1 // SPDX-License-Identifier: GPL-2.0
3 * SIRF hardware spinlock driver
5 * Copyright (c) 2015 Cambridge Silicon Radio Limited, a CSR plc group company.
8 #include <linux/kernel.h>
9 #include <linux/module.h>
10 #include <linux/device.h>
12 #include <linux/slab.h>
13 #include <linux/spinlock.h>
14 #include <linux/hwspinlock.h>
15 #include <linux/platform_device.h>
17 #include <linux/of_address.h>
19 #include "hwspinlock_internal.h"
21 struct sirf_hwspinlock {
22 void __iomem *io_base;
23 struct hwspinlock_device bank;
26 /* Number of Hardware Spinlocks*/
27 #define HW_SPINLOCK_NUMBER 30
29 /* Hardware spinlock register offsets */
30 #define HW_SPINLOCK_BASE 0x404
31 #define HW_SPINLOCK_OFFSET(x) (HW_SPINLOCK_BASE + 0x4 * (x))
33 static int sirf_hwspinlock_trylock(struct hwspinlock *lock)
35 void __iomem *lock_addr = lock->priv;
37 /* attempt to acquire the lock by reading value == 1 from it */
38 return !!readl(lock_addr);
41 static void sirf_hwspinlock_unlock(struct hwspinlock *lock)
43 void __iomem *lock_addr = lock->priv;
45 /* release the lock by writing 0 to it */
49 static const struct hwspinlock_ops sirf_hwspinlock_ops = {
50 .trylock = sirf_hwspinlock_trylock,
51 .unlock = sirf_hwspinlock_unlock,
54 static int sirf_hwspinlock_probe(struct platform_device *pdev)
56 struct sirf_hwspinlock *hwspin;
57 struct hwspinlock *hwlock;
60 if (!pdev->dev.of_node)
63 hwspin = devm_kzalloc(&pdev->dev,
64 struct_size(hwspin, bank.lock,
70 /* retrieve io base */
71 hwspin->io_base = devm_platform_ioremap_resource(pdev, 0);
72 if (IS_ERR(hwspin->io_base))
73 return PTR_ERR(hwspin->io_base);
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);
80 platform_set_drvdata(pdev, hwspin);
82 return hwspin_lock_register(&hwspin->bank, &pdev->dev,
83 &sirf_hwspinlock_ops, 0,
87 static int sirf_hwspinlock_remove(struct platform_device *pdev)
89 struct sirf_hwspinlock *hwspin = platform_get_drvdata(pdev);
92 ret = hwspin_lock_unregister(&hwspin->bank);
94 dev_err(&pdev->dev, "%s failed: %d\n", __func__, ret);
101 static const struct of_device_id sirf_hwpinlock_ids[] = {
102 { .compatible = "sirf,hwspinlock", },
105 MODULE_DEVICE_TABLE(of, sirf_hwpinlock_ids);
107 static struct platform_driver sirf_hwspinlock_driver = {
108 .probe = sirf_hwspinlock_probe,
109 .remove = sirf_hwspinlock_remove,
111 .name = "atlas7_hwspinlock",
112 .of_match_table = of_match_ptr(sirf_hwpinlock_ids),
116 module_platform_driver(sirf_hwspinlock_driver);
118 MODULE_LICENSE("GPL v2");
119 MODULE_DESCRIPTION("SIRF Hardware spinlock driver");
120 MODULE_AUTHOR("Wei Chen <wei.chen@csr.com>");