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Commit 4272568b authored by Johan Hovold's avatar Johan Hovold Committed by Greg Kroah-Hartman
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USB: aircable: rewrite using generic read and write implementations 

Kill circular buffers for tx and rx as well as read work thread, and
switch to generic kfifo-based write implementation.

This is an example of how prepare_write_buffer and process_read_urb can
be used to handle protocols with packet headers.

Please note the diffstat which shows that the same functionality is now
provided using only a tenth of the code (including whitespace and
comments, though).
Tested-by: default avatarNaranjo, Manuel Francisco <naranjo.manuel@gmail.com>
Signed-off-by: default avatarJohan Hovold <jhovold@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent e8770484
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Showing with 47 additions and 453 deletions
drivers/usb/serial/aircable.c
View file @ 4272568b
/*
* AIRcable USB Bluetooth Dongle Driver.
*
* Copyright (C) 2010 Johan Hovold <jhovold@gmail.com>
* Copyright (C) 2006 Manuel Francisco Naranjo (naranjo.manuel@gmail.com)
*
* 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.
......@@ -42,10 +44,10 @@
*
*/
#include <asm/unaligned.h>
#include <linux/tty.h>
#include <linux/slab.h>
#include <linux/tty_flip.h>
#include <linux/circ_buf.h>
#include <linux/usb.h>
#include <linux/usb/serial.h>
......@@ -55,16 +57,12 @@ static int debug;
#define AIRCABLE_VID 0x16CA
#define AIRCABLE_USB_PID 0x1502
/* write buffer size defines */
#define AIRCABLE_BUF_SIZE 2048
/* Protocol Stuff */
#define HCI_HEADER_LENGTH 0x4
#define TX_HEADER_0 0x20
#define TX_HEADER_1 0x29
#define RX_HEADER_0 0x00
#define RX_HEADER_1 0x20
#define MAX_HCI_FRAMESIZE 60
#define HCI_COMPLETE_FRAME 64
/* rx_flags */
......@@ -74,8 +72,8 @@ static int debug;
/*
* Version Information
*/
#define DRIVER_VERSION "v1.0b2"
#define DRIVER_AUTHOR "Naranjo, Manuel Francisco <naranjo.manuel@gmail.com>"
#define DRIVER_VERSION "v2.0"
#define DRIVER_AUTHOR "Naranjo, Manuel Francisco <naranjo.manuel@gmail.com>, Johan Hovold <jhovold@gmail.com>"
#define DRIVER_DESC "AIRcable USB Driver"
/* ID table that will be registered with USB core */
......@@ -85,225 +83,19 @@ static const struct usb_device_id id_table[] = {
};
MODULE_DEVICE_TABLE(usb, id_table);
/* Internal Structure */
struct aircable_private {
spinlock_t rx_lock; /* spinlock for the receive lines */
struct circ_buf *tx_buf; /* write buffer */
struct circ_buf *rx_buf; /* read buffer */
int rx_flags; /* for throttilng */
struct work_struct rx_work; /* work cue for the receiving line */
struct usb_serial_port *port; /* USB port with which associated */
};
/* Private methods */
/* Circular Buffer Methods, code from ti_usb_3410_5052 used */
/*
* serial_buf_clear
*
* Clear out all data in the circular buffer.
*/
static void serial_buf_clear(struct circ_buf *cb)
{
cb->head = cb->tail = 0;
}
/*
* serial_buf_alloc
*
* Allocate a circular buffer and all associated memory.
*/
static struct circ_buf *serial_buf_alloc(void)
{
struct circ_buf *cb;
cb = kmalloc(sizeof(struct circ_buf), GFP_KERNEL);
if (cb == NULL)
return NULL;
cb->buf = kmalloc(AIRCABLE_BUF_SIZE, GFP_KERNEL);
if (cb->buf == NULL) {
kfree(cb);
return NULL;
}
serial_buf_clear(cb);
return cb;
}
/*
* serial_buf_free
*
* Free the buffer and all associated memory.
*/
static void serial_buf_free(struct circ_buf *cb)
{
kfree(cb->buf);
kfree(cb);
}
/*
* serial_buf_data_avail
*
* Return the number of bytes of data available in the circular
* buffer.
*/
static int serial_buf_data_avail(struct circ_buf *cb)
{
return CIRC_CNT(cb->head, cb->tail, AIRCABLE_BUF_SIZE);
}
/*
* serial_buf_put
*
* Copy data data from a user buffer and put it into the circular buffer.
* Restrict to the amount of space available.
