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1// SPDX-License-Identifier: GPL-2.0-only2/*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 0x0120#define LTC3676_BUCK2 0x0221#define LTC3676_BUCK3 0x0322#define LTC3676_BUCK4 0x0423#define LTC3676_LDOA 0x0524#define LTC3676_LDOB 0x0625#define LTC3676_SQD1 0x0726#define LTC3676_SQD2 0x0827#define LTC3676_CNTRL 0x0928#define LTC3676_DVB1A 0x0A29#define LTC3676_DVB1B 0x0B30#define LTC3676_DVB2A 0x0C31#define LTC3676_DVB2B 0x0D32#define LTC3676_DVB3A 0x0E33#define LTC3676_DVB3B 0x0F34#define LTC3676_DVB4A 0x1035#define LTC3676_DVB4B 0x1136#define LTC3676_MSKIRQ 0x1237#define LTC3676_MSKPG 0x1338#define LTC3676_USER 0x1439#define LTC3676_IRQSTAT 0x1540#define LTC3676_PGSTATL 0x1641#define LTC3676_PGSTATRT 0x1742#define LTC3676_HRST 0x1E43#define LTC3676_CLIRQ 0x1F44 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 = <c3676->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 = <c3676_ ## _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_MAPLE,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, <c3676_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 = <c3676->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 .probe_type = PROBE_PREFER_ASYNCHRONOUS,375 .of_match_table = of_match_ptr(ltc3676_of_match),376 },377 .probe = ltc3676_regulator_probe,378 .id_table = ltc3676_i2c_id,379};380module_i2c_driver(ltc3676_driver);381 382MODULE_AUTHOR("Tim Harvey <tharvey@gateworks.com>");383MODULE_DESCRIPTION("Regulator driver for Linear Technology LTC3676");384MODULE_LICENSE("GPL v2");385