1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * tc654.c - Linux kernel modules for fan speed controller 4 * 5 * Copyright (C) 2016 Allied Telesis Labs NZ 6 */ 7 8 #include <linux/bitops.h> 9 #include <linux/err.h> 10 #include <linux/hwmon.h> 11 #include <linux/hwmon-sysfs.h> 12 #include <linux/i2c.h> 13 #include <linux/init.h> 14 #include <linux/jiffies.h> 15 #include <linux/module.h> 16 #include <linux/mutex.h> 17 #include <linux/slab.h> 18 #include <linux/util_macros.h> 19 20 enum tc654_regs { 21 TC654_REG_RPM1 = 0x00, /* RPM Output 1 */ 22 TC654_REG_RPM2 = 0x01, /* RPM Output 2 */ 23 TC654_REG_FAN_FAULT1 = 0x02, /* Fan Fault 1 Threshold */ 24 TC654_REG_FAN_FAULT2 = 0x03, /* Fan Fault 2 Threshold */ 25 TC654_REG_CONFIG = 0x04, /* Configuration */ 26 TC654_REG_STATUS = 0x05, /* Status */ 27 TC654_REG_DUTY_CYCLE = 0x06, /* Fan Speed Duty Cycle */ 28 TC654_REG_MFR_ID = 0x07, /* Manufacturer Identification */ 29 TC654_REG_VER_ID = 0x08, /* Version Identification */ 30 }; 31 32 /* Macros to easily index the registers */ 33 #define TC654_REG_RPM(idx) (TC654_REG_RPM1 + (idx)) 34 #define TC654_REG_FAN_FAULT(idx) (TC654_REG_FAN_FAULT1 + (idx)) 35 36 /* Config register bits */ 37 #define TC654_REG_CONFIG_RES BIT(6) /* Resolution Selection */ 38 #define TC654_REG_CONFIG_DUTYC BIT(5) /* Duty Cycle Control */ 39 #define TC654_REG_CONFIG_SDM BIT(0) /* Shutdown Mode */ 40 41 /* Status register bits */ 42 #define TC654_REG_STATUS_F2F BIT(1) /* Fan 2 Fault */ 43 #define TC654_REG_STATUS_F1F BIT(0) /* Fan 1 Fault */ 44 45 /* RPM resolution for RPM Output registers */ 46 #define TC654_HIGH_RPM_RESOLUTION 25 /* 25 RPM resolution */ 47 #define TC654_LOW_RPM_RESOLUTION 50 /* 50 RPM resolution */ 48 49 /* Convert to the fan fault RPM threshold from register value */ 50 #define TC654_FAN_FAULT_FROM_REG(val) ((val) * 50) /* 50 RPM resolution */ 51 52 /* Convert to register value from the fan fault RPM threshold */ 53 #define TC654_FAN_FAULT_TO_REG(val) (((val) / 50) & 0xff) 54 55 /* Register data is read (and cached) at most once per second. */ 56 #define TC654_UPDATE_INTERVAL HZ 57 58 struct tc654_data { 59 struct i2c_client *client; 60 61 /* update mutex */ 62 struct mutex update_lock; 63 64 /* tc654 register cache */ 65 bool valid; 66 unsigned long last_updated; /* in jiffies */ 67 68 u8 rpm_output[2]; /* The fan RPM data for fans 1 and 2 is then 69 * written to registers RPM1 and RPM2 70 */ 71 u8 fan_fault[2]; /* The Fan Fault Threshold Registers are used to 72 * set the fan fault threshold levels for fan 1 73 * and fan 2 74 */ 75 u8 config; /* The Configuration Register is an 8-bit read/ 76 * writable multi-function control register 77 * 7: Fan Fault Clear 78 * 1 = Clear Fan Fault 79 * 0 = Normal Operation (default) 80 * 6: Resolution Selection for RPM Output Registers 81 * RPM Output Registers (RPM1 and RPM2) will be 82 * set for 83 * 1 = 25 RPM (9-bit) resolution 84 * 0 = 50 RPM (8-bit) resolution (default) 85 * 5: Duty Cycle Control Method 86 * The V OUT duty cycle will be controlled via 87 * 1 = the SMBus interface. 88 * 0 = via the V IN analog input pin. (default) 89 * 4,3: Fan 2 Pulses Per Rotation 90 * 00 = 1 91 * 01 = 2 (default) 92 * 10 = 4 93 * 11 = 8 94 * 2,1: Fan 1 Pulses Per Rotation 95 * 00 = 1 96 * 01 = 2 (default) 97 * 10 = 4 98 * 11 = 8 99 * 0: Shutdown Mode 100 * 1 = Shutdown mode. 101 * 0 = Normal operation. (default) 102 */ 103 u8 status; /* The Status register provides all the information 104 * about what is going on within the TC654/TC655 105 * devices. 