drivers/regulator/ltc3589.c

   1 /*
   2  * Linear Technology LTC3589,LTC3589-1 regulator support
   3  *
   4  * Copyright (c) 2014 Philipp Zabel <p.zabel@pengutronix.de>, Pengutronix
   5  *
   6  * See file CREDITS for list of people who contributed to this
   7  * project.
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2
  11  * as published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  */
  19 #include <linux/i2c.h>
  20 #include <linux/init.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/module.h>
  23 #include <linux/kernel.h>
  24 #include <linux/of.h>
  25 #include <linux/regmap.h>
  26 #include <linux/regulator/driver.h>
  27 #include <linux/regulator/of_regulator.h>
  28
  29 #define DRIVER_NAME             "ltc3589"
  30
  31 #define LTC3589_IRQSTAT         0x02
  32 #define LTC3589_SCR1            0x07
  33 #define LTC3589_OVEN            0x10
  34 #define LTC3589_SCR2            0x12
  35 #define LTC3589_PGSTAT          0x13
  36 #define LTC3589_VCCR            0x20
  37 #define LTC3589_CLIRQ           0x21
  38 #define LTC3589_B1DTV1          0x23
  39 #define LTC3589_B1DTV2          0x24
  40 #define LTC3589_VRRCR           0x25
  41 #define LTC3589_B2DTV1          0x26
  42 #define LTC3589_B2DTV2          0x27
  43 #define LTC3589_B3DTV1          0x29
  44 #define LTC3589_B3DTV2          0x2a
  45 #define LTC3589_L2DTV1          0x32
  46 #define LTC3589_L2DTV2          0x33
  47
  48 #define LTC3589_IRQSTAT_PGOOD_TIMEOUT   BIT(3)
  49 #define LTC3589_IRQSTAT_UNDERVOLT_WARN  BIT(4)
  50 #define LTC3589_IRQSTAT_UNDERVOLT_FAULT BIT(5)
  51 #define LTC3589_IRQSTAT_THERMAL_WARN    BIT(6)
  52 #define LTC3589_IRQSTAT_THERMAL_FAULT   BIT(7)
  53
  54 #define LTC3589_OVEN_SW1                BIT(0)
  55 #define LTC3589_OVEN_SW2                BIT(1)
  56 #define LTC3589_OVEN_SW3                BIT(2)
  57 #define LTC3589_OVEN_BB_OUT             BIT(3)
  58 #define LTC3589_OVEN_LDO2               BIT(4)
  59 #define LTC3589_OVEN_LDO3               BIT(5)
  60 #define LTC3589_OVEN_LDO4               BIT(6)
  61 #define LTC3589_OVEN_SW_CTRL            BIT(7)
  62
  63 #define LTC3589_VCCR_SW1_GO             BIT(0)
  64 #define LTC3589_VCCR_SW2_GO             BIT(2)
  65 #define LTC3589_VCCR_SW3_GO             BIT(4)
  66 #define LTC3589_VCCR_LDO2_GO            BIT(6)
  67
  68 enum ltc3589_variant {
  69         LTC3589,
  70         LTC3589_1,
  71         LTC3589_2,
  72 };
  73
  74 enum ltc3589_reg {
  75         LTC3589_SW1,
  76         LTC3589_SW2,
  77         LTC3589_SW3,
  78         LTC3589_BB_OUT,
  79         LTC3589_LDO1,
  80         LTC3589_LDO2,
  81         LTC3589_LDO3,
  82         LTC3589_LDO4,
  83         LTC3589_NUM_REGULATORS,
  84 };
  85
  86 struct ltc3589_regulator {
  87         struct regulator_desc desc;
  88
  89         /* External feedback voltage divider */
  90         unsigned int r1;
  91         unsigned int r2;
  92 };
  93
  94 struct ltc3589 {
  95         struct regmap *regmap;
  96         struct device *dev;
  97         enum ltc3589_variant variant;
  98         struct ltc3589_regulator regulator_descs[LTC3589_NUM_REGULATORS];
  99         struct regulator_dev *regulators[LTC3589_NUM_REGULATORS];
 100 };
 101
 102 static const int ltc3589_ldo4[] = {
 103         2800000, 2500000, 1800000, 3300000,
 104 };
 105
 106 static const int ltc3589_12_ldo4[] = {
 107         1200000, 1800000, 2500000, 3200000,
 108 };
 109
 110 static int ltc3589_set_ramp_delay(struct regulator_dev *rdev, int ramp_delay)
