V4L/DVB (4228a): pvrusb2 to kernel 2.6.18

Implement V4L2 driver for the Hauppauge PVR USB2 TV tuner.

The Hauppauge PVR USB2 is a USB connected TV tuner with an embedded
cx23416 hardware MPEG2 encoder.  There are two major variants of this
device; this driver handles both.  Any V4L2 application which
understands MPEG2 video stream data should be able to work with this
device.

Signed-off-by: Mike Isely <isely@pobox.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

1 files changed, 695 insertions, 0 deletions

diff --git a/drivers/media/video/pvrusb2/pvrusb2-io.c b/drivers/media/video/pvrusb2/pvrusb2-io.c
new file mode 100644
index 00000000000..a984c91f571
--- /dev/null
+++ b/drivers/media/video/pvrusb2/pvrusb2-io.c
@@ -0,0 +1,695 @@
+/*
+ *
+ *  $Id$
+ *
+ *  Copyright (C) 2005 Mike Isely <isely@pobox.com>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License
+ *
+ *  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 General Public License for more details.
+ *
+ *  You should have received a copy of the GNU 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
+ *
+ */
+
+#include "pvrusb2-io.h"
+#include "pvrusb2-debug.h"
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/mutex.h>
+
+#define BUFFER_SIG 0x47653271
+
+// #define SANITY_CHECK_BUFFERS
+
+
+#ifdef SANITY_CHECK_BUFFERS
+#define BUFFER_CHECK(bp) do { \
+	if ((bp)->signature != BUFFER_SIG) { \
+		pvr2_trace(PVR2_TRACE_ERROR_LEGS, \
+		"Buffer %p is bad at %s:%d", \
+		(bp),__FILE__,__LINE__); \
+		pvr2_buffer_describe(bp,"BadSig"); \
+		BUG(); \
+	} \
+} while (0)
+#else
+#define BUFFER_CHECK(bp) do {} while(0)
+#endif
+
+struct pvr2_stream {
+	/* Buffers queued for reading */
+	struct list_head queued_list;
+	unsigned int q_count;
+	unsigned int q_bcount;
+	/* Buffers with retrieved data */
+	struct list_head ready_list;
+	unsigned int r_count;
+	unsigned int r_bcount;
+	/* Buffers available for use */
+	struct list_head idle_list;
+	unsigned int i_count;
+	unsigned int i_bcount;
+	/* Pointers to all buffers */
+	struct pvr2_buffer **buffers;
+	/* Array size of buffers */
+	unsigned int buffer_slot_count;
+	/* Total buffers actually in circulation */
+	unsigned int buffer_total_count;
+	/* Designed number of buffers to be in circulation */
+	unsigned int buffer_target_count;
+	/* Executed when ready list become non-empty */
+	pvr2_stream_callback callback_func;
+	void *callback_data;
+	/* Context for transfer endpoint */
+	struct usb_device *dev;
+	int endpoint;
+	/* Overhead for mutex enforcement */
+	spinlock_t list_lock;
+	struct mutex mutex;
+	/* Tracking state for tolerating errors */
+	unsigned int fail_count;
+	unsigned int fail_tolerance;
+};
+
+struct pvr2_buffer {
+	int id;
+	int signature;
+	enum pvr2_buffer_state state;
+	void *ptr;               /* Pointer to storage area */
+	unsigned int max_count;  /* Size of storage area */
+	unsigned int used_count; /* Amount of valid data in storage area */
+	int status;              /* Transfer result status */
+	struct pvr2_stream *stream;
+	struct list_head list_overhead;
+	struct urb *purb;
+};
+
+const char *pvr2_buffer_state_decode(enum pvr2_buffer_state st)
+{
+	switch (st) {
+	case pvr2_buffer_state_none: return "none";
+	case pvr2_buffer_state_idle: return "idle";
+	case pvr2_buffer_state_queued: return "queued";
+	case pvr2_buffer_state_ready: return "ready";
+	}
+	return "unknown";
+}
+
+void pvr2_buffer_describe(struct pvr2_buffer *bp,const char *msg)
+{
+	pvr2_trace(PVR2_TRACE_INFO,
+		   "buffer%s%s %p state=%s id=%d status=%d"
+		   " stream=%p purb=%p sig=0x%x",
+		   (msg ? " " : ""),
+		   (msg ? msg : ""),
+		   bp,
+		   (bp ? pvr2_buffer_state_decode(bp->state) : "(invalid)"),
+		   (bp ? bp->id : 0),
+		   (bp ? bp->status : 0),
+		   (bp ? bp->stream : 0),
