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16#include <linux/module.h>
17#include <linux/delay.h>
18#include <linux/io.h>
19#include <linux/slab.h>
20#include <linux/spinlock.h>
21#include <linux/hwspinlock.h>
22#include <linux/platform_device.h>
23
24#include "hwspinlock_internal.h"
25
26
27
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30
31
32
33#define U8500_MAX_SEMAPHORE 32
34#define RESET_SEMAPHORE (0)
35
36
37
38
39
40
41
42#define HSEM_MASTER_ID 0x01
43
44#define HSEM_REGISTER_OFFSET 0x08
45
46#define HSEM_CTRL_REG 0x00
47#define HSEM_ICRALL 0x90
48#define HSEM_PROTOCOL_1 0x01
49
50static int u8500_hsem_trylock(struct hwspinlock *lock)
51{
52 void __iomem *lock_addr = lock->priv;
53
54 writel(HSEM_MASTER_ID, lock_addr);
55
56
57
58
59
60 return (HSEM_MASTER_ID == (0x0F & readl(lock_addr)));
61}
62
63static void u8500_hsem_unlock(struct hwspinlock *lock)
64{
65 void __iomem *lock_addr = lock->priv;
66
67
68 writel(RESET_SEMAPHORE, lock_addr);
69}
70
71
72
73
74static void u8500_hsem_relax(struct hwspinlock *lock)
75{
76 ndelay(50);
77}
78
79static const struct hwspinlock_ops u8500_hwspinlock_ops = {
80 .trylock = u8500_hsem_trylock,
81 .unlock = u8500_hsem_unlock,
82 .relax = u8500_hsem_relax,
83};
84
85static int u8500_hsem_probe(struct platform_device *pdev)
86{
87 struct hwspinlock_pdata *pdata = pdev->dev.platform_data;
88 struct hwspinlock_device *bank;
89 struct hwspinlock *hwlock;
90 void __iomem *io_base;
91 int i, num_locks = U8500_MAX_SEMAPHORE;
92 ulong val;
93
94 if (!pdata)
95 return -ENODEV;
96
97 io_base = devm_platform_ioremap_resource(pdev, 0);
98 if (IS_ERR(io_base))
99 return PTR_ERR(io_base);
100
101
102 val = readl(io_base + HSEM_CTRL_REG);
103 writel((val & ~HSEM_PROTOCOL_1), io_base + HSEM_CTRL_REG);
104
105
106 writel(0xFFFF, io_base + HSEM_ICRALL);
107
108 bank = devm_kzalloc(&pdev->dev, struct_size(bank, lock, num_locks),
109 GFP_KERNEL);
110 if (!bank)
111 return -ENOMEM;
112
113 platform_set_drvdata(pdev, bank);
114
115 for (i = 0, hwlock = &bank->lock[0]; i < num_locks; i++, hwlock++)
116 hwlock->priv = io_base + HSEM_REGISTER_OFFSET + sizeof(u32) * i;
117
118 return devm_hwspin_lock_register(&pdev->dev, bank,
119 &u8500_hwspinlock_ops,
120 pdata->base_id, num_locks);
121}
122
123static int u8500_hsem_remove(struct platform_device *pdev)
124{
125 struct hwspinlock_device *bank = platform_get_drvdata(pdev);
126 void __iomem *io_base = bank->lock[0].priv - HSEM_REGISTER_OFFSET;
127
128
129 writel(0xFFFF, io_base + HSEM_ICRALL);
130
131 return 0;
132}
133
134static struct platform_driver u8500_hsem_driver = {
135 .probe = u8500_hsem_probe,
136 .remove = u8500_hsem_remove,
137 .driver = {
138 .name = "u8500_hsem",
139 },
140};
141
142static int __init u8500_hsem_init(void)
143{
144 return platform_driver_register(&u8500_hsem_driver);
145}
146
147postcore_initcall(u8500_hsem_init);
148
149static void __exit u8500_hsem_exit(void)
150{
151 platform_driver_unregister(&u8500_hsem_driver);
152}
153module_exit(u8500_hsem_exit);
154
155MODULE_LICENSE("GPL v2");
156MODULE_DESCRIPTION("Hardware Spinlock driver for u8500");
157MODULE_AUTHOR("Mathieu Poirier <mathieu.poirier@linaro.org>");
158