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- // SPDX-License-Identifier: GPL-2.0
- /*
- * Light hardware spinlock driver
- *
- * Copyright (C) 2020-2025 Alibaba Group Holding Limited
- */
- #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 light_hwspinlock {
- void __iomem *io_base;
- struct hwspinlock_device bank;
- };
- #define HW_SPINLOCK_NUMBER 64
- #define HW_SPINLOCK_OFFSET(x) (0x4 * (x))
- static int light_hwspinlock_trylock(struct hwspinlock *lock)
- {
- void __iomem *lock_addr = lock->priv;
- return !readl(lock_addr);
- }
- static void light_hwspinlock_unlock(struct hwspinlock *lock)
- {
- void __iomem *lock_addr = lock->priv;
- writel(0, lock_addr);
- }
- static const struct hwspinlock_ops light_hwspinlock_ops = {
- .trylock = light_hwspinlock_trylock,
- .unlock = light_hwspinlock_unlock,
- };
- static int light_hwspinlock_probe(struct platform_device *pdev)
- {
- struct light_hwspinlock *hwspin;
- struct hwspinlock *hwlock;
- int idx, ret;
- if (!pdev->dev.of_node)
- return -ENODEV;
- hwspin = devm_kzalloc(&pdev->dev,
- struct_size(hwspin, bank.lock,
- 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;
- pr_info("io_base: 0x%lx\n", (long)hwspin->io_base);
- 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,
- &light_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 light_hwspinlock_remove(struct platform_device *pdev)
- {
- struct light_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 light_hwpinlock_ids[] = {
- { .compatible = "light,hwspinlock", },
- {},
- };
- MODULE_DEVICE_TABLE(of, light_hwpinlock_ids);
- static struct platform_driver light_hwspinlock_driver = {
- .probe = light_hwspinlock_probe,
- .remove = light_hwspinlock_remove,
- .driver = {
- .name = "light_hwspinlock",
- .of_match_table = of_match_ptr(light_hwpinlock_ids),
- },
- };
- module_platform_driver(light_hwspinlock_driver);
- MODULE_LICENSE("GPL v2");
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