1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Device driver for regulators in MAX5970 and MAX5978 IC 4 * 5 * Copyright (c) 2022 9elements GmbH 6 * 7 * Author: Patrick Rudolph <patrick.rudolph@9elements.com> 8 */ 9 10 #include <linux/bitops.h> 11 #include <linux/device.h> 12 #include <linux/err.h> 13 #include <linux/module.h> 14 #include <linux/io.h> 15 #include <linux/of.h> 16 #include <linux/i2c.h> 17 #include <linux/regmap.h> 18 #include <linux/regulator/driver.h> 19 #include <linux/regulator/machine.h> 20 #include <linux/regulator/of_regulator.h> 21 #include <linux/platform_device.h> 22 23 #include <linux/mfd/max5970.h> 24 25 struct max5970_regulator { 26 int num_switches, mon_rng, irng, shunt_micro_ohms, lim_uA; 27 struct regmap *regmap; 28 }; 29 30 enum max597x_regulator_id { 31 MAX597X_SW0, 32 MAX597X_SW1, 33 }; 34 35 static int max597x_uvp_ovp_check_mode(struct regulator_dev *rdev, int severity) 36 { 37 int ret, reg; 38 39 /* Status1 register contains the soft strap values sampled at POR */ 40 ret = regmap_read(rdev->regmap, MAX5970_REG_STATUS1, ®); 41 if (ret) 42 return ret; 43 44 /* Check soft straps match requested mode */ 45 if (severity == REGULATOR_SEVERITY_PROT) { 46 if (STATUS1_PROT(reg) != STATUS1_PROT_SHUTDOWN) 47 return -EOPNOTSUPP; 48 49 return 0; 50 } 51 if (STATUS1_PROT(reg) == STATUS1_PROT_SHUTDOWN) 52 return -EOPNOTSUPP; 53 54 return 0; 55 } 56 57 static int max597x_set_vp(struct regulator_dev *rdev, int lim_uV, int severity, 58 bool enable, bool overvoltage) 59 { 60 int off_h, off_l, reg, ret; 61 struct max5970_regulator *data = rdev_get_drvdata(rdev); 62 int channel = rdev_get_id(rdev); 63 64 if (overvoltage) { 65 if (severity == REGULATOR_SEVERITY_WARN) { 66 off_h = MAX5970_REG_CH_OV_WARN_H(channel); 67 off_l = MAX5970_REG_CH_OV_WARN_L(channel); 68 } else { 69 off_h = MAX5970_REG_CH_OV_CRIT_H(channel); 70 off_l = MAX5970_REG_CH_OV_CRIT_L(channel); 71 } 72 } else { 73 if (severity == REGULATOR_SEVERITY_WARN) { 74 off_h = MAX5970_REG_CH_UV_WARN_H(channel); 75 off_l = MAX5970_REG_CH_UV_WARN_L(channel); 76 } else { 77 off_h = MAX5970_REG_CH_UV_CRIT_H(channel); 78 off_l = MAX5970_REG_CH_UV_CRIT_L(channel); 79 } 80 } 81 82 if (enable) 83 /* reg = ADC_MASK * (lim_uV / 1000000) / (data->mon_rng / 1000000) */ 84 reg = ADC_MASK * lim_uV / data->mon_rng; 85 else 86 reg = 0; 87 88 ret = regmap_write(rdev->regmap, off_h, MAX5970_VAL2REG_H(reg)); 89 if (ret) 90 return ret; 91 92 ret = regmap_write(rdev->regmap, off_l, MAX5970_VAL2REG_L(reg)); 93 if (ret) 94 return ret; 95 96 return 0; 97 } 98 99 static int max597x_set_uvp(struct regulator_dev *rdev, int lim_uV, int severity, 100 bool enable) 101 { 102 int ret; 103 104 /* 105 * MAX5970 has enable control as a special value in limit reg. Can't 106 * set limit but keep feature disabled or enable W/O given limit. 107 */ 108 if ((lim_uV && !enable) || (!lim_uV && enable)) 109 return -EINVAL; 110 111 ret = max597x_uvp_ovp_check_mode(rdev, severity); 112 if (ret) 113 return ret; 114 115 return max597x_set_vp(rdev, lim_uV, severity, enable, false); 116 } 117 118 static int max597x_set_ovp(struct regulator_dev *rdev, int lim_uV, int severity, 119 bool enable) 120 { 121 int ret; 122 123 /* 124 * MAX5970 has enable control as a special value in limit reg. Can't 125 * set limit but keep feature disabled or enable W/O given limit. 