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ff591a91 AB |
1 | /* |
2 | * Copyright (C) 2015 Alban Bedel <albeu@free.fr> | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License as published by | |
6 | * the Free Software Foundation; either version 2 of the License, or | |
7 | * (at your option) any later version. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | */ | |
14 | ||
15 | #include <linux/module.h> | |
16 | #include <linux/platform_device.h> | |
17 | #include <linux/reset-controller.h> | |
ba64e27e | 18 | #include <linux/reboot.h> |
ff591a91 AB |
19 | |
20 | struct ath79_reset { | |
21 | struct reset_controller_dev rcdev; | |
ba64e27e | 22 | struct notifier_block restart_nb; |
ff591a91 AB |
23 | void __iomem *base; |
24 | spinlock_t lock; | |
25 | }; | |
26 | ||
ba64e27e AB |
27 | #define FULL_CHIP_RESET 24 |
28 | ||
ff591a91 AB |
29 | static int ath79_reset_update(struct reset_controller_dev *rcdev, |
30 | unsigned long id, bool assert) | |
31 | { | |
32 | struct ath79_reset *ath79_reset = | |
33 | container_of(rcdev, struct ath79_reset, rcdev); | |
34 | unsigned long flags; | |
35 | u32 val; | |
36 | ||
37 | spin_lock_irqsave(&ath79_reset->lock, flags); | |
38 | val = readl(ath79_reset->base); | |
39 | if (assert) | |
40 | val |= BIT(id); | |
41 | else | |
42 | val &= ~BIT(id); | |
43 | writel(val, ath79_reset->base); | |
44 | spin_unlock_irqrestore(&ath79_reset->lock, flags); | |
45 | ||
46 | return 0; | |
47 | } | |
48 | ||
49 | static int ath79_reset_assert(struct reset_controller_dev *rcdev, | |
50 | unsigned long id) | |
51 | { | |
52 | return ath79_reset_update(rcdev, id, true); | |
53 | } | |
54 | ||
55 | static int ath79_reset_deassert(struct reset_controller_dev *rcdev, | |
56 | unsigned long id) | |
57 | { | |
58 | return ath79_reset_update(rcdev, id, false); | |
59 | } | |
60 | ||
61 | static int ath79_reset_status(struct reset_controller_dev *rcdev, | |
62 | unsigned long id) | |
63 | { | |
64 | struct ath79_reset *ath79_reset = | |
65 | container_of(rcdev, struct ath79_reset, rcdev); | |
66 | u32 val; | |
67 | ||
68 | val = readl(ath79_reset->base); | |
69 | ||
70 | return !!(val & BIT(id)); | |
71 | } | |
72 | ||
d2f79f22 | 73 | static const struct reset_control_ops ath79_reset_ops = { |
ff591a91 AB |
74 | .assert = ath79_reset_assert, |
75 | .deassert = ath79_reset_deassert, | |
76 | .status = ath79_reset_status, | |
77 | }; | |
78 | ||
ba64e27e AB |
79 | static int ath79_reset_restart_handler(struct notifier_block *nb, |
80 | unsigned long action, void *data) | |
81 | { | |
82 | struct ath79_reset *ath79_reset = | |
83 | container_of(nb, struct ath79_reset, restart_nb); | |
84 | ||
85 | ath79_reset_assert(&ath79_reset->rcdev, FULL_CHIP_RESET); | |
86 | ||
87 | return NOTIFY_DONE; | |
88 | } | |
89 | ||
ff591a91 AB |
90 | static int ath79_reset_probe(struct platform_device *pdev) |
91 | { | |
92 | struct ath79_reset *ath79_reset; | |
93 | struct resource *res; | |
ba64e27e | 94 | int err; |
ff591a91 AB |
95 | |
96 | ath79_reset = devm_kzalloc(&pdev->dev, | |
97 | sizeof(*ath79_reset), GFP_KERNEL); | |
98 | if (!ath79_reset) | |
99 | return -ENOMEM; | |
100 | ||
101 | platform_set_drvdata(pdev, ath79_reset); | |
102 | ||
103 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
104 | ath79_reset->base = devm_ioremap_resource(&pdev->dev, res); | |
105 | if (IS_ERR(ath79_reset->base)) | |
106 | return PTR_ERR(ath79_reset->base); | |
107 | ||
f319cb84 | 108 | spin_lock_init(&ath79_reset->lock); |
ff591a91 AB |
109 | ath79_reset->rcdev.ops = &ath79_reset_ops; |
110 | ath79_reset->rcdev.owner = THIS_MODULE; | |
111 | ath79_reset->rcdev.of_node = pdev->dev.of_node; | |
112 | ath79_reset->rcdev.of_reset_n_cells = 1; | |
113 | ath79_reset->rcdev.nr_resets = 32; | |
114 | ||
ba64e27e AB |
115 | err = reset_controller_register(&ath79_reset->rcdev); |
116 | if (err) | |
117 | return err; | |
118 | ||
119 | ath79_reset->restart_nb.notifier_call = ath79_reset_restart_handler; | |
120 | ath79_reset->restart_nb.priority = 128; | |
121 | ||
122 | err = register_restart_handler(&ath79_reset->restart_nb); | |
123 | if (err) | |
124 | dev_warn(&pdev->dev, "Failed to register restart handler\n"); | |
125 | ||
126 | return 0; | |
ff591a91 AB |
127 | } |
128 | ||
129 | static int ath79_reset_remove(struct platform_device *pdev) | |
130 | { | |
131 | struct ath79_reset *ath79_reset = platform_get_drvdata(pdev); | |
132 | ||
ba64e27e | 133 | unregister_restart_handler(&ath79_reset->restart_nb); |
ff591a91 AB |
134 | reset_controller_unregister(&ath79_reset->rcdev); |
135 | ||
136 | return 0; | |
137 | } | |
138 | ||
139 | static const struct of_device_id ath79_reset_dt_ids[] = { | |
140 | { .compatible = "qca,ar7100-reset", }, | |
141 | { }, | |
142 | }; | |
143 | MODULE_DEVICE_TABLE(of, ath79_reset_dt_ids); | |
144 | ||
145 | static struct platform_driver ath79_reset_driver = { | |
146 | .probe = ath79_reset_probe, | |
147 | .remove = ath79_reset_remove, | |
148 | .driver = { | |
149 | .name = "ath79-reset", | |
150 | .of_match_table = ath79_reset_dt_ids, | |
151 | }, | |
152 | }; | |
153 | module_platform_driver(ath79_reset_driver); | |
154 | ||
155 | MODULE_AUTHOR("Alban Bedel <albeu@free.fr>"); | |
156 | MODULE_DESCRIPTION("AR71xx Reset Controller Driver"); | |
157 | MODULE_LICENSE("GPL"); |