1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * Copyright (c) 2016-2017 Linaro Ltd. |
4 | * Copyright (c) 2016-2017 HiSilicon Technologies Co., Ltd. |
5 | */ |
6 | #include <linux/kernel.h> |
7 | #include <linux/mfd/syscon.h> |
8 | #include <linux/module.h> |
9 | #include <linux/of.h> |
10 | #include <linux/platform_device.h> |
11 | #include <linux/regmap.h> |
12 | #include <linux/reset-controller.h> |
13 | |
14 | struct hi3660_reset_controller { |
15 | struct reset_controller_dev rst; |
16 | struct regmap *map; |
17 | }; |
18 | |
19 | #define to_hi3660_reset_controller(_rst) \ |
20 | container_of(_rst, struct hi3660_reset_controller, rst) |
21 | |
22 | static int hi3660_reset_program_hw(struct reset_controller_dev *rcdev, |
23 | unsigned long idx, bool assert) |
24 | { |
25 | struct hi3660_reset_controller *rc = to_hi3660_reset_controller(rcdev); |
26 | unsigned int offset = idx >> 8; |
27 | unsigned int mask = BIT(idx & 0x1f); |
28 | |
29 | if (assert) |
30 | return regmap_write(map: rc->map, reg: offset, val: mask); |
31 | else |
32 | return regmap_write(map: rc->map, reg: offset + 4, val: mask); |
33 | } |
34 | |
35 | static int hi3660_reset_assert(struct reset_controller_dev *rcdev, |
36 | unsigned long idx) |
37 | { |
38 | return hi3660_reset_program_hw(rcdev, idx, assert: true); |
39 | } |
40 | |
41 | static int hi3660_reset_deassert(struct reset_controller_dev *rcdev, |
42 | unsigned long idx) |
43 | { |
44 | return hi3660_reset_program_hw(rcdev, idx, assert: false); |
45 | } |
46 | |
47 | static int hi3660_reset_dev(struct reset_controller_dev *rcdev, |
48 | unsigned long idx) |
49 | { |
50 | int err; |
51 | |
52 | err = hi3660_reset_assert(rcdev, idx); |
53 | if (err) |
54 | return err; |
55 | |
56 | return hi3660_reset_deassert(rcdev, idx); |
57 | } |
58 | |
59 | static const struct reset_control_ops hi3660_reset_ops = { |
60 | .reset = hi3660_reset_dev, |
61 | .assert = hi3660_reset_assert, |
62 | .deassert = hi3660_reset_deassert, |
63 | }; |
64 | |
65 | static int hi3660_reset_xlate(struct reset_controller_dev *rcdev, |
66 | const struct of_phandle_args *reset_spec) |
67 | { |
68 | unsigned int offset, bit; |
69 | |
70 | offset = reset_spec->args[0]; |
71 | bit = reset_spec->args[1]; |
72 | |
73 | return (offset << 8) | bit; |
74 | } |
75 | |
76 | static int hi3660_reset_probe(struct platform_device *pdev) |
77 | { |
78 | struct hi3660_reset_controller *rc; |
79 | struct device_node *np = pdev->dev.of_node; |
80 | struct device *dev = &pdev->dev; |
81 | |
82 | rc = devm_kzalloc(dev, size: sizeof(*rc), GFP_KERNEL); |
83 | if (!rc) |
84 | return -ENOMEM; |
85 | |
86 | rc->map = syscon_regmap_lookup_by_phandle(np, property: "hisilicon,rst-syscon" ); |
87 | if (rc->map == ERR_PTR(error: -ENODEV)) { |
88 | /* fall back to the deprecated compatible */ |
89 | rc->map = syscon_regmap_lookup_by_phandle(np, |
90 | property: "hisi,rst-syscon" ); |
91 | } |
92 | if (IS_ERR(ptr: rc->map)) { |
93 | return dev_err_probe(dev, err: PTR_ERR(ptr: rc->map), |
94 | fmt: "failed to get hisilicon,rst-syscon\n" ); |
95 | } |
96 | |
97 | rc->rst.ops = &hi3660_reset_ops, |
98 | rc->rst.of_node = np; |
99 | rc->rst.of_reset_n_cells = 2; |
100 | rc->rst.of_xlate = hi3660_reset_xlate; |
101 | |
102 | return reset_controller_register(rcdev: &rc->rst); |
103 | } |
104 | |
105 | static const struct of_device_id hi3660_reset_match[] = { |
106 | { .compatible = "hisilicon,hi3660-reset" , }, |
107 | {}, |
108 | }; |
109 | MODULE_DEVICE_TABLE(of, hi3660_reset_match); |
110 | |
111 | static struct platform_driver hi3660_reset_driver = { |
112 | .probe = hi3660_reset_probe, |
113 | .driver = { |
114 | .name = "hi3660-reset" , |
115 | .of_match_table = hi3660_reset_match, |
116 | }, |
117 | }; |
118 | |
119 | static int __init hi3660_reset_init(void) |
120 | { |
121 | return platform_driver_register(&hi3660_reset_driver); |
122 | } |
123 | arch_initcall(hi3660_reset_init); |
124 | |
125 | MODULE_LICENSE("GPL" ); |
126 | MODULE_ALIAS("platform:hi3660-reset" ); |
127 | MODULE_DESCRIPTION("HiSilicon Hi3660 Reset Driver" ); |
128 | |