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1// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
2/*
3 * Amlogic Meson Reset Controller driver
4 *
5 * Copyright (c) 2016 BayLibre, SAS.
6 * Author: Neil Armstrong <narmstrong@baylibre.com>
7 */
8#include <linux/err.h>
9#include <linux/init.h>
10#include <linux/io.h>
11#include <linux/of.h>
12#include <linux/module.h>
13#include <linux/platform_device.h>
14#include <linux/reset-controller.h>
15#include <linux/slab.h>
16#include <linux/types.h>
17
18#define BITS_PER_REG 32
19
20struct meson_reset_param {
21 int reg_count;
22 int level_offset;
23};
24
25struct meson_reset {
26 void __iomem *reg_base;
27 const struct meson_reset_param *param;
28 struct reset_controller_dev rcdev;
29 spinlock_t lock;
30};
31
32static int meson_reset_reset(struct reset_controller_dev *rcdev,
33 unsigned long id)
34{
35 struct meson_reset *data =
36 container_of(rcdev, struct meson_reset, rcdev);
37 unsigned int bank = id / BITS_PER_REG;
38 unsigned int offset = id % BITS_PER_REG;
39 void __iomem *reg_addr = data->reg_base + (bank << 2);
40
41 writel(BIT(offset), reg_addr);
42
43 return 0;
44}
45
46static int meson_reset_level(struct reset_controller_dev *rcdev,
47 unsigned long id, bool assert)
48{
49 struct meson_reset *data =
50 container_of(rcdev, struct meson_reset, rcdev);
51 unsigned int bank = id / BITS_PER_REG;
52 unsigned int offset = id % BITS_PER_REG;
53 void __iomem *reg_addr;
54 unsigned long flags;
55 u32 reg;
56
57 reg_addr = data->reg_base + data->param->level_offset + (bank << 2);
58
59 spin_lock_irqsave(&data->lock, flags);
60
61 reg = readl(reg_addr);
62 if (assert)
63 writel(reg & ~BIT(offset), reg_addr);
64 else
65 writel(reg | BIT(offset), reg_addr);
66
67 spin_unlock_irqrestore(&data->lock, flags);
68
69 return 0;
70}
71
72static int meson_reset_assert(struct reset_controller_dev *rcdev,
73 unsigned long id)
74{
75 return meson_reset_level(rcdev, id, true);
76}
77
78static int meson_reset_deassert(struct reset_controller_dev *rcdev,
79 unsigned long id)
80{
81 return meson_reset_level(rcdev, id, false);
82}
83
84static const struct reset_control_ops meson_reset_ops = {
85 .reset = meson_reset_reset,
86 .assert = meson_reset_assert,
87 .deassert = meson_reset_deassert,
88};
89
90static const struct meson_reset_param meson8b_param = {
91 .reg_count = 8,
92 .level_offset = 0x7c,
93};
94
95static const struct meson_reset_param meson_a1_param = {
96 .reg_count = 3,
97 .level_offset = 0x40,
98};
99
100static const struct meson_reset_param meson_s4_param = {
101 .reg_count = 6,
102 .level_offset = 0x40,
103};
104
105static const struct of_device_id meson_reset_dt_ids[] = {
106 { .compatible = "amlogic,meson8b-reset", .data = &meson8b_param},
107 { .compatible = "amlogic,meson-gxbb-reset", .data = &meson8b_param},
108 { .compatible = "amlogic,meson-axg-reset", .data = &meson8b_param},
109 { .compatible = "amlogic,meson-a1-reset", .data = &meson_a1_param},
110 { .compatible = "amlogic,meson-s4-reset", .data = &meson_s4_param},
111 { .compatible = "amlogic,c3-reset", .data = &meson_s4_param},
112 { /* sentinel */ },
113};
114MODULE_DEVICE_TABLE(of, meson_reset_dt_ids);
115
116static int meson_reset_probe(struct platform_device *pdev)
117{
118 struct meson_reset *data;
119
120 data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
121 if (!data)
122 return -ENOMEM;
123
124 data->reg_base = devm_platform_ioremap_resource(pdev, 0);
125 if (IS_ERR(data->reg_base))
126 return PTR_ERR(data->reg_base);
127
128 data->param = of_device_get_match_data(&pdev->dev);
129 if (!data->param)
130 return -ENODEV;
131
132 spin_lock_init(&data->lock);
133
134 data->rcdev.owner = THIS_MODULE;
135 data->rcdev.nr_resets = data->param->reg_count * BITS_PER_REG;
136 data->rcdev.ops = &meson_reset_ops;
137 data->rcdev.of_node = pdev->dev.of_node;
138
139 return devm_reset_controller_register(&pdev->dev, &data->rcdev);
140}
141
142static struct platform_driver meson_reset_driver = {
143 .probe = meson_reset_probe,
144 .driver = {
145 .name = "meson_reset",
146 .of_match_table = meson_reset_dt_ids,
147 },
148};
149module_platform_driver(meson_reset_driver);
150
151MODULE_DESCRIPTION("Amlogic Meson Reset Controller driver");
152MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
153MODULE_LICENSE("Dual BSD/GPL");
1/*
2 * This file is provided under a dual BSD/GPLv2 license. When using or
3 * redistributing this file, you may do so under either license.
