1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Driver for Linear Technology LTC2945 I2C Power Monitor 4 * 5 * Copyright (c) 2014 Guenter Roeck 6 */ 7 8 #include <linux/kernel.h> 9 #include <linux/module.h> 10 #include <linux/err.h> 11 #include <linux/slab.h> 12 #include <linux/i2c.h> 13 #include <linux/hwmon.h> 14 #include <linux/hwmon-sysfs.h> 15 #include <linux/jiffies.h> 16 #include <linux/regmap.h> 17 18 /* chip registers */ 19 #define LTC2945_CONTROL 0x00 20 #define LTC2945_ALERT 0x01 21 #define LTC2945_STATUS 0x02 22 #define LTC2945_FAULT 0x03 23 #define LTC2945_POWER_H 0x05 24 #define LTC2945_MAX_POWER_H 0x08 25 #define LTC2945_MIN_POWER_H 0x0b 26 #define LTC2945_MAX_POWER_THRES_H 0x0e 27 #define LTC2945_MIN_POWER_THRES_H 0x11 28 #define LTC2945_SENSE_H 0x14 29 #define LTC2945_MAX_SENSE_H 0x16 30 #define LTC2945_MIN_SENSE_H 0x18 31 #define LTC2945_MAX_SENSE_THRES_H 0x1a 32 #define LTC2945_MIN_SENSE_THRES_H 0x1c 33 #define LTC2945_VIN_H 0x1e 34 #define LTC2945_MAX_VIN_H 0x20 35 #define LTC2945_MIN_VIN_H 0x22 36 #define LTC2945_MAX_VIN_THRES_H 0x24 37 #define LTC2945_MIN_VIN_THRES_H 0x26 38 #define LTC2945_ADIN_H 0x28 39 #define LTC2945_MAX_ADIN_H 0x2a 40 #define LTC2945_MIN_ADIN_H 0x2c 41 #define LTC2945_MAX_ADIN_THRES_H 0x2e 42 #define LTC2945_MIN_ADIN_THRES_H 0x30 43 #define LTC2945_MIN_ADIN_THRES_L 0x31 44 45 /* Fault register bits */ 46 47 #define FAULT_ADIN_UV (1 << 0) 48 #define FAULT_ADIN_OV (1 << 1) 49 #define FAULT_VIN_UV (1 << 2) 50 #define FAULT_VIN_OV (1 << 3) 51 #define FAULT_SENSE_UV (1 << 4) 52 #define FAULT_SENSE_OV (1 << 5) 53 #define FAULT_POWER_UV (1 << 6) 54 #define FAULT_POWER_OV (1 << 7) 55 56 /* Control register bits */ 57 58 #define CONTROL_MULT_SELECT (1 << 0) 59 #define CONTROL_TEST_MODE (1 << 4) 60 61 static inline bool is_power_reg(u8 reg) 62 { 63 return reg < LTC2945_SENSE_H; 64 } 65 66 /* Return the value from the given register in uW, mV, or mA */ 67 static long long ltc2945_reg_to_val(struct device *dev, u8 reg) 68 { 69 struct regmap *regmap = dev_get_drvdata(dev); 70 unsigned int control; 71 u8 buf[3]; 72 long long val; 73 int ret; 74 75 ret = regmap_bulk_read(regmap, reg, buf, 76 is_power_reg(reg) ? 3 : 2); 77 if (ret < 0) 78 return ret; 79 80 if (is_power_reg(reg)) { 81 /* power */ 82 val = (buf[0] << 16) + (buf[1] << 8) + buf[2]; 83 } else { 84 /* current, voltage */ 85 val = (buf[0] << 4) + (buf[1] >> 4); 86 } 87 88 switch (reg) { 89 case LTC2945_POWER_H: 90 case LTC2945_MAX_POWER_H: 91 case LTC2945_MIN_POWER_H: 92 case LTC2945_MAX_POWER_THRES_H: 93 case LTC2945_MIN_POWER_THRES_H: 94 /* 95 * Convert to uW by assuming current is measured with 96 * an 1mOhm sense resistor, similar to current 97 * measurements. 98 * Control register bit 0 selects if voltage at SENSE+/VDD 99 * or voltage at ADIN is used to measure power. 