1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Remote processor messaging - sample client driver
4  *
5  * Copyright (C) 2011 Texas Instruments, Inc.
6  * Copyright (C) 2011 Google, Inc.
7  *
8  * Ohad Ben-Cohen <ohad@wizery.com>
9  * Brian Swetland <swetland@google.com>
10  */
11 
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/rpmsg.h>
15 
16 #define MSG		"hello world!"
17 
18 static int count = 100;
19 module_param(count, int, 0644);
20 
21 struct instance_data {
22 	int rx_count;
23 };
24 
25 static int rpmsg_sample_cb(struct rpmsg_device *rpdev, void *data, int len,
26 						void *priv, u32 src)
27 {
28 	int ret;
29 	struct instance_data *idata = dev_get_drvdata(&rpdev->dev);
30 
31 	dev_info(&rpdev->dev, "incoming msg %d (src: 0x%x)\n",
32 		 ++idata->rx_count, src);
33 
34 	print_hex_dump_debug(__func__, DUMP_PREFIX_NONE, 16, 1, data, len,
35 			     true);
36 
37 	/* samples should not live forever */
38 	if (idata->rx_count >= count) {
39 		dev_info(&rpdev->dev, "goodbye!\n");
40 		return 0;
41 	}
42 
43 	/* send a new message now */
44 	ret = rpmsg_send(rpdev->ept, MSG, strlen(MSG));
45 	if (ret)
46 		dev_err(&rpdev->dev, "rpmsg_send failed: %d\n", ret);
47 
48 	return 0;
49 }
50 
51 static int rpmsg_sample_probe(struct rpmsg_device *rpdev)
52 {
53 	int ret;
54 	struct instance_data *idata;
55 
56 	dev_info(&rpdev->dev, "new channel: 0x%x -> 0x%x!\n",
57 					rpdev->src, rpdev->dst);
58 
59 	idata = devm_kzalloc(&rpdev->dev, sizeof(*idata), GFP_KERNEL);
60 	if (!idata)
61 		return -ENOMEM;
62 
63 	dev_set_drvdata(&rpdev->dev, idata);
64 
65 	/* send a message to our remote processor */
66 	ret = rpmsg_send(rpdev->ept, MSG, strlen(MSG));
67 	if (ret) {
68 		dev_err(&rpdev->dev, "rpmsg_send failed: %d\n", ret);
69 		return ret;
70 	}
71 
72 	return 0;
73 }
74 
75 static void rpmsg_sample_remove(struct rpmsg_device *rpdev)
76 {
77 	dev_info(&rpdev->dev, "rpmsg sample client driver is removed\n");
78 }
79 
80 static struct rpmsg_device_id rpmsg_driver_sample_id_table[] = {
81 	{ .name	= "rpmsg-client-sample" },
82 	{ },
83 };
84 MODULE_DEVICE_TABLE(rpmsg, rpmsg_driver_sample_id_table);
85 
86 static struct rpmsg_driver rpmsg_sample_client = {
87 	.drv.name	= KBUILD_MODNAME,
88 	.id_table	= rpmsg_driver_sample_id_table,
89 	.probe		= rpmsg_sample_probe,
90 	.callback	= rpmsg_sample_cb,
91 	.remove		= rpmsg_sample_remove,
92 };
93 module_rpmsg_driver(rpmsg_sample_client);
94 
95 MODULE_DESCRIPTION("Remote processor messaging sample client driver");
96 MODULE_LICENSE("GPL v2");
97