qcom_hwspinlock.c
4.43 KB
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
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
/*
* Copyright (c) 2013, The Linux Foundation. All rights reserved.
* Copyright (c) 2015, Sony Mobile Communications AB
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/hwspinlock.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/regmap.h>
#include "hwspinlock_internal.h"
#define QCOM_MUTEX_APPS_PROC_ID 1
#define QCOM_MUTEX_NUM_LOCKS 32
static int qcom_hwspinlock_trylock(struct hwspinlock *lock)
{
struct regmap_field *field = lock->priv;
u32 lock_owner;
int ret;
ret = regmap_field_write(field, QCOM_MUTEX_APPS_PROC_ID);
if (ret)
return ret;
ret = regmap_field_read(field, &lock_owner);
if (ret)
return ret;
return lock_owner == QCOM_MUTEX_APPS_PROC_ID;
}
static void qcom_hwspinlock_unlock(struct hwspinlock *lock)
{
struct regmap_field *field = lock->priv;
u32 lock_owner;
int ret;
ret = regmap_field_read(field, &lock_owner);
if (ret) {
pr_err("%s: unable to query spinlock owner\n", __func__);
return;
}
if (lock_owner != QCOM_MUTEX_APPS_PROC_ID) {
pr_err("%s: spinlock not owned by us (actual owner is %d)\n",
__func__, lock_owner);
}
ret = regmap_field_write(field, 0);
if (ret)
pr_err("%s: failed to unlock spinlock\n", __func__);
}
static const struct hwspinlock_ops qcom_hwspinlock_ops = {
.trylock = qcom_hwspinlock_trylock,
.unlock = qcom_hwspinlock_unlock,
};
static const struct of_device_id qcom_hwspinlock_of_match[] = {
{ .compatible = "qcom,sfpb-mutex" },
{ .compatible = "qcom,tcsr-mutex" },
{ }
};
MODULE_DEVICE_TABLE(of, qcom_hwspinlock_of_match);
static int qcom_hwspinlock_probe(struct platform_device *pdev)
{
struct hwspinlock_device *bank;
struct device_node *syscon;
struct reg_field field;
struct regmap *regmap;
size_t array_size;
u32 stride;
u32 base;
int ret;
int i;
syscon = of_parse_phandle(pdev->dev.of_node, "syscon", 0);
if (!syscon) {
dev_err(&pdev->dev, "no syscon property\n");
return -ENODEV;
}
regmap = syscon_node_to_regmap(syscon);
if (IS_ERR(regmap))
return PTR_ERR(regmap);
ret = of_property_read_u32_index(pdev->dev.of_node, "syscon", 1, &base);
if (ret < 0) {
dev_err(&pdev->dev, "no offset in syscon\n");
return -EINVAL;
}
ret = of_property_read_u32_index(pdev->dev.of_node, "syscon", 2, &stride);
if (ret < 0) {
dev_err(&pdev->dev, "no stride syscon\n");
return -EINVAL;
}
array_size = QCOM_MUTEX_NUM_LOCKS * sizeof(struct hwspinlock);
bank = devm_kzalloc(&pdev->dev, sizeof(*bank) + array_size, GFP_KERNEL);
if (!bank)
return -ENOMEM;
platform_set_drvdata(pdev, bank);
for (i = 0; i < QCOM_MUTEX_NUM_LOCKS; i++) {
field.reg = base + i * stride;
field.lsb = 0;
field.msb = 31;
bank->lock[i].priv = devm_regmap_field_alloc(&pdev->dev,
regmap, field);
}
pm_runtime_enable(&pdev->dev);
ret = hwspin_lock_register(bank, &pdev->dev, &qcom_hwspinlock_ops,
0, QCOM_MUTEX_NUM_LOCKS);
if (ret)
pm_runtime_disable(&pdev->dev);
return ret;
}
static int qcom_hwspinlock_remove(struct platform_device *pdev)
{
struct hwspinlock_device *bank = platform_get_drvdata(pdev);
int ret;
ret = hwspin_lock_unregister(bank);
if (ret) {
dev_err(&pdev->dev, "%s failed: %d\n", __func__, ret);
return ret;
}
pm_runtime_disable(&pdev->dev);
return 0;
}
static struct platform_driver qcom_hwspinlock_driver = {
.probe = qcom_hwspinlock_probe,
.remove = qcom_hwspinlock_remove,
.driver = {
.name = "qcom_hwspinlock",
.of_match_table = qcom_hwspinlock_of_match,
},
};
static int __init qcom_hwspinlock_init(void)
{
return platform_driver_register(&qcom_hwspinlock_driver);
}
/* board init code might need to reserve hwspinlocks for predefined purposes */
postcore_initcall(qcom_hwspinlock_init);
static void __exit qcom_hwspinlock_exit(void)
{
platform_driver_unregister(&qcom_hwspinlock_driver);
}
module_exit(qcom_hwspinlock_exit);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Hardware spinlock driver for Qualcomm SoCs");