1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (c) 2016, Fuzhou Rockchip Electronics Co., Ltd
4 */
5
6#include <linux/init.h>
7#include <linux/module.h>
8#include <linux/kernel.h>
9#include <linux/of.h>
10#include <linux/platform_device.h>
11#include <linux/reboot.h>
12#include <linux/regmap.h>
13#include <linux/mfd/syscon.h>
14#include <linux/reboot-mode.h>
15
16struct syscon_reboot_mode {
17	struct regmap *map;
18	struct reboot_mode_driver reboot;
19	u32 offset;
20	u32 mask;
21};
22
23static int syscon_reboot_mode_write(struct reboot_mode_driver *reboot,
24				    unsigned int magic)
25{
26	struct syscon_reboot_mode *syscon_rbm;
27	int ret;
28
29	syscon_rbm = container_of(reboot, struct syscon_reboot_mode, reboot);
30
31	ret = regmap_update_bits(syscon_rbm->map, syscon_rbm->offset,
32				 syscon_rbm->mask, magic);
33	if (ret < 0)
34		dev_err(reboot->dev, "update reboot mode bits failed\n");
35
36	return ret;
37}
38
39static int syscon_reboot_mode_probe(struct platform_device *pdev)
40{
41	int ret;
42	struct syscon_reboot_mode *syscon_rbm;
43
44	syscon_rbm = devm_kzalloc(&pdev->dev, sizeof(*syscon_rbm), GFP_KERNEL);
45	if (!syscon_rbm)
46		return -ENOMEM;
47
48	syscon_rbm->reboot.dev = &pdev->dev;
49	syscon_rbm->reboot.write = syscon_reboot_mode_write;
50	syscon_rbm->mask = 0xffffffff;
51
52	syscon_rbm->map = syscon_node_to_regmap(pdev->dev.parent->of_node);
53	if (IS_ERR(syscon_rbm->map))
54		return PTR_ERR(syscon_rbm->map);
55
56	if (of_property_read_u32(pdev->dev.of_node, "offset",
57	    &syscon_rbm->offset))
58		return -EINVAL;
59
60	of_property_read_u32(pdev->dev.of_node, "mask", &syscon_rbm->mask);
61
62	ret = devm_reboot_mode_register(&pdev->dev, &syscon_rbm->reboot);
63	if (ret)
64		dev_err(&pdev->dev, "can't register reboot mode\n");
65
66	return ret;
67}
68
69static const struct of_device_id syscon_reboot_mode_of_match[] = {
70	{ .compatible = "syscon-reboot-mode" },
71	{}
72};
73MODULE_DEVICE_TABLE(of, syscon_reboot_mode_of_match);
74
75static struct platform_driver syscon_reboot_mode_driver = {
76	.probe = syscon_reboot_mode_probe,
77	.driver = {
78		.name = "syscon-reboot-mode",
79		.of_match_table = syscon_reboot_mode_of_match,
80	},
81};
82module_platform_driver(syscon_reboot_mode_driver);
83
84MODULE_AUTHOR("Andy Yan <andy.yan@rock-chips.com");
85MODULE_DESCRIPTION("SYSCON reboot mode driver");
86MODULE_LICENSE("GPL v2");
87