linux/drivers/regulator/ltc3676.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (C) 2016 Gateworks Corporation, Inc. All Rights Reserved.
   4 */
   5#include <linux/i2c.h>
   6#include <linux/init.h>
   7#include <linux/interrupt.h>
   8#include <linux/module.h>
   9#include <linux/kernel.h>
  10#include <linux/of.h>
  11#include <linux/regmap.h>
  12#include <linux/regulator/driver.h>
  13#include <linux/regulator/machine.h>
  14#include <linux/regulator/of_regulator.h>
  15
  16#define DRIVER_NAME             "ltc3676"
  17
  18/* LTC3676 Registers */
  19#define LTC3676_BUCK1     0x01
  20#define LTC3676_BUCK2     0x02
  21#define LTC3676_BUCK3     0x03
  22#define LTC3676_BUCK4     0x04
  23#define LTC3676_LDOA      0x05
  24#define LTC3676_LDOB      0x06
  25#define LTC3676_SQD1      0x07
  26#define LTC3676_SQD2      0x08
  27#define LTC3676_CNTRL     0x09
  28#define LTC3676_DVB1A     0x0A
  29#define LTC3676_DVB1B     0x0B
  30#define LTC3676_DVB2A     0x0C
  31#define LTC3676_DVB2B     0x0D
  32#define LTC3676_DVB3A     0x0E
  33#define LTC3676_DVB3B     0x0F
  34#define LTC3676_DVB4A     0x10
  35#define LTC3676_DVB4B     0x11
  36#define LTC3676_MSKIRQ    0x12
  37#define LTC3676_MSKPG     0x13
  38#define LTC3676_USER      0x14
  39#define LTC3676_IRQSTAT   0x15
  40#define LTC3676_PGSTATL   0x16
  41#define LTC3676_PGSTATRT  0x17
  42#define LTC3676_HRST      0x1E
  43#define LTC3676_CLIRQ     0x1F
  44
  45#define LTC3676_DVBxA_REF_SELECT        BIT(5)
  46#define LTC3676_DVBxB_PGOOD_MASK        BIT(5)
  47
  48#define LTC3676_IRQSTAT_PGOOD_TIMEOUT   BIT(3)
  49#define LTC3676_IRQSTAT_UNDERVOLT_WARN  BIT(4)
  50#define LTC3676_IRQSTAT_UNDERVOLT_FAULT BIT(5)
  51#define LTC3676_IRQSTAT_THERMAL_WARN    BIT(6)
  52#define LTC3676_IRQSTAT_THERMAL_FAULT   BIT(7)
  53
  54enum ltc3676_reg {
  55        LTC3676_SW1,
  56        LTC3676_SW2,
  57        LTC3676_SW3,
  58        LTC3676_SW4,
  59        LTC3676_LDO1,
  60        LTC3676_LDO2,
  61        LTC3676_LDO3,
  62        LTC3676_LDO4,
  63        LTC3676_NUM_REGULATORS,
  64};
  65
  66struct ltc3676 {
  67        struct regmap *regmap;
  68        struct device *dev;
  69        struct regulator_desc regulator_descs[LTC3676_NUM_REGULATORS];
  70        struct regulator_dev *regulators[LTC3676_NUM_REGULATORS];
  71};
  72
  73static int ltc3676_set_suspend_voltage(struct regulator_dev *rdev, int uV)
  74{
  75        struct ltc3676 *ltc3676 = rdev_get_drvdata(rdev);
  76        struct device *dev = ltc3676->dev;
  77        int dcdc = rdev_get_id(rdev);
  78        int sel;
  79
  80        dev_dbg(dev, "%s id=%d uV=%d\n", __func__, dcdc, uV);
  81        sel = regulator_map_voltage_linear(rdev, uV, uV);
  82        if (sel < 0)
  83                return sel;
  84
  85        /* DVBB register follows right after the corresponding DVBA register */
  86        return regmap_update_bits(ltc3676->regmap, rdev->desc->vsel_reg + 1,
  87                                  rdev->desc->vsel_mask, sel);
  88}
  89
  90static int ltc3676_set_suspend_mode(struct regulator_dev *rdev,
  91                                    unsigned int mode)
  92{
  93        struct ltc3676 *ltc3676= rdev_get_drvdata(rdev);
  94        struct device *dev = ltc3676->dev;
  95        int mask, val;
  96        int dcdc = rdev_get_id(rdev);
  97
  98        dev_dbg(dev, "%s id=%d mode=%d\n", __func__, dcdc, mode);
  99
 100        mask = LTC3676_DVBxA_REF_SELECT;
 101        switch (mode) {
 102        case REGULATOR_MODE_STANDBY:
 103                val = 0; /* select DVBxA */
 104                break;
 105        case REGULATOR_MODE_NORMAL:
 106                val = LTC3676_DVBxA_REF_SELECT; /* select DVBxB */
 107                break;
 108        default:
 109                dev_warn(&rdev->dev, "%s: regulator mode: 0x%x not supported\n",
