linux/drivers/usb/serial/opticon.c
Alan Stern f9c99bb8b3 USB: usb-serial: replace shutdown with disconnect, release
This patch (as1254) splits up the shutdown method of usb_serial_driver
into a disconnect and a release method.

The problem is that the usb-serial core was calling shutdown during
disconnect handling, but drivers didn't expect it to be called until
after all the open file references had been closed.  The result was an
oops when the close method tried to use memory that had been
deallocated by shutdown.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-06-15 21:44:47 -07:00

567 lines
14 KiB
C

/*
* Opticon USB barcode to serial driver
*
* Copyright (C) 2008 - 2009 Greg Kroah-Hartman <gregkh@suse.de>
* Copyright (C) 2008 - 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/serial.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(0x065a, 0x0009) },
{ },
};
MODULE_DEVICE_TABLE(usb, id_table);
/* This structure holds all of the individual device information */
struct opticon_private {
struct usb_device *udev;
struct usb_serial *serial;
struct usb_serial_port *port;
unsigned char *bulk_in_buffer;
struct urb *bulk_read_urb;
int buffer_size;
u8 bulk_address;
spinlock_t lock; /* protects the following flags */
bool throttled;
bool actually_throttled;
bool rts;
int outstanding_urbs;
};
/* max number of write urbs in flight */
#define URB_UPPER_LIMIT 4
static void opticon_bulk_callback(struct urb *urb)
{
struct opticon_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 > 2) {
data_length = urb->actual_length - 2;
/*
* Data from the device comes with a 2 byte header:
*
* <0x00><0x00>data...
* This is real data to be sent to the tty layer
* <0x00><0x01)level
* This is a RTS level change, the third byte is the RTS
* value (0 for low, 1 for high).
*/
if ((data[0] == 0x00) && (data[1] == 0x00)) {
/* real data, send it 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,
available_room);
tty_flip_buffer_push(tty);
}
tty_kref_put(tty);
}
} else {
if ((data[0] == 0x00) && (data[1] == 0x01)) {
if (data[2] == 0x00)
priv->rts = false;
else
priv->rts = true;
} else {
dev_dbg(&priv->udev->dev,
"Unknown data packet received from the device:"
" %2x %2x\n",
data[0], data[1]);
}
}
} 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_bulk_urb(priv->bulk_read_urb, priv->udev,
usb_rcvbulkpipe(priv->udev,
priv->bulk_address),
priv->bulk_in_buffer, priv->buffer_size,
opticon_bulk_callback, priv);
result = usb_submit_urb(port->read_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 opticon_open(struct tty_struct *tty, struct usb_serial_port *port,
struct file *filp)
{
struct opticon_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_bulk_urb(priv->bulk_read_urb, priv->udev,
usb_rcvbulkpipe(priv->udev,
priv->bulk_address),
priv->bulk_in_buffer, priv->buffer_size,
opticon_bulk_callback, priv);
result = usb_submit_urb(priv->bulk_read_urb, GFP_KERNEL);
if (result)
dev_err(&port->dev,
"%s - failed resubmitting read urb, error %d\n",
__func__, result);
return result;
}
static void opticon_close(struct usb_serial_port *port)
{
struct opticon_private *priv = usb_get_serial_data(port->serial);
dbg("%s - port %d", __func__, port->number);
/* shutdown our urbs */
usb_kill_urb(priv->bulk_read_urb);
}
static void opticon_write_bulk_callback(struct urb *urb)
{
struct opticon_private *priv = urb->context;
int status = urb->status;
unsigned long flags;
/* free up the transfer buffer, as usb_free_urb() does not do this */
kfree(urb->transfer_buffer);
if (status)
dbg("%s - nonzero write bulk status received: %d",
__func__, status);
spin_lock_irqsave(&priv->lock, flags);
--priv->outstanding_urbs;
spin_unlock_irqrestore(&priv->lock, flags);
usb_serial_port_softint(priv->port);
