164 lines
3.9 KiB
C
164 lines
3.9 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Copyright (C) STMicroelectronics SA 2018
|
|
* Author: Benjamin Gaignard <benjamin.gaignard@st.com> for STMicroelectronics.
|
|
*/
|
|
|
|
#include <linux/clk.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/hwspinlock.h>
|
|
#include <linux/io.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/of.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/pm_runtime.h>
|
|
|
|
#include "hwspinlock_internal.h"
|
|
|
|
#define STM32_MUTEX_COREID BIT(8)
|
|
#define STM32_MUTEX_LOCK_BIT BIT(31)
|
|
#define STM32_MUTEX_NUM_LOCKS 32
|
|
|
|
struct stm32_hwspinlock {
|
|
struct clk *clk;
|
|
struct hwspinlock_device bank;
|
|
};
|
|
|
|
static int stm32_hwspinlock_trylock(struct hwspinlock *lock)
|
|
{
|
|
void __iomem *lock_addr = lock->priv;
|
|
u32 status;
|
|
|
|
writel(STM32_MUTEX_LOCK_BIT | STM32_MUTEX_COREID, lock_addr);
|
|
status = readl(lock_addr);
|
|
|
|
return status == (STM32_MUTEX_LOCK_BIT | STM32_MUTEX_COREID);
|
|
}
|
|
|
|
static void stm32_hwspinlock_unlock(struct hwspinlock *lock)
|
|
{
|
|
void __iomem *lock_addr = lock->priv;
|
|
|
|
writel(STM32_MUTEX_COREID, lock_addr);
|
|
}
|
|
|
|
static void stm32_hwspinlock_relax(struct hwspinlock *lock)
|
|
{
|
|
ndelay(50);
|
|
}
|
|
|
|
static const struct hwspinlock_ops stm32_hwspinlock_ops = {
|
|
.trylock = stm32_hwspinlock_trylock,
|
|
.unlock = stm32_hwspinlock_unlock,
|
|
.relax = stm32_hwspinlock_relax,
|
|
};
|
|
|
|
static int stm32_hwspinlock_probe(struct platform_device *pdev)
|
|
{
|
|
struct stm32_hwspinlock *hw;
|
|
void __iomem *io_base;
|
|
struct resource *res;
|
|
size_t array_size;
|
|
int i, ret;
|
|
|
|
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
|
io_base = devm_ioremap_resource(&pdev->dev, res);
|
|
if (IS_ERR(io_base))
|
|
return PTR_ERR(io_base);
|
|
|
|
array_size = STM32_MUTEX_NUM_LOCKS * sizeof(struct hwspinlock);
|
|
hw = devm_kzalloc(&pdev->dev, sizeof(*hw) + array_size, GFP_KERNEL);
|
|
if (!hw)
|
|
return -ENOMEM;
|
|
|
|
hw->clk = devm_clk_get(&pdev->dev, "hsem");
|
|
if (IS_ERR(hw->clk))
|
|
return PTR_ERR(hw->clk);
|
|
|
|
for (i = 0; i < STM32_MUTEX_NUM_LOCKS; i++)
|
|
hw->bank.lock[i].priv = io_base + i * sizeof(u32);
|
|
|
|
platform_set_drvdata(pdev, hw);
|
|
pm_runtime_enable(&pdev->dev);
|
|
|
|
ret = hwspin_lock_register(&hw->bank, &pdev->dev, &stm32_hwspinlock_ops,
|
|
0, STM32_MUTEX_NUM_LOCKS);
|
|
|
|
if (ret)
|
|
pm_runtime_disable(&pdev->dev);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int stm32_hwspinlock_remove(struct platform_device *pdev)
|
|
{
|
|
struct stm32_hwspinlock *hw = platform_get_drvdata(pdev);
|
|
int ret;
|
|
|
|
ret = hwspin_lock_unregister(&hw->bank);
|
|
if (ret)
|
|
dev_err(&pdev->dev, "%s failed: %d\n", __func__, ret);
|
|
|
|
pm_runtime_disable(&pdev->dev);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int __maybe_unused stm32_hwspinlock_runtime_suspend(struct device *dev)
|
|
{
|
|
struct stm32_hwspinlock *hw = dev_get_drvdata(dev);
|
|
|
|
clk_disable_unprepare(hw->clk);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int __maybe_unused stm32_hwspinlock_runtime_resume(struct device *dev)
|
|
{
|
|
struct stm32_hwspinlock *hw = dev_get_drvdata(dev);
|
|
|
|
clk_prepare_enable(hw->clk);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct dev_pm_ops stm32_hwspinlock_pm_ops = {
|
|
SET_RUNTIME_PM_OPS(stm32_hwspinlock_runtime_suspend,
|
|
stm32_hwspinlock_runtime_resume,
|
|
NULL)
|
|
};
|
|
|
|
static const struct of_device_id stm32_hwpinlock_ids[] = {
|
|
{ .compatible = "st,stm32-hwspinlock", },
|
|
{},
|
|
};
|
|
MODULE_DEVICE_TABLE(of, stm32_hwpinlock_ids);
|
|
|
|
static struct platform_driver stm32_hwspinlock_driver = {
|
|
.probe = stm32_hwspinlock_probe,
|
|
.remove = stm32_hwspinlock_remove,
|
|
.driver = {
|
|
.name = "stm32_hwspinlock",
|
|
.of_match_table = stm32_hwpinlock_ids,
|
|
.pm = &stm32_hwspinlock_pm_ops,
|
|
},
|
|
};
|
|
|
|
static int __init stm32_hwspinlock_init(void)
|
|
{
|
|
return platform_driver_register(&stm32_hwspinlock_driver);
|
|
}
|
|
/* board init code might need to reserve hwspinlocks for predefined purposes */
|
|
postcore_initcall(stm32_hwspinlock_init);
|
|
|
|
static void __exit stm32_hwspinlock_exit(void)
|
|
{
|
|
platform_driver_unregister(&stm32_hwspinlock_driver);
|
|
}
|
|
module_exit(stm32_hwspinlock_exit);
|
|
|
|
MODULE_LICENSE("GPL v2");
|
|
MODULE_DESCRIPTION("Hardware spinlock driver for STM32 SoCs");
|
|
MODULE_AUTHOR("Benjamin Gaignard <benjamin.gaignard@st.com>");
|