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1// SPDX-License-Identifier: GPL-2.02/*3 * System Control and Management Interface(SCMI) based hwmon sensor driver4 *5 * Copyright (C) 2018-2021 ARM Ltd.6 * Sudeep Holla <sudeep.holla@arm.com>7 */8 9#include <linux/hwmon.h>10#include <linux/module.h>11#include <linux/scmi_protocol.h>12#include <linux/slab.h>13#include <linux/sysfs.h>14#include <linux/thermal.h>15 16static const struct scmi_sensor_proto_ops *sensor_ops;17 18struct scmi_sensors {19 const struct scmi_protocol_handle *ph;20 const struct scmi_sensor_info **info[hwmon_max];21};22 23struct scmi_thermal_sensor {24 const struct scmi_protocol_handle *ph;25 const struct scmi_sensor_info *info;26};27 28static inline u64 __pow10(u8 x)29{30 u64 r = 1;31 32 while (x--)33 r *= 10;34 35 return r;36}37 38static int scmi_hwmon_scale(const struct scmi_sensor_info *sensor, u64 *value)39{40 int scale = sensor->scale;41 u64 f;42 43 switch (sensor->type) {44 case TEMPERATURE_C:45 case VOLTAGE:46 case CURRENT:47 scale += 3;48 break;49 case POWER:50 case ENERGY:51 scale += 6;52 break;53 default:54 break;55 }56 57 if (scale == 0)58 return 0;59 60 if (abs(scale) > 19)61 return -E2BIG;62 63 f = __pow10(abs(scale));64 if (scale > 0)65 *value *= f;66 else67 *value = div64_u64(*value, f);68 69 return 0;70}71 72static int scmi_hwmon_read_scaled_value(const struct scmi_protocol_handle *ph,73 const struct scmi_sensor_info *sensor,74 long *val)75{76 int ret;77 u64 value;78 79 ret = sensor_ops->reading_get(ph, sensor->id, &value);80 if (ret)81 return ret;82 83 ret = scmi_hwmon_scale(sensor, &value);84 if (!ret)85 *val = value;86 87 return ret;88}89 90static int scmi_hwmon_read(struct device *dev, enum hwmon_sensor_types type,91 u32 attr, int channel, long *val)92{93 const struct scmi_sensor_info *sensor;94 struct scmi_sensors *scmi_sensors = dev_get_drvdata(dev);95 96 sensor = *(scmi_sensors->info[type] + channel);97 98 return scmi_hwmon_read_scaled_value(scmi_sensors->ph, sensor, val);99}100 101static int102scmi_hwmon_read_string(struct device *dev, enum hwmon_sensor_types type,103 u32 attr, int channel, const char **str)104{105 const struct scmi_sensor_info *sensor;106 struct scmi_sensors *scmi_sensors = dev_get_drvdata(dev);107 108 sensor = *(scmi_sensors->info[type] + channel);109 *str = sensor->name;110 111 return 0;112}113 114static umode_t115scmi_hwmon_is_visible(const void *drvdata, enum hwmon_sensor_types type,116 u32 attr, int channel)117{118 const struct scmi_sensor_info *sensor;119 const struct scmi_sensors *scmi_sensors = drvdata;120 121 sensor = *(scmi_sensors->info[type] + channel);122 if (sensor)123 return 0444;124 125 return 0;126}127 128static const struct hwmon_ops scmi_hwmon_ops = {129 .is_visible = scmi_hwmon_is_visible,130 .read = scmi_hwmon_read,131 .read_string = scmi_hwmon_read_string,132};133 134static struct hwmon_chip_info scmi_chip_info = {135 .ops = &scmi_hwmon_ops,136 .info = NULL,137};138 139static int scmi_hwmon_thermal_get_temp(struct thermal_zone_device *tz,140 int *temp)141{142 int ret;143 long value;144 struct scmi_thermal_sensor *th_sensor = thermal_zone_device_priv(tz);145 146 ret = scmi_hwmon_read_scaled_value(th_sensor->ph, th_sensor->info,147 &value);148 if (!ret)149 *temp = value;150 151 return ret;152}153 154static const struct thermal_zone_device_ops scmi_hwmon_thermal_ops = {155 .get_temp = scmi_hwmon_thermal_get_temp,156};157 158static int scmi_hwmon_add_chan_info(struct hwmon_channel_info *scmi_hwmon_chan,159 struct device *dev, int num,160 enum hwmon_sensor_types type, u32 config)161{162 int i;163 u32 *cfg = devm_kcalloc(dev, num + 1, sizeof(*cfg), GFP_KERNEL);164 165 if (!cfg)166 return -ENOMEM;167 168 scmi_hwmon_chan->type = type;169 scmi_hwmon_chan->config = cfg;170 for (i = 0; i < num; i++, cfg++)171 *cfg = config;172 173 return 0;174}175 176static enum hwmon_sensor_types scmi_types[] = {177 [TEMPERATURE_C] = hwmon_temp,178 [VOLTAGE] = hwmon_in,179 [CURRENT] = hwmon_curr,180 [POWER] = hwmon_power,181 [ENERGY] = hwmon_energy,182};183 184static u32 hwmon_attributes[hwmon_max] = {185 [hwmon_temp] = HWMON_T_INPUT | HWMON_T_LABEL,186 [hwmon_in] = HWMON_I_INPUT | HWMON_I_LABEL,187 [hwmon_curr] = HWMON_C_INPUT | HWMON_C_LABEL,188 [hwmon_power] = HWMON_P_INPUT | HWMON_P_LABEL,189 [hwmon_energy] = HWMON_E_INPUT | HWMON_E_LABEL,190};191 192static int scmi_thermal_sensor_register(struct device *dev,193 const struct scmi_protocol_handle *ph,194 const struct scmi_sensor_info *sensor)195{196 struct scmi_thermal_sensor *th_sensor;197 struct thermal_zone_device *tzd;198 199 th_sensor = devm_kzalloc(dev, sizeof(*th_sensor), GFP_KERNEL);200 if (!th_sensor)201 return -ENOMEM;202 203 th_sensor->ph = ph;204 th_sensor->info = sensor;205 206 /*207 * Try to register a temperature sensor with the Thermal Framework:208 * skip sensors not defined as part of any thermal zone (-ENODEV) but209 * report any other errors related to misconfigured zones/sensors.210 */211 tzd = devm_thermal_of_zone_register(dev, th_sensor->info->id, th_sensor,212 &scmi_hwmon_thermal_ops);213 if (IS_ERR(tzd)) {214 devm_kfree(dev, th_sensor);215 216 if (PTR_ERR(tzd) != -ENODEV)217 return PTR_ERR(tzd);218 219 dev_dbg(dev, "Sensor '%s' not attached to any thermal zone.\n",220 sensor->name);221 } else {222 dev_dbg(dev, "Sensor '%s' attached to thermal zone ID:%d\n",223 sensor->name, thermal_zone_device_id(tzd));224 }225 226 return 0;227}228 229static int scmi_hwmon_probe(struct scmi_device *sdev)230{231 int i, idx;232 u16 nr_sensors;233 enum hwmon_sensor_types type;234 struct scmi_sensors *scmi_sensors;235 const struct scmi_sensor_info *sensor;236 int nr_count[hwmon_max] = {0}, nr_types = 0, nr_count_temp = 0;237 const struct hwmon_chip_info *chip_info;238 struct device *hwdev, *dev = &sdev->dev;239 struct hwmon_channel_info *scmi_hwmon_chan;240 const struct hwmon_channel_info **ptr_scmi_ci;241 const struct scmi_handle *handle = sdev->handle;242 struct scmi_protocol_handle *ph;243 244 if (!handle)245 return -ENODEV;246 247 sensor_ops = handle->devm_protocol_get(sdev, SCMI_PROTOCOL_SENSOR, &ph);248 if (IS_ERR(sensor_ops))249 return PTR_ERR(sensor_ops);250 251 nr_sensors = sensor_ops->count_get(ph);252 if (!nr_sensors)253 return -EIO;254 255 scmi_sensors = devm_kzalloc(dev, sizeof(*scmi_sensors), GFP_KERNEL);256 if (!scmi_sensors)257 return -ENOMEM;258 259 scmi_sensors->ph = ph;260 261 for (i = 0; i < nr_sensors; i++) {262 sensor = sensor_ops->info_get(ph, i);263 if (!sensor)264 return -EINVAL;265 266 switch (sensor->type) {267 case TEMPERATURE_C:268 case VOLTAGE:269 case CURRENT:270 case POWER:271 case ENERGY:272 type = scmi_types[sensor->type];273 if (!nr_count[type])274 nr_types++;275 nr_count[type]++;276 break;277 }278 }279 280 if (nr_count[hwmon_temp])281 nr_count_temp = nr_count[hwmon_temp];282 283 scmi_hwmon_chan = devm_kcalloc(dev, nr_types, sizeof(*scmi_hwmon_chan),284 GFP_KERNEL);285 if (!scmi_hwmon_chan)286 return -ENOMEM;287 288 ptr_scmi_ci = devm_kcalloc(dev, nr_types + 1, sizeof(*ptr_scmi_ci),289 GFP_KERNEL);290 if (!ptr_scmi_ci)291 return -ENOMEM;292 293 scmi_chip_info.info = ptr_scmi_ci;294 chip_info = &scmi_chip_info;295 296 for (type = 0; type < hwmon_max; type++) {297 if (!nr_count[type])298 continue;299 300 scmi_hwmon_add_chan_info(scmi_hwmon_chan, dev, nr_count[type],301 type, hwmon_attributes[type]);302 *ptr_scmi_ci++ = scmi_hwmon_chan++;303 304 scmi_sensors->info[type] =305 devm_kcalloc(dev, nr_count[type],306 sizeof(*scmi_sensors->info), GFP_KERNEL);307 if (!scmi_sensors->info[type])308 return -ENOMEM;309 }310 311 for (i = nr_sensors - 1; i >= 0 ; i--) {312 sensor = sensor_ops->info_get(ph, i);313 if (!sensor)314 continue;315 316 switch (sensor->type) {317 case TEMPERATURE_C:318 case VOLTAGE:319 case CURRENT:320 case POWER:321 case ENERGY:322 type = scmi_types[sensor->type];323 idx = --nr_count[type];324 *(scmi_sensors->info[type] + idx) = sensor;325 break;326 }327 }328 329 hwdev = devm_hwmon_device_register_with_info(dev, "scmi_sensors",330 scmi_sensors, chip_info,331 NULL);332 if (IS_ERR(hwdev))333 return PTR_ERR(hwdev);334 335 for (i = 0; i < nr_count_temp; i++) {336 int ret;337 338 sensor = *(scmi_sensors->info[hwmon_temp] + i);339 if (!sensor)340 continue;341 342 /*343 * Warn on any misconfiguration related to thermal zones but344 * bail out of probing only on memory errors.345 */346 ret = scmi_thermal_sensor_register(dev, ph, sensor);347 if (ret) {348 if (ret == -ENOMEM)349 return ret;350 dev_warn(dev,351 "Thermal zone misconfigured for %s. err=%d\n",352 sensor->name, ret);353 }354 }355 356 return 0;357}358 359static const struct scmi_device_id scmi_id_table[] = {360 { SCMI_PROTOCOL_SENSOR, "hwmon" },361 { },362};363MODULE_DEVICE_TABLE(scmi, scmi_id_table);364 365static struct scmi_driver scmi_hwmon_drv = {366 .name = "scmi-hwmon",367 .probe = scmi_hwmon_probe,368 .id_table = scmi_id_table,369};370module_scmi_driver(scmi_hwmon_drv);371 372MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");373MODULE_DESCRIPTION("ARM SCMI HWMON interface driver");374MODULE_LICENSE("GPL v2");375