}
static int opticon_write(struct tty_struct *tty, struct usb_serial_port *port,
const unsigned char *buf, int count)
{
struct opticon_private *priv = usb_get_serial_data(port->serial);
struct usb_serial *serial = port->serial;
struct urb *urb;
unsigned char *buffer;
unsigned long flags;
int status;
dbg("%s - port %d", __func__, port->number);
spin_lock_irqsave(&priv->lock, flags);
if (priv->outstanding_urbs > URB_UPPER_LIMIT) {
spin_unlock_irqrestore(&priv->lock, flags);
dbg("%s - write limit hit\n", __func__);
return 0;
}
priv->outstanding_urbs++;
spin_unlock_irqrestore(&priv->lock, flags);
buffer = kmalloc(count, GFP_ATOMIC);
if (!buffer) {
dev_err(&port->dev, "out of memory\n");
count = -ENOMEM;
goto error_no_buffer;
}
urb = usb_alloc_urb(0, GFP_ATOMIC);
if (!urb) {
dev_err(&port->dev, "no more free urbs\n");
count = -ENOMEM;
goto error_no_urb;
}
memcpy(buffer, buf, count);
usb_serial_debug_data(debug, &port->dev, __func__, count, buffer);
usb_fill_bulk_urb(urb, serial->dev,
usb_sndbulkpipe(serial->dev,
port->bulk_out_endpointAddress),
buffer, count, opticon_write_bulk_callback, priv);
/* send it down the pipe */
status = usb_submit_urb(urb, GFP_ATOMIC);
if (status) {
dev_err(&port->dev,
"%s - usb_submit_urb(write bulk) failed with status = %d\n",
__func__, status);
count = status;
goto error;
}
/* we are done with this urb, so let the host driver
* really free it when it is finished with it */
usb_free_urb(urb);
return count;
error:
usb_free_urb(urb);
error_no_urb:
kfree(buffer);
error_no_buffer:
spin_lock_irqsave(&priv->lock, flags);
--priv->outstanding_urbs;
spin_unlock_irqrestore(&priv->lock, flags);
return count;
}
static int opticon_write_room(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
struct opticon_private *priv = usb_get_serial_data(port->serial);
unsigned long flags;
dbg("%s - port %d", __func__, port->number);
/*
* We really can take almost anything the user throws at us
* but let's pick a nice big number to tell the tty
* layer that we have lots of free space, unless we don't.
*/
spin_lock_irqsave(&priv->lock, flags);
if (priv->outstanding_urbs > URB_UPPER_LIMIT * 2 / 3) {
spin_unlock_irqrestore(&priv->lock, flags);
dbg("%s - write limit hit\n", __func__);
return 0;
}
spin_unlock_irqrestore(&priv->lock, flags);
return 2048;
}
static void opticon_throttle(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
struct opticon_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 opticon_unthrottle(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
struct opticon_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->bulk_read_urb->dev = port->serial->dev;
result = usb_submit_urb(priv->bulk_read_urb, GFP_ATOMIC);
if (result)
dev_err(&port->dev,
"%s - failed submitting read urb, error %d\n",
__func__, result);
}
static int opticon_tiocmget(struct tty_struct *tty, struct file *file)
{
struct usb_serial_port *port = tty->driver_data;
struct opticon_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);
if (priv->rts)
result = TIOCM_RTS;
spin_unlock_irqrestore(&priv->lock, flags);
dbg("%s - %x", __func__, result);
return result;
}
static int get_serial_info(struct opticon_private *priv,
struct serial_struct __user *serial)
{
struct serial_struct tmp;
if (!serial)
return -EFAULT;
memset(&tmp, 0x00, sizeof(tmp));
/* fake emulate a 16550 uart to make userspace code happy */
tmp.type = PORT_16550A;
tmp.line = priv->serial->minor;
tmp.port = 0;
tmp.irq = 0;
tmp.flags = ASYNC_SKIP_TEST | ASYNC_AUTO_IRQ;
tmp.xmit_fifo_size = 1024;
tmp.baud_base = 9600;
tmp.close_delay = 5*HZ;
tmp.closing_wait = 30*HZ;
if (copy_to_user(serial, &tmp, sizeof(*serial)))
return -EFAULT;
return 0;
}
static int opticon_ioctl(struct tty_struct *tty, struct file *file,
