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> |
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(map: ksr->map, K210_SYSCTL_PERI_RESET, BIT(id), val: 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(map: ksr->map, K210_SYSCTL_PERI_RESET, BIT(id), val: 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(map: ksr->map, K210_SYSCTL_PERI_RESET, val: ®); |
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(node: dev->of_node); |
94 | struct k210_rst *ksr; |
95 | |
96 | dev_info(dev, "K210 reset controller\n" ); |
97 | |
98 | ksr = devm_kzalloc(dev, size: sizeof(*ksr), GFP_KERNEL); |
99 | if (!ksr) |
100 | return -ENOMEM; |
101 | |
102 | ksr->map = syscon_node_to_regmap(np: parent_np); |
103 | of_node_put(node: parent_np); |
104 | if (IS_ERR(ptr: ksr->map)) |
105 | return PTR_ERR(ptr: 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, rcdev: &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); |
131 | |