samples/rpmsg/rpmsg_client_sample.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Remote processor messaging - sample client driver
0004  *
0005  * Copyright (C) 2011 Texas Instruments, Inc.
0006  * Copyright (C) 2011 Google, Inc.
0007  *
0008  * Ohad Ben-Cohen <ohad@wizery.com>
0009  * Brian Swetland <swetland@google.com>
0010  */
0011
0012 #include <linux/kernel.h>
0013 #include <linux/module.h>
0014 #include <linux/rpmsg.h>
0015
0016 #define MSG     "hello world!"
0017
0018 static int count = 100;
0019 module_param(count, int, 0644);
0020
0021 struct instance_data {
0022     int rx_count;
0023 };
0024
0025 static int rpmsg_sample_cb(struct rpmsg_device *rpdev, void *data, int len,
0026                         void *priv, u32 src)
0027 {
0028     int ret;
0029     struct instance_data *idata = dev_get_drvdata(&rpdev->dev);
0030
0031     dev_info(&rpdev->dev, "incoming msg %d (src: 0x%x)\n",
0032          ++idata->rx_count, src);
0033
0034     print_hex_dump_debug(__func__, DUMP_PREFIX_NONE, 16, 1, data, len,
0035                  true);
0036
0037     /* samples should not live forever */
0038     if (idata->rx_count >= count) {
0039         dev_info(&rpdev->dev, "goodbye!\n");
0040         return 0;
0041     }
0042
0043     /* send a new message now */
0044     ret = rpmsg_send(rpdev->ept, MSG, strlen(MSG));
0045     if (ret)
0046         dev_err(&rpdev->dev, "rpmsg_send failed: %d\n", ret);
0047
0048     return 0;
0049 }
0050
0051 static int rpmsg_sample_probe(struct rpmsg_device *rpdev)
0052 {
0053     int ret;
0054     struct instance_data *idata;
0055
0056     dev_info(&rpdev->dev, "new channel: 0x%x -> 0x%x!\n",
0057                     rpdev->src, rpdev->dst);
0058
0059     idata = devm_kzalloc(&rpdev->dev, sizeof(*idata), GFP_KERNEL);
0060     if (!idata)
0061         return -ENOMEM;
0062
0063     dev_set_drvdata(&rpdev->dev, idata);
0064
0065     /* send a message to our remote processor */
0066     ret = rpmsg_send(rpdev->ept, MSG, strlen(MSG));
0067     if (ret) {
0068         dev_err(&rpdev->dev, "rpmsg_send failed: %d\n", ret);
0069         return ret;
0070     }
0071
0072     return 0;
0073 }
0074
0075 static void rpmsg_sample_remove(struct rpmsg_device *rpdev)
0076 {
0077     dev_info(&rpdev->dev, "rpmsg sample client driver is removed\n");
0078 }
0079
0080 static struct rpmsg_device_id rpmsg_driver_sample_id_table[] = {
0081     { .name = "rpmsg-client-sample" },
0082     { },
0083 };
0084 MODULE_DEVICE_TABLE(rpmsg, rpmsg_driver_sample_id_table);
0085
0086 static struct rpmsg_driver rpmsg_sample_client = {
0087     .drv.name   = KBUILD_MODNAME,
0088     .id_table   = rpmsg_driver_sample_id_table,
0089     .probe      = rpmsg_sample_probe,
0090     .callback   = rpmsg_sample_cb,
0091     .remove     = rpmsg_sample_remove,
0092 };
0093 module_rpmsg_driver(rpmsg_sample_client);
0094
0095 MODULE_DESCRIPTION("Remote processor messaging sample client driver");
0096 MODULE_LICENSE("GPL v2");