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authorJohan Hovold <jhovold@gmail.com>2010-05-16 20:33:51 +0200
committerGreg Kroah-Hartman <gregkh@suse.de>2010-05-20 13:21:49 -0700
commite3c1803f8b33fb97005202fa3645501ebb946d93 (patch)
tree1e91d0181ab866413fccb9503f5949b0188048fe /drivers/usb
parent117fb8d086cfc6e51c729fe5533bb83cb55c150a (diff)
downloadlinux-e3c1803f8b33fb97005202fa3645501ebb946d93.tar.bz2
USB: oti6858: use kfifo to implement write buffering
Kill custom fifo implementation. Use private write fifo to minimise changes to lock handling. Compile-only tested. Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb')
-rw-r--r--drivers/usb/serial/oti6858.c218
1 files changed, 17 insertions, 201 deletions
diff --git a/drivers/usb/serial/oti6858.c b/drivers/usb/serial/oti6858.c
index 525d8523df95..a65be37bf129 100644
--- a/drivers/usb/serial/oti6858.c
+++ b/drivers/usb/serial/oti6858.c
@@ -51,12 +51,13 @@
#include <linux/usb.h>
#include <linux/usb/serial.h>
#include <linux/uaccess.h>
+#include <linux/kfifo.h>
#include "oti6858.h"
#define OTI6858_DESCRIPTION \
"Ours Technology Inc. OTi-6858 USB to serial adapter driver"
#define OTI6858_AUTHOR "Tomasz Michal Lukaszewski <FIXME@FIXME>"
-#define OTI6858_VERSION "0.1"
+#define OTI6858_VERSION "0.2"
static const struct usb_device_id id_table[] = {
{ USB_DEVICE(OTI6858_VENDOR_ID, OTI6858_PRODUCT_ID) },
@@ -75,17 +76,7 @@ static struct usb_driver oti6858_driver = {
static int debug;
-
-/* buffering code, copied from pl2303 driver */
-#define PL2303_BUF_SIZE 1024
-#define PL2303_TMP_BUF_SIZE 1024
-
-struct oti6858_buf {
- unsigned int buf_size;
- char *buf_buf;
- char *buf_get;
- char *buf_put;
-};
+#define OTI6858_FIFO_SIZE 1024
/* requests */
#define OTI6858_REQ_GET_STATUS (USB_DIR_IN | USB_TYPE_VENDOR | 0x00)
@@ -161,18 +152,6 @@ static int oti6858_tiocmset(struct tty_struct *tty, struct file *file,
static int oti6858_startup(struct usb_serial *serial);
static void oti6858_release(struct usb_serial *serial);
-/* functions operating on buffers */
-static struct oti6858_buf *oti6858_buf_alloc(unsigned int size);
-static void oti6858_buf_free(struct oti6858_buf *pb);
-static void oti6858_buf_clear(struct oti6858_buf *pb);
-static unsigned int oti6858_buf_data_avail(struct oti6858_buf *pb);
-static unsigned int oti6858_buf_space_avail(struct oti6858_buf *pb);
-static unsigned int oti6858_buf_put(struct oti6858_buf *pb, const char *buf,
- unsigned int count);
-static unsigned int oti6858_buf_get(struct oti6858_buf *pb, char *buf,
- unsigned int count);
-
-
/* device info */
static struct usb_serial_driver oti6858_device = {
.driver = {
@@ -201,7 +180,7 @@ static struct usb_serial_driver oti6858_device = {
struct oti6858_private {
spinlock_t lock;
- struct oti6858_buf *buf;
+ struct kfifo write_fifo;
struct oti6858_control_pkt status;
struct {
@@ -315,7 +294,7 @@ static void send_data(struct work_struct *work)
}
priv->flags.write_urb_in_use = 1;
- count = oti6858_buf_data_avail(priv->buf);
+ count = kfifo_len(&priv->write_fifo);
spin_unlock_irqrestore(&priv->lock, flags);
if (count > port->bulk_out_size)
count = port->bulk_out_size;
@@ -350,10 +329,9 @@ static void send_data(struct work_struct *work)
return;
}
