xref: /openbmc/linux/drivers/power/reset/qcom-pon.c (revision 801b27e8)
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 
22 struct 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 
30 static 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 
47 static 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 
88 static 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 };
96 MODULE_DEVICE_TABLE(of, pm8916_pon_id_table);
97 
98 static 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 };
105 module_platform_driver(pm8916_pon_driver);
106 
107 MODULE_DESCRIPTION("pm8916 Power On driver");
108 MODULE_LICENSE("GPL v2");
109