1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * max31790.c - Part of lm_sensors, Linux kernel modules for hardware 4 * monitoring. 5 * 6 * (C) 2015 by Il Han <corone.il.han@gmail.com> 7 */ 8 9 #include <linux/err.h> 10 #include <linux/hwmon.h> 11 #include <linux/i2c.h> 12 #include <linux/init.h> 13 #include <linux/jiffies.h> 14 #include <linux/module.h> 15 #include <linux/slab.h> 16 17 /* MAX31790 registers */ 18 #define MAX31790_REG_GLOBAL_CONFIG 0x00 19 #define MAX31790_REG_FAN_CONFIG(ch) (0x02 + (ch)) 20 #define MAX31790_REG_FAN_DYNAMICS(ch) (0x08 + (ch)) 21 #define MAX31790_REG_FAN_FAULT_STATUS2 0x10 22 #define MAX31790_REG_FAN_FAULT_STATUS1 0x11 23 #define MAX31790_REG_TACH_COUNT(ch) (0x18 + (ch) * 2) 24 #define MAX31790_REG_PWM_DUTY_CYCLE(ch) (0x30 + (ch) * 2) 25 #define MAX31790_REG_PWMOUT(ch) (0x40 + (ch) * 2) 26 #define MAX31790_REG_TARGET_COUNT(ch) (0x50 + (ch) * 2) 27 28 /* Fan Config register bits */ 29 #define MAX31790_FAN_CFG_RPM_MODE 0x80 30 #define MAX31790_FAN_CFG_TACH_INPUT_EN 0x08 31 #define MAX31790_FAN_CFG_TACH_INPUT 0x01 32 33 /* Fan Dynamics register bits */ 34 #define MAX31790_FAN_DYN_SR_SHIFT 5 35 #define MAX31790_FAN_DYN_SR_MASK 0xE0 36 #define SR_FROM_REG(reg) (((reg) & MAX31790_FAN_DYN_SR_MASK) \ 37 >> MAX31790_FAN_DYN_SR_SHIFT) 38 39 #define FAN_RPM_MIN 120 40 #define FAN_RPM_MAX 7864320 41 42 #define RPM_FROM_REG(reg, sr) (((reg) >> 4) ? \ 43 ((60 * (sr) * 8192) / ((reg) >> 4)) : \ 44 FAN_RPM_MAX) 45 #define RPM_TO_REG(rpm, sr) ((60 * (sr) * 8192) / ((rpm) * 2)) 46 47 #define NR_CHANNEL 6 48 49 /* 50 * Client data (each client gets its own) 51 */ 52 struct max31790_data { 53 struct i2c_client *client; 54 struct mutex update_lock; 55 bool valid; /* zero until following fields are valid */ 56 unsigned long last_updated; /* in jiffies */ 57 58 /* register values */ 59 u8 fan_config[NR_CHANNEL]; 60 u8 fan_dynamics[NR_CHANNEL]; 61 u16 fault_status; 62 u16 tach[NR_CHANNEL * 2]; 63 u16 pwm[NR_CHANNEL]; 64 u16 target_count[NR_CHANNEL]; 65 }; 66 67 static struct max31790_data *max31790_update_device(struct device *dev) 68 { 69 struct max31790_data *data = dev_get_drvdata(dev); 70 struct i2c_client *client = data->client; 71 struct max31790_data *ret = data; 72 int i; 73 int rv; 74 75 mutex_lock(&data->update_lock); 76 77 if (time_after(jiffies, data->last_updated + HZ) || !data->valid) { 78 rv = i2c_smbus_read_byte_data(client, 79 MAX31790_REG_FAN_FAULT_STATUS1); 80 if (rv < 0) 81 goto abort; 82 data->fault_status = rv & 0x3F; 83 84 rv = i2c_smbus_read_byte_data(client, 85 MAX31790_REG_FAN_FAULT_STATUS2); 86 if (rv < 0) 87 goto abort; 88 data->fault_status |= (rv & 0x3F) << 6; 89 90 for (i = 0; i < NR_CHANNEL; i++) { 91 rv = i2c_smbus_read_word_swapped(client, 92 MAX31790_REG_TACH_COUNT(i)); 93 if (rv < 0) 94 goto abort; 95 data->tach[i] = rv; 96 97 if (data->fan_config[i] 98 & MAX31790_FAN_CFG_TACH_INPUT) { 99 rv = i2c_smbus_read_word_swapped(client, 100 MAX31790_REG_TACH_COUNT(NR_CHANNEL 101 + i)); 102 if (rv < 0) 103 goto abort; 104 data->tach[NR_CHANNEL + i] = rv; 105 } else { 106 rv = i2c_smbus_read_word_swapped(client, 107 MAX31790_REG_PWMOUT(i)); 108 if (rv < 0) 109 goto abort; 110 data->pwm[i] = rv; 111 112 rv = i2c_smbus_read_word_swapped(client, 113 