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