126 */ 127 if ((lim_uV && !enable) || (!lim_uV && enable)) 128 return -EINVAL; 129 130 ret = max597x_uvp_ovp_check_mode(rdev, severity); 131 if (ret) 132 return ret; 133 134 return max597x_set_vp(rdev, lim_uV, severity, enable, true); 135 } 136 137 static int max597x_set_ocp(struct regulator_dev *rdev, int lim_uA, 138 int severity, bool enable) 139 { 140 int val, reg; 141 unsigned int vthst, vthfst; 142 143 struct max5970_regulator *data = rdev_get_drvdata(rdev); 144 int rdev_id = rdev_get_id(rdev); 145 /* 146 * MAX5970 doesn't has enable control for ocp. 147 * If limit is specified but enable is not set then hold the value in 148 * variable & later use it when ocp needs to be enabled. 149 */ 150 if (lim_uA != 0 && lim_uA != data->lim_uA) 151 data->lim_uA = lim_uA; 152 153 if (severity != REGULATOR_SEVERITY_PROT) 154 return -EINVAL; 155 156 if (enable) { 157 158 /* Calc Vtrip threshold in uV. */ 159 vthst = 160 div_u64(mul_u32_u32(data->shunt_micro_ohms, data->lim_uA), 161 1000000); 162 163 /* 164 * As recommended in datasheed, add 20% margin to avoid 165 * spurious event & passive component tolerance. 166 */ 167 vthst = div_u64(mul_u32_u32(vthst, 120), 100); 168 169 /* Calc fast Vtrip threshold in uV */ 170 vthfst = vthst * (MAX5970_FAST2SLOW_RATIO / 100); 171 172 if (vthfst > data->irng) { 173 dev_err(&rdev->dev, "Current limit out of range\n"); 174 return -EINVAL; 175 } 176 /* Fast trip threshold to be programmed */ 177 val = div_u64(mul_u32_u32(0xFF, vthfst), data->irng); 178 } else 179 /* 180 * Since there is no option to disable ocp, set limit to max 181 * value 182 */ 183 val = 0xFF; 184 185 reg = MAX5970_REG_DAC_FAST(rdev_id); 186 187 return regmap_write(rdev->regmap, reg, val); 188 } 189 190 static int max597x_get_status(struct regulator_dev *rdev) 191 { 192 int val, ret; 193 194 ret = regmap_read(rdev->regmap, MAX5970_REG_STATUS3, &val); 195 if (ret) 196 return ret; 197 198 if (val & MAX5970_STATUS3_ALERT) 199 return REGULATOR_STATUS_ERROR; 200 201 ret = regulator_is_enabled_regmap(rdev); 202 if (ret < 0) 203 return ret; 204 205 if (ret) 206 return REGULATOR_STATUS_ON; 207 208 return REGULATOR_STATUS_OFF; 209 } 210 211 static const struct regulator_ops max597x_switch_ops = { 212 .enable = regulator_enable_regmap, 213 .disable = regulator_disable_regmap, 214 .is_enabled = regulator_is_enabled_regmap, 215 .get_status = max597x_get_status, 216 .set_over_voltage_protection = max597x_set_ovp, 217 .set_under_voltage_protection = max597x_set_uvp, 218 .set_over_current_protection = max597x_set_ocp, 219 }; 220 221 static int max597x_dt_parse(struct device_node *np, 222 const struct regulator_desc *desc, 223 struct regulator_config *cfg) 224 { 225 struct max5970_regulator *data = cfg->driver_data; 226 int ret = 0; 227 228 ret = 229 of_property_read_u32(np, "shunt-resistor-micro-ohms", 230 &data->shunt_micro_ohms); 231 if (ret < 0) 232 dev_err(cfg->dev, 233 "property 'shunt-resistor-micro-ohms' not found, err %d\n", 234 ret); 235 return ret; 236 237 } 238 239 #define MAX597X_SWITCH(_ID, _ereg, _chan, _supply) { \ 240 .name = #_ID, \ 241 .of_match = of_match_ptr(#_ID), \ 242 .ops = &max597x_switch_ops, \ 243 .regulators_node = of_match_ptr("regulators"), \ 244 .type = REGULATOR_VOLTAGE, \ 245 .id = MAX597X_##_ID, \ 246 .owner = THIS_MODULE, \ 247 .supply_name = _supply, \ 248 .enable_reg = _ereg, \ 249 .enable_mask = CHXEN((_chan)), \ 250 .of_parse_cb = max597x_dt_parse, \ 251 } 252 253 static const struct regulator_desc regulators[] = { 254 MAX597X_SWITCH(SW0, MAX5970_REG_CHXEN, 0, "vss1"), 255 MAX597X_SWITCH(SW1, MAX5970_REG_CHXEN, 1, "vss2"), 256 }; 257 258 