1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Spreadtrum hardware spinlock driver
  4 * Copyright (C) 2017 Spreadtrum  - http://www.spreadtrum.com
  5 */
  6
  7#include <linux/bitops.h>
  8#include <linux/clk.h>
  9#include <linux/delay.h>
 10#include <linux/device.h>
 11#include <linux/hwspinlock.h>
 12#include <linux/io.h>
 13#include <linux/kernel.h>
 14#include <linux/module.h>
 15#include <linux/of.h>
 16#include <linux/of_device.h>
 17#include <linux/platform_device.h>
 18#include <linux/pm_runtime.h>
 19#include <linux/slab.h>
 20
 21#include "hwspinlock_internal.h"
 22
 23/* hwspinlock registers definition */
 24#define HWSPINLOCK_RECCTRL		0x4
 25#define HWSPINLOCK_MASTERID(_X_)	(0x80 + 0x4 * (_X_))
 26#define HWSPINLOCK_TOKEN(_X_)		(0x800 + 0x4 * (_X_))
 27
 28/* unlocked value */
 29#define HWSPINLOCK_NOTTAKEN		0x55aa10c5
 30/* bits definition of RECCTRL reg */
 31#define HWSPINLOCK_USER_BITS		0x1
 32
 33/* hwspinlock number */
 34#define SPRD_HWLOCKS_NUM		32
 35
 36struct sprd_hwspinlock_dev {
 37	void __iomem *base;
 38	struct clk *clk;
 39	struct hwspinlock_device bank;
 40};
 41
 42/* try to lock the hardware spinlock */
 43static int sprd_hwspinlock_trylock(struct hwspinlock *lock)
 44{
 45	struct sprd_hwspinlock_dev *sprd_hwlock =
 46		dev_get_drvdata(lock->bank->dev);
 47	void __iomem *addr = lock->priv;
 48	int user_id, lock_id;
 49
 50	if (!readl(addr))
 51		return 1;
 52
 53	lock_id = hwlock_to_id(lock);
 54	/* get the hardware spinlock master/user id */
 55	user_id = readl(sprd_hwlock->base + HWSPINLOCK_MASTERID(lock_id));
 56	dev_warn(sprd_hwlock->bank.dev,
 57		 "hwspinlock [%d] lock failed and master/user id = %d!\n",
 58		 lock_id, user_id);
 59	return 0;
 60}
 61
 62/* unlock the hardware spinlock */
 63static void sprd_hwspinlock_unlock(struct hwspinlock *lock)
 64{
 65	void __iomem *lock_addr = lock->priv;
 66
 67	writel(HWSPINLOCK_NOTTAKEN, lock_addr);
 68}
 69
 70/* The specs recommended below number as the retry delay time */
 71static void sprd_hwspinlock_relax(struct hwspinlock *lock)
 72{
 73	ndelay(10);
 74}
 75
 76static const struct hwspinlock_ops sprd_hwspinlock_ops = {
 77	.trylock = sprd_hwspinlock_trylock,
 78	.unlock = sprd_hwspinlock_unlock,
 79	.relax = sprd_hwspinlock_relax,
 80};
 81
 82static int sprd_hwspinlock_probe(struct platform_device *pdev)
 83{
 84	struct sprd_hwspinlock_dev *sprd_hwlock;
 85	struct hwspinlock *lock;
 86	struct resource *res;
 87	int i, ret;
 88
 89	if (!pdev->dev.of_node)
 90		return -ENODEV;
 91
 92	sprd_hwlock = devm_kzalloc(&pdev->dev,
 93				   sizeof(struct sprd_hwspinlock_dev) +
 94				   SPRD_HWLOCKS_NUM * sizeof(*lock),
 95				   GFP_KERNEL);
 96	if (!sprd_hwlock)
 97		return -ENOMEM;
 98
 99	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
100	sprd_hwlock->base = devm_ioremap_resource(&pdev->dev, res);
101	if (IS_ERR(sprd_hwlock->base))
102		return PTR_ERR(sprd_hwlock->base);
103
104	sprd_hwlock->clk = devm_clk_get(&pdev->dev, "enable");
105	if (IS_ERR(sprd_hwlock->clk)) {
106		dev_err(&pdev->dev, "get hwspinlock clock failed!\n");
107		return PTR_ERR(sprd_hwlock->clk);
108	}
109
110	clk_prepare_enable(sprd_hwlock->clk);
111
112	/* set the hwspinlock to record user id to identify subsystems */
113	writel(HWSPINLOCK_USER_BITS, sprd_hwlock->base + HWSPINLOCK_RECCTRL);
114
115	for (i = 0; i < SPRD_HWLOCKS_NUM; i++) {
116		lock = &sprd_hwlock->bank.lock[i];
117		lock->priv = sprd_hwlock->base + HWSPINLOCK_TOKEN(i);
118	}
119
120	platform_set_drvdata(pdev, sprd_hwlock);
121	pm_runtime_enable(&pdev->dev);
122
123	ret = hwspin_lock_register(&sprd_hwlock->bank, &pdev->dev,
124				   &sprd_hwspinlock_ops, 0, SPRD_HWLOCKS_NUM);
125	if (ret) {
126		pm_runtime_disable(&pdev->dev);
127		clk_disable_unprepare(sprd_hwlock->clk);
128		return ret;
129	}
130
131	return 0;
132}
133
134static int sprd_hwspinlock_remove(struct platform_device *pdev)
135{
136	struct sprd_hwspinlock_dev *sprd_hwlock = platform_get_drvdata(pdev);
137
138	hwspin_lock_unregister(&sprd_hwlock->bank);
139	pm_runtime_disable(&pdev->dev);
140	clk_disable_unprepare(sprd_hwlock->clk);
141	return 0;
142}
143
144static const struct of_device_id sprd_hwspinlock_of_match[] = {
145	{ .compatible = "sprd,hwspinlock-r3p0", },
146	{ /* sentinel */ }
147};
148MODULE_DEVICE_TABLE(of, sprd_hwspinlock_of_match);
149
150static struct platform_driver sprd_hwspinlock_driver = {
151	.probe = sprd_hwspinlock_probe,
152	.remove = sprd_hwspinlock_remove,
153	.driver = {
154		.name = "sprd_hwspinlock",
155		.of_match_table = of_match_ptr(sprd_hwspinlock_of_match),
156	},
157};
158
159static int __init sprd_hwspinlock_init(void)
160{
161	return platform_driver_register(&sprd_hwspinlock_driver);
162}
163postcore_initcall(sprd_hwspinlock_init);
164
165static void __exit sprd_hwspinlock_exit(void)
166{
167	platform_driver_unregister(&sprd_hwspinlock_driver);
168}
169module_exit(sprd_hwspinlock_exit);
170
171MODULE_LICENSE("GPL v2");
172MODULE_DESCRIPTION("Hardware spinlock driver for Spreadtrum");
173MODULE_AUTHOR("Baolin Wang <baolin.wang@spreadtrum.com>");
174MODULE_AUTHOR("Lanqing Liu <lanqing.liu@spreadtrum.com>");
175MODULE_AUTHOR("Long Cheng <aiden.cheng@spreadtrum.com>");