linux/drivers/regulator/ltc3589.c
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   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/of_device.h>
  26#include <linux/regmap.h>
  27#include <linux/regulator/driver.h>
  28#include <linux/regulator/of_regulator.h>
  29
  30#define DRIVER_NAME             "ltc3589"
  31
  32#define LTC3589_IRQSTAT         0x02
  33#define LTC3589_SCR1            0x07
  34#define LTC3589_OVEN            0x10
  35#define LTC3589_SCR2            0x12
  36#define LTC3589_PGSTAT          0x13
  37#define LTC3589_VCCR            0x20
  38#define LTC3589_CLIRQ           0x21
  39#define LTC3589_B1DTV1          0x23
  40#define LTC3589_B1DTV2          0x24
  41#define LTC3589_VRRCR           0x25
  42#define LTC3589_B2DTV1          0x26
  43#define LTC3589_B2DTV2          0x27
  44#define LTC3589_B3DTV1          0x29
  45#define LTC3589_B3DTV2          0x2a
  46#define LTC3589_L2DTV1          0x32
  47#define LTC3589_L2DTV2          0x33
  48
  49#define LTC3589_IRQSTAT_PGOOD_TIMEOUT   BIT(3)
  50#define LTC3589_IRQSTAT_UNDERVOLT_WARN  BIT(4)
  51#define LTC3589_IRQSTAT_UNDERVOLT_FAULT BIT(5)
  52#define LTC3589_IRQSTAT_THERMAL_WARN    BIT(6)
  53#define LTC3589_IRQSTAT_THERMAL_FAULT   BIT(7)
  54
  55#define LTC3589_OVEN_SW1                BIT(0)
  56#define LTC3589_OVEN_SW2                BIT(1)
  57#define LTC3589_OVEN_SW3                BIT(2)
  58#define LTC3589_OVEN_BB_OUT             BIT(3)
  59#define LTC3589_OVEN_LDO2               BIT(4)
  60#define LTC3589_OVEN_LDO3               BIT(5)
  61#define LTC3589_OVEN_LDO4               BIT(6)
  62#define LTC3589_OVEN_SW_CTRL            BIT(7)
  63
  64#define LTC3589_VCCR_SW1_GO             BIT(0)
  65#define LTC3589_VCCR_SW2_GO             BIT(2)
  66#define LTC3589_VCCR_SW3_GO             BIT(4)
  67#define LTC3589_VCCR_LDO2_GO            BIT(6)
  68
  69enum ltc3589_variant {
  70        LTC3589,
  71        LTC3589_1,
  72        LTC3589_2,
  73};
  74
  75enum ltc3589_reg {
  76        LTC3589_SW1,
  77        LTC3589_SW2,
  78        LTC3589_SW3,
  79        LTC3589_BB_OUT,
  80        LTC3589_LDO1,
  81        LTC3589_LDO2,
  82        LTC3589_LDO3,
  83        LTC3589_LDO4,
  84        LTC3589_NUM_REGULATORS,
  85};
  86
  87struct ltc3589_regulator {
  88        struct regulator_desc desc;
  89
  90        /* External feedback voltage divider */
  91        unsigned int r1;
  92        unsigned int r2;
  93};
  94
  95struct ltc3589 {
  96        struct regmap *regmap;
  97        struct device *dev;
  98        enum ltc3589_variant variant;
  99        struct ltc3589_regulator regulator_descs[LTC3589_NUM_REGULATORS];
 100        struct regulator_dev *regulators[LTC3589_NUM_REGULATORS];
 101};
 102
 103static const int ltc3589_ldo4[] = {
 104        2800000, 2500000, 1800000, 3300000,
 105};
 106
 107static const int ltc3589_12_ldo4[] = {
 108        1200000, 1800000, 2500000, 3200000,
 109};
 110
 111static int ltc3589_set_ramp_delay(struct regulator_dev *rdev, int ramp_delay)
 112{
 113        struct ltc3589 *ltc3589 = rdev_get_drvdata(rdev);
 114        int sel, shift;
 115
 116        if (unlikely(ramp_delay <= 0))
 117                return -EINVAL;
 118
 119        /* VRRCR slew rate offsets are the same as VCCR go bit offsets */
 120        shift = ffs(rdev->desc->apply_bit) - 1;
 121
 122        /* The slew rate can be set to 0.88, 1.75, 3.5, or 7 mV/uS */
 123        for (sel = 0; sel < 4; sel++) {
 124                if ((880 << sel) >= ramp_delay) {
