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// SPDX-License-Identifier: GPL-2.0
/*
* Symbol USB barcode to serial driver
*
* Copyright (C) 2013 Johan Hovold <jhovold@gmail.com>
* Copyright (C) 2009 Greg Kroah-Hartman <gregkh@suse.de>
* Copyright (C) 2009 Novell Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version
* 2 as published by the Free Software Foundation.
*/
#include <linux/kernel.h>
#include <linux/tty.h>
#include <linux/slab.h>
#include <linux/tty_driver.h>
#include <linux/tty_flip.h>
#include <linux/module.h>
#include <linux/usb.h>
#include <linux/usb/serial.h>
#include <linux/uaccess.h>
static const struct usb_device_id id_table[] = {
{ USB_DEVICE(0x05e0, 0x0600) },
{ },
};
MODULE_DEVICE_TABLE(usb, id_table);
struct symbol_private {
spinlock_t lock; /* protects the following flags */
bool throttled;
bool actually_throttled;
};
static void symbol_int_callback(struct urb *urb)
{
struct usb_serial_port *port = urb->context;
struct symbol_private *priv = usb_get_serial_port_data(port);
unsigned char *data = urb->transfer_buffer;
int status = urb->status;
int result;
int data_length;
switch (status) {
case 0:
/* success */
break;
case -ECONNRESET:
case -ENOENT:
case -ESHUTDOWN:
/* this urb is terminated, clean up */
dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
__func__, status);
return;
default:
dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
__func__, status);
goto exit;
}
usb_serial_debug_data(&port->dev, __func__, urb->actual_length, data);
/*
* Data from the device comes with a 1 byte header:
*
* <size of data> <data>...
*/
if (urb->actual_length > 1) {
data_length = data[0];
if (data_length > (urb->actual_length - 1))
data_length = urb->actual_length - 1;
tty_insert_flip_string(&port->port, &data[1], data_length);
tty_flip_buffer_push(&port->port);
} else {
dev_dbg(&port->dev, "%s - short packet\n", __func__);
}
exit:
spin_lock(&priv->lock);
/* Continue trying to always read if we should */
if (!priv->throttled) {
result = usb_submit_urb(port->interrupt_in_urb, GFP_ATOMIC);
if (result)
dev_err(&port->dev,
"%s - failed resubmitting read urb, error %d\n",
__func__, result);
} else
priv->actually_throttled = true;
spin_unlock(&priv->lock);
}
static int symbol_open(struct tty_struct *tty, struct usb_serial_port *port)
{
struct symbol_private *priv = usb_get_serial_port_data(port);
unsigned long flags;
int result = 0;
spin_lock_irqsave(&priv->lock, flags);
priv->throttled = false;
priv->actually_throttled = false;
spin_unlock_irqrestore(&priv->lock, flags);
/* Start reading from the device */
result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
if (result)
dev_err(&port->dev,
"%s - failed resubmitting read urb, error %d\n",
__func__, result);
return result;
}
static void symbol_close(struct usb_serial_port *port)
{
usb_kill_urb(port->interrupt_in_urb);
}
static void symbol_throttle(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
struct symbol_private *priv = usb_get_serial_port_data(port);
spin_lock_irq(&priv->lock);
priv->throttled = true;
spin_unlock_irq(&priv->lock);
}
static void symbol_unthrottle(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
struct symbol_private *priv = usb_get_serial_port_data(port);
int result;
bool was_throttled;
spin_lock_irq(&priv->lock);
priv->throttled = false;
was_throttled = priv->actually_throttled;
priv->actually_throttled = false;
spin_unlock_irq(&priv->lock);
if (was_throttled) {
result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
if (result)
dev_err(&port->dev,
"%s - failed submitting read urb, error %d\n",
__func__, result);
}
}
static int symbol_port_probe(struct usb_serial_port *port)
{
struct symbol_private *priv;
priv = kzalloc(sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
spin_lock_init(&priv->lock);
usb_set_serial_port_data(port, priv);
return 0;
}
static int symbol_port_remove(struct usb_serial_port *port)
{
struct symbol_private *priv = usb_get_serial_port_data(port);
kfree(priv);
return 0;
}
static struct usb_serial_driver symbol_device = {
.driver = {
.owner = THIS_MODULE,
.name = "symbol",
},
.id_table = id_table,
.num_ports = 1,
.num_interrupt_in = 1,
.port_probe = symbol_port_probe,
.port_remove = symbol_port_remove,
.open = symbol_open,
.close = symbol_close,
.throttle = symbol_throttle,
.unthrottle = symbol_unthrottle,
.read_int_callback = symbol_int_callback,
};
static struct usb_serial_driver * const serial_drivers[] = {
&symbol_device, NULL
};
module_usb_serial_driver(serial_drivers, id_table);
MODULE_LICENSE("GPL");
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