1// SPDX-License-Identifier: GPL-2.0
2// Copyright (c) 2017-18 Linaro Limited
3
4#include <linux/delay.h>
5#include <linux/errno.h>
6#include <linux/kernel.h>
7#include <linux/module.h>
8#include <linux/of.h>
9#include <linux/of_platform.h>
10#include <linux/platform_device.h>
11#include <linux/reboot.h>
12#include <linux/reboot-mode.h>
13#include <linux/regmap.h>
14
15#define PON_SOFT_RB_SPARE		0x8f
16
17#define GEN1_REASON_SHIFT		2
18#define GEN2_REASON_SHIFT		1
19
20struct pm8916_pon {
21	struct device *dev;
22	struct regmap *regmap;
23	u32 baseaddr;
24	struct reboot_mode_driver reboot_mode;
25	long reason_shift;
26};
27
28static int pm8916_reboot_mode_write(struct reboot_mode_driver *reboot,
29				    unsigned int magic)
30{
31	struct pm8916_pon *pon = container_of
32			(reboot, struct pm8916_pon, reboot_mode);
33	int ret;
34
35	ret = regmap_update_bits(pon->regmap,
36				 pon->baseaddr + PON_SOFT_RB_SPARE,
37				 GENMASK(7, pon->reason_shift),
38				 magic << pon->reason_shift);
39	if (ret < 0)
40		dev_err(pon->dev, "update reboot mode bits failed\n");
41
42	return ret;
43}
44
45static int pm8916_pon_probe(struct platform_device *pdev)
46{
47	struct pm8916_pon *pon;
48	int error;
49
50	pon = devm_kzalloc(&pdev->dev, sizeof(*pon), GFP_KERNEL);
51	if (!pon)
52		return -ENOMEM;
53
54	pon->dev = &pdev->dev;
55
56	pon->regmap = dev_get_regmap(pdev->dev.parent, NULL);
57	if (!pon->regmap) {
58		dev_err(&pdev->dev, "failed to locate regmap\n");
59		return -ENODEV;
60	}
61
62	error = of_property_read_u32(pdev->dev.of_node, "reg",
63				     &pon->baseaddr);
64	if (error)
65		return error;
66
67	pon->reboot_mode.dev = &pdev->dev;
68	pon->reason_shift = (long)of_device_get_match_data(&pdev->dev);
69	pon->reboot_mode.write = pm8916_reboot_mode_write;
70	error = devm_reboot_mode_register(&pdev->dev, &pon->reboot_mode);
71	if (error) {
72		dev_err(&pdev->dev, "can't register reboot mode\n");
73		return error;
74	}
75
76	platform_set_drvdata(pdev, pon);
77
78	return devm_of_platform_populate(&pdev->dev);
79}
80
81static const struct of_device_id pm8916_pon_id_table[] = {
82	{ .compatible = "qcom,pm8916-pon", .data = (void *)GEN1_REASON_SHIFT },
83	{ .compatible = "qcom,pms405-pon", .data = (void *)GEN1_REASON_SHIFT },
84	{ .compatible = "qcom,pm8998-pon", .data = (void *)GEN2_REASON_SHIFT },
85	{ }
86};
87MODULE_DEVICE_TABLE(of, pm8916_pon_id_table);
88
89static struct platform_driver pm8916_pon_driver = {
90	.probe = pm8916_pon_probe,
91	.driver = {
92		.name = "pm8916-pon",
93		.of_match_table = of_match_ptr(pm8916_pon_id_table),
94	},
95};
96module_platform_driver(pm8916_pon_driver);
97
98MODULE_DESCRIPTION("pm8916 Power On driver");
99MODULE_LICENSE("GPL v2");
100