LXR linux/drivers/regulator/sy8106a-regulator.c

   1// SPDX-License-Identifier: GPL-2.0+
   2//
   3// sy8106a-regulator.c - Regulator device driver for SY8106A
   4//
   5// Copyright (C) 2016 Ondřej Jirman <megous@megous.com>
   6// Copyright (c) 2017-2018 Icenowy Zheng <icenowy@aosc.io>
   7
   8#include <linux/err.h>
   9#include <linux/i2c.h>
  10#include <linux/module.h>
  11#include <linux/regmap.h>
  12#include <linux/regulator/driver.h>
  13#include <linux/regulator/of_regulator.h>
  14
  15#define SY8106A_REG_VOUT1_SEL           0x01
  16#define SY8106A_REG_VOUT_COM            0x02
  17#define SY8106A_REG_VOUT1_SEL_MASK      0x7f
  18#define SY8106A_DISABLE_REG             BIT(0)
  19/*
  20 * The I2C controlled voltage will only work when this bit is set; otherwise
  21 * it will behave like a fixed regulator.
  22 */
  23#define SY8106A_GO_BIT                  BIT(7)
  24
  25static const struct regmap_config sy8106a_regmap_config = {
  26        .reg_bits = 8,
  27        .val_bits = 8,
  28};
  29
  30static const struct regulator_ops sy8106a_ops = {
  31        .set_voltage_sel = regulator_set_voltage_sel_regmap,
  32        .set_voltage_time_sel = regulator_set_voltage_time_sel,
  33        .get_voltage_sel = regulator_get_voltage_sel_regmap,
  34        .list_voltage = regulator_list_voltage_linear,
  35        /* Enabling/disabling the regulator is not yet implemented */
  36};
  37
  38/* Default limits measured in millivolts */
  39#define SY8106A_MIN_MV          680
  40#define SY8106A_MAX_MV          1950
  41#define SY8106A_STEP_MV         10
  42
  43static const struct regulator_desc sy8106a_reg = {
  44        .name = "SY8106A",
  45        .id = 0,
  46        .ops = &sy8106a_ops,
  47        .type = REGULATOR_VOLTAGE,
  48        .n_voltages = ((SY8106A_MAX_MV - SY8106A_MIN_MV) / SY8106A_STEP_MV) + 1,
  49        .min_uV = (SY8106A_MIN_MV * 1000),
  50        .uV_step = (SY8106A_STEP_MV * 1000),
  51        .vsel_reg = SY8106A_REG_VOUT1_SEL,
  52        .vsel_mask = SY8106A_REG_VOUT1_SEL_MASK,
  53        /*
  54         * This ramp_delay is a conservative default value which works on
  55         * H3/H5 boards VDD-CPUX situations.
  56         */
  57        .ramp_delay = 200,
  58        .owner = THIS_MODULE,
  59};
  60
  61/*
  62 * I2C driver interface functions
  63 */
  64static int sy8106a_i2c_probe(struct i2c_client *i2c,
  65                            const struct i2c_device_id *id)
  66{
  67        struct device *dev = &i2c->dev;
  68        struct regulator_dev *rdev;
  69        struct regulator_config config = { };
  70        struct regmap *regmap;
  71        unsigned int reg, vsel;
  72        u32 fixed_voltage;
  73        int error;
  74
  75        error = of_property_read_u32(dev->of_node, "silergy,fixed-microvolt",
  76                                     &fixed_voltage);
  77        if (error)
  78                return error;
  79
  80        if (fixed_voltage < SY8106A_MIN_MV * 1000 ||
  81            fixed_voltage > SY8106A_MAX_MV * 1000)
  82                return -EINVAL;
  83
  84        regmap = devm_regmap_init_i2c(i2c, &sy8106a_regmap_config);
  85        if (IS_ERR(regmap)) {
  86                error = PTR_ERR(regmap);
  87                dev_err(dev, "Failed to allocate register map: %d\n", error);
  88                return error;
  89        }
  90
  91        config.dev = &i2c->dev;
  92        config.regmap = regmap;
  93
  94        config.of_node = dev->of_node;
  95        config.init_data = of_get_regulator_init_data(dev, dev->of_node,
  96                                                      &sy8106a_reg);
  97
  98        if (!config.init_data)
  99                return -ENOMEM;
 100
 101        /* Ensure GO_BIT is enabled when probing */
 102        error = regmap_read(regmap, SY8106A_REG_VOUT1_SEL, &reg);
 103        if (error)
 104                return error;
 105
 106        if (!(reg & SY8106A_GO_BIT)) {
 107                vsel = (fixed_voltage / 1000 - SY8106A_MIN_MV) /
 108                       SY8106A_STEP_MV;
 109
 110                error = regmap_write(regmap, SY8106A_REG_VOUT1_SEL,
 111                                     vsel | SY8106A_GO_BIT);
 112                if (error)
 113                        return error;
 114        }
 115
 116        /* Probe regulator */
 117        rdev = devm_regulator_register(&i2c->dev, &sy8106a_reg, &config);
 118        if (IS_ERR(rdev)) {
 119                error = PTR_ERR(rdev);
 120                dev_err(&i2c->dev, "Failed to register SY8106A regulator: %d\n", error);
 121                return error;
 122        }
 123
 124        return 0;
 125}
 126
 127static const struct of_device_id sy8106a_i2c_of_match[] = {
 128        { .compatible = "silergy,sy8106a" },
 129        { },
 130};
 131MODULE_DEVICE_TABLE(of, sy8106a_i2c_of_match);
 132
 133static const struct i2c_device_id sy8106a_i2c_id[] = {
 134        { "sy8106a", 0 },
 135        { },
 136};
 137MODULE_DEVICE_TABLE(i2c, sy8106a_i2c_id);
 138
 139static struct i2c_driver sy8106a_regulator_driver = {
 140        .driver = {
 141                .name = "sy8106a",
 142                .of_match_table = of_match_ptr(sy8106a_i2c_of_match),
 143        },
 144        .probe = sy8106a_i2c_probe,
 145        .id_table = sy8106a_i2c_id,
 146};
 147
 148module_i2c_driver(sy8106a_regulator_driver);
 149
 150MODULE_AUTHOR("Ondřej Jirman <megous@megous.com>");
 151MODULE_AUTHOR("Icenowy Zheng <icenowy@aosc.io>");
 152MODULE_DESCRIPTION("Regulator device driver for Silergy SY8106A");
 153MODULE_LICENSE("GPL");
 154