 125                        return regmap_update_bits(ltc3589->regmap,
 126                                                  LTC3589_VRRCR,
 127                                                  0x3 << shift, sel << shift);
 128                }
 129        }
 130        return -EINVAL;
 131}
 132
 133static int ltc3589_set_suspend_voltage(struct regulator_dev *rdev, int uV)
 134{
 135        struct ltc3589 *ltc3589 = rdev_get_drvdata(rdev);
 136        int sel;
 137
 138        sel = regulator_map_voltage_linear(rdev, uV, uV);
 139        if (sel < 0)
 140                return sel;
 141
 142        /* DTV2 register follows right after the corresponding DTV1 register */
 143        return regmap_update_bits(ltc3589->regmap, rdev->desc->vsel_reg + 1,
 144                                  rdev->desc->vsel_mask, sel);
 145}
 146
 147static int ltc3589_set_suspend_mode(struct regulator_dev *rdev,
 148                                    unsigned int mode)
 149{
 150        struct ltc3589 *ltc3589 = rdev_get_drvdata(rdev);
 151        int mask, bit = 0;
 152
 153        /* VCCR reference selects are right next to the VCCR go bits */
 154        mask = rdev->desc->apply_bit << 1;
 155
 156        if (mode == REGULATOR_MODE_STANDBY)
 157                bit = mask;     /* Select DTV2 */
 158
 159        mask |= rdev->desc->apply_bit;
 160        bit |= rdev->desc->apply_bit;
 161        return regmap_update_bits(ltc3589->regmap, LTC3589_VCCR, mask, bit);
 162}
 163
 164/* SW1, SW2, SW3, LDO2 */
 165static const struct regulator_ops ltc3589_linear_regulator_ops = {
 166        .enable = regulator_enable_regmap,
 167        .disable = regulator_disable_regmap,
 168        .is_enabled = regulator_is_enabled_regmap,
 169        .list_voltage = regulator_list_voltage_linear,
 170        .set_voltage_sel = regulator_set_voltage_sel_regmap,
 171        .get_voltage_sel = regulator_get_voltage_sel_regmap,
 172        .set_ramp_delay = ltc3589_set_ramp_delay,
 173        .set_voltage_time_sel = regulator_set_voltage_time_sel,
 174        .set_suspend_voltage = ltc3589_set_suspend_voltage,
 175        .set_suspend_mode = ltc3589_set_suspend_mode,
 176};
 177
 178/* BB_OUT, LDO3 */
 179static const struct regulator_ops ltc3589_fixed_regulator_ops = {
 180        .enable = regulator_enable_regmap,
 181        .disable = regulator_disable_regmap,
 182        .is_enabled = regulator_is_enabled_regmap,
 183};
 184
 185/* LDO1 */
 186static const struct regulator_ops ltc3589_fixed_standby_regulator_ops = {
 187};
 188
 189/* LDO4 */
 190static const struct regulator_ops ltc3589_table_regulator_ops = {
 191        .enable = regulator_enable_regmap,
 192        .disable = regulator_disable_regmap,
 193        .is_enabled = regulator_is_enabled_regmap,
 194        .list_voltage = regulator_list_voltage_table,
 195        .set_voltage_sel = regulator_set_voltage_sel_regmap,
 196        .get_voltage_sel = regulator_get_voltage_sel_regmap,
 197};
 198
 199
 200#define LTC3589_REG(_name, _ops, en_bit, dtv1_reg, dtv_mask, go_bit)    \
 201        [LTC3589_ ## _name] = {                                         \
 202                .desc = {                                               \
 203                        .name = #_name,                                 \
 204                        .n_voltages = (dtv_mask) + 1,                   \
 205                        .min_uV = (go_bit) ? 362500 : 0,                \
 206                        .uV_step = (go_bit) ? 12500 : 0,                \