 111 {
 112         struct ltc3589 *ltc3589 = rdev_get_drvdata(rdev);
 113         int sel, shift;
 114
 115         if (unlikely(ramp_delay <= 0))
 116                 return -EINVAL;
 117
 118         /* VRRCR slew rate offsets are the same as VCCR go bit offsets */
 119         shift = ffs(rdev->desc->apply_bit) - 1;
 120
 121         /* The slew rate can be set to 0.88, 1.75, 3.5, or 7 mV/uS */
 122         for (sel = 0; sel < 4; sel++) {
 123                 if ((880 << sel) >= ramp_delay) {
 124                         return regmap_update_bits(ltc3589->regmap,
 125                                                   LTC3589_VRRCR,
 126                                                   0x3 << shift, sel << shift);
 127                 }
 128         }
 129         return -EINVAL;
 130 }
 131
 132 static int ltc3589_set_suspend_voltage(struct regulator_dev *rdev, int uV)
 133 {
 134         struct ltc3589 *ltc3589 = rdev_get_drvdata(rdev);
 135         int sel;
 136
 137         sel = regulator_map_voltage_linear(rdev, uV, uV);
 138         if (sel < 0)
 139                 return sel;
 140
 141         /* DTV2 register follows right after the corresponding DTV1 register */
 142         return regmap_update_bits(ltc3589->regmap, rdev->desc->vsel_reg + 1,
 143                                   rdev->desc->vsel_mask, sel);
 144 }
 145
 146 static int ltc3589_set_suspend_mode(struct regulator_dev *rdev,
 147                                     unsigned int mode)
 148 {
 149         struct ltc3589 *ltc3589 = rdev_get_drvdata(rdev);
 150         int mask, bit = 0;
 151
 152         /* VCCR reference selects are right next to the VCCR go bits */
 153         mask = rdev->desc->apply_bit << 1;
 154
 155         if (mode == REGULATOR_MODE_STANDBY)
 156                 bit = mask;     /* Select DTV2 */
 157
 158         mask |= rdev->desc->apply_bit;
 159         bit |= rdev->desc->apply_bit;
 160         return regmap_update_bits(ltc3589->regmap, LTC3589_VCCR, mask, bit);
 161 }
 162
 163 /* SW1, SW2, SW3, LDO2 */
 164 static const struct regulator_ops ltc3589_linear_regulator_ops = {
 165         .enable = regulator_enable_regmap,
 166         .disable = regulator_disable_regmap,
 167         .is_enabled = regulator_is_enabled_regmap,
 168         .list_voltage = regulator_list_voltage_linear,
 169         .set_voltage_sel = regulator_set_voltage_sel_regmap,
 170         .get_voltage_sel = regulator_get_voltage_sel_regmap,
 171         .set_ramp_delay = ltc3589_set_ramp_delay,
 172         .set_voltage_time_sel = regulator_set_voltage_time_sel,
 173         .set_suspend_voltage = ltc3589_set_suspend_voltage,
 174         .set_suspend_mode = ltc3589_set_suspend_mode,
 175 };
 176
 177 /* BB_OUT, LDO3 */
 178 static const struct regulator_ops ltc3589_fixed_regulator_ops = {
 179         .enable = regulator_enable_regmap,
 180         .disable = regulator_disable_regmap,
 181         .is_enabled = regulator_is_enabled_regmap,
 182 };
 183
 184 /* LDO1 */
 185 static const struct regulator_ops ltc3589_fixed_standby_regulator_ops = {
 186 };
 187
 188 /* LDO4 */
 189 static const struct regulator_ops ltc3589_table_regulator_ops = {
 190         .enable = regulator_enable_regmap,
 191         .disable = regulator_disable_regmap,
 192         .is_enabled = regulator_is_enabled_regmap,
 193         .list_voltage = regulator_list_voltage_table,
 194         .set_voltage_sel = regulator_set_voltage_sel_regmap,
 195         .get_voltage_sel = regulator_get_voltage_sel_regmap,