106 * 7,6: Unimplemented, Read as '0' 107 * 5: Over-Temperature Fault Condition 108 * 1 = Over-Temperature condition has occurred 109 * 0 = Normal operation. V IN is less than 2.6V 110 * 4: RPM2 Counter Overflow 111 * 1 = Fault condition 112 * 0 = Normal operation 113 * 3: RPM1 Counter Overflow 114 * 1 = Fault condition 115 * 0 = Normal operation 116 * 2: V IN Input Status 117 * 1 = V IN is open 118 * 0 = Normal operation. voltage present at V IN 119 * 1: Fan 2 Fault 120 * 1 = Fault condition 121 * 0 = Normal operation 122 * 0: Fan 1 Fault 123 * 1 = Fault condition 124 * 0 = Normal operation 125 */ 126 u8 duty_cycle; /* The DUTY_CYCLE register is a 4-bit read/ 127 * writable register used to control the duty 128 * cycle of the V OUT output. 129 */ 130 }; 131 132 /* helper to grab and cache data, at most one time per second */ 133 static struct tc654_data *tc654_update_client(struct device *dev) 134 { 135 struct tc654_data *data = dev_get_drvdata(dev); 136 struct i2c_client *client = data->client; 137 int ret = 0; 138 139 mutex_lock(&data->update_lock); 140 if (time_before(jiffies, data->last_updated + TC654_UPDATE_INTERVAL) && 141 likely(data->valid)) 142 goto out; 143 144 ret = i2c_smbus_read_byte_data(client, TC654_REG_RPM(0)); 145 if (ret < 0) 146 goto out; 147 data->rpm_output[0] = ret; 148 149 ret = i2c_smbus_read_byte_data(client, TC654_REG_RPM(1)); 150 if (ret < 0) 151 goto out; 152 data->rpm_output[1] = ret; 153 154 ret = i2c_smbus_read_byte_data(client, TC654_REG_FAN_FAULT(0)); 155 if (ret < 0) 156 goto out; 157 data->fan_fault[0] = ret; 158 159 ret = i2c_smbus_read_byte_data(client, TC654_REG_FAN_FAULT(1)); 160 if (ret < 0) 161 goto out; 162 data->fan_fault[1] = ret; 163 164 ret = i2c_smbus_read_byte_data(client, TC654_REG_CONFIG); 165 if (ret < 0) 166 goto out; 167 data->config = ret; 168 169 ret = i2c_smbus_read_byte_data(client, TC654_REG_STATUS); 170 if (ret < 0) 171 goto out; 172 data->status = ret; 173 174 ret = i2c_smbus_read_byte_data(client, TC654_REG_DUTY_CYCLE); 175 if (ret < 0) 176 goto out; 177 data->duty_cycle = ret & 0x0f; 178 179 data->last_updated = jiffies; 180 data->valid = true; 181 out: 182 mutex_unlock(&data->update_lock); 183 184 if (ret < 0) /* upon error, encode it in return value */ 185 data = ERR_PTR(ret); 186 187 return data; 188 } 189 190 /* 191 * sysfs attributes 192 */ 193 194 static ssize_t fan_show(struct device *dev, struct device_attribute *da, 195 char *buf) 196 { 197 int nr = to_sensor_dev_attr(da)->index; 198 struct tc654_data *data = tc654_update_client(dev); 199 int val; 200 201 if (IS_ERR(data)) 202 return PTR_ERR(data); 203 204 if (data->config & TC654_REG_CONFIG_RES) 205 val = data->rpm_output[nr] * TC654_HIGH_RPM_RESOLUTION; 206 else 207 val = data->rpm_output[nr] * TC654_LOW_RPM_RESOLUTION; 208 209 return sprintf(buf, "%d\n", val); 210 } 211 212 static ssize_t fan_min_show(struct device *dev, struct device_attribute *da, 213 char *buf) 214 { 215 int nr = to_sensor_dev_attr(da)->index; 216 struct tc654_data *data = tc654_update_client(dev); 217 218 if (IS_ERR(data)) 219 return PTR_ERR(data); 220 221 return sprintf(buf, "%d\n", 222 TC654_FAN_FAULT_FROM_REG(data->fan_fault[nr])); 223 } 224 225 static ssize_t fan_min_store(struct device *dev, struct device_attribute *da, 226 const char *buf, size_t count) 227 { 228 int nr = to_sensor_dev_attr(da)->index; 229 struct tc654_data *data = dev_get_drvdata(dev); 230 struct i2c_client *client = data->client; 231 unsigned long val; 232 int ret; 