drivers/ieee1394/iso.h - maze/linux - Git at Google

 /*
  * IEEE 1394 for Linux
  *
  * kernel ISO transmission/reception
  *
  * Copyright (C) 2002 Maas Digital LLC
  *
  * This code is licensed under the GPL.  See the file COPYING in the root
  * directory of the kernel sources for details.
  */

 #ifndef IEEE1394_ISO_H
 #define IEEE1394_ISO_H

 #include <linux/spinlock_types.h>
 #include <asm/atomic.h>
 #include <asm/types.h>

 #include "dma.h"

 struct hpsb_host;

 /* high-level ISO interface */

 /*
  * This API sends and receives isochronous packets on a large,
  * virtually-contiguous kernel memory buffer. The buffer may be mapped
  * into a user-space process for zero-copy transmission and reception.
  *
  * There are no explicit boundaries between packets in the buffer. A
  * packet may be transmitted or received at any location. However,
  * low-level drivers may impose certain restrictions on alignment or
  * size of packets. (e.g. in OHCI no packet may cross a page boundary,
  * and packets should be quadlet-aligned)
  */

 /* Packet descriptor - the API maintains a ring buffer of these packet
  * descriptors in kernel memory (hpsb_iso.infos[]).  */
 struct hpsb_iso_packet_info {
 	/* offset of data payload relative to the first byte of the buffer */
 	__u32 offset;

 	/* length of the data payload, in bytes (not including the isochronous
 	 * header) */
 	__u16 len;

 	/* (recv only) the cycle number (mod 8000) on which the packet was
 	 * received */
 	__u16 cycle;

 	/* (recv only) channel on which the packet was received */
 	__u8 channel;

 	/* 2-bit 'tag' and 4-bit 'sy' fields of the isochronous header */
 	__u8 tag;
 	__u8 sy;

 	/* length in bytes of the packet including header/trailer.
 	 * MUST be at structure end, since the first part of this structure is
 	 * also defined in raw1394.h (i.e. struct raw1394_iso_packet_info), is
 	 * copied to userspace and is accessed there through libraw1394. */
 	__u16 total_len;
 };

 enum hpsb_iso_type { HPSB_ISO_RECV = 0, HPSB_ISO_XMIT = 1 };

 /* The mode of the dma when receiving iso data. Must be supported by chip */
 enum raw1394_iso_dma_recv_mode {
 	HPSB_ISO_DMA_DEFAULT = -1,
 	HPSB_ISO_DMA_OLD_ABI = 0,
 	HPSB_ISO_DMA_BUFFERFILL = 1,
 	HPSB_ISO_DMA_PACKET_PER_BUFFER = 2
 };

 struct hpsb_iso {
 	enum hpsb_iso_type type;

 	/* pointer to low-level driver and its private data */
 	struct hpsb_host *host;
 	void *hostdata;

 	/* a function to be called (from interrupt context) after
 	 * outgoing packets have been sent, or incoming packets have
 	 * arrived */
 	void (*callback)(struct hpsb_iso*);

 	/* wait for buffer space */
 	wait_queue_head_t waitq;

 	int speed; /* IEEE1394_SPEED_100, 200, or 400 */
 	int channel; /* -1 if multichannel */
 	int dma_mode; /* dma receive mode */


 	/* greatest # of packets between interrupts - controls
 	 * the maximum latency of the buffer */
 	int irq_interval;

 	/* the buffer for packet data payloads */
 	struct dma_region data_buf;

 	/* size of data_buf, in bytes (always a multiple of PAGE_SIZE) */
 	unsigned int buf_size;

 	/* # of packets in the ringbuffer */
 	unsigned int buf_packets;

 	/* protects packet cursors */
 	spinlock_t lock;

 	/* the index of the next packet that will be produced
 	   or consumed by the user */
 	int first_packet;

 	/* the index of the next packet that will be transmitted
 	   or received by the 1394 hardware */
 	int pkt_dma;

 	/* how many packets, starting at first_packet:
 	 * (transmit) are ready to be filled with data
 	 * (receive)  contain received data */
 	int n_ready_packets;

