1 /* 2 * Copyright (C) 2016 Gateworks Corporation, Inc. All Rights Reserved. 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 version 2 6 * as published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it will be useful, 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11 * GNU General Public License for more details. 12 * 13 */ 14 #include <linux/i2c.h> 15 #include <linux/init.h> 16 #include <linux/interrupt.h> 17 #include <linux/module.h> 18 #include <linux/kernel.h> 19 #include <linux/of.h> 20 #include <linux/regmap.h> 21 #include <linux/regulator/driver.h> 22 #include <linux/regulator/machine.h> 23 #include <linux/regulator/of_regulator.h> 24 25 #define DRIVER_NAME "ltc3676" 26 27 /* LTC3676 Registers */ 28 #define LTC3676_BUCK1 0x01 29 #define LTC3676_BUCK2 0x02 30 #define LTC3676_BUCK3 0x03 31 #define LTC3676_BUCK4 0x04 32 #define LTC3676_LDOA 0x05 33 #define LTC3676_LDOB 0x06 34 #define LTC3676_SQD1 0x07 35 #define LTC3676_SQD2 0x08 36 #define LTC3676_CNTRL 0x09 37 #define LTC3676_DVB1A 0x0A 38 #define LTC3676_DVB1B 0x0B 39 #define LTC3676_DVB2A 0x0C 40 #define LTC3676_DVB2B 0x0D 41 #define LTC3676_DVB3A 0x0E 42 #define LTC3676_DVB3B 0x0F 43 #define LTC3676_DVB4A 0x10 44 #define LTC3676_DVB4B 0x11 45 #define LTC3676_MSKIRQ 0x12 46 #define LTC3676_MSKPG 0x13 47 #define LTC3676_USER 0x14 48 #define LTC3676_IRQSTAT 0x15 49 #define LTC3676_PGSTATL 0x16 50 #define LTC3676_PGSTATRT 0x17 51 #define LTC3676_HRST 0x1E 52 #define LTC3676_CLIRQ 0x1F 53 54 #define LTC3676_DVBxA_REF_SELECT BIT(5) 55 #define LTC3676_DVBxB_PGOOD_MASK BIT(5) 56 57 #define LTC3676_IRQSTAT_PGOOD_TIMEOUT BIT(3) 58 #define LTC3676_IRQSTAT_UNDERVOLT_WARN BIT(4) 59 #define LTC3676_IRQSTAT_UNDERVOLT_FAULT BIT(5) 60 #define LTC3676_IRQSTAT_THERMAL_WARN BIT(6) 61 #define LTC3676_IRQSTAT_THERMAL_FAULT BIT(7) 62 63 enum ltc3676_reg { 64 LTC3676_SW1, 65 LTC3676_SW2, 66 LTC3676_SW3, 67 LTC3676_SW4, 68 LTC3676_LDO1, 69 LTC3676_LDO2, 70 LTC3676_LDO3, 71 LTC3676_LDO4, 72 LTC3676_NUM_REGULATORS, 73 }; 74 75 struct ltc3676 { 76 struct regmap *regmap; 77 struct device *dev; 78 struct regulator_desc regulator_descs[LTC3676_NUM_REGULATORS]; 79 struct regulator_dev *regulators[LTC3676_NUM_REGULATORS]; 80 }; 81 82 static int ltc3676_set_suspend_voltage(struct regulator_dev *rdev, int uV) 83 { 84 struct ltc3676 *ltc3676 = rdev_get_drvdata(rdev); 85 struct device *dev = ltc3676->dev; 86 int dcdc = rdev_get_id(rdev); 87 int sel; 88 89 dev_dbg(dev, "%s id=%d uV=%d\n", __func__, dcdc, uV); 90 sel = regulator_map_voltage_linear(rdev, uV, uV); 91 if (sel < 0) 92 return sel; 93 94 /* DVBB register follows right after the corresponding DVBA register */ 95 return regmap_update_bits(ltc3676->regmap, rdev->desc->vsel_reg + 1, 96 rdev->desc->vsel_mask, sel); 97 } 98 99 static int ltc3676_set_suspend_mode(struct regulator_dev *rdev, 100 unsigned int mode) 101 { 102 struct ltc3676 *ltc3676= rdev_get_drvdata(rdev); 103 struct device *dev = ltc3676->dev; 104 int mask, val; 105 int dcdc = rdev_get_id(rdev); 106 107 dev_dbg(dev, "%s id=%d mode=%d\n", __func__, dcdc, mode); 108 109 mask = LTC3676_DVBxA_REF_SELECT; 110 switch (mode) { 111 case REGULATOR_MODE_STANDBY: 112 val = 0; /* select DVBxA */ 113 break; 114 case REGULATOR_MODE_NORMAL: 115 val = LTC3676_DVBxA_REF_SELECT; /* select DVBxB */ 116 break; 117 default: 118 dev_warn(&rdev->dev, "%s: regulator mode: 0x%x not supported\n", 119 rdev->desc->name, mode); 120 return -EINVAL; 121 } 122 123 return regmap_update_bits(ltc3676->regmap, rdev->desc->vsel_reg, 124 mask, val); 125 } 126 127 static int ltc3676_set_voltage_sel(struct regulator_dev *rdev, unsigned selector) 128 { 129 struct ltc3676 *ltc3676 = rdev_get_drvdata(rdev); 130 struct device *dev = ltc3676->dev; 131 int ret, dcdc = rdev_get_id(rdev); 132 133 dev_dbg(dev, "%s id=%d selector=%d\n", __func__, dcdc, selector); 134 135 ret = regmap_update_bits(ltc3676->regmap, rdev->desc->vsel_reg + 1, 136 LTC3676_DVBxB_PGOOD_MASK, 137 LTC3676_DVBxB_PGOOD_MASK); 138 if (ret) 139 return ret; 140 141 return regulator_set_voltage_sel_regmap(rdev, selector); 142 } 143 144 static inline unsigned int ltc3676_scale(unsigned int uV, u32 r1, u32 r2) 145 { 146 uint64_t tmp; 147 if (uV == 0) 148 return 0; 149 tmp = (uint64_t)uV * r1; 150 do_div(tmp, r2); 151 return uV + (unsigned int)tmp; 152 } 153 154 static int ltc3676_of_parse_cb(struct device_node *np, 155 const struct regulator_desc *desc, 156 struct regulator_config *config) 157 { 158 struct ltc3676 *ltc3676 = config->driver_data; 159 struct regulator_desc *rdesc = <c3676->regulator_descs[desc->id]; 160 u32 r[2]; 161 int ret; 162 163 /* LDO3 has a fixed output */ 164 if (desc->id == LTC3676_LDO3) 165 return 0; 166 167 ret = of_property_read_u32_array(np, "lltc,fb-voltage-divider", r, 2); 168 if (ret) { 169 dev_err(ltc3676->dev, "Failed to parse voltage divider: %d\n", 170 ret); 171 return ret; 172 } 173 174 rdesc->min_uV = ltc3676_scale(desc->min_uV, r[0], r[1]); 175 rdesc->uV_step = ltc3676_scale(desc->uV_step, r[0], r[1]); 176 rdesc->fixed_uV = ltc3676_scale(desc->fixed_uV, r[0], r[1]); 177 178 return 0; 179 } 180 181 /* SW1, SW2, SW3, SW4 linear 0.8V-3.3V with scalar via R1/R2 feeback res */ 182 static const struct regulator_ops ltc3676_linear_regulator_ops = { 183 .enable = regulator_enable_regmap, 184 .disable = regulator_disable_regmap, 185 .is_enabled = regulator_is_enabled_regmap, 186 .list_voltage = regulator_list_voltage_linear, 187 .set_voltage_sel = ltc3676_set_voltage_sel, 188 .get_voltage_sel = regulator_get_voltage_sel_regmap, 189 .set_suspend_voltage = ltc3676_set_suspend_voltage, 190 .set_suspend_mode = ltc3676_set_suspend_mode, 191 }; 192 193 /* LDO1 always on fixed 0.8V-3.3V via scalar via R1/R2 feeback res */ 194 static const struct regulator_ops ltc3676_fixed_standby_regulator_ops = { 195 }; 196 197 /* LDO2, LDO3 fixed (LDO2 has external scalar via R1/R2 feedback res) */ 198 static const struct regulator_ops ltc3676_fixed_regulator_ops = { 199 .enable = regulator_enable_regmap, 200 .disable = regulator_disable_regmap, 201 .is_enabled = regulator_is_enabled_regmap, 202 }; 203 204 #define LTC3676_REG(_id, _name, _ops, en_reg, en_bit, dvba_reg, dvb_mask) \ 205 [LTC3676_ ## _id] = { \ 206 .name = #_name, \ 207 .of_match = of_match_ptr(#_name), \ 208 .regulators_node = of_match_ptr("regulators"), \ 209 .of_parse_cb = ltc3676_of_parse_cb, \ 210 .n_voltages = (dvb_mask) + 1, \ 211 .min_uV = (dvba_reg) ? 412500 : 0, \ 212 .uV_step = (dvba_reg) ? 12500 : 0, \ 213 .ramp_delay = (dvba_reg) ? 800 : 0, \ 214 .fixed_uV = (dvb_mask) ? 