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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
f0745f36 LJ |
2 | /* |
3 | * Copyright (C) 2014 STMicroelectronics | |
4 | * | |
5 | * Power off Restart driver, used in STMicroelectronics devices. | |
6 | * | |
7 | * Author: Christophe Kerello <christophe.kerello@st.com> | |
f0745f36 LJ |
8 | */ |
9 | ||
10 | #include <linux/module.h> | |
11 | #include <linux/of.h> | |
12 | #include <linux/of_platform.h> | |
13 | #include <linux/platform_device.h> | |
14 | #include <linux/mfd/syscon.h> | |
453fe4f1 | 15 | #include <linux/reboot.h> |
f0745f36 LJ |
16 | #include <linux/regmap.h> |
17 | ||
f0745f36 LJ |
18 | struct reset_syscfg { |
19 | struct regmap *regmap; | |
20 | /* syscfg used for reset */ | |
21 | unsigned int offset_rst; | |
22 | unsigned int mask_rst; | |
23 | /* syscfg used for unmask the reset */ | |
24 | unsigned int offset_rst_msk; | |
25 | unsigned int mask_rst_msk; | |
26 | }; | |
27 | ||
f0745f36 LJ |
28 | /* STiH407 */ |
29 | #define STIH407_SYSCFG_4000 0x0 | |
30 | #define STIH407_SYSCFG_4008 0x20 | |
31 | ||
32 | static struct reset_syscfg stih407_reset = { | |
33 | .offset_rst = STIH407_SYSCFG_4000, | |
34 | .mask_rst = BIT(0), | |
35 | .offset_rst_msk = STIH407_SYSCFG_4008, | |
36 | .mask_rst_msk = BIT(0) | |
37 | }; | |
38 | ||
f0745f36 LJ |
39 | |
40 | static struct reset_syscfg *st_restart_syscfg; | |
41 | ||
453fe4f1 GR |
42 | static int st_restart(struct notifier_block *this, unsigned long mode, |
43 | void *cmd) | |
f0745f36 LJ |
44 | { |
45 | /* reset syscfg updated */ | |
46 | regmap_update_bits(st_restart_syscfg->regmap, | |
47 | st_restart_syscfg->offset_rst, | |
48 | st_restart_syscfg->mask_rst, | |
49 | 0); | |
50 | ||
51 | /* unmask the reset */ | |
52 | regmap_update_bits(st_restart_syscfg->regmap, | |
53 | st_restart_syscfg->offset_rst_msk, | |
54 | st_restart_syscfg->mask_rst_msk, | |
55 | 0); | |
453fe4f1 GR |
56 | |
57 | return NOTIFY_DONE; | |
f0745f36 LJ |
58 | } |
59 | ||
453fe4f1 GR |
60 | static struct notifier_block st_restart_nb = { |
61 | .notifier_call = st_restart, | |
62 | .priority = 192, | |
63 | }; | |
64 | ||
8fb08855 | 65 | static const struct of_device_id st_reset_of_match[] = { |
f0745f36 | 66 | { |
f0745f36 LJ |
67 | .compatible = "st,stih407-restart", |
68 | .data = (void *)&stih407_reset, | |
f0745f36 LJ |
69 | }, |
70 | {} | |
71 | }; | |
72 | ||
73 | static int st_reset_probe(struct platform_device *pdev) | |
74 | { | |
75 | struct device_node *np = pdev->dev.of_node; | |
76 | const struct of_device_id *match; | |
77 | struct device *dev = &pdev->dev; | |
78 | ||
79 | match = of_match_device(st_reset_of_match, dev); | |
80 | if (!match) | |
81 | return -ENODEV; | |
82 | ||
83 | st_restart_syscfg = (struct reset_syscfg *)match->data; | |
84 | ||
85 | st_restart_syscfg->regmap = | |
86 | syscon_regmap_lookup_by_phandle(np, "st,syscfg"); | |
87 | if (IS_ERR(st_restart_syscfg->regmap)) { | |
88 | dev_err(dev, "No syscfg phandle specified\n"); | |
89 | return PTR_ERR(st_restart_syscfg->regmap); | |
90 | } | |
91 | ||
453fe4f1 | 92 | return register_restart_handler(&st_restart_nb); |
f0745f36 LJ |
93 | } |
94 | ||
95 | static struct platform_driver st_reset_driver = { | |
96 | .probe = st_reset_probe, | |
97 | .driver = { | |
98 | .name = "st_reset", | |
99 | .of_match_table = st_reset_of_match, | |
100 | }, | |
101 | }; | |
102 | ||
103 | static int __init st_reset_init(void) | |
104 | { | |
105 | return platform_driver_register(&st_reset_driver); | |
106 | } | |
107 | ||
108 | device_initcall(st_reset_init); | |
109 | ||
110 | MODULE_AUTHOR("Christophe Kerello <christophe.kerello@st.com>"); | |
111 | MODULE_DESCRIPTION("STMicroelectronics Power off Restart driver"); | |
112 | MODULE_LICENSE("GPL v2"); |