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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 | // SPDX-License-Identifier: GPL-2.0 /* * System Control and Power Interface(SCPI) based hwmon sensor driver * * Copyright (C) 2015 ARM Ltd. * Punit Agrawal <punit.agrawal@arm.com> */ #include <linux/hwmon.h> #include <linux/module.h> #include <linux/of_device.h> #include <linux/platform_device.h> #include <linux/scpi_protocol.h> #include <linux/slab.h> #include <linux/sysfs.h> #include <linux/thermal.h> struct sensor_data { unsigned int scale; struct scpi_sensor_info info; struct device_attribute dev_attr_input; struct device_attribute dev_attr_label; char input[20]; char label[20]; }; struct scpi_thermal_zone { int sensor_id; struct scpi_sensors *scpi_sensors; }; struct scpi_sensors { struct scpi_ops *scpi_ops; struct sensor_data *data; struct list_head thermal_zones; struct attribute **attrs; struct attribute_group group; const struct attribute_group *groups[2]; }; static const u32 gxbb_scpi_scale[] = { [TEMPERATURE] = 1, /* (celsius) */ [VOLTAGE] = 1000, /* (millivolts) */ [CURRENT] = 1000, /* (milliamperes) */ [POWER] = 1000000, /* (microwatts) */ [ENERGY] = 1000000, /* (microjoules) */ }; static const u32 scpi_scale[] = { [TEMPERATURE] = 1000, /* (millicelsius) */ [VOLTAGE] = 1000, /* (millivolts) */ [CURRENT] = 1000, /* (milliamperes) */ [POWER] = 1000000, /* (microwatts) */ [ENERGY] = 1000000, /* (microjoules) */ }; static void scpi_scale_reading(u64 *value, struct sensor_data *sensor) { if (scpi_scale[sensor->info.class] != sensor->scale) { *value *= scpi_scale[sensor->info.class]; do_div(*value, sensor->scale); } } static int scpi_read_temp(struct thermal_zone_device *tz, int *temp) { struct scpi_thermal_zone *zone = tz->devdata; struct scpi_sensors *scpi_sensors = zone->scpi_sensors; struct scpi_ops *scpi_ops = scpi_sensors->scpi_ops; struct sensor_data *sensor = &scpi_sensors->data[zone->sensor_id]; u64 value; int ret; ret = scpi_ops->sensor_get_value(sensor->info.sensor_id, &value); if (ret) return ret; scpi_scale_reading(&value, sensor); *temp = value; return 0; } /* hwmon callback functions */ static ssize_t scpi_show_sensor(struct device *dev, struct device_attribute *attr, char *buf) { struct scpi_sensors *scpi_sensors = dev_get_drvdata(dev); struct scpi_ops *scpi_ops = scpi_sensors->scpi_ops; struct sensor_data *sensor; u64 value; int ret; sensor = container_of(attr, struct sensor_data, dev_attr_input); ret = scpi_ops->sensor_get_value(sensor->info.sensor_id, &value); if (ret) return ret; scpi_scale_reading(&value, sensor); /* * Temperature sensor values are treated as signed values based on * observation even though that is not explicitly specified, and * because an unsigned u64 temperature does not really make practical * sense especially when the temperature is below zero degrees Celsius. */ if (sensor->info.class == TEMPERATURE) return sprintf(buf, "%lld\n", (s64)value); return sprintf(buf, "%llu\n", value); } static ssize_t scpi_show_label(struct device *dev, struct device_attribute *attr, char *buf) { struct sensor_data *sensor; sensor = container_of(attr, struct sensor_data, dev_attr_label); return sprintf(buf, "%s\n", sensor->info.name); } static const struct thermal_zone_device_ops scpi_sensor_ops = { .get_temp = scpi_read_temp, }; static const struct of_device_id scpi_of_match[] = { {.compatible = "arm,scpi-sensors", .data = &scpi_scale}, {.compatible = "amlogic,meson-gxbb-scpi-sensors", .data = &gxbb_scpi_scale}, {}, }; MODULE_DEVICE_TABLE(of, scpi_of_match); static int scpi_hwmon_probe(struct platform_device *pdev) { u16 nr_sensors, i; const u32 *scale; int num_temp = 0, num_volt = 0, num_current = 0, num_power = 0; int num_energy = 0; struct scpi_ops *scpi_ops; struct device *hwdev, *dev = &pdev->dev; struct scpi_sensors *scpi_sensors; int idx, ret; scpi_ops = get_scpi_ops(); if (!scpi_ops) return -EPROBE_DEFER; ret = scpi_ops->sensor_get_capability(&nr_sensors); if (ret) return ret; if (!nr_sensors) return -ENODEV; scpi_sensors = devm_kzalloc(dev, sizeof(*scpi_sensors), GFP_KERNEL); if (!scpi_sensors) return -ENOMEM; scpi_sensors->data = devm_kcalloc(dev, nr_sensors, sizeof(*scpi_sensors->data), GFP_KERNEL); if (!scpi_sensors->data) return -ENOMEM; scpi_sensors->attrs = devm_kcalloc(dev, (nr_sensors * 2) + 1, sizeof(*scpi_sensors->attrs), GFP_KERNEL); if (!scpi_sensors->attrs) return -ENOMEM; scpi_sensors->scpi_ops = scpi_ops; scale = of_device_get_match_data(&pdev->dev); if (!scale) { dev_err(&pdev->dev, "Unable to initialize scpi-hwmon data\n"); return -ENODEV; } for (i = 0, idx = 0; i < nr_sensors; i++) { struct sensor_data *sensor = &scpi_sensors->data[idx]; ret = scpi_ops->sensor_get_info(i, &sensor->info); if (ret) return ret; switch (sensor->info.class) { case TEMPERATURE: snprintf(sensor->input, sizeof(sensor->input), "temp%d_input", num_temp + 1); snprintf(sensor->label, sizeof(sensor->input), "temp%d_label", num_temp + 1); num_temp++; break; case VOLTAGE: snprintf(sensor->input, sizeof(sensor->input), "in%d_input", num_volt); snprintf(sensor->label, sizeof(sensor->input), "in%d_label", num_volt); num_volt++; break; case CURRENT: snprintf(sensor->input, sizeof(sensor->input), "curr%d_input", num_current + 1); snprintf(sensor->label, sizeof(sensor->input), "curr%d_label", num_current + 1); num_current++; break; case POWER: snprintf(sensor->input, sizeof(sensor->input), "power%d_input", num_power + 1); snprintf(sensor->label, sizeof(sensor->input), "power%d_label", num_power + 1); num_power++; break; case ENERGY: snprintf(sensor->input, sizeof(sensor->input), "energy%d_input", num_energy + 1); snprintf(sensor->label, sizeof(sensor->input), "energy%d_label", num_energy + 1); num_energy++; break; default: continue; } sensor->scale = scale[sensor->info.class]; sensor->dev_attr_input.attr.mode = 0444; sensor->dev_attr_input.show = scpi_show_sensor; sensor->dev_attr_input.attr.name = sensor->input; sensor->dev_attr_label.attr.mode = 0444; sensor->dev_attr_label.show = scpi_show_label; sensor->dev_attr_label.attr.name = sensor->label; scpi_sensors->attrs[idx << 1] = &sensor->dev_attr_input.attr; scpi_sensors->attrs[(idx << 1) + 1] = &sensor->dev_attr_label.attr; sysfs_attr_init(scpi_sensors->attrs[idx << 1]); sysfs_attr_init(scpi_sensors->attrs[(idx << 1) + 1]); idx++; } scpi_sensors->group.attrs = scpi_sensors->attrs; scpi_sensors->groups[0] = &scpi_sensors->group; platform_set_drvdata(pdev, scpi_sensors); hwdev = devm_hwmon_device_register_with_groups(dev, "scpi_sensors", scpi_sensors, scpi_sensors->groups); if (IS_ERR(hwdev)) return PTR_ERR(hwdev); /* * Register the temperature sensors with the thermal framework * to allow their usage in setting up the thermal zones from * device tree. * * NOTE: Not all temperature sensors maybe used for thermal * control */ INIT_LIST_HEAD(&scpi_sensors->thermal_zones); for (i = 0; i < nr_sensors; i++) { struct sensor_data *sensor = &scpi_sensors->data[i]; struct thermal_zone_device *z; struct scpi_thermal_zone *zone; if (sensor->info.class != TEMPERATURE) continue; zone = devm_kzalloc(dev, sizeof(*zone), GFP_KERNEL); if (!zone) return -ENOMEM; zone->sensor_id = i; zone->scpi_sensors = scpi_sensors; z = devm_thermal_of_zone_register(dev, sensor->info.sensor_id, zone, &scpi_sensor_ops); /* * The call to thermal_zone_of_sensor_register returns * an error for sensors that are not associated with * any thermal zones or if the thermal subsystem is * not configured. */ if (IS_ERR(z)) devm_kfree(dev, zone); } return 0; } static struct platform_driver scpi_hwmon_platdrv = { .driver = { .name = "scpi-hwmon", .of_match_table = scpi_of_match, }, .probe = scpi_hwmon_probe, }; module_platform_driver(scpi_hwmon_platdrv); MODULE_AUTHOR("Punit Agrawal <punit.agrawal@arm.com>"); MODULE_DESCRIPTION("ARM SCPI HWMON interface driver"); MODULE_LICENSE("GPL v2"); |