 196 };
 197
 198
 199 #define LTC3589_REG(_name, _ops, en_bit, dtv1_reg, dtv_mask, go_bit)    \
 200         [LTC3589_ ## _name] = {                                         \
 201                 .desc = {                                               \
 202                         .name = #_name,                                 \
 203                         .n_voltages = (dtv_mask) + 1,                   \
 204                         .min_uV = (go_bit) ? 362500 : 0,                \
 205                         .uV_step = (go_bit) ? 12500 : 0,                \
 206                         .ramp_delay = (go_bit) ? 1750 : 0,              \
 207                         .fixed_uV = (dtv_mask) ? 0 : 800000,            \
 208                         .ops = &ltc3589_ ## _ops ## _regulator_ops,     \
 209                         .type = REGULATOR_VOLTAGE,                      \
 210                         .id = LTC3589_ ## _name,                        \
 211                         .owner = THIS_MODULE,                           \
 212                         .vsel_reg = (dtv1_reg),                 \
 213                         .vsel_mask = (dtv_mask),                        \
 214                         .apply_reg = (go_bit) ? LTC3589_VCCR : 0,       \
 215                         .apply_bit = (go_bit),                          \
 216                         .enable_reg = (en_bit) ? LTC3589_OVEN : 0,      \
 217                         .enable_mask = (en_bit),                        \
 218                 },                                                      \
 219         }
 220
 221 #define LTC3589_LINEAR_REG(_name, _dtv1)                                \
 222         LTC3589_REG(_name, linear, LTC3589_OVEN_ ## _name,              \
 223                     LTC3589_ ## _dtv1, 0x1f,                            \
 224                     LTC3589_VCCR_ ## _name ## _GO)
 225
 226 #define LTC3589_FIXED_REG(_name) \
 227         LTC3589_REG(_name, fixed, LTC3589_OVEN_ ## _name, 0, 0, 0)
 228
 229 static struct ltc3589_regulator ltc3589_regulators[LTC3589_NUM_REGULATORS] = {
 230         LTC3589_LINEAR_REG(SW1, B1DTV1),
 231         LTC3589_LINEAR_REG(SW2, B2DTV1),
 232         LTC3589_LINEAR_REG(SW3, B3DTV1),
 233         LTC3589_FIXED_REG(BB_OUT),
 234         LTC3589_REG(LDO1, fixed_standby, 0, 0, 0, 0),
 235         LTC3589_LINEAR_REG(LDO2, L2DTV1),
 236         LTC3589_FIXED_REG(LDO3),
 237         LTC3589_REG(LDO4, table, LTC3589_OVEN_LDO4, LTC3589_L2DTV2, 0x60, 0),
 238 };
 239
 240 #ifdef CONFIG_OF
 241 static struct of_regulator_match ltc3589_matches[LTC3589_NUM_REGULATORS] = {
 242         { .name = "sw1",    },
 243         { .name = "sw2",    },
 244         { .name = "sw3",    },
 245         { .name = "bb-out", },
 246         { .name = "ldo1",   }, /* standby */
 247         { .name = "ldo2",   },
 248         { .name = "ldo3",   },
 249         { .name = "ldo4",   },
 250 };
 251
 252 static int ltc3589_parse_regulators_dt(struct ltc3589 *ltc3589)
 253 {
 254         struct device *dev = ltc3589->dev;
 255         struct device_node *node;
 256         int i, ret;
 257
 258         node = of_get_child_by_name(dev->of_node, "regulators");
 259         if (!node) {
 260                 dev_err(dev, "regulators node not found\n");
 261                 return -EINVAL;
 262         }
 263
 264         ret = of_regulator_match(dev, node, ltc3589_matches,
 265                                  ARRAY_SIZE(ltc3589_matches));
 266         of_node_put(node);
