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1 | /* |
2 | * Spreadtrum hardware spinlock driver | |
3 | * Copyright (C) 2017 Spreadtrum - http://www.spreadtrum.com | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or | |
6 | * modify it under the terms of the GNU General Public License | |
7 | * version 2 as published by the Free Software Foundation. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, but | |
10 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
12 | * General Public License for more details. | |
13 | */ | |
14 | ||
15 | #include <linux/bitops.h> | |
16 | #include <linux/clk.h> | |
17 | #include <linux/delay.h> | |
18 | #include <linux/device.h> | |
19 | #include <linux/hwspinlock.h> | |
20 | #include <linux/io.h> | |
21 | #include <linux/kernel.h> | |
22 | #include <linux/module.h> | |
23 | #include <linux/of.h> | |
24 | #include <linux/of_device.h> | |
25 | #include <linux/platform_device.h> | |
26 | #include <linux/pm_runtime.h> | |
27 | #include <linux/slab.h> | |
28 | ||
29 | #include "hwspinlock_internal.h" | |
30 | ||
31 | /* hwspinlock registers definition */ | |
32 | #define HWSPINLOCK_RECCTRL 0x4 | |
33 | #define HWSPINLOCK_MASTERID(_X_) (0x80 + 0x4 * (_X_)) | |
34 | #define HWSPINLOCK_TOKEN(_X_) (0x800 + 0x4 * (_X_)) | |
35 | ||
36 | /* unlocked value */ | |
37 | #define HWSPINLOCK_NOTTAKEN 0x55aa10c5 | |
38 | /* bits definition of RECCTRL reg */ | |
39 | #define HWSPINLOCK_USER_BITS 0x1 | |
40 | ||
41 | /* hwspinlock number */ | |
42 | #define SPRD_HWLOCKS_NUM 32 | |
43 | ||
44 | struct sprd_hwspinlock_dev { | |
45 | void __iomem *base; | |
46 | struct clk *clk; | |
47 | struct hwspinlock_device bank; | |
48 | }; | |
49 | ||
50 | /* try to lock the hardware spinlock */ | |
51 | static int sprd_hwspinlock_trylock(struct hwspinlock *lock) | |
52 | { | |
53 | struct sprd_hwspinlock_dev *sprd_hwlock = | |
54 | dev_get_drvdata(lock->bank->dev); | |
55 | void __iomem *addr = lock->priv; | |
56 | int user_id, lock_id; | |
57 | ||
58 | if (!readl(addr)) | |
59 | return 1; | |
60 | ||
61 | lock_id = hwlock_to_id(lock); | |
62 | /* get the hardware spinlock master/user id */ | |
63 | user_id = readl(sprd_hwlock->base + HWSPINLOCK_MASTERID(lock_id)); | |
64 | dev_warn(sprd_hwlock->bank.dev, | |
65 | "hwspinlock [%d] lock failed and master/user id = %d!\n", | |
66 | lock_id, user_id); | |
67 | return 0; | |
68 | } | |
69 | ||
70 | /* unlock the hardware spinlock */ | |
71 | static void sprd_hwspinlock_unlock(struct hwspinlock *lock) | |
72 | { | |
73 | void __iomem *lock_addr = lock->priv; | |
74 | ||
75 | writel(HWSPINLOCK_NOTTAKEN, lock_addr); | |
76 | } | |
77 | ||
78 | /* The specs recommended below number as the retry delay time */ | |
79 | static void sprd_hwspinlock_relax(struct hwspinlock *lock) | |
80 | { | |
81 | ndelay(10); | |
82 | } | |
83 | ||
84 | static const struct hwspinlock_ops sprd_hwspinlock_ops = { | |
85 | .trylock = sprd_hwspinlock_trylock, | |
86 | .unlock = sprd_hwspinlock_unlock, | |
87 | .relax = sprd_hwspinlock_relax, | |
88 | }; | |
89 | ||
90 | static int sprd_hwspinlock_probe(struct platform_device *pdev) | |
91 | { | |
92 | struct sprd_hwspinlock_dev *sprd_hwlock; | |
93 | struct hwspinlock *lock; | |
94 | struct resource *res; | |
