Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
[linux-2.6-microblaze.git] / drivers / hwspinlock / qcom_hwspinlock.c
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/regmap.h>
16
17 #include "hwspinlock_internal.h"
18
19 #define QCOM_MUTEX_APPS_PROC_ID 1
20 #define QCOM_MUTEX_NUM_LOCKS    32
21
22 static int qcom_hwspinlock_trylock(struct hwspinlock *lock)
23 {
24         struct regmap_field *field = lock->priv;
25         u32 lock_owner;
26         int ret;
27
28         ret = regmap_field_write(field, QCOM_MUTEX_APPS_PROC_ID);
29         if (ret)
30                 return ret;
31
32         ret = regmap_field_read(field, &lock_owner);
33         if (ret)
34                 return ret;
35
36         return lock_owner == QCOM_MUTEX_APPS_PROC_ID;
37 }
38
39 static void qcom_hwspinlock_unlock(struct hwspinlock *lock)
40 {
41         struct regmap_field *field = lock->priv;
42         u32 lock_owner;
43         int ret;
44
45         ret = regmap_field_read(field, &lock_owner);
46         if (ret) {
47                 pr_err("%s: unable to query spinlock owner\n", __func__);
48                 return;
49         }
50
51         if (lock_owner != QCOM_MUTEX_APPS_PROC_ID) {
52                 pr_err("%s: spinlock not owned by us (actual owner is %d)\n",
53                                 __func__, lock_owner);
54         }
55
56         ret = regmap_field_write(field, 0);
57         if (ret)
58                 pr_err("%s: failed to unlock spinlock\n", __func__);
59 }
60
61 static const struct hwspinlock_ops qcom_hwspinlock_ops = {
62         .trylock        = qcom_hwspinlock_trylock,
63         .unlock         = qcom_hwspinlock_unlock,
64 };
65
66 static const struct of_device_id qcom_hwspinlock_of_match[] = {
67         { .compatible = "qcom,sfpb-mutex" },
68         { .compatible = "qcom,tcsr-mutex" },
69         { }
70 };
71 MODULE_DEVICE_TABLE(of, qcom_hwspinlock_of_match);
72
73 static struct regmap *qcom_hwspinlock_probe_syscon(struct platform_device *pdev,
74                                                    u32 *base, u32 *stride)
75 {
76         struct device_node *syscon;
77         struct regmap *regmap;
78         int ret;
79
80         syscon = of_parse_phandle(pdev->dev.of_node, "syscon", 0);
81         if (!syscon)
82                 return ERR_PTR(-ENODEV);
83
84         regmap = syscon_node_to_regmap(syscon);
85         of_node_put(syscon);
86         if (IS_ERR(regmap))
87                 return regmap;
88
89         ret = of_property_read_u32_index(pdev->dev.of_node, "syscon", 1, base);
90         if (ret < 0) {
91                 dev_err(&pdev->dev, "no offset in syscon\n");
92                 return ERR_PTR(-EINVAL);
93         }
94
95         ret = of_property_read_u32_index(pdev->dev.of_node, "syscon", 2, stride);
96         if (ret < 0) {
97                 dev_err(&pdev->dev, "no stride syscon\n");
98                 return ERR_PTR(-EINVAL);
99         }
100
101         return regmap;
102 }
103
104 static const struct regmap_config tcsr_mutex_config = {
105         .reg_bits               = 32,
106         .reg_stride             = 4,
107         .val_bits               = 32,
108         .max_register           = 0x40000,
109         .fast_io                = true,
110 };
111
112 static struct regmap *qcom_hwspinlock_probe_mmio(struct platform_device *pdev,
113                                                  u32 *offset, u32 *stride)
114 {
115         struct device *dev = &pdev->dev;
116         void __iomem *base;
117
118         /* All modern platform has offset 0 and stride of 4k */
119         *offset = 0;
120         *stride = 0x1000;
121
122         base = devm_platform_ioremap_resource(pdev, 0);
123         if (IS_ERR(base))
124                 return ERR_CAST(base);
125
126         return devm_regmap_init_mmio(dev, base, &tcsr_mutex_config);
127 }
128
129 static int qcom_hwspinlock_probe(struct platform_device *pdev)
130 {
131         struct hwspinlock_device *bank;
132         struct reg_field field;
133         struct regmap *regmap;
134         size_t array_size;
135         u32 stride;
136         u32 base;
137         int i;
138
139         regmap = qcom_hwspinlock_probe_syscon(pdev, &base, &stride);
140         if (IS_ERR(regmap) && PTR_ERR(regmap) == -ENODEV)
141                 regmap = qcom_hwspinlock_probe_mmio(pdev, &base, &stride);
142
143         if (IS_ERR(regmap))
144                 return PTR_ERR(regmap);
145
146         array_size = QCOM_MUTEX_NUM_LOCKS * sizeof(struct hwspinlock);
147         bank = devm_kzalloc(&pdev->dev, sizeof(*bank) + array_size, GFP_KERNEL);
148         if (!bank)
149                 return -ENOMEM;
150
151         platform_set_drvdata(pdev, bank);
152
153         for (i = 0; i < QCOM_MUTEX_NUM_LOCKS; i++) {
154                 field.reg = base + i * stride;
155                 field.lsb = 0;
156                 field.msb = 31;
157
158                 bank->lock[i].priv = devm_regmap_field_alloc(&pdev->dev,
159                                                              regmap, field);
160         }
161
162         return devm_hwspin_lock_register(&pdev->dev, bank, &qcom_hwspinlock_ops,
163                                          0, QCOM_MUTEX_NUM_LOCKS);
164 }
165
166 static struct platform_driver qcom_hwspinlock_driver = {
167         .probe          = qcom_hwspinlock_probe,
168         .driver         = {
169                 .name   = "qcom_hwspinlock",
170                 .of_match_table = qcom_hwspinlock_of_match,
171         },
172 };
173
174 static int __init qcom_hwspinlock_init(void)
175 {
176         return platform_driver_register(&qcom_hwspinlock_driver);
177 }
178 /* board init code might need to reserve hwspinlocks for predefined purposes */
179 postcore_initcall(qcom_hwspinlock_init);
180
181 static void __exit qcom_hwspinlock_exit(void)
182 {
183         platform_driver_unregister(&qcom_hwspinlock_driver);
184 }
185 module_exit(qcom_hwspinlock_exit);
186
187 MODULE_LICENSE("GPL v2");
188 MODULE_DESCRIPTION("Hardware spinlock driver for Qualcomm SoCs");