android_kernel_xiaomi_sm8350/drivers/usb/serial/symbolserial.c
Alan Cox 22654b41a7 symbol: Remove various bits of left over junk
There are various bits of code here that are unfinished and instead of
being harmless either confuse or spew stuff into the logs at higher than
debug level. They can and should go away.

Also remove the bogus use of tty->lowlatency. We fixed the need for this hack
long ago (with the flip buffer rewrite) but people keep copying it into drivers.

Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-06 14:36:42 -07:00

333 lines
8.1 KiB
C

/*
* Symbol USB barcode to serial driver
*
* 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/init.h>
#include <linux/tty.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 int debug;
static struct usb_device_id id_table[] = {
{ USB_DEVICE(0x05e0, 0x0600) },
{ },
};
MODULE_DEVICE_TABLE(usb, id_table);
/* This structure holds all of the individual device information */
struct symbol_private {
struct usb_device *udev;
struct usb_serial *serial;
struct usb_serial_port *port;
unsigned char *int_buffer;
struct urb *int_urb;
int buffer_size;
u8 bInterval;
u8 int_address;
spinlock_t lock; /* protects the following flags */
bool throttled;
bool actually_throttled;
bool rts;
};
static void symbol_int_callback(struct urb *urb)
{
struct symbol_private *priv = urb->context;
unsigned char *data = urb->transfer_buffer;
struct usb_serial_port *port = priv->port;
int status = urb->status;
struct tty_struct *tty;
int result;
int available_room = 0;
int data_length;
dbg("%s - port %d", __func__, port->number);
switch (status) {
case 0:
/* success */
break;
case -ECONNRESET:
case -ENOENT:
case -ESHUTDOWN:
/* this urb is terminated, clean up */
dbg("%s - urb shutting down with status: %d",
__func__, status);
return;
default:
dbg("%s - nonzero urb status received: %d",
__func__, status);
goto exit;
}
usb_serial_debug_data(debug, &port->dev, __func__, urb->actual_length,
data);
if (urb->actual_length > 1) {
data_length = urb->actual_length - 1;
/*
* Data from the device comes with a 1 byte header:
*
* <size of data>data...
* This is real data to be sent to the tty layer
* we pretty much just ignore the size and send everything
* else to the tty layer.
*/
tty = tty_port_tty_get(&port->port);
if (tty) {
available_room = tty_buffer_request_room(tty,
data_length);
if (available_room) {
tty_insert_flip_string(tty, &data[1],
available_room);
tty_flip_buffer_push(tty);
}
tty_kref_put(tty);
}
} else {
dev_dbg(&priv->udev->dev,
"Improper ammount of data received from the device, "
"%d bytes", urb->actual_length);
}
exit:
spin_lock(&priv->lock);
/* Continue trying to always read if we should */
if (!priv->throttled) {
usb_fill_int_urb(priv->int_urb, priv->udev,
usb_rcvintpipe(priv->udev,
priv->int_address),
priv->int_buffer, priv->buffer_size,
symbol_int_callback, priv, priv->bInterval);
result = usb_submit_urb(priv->int_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 file *filp)
{
struct symbol_private *priv = usb_get_serial_data(port->serial);
unsigned long flags;
int result = 0;
dbg("%s - port %d", __func__, port->number);
spin_lock_irqsave(&priv->lock, flags);
priv->throttled = false;
priv->actually_throttled = false;
priv->port = port;
spin_unlock_irqrestore(&priv->lock, flags);
/* Start reading from the device */
usb_fill_int_urb(priv->int_urb, priv->udev,
usb_rcvintpipe(priv->udev, priv->int_address),
priv->int_buffer, priv->buffer_size,
symbol_int_callback, priv, priv->bInterval);
result = usb_submit_urb(priv->int_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 tty_struct *tty, struct usb_serial_port *port,
struct file *filp)
{
struct symbol_private *priv = usb_get_serial_data(port->serial);
dbg("%s - port %d", __func__, port->number);
/* shutdown our urbs */
usb_kill_urb(priv->int_urb);