0 : 725000, \ 215 .ops = <c3676_ ## _ops ## _regulator_ops, \ 216 .type = REGULATOR_VOLTAGE, \ 217 .id = LTC3676_ ## _id, \ 218 .owner = THIS_MODULE, \ 219 .vsel_reg = (dvba_reg), \ 220 .vsel_mask = (dvb_mask), \ 221 .enable_reg = (en_reg), \ 222 .enable_mask = (1 << en_bit), \ 223 } 224 225 #define LTC3676_LINEAR_REG(_id, _name, _en, _dvba) \ 226 LTC3676_REG(_id, _name, linear, \ 227 LTC3676_ ## _en, 7, \ 228 LTC3676_ ## _dvba, 0x1f) 229 230 #define LTC3676_FIXED_REG(_id, _name, _en_reg, _en_bit) \ 231 LTC3676_REG(_id, _name, fixed, LTC3676_ ## _en_reg, _en_bit, 0, 0) 232 233 static struct regulator_desc ltc3676_regulators[LTC3676_NUM_REGULATORS] = { 234 LTC3676_LINEAR_REG(SW1, sw1, BUCK1, DVB1A), 235 LTC3676_LINEAR_REG(SW2, sw2, BUCK2, DVB2A), 236 LTC3676_LINEAR_REG(SW3, sw3, BUCK3, DVB3A), 237 LTC3676_LINEAR_REG(SW4, sw4, BUCK4, DVB4A), 238 LTC3676_REG(LDO1, ldo1, fixed_standby, 0, 0, 0, 0), 239 LTC3676_FIXED_REG(LDO2, ldo2, LDOA, 2), 240 LTC3676_FIXED_REG(LDO3, ldo3, LDOA, 5), 241 LTC3676_FIXED_REG(LDO4, ldo4, LDOB, 2), 242 }; 243 244 static bool ltc3676_writeable_reg(struct device *dev, unsigned int reg) 245 { 246 switch (reg) { 247 case LTC3676_IRQSTAT: 248 case LTC3676_BUCK1: 249 case LTC3676_BUCK2: 250 case LTC3676_BUCK3: 251 case LTC3676_BUCK4: 252 case LTC3676_LDOA: 253 case LTC3676_LDOB: 254 case LTC3676_SQD1: 255 case LTC3676_SQD2: 256 case LTC3676_CNTRL: 257 case LTC3676_DVB1A: 258 case LTC3676_DVB1B: 259 case LTC3676_DVB2A: 260 case LTC3676_DVB2B: 261 case LTC3676_DVB3A: 262 case LTC3676_DVB3B: 263 case LTC3676_DVB4A: 264 case LTC3676_DVB4B: 265 case LTC3676_MSKIRQ: 266 case LTC3676_MSKPG: 267 case LTC3676_USER: 268 case LTC3676_HRST: 269 case LTC3676_CLIRQ: 270 return true; 271 } 272 return false; 273 } 274 275 static bool ltc3676_readable_reg(struct device *dev, unsigned int reg) 276 { 277 switch (reg) { 278 case LTC3676_IRQSTAT: 279 case LTC3676_BUCK1: 280 case LTC3676_BUCK2: 281 case LTC3676_BUCK3: 282 case LTC3676_BUCK4: 283 case LTC3676_LDOA: 284 case LTC3676_LDOB: 285 case LTC3676_SQD1: 286 case LTC3676_SQD2: 287 case LTC3676_CNTRL: 288 case LTC3676_DVB1A: 289 case LTC3676_DVB1B: 290 case LTC3676_DVB2A: 291 case LTC3676_DVB2B: 292 case LTC3676_DVB3A: 293 case LTC3676_DVB3B: 294 case LTC3676_DVB4A: 295 case LTC3676_DVB4B: 296 case LTC3676_MSKIRQ: 297 case LTC3676_MSKPG: 298 case LTC3676_USER: 299 case LTC3676_HRST: 300 case LTC3676_CLIRQ: 301 return true; 302 } 303 return false; 304 } 305 306 static bool ltc3676_volatile_reg(struct device *dev, unsigned int reg) 307 { 308 switch (reg) { 309 case LTC3676_IRQSTAT: 310 case LTC3676_PGSTATL: 311 case LTC3676_PGSTATRT: 312 return true; 313 } 314 return false; 315 } 316 317 static const struct regmap_config ltc3676_regmap_config = { 318 .reg_bits = 8, 319 .val_bits = 8, 320 .writeable_reg = ltc3676_writeable_reg, 321 .readable_reg = ltc3676_readable_reg, 322 .volatile_reg = ltc3676_volatile_reg, 323 .max_register = LTC3676_CLIRQ, 324 .use_single_rw = true, 325 .cache_type = REGCACHE_RBTREE, 326 }; 327 328 static irqreturn_t ltc3676_isr(int irq, void *dev_id) 329 { 330 struct ltc3676 *ltc3676 = dev_id; 331 struct device *dev = ltc3676->dev; 332 unsigned int i, irqstat, event; 333 334 regmap_read(ltc3676->regmap, LTC3676_IRQSTAT, &irqstat); 