blob: c752447fbac7883f96290889e382639033975b53 [file] [log] [blame]
Bjorn Andersson19a0f612015-03-24 10:11:05 -07001/*
2 * Copyright (c) 2013, The Linux Foundation. All rights reserved.
3 * Copyright (c) 2015, Sony Mobile Communications AB
4 *
5 * This software is licensed under the terms of the GNU General Public
6 * License version 2, as published by the Free Software Foundation, and
7 * may be copied, distributed, and modified under those terms.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 */
14
15#include <linux/hwspinlock.h>
16#include <linux/io.h>
17#include <linux/kernel.h>
18#include <linux/mfd/syscon.h>
19#include <linux/module.h>
20#include <linux/of.h>
21#include <linux/of_device.h>
22#include <linux/platform_device.h>
23#include <linux/pm_runtime.h>
24#include <linux/regmap.h>
25
26#include "hwspinlock_internal.h"
27
28#define QCOM_MUTEX_APPS_PROC_ID 1
29#define QCOM_MUTEX_NUM_LOCKS 32
30
31static int qcom_hwspinlock_trylock(struct hwspinlock *lock)
32{
33 struct regmap_field *field = lock->priv;
34 u32 lock_owner;
35 int ret;
36
37 ret = regmap_field_write(field, QCOM_MUTEX_APPS_PROC_ID);
38 if (ret)
39 return ret;
40
41 ret = regmap_field_read(field, &lock_owner);
42 if (ret)
43 return ret;
44
45 return lock_owner == QCOM_MUTEX_APPS_PROC_ID;
46}
47
48static void qcom_hwspinlock_unlock(struct hwspinlock *lock)
49{
50 struct regmap_field *field = lock->priv;
51 u32 lock_owner;
52 int ret;
53
54 ret = regmap_field_read(field, &lock_owner);
55 if (ret) {
56 pr_err("%s: unable to query spinlock owner\n", __func__);
57 return;
58 }
59
60 if (lock_owner != QCOM_MUTEX_APPS_PROC_ID) {
61 pr_err("%s: spinlock not owned by us (actual owner is %d)\n",
62 __func__, lock_owner);
63 }
64
65 ret = regmap_field_write(field, 0);
66 if (ret)
67 pr_err("%s: failed to unlock spinlock\n", __func__);
68}
69
70static const struct hwspinlock_ops qcom_hwspinlock_ops = {
71 .trylock = qcom_hwspinlock_trylock,
72 .unlock = qcom_hwspinlock_unlock,
73};
74
75static const struct of_device_id qcom_hwspinlock_of_match[] = {
76 { .compatible = "qcom,sfpb-mutex" },
77 { .compatible = "qcom,tcsr-mutex" },
78 { }
79};
80MODULE_DEVICE_TABLE(of, qcom_hwspinlock_of_match);
81
82static int qcom_hwspinlock_probe(struct platform_device *pdev)
83{
84 struct hwspinlock_device *bank;
85 struct device_node *syscon;
86 struct reg_field field;
87 struct regmap *regmap;
88 size_t array_size;
89 u32 stride;
90 u32 base;
91 int ret;
92 int i;
93
94 syscon = of_parse_phandle(pdev->dev.of_node, "syscon", 0);
95 if (!syscon) {
96 dev_err(&pdev->dev, "no syscon property\n");
97 return -ENODEV;
98 }
99
100 regmap = syscon_node_to_regmap(syscon);
101 if (IS_ERR(regmap))
102 return PTR_ERR(regmap);
103
104 ret = of_property_read_u32_index(pdev->dev.of_node, "syscon", 1, &base);
105 if (ret < 0) {
106 dev_err(&pdev->dev, "no offset in syscon\n");
107 return -EINVAL;
108 }
109
110 ret = of_property_read_u32_index(pdev->dev.of_node, "syscon", 2, &stride);
111 if (ret < 0) {
112 dev_err(&pdev->dev, "no stride syscon\n");
113 return -EINVAL;
114 }
115
116 array_size = QCOM_MUTEX_NUM_LOCKS * sizeof(struct hwspinlock);
117 bank = devm_kzalloc(&pdev->dev, sizeof(*bank) + array_size, GFP_KERNEL);
118 if (!bank)
119 return -ENOMEM;
120
121 platform_set_drvdata(pdev, bank);
122
123 for (i = 0; i < QCOM_MUTEX_NUM_LOCKS; i++) {
124 field.reg = base + i * stride;
125 field.lsb = 0;
Bjorn Anderssonbd5717a2015-06-26 14:47:21 -0700126 field.msb = 31;
Bjorn Andersson19a0f612015-03-24 10:11:05 -0700127
128 bank->lock[i].priv = devm_regmap_field_alloc(&pdev->dev,
129 regmap, field);
130 }
131
132 pm_runtime_enable(&pdev->dev);
133
134 ret = hwspin_lock_register(bank, &pdev->dev, &qcom_hwspinlock_ops,
135 0, QCOM_MUTEX_NUM_LOCKS);
136 if (ret)
137 pm_runtime_disable(&pdev->dev);
138
139 return ret;
140}
141
142static int qcom_hwspinlock_remove(struct platform_device *pdev)
143{
144 struct hwspinlock_device *bank = platform_get_drvdata(pdev);
145 int ret;
146
147 ret = hwspin_lock_unregister(bank);
148 if (ret) {
149 dev_err(&pdev->dev, "%s failed: %d\n", __func__, ret);
150 return ret;
151 }
152
153 pm_runtime_disable(&pdev->dev);
154
155 return 0;
156}
157
158static struct platform_driver qcom_hwspinlock_driver = {
159 .probe = qcom_hwspinlock_probe,
160 .remove = qcom_hwspinlock_remove,
161 .driver = {
162 .name = "qcom_hwspinlock",
163 .of_match_table = qcom_hwspinlock_of_match,
164 },
165};
166
167static int __init qcom_hwspinlock_init(void)
168{
169 return platform_driver_register(&qcom_hwspinlock_driver);
170}
171/* board init code might need to reserve hwspinlocks for predefined purposes */
172postcore_initcall(qcom_hwspinlock_init);
173
174static void __exit qcom_hwspinlock_exit(void)
175{
176 platform_driver_unregister(&qcom_hwspinlock_driver);
177}
178module_exit(qcom_hwspinlock_exit);
179
180MODULE_LICENSE("GPL v2");
181MODULE_DESCRIPTION("Hardware spinlock driver for Qualcomm SoCs");