diff options
Diffstat (limited to 'drivers/hwmon/cros_ec_hwmon.c')
| -rw-r--r-- | drivers/hwmon/cros_ec_hwmon.c | 597 |
1 files changed, 597 insertions, 0 deletions
diff --git a/drivers/hwmon/cros_ec_hwmon.c b/drivers/hwmon/cros_ec_hwmon.c new file mode 100644 index 000000000000..48331703f2f5 --- /dev/null +++ b/drivers/hwmon/cros_ec_hwmon.c @@ -0,0 +1,597 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * ChromeOS EC driver for hwmon + * + * Copyright (C) 2024 Thomas Weißschuh <linux@weissschuh.net> + */ + +#include <linux/device.h> +#include <linux/hwmon.h> +#include <linux/math.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/platform_data/cros_ec_commands.h> +#include <linux/platform_data/cros_ec_proto.h> +#include <linux/thermal.h> +#include <linux/types.h> +#include <linux/units.h> + +#define DRV_NAME "cros-ec-hwmon" + +#define CROS_EC_HWMON_PWM_GET_FAN_DUTY_CMD_VERSION 0 +#define CROS_EC_HWMON_PWM_SET_FAN_DUTY_CMD_VERSION 1 +#define CROS_EC_HWMON_THERMAL_AUTO_FAN_CTRL_CMD_VERSION 2 + +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; + bool fan_control_supported; + u8 manual_fans; /* bits to indicate whether the fan is set to manual */ + u8 manual_fan_pwm[EC_FAN_SPEED_ENTRIES]; +}; + +struct cros_ec_hwmon_cooling_priv { + struct cros_ec_hwmon_priv *hwmon_priv; + u8 index; +}; + +static int cros_ec_hwmon_read_fan_speed(struct cros_ec_device *cros_ec, u8 index, u16 *speed) +{ + int ret; + __le16 __speed; + + 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_pwm_value(struct cros_ec_device *cros_ec, u8 index, u8 *pwm_value) +{ + struct ec_params_pwm_get_fan_duty req = { + .fan_idx = index, + }; + struct ec_response_pwm_get_fan_duty resp; + int ret; + + ret = cros_ec_cmd(cros_ec, CROS_EC_HWMON_PWM_GET_FAN_DUTY_CMD_VERSION, + EC_CMD_PWM_GET_FAN_DUTY, &req, sizeof(req), &resp, sizeof(resp)); + if (ret < 0) + return ret; + + *pwm_value = (u8)DIV_ROUND_CLOSEST(le32_to_cpu(resp.percent) * 255, 100); + return 0; +} + +static int cros_ec_hwmon_read_pwm_enable(struct cros_ec_device *cros_ec, u8 index, + u8 *control_method) +{ + struct ec_params_auto_fan_ctrl_v2 req = { + .cmd = EC_AUTO_FAN_CONTROL_CMD_GET, + .fan_idx = index, + }; + struct ec_response_auto_fan_control resp; + int ret; + + ret = cros_ec_cmd(cros_ec, CROS_EC_HWMON_THERMAL_AUTO_FAN_CTRL_CMD_VERSION, + EC_CMD_THERMAL_AUTO_FAN_CTRL, &req, sizeof(req), &resp, sizeof(resp)); + if (ret < 0) + return ret; + + *control_method = resp.is_auto ? 2 : 1; + 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; + u8 control_method; + u8 pwm_value; + 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_pwm) { + if (attr == hwmon_pwm_enable) { + ret = cros_ec_hwmon_read_pwm_enable(priv->cros_ec, channel, + &control_method); + if (ret == 0) + *val = control_method; + } else if (attr == hwmon_pwm_input) { + ret = cros_ec_hwmon_read_pwm_value(priv->cros_ec, channel, &pwm_value); + if (ret == 0) + *val = pwm_value; + } + } 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 int cros_ec_hwmon_set_fan_pwm_val(struct cros_ec_device *cros_ec, u8 index, u8 val) +{ + struct ec_params_pwm_set_fan_duty_v1 req = { + .fan_idx = index, + .percent = DIV_ROUND_CLOSEST((uint32_t)val * 100, 255), + }; + int ret; + + ret = cros_ec_cmd(cros_ec, CROS_EC_HWMON_PWM_SET_FAN_DUTY_CMD_VERSION, + EC_CMD_PWM_SET_FAN_DUTY, &req, sizeof(req), NULL, 0); + if (ret < 0) + return ret; + return 0; +} + +static int cros_ec_hwmon_write_pwm_input(struct cros_ec_device *cros_ec, u8 index, u8 val) +{ + u8 control_method; + int ret; + + ret = cros_ec_hwmon_read_pwm_enable(cros_ec, index, &control_method); + if (ret) + return ret; + if (control_method != 1) + return -EOPNOTSUPP; + + return cros_ec_hwmon_set_fan_pwm_val(cros_ec, index, val); +} + +static int cros_ec_hwmon_write_pwm_enable(struct cros_ec_device *cros_ec, u8 index, u8 val) +{ + struct ec_params_auto_fan_ctrl_v2 req = { + .fan_idx = index, + .cmd = EC_AUTO_FAN_CONTROL_CMD_SET, + }; + int ret; + + /* No CrOS EC supports no fan speed control */ + if (val == 0) + return -EOPNOTSUPP; + + req.set_auto = (val != 1) ? true : false; + ret = cros_ec_cmd(cros_ec, CROS_EC_HWMON_THERMAL_AUTO_FAN_CTRL_CMD_VERSION, + EC_CMD_THERMAL_AUTO_FAN_CTRL, &req, sizeof(req), NULL, 0); + if (ret < 0) + return ret; + return 0; +} + +static int cros_ec_hwmon_write(struct device *dev, enum hwmon_sensor_types type, u32 attr, + int channel, long val) +{ + struct cros_ec_hwmon_priv *priv = dev_get_drvdata(dev); + + if (type == hwmon_pwm) { + switch (attr) { + case hwmon_pwm_input: + return cros_ec_hwmon_write_pwm_input(priv->cros_ec, channel, val); + case hwmon_pwm_enable: + return cros_ec_hwmon_write_pwm_enable(priv->cros_ec, channel, val); + default: + return -EOPNOTSUPP; + } + } + + 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_pwm) { + if (priv->fan_control_supported && priv->usable_fans & BIT(channel)) + return 0644; + } 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(chip, HWMON_C_REGISTER_TZ), + 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(pwm, + HWMON_PWM_INPUT | HWMON_PWM_ENABLE, + HWMON_PWM_INPUT | HWMON_PWM_ENABLE, + HWMON_PWM_INPUT | HWMON_PWM_ENABLE, + HWMON_PWM_INPUT | HWMON_PWM_ENABLE), + 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 int cros_ec_hwmon_cooling_get_max_state(struct thermal_cooling_device *cdev, + unsigned long *val) +{ + *val = 255; + return 0; +} + +static int cros_ec_hwmon_cooling_get_cur_state(struct thermal_cooling_device *cdev, + unsigned long *val) +{ + const struct cros_ec_hwmon_cooling_priv *priv = cdev->devdata; + u8 read_val; + int ret; + + ret = cros_ec_hwmon_read_pwm_value(priv->hwmon_priv->cros_ec, priv->index, &read_val); + if (ret) + return ret; + + *val = read_val; + return 0; +} + +static int cros_ec_hwmon_cooling_set_cur_state(struct thermal_cooling_device *cdev, + unsigned long val) +{ + const struct cros_ec_hwmon_cooling_priv *priv = cdev->devdata; + + return cros_ec_hwmon_write_pwm_input(priv->hwmon_priv->cros_ec, priv->index, val); +} + +static const struct thermal_cooling_device_ops cros_ec_thermal_cooling_ops = { + .get_max_state = cros_ec_hwmon_cooling_get_max_state, + .get_cur_state = cros_ec_hwmon_cooling_get_cur_state, + .set_cur_state = cros_ec_hwmon_cooling_set_cur_state, +}; + +static const struct hwmon_ops cros_ec_hwmon_ops = { + .read = cros_ec_hwmon_read, + .read_string = cros_ec_hwmon_read_string, + .write = cros_ec_hwmon_write, + .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 inline bool is_cros_ec_cmd_available(struct cros_ec_device *cros_ec, + u16 cmd, u8 version) +{ + int ret; + + ret = cros_ec_get_cmd_versions(cros_ec, cmd); + return ret >= 0 && (ret & EC_VER_MASK(version)); +} + +static bool cros_ec_hwmon_probe_fan_control_supported(struct cros_ec_device *cros_ec) +{ + return is_cros_ec_cmd_available(cros_ec, EC_CMD_PWM_GET_FAN_DUTY, + CROS_EC_HWMON_PWM_GET_FAN_DUTY_CMD_VERSION) && + is_cros_ec_cmd_available(cros_ec, EC_CMD_PWM_SET_FAN_DUTY, + CROS_EC_HWMON_PWM_SET_FAN_DUTY_CMD_VERSION) && + is_cros_ec_cmd_available(cros_ec, EC_CMD_THERMAL_AUTO_FAN_CTRL, + CROS_EC_HWMON_THERMAL_AUTO_FAN_CTRL_CMD_VERSION); +} + +static void cros_ec_hwmon_register_fan_cooling_devices(struct device *dev, + struct cros_ec_hwmon_priv *priv) +{ + struct cros_ec_hwmon_cooling_priv *cpriv; + struct thermal_cooling_device *cdev; + const char *type; + size_t i; + + if (!IS_ENABLED(CONFIG_THERMAL)) + return; + + if (!priv->fan_control_supported) + return; + + for (i = 0; i < EC_FAN_SPEED_ENTRIES; i++) { + if (!