diff --git a/Documentation/hwmon/cros_ec_hwmon.rst b/Documentation/hwmon/cros_ec_hwmon.rst new file mode 100644 index 000000000000..47ecae983bdb --- /dev/null +++ b/Documentation/hwmon/cros_ec_hwmon.rst @@ -0,0 +1,26 @@ +.. SPDX-License-Identifier: GPL-2.0-or-later + +Kernel driver cros_ec_hwmon +=========================== + +Supported chips: + + * ChromeOS embedded controllers. + + Prefix: 'cros_ec' + + Addresses scanned: - + +Author: + + - Thomas Weißschuh + +Description +----------- + +This driver implements support for hardware monitoring commands exposed by the +ChromeOS embedded controller used in Chromebooks and other devices. + +The channel labels exposed via hwmon are retrieved from the EC itself. + +Fan and temperature readings are supported. diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst index 03d313af469a..342ea5deba24 100644 --- a/Documentation/hwmon/index.rst +++ b/Documentation/hwmon/index.rst @@ -58,6 +58,7 @@ Hardware Monitoring Kernel Drivers coretemp corsair-cpro corsair-psu + cros_ec_hwmon da9052 da9055 dell-smm-hwmon diff --git a/MAINTAINERS b/MAINTAINERS index d6c90161c7bf..e4e6aad46668 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -5135,6 +5135,14 @@ S: Maintained F: Documentation/devicetree/bindings/sound/google,cros-ec-codec.yaml F: sound/soc/codecs/cros_ec_codec.* +CHROMEOS EC HARDWARE MONITORING +M: Thomas Weißschuh +L: chrome-platform@lists.linux.dev +L: linux-hwmon@vger.kernel.org +S: Maintained +F: Documentation/hwmon/cros_ec_hwmon.rst +F: drivers/hwmon/cros_ec_hwmon.c + CHROMEOS EC SUBDRIVERS M: Benson Leung R: Guenter Roeck diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig index e14ae18a973b..702dc45ea405 100644 --- a/drivers/hwmon/Kconfig +++ b/drivers/hwmon/Kconfig @@ -506,6 +506,17 @@ config SENSORS_CORSAIR_PSU This driver can also be built as a module. If so, the module will be called corsair-psu. +config SENSORS_CROS_EC + tristate "ChromeOS Embedded Controller sensors" + depends on MFD_CROS_EC_DEV + default MFD_CROS_EC_DEV + help + If you say yes here you get support for ChromeOS Embedded Controller + sensors. + + This driver can also be built as a module. If so, the module + will be called cros_ec_hwmon. + config SENSORS_DRIVETEMP tristate "Hard disk drives with temperature sensors" depends on SCSI && ATA diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile index e3f25475d1f0..4fb14dd1eafd 100644 --- a/drivers/hwmon/Makefile +++ b/drivers/hwmon/Makefile @@ -64,6 +64,7 @@ obj-$(CONFIG_SENSORS_CHIPCAP2) += chipcap2.o obj-$(CONFIG_SENSORS_CORETEMP) += coretemp.o obj-$(CONFIG_SENSORS_CORSAIR_CPRO) += corsair-cpro.o obj-$(CONFIG_SENSORS_CORSAIR_PSU) += corsair-psu.o +obj-$(CONFIG_SENSORS_CROS_EC) += cros_ec_hwmon.o obj-$(CONFIG_SENSORS_DA9052_ADC)+= da9052-hwmon.o obj-$(CONFIG_SENSORS_DA9055)+= da9055-hwmon.o obj-$(CONFIG_SENSORS_DELL_SMM) += dell-smm-hwmon.o diff --git a/drivers/hwmon/cros_ec_hwmon.c b/drivers/hwmon/cros_ec_hwmon.c new file mode 100644 index 000000000000..41f268fa8260 --- /dev/null +++ b/drivers/hwmon/cros_ec_hwmon.c @@ -0,0 +1,282 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * ChromeOS EC driver for hwmon + * + * Copyright (C) 2024 Thomas Weißschuh + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define DRV_NAME "cros-ec-hwmon" + +struct cros_ec_hwmon_priv { + struct cros_ec_device *cros_ec; + const char *temp_sensor_names[EC_TEMP_SENSOR_ENTRIES + EC_TEMP_SENSOR_B_ENTRIES]; + u8 usable_fans; +}; + +static int cros_ec_hwmon_read_fan_speed(struct cros_ec_device *cros_ec, u8 index, u16 *speed) +{ + int ret; + + ret = cros_ec_cmd_readmem(cros_ec, EC_MEMMAP_FAN + index * 2, 2, speed); + if (ret < 0) + return ret; + + *speed = le16_to_cpu(*speed); + return 0; +} + +static int cros_ec_hwmon_read_temp(struct cros_ec_device *cros_ec, u8 index, u8 *temp) +{ + unsigned int offset; + int ret; + + if (index < EC_TEMP_SENSOR_ENTRIES) + offset = EC_MEMMAP_TEMP_SENSOR + index; + else + offset = EC_MEMMAP_TEMP_SENSOR_B + index - EC_TEMP_SENSOR_ENTRIES; + + ret = cros_ec_cmd_readmem(cros_ec, offset, 1, temp); + if (ret < 0) + return ret; + return 0; +} + +static bool cros_ec_hwmon_is_error_fan(u16 speed) +{ + return speed == EC_FAN_SPEED_NOT_PRESENT || speed == EC_FAN_SPEED_STALLED; +} + +static bool cros_ec_hwmon_is_error_temp(u8 temp) +{ + return temp == EC_TEMP_SENSOR_NOT_PRESENT || + temp == EC_TEMP_SENSOR_ERROR || + temp == EC_TEMP_SENSOR_NOT_POWERED || + temp == EC_TEMP_SENSOR_NOT_CALIBRATED; +} + +static long cros_ec_hwmon_temp_to_millicelsius(u8 temp) +{ + return kelvin_to_millicelsius((((long)temp) + EC_TEMP_SENSOR_OFFSET)); +} + +static int cros_ec_hwmon_read(struct device *dev, enum hwmon_sensor_types type, + u32 attr, int channel, long *val) +{ + struct cros_ec_hwmon_priv *priv = dev_get_drvdata(dev); + int ret = -EOPNOTSUPP; + u16 speed; + u8 temp; + + if (type == hwmon_fan) { + if (attr == hwmon_fan_input) { + ret = cros_ec_hwmon_read_fan_speed(priv->cros_ec, channel, &speed); + if (ret == 0) { + if (cros_ec_hwmon_is_error_fan(speed)) + ret = -ENODATA; + else + *val = speed; + } + } else if (attr == hwmon_fan_fault) { + ret = cros_ec_hwmon_read_fan_speed(priv->cros_ec, channel, &speed); + if (ret == 0) + *val = cros_ec_hwmon_is_error_fan(speed); + } + } else if (type == hwmon_temp) { + if (attr == hwmon_temp_input) { + ret = cros_ec_hwmon_read_temp(priv->cros_ec, channel, &temp); + if (ret == 0) { + if (cros_ec_hwmon_is_error_temp(temp)) + ret = -ENODATA; + else + *val = cros_ec_hwmon_temp_to_millicelsius(temp); + } + } else if (attr == hwmon_temp_fault) { + ret = cros_ec_hwmon_read_temp(priv->cros_ec, channel, &temp); + if (ret == 0) + *val = cros_ec_hwmon_is_error_temp(temp); + } + } + + return ret; +} + +static int cros_ec_hwmon_read_string(struct device *dev, enum hwmon_sensor_types type, + u32 attr, int channel, const char **str) +{ + struct cros_ec_hwmon_priv *priv = dev_get_drvdata(dev); + + if (type == hwmon_temp && attr == hwmon_temp_label) { + *str = priv->temp_sensor_names[channel]; + return 0; + } + + return -EOPNOTSUPP; +} + +static umode_t cros_ec_hwmon_is_visible(const void *data, enum hwmon_sensor_types type, + u32 attr, int channel) +{ + const struct cros_ec_hwmon_priv *priv = data; + + if (type == hwmon_fan) { + if (priv->usable_fans & BIT(channel)) + return 0444; + } else if (type == hwmon_temp) { + if (priv->temp_sensor_names[channel]) + return 0444; + } + + return 0; +} + +static const struct hwmon_channel_info * const cros_ec_hwmon_info[] = { + HWMON_CHANNEL_INFO(fan, + HWMON_F_INPUT | HWMON_F_FAULT, + HWMON_F_INPUT | HWMON_F_FAULT, + HWMON_F_INPUT | HWMON_F_FAULT, + HWMON_F_INPUT | HWMON_F_FAULT), + HWMON_CHANNEL_INFO(temp, + HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL, + HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL, + HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL, + HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL, + HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL, + HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL, + HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL, + HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL, + HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL, + HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL, + HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL, + HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL, + HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL, + HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL, + HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL, + HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL, + HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL, + HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL, + HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL, + HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL, + HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL, + HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL, + HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL, + HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL), + NULL +}; + +static const struct hwmon_ops cros_ec_hwmon_ops = { + .read = cros_ec_hwmon_read, + .read_string = cros_ec_hwmon_read_string, + .is_visible = cros_ec_hwmon_is_visible, +}; + +static const struct hwmon_chip_info cros_ec_hwmon_chip_info = { + .ops = &cros_ec_hwmon_ops, + .info = cros_ec_hwmon_info, +}; + +static void cros_ec_hwmon_probe_temp_sensors(struct device *dev, struct cros_ec_hwmon_priv *priv, + u8 thermal_version) +{ + struct ec_params_temp_sensor_get_info req = {}; + struct ec_response_temp_sensor_get_info resp; + size_t candidates, i, sensor_name_size; + int ret; + u8 temp; + + if (thermal_version < 2) + candidates = EC_TEMP_SENSOR_ENTRIES; + else + candidates = ARRAY_SIZE(priv->temp_sensor_names); + + for (i = 0; i < candidates; i++) { + if (cros_ec_hwmon_read_temp(priv->cros_ec, i, &temp) < 0) + continue; + + if (temp == EC_TEMP_SENSOR_NOT_PRESENT) + continue; + + req.id = i; + ret = cros_ec_cmd(priv->cros_ec, 0, EC_CMD_TEMP_SENSOR_GET_INFO, + &req, sizeof(req), &resp, sizeof(resp)); + if (ret < 0) + continue; + + sensor_name_size = strnlen(resp.sensor_name, sizeof(resp.sensor_name)); + priv->temp_sensor_names[i] = devm_kasprintf(dev, GFP_KERNEL, "%*s", + (int)sensor_name_size, + resp.sensor_name); + } +} + +static void cros_ec_hwmon_probe_fans(struct cros_ec_hwmon_priv *priv) +{ + u16 speed; + size_t i; + int ret; + + for (i = 0; i < EC_FAN_SPEED_ENTRIES; i++) { + ret = cros_ec_hwmon_read_fan_speed(priv->cros_ec, i, &speed); + if (ret == 0 && speed != EC_FAN_SPEED_NOT_PRESENT) + priv->usable_fans |= BIT(i); + } +} + +static int cros_ec_hwmon_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent); + struct cros_ec_device *cros_ec = ec_dev->ec_dev; + struct cros_ec_hwmon_priv *priv; + struct device *hwmon_dev; + u8 thermal_version; + int ret; + + ret = cros_ec_cmd_readmem(cros_ec, EC_MEMMAP_THERMAL_VERSION, 1, &thermal_version); + if (ret < 0) + return ret; + + /* Covers both fan and temp sensors */ + if (thermal_version == 0) + return -ENODEV; + + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->cros_ec = cros_ec; + + cros_ec_hwmon_probe_temp_sensors(dev, priv, thermal_version); + cros_ec_hwmon_probe_fans(priv); + + hwmon_dev = devm_hwmon_device_register_with_info(dev, "cros_ec", priv, + &cros_ec_hwmon_chip_info, NULL); + + return PTR_ERR_OR_ZERO(hwmon_dev); +} + +static const struct platform_device_id cros_ec_hwmon_id[] = { + { DRV_NAME, 0 }, + {} +}; + +static struct platform_driver cros_ec_hwmon_driver = { + .driver.name = DRV_NAME, + .probe = cros_ec_hwmon_probe, + .id_table = cros_ec_hwmon_id, +}; +module_platform_driver(cros_ec_hwmon_driver); + +MODULE_DEVICE_TABLE(platform, cros_ec_hwmon_id); +MODULE_DESCRIPTION("ChromeOS EC Hardware Monitoring Driver"); +MODULE_AUTHOR("Thomas Weißschuh