Merge tag 'hwlock-v4.18' of git://github.com/andersson/remoteproc
[muen/linux.git] / drivers / hwspinlock / sirf_hwspinlock.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * SIRF hardware spinlock driver
4  *
5  * Copyright (c) 2015 Cambridge Silicon Radio Limited, a CSR plc group company.
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
64         hwspin = devm_kzalloc(&pdev->dev,
65                               struct_size(hwspin, bank.lock,
66                                           HW_SPINLOCK_NUMBER),
67                               GFP_KERNEL);
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>");