 	/* how many times the buffer has overflowed or underflowed */
 	atomic_t overflows;

 	/* Current number of bytes lost in discarded packets */
 	int bytes_discarded;

 	/* private flags to track initialization progress */
 #define HPSB_ISO_DRIVER_INIT     (1<<0)
 #define HPSB_ISO_DRIVER_STARTED  (1<<1)
 	unsigned int flags;

 	/* # of packets left to prebuffer (xmit only) */
 	int prebuffer;

 	/* starting cycle for DMA (xmit only) */
 	int start_cycle;

 	/* cycle at which next packet will be transmitted,
 	 * -1 if not known */
 	int xmit_cycle;

 	/* ringbuffer of packet descriptors in regular kernel memory
 	 * XXX Keep this last, since we use over-allocated memory from
 	 * this entry to fill this field. */
 	struct hpsb_iso_packet_info *infos;
 };

 /* functions available to high-level drivers (e.g. raw1394) */

 /* allocate the buffer and DMA context */

 struct hpsb_iso* hpsb_iso_xmit_init(struct hpsb_host *host,
 				    unsigned int data_buf_size,
 				    unsigned int buf_packets,
 				    int channel,
 				    int speed,
 				    int irq_interval,
 				    void (*callback)(struct hpsb_iso*));

 /* note: if channel = -1, multi-channel receive is enabled */
 struct hpsb_iso* hpsb_iso_recv_init(struct hpsb_host *host,
 				    unsigned int data_buf_size,
 				    unsigned int buf_packets,
 				    int channel,
 				    int dma_mode,
 				    int irq_interval,
 				    void (*callback)(struct hpsb_iso*));

 /* multi-channel only */
 int hpsb_iso_recv_listen_channel(struct hpsb_iso *iso, unsigned char channel);
 int hpsb_iso_recv_unlisten_channel(struct hpsb_iso *iso, unsigned char channel);
 int hpsb_iso_recv_set_channel_mask(struct hpsb_iso *iso, u64 mask);

 /* start/stop DMA */
 int hpsb_iso_xmit_start(struct hpsb_iso *iso, int start_on_cycle,
 			int prebuffer);
 int hpsb_iso_recv_start(struct hpsb_iso *iso, int start_on_cycle,
 			int tag_mask, int sync);
 void hpsb_iso_stop(struct hpsb_iso *iso);

 /* deallocate buffer and DMA context */
 void hpsb_iso_shutdown(struct hpsb_iso *iso);

 /* queue a packet for transmission.
  * 'offset' is relative to the beginning of the DMA buffer, where the packet's
  * data payload should already have been placed. */
 int hpsb_iso_xmit_queue_packet(struct hpsb_iso *iso, u32 offset, u16 len,
 			       u8 tag, u8 sy);

 /* wait until all queued packets have been transmitted to the bus */
 int hpsb_iso_xmit_sync(struct hpsb_iso *iso);

 /* N packets have been read out of the buffer, re-use the buffer space */
 int  hpsb_iso_recv_release_packets(struct hpsb_iso *recv,
 				   unsigned int n_packets);

 /* check for arrival of new packets immediately (even if irq_interval
  * has not yet been reached) */
 int hpsb_iso_recv_flush(struct hpsb_iso *iso);

 /* returns # of packets ready to send or receive */
 int hpsb_iso_n_ready(struct hpsb_iso *iso);

 /* the following are callbacks available to low-level drivers */

 /* call after a packet has been transmitted to the bus (interrupt context is OK)
  * 'cycle' is the _exact_ cycle the packet was sent on
  * 'error' should be non-zero if some sort of error occurred when sending the
  *  packet */
 void hpsb_iso_packet_sent(struct hpsb_iso *iso, int cycle, int error);

 /* call after a packet has been received (interrupt context OK) */
 void hpsb_iso_packet_received(struct hpsb_iso *iso, u32 offset, u16 len,
 			      u16 total_len, u16 cycle, u8 channel, u8 tag,
 			      u8 sy);

