xref: /linux/drivers/hwspinlock/qcom_hwspinlock.c (revision 55d0969c451159cff86949b38c39171cab962069)
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 struct qcom_hwspinlock_of_data {
23 	u32 offset;
24 	u32 stride;
25 	const struct regmap_config *regmap_config;
26 };
27 
28 static int qcom_hwspinlock_trylock(struct hwspinlock *lock)
29 {
30 	struct regmap_field *field = lock->priv;
31 	u32 lock_owner;
32 	int ret;
33 
34 	ret = regmap_field_write(field, QCOM_MUTEX_APPS_PROC_ID);
35 	if (ret)
36 		return ret;
37 
38 	ret = regmap_field_read(field, &lock_owner);
39 	if (ret)
40 		return ret;
41 
42 	return lock_owner == QCOM_MUTEX_APPS_PROC_ID;
43 }
44 
45 static void qcom_hwspinlock_unlock(struct hwspinlock *lock)
46 {
47 	struct regmap_field *field = lock->priv;
48 	u32 lock_owner;
49 	int ret;
50 
51 	ret = regmap_field_read(field, &lock_owner);
52 	if (ret) {
53 		pr_err("%s: unable to query spinlock owner\n", __func__);
54 		return;
55 	}
56 
57 	if (lock_owner != QCOM_MUTEX_APPS_PROC_ID) {
58 		pr_err("%s: spinlock not owned by us (actual owner is %d)\n",
59 				__func__, lock_owner);
60 	}
61 
62 	ret = regmap_field_write(field, 0);
63 	if (ret)
64 		pr_err("%s: failed to unlock spinlock\n", __func__);
65 }
66 
67 static int qcom_hwspinlock_bust(struct hwspinlock *lock, unsigned int id)
68 {
69 	struct regmap_field *field = lock->priv;
70 	u32 owner;
71 	int ret;
72 
73 	ret = regmap_field_read(field, &owner);
74 	if (ret) {
75 		dev_err(lock->bank->dev, "unable to query spinlock owner\n");
76 		return ret;
77 	}
78 
79 	if (owner != id)
80 		return 0;
81 
82 	ret = regmap_field_write(field, 0);
83 	if (ret) {
84 		dev_err(lock->bank->dev, "failed to bust spinlock\n");
85 		return ret;
86 	}
87 
88 	return 0;
89 }
90 
91 static const struct hwspinlock_ops qcom_hwspinlock_ops = {
92 	.trylock	= qcom_hwspinlock_trylock,
93 	.unlock		= qcom_hwspinlock_unlock,
94 	.bust		= qcom_hwspinlock_bust,
95 };
96 
97 static const struct regmap_config sfpb_mutex_config = {
98 	.reg_bits		= 32,
99 	.reg_stride		= 4,
100 	.val_bits		= 32,
101 	.max_register		= 0x100,
102 	.fast_io		= true,
103 };
104 
105 static const struct qcom_hwspinlock_of_data of_sfpb_mutex = {
106 	.offset = 0x4,
107 	.stride = 0x4,
108 	.regmap_config = &sfpb_mutex_config,
109 };
110 
111 static const struct regmap_config tcsr_msm8226_mutex_config = {
112 	.reg_bits		= 32,
113 	.reg_stride		= 4,
114 	.val_bits		= 32,
115 	.max_register		= 0x1000,
116 	.fast_io		= true,
117 };
118 
119 static const struct qcom_hwspinlock_of_data of_msm8226_tcsr_mutex = {
120 	.offset = 0,
121 	.stride = 0x80,
122 	.regmap_config = &tcsr_msm8226_mutex_config,
123 };
124 
125 static const struct regmap_config tcsr_mutex_config = {
126 	.reg_bits		= 32,
127 	.reg_stride		= 4,
128 	.val_bits		= 32,
129 	.max_register		= 0x20000,
130 	.fast_io		= true,
131 };
132 
133 static const struct qcom_hwspinlock_of_data of_tcsr_mutex = {
134 	.offset = 0,
135 	.stride = 0x1000,
136 	.regmap_config = &tcsr_mutex_config,
137 };
138 
139 static const struct of_device_id qcom_hwspinlock_of_match[] = {
140 	{ .compatible = "qcom,sfpb-mutex", .data = &of_sfpb_mutex },
141 	{ .compatible = "qcom,tcsr-mutex", .data = &of_tcsr_mutex },
142 	{ .compatible = "qcom,apq8084-tcsr-mutex", .data = &of_msm8226_tcsr_mutex },
143 	{ .compatible = "qcom,msm8226-tcsr-mutex", .data = &of_msm8226_tcsr_mutex },
144 	{ .compatible = "qcom,msm8974-tcsr-mutex", .data = &of_msm8226_tcsr_mutex },
