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 struct instance_data {
28 	int rx_count;
29 };
30 
31 static int rpmsg_sample_cb(struct rpmsg_device *rpdev, void *data, int len,
32 						void *priv, u32 src)
33 {
34 	int ret;
35 	struct instance_data *idata = dev_get_drvdata(&rpdev->dev);
36 
37 	dev_info(&rpdev->dev, "incoming msg %d (src: 0x%x)\n",
38 		 ++idata->rx_count, src);
39 
40 	print_hex_dump(KERN_DEBUG, __func__, DUMP_PREFIX_NONE, 16, 1,
41 		       data, len,  true);
42 
43 	/* samples should not live forever */
44 	if (idata->rx_count >= MSG_LIMIT) {
45 		dev_info(&rpdev->dev, "goodbye!\n");
46 		return 0;
47 	}
48 
49 	/* send a new message now */
50 	ret = rpmsg_send(rpdev->ept, MSG, strlen(MSG));
51 	if (ret)
52 		dev_err(&rpdev->dev, "rpmsg_send failed: %d\n", ret);
53 
54 	return 0;
55 }
56 
57 static int rpmsg_sample_probe(struct rpmsg_device *rpdev)
58 {
59 	int ret;
60 	struct instance_data *idata;
61 
62 	dev_info(&rpdev->dev, "new channel: 0x%x -> 0x%x!\n",
63 					rpdev->src, rpdev->dst);
64 
65 	idata = devm_kzalloc(&rpdev->dev, sizeof(*idata), GFP_KERNEL);
66 	if (!idata)
67 		return -ENOMEM;
68 
69 	dev_set_drvdata(&rpdev->dev, idata);
70 
71 	/* send a message to our remote processor */
72 	ret = rpmsg_send(rpdev->ept, MSG, strlen(MSG));
73 	if (ret) {
74 		dev_err(&rpdev->dev, "rpmsg_send failed: %d\n", ret);
75 		return ret;
76 	}
77 
78 	return 0;
79 }
80 
81 static void rpmsg_sample_remove(struct rpmsg_device *rpdev)
82 {
83 	dev_info(&rpdev->dev, "rpmsg sample client driver is removed\n");
84 }
85 
86 static struct rpmsg_device_id rpmsg_driver_sample_id_table[] = {
87 	{ .name	= "rpmsg-client-sample" },
88 	{ },
89 };
90 MODULE_DEVICE_TABLE(rpmsg, rpmsg_driver_sample_id_table);
91 
92 static struct rpmsg_driver rpmsg_sample_client = {
93 	.drv.name	= KBUILD_MODNAME,
94 	.id_table	= rpmsg_driver_sample_id_table,
95 	.probe		= rpmsg_sample_probe,
96 	.callback	= rpmsg_sample_cb,
97 	.remove		= rpmsg_sample_remove,
98 };
99 module_rpmsg_driver(rpmsg_sample_client);
100 
101 MODULE_DESCRIPTION("Remote processor messaging sample client driver");
102 MODULE_LICENSE("GPL v2");
103