 207                        .ramp_delay = (go_bit) ? 1750 : 0,              \
 208                        .fixed_uV = (dtv_mask) ? 0 : 800000,            \
 209                        .ops = &ltc3589_ ## _ops ## _regulator_ops,     \
 210                        .type = REGULATOR_VOLTAGE,                      \
 211                        .id = LTC3589_ ## _name,                        \
 212                        .owner = THIS_MODULE,                           \
 213                        .vsel_reg = (dtv1_reg),                 \
 214                        .vsel_mask = (dtv_mask),                        \
 215                        .apply_reg = (go_bit) ? LTC3589_VCCR : 0,       \
 216                        .apply_bit = (go_bit),                          \
 217                        .enable_reg = (en_bit) ? LTC3589_OVEN : 0,      \
 218                        .enable_mask = (en_bit),                        \
 219                },                                                      \
 220        }
 221
 222#define LTC3589_LINEAR_REG(_name, _dtv1)                                \
 223        LTC3589_REG(_name, linear, LTC3589_OVEN_ ## _name,              \
 224                    LTC3589_ ## _dtv1, 0x1f,                            \
 225                    LTC3589_VCCR_ ## _name ## _GO)
 226
 227#define LTC3589_FIXED_REG(_name) \
 228        LTC3589_REG(_name, fixed, LTC3589_OVEN_ ## _name, 0, 0, 0)
 229
 230static struct ltc3589_regulator ltc3589_regulators[LTC3589_NUM_REGULATORS] = {
 231        LTC3589_LINEAR_REG(SW1, B1DTV1),
 232        LTC3589_LINEAR_REG(SW2, B2DTV1),
 233        LTC3589_LINEAR_REG(SW3, B3DTV1),
 234        LTC3589_FIXED_REG(BB_OUT),
 235        LTC3589_REG(LDO1, fixed_standby, 0, 0, 0, 0),
 236        LTC3589_LINEAR_REG(LDO2, L2DTV1),
 237        LTC3589_FIXED_REG(LDO3),
 238        LTC3589_REG(LDO4, table, LTC3589_OVEN_LDO4, LTC3589_L2DTV2, 0x60, 0),
 239};
 240
 241#ifdef CONFIG_OF
 242static struct of_regulator_match ltc3589_matches[LTC3589_NUM_REGULATORS] = {
 243        { .name = "sw1",    },
 244        { .name = "sw2",    },
 245        { .name = "sw3",    },
 246        { .name = "bb-out", },
 247        { .name = "ldo1",   }, /* standby */
 248        { .name = "ldo2",   },
 249        { .name = "ldo3",   },
 250        { .name = "ldo4",   },
 251};
 252
 253static int ltc3589_parse_regulators_dt(struct ltc3589 *ltc3589)
 254{
 255        struct device *dev = ltc3589->dev;
 256        struct device_node *node;
 257        int i, ret;
 258
 259        node = of_get_child_by_name(dev->of_node, "regulators");
 260        if (!node) {
 261                dev_err(dev, "regulators node not found\n");
 262                return -EINVAL;
 263        }
 264
 265        ret = of_regulator_match(dev, node, ltc3589_matches,
 266                                 ARRAY_SIZE(ltc3589_matches));
 267        of_node_put(node);
 268        if (ret < 0) {
 269                dev_err(dev, "Error parsing regulator init data: %d\n", ret);
 270                return ret;
 271        }
 272        if (ret != LTC3589_NUM_REGULATORS) {
 273                dev_err(dev, "Only %d regulators described in device tree\n",
 274                        ret);
 275                return -EINVAL;
 276        }
 277
 278        /* Parse feedback voltage dividers. LDO3 and LDO4 don't have them */
 279        for (i = 0; i < LTC3589_LDO3; i++) {
 280                struct ltc3589_regulator *desc = &ltc3589->regulator_descs[i];