MAX31790_REG_TARGET_COUNT(i)); 114 if (rv < 0) 115 goto abort; 116 data->target_count[i] = rv; 117 } 118 } 119 120 data->last_updated = jiffies; 121 data->valid = true; 122 } 123 goto done; 124 125 abort: 126 data->valid = false; 127 ret = ERR_PTR(rv); 128 129 done: 130 mutex_unlock(&data->update_lock); 131 132 return ret; 133 } 134 135 static const u8 tach_period[8] = { 1, 2, 4, 8, 16, 32, 32, 32 }; 136 137 static u8 get_tach_period(u8 fan_dynamics) 138 { 139 return tach_period[SR_FROM_REG(fan_dynamics)]; 140 } 141 142 static u8 bits_for_tach_period(int rpm) 143 { 144 u8 bits; 145 146 if (rpm < 500) 147 bits = 0x0; 148 else if (rpm < 1000) 149 bits = 0x1; 150 else if (rpm < 2000) 151 bits = 0x2; 152 else if (rpm < 4000) 153 bits = 0x3; 154 else if (rpm < 8000) 155 bits = 0x4; 156 else 157 bits = 0x5; 158 159 return bits; 160 } 161 162 static int max31790_read_fan(struct device *dev, u32 attr, int channel, 163 long *val) 164 { 165 struct max31790_data *data = max31790_update_device(dev); 166 int sr, rpm; 167 168 if (IS_ERR(data)) 169 return PTR_ERR(data); 170 171 switch (attr) { 172 case hwmon_fan_input: 173 sr = get_tach_period(data->fan_dynamics[channel]); 174 rpm = RPM_FROM_REG(data->tach[channel], sr); 175 *val = rpm; 176 return 0; 177 case hwmon_fan_target: 178 sr = get_tach_period(data->fan_dynamics[channel]); 179 rpm = RPM_FROM_REG(data->target_count[channel], sr); 180 *val = rpm; 181 return 0; 182 case hwmon_fan_fault: 183 *val = !!(data->fault_status & (1 << channel)); 184 return 0; 185 default: 186 return -EOPNOTSUPP; 187 } 188 } 189 190 static int max31790_write_fan(struct device *dev, u32 attr, int channel, 191 long val) 192 { 193 struct max31790_data *data = dev_get_drvdata(dev); 194 struct i2c_client *client = data->client; 195 int target_count; 196 int err = 0; 197 u8 bits; 198 int sr; 199 200 mutex_lock(&data->update_lock); 201 202 switch (attr) { 203 case hwmon_fan_target: 204 val = clamp_val(val, FAN_RPM_MIN, FAN_RPM_MAX); 205 bits = bits_for_tach_period(val); 206 data->fan_dynamics[channel] = 207 ((data->fan_dynamics[channel] & 208 ~MAX31790_FAN_DYN_SR_MASK) | 209 (bits << MAX31790_FAN_DYN_SR_SHIFT)); 210 err = i2c_smbus_write_byte_data(client, 211 MAX31790_REG_FAN_DYNAMICS(channel), 212 data->fan_dynamics[channel]); 213 if (err < 0) 214 break; 215 216 sr = get_tach_period(data->fan_dynamics[channel]); 217 target_count = RPM_TO_REG(val, sr); 218 target_count = clamp_val(target_count, 0x1, 0x7FF); 219 220 data->target_count[channel] = target_count << 5; 221 222 err = i2c_smbus_write_word_swapped(client, 223 MAX31790_REG_TARGET_COUNT(channel), 224 data->target_count[channel]); 225 break; 226 default: 227 err = -EOPNOTSUPP; 228 break; 229 } 230 231 mutex_unlock(&data->update_lock); 232 233 return err; 234 } 235 236 static umode_t max31790_fan_is_visible(const void *_data, u32 attr, int channel) 237 { 238 const struct max31790_data *data = _data; 239 u8 fan_config = data->fan_config[channel % NR_CHANNEL]; 240 241 switch (attr) { 242 case hwmon_fan_input: 243 case hwmon_fan_fault: 244 if (channel < NR_CHANNEL || 245 (fan_config & MAX31790_FAN_CFG_TACH_INPUT)) 246 return 0444; 247 return 0; 248 case hwmon_fan_target: 249 if (channel < NR_CHANNEL && 250 !