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 | |
33 | struct 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 */ |
40 | static int sprd_hwspinlock_trylock(struct hwspinlock *lock) |
41 | { |
42 | struct sprd_hwspinlock_dev *sprd_hwlock = |
43 | dev_get_drvdata(dev: 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(hwlock: lock); |
51 | /* get the hardware spinlock master/user id */ |
52 | user_id = readl(addr: 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 */ |
60 | static void sprd_hwspinlock_unlock(struct hwspinlock *lock) |
61 | { |
62 | void __iomem *lock_addr = lock->priv; |
63 | |
64 | writel(HWSPINLOCK_NOTTAKEN, addr: lock_addr); |
65 | } |
66 | |
67 | /* The specs recommended below number as the retry delay time */ |
68 | static void sprd_hwspinlock_relax(struct hwspinlock *lock) |
69 | { |
70 | ndelay(10); |
71 | } |
72 | |
73 | static const struct hwspinlock_ops sprd_hwspinlock_ops = { |
74 | .trylock = sprd_hwspinlock_trylock, |
75 | .unlock = sprd_hwspinlock_unlock, |
76 | .relax = sprd_hwspinlock_relax, |
77 | }; |
78 | |
79 | static void sprd_hwspinlock_disable(void *data) |
80 | { |
81 | struct sprd_hwspinlock_dev *sprd_hwlock = data; |
82 | |
83 | clk_disable_unprepare(clk: sprd_hwlock->clk); |
84 | } |
85 | |
86 | static 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(dev: &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, index: 0); |
102 | if (IS_ERR(ptr: sprd_hwlock->base)) |
103 | return PTR_ERR(ptr: sprd_hwlock->base); |
104 | |
105 | sprd_hwlock->clk = devm_clk_get(dev: &pdev->dev, id: "enable" ); |
106 | if (IS_ERR(ptr: sprd_hwlock->clk)) { |
107 | dev_err(&pdev->dev, "get hwspinlock clock failed!\n" ); |
108 | return PTR_ERR(ptr: sprd_hwlock->clk); |
109 | } |
110 | |
111 | ret = clk_prepare_enable(clk: 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, addr: 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, data: sprd_hwlock); |
132 | |
133 | return devm_hwspin_lock_register(dev: &pdev->dev, bank: &sprd_hwlock->bank, |
134 | ops: &sprd_hwspinlock_ops, base_id: 0, |
135 | SPRD_HWLOCKS_NUM); |
136 | } |
137 | |
138 | static const struct of_device_id sprd_hwspinlock_of_match[] = { |
139 | { .compatible = "sprd,hwspinlock-r3p0" , }, |
140 | { /* sentinel */ } |
141 | }; |
142 | MODULE_DEVICE_TABLE(of, sprd_hwspinlock_of_match); |
143 | |
144 | static 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 | }; |
151 | module_platform_driver(sprd_hwspinlock_driver); |
152 | |
153 | MODULE_LICENSE("GPL v2" ); |
154 | MODULE_DESCRIPTION("Hardware spinlock driver for Spreadtrum" ); |
155 | MODULE_AUTHOR("Baolin Wang <baolin.wang@spreadtrum.com>" ); |
156 | MODULE_AUTHOR("Lanqing Liu <lanqing.liu@spreadtrum.com>" ); |
157 | MODULE_AUTHOR("Long Cheng <aiden.cheng@spreadtrum.com>" ); |
158 | |