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