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b38386f4 BX |
1 | /* |
2 | * ZTE's zx2967 family reset controller driver | |
3 | * | |
4 | * Copyright (C) 2017 ZTE Ltd. | |
5 | * | |
6 | * Author: Baoyou Xie <baoyou.xie@linaro.org> | |
7 | * | |
8 | * License terms: GNU General Public License (GPL) version 2 | |
9 | */ | |
10 | ||
b38386f4 BX |
11 | #include <linux/of_address.h> |
12 | #include <linux/platform_device.h> | |
13 | #include <linux/reset-controller.h> | |
14 | ||
15 | struct zx2967_reset { | |
16 | void __iomem *reg_base; | |
17 | spinlock_t lock; | |
18 | struct reset_controller_dev rcdev; | |
19 | }; | |
20 | ||
21 | static int zx2967_reset_act(struct reset_controller_dev *rcdev, | |
22 | unsigned long id, bool assert) | |
23 | { | |
24 | struct zx2967_reset *reset = NULL; | |
25 | int bank = id / 32; | |
26 | int offset = id % 32; | |
27 | u32 reg; | |
28 | unsigned long flags; | |
29 | ||
30 | reset = container_of(rcdev, struct zx2967_reset, rcdev); | |
31 | ||
32 | spin_lock_irqsave(&reset->lock, flags); | |
33 | ||
34 | reg = readl_relaxed(reset->reg_base + (bank * 4)); | |
35 | if (assert) | |
36 | reg &= ~BIT(offset); | |
37 | else | |
38 | reg |= BIT(offset); | |
39 | writel_relaxed(reg, reset->reg_base + (bank * 4)); | |
40 | ||
41 | spin_unlock_irqrestore(&reset->lock, flags); | |
42 | ||
43 | return 0; | |
44 | } | |
45 | ||
46 | static int zx2967_reset_assert(struct reset_controller_dev *rcdev, | |
47 | unsigned long id) | |
48 | { | |
49 | return zx2967_reset_act(rcdev, id, true); | |
50 | } | |
51 | ||
52 | static int zx2967_reset_deassert(struct reset_controller_dev *rcdev, | |
53 | unsigned long id) | |
54 | { | |
55 | return zx2967_reset_act(rcdev, id, false); | |
56 | } | |
57 | ||
58 | static struct reset_control_ops zx2967_reset_ops = { | |
59 | .assert = zx2967_reset_assert, | |
60 | .deassert = zx2967_reset_deassert, | |
61 | }; | |
62 | ||
63 | static int zx2967_reset_probe(struct platform_device *pdev) | |
64 | { | |
65 | struct zx2967_reset *reset; | |
66 | struct resource *res; | |
67 | ||
68 | reset = devm_kzalloc(&pdev->dev, sizeof(*reset), GFP_KERNEL); | |
69 | if (!reset) | |
70 | return -ENOMEM; | |
71 | ||
72 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
73 | reset->reg_base = devm_ioremap_resource(&pdev->dev, res); | |
74 | if (IS_ERR(reset->reg_base)) | |
75 | return PTR_ERR(reset->reg_base); | |
76 | ||
77 | spin_lock_init(&reset->lock); | |
78 | ||
79 | reset->rcdev.owner = THIS_MODULE; | |
80 | reset->rcdev.nr_resets = resource_size(res) * 8; | |
81 | reset->rcdev.ops = &zx2967_reset_ops; | |
82 | reset->rcdev.of_node = pdev->dev.of_node; | |
83 | ||
84 | return devm_reset_controller_register(&pdev->dev, &reset->rcdev); | |
85 | } | |
86 | ||
87 | static const struct of_device_id zx2967_reset_dt_ids[] = { | |
88 | { .compatible = "zte,zx296718-reset", }, | |
89 | {}, | |
90 | }; | |
b38386f4 BX |
91 | |
92 | static struct platform_driver zx2967_reset_driver = { | |
93 | .probe = zx2967_reset_probe, | |
94 | .driver = { | |
95 | .name = "zx2967-reset", | |
96 | .of_match_table = zx2967_reset_dt_ids, | |
97 | }, | |
98 | }; | |
b38386f4 | 99 | builtin_platform_driver(zx2967_reset_driver); |