 110                         rdev->desc->name, mode);
 111                return -EINVAL;
 112        }
 113
 114        return regmap_update_bits(ltc3676->regmap, rdev->desc->vsel_reg,
 115                                  mask, val);
 116}
 117
 118static int ltc3676_set_voltage_sel(struct regulator_dev *rdev, unsigned selector)
 119{
 120        struct ltc3676 *ltc3676 = rdev_get_drvdata(rdev);
 121        struct device *dev = ltc3676->dev;
 122        int ret, dcdc = rdev_get_id(rdev);
 123
 124        dev_dbg(dev, "%s id=%d selector=%d\n", __func__, dcdc, selector);
 125
 126        ret = regmap_update_bits(ltc3676->regmap, rdev->desc->vsel_reg + 1,
 127                                 LTC3676_DVBxB_PGOOD_MASK,
 128                                 LTC3676_DVBxB_PGOOD_MASK);
 129        if (ret)
 130                return ret;
 131
 132        return regulator_set_voltage_sel_regmap(rdev, selector);
 133}
 134
 135static inline unsigned int ltc3676_scale(unsigned int uV, u32 r1, u32 r2)
 136{
 137        uint64_t tmp;
 138        if (uV == 0)
 139                return 0;
 140        tmp = (uint64_t)uV * r1;
 141        do_div(tmp, r2);
 142        return uV + (unsigned int)tmp;
 143}
 144
 145static int ltc3676_of_parse_cb(struct device_node *np,
 146                               const struct regulator_desc *desc,
 147                               struct regulator_config *config)
 148{
 149        struct ltc3676 *ltc3676 = config->driver_data;
 150        struct regulator_desc *rdesc = &ltc3676->regulator_descs[desc->id];
 151        u32 r[2];
 152        int ret;
 153
 154        /* LDO3 has a fixed output */
 155        if (desc->id == LTC3676_LDO3)
 156                return 0;
 157
 158        ret = of_property_read_u32_array(np, "lltc,fb-voltage-divider", r, 2);
 159        if (ret) {
 160                dev_err(ltc3676->dev, "Failed to parse voltage divider: %d\n",
 161                        ret);
 162                return ret;
 163        }
 164
 165        rdesc->min_uV = ltc3676_scale(desc->min_uV, r[0], r[1]);
 166        rdesc->uV_step = ltc3676_scale(desc->uV_step, r[0], r[1]);
 167        rdesc->fixed_uV = ltc3676_scale(desc->fixed_uV, r[0], r[1]);
 168
 169        return 0;
 170}
 171
 172/* SW1, SW2, SW3, SW4 linear 0.8V-3.3V with scalar via R1/R2 feeback res */
 173static const struct regulator_ops ltc3676_linear_regulator_ops = {
 174        .enable = regulator_enable_regmap,
 175        .disable = regulator_disable_regmap,
 176        .is_enabled = regulator_is_enabled_regmap,
 177        .list_voltage = regulator_list_voltage_linear,
 178        .set_voltage_sel = ltc3676_set_voltage_sel,
 179        .get_voltage_sel = regulator_get_voltage_sel_regmap,
 180        .set_suspend_voltage = ltc3676_set_suspend_voltage,
 181        .set_suspend_mode = ltc3676_set_suspend_mode,
 182};
 183
 184/* LDO1 always on fixed 0.8V-3.3V via scalar via R1/R2 feeback res */
 185static const struct regulator_ops ltc3676_fixed_standby_regulator_ops = {
 186};
 187
 188/* LDO2, LDO3 fixed (LDO2 has external scalar via R1/R2 feedback res) */
 189static const struct regulator_ops ltc3676_fixed_regulator_ops = {
 190        .enable = regulator_enable_regmap,
 191        .disable = regulator_disable_regmap,
 192        .is_enabled = regulator_is_enabled_regmap,
 193};
 194
 195#define LTC3676_REG(_id, _name, _ops, en_reg, en_bit, dvba_reg, dvb_mask)   \
 196        [LTC3676_ ## _id] = {                                        \
 197                .name = #_name,                                \
 198                .of_match = of_match_ptr(#_name),              \
 199                .regulators_node = of_match_ptr("regulators"), \
 200                .of_parse_cb = ltc3676_of_parse_cb,            \
 201                .n_voltages = (dvb_mask) + 1,                  \
