diff options
Diffstat (limited to 'v4l/kernel-2.6.20/dvb_ringbuffer.h')
| -rw-r--r-- | v4l/kernel-2.6.20/dvb_ringbuffer.h | 174 |
1 files changed, 0 insertions, 174 deletions
diff --git a/v4l/kernel-2.6.20/dvb_ringbuffer.h b/v4l/kernel-2.6.20/dvb_ringbuffer.h deleted file mode 100644 index d97714e..0000000 --- a/v4l/kernel-2.6.20/dvb_ringbuffer.h +++ /dev/null @@ -1,174 +0,0 @@ -/* - * - * dvb_ringbuffer.h: ring buffer implementation for the dvb driver - * - * Copyright (C) 2003 Oliver Endriss - * Copyright (C) 2004 Andrew de Quincey - * - * based on code originally found in av7110.c & dvb_ci.c: - * Copyright (C) 1999-2003 Ralph Metzler & Marcus Metzler - * for convergence integrated media GmbH - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU Lesser General Public License - * as published by the Free Software Foundation; either version 2.1 - * of the License, or (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU Lesser General Public License for more details. - * - * You should have received a copy of the GNU Lesser General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. - */ - -#ifndef _DVB_RINGBUFFER_H_ -#define _DVB_RINGBUFFER_H_ - -#include <linux/spinlock.h> -#include <linux/wait.h> - -struct dvb_ringbuffer { - u8 *data; - ssize_t size; - ssize_t pread; - ssize_t pwrite; - int error; - - wait_queue_head_t queue; - spinlock_t lock; -}; - -#define DVB_RINGBUFFER_PKTHDRSIZE 3 - - -/* -** Notes: -** ------ -** (1) For performance reasons read and write routines don't check buffer sizes -** and/or number of bytes free/available. This has to be done before these -** routines are called. For example: -** -** *** write <buflen> bytes *** -** free = dvb_ringbuffer_free(rbuf); -** if (free >= buflen) -** count = dvb_ringbuffer_write(rbuf, buffer, buflen); -** else -** ... -** -** *** read min. 1000, max. <bufsize> bytes *** -** avail = dvb_ringbuffer_avail(rbuf); -** if (avail >= 1000) -** count = dvb_ringbuffer_read(rbuf, buffer, min(avail, bufsize), 0); -** else -** ... -** -** (2) If there is exactly one reader and one writer, there is no need -** to lock read or write operations. -** Two or more readers must be locked against each other. -** Flushing the buffer counts as a read operation. -** Two or more writers must be locked against each other. -*/ - -/* initialize ring buffer, lock and queue */ -extern void dvb_ringbuffer_init(struct dvb_ringbuffer *rbuf, void *data, size_t len); - -/* test whether buffer is empty */ -extern int dvb_ringbuffer_empty(struct dvb_ringbuffer *rbuf); - -/* return the number of free bytes in the buffer */ -extern ssize_t dvb_ringbuffer_free(struct dvb_ringbuffer *rbuf); - -/* return the number of bytes waiting in the buffer */ -extern ssize_t dvb_ringbuffer_avail(struct dvb_ringbuffer *rbuf); - - -/* read routines & macros */ -/* ---------------------- */ -/* flush buffer */ -extern void dvb_ringbuffer_flush(struct dvb_ringbuffer *rbuf); - -/* flush buffer protected by spinlock and wake-up waiting task(s) */ -extern void dvb_ringbuffer_flush_spinlock_wakeup(struct dvb_ringbuffer *rbuf); - -/* peek at byte <offs> in the buffer */ -#define DVB_RINGBUFFER_PEEK(rbuf,offs) \ - (rbuf)->data[((rbuf)->pread+(offs))%(rbuf)->size] - -/* advance read ptr by <num> bytes */ -#define DVB_RINGBUFFER_SKIP(rbuf,num) \ - (rbuf)->pread=((rbuf)->pread+(num))%(rbuf)->size - -/* -** read <len> bytes from ring buffer into <buf> -** <usermem> specifies whether <buf> resides in user space -** returns number of bytes transferred or -EFAULT -*/ -extern ssize_t dvb_ringbuffer_read(struct dvb_ringbuffer *rbuf, u8 *buf, - size_t len, int usermem); - - -/* write routines & macros */ -/* ----------------------- */ -/* write single byte to ring buffer */ -#define DVB_RINGBUFFER_WRITE_BYTE(rbuf,byte) \ - { (rbuf)->data[(rbuf)->pwrite]=(byte); \ - (rbuf)->pwrite=((rbuf)->pwrite+1)%(rbuf)->size; } -/* -** write <len> bytes to ring buffer -** <usermem> specifies whether <buf> resides in user space -** returns number of bytes transferred or -EFAULT -*/ -extern ssize_t dvb_ringbuffer_write(struct dvb_ringbuffer *rbuf, const u8 *buf, - size_t len); - - -/** - * Write a packet into the ringbuffer. - * - * <rbuf> Ringbuffer to write to. - * <buf> Buffer to write. - * <len> Length of buffer (currently limited to 65535 bytes max). - * returns Number of bytes written, or -EFAULT, -ENOMEM, -EVINAL. - */ -extern ssize_t dvb_ringbuffer_pkt_write(struct dvb_ringbuffer *rbuf, u8* buf, - size_t len); - -/** - * Read from a packet in the ringbuffer. Note: unlike dvb_ringbuffer_read(), this - * does NOT update the read pointer in the ringbuffer. You must use - * dvb_ringbuffer_pkt_dispose() to mark a packet as no longer required. - * - * <rbuf> Ringbuffer concerned. - * <idx> Packet index as returned by dvb_ringbuffer_pkt_next(). - * <offset> Offset into packet to read from. - * <buf> Destination buffer for data. - * <len> Size of destination buffer. - * <usermem> Set to 1 if <buf> is in userspace. - * returns Number of bytes read, or -EFAULT. - */ -extern ssize_t dvb_ringbuffer_pkt_read(struct dvb_ringbuffer *rbuf, size_t idx, - int offset, u8* buf, size_t len, int usermem); - -/** - * Dispose of a packet in the ring buffer. - * - * <rbuf> Ring buffer concerned. - * <idx> Packet index as returned by dvb_ringbuffer_pkt_next(). - */ -extern void dvb_ringbuffer_pkt_dispose(struct dvb_ringbuffer *rbuf, size_t idx); - -/** - * Get the index of the next packet in a ringbuffer. - * - * <rbuf> Ringbuffer concerned. - * <idx> Previous packet index, or -1 to return the first packet index. - * <pktlen> On success, will be updated to contain the length of the packet in bytes. - * returns Packet index (if >=0), or -1 if no packets available. - */ -extern ssize_t dvb_ringbuffer_pkt_next(struct dvb_ringbuffer *rbuf, size_t idx, size_t* pktlen); - - -#endif /* _DVB_RINGBUFFER_H_ */ |