1 // SPDX-License-Identifier: GPL-2.0
2 //
3 // Copyright (C) 2012 ARM Limited
4
5 #define DRVNAME "vexpress-regulator"
6 #define pr_fmt(fmt) DRVNAME ": " fmt
7
8 #include <linux/device.h>
9 #include <linux/err.h>
10 #include <linux/module.h>
11 #include <linux/mod_devicetable.h>
12 #include <linux/platform_device.h>
13 #include <linux/regulator/driver.h>
14 #include <linux/regulator/machine.h>
15 #include <linux/regulator/of_regulator.h>
16 #include <linux/vexpress.h>
17
vexpress_regulator_get_voltage(struct regulator_dev * regdev)18 static int vexpress_regulator_get_voltage(struct regulator_dev *regdev)
19 {
20 unsigned int uV;
21 int err = regmap_read(regdev->regmap, 0, &uV);
22
23 return err ? err : uV;
24 }
25
vexpress_regulator_set_voltage(struct regulator_dev * regdev,int min_uV,int max_uV,unsigned * selector)26 static int vexpress_regulator_set_voltage(struct regulator_dev *regdev,
27 int min_uV, int max_uV, unsigned *selector)
28 {
29 return regmap_write(regdev->regmap, 0, min_uV);
30 }
31
32 static const struct regulator_ops vexpress_regulator_ops_ro = {
33 .get_voltage = vexpress_regulator_get_voltage,
34 };
35
36 static const struct regulator_ops vexpress_regulator_ops = {
37 .get_voltage = vexpress_regulator_get_voltage,
38 .set_voltage = vexpress_regulator_set_voltage,
39 };
40
vexpress_regulator_probe(struct platform_device * pdev)41 static int vexpress_regulator_probe(struct platform_device *pdev)
42 {
43 struct regulator_desc *desc;
44 struct regulator_init_data *init_data;
45 struct regulator_config config = { };
46 struct regulator_dev *rdev;
47 struct regmap *regmap;
48
49 desc = devm_kzalloc(&pdev->dev, sizeof(*desc), GFP_KERNEL);
50 if (!desc)
51 return -ENOMEM;
52
53 regmap = devm_regmap_init_vexpress_config(&pdev->dev);
54 if (IS_ERR(regmap))
55 return PTR_ERR(regmap);
56
57 desc->name = dev_name(&pdev->dev);
58 desc->type = REGULATOR_VOLTAGE;
59 desc->owner = THIS_MODULE;
60 desc->continuous_voltage_range = true;
61
62 init_data = of_get_regulator_init_data(&pdev->dev, pdev->dev.of_node,
63 desc);
64 if (!init_data)
65 return -EINVAL;
66
67 init_data->constraints.apply_uV = 0;
68 if (init_data->constraints.min_uV && init_data->constraints.max_uV)
69 desc->ops = &vexpress_regulator_ops;
70 else
71 desc->ops = &vexpress_regulator_ops_ro;
72
73 config.regmap = regmap;
74 config.dev = &pdev->dev;
75 config.init_data = init_data;
76 config.of_node = pdev->dev.of_node;
77
78 rdev = devm_regulator_register(&pdev->dev, desc, &config);
79 return PTR_ERR_OR_ZERO(rdev);
80 }
81
82 static const struct of_device_id vexpress_regulator_of_match[] = {
83 { .compatible = "arm,vexpress-volt", },
84 { }
85 };
86 MODULE_DEVICE_TABLE(of, vexpress_regulator_of_match);
87
88 static struct platform_driver vexpress_regulator_driver = {
89 .probe = vexpress_regulator_probe,
90 .driver = {
91 .name = DRVNAME,
92 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
93 .of_match_table = vexpress_regulator_of_match,
94 },
95 };
96
97 module_platform_driver(vexpress_regulator_driver);
98
99 MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>");
100 MODULE_DESCRIPTION("Versatile Express regulator");
101 MODULE_LICENSE("GPL");
102 MODULE_ALIAS("platform:vexpress-regulator");
103