100 */ 101 ret = regmap_read(regmap, LTC2945_CONTROL, &control); 102 if (ret < 0) 103 return ret; 104 if (control & CONTROL_MULT_SELECT) { 105 /* 25 mV * 25 uV = 0.625 uV resolution. */ 106 val *= 625LL; 107 } else { 108 /* 0.5 mV * 25 uV = 0.0125 uV resolution. */ 109 val = (val * 25LL) >> 1; 110 } 111 break; 112 case LTC2945_VIN_H: 113 case LTC2945_MAX_VIN_H: 114 case LTC2945_MIN_VIN_H: 115 case LTC2945_MAX_VIN_THRES_H: 116 case LTC2945_MIN_VIN_THRES_H: 117 /* 25 mV resolution. Convert to mV. */ 118 val *= 25; 119 break; 120 case LTC2945_ADIN_H: 121 case LTC2945_MAX_ADIN_H: 122 case LTC2945_MIN_ADIN_THRES_H: 123 case LTC2945_MAX_ADIN_THRES_H: 124 case LTC2945_MIN_ADIN_H: 125 /* 0.5mV resolution. Convert to mV. */ 126 val = val >> 1; 127 break; 128 case LTC2945_SENSE_H: 129 case LTC2945_MAX_SENSE_H: 130 case LTC2945_MIN_SENSE_H: 131 case LTC2945_MAX_SENSE_THRES_H: 132 case LTC2945_MIN_SENSE_THRES_H: 133 /* 134 * 25 uV resolution. Convert to current as measured with 135 * an 1 mOhm sense resistor, in mA. If a different sense 136 * resistor is installed, calculate the actual current by 137 * dividing the reported current by the sense resistor value 138 * in mOhm. 139 */ 140 val *= 25; 141 break; 142 default: 143 return -EINVAL; 144 } 145 return val; 146 } 147 148 static int ltc2945_val_to_reg(struct device *dev, u8 reg, 149 unsigned long val) 150 { 151 struct regmap *regmap = dev_get_drvdata(dev); 152 unsigned int control; 153 int ret; 154 155 switch (reg) { 156 case LTC2945_POWER_H: 157 case LTC2945_MAX_POWER_H: 158 case LTC2945_MIN_POWER_H: 159 case LTC2945_MAX_POWER_THRES_H: 160 case LTC2945_MIN_POWER_THRES_H: 161 /* 162 * Convert to register value by assuming current is measured 163 * with an 1mOhm sense resistor, similar to current 164 * measurements. 165 * Control register bit 0 selects if voltage at SENSE+/VDD 166 * or voltage at ADIN is used to measure power, which in turn 167 * determines register calculations. 168 */ 169 ret = regmap_read(regmap, LTC2945_CONTROL, &control); 170 if (ret < 0) 171 return ret; 172 if (control & CONTROL_MULT_SELECT) { 173 /* 25 mV * 25 uV = 0.625 uV resolution. */ 174 val = DIV_ROUND_CLOSEST(val, 625); 175 } else { 176 /* 177 * 0.5 mV * 25 uV = 0.0125 uV resolution. 178 * Divide first to avoid overflow; 179 * accept loss of accuracy. 180 */ 181 val = DIV_ROUND_CLOSEST(val, 25) * 2; 182 } 183 break; 184 case LTC2945_VIN_H: 185 case LTC2945_MAX_VIN_H: 186 case LTC2945_MIN_VIN_H: 187 case LTC2945_MAX_VIN_THRES_H: 188 case LTC2945_MIN_VIN_THRES_H: 189 /* 25 mV resolution. */ 190 val /= 25; 191 break; 192 case LTC2945_ADIN_H: 193 case LTC2945_MAX_ADIN_H: 194 case LTC2945_MIN_ADIN_THRES_H: 195 case LTC2945_MAX_ADIN_THRES_H: 196 case LTC2945_MIN_ADIN_H: 197 /* 0.5mV resolution. */ 198 val *= 2; 199 break; 200 case LTC2945_SENSE_H: 201 case LTC2945_MAX_SENSE_H: 202 case LTC2945_MIN_SENSE_H: 203 case LTC2945_MAX_SENSE_THRES_H: 204 case LTC2945_MIN_SENSE_THRES_H: 205 /* 206 * 25 uV resolution. Convert to current as measured with 207 * an 1 mOhm sense resistor, in mA. If a different sense 208 * resistor is installed, calculate the actual current by 209 * dividing the reported current by the sense resistor value 210 * in mOhm. 211 */ 212 val = DIV_ROUND_CLOSEST(val, 25); 213 break; 214 default: 215 return -EINVAL; 