From a282998181bd11d10f7ab6e378683a4e11d5122e Mon Sep 17 00:00:00 2001 From: Marco Rodolfi Date: Wed, 10 Jun 2026 12:23:17 +0200 Subject: [PATCH 1/4] mfd: Add MFD core driver for Steam Deck Add MFD core driver for Steam Deck. Doesn't really do much so far besides instantiating a number of MFD cells that implement all the interesting functionality. (cherry picked from commit 5f534c2d6ebdefccb9c024eb0f013bc1c0c622d9) [fwd-ported to v6.11 and v7.0] Signed-off-by: Cristian Ciocaltea Signed-off-by: Marco Rodolfi --- drivers/mfd/Kconfig | 12 ++++ drivers/mfd/Makefile | 2 + drivers/mfd/steamdeck.c | 127 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 141 insertions(+) create mode 100644 drivers/mfd/steamdeck.c diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig index 7192c9d1d268e..1edfdd34119ec 100644 --- a/drivers/mfd/Kconfig +++ b/drivers/mfd/Kconfig @@ -2580,5 +2580,17 @@ config MFD_MAX7360 additional drivers must be enabled in order to use the functionality of the device. +config MFD_STEAMDECK + tristate "Valve Steam Deck" + select MFD_CORE + depends on ACPI + depends on X86_64 || COMPILE_TEST + help + This driver registers various MFD cells that expose aspects + of Steam Deck specific ACPI functionality. + + Say N here, unless you are running on Steam Deck hardware. + + endmenu endif diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile index e75e8045c28af..72adf78840c63 100644 --- a/drivers/mfd/Makefile +++ b/drivers/mfd/Makefile @@ -304,3 +304,5 @@ obj-$(CONFIG_MFD_RSMU_SPI) += rsmu_spi.o rsmu_core.o obj-$(CONFIG_MFD_UPBOARD_FPGA) += upboard-fpga.o obj-$(CONFIG_MFD_LOONGSON_SE) += loongson-se.o + +obj-$(CONFIG_MFD_STEAMDECK) += steamdeck.o diff --git a/drivers/mfd/steamdeck.c b/drivers/mfd/steamdeck.c new file mode 100644 index 0000000000000..0e504b3c2796e --- /dev/null +++ b/drivers/mfd/steamdeck.c @@ -0,0 +1,127 @@ +// SPDX-License-Identifier: GPL-2.0+ + +/* + * Steam Deck EC MFD core driver + * + * Copyright (C) 2021-2022 Valve Corporation + * + */ + +#include +#include +#include + +#define STEAMDECK_STA_OK \ + (ACPI_STA_DEVICE_ENABLED | \ + ACPI_STA_DEVICE_PRESENT | \ + ACPI_STA_DEVICE_FUNCTIONING) + +struct steamdeck { + struct acpi_device *adev; + struct device *dev; +}; + +#define STEAMDECK_ATTR_RO(_name, _method) \ + static ssize_t _name##_show(struct device *dev, \ + struct device_attribute *attr, \ + char *buf) \ + { \ + struct steamdeck *sd = dev_get_drvdata(dev); \ + unsigned long long val; \ + \ + if (ACPI_FAILURE(acpi_evaluate_integer( \ + sd->adev->handle, \ + _method, NULL, &val))) \ + return -EIO; \ + \ + return sysfs_emit(buf, "%llu\n", val); \ + } \ + static DEVICE_ATTR_RO(_name) + +STEAMDECK_ATTR_RO(firmware_version, "PDFW"); +STEAMDECK_ATTR_RO(board_id, "BOID"); + +static struct attribute *steamdeck_attrs[] = { + &dev_attr_firmware_version.attr, + &dev_attr_board_id.attr, + NULL +}; + +ATTRIBUTE_GROUPS(steamdeck); + +static const struct mfd_cell steamdeck_cells[] = { + { .name = "steamdeck-hwmon" }, + { .name = "steamdeck-leds" }, + { .name = "steamdeck-extcon" }, +}; + +static void steamdeck_remove_sysfs_groups(void *data) +{ + struct steamdeck *sd = data; + + sysfs_remove_groups(&sd->dev->kobj, steamdeck_groups); +} + +static int steamdeck_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + unsigned long long sta; + struct steamdeck *sd; + acpi_status status; + int ret; + + sd = devm_kzalloc(dev, sizeof(*sd), GFP_KERNEL); + if (!sd) + return -ENOMEM; + sd->adev = ACPI_COMPANION(dev); + sd->dev = dev; + platform_set_drvdata(pdev, sd); + + status = acpi_evaluate_integer(sd->adev->handle, "_STA", + NULL, &sta); + if (ACPI_FAILURE(status)) { + dev_err(dev, "Status check failed (0x%x)\n", status); + return -EINVAL; + } + + if ((sta & STEAMDECK_STA_OK) != STEAMDECK_STA_OK) { + dev_err(dev, "Device is not ready\n"); + return -EINVAL; + } + + ret = sysfs_create_groups(&dev->kobj, steamdeck_groups); + if (ret) { + dev_err(dev, "Failed to create sysfs group\n"); + return ret; + } + + ret = devm_add_action_or_reset(dev, steamdeck_remove_sysfs_groups, + sd); + if (ret) { + dev_err(dev, "Failed to register devres action\n"); + return ret; + } + + return devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE, + steamdeck_cells, ARRAY_SIZE(steamdeck_cells), + NULL, 0, NULL); +} + +static const struct acpi_device_id steamdeck_device_ids[] = { + { "VLV0100", 0 }, + { "", 0 }, +}; +MODULE_DEVICE_TABLE(acpi, steamdeck_device_ids); + +static struct platform_driver steamdeck_driver = { + .probe = steamdeck_probe, + .driver = { + .name = "steamdeck", + .acpi_match_table = steamdeck_device_ids, + }, +}; +module_platform_driver(steamdeck_driver); + +MODULE_AUTHOR("Andrey Smirnov "); +MODULE_DESCRIPTION("Steam Deck EC MFD core driver"); +MODULE_LICENSE("GPL"); From cb3713f23d48663062083383151ed43a02557d09 Mon Sep 17 00:00:00 2001 From: Marco Rodolfi Date: Wed, 10 Jun 2026 12:25:16 +0200 Subject: [PATCH 2/4] mfd: steamdeck: Expose controller board power in sysfs As of version 118 Deck's BIOS implements "SCBP" method that allows gating power of the controller board (VBUS). Add a basic WO method to our root MFD device to allow toggling that. Signed-off-by: Andrey Smirnov (cherry picked from commit f97f32718acc10cbb51fef925842392e80904d74) Signed-off-by: Cristian Ciocaltea --- drivers/mfd/steamdeck.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/drivers/mfd/steamdeck.c b/drivers/mfd/steamdeck.c index 0e504b3c2796e..a60fa7db91415 100644 --- a/drivers/mfd/steamdeck.c +++ b/drivers/mfd/steamdeck.c @@ -41,9 +41,29 @@ struct steamdeck { STEAMDECK_ATTR_RO(firmware_version, "PDFW"); STEAMDECK_ATTR_RO(board_id, "BOID"); +static ssize_t controller_board_power_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct steamdeck *sd = dev_get_drvdata(dev); + bool enabled; + ssize_t ret = kstrtobool(buf, &enabled); + + if (ret) + return ret; + + if (ACPI_FAILURE(acpi_execute_simple_method(sd->adev->handle, + "SCBP", enabled))) + return -EIO; + + return count; +} +static DEVICE_ATTR_WO(controller_board_power); + static struct attribute *steamdeck_attrs[] = { &dev_attr_firmware_version.attr, &dev_attr_board_id.attr, + &dev_attr_controller_board_power.attr, NULL }; From e9ba758ac85730f7f0d3567d0df69339fe7542a5 Mon Sep 17 00:00:00 2001 From: Marco Rodolfi Date: Wed, 10 Jun 2026 12:30:35 +0200 Subject: [PATCH 3/4] hwmon: Add