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
18static int count = 100;
19module_param(count, int, 0644);
20
21struct instance_data {
22	int rx_count;
23};
24
25static 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
51static 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
75static void rpmsg_sample_remove(struct rpmsg_device *rpdev)
76{
77	dev_info(&rpdev->dev, "rpmsg sample client driver is removed\n");
78}
79
80static struct rpmsg_device_id rpmsg_driver_sample_id_table[] = {
81	{ .name	= "rpmsg-client-sample" },
82	{ },
83};
84MODULE_DEVICE_TABLE(rpmsg, rpmsg_driver_sample_id_table);
85
86static 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};
93module_rpmsg_driver(rpmsg_sample_client);
94
95MODULE_DESCRIPTION("Remote processor messaging sample client driver");
96MODULE_LICENSE("GPL v2");
97