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>");
172