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50a52280 | 1 | // SPDX-License-Identifier: GPL-2.0 |
cc16d664 WC |
2 | /* |
3 | * SIRF hardware spinlock driver | |
4 | * | |
5 | * Copyright (c) 2015 Cambridge Silicon Radio Limited, a CSR plc group company. | |
cc16d664 WC |
6 | */ |
7 | ||
8 | #include <linux/kernel.h> | |
9 | #include <linux/module.h> | |
10 | #include <linux/device.h> | |
11 | #include <linux/io.h> | |
12 | #include <linux/pm_runtime.h> | |
13 | #include <linux/slab.h> | |
14 | #include <linux/spinlock.h> | |
15 | #include <linux/hwspinlock.h> | |
16 | #include <linux/platform_device.h> | |
17 | #include <linux/of.h> | |
18 | #include <linux/of_address.h> | |
19 | ||
20 | #include "hwspinlock_internal.h" | |
21 | ||
22 | struct sirf_hwspinlock { | |
23 | void __iomem *io_base; | |
24 | struct hwspinlock_device bank; | |
25 | }; | |
26 | ||
27 | /* Number of Hardware Spinlocks*/ | |
28 | #define HW_SPINLOCK_NUMBER 30 | |
29 | ||
30 | /* Hardware spinlock register offsets */ | |
31 | #define HW_SPINLOCK_BASE 0x404 | |
32 | #define HW_SPINLOCK_OFFSET(x) (HW_SPINLOCK_BASE + 0x4 * (x)) | |
33 | ||
34 | static int sirf_hwspinlock_trylock(struct hwspinlock *lock) | |
35 | { | |
36 | void __iomem *lock_addr = lock->priv; | |
37 | ||
38 | /* attempt to acquire the lock by reading value == 1 from it */ | |
39 | return !!readl(lock_addr); | |
40 | } | |
41 | ||
42 | static void sirf_hwspinlock_unlock(struct hwspinlock *lock) | |
43 | { | |
44 | void __iomem *lock_addr = lock->priv; | |
45 | ||
46 | /* release the lock by writing 0 to it */ | |
47 | writel(0, lock_addr); | |
48 | } | |
49 | ||
50 | static const struct hwspinlock_ops sirf_hwspinlock_ops = { | |
51 | .trylock = sirf_hwspinlock_trylock, | |
52 | .unlock = sirf_hwspinlock_unlock, | |
53 | }; | |
54 | ||
55 | static int sirf_hwspinlock_probe(struct platform_device *pdev) | |
56 | { | |
57 | struct sirf_hwspinlock *hwspin; | |
58 | struct hwspinlock *hwlock; | |
59 | int idx, ret; | |
60 | ||
61 | if (!pdev->dev.of_node) | |
62 | return -ENODEV; | |
63 | ||
0ed2dd03 KC |
64 | hwspin = devm_kzalloc(&pdev->dev, |
65 | struct_size(hwspin, bank.lock, | |
66 | HW_SPINLOCK_NUMBER), | |
67 | GFP_KERNEL); | |
cc16d664 WC |
68 | if (!hwspin) |
69 | return -ENOMEM; | |
70 | ||
71 | /* retrieve io base */ | |
72 | hwspin->io_base = of_iomap(pdev->dev.of_node, 0); | |
73 | if (!hwspin->io_base) | |
74 | return -ENOMEM; | |
75 | ||
76 | for (idx = 0; idx < HW_SPINLOCK_NUMBER; idx++) { | |
77 | hwlock = &hwspin->bank.lock[idx]; | |
78 | hwlock->priv = hwspin->io_base + HW_SPINLOCK_OFFSET(idx); | |
79 | } | |
80 | ||
81 | platform_set_drvdata(pdev, hwspin); | |
82 | ||
83 | pm_runtime_enable(&pdev->dev); | |
84 | ||
85 | ret = hwspin_lock_register(&hwspin->bank, &pdev->dev, | |
86 | &sirf_hwspinlock_ops, 0, | |
87 | HW_SPINLOCK_NUMBER); | |
88 | if (ret) | |
89 | goto reg_failed; | |
90 | ||
91 | return 0; | |
92 | ||
93 | reg_failed: | |
94 | pm_runtime_disable(&pdev->dev); | |
95 | iounmap(hwspin->io_base); | |
96 | ||
97 | return ret; | |
98 | } | |
99 | ||
100 | static int sirf_hwspinlock_remove(struct platform_device *pdev) | |
101 | { | |
102 | struct sirf_hwspinlock *hwspin = platform_get_drvdata(pdev); | |
103 | int ret; | |
104 | ||
105 | ret = hwspin_lock_unregister(&hwspin->bank); | |
106 | if (ret) { | |
107 | dev_err(&pdev->dev, "%s failed: %d\n", __func__, ret); | |
108 | return ret; | |
109 | } | |
110 | ||
111 | pm_runtime_disable(&pdev->dev); | |
112 | ||
113 | iounmap(hwspin->io_base); | |
114 | ||
115 | return 0; | |
116 | } | |
117 | ||
118 | static const struct of_device_id sirf_hwpinlock_ids[] = { | |
119 | { .compatible = "sirf,hwspinlock", }, | |
120 | {}, | |
121 | }; | |
122 | MODULE_DEVICE_TABLE(of, sirf_hwpinlock_ids); | |
123 | ||
124 | static struct platform_driver sirf_hwspinlock_driver = { | |
125 | .probe = sirf_hwspinlock_probe, | |
126 | .remove = sirf_hwspinlock_remove, | |
127 | .driver = { | |
128 | .name = "atlas7_hwspinlock", | |
129 | .of_match_table = of_match_ptr(sirf_hwpinlock_ids), | |
130 | }, | |
131 | }; | |
132 | ||
133 | module_platform_driver(sirf_hwspinlock_driver); | |
134 | ||
135 | MODULE_LICENSE("GPL v2"); | |
136 | MODULE_DESCRIPTION("SIRF Hardware spinlock driver"); | |
137 | MODULE_AUTHOR("Wei Chen <wei.chen@csr.com>"); |