- spin_lock_irqsave(&priv->lock, flags);
- oti6858_buf_get(priv->buf, port->write_urb->transfer_buffer, count);
- spin_unlock_irqrestore(&priv->lock, flags);
-
+ count = kfifo_out_locked(&priv->write_fifo,
+ port->write_urb->transfer_buffer,
+ count, &priv->lock);
port->write_urb->transfer_buffer_length = count;
port->write_urb->dev = port->serial->dev;
result = usb_submit_urb(port->write_urb, GFP_NOIO);
@@ -376,8 +354,8 @@ static int oti6858_startup(struct usb_serial *serial)
priv = kzalloc(sizeof(struct oti6858_private), GFP_KERNEL);
if (!priv)
break;
- priv->buf = oti6858_buf_alloc(PL2303_BUF_SIZE);
- if (priv->buf == NULL) {
+ if (kfifo_alloc(&priv->write_fifo, OTI6858_FIFO_SIZE,
+ GFP_KERNEL)) {
kfree(priv);
break;
}
@@ -397,7 +375,7 @@ static int oti6858_startup(struct usb_serial *serial)
for (--i; i >= 0; --i) {
priv = usb_get_serial_port_data(serial->port[i]);
- oti6858_buf_free(priv->buf);
+ kfifo_free(&priv->write_fifo);
kfree(priv);
usb_set_serial_port_data(serial->port[i], NULL);
}
@@ -408,16 +386,13 @@ static int oti6858_write(struct tty_struct *tty, struct usb_serial_port *port,
const unsigned char *buf, int count)
{
struct oti6858_private *priv = usb_get_serial_port_data(port);
- unsigned long flags;
dbg("%s(port = %d, count = %d)", __func__, port->number, count);
if (!count)
return count;
- spin_lock_irqsave(&priv->lock, flags);
- count = oti6858_buf_put(priv->buf, buf, count);
- spin_unlock_irqrestore(&priv->lock, flags);
+ count = kfifo_in_locked(&priv->write_fifo, buf, count, &priv->lock);
return count;
}
@@ -432,7 +407,7 @@ static int oti6858_write_room(struct tty_struct *tty)
dbg("%s(port = %d)", __func__, port->number);
spin_lock_irqsave(&priv->lock, flags);
- room = oti6858_buf_space_avail(priv->buf);
+ room = kfifo_avail(&priv->write_fifo);
spin_unlock_irqrestore(&priv->lock, flags);
return room;
@@ -448,7 +423,7 @@ static int oti6858_chars_in_buffer(struct tty_struct *tty)
dbg("%s(port = %d)", __func__, port->number);
spin_lock_irqsave(&priv->lock, flags);
- chars = oti6858_buf_data_avail(priv->buf);
+ chars = kfifo_len(&priv->write_fifo);
spin_unlock_irqrestore(&priv->lock, flags);
return chars;
@@ -642,7 +617,7 @@ static void oti6858_close(struct usb_serial_port *port)
spin_lock_irqsave(&priv->lock, flags);
/* clear out any remaining data in the buffer */
- oti6858_buf_clear(priv->buf);
+ kfifo_reset_out(&priv->write_fifo);
spin_unlock_irqrestore(&priv->lock, flags);
dbg("%s(): after buf_clear()", __func__);
@@ -793,7 +768,7 @@ static void oti6858_release(struct usb_serial *serial)
for (i = 0; i < serial->num_ports; ++i) {
priv = usb_get_serial_port_data(serial->port[i]);
if (priv) {
- oti6858_buf_free(priv->buf);
+ kfifo_free(&priv->write_fifo);
kfree(priv);
}
}
@@ -892,7 +867,7 @@ static void oti6858_read_int_callback(struct urb *urb)
spin_lock_irqsave(&priv->lock, flags);
if (priv->flags.write_urb_in_use == 0
- && oti6858_buf_data_avail(priv->buf) != 0) {
+ && kfifo_len(&priv->write_fifo) != 0) {
schedule_delayed_work(&priv->delayed_write_work, 0);
resubmit = 0;
}
@@ -1014,165 +989,6 @@ static void oti6858_write_bulk_callback(struct urb *urb)
}
}
-
-/*
- * oti6858_buf_alloc
- *
- * Allocate a circular buffer and all associated memory.
