summaryrefslogtreecommitdiff
path: root/drivers/rpmsg/rpmsg_ctrl.c
blob: 433253835690806a8f75749a2e2d6e79e33ab8e2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2022, STMicroelectronics
 * Copyright (c) 2016, Linaro Ltd.
 * Copyright (c) 2012, Michal Simek <monstr@monstr.eu>
 * Copyright (c) 2012, PetaLogix
 * Copyright (c) 2011, Texas Instruments, Inc.
 * Copyright (c) 2011, Google, Inc.
 *
 * Based on rpmsg performance statistics driver by Michal Simek, which in turn
 * was based on TI & Google OMX rpmsg driver.
 */

#define pr_fmt(fmt)		KBUILD_MODNAME ": " fmt

#include <linux/cdev.h>
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/idr.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/rpmsg.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <uapi/linux/rpmsg.h>

#include "rpmsg_char.h"
#include "rpmsg_internal.h"

#define RPMSG_DEV_MAX	(MINORMASK + 1)

static dev_t rpmsg_major;

static DEFINE_IDA(rpmsg_ctrl_ida);
static DEFINE_IDA(rpmsg_minor_ida);

#define dev_to_ctrldev(dev) container_of(dev, struct rpmsg_ctrldev, dev)
#define cdev_to_ctrldev(i_cdev) container_of(i_cdev, struct rpmsg_ctrldev, cdev)

/**
 * struct rpmsg_ctrldev - control device for instantiating endpoint devices
 * @rpdev:	underlaying rpmsg device
 * @cdev:	cdev for the ctrl device
 * @dev:	device for the ctrl device
 * @ctrl_lock:	serialize the ioctrls.
 */
struct rpmsg_ctrldev {
	struct rpmsg_device *rpdev;
	struct cdev cdev;
	struct device dev;
	struct mutex ctrl_lock;
};

static int rpmsg_ctrldev_open(struct inode *inode, struct file *filp)
{
	struct rpmsg_ctrldev *ctrldev = cdev_to_ctrldev(inode->i_cdev);

	get_device(&ctrldev->dev);
	filp->private_data = ctrldev;

	return 0;
}

static int rpmsg_ctrldev_release(struct inode *inode, struct file *filp)
{
	struct rpmsg_ctrldev *ctrldev = cdev_to_ctrldev(inode->i_cdev);

	put_device(&ctrldev->dev);

	return 0;
}

static long rpmsg_ctrldev_ioctl(struct file *fp, unsigned int cmd,
				unsigned long arg)
{
	struct rpmsg_ctrldev *ctrldev = fp->private_data;
	void __user *argp = (void __user *)arg;
	struct rpmsg_endpoint_info eptinfo;
	struct rpmsg_channel_info chinfo;
	struct rpmsg_device *rpdev;
	int ret = 0;

	if (copy_from_user(&eptinfo, argp, sizeof(eptinfo)))
		return -EFAULT;

	memcpy(chinfo.name, eptinfo.name, RPMSG_NAME_SIZE);
	chinfo.name[RPMSG_NAME_SIZE - 1] = '\0';
	chinfo.src = eptinfo.src;
	chinfo.dst = eptinfo.dst;

	mutex_lock(&ctrldev->ctrl_lock);
	switch (cmd) {
	case RPMSG_CREATE_EPT_IOCTL:
		ret = rpmsg_chrdev_eptdev_create(ctrldev->rpdev, &ctrldev->dev, chinfo);
		break;

	case RPMSG_CREATE_DEV_IOCTL:
		rpdev = rpmsg_create_channel(ctrldev->rpdev, &chinfo);
		if (!rpdev) {
			dev_err(&ctrldev->dev, "failed to create %s channel\n", chinfo.name);
			ret = -ENXIO;
		}
		break;

	case RPMSG_RELEASE_DEV_IOCTL:
		ret = rpmsg_release_channel(ctrldev->rpdev, &chinfo);
		if (ret)
			dev_err(&ctrldev->dev, "failed to release %s channel (%d)\n",
				chinfo.name, ret);
		break;

	default:
		ret = -EINVAL;
	}
	mutex_unlock(&ctrldev->ctrl_lock);

	return ret;
};

