1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (c) 2013, The Linux Foundation. All rights reserved.
4 * Copyright (c) 2015, Sony Mobile Communications AB
5 */
6
7 #include <linux/hwspinlock.h>
8 #include <linux/io.h>
9 #include <linux/kernel.h>
10 #include <linux/mfd/syscon.h>
11 #include <linux/module.h>
12 #include <linux/of.h>
13 #include <linux/of_device.h>
14 #include <linux/platform_device.h>
15 #include <linux/pm_runtime.h>
16 #include <linux/regmap.h>
17
18 #include "hwspinlock_internal.h"
19
20 #define QCOM_MUTEX_APPS_PROC_ID 1
21 #define QCOM_MUTEX_NUM_LOCKS 32
22
qcom_hwspinlock_trylock(struct hwspinlock * lock)23 static int qcom_hwspinlock_trylock(struct hwspinlock *lock)
24 {
25 struct regmap_field *field = lock->priv;
26 u32 lock_owner;
27 int ret;
28
29 ret = regmap_field_write(field, QCOM_MUTEX_APPS_PROC_ID);
30 if (ret)
31 return ret;
32
33 ret = regmap_field_read(field, &lock_owner);
34 if (ret)
35 return ret;
36
37 return lock_owner == QCOM_MUTEX_APPS_PROC_ID;
38 }
39
qcom_hwspinlock_unlock(struct hwspinlock * lock)40 static void qcom_hwspinlock_unlock(struct hwspinlock *lock)
41 {
42 struct regmap_field *field = lock->priv;
43 u32 lock_owner;
44 int ret;
45
46 ret = regmap_field_read(field, &lock_owner);
47 if (ret) {
48 pr_err("%s: unable to query spinlock owner\n", __func__);
49 return;
50 }
51
52 if (lock_owner != QCOM_MUTEX_APPS_PROC_ID) {
53 pr_err("%s: spinlock not owned by us (actual owner is %d)\n",
54 __func__, lock_owner);
55 }
56
57 ret = regmap_field_write(field, 0);
58 if (ret)
59 pr_err("%s: failed to unlock spinlock\n", __func__);
60 }
61
62 static const struct hwspinlock_ops qcom_hwspinlock_ops = {
63 .trylock = qcom_hwspinlock_trylock,
64 .unlock = qcom_hwspinlock_unlock,
65 };
66
67 static const struct of_device_id qcom_hwspinlock_of_match[] = {
68 { .compatible = "qcom,sfpb-mutex" },
69 { .compatible = "qcom,tcsr-mutex" },
70 { }
71 };
72 MODULE_DEVICE_TABLE(of, qcom_hwspinlock_of_match);
73
qcom_hwspinlock_probe(struct platform_device * pdev)74 static int qcom_hwspinlock_probe(struct platform_device *pdev)
75 {
76 struct hwspinlock_device *bank;
77 struct device_node *syscon;
78 struct reg_field field;
79 struct regmap *regmap;
80 size_t array_size;
81 u32 stride;
82 u32 base;
83 int ret;
84 int i;
85
86 syscon = of_parse_phandle(pdev->dev.of_node, "syscon", 0);
87 if (!syscon) {
88 dev_err(&pdev->dev, "no syscon property\n");
89 return -ENODEV;
90 }
91
92 regmap = syscon_node_to_regmap(syscon);
93 of_node_put(syscon);
94 if (IS_ERR(regmap))
95 return PTR_ERR(regmap);
96
97 ret = of_property_read_u32_index(pdev->dev.of_node, "syscon", 1, &base);
98 if (ret < 0) {
99 dev_err(&pdev->dev, "no offset in syscon\n");
100 return -EINVAL;
101 }
102
103 ret = of_property_read_u32_index(pdev->dev.of_node, "syscon", 2, &stride);
104 if (ret < 0) {
105 dev_err(&pdev->dev, "no stride syscon\n");
106 return -EINVAL;
107 }
108
109 array_size = QCOM_MUTEX_NUM_LOCKS * sizeof(struct hwspinlock);
110 bank = devm_kzalloc(&pdev->dev, sizeof(*bank) + array_size, GFP_KERNEL);
111 if (!bank)
112 return -ENOMEM;
113
114 platform_set_drvdata(pdev, bank);
115
116 for (i = 0; i < QCOM_MUTEX_NUM_LOCKS; i++) {
117 field.reg = base + i * stride;
118 field.lsb = 0;
119 field.msb = 31;
120
121 bank->lock[i].priv = devm_regmap_field_alloc(&pdev->dev,
122 regmap, field);
123 }
124
125 pm_runtime_enable(&pdev->dev);
126
127 ret = hwspin_lock_register(bank, &pdev->dev, &qcom_hwspinlock_ops,
128 0, QCOM_MUTEX_NUM_LOCKS);
129 if (ret)
130 pm_runtime_disable(&pdev->dev);
131
132 return ret;
133 }
134
qcom_hwspinlock_remove(struct platform_device * pdev)135 static int qcom_hwspinlock_remove(struct platform_device *pdev)
136 {
137 struct hwspinlock_device *bank = platform_get_drvdata(pdev);
138 int ret;
139
140 ret = hwspin_lock_unregister(bank);
141 if (ret) {
142 dev_err(&pdev->dev, "%s failed: %d\n", __func__, ret);
143 return ret;
144 }
145
146 pm_runtime_disable(&pdev->dev);
147
148 return 0;
149 }
150
151 static struct platform_driver qcom_hwspinlock_driver = {
152 .probe = qcom_hwspinlock_probe,
153 .remove = qcom_hwspinlock_remove,
154 .driver = {
155 .name = "qcom_hwspinlock",
156 .of_match_table = qcom_hwspinlock_of_match,
157 },
158 };
159
qcom_hwspinlock_init(void)160 static int __init qcom_hwspinlock_init(void)
161 {
162 return platform_driver_register(&qcom_hwspinlock_driver);
163 }
164 /* board init code might need to reserve hwspinlocks for predefined purposes */
165 postcore_initcall(qcom_hwspinlock_init);
166
qcom_hwspinlock_exit(void)167 static void __exit qcom_hwspinlock_exit(void)
168 {
169 platform_driver_unregister(&qcom_hwspinlock_driver);
170 }
171 module_exit(qcom_hwspinlock_exit);
172
173 MODULE_LICENSE("GPL v2");
174 MODULE_DESCRIPTION("Hardware spinlock driver for Qualcomm SoCs");
175