Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
[platform/kernel/linux-rpi.git] / 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
25 static const struct regmap_config sy8106a_regmap_config = {
26         .reg_bits = 8,
27         .val_bits = 8,
28 };
29
30 static 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
43 static 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  */
64 static int sy8106a_i2c_probe(struct i2c_client *i2c)
65 {
66         struct device *dev = &i2c->dev;
67         struct regulator_dev *rdev;
68         struct regulator_config config = { };
69         struct regmap *regmap;
70         unsigned int reg, vsel;
71         u32 fixed_voltage;
72         int error;
73
74         error = of_property_read_u32(dev->of_node, "silergy,fixed-microvolt",
75                                      &fixed_voltage);
76         if (error)
77                 return error;
78
79         if (fixed_voltage < SY8106A_MIN_MV * 1000 ||
80             fixed_voltage > SY8106A_MAX_MV * 1000)
81                 return -EINVAL;
82
83         regmap = devm_regmap_init_i2c(i2c, &sy8106a_regmap_config);
84         if (IS_ERR(regmap)) {
85                 error = PTR_ERR(regmap);
86                 dev_err(dev, "Failed to allocate register map: %d\n", error);
87                 return error;
88         }
89
90         config.dev = &i2c->dev;
91         config.regmap = regmap;
92
93         config.of_node = dev->of_node;
94         config.init_data = of_get_regulator_init_data(dev, dev->of_node,
95                                                       &sy8106a_reg);
96
97         if (!config.init_data)
98                 return -ENOMEM;
99
100         /* Ensure GO_BIT is enabled when probing */
101         error = regmap_read(regmap, SY8106A_REG_VOUT1_SEL, &reg);
102         if (error)
103                 return error;
104
105         if (!(reg & SY8106A_GO_BIT)) {
106                 vsel = (fixed_voltage / 1000 - SY8106A_MIN_MV) /
107                        SY8106A_STEP_MV;
108
109                 error = regmap_write(regmap, SY8106A_REG_VOUT1_SEL,
110                                      vsel | SY8106A_GO_BIT);
111                 if (error)
112                         return error;
113         }
114
115         /* Probe regulator */
116         rdev = devm_regulator_register(&i2c->dev, &sy8106a_reg, &config);
117         if (IS_ERR(rdev)) {
118                 error = PTR_ERR(rdev);
119                 dev_err(&i2c->dev, "Failed to register SY8106A regulator: %d\n", error);
120                 return error;
121         }
122
123         return 0;
124 }
125
126 static const struct of_device_id __maybe_unused sy8106a_i2c_of_match[] = {
127         { .compatible = "silergy,sy8106a" },
128         { },
129 };
130 MODULE_DEVICE_TABLE(of, sy8106a_i2c_of_match);
131
132 static const struct i2c_device_id sy8106a_i2c_id[] = {
133         { "sy8106a", 0 },
134         { },
135 };
136 MODULE_DEVICE_TABLE(i2c, sy8106a_i2c_id);
137
138 static struct i2c_driver sy8106a_regulator_driver = {
139         .driver = {
140                 .name = "sy8106a",
141                 .of_match_table = of_match_ptr(sy8106a_i2c_of_match),
142         },
143         .probe_new = sy8106a_i2c_probe,
144         .id_table = sy8106a_i2c_id,
145 };
146
147 module_i2c_driver(sy8106a_regulator_driver);
148
149 MODULE_AUTHOR("Ondřej Jirman <megous@megous.com>");
150 MODULE_AUTHOR("Icenowy Zheng <icenowy@aosc.io>");
151 MODULE_DESCRIPTION("Regulator device driver for Silergy SY8106A");
152 MODULE_LICENSE("GPL");