- */
-static struct oti6858_buf *oti6858_buf_alloc(unsigned int size)
-{
- struct oti6858_buf *pb;
-
- if (size == 0)
- return NULL;
-
- pb = kmalloc(sizeof(struct oti6858_buf), GFP_KERNEL);
- if (pb == NULL)
- return NULL;
-
- pb->buf_buf = kmalloc(size, GFP_KERNEL);
- if (pb->buf_buf == NULL) {
- kfree(pb);
- return NULL;
- }
-
- pb->buf_size = size;
- pb->buf_get = pb->buf_put = pb->buf_buf;
-
- return pb;
-}
-
-/*
- * oti6858_buf_free
- *
- * Free the buffer and all associated memory.
- */
-static void oti6858_buf_free(struct oti6858_buf *pb)
-{
- if (pb) {
- kfree(pb->buf_buf);
- kfree(pb);
- }
-}
-
-/*
- * oti6858_buf_clear
- *
- * Clear out all data in the circular buffer.
- */
-static void oti6858_buf_clear(struct oti6858_buf *pb)
-{
- if (pb != NULL) {
- /* equivalent to a get of all data available */
- pb->buf_get = pb->buf_put;
- }
-}
-
-/*
- * oti6858_buf_data_avail
- *
- * Return the number of bytes of data available in the circular
- * buffer.
- */
-static unsigned int oti6858_buf_data_avail(struct oti6858_buf *pb)
-{
- if (pb == NULL)
- return 0;
- return (pb->buf_size + pb->buf_put - pb->buf_get) % pb->buf_size;
-}
-
-/*
- * oti6858_buf_space_avail
- *
- * Return the number of bytes of space available in the circular
- * buffer.
- */
-static unsigned int oti6858_buf_space_avail(struct oti6858_buf *pb)
-{
- if (pb == NULL)
- return 0;
- return (pb->buf_size + pb->buf_get - pb->buf_put - 1) % pb->buf_size;
-}
-
-/*
- * oti6858_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 unsigned int oti6858_buf_put(struct oti6858_buf *pb, const char *buf,
- unsigned int count)
-{
- unsigned int len;
-
- if (pb == NULL)
- return 0;
-
- len = oti6858_buf_space_avail(pb);
- if (count > len)
- count = len;
-
- if (count == 0)
- return 0;
-
- len = pb->buf_buf + pb->buf_size - pb->buf_put;
- if (count > len) {
- memcpy(pb->buf_put, buf, len);
- memcpy(pb->buf_buf, buf+len, count - len);
- pb->buf_put = pb->buf_buf + count - len;
- } else {
- memcpy(pb->buf_put, buf, count);
- if (count < len)
- pb->buf_put += count;
- else /* count == len */
- pb->buf_put = pb->buf_buf;
- }
-
- return count;
-}
-
-/*
- * oti6858_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 unsigned int oti6858_buf_get(struct oti6858_buf *pb, char *buf,
- unsigned int count)
-{
- unsigned int len;
-
- if (pb == NULL)
- return 0;
-
- len = oti6858_buf_data_avail(pb);
- if (count > len)
- count = len;
-
- if (count == 0)
- return 0;
-
- len = pb->buf_buf + pb->buf_size - pb->buf_get;
- if (count > len) {
- memcpy(buf, pb->buf_get, len);
- memcpy(buf+len, pb->buf_buf, count - len);
- pb->buf_get = pb->buf_buf + count - len;
- } else {
- memcpy(buf, pb->buf_get, count);
- if (count < len)
- pb->buf_get += count;
- else /* count == len */
- pb->buf_get = pb->buf_buf;
- }
-
- return count;
-}
-
/* module description and (de)initialization */
static int __init oti6858_init(void)