233 234 if (kstrtoul(buf, 10, &val)) 235 return -EINVAL; 236 237 val = clamp_val(val, 0, 12750); 238 239 mutex_lock(&data->update_lock); 240 241 data->fan_fault[nr] = TC654_FAN_FAULT_TO_REG(val); 242 ret = i2c_smbus_write_byte_data(client, TC654_REG_FAN_FAULT(nr), 243 data->fan_fault[nr]); 244 245 mutex_unlock(&data->update_lock); 246 return ret < 0 ? ret : count; 247 } 248 249 static ssize_t fan_alarm_show(struct device *dev, struct device_attribute *da, 250 char *buf) 251 { 252 int nr = to_sensor_dev_attr(da)->index; 253 struct tc654_data *data = tc654_update_client(dev); 254 int val; 255 256 if (IS_ERR(data)) 257 return PTR_ERR(data); 258 259 if (nr == 0) 260 val = !!(data->status & TC654_REG_STATUS_F1F); 261 else 262 val = !!(data->status & TC654_REG_STATUS_F2F); 263 264 return sprintf(buf, "%d\n", val); 265 } 266 267 static const u8 TC654_FAN_PULSE_SHIFT[] = { 1, 3 }; 268 269 static ssize_t fan_pulses_show(struct device *dev, 270 struct device_attribute *da, char *buf) 271 { 272 int nr = to_sensor_dev_attr(da)->index; 273 struct tc654_data *data = tc654_update_client(dev); 274 u8 val; 275 276 if (IS_ERR(data)) 277 return PTR_ERR(data); 278 279 val = BIT((data->config >> TC654_FAN_PULSE_SHIFT[nr]) & 0x03); 280 return sprintf(buf, "%d\n", val); 281 } 282 283 static ssize_t fan_pulses_store(struct device *dev, 284 struct device_attribute *da, const char *buf, 285 size_t count) 286 { 287 int nr = to_sensor_dev_attr(da)->index; 288 struct tc654_data *data = dev_get_drvdata(dev); 289 struct i2c_client *client = data->client; 290 u8 config; 291 unsigned long val; 292 int ret; 293 294 if (kstrtoul(buf, 10, &val)) 295 return -EINVAL; 296 297 switch (val) { 298 case 1: 299 config = 0; 300 break; 301 case 2: 302 config = 1; 303 break; 304 case 4: 305 config = 2; 306 break; 307 case 8: 308 config = 3; 309 break; 310 default: 311 return -EINVAL; 312 } 313 314 mutex_lock(&data->update_lock); 315 316 data->config &= ~(0x03 << TC654_FAN_PULSE_SHIFT[nr]); 317 data->config |= (config << TC654_FAN_PULSE_SHIFT[nr]); 318 ret = i2c_smbus_write_byte_data(client, TC654_REG_CONFIG, data->config); 319 320 mutex_unlock(&data->update_lock); 321 return ret < 0 ? ret : count; 322 } 323 324 static ssize_t pwm_mode_show(struct device *dev, struct device_attribute *da, 325 char *buf) 326 { 327 struct tc654_data *data = tc654_update_client(dev); 328 329 if (IS_ERR(data)) 330 return PTR_ERR(data); 331 332 return sprintf(buf, "%d\n", !!(data->config & TC654_REG_CONFIG_DUTYC)); 333 } 334 335 static ssize_t pwm_mode_store(struct device *dev, struct device_attribute *da, 336 const char *buf, size_t count) 337 { 338 struct tc654_data *data = dev_get_drvdata(dev); 339 struct i2c_client *client = data->client; 340 unsigned long val; 341 int ret; 342 343 if (kstrtoul(buf, 10, &val)) 344 return -EINVAL; 345 346 if (val != 0 && val != 1) 347 return -EINVAL; 348 349 mutex_lock(&data->update_lock); 350 351 if (val) 352 data->config |= TC654_REG_CONFIG_DUTYC; 353 else 354 data->config &= ~TC654_REG_CONFIG_DUTYC; 355 356 ret = i2c_smbus_write_byte_data(client, TC654_REG_CONFIG, data->config); 357 358 mutex_unlock(&data->update_lock); 359 return ret < 0 ? ret : count; 360 } 361 362 static const int tc654_pwm_map[16] = { 77, 88, 102, 112, 124, 136, 148, 160, 363 172, 184, 196, 207, 219, 231, 243, 255}; 364 365 static ssize_t pwm_show(struct device *dev, struct device_attribute *da, 366 char *buf) 367 { 368 struct tc654_data *data = tc654_update_client(dev); 369 int pwm; 370 371 if (IS_ERR(data)) 372 