(fan_config & MAX31790_FAN_CFG_TACH_INPUT)) 251 return 0644; 252 return 0; 253 default: 254 return 0; 255 } 256 } 257 258 static int max31790_read_pwm(struct device *dev, u32 attr, int channel, 259 long *val) 260 { 261 struct max31790_data *data = max31790_update_device(dev); 262 u8 fan_config; 263 264 if (IS_ERR(data)) 265 return PTR_ERR(data); 266 267 fan_config = data->fan_config[channel]; 268 269 switch (attr) { 270 case hwmon_pwm_input: 271 *val = data->pwm[channel] >> 8; 272 return 0; 273 case hwmon_pwm_enable: 274 if (fan_config & MAX31790_FAN_CFG_RPM_MODE) 275 *val = 2; 276 else if (fan_config & MAX31790_FAN_CFG_TACH_INPUT_EN) 277 *val = 1; 278 else 279 *val = 0; 280 return 0; 281 default: 282 return -EOPNOTSUPP; 283 } 284 } 285 286 static int max31790_write_pwm(struct device *dev, u32 attr, int channel, 287 long val) 288 { 289 struct max31790_data *data = dev_get_drvdata(dev); 290 struct i2c_client *client = data->client; 291 u8 fan_config; 292 int err = 0; 293 294 mutex_lock(&data->update_lock); 295 296 switch (attr) { 297 case hwmon_pwm_input: 298 if (val < 0 || val > 255) { 299 err = -EINVAL; 300 break; 301 } 302 data->pwm[channel] = val << 8; 303 err = i2c_smbus_write_word_swapped(client, 304 MAX31790_REG_PWMOUT(channel), 305 data->pwm[channel]); 306 break; 307 case hwmon_pwm_enable: 308 fan_config = data->fan_config[channel]; 309 if (val == 0) { 310 fan_config &= ~(MAX31790_FAN_CFG_TACH_INPUT_EN | 311 MAX31790_FAN_CFG_RPM_MODE); 312 } else if (val == 1) { 313 fan_config = (fan_config | 314 MAX31790_FAN_CFG_TACH_INPUT_EN) & 315 ~MAX31790_FAN_CFG_RPM_MODE; 316 } else if (val == 2) { 317 fan_config |= MAX31790_FAN_CFG_TACH_INPUT_EN | 318 MAX31790_FAN_CFG_RPM_MODE; 319 } else { 320 err = -EINVAL; 321 break; 322 } 323 data->fan_config[channel] = fan_config; 324 err = i2c_smbus_write_byte_data(client, 325 MAX31790_REG_FAN_CONFIG(channel), 326 fan_config); 327 break; 328 default: 329 err = -EOPNOTSUPP; 330 break; 331 } 332 333 mutex_unlock(&data->update_lock); 334 335 return err; 336 } 337 338 static umode_t max31790_pwm_is_visible(const void *_data, u32 attr, int channel) 339 { 340 const struct max31790_data *data = _data; 341 u8 fan_config = data->fan_config[channel]; 342 343 switch (attr) { 344 case hwmon_pwm_input: 345 case hwmon_pwm_enable: 346 if (!(fan_config & MAX31790_FAN_CFG_TACH_INPUT)) 347 return 0644; 348 return 0; 349 default: 350 return 0; 351 } 352 } 353 354 static int max31790_read(struct device *dev, enum hwmon_sensor_types type, 355 u32 attr, int channel, long *val) 356 { 357 switch (type) { 358 case hwmon_fan: 359 return max31790_read_fan(dev, attr, channel, val); 360 case hwmon_pwm: 361 return max31790_read_pwm(dev, attr, channel, val); 362 default: 363 return -EOPNOTSUPP; 364 } 365 } 366 367 static int max31790_write(struct device *dev, enum hwmon_sensor_types type, 368 u32 attr, int channel, long val) 369 { 370 switch (type) { 371 case hwmon_fan: 372 return max31790_write_fan(dev, attr, channel, val); 373 case hwmon_pwm: 374 return max31790_write_pwm(dev, attr, channel, val); 375 default: 376 return -EOPNOTSUPP; 377 } 378 } 379 380 static umode_t max31790_is_visible(const void *data, 381 enum hwmon_sensor_types type, 382 u32 attr, int channel) 383 { 384 switch (type) { 385 case hwmon_fan: 386 return