1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * System Control and Management Interface(SCMI) based hwmon sensor driver 4 * 5 * Copyright (C) 2018 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 16 struct scmi_sensors { 17 const struct scmi_handle *handle; 18 const struct scmi_sensor_info **info[hwmon_max]; 19 }; 20 21 static inline u64 __pow10(u8 x) 22 { 23 u64 r = 1; 24 25 while (x--) 26 r *= 10; 27 28 return r; 29 } 30 31 static int scmi_hwmon_scale(const struct scmi_sensor_info *sensor, u64 *value) 32 { 33 s8 scale = sensor->scale; 34 u64 f; 35 36 switch (sensor->type) { 37 case TEMPERATURE_C: 38 case VOLTAGE: 39 case CURRENT: 40 scale += 3; 41 break; 42 case POWER: 43 case ENERGY: 44 scale += 6; 45 break; 46 default: 47 break; 48 } 49 50 if (scale == 0) 51 return 0; 52 53 if (abs(scale) > 19) 54 return -E2BIG; 55 56 f = __pow10(abs(scale)); 57 if (scale > 0) 58 *value *= f; 59 else 60 *value = div64_u64(*value, f); 61 62 return 0; 63 } 64 65 static int scmi_hwmon_read(struct device *dev, enum hwmon_sensor_types type, 66 u32 attr, int channel, long *val) 67 { 68 int ret; 69 u64 value; 70 const struct scmi_sensor_info *sensor; 71 struct scmi_sensors *scmi_sensors = dev_get_drvdata(dev); 72 const struct scmi_handle *h = scmi_sensors->handle; 73 74 sensor = *(scmi_sensors->info[type] + channel); 75 ret = h->sensor_ops->reading_get(h, sensor->id, &value); 76 if (ret) 77 return ret; 78 79 ret = scmi_hwmon_scale(sensor, &value); 80 if (!ret) 81 *val = value; 82 83 return ret; 84 } 85 86 static int 87 scmi_hwmon_read_string(struct device *dev, enum hwmon_sensor_types type, 88 u32 attr, int channel, const char **str) 89 { 90 const struct scmi_sensor_info *sensor; 91 struct scmi_sensors *scmi_sensors = dev_get_drvdata(dev); 92 93 sensor = *(scmi_sensors->info[type] + channel); 94 *str = sensor->name; 95 96 return 0; 97 } 98 99 static umode_t 100 scmi_hwmon_is_visible(const void *drvdata, enum hwmon_sensor_types type, 101 u32 attr, int channel) 102 { 103 const struct scmi_sensor_info *sensor; 104 const struct scmi_sensors *scmi_sensors = drvdata; 105 106 sensor = *(scmi_sensors->info[type] + channel); 107 if (sensor) 108 return 0444; 109 110 return 0; 111 } 112 113 static const struct hwmon_ops scmi_hwmon_ops = { 114 .is_visible = scmi_hwmon_is_visible, 115 .read = scmi_hwmon_read, 116 .read_string = scmi_hwmon_read_string, 117 }; 118 119 static struct hwmon_chip_info scmi_chip_info = { 120 .ops = &scmi_hwmon_ops, 121 .info = NULL, 122 }; 123 124 static int scmi_hwmon_add_chan_info(struct hwmon_channel_info *scmi_hwmon_chan, 125 struct device *dev, int num, 126 enum hwmon_sensor_types type, u32 config) 127 { 128 int i; 129 u32 *cfg = devm_kcalloc(dev, num + 1, sizeof(*cfg), GFP_KERNEL); 130 131 if (!cfg) 132 return -ENOMEM; 133 134 scmi_hwmon_chan->type = type; 135 scmi_hwmon_chan->config = cfg; 136 for (i = 0; i < num; i++, cfg++) 137 *cfg = config; 138 139 return 0; 140 } 141 142 static enum hwmon_sensor_types scmi_types[] = { 143 [TEMPERATURE_C] = hwmon_temp, 144 [VOLTAGE] = hwmon_in, 145 [CURRENT] = hwmon_curr, 146 [POWER] = hwmon_power, 147 [ENERGY] = hwmon_energy, 148 }; 149 150 static u32 hwmon_attributes[] = { 151 [hwmon_chip] = HWMON_C_REGISTER_TZ, 152 [hwmon_temp] = HWMON_T_INPUT | HWMON_T_LABEL, 153 [hwmon_in] = HWMON_I_INPUT | HWMON_I_LABEL, 154 [hwmon_curr] = HWMON_C_INPUT | HWMON_C_LABEL, 155 [hwmon_power] = HWMON_P_INPUT | HWMON_P_LABEL, 156 [hwmon_energy] = HWMON_E_INPUT | HWMON_E_LABEL, 157 }; 158 159 static int scmi_hwmon_probe(struct scmi_device *sdev) 160 { 161 int i, idx; 162 u16 nr_sensors; 163 enum hwmon_sensor_types type; 164 struct scmi_sensors *scmi_sensors; 165 const struct scmi_sensor_info *sensor; 166 int nr_count[hwmon_max] = {0}, nr_types = 0; 167 const struct hwmon_chip_info *chip_info; 168 struct device *hwdev, *dev = &sdev->dev; 169 struct hwmon_channel_info *scmi_hwmon_chan; 170 const struct hwmon_channel_info **ptr_scmi_ci; 171 const struct scmi_handle *handle = sdev->handle; 172 173 if (!handle || !handle->sensor_ops) 174 return -ENODEV; 175 176 nr_sensors = handle->sensor_ops->count_get(handle); 177 if (!nr_sensors) 178 return -EIO; 179 180 scmi_sensors = devm_kzalloc(dev, sizeof(*scmi_sensors), GFP_KERNEL); 181 if (!scmi_sensors) 182 return -ENOMEM; 183 184 scmi_sensors->handle = handle; 185 186 for (i = 0; i < nr_sensors; i++) { 187 sensor = handle->sensor_ops->info_get(handle, i); 188 if (!sensor) 189 return -EINVAL; 190 191 switch (sensor->type) { 192 case TEMPERATURE_C: 193 case VOLTAGE: 194 case CURRENT: 195 case POWER: 196 case ENERGY: 197 type = scmi_types[sensor->type]; 198 if (!nr_count[type]) 199 nr_types++; 200 nr_count[type]++; 201 break; 202 } 203 } 204 205 if (nr_count[hwmon_temp]) 206 nr_count[hwmon_chip]++, nr_types++; 207 208 scmi_hwmon_chan = devm_kcalloc(dev, nr_types, sizeof(*scmi_hwmon_chan), 209 GFP_KERNEL); 210 if (!scmi_hwmon_chan) 211 return -ENOMEM; 212 213 ptr_scmi_ci = devm_kcalloc(dev, nr_types + 1, sizeof(*ptr_scmi_ci), 214 GFP_KERNEL); 215 if (!ptr_scmi_ci) 216 return -ENOMEM; 217 218 scmi_chip_info.info = ptr_scmi_ci; 219 chip_info = &scmi_chip_info; 220 221 for (type = 0; type < hwmon_max; type++) { 222 if (!nr_count[type]) 223 continue; 224 225 scmi_hwmon_add_chan_info(scmi_hwmon_chan, dev, nr_count[type], 226 type, hwmon_attributes[type]); 227 *ptr_scmi_ci++ = scmi_hwmon_chan++; 228 229 scmi_sensors->info[type] = 230 devm_kcalloc(dev, nr_count[type], 231 sizeof(*scmi_sensors->info), GFP_KERNEL); 232 if (!scmi_sensors->info[type]) 233 return -ENOMEM; 234 } 235 236 for (i = nr_sensors - 1; i >= 0 ; i--) { 237 sensor = handle->sensor_ops->info_get(handle, i); 238 if (!sensor) 239 continue; 240 241 switch (sensor->type) { 242 case TEMPERATURE_C: 243 case VOLTAGE: 244 case CURRENT: 245 case POWER: 246 case ENERGY: 247 type = scmi_types[sensor->type]; 248 idx = --nr_count[type]; 249 *(scmi_sensors->info[type] + idx) = sensor; 250 break; 251 } 252 } 253 254 hwdev = devm_hwmon_device_register_with_info(dev, "scmi_sensors", 255 scmi_sensors, chip_info, 256 NULL); 257 258 return PTR_ERR_OR_ZERO(hwdev); 259 } 260 261 static const struct scmi_device_id scmi_id_table[] = { 262 { SCMI_PROTOCOL_SENSOR, "hwmon" }, 263 { }, 264 }; 265 MODULE_DEVICE_TABLE(scmi, scmi_id_table); 266 267 static struct scmi_driver scmi_hwmon_drv = { 268 .name = "scmi-hwmon", 269 .probe = scmi_hwmon_probe, 270 .id_table = scmi_id_table, 271 }; 272 module_scmi_driver(scmi_hwmon_drv); 273 274 MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>"); 275 MODULE_DESCRIPTION("ARM SCMI HWMON interface driver"); 276 MODULE_LICENSE("GPL v2"); 277