145 	{ .compatible = "qcom,msm8994-tcsr-mutex", .data = &of_msm8226_tcsr_mutex },
146 	{ }
147 };
148 MODULE_DEVICE_TABLE(of, qcom_hwspinlock_of_match);
149 
150 static struct regmap *qcom_hwspinlock_probe_syscon(struct platform_device *pdev,
151 						   u32 *base, u32 *stride)
152 {
153 	struct device_node *syscon;
154 	struct regmap *regmap;
155 	int ret;
156 
157 	syscon = of_parse_phandle(pdev->dev.of_node, "syscon", 0);
158 	if (!syscon)
159 		return ERR_PTR(-ENODEV);
160 
161 	regmap = syscon_node_to_regmap(syscon);
162 	of_node_put(syscon);
163 	if (IS_ERR(regmap))
164 		return regmap;
165 
166 	ret = of_property_read_u32_index(pdev->dev.of_node, "syscon", 1, base);
167 	if (ret < 0) {
168 		dev_err(&pdev->dev, "no offset in syscon\n");
169 		return ERR_PTR(-EINVAL);
170 	}
171 
172 	ret = of_property_read_u32_index(pdev->dev.of_node, "syscon", 2, stride);
173 	if (ret < 0) {
174 		dev_err(&pdev->dev, "no stride syscon\n");
175 		return ERR_PTR(-EINVAL);
176 	}
177 
178 	return regmap;
179 }
180 
181 static struct regmap *qcom_hwspinlock_probe_mmio(struct platform_device *pdev,
182 						 u32 *offset, u32 *stride)
183 {
184 	const struct qcom_hwspinlock_of_data *data;
185 	struct device *dev = &pdev->dev;
186 	void __iomem *base;
187 
188 	data = of_device_get_match_data(dev);
189 	if (!data->regmap_config)
190 		return ERR_PTR(-EINVAL);
191 
192 	*offset = data->offset;
193 	*stride = data->stride;
194 
195 	base = devm_platform_ioremap_resource(pdev, 0);
196 	if (IS_ERR(base))
197 		return ERR_CAST(base);
198 
199 	return devm_regmap_init_mmio(dev, base, data->regmap_config);
200 }
201 
202 static int qcom_hwspinlock_probe(struct platform_device *pdev)
203 {
204 	struct hwspinlock_device *bank;
205 	struct reg_field field;
206 	struct regmap *regmap;
207 	size_t array_size;
208 	u32 stride;
209 	u32 base;
210 	int i;
211 
212 	regmap = qcom_hwspinlock_probe_syscon(pdev, &base, &stride);
213 	if (IS_ERR(regmap) && PTR_ERR(regmap) == -ENODEV)
214 		regmap = qcom_hwspinlock_probe_mmio(pdev, &base, &stride);
215 
216 	if (IS_ERR(regmap))
217 		return PTR_ERR(regmap);
218 
219 	array_size = QCOM_MUTEX_NUM_LOCKS * sizeof(struct hwspinlock);
220 	bank = devm_kzalloc(&pdev->dev, sizeof(*bank) + array_size, GFP_KERNEL);
221 	if (!bank)
222 		return -ENOMEM;
223 
224 	platform_set_drvdata(pdev, bank);
225 
226 	for (i = 0; i < QCOM_MUTEX_NUM_LOCKS; i++) {
227 		field.reg = base + i * stride;
228 		field.lsb = 0;
229 		field.msb = 31;
230 
231 		bank->lock[i].priv = devm_regmap_field_alloc(&pdev->dev,
232 							     regmap, field);
233 		if (IS_ERR(bank->lock[i].priv))
234 			return PTR_ERR(bank->lock[i].priv);
235 	}
236 
237 	return devm_hwspin_lock_register(&pdev->dev, bank, &qcom_hwspinlock_ops,
238 					 0, QCOM_MUTEX_NUM_LOCKS);
239 }
240 
241 static struct platform_driver qcom_hwspinlock_driver = {
242 	.probe		= qcom_hwspinlock_probe,
243 	.driver		= {
244 		.name	= "qcom_hwspinlock",
245 		.of_match_table = qcom_hwspinlock_of_match,
246 	},
247 };
248 
249 static int __init qcom_hwspinlock_init(void)
250 {
251 	return platform_driver_register(&qcom_hwspinlock_driver);
252 }
253 /* board init code might need to reserve hwspinlocks for predefined purposes */
254 postcore_initcall(qcom_hwspinlock_init);
255 
256 static void __exit qcom_hwspinlock_exit(void)
257 {
258 	platform_driver_unregister(&qcom_hwspinlock_driver);
259 }
260 module_exit(qcom_hwspinlock_exit);
261 
262 MODULE_LICENSE("GPL v2");
263 MODULE_DESCRIPTION("Hardware spinlock driver for Qualcomm SoCs");
264