216 } 217 return val; 218 } 219 220 static ssize_t ltc2945_value_show(struct device *dev, 221 struct device_attribute *da, char *buf) 222 { 223 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 224 long long value; 225 226 value = ltc2945_reg_to_val(dev, attr->index); 227 if (value < 0) 228 return value; 229 return snprintf(buf, PAGE_SIZE, "%lld\n", value); 230 } 231 232 static ssize_t ltc2945_value_store(struct device *dev, 233 struct device_attribute *da, 234 const char *buf, size_t count) 235 { 236 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 237 struct regmap *regmap = dev_get_drvdata(dev); 238 u8 reg = attr->index; 239 unsigned long val; 240 u8 regbuf[3]; 241 int num_regs; 242 int regval; 243 int ret; 244 245 ret = kstrtoul(buf, 10, &val); 246 if (ret) 247 return ret; 248 249 /* convert to register value, then clamp and write result */ 250 regval = ltc2945_val_to_reg(dev, reg, val); 251 if (is_power_reg(reg)) { 252 regval = clamp_val(regval, 0, 0xffffff); 253 regbuf[0] = regval >> 16; 254 regbuf[1] = (regval >> 8) & 0xff; 255 regbuf[2] = regval; 256 num_regs = 3; 257 } else { 258 regval = clamp_val(regval, 0, 0xfff) << 4; 259 regbuf[0] = regval >> 8; 260 regbuf[1] = regval & 0xff; 261 num_regs = 2; 262 } 263 ret = regmap_bulk_write(regmap, reg, regbuf, num_regs); 264 return ret < 0 ? ret : count; 265 } 266 267 static ssize_t ltc2945_history_store(struct device *dev, 268 struct device_attribute *da, 269 const char *buf, size_t count) 270 { 271 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 272 struct regmap *regmap = dev_get_drvdata(dev); 273 u8 reg = attr->index; 274 int num_regs = is_power_reg(reg) ? 3 : 2; 275 u8 buf_min[3] = { 0xff, 0xff, 0xff }; 276 u8 buf_max[3] = { 0, 0, 0 }; 277 unsigned long val; 278 int ret; 279 280 ret = kstrtoul(buf, 10, &val); 281 if (ret) 282 return ret; 283 if (val != 1) 284 return -EINVAL; 285 286 ret = regmap_update_bits(regmap, LTC2945_CONTROL, CONTROL_TEST_MODE, 287 CONTROL_TEST_MODE); 288 289 /* Reset minimum */ 290 ret = regmap_bulk_write(regmap, reg, buf_min, num_regs); 291 if (ret) 292 return ret; 293 294 switch (reg) { 295 case LTC2945_MIN_POWER_H: 296 reg = LTC2945_MAX_POWER_H; 297 break; 298 case LTC2945_MIN_SENSE_H: 299 reg = LTC2945_MAX_SENSE_H; 300 break; 301 case LTC2945_MIN_VIN_H: 302 reg = LTC2945_MAX_VIN_H; 303 break; 304 case LTC2945_MIN_ADIN_H: 305 reg = LTC2945_MAX_ADIN_H; 306 break; 307 default: 308 WARN_ONCE(1, "Bad register: 0x%x\n", reg); 309 return -EINVAL; 310 } 311 /* Reset maximum */ 312 ret = regmap_bulk_write(regmap, reg, buf_max, num_regs); 313 314 /* Try resetting test mode even if there was an error */ 315 regmap_update_bits(regmap, LTC2945_CONTROL, CONTROL_TEST_MODE, 0); 316 317 return ret ? : count; 318 } 319 320 static ssize_t ltc2945_bool_show(struct device *dev, 321 struct device_attribute *da, char *buf) 322 { 323 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 324 struct regmap *regmap = dev_get_drvdata(dev); 325 unsigned int fault; 326 int ret; 327 328 ret = regmap_read(regmap, LTC2945_FAULT, &fault); 