static int max597x_regmap_read_clear(struct regmap *map, unsigned int reg, 259 unsigned int *val) 260 { 261 int ret; 262 263 ret = regmap_read(map, reg, val); 264 if (ret) 265 return ret; 266 267 if (*val) 268 return regmap_write(map, reg, *val); 269 270 return 0; 271 } 272 273 static int max597x_irq_handler(int irq, struct regulator_irq_data *rid, 274 unsigned long *dev_mask) 275 { 276 struct regulator_err_state *stat; 277 struct max5970_regulator *d = (struct max5970_regulator *)rid->data; 278 int val, ret, i; 279 280 ret = max597x_regmap_read_clear(d->regmap, MAX5970_REG_FAULT0, &val); 281 if (ret) 282 return REGULATOR_FAILED_RETRY; 283 284 *dev_mask = 0; 285 for (i = 0; i < d->num_switches; i++) { 286 stat = &rid->states[i]; 287 stat->notifs = 0; 288 stat->errors = 0; 289 } 290 291 for (i = 0; i < d->num_switches; i++) { 292 stat = &rid->states[i]; 293 294 if (val & UV_STATUS_CRIT(i)) { 295 *dev_mask |= 1 << i; 296 stat->notifs |= REGULATOR_EVENT_UNDER_VOLTAGE; 297 stat->errors |= REGULATOR_ERROR_UNDER_VOLTAGE; 298 } else if (val & UV_STATUS_WARN(i)) { 299 *dev_mask |= 1 << i; 300 stat->notifs |= REGULATOR_EVENT_UNDER_VOLTAGE_WARN; 301 stat->errors |= REGULATOR_ERROR_UNDER_VOLTAGE_WARN; 302 } 303 } 304 305 ret = max597x_regmap_read_clear(d->regmap, MAX5970_REG_FAULT1, &val); 306 if (ret) 307 return REGULATOR_FAILED_RETRY; 308 309 for (i = 0; i < d->num_switches; i++) { 310 stat = &rid->states[i]; 311 312 if (val & OV_STATUS_CRIT(i)) { 313 *dev_mask |= 1 << i; 314 stat->notifs |= REGULATOR_EVENT_REGULATION_OUT; 315 stat->errors |= REGULATOR_ERROR_REGULATION_OUT; 316 } else if (val & OV_STATUS_WARN(i)) { 317 *dev_mask |= 1 << i; 318 stat->notifs |= REGULATOR_EVENT_OVER_VOLTAGE_WARN; 319 stat->errors |= REGULATOR_ERROR_OVER_VOLTAGE_WARN; 320 } 321 } 322 323 ret = max597x_regmap_read_clear(d->regmap, MAX5970_REG_FAULT2, &val); 324 if (ret) 325 return REGULATOR_FAILED_RETRY; 326 327 for (i = 0; i < d->num_switches; i++) { 328 stat = &rid->states[i]; 329 330 if (val & OC_STATUS_WARN(i)) { 331 *dev_mask |= 1 << i; 332 stat->notifs |= REGULATOR_EVENT_OVER_CURRENT_WARN; 333 stat->errors |= REGULATOR_ERROR_OVER_CURRENT_WARN; 334 } 335 } 336 337 ret = regmap_read(d->regmap, MAX5970_REG_STATUS0, &val); 338 if (ret) 339 return REGULATOR_FAILED_RETRY; 340 341 for (i = 0; i < d->num_switches; i++) { 342 stat = &rid->states[i]; 343 344 if ((val & MAX5970_CB_IFAULTF(i)) 345 || (val & MAX5970_CB_IFAULTS(i))) { 346 *dev_mask |= 1 << i; 347 stat->notifs |= 348 REGULATOR_EVENT_OVER_CURRENT | 349 REGULATOR_EVENT_DISABLE; 350 stat->errors |= 351 REGULATOR_ERROR_OVER_CURRENT | REGULATOR_ERROR_FAIL; 352 353 /* Clear the sub-IRQ status */ 354 regulator_disable_regmap(stat->rdev); 355 } 356 } 357 return 0; 358 } 359 360 static int max597x_adc_range(struct regmap *regmap, const int ch, 361 u32 *irng, u32 *mon_rng) 362 { 363 unsigned int reg; 364 int ret; 365 366 /* Decode current ADC range */ 367 ret = regmap_read(regmap, MAX5970_REG_STATUS2, ®); 368 if (ret) 369 return ret; 370 switch (MAX5970_IRNG(reg, ch)) { 371 case 0: 372 *irng = 100000; /* 100 mV */ 373 break; 374 case 1: 375 *irng = 50000; /* 50 mV */ 376 break; 377 case 2: 378 *irng = 25000; /* 25 mV */ 379 break; 380 default: 381 return -EINVAL; 382 } 383 384 /* Decode current voltage monitor range */ 385 ret = regmap_read(regmap, MAX5970_REG_MON_RANGE, ®); 386 if (ret) 387 return ret; 388 389 *mon_rng = MAX5970_MON_MAX_RANGE_UV >> MAX5970_MON(reg, ch); 390 391 return 0; 392 } 393 394 static