0c4caaa7e88f67eea0fac12b0efe6cb75486d987
[muen/linux.git] / drivers / power / reset / qcom-pon.c
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 struct pm8916_pon {
18         struct device *dev;
19         struct regmap *regmap;
20         u32 baseaddr;
21         struct reboot_mode_driver reboot_mode;
22 };
23
24 static int pm8916_reboot_mode_write(struct reboot_mode_driver *reboot,
25                                     unsigned int magic)
26 {
27         struct pm8916_pon *pon = container_of
28                         (reboot, struct pm8916_pon, reboot_mode);
29         int ret;
30
31         ret = regmap_update_bits(pon->regmap,
32                                  pon->baseaddr + PON_SOFT_RB_SPARE,
33                                  0xfc, magic << 2);
34         if (ret < 0)
35                 dev_err(pon->dev, "update reboot mode bits failed\n");
36
37         return ret;
38 }
39
40 static int pm8916_pon_probe(struct platform_device *pdev)
41 {
42         struct pm8916_pon *pon;
43         int error;
44
45         pon = devm_kzalloc(&pdev->dev, sizeof(*pon), GFP_KERNEL);
46         if (!pon)
47                 return -ENOMEM;
48
49         pon->dev = &pdev->dev;
50
51         pon->regmap = dev_get_regmap(pdev->dev.parent, NULL);
52         if (!pon->regmap) {
53                 dev_err(&pdev->dev, "failed to locate regmap\n");
54                 return -ENODEV;
55         }
56
57         error = of_property_read_u32(pdev->dev.of_node, "reg",
58                                      &pon->baseaddr);
59         if (error)
60                 return error;
61
62         pon->reboot_mode.dev = &pdev->dev;
63         pon->reboot_mode.write = pm8916_reboot_mode_write;
64         error = devm_reboot_mode_register(&pdev->dev, &pon->reboot_mode);
65         if (error) {
66                 dev_err(&pdev->dev, "can't register reboot mode\n");
67                 return error;
68         }
69
70         platform_set_drvdata(pdev, pon);
71
72         return devm_of_platform_populate(&pdev->dev);
73 }
74
75 static const struct of_device_id pm8916_pon_id_table[] = {
76         { .compatible = "qcom,pm8916-pon" },
77         { }
78 };
79 MODULE_DEVICE_TABLE(of, pm8916_pon_id_table);
80
81 static struct platform_driver pm8916_pon_driver = {
82         .probe = pm8916_pon_probe,
83         .driver = {
84                 .name = "pm8916-pon",
85                 .of_match_table = of_match_ptr(pm8916_pon_id_table),
86         },
87 };
88 module_platform_driver(pm8916_pon_driver);
89
90 MODULE_DESCRIPTION("pm8916 Power On driver");
91 MODULE_LICENSE("GPL v2");