253 lines
6.3 KiB
C
253 lines
6.3 KiB
C
/*
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* Copyright (C) 2015-2016 Freescale Semiconductor, Inc.
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* Copyright (C) 2017 NXP
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*
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* derived from the omap-rpmsg implementation.
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* Remote processor messaging transport - tty driver
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*
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* The code contained herein is licensed under the GNU General Public
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* License. You may obtain a copy of the GNU General Public License
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* Version 2 or later at the following locations:
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*
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* http://www.opensource.org/licenses/gpl-license.html
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* http://www.gnu.org/copyleft/gpl.html
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*/
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#include <linux/delay.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/rpmsg.h>
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#include <linux/tty.h>
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#include <linux/tty_driver.h>
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#include <linux/tty_flip.h>
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#include <linux/virtio.h>
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/* this needs to be less then (RPMSG_BUF_SIZE - sizeof(struct rpmsg_hdr)) */
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#define RPMSG_MAX_SIZE 256
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#define MSG "hello world!"
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/*
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* struct rpmsgtty_port - Wrapper struct for imx rpmsg tty port.
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* @port: TTY port data
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*/
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struct rpmsgtty_port {
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struct tty_port port;
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spinlock_t rx_lock;
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struct rpmsg_device *rpdev;
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struct tty_driver *rpmsgtty_driver;
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};
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static int rpmsg_tty_cb(struct rpmsg_device *rpdev, void *data, int len,
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void *priv, u32 src)
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{
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int space;
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unsigned char *cbuf;
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struct rpmsgtty_port *cport = dev_get_drvdata(&rpdev->dev);
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/* flush the recv-ed none-zero data to tty node */
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if (len == 0)
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return 0;
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dev_dbg(&rpdev->dev, "msg(<- src 0x%x) len %d\n", src, len);
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print_hex_dump(KERN_DEBUG, __func__, DUMP_PREFIX_NONE, 16, 1,
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data, len, true);
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spin_lock_bh(&cport->rx_lock);
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space = tty_prepare_flip_string(&cport->port, &cbuf, len);
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if (space <= 0) {
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dev_err(&rpdev->dev, "No memory for tty_prepare_flip_string\n");
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spin_unlock_bh(&cport->rx_lock);
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return -ENOMEM;
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}
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memcpy(cbuf, data, len);
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tty_flip_buffer_push(&cport->port);
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spin_unlock_bh(&cport->rx_lock);
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return 0;
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}
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static struct tty_port_operations rpmsgtty_port_ops = { };
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static int rpmsgtty_install(struct tty_driver *driver, struct tty_struct *tty)
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{
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struct rpmsgtty_port *cport = driver->driver_state;
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return tty_port_install(&cport->port, driver, tty);
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}
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static int rpmsgtty_open(struct tty_struct *tty, struct file *filp)
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{
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return tty_port_open(tty->port, tty, filp);
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}
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static void rpmsgtty_close(struct tty_struct *tty, struct file *filp)
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{
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return tty_port_close(tty->port, tty, filp);
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}
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static int rpmsgtty_write(struct tty_struct *tty, const unsigned char *buf,
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int total)
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{
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int count, ret = 0;
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const unsigned char *tbuf;
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struct rpmsgtty_port *rptty_port = container_of(tty->port,
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struct rpmsgtty_port, port);
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struct rpmsg_device *rpdev = rptty_port->rpdev;
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if (NULL == buf) {
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pr_err("buf shouldn't be null.\n");
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return -ENOMEM;
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}
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count = total;
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tbuf = buf;
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do {
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/* send a message to our remote processor */
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ret = rpmsg_send(rpdev->ept, (void *)tbuf,
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count > RPMSG_MAX_SIZE ? RPMSG_MAX_SIZE : count);
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if (ret) {
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dev_err(&rpdev->dev, "rpmsg_send failed: %d\n", ret);
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return ret;
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}
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if (count > RPMSG_MAX_SIZE) {
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count -= RPMSG_MAX_SIZE;
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tbuf += RPMSG_MAX_SIZE;
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} else {
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count = 0;
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}
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} while (count > 0);
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return total;
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}
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static int rpmsgtty_write_room(struct tty_struct *tty)
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{
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/* report the space in the rpmsg buffer */