int max597x_setup_irq(struct device *dev, 395 int irq, 396 struct regulator_dev *rdevs[MAX5970_NUM_SWITCHES], 397 int num_switches, struct max5970_regulator *data) 398 { 399 struct regulator_irq_desc max597x_notif = { 400 .name = "max597x-irq", 401 .map_event = max597x_irq_handler, 402 .data = data, 403 }; 404 int errs = REGULATOR_ERROR_UNDER_VOLTAGE | 405 REGULATOR_ERROR_UNDER_VOLTAGE_WARN | 406 REGULATOR_ERROR_OVER_VOLTAGE_WARN | 407 REGULATOR_ERROR_REGULATION_OUT | 408 REGULATOR_ERROR_OVER_CURRENT | 409 REGULATOR_ERROR_OVER_CURRENT_WARN | REGULATOR_ERROR_FAIL; 410 void *irq_helper; 411 412 /* Register notifiers - can fail if IRQ is not given */ 413 irq_helper = devm_regulator_irq_helper(dev, &max597x_notif, 414 irq, 0, errs, NULL, 415 &rdevs[0], num_switches); 416 if (IS_ERR(irq_helper)) { 417 if (PTR_ERR(irq_helper) == -EPROBE_DEFER) 418 return -EPROBE_DEFER; 419 420 dev_warn(dev, "IRQ disabled %pe\n", irq_helper); 421 } 422 423 return 0; 424 } 425 426 static int max597x_regulator_probe(struct platform_device *pdev) 427 { 428 struct max5970_data *max597x; 429 struct regmap *regmap = dev_get_regmap(pdev->dev.parent, NULL); 430 struct max5970_regulator *data; 431 struct i2c_client *i2c = to_i2c_client(pdev->dev.parent); 432 struct regulator_config config = { }; 433 struct regulator_dev *rdev; 434 struct regulator_dev *rdevs[MAX5970_NUM_SWITCHES]; 435 int num_switches; 436 int ret, i; 437 438 if (!regmap) 439 return -EPROBE_DEFER; 440 441 max597x = devm_kzalloc(&i2c->dev, sizeof(struct max5970_data), GFP_KERNEL); 442 if (!max597x) 443 return -ENOMEM; 444 445 i2c_set_clientdata(i2c, max597x); 446 447 if (of_device_is_compatible(i2c->dev.of_node, "maxim,max5978")) 448 max597x->num_switches = MAX5978_NUM_SWITCHES; 449 else if (of_device_is_compatible(i2c->dev.of_node, "maxim,max5970")) 450 max597x->num_switches = MAX5970_NUM_SWITCHES; 451 else 452 return -ENODEV; 453 454 i2c_set_clientdata(i2c, max597x); 455 num_switches = max597x->num_switches; 456 457 for (i = 0; i < num_switches; i++) { 458 data = 459 devm_kzalloc(&i2c->dev, sizeof(struct max5970_regulator), 460 GFP_KERNEL); 461 if (!data) 462 return -ENOMEM; 463 464 data->num_switches = num_switches; 465 data->regmap = regmap; 466 467 ret = max597x_adc_range(regmap, i, &max597x->irng[i], &max597x->mon_rng[i]); 468 if (ret < 0) 469 return ret; 470 471 data->irng = max597x->irng[i]; 472 data->mon_rng = max597x->mon_rng[i]; 473 474 config.dev = &i2c->dev; 475 config.driver_data = (void *)data; 476 config.regmap = data->regmap; 477 rdev = devm_regulator_register(&i2c->dev, 478 ®ulators[i], &config); 479 if (IS_ERR(rdev)) { 480 dev_err(&i2c->dev, "failed to register regulator %s\n", 481 regulators[i].name); 482 return PTR_ERR(rdev); 483 } 484 rdevs[i] = rdev; 485 max597x->shunt_micro_ohms[i] = data->shunt_micro_ohms; 486 } 487 488 if (i2c->irq) { 489 ret = 490 max597x_setup_irq(&i2c->dev, i2c->irq, rdevs, num_switches, 491 data); 492 if (ret) { 493 dev_err(&i2c->dev, "IRQ setup failed"); 494 return ret; 495 } 496 } 497 498 return ret; 499 } 500 501 static struct platform_driver max597x_regulator_driver = { 502 .driver = { 503 .name = "max5970-regulator", 504 .probe_type = PROBE_PREFER_ASYNCHRONOUS, 505 }, 506 .probe = max597x_regulator_probe, 507 }; 508 509 module_platform_driver(max597x_regulator_driver); 510 511 512 MODULE_AUTHOR("Patrick Rudolph <patrick.rudolph@9elements.com>"); 513 MODULE_DESCRIPTION("MAX5970_hot-swap controller driver"); 514 MODULE_LICENSE("GPL v2"); 515