1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
|
// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
/*
* Amlogic Meson Reset Controller driver
*
* Copyright (c) 2016 BayLibre, SAS.
* Author: Neil Armstrong <narmstrong@baylibre.com>
*/
#include <linux/err.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/reset-controller.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/of_device.h>
#define BITS_PER_REG 32
struct meson_reset_param {
int reg_count;
int level_offset;
};
struct meson_reset {
void __iomem *reg_base;
const struct meson_reset_param *param;
struct reset_controller_dev rcdev;
spinlock_t lock;
};
static int meson_reset_reset(struct reset_controller_dev *rcdev,
unsigned long id)
{
struct meson_reset *data =
container_of(rcdev, struct meson_reset, rcdev);
unsigned int bank = id / BITS_PER_REG;
unsigned int offset = id % BITS_PER_REG;
void __iomem *reg_addr = data->reg_base + (bank << 2);
writel(BIT(offset), reg_addr);
return 0;
}
static int meson_reset_level(struct reset_controller_dev *rcdev,
unsigned long id, bool assert)
{
struct meson_reset *data =
container_of(rcdev, struct meson_reset, rcdev);
unsigned int bank = id / BITS_PER_REG;
unsigned int offset = id % BITS_PER_REG;
void __iomem *reg_addr;
unsigned long flags;
u32 reg;
reg_addr = data->reg_base + data->param->level_offset + (bank << 2);
spin_lock_irqsave(&data->lock, flags);
reg = readl(reg_addr);
if (assert)
writel(reg & ~BIT(offset), reg_addr);
else
writel(reg | BIT(offset), reg_addr);
spin_unlock_irqrestore(&data->lock, flags);
return 0;
}
static int meson_reset_assert(struct reset_controller_dev *rcdev,
unsigned long id)
{
return meson_reset_level(rcdev, id, true);
}
static int meson_reset_deassert(struct reset_controller_dev *rcdev,
unsigned long id)
{
return meson_reset_level(rcdev, id, false);
}
static const struct reset_control_ops meson_reset_ops = {
.reset = meson_reset_reset,
.assert = meson_reset_assert,
.deassert = meson_reset_deassert,
};
static const struct meson_reset_param meson8b_param = {
.reg_count = 8,
.level_offset = 0x7c,
};
static const struct meson_reset_param meson_a1_param = {
.reg_count = 3,
.level_offset = 0x40,
};
static const struct of_device_id meson_reset_dt_ids[] = {
{ .compatible = "amlogic,meson8b-reset", .data = &meson8b_param},
{ .compatible = "amlogic,meson-gxbb-reset", .data = &meson8b_param},
{ .compatible = "amlogic,meson-axg-reset", .data = &meson8b_param},
{ .compatible = "amlogic,meson-a1-reset", .data = &meson_a1_param},
{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, meson_reset_dt_ids);
static int meson_reset_probe(struct platform_device *pdev)
{
struct meson_reset *data;
struct resource *res;
data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
data->reg_base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(data->reg_base))
return PTR_ERR(data->reg_base);
data->param = of_device_get_match_data(&pdev->dev);
if (!data->param)
return -ENODEV;
platform_set_drvdata(pdev, data);
spin_lock_init(&data->lock);
data->rcdev.owner = THIS_MODULE;
data->rcdev.nr_resets = data->param->reg_count * BITS_PER_REG;
data->rcdev.ops = &meson_reset_ops;
data->rcdev.of_node = pdev->dev.of_node;
return devm_reset_controller_register(&pdev->dev, &data->rcdev);
}
static struct platform_driver meson_reset_driver = {
.probe = meson_reset_probe,
.driver = {
.name = "meson_reset",
.of_match_table = meson_reset_dt_ids,
},
};
module_platform_driver(meson_reset_driver);
MODULE_DESCRIPTION("Amlogic Meson Reset Controller driver");
MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
MODULE_LICENSE("Dual BSD/GPL");
|
