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/*
* 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>");
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