329 if (ret < 0) 330 return ret; 331 332 fault &= attr->index; 333 if (fault) /* Clear reported faults in chip register */ 334 regmap_update_bits(regmap, LTC2945_FAULT, attr->index, 0); 335 336 return snprintf(buf, PAGE_SIZE, "%d\n", !!fault); 337 } 338 339 /* Input voltages */ 340 341 static SENSOR_DEVICE_ATTR_RO(in1_input, ltc2945_value, LTC2945_VIN_H); 342 static SENSOR_DEVICE_ATTR_RW(in1_min, ltc2945_value, LTC2945_MIN_VIN_THRES_H); 343 static SENSOR_DEVICE_ATTR_RW(in1_max, ltc2945_value, LTC2945_MAX_VIN_THRES_H); 344 static SENSOR_DEVICE_ATTR_RO(in1_lowest, ltc2945_value, LTC2945_MIN_VIN_H); 345 static SENSOR_DEVICE_ATTR_RO(in1_highest, ltc2945_value, LTC2945_MAX_VIN_H); 346 static SENSOR_DEVICE_ATTR_WO(in1_reset_history, ltc2945_history, 347 LTC2945_MIN_VIN_H); 348 349 static SENSOR_DEVICE_ATTR_RO(in2_input, ltc2945_value, LTC2945_ADIN_H); 350 static SENSOR_DEVICE_ATTR_RW(in2_min, ltc2945_value, LTC2945_MIN_ADIN_THRES_H); 351 static SENSOR_DEVICE_ATTR_RW(in2_max, ltc2945_value, LTC2945_MAX_ADIN_THRES_H); 352 static SENSOR_DEVICE_ATTR_RO(in2_lowest, ltc2945_value, LTC2945_MIN_ADIN_H); 353 static SENSOR_DEVICE_ATTR_RO(in2_highest, ltc2945_value, LTC2945_MAX_ADIN_H); 354 static SENSOR_DEVICE_ATTR_WO(in2_reset_history, ltc2945_history, 355 LTC2945_MIN_ADIN_H); 356 357 /* Voltage alarms */ 358 359 static SENSOR_DEVICE_ATTR_RO(in1_min_alarm, ltc2945_bool, FAULT_VIN_UV); 360 static SENSOR_DEVICE_ATTR_RO(in1_max_alarm, ltc2945_bool, FAULT_VIN_OV); 361 static SENSOR_DEVICE_ATTR_RO(in2_min_alarm, ltc2945_bool, FAULT_ADIN_UV); 362 static SENSOR_DEVICE_ATTR_RO(in2_max_alarm, ltc2945_bool, FAULT_ADIN_OV); 363 364 /* Currents (via sense resistor) */ 365 366 static SENSOR_DEVICE_ATTR_RO(curr1_input, ltc2945_value, LTC2945_SENSE_H); 367 static SENSOR_DEVICE_ATTR_RW(curr1_min, ltc2945_value, 368 LTC2945_MIN_SENSE_THRES_H); 369 static SENSOR_DEVICE_ATTR_RW(curr1_max, ltc2945_value, 370 LTC2945_MAX_SENSE_THRES_H); 371 static SENSOR_DEVICE_ATTR_RO(curr1_lowest, ltc2945_value, LTC2945_MIN_SENSE_H); 372 static SENSOR_DEVICE_ATTR_RO(curr1_highest, ltc2945_value, 373 LTC2945_MAX_SENSE_H); 374 static SENSOR_DEVICE_ATTR_WO(curr1_reset_history, ltc2945_history, 375 LTC2945_MIN_SENSE_H); 376 377 /* Current alarms */ 378 379 static SENSOR_DEVICE_ATTR_RO(curr1_min_alarm, ltc2945_bool, FAULT_SENSE_UV); 380 static SENSOR_DEVICE_ATTR_RO(curr1_max_alarm, ltc2945_bool, FAULT_SENSE_OV); 381 382 /* Power */ 383 384 static SENSOR_DEVICE_ATTR_RO(power1_input, ltc2945_value, LTC2945_POWER_H); 385 static SENSOR_DEVICE_ATTR_RW(power1_min, ltc2945_value, 386 LTC2945_MIN_POWER_THRES_H); 387 static SENSOR_DEVICE_ATTR_RW(power1_max, ltc2945_value, 388 LTC2945_MAX_POWER_THRES_H); 389 static SENSOR_DEVICE_ATTR_RO(power1_input_lowest, ltc2945_value, 390 LTC2945_MIN_POWER_H); 391 static SENSOR_DEVICE_ATTR_RO(power1_input_highest, ltc2945_value, 392 LTC2945_MAX_POWER_H); 393 static SENSOR_DEVICE_ATTR_WO(power1_reset_history, ltc2945_history, 394 LTC2945_MIN_POWER_H); 395 396 /* Power alarms */ 397 398 static SENSOR_DEVICE_ATTR_RO(power1_min_alarm, ltc2945_bool, FAULT_POWER_UV); 