diff options
Diffstat (limited to 'drivers/hwspinlock/sirf_hwspinlock.c')
-rw-r--r-- | drivers/hwspinlock/sirf_hwspinlock.c | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/drivers/hwspinlock/sirf_hwspinlock.c b/drivers/hwspinlock/sirf_hwspinlock.c new file mode 100644 index 000000000000..16018544d431 --- /dev/null +++ b/drivers/hwspinlock/sirf_hwspinlock.c | |||
@@ -0,0 +1,136 @@ | |||
1 | /* | ||
2 | * SIRF hardware spinlock driver | ||
3 | * | ||
4 | * Copyright (c) 2015 Cambridge Silicon Radio Limited, a CSR plc group company. | ||
5 | * | ||
6 | * Licensed under GPLv2. | ||
7 | */ | ||
8 | |||
9 | #include <linux/kernel.h> | ||
10 | #include <linux/module.h> | ||
11 | #include <linux/device.h> | ||
12 | #include <linux/io.h> | ||
13 | #include <linux/pm_runtime.h> | ||
14 | #include <linux/slab.h> | ||
15 | #include <linux/spinlock.h> | ||
16 | #include <linux/hwspinlock.h> | ||
17 | #include <linux/platform_device.h> | ||
18 | #include <linux/of.h> | ||
19 | #include <linux/of_address.h> | ||
20 | |||
21 | #include "hwspinlock_internal.h" | ||
22 | |||
23 | struct sirf_hwspinlock { | ||
24 | void __iomem *io_base; | ||
25 | struct hwspinlock_device bank; | ||
26 | }; | ||
27 | |||
28 | /* Number of Hardware Spinlocks*/ | ||
29 | #define HW_SPINLOCK_NUMBER 30 | ||
30 | |||
31 | /* Hardware spinlock register offsets */ | ||
32 | #define HW_SPINLOCK_BASE 0x404 | ||
33 | #define HW_SPINLOCK_OFFSET(x) (HW_SPINLOCK_BASE + 0x4 * (x)) | ||
34 | |||
35 | static int sirf_hwspinlock_trylock(struct hwspinlock *lock) | ||
36 | { | ||
37 | void __iomem *lock_addr = lock->priv; | ||
38 | |||
39 | /* attempt to acquire the lock by reading value == 1 from it */ | ||
40 | return !!readl(lock_addr); | ||
41 | } | ||
42 | |||
43 | static void sirf_hwspinlock_unlock(struct hwspinlock *lock) | ||
44 | { | ||
45 | void __iomem *lock_addr = lock->priv; | ||
46 | |||
47 | /* release the lock by writing 0 to it */ | ||
48 | writel(0, lock_addr); | ||
49 | } | ||
50 | |||
51 | static const struct hwspinlock_ops sirf_hwspinlock_ops = { | ||
52 | .trylock = sirf_hwspinlock_trylock, | ||
53 | .unlock = sirf_hwspinlock_unlock, | ||
54 | }; | ||
55 | |||
56 | static int sirf_hwspinlock_probe(struct platform_device *pdev) | ||
57 | { | ||
58 | struct sirf_hwspinlock *hwspin; | ||
59 | struct hwspinlock *hwlock; | ||
60 | int idx, ret; | ||
61 | |||
62 | if (!pdev->dev.of_node) | ||
63 | return -ENODEV; | ||
64 | |||
65 | hwspin = devm_kzalloc(&pdev->dev, sizeof(*hwspin) + | ||
66 | sizeof(*hwlock) * HW_SPINLOCK_NUMBER, GFP_KERNEL); | ||
67 | if (!hwspin) | ||
68 | return -ENOMEM; | ||
69 | |||
70 | /* retrieve io base */ | ||
71 | hwspin->io_base = of_iomap(pdev->dev.of_node, 0); | ||
72 | if (!hwspin->io_base) | ||
73 | return -ENOMEM; | ||
74 | |||
75 | for (idx = 0; idx < HW_SPINLOCK_NUMBER; idx++) { | ||
76 | hwlock = &hwspin->bank.lock[idx]; | ||
77 | hwlock->priv = hwspin->io_base + HW_SPINLOCK_OFFSET(idx); | ||
78 | } | ||
79 | |||
80 | platform_set_drvdata(pdev, hwspin); | ||
81 | |||
82 | pm_runtime_enable(&pdev->dev); | ||
83 | |||
84 | ret = hwspin_lock_register(&hwspin->bank, &pdev->dev, | ||
85 | &sirf_hwspinlock_ops, 0, | ||
86 | HW_SPINLOCK_NUMBER); | ||
87 | if (ret) | ||
88 | goto reg_failed; | ||
89 | |||
90 | return 0; | ||
91 | |||
92 | reg_failed: | ||
93 | pm_runtime_disable(&pdev->dev); | ||
94 | iounmap(hwspin->io_base); | ||
95 | |||
96 | return ret; | ||
97 | } | ||
98 | |||
99 | static int sirf_hwspinlock_remove(struct platform_device *pdev) | ||
100 | { | ||
101 | struct sirf_hwspinlock *hwspin = platform_get_drvdata(pdev); | ||
102 | int ret; | ||
103 | |||
104 | ret = hwspin_lock_unregister(&hwspin->bank); | ||
105 | if (ret) { | ||
106 | dev_err(&pdev->dev, "%s failed: %d\n", __func__, ret); | ||
107 | return ret; | ||
108 | } | ||
109 | |||
110 | pm_runtime_disable(&pdev->dev); | ||
111 | |||
112 | iounmap(hwspin->io_base); | ||
113 | |||
114 | return 0; | ||
115 | } | ||
116 | |||
117 | static const struct of_device_id sirf_hwpinlock_ids[] = { | ||
118 | { .compatible = "sirf,hwspinlock", }, | ||
119 | {}, | ||
120 | }; | ||
121 | MODULE_DEVICE_TABLE(of, sirf_hwpinlock_ids); | ||
122 | |||
123 | static struct platform_driver sirf_hwspinlock_driver = { | ||
124 | .probe = sirf_hwspinlock_probe, | ||
125 | .remove = sirf_hwspinlock_remove, | ||
126 | .driver = { | ||
127 | .name = "atlas7_hwspinlock", | ||
128 | .of_match_table = of_match_ptr(sirf_hwpinlock_ids), | ||
129 | }, | ||
130 | }; | ||
131 | |||
132 | module_platform_driver(sirf_hwspinlock_driver); | ||
133 | |||
134 | MODULE_LICENSE("GPL v2"); | ||
135 | MODULE_DESCRIPTION("SIRF Hardware spinlock driver"); | ||
136 | MODULE_AUTHOR("Wei Chen <wei.chen@csr.com>"); | ||