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: Naranjo, Manuel Francisco <naranjo.manuel@gmail.com>
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/serial/aircable.c b/drivers/usb/serial/aircable.c
index 4fd7af9..cac51629 100644
--- a/drivers/usb/serial/aircable.c
+++ b/drivers/usb/serial/aircable.c
@@ -1,7 +1,9 @@
/*
* 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 @@
#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 @@
/*
* 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 */
@@ -85,226 +83,20 @@
};
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)
+static int aircable_prepare_write_buffer(struct usb_serial_port *port,
+ void **dest, size_t size, const void *src, size_t count)
{
- cb->head = cb->tail = 0;
-}
+ unsigned char *buf = *dest;
-/*
- * 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)
-{
- 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;
- }
-
+ 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);
+ put_unaligned_le16(count, &buf[2]);
- 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);
+ return count;
}
-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);
-
- tty_flip_buffer_push(tty);
-
- if (serial_buf_data_avail(priv->rx_buf))
- schedule_work(&priv->rx_work);
-out:
- tty_kref_put(tty);
- return;
-}
-/* End of private methods */
-
static int aircable_probe(struct usb_serial *serial,
const struct usb_device_id *id)
{
@@ -330,247 +122,50 @@
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;
+ if (has_headers) {
+ len -= HCI_HEADER_LENGTH;
+ packet += HCI_HEADER_LENGTH;
+ }
+ if (len <= 0) {
+ dbg("%s - malformed packet", __func__);
+ return 0;
}
- /* Allocation of Circular Buffers */
- priv->tx_buf = serial_buf_alloc();
- if (priv->tx_buf == NULL) {
- kfree(priv);
- return -ENOMEM;
- }
+ tty_insert_flip_string(tty, packet, len);
- priv->rx_buf = serial_buf_alloc();
- if (priv->rx_buf == NULL) {
- kfree(priv->tx_buf);
- kfree(priv);
- return -ENOMEM;
- }
-
- 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);
-
- return 0;
+ return len;
}
-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;
-
-}
-
-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;
+ if (!tty)
+ return;
- remaining = urb->actual_length;
- no_packages = urb->actual_length / (HCI_COMPLETE_FRAME);
+ has_headers = (urb->actual_length > 2 && data[0] == RX_HEADER_0);
- if (urb->actual_length % HCI_COMPLETE_FRAME != 0)
- no_packages++;
-
- for (i = 0; i < no_packages; i++) {
- if (remaining > (HCI_COMPLETE_FRAME))
- package_length = HCI_COMPLETE_FRAME;
- else
- package_length = remaining;
- remaining -= package_length;
-
- 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);
}
+
+ if (count)
+ tty_flip_buffer_push(tty);
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);
}
static struct usb_driver aircable_driver = {
@@ -589,15 +184,14 @@
.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)