 281                struct device_node *np = ltc3589_matches[i].of_node;
 282                u32 vdiv[2];
 283
 284                ret = of_property_read_u32_array(np, "lltc,fb-voltage-divider",
 285                                                 vdiv, 2);
 286                if (ret) {
 287                        dev_err(dev, "Failed to parse voltage divider: %d\n",
 288                                ret);
 289                        return ret;
 290                }
 291
 292                desc->r1 = vdiv[0];
 293                desc->r2 = vdiv[1];
 294        }
 295
 296        return 0;
 297}
 298
 299static inline struct regulator_init_data *match_init_data(int index)
 300{
 301        return ltc3589_matches[index].init_data;
 302}
 303
 304static inline struct device_node *match_of_node(int index)
 305{
 306        return ltc3589_matches[index].of_node;
 307}
 308#else
 309static inline int ltc3589_parse_regulators_dt(struct ltc3589 *ltc3589)
 310{
 311        return 0;
 312}
 313
 314static inline struct regulator_init_data *match_init_data(int index)
 315{
 316        return NULL;
 317}
 318
 319static inline struct device_node *match_of_node(int index)
 320{
 321        return NULL;
 322}
 323#endif
 324
 325static bool ltc3589_writeable_reg(struct device *dev, unsigned int reg)
 326{
 327        switch (reg) {
 328        case LTC3589_IRQSTAT:
 329        case LTC3589_SCR1:
 330        case LTC3589_OVEN:
 331        case LTC3589_SCR2:
 332        case LTC3589_VCCR:
 333        case LTC3589_CLIRQ:
 334        case LTC3589_B1DTV1:
 335        case LTC3589_B1DTV2:
 336        case LTC3589_VRRCR:
 337        case LTC3589_B2DTV1:
 338        case LTC3589_B2DTV2:
 339        case LTC3589_B3DTV1:
 340        case LTC3589_B3DTV2:
 341        case LTC3589_L2DTV1:
 342        case LTC3589_L2DTV2:
 343                return true;
 344        }
 345        return false;
 346}
 347
 348static bool ltc3589_readable_reg(struct device *dev, unsigned int reg)
 349{
 350        switch (reg) {
 351        case LTC3589_IRQSTAT:
 352        case LTC3589_SCR1:
 353        case LTC3589_OVEN:
 354        case LTC3589_SCR2:
 355        case LTC3589_PGSTAT:
 356        case LTC3589_VCCR:
 357        case LTC3589_B1DTV1:
 358        case LTC3589_B1DTV2:
 359        case LTC3589_VRRCR:
 360        case LTC3589_B2DTV1:
 361        case LTC3589_B2DTV2:
 362        case LTC3589_B3DTV1:
 363        case LTC3589_B3DTV2:
 364        case LTC3589_L2DTV1:
 365        case LTC3589_L2DTV2:
 366                return true;
 367        }
 368        return false;
 369}
 370
 371static bool ltc3589_volatile_reg(struct device *dev, unsigned int reg)
 372{
 373        switch (reg) {
 374        case LTC3589_IRQSTAT:
 375        case LTC3589_PGSTAT:
 376        case LTC3589_VCCR:
 377                return true;
 378        }
 379        return false;
 380}
 381
 382static const struct reg_default ltc3589_reg_defaults[] = {
 383        { LTC3589_SCR1,   0x00 },
 384        { LTC3589_OVEN,   0x00 },
 385        { LTC3589_SCR2,   0x00 },
 386        { LTC3589_VCCR,   0x00 },
 387        { LTC3589_B1DTV1, 0x19 },
 388        { LTC3589_B1DTV2, 0x19 },
 389        { LTC3589_VRRCR,  0xff },
 390        { LTC3589_B2DTV1, 0x19 },
 391        { LTC3589_B2DTV2, 0x19 },
 392        { LTC3589_B3DTV1, 0x19 },
 393        { LTC3589_B3DTV2, 0x19 },
 394        { LTC3589_L2DTV1, 0x19 },
 395        { LTC3589_L2DTV2, 0x19 },
 396};
 397
 398static const struct regmap_config ltc3589_regmap_config = {
