linux/drivers/regulator/max1586.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * max1586.c  --  Voltage and current regulation for the Maxim 1586
   4 *
   5 * Copyright (C) 2008 Robert Jarzmik
   6 */
   7#include <linux/module.h>
   8#include <linux/err.h>
   9#include <linux/i2c.h>
  10#include <linux/platform_device.h>
  11#include <linux/regulator/driver.h>
  12#include <linux/slab.h>
  13#include <linux/regulator/max1586.h>
  14#include <linux/of_device.h>
  15#include <linux/regulator/of_regulator.h>
  16
  17#define MAX1586_V3_MAX_VSEL 31
  18#define MAX1586_V6_MAX_VSEL 3
  19
  20#define MAX1586_V3_MIN_UV   700000
  21#define MAX1586_V3_MAX_UV  1475000
  22
  23#define MAX1586_V6_MIN_UV        0
  24#define MAX1586_V6_MAX_UV  3000000
  25
  26#define I2C_V3_SELECT (0 << 5)
  27#define I2C_V6_SELECT (1 << 5)
  28
  29struct max1586_data {
  30        struct i2c_client *client;
  31
  32        /* min/max V3 voltage */
  33        unsigned int min_uV;
  34        unsigned int max_uV;
  35
  36        unsigned int v3_curr_sel;
  37        unsigned int v6_curr_sel;
  38};
  39
  40/*
  41 * V6 voltage
  42 * On I2C bus, sending a "x" byte to the max1586 means :
  43 *   set V6 to either 0V, 1.8V, 2.5V, 3V depending on (x & 0x3)
  44 * As regulator framework doesn't accept voltages to be 0V, we use 1uV.
  45 */
  46static const unsigned int v6_voltages_uv[] = { 1, 1800000, 2500000, 3000000 };
  47
  48/*
  49 * V3 voltage
  50 * On I2C bus, sending a "x" byte to the max1586 means :
  51 *   set V3 to 0.700V + (x & 0x1f) * 0.025V
  52 * This voltage can be increased by external resistors
  53 * R24 and R25=100kOhm as described in the data sheet.
  54 * The gain is approximately: 1 + R24/R25 + R24/185.5kOhm
  55 */
  56static int max1586_v3_get_voltage_sel(struct regulator_dev *rdev)
  57{
  58        struct max1586_data *max1586 = rdev_get_drvdata(rdev);
  59
  60        return max1586->v3_curr_sel;
  61}
  62
  63static int max1586_v3_set_voltage_sel(struct regulator_dev *rdev,
  64                                      unsigned selector)
  65{
  66        struct max1586_data *max1586 = rdev_get_drvdata(rdev);
  67        struct i2c_client *client = max1586->client;
  68        int ret;
  69        u8 v3_prog;
  70
  71        dev_dbg(&client->dev, "changing voltage v3 to %dmv\n",
  72                regulator_list_voltage_linear(rdev, selector) / 1000);
  73
  74        v3_prog = I2C_V3_SELECT | (u8) selector;
  75        ret = i2c_smbus_write_byte(client, v3_prog);
  76        if (ret)
  77                return ret;
  78
  79        max1586->v3_curr_sel = selector;
  80
  81        return 0;
  82}
  83
  84static int max1586_v6_get_voltage_sel(struct regulator_dev *rdev)
  85{
  86        struct max1586_data *max1586 = rdev_get_drvdata(rdev);
  87
  88        return max1586->v6_curr_sel;
  89}
  90
  91static int max1586_v6_set_voltage_sel(struct regulator_dev *rdev,
  92                                      unsigned int selector)
  93{
  94        struct max1586_data *max1586 = rdev_get_drvdata(rdev);
  95        struct i2c_client *client = max1586->client;
  96        u8 v6_prog;
  97        int ret;
  98
  99        dev_dbg(&client->dev, "changing voltage v6 to %dmv\n",
 100                rdev->desc->volt_table[selector] / 1000);
 101
 102        v6_prog = I2C_V6_SELECT | (u8) selector;
 103        ret = i2c_smbus_write_byte(client, v6_prog);
 104        if (ret)
 105                return ret;
 106
 107        max1586->v6_curr_sel = selector;
 108
 109        return 0;
 110}
 111
 112/*
 113 * The Maxim 1586 controls V3 and V6 voltages, but offers no way of reading back
 114 * the set up value.