max31790_fan_is_visible(data, attr, channel); 387 case hwmon_pwm: 388 return max31790_pwm_is_visible(data, attr, channel); 389 default: 390 return 0; 391 } 392 } 393 394 static const struct hwmon_channel_info *max31790_info[] = { 395 HWMON_CHANNEL_INFO(fan, 396 HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT, 397 HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT, 398 HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT, 399 HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT, 400 HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT, 401 HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT, 402 HWMON_F_INPUT | HWMON_F_FAULT, 403 HWMON_F_INPUT | HWMON_F_FAULT, 404 HWMON_F_INPUT | HWMON_F_FAULT, 405 HWMON_F_INPUT | HWMON_F_FAULT, 406 HWMON_F_INPUT | HWMON_F_FAULT, 407 HWMON_F_INPUT | HWMON_F_FAULT), 408 HWMON_CHANNEL_INFO(pwm, 409 HWMON_PWM_INPUT | HWMON_PWM_ENABLE, 410 HWMON_PWM_INPUT | HWMON_PWM_ENABLE, 411 HWMON_PWM_INPUT | HWMON_PWM_ENABLE, 412 HWMON_PWM_INPUT | HWMON_PWM_ENABLE, 413 HWMON_PWM_INPUT | HWMON_PWM_ENABLE, 414 HWMON_PWM_INPUT | HWMON_PWM_ENABLE), 415 NULL 416 }; 417 418 static const struct hwmon_ops max31790_hwmon_ops = { 419 .is_visible = max31790_is_visible, 420 .read = max31790_read, 421 .write = max31790_write, 422 }; 423 424 static const struct hwmon_chip_info max31790_chip_info = { 425 .ops = &max31790_hwmon_ops, 426 .info = max31790_info, 427 }; 428 429 static int max31790_init_client(struct i2c_client *client, 430 struct max31790_data *data) 431 { 432 int i, rv; 433 434 for (i = 0; i < NR_CHANNEL; i++) { 435 rv = i2c_smbus_read_byte_data(client, 436 MAX31790_REG_FAN_CONFIG(i)); 437 if (rv < 0) 438 return rv; 439 data->fan_config[i] = rv; 440 441 rv = i2c_smbus_read_byte_data(client, 442 MAX31790_REG_FAN_DYNAMICS(i)); 443 if (rv < 0) 444 return rv; 445 data->fan_dynamics[i] = rv; 446 } 447 448 return 0; 449 } 450 451 static int max31790_probe(struct i2c_client *client, 452 const struct i2c_device_id *id) 453 { 454 struct i2c_adapter *adapter = client->adapter; 455 struct device *dev = &client->dev; 456 struct max31790_data *data; 457 struct device *hwmon_dev; 458 int err; 459 460 if (!i2c_check_functionality(adapter, 461 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA)) 462 return -ENODEV; 463 464 data = devm_kzalloc(dev, sizeof(struct max31790_data), GFP_KERNEL); 465 if (!data) 466 return -ENOMEM; 467 468 data->client = client; 469 mutex_init(&data->update_lock); 470 471 /* 472 * Initialize the max31790 chip 473 */ 474 err = max31790_init_client(client, data); 475 if (err) 476 return err; 477 478 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, 479 data, 480 &max31790_chip_info, 481 NULL); 482 483 return PTR_ERR_OR_ZERO(hwmon_dev); 484 } 485 486 static const struct i2c_device_id max31790_id[] = { 487 { "max31790", 0 }, 488 { } 489 }; 490 MODULE_DEVICE_TABLE(i2c, max31790_id); 491 492 static struct i2c_driver max31790_driver = { 493 .class = I2C_CLASS_HWMON, 494 .probe = max31790_probe, 495 .driver = { 496 .name = "max31790", 497 }, 498 .id_table = max31790_id, 499 }; 500 501 module_i2c_driver(max31790_driver); 502 503 MODULE_AUTHOR("Il Han <corone.il.han@gmail.com>"); 504 MODULE_DESCRIPTION("MAX31790 sensor driver"); 505 MODULE_LICENSE("GPL"); 506