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