 267         if (ret < 0) {
 268                 dev_err(dev, "Error parsing regulator init data: %d\n", ret);
 269                 return ret;
 270         }
 271         if (ret != LTC3589_NUM_REGULATORS) {
 272                 dev_err(dev, "Only %d regulators described in device tree\n",
 273                         ret);
 274                 return -EINVAL;
 275         }
 276
 277         /* Parse feedback voltage dividers. LDO3 and LDO4 don't have them */
 278         for (i = 0; i < LTC3589_LDO3; i++) {
 279                 struct ltc3589_regulator *desc = &ltc3589->regulator_descs[i];
 280                 struct device_node *np = ltc3589_matches[i].of_node;
 281                 u32 vdiv[2];
 282
 283                 ret = of_property_read_u32_array(np, "lltc,fb-voltage-divider",
 284                                                  vdiv, 2);
 285                 if (ret) {
 286                         dev_err(dev, "Failed to parse voltage divider: %d\n",
 287                                 ret);
 288                         return ret;
 289                 }
 290
 291                 desc->r1 = vdiv[0];
 292                 desc->r2 = vdiv[1];
 293         }
 294
 295         return 0;
 296 }
 297
 298 static inline struct regulator_init_data *match_init_data(int index)
 299 {
 300         return ltc3589_matches[index].init_data;
 301 }
 302
 303 static inline struct device_node *match_of_node(int index)
 304 {
 305         return ltc3589_matches[index].of_node;
 306 }
 307 #else
 308 static inline int ltc3589_parse_regulators_dt(struct ltc3589 *ltc3589)
 309 {
 310         return 0;
 311 }
 312
 313 static inline struct regulator_init_data *match_init_data(int index)
 314 {
 315         return NULL;
 316 }
 317
 318 static inline struct device_node *match_of_node(int index)
 319 {
 320         return NULL;
 321 }
 322 #endif
 323
 324 static bool ltc3589_writeable_reg(struct device *dev, unsigned int reg)
 325 {
 326         switch (reg) {
 327         case LTC3589_IRQSTAT:
 328         case LTC3589_SCR1:
 329         case LTC3589_OVEN:
 330         case LTC3589_SCR2:
 331         case LTC3589_VCCR:
 332         case LTC3589_CLIRQ:
 333         case LTC3589_B1DTV1:
 334         case LTC3589_B1DTV2:
 335         case LTC3589_VRRCR:
 336         case LTC3589_B2DTV1:
 337         case LTC3589_B2DTV2:
 338         case LTC3589_B3DTV1:
 339         case LTC3589_B3DTV2:
 340         case LTC3589_L2DTV1:
 341         case LTC3589_L2DTV2:
 342                 return true;
 343         }
 344         return false;
 345 }
 346
 347 static bool ltc3589_readable_reg(struct device *dev, unsigned int reg)
 348 {
 349         switch (reg) {
 350         case LTC3589_IRQSTAT:
 351         case LTC3589_SCR1:
 352         case LTC3589_OVEN:
 353         case LTC3589_SCR2:
 354         case LTC3589_PGSTAT:
 355         case LTC3589_VCCR:
 356         case LTC3589_B1DTV1:
 357         case LTC3589_B1DTV2:
 358         case LTC3589_VRRCR:
 359         case LTC3589_B2DTV1:
 360         case LTC3589_B2DTV2:
 361         case LTC3589_B3DTV1:
 362         case LTC3589_B3DTV2:
 363         case LTC3589_L2DTV1:
 364         case LTC3589_L2DTV2:
 365                 return true;
 366         }
 367         return false;
 368 }
 369
 370 static bool ltc3589_volatile_reg(struct device *dev, unsigned int reg)
 371 {
 372         switch (reg) {
 373         case LTC3589_IRQSTAT:
 374         case LTC3589_PGSTAT:
 375         case LTC3589_VCCR:
 376                 return true;
