1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * dummy.c
4 *
5 * Copyright 2010 Wolfson Microelectronics PLC.
6 *
7 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
8 *
9 * This is useful for systems with mixed controllable and
10 * non-controllable regulators, as well as for allowing testing on
11 * systems with no controllable regulators.
12 */
13
14#include <linux/err.h>
15#include <linux/export.h>
16#include <linux/platform_device.h>
17#include <linux/regulator/driver.h>
18#include <linux/regulator/machine.h>
19
20#include "dummy.h"
21
22struct regulator_dev *dummy_regulator_rdev;
23
24static const struct regulator_init_data dummy_initdata = {
25	.constraints = {
26		.always_on = 1,
27	},
28};
29
30static const struct regulator_ops dummy_ops;
31
32static const struct regulator_desc dummy_desc = {
33	.name = "regulator-dummy",
34	.id = -1,
35	.type = REGULATOR_VOLTAGE,
36	.owner = THIS_MODULE,
37	.ops = &dummy_ops,
38};
39
40static int dummy_regulator_probe(struct platform_device *pdev)
41{
42	struct regulator_config config = { };
43	int ret;
44
45	config.dev = &pdev->dev;
46	config.init_data = &dummy_initdata;
47
48	dummy_regulator_rdev = devm_regulator_register(&pdev->dev, &dummy_desc,
49						       &config);
50	if (IS_ERR(dummy_regulator_rdev)) {
51		ret = PTR_ERR(dummy_regulator_rdev);
52		pr_err("Failed to register regulator: %d\n", ret);
53		return ret;
54	}
55
56	return 0;
57}
58
59static struct platform_driver dummy_regulator_driver = {
60	.probe		= dummy_regulator_probe,
61	.driver		= {
62		.name		= "reg-dummy",
63		.probe_type	= PROBE_PREFER_ASYNCHRONOUS,
64	},
65};
66
67static struct platform_device *dummy_pdev;
68
69void __init regulator_dummy_init(void)
70{
71	int ret;
72
73	dummy_pdev = platform_device_alloc("reg-dummy", -1);
74	if (!dummy_pdev) {
75		pr_err("Failed to allocate dummy regulator device\n");
76		return;
77	}
78
79	ret = platform_device_add(dummy_pdev);
80	if (ret != 0) {
81		pr_err("Failed to register dummy regulator device: %d\n", ret);
82		platform_device_put(dummy_pdev);
83		return;
84	}
85
86	ret = platform_driver_register(&dummy_regulator_driver);
87	if (ret != 0) {
88		pr_err("Failed to register dummy regulator driver: %d\n", ret);
89		platform_device_unregister(dummy_pdev);
90	}
91}
92