tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
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>");