drivers/regulator/ltc3676.c

   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
  54 enum 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
  66 struct 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
  73 static 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
  90 static 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
 118 static 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
 135 static 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
 145 static 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 */
 173 static 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 */
 185 static const struct regulator_ops ltc3676_fixed_standby_regulator_ops = {
 186 };
 187
 188 /* LDO2, LDO3 fixed (LDO2 has external scalar via R1/R2 feedback res) */
 189 static 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
 224 static 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
 235 static 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
 246 static 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
 255 static 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
 267 static 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_lock(ltc3676->regulators[i]);
 281                         regulator_notifier_call_chain(ltc3676->regulators[i],
 282                                                       event, NULL);
 283                         regulator_unlock(ltc3676->regulators[i]);
 284                 }
 285         }
 286
 287         if (irqstat & LTC3676_IRQSTAT_UNDERVOLT_WARN) {
 288                 dev_info(dev, "Undervoltage Warning\n");
 289                 event = REGULATOR_EVENT_UNDER_VOLTAGE;
 290                 for (i = 0; i < LTC3676_NUM_REGULATORS; i++) {
 291                         regulator_lock(ltc3676->regulators[i]);
 292                         regulator_notifier_call_chain(ltc3676->regulators[i],
 293                                                       event, NULL);
 294                         regulator_unlock(ltc3676->regulators[i]);
 295                 }
 296         }
 297
 298         /* Clear warning condition */
 299         regmap_write(ltc3676->regmap, LTC3676_CLIRQ, 0);
 300
 301         return IRQ_HANDLED;
 302 }
 303
 304 static int ltc3676_regulator_probe(struct i2c_client *client)
 305 {
 306         struct device *dev = &client->dev;
 307         struct regulator_init_data *init_data = dev_get_platdata(dev);
 308         struct regulator_desc *descs;
 309         struct ltc3676 *ltc3676;
 310         int i, ret;
 311
 312         ltc3676 = devm_kzalloc(dev, sizeof(*ltc3676), GFP_KERNEL);
 313         if (!ltc3676)
 314                 return -ENOMEM;
 315
 316         i2c_set_clientdata(client, ltc3676);
 317         ltc3676->dev = dev;
 318
 319         descs = ltc3676->regulator_descs;
 320         memcpy(descs, ltc3676_regulators, sizeof(ltc3676_regulators));
 321         descs[LTC3676_LDO3].fixed_uV = 1800000; /* LDO3 is fixed 1.8V */
 322
 323         ltc3676->regmap = devm_regmap_init_i2c(client, &ltc3676_regmap_config);
 324         if (IS_ERR(ltc3676->regmap)) {
 325                 ret = PTR_ERR(ltc3676->regmap);
 326                 dev_err(dev, "failed to initialize regmap: %d\n", ret);
 327                 return ret;
 328         }
 329
 330         for (i = 0; i < LTC3676_NUM_REGULATORS; i++) {
 331                 struct regulator_desc *desc = &ltc3676->regulator_descs[i];
 332                 struct regulator_config config = { };
 333
 334                 if (init_data)
 335                         config.init_data = &init_data[i];
 336
 337                 config.dev = dev;
 338                 config.driver_data = ltc3676;
 339
 340                 ltc3676->regulators[i] = devm_regulator_register(dev, desc,
 341                                                                  &config);
 342                 if (IS_ERR(ltc3676->regulators[i])) {
 343                         ret = PTR_ERR(ltc3676->regulators[i]);
 344                         dev_err(dev, "failed to register regulator %s: %d\n",
 345                                 desc->name, ret);
 346                         return ret;
 347                 }
 348         }
 349
 350         regmap_write(ltc3676->regmap, LTC3676_CLIRQ, 0);
 351         if (client->irq) {
 352                 ret = devm_request_threaded_irq(dev, client->irq, NULL,
 353                                                 ltc3676_isr,
 354                                                 IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 355                                                 client->name, ltc3676);
 356                 if (ret) {
 357                         dev_err(dev, "Failed to request IRQ: %d\n", ret);
 358                         return ret;
 359                 }
 360         }
 361
 362         return 0;
 363 }
 364
 365 static const struct i2c_device_id ltc3676_i2c_id[] = {
 366         { "ltc3676" },
 367         { }
 368 };
 369 MODULE_DEVICE_TABLE(i2c, ltc3676_i2c_id);
 370
 371 static const struct of_device_id ltc3676_of_match[] = {
 372         { .compatible = "lltc,ltc3676" },
 373         { },
 374 };
 375 MODULE_DEVICE_TABLE(of, ltc3676_of_match);
 376
 377 static struct i2c_driver ltc3676_driver = {
 378         .driver = {
 379                 .name = DRIVER_NAME,
 380                 .of_match_table = of_match_ptr(ltc3676_of_match),
 381         },
 382         .probe_new = ltc3676_regulator_probe,
 383         .id_table = ltc3676_i2c_id,
 384 };
 385 module_i2c_driver(ltc3676_driver);
 386
 387 MODULE_AUTHOR("Tim Harvey <tharvey@gateworks.com>");
 388 MODULE_DESCRIPTION("Regulator driver for Linear Technology LTC3676");
 389 MODULE_LICENSE("GPL v2");