*
* Return the number of bytes copied.
*/
static int serial_buf_put(struct circ_buf *cb, const char *buf, int count)
{
int c, ret = 0;
while (1) {
c = CIRC_SPACE_TO_END(cb->head, cb->tail, AIRCABLE_BUF_SIZE);
if (count < c)
c = count;
if (c <= 0)
break;
memcpy(cb->buf + cb->head, buf, c);
cb->head = (cb->head + c) & (AIRCABLE_BUF_SIZE-1);
buf += c;
count -= c;
ret = c;
}
return ret;
}
/*
* serial_buf_get
*
* Get data from the circular buffer and copy to the given buffer.
* Restrict to the amount of data available.
*
* Return the number of bytes copied.
*/
static int serial_buf_get(struct circ_buf *cb, char *buf, int count)
static int aircable_prepare_write_buffer(struct usb_serial_port *port,
void **dest, size_t size, const void *src, size_t count)
{
int c, ret = 0;
while (1) {
c = CIRC_CNT_TO_END(cb->head, cb->tail, AIRCABLE_BUF_SIZE);
if (count < c)
c = count;
if (c <= 0)
break;
memcpy(buf, cb->buf + cb->tail, c);
cb->tail = (cb->tail + c) & (AIRCABLE_BUF_SIZE-1);
buf += c;
count -= c;
ret = c;
}
return ret;
}
/* End of circula buffer methods */
static void aircable_send(struct usb_serial_port *port)
{
int count, result;
struct aircable_private *priv = usb_get_serial_port_data(port);
unsigned char *buf;
__le16 *dbuf;
dbg("%s - port %d", __func__, port->number);
if (port->write_urb_busy)
return;
count = min(serial_buf_data_avail(priv->tx_buf), MAX_HCI_FRAMESIZE);
if (count == 0)
return;
buf = kzalloc(count + HCI_HEADER_LENGTH, GFP_ATOMIC);
if (!buf) {
dev_err(&port->dev, "%s- kzalloc(%d) failed.\n",
__func__, count + HCI_HEADER_LENGTH);
return;
}
unsigned char *buf = *dest;
count = kfifo_out_locked(&port->write_fifo, buf + HCI_HEADER_LENGTH,
size - HCI_HEADER_LENGTH, &port->lock);
buf[0] = TX_HEADER_0;
buf[1] = TX_HEADER_1;
dbuf = (__le16 *)&buf[2];
*dbuf = cpu_to_le16((u16)count);
serial_buf_get(priv->tx_buf, buf + HCI_HEADER_LENGTH,
MAX_HCI_FRAMESIZE);
memcpy(port->write_urb->transfer_buffer, buf,
count + HCI_HEADER_LENGTH);
kfree(buf);
port->write_urb_busy = 1;
usb_serial_debug_data(debug, &port->dev, __func__,
count + HCI_HEADER_LENGTH,
port->write_urb->transfer_buffer);
port->write_urb->transfer_buffer_length = count + HCI_HEADER_LENGTH;
port->write_urb->dev = port->serial->dev;
result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
if (result) {
dev_err(&port->dev,
"%s - failed submitting write urb, error %d\n",
__func__, result);
port->write_urb_busy = 0;
}
schedule_work(&port->work);
}
static void aircable_read(struct work_struct *work)
{
struct aircable_private *priv =
container_of(work, struct aircable_private, rx_work);
struct usb_serial_port *port = priv->port;
struct tty_struct *tty;
unsigned char *data;
int count;
if (priv->rx_flags & THROTTLED) {
if (priv->rx_flags & ACTUALLY_THROTTLED)
schedule_work(&priv->rx_work);
return;
}
/* By now I will flush data to the tty in packages of no more than
* 64 bytes, to ensure I do not get throttled.
* Ask USB mailing list for better aproach.
