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>");
158