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_readable_writeable_reg(struct device *dev, unsigned int reg) 245 { 246 switch (reg) { 247 case LTC3676_BUCK1 ... LTC3676_IRQSTAT: 248 case LTC3676_HRST: 249 case LTC3676_CLIRQ: 250 return true; 251 } 252 return false; 253 } 254 255 static bool ltc3676_volatile_reg(struct device *dev, unsigned int reg) 256 { 257 switch (reg) { 258 case LTC3676_IRQSTAT ... LTC3676_PGSTATRT: 259 return true; 260 } 261 return false; 262 } 263 264 static const struct regmap_config ltc3676_regmap_config = { 265 .reg_bits = 8, 266 .val_bits = 8, 267 .writeable_reg = ltc3676_readable_writeable_reg, 268 .readable_reg = ltc3676_readable_writeable_reg, 269 .volatile_reg = ltc3676_volatile_reg, 270 .max_register = LTC3676_CLIRQ, 271 .use_single_read = true, 272 .use_single_write = true, 273 .cache_type = REGCACHE_RBTREE, 274 }; 275 276 static irqreturn_t ltc3676_isr(int irq, void *dev_id) 277 { 278 struct ltc3676 *ltc3676 = dev_id; 279 struct device *dev = ltc3676->dev; 280 unsigned int i, irqstat, event; 281 282 regmap_read(ltc3676->regmap, LTC3676_IRQSTAT, &irqstat); 283 284 dev_dbg(dev, "irq%d irqstat=0x%02x\n", irq, irqstat); 285 if (irqstat & LTC3676_IRQSTAT_THERMAL_WARN) { 286 dev_warn(dev, "Over-temperature Warning\n"); 287 event = REGULATOR_EVENT_OVER_TEMP; 288 for (i = 0; i < LTC3676_NUM_REGULATORS; i++) 289 regulator_notifier_call_chain(ltc3676->regulators[i], 290 event, NULL); 291 } 292 293 if (irqstat & LTC3676_IRQSTAT_UNDERVOLT_WARN) { 294 dev_info(dev, "Undervoltage Warning\n"); 295 event = REGULATOR_EVENT_UNDER_VOLTAGE; 296 for (i = 0; i < LTC3676_NUM_REGULATORS; i++) 297 regulator_notifier_call_chain(ltc3676->regulators[i], 298 event, NULL); 299 } 300 301 /* Clear warning condition */ 302 regmap_write(ltc3676->regmap, LTC3676_CLIRQ, 0); 303 304 return IRQ_HANDLED; 305 } 306 307 static int ltc3676_regulator_probe(struct i2c_client *client, 308 const struct i2c_device_id *id) 309 { 310 struct device *dev = &client->dev; 311 struct regulator_init_data *init_data = dev_get_platdata(dev); 312 struct regulator_desc *descs; 313 struct ltc3676 *ltc3676; 314 int i, ret; 315 316 ltc3676 = devm_kzalloc(dev, sizeof(*ltc3676), GFP_KERNEL); 317 if (!ltc3676) 318 return -ENOMEM; 319 320 i2c_set_clientdata(client, ltc3676); 321 ltc3676->dev = dev; 322 323 descs = ltc3676->regulator_descs; 324 memcpy(descs, ltc3676_regulators, sizeof(ltc3676_regulators)); 325 descs[LTC3676_LDO3].fixed_uV = 1800000; /* LDO3 is fixed 1.8V */ 326 327 ltc3676->regmap = devm_regmap_init_i2c(client, <c3676_regmap_config); 328 if (IS_ERR(ltc3676->regmap)) { 329 ret = PTR_ERR(ltc3676->regmap); 330 dev_err(dev, "failed to initialize regmap: %d\n", ret); 331 return ret; 332 } 333 334 for (i = 0; i < LTC3676_NUM_REGULATORS; i++) { 335 struct regulator_desc *desc = <c3676->regulator_descs[i]; 336 struct regulator_config config = { }; 337 338 if (init_data) 339 config.init_data = &init_data[i]; 340 341 config.dev = dev; 342 config.driver_data = ltc3676; 343 344 ltc3676->regulators[i] = devm_regulator_register(dev, desc, 345 &config); 346 if (IS_ERR(ltc3676->regulators[i])) { 347 ret = PTR_ERR(ltc3676->regulators[i]); 348 dev_err(dev, "failed to register regulator %s: %d\n", 349 desc->name, ret); 350 return ret; 351 } 352 } 353 354 regmap_write(ltc3676->regmap, LTC3676_CLIRQ, 0); 355 if (client->irq) { 356 ret = devm_request_threaded_irq(dev, client->irq, NULL, 357 ltc3676_isr, 358 IRQF_TRIGGER_LOW | IRQF_ONESHOT, 359 client->name, ltc3676); 360 if (ret) { 361 dev_err(dev, "Failed to request IRQ: %d\n", ret); 362 return ret; 363 } 364 } 365 366 return 0; 367 } 368 369 static const struct i2c_device_id ltc3676_i2c_id[] = { 370 { "ltc3676" }, 371 { } 372 }; 373 MODULE_DEVICE_TABLE(i2c, ltc3676_i2c_id); 374 375 static const struct of_device_id ltc3676_of_match[] = { 376 { .compatible = "lltc,ltc3676" }, 377 { }, 378 }; 379 MODULE_DEVICE_TABLE(of, ltc3676_of_match); 380 381 static struct i2c_driver ltc3676_driver = { 382 .driver = { 383 .name = DRIVER_NAME, 384 .of_match_table = of_match_ptr(ltc3676_of_match), 385 }, 386 .probe = ltc3676_regulator_probe, 387 .id_table = ltc3676_i2c_id, 388 }; 389 module_i2c_driver(ltc3676_driver); 390 391 MODULE_AUTHOR("Tim Harvey <tharvey@gateworks.com>"); 392 MODULE_DESCRIPTION("Regulator driver for Linear Technology LTC3676"); 393 MODULE_LICENSE("GPL v2"); 394