335 336 dev_dbg(dev, "irq%d irqstat=0x%02x\n", irq, irqstat); 337 if (irqstat & LTC3676_IRQSTAT_THERMAL_WARN) { 338 dev_warn(dev, "Over-temperature Warning\n"); 339 event = REGULATOR_EVENT_OVER_TEMP; 340 for (i = 0; i < LTC3676_NUM_REGULATORS; i++) 341 regulator_notifier_call_chain(ltc3676->regulators[i], 342 event, NULL); 343 } 344 345 if (irqstat & LTC3676_IRQSTAT_UNDERVOLT_WARN) { 346 dev_info(dev, "Undervoltage Warning\n"); 347 event = REGULATOR_EVENT_UNDER_VOLTAGE; 348 for (i = 0; i < LTC3676_NUM_REGULATORS; i++) 349 regulator_notifier_call_chain(ltc3676->regulators[i], 350 event, NULL); 351 } 352 353 /* Clear warning condition */ 354 regmap_write(ltc3676->regmap, LTC3676_CLIRQ, 0); 355 356 return IRQ_HANDLED; 357 } 358 359 static int ltc3676_regulator_probe(struct i2c_client *client, 360 const struct i2c_device_id *id) 361 { 362 struct device *dev = &client->dev; 363 struct regulator_init_data *init_data = dev_get_platdata(dev); 364 struct regulator_desc *descs; 365 struct ltc3676 *ltc3676; 366 int i, ret; 367 368 ltc3676 = devm_kzalloc(dev, sizeof(*ltc3676), GFP_KERNEL); 369 if (!ltc3676) 370 return -ENOMEM; 371 372 i2c_set_clientdata(client, ltc3676); 373 ltc3676->dev = dev; 374 375 descs = ltc3676->regulator_descs; 376 memcpy(descs, ltc3676_regulators, sizeof(ltc3676_regulators)); 377 descs[LTC3676_LDO3].fixed_uV = 1800000; /* LDO3 is fixed 1.8V */ 378 379 ltc3676->regmap = devm_regmap_init_i2c(client, <c3676_regmap_config); 380 if (IS_ERR(ltc3676->regmap)) { 381 ret = PTR_ERR(ltc3676->regmap); 382 dev_err(dev, "failed to initialize regmap: %d\n", ret); 383 return ret; 384 } 385 386 for (i = 0; i < LTC3676_NUM_REGULATORS; i++) { 387 struct regulator_desc *desc = <c3676->regulator_descs[i]; 388 struct regulator_config config = { }; 389 390 if (init_data) 391 config.init_data = &init_data[i]; 392 393 config.dev = dev; 394 config.driver_data = ltc3676; 395 396 ltc3676->regulators[i] = devm_regulator_register(dev, desc, 397 &config); 398 if (IS_ERR(ltc3676->regulators[i])) { 399 ret = PTR_ERR(ltc3676->regulators[i]); 400 dev_err(dev, "failed to register regulator %s: %d\n", 401 desc->name, ret); 402 return ret; 403 } 404 } 405 406 regmap_write(ltc3676->regmap, LTC3676_CLIRQ, 0); 407 if (client->irq) { 408 ret = devm_request_threaded_irq(dev, client->irq, NULL, 409 ltc3676_isr, 410 IRQF_TRIGGER_LOW | IRQF_ONESHOT, 411 client->name, ltc3676); 412 if (ret) { 413 dev_err(dev, "Failed to request IRQ: %d\n", ret); 414 return ret; 415 } 416 } 417 418 return 0; 419 } 420 421 static const struct i2c_device_id ltc3676_i2c_id[] = { 422 { "ltc3676" }, 423 { } 424 }; 425 MODULE_DEVICE_TABLE(i2c, ltc3676_i2c_id); 426 427 static const struct of_device_id ltc3676_of_match[] = { 428 { .compatible = "lltc,ltc3676" }, 429 { }, 430 }; 431 MODULE_DEVICE_TABLE(of, ltc3676_of_match); 432 433 static struct i2c_driver ltc3676_driver = { 434 .driver = { 435 .name = DRIVER_NAME, 436 .of_match_table = of_match_ptr(ltc3676_of_match), 437 }, 438 .probe = ltc3676_regulator_probe, 439 .id_table = ltc3676_i2c_id, 440 }; 441 module_i2c_driver(ltc3676_driver); 442 443 MODULE_AUTHOR("Tim Harvey <tharvey@gateworks.com>"); 444 MODULE_DESCRIPTION("Regulator driver for Linear Technology LTC1376"); 445 MODULE_LICENSE("GPL v2"); 446