samples/rpmsg/rpmsg_client_sample.c

   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");