1 /*
2  * Remote processor messaging - sample client driver
3  *
4  * Copyright (C) 2011 Texas Instruments, Inc.
5  * Copyright (C) 2011 Google, Inc.
6  *
7  * Ohad Ben-Cohen <ohad@wizery.com>
8  * Brian Swetland <swetland@google.com>
9  *
10  * This software is licensed under the terms of the GNU General Public
11  * License version 2, as published by the Free Software Foundation, and
12  * may be copied, distributed, and modified under those terms.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  */
19 
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/rpmsg.h>
23 
24 #define MSG		"hello world!"
25 #define MSG_LIMIT	100
26 
27 static void rpmsg_sample_cb(struct rpmsg_channel *rpdev, void *data, int len,
28 						void *priv, u32 src)
29 {
30 	int ret;
31 	static int rx_count;
32 
33 	dev_info(&rpdev->dev, "incoming msg %d (src: 0x%x)\n", ++rx_count, src);
34 
35 	print_hex_dump(KERN_DEBUG, __func__, DUMP_PREFIX_NONE, 16, 1,
36 		       data, len,  true);
37 
38 	/* samples should not live forever */
39 	if (rx_count >= MSG_LIMIT) {
40 		dev_info(&rpdev->dev, "goodbye!\n");
41 		return;
42 	}
43 
44 	/* send a new message now */
45 	ret = rpmsg_send(rpdev, MSG, strlen(MSG));
46 	if (ret)
47 		dev_err(&rpdev->dev, "rpmsg_send failed: %d\n", ret);
48 }
49 
50 static int rpmsg_sample_probe(struct rpmsg_channel *rpdev)
51 {
52 	int ret;
53 
54 	dev_info(&rpdev->dev, "new channel: 0x%x -> 0x%x!\n",
55 					rpdev->src, rpdev->dst);
56 
57 	/* send a message to our remote processor */
58 	ret = rpmsg_send(rpdev, MSG, strlen(MSG));
59 	if (ret) {
60 		dev_err(&rpdev->dev, "rpmsg_send failed: %d\n", ret);
61 		return ret;
62 	}
63 
64 	return 0;
65 }
66 
67 static void rpmsg_sample_remove(struct rpmsg_channel *rpdev)
68 {
69 	dev_info(&rpdev->dev, "rpmsg sample client driver is removed\n");
70 }
71 
72 static struct rpmsg_device_id rpmsg_driver_sample_id_table[] = {
73 	{ .name	= "rpmsg-client-sample" },
74 	{ },
75 };
76 MODULE_DEVICE_TABLE(rpmsg, rpmsg_driver_sample_id_table);
77 
78 static struct rpmsg_driver rpmsg_sample_client = {
79 	.drv.name	= KBUILD_MODNAME,
80 	.drv.owner	= THIS_MODULE,
81 	.id_table	= rpmsg_driver_sample_id_table,
82 	.probe		= rpmsg_sample_probe,
83 	.callback	= rpmsg_sample_cb,
84 	.remove		= rpmsg_sample_remove,
85 };
86 
87 static int __init rpmsg_client_sample_init(void)
88 {
89 	return register_rpmsg_driver(&rpmsg_sample_client);
90 }
91 module_init(rpmsg_client_sample_init);
92 
93 static void __exit rpmsg_client_sample_fini(void)
94 {
95 	unregister_rpmsg_driver(&rpmsg_sample_client);
96 }
97 module_exit(rpmsg_client_sample_fini);
98 
99 MODULE_DESCRIPTION("Remote processor messaging sample client driver");
100 MODULE_LICENSE("GPL v2");
101