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return RPMSG_MAX_SIZE;
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}
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static const struct tty_operations imxrpmsgtty_ops = {
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.install = rpmsgtty_install,
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.open = rpmsgtty_open,
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.close = rpmsgtty_close,
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.write = rpmsgtty_write,
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.write_room = rpmsgtty_write_room,
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};
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static int rpmsg_tty_probe(struct rpmsg_device *rpdev)
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{
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int ret;
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struct rpmsgtty_port *cport;
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struct tty_driver *rpmsgtty_driver;
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dev_info(&rpdev->dev, "new channel: 0x%x -> 0x%x!\n",
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rpdev->src, rpdev->dst);
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cport = devm_kzalloc(&rpdev->dev, sizeof(*cport), GFP_KERNEL);
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if (!cport)
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return -ENOMEM;
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rpmsgtty_driver = tty_alloc_driver(1, TTY_DRIVER_UNNUMBERED_NODE);
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if (IS_ERR(rpmsgtty_driver)) {
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kfree(cport);
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return PTR_ERR(rpmsgtty_driver);
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}
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rpmsgtty_driver->driver_name = "rpmsg_tty";
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rpmsgtty_driver->name = kasprintf(GFP_KERNEL, "ttyRPMSG%d", rpdev->dst);
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rpmsgtty_driver->major = UNNAMED_MAJOR;
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rpmsgtty_driver->minor_start = 0;
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rpmsgtty_driver->type = TTY_DRIVER_TYPE_CONSOLE;
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rpmsgtty_driver->init_termios = tty_std_termios;
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tty_set_operations(rpmsgtty_driver, &imxrpmsgtty_ops);
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tty_port_init(&cport->port);
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cport->port.ops = &rpmsgtty_port_ops;
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spin_lock_init(&cport->rx_lock);
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cport->port.low_latency = cport->port.flags | ASYNC_LOW_LATENCY;
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cport->rpdev = rpdev;
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dev_set_drvdata(&rpdev->dev, cport);
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rpmsgtty_driver->driver_state = cport;
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cport->rpmsgtty_driver = rpmsgtty_driver;
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ret = tty_register_driver(cport->rpmsgtty_driver);
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if (ret < 0) {
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pr_err("Couldn't install rpmsg tty driver: ret %d\n", ret);
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goto error1;
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} else {
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pr_info("Install rpmsg tty driver!\n");
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}
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/*
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* send a message to our remote processor, and tell remote
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* processor about this channel
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*/
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ret = rpmsg_send(rpdev->ept, MSG, strlen(MSG));
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if (ret) {
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dev_err(&rpdev->dev, "rpmsg_send failed: %d\n", ret);
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goto error;
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}
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return 0;
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error:
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tty_unregister_driver(cport->rpmsgtty_driver);
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error1:
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put_tty_driver(cport->rpmsgtty_driver);
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tty_port_destroy(&cport->port);
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cport->rpmsgtty_driver = NULL;
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kfree(cport);
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return ret;
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}
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static void rpmsg_tty_remove(struct rpmsg_device *rpdev)
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{
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struct rpmsgtty_port *cport = dev_get_drvdata(&rpdev->dev);
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dev_info(&rpdev->dev, "rpmsg tty driver is removed\n");
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tty_unregister_driver(cport->rpmsgtty_driver);
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kfree(cport->rpmsgtty_driver->name);
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put_tty_driver(cport->rpmsgtty_driver);
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tty_port_destroy(&cport->port);
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cport->rpmsgtty_driver = NULL;
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}
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static struct rpmsg_device_id rpmsg_driver_tty_id_table[] = {
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{ .name = "rpmsg-virtual-tty-channel-1" },
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{ .name = "rpmsg-virtual-tty-channel" },
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{ .name = "rpmsg-openamp-demo-channel" },
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{ },
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};
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MODULE_DEVICE_TABLE(rpmsg, rpmsg_driver_tty_id_table);
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static struct rpmsg_driver rpmsg_tty_driver = {
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.drv.name = KBUILD_MODNAME,
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.drv.owner = THIS_MODULE,
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.id_table = rpmsg_driver_tty_id_table,
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.probe = rpmsg_tty_probe,
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.callback = rpmsg_tty_cb,
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.remove = rpmsg_tty_remove,
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};
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static int __init init(void)
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{
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return register_rpmsg_driver(&rpmsg_tty_driver);
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}
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static void __exit fini(void)
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{
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unregister_rpmsg_driver(&rpmsg_tty_driver);
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}
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module_init(init);
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module_exit(fini);
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MODULE_AUTHOR("Freescale Semiconductor, Inc.");
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MODULE_DESCRIPTION("iMX virtio remote processor messaging tty driver");
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MODULE_LICENSE("GPL v2");
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