 /* call to wake waiting processes after buffer space has opened up. */
 void hpsb_iso_wake(struct hpsb_iso *iso);

 #endif /* IEEE1394_ISO_H */
	/*
	* IEEE 1394 for Linux
	*
	* kernel ISO transmission/reception
	*
	* Copyright (C) 2002 Maas Digital LLC
	*
	* This code is licensed under the GPL. See the file COPYING in the root
	* directory of the kernel sources for details.
	*/

	#ifndef IEEE1394_ISO_H
	#define IEEE1394_ISO_H

	#include <linux/spinlock_types.h>
	#include <asm/atomic.h>
	#include <asm/types.h>

	#include "dma.h"

	struct hpsb_host;

	/* high-level ISO interface */

	/*
	* This API sends and receives isochronous packets on a large,
	* virtually-contiguous kernel memory buffer. The buffer may be mapped
	* into a user-space process for zero-copy transmission and reception.
	*
	* There are no explicit boundaries between packets in the buffer. A
	* packet may be transmitted or received at any location. However,
	* low-level drivers may impose certain restrictions on alignment or
	* size of packets. (e.g. in OHCI no packet may cross a page boundary,
	* and packets should be quadlet-aligned)
	*/

	/* Packet descriptor - the API maintains a ring buffer of these packet
	* descriptors in kernel memory (hpsb_iso.infos[]). */
	struct hpsb_iso_packet_info {
	/* offset of data payload relative to the first byte of the buffer */
	__u32 offset;

	/* length of the data payload, in bytes (not including the isochronous
	* header) */
	__u16 len;

	/* (recv only) the cycle number (mod 8000) on which the packet was
	* received */
	__u16 cycle;

	/* (recv only) channel on which the packet was received */
	__u8 channel;

	/* 2-bit 'tag' and 4-bit 'sy' fields of the isochronous header */
	__u8 tag;
	__u8 sy;

	/* length in bytes of the packet including header/trailer.
	* MUST be at structure end, since the first part of this structure is
	* also defined in raw1394.h (i.e. struct raw1394_iso_packet_info), is
	* copied to userspace and is accessed there through libraw1394. */
	__u16 total_len;
	};

	enum hpsb_iso_type { HPSB_ISO_RECV = 0, HPSB_ISO_XMIT = 1 };

	/* The mode of the dma when receiving iso data. Must be supported by chip */
	enum raw1394_iso_dma_recv_mode {
	HPSB_ISO_DMA_DEFAULT = -1,
	HPSB_ISO_DMA_OLD_ABI = 0,
	HPSB_ISO_DMA_BUFFERFILL = 1,
	HPSB_ISO_DMA_PACKET_PER_BUFFER = 2
	};

	struct hpsb_iso {
	enum hpsb_iso_type type;

	/* pointer to low-level driver and its private data */
	struct hpsb_host *host;
	void *hostdata;

	/* a function to be called (from interrupt context) after
	* outgoing packets have been sent, or incoming packets have
	* arrived */
	void (callback)(struct hpsb_iso);

	/* wait for buffer space */
	wait_queue_head_t waitq;

	int speed; /* IEEE1394_SPEED_100, 200, or 400 */
	int channel; /* -1 if multichannel */
	int dma_mode; /* dma receive mode */


	/* greatest # of packets between interrupts - controls
	* the maximum latency of the buffer */
	int irq_interval;

	/* the buffer for packet data payloads */
	struct dma_region data_buf;

	/* size of data_buf, in bytes (always a multiple of PAGE_SIZE) */
	unsigned int buf_size;

	/* # of packets in the ringbuffer */
	unsigned int buf_packets;

	/* protects packet cursors */
	spinlock_t lock;

	/* the index of the next packet that will be produced
	or consumed by the user */
	int first_packet;

	/* the index of the next packet that will be transmitted
	or received by the 1394 hardware */
	int pkt_dma;

	/* how many packets, starting at first_packet:
	* (transmit) are ready to be filled with data
	* (receive) contain received data */
	int n_ready_packets;

