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