return PTR_ERR(data); 373 374 if (data->config & TC654_REG_CONFIG_SDM) 375 pwm = 0; 376 else 377 pwm = tc654_pwm_map[data->duty_cycle]; 378 379 return sprintf(buf, "%d\n", pwm); 380 } 381 382 static ssize_t pwm_store(struct device *dev, struct device_attribute *da, 383 const char *buf, size_t count) 384 { 385 struct tc654_data *data = dev_get_drvdata(dev); 386 struct i2c_client *client = data->client; 387 unsigned long val; 388 int ret; 389 390 if (kstrtoul(buf, 10, &val)) 391 return -EINVAL; 392 if (val > 255) 393 return -EINVAL; 394 395 mutex_lock(&data->update_lock); 396 397 if (val == 0) 398 data->config |= TC654_REG_CONFIG_SDM; 399 else 400 data->config &= ~TC654_REG_CONFIG_SDM; 401 402 data->duty_cycle = find_closest(val, tc654_pwm_map, 403 ARRAY_SIZE(tc654_pwm_map)); 404 405 ret = i2c_smbus_write_byte_data(client, TC654_REG_CONFIG, data->config); 406 if (ret < 0) 407 goto out; 408 409 ret = i2c_smbus_write_byte_data(client, TC654_REG_DUTY_CYCLE, 410 data->duty_cycle); 411 412 out: 413 mutex_unlock(&data->update_lock); 414 return ret < 0 ? ret : count; 415 } 416 417 static SENSOR_DEVICE_ATTR_RO(fan1_input, fan, 0); 418 static SENSOR_DEVICE_ATTR_RO(fan2_input, fan, 1); 419 static SENSOR_DEVICE_ATTR_RW(fan1_min, fan_min, 0); 420 static SENSOR_DEVICE_ATTR_RW(fan2_min, fan_min, 1); 421 static SENSOR_DEVICE_ATTR_RO(fan1_alarm, fan_alarm, 0); 422 static SENSOR_DEVICE_ATTR_RO(fan2_alarm, fan_alarm, 1); 423 static SENSOR_DEVICE_ATTR_RW(fan1_pulses, fan_pulses, 0); 424 static SENSOR_DEVICE_ATTR_RW(fan2_pulses, fan_pulses, 1); 425 static SENSOR_DEVICE_ATTR_RW(pwm1_mode, pwm_mode, 0); 426 static SENSOR_DEVICE_ATTR_RW(pwm1, pwm, 0); 427 428 /* Driver data */ 429 static struct attribute *tc654_attrs[] = { 430 &sensor_dev_attr_fan1_input.dev_attr.attr, 431 &sensor_dev_attr_fan2_input.dev_attr.attr, 432 &sensor_dev_attr_fan1_min.dev_attr.attr, 433 &sensor_dev_attr_fan2_min.dev_attr.attr, 434 &sensor_dev_attr_fan1_alarm.dev_attr.attr, 435 &sensor_dev_attr_fan2_alarm.dev_attr.attr, 436 &sensor_dev_attr_fan1_pulses.dev_attr.attr, 437 &sensor_dev_attr_fan2_pulses.dev_attr.attr, 438 &sensor_dev_attr_pwm1_mode.dev_attr.attr, 439 &sensor_dev_attr_pwm1.dev_attr.attr, 440 NULL 441 }; 442 443 ATTRIBUTE_GROUPS(tc654); 444 445 /* 446 * device probe and removal 447 */ 448 449 static int tc654_probe(struct i2c_client *client, 450 const struct i2c_device_id *id) 451 { 452 struct device *dev = &client->dev; 453 struct tc654_data *data; 454 struct device *hwmon_dev; 455 int ret; 456 457 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA)) 458 return -ENODEV; 459 460 data = devm_kzalloc(dev, sizeof(struct tc654_data), GFP_KERNEL); 461 if (!data) 462 return -ENOMEM; 463 464 data->client = client; 465 mutex_init(&data->update_lock); 466 467 ret = i2c_smbus_read_byte_data(client, TC654_REG_CONFIG); 468 if (ret < 0) 469 return ret; 470 471 data->config = ret; 472 473 hwmon_dev = 474 devm_hwmon_device_register_with_groups(dev, client->name, data, 475 tc654_groups); 476 return PTR_ERR_OR_ZERO(hwmon_dev); 477 } 478 479 static const struct i2c_device_id tc654_id[] = { 480 {"tc654", 0}, 481 {"tc655", 0}, 482 {} 483 }; 484 485 MODULE_DEVICE_TABLE(i2c, tc654_id); 486 487 static struct i2c_driver tc654_driver = { 488 .driver = { 489 .name = "tc654", 490 }, 491 .probe = tc654_probe, 492 .id_table = tc654_id, 493 }; 494 495 module_i2c_driver(tc654_driver); 496 497 MODULE_AUTHOR("Allied Telesis Labs"); 498 MODULE_DESCRIPTION("Microchip TC654/TC655 driver"); 499 MODULE_LICENSE("GPL"); 500