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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> | |
18 | ||
19 | struct ath79_reset { | |
20 | struct reset_controller_dev rcdev; | |
21 | void __iomem *base; | |
22 | spinlock_t lock; | |
23 | }; | |
24 | ||
25 | static int ath79_reset_update(struct reset_controller_dev *rcdev, | |
26 | unsigned long id, bool assert) | |
27 | { | |
28 | struct ath79_reset *ath79_reset = | |
29 | container_of(rcdev, struct ath79_reset, rcdev); | |
30 | unsigned long flags; | |
31 | u32 val; | |
32 | ||
33 | spin_lock_irqsave(&ath79_reset->lock, flags); | |
34 | val = readl(ath79_reset->base); | |
35 | if (assert) | |
36 | val |= BIT(id); | |
37 | else | |
38 | val &= ~BIT(id); | |
39 | writel(val, ath79_reset->base); | |
40 | spin_unlock_irqrestore(&ath79_reset->lock, flags); | |
41 | ||
42 | return 0; | |
43 | } | |
44 | ||
45 | static int ath79_reset_assert(struct reset_controller_dev *rcdev, | |
46 | unsigned long id) | |
47 | { | |
48 | return ath79_reset_update(rcdev, id, true); | |
49 | } | |
50 | ||
51 | static int ath79_reset_deassert(struct reset_controller_dev *rcdev, | |
52 | unsigned long id) | |
53 | { | |
54 | return ath79_reset_update(rcdev, id, false); | |
55 | } | |
56 | ||
57 | static int ath79_reset_status(struct reset_controller_dev *rcdev, | |
58 | unsigned long id) | |
59 | { | |
60 | struct ath79_reset *ath79_reset = | |
61 | container_of(rcdev, struct ath79_reset, rcdev); | |
62 | u32 val; | |
63 | ||
64 | val = readl(ath79_reset->base); | |
65 | ||
66 | return !!(val & BIT(id)); | |
67 | } | |
68 | ||
69 | static struct reset_control_ops ath79_reset_ops = { | |
70 | .assert = ath79_reset_assert, | |
71 | .deassert = ath79_reset_deassert, | |
72 | .status = ath79_reset_status, | |
73 | }; | |
74 | ||
75 | static int ath79_reset_probe(struct platform_device *pdev) | |
76 | { | |
77 | struct ath79_reset *ath79_reset; | |
78 | struct resource *res; | |
79 | ||
80 | ath79_reset = devm_kzalloc(&pdev->dev, | |
81 | sizeof(*ath79_reset), GFP_KERNEL); | |
82 | if (!ath79_reset) | |
83 | return -ENOMEM; | |
84 | ||
85 | platform_set_drvdata(pdev, ath79_reset); | |
86 | ||
87 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
88 | ath79_reset->base = devm_ioremap_resource(&pdev->dev, res); | |
89 | if (IS_ERR(ath79_reset->base)) | |
90 | return PTR_ERR(ath79_reset->base); | |
91 | ||
92 | ath79_reset->rcdev.ops = &ath79_reset_ops; | |
93 | ath79_reset->rcdev.owner = THIS_MODULE; | |
94 | ath79_reset->rcdev.of_node = pdev->dev.of_node; | |
95 | ath79_reset->rcdev.of_reset_n_cells = 1; | |
96 | ath79_reset->rcdev.nr_resets = 32; | |
97 | ||
98 | return reset_controller_register(&ath79_reset->rcdev); | |
99 | } | |
100 | ||
101 | static int ath79_reset_remove(struct platform_device *pdev) | |
102 | { | |
103 | struct ath79_reset *ath79_reset = platform_get_drvdata(pdev); | |
104 | ||
105 | reset_controller_unregister(&ath79_reset->rcdev); | |
106 | ||
107 | return 0; | |
108 | } | |
109 | ||
110 | static const struct of_device_id ath79_reset_dt_ids[] = { | |
111 | { .compatible = "qca,ar7100-reset", }, | |
112 | { }, | |
113 | }; | |
114 | MODULE_DEVICE_TABLE(of, ath79_reset_dt_ids); | |
115 | ||
116 | static struct platform_driver ath79_reset_driver = { | |
117 | .probe = ath79_reset_probe, | |
118 | .remove = ath79_reset_remove, | |
119 | .driver = { | |
120 | .name = "ath79-reset", | |
121 | .of_match_table = ath79_reset_dt_ids, | |
122 | }, | |
123 | }; | |
124 | module_platform_driver(ath79_reset_driver); | |
125 | ||
126 | MODULE_AUTHOR("Alban Bedel <albeu@free.fr>"); | |
127 | MODULE_DESCRIPTION("AR71xx Reset Controller Driver"); | |
128 | MODULE_LICENSE("GPL"); |