![Jiri Slaby](/assets/img/avatar_default.png)
Now, we start converting tty buffer functions to actually use tty_port. This will allow us to get rid of the need of tty in many call sites. Only tty_port will needed and hence no more tty_port_tty_get in those paths. Now, the one where most of tty_port_tty_get gets removed: tty_flip_buffer_push. IOW we also closed all the races in drivers not using tty_port_tty_get at all yet. Also we move tty_flip_buffer_push declaration from include/linux/tty.h to include/linux/tty_flip.h to all others while we are changing it anyway. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
237 lines
5.5 KiB
C
237 lines
5.5 KiB
C
/*
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* Copyright (C) 2007 Google, Inc.
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* Copyright (c) 2011, Code Aurora Forum. All rights reserved.
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* Author: Brian Swetland <swetland@google.com>
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*
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* This software is licensed under the terms of the GNU General Public
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* License version 2, as published by the Free Software Foundation, and
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* may be copied, distributed, and modified under those terms.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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*/
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#include <linux/module.h>
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#include <linux/fs.h>
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#include <linux/cdev.h>
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#include <linux/device.h>
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#include <linux/wait.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 <mach/msm_smd.h>
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#define MAX_SMD_TTYS 32
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struct smd_tty_info {
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struct tty_port port;
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smd_channel_t *ch;
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};
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struct smd_tty_channel_desc {
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int id;
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const char *name;
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};
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static struct smd_tty_info smd_tty[MAX_SMD_TTYS];
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static const struct smd_tty_channel_desc smd_default_tty_channels[] = {
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{ .id = 0, .name = "SMD_DS" },
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{ .id = 27, .name = "SMD_GPSNMEA" },
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};
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static const struct smd_tty_channel_desc *smd_tty_channels =
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smd_default_tty_channels;
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static int smd_tty_channels_len = ARRAY_SIZE(smd_default_tty_channels);
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static void smd_tty_notify(void *priv, unsigned event)
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{
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unsigned char *ptr;
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int avail;
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struct smd_tty_info *info = priv;
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struct tty_struct *tty;
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if (event != SMD_EVENT_DATA)
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return;
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tty = tty_port_tty_get(&info->port);
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if (!tty)
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return;
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for (;;) {
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if (test_bit(TTY_THROTTLED, &tty->flags))
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break;
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avail = smd_read_avail(info->ch);
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if (avail == 0)
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break;
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avail = tty_prepare_flip_string(&info->port, &ptr, avail);
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if (smd_read(info->ch, ptr, avail) != avail) {
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/* shouldn't be possible since we're in interrupt
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** context here and nobody else could 'steal' our
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** characters.
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*/
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pr_err("OOPS - smd_tty_buffer mismatch?!");
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}
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tty_flip_buffer_push(&info->port);
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}
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/* XXX only when writable and necessary */
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tty_wakeup(tty);
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tty_kref_put(tty);
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}
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static int smd_tty_port_activate(struct tty_port *tport, struct tty_struct *tty)
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{
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int i, res = 0;
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int n = tty->index;
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const char *name = NULL;
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struct smd_tty_info *info = smd_tty + n;
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for (i = 0; i < smd_tty_channels_len; i++) {
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if (smd_tty_channels[i].id == n) {
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name = smd_tty_channels[i].name;
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break;
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}
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}
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if (!name)
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return -ENODEV;
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if (info->ch)
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smd_kick(info->ch);
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else
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res = smd_open(name, &info->ch, info, smd_tty_notify);
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if (!res)
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tty->driver_data = info;
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return res;
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}
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static void smd_tty_port_shutdown(struct tty_port *tport)
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{
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struct smd_tty_info *info;
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struct tty_struct *tty = tty_port_tty_get(tport);
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info = tty->driver_data;
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if (info->ch) {
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smd_close(info->ch);
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info->ch = 0;
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}
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tty->driver_data = 0;
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tty_kref_put(tty);
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}
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static int smd_tty_open(struct tty_struct *tty, struct file *f)
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{
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struct smd_tty_info *info = smd_tty + tty->index;
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return tty_port_open(&info->port, tty, f);
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}
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static void smd_tty_close(struct tty_struct *tty, struct file *f)
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{
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struct smd_tty_info *info = tty->driver_data;
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tty_port_close(&info->port, tty, f);
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}
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static int smd_tty_write(struct tty_struct *tty,
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const unsigned char *buf, int len)
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{
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struct smd_tty_info *info = tty->driver_data;
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int avail;
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/* if we're writing to a packet channel we will
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** never be able to write more data than there
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** is currently space for
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*/
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avail = smd_write_avail(info->ch);
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if (len > avail)
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len = avail;
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return smd_write(info->ch, buf, len);
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}
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static int smd_tty_write_room(struct tty_struct *tty)
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{
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struct smd_tty_info *info = tty->driver_data;
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return smd_write_avail(info->ch);
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}
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static int smd_tty_chars_in_buffer(struct tty_struct *tty)
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{
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struct smd_tty_info *info = tty->driver_data;
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return smd_read_avail(info->ch);
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}
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static void smd_tty_unthrottle(struct tty_struct *tty)
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{
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struct smd_tty_info *info = tty->driver_data;
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smd_kick(info->ch);
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}
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static const struct tty_port_operations smd_tty_port_ops = {
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.shutdown = smd_tty_port_shutdown,
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.activate = smd_tty_port_activate,
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};
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static const struct tty_operations smd_tty_ops = {
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.open = smd_tty_open,
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.close = smd_tty_close,
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.write = smd_tty_write,
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.write_room = smd_tty_write_room,
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.chars_in_buffer = smd_tty_chars_in_buffer,
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.unthrottle = smd_tty_unthrottle,
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};
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static struct tty_driver *smd_tty_driver;
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static int __init smd_tty_init(void)
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{
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int ret, i;
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smd_tty_driver = alloc_tty_driver(MAX_SMD_TTYS);
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if (smd_tty_driver == 0)
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return -ENOMEM;
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smd_tty_driver->driver_name = "smd_tty_driver";
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smd_tty_driver->name = "smd";
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smd_tty_driver->major = 0;
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smd_tty_driver->minor_start = 0;
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smd_tty_driver->type = TTY_DRIVER_TYPE_SERIAL;
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smd_tty_driver->subtype = SERIAL_TYPE_NORMAL;
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smd_tty_driver->init_termios = tty_std_termios;
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smd_tty_driver->init_termios.c_iflag = 0;
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smd_tty_driver->init_termios.c_oflag = 0;
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smd_tty_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
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smd_tty_driver->init_termios.c_lflag = 0;
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smd_tty_driver->flags = TTY_DRIVER_RESET_TERMIOS |
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TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
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tty_set_operations(smd_tty_driver, &smd_tty_ops);
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ret = tty_register_driver(smd_tty_driver);
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if (ret)
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return ret;
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for (i = 0; i < smd_tty_channels_len; i++) {
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struct tty_port *port = &smd_tty[smd_tty_channels[i].id].port;
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tty_port_init(port);
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port->ops = &smd_tty_port_ops;
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tty_port_register_device(port, smd_tty_driver,
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smd_tty_channels[i].id, NULL);
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}
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return 0;
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}
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module_init(smd_tty_init);
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