sirf_hwspinlock.c
3.02 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
/*
* SIRF hardware spinlock driver
*
* Copyright (c) 2015 Cambridge Silicon Radio Limited, a CSR plc group company.
*
* Licensed under GPLv2.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/io.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/hwspinlock.h>
#include <linux/platform_device.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include "hwspinlock_internal.h"
struct sirf_hwspinlock {
void __iomem *io_base;
struct hwspinlock_device bank;
};
/* Number of Hardware Spinlocks*/
#define HW_SPINLOCK_NUMBER 30
/* Hardware spinlock register offsets */
#define HW_SPINLOCK_BASE 0x404
#define HW_SPINLOCK_OFFSET(x) (HW_SPINLOCK_BASE + 0x4 * (x))
static int sirf_hwspinlock_trylock(struct hwspinlock *lock)
{
void __iomem *lock_addr = lock->priv;
/* attempt to acquire the lock by reading value == 1 from it */
return !!readl(lock_addr);
}
static void sirf_hwspinlock_unlock(struct hwspinlock *lock)
{
void __iomem *lock_addr = lock->priv;
/* release the lock by writing 0 to it */
writel(0, lock_addr);
}
static const struct hwspinlock_ops sirf_hwspinlock_ops = {
.trylock = sirf_hwspinlock_trylock,
.unlock = sirf_hwspinlock_unlock,
};
static int sirf_hwspinlock_probe(struct platform_device *pdev)
{
struct sirf_hwspinlock *hwspin;
struct hwspinlock *hwlock;
int idx, ret;
if (!pdev->dev.of_node)
return -ENODEV;
hwspin = devm_kzalloc(&pdev->dev, sizeof(*hwspin) +
sizeof(*hwlock) * HW_SPINLOCK_NUMBER, GFP_KERNEL);
if (!hwspin)
return -ENOMEM;
/* retrieve io base */
hwspin->io_base = of_iomap(pdev->dev.of_node, 0);
if (!hwspin->io_base)
return -ENOMEM;
for (idx = 0; idx < HW_SPINLOCK_NUMBER; idx++) {
hwlock = &hwspin->bank.lock[idx];
hwlock->priv = hwspin->io_base + HW_SPINLOCK_OFFSET(idx);
}
platform_set_drvdata(pdev, hwspin);
pm_runtime_enable(&pdev->dev);
ret = hwspin_lock_register(&hwspin->bank, &pdev->dev,
&sirf_hwspinlock_ops, 0,
HW_SPINLOCK_NUMBER);
if (ret)
goto reg_failed;
return 0;
reg_failed:
pm_runtime_disable(&pdev->dev);
iounmap(hwspin->io_base);
return ret;
}
static int sirf_hwspinlock_remove(struct platform_device *pdev)
{
struct sirf_hwspinlock *hwspin = platform_get_drvdata(pdev);
int ret;
ret = hwspin_lock_unregister(&hwspin->bank);
if (ret) {
dev_err(&pdev->dev, "%s failed: %d\n", __func__, ret);
return ret;
}
pm_runtime_disable(&pdev->dev);
iounmap(hwspin->io_base);
return 0;
}
static const struct of_device_id sirf_hwpinlock_ids[] = {
{ .compatible = "sirf,hwspinlock", },
{},
};
MODULE_DEVICE_TABLE(of, sirf_hwpinlock_ids);
static struct platform_driver sirf_hwspinlock_driver = {
.probe = sirf_hwspinlock_probe,
.remove = sirf_hwspinlock_remove,
.driver = {
.name = "atlas7_hwspinlock",
.of_match_table = of_match_ptr(sirf_hwpinlock_ids),
},
};
module_platform_driver(sirf_hwspinlock_driver);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("SIRF Hardware spinlock driver");
MODULE_AUTHOR("Wei Chen <wei.chen@csr.com>");