 202                .min_uV = (dvba_reg) ? 412500 : 0,             \
 203                .uV_step = (dvba_reg) ? 12500 : 0,             \
 204                .ramp_delay = (dvba_reg) ? 800 : 0,            \
 205                .fixed_uV = (dvb_mask) ? 0 : 725000,           \
 206                .ops = &ltc3676_ ## _ops ## _regulator_ops,    \
 207                .type = REGULATOR_VOLTAGE,                     \
 208                .id = LTC3676_ ## _id,                         \
 209                .owner = THIS_MODULE,                          \
 210                .vsel_reg = (dvba_reg),                        \
 211                .vsel_mask = (dvb_mask),                       \
 212                .enable_reg = (en_reg),                        \
 213                .enable_mask = (1 << en_bit),                  \
 214        }
 215
 216#define LTC3676_LINEAR_REG(_id, _name, _en, _dvba)                     \
 217        LTC3676_REG(_id, _name, linear,                                \
 218                    LTC3676_ ## _en, 7,                                \
 219                    LTC3676_ ## _dvba, 0x1f)
 220
 221#define LTC3676_FIXED_REG(_id, _name, _en_reg, _en_bit)                \
 222        LTC3676_REG(_id, _name, fixed, LTC3676_ ## _en_reg, _en_bit, 0, 0)
 223
 224static const struct regulator_desc ltc3676_regulators[LTC3676_NUM_REGULATORS] = {
 225        LTC3676_LINEAR_REG(SW1, sw1, BUCK1, DVB1A),
 226        LTC3676_LINEAR_REG(SW2, sw2, BUCK2, DVB2A),
 227        LTC3676_LINEAR_REG(SW3, sw3, BUCK3, DVB3A),
 228        LTC3676_LINEAR_REG(SW4, sw4, BUCK4, DVB4A),
 229        LTC3676_REG(LDO1, ldo1, fixed_standby, 0, 0, 0, 0),
 230        LTC3676_FIXED_REG(LDO2, ldo2, LDOA, 2),
 231        LTC3676_FIXED_REG(LDO3, ldo3, LDOA, 5),
 232        LTC3676_FIXED_REG(LDO4, ldo4, LDOB, 2),
 233};
 234
 235static bool ltc3676_readable_writeable_reg(struct device *dev, unsigned int reg)
 236{
 237        switch (reg) {
 238        case LTC3676_BUCK1 ... LTC3676_IRQSTAT:
 239        case LTC3676_HRST:
 240        case LTC3676_CLIRQ:
 241                return true;
 242        }
 243        return false;
 244}
 245
 246static bool ltc3676_volatile_reg(struct device *dev, unsigned int reg)
 247{
 248        switch (reg) {
 249        case LTC3676_IRQSTAT ... LTC3676_PGSTATRT:
 250                return true;
 251        }
 252        return false;
 253}
 254
 255static const struct regmap_config ltc3676_regmap_config = {
 256        .reg_bits = 8,
 257        .val_bits = 8,
 258        .writeable_reg = ltc3676_readable_writeable_reg,
 259        .readable_reg = ltc3676_readable_writeable_reg,
 260        .volatile_reg = ltc3676_volatile_reg,
 261        .max_register = LTC3676_CLIRQ,
 262        .use_single_read = true,
 263        .use_single_write = true,
 264        .cache_type = REGCACHE_RBTREE,
 265};
 266
 267static irqreturn_t ltc3676_isr(int irq, void *dev_id)
 268{
 269        struct ltc3676 *ltc3676 = dev_id;
 270        struct device *dev = ltc3676->dev;
 271        unsigned int i, irqstat, event;
 272
 273        regmap_read(ltc3676->regmap, LTC3676_IRQSTAT, &irqstat);
 274
 275        dev_dbg(dev, "irq%d irqstat=0x%02x\n", irq, irqstat);
 276        if (irqstat & LTC3676_IRQSTAT_THERMAL_WARN) {
 277                dev_warn(dev, "Over-temperature Warning\n");
 278                event = REGULATOR_EVENT_OVER_TEMP;
 279                for (i = 0; i < LTC3676_NUM_REGULATORS; i++)
 280                        regulator_notifier_call_chain(ltc3676->regulators[i],
 281                                                      event, NULL);
 282        }
 283
 284        if (irqstat & LTC3676_IRQSTAT_UNDERVOLT_WARN) {
 285                dev_info(dev, "Undervoltage Warning\n");
 286                event = REGULATOR_EVENT_UNDER_VOLTAGE;
