From 4272568b3dd8dbad36014a107c0fbbef6400c917 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Wed, 5 May 2010 23:45:24 +0200 Subject: [PATCH] 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 Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- drivers/usb/serial/aircable.c | 500 ++++------------------------------ 1 file changed, 47 insertions(+), 453 deletions(-) diff --git a/drivers/usb/serial/aircable.c b/drivers/usb/serial/aircable.c index 4fd7af98b1a..cac5162937b 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 * 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 #include #include #include -#include #include #include @@ -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 " +#define DRIVER_VERSION "v2.0" +#define DRIVER_AUTHOR "Naranjo, Manuel Francisco , Johan Hovold " #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) -{ - 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) +static int aircable_prepare_write_buffer(struct usb_serial_port *port, + void **dest, size_t size, const void *src, size_t count) { - 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. */ + put_unaligned_le16(count, &buf[2]); - 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; + 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) -{ - 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; - } - - 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; -} - -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) +static int aircable_process_packet(struct tty_struct *tty, + struct usb_serial_port *port, int has_headers, + char *packet, int len) { - 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; + if (has_headers) { + len -= HCI_HEADER_LENGTH; + packet += HCI_HEADER_LENGTH; } - - 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) -{ - 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; + if (len <= 0) { + dbg("%s - malformed packet", __func__); + return 0; } - port->write_urb_busy = 0; + tty_insert_flip_string(tty, packet, len); - aircable_send(port); + return len; } -static void aircable_read_bulk_callback(struct urb *urb) +static void aircable_process_read_urb(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) -- 2.20.1