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Commit 117fb8d0 authored by Johan Hovold's avatar Johan Hovold Committed by Greg Kroah-Hartman
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USB: cypress_m8: use kfifo to implement write buffering 



Kill custom fifo implementation.

Note that cypress_m8 has no port write fifo as it has no bulk-out
endpoint.

Compile-only tested.

Signed-off-by: default avatarJohan Hovold <jhovold@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent c4f4736f

drivers/usb/serial/cypress_m8.c

+17 −222
Original line number Diff line number Diff line
@@ -64,6 +64,7 @@ 
#include <linux/usb.h>

#include <linux/usb/serial.h>

#include <linux/serial.h>

#include <linux/kfifo.h>

#include <linux/delay.h>

#include <linux/uaccess.h>

#include <asm/unaligned.h>
@@ -79,7 +80,7 @@ static int unstable_bauds; 
/*

 * Version Information

 */

#define DRIVER_VERSION "v1.09"

#define DRIVER_VERSION "v1.10"

#define DRIVER_AUTHOR "Lonnie Mendez <dignome@gmail.com>, Neil Whelchel <koyama@firstlight.net>"

#define DRIVER_DESC "Cypress USB to Serial Driver"
@@ -134,7 +135,7 @@ struct cypress_private { 
	int bytes_out;			   /* used for statistics */

	int cmd_count;			   /* used for statistics */

	int cmd_ctrl;			   /* always set this to 1 before issuing a command */

	struct cypress_buf *buf;	   /* write buffer */

	struct kfifo write_fifo;	   /* write fifo */

	int write_urb_in_use;		   /* write urb in use indicator */

	int write_urb_interval;            /* interval to use for write urb */

	int read_urb_interval;             /* interval to use for read urb */
@@ -156,14 +157,6 @@ struct cypress_private { 
	struct ktermios tmp_termios; 	   /* stores the old termios settings */

};



/* write buffer structure */

struct cypress_buf {

	unsigned int	buf_size;

	char		*buf_buf;

	char		*buf_get;

	char		*buf_put;

};



/* function prototypes for the Cypress USB to serial device */

static int  cypress_earthmate_startup(struct usb_serial *serial);

static int  cypress_hidcom_startup(struct usb_serial *serial);
@@ -189,17 +182,6 @@ static void cypress_unthrottle(struct tty_struct *tty); 
static void cypress_set_dead(struct usb_serial_port *port);

static void cypress_read_int_callback(struct urb *urb);

static void cypress_write_int_callback(struct urb *urb);

/* write buffer functions */

static struct cypress_buf *cypress_buf_alloc(unsigned int size);

static void cypress_buf_free(struct cypress_buf *cb);

static void cypress_buf_clear(struct cypress_buf *cb);

static unsigned int cypress_buf_data_avail(struct cypress_buf *cb);

static unsigned int cypress_buf_space_avail(struct cypress_buf *cb);

static unsigned int cypress_buf_put(struct cypress_buf *cb,

					const char *buf, unsigned int count);

static unsigned int cypress_buf_get(struct cypress_buf *cb,

					char *buf, unsigned int count);





static struct usb_serial_driver cypress_earthmate_device = {

	.driver = {
@@ -502,8 +484,7 @@ static int generic_startup(struct usb_serial *serial) 


	priv->comm_is_ok = !0;

	spin_lock_init(&priv->lock);

	priv->buf = cypress_buf_alloc(CYPRESS_BUF_SIZE);

	if (priv->buf == NULL) {

	if (kfifo_alloc(&priv->write_fifo, CYPRESS_BUF_SIZE, GFP_KERNEL)) {

		kfree(priv);

		return -ENOMEM;

	}
@@ -626,7 +607,7 @@ static void cypress_release(struct usb_serial *serial) 
	priv = usb_get_serial_port_data(serial->port[0]);



	if (priv) {

		cypress_buf_free(priv->buf);

		kfifo_free(&priv->write_fifo);

		kfree(priv);

	}

}
@@ -703,6 +684,7 @@ static void cypress_dtr_rts(struct usb_serial_port *port, int on) 
static void cypress_close(struct usb_serial_port *port)

{

	struct cypress_private *priv = usb_get_serial_port_data(port);

	unsigned long flags;



	dbg("%s - port %d", __func__, port->number);
@@ -712,12 +694,14 @@ static void cypress_close(struct usb_serial_port *port) 
		mutex_unlock(&port->serial->disc_mutex);

		return;

	}

	cypress_buf_clear(priv->buf);

	spin_lock_irqsave(&priv->lock, flags);

	kfifo_reset_out(&priv->write_fifo);

	spin_unlock_irqrestore(&priv->lock, flags);



	dbg("%s - stopping urbs", __func__);

	usb_kill_urb(port->interrupt_in_urb);

	usb_kill_urb(port->interrupt_out_urb);





	if (stats)

		dev_info(&port->dev, "Statistics: %d Bytes In | %d Bytes Out | %d Commands Issued\n",

			priv->bytes_in, priv->bytes_out, priv->cmd_count);
@@ -729,7 +713,6 @@ static int cypress_write(struct tty_struct *tty, struct usb_serial_port *port, 
					const unsigned char *buf, int count)

