_xps_ec_driver); > + > +MODULE_AUTHOR("Aleksandrs Vinarskis "); > +MODULE_DESCRIPTION("Dell XPS 13 9345 Embedded Controller"); > +MODULE_LICENSE("GPL"); > > -- i.