driver for Steam Deck's EC sensors Add driver for sensors exposed by EC firmware on Steam Deck hardware. (cherry picked from commit 6917aac77bee6185ae3920b936cdbe7876118c0b) [fwd-ported to v7.0] Signed-off-by: Cristian Ciocaltea Signed-off-by: Marco Rodolfi --- drivers/hwmon/Kconfig | 11 ++ drivers/hwmon/Makefile | 1 + drivers/hwmon/steamdeck-hwmon.c | 224 ++++++++++++++++++++++++++++++++ 3 files changed, 236 insertions(+) create mode 100644 drivers/hwmon/steamdeck-hwmon.c diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig index 14e4cea48acc4..c149b47bd4dbb 100644 --- a/drivers/hwmon/Kconfig +++ b/drivers/hwmon/Kconfig @@ -2160,6 +2160,17 @@ config SENSORS_SCH5636 This driver can also be built as a module. If so, the module will be called sch5636. +config SENSORS_STEAMDECK + tristate "Steam Deck EC sensors" + depends on MFD_STEAMDECK + help + If you say yes here you get support for the hardware + monitoring features exposed by EC firmware on Steam Deck + devices + + This driver can also be built as a module. If so, the module + will be called steamdeck-hwmon. + config SENSORS_STTS751 tristate "ST Microelectronics STTS751" depends on I2C diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile index 982ee2c6f9deb..5fcb26e0d84c2 100644 --- a/drivers/hwmon/Makefile +++ b/drivers/hwmon/Makefile @@ -219,6 +219,7 @@ obj-$(CONFIG_SENSORS_SMSC47M1) += smsc47m1.o obj-$(CONFIG_SENSORS_SMSC47M192)+= smsc47m192.o obj-$(CONFIG_SENSORS_SPARX5) += sparx5-temp.o obj-$(CONFIG_SENSORS_SPD5118) += spd5118.o +obj-$(CONFIG_SENSORS_STEAMDECK) += steamdeck-hwmon.o obj-$(CONFIG_SENSORS_STTS751) += stts751.o obj-$(CONFIG_SENSORS_SURFACE_FAN)+= surface_fan.o obj-$(CONFIG_SENSORS_SURFACE_TEMP)+= surface_temp.o diff --git a/drivers/hwmon/steamdeck-hwmon.c b/drivers/hwmon/steamdeck-hwmon.c new file mode 100644 index 0000000000000..fab9e9460bd40 --- /dev/null +++ b/drivers/hwmon/steamdeck-hwmon.c @@ -0,0 +1,224 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Steam Deck EC sensors driver + * + * Copyright (C) 2021-2022 Valve Corporation + */ + +#include +#include +#include + +#define STEAMDECK_HWMON_NAME "steamdeck-hwmon" + +struct steamdeck_hwmon { + struct acpi_device *adev; +}; + +static long +steamdeck_hwmon_get(struct steamdeck_hwmon *sd, const char *method) +{ + unsigned long long val; + if (ACPI_FAILURE(acpi_evaluate_integer(sd->adev->handle, + (char *)method, NULL, &val))) + return -EIO; + + return val; +} + +static int +steamdeck_hwmon_read(struct device *dev, enum hwmon_sensor_types type, + u32 attr, int channel, long *out) +{ + struct steamdeck_hwmon *sd = dev_get_drvdata(dev); + + switch (type) { + case hwmon_curr: + if (attr != hwmon_curr_input) + return -EOPNOTSUPP; + + *out = steamdeck_hwmon_get(sd, "PDAM"); + if (*out < 0) + return *out; + break; + case hwmon_in: + if (attr != hwmon_in_input) + return -EOPNOTSUPP; + + *out = steamdeck_hwmon_get(sd, "PDVL"); + if (*out < 0) + return *out; + break; + case hwmon_temp: + if (attr != hwmon_temp_input) + return -EOPNOTSUPP; + + *out = steamdeck_hwmon_get(sd, "BATT"); + if (*out < 0) + return *out; + /* + * Assuming BATT returns deg C we need to mutiply it + * by 1000 to convert to mC + */ + *out *= 1000; + break; + case hwmon_fan: + switch (attr) { + case hwmon_fan_input: + *out = steamdeck_hwmon_get(sd, "FANR"); + if (*out < 0) + return *out; + break; + case hwmon_fan_target: + *out = steamdeck_hwmon_get(sd, "FSSR"); + if (*out < 0) + return *out; + break; + case hwmon_fan_fault: + *out = steamdeck_hwmon_get(sd, "FANC"); + if (*out < 0) + return *out; + /* + * FANC (Fan check): + * 0: Abnormal + * 1: Normal + */ + *out = !