*/
tty = tty_port_tty_get(&port->port);
if (!tty) {
schedule_work(&priv->rx_work);
dev_err(&port->dev, "%s - No tty available\n", __func__);
return ;
}
count = min(64, serial_buf_data_avail(priv->rx_buf));
if (count <= 0)
goto out; /* We have finished sending everything. */
tty_prepare_flip_string(tty, &data, count);
if (!data) {
dev_err(&port->dev, "%s- kzalloc(%d) failed.",
__func__, count);
goto out;
}
serial_buf_get(priv->rx_buf, data, count);
put_unaligned_le16(count, &buf[2]);
tty_flip_buffer_push(tty);
if (serial_buf_data_avail(priv->rx_buf))
schedule_work(&priv->rx_work);
out:
tty_kref_put(tty);
return;
return count;
}
/* End of private methods */
static int aircable_probe(struct usb_serial *serial,
const struct usb_device_id *id)
......@@ -330,247 +122,50 @@ static int aircable_probe(struct usb_serial *serial,
return 0;
}
static int aircable_attach(struct usb_serial *serial)
static int aircable_process_packet(struct tty_struct *tty,
struct usb_serial_port *port, int has_headers,
char *packet, int len)
{
struct usb_serial_port *port = serial->port[0];
struct aircable_private *priv;
priv = kzalloc(sizeof(struct aircable_private), GFP_KERNEL);
if (!priv) {
dev_err(&port->dev, "%s- kmalloc(%Zd) failed.\n", __func__,
sizeof(struct aircable_private));
return -ENOMEM;
}
/* Allocation of Circular Buffers */
priv->tx_buf = serial_buf_alloc();
if (priv->tx_buf == NULL) {
kfree(priv);
return -ENOMEM;
}
priv->rx_buf = serial_buf_alloc();
if (priv->rx_buf == NULL) {
kfree(priv->tx_buf);
kfree(priv);
return -ENOMEM;
if (has_headers) {
len -= HCI_HEADER_LENGTH;
packet += HCI_HEADER_LENGTH;
}
priv->rx_flags &= ~(THROTTLED | ACTUALLY_THROTTLED);
priv->port = port;
INIT_WORK(&priv->rx_work, aircable_read);
usb_set_serial_port_data(serial->port[0], priv);
if (len <= 0) {
dbg("%s - malformed packet", __func__);
return 0;
}
static void aircable_release(struct usb_serial *serial)
{
struct usb_serial_port *port = serial->port[0];
struct aircable_private *priv = usb_get_serial_port_data(port);
dbg("%s", __func__);
if (priv) {
serial_buf_free(priv->tx_buf);
serial_buf_free(priv->rx_buf);
kfree(priv);
}
}
static int aircable_write_room(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
struct aircable_private *priv = usb_get_serial_port_data(port);
return serial_buf_data_avail(priv->tx_buf);
}
static int aircable_write(struct tty_struct *tty, struct usb_serial_port *port,
const unsigned char *source, int count)
{
struct aircable_private *priv = usb_get_serial_port_data(port);
int temp;
dbg("%s - port %d, %d bytes", __func__, port->number, count);
usb_serial_debug_data(debug, &port->dev, __func__, count, source);
if (!count) {
dbg("%s - write request of 0 bytes", __func__);
return count;
}
temp = serial_buf_put(priv->tx_buf, source, count);
aircable_send(port);
if (count > AIRCABLE_BUF_SIZE)
count = AIRCABLE_BUF_SIZE;
return count;
tty_insert_flip_string(tty, packet, len);
return len;
}
static void aircable_write_bulk_callback(struct urb *urb)
static void aircable_process_read_urb(struct urb *urb)
{
struct usb_serial_port *port = urb->context;
int status = urb->status;
int result;
dbg("%s - urb status: %d", __func__ , status);
/* This has been taken from cypress_m8.c cypress_write_int_callback */
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);
port->write_urb_busy = 0;
return;
default:
/* error in the urb, so we have to resubmit it */
dbg("%s - Overflow in write", __func__);
dbg("%s - nonzero write bulk status received: %d",
__func__, status);
port->write_urb->transfer_buffer_length = 1;
port->write_urb->dev = port->serial->dev;
result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
if (result)
dev_err(&urb->dev->dev,
"%s - failed resubmitting write urb, error %d\n",
__func__, result);
else
return;
}
port->write_urb_busy = 0;
aircable_send(port);
}
static void aircable_read_bulk_callback(struct urb *urb)
{
struct usb_serial_port *port = urb->context;
struct aircable_private *priv = usb_get_serial_port_data(port);
char *data = (char *)urb->transfer_buffer;
struct tty_struct *tty;
unsigned long no_packages, remaining, package_length, i;
int result, shift = 0;
