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
20#define NO_REASON_SHIFT			0
21
22struct pm8916_pon {
23	struct device *dev;
24	struct regmap *regmap;
25	u32 baseaddr;
26	struct reboot_mode_driver reboot_mode;
27	long reason_shift;
28};
29
30static int pm8916_reboot_mode_write(struct reboot_mode_driver *reboot,
31				    unsigned int magic)
32{
33	struct pm8916_pon *pon = container_of
34			(reboot, struct pm8916_pon, reboot_mode);
35	int ret;
36
37	ret = regmap_update_bits(pon->regmap,
38				 pon->baseaddr + PON_SOFT_RB_SPARE,
39				 GENMASK(7, pon->reason_shift),
40				 magic << pon->reason_shift);
41	if (ret < 0)
42		dev_err(pon->dev, "update reboot mode bits failed\n");
43
44	return ret;
45}
46
47static int pm8916_pon_probe(struct platform_device *pdev)
48{
49	struct pm8916_pon *pon;
50	long reason_shift;
51	int error;
52
53	pon = devm_kzalloc(&pdev->dev, sizeof(*pon), GFP_KERNEL);
54	if (!pon)
55		return -ENOMEM;
56
57	pon->dev = &pdev->dev;
58
59	pon->regmap = dev_get_regmap(pdev->dev.parent, NULL);
60	if (!pon->regmap) {
61		dev_err(&pdev->dev, "failed to locate regmap\n");
62		return -ENODEV;
63	}
64
65	error = of_property_read_u32(pdev->dev.of_node, "reg",
66				     &pon->baseaddr);
67	if (error)
68		return error;
69
70	reason_shift = (long)of_device_get_match_data(&pdev->dev);
71
72	if (reason_shift != NO_REASON_SHIFT) {
73		pon->reboot_mode.dev = &pdev->dev;
74		pon->reason_shift = reason_shift;
75		pon->reboot_mode.write = pm8916_reboot_mode_write;
76		error = devm_reboot_mode_register(&pdev->dev, &pon->reboot_mode);
77		if (error) {
78			dev_err(&pdev->dev, "can't register reboot mode\n");
79			return error;
80		}
81	}
82
83	platform_set_drvdata(pdev, pon);
84
85	return devm_of_platform_populate(&pdev->dev);
86}
87
88static const struct of_device_id pm8916_pon_id_table[] = {
89	{ .compatible = "qcom,pm8916-pon", .data = (void *)GEN1_REASON_SHIFT },
90	{ .compatible = "qcom,pm8941-pon", .data = (void *)NO_REASON_SHIFT },
91	{ .compatible = "qcom,pms405-pon", .data = (void *)GEN1_REASON_SHIFT },
92	{ .compatible = "qcom,pm8998-pon", .data = (void *)GEN2_REASON_SHIFT },
93	{ .compatible = "qcom,pmk8350-pon", .data = (void *)GEN2_REASON_SHIFT },
94	{ }
95};
96MODULE_DEVICE_TABLE(of, pm8916_pon_id_table);
97
98static struct platform_driver pm8916_pon_driver = {
99	.probe = pm8916_pon_probe,
100	.driver = {
101		.name = "pm8916-pon",
102		.of_match_table = pm8916_pon_id_table,
103	},
104};
105module_platform_driver(pm8916_pon_driver);
106
107MODULE_DESCRIPTION("pm8916 Power On driver");
108MODULE_LICENSE("GPL v2");
109