GNU Linux-libre 5.10.219-gnu1
[releases.git] / drivers / hwspinlock / sprd_hwspinlock.c
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
35 struct 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 */
42 static 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 */
62 static 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 */
70 static void sprd_hwspinlock_relax(struct hwspinlock *lock)
71 {
72         ndelay(10);
73 }
74
75 static const struct hwspinlock_ops sprd_hwspinlock_ops = {
76         .trylock = sprd_hwspinlock_trylock,
77         .unlock = sprd_hwspinlock_unlock,
78         .relax = sprd_hwspinlock_relax,
79 };
80
81 static 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
88 static 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
141 static const struct of_device_id sprd_hwspinlock_of_match[] = {
142         { .compatible = "sprd,hwspinlock-r3p0", },
143         { /* sentinel */ }
144 };
145 MODULE_DEVICE_TABLE(of, sprd_hwspinlock_of_match);
146
147 static 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
155 static int __init sprd_hwspinlock_init(void)
156 {
157         return platform_driver_register(&sprd_hwspinlock_driver);
158 }
159 postcore_initcall(sprd_hwspinlock_init);
160
161 static void __exit sprd_hwspinlock_exit(void)
162 {
163         platform_driver_unregister(&sprd_hwspinlock_driver);
164 }
165 module_exit(sprd_hwspinlock_exit);
166
167 MODULE_LICENSE("GPL v2");
168 MODULE_DESCRIPTION("Hardware spinlock driver for Spreadtrum");
169 MODULE_AUTHOR("Baolin Wang <baolin.wang@spreadtrum.com>");
170 MODULE_AUTHOR("Lanqing Liu <lanqing.liu@spreadtrum.com>");
171 MODULE_AUTHOR("Long Cheng <aiden.cheng@spreadtrum.com>");