| /* |
| * Copyright (C) 2015 Freescale Semiconductor, Inc. |
| * |
| * derived from the omap-rpmsg implementation. |
| * Remote processor messaging transport - pingpong driver |
| * |
| * The code contained herein is licensed under the GNU General Public |
| * License. You may obtain a copy of the GNU General Public License |
| * Version 2 or later at the following locations: |
| * |
| * http://www.opensource.org/licenses/gpl-license.html |
| * http://www.gnu.org/copyleft/gpl.html |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/virtio.h> |
| #include <linux/rpmsg.h> |
| |
| #define MSG "hello world!" |
| #define MSG_LIMIT 100000 |
| static unsigned int rpmsg_pingpong; |
| static int rx_count; |
| |
| static void rpmsg_pingpong_cb(struct rpmsg_channel *rpdev, void *data, int len, |
| void *priv, u32 src) |
| { |
| int err; |
| |
| /* reply */ |
| rpmsg_pingpong = *(unsigned int *)data; |
| pr_info("get %d (src: 0x%x)\n", |
| rpmsg_pingpong, src); |
| rx_count++; |
| |
| /* pingpongs should not live forever */ |
| if (rx_count >= MSG_LIMIT) { |
| dev_info(&rpdev->dev, "goodbye!\n"); |
| return; |
| } |
| rpmsg_pingpong++; |
| err = rpmsg_sendto(rpdev, (void *)(&rpmsg_pingpong), 4, src); |
| |
| if (err) |
| dev_err(&rpdev->dev, "rpmsg_send failed: %d\n", err); |
| } |
| |
| static int rpmsg_pingpong_probe(struct rpmsg_channel *rpdev) |
| { |
| int err; |
| |
| dev_info(&rpdev->dev, "new channel: 0x%x -> 0x%x!\n", |
| rpdev->src, rpdev->dst); |
| |
| /* |
| * send a message to our remote processor, and tell remote |
| * processor about this channel |
| */ |
| err = rpmsg_send(rpdev, MSG, strlen(MSG)); |
| if (err) { |
| dev_err(&rpdev->dev, "rpmsg_send failed: %d\n", err); |
| return err; |
| } |
| |
| rpmsg_pingpong = 0; |
| rx_count = 0; |
| err = rpmsg_sendto(rpdev, (void *)(&rpmsg_pingpong), 4, rpdev->dst); |
| if (err) { |
| dev_err(&rpdev->dev, "rpmsg_send failed: %d\n", err); |
| return err; |
| } |
| |
| return 0; |
| } |
| |
| static void rpmsg_pingpong_remove(struct rpmsg_channel *rpdev) |
| { |
| dev_info(&rpdev->dev, "rpmsg pingpong driver is removed\n"); |
| } |
| |
| static struct rpmsg_device_id rpmsg_driver_pingpong_id_table[] = { |
| { .name = "rpmsg-openamp-demo-channel" }, |
| { }, |
| }; |
| MODULE_DEVICE_TABLE(rpmsg, rpmsg_driver_pingpong_id_table); |
| |
| static struct rpmsg_driver rpmsg_pingpong_driver = { |
| .drv.name = KBUILD_MODNAME, |
| .drv.owner = THIS_MODULE, |
| .id_table = rpmsg_driver_pingpong_id_table, |
| .probe = rpmsg_pingpong_probe, |
| .callback = rpmsg_pingpong_cb, |
| .remove = rpmsg_pingpong_remove, |
| }; |
| |
| static int __init init(void) |
| { |
| return register_rpmsg_driver(&rpmsg_pingpong_driver); |
| } |
| |
| static void __exit fini(void) |
| { |
| unregister_rpmsg_driver(&rpmsg_pingpong_driver); |
| } |
| module_init(init); |
| module_exit(fini); |
| |
| MODULE_AUTHOR("Freescale Semiconductor, Inc."); |
| MODULE_DESCRIPTION("iMX virtio remote processor messaging pingpong driver"); |
| MODULE_LICENSE("GPL v2"); |