1 /* 2 * Copyright (C) 2017 IBM Corp. 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License as published by 6 * the Free Software Foundation; either version 2 of the License, or 7 * (at your option) any later version. 8 * 9 * Driver for the Nuvoton W83773G SMBus temperature sensor IC. 10 * Supported models: W83773G 11 */ 12 13 #include <linux/module.h> 14 #include <linux/init.h> 15 #include <linux/i2c.h> 16 #include <linux/hwmon.h> 17 #include <linux/hwmon-sysfs.h> 18 #include <linux/err.h> 19 #include <linux/of_device.h> 20 #include <linux/regmap.h> 21 22 /* W83773 has 3 channels */ 23 #define W83773_CHANNELS 3 24 25 /* The W83773 registers */ 26 #define W83773_CONVERSION_RATE_REG_READ 0x04 27 #define W83773_CONVERSION_RATE_REG_WRITE 0x0A 28 #define W83773_MANUFACTURER_ID_REG 0xFE 29 #define W83773_LOCAL_TEMP 0x00 30 31 static const u8 W83773_STATUS[2] = { 0x02, 0x17 }; 32 33 static const u8 W83773_TEMP_LSB[2] = { 0x10, 0x25 }; 34 static const u8 W83773_TEMP_MSB[2] = { 0x01, 0x24 }; 35 36 static const u8 W83773_OFFSET_LSB[2] = { 0x12, 0x16 }; 37 static const u8 W83773_OFFSET_MSB[2] = { 0x11, 0x15 }; 38 39 /* this is the number of sensors in the device */ 40 static const struct i2c_device_id w83773_id[] = { 41 { "w83773g" }, 42 { } 43 }; 44 45 MODULE_DEVICE_TABLE(i2c, w83773_id); 46 47 static const struct of_device_id w83773_of_match[] = { 48 { 49 .compatible = "nuvoton,w83773g" 50 }, 51 { }, 52 }; 53 MODULE_DEVICE_TABLE(of, w83773_of_match); 54 55 static inline long temp_of_local(s8 reg) 56 { 57 return reg * 1000; 58 } 59 60 static inline long temp_of_remote(s8 hb, u8 lb) 61 { 62 return (hb << 3 | lb >> 5) * 125; 63 } 64 65 static int get_local_temp(struct regmap *regmap, long *val) 66 { 67 unsigned int regval; 68 int ret; 69 70 ret = regmap_read(regmap, W83773_LOCAL_TEMP, ®val); 71 if (ret < 0) 72 return ret; 73 74 *val = temp_of_local(regval); 75 return 0; 76 } 77 78 static int get_remote_temp(struct regmap *regmap, int index, long *val) 79 { 80 unsigned int regval_high; 81 unsigned int regval_low; 82 int ret; 83 84 ret = regmap_read(regmap, W83773_TEMP_MSB[index], ®val_high); 85 if (ret < 0) 86 return ret; 87 88 ret = regmap_read(regmap, W83773_TEMP_LSB[index], ®val_low); 89 if (ret < 0) 90 return ret; 91 92 *val = temp_of_remote(regval_high, regval_low); 93 return 0; 94 } 95 96 static int get_fault(struct regmap *regmap, int index, long *val) 97 { 98 unsigned int regval; 99 int ret; 100 101 ret = regmap_read(regmap, W83773_STATUS[index], ®val); 102 if (ret < 0) 103 return ret; 104 105 *val = (regval & 0x04) >> 2; 106 return 0; 107 } 108 109 static int get_offset(struct regmap *regmap, int index, long *val) 110 { 111 unsigned int regval_high; 112 unsigned int regval_low; 113 int ret; 114 115 ret = regmap_read(regmap, W83773_OFFSET_MSB[index], ®val_high); 116 if (ret < 0) 117 return ret; 118 119 ret = regmap_read(regmap, W83773_OFFSET_LSB[index], ®val_low); 120 if (ret < 0) 121 return ret; 122 123 *val = temp_of_remote(regval_high, regval_low); 124 return 0; 125 } 126 127 static int set_offset(struct regmap *regmap, int index, long val) 128 { 129 int ret; 130 u8 high_byte; 131 u8 low_byte; 132 133 val = clamp_val(val, -127825, 127825); 134 /* offset value equals to (high_byte << 3 | low_byte >> 5) * 125 */ 135 val /= 125; 136 high_byte = val >> 3; 137 low_byte = (val & 0x07) << 5; 138 139 ret = regmap_write(regmap, W83773_OFFSET_MSB[index], high_byte); 140 if (ret < 0) 141 return ret; 142 143 return regmap_write(regmap, W83773_OFFSET_LSB[index], low_byte); 144 } 145 146 static int get_update_interval(struct regmap *regmap, long *val) 147 { 148 unsigned int regval; 149 int ret; 150 151 ret = regmap_read(regmap, W83773_CONVERSION_RATE_REG_READ, ®val); 152 if (ret < 0) 153 return ret; 154 155 *val = 16000 >> regval; 156 return 0; 157 } 158 159 static int set_update_interval(struct regmap *regmap, long val) 160 { 161 int rate; 162 163 /* 164 * For valid rates, interval can be calculated as 165 * interval = (1 << (8 - rate)) * 62.5; 166 * Rounded rate is therefore 167 * rate = 8 - __fls(interval * 8 / (62.5 * 7)); 168 * Use clamp_val() to avoid overflows, and to ensure valid