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Release 4.14 drivers/hwspinlock/sprd_hwspinlock.c

/*
 * Spreadtrum hardware spinlock driver
 * Copyright (C) 2017 Spreadtrum  - http://www.spreadtrum.com
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 */

#include <linux/bitops.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/hwspinlock.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>

#include "hwspinlock_internal.h"

/* hwspinlock registers definition */

#define HWSPINLOCK_RECCTRL		0x4

#define HWSPINLOCK_MASTERID(_X_)	(0x80 + 0x4 * (_X_))

#define HWSPINLOCK_TOKEN(_X_)		(0x800 + 0x4 * (_X_))

/* unlocked value */

#define HWSPINLOCK_NOTTAKEN		0x55aa10c5
/* bits definition of RECCTRL reg */

#define HWSPINLOCK_USER_BITS		0x1

/* hwspinlock number */

#define SPRD_HWLOCKS_NUM		32


struct sprd_hwspinlock_dev {
	
void __iomem *base;
	
struct clk *clk;
	
struct hwspinlock_device bank;
};

/* try to lock the hardware spinlock */

static int sprd_hwspinlock_trylock(struct hwspinlock *lock) { struct sprd_hwspinlock_dev *sprd_hwlock = dev_get_drvdata(lock->bank->dev); void __iomem *addr = lock->priv; int user_id, lock_id; if (!readl(addr)) return 1; lock_id = hwlock_to_id(lock); /* get the hardware spinlock master/user id */ user_id = readl(sprd_hwlock->base + HWSPINLOCK_MASTERID(lock_id)); dev_warn(sprd_hwlock->bank.dev, "hwspinlock [%d] lock failed and master/user id = %d!\n", lock_id, user_id); return 0; }

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/* unlock the hardware spinlock */
static void sprd_hwspinlock_unlock(struct hwspinlock *lock) { void __iomem *lock_addr = lock->priv; writel(HWSPINLOCK_NOTTAKEN, lock_addr); }

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/* The specs recommended below number as the retry delay time */
static void sprd_hwspinlock_relax(struct hwspinlock *lock) { ndelay(10); }

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static const struct hwspinlock_ops sprd_hwspinlock_ops = { .trylock = sprd_hwspinlock_trylock, .unlock = sprd_hwspinlock_unlock, .relax = sprd_hwspinlock_relax, };
static int sprd_hwspinlock_probe(struct platform_device *pdev) { struct sprd_hwspinlock_dev *sprd_hwlock; struct hwspinlock *lock; struct resource *res; int i, ret; if (!pdev->dev.of_node) return -ENODEV; sprd_hwlock = devm_kzalloc(&pdev->dev, sizeof(struct sprd_hwspinlock_dev) + SPRD_HWLOCKS_NUM * sizeof(*lock), GFP_KERNEL); if (!sprd_hwlock) return -ENOMEM; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); sprd_hwlock->base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(sprd_hwlock->base)) return PTR_ERR(sprd_hwlock->base); sprd_hwlock->clk = devm_clk_get(&pdev->dev, "enable"); if (IS_ERR(sprd_hwlock->clk)) { dev_err(&pdev->dev, "get hwspinlock clock failed!\n"); return PTR_ERR(sprd_hwlock->clk); } clk_prepare_enable(sprd_hwlock->clk); /* set the hwspinlock to record user id to identify subsystems */ writel(HWSPINLOCK_USER_BITS, sprd_hwlock->base + HWSPINLOCK_RECCTRL); for (i = 0; i < SPRD_HWLOCKS_NUM; i++) { lock = &sprd_hwlock->bank.lock[i]; lock->priv = sprd_hwlock->base + HWSPINLOCK_TOKEN(i); } platform_set_drvdata(pdev, sprd_hwlock); pm_runtime_enable(&pdev->dev); ret = hwspin_lock_register(&sprd_hwlock->bank, &pdev->dev, &sprd_hwspinlock_ops, 0, SPRD_HWLOCKS_NUM); if (ret) { pm_runtime_disable(&pdev->dev); clk_disable_unprepare(sprd_hwlock->clk); return ret; } return 0; }

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static int sprd_hwspinlock_remove(struct platform_device *pdev) { struct sprd_hwspinlock_dev *sprd_hwlock = platform_get_drvdata(pdev); hwspin_lock_unregister(&sprd_hwlock->bank); pm_runtime_disable(&pdev->dev); clk_disable_unprepare(sprd_hwlock->clk); return 0; }

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static const struct of_device_id sprd_hwspinlock_of_match[] = { { .compatible = "sprd,hwspinlock-r3p0", }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, sprd_hwspinlock_of_match); static struct platform_driver sprd_hwspinlock_driver = { .probe = sprd_hwspinlock_probe, .remove = sprd_hwspinlock_remove, .driver = { .name = "sprd_hwspinlock", .of_match_table = of_match_ptr(sprd_hwspinlock_of_match), }, };
static int __init sprd_hwspinlock_init(void) { return platform_driver_register(&sprd_hwspinlock_driver); }

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postcore_initcall(sprd_hwspinlock_init);
static void __exit sprd_hwspinlock_exit(void) { platform_driver_unregister(&sprd_hwspinlock_driver); }

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module_exit(sprd_hwspinlock_exit); MODULE_LICENSE("GPL v2"); MODULE_DESCRIPTION("Hardware spinlock driver for Spreadtrum"); MODULE_AUTHOR("Baolin Wang <baolin.wang@spreadtrum.com>"); MODULE_AUTHOR("Lanqing Liu <lanqing.liu@spreadtrum.com>"); MODULE_AUTHOR("Long Cheng <aiden.cheng@spreadtrum.com>");

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