unsigned int cmd, unsigned long arg)
{
struct usb_serial_port *port = tty->driver_data;
struct opticon_private *priv = usb_get_serial_data(port->serial);
dbg("%s - port %d, cmd = 0x%x", __func__, port->number, cmd);
switch (cmd) {
case TIOCGSERIAL:
return get_serial_info(priv,
(struct serial_struct __user *)arg);
}
return -ENOIOCTLCMD;
}
static int opticon_startup(struct usb_serial *serial)
{
struct opticon_private *priv;
struct usb_host_interface *intf;
int i;
int retval = -ENOMEM;
bool bulk_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 bulk 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_bulk_in(endpoint))
continue;
priv->bulk_read_urb = usb_alloc_urb(0, GFP_KERNEL);
if (!priv->bulk_read_urb) {
dev_err(&priv->udev->dev, "out of memory\n");
goto error;
}
priv->buffer_size = le16_to_cpu(endpoint->wMaxPacketSize) * 2;
priv->bulk_in_buffer = kmalloc(priv->buffer_size, GFP_KERNEL);
if (!priv->bulk_in_buffer) {
dev_err(&priv->udev->dev, "out of memory\n");
goto error;
}
priv->bulk_address = endpoint->bEndpointAddress;
/* set up our bulk urb */
usb_fill_bulk_urb(priv->bulk_read_urb, priv->udev,
usb_rcvbulkpipe(priv->udev,
endpoint->bEndpointAddress),
priv->bulk_in_buffer, priv->buffer_size,
opticon_bulk_callback, priv);
bulk_in_found = true;
break;
}
if (!bulk_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->bulk_read_urb);
kfree(priv->bulk_in_buffer);
kfree(priv);
return retval;
}
static void opticon_disconnect(struct usb_serial *serial)
{
struct opticon_private *priv = usb_get_serial_data(serial);
dbg("%s", __func__);
usb_kill_urb(priv->bulk_read_urb);
usb_free_urb(priv->bulk_read_urb);
}
static void opticon_release(struct usb_serial *serial)
{
struct opticon_private *priv = usb_get_serial_data(serial);
dbg("%s", __func__);
kfree(priv->bulk_in_buffer);
kfree(priv);
}
static int opticon_suspend(struct usb_interface *intf, pm_message_t message)
{
struct usb_serial *serial = usb_get_intfdata(intf);
struct opticon_private *priv = usb_get_serial_data(serial);
usb_kill_urb(priv->bulk_read_urb);
return 0;
}
static int opticon_resume(struct usb_interface *intf)
{
struct usb_serial *serial = usb_get_intfdata(intf);
struct opticon_private *priv = usb_get_serial_data(serial);
struct usb_serial_port *port = serial->port[0];
int result;
mutex_lock(&port->mutex);
if (port->port.count)
result = usb_submit_urb(priv->bulk_read_urb, GFP_NOIO);
else
result = 0;
mutex_unlock(&port->mutex);
return result;
}
static struct usb_driver opticon_driver = {
.name = "opticon",
.probe = usb_serial_probe,
.disconnect = usb_serial_disconnect,
.suspend = opticon_suspend,
.resume = opticon_resume,
.id_table = id_table,
.no_dynamic_id = 1,
};
static struct usb_serial_driver opticon_device = {
.driver = {
.owner = THIS_MODULE,
.name = "opticon",
},
.id_table = id_table,
.usb_driver = &opticon_driver,
.num_ports = 1,
.attach = opticon_startup,
.open = opticon_open,
.close = opticon_close,
.write = opticon_write,
.write_room = opticon_write_room,
.disconnect = opticon_disconnect,
.release = opticon_release,
.throttle = opticon_throttle,
.unthrottle = opticon_unthrottle,
.ioctl = opticon_ioctl,
.tiocmget = opticon_tiocmget,
};
static int __init opticon_init(void)
{
int retval;
retval = usb_serial_register(&opticon_device);
if (retval)
return retval;
retval = usb_register(&opticon_driver);
if (retval)
usb_serial_deregister(&opticon_device);
return retval;
}
static void __exit opticon_exit(void)
{
usb_deregister(&opticon_driver);
usb_serial_deregister(&opticon_device);
}
module_init(opticon_init);
module_exit(opticon_exit);
MODULE_LICENSE("GPL");
module_param(debug, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(debug, "Debug enabled or not");