projects/linux·blob master · refs

206 lines · 3.5 KiB

1// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2/*
3 * SP7021 reset driver
4 *
5 * Copyright (C) Sunplus Technology Co., Ltd.
6 * All rights reserved.
7 */
8
9#include <linux/io.h>
10#include <linux/init.h>
11#include <linux/platform_device.h>
12#include <linux/reset-controller.h>
13#include <linux/reboot.h>
14
15/* HIWORD_MASK_REG BITS */
16#define BITS_PER_HWM_REG 16
17
18/* resets HW info: reg_index_shift */
19static const u32 sp_resets[] = {
20/* SP7021: mo_reset0 ~ mo_reset9 */
21 0x00,
22 0x02,
23 0x03,
24 0x04,
25 0x05,
26 0x06,
27 0x07,
28 0x08,
29 0x09,
30 0x0a,
31 0x0b,
32 0x0d,
33 0x0e,
34 0x0f,
35 0x10,
36 0x12,
37 0x14,
38 0x15,
39 0x16,
40 0x17,
41 0x18,
42 0x19,
43 0x1a,
44 0x1b,
45 0x1c,
46 0x1d,
47 0x1e,
48 0x1f,
49 0x20,
50 0x21,
51 0x22,
52 0x23,
53 0x24,
54 0x25,
55 0x26,
56 0x2a,
57 0x2b,
58 0x2d,
59 0x2e,
60 0x30,
61 0x31,
62 0x32,
63 0x33,
64 0x3d,
65 0x3e,
66 0x3f,
67 0x42,
68 0x44,
69 0x4b,
70 0x4c,
71 0x4d,
72 0x4e,
73 0x4f,
74 0x50,
75 0x55,
76 0x60,
77 0x61,
78 0x6a,
79 0x6f,
80 0x70,
81 0x73,
82 0x74,
83 0x86,
84 0x8a,
85 0x8b,
86 0x8d,
87 0x8e,
88 0x8f,
89 0x90,
90 0x92,
91 0x93,
92 0x94,
93 0x95,
94 0x96,
95 0x97,
96 0x98,
97 0x99,
98};
99
100struct sp_reset {
101 struct reset_controller_dev rcdev;
102 void __iomem *base;
103};
104
105static inline struct sp_reset *to_sp_reset(struct reset_controller_dev *rcdev)
106{
107 return container_of(rcdev, struct sp_reset, rcdev);
108}
109
110static int sp_reset_update(struct reset_controller_dev *rcdev,
111 unsigned long id, bool assert)
112{
113 struct sp_reset *reset = to_sp_reset(rcdev);
114 int index = sp_resets[id] / BITS_PER_HWM_REG;
115 int shift = sp_resets[id] % BITS_PER_HWM_REG;
116 u32 val;
117
118 val = (1 << (16 + shift)) | (assert << shift);
119 writel(val, reset->base + (index * 4));
120
121 return 0;
122}
123
124static int sp_reset_assert(struct reset_controller_dev *rcdev,
125 unsigned long id)
126{
127 return sp_reset_update(rcdev, id, true);
128}
129
130static int sp_reset_deassert(struct reset_controller_dev *rcdev,
131 unsigned long id)
132{
133 return sp_reset_update(rcdev, id, false);
134}
135
136static int sp_reset_status(struct reset_controller_dev *rcdev,
137 unsigned long id)
138{
139 struct sp_reset *reset = to_sp_reset(rcdev);
140 int index = sp_resets[id] / BITS_PER_HWM_REG;
141 int shift = sp_resets[id] % BITS_PER_HWM_REG;
142 u32 reg;
143
144 reg = readl(reset->base + (index * 4));
145
146 return !!(reg & BIT(shift));
147}
148
149static const struct reset_control_ops sp_reset_ops = {
150 .assert = sp_reset_assert,
151 .deassert = sp_reset_deassert,
152 .status = sp_reset_status,
153};
154
155static int sp_restart(struct sys_off_data *data)
156{
157 struct sp_reset *reset = data->cb_data;
158
159 sp_reset_assert(&reset->rcdev, 0);
160 sp_reset_deassert(&reset->rcdev, 0);
161
162 return NOTIFY_DONE;
163}
164
165static int sp_reset_probe(struct platform_device *pdev)
166{
167 struct device *dev = &pdev->dev;
168 struct sp_reset *reset;
169 struct resource *res;
170 int ret;
171
172 reset = devm_kzalloc(dev, sizeof(*reset), GFP_KERNEL);
173 if (!reset)
174 return -ENOMEM;
175
176 reset->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
177 if (IS_ERR(reset->base))
178 return PTR_ERR(reset->base);
179
180 reset->rcdev.ops = &sp_reset_ops;
181 reset->rcdev.owner = THIS_MODULE;
182 reset->rcdev.of_node = dev->of_node;
183 reset->rcdev.nr_resets = resource_size(res) / 4 * BITS_PER_HWM_REG;
184
185 ret = devm_reset_controller_register(dev, &reset->rcdev);
186 if (ret)
187 return ret;
188
189 return devm_register_sys_off_handler(&pdev->dev, SYS_OFF_MODE_RESTART,
190 192, sp_restart, reset);
191}
192
193static const struct of_device_id sp_reset_dt_ids[] = {
194 {.compatible = "sunplus,sp7021-reset",},
195 { /* sentinel */ },
196};
197
198static struct platform_driver sp_reset_driver = {
199 .probe = sp_reset_probe,
200 .driver = {
201 .name = "sunplus-reset",
202 .of_match_table = sp_reset_dt_ids,
203 .suppress_bind_attrs = true,
204 },
205};
206builtin_platform_driver(sp_reset_driver);