 115 */
 116static const struct regulator_ops max1586_v3_ops = {
 117        .get_voltage_sel = max1586_v3_get_voltage_sel,
 118        .set_voltage_sel = max1586_v3_set_voltage_sel,
 119        .list_voltage = regulator_list_voltage_linear,
 120        .map_voltage = regulator_map_voltage_linear,
 121};
 122
 123static const struct regulator_ops max1586_v6_ops = {
 124        .get_voltage_sel = max1586_v6_get_voltage_sel,
 125        .set_voltage_sel = max1586_v6_set_voltage_sel,
 126        .list_voltage = regulator_list_voltage_table,
 127};
 128
 129static struct regulator_desc max1586_reg[] = {
 130        {
 131                .name = "Output_V3",
 132                .id = MAX1586_V3,
 133                .ops = &max1586_v3_ops,
 134                .type = REGULATOR_VOLTAGE,
 135                .n_voltages = MAX1586_V3_MAX_VSEL + 1,
 136                .owner = THIS_MODULE,
 137        },
 138        {
 139                .name = "Output_V6",
 140                .id = MAX1586_V6,
 141                .ops = &max1586_v6_ops,
 142                .type = REGULATOR_VOLTAGE,
 143                .n_voltages = MAX1586_V6_MAX_VSEL + 1,
 144                .volt_table = v6_voltages_uv,
 145                .owner = THIS_MODULE,
 146        },
 147};
 148
 149static int of_get_max1586_platform_data(struct device *dev,
 150                                 struct max1586_platform_data *pdata)
 151{
 152        struct max1586_subdev_data *sub;
 153        struct of_regulator_match rmatch[ARRAY_SIZE(max1586_reg)] = { };
 154        struct device_node *np = dev->of_node;
 155        int i, matched;
 156
 157        if (of_property_read_u32(np, "v3-gain",
 158                                 &pdata->v3_gain) < 0) {
 159                dev_err(dev, "%pOF has no 'v3-gain' property\n", np);
 160                return -EINVAL;
 161        }
 162
 163        np = of_get_child_by_name(np, "regulators");
 164        if (!np) {
 165                dev_err(dev, "missing 'regulators' subnode in DT\n");
 166                return -EINVAL;
 167        }
 168
 169        for (i = 0; i < ARRAY_SIZE(rmatch); i++)
 170                rmatch[i].name = max1586_reg[i].name;
 171
 172        matched = of_regulator_match(dev, np, rmatch, ARRAY_SIZE(rmatch));
 173        of_node_put(np);
 174        /*
 175         * If matched is 0, ie. neither Output_V3 nor Output_V6 have been found,
 176         * return 0, which signals the normal situation where no subregulator is
 177         * available. This is normal because the max1586 doesn't provide any
 178         * readback support, so the subregulators can't report any status
 179         * anyway.  If matched < 0, return the error.
