1// SPDX-License-Identifier: GPL-2.0-only
2/*
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 6250
18#define MAX20411_BASE_UV 243750
19#define MAX20411_MIN_SEL 41 /* 0.5V */
20#define MAX20411_MAX_SEL 165 /* 1.275V */
21#define MAX20411_VID_OFFSET 0x7
22#define MAX20411_VID_MASK 0xff
23#define MAX20411_SLEW_OFFSET 0x6
24#define MAX20411_SLEW_DVS_MASK 0xc
25#define MAX20411_SLEW_SR_MASK 0x3
26
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(map: rdev->regmap, reg: rdev->desc->vsel_reg, val: &val);
44 if (ret)
45 return ret;
46
47 val &= rdev->desc->vsel_mask;
48 voltage = regulator_list_voltage_linear(rdev, selector: val);
49
50 /* get rate */
51 ret = regmap_read(map: rdev->regmap, MAX20411_SLEW_OFFSET, val: &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 * 6.25mV
83 * 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, size: 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(ptr: max20411->regmap)) {
112 dev_err(dev, "Failed to allocate regmap!\n");
113 return PTR_ERR(ptr: 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(dev: max20411->dev, node: max20411->of_node, desc: &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(dev: max20411->dev, con_id: "enable", flags: GPIOD_ASIS);
130 if (IS_ERR(ptr: cfg.ena_gpiod))
131 return dev_err_probe(dev, err: PTR_ERR(ptr: cfg.ena_gpiod),
132 fmt: "unable to acquire enable gpio\n");
133
134 max20411->rdev = devm_regulator_register(dev: max20411->dev, regulator_desc: &max20411->desc, config: &cfg);
135 if (IS_ERR(ptr: max20411->rdev))
136 dev_err(max20411->dev, "Failed to register regulator\n");
137
138 return PTR_ERR_OR_ZERO(ptr: 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

source code of linux/drivers/regulator/max20411-regulator.c