 287                for (i = 0; i < LTC3676_NUM_REGULATORS; i++)
 288                        regulator_notifier_call_chain(ltc3676->regulators[i],
 289                                                      event, NULL);
 290        }
 291
 292        /* Clear warning condition */
 293        regmap_write(ltc3676->regmap, LTC3676_CLIRQ, 0);
 294
 295        return IRQ_HANDLED;
 296}
 297
 298static int ltc3676_regulator_probe(struct i2c_client *client)
 299{
 300        struct device *dev = &client->dev;
 301        struct regulator_init_data *init_data = dev_get_platdata(dev);
 302        struct regulator_desc *descs;
 303        struct ltc3676 *ltc3676;
 304        int i, ret;
 305
 306        ltc3676 = devm_kzalloc(dev, sizeof(*ltc3676), GFP_KERNEL);
 307        if (!ltc3676)
 308                return -ENOMEM;
 309
 310        i2c_set_clientdata(client, ltc3676);
 311        ltc3676->dev = dev;
 312
 313        descs = ltc3676->regulator_descs;
 314        memcpy(descs, ltc3676_regulators, sizeof(ltc3676_regulators));
 315        descs[LTC3676_LDO3].fixed_uV = 1800000; /* LDO3 is fixed 1.8V */
 316
 317        ltc3676->regmap = devm_regmap_init_i2c(client, &ltc3676_regmap_config);
 318        if (IS_ERR(ltc3676->regmap)) {
 319                ret = PTR_ERR(ltc3676->regmap);
 320                dev_err(dev, "failed to initialize regmap: %d\n", ret);
 321                return ret;
 322        }
 323
 324        for (i = 0; i < LTC3676_NUM_REGULATORS; i++) {
 325                struct regulator_desc *desc = &ltc3676->regulator_descs[i];
 326                struct regulator_config config = { };
 327
 328                if (init_data)
 329                        config.init_data = &init_data[i];
 330
 331                config.dev = dev;
 332                config.driver_data = ltc3676;
 333
 334                ltc3676->regulators[i] = devm_regulator_register(dev, desc,
 335                                                                 &config);
 336                if (IS_ERR(ltc3676->regulators[i])) {
 337                        ret = PTR_ERR(ltc3676->regulators[i]);
 338                        dev_err(dev, "failed to register regulator %s: %d\n",
 339                                desc->name, ret);
 340                        return ret;
 341                }
 342        }
 343
 344        regmap_write(ltc3676->regmap, LTC3676_CLIRQ, 0);
 345        if (client->irq) {
 346                ret = devm_request_threaded_irq(dev, client->irq, NULL,
 347                                                ltc3676_isr,
 348                                                IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 349                                                client->name, ltc3676);
 350                if (ret) {
 351                        dev_err(dev, "Failed to request IRQ: %d\n", ret);
 352                        return ret;
 353                }
 354        }
 355
 356        return 0;
 357}
 358
 359static const struct i2c_device_id ltc3676_i2c_id[] = {
 360        { "ltc3676" },
 361        { }
 362};
 363MODULE_DEVICE_TABLE(i2c, ltc3676_i2c_id);
 364
 365static const struct of_device_id __maybe_unused ltc3676_of_match[] = {
 366        { .compatible = "lltc,ltc3676" },
 367        { },
 368};
 369MODULE_DEVICE_TABLE(of, ltc3676_of_match);
 370
 371static struct i2c_driver ltc3676_driver = {
 372        .driver = {
 373                .name = DRIVER_NAME,
 374                .of_match_table = of_match_ptr(ltc3676_of_match),
 375        },
 376        .probe_new = ltc3676_regulator_probe,
 377        .id_table = ltc3676_i2c_id,
 378};
 379module_i2c_driver(ltc3676_driver);
 380
 381MODULE_AUTHOR("Tim Harvey <tharvey@gateworks.com>");
 382MODULE_DESCRIPTION("Regulator driver for Linear Technology LTC3676");
 383MODULE_LICENSE("GPL v2");
 384