399 static SENSOR_DEVICE_ATTR_RO(power1_max_alarm, ltc2945_bool, FAULT_POWER_OV); 400 401 static struct attribute *ltc2945_attrs[] = { 402 &sensor_dev_attr_in1_input.dev_attr.attr, 403 &sensor_dev_attr_in1_min.dev_attr.attr, 404 &sensor_dev_attr_in1_max.dev_attr.attr, 405 &sensor_dev_attr_in1_lowest.dev_attr.attr, 406 &sensor_dev_attr_in1_highest.dev_attr.attr, 407 &sensor_dev_attr_in1_reset_history.dev_attr.attr, 408 &sensor_dev_attr_in1_min_alarm.dev_attr.attr, 409 &sensor_dev_attr_in1_max_alarm.dev_attr.attr, 410 411 &sensor_dev_attr_in2_input.dev_attr.attr, 412 &sensor_dev_attr_in2_min.dev_attr.attr, 413 &sensor_dev_attr_in2_max.dev_attr.attr, 414 &sensor_dev_attr_in2_lowest.dev_attr.attr, 415 &sensor_dev_attr_in2_highest.dev_attr.attr, 416 &sensor_dev_attr_in2_reset_history.dev_attr.attr, 417 &sensor_dev_attr_in2_min_alarm.dev_attr.attr, 418 &sensor_dev_attr_in2_max_alarm.dev_attr.attr, 419 420 &sensor_dev_attr_curr1_input.dev_attr.attr, 421 &sensor_dev_attr_curr1_min.dev_attr.attr, 422 &sensor_dev_attr_curr1_max.dev_attr.attr, 423 &sensor_dev_attr_curr1_lowest.dev_attr.attr, 424 &sensor_dev_attr_curr1_highest.dev_attr.attr, 425 &sensor_dev_attr_curr1_reset_history.dev_attr.attr, 426 &sensor_dev_attr_curr1_min_alarm.dev_attr.attr, 427 &sensor_dev_attr_curr1_max_alarm.dev_attr.attr, 428 429 &sensor_dev_attr_power1_input.dev_attr.attr, 430 &sensor_dev_attr_power1_min.dev_attr.attr, 431 &sensor_dev_attr_power1_max.dev_attr.attr, 432 &sensor_dev_attr_power1_input_lowest.dev_attr.attr, 433 &sensor_dev_attr_power1_input_highest.dev_attr.attr, 434 &sensor_dev_attr_power1_reset_history.dev_attr.attr, 435 &sensor_dev_attr_power1_min_alarm.dev_attr.attr, 436 &sensor_dev_attr_power1_max_alarm.dev_attr.attr, 437 438 NULL, 439 }; 440 ATTRIBUTE_GROUPS(ltc2945); 441 442 static const struct regmap_config ltc2945_regmap_config = { 443 .reg_bits = 8, 444 .val_bits = 8, 445 .max_register = LTC2945_MIN_ADIN_THRES_L, 446 }; 447 448 static int ltc2945_probe(struct i2c_client *client, 449 const struct i2c_device_id *id) 450 { 451 struct device *dev = &client->dev; 452 struct device *hwmon_dev; 453 struct regmap *regmap; 454 455 regmap = devm_regmap_init_i2c(client, <c2945_regmap_config); 456 if (IS_ERR(regmap)) { 457 dev_err(dev, "failed to allocate register map\n"); 458 return PTR_ERR(regmap); 459 } 460 461 /* Clear faults */ 462 regmap_write(regmap, LTC2945_FAULT, 0x00); 463 464 hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name, 465 regmap, 466 ltc2945_groups); 467 return PTR_ERR_OR_ZERO(hwmon_dev); 468 } 469 470 static const struct i2c_device_id ltc2945_id[] = { 471 {"ltc2945", 0}, 472 { } 473 }; 474 475 MODULE_DEVICE_TABLE(i2c, ltc2945_id); 476 477 static struct i2c_driver ltc2945_driver = { 478 .driver = { 479 .name = "ltc2945", 480 }, 481 .probe = ltc2945_probe, 482 .id_table = ltc2945_id, 483 }; 484 485 module_i2c_driver(ltc2945_driver); 486 487 MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>"); 488 MODULE_DESCRIPTION("LTC2945 driver"); 489 MODULE_LICENSE("GPL"); 490