}
static void symbol_throttle(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
struct symbol_private *priv = usb_get_serial_data(port->serial);
unsigned long flags;
dbg("%s - port %d", __func__, port->number);
spin_lock_irqsave(&priv->lock, flags);
priv->throttled = true;
spin_unlock_irqrestore(&priv->lock, flags);
}
static void symbol_unthrottle(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
struct symbol_private *priv = usb_get_serial_data(port->serial);
unsigned long flags;
int result;
dbg("%s - port %d", __func__, port->number);
spin_lock_irqsave(&priv->lock, flags);
priv->throttled = false;
priv->actually_throttled = false;
spin_unlock_irqrestore(&priv->lock, flags);
priv->int_urb->dev = port->serial->dev;
result = usb_submit_urb(priv->int_urb, GFP_ATOMIC);
if (result)
dev_err(&port->dev,
"%s - failed submitting read urb, error %d\n",
__func__, result);
}
static int symbol_startup(struct usb_serial *serial)
{
struct symbol_private *priv;
struct usb_host_interface *intf;
int i;
int retval = -ENOMEM;
bool int_in_found = false;
/* create our private serial structure */
priv = kzalloc(sizeof(*priv), GFP_KERNEL);
if (priv == NULL) {
dev_err(&serial->dev->dev, "%s - Out of memory\n", __func__);
return -ENOMEM;
}
spin_lock_init(&priv->lock);
priv->serial = serial;
priv->port = serial->port[0];
priv->udev = serial->dev;
/* find our interrupt endpoint */
intf = serial->interface->altsetting;
for (i = 0; i < intf->desc.bNumEndpoints; ++i) {
struct usb_endpoint_descriptor *endpoint;
endpoint = &intf->endpoint[i].desc;
if (!usb_endpoint_is_int_in(endpoint))
continue;
priv->int_urb = usb_alloc_urb(0, GFP_KERNEL);
if (!priv->int_urb) {
dev_err(&priv->udev->dev, "out of memory\n");
goto error;
}
priv->buffer_size = le16_to_cpu(endpoint->wMaxPacketSize) * 2;
priv->int_buffer = kmalloc(priv->buffer_size, GFP_KERNEL);
if (!priv->int_buffer) {
dev_err(&priv->udev->dev, "out of memory\n");
goto error;
}
priv->int_address = endpoint->bEndpointAddress;
priv->bInterval = endpoint->bInterval;
/* set up our int urb */
usb_fill_int_urb(priv->int_urb, priv->udev,
usb_rcvintpipe(priv->udev,
endpoint->bEndpointAddress),
priv->int_buffer, priv->buffer_size,
symbol_int_callback, priv, priv->bInterval);
int_in_found = true;
break;
}
if (!int_in_found) {
dev_err(&priv->udev->dev,
"Error - the proper endpoints were not found!\n");
goto error;
}
usb_set_serial_data(serial, priv);
return 0;
error:
usb_free_urb(priv->int_urb);
kfree(priv->int_buffer);
kfree(priv);
return retval;
}
static void symbol_shutdown(struct usb_serial *serial)
{
struct symbol_private *priv = usb_get_serial_data(serial);
dbg("%s", __func__);
usb_kill_urb(priv->int_urb);
usb_free_urb(priv->int_urb);
kfree(priv->int_buffer);
kfree(priv);
usb_set_serial_data(serial, NULL);
}
static struct usb_driver symbol_driver = {
.name = "symbol",
.probe = usb_serial_probe,
.disconnect = usb_serial_disconnect,
.id_table = id_table,
.no_dynamic_id = 1,
};
static struct usb_serial_driver symbol_device = {
.driver = {
.owner = THIS_MODULE,
.name = "symbol",
},
.id_table = id_table,
.usb_driver = &symbol_driver,
.num_ports = 1,
.attach = symbol_startup,
.open = symbol_open,
.close = symbol_close,
.shutdown = symbol_shutdown,
.throttle = symbol_throttle,
.unthrottle = symbol_unthrottle,
};
static int __init symbol_init(void)
{
int retval;
retval = usb_serial_register(&symbol_device);
if (retval)
return retval;
retval = usb_register(&symbol_driver);
if (retval)
usb_serial_deregister(&symbol_device);
return retval;
}
static void __exit symbol_exit(void)
{
usb_deregister(&symbol_driver);
usb_serial_deregister(&symbol_device);
}
module_init(symbol_init);
module_exit(symbol_exit);
MODULE_LICENSE("GPL");
module_param(debug, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug, "Debug enabled or not");