 377         }
 378         return false;
 379 }
 380
 381 static const struct reg_default ltc3589_reg_defaults[] = {
 382         { LTC3589_SCR1,   0x00 },
 383         { LTC3589_OVEN,   0x00 },
 384         { LTC3589_SCR2,   0x00 },
 385         { LTC3589_VCCR,   0x00 },
 386         { LTC3589_B1DTV1, 0x19 },
 387         { LTC3589_B1DTV2, 0x19 },
 388         { LTC3589_VRRCR,  0xff },
 389         { LTC3589_B2DTV1, 0x19 },
 390         { LTC3589_B2DTV2, 0x19 },
 391         { LTC3589_B3DTV1, 0x19 },
 392         { LTC3589_B3DTV2, 0x19 },
 393         { LTC3589_L2DTV1, 0x19 },
 394         { LTC3589_L2DTV2, 0x19 },
 395 };
 396
 397 static const struct regmap_config ltc3589_regmap_config = {
 398         .reg_bits = 8,
 399         .val_bits = 8,
 400         .writeable_reg = ltc3589_writeable_reg,
 401         .readable_reg = ltc3589_readable_reg,
 402         .volatile_reg = ltc3589_volatile_reg,
 403         .max_register = LTC3589_L2DTV2,
 404         .reg_defaults = ltc3589_reg_defaults,
 405         .num_reg_defaults = ARRAY_SIZE(ltc3589_reg_defaults),
 406         .use_single_rw = true,
 407         .cache_type = REGCACHE_RBTREE,
 408 };
 409
 410
 411 static irqreturn_t ltc3589_isr(int irq, void *dev_id)
 412 {
 413         struct ltc3589 *ltc3589 = dev_id;
 414         unsigned int i, irqstat, event;
 415
 416         regmap_read(ltc3589->regmap, LTC3589_IRQSTAT, &irqstat);
 417
 418         if (irqstat & LTC3589_IRQSTAT_THERMAL_WARN) {
 419                 event = REGULATOR_EVENT_OVER_TEMP;
 420                 for (i = 0; i < LTC3589_NUM_REGULATORS; i++)
 421                         regulator_notifier_call_chain(ltc3589->regulators[i],
 422                                                       event, NULL);
 423         }
 424
 425         if (irqstat & LTC3589_IRQSTAT_UNDERVOLT_WARN) {
 426                 event = REGULATOR_EVENT_UNDER_VOLTAGE;
 427                 for (i = 0; i < LTC3589_NUM_REGULATORS; i++)
 428                         regulator_notifier_call_chain(ltc3589->regulators[i],
 429                                                       event, NULL);
 430         }
 431
 432         /* Clear warning condition */
 433         regmap_write(ltc3589->regmap, LTC3589_CLIRQ, 0);
 434
 435         return IRQ_HANDLED;
 436 }
 437
 438 static inline unsigned int ltc3589_scale(unsigned int uV, u32 r1, u32 r2)
 439 {
 440         uint64_t tmp;
 441         if (uV == 0)
 442                 return 0;
 443         tmp = (uint64_t)uV * r1;
 444         do_div(tmp, r2);
 445         return uV + (unsigned int)tmp;
 446 }
 447
 448 static void ltc3589_apply_fb_voltage_divider(struct ltc3589_regulator *rdesc)
 449 {
 450         struct regulator_desc *desc = &rdesc->desc;
 451
 452         if (!rdesc->r1 || !rdesc->r2)
 453                 return;
 454
 455         desc->min_uV = ltc3589_scale(desc->min_uV, rdesc->r1, rdesc->r2);
 456         desc->uV_step = ltc3589_scale(desc->uV_step, rdesc->r1, rdesc->r2);
 457         desc->fixed_uV = ltc3589_scale(desc->fixed_uV, rdesc->r1, rdesc->r2);
 458 }
 459
 460 static int ltc3589_probe(struct i2c_client *client,
 461                          const struct i2c_device_id *id)
 462 {
 463         struct device *dev = &client->dev;
 464         struct ltc3589_regulator *descs;
 465         struct ltc3589 *ltc3589;
 466         int i, ret;
 467
 468         ltc3589 = devm_kzalloc(dev, sizeof(*ltc3589), GFP_KERNEL);
 469         if (!ltc3589)
 470                 return -ENOMEM;
 471
 472         i2c_set_clientdata(client, ltc3589);