static const struct file_operations rpmsg_ctrldev_fops = {
	.owner = THIS_MODULE,
	.open = rpmsg_ctrldev_open,
	.release = rpmsg_ctrldev_release,
	.unlocked_ioctl = rpmsg_ctrldev_ioctl,
	.compat_ioctl = compat_ptr_ioctl,
};

static void rpmsg_ctrldev_release_device(struct device *dev)
{
	struct rpmsg_ctrldev *ctrldev = dev_to_ctrldev(dev);

	ida_simple_remove(&rpmsg_ctrl_ida, dev->id);
	ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt));
	kfree(ctrldev);
}

static int rpmsg_ctrldev_probe(struct rpmsg_device *rpdev)
{
	struct rpmsg_ctrldev *ctrldev;
	struct device *dev;
	int ret;

	ctrldev = kzalloc(sizeof(*ctrldev), GFP_KERNEL);
	if (!ctrldev)
		return -ENOMEM;

	ctrldev->rpdev = rpdev;

	dev = &ctrldev->dev;
	device_initialize(dev);
	dev->parent = &rpdev->dev;
	dev->class = rpmsg_class;

	mutex_init(&ctrldev->ctrl_lock);
	cdev_init(&ctrldev->cdev, &rpmsg_ctrldev_fops);
	ctrldev->cdev.owner = THIS_MODULE;

	ret = ida_simple_get(&rpmsg_minor_ida, 0, RPMSG_DEV_MAX, GFP_KERNEL);
	if (ret < 0)
		goto free_ctrldev;
	dev->devt = MKDEV(MAJOR(rpmsg_major), ret);

	ret = ida_simple_get(&rpmsg_ctrl_ida, 0, 0, GFP_KERNEL);
	if (ret < 0)
		goto free_minor_ida;
	dev->id = ret;
	dev_set_name(&ctrldev->dev, "rpmsg_ctrl%d", ret);

	ret = cdev_device_add(&ctrldev->cdev, &ctrldev->dev);
	if (ret)
		goto free_ctrl_ida;

	/* We can now rely on the release function for cleanup */
	dev->release = rpmsg_ctrldev_release_device;

	dev_set_drvdata(&rpdev->dev, ctrldev);

	return ret;

free_ctrl_ida:
	ida_simple_remove(&rpmsg_ctrl_ida, dev->id);
free_minor_ida:
	ida_simple_remove(&rpmsg_minor_ida, MINOR(dev->devt));
free_ctrldev:
	put_device(dev);
	kfree(ctrldev);

	return ret;
}

static void rpmsg_ctrldev_remove(struct rpmsg_device *rpdev)
{
	struct rpmsg_ctrldev *ctrldev = dev_get_drvdata(&rpdev->dev);
	int ret;

	mutex_lock(&ctrldev->ctrl_lock);
	/* Destroy all endpoints */
	ret = device_for_each_child(&ctrldev->dev, NULL, rpmsg_chrdev_eptdev_destroy);
	if (ret)
		dev_warn(&rpdev->dev, "failed to nuke endpoints: %d\n", ret);
	mutex_unlock(&ctrldev->ctrl_lock);

	cdev_device_del(&ctrldev->cdev, &ctrldev->dev);
	put_device(&ctrldev->dev);
}

static struct rpmsg_driver rpmsg_ctrldev_driver = {
	.probe = rpmsg_ctrldev_probe,
	.remove = rpmsg_ctrldev_remove,
	.drv = {
		.name = "rpmsg_ctrl",
	},
};

static int rpmsg_ctrldev_init(void)
{
	int ret;

	ret = alloc_chrdev_region(&rpmsg_major, 0, RPMSG_DEV_MAX, "rpmsg_ctrl");
	if (ret < 0) {
		pr_err("failed to allocate char dev region\n");
		return ret;
	}

	ret = register_rpmsg_driver(&rpmsg_ctrldev_driver);
	if (ret < 0) {
		pr_err("failed to register rpmsg driver\n");
		unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
	}

	return ret;
}
postcore_initcall(rpmsg_ctrldev_init);

static void rpmsg_ctrldev_exit(void)
{
	unregister_rpmsg_driver(&rpmsg_ctrldev_driver);
	unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
}
module_exit(rpmsg_ctrldev_exit);

MODULE_DESCRIPTION("rpmsg control interface");
MODULE_ALIAS("rpmsg:" KBUILD_MODNAME);
MODULE_LICENSE("GPL v2");