1 /* 2 * System Control and Power Interface(SCPI) based hwmon sensor driver 3 * 4 * Copyright (C) 2015 ARM Ltd. 5 * Punit Agrawal <punit.agrawal@arm.com> 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 * 11 * This program is distributed "as is" WITHOUT ANY WARRANTY of any 12 * kind, whether express or implied; without even the implied warranty 13 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 */ 16 17 #include <linux/hwmon.h> 18 #include <linux/module.h> 19 #include <linux/platform_device.h> 20 #include <linux/scpi_protocol.h> 21 #include <linux/slab.h> 22 #include <linux/sysfs.h> 23 #include <linux/thermal.h> 24 25 struct sensor_data { 26 struct scpi_sensor_info info; 27 struct device_attribute dev_attr_input; 28 struct device_attribute dev_attr_label; 29 char input[20]; 30 char label[20]; 31 }; 32 33 struct scpi_thermal_zone { 34 struct list_head list; 35 int sensor_id; 36 struct scpi_sensors *scpi_sensors; 37 struct thermal_zone_device *tzd; 38 }; 39 40 struct scpi_sensors { 41 struct scpi_ops *scpi_ops; 42 struct sensor_data *data; 43 struct list_head thermal_zones; 44 struct attribute **attrs; 45 struct attribute_group group; 46 const struct attribute_group *groups[2]; 47 }; 48 49 static int scpi_read_temp(void *dev, int *temp) 50 { 51 struct scpi_thermal_zone *zone = dev; 52 struct scpi_sensors *scpi_sensors = zone->scpi_sensors; 53 struct scpi_ops *scpi_ops = scpi_sensors->scpi_ops; 54 struct sensor_data *sensor = &scpi_sensors->data[zone->sensor_id]; 55 u64 value; 56 int ret; 57 58 ret = scpi_ops->sensor_get_value(sensor->info.sensor_id, &value); 59 if (ret) 60 return ret; 61 62 *temp = value; 63 return 0; 64 } 65 66 /* hwmon callback functions */ 67 static ssize_t 68 scpi_show_sensor(struct device *dev, struct device_attribute *attr, char *buf) 69 { 70 struct scpi_sensors *scpi_sensors = dev_get_drvdata(dev); 71 struct scpi_ops *scpi_ops = scpi_sensors->scpi_ops; 72 struct sensor_data *sensor; 73 u64 value; 74 int ret; 75 76 sensor = container_of(attr, struct sensor_data, dev_attr_input); 77 78 ret = scpi_ops->sensor_get_value(sensor->info.sensor_id, &value); 79 if (ret) 80 return ret; 81 82 return sprintf(buf, "%llu\n", value); 83 } 84 85 static ssize_t 86 scpi_show_label(struct device *dev, struct device_attribute *attr, char *buf) 87 { 88 struct sensor_data *sensor; 89 90 sensor = container_of(attr, struct sensor_data, dev_attr_label); 91 92 return sprintf(buf, "%s\n", sensor->info.name); 93 } 94 95 static void 96 unregister_thermal_zones(struct platform_device *pdev, 97 struct scpi_sensors *scpi_sensors) 98 { 99 struct list_head *pos; 100 101 list_for_each(pos, &scpi_sensors->thermal_zones) { 102 struct scpi_thermal_zone *zone; 103 104 zone = list_entry(pos, struct scpi_thermal_zone, list); 105 thermal_zone_of_sensor_unregister(&pdev->dev, zone->tzd); 106 } 107 } 108 109 static struct thermal_zone_of_device_ops scpi_sensor_ops = { 110 .get_temp = scpi_read_temp, 111 }; 112 113 static int scpi_hwmon_probe(struct platform_device *pdev) 114 { 115 u16 nr_sensors, i; 116 int num_temp = 0, num_volt = 0, num_current = 0, num_power = 0; 117 int num_energy = 0; 118 struct scpi_ops *scpi_ops; 119 struct device *hwdev, *dev = &pdev->dev; 120 struct scpi_sensors *scpi_sensors; 121 int ret, idx; 122 123 scpi_ops = get_scpi_ops(); 124 if (!scpi_ops) 125 return -EPROBE_DEFER; 126 127 ret = scpi_ops->sensor_get_capability(&nr_sensors); 128 if (ret) 129 return ret; 130 131 if (!nr_sensors) 132 return -ENODEV; 133 134 scpi_sensors = devm_kzalloc(dev, sizeof(*scpi_sensors), GFP_KERNEL); 135 if (!scpi_sensors) 136 return -ENOMEM; 137 138 scpi_sensors->data = devm_kcalloc(dev, nr_sensors, 139 sizeof(*scpi_sensors->data), GFP_KERNEL); 140 if (!scpi_sensors->data) 141 return -ENOMEM; 142 143 scpi_sensors->attrs = devm_kcalloc(dev, (nr_sensors * 2) + 1, 144 sizeof(*scpi_sensors->attrs), GFP_KERNEL); 145 if (!scpi_sensors->attrs) 146 return -ENOMEM; 147 148 scpi_sensors->scpi_ops = scpi_ops; 149 150 for (i = 0, idx = 0; i < nr_sensors; i++) { 151 struct sensor_data *sensor = &scpi_sensors->data[idx]; 152 153 ret = scpi_ops->sensor_get_info(i, &sensor->info); 154 if (ret) 155 return ret; 156 157 switch (sensor->info.class) { 158 case TEMPERATURE: 159 snprintf(sensor->input, sizeof(sensor->input), 160 "temp%d_input", num_temp + 1); 161 snprintf(sensor->label, sizeof(sensor->input), 162 "temp%d_label", num_temp + 1); 163 num_temp++; 164 break; 165 case VOLTAGE: 166 snprintf(sensor->input, sizeof(sensor->input), 167 "in%d_input", num_volt); 168 snprintf(sensor->label, sizeof(sensor->input), 169 "in%d_label", num_volt); 170 num_volt++; 171 break; 172 case CURRENT: 173 snprintf(sensor->input, sizeof(sensor->input), 174 "curr%d_input", num_current + 1); 175 snprintf(sensor->label, sizeof(sensor->input), 176 "curr%d_label", num_current + 1); 177 num_current++; 178 break; 179 case POWER: 180 snprintf(sensor->input, sizeof(sensor->input), 181 "power%d_input", num_power + 1); 182 snprintf(sensor->label, sizeof(sensor->input), 183 "power%d_label", num_power + 1); 184 num_power++; 185 break; 186 case ENERGY: 187 snprintf(sensor->input, sizeof(sensor->input), 188 "energy%d_input", num_energy + 1); 189 snprintf(sensor->label, sizeof(sensor->input), 190 "energy%d_label", num_energy + 1); 191 num_energy++; 192 break; 193 default: 194 continue; 195 } 196 197 sensor->dev_attr_input.attr.mode = S_IRUGO; 198 sensor->dev_attr_input.show = scpi_show_sensor; 199 sensor->dev_attr_input.attr.name = sensor->input; 200 201 sensor->dev_attr_label.attr.mode = S_IRUGO; 202 sensor->dev_attr_label.show = scpi_show_label; 203 sensor->dev_attr_label.attr.name = sensor->label; 204 205 scpi_sensors->attrs[idx << 1] = &sensor->dev_attr_input.attr; 206 scpi_sensors->attrs[(idx << 1) + 1] = &sensor->dev_attr_label.attr; 207 208 sysfs_attr_init(scpi_sensors->attrs[idx << 1]); 209 sysfs_attr_init(scpi_sensors->attrs[(idx << 1) + 1]); 210 idx++; 211 } 212 213 scpi_sensors->group.attrs = scpi_sensors->attrs; 214 scpi_sensors->groups[0] = &scpi_sensors->group; 215 216 platform_set_drvdata(pdev, scpi_sensors); 217 218 hwdev = devm_hwmon_device_register_with_groups(dev, 219 "scpi_sensors", scpi_sensors, scpi_sensors->groups); 220 221 if (IS_ERR(hwdev)) 222 return PTR_ERR(hwdev); 223 224 /* 225 * Register the temperature sensors with the thermal framework 226 * to allow their usage in setting up the thermal zones from 227 * device tree. 228 * 229 * NOTE: Not all temperature sensors maybe used for thermal 230 * control 231 */ 232 INIT_LIST_HEAD(&scpi_sensors->thermal_zones); 233 for (i = 0; i < nr_sensors; i++) { 234 struct sensor_data *sensor = &scpi_sensors->data[i]; 235 struct scpi_thermal_zone *zone; 236 237 if (sensor->info.class != TEMPERATURE) 238 continue; 239 240 zone = devm_kzalloc(dev, sizeof(*zone), GFP_KERNEL); 241 if (!zone) { 242 ret = -ENOMEM; 243 goto unregister_tzd; 244 } 245 246 zone->sensor_id = i; 247 zone->scpi_sensors = scpi_sensors; 248 zone->tzd = thermal_zone_of_sensor_register(dev, 249 sensor->info.sensor_id, zone, &scpi_sensor_ops); 250 /* 251 * The call to thermal_zone_of_sensor_register returns 252 * an error for sensors that are not associated with 253 * any thermal zones or if the thermal subsystem is 254 * not configured. 255 */ 256 if (IS_ERR(zone->tzd)) { 257 devm_kfree(dev, zone); 258 continue; 259 } 260 list_add(&zone->list, &scpi_sensors->thermal_zones); 261 } 262 263 return 0; 264 265 unregister_tzd: 266 unregister_thermal_zones(pdev, scpi_sensors); 267 return ret; 268 } 269 270 static int scpi_hwmon_remove(struct platform_device *pdev) 271 { 272 struct scpi_sensors *scpi_sensors = platform_get_drvdata(pdev); 273 274 unregister_thermal_zones(pdev, scpi_sensors); 275 276 return 0; 277 } 278 279 static const struct of_device_id scpi_of_match[] = { 280 {.compatible = "arm,scpi-sensors"}, 281 {}, 282 }; 283 284 static struct platform_driver scpi_hwmon_platdrv = { 285 .driver = { 286 .name = "scpi-hwmon", 287 .owner = THIS_MODULE, 288 .of_match_table = scpi_of_match, 289 }, 290 .probe = scpi_hwmon_probe, 291 .remove = scpi_hwmon_remove, 292 }; 293 module_platform_driver(scpi_hwmon_platdrv); 294 295 MODULE_AUTHOR("Punit Agrawal <punit.agrawal@arm.com>"); 296 MODULE_DESCRIPTION("ARM SCPI HWMON interface driver"); 297 MODULE_LICENSE("GPL v2"); 298