// SPDX-License-Identifier: GPL-2.0
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// Copyright (c) 2018 Fuzhou Rockchip Electronics Co., Ltd
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/device.h>
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#include <linux/io.h>
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#include <linux/slab.h>
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#include <linux/hwspinlock.h>
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#include <linux/platform_device.h>
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#include <linux/of.h>
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#include "hwspinlock_internal.h"
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struct rockchip_hwspinlock {
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void __iomem *io_base;
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struct hwspinlock_device bank;
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};
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/* Number of Hardware Spinlocks*/
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#define HWSPINLOCK_NUMBER 64
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/* Hardware spinlock register offsets */
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#define HWSPINLOCK_OFFSET(x) (0x4 * (x))
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#define HWSPINLOCK_OWNER_ID 0x01
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static int rockchip_hwspinlock_trylock(struct hwspinlock *lock)
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{
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void __iomem *lock_addr = lock->priv;
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writel(HWSPINLOCK_OWNER_ID, lock_addr);
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/*
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* Get only first 4 bits and compare to HWSPINLOCK_OWNER_ID,
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* if equal, we attempt to acquire the lock, otherwise,
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* someone else has it.
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*/
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return (HWSPINLOCK_OWNER_ID == (0x0F & readl(lock_addr)));
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}
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static void rockchip_hwspinlock_unlock(struct hwspinlock *lock)
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{
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void __iomem *lock_addr = lock->priv;
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/* Release the lock by writing 0 to it */
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writel(0, lock_addr);
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}
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static const struct hwspinlock_ops rockchip_hwspinlock_ops = {
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.trylock = rockchip_hwspinlock_trylock,
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.unlock = rockchip_hwspinlock_unlock,
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};
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static int rockchip_hwspinlock_probe(struct platform_device *pdev)
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{
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struct rockchip_hwspinlock *hwspin;
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struct hwspinlock *hwlock;
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int idx;
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hwspin = devm_kzalloc(&pdev->dev,
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struct_size(hwspin, bank.lock, HWSPINLOCK_NUMBER),
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GFP_KERNEL);
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if (!hwspin)
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return -ENOMEM;
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hwspin->io_base = devm_platform_ioremap_resource(pdev, 0);
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if (IS_ERR(hwspin->io_base))
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return PTR_ERR(hwspin->io_base);
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for (idx = 0; idx < HWSPINLOCK_NUMBER; idx++) {
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hwlock = &hwspin->bank.lock[idx];
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hwlock->priv = hwspin->io_base + HWSPINLOCK_OFFSET(idx);
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}
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platform_set_drvdata(pdev, hwspin);
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return devm_hwspin_lock_register(&pdev->dev, &hwspin->bank,
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&rockchip_hwspinlock_ops, 0,
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HWSPINLOCK_NUMBER);
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}
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static const struct of_device_id rockchip_hwpinlock_ids[] = {
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{ .compatible = "rockchip,hwspinlock", },
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{},
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};
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MODULE_DEVICE_TABLE(of, rockchip_hwpinlock_ids);
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static struct platform_driver rockchip_hwspinlock_driver = {
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.probe = rockchip_hwspinlock_probe,
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.driver = {
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.name = "rockchip_hwspinlock",
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.of_match_table = of_match_ptr(rockchip_hwpinlock_ids),
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},
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};
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static int __init rockchip_hwspinlock_init(void)
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{
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return platform_driver_register(&rockchip_hwspinlock_driver);
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}
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postcore_initcall(rockchip_hwspinlock_init);
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static void __exit rockchip_hwspinlock_exit(void)
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{
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platform_driver_unregister(&rockchip_hwspinlock_driver);
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}
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module_exit(rockchip_hwspinlock_exit);
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MODULE_LICENSE("GPL v2");
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MODULE_DESCRIPTION("Rockchip Hardware spinlock driver");
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MODULE_AUTHOR("Frank Wang <frank.wang@rock-chips.com>");
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