*out; + break; + default: + return -EOPNOTSUPP; + } + break; + default: + return -EOPNOTSUPP; + } + + return 0; +} + +static int +steamdeck_hwmon_read_string(struct device *dev, enum hwmon_sensor_types type, + u32 attr, int channel, const char **str) +{ + switch (type) { + /* + * These two aren't, strictly speaking, measured. EC + * firmware just reports what PD negotiation resulted + * in. + */ + case hwmon_curr: + *str = "PD Contract Current"; + break; + case hwmon_in: + *str = "PD Contract Voltage"; + break; + case hwmon_temp: + *str = "Battery Temp"; + break; + case hwmon_fan: + *str = "System Fan"; + break; + default: + return -EOPNOTSUPP; + } + + return 0; +} + +static int +steamdeck_hwmon_write(struct device *dev, enum hwmon_sensor_types type, + u32 attr, int channel, long val) +{ + struct steamdeck_hwmon *sd = dev_get_drvdata(dev); + + if (type != hwmon_fan || + attr != hwmon_fan_target) + return -EOPNOTSUPP; + + val = clamp_val(val, 0, 7300); + + if (ACPI_FAILURE(acpi_execute_simple_method(sd->adev->handle, + "FANS", val))) + return -EIO; + + return 0; +} + +static umode_t +steamdeck_hwmon_is_visible(const void *data, enum hwmon_sensor_types type, + u32 attr, int channel) +{ + if (type == hwmon_fan && + attr == hwmon_fan_target) + return 0644; + + return 0444; +} + +static const struct hwmon_channel_info *steamdeck_hwmon_info[] = { + HWMON_CHANNEL_INFO(in, + HWMON_I_INPUT | HWMON_I_LABEL), + HWMON_CHANNEL_INFO(curr, + HWMON_C_INPUT | HWMON_C_LABEL), + HWMON_CHANNEL_INFO(temp, + HWMON_T_INPUT | HWMON_T_LABEL), + HWMON_CHANNEL_INFO(fan, + HWMON_F_INPUT | HWMON_F_LABEL | + HWMON_F_TARGET | HWMON_F_FAULT), + NULL +}; + +static const struct hwmon_ops steamdeck_hwmon_ops = { + .is_visible = steamdeck_hwmon_is_visible, + .read = steamdeck_hwmon_read, + .read_string = steamdeck_hwmon_read_string, + .write = steamdeck_hwmon_write, +}; + +static const struct hwmon_chip_info steamdeck_hwmon_chip_info = { + .ops = &steamdeck_hwmon_ops, + .info = steamdeck_hwmon_info, +}; + +static int steamdeck_hwmon_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct steamdeck_hwmon *sd; + struct device *hwmon; + + sd = devm_kzalloc(dev, sizeof(*sd), GFP_KERNEL); + if (!sd) + return -ENOMEM; + + sd->adev = ACPI_COMPANION(dev->parent); + hwmon = devm_hwmon_device_register_with_info(dev, + "steamdeck_hwmon", + sd, + &steamdeck_hwmon_chip_info, + NULL); + if (IS_ERR(hwmon)) { + dev_err(dev, "Failed to register HWMON device"); + return PTR_ERR(hwmon); + } + + return 0; +} + +static const struct platform_device_id steamdeck_hwmon_id_table[] = { + { .name = STEAMDECK_HWMON_NAME }, + {} +}; +MODULE_DEVICE_TABLE(platform, steamdeck_hwmon_id_table); + +static struct platform_driver steamdeck_hwmon_driver = { + .probe = steamdeck_hwmon_probe, + .driver = { + .name = STEAMDECK_HWMON_NAME, + }, + .id_table = steamdeck_hwmon_id_table, +}; +module_platform_driver(steamdeck_hwmon_driver); + +MODULE_AUTHOR("Andrey Smirnov "); +MODULE_DESCRIPTION("Steam Deck EC sensors driver"); +MODULE_LICENSE("GPL"); From c1843c72278b999ec72997fc83a4a7cc6c177032 Mon Sep 17 00:00:00 2001 From: Marco Rodolfi Date: Wed, 10 Jun 2026 13:46:34 +0200 Subject: [PATCH 4/4] hwmon: steamdeck-hwmon: Add support for max battery level/rate Add support for max battery level/charge rate attributes. Signed-off-by: Andrey Smirnov --- drivers/hwmon/steamdeck-hwmon.c | 72 ++++++++++++++++++++++++++++++++- 1 file changed, 71 insertions(+), 1 deletion(-) diff --git a/drivers/hwmon/steamdeck-hwmon.c b/drivers/hwmon/steamdeck-hwmon.c index fab9e9460bd40..9d0a5471b1811 100644 --- a/drivers/hwmon/steamdeck-hwmon.c +++ b/drivers/hwmon/steamdeck-hwmon.c @@ -180,6 +180,76 @@ static const struct hwmon_chip_info steamdeck_hwmon_chip_info = { .info = steamdeck_hwmon_info, }; + +static ssize_t +steamdeck_hwmon_simple_store(struct device *dev, const char *buf, size_t count, + const char *method, + unsigned long upper_limit) +{ + struct steamdeck_hwmon *sd = dev_get_drvdata(dev); + unsigned long value; + + if (kstrtoul(buf, 10, &value) || value >= upper_limit) + return -EINVAL; + + if (ACPI_FAILURE(acpi_execute_simple_method(sd->adev->handle, + (char *)method, value))) + return -EIO; + + return count; +} + +static ssize_t +steamdeck_hwmon_simple_show(struct device *dev, char *buf, + const char *method) +{ + struct steamdeck_hwmon *sd = dev_get_drvdata(dev); + unsigned long value; + + value = steamdeck_hwmon_get(sd, method); + if (value < 0) + return value; + + return sprintf(buf, "%ld\n", value); +} + +#define STEAMDECK_HWMON_ATTR_RW(_name, _set_method, _get_method, \ + _upper_limit) \ + static ssize_t _name##_show(struct device *dev, \ + struct device_attribute *attr, \ + char *buf) \ + { \ + return steamdeck_hwmon_simple_show(dev, buf, \ + _get_method); \ + } \ + static ssize_t _name##_store(struct device *dev, \ + struct device_attribute *attr, \ + const char *buf, size_t count) \ + { \ + return steamdeck_hwmon_simple_store(dev, buf, count, \ + _set_method, \ + _upper_limit); \ + } \ + static DEVICE_ATTR_RW(_name) + +STEAMDECK_HWMON_ATTR_RW(max_battery_charge_level, "FCBL", "SFBL", 101); +STEAMDECK_HWMON_ATTR_RW(max_battery_charge_rate, "CHGR", "GCHR", 101); + +static struct attribute *steamdeck_hwmon_attributes[] = { + &dev_attr_max_battery_charge_level.attr, + &dev_attr_max_battery_charge_rate.attr, + NULL +}; + +static const struct attribute_group steamdeck_hwmon_group = { + .attrs = steamdeck_hwmon_attributes, +}; + +static const struct attribute_group *steamdeck_hwmon_groups[] = { + &steamdeck_hwmon_group, + NULL +}; + static int steamdeck_hwmon_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; @@ -195,7 +265,7 @@ static int steamdeck_hwmon_probe(struct platform_device *pdev) "steamdeck_hwmon", sd, &steamdeck_hwmon_chip_info, - NULL); + steamdeck_hwmon_groups); if (IS_ERR(hwmon)) { dev_err(dev, "Failed to register HWMON device"); return PTR_ERR(hwmon);