[mirror_ubuntu-zesty-kernel.git] / drivers / hwspinlock / sirf_hwspinlock.c

/*
 * SIRF hardware spinlock driver
 *
 * Copyright (c) 2015 Cambridge Silicon Radio Limited, a CSR plc group company.
 *
 * Licensed under GPLv2.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/io.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/hwspinlock.h>
#include <linux/platform_device.h>
#include <linux/of.h>
#include <linux/of_address.h>

#include "hwspinlock_internal.h"

struct sirf_hwspinlock {
	void __iomem *io_base;
	struct hwspinlock_device bank;
};

/* Number of Hardware Spinlocks*/
#define	HW_SPINLOCK_NUMBER	30

/* Hardware spinlock register offsets */
#define HW_SPINLOCK_BASE	0x404
#define HW_SPINLOCK_OFFSET(x)	(HW_SPINLOCK_BASE + 0x4 * (x))

static int sirf_hwspinlock_trylock(struct hwspinlock *lock)
{
	void __iomem *lock_addr = lock->priv;

	/* attempt to acquire the lock by reading value == 1 from it */
	return !!readl(lock_addr);
}

static void sirf_hwspinlock_unlock(struct hwspinlock *lock)
{
	void __iomem *lock_addr = lock->priv;

	/* release the lock by writing 0 to it */
	writel(0, lock_addr);
}

static const struct hwspinlock_ops sirf_hwspinlock_ops = {
	.trylock = sirf_hwspinlock_trylock,
	.unlock = sirf_hwspinlock_unlock,
};

static int sirf_hwspinlock_probe(struct platform_device *pdev)
{
	struct sirf_hwspinlock *hwspin;
	struct hwspinlock *hwlock;
	int idx, ret;

	if (!pdev->dev.of_node)
		return -ENODEV;

	hwspin = devm_kzalloc(&pdev->dev, sizeof(*hwspin) +
			sizeof(*hwlock) * HW_SPINLOCK_NUMBER, GFP_KERNEL);
	if (!hwspin)
		return -ENOMEM;

	/* retrieve io base */
	hwspin->io_base = of_iomap(pdev->dev.of_node, 0);
	if (!hwspin->io_base)
		return -ENOMEM;

	for (idx = 0; idx < HW_SPINLOCK_NUMBER; idx++) {
		hwlock = &hwspin->bank.lock[idx];
		hwlock->priv = hwspin->io_base + HW_SPINLOCK_OFFSET(idx);
	}

	platform_set_drvdata(pdev, hwspin);

	pm_runtime_enable(&pdev->dev);

	ret = hwspin_lock_register(&hwspin->bank, &pdev->dev,
				   &sirf_hwspinlock_ops, 0,
				   HW_SPINLOCK_NUMBER);
	if (ret)
		goto reg_failed;

	return 0;

reg_failed:
	pm_runtime_disable(&pdev->dev);
	iounmap(hwspin->io_base);

	return ret;
}

static int sirf_hwspinlock_remove(struct platform_device *pdev)
{
	struct sirf_hwspinlock *hwspin = platform_get_drvdata(pdev);
	int ret;

	ret = hwspin_lock_unregister(&hwspin->bank);
	if (ret) {
		dev_err(&pdev->dev, "%s failed: %d\n", __func__, ret);
		return ret;
	}

	pm_runtime_disable(&pdev->dev);

	iounmap(hwspin->io_base);

	return 0;
}

static const struct of_device_id sirf_hwpinlock_ids[] = {
	{ .compatible = "sirf,hwspinlock", },
	{},
};
MODULE_DEVICE_TABLE(of, sirf_hwpinlock_ids);

static struct platform_driver sirf_hwspinlock_driver = {
	.probe = sirf_hwspinlock_probe,
	.remove = sirf_hwspinlock_remove,
	.driver = {
		.name = "atlas7_hwspinlock",
		.of_match_table = of_match_ptr(sirf_hwpinlock_ids),
	},
};

module_platform_driver(sirf_hwspinlock_driver);

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("SIRF Hardware spinlock driver");
MODULE_AUTHOR("Wei Chen <wei.chen@csr.com>");
Commit	Line	Data
cc16d664 WC	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>");