(priv->usable_fans & BIT(i))) + continue; + + cpriv = devm_kzalloc(dev, sizeof(*cpriv), GFP_KERNEL); + if (!cpriv) + continue; + + type = devm_kasprintf(dev, GFP_KERNEL, "%s-fan%zu", dev_name(dev), i); + if (!type) { + dev_warn(dev, "no memory to compose cooling device type for fan %zu\n", i); + continue; + } + + cpriv->hwmon_priv = priv; + cpriv->index = i; + cdev = devm_thermal_of_cooling_device_register(dev, NULL, type, cpriv, + &cros_ec_thermal_cooling_ops); + if (IS_ERR(cdev)) { + dev_warn(dev, "failed to register fan %zu as a cooling device: %pe\n", i, + cdev); + continue; + } + } +} + +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); + priv->fan_control_supported = cros_ec_hwmon_probe_fan_control_supported(priv->cros_ec); + cros_ec_hwmon_register_fan_cooling_devices(dev, priv); + + hwmon_dev = devm_hwmon_device_register_with_info(dev, "cros_ec", priv, + &cros_ec_hwmon_chip_info, NULL); + platform_set_drvdata(pdev, priv); + + return PTR_ERR_OR_ZERO(hwmon_dev); +} + +static int cros_ec_hwmon_suspend(struct platform_device *pdev, pm_message_t state) +{ + struct cros_ec_hwmon_priv *priv = platform_get_drvdata(pdev); + u8 control_method; + size_t i; + int ret; + + if (!priv->fan_control_supported) + return 0; + + /* EC sets fan control to auto after suspended, store settings before suspending. */ + for (i = 0; i < EC_FAN_SPEED_ENTRIES; i++) { + if (!(priv->usable_fans & BIT(i))) + continue; + + ret = cros_ec_hwmon_read_pwm_enable(priv->cros_ec, i, &control_method); + if (ret) { + dev_warn(&pdev->dev, "failed to get mode setting for fan %zu: %d\n", i, + ret); + continue; + } + + if (control_method != 1) { + priv->manual_fans &= ~BIT(i); + continue; + } else { + priv->manual_fans |= BIT(i); + } + + ret = cros_ec_hwmon_read_pwm_value(priv->cros_ec, i, &priv->manual_fan_pwm[i]); + /* + * If storing the value failed, invalidate the stored mode value by setting it + * to auto control. EC will automatically switch to auto mode for that fan after + * suspended. + */ + if (ret) { + dev_warn(&pdev->dev, "failed to get PWM setting for fan %zu: %pe\n", i, + ERR_PTR(ret)); + priv->manual_fans &= ~BIT(i); + continue; + } + } + + return 0; +} + +static int cros_ec_hwmon_resume(struct platform_device *pdev) +{ + const struct cros_ec_hwmon_priv *priv = platform_get_drvdata(pdev); + size_t i; + int ret; + + if (!priv->fan_control_supported) + return 0; + + /* EC sets fan control to auto after suspend, restore to settings before suspend. */ + for (i = 0; i < EC_FAN_SPEED_ENTRIES; i++) { + if (!(priv->manual_fans & BIT(i))) + continue; + + /* + * Setting fan PWM value to EC will change the mode to manual for that fan in EC as + * well, so we do not need to issue a separate fan mode to manual call. + */ + ret = cros_ec_hwmon_set_fan_pwm_val(priv->cros_ec, i, priv->manual_fan_pwm[i]); + if (ret) + dev_warn(&pdev->dev, "failed to restore settings for fan %zu: %pe\n", i, + ERR_PTR(ret)); + } + + return 0; +} + +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, + .suspend = pm_ptr(cros_ec_hwmon_suspend), + .resume = pm_ptr(cros_ec_hwmon_resume), + .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 <linux@weissschuh.net"); +MODULE_LICENSE("GPL"); |