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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Copyright (c) 2021, The Linux Foundation. All rights reserved.4 * Copyright (c) 2022, Linaro Ltd.5 */6 7#include <linux/bitfield.h>8#include <linux/gpio/consumer.h>9#include <linux/i2c.h>10#include <linux/module.h>11#include <linux/of_platform.h>12#include <linux/regmap.h>13#include <linux/regulator/driver.h>14#include <linux/regulator/machine.h>15#include <linux/regulator/of_regulator.h>16 17#define MAX20411_UV_STEP 625018#define MAX20411_BASE_UV 24375019#define MAX20411_MIN_SEL 41 /* 0.5V */20#define MAX20411_MAX_SEL 165 /* 1.275V */21#define MAX20411_VID_OFFSET 0x722#define MAX20411_VID_MASK 0xff23#define MAX20411_SLEW_OFFSET 0x624#define MAX20411_SLEW_DVS_MASK 0xc25#define MAX20411_SLEW_SR_MASK 0x326 27struct max20411 {28 struct device *dev;29 struct device_node *of_node;30 struct regulator_desc desc;31 struct regulator_dev *rdev;32 struct regmap *regmap;33};34 35static const unsigned int max20411_slew_rates[] = { 13100, 6600, 3300, 1600 };36 37static int max20411_enable_time(struct regulator_dev *rdev)38{39 int voltage, rate, ret;40 unsigned int val;41 42 /* get voltage */43 ret = regmap_read(rdev->regmap, rdev->desc->vsel_reg, &val);44 if (ret)45 return ret;46 47 val &= rdev->desc->vsel_mask;48 voltage = regulator_list_voltage_linear(rdev, val);49 50 /* get rate */51 ret = regmap_read(rdev->regmap, MAX20411_SLEW_OFFSET, &val);52 if (ret)53 return ret;54 55 val = FIELD_GET(MAX20411_SLEW_SR_MASK, val);56 rate = max20411_slew_rates[val];57 58 return DIV_ROUND_UP(voltage, rate);59}60 61static const struct regmap_config max20411_regmap_config = {62 .reg_bits = 8,63 .val_bits = 8,64 .max_register = 0xe,65};66 67static const struct regulator_ops max20411_ops = {68 .get_voltage_sel = regulator_get_voltage_sel_regmap,69 .set_voltage_sel = regulator_set_voltage_sel_regmap,70 .list_voltage = regulator_list_voltage_linear,71 .enable_time = max20411_enable_time,72};73 74static const struct regulator_desc max20411_desc = {75 .ops = &max20411_ops,76 .owner = THIS_MODULE,77 .type = REGULATOR_VOLTAGE,78 .supply_name = "vin",79 .name = "max20411",80 81 /*82 * voltage = 0.24375V + selector * 6.25mV83 * with valid selector between 41 to 165 (0.5V to 1.275V)84 */85 .min_uV = MAX20411_BASE_UV,86 .uV_step = MAX20411_UV_STEP,87 .linear_min_sel = MAX20411_MIN_SEL,88 .n_voltages = MAX20411_MAX_SEL + 1,89 90 .vsel_reg = MAX20411_VID_OFFSET,91 .vsel_mask = MAX20411_VID_MASK,92 93 .ramp_reg = MAX20411_SLEW_OFFSET,94 .ramp_mask = MAX20411_SLEW_DVS_MASK,95 .ramp_delay_table = max20411_slew_rates,96 .n_ramp_values = ARRAY_SIZE(max20411_slew_rates),97};98 99static int max20411_probe(struct i2c_client *client)100{101 struct regulator_init_data *init_data;102 struct device *dev = &client->dev;103 struct regulator_config cfg = {};104 struct max20411 *max20411;105 106 max20411 = devm_kzalloc(dev, sizeof(*max20411), GFP_KERNEL);107 if (!max20411)108 return -ENOMEM;109 110 max20411->regmap = devm_regmap_init_i2c(client, &max20411_regmap_config);111 if (IS_ERR(max20411->regmap)) {112 dev_err(dev, "Failed to allocate regmap!\n");113 return PTR_ERR(max20411->regmap);114 }115 116 max20411->dev = dev;117 max20411->of_node = dev->of_node;118 119 max20411->desc = max20411_desc;120 init_data = of_get_regulator_init_data(max20411->dev, max20411->of_node, &max20411->desc);121 if (!init_data)122 return -ENODATA;123 124 cfg.dev = max20411->dev;125 cfg.init_data = init_data;126 cfg.of_node = max20411->of_node;127 cfg.driver_data = max20411;128 129 cfg.ena_gpiod = gpiod_get(max20411->dev, "enable", GPIOD_ASIS);130 if (IS_ERR(cfg.ena_gpiod))131 return dev_err_probe(dev, PTR_ERR(cfg.ena_gpiod),132 "unable to acquire enable gpio\n");133 134 max20411->rdev = devm_regulator_register(max20411->dev, &max20411->desc, &cfg);135 if (IS_ERR(max20411->rdev))136 dev_err(max20411->dev, "Failed to register regulator\n");137 138 return PTR_ERR_OR_ZERO(max20411->rdev);139}140 141static const struct of_device_id of_max20411_match_tbl[] = {142 { .compatible = "maxim,max20411", },143 { },144};145MODULE_DEVICE_TABLE(of, of_max20411_match_tbl);146 147static const struct i2c_device_id max20411_id[] = {148 { "max20411" },149 { }150};151MODULE_DEVICE_TABLE(i2c, max20411_id);152 153static struct i2c_driver max20411_i2c_driver = {154 .driver = {155 .name = "max20411",156 .probe_type = PROBE_PREFER_ASYNCHRONOUS,157 .of_match_table = of_max20411_match_tbl,158 },159 .probe = max20411_probe,160 .id_table = max20411_id,161};162module_i2c_driver(max20411_i2c_driver);163 164MODULE_DESCRIPTION("Maxim MAX20411 High-Efficiency Single Step-Down Converter driver");165MODULE_LICENSE("GPL");166