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5a2308da DLM |
1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* | |
3 | * Copyright (c) 2020 Western Digital Corporation or its affiliates. | |
4 | */ | |
5 | #include <linux/of.h> | |
5a2308da DLM |
6 | #include <linux/platform_device.h> |
7 | #include <linux/reset-controller.h> | |
8 | #include <linux/delay.h> | |
9 | #include <linux/mfd/syscon.h> | |
10 | #include <linux/regmap.h> | |
11 | #include <soc/canaan/k210-sysctl.h> | |
12 | ||
13 | #include <dt-bindings/reset/k210-rst.h> | |
14 | ||
15 | #define K210_RST_MASK 0x27FFFFFF | |
16 | ||
17 | struct k210_rst { | |
18 | struct regmap *map; | |
19 | struct reset_controller_dev rcdev; | |
20 | }; | |
21 | ||
22 | static inline struct k210_rst * | |
23 | to_k210_rst(struct reset_controller_dev *rcdev) | |
24 | { | |
25 | return container_of(rcdev, struct k210_rst, rcdev); | |
26 | } | |
27 | ||
28 | static inline int k210_rst_assert(struct reset_controller_dev *rcdev, | |
29 | unsigned long id) | |
30 | { | |
31 | struct k210_rst *ksr = to_k210_rst(rcdev); | |
32 | ||
33 | return regmap_update_bits(ksr->map, K210_SYSCTL_PERI_RESET, BIT(id), 1); | |
34 | } | |
35 | ||
36 | static inline int k210_rst_deassert(struct reset_controller_dev *rcdev, | |
37 | unsigned long id) | |
38 | { | |
39 | struct k210_rst *ksr = to_k210_rst(rcdev); | |
40 | ||
41 | return regmap_update_bits(ksr->map, K210_SYSCTL_PERI_RESET, BIT(id), 0); | |
42 | } | |
43 | ||
44 | static int k210_rst_reset(struct reset_controller_dev *rcdev, | |
45 | unsigned long id) | |
46 | { | |
47 | int ret; | |
48 | ||
49 | ret = k210_rst_assert(rcdev, id); | |
50 | if (ret == 0) { | |
51 | udelay(10); | |
52 | ret = k210_rst_deassert(rcdev, id); | |
53 | } | |
54 | ||
55 | return ret; | |
56 | } | |
57 | ||
58 | static int k210_rst_status(struct reset_controller_dev *rcdev, | |
59 | unsigned long id) | |
60 | { | |
61 | struct k210_rst *ksr = to_k210_rst(rcdev); | |
62 | u32 reg, bit = BIT(id); | |
63 | int ret; | |
64 | ||
65 | ret = regmap_read(ksr->map, K210_SYSCTL_PERI_RESET, ®); | |
66 | if (ret) | |
67 | return ret; | |
68 | ||
69 | return reg & bit; | |
70 | } | |
71 | ||
72 | static int k210_rst_xlate(struct reset_controller_dev *rcdev, | |
73 | const struct of_phandle_args *reset_spec) | |
74 | { | |
75 | unsigned long id = reset_spec->args[0]; | |
76 | ||
77 | if (!(BIT(id) & K210_RST_MASK)) | |
78 | return -EINVAL; | |
79 | ||
80 | return id; | |
81 | } | |
82 | ||
83 | static const struct reset_control_ops k210_rst_ops = { | |
84 | .assert = k210_rst_assert, | |
85 | .deassert = k210_rst_deassert, | |
86 | .reset = k210_rst_reset, | |
87 | .status = k210_rst_status, | |
88 | }; | |
89 | ||
90 | static int k210_rst_probe(struct platform_device *pdev) | |
91 | { | |
92 | struct device *dev = &pdev->dev; | |
93 | struct device_node *parent_np = of_get_parent(dev->of_node); | |
94 | struct k210_rst *ksr; | |
95 | ||
96 | dev_info(dev, "K210 reset controller\n"); | |
97 | ||
98 | ksr = devm_kzalloc(dev, sizeof(*ksr), GFP_KERNEL); | |
99 | if (!ksr) | |
100 | return -ENOMEM; | |
101 | ||
102 | ksr->map = syscon_node_to_regmap(parent_np); | |
103 | of_node_put(parent_np); | |
104 | if (IS_ERR(ksr->map)) | |
105 | return PTR_ERR(ksr->map); | |
106 | ||
107 | ksr->rcdev.owner = THIS_MODULE; | |
108 | ksr->rcdev.dev = dev; | |
109 | ksr->rcdev.of_node = dev->of_node; | |
110 | ksr->rcdev.ops = &k210_rst_ops; | |
111 | ksr->rcdev.nr_resets = fls(K210_RST_MASK); | |
112 | ksr->rcdev.of_reset_n_cells = 1; | |
113 | ksr->rcdev.of_xlate = k210_rst_xlate; | |
114 | ||
115 | return devm_reset_controller_register(dev, &ksr->rcdev); | |
116 | } | |
117 | ||
118 | static const struct of_device_id k210_rst_dt_ids[] = { | |
119 | { .compatible = "canaan,k210-rst" }, | |
120 | { /* sentinel */ }, | |
121 | }; | |
122 | ||
123 | static struct platform_driver k210_rst_driver = { | |
124 | .probe = k210_rst_probe, | |
125 | .driver = { | |
126 | .name = "k210-rst", | |
127 | .of_match_table = k210_rst_dt_ids, | |
128 | }, | |
129 | }; | |
130 | builtin_platform_driver(k210_rst_driver); |