input 169 * for __fls. 170 */ 171 val = clamp_val(val, 62, 16000) * 10; 172 rate = 8 - __fls((val * 8 / (625 * 7))); 173 return regmap_write(regmap, W83773_CONVERSION_RATE_REG_WRITE, rate); 174 } 175 176 static int w83773_read(struct device *dev, enum hwmon_sensor_types type, 177 u32 attr, int channel, long *val) 178 { 179 struct regmap *regmap = dev_get_drvdata(dev); 180 181 if (type == hwmon_chip) { 182 if (attr == hwmon_chip_update_interval) 183 return get_update_interval(regmap, val); 184 return -EOPNOTSUPP; 185 } 186 187 switch (attr) { 188 case hwmon_temp_input: 189 if (channel == 0) 190 return get_local_temp(regmap, val); 191 return get_remote_temp(regmap, channel - 1, val); 192 case hwmon_temp_fault: 193 return get_fault(regmap, channel - 1, val); 194 case hwmon_temp_offset: 195 return get_offset(regmap, channel - 1, val); 196 default: 197 return -EOPNOTSUPP; 198 } 199 } 200 201 static int w83773_write(struct device *dev, enum hwmon_sensor_types type, 202 u32 attr, int channel, long val) 203 { 204 struct regmap *regmap = dev_get_drvdata(dev); 205 206 if (type == hwmon_chip && attr == hwmon_chip_update_interval) 207 return set_update_interval(regmap, val); 208 209 if (type == hwmon_temp && attr == hwmon_temp_offset) 210 return set_offset(regmap, channel - 1, val); 211 212 return -EOPNOTSUPP; 213 } 214 215 static umode_t w83773_is_visible(const void *data, enum hwmon_sensor_types type, 216 u32 attr, int channel) 217 { 218 switch (type) { 219 case hwmon_chip: 220 switch (attr) { 221 case hwmon_chip_update_interval: 222 return 0644; 223 } 224 break; 225 case hwmon_temp: 226 switch (attr) { 227 case hwmon_temp_input: 228 case hwmon_temp_fault: 229 return 0444; 230 case hwmon_temp_offset: 231 return 0644; 232 } 233 break; 234 default: 235 break; 236 } 237 return 0; 238 } 239 240 static const u32 w83773_chip_config[] = { 241 HWMON_C_REGISTER_TZ | HWMON_C_UPDATE_INTERVAL, 242 0 243 }; 244 245 static const struct hwmon_channel_info w83773_chip = { 246 .type = hwmon_chip, 247 .config = w83773_chip_config, 248 }; 249 250 static const u32 w83773_temp_config[] = { 251 HWMON_T_INPUT, 252 HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_OFFSET, 253 HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_OFFSET, 254 0 255 }; 256 257 static const struct hwmon_channel_info w83773_temp = { 258 .type = hwmon_temp, 259 .config = w83773_temp_config, 260 }; 261 262 static const struct hwmon_channel_info *w83773_info[] = { 263 &w83773_chip, 264 &w83773_temp, 265 NULL 266 }; 267 268 static const struct hwmon_ops w83773_ops = { 269 .is_visible = w83773_is_visible, 270 .read = w83773_read, 271 .write = w83773_write, 272 }; 273 274 static const struct hwmon_chip_info w83773_chip_info = { 275 .ops = &w83773_ops, 276 .info = w83773_info, 277 }; 278 279 static const struct regmap_config w83773_regmap_config = { 280 .reg_bits = 8, 281 .val_bits = 8, 282 }; 283 284 static int w83773_probe(struct i2c_client *client, 285 const struct i2c_device_id *id) 286 { 287 struct device *dev = &client->dev; 288 struct device *hwmon_dev; 289 struct regmap *regmap; 290 int ret; 291 292 regmap = devm_regmap_init_i2c(client, &w83773_regmap_config); 293 if (IS_ERR(regmap)) { 294 dev_err(dev, "failed to allocate register map\n"); 295 return PTR_ERR(regmap); 296 } 297 298 /* Set the conversion rate to 2 Hz */ 299 ret = regmap_write(regmap, W83773_CONVERSION_RATE_REG_WRITE, 0x05); 300 if (ret < 0) { 301 dev_err(&client->dev, "error writing config rate register\n"); 302 return ret; 303 } 304 305 i2c_set_clientdata(client, regmap); 306 307 hwmon_dev = devm_hwmon_device_register_with_info(dev, 308 client->name, 309 regmap, 310 &w83773_chip_info, 311 NULL); 312 return PTR_ERR_OR_ZERO(hwmon_dev); 313 } 314 315 static struct i2c_driver w83773_driver = { 316 .class = I2C_CLASS_HWMON, 317 .driver = { 318 .name = "w83773g", 319 .of_match_table = of_match_ptr(w83773_of_match), 320 }, 321 .probe = w83773_probe, 322 .id_table = w83773_id, 323 }; 324 325 module_i2c_driver(w83773_driver); 326 327 MODULE_AUTHOR("Lei YU <mine260309@gmail.com>"); 328 MODULE_DESCRIPTION("W83773G temperature sensor driver"); 329 MODULE_LICENSE("GPL"); 330