unsigned char *temp;
int status = urb->status;
dbg("%s - port %d", __func__, port->number);
if (status) {
dbg("%s - urb status = %d", __func__, status);
if (status == -EPROTO) {
dbg("%s - caught -EPROTO, resubmitting the urb",
__func__);
usb_fill_bulk_urb(port->read_urb, port->serial->dev,
usb_rcvbulkpipe(port->serial->dev,
port->bulk_in_endpointAddress),
port->read_urb->transfer_buffer,
port->read_urb->transfer_buffer_length,
aircable_read_bulk_callback, port);
result = usb_submit_urb(urb, GFP_ATOMIC);
if (result)
dev_err(&urb->dev->dev,
"%s - failed resubmitting read urb, error %d\n",
__func__, result);
return;
}
dbg("%s - unable to handle the error, exiting.", __func__);
return;
}
usb_serial_debug_data(debug, &port->dev, __func__,
urb->actual_length, urb->transfer_buffer);
int has_headers;
int count;
int len;
int i;
tty = tty_port_tty_get(&port->port);
if (tty && urb->actual_length) {
if (urb->actual_length <= 2) {
/* This is an incomplete package */
serial_buf_put(priv->rx_buf, urb->transfer_buffer,
urb->actual_length);
} else {
temp = urb->transfer_buffer;
if (temp[0] == RX_HEADER_0)
shift = HCI_HEADER_LENGTH;
remaining = urb->actual_length;
no_packages = urb->actual_length / (HCI_COMPLETE_FRAME);
if (urb->actual_length % HCI_COMPLETE_FRAME != 0)
no_packages++;
if (!tty)
return;
for (i = 0; i < no_packages; i++) {
if (remaining > (HCI_COMPLETE_FRAME))
package_length = HCI_COMPLETE_FRAME;
else
package_length = remaining;
remaining -= package_length;
has_headers = (urb->actual_length > 2 && data[0] == RX_HEADER_0);
serial_buf_put(priv->rx_buf,
urb->transfer_buffer + shift +
(HCI_COMPLETE_FRAME) * (i),
package_length - shift);
}
}
aircable_read(&priv->rx_work);
count = 0;
for (i = 0; i < urb->actual_length; i += HCI_COMPLETE_FRAME) {
len = min_t(int, urb->actual_length - i, HCI_COMPLETE_FRAME);
count += aircable_process_packet(tty, port, has_headers,
&data[i], len);
}
tty_kref_put(tty);
/* Schedule the next read */
usb_fill_bulk_urb(port->read_urb, port->serial->dev,
usb_rcvbulkpipe(port->serial->dev,
port->bulk_in_endpointAddress),
port->read_urb->transfer_buffer,
port->read_urb->transfer_buffer_length,
aircable_read_bulk_callback, port);
result = usb_submit_urb(urb, GFP_ATOMIC);
if (result && result != -EPERM)
dev_err(&urb->dev->dev,
"%s - failed resubmitting read urb, error %d\n",
__func__, result);
}
/* Based on ftdi_sio.c throttle */
static void aircable_throttle(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
struct aircable_private *priv = usb_get_serial_port_data(port);
dbg("%s - port %d", __func__, port->number);
spin_lock_irq(&priv->rx_lock);
priv->rx_flags |= THROTTLED;
spin_unlock_irq(&priv->rx_lock);
}
/* Based on ftdi_sio.c unthrottle */
static void aircable_unthrottle(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
struct aircable_private *priv = usb_get_serial_port_data(port);
int actually_throttled;
dbg("%s - port %d", __func__, port->number);
spin_lock_irq(&priv->rx_lock);
actually_throttled = priv->rx_flags & ACTUALLY_THROTTLED;
priv->rx_flags &= ~(THROTTLED | ACTUALLY_THROTTLED);
spin_unlock_irq(&priv->rx_lock);
if (actually_throttled)
schedule_work(&priv->rx_work);
if (count)
tty_flip_buffer_push(tty);
tty_kref_put(tty);
}
static struct usb_driver aircable_driver = {
......@@ -589,15 +184,14 @@ static struct usb_serial_driver aircable_device = {
.usb_driver = &aircable_driver,
.id_table = id_table,
.num_ports = 1,
.attach = aircable_attach,
.bulk_out_size = HCI_COMPLETE_FRAME,
/* Must modify prepare_write_buffer if multi_urb_write is changed. */
.multi_urb_write = 0,
.probe = aircable_probe,
.release = aircable_release,
.write = aircable_write,
.write_room = aircable_write_room,
.write_bulk_callback = aircable_write_bulk_callback,
.read_bulk_callback = aircable_read_bulk_callback,
.throttle = aircable_throttle,
.unthrottle = aircable_unthrottle,
.process_read_urb = aircable_process_read_urb,
.prepare_write_buffer = aircable_prepare_write_buffer,
.throttle = usb_serial_generic_throttle,
.unthrottle = usb_serial_generic_unthrottle,
};
static int __init aircable_init(void)
......
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