 473         ltc3589->variant = id->driver_data;
 474         ltc3589->dev = dev;
 475
 476         descs = ltc3589->regulator_descs;
 477         memcpy(descs, ltc3589_regulators, sizeof(ltc3589_regulators));
 478         if (ltc3589->variant == LTC3589) {
 479                 descs[LTC3589_LDO3].desc.fixed_uV = 1800000;
 480                 descs[LTC3589_LDO4].desc.volt_table = ltc3589_ldo4;
 481         } else {
 482                 descs[LTC3589_LDO3].desc.fixed_uV = 2800000;
 483                 descs[LTC3589_LDO4].desc.volt_table = ltc3589_12_ldo4;
 484         }
 485
 486         ltc3589->regmap = devm_regmap_init_i2c(client, &ltc3589_regmap_config);
 487         if (IS_ERR(ltc3589->regmap)) {
 488                 ret = PTR_ERR(ltc3589->regmap);
 489                 dev_err(dev, "failed to initialize regmap: %d\n", ret);
 490                 return ret;
 491         }
 492
 493         ret = ltc3589_parse_regulators_dt(ltc3589);
 494         if (ret)
 495                 return ret;
 496
 497         for (i = 0; i < LTC3589_NUM_REGULATORS; i++) {
 498                 struct ltc3589_regulator *rdesc = &ltc3589->regulator_descs[i];
 499                 struct regulator_desc *desc = &rdesc->desc;
 500                 struct regulator_init_data *init_data;
 501                 struct regulator_config config = { };
 502
 503                 init_data = match_init_data(i);
 504
 505                 if (i < LTC3589_LDO3)
 506                         ltc3589_apply_fb_voltage_divider(rdesc);
 507
 508                 config.dev = dev;
 509                 config.init_data = init_data;
 510                 config.driver_data = ltc3589;
 511                 config.of_node = match_of_node(i);
 512
 513                 ltc3589->regulators[i] = devm_regulator_register(dev, desc,
 514                                                                  &config);
 515                 if (IS_ERR(ltc3589->regulators[i])) {
 516                         ret = PTR_ERR(ltc3589->regulators[i]);
 517                         dev_err(dev, "failed to register regulator %s: %d\n",
 518                                 desc->name, ret);
 519                         return ret;
 520                 }
 521         }
 522
 523         if (client->irq) {
 524                 ret = devm_request_threaded_irq(dev, client->irq, NULL,
 525                                                 ltc3589_isr,
 526                                                 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 527                                                 client->name, ltc3589);
 528                 if (ret) {
 529                         dev_err(dev, "Failed to request IRQ: %d\n", ret);
 530                         return ret;
 531                 }
 532         }
 533
 534         return 0;
 535 }
 536
 537 static struct i2c_device_id ltc3589_i2c_id[] = {
 538         { "ltc3589",   LTC3589   },
 539         { "ltc3589-1", LTC3589_1 },
 540         { "ltc3589-2", LTC3589_2 },
 541         { }
 542 };
 543 MODULE_DEVICE_TABLE(i2c, ltc3589_i2c_id);
 544
 545 static struct i2c_driver ltc3589_driver = {
 546         .driver = {
 547                 .name = DRIVER_NAME,
 548         },
 549         .probe = ltc3589_probe,
 550         .id_table = ltc3589_i2c_id,
 551 };
 552 module_i2c_driver(ltc3589_driver);
 553
 554 MODULE_AUTHOR("Philipp Zabel <p.zabel@pengutronix.de>");
 555 MODULE_DESCRIPTION("Regulator driver for Linear Technology LTC3589(-1,2)");
 556 MODULE_LICENSE("GPL v2");