 399        .reg_bits = 8,
 400        .val_bits = 8,
 401        .writeable_reg = ltc3589_writeable_reg,
 402        .readable_reg = ltc3589_readable_reg,
 403        .volatile_reg = ltc3589_volatile_reg,
 404        .max_register = LTC3589_L2DTV2,
 405        .reg_defaults = ltc3589_reg_defaults,
 406        .num_reg_defaults = ARRAY_SIZE(ltc3589_reg_defaults),
 407        .use_single_rw = true,
 408        .cache_type = REGCACHE_RBTREE,
 409};
 410
 411
 412static irqreturn_t ltc3589_isr(int irq, void *dev_id)
 413{
 414        struct ltc3589 *ltc3589 = dev_id;
 415        unsigned int i, irqstat, event;
 416
 417        regmap_read(ltc3589->regmap, LTC3589_IRQSTAT, &irqstat);
 418
 419        if (irqstat & LTC3589_IRQSTAT_THERMAL_WARN) {
 420                event = REGULATOR_EVENT_OVER_TEMP;
 421                for (i = 0; i < LTC3589_NUM_REGULATORS; i++)
 422                        regulator_notifier_call_chain(ltc3589->regulators[i],
 423                                                      event, NULL);
 424        }
 425
 426        if (irqstat & LTC3589_IRQSTAT_UNDERVOLT_WARN) {
 427                event = REGULATOR_EVENT_UNDER_VOLTAGE;
 428                for (i = 0; i < LTC3589_NUM_REGULATORS; i++)
 429                        regulator_notifier_call_chain(ltc3589->regulators[i],
 430                                                      event, NULL);
 431        }
 432
 433        /* Clear warning condition */
 434        regmap_write(ltc3589->regmap, LTC3589_CLIRQ, 0);
 435
 436        return IRQ_HANDLED;
 437}
 438
 439static inline unsigned int ltc3589_scale(unsigned int uV, u32 r1, u32 r2)
 440{
 441        uint64_t tmp;
 442        if (uV == 0)
 443                return 0;
 444        tmp = (uint64_t)uV * r1;
 445        do_div(tmp, r2);
 446        return uV + (unsigned int)tmp;
 447}
 448
 449static void ltc3589_apply_fb_voltage_divider(struct ltc3589_regulator *rdesc)
 450{
 451        struct regulator_desc *desc = &rdesc->desc;
 452
 453        if (!rdesc->r1 || !rdesc->r2)
 454                return;
 455
 456        desc->min_uV = ltc3589_scale(desc->min_uV, rdesc->r1, rdesc->r2);
 457        desc->uV_step = ltc3589_scale(desc->uV_step, rdesc->r1, rdesc->r2);
 458        desc->fixed_uV = ltc3589_scale(desc->fixed_uV, rdesc->r1, rdesc->r2);
 459}
 460
 461static int ltc3589_probe(struct i2c_client *client,
 462                         const struct i2c_device_id *id)
 463{
 464        struct device *dev = &client->dev;
 465        struct ltc3589_regulator *descs;
 466        struct ltc3589 *ltc3589;
 467        int i, ret;
 468
 469        ltc3589 = devm_kzalloc(dev, sizeof(*ltc3589), GFP_KERNEL);
 470        if (!ltc3589)
 471                return -ENOMEM;
 472
 473        i2c_set_clientdata(client, ltc3589);
 474        if (client->dev.of_node)
 475                ltc3589->variant = (enum ltc3589_variant)
 476                        of_device_get_match_data(&client->dev);
 477        else
 478                ltc3589->variant = id->driver_data;
 479        ltc3589->dev = dev;
 480
 481        descs = ltc3589->regulator_descs;
 482        memcpy(descs, ltc3589_regulators, sizeof(ltc3589_regulators));
 483        if (ltc3589->variant == LTC3589) {
 484                descs[LTC3589_LDO3].desc.fixed_uV = 1800000;
 485                descs[LTC3589_LDO4].desc.volt_table = ltc3589_ldo4;
 486        } else {
 487                descs[LTC3589_LDO3].desc.fixed_uV = 2800000;
 488                descs[LTC3589_LDO4].desc.volt_table = ltc3589_12_ldo4;
