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 | |
27 | struct 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 | |
35 | static const unsigned int max20411_slew_rates[] = { 13100, 6600, 3300, 1600 }; |
36 | |
37 | static 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 | |
61 | static const struct regmap_config max20411_regmap_config = { |
62 | .reg_bits = 8, |
63 | .val_bits = 8, |
64 | .max_register = 0xe, |
65 | }; |
66 | |
67 | static 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 | |
74 | static 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 | |
99 | static 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 | |
141 | static const struct of_device_id of_max20411_match_tbl[] = { |
142 | { .compatible = "maxim,max20411" , }, |
143 | { }, |
144 | }; |
145 | MODULE_DEVICE_TABLE(of, of_max20411_match_tbl); |
146 | |
147 | static const struct i2c_device_id max20411_id[] = { |
148 | { "max20411" , 0 }, |
149 | { }, |
150 | }; |
151 | MODULE_DEVICE_TABLE(i2c, max20411_id); |
152 | |
153 | static 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 | }; |
162 | module_i2c_driver(max20411_i2c_driver); |
163 | |
164 | MODULE_LICENSE("GPL" ); |
165 | |