samples/rpmsg/rpmsg_client_sample.c

   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");