patch-2.4.21 linux-2.4.21/drivers/ieee1394/iso.h

• Lines: 185
• Date: 2003-06-13 07:51:34.000000000 -0700
• Orig file: linux-2.4.20/drivers/ieee1394/iso.h
• Orig date: 1969-12-31 16:00:00.000000000 -0800

diff -urN linux-2.4.20/drivers/ieee1394/iso.h linux-2.4.21/drivers/ieee1394/iso.h
@@ -0,0 +1,184 @@
+/*
+ * 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 "hosts.h"
+#include "dma.h"
+
+/* 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;
+};
+
+enum hpsb_iso_type { HPSB_ISO_RECV = 0, HPSB_ISO_XMIT = 1 };
+
+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; /* SPEED_100, 200, or 400 */
+	int channel; /* -1 if multichannel */
+
+	/* 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;
+
+	/* ringbuffer of packet descriptors in regular kernel memory */
+	struct hpsb_iso_packet_info *infos;
+
+	/* # 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;
+
+	/* 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;
+};
+
+/* 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 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);
+
+/* 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 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 */