 180         */
 181        if (matched <= 0)
 182                return matched;
 183
 184        pdata->subdevs = devm_kcalloc(dev,
 185                                      matched,
 186                                      sizeof(struct max1586_subdev_data),
 187                                      GFP_KERNEL);
 188        if (!pdata->subdevs)
 189                return -ENOMEM;
 190
 191        pdata->num_subdevs = matched;
 192        sub = pdata->subdevs;
 193
 194        for (i = 0; i < matched; i++) {
 195                sub->id = i;
 196                sub->name = rmatch[i].of_node->name;
 197                sub->platform_data = rmatch[i].init_data;
 198                sub++;
 199        }
 200
 201        return 0;
 202}
 203
 204static const struct of_device_id __maybe_unused max1586_of_match[] = {
 205        { .compatible = "maxim,max1586", },
 206        {},
 207};
 208MODULE_DEVICE_TABLE(of, max1586_of_match);
 209
 210static int max1586_pmic_probe(struct i2c_client *client,
 211                                        const struct i2c_device_id *i2c_id)
 212{
 213        struct max1586_platform_data *pdata, pdata_of;
 214        struct regulator_config config = { };
 215        struct max1586_data *max1586;
 216        int i, id, ret;
 217        const struct of_device_id *match;
 218
 219        pdata = dev_get_platdata(&client->dev);
 220        if (client->dev.of_node && !pdata) {
 221                match = of_match_device(of_match_ptr(max1586_of_match),
 222                                        &client->dev);
 223                if (!match) {
 224                        dev_err(&client->dev, "Error: No device match found\n");
 225                        return -ENODEV;
 226                }
 227                ret = of_get_max1586_platform_data(&client->dev, &pdata_of);
 228                if (ret < 0)
 229                        return ret;
 230                pdata = &pdata_of;
 231        }
 232
 233        max1586 = devm_kzalloc(&client->dev, sizeof(struct max1586_data),
 234                        GFP_KERNEL);
 235        if (!max1586)
 236                return -ENOMEM;
 237
 238        max1586->client = client;
 239
 240        if (!pdata->v3_gain)
 241                return -EINVAL;
 242
 243        max1586->min_uV = MAX1586_V3_MIN_UV / 1000 * pdata->v3_gain / 1000;
 244        max1586->max_uV = MAX1586_V3_MAX_UV / 1000 * pdata->v3_gain / 1000;
 245
 246        /* Set curr_sel to default voltage on power-up */
 247        max1586->v3_curr_sel = 24; /* 1.3V */
 248        max1586->v6_curr_sel = 0;
 249
 250        for (i = 0; i < pdata->num_subdevs && i <= MAX1586_V6; i++) {
 251                struct regulator_dev *rdev;
 252
 253                id = pdata->subdevs[i].id;
 254                if (!pdata->subdevs[i].platform_data)
 255                        continue;
 256                if (id < MAX1586_V3 || id > MAX1586_V6) {
 257                        dev_err(&client->dev, "invalid regulator id %d\n", id);
 258                        return -EINVAL;
 259                }
 260
 261                if (id == MAX1586_V3) {
 262                        max1586_reg[id].min_uV = max1586->min_uV;
 263                        max1586_reg[id].uV_step =
 264                                        (max1586->max_uV - max1586->min_uV) /
 265                                        MAX1586_V3_MAX_VSEL;
 266                }
 267
 268                config.dev = &client->dev;
 269                config.init_data = pdata->subdevs[i].platform_data;
 270                config.driver_data = max1586;
 271
 272                rdev = devm_regulator_register(&client->dev,
 273                                                  &max1586_reg[id], &config);
 274                if (IS_ERR(rdev)) {
 275                        dev_err(&client->dev, "failed to register %s\n",
 276                                max1586_reg[id].name);
 277                        return PTR_ERR(rdev);
 278                }
 279        }
 280
 281        i2c_set_clientdata(client, max1586);
 282        dev_info(&client->dev, "Maxim 1586 regulator driver loaded\n");
 283        return 0;
 284}
 285
 286static const struct i2c_device_id max1586_id[] = {
 287        { "max1586", 0 },
 288        { }
 289};
 290MODULE_DEVICE_TABLE(i2c, max1586_id);
 291
 292static struct i2c_driver max1586_pmic_driver = {
 293        .probe = max1586_pmic_probe,
 294        .driver         = {
 295                .name   = "max1586",
 296                .of_match_table = of_match_ptr(max1586_of_match),
 297        },
 298        .id_table       = max1586_id,
 299};
 300
 301static int __init max1586_pmic_init(void)
 302{
 303        return i2c_add_driver(&max1586_pmic_driver);
 304}
 305subsys_initcall(max1586_pmic_init);
 306
 307static void __exit max1586_pmic_exit(void)
 308{
 309        i2c_del_driver(&max1586_pmic_driver);
 310}
 311module_exit(max1586_pmic_exit);
 312
 313/* Module information */
 314MODULE_DESCRIPTION("MAXIM 1586 voltage regulator driver");
 315MODULE_AUTHOR("Robert Jarzmik");
 316MODULE_LICENSE("GPL");
 317