{

	struct cypress_private *priv = usb_get_serial_port_data(port);

	unsigned long flags;



	dbg("%s - port %d, %d bytes", __func__, port->number, count);
@@ -744,9 +727,7 @@ static int cypress_write(struct tty_struct *tty, struct usb_serial_port *port, 
	if (!count)

		return count;



	spin_lock_irqsave(&priv->lock, flags);

	count = cypress_buf_put(priv->buf, buf, count);

	spin_unlock_irqrestore(&priv->lock, flags);

	count = kfifo_in_locked(&priv->write_fifo, buf, count, &priv->lock);



finish:

	cypress_send(port);
@@ -806,9 +787,10 @@ static void cypress_send(struct usb_serial_port *port) 
	} else

		spin_unlock_irqrestore(&priv->lock, flags);



	count = cypress_buf_get(priv->buf, &port->interrupt_out_buffer[offset],

				port->interrupt_out_size-offset);



	count = kfifo_out_locked(&priv->write_fifo,

					&port->interrupt_out_buffer[offset],

					port->interrupt_out_size - offset,

					&priv->lock);

	if (count == 0)

		return;
@@ -874,7 +856,7 @@ static int cypress_write_room(struct tty_struct *tty) 
	dbg("%s - port %d", __func__, port->number);



	spin_lock_irqsave(&priv->lock, flags);

	room = cypress_buf_space_avail(priv->buf);

	room = kfifo_avail(&priv->write_fifo);

	spin_unlock_irqrestore(&priv->lock, flags);



	dbg("%s - returns %d", __func__, room);
@@ -1142,7 +1124,7 @@ static int cypress_chars_in_buffer(struct tty_struct *tty) 
	dbg("%s - port %d", __func__, port->number);



	spin_lock_irqsave(&priv->lock, flags);

	chars = cypress_buf_data_avail(priv->buf);

	chars = kfifo_len(&priv->write_fifo);

	spin_unlock_irqrestore(&priv->lock, flags);



	dbg("%s - returns %d", __func__, chars);
@@ -1395,193 +1377,6 @@ static void cypress_write_int_callback(struct urb *urb) 
}





/*****************************************************************************

 * Write buffer functions - buffering code from pl2303 used

 *****************************************************************************/



/*

 * cypress_buf_alloc

 *

 * Allocate a circular buffer and all associated memory.

 */



static struct cypress_buf *cypress_buf_alloc(unsigned int size)

{



	struct cypress_buf *cb;





	if (size == 0)

		return NULL;



	cb = kmalloc(sizeof(struct cypress_buf), GFP_KERNEL);

	if (cb == NULL)

		return NULL;



	cb->buf_buf = kmalloc(size, GFP_KERNEL);

	if (cb->buf_buf == NULL) {

		kfree(cb);

		return NULL;

	}



	cb->buf_size = size;

	cb->buf_get = cb->buf_put = cb->buf_buf;



	return cb;



}





/*

 * cypress_buf_free

 *

 * Free the buffer and all associated memory.

 */



static void cypress_buf_free(struct cypress_buf *cb)

{

	if (cb) {

		kfree(cb->buf_buf);

		kfree(cb);

	}

}





/*

 * cypress_buf_clear

 *

 * Clear out all data in the circular buffer.

 */



static void cypress_buf_clear(struct cypress_buf *cb)

{

	if (cb != NULL)

		cb->buf_get = cb->buf_put;

		/* equivalent to a get of all data available */

}





/*

 * cypress_buf_data_avail

 *

 * Return the number of bytes of data available in the circular

 * buffer.

 */



static unsigned int cypress_buf_data_avail(struct cypress_buf *cb)

{

	if (cb != NULL)

		return (cb->buf_size + cb->buf_put - cb->buf_get)

							% cb->buf_size;

	else

		return 0;

}





/*

 * cypress_buf_space_avail

 *

 * Return the number of bytes of space available in the circular

 * buffer.

 */



static unsigned int cypress_buf_space_avail(struct cypress_buf *cb)

{

	if (cb != NULL)

		return (cb->buf_size + cb->buf_get - cb->buf_put - 1)

							% cb->buf_size;

	else

		return 0;

}





/*

 * cypress_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 cypress_buf_put(struct cypress_buf *cb, const char *buf,

	unsigned int count)

{



	unsigned int len;





	if (cb == NULL)

		return 0;



	len  = cypress_buf_space_avail(cb);

	if (count > len)

		count = len;



	if (count == 0)

		return 0;



	len = cb->buf_buf + cb->buf_size - cb->buf_put;

	if (count > len) {

		memcpy(cb->buf_put, buf, len);

		memcpy(cb->buf_buf, buf+len, count - len);

		cb->buf_put = cb->buf_buf + count - len;

	} else {

		memcpy(cb->buf_put, buf, count);

		if (count < len)

			cb->buf_put += count;

		else /* count == len */

			cb->buf_put = cb->buf_buf;

	}



	return count;



}





/*

 * cypress_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 cypress_buf_get(struct cypress_buf *cb, char *buf,

	unsigned int count)

{



	unsigned int len;





	if (cb == NULL)

		return 0;



	len = cypress_buf_data_avail(cb);

	if (count > len)

		count = len;



	if (count == 0)

		return 0;



	len = cb->buf_buf + cb->buf_size - cb->buf_get;

	if (count > len) {

		memcpy(buf, cb->buf_get, len);

		memcpy(buf+len, cb->buf_buf, count - len);

		cb->buf_get = cb->buf_buf + count - len;

	} else {

		memcpy(buf, cb->buf_get, count);

		if (count < len)

			cb->buf_get += count;

		else /* count == len */

			cb->buf_get = cb->buf_buf;

	}



	return count;



}



/*****************************************************************************

 * Module functions

 *****************************************************************************/