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(map: pon->regmap,
38 reg: pon->baseaddr + PON_SOFT_RB_SPARE,
39 GENMASK(7, pon->reason_shift),
40 val: 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(dev: &pdev->dev, size: sizeof(*pon), GFP_KERNEL);
54 if (!pon)
55 return -ENOMEM;
56
57 pon->dev = &pdev->dev;
58
59 pon->regmap = dev_get_regmap(dev: 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(np: pdev->dev.of_node, propname: "reg",
66 out_value: &pon->baseaddr);
67 if (error)
68 return error;
69
70 reason_shift = (long)of_device_get_match_data(dev: &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(dev: &pdev->dev, reboot: &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, data: pon);
84
85 return devm_of_platform_populate(dev: &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

source code of linux/drivers/power/reset/qcom-pon.c