4 *
5 * GPL LICENSE SUMMARY
6 *
7 * Copyright (c) 2016 BayLibre, SAS.
8 * Author: Neil Armstrong <narmstrong@baylibre.com>
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of version 2 of the GNU General Public License as
12 * published by the Free Software Foundation.
13 *
14 * This program is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, see <http://www.gnu.org/licenses/>.
21 * The full GNU General Public License is included in this distribution
22 * in the file called COPYING.
23 *
24 * BSD LICENSE
25 *
26 * Copyright (c) 2016 BayLibre, SAS.
27 * Author: Neil Armstrong <narmstrong@baylibre.com>
28 *
29 * Redistribution and use in source and binary forms, with or without
30 * modification, are permitted provided that the following conditions
31 * are met:
32 *
33 * * Redistributions of source code must retain the above copyright
34 * notice, this list of conditions and the following disclaimer.
35 * * Redistributions in binary form must reproduce the above copyright
36 * notice, this list of conditions and the following disclaimer in
37 * the documentation and/or other materials provided with the
38 * distribution.
39 * * Neither the name of Intel Corporation nor the names of its
40 * contributors may be used to endorse or promote products derived
41 * from this software without specific prior written permission.
42 *
43 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
44 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
45 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
46 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
47 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
48 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
49 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
50 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
51 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
52 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
53 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
54 */
55#include <linux/err.h>
56#include <linux/module.h>
57#include <linux/io.h>
58#include <linux/of.h>
59#include <linux/platform_device.h>
60#include <linux/reset-controller.h>
61#include <linux/slab.h>
62#include <linux/types.h>
63
64#define REG_COUNT 8
65#define BITS_PER_REG 32
66
67struct meson_reset {
68 void __iomem *reg_base;
69 struct reset_controller_dev rcdev;
70};
71
72static int meson_reset_reset(struct reset_controller_dev *rcdev,
73 unsigned long id)
74{
75 struct meson_reset *data =
76 container_of(rcdev, struct meson_reset, rcdev);
77 unsigned int bank = id / BITS_PER_REG;
78 unsigned int offset = id % BITS_PER_REG;
79 void __iomem *reg_addr = data->reg_base + (bank << 2);
80
81 if (bank >= REG_COUNT)
82 return -EINVAL;
83
84 writel(BIT(offset), reg_addr);
85
86 return 0;
87}
88
89static const struct reset_control_ops meson_reset_ops = {
90 .reset = meson_reset_reset,
91};
92
93static const struct of_device_id meson_reset_dt_ids[] = {
94 { .compatible = "amlogic,meson8b-reset", },
95 { .compatible = "amlogic,meson-gxbb-reset", },
96 { /* sentinel */ },
97};
98MODULE_DEVICE_TABLE(of, meson_reset_dt_ids);
99
100static int meson_reset_probe(struct platform_device *pdev)
101{
102 struct meson_reset *data;
103 struct resource *res;
104
105 data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
106 if (!data)
107 return -ENOMEM;
108
109 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
110 data->reg_base = devm_ioremap_resource(&pdev->dev, res);
111 if (IS_ERR(data->reg_base))
112 return PTR_ERR(data->reg_base);
113
114 platform_set_drvdata(pdev, data);
115
116 data->rcdev.owner = THIS_MODULE;
117 data->rcdev.nr_resets = REG_COUNT * BITS_PER_REG;
118 data->rcdev.ops = &meson_reset_ops;
119 data->rcdev.of_node = pdev->dev.of_node;
120
121 return devm_reset_controller_register(&pdev->dev, &data->rcdev);
122}
123
124static struct platform_driver meson_reset_driver = {
125 .probe = meson_reset_probe,
126 .driver = {
127 .name = "meson_reset",
128 .of_match_table = meson_reset_dt_ids,
129 },
130};
131
132module_platform_driver(meson_reset_driver);
133
134MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
135MODULE_DESCRIPTION("Amlogic Meson Reset Controller driver");
136MODULE_LICENSE("Dual BSD/GPL");