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b9ddb2500e
The AM64x SoC contains a HwSpinlock IP instance in the MAIN domain, and is a minor variant of the IP on the current TI K3 SoCs such as AM64x, J721E or J7200 SoCs. The IP is not built with the K3 safety feature in hardware, and has slightly different integration into the overall SoC. Add the support for this IP through a new compatible. Signed-off-by: Suman Anna <s-anna@ti.com> Link: https://lore.kernel.org/r/20210209172240.2305-3-s-anna@ti.com Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
201 lines
5.0 KiB
C
201 lines
5.0 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* OMAP hardware spinlock driver
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*
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* Copyright (C) 2010-2021 Texas Instruments Incorporated - https://www.ti.com
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*
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* Contact: Simon Que <sque@ti.com>
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* Hari Kanigeri <h-kanigeri2@ti.com>
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* Ohad Ben-Cohen <ohad@wizery.com>
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* Suman Anna <s-anna@ti.com>
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*/
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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/delay.h>
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#include <linux/io.h>
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#include <linux/bitops.h>
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#include <linux/pm_runtime.h>
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#include <linux/slab.h>
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#include <linux/spinlock.h>
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#include <linux/hwspinlock.h>
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#include <linux/of.h>
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#include <linux/platform_device.h>
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#include "hwspinlock_internal.h"
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/* Spinlock register offsets */
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#define SYSSTATUS_OFFSET 0x0014
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#define LOCK_BASE_OFFSET 0x0800
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#define SPINLOCK_NUMLOCKS_BIT_OFFSET (24)
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/* Possible values of SPINLOCK_LOCK_REG */
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#define SPINLOCK_NOTTAKEN (0) /* free */
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#define SPINLOCK_TAKEN (1) /* locked */
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static int omap_hwspinlock_trylock(struct hwspinlock *lock)
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{
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void __iomem *lock_addr = lock->priv;
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/* attempt to acquire the lock by reading its value */
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return (SPINLOCK_NOTTAKEN == readl(lock_addr));
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}
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static void omap_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(SPINLOCK_NOTTAKEN, lock_addr);
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}
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/*
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* relax the OMAP interconnect while spinning on it.
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*
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* The specs recommended that the retry delay time will be
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* just over half of the time that a requester would be
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* expected to hold the lock.
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*
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* The number below is taken from an hardware specs example,
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* obviously it is somewhat arbitrary.
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*/
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static void omap_hwspinlock_relax(struct hwspinlock *lock)
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{
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ndelay(50);
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}
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static const struct hwspinlock_ops omap_hwspinlock_ops = {
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.trylock = omap_hwspinlock_trylock,
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.unlock = omap_hwspinlock_unlock,
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.relax = omap_hwspinlock_relax,
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};
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static int omap_hwspinlock_probe(struct platform_device *pdev)
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{
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struct device_node *node = pdev->dev.of_node;
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struct hwspinlock_device *bank;
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struct hwspinlock *hwlock;
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void __iomem *io_base;
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int num_locks, i, ret;
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/* Only a single hwspinlock block device is supported */
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int base_id = 0;
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if (!node)
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return -ENODEV;
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io_base = devm_platform_ioremap_resource(pdev, 0);
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if (IS_ERR(io_base))
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return PTR_ERR(io_base);
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/*
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* make sure the module is enabled and clocked before reading
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* the module SYSSTATUS register
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*/
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pm_runtime_enable(&pdev->dev);
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ret = pm_runtime_get_sync(&pdev->dev);
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if (ret < 0) {
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pm_runtime_put_noidle(&pdev->dev);
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goto runtime_err;
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}
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/* Determine number of locks */
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i = readl(io_base + SYSSTATUS_OFFSET);
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i >>= SPINLOCK_NUMLOCKS_BIT_OFFSET;
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/*
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* runtime PM will make sure the clock of this module is
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* enabled again iff at least one lock is requested
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*/
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ret = pm_runtime_put(&pdev->dev);
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if (ret < 0)
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goto runtime_err;
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/* one of the four lsb's must be set, and nothing else */
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if (hweight_long(i & 0xf) != 1 || i > 8) {
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ret = -EINVAL;
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goto runtime_err;
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}
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num_locks = i * 32; /* actual number of locks in this device */
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bank = devm_kzalloc(&pdev->dev, struct_size(bank, lock, num_locks),
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GFP_KERNEL);
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if (!bank) {
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ret = -ENOMEM;
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goto runtime_err;
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}
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platform_set_drvdata(pdev, bank);
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for (i = 0, hwlock = &bank->lock[0]; i < num_locks; i++, hwlock++)
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hwlock->priv = io_base + LOCK_BASE_OFFSET + sizeof(u32) * i;
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ret = hwspin_lock_register(bank, &pdev->dev, &omap_hwspinlock_ops,
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base_id, num_locks);
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if (ret)
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goto runtime_err;
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dev_dbg(&pdev->dev, "Registered %d locks with HwSpinlock core\n",
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num_locks);
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return 0;
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runtime_err:
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pm_runtime_disable(&pdev->dev);
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return ret;
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}
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static int omap_hwspinlock_remove(struct platform_device *pdev)
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{
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struct hwspinlock_device *bank = platform_get_drvdata(pdev);
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int ret;
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ret = hwspin_lock_unregister(bank);
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if (ret) {
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dev_err(&pdev->dev, "%s failed: %d\n", __func__, ret);
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return ret;
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}
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pm_runtime_disable(&pdev->dev);
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return 0;
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}
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static const struct of_device_id omap_hwspinlock_of_match[] = {
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{ .compatible = "ti,omap4-hwspinlock", },
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{ .compatible = "ti,am64-hwspinlock", },
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{ .compatible = "ti,am654-hwspinlock", },
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{ /* end */ },
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};
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MODULE_DEVICE_TABLE(of, omap_hwspinlock_of_match);
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static struct platform_driver omap_hwspinlock_driver = {
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.probe = omap_hwspinlock_probe,
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.remove = omap_hwspinlock_remove,
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.driver = {
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.name = "omap_hwspinlock",
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.of_match_table = of_match_ptr(omap_hwspinlock_of_match),
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},
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};
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static int __init omap_hwspinlock_init(void)
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{
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return platform_driver_register(&omap_hwspinlock_driver);
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}
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/* board init code might need to reserve hwspinlocks for predefined purposes */
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postcore_initcall(omap_hwspinlock_init);
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static void __exit omap_hwspinlock_exit(void)
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{
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platform_driver_unregister(&omap_hwspinlock_driver);
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}
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module_exit(omap_hwspinlock_exit);
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MODULE_LICENSE("GPL v2");
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MODULE_DESCRIPTION("Hardware spinlock driver for OMAP");
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MODULE_AUTHOR("Simon Que <sque@ti.com>");
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MODULE_AUTHOR("Hari Kanigeri <h-kanigeri2@ti.com>");
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MODULE_AUTHOR("Ohad Ben-Cohen <ohad@wizery.com>");
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