95 | int i, ret; | |
96 | ||
97 | if (!pdev->dev.of_node) | |
98 | return -ENODEV; | |
99 | ||
100 | sprd_hwlock = devm_kzalloc(&pdev->dev, | |
101 | sizeof(struct sprd_hwspinlock_dev) + | |
102 | SPRD_HWLOCKS_NUM * sizeof(*lock), | |
103 | GFP_KERNEL); | |
104 | if (!sprd_hwlock) | |
105 | return -ENOMEM; | |
106 | ||
107 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
108 | sprd_hwlock->base = devm_ioremap_resource(&pdev->dev, res); | |
109 | if (IS_ERR(sprd_hwlock->base)) | |
110 | return PTR_ERR(sprd_hwlock->base); | |
111 | ||
112 | sprd_hwlock->clk = devm_clk_get(&pdev->dev, "enable"); | |
113 | if (IS_ERR(sprd_hwlock->clk)) { | |
114 | dev_err(&pdev->dev, "get hwspinlock clock failed!\n"); | |
115 | return PTR_ERR(sprd_hwlock->clk); | |
116 | } | |
117 | ||
118 | clk_prepare_enable(sprd_hwlock->clk); | |
119 | ||
120 | /* set the hwspinlock to record user id to identify subsystems */ | |
121 | writel(HWSPINLOCK_USER_BITS, sprd_hwlock->base + HWSPINLOCK_RECCTRL); | |
122 | ||
123 | for (i = 0; i < SPRD_HWLOCKS_NUM; i++) { | |
124 | lock = &sprd_hwlock->bank.lock[i]; | |
125 | lock->priv = sprd_hwlock->base + HWSPINLOCK_TOKEN(i); | |
126 | } | |
127 | ||
128 | platform_set_drvdata(pdev, sprd_hwlock); | |
129 | pm_runtime_enable(&pdev->dev); | |
130 | ||
131 | ret = hwspin_lock_register(&sprd_hwlock->bank, &pdev->dev, | |
132 | &sprd_hwspinlock_ops, 0, SPRD_HWLOCKS_NUM); | |
133 | if (ret) { | |
134 | pm_runtime_disable(&pdev->dev); | |
135 | clk_disable_unprepare(sprd_hwlock->clk); | |
136 | return ret; | |
137 | } | |
138 | ||
139 | return 0; | |
140 | } | |
141 | ||
142 | static int sprd_hwspinlock_remove(struct platform_device *pdev) | |
143 | { | |
144 | struct sprd_hwspinlock_dev *sprd_hwlock = platform_get_drvdata(pdev); | |
145 | ||
146 | hwspin_lock_unregister(&sprd_hwlock->bank); | |
147 | pm_runtime_disable(&pdev->dev); | |
148 | clk_disable_unprepare(sprd_hwlock->clk); | |
149 | return 0; | |
150 | } | |
151 | ||
152 | static const struct of_device_id sprd_hwspinlock_of_match[] = { | |
153 | { .compatible = "sprd,hwspinlock-r3p0", }, | |
154 | { /* sentinel */ } | |
155 | }; | |
156 | MODULE_DEVICE_TABLE(of, sprd_hwspinlock_of_match); | |
157 | ||
158 | static struct platform_driver sprd_hwspinlock_driver = { | |
159 | .probe = sprd_hwspinlock_probe, | |
160 | .remove = sprd_hwspinlock_remove, | |
161 | .driver = { | |
162 | .name = "sprd_hwspinlock", | |
163 | .of_match_table = of_match_ptr(sprd_hwspinlock_of_match), | |
164 | }, | |
165 | }; | |
166 | ||
167 | static int __init sprd_hwspinlock_init(void) | |
168 | { | |
169 | return platform_driver_register(&sprd_hwspinlock_driver); | |
170 | } | |
171 | postcore_initcall(sprd_hwspinlock_init); | |
172 | ||
173 | static void __exit sprd_hwspinlock_exit(void) | |
174 | { | |
175 | platform_driver_unregister(&sprd_hwspinlock_driver); | |
176 | } | |
177 | module_exit(sprd_hwspinlock_exit); | |
178 | ||
179 | MODULE_LICENSE("GPL v2"); | |
180 | MODULE_DESCRIPTION("Hardware spinlock driver for Spreadtrum"); | |
181 | MODULE_AUTHOR("Baolin Wang <baolin.wang@spreadtrum.com>"); | |
182 | MODULE_AUTHOR("Lanqing Liu <lanqing.liu@spreadtrum.com>"); | |
183 | MODULE_AUTHOR("Long Cheng <aiden.cheng@spreadtrum.com>"); |