spacemit-p1-reboot.c

 1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 * Copyright (C) 2025 by Aurelien Jarno
 4 */
 5
 6#include <linux/bits.h>
 7#include <linux/mod_devicetable.h>
 8#include <linux/platform_device.h>
 9#include <linux/regmap.h>
10#include <linux/reboot.h>
11
12/* Power Control Register 2 */
13#define PWR_CTRL2		0x7e
14#define PWR_CTRL2_SHUTDOWN	BIT(2)	/* Shutdown request */
15#define PWR_CTRL2_RST		BIT(1)	/* Reset request */
16
17static int spacemit_p1_pwroff_handler(struct sys_off_data *data)
18{
19	struct regmap *regmap = data->cb_data;
20	int ret;
21
22	/* Put the PMIC into shutdown state */
23	ret = regmap_set_bits(regmap, PWR_CTRL2, PWR_CTRL2_SHUTDOWN);
24	if (ret) {
25		dev_err(data->dev, "shutdown failed: %d\n", ret);
26		return notifier_from_errno(ret);
27	}
28
29	return NOTIFY_DONE;
30}
31
32static int spacemit_p1_restart_handler(struct sys_off_data *data)
33{
34	struct regmap *regmap = data->cb_data;
35	int ret;
36
37	/* Put the PMIC into reset state */
38	ret = regmap_set_bits(regmap, PWR_CTRL2, PWR_CTRL2_RST);
39	if (ret) {
40		dev_err(data->dev, "restart failed: %d\n", ret);
41		return notifier_from_errno(ret);
42	}
43
44	return NOTIFY_DONE;
45}
46
47static int spacemit_p1_reboot_probe(struct platform_device *pdev)
48{
49	struct device *dev = &pdev->dev;
50	struct regmap *regmap;
51	int ret;
52
53	regmap = dev_get_regmap(dev->parent, NULL);
54	if (!regmap)
55		return -ENODEV;
56
57	ret = devm_register_power_off_handler(dev, &spacemit_p1_pwroff_handler,
58					      regmap);
59	if (ret)
60		return dev_err_probe(dev, ret,
61				     "Failed to register power off handler\n");
62
63	ret = devm_register_restart_handler(dev, spacemit_p1_restart_handler,
64					    regmap);
65	if (ret)
66		return dev_err_probe(dev, ret,
67				     "Failed to register restart handler\n");
68
69	return 0;
70}
71
72static const struct platform_device_id spacemit_p1_reboot_id_table[] = {
73	{ "spacemit-p1-reboot", },
74	{ /* sentinel */ },
75};
76MODULE_DEVICE_TABLE(platform, spacemit_p1_reboot_id_table);
77
78static struct platform_driver spacemit_p1_reboot_driver = {
79	.driver = {
80		.name = "spacemit-p1-reboot",
81	},
82	.probe = spacemit_p1_reboot_probe,
83	.id_table = spacemit_p1_reboot_id_table,
84};
85module_platform_driver(spacemit_p1_reboot_driver);
86
87MODULE_DESCRIPTION("SpacemiT P1 reboot/poweroff driver");
88MODULE_LICENSE("GPL");