284 lines · c
1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * ChromeOS EC driver for hwmon4 *5 * Copyright (C) 2024 Thomas Weißschuh <linux@weissschuh.net>6 */7 8#include <linux/device.h>9#include <linux/hwmon.h>10#include <linux/mod_devicetable.h>11#include <linux/module.h>12#include <linux/platform_device.h>13#include <linux/platform_data/cros_ec_commands.h>14#include <linux/platform_data/cros_ec_proto.h>15#include <linux/types.h>16#include <linux/units.h>17 18#define DRV_NAME "cros-ec-hwmon"19 20struct cros_ec_hwmon_priv {21 struct cros_ec_device *cros_ec;22 const char *temp_sensor_names[EC_TEMP_SENSOR_ENTRIES + EC_TEMP_SENSOR_B_ENTRIES];23 u8 usable_fans;24};25 26static int cros_ec_hwmon_read_fan_speed(struct cros_ec_device *cros_ec, u8 index, u16 *speed)27{28 int ret;29 __le16 __speed;30 31 ret = cros_ec_cmd_readmem(cros_ec, EC_MEMMAP_FAN + index * 2, 2, &__speed);32 if (ret < 0)33 return ret;34 35 *speed = le16_to_cpu(__speed);36 return 0;37}38 39static int cros_ec_hwmon_read_temp(struct cros_ec_device *cros_ec, u8 index, u8 *temp)40{41 unsigned int offset;42 int ret;43 44 if (index < EC_TEMP_SENSOR_ENTRIES)45 offset = EC_MEMMAP_TEMP_SENSOR + index;46 else47 offset = EC_MEMMAP_TEMP_SENSOR_B + index - EC_TEMP_SENSOR_ENTRIES;48 49 ret = cros_ec_cmd_readmem(cros_ec, offset, 1, temp);50 if (ret < 0)51 return ret;52 return 0;53}54 55static bool cros_ec_hwmon_is_error_fan(u16 speed)56{57 return speed == EC_FAN_SPEED_NOT_PRESENT || speed == EC_FAN_SPEED_STALLED;58}59 60static bool cros_ec_hwmon_is_error_temp(u8 temp)61{62 return temp == EC_TEMP_SENSOR_NOT_PRESENT ||63 temp == EC_TEMP_SENSOR_ERROR ||64 temp == EC_TEMP_SENSOR_NOT_POWERED ||65 temp == EC_TEMP_SENSOR_NOT_CALIBRATED;66}67 68static long cros_ec_hwmon_temp_to_millicelsius(u8 temp)69{70 return kelvin_to_millicelsius((((long)temp) + EC_TEMP_SENSOR_OFFSET));71}72 73static int cros_ec_hwmon_read(struct device *dev, enum hwmon_sensor_types type,74 u32 attr, int channel, long *val)75{76 struct cros_ec_hwmon_priv *priv = dev_get_drvdata(dev);77 int ret = -EOPNOTSUPP;78 u16 speed;79 u8 temp;80 81 if (type == hwmon_fan) {82 if (attr == hwmon_fan_input) {83 ret = cros_ec_hwmon_read_fan_speed(priv->cros_ec, channel, &speed);84 if (ret == 0) {85 if (cros_ec_hwmon_is_error_fan(speed))86 ret = -ENODATA;87 else88 *val = speed;89 }90 } else if (attr == hwmon_fan_fault) {91 ret = cros_ec_hwmon_read_fan_speed(priv->cros_ec, channel, &speed);92 if (ret == 0)93 *val = cros_ec_hwmon_is_error_fan(speed);94 }95 } else if (type == hwmon_temp) {96 if (attr == hwmon_temp_input) {97 ret = cros_ec_hwmon_read_temp(priv->cros_ec, channel, &temp);98 if (ret == 0) {99 if (cros_ec_hwmon_is_error_temp(temp))100 ret = -ENODATA;101 else102 *val = cros_ec_hwmon_temp_to_millicelsius(temp);103 }104 } else if (attr == hwmon_temp_fault) {105 ret = cros_ec_hwmon_read_temp(priv->cros_ec, channel, &temp);106 if (ret == 0)107 *val = cros_ec_hwmon_is_error_temp(temp);108 }109 }110 111 return ret;112}113 114static int cros_ec_hwmon_read_string(struct device *dev, enum hwmon_sensor_types type,115 u32 attr, int channel, const char **str)116{117 struct cros_ec_hwmon_priv *priv = dev_get_drvdata(dev);118 119 if (type == hwmon_temp && attr == hwmon_temp_label) {120 *str = priv->temp_sensor_names[channel];121 return 0;122 }123 124 return -EOPNOTSUPP;125}126 127static umode_t cros_ec_hwmon_is_visible(const void *data, enum hwmon_sensor_types type,128 u32 attr, int channel)129{130 const struct cros_ec_hwmon_priv *priv = data;131 132 if (type == hwmon_fan) {133 if (priv->usable_fans & BIT(channel))134 return 0444;135 } else if (type == hwmon_temp) {136 if (priv->temp_sensor_names[channel])137 return 0444;138 }139 140 return 0;141}142 143static const struct hwmon_channel_info * const cros_ec_hwmon_info[] = {144 HWMON_CHANNEL_INFO(fan,145 HWMON_F_INPUT | HWMON_F_FAULT,146 HWMON_F_INPUT | HWMON_F_FAULT,147 HWMON_F_INPUT | HWMON_F_FAULT,148 HWMON_F_INPUT | HWMON_F_FAULT),149 HWMON_CHANNEL_INFO(temp,150 HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL,151 HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL,152 HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL,153 HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL,154 HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL,155 HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL,156 HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL,157 HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL,158 HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL,159 HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL,160 HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL,161 HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL,162 HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL,163 HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL,164 HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL,165 HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL,166 HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL,167 HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL,168 HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL,169 HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL,170 HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL,171 HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL,172 HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL,173 HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_LABEL),174 NULL175};176 177static const struct hwmon_ops cros_ec_hwmon_ops = {178 .read = cros_ec_hwmon_read,179 .read_string = cros_ec_hwmon_read_string,180 .is_visible = cros_ec_hwmon_is_visible,181};182 183static const struct hwmon_chip_info cros_ec_hwmon_chip_info = {184 .ops = &cros_ec_hwmon_ops,185 .info = cros_ec_hwmon_info,186};187 188static void cros_ec_hwmon_probe_temp_sensors(struct device *dev, struct cros_ec_hwmon_priv *priv,189 u8 thermal_version)190{191 struct ec_params_temp_sensor_get_info req = {};192 struct ec_response_temp_sensor_get_info resp;193 size_t candidates, i, sensor_name_size;194 int ret;195 u8 temp;196 197 if (thermal_version < 2)198 candidates = EC_TEMP_SENSOR_ENTRIES;199 else200 candidates = ARRAY_SIZE(priv->temp_sensor_names);201 202 for (i = 0; i < candidates; i++) {203 if (cros_ec_hwmon_read_temp(priv->cros_ec, i, &temp) < 0)204 continue;205 206 if (temp == EC_TEMP_SENSOR_NOT_PRESENT)207 continue;208 209 req.id = i;210 ret = cros_ec_cmd(priv->cros_ec, 0, EC_CMD_TEMP_SENSOR_GET_INFO,211 &req, sizeof(req), &resp, sizeof(resp));212 if (ret < 0)213 continue;214 215 sensor_name_size = strnlen(resp.sensor_name, sizeof(resp.sensor_name));216 priv->temp_sensor_names[i] = devm_kasprintf(dev, GFP_KERNEL, "%.*s",217 (int)sensor_name_size,218 resp.sensor_name);219 }220}221 222static void cros_ec_hwmon_probe_fans(struct cros_ec_hwmon_priv *priv)223{224 u16 speed;225 size_t i;226 int ret;227 228 for (i = 0; i < EC_FAN_SPEED_ENTRIES; i++) {229 ret = cros_ec_hwmon_read_fan_speed(priv->cros_ec, i, &speed);230 if (ret == 0 && speed != EC_FAN_SPEED_NOT_PRESENT)231 priv->usable_fans |= BIT(i);232 }233}234 235static int cros_ec_hwmon_probe(struct platform_device *pdev)236{237 struct device *dev = &pdev->dev;238 struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent);239 struct cros_ec_device *cros_ec = ec_dev->ec_dev;240 struct cros_ec_hwmon_priv *priv;241 struct device *hwmon_dev;242 u8 thermal_version;243 int ret;244 245 ret = cros_ec_cmd_readmem(cros_ec, EC_MEMMAP_THERMAL_VERSION, 1, &thermal_version);246 if (ret < 0)247 return ret;248 249 /* Covers both fan and temp sensors */250 if (thermal_version == 0)251 return -ENODEV;252 253 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);254 if (!priv)255 return -ENOMEM;256 257 priv->cros_ec = cros_ec;258 259 cros_ec_hwmon_probe_temp_sensors(dev, priv, thermal_version);260 cros_ec_hwmon_probe_fans(priv);261 262 hwmon_dev = devm_hwmon_device_register_with_info(dev, "cros_ec", priv,263 &cros_ec_hwmon_chip_info, NULL);264 265 return PTR_ERR_OR_ZERO(hwmon_dev);266}267 268static const struct platform_device_id cros_ec_hwmon_id[] = {269 { DRV_NAME, 0 },270 {}271};272 273static struct platform_driver cros_ec_hwmon_driver = {274 .driver.name = DRV_NAME,275 .probe = cros_ec_hwmon_probe,276 .id_table = cros_ec_hwmon_id,277};278module_platform_driver(cros_ec_hwmon_driver);279 280MODULE_DEVICE_TABLE(platform, cros_ec_hwmon_id);281MODULE_DESCRIPTION("ChromeOS EC Hardware Monitoring Driver");282MODULE_AUTHOR("Thomas Weißschuh <linux@weissschuh.net");283MODULE_LICENSE("GPL");284