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linux-next/drivers/hwspinlock/sprd_hwspinlock.c
Baolin Wang d8c8bbbb1a hwspinlock: sprd: Add hardware spinlock driver
The Spreadtrum hardware spinlock device can provide hardware assistance
for synchronization between the multiple subsystems.

Signed-off-by: Baolin Wang <baolin.wang@spreadtrum.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
2017-05-17 10:52:52 -07:00

184 lines
5.0 KiB
C

/*
* Spreadtrum hardware spinlock driver
* Copyright (C) 2017 Spreadtrum - http://www.spreadtrum.com
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*/
#include <linux/bitops.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/hwspinlock.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>
#include "hwspinlock_internal.h"
/* hwspinlock registers definition */
#define HWSPINLOCK_RECCTRL 0x4
#define HWSPINLOCK_MASTERID(_X_) (0x80 + 0x4 * (_X_))
#define HWSPINLOCK_TOKEN(_X_) (0x800 + 0x4 * (_X_))
/* unlocked value */
#define HWSPINLOCK_NOTTAKEN 0x55aa10c5
/* bits definition of RECCTRL reg */
#define HWSPINLOCK_USER_BITS 0x1
/* hwspinlock number */
#define SPRD_HWLOCKS_NUM 32
struct sprd_hwspinlock_dev {
void __iomem *base;
struct clk *clk;
struct hwspinlock_device bank;
};
/* try to lock the hardware spinlock */
static int sprd_hwspinlock_trylock(struct hwspinlock *lock)
{
struct sprd_hwspinlock_dev *sprd_hwlock =
dev_get_drvdata(lock->bank->dev);
void __iomem *addr = lock->priv;
int user_id, lock_id;
if (!readl(addr))
return 1;
lock_id = hwlock_to_id(lock);
/* get the hardware spinlock master/user id */
user_id = readl(sprd_hwlock->base + HWSPINLOCK_MASTERID(lock_id));
dev_warn(sprd_hwlock->bank.dev,
"hwspinlock [%d] lock failed and master/user id = %d!\n",
lock_id, user_id);
return 0;
}
/* unlock the hardware spinlock */
static void sprd_hwspinlock_unlock(struct hwspinlock *lock)
{
void __iomem *lock_addr = lock->priv;
writel(HWSPINLOCK_NOTTAKEN, lock_addr);
}
/* The specs recommended below number as the retry delay time */
static void sprd_hwspinlock_relax(struct hwspinlock *lock)
{
ndelay(10);
}
static const struct hwspinlock_ops sprd_hwspinlock_ops = {
.trylock = sprd_hwspinlock_trylock,
.unlock = sprd_hwspinlock_unlock,
.relax = sprd_hwspinlock_relax,
};
static int sprd_hwspinlock_probe(struct platform_device *pdev)
{
struct sprd_hwspinlock_dev *sprd_hwlock;
struct hwspinlock *lock;
struct resource *res;
int i, ret;
if (!pdev->dev.of_node)
return -ENODEV;
sprd_hwlock = devm_kzalloc(&pdev->dev,
sizeof(struct sprd_hwspinlock_dev) +
SPRD_HWLOCKS_NUM * sizeof(*lock),
GFP_KERNEL);
if (!sprd_hwlock)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
sprd_hwlock->base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(sprd_hwlock->base))
return PTR_ERR(sprd_hwlock->base);
sprd_hwlock->clk = devm_clk_get(&pdev->dev, "enable");
if (IS_ERR(sprd_hwlock->clk)) {
dev_err(&pdev->dev, "get hwspinlock clock failed!\n");
return PTR_ERR(sprd_hwlock->clk);
}
clk_prepare_enable(sprd_hwlock->clk);
/* set the hwspinlock to record user id to identify subsystems */
writel(HWSPINLOCK_USER_BITS, sprd_hwlock->base + HWSPINLOCK_RECCTRL);
for (i = 0; i < SPRD_HWLOCKS_NUM; i++) {
lock = &sprd_hwlock->bank.lock[i];
lock->priv = sprd_hwlock->base + HWSPINLOCK_TOKEN(i);
}
platform_set_drvdata(pdev, sprd_hwlock);
pm_runtime_enable(&pdev->dev);
ret = hwspin_lock_register(&sprd_hwlock->bank, &pdev->dev,
&sprd_hwspinlock_ops, 0, SPRD_HWLOCKS_NUM);
if (ret) {
pm_runtime_disable(&pdev->dev);
clk_disable_unprepare(sprd_hwlock->clk);
return ret;
}
return 0;
}
static int sprd_hwspinlock_remove(struct platform_device *pdev)
{
struct sprd_hwspinlock_dev *sprd_hwlock = platform_get_drvdata(pdev);
hwspin_lock_unregister(&sprd_hwlock->bank);
pm_runtime_disable(&pdev->dev);
clk_disable_unprepare(sprd_hwlock->clk);
return 0;
}
static const struct of_device_id sprd_hwspinlock_of_match[] = {
{ .compatible = "sprd,hwspinlock-r3p0", },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, sprd_hwspinlock_of_match);
static struct platform_driver sprd_hwspinlock_driver = {
.probe = sprd_hwspinlock_probe,
.remove = sprd_hwspinlock_remove,
.driver = {
.name = "sprd_hwspinlock",
.of_match_table = of_match_ptr(sprd_hwspinlock_of_match),
},
};
static int __init sprd_hwspinlock_init(void)
{
return platform_driver_register(&sprd_hwspinlock_driver);
}
postcore_initcall(sprd_hwspinlock_init);
static void __exit sprd_hwspinlock_exit(void)
{
platform_driver_unregister(&sprd_hwspinlock_driver);
}
module_exit(sprd_hwspinlock_exit);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Hardware spinlock driver for Spreadtrum");
MODULE_AUTHOR("Baolin Wang <baolin.wang@spreadtrum.com>");
MODULE_AUTHOR("Lanqing Liu <lanqing.liu@spreadtrum.com>");
MODULE_AUTHOR("Long Cheng <aiden.cheng@spreadtrum.com>");