 489        }
 490
 491        ltc3589->regmap = devm_regmap_init_i2c(client, &ltc3589_regmap_config);
 492        if (IS_ERR(ltc3589->regmap)) {
 493                ret = PTR_ERR(ltc3589->regmap);
 494                dev_err(dev, "failed to initialize regmap: %d\n", ret);
 495                return ret;
 496        }
 497
 498        ret = ltc3589_parse_regulators_dt(ltc3589);
 499        if (ret)
 500                return ret;
 501
 502        for (i = 0; i < LTC3589_NUM_REGULATORS; i++) {
 503                struct ltc3589_regulator *rdesc = &ltc3589->regulator_descs[i];
 504                struct regulator_desc *desc = &rdesc->desc;
 505                struct regulator_init_data *init_data;
 506                struct regulator_config config = { };
 507
 508                init_data = match_init_data(i);
 509
 510                if (i < LTC3589_LDO3)
 511                        ltc3589_apply_fb_voltage_divider(rdesc);
 512
 513                config.dev = dev;
 514                config.init_data = init_data;
 515                config.driver_data = ltc3589;
 516                config.of_node = match_of_node(i);
 517
 518                ltc3589->regulators[i] = devm_regulator_register(dev, desc,
 519                                                                 &config);
 520                if (IS_ERR(ltc3589->regulators[i])) {
 521                        ret = PTR_ERR(ltc3589->regulators[i]);
 522                        dev_err(dev, "failed to register regulator %s: %d\n",
 523                                desc->name, ret);
 524                        return ret;
 525                }
 526        }
 527
 528        if (client->irq) {
 529                ret = devm_request_threaded_irq(dev, client->irq, NULL,
 530                                                ltc3589_isr,
 531                                                IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 532                                                client->name, ltc3589);
 533                if (ret) {
 534                        dev_err(dev, "Failed to request IRQ: %d\n", ret);
 535                        return ret;
 536                }
 537        }
 538
 539        return 0;
 540}
 541
 542static const struct i2c_device_id ltc3589_i2c_id[] = {
 543        { "ltc3589",   LTC3589   },
 544        { "ltc3589-1", LTC3589_1 },
 545        { "ltc3589-2", LTC3589_2 },
 546        { }
 547};
 548MODULE_DEVICE_TABLE(i2c, ltc3589_i2c_id);
 549
 550static const struct of_device_id ltc3589_of_match[] = {
 551        {
 552                .compatible = "lltc,ltc3589",
 553                .data = (void *)LTC3589,
 554        },
 555        {
 556                .compatible = "lltc,ltc3589-1",
 557                .data = (void *)LTC3589_1,
 558        },
 559        {
 560                .compatible = "lltc,ltc3589-2",
 561                .data = (void *)LTC3589_2,
 562        },
 563        { },
 564};
 565MODULE_DEVICE_TABLE(of, ltc3589_of_match);
 566
 567static struct i2c_driver ltc3589_driver = {
 568        .driver = {
 569                .name = DRIVER_NAME,
 570                .of_match_table = of_match_ptr(ltc3589_of_match),
 571        },
 572        .probe = ltc3589_probe,
 573        .id_table = ltc3589_i2c_id,
 574};
 575module_i2c_driver(ltc3589_driver);
 576
 577MODULE_AUTHOR("Philipp Zabel <p.zabel@pengutronix.de>");
 578MODULE_DESCRIPTION("Regulator driver for Linear Technology LTC3589(-1,2)");
 579MODULE_LICENSE("GPL v2");
 580