	/* how many times the buffer has overflowed or underflowed */
	atomic_t overflows;

	/* Current number of bytes lost in discarded packets */
	int bytes_discarded;

	/* private flags to track initialization progress */
	#define HPSB_ISO_DRIVER_INIT (1<<0)
	#define HPSB_ISO_DRIVER_STARTED (1<<1)
	unsigned int flags;

	/* # of packets left to prebuffer (xmit only) */
	int prebuffer;

	/* starting cycle for DMA (xmit only) */
	int start_cycle;

	/* cycle at which next packet will be transmitted,
	* -1 if not known */
	int xmit_cycle;

	/* ringbuffer of packet descriptors in regular kernel memory
	* XXX Keep this last, since we use over-allocated memory from
	* this entry to fill this field. */
	struct hpsb_iso_packet_info *infos;
	};

	/* functions available to high-level drivers (e.g. raw1394) */

	/* allocate the buffer and DMA context */

	struct hpsb_iso* hpsb_iso_xmit_init(struct hpsb_host *host,
	unsigned int data_buf_size,
	unsigned int buf_packets,
	int channel,
	int speed,
	int irq_interval,
	void (callback)(struct hpsb_iso));

	/* note: if channel = -1, multi-channel receive is enabled */
	struct hpsb_iso* hpsb_iso_recv_init(struct hpsb_host *host,
	unsigned int data_buf_size,
	unsigned int buf_packets,
	int channel,
	int dma_mode,
	int irq_interval,
	void (callback)(struct hpsb_iso));

	/* multi-channel only */
	int hpsb_iso_recv_listen_channel(struct hpsb_iso *iso, unsigned char channel);
	int hpsb_iso_recv_unlisten_channel(struct hpsb_iso *iso, unsigned char channel);
	int hpsb_iso_recv_set_channel_mask(struct hpsb_iso *iso, u64 mask);

	/* start/stop DMA */
	int hpsb_iso_xmit_start(struct hpsb_iso *iso, int start_on_cycle,
	int prebuffer);
	int hpsb_iso_recv_start(struct hpsb_iso *iso, int start_on_cycle,
	int tag_mask, int sync);
	void hpsb_iso_stop(struct hpsb_iso *iso);

	/* deallocate buffer and DMA context */
	void hpsb_iso_shutdown(struct hpsb_iso *iso);

	/* queue a packet for transmission.
	* 'offset' is relative to the beginning of the DMA buffer, where the packet's
	* data payload should already have been placed. */
	int hpsb_iso_xmit_queue_packet(struct hpsb_iso *iso, u32 offset, u16 len,
	u8 tag, u8 sy);

	/* wait until all queued packets have been transmitted to the bus */
	int hpsb_iso_xmit_sync(struct hpsb_iso *iso);

	/* N packets have been read out of the buffer, re-use the buffer space */
	int hpsb_iso_recv_release_packets(struct hpsb_iso *recv,
	unsigned int n_packets);

	/* check for arrival of new packets immediately (even if irq_interval
	* has not yet been reached) */
	int hpsb_iso_recv_flush(struct hpsb_iso *iso);

	/* returns # of packets ready to send or receive */
	int hpsb_iso_n_ready(struct hpsb_iso *iso);

	/* the following are callbacks available to low-level drivers */

	/* call after a packet has been transmitted to the bus (interrupt context is OK)
	* 'cycle' is the _exact_ cycle the packet was sent on
	* 'error' should be non-zero if some sort of error occurred when sending the
	* packet */
	void hpsb_iso_packet_sent(struct hpsb_iso *iso, int cycle, int error);

	/* call after a packet has been received (interrupt context OK) */
	void hpsb_iso_packet_received(struct hpsb_iso *iso, u32 offset, u16 len,
	u16 total_len, u16 cycle, u8 channel, u8 tag,
	u8 sy);

	/* call to wake waiting processes after buffer space has opened up. */
	void hpsb_iso_wake(struct hpsb_iso *iso);

	#endif /* IEEE1394_ISO_H */