|
| 1 | +// SPDX-License-Identifier: GPL-2.0-or-later |
| 2 | +/* |
| 3 | + * ChromeOS EC driver for hwmon |
| 4 | + * |
| 5 | + * Copyright (C) 2024 Thomas Weißschuh <[email protected]> |
| 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 | + |
| 20 | +struct 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 | + |
| 26 | +static 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 | + |
| 39 | +static 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 | + else |
| 47 | + 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 | + |
| 55 | +static 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 | + |
| 60 | +static 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 | + |
| 68 | +static long cros_ec_hwmon_temp_to_millicelsius(u8 temp) |
| 69 | +{ |
| 70 | + return kelvin_to_millicelsius((((long)temp) + EC_TEMP_SENSOR_OFFSET)); |
| 71 | +} |
| 72 | + |
| 73 | +static 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 | + else |
| 88 | + *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 | + else |
| 102 | + *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 | + |
| 114 | +static 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 | + |
| 127 | +static 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 | + |
| 143 | +static 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 | + NULL |
| 175 | +}; |
| 176 | + |
| 177 | +static 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 | + |
| 183 | +static const struct hwmon_chip_info cros_ec_hwmon_chip_info = { |
| 184 | + .ops = &cros_ec_hwmon_ops, |
| 185 | + .info = cros_ec_hwmon_info, |
| 186 | +}; |
| 187 | + |
| 188 | +static 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 | + else |
| 200 | + 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 | + |
| 222 | +static 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 | + |
| 235 | +static 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 | + |
| 268 | +static const struct platform_device_id cros_ec_hwmon_id[] = { |
| 269 | + { DRV_NAME, 0 }, |
| 270 | + {} |
| 271 | +}; |
| 272 | + |
| 273 | +static 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 | +}; |
| 278 | +module_platform_driver(cros_ec_hwmon_driver); |
| 279 | + |
| 280 | +MODULE_DEVICE_TABLE(platform, cros_ec_hwmon_id); |
| 281 | +MODULE_DESCRIPTION("ChromeOS EC Hardware Monitoring Driver"); |
| 282 | +MODULE_AUTHOR( "Thomas Weißschuh <[email protected]"); |
| 283 | +MODULE_LICENSE("GPL"); |
0 commit comments