+		   (bp ? bp->purb : 0),
+		   (bp ? bp->signature : 0));
+}
+
+static void pvr2_buffer_remove(struct pvr2_buffer *bp)
+{
+	unsigned int *cnt;
+	unsigned int *bcnt;
+	unsigned int ccnt;
+	struct pvr2_stream *sp = bp->stream;
+	switch (bp->state) {
+	case pvr2_buffer_state_idle:
+		cnt = &sp->i_count;
+		bcnt = &sp->i_bcount;
+		ccnt = bp->max_count;
+		break;
+	case pvr2_buffer_state_queued:
+		cnt = &sp->q_count;
+		bcnt = &sp->q_bcount;
+		ccnt = bp->max_count;
+		break;
+	case pvr2_buffer_state_ready:
+		cnt = &sp->r_count;
+		bcnt = &sp->r_bcount;
+		ccnt = bp->used_count;
+		break;
+	default:
+		return;
+	}
+	list_del_init(&bp->list_overhead);
+	(*cnt)--;
+	(*bcnt) -= ccnt;
+	pvr2_trace(PVR2_TRACE_BUF_FLOW,
+		   "/*---TRACE_FLOW---*/"
+		   " bufferPool     %8s dec cap=%07d cnt=%02d",
+		   pvr2_buffer_state_decode(bp->state),*bcnt,*cnt);
+	bp->state = pvr2_buffer_state_none;
+}
+
+static void pvr2_buffer_set_none(struct pvr2_buffer *bp)
+{
+	unsigned long irq_flags;
+	struct pvr2_stream *sp;
+	BUFFER_CHECK(bp);
+	sp = bp->stream;
+	pvr2_trace(PVR2_TRACE_BUF_FLOW,
+		   "/*---TRACE_FLOW---*/ bufferState    %p %6s --> %6s",
+		   bp,
+		   pvr2_buffer_state_decode(bp->state),
+		   pvr2_buffer_state_decode(pvr2_buffer_state_none));
+	spin_lock_irqsave(&sp->list_lock,irq_flags);
+	pvr2_buffer_remove(bp);
+	spin_unlock_irqrestore(&sp->list_lock,irq_flags);
+}
+
+static int pvr2_buffer_set_ready(struct pvr2_buffer *bp)
+{
+	int fl;
+	unsigned long irq_flags;
+	struct pvr2_stream *sp;
+	BUFFER_CHECK(bp);
+	sp = bp->stream;
+	pvr2_trace(PVR2_TRACE_BUF_FLOW,
+		   "/*---TRACE_FLOW---*/ bufferState    %p %6s --> %6s",
+		   bp,
+		   pvr2_buffer_state_decode(bp->state),
+		   pvr2_buffer_state_decode(pvr2_buffer_state_ready));
+	spin_lock_irqsave(&sp->list_lock,irq_flags);
+	fl = (sp->r_count == 0);
+	pvr2_buffer_remove(bp);
+	list_add_tail(&bp->list_overhead,&sp->ready_list);
+	bp->state = pvr2_buffer_state_ready;
+	(sp->r_count)++;
+	sp->r_bcount += bp->used_count;
+	pvr2_trace(PVR2_TRACE_BUF_FLOW,
+		   "/*---TRACE_FLOW---*/"
+		   " bufferPool     %8s inc cap=%07d cnt=%02d",
+		   pvr2_buffer_state_decode(bp->state),
+		   sp->r_bcount,sp->r_count);
+	spin_unlock_irqrestore(&sp->list_lock,irq_flags);
+	return fl;
+}
+
+static void pvr2_buffer_set_idle(struct pvr2_buffer *bp)
+{
+	unsigned long irq_flags;
+	struct pvr2_stream *sp;
+	BUFFER_CHECK(bp);
+	sp = bp->stream;
+	pvr2_trace(PVR2_TRACE_BUF_FLOW,
+		   "/*---TRACE_FLOW---*/ bufferState    %p %6s --> %6s",
+		   bp,
+		   pvr2_buffer_state_decode(bp->state),
+		   pvr2_buffer_state_decode(pvr2_buffer_state_idle));
+	spin_lock_irqsave(&sp->list_lock,irq_flags);
+	pvr2_buffer_remove(bp);
+	list_add_tail(&bp->list_overhead,&sp->idle_list);
+	bp->state = pvr2_buffer_state_idle;
+	(sp->i_count)++;
+	sp->i_bcount += bp->max_count;
+	pvr2_trace(PVR2_TRACE_BUF_FLOW,
+		   "/*---TRACE_FLOW---*/"
+		   " bufferPool     %8s inc cap=%07d cnt=%02d",
+		   pvr2_buffer_state_decode(bp->state),
+		   sp->i_bcount,sp->i_count);
+	spin_unlock_irqrestore(&sp->list_lock,irq_flags);
+}
+
+static void pvr2_buffer_set_queued(struct pvr2_buffer *bp)
+{
+	unsigned long irq_flags;
+	struct pvr2_stream *sp;
+	BUFFER_CHECK(bp);
+	sp = bp->stream;
+	pvr2_trace(PVR2_TRACE_BUF_FLOW,
+		   "/*---TRACE_FLOW---*/ bufferState    %p %6s --> %6s",
+		   bp,
+		   pvr2_buffer_state_decode(bp->state),
+		   pvr2_buffer_state_decode(pvr2_buffer_state_queued));
+	spin_lock_irqsave(&sp->list_lock,irq_flags);
+	pvr2_buffer_remove(bp);
+	list_add_tail(&bp->list_overhead,&sp->queued_list);
+	bp->state = pvr2_buffer_state_queued;
+	(sp->q_count)++;
+	sp->q_bcount += bp->max_count;
+	pvr2_trace(PVR2_TRACE_BUF_FLOW,
+		   "/*---TRACE_FLOW---*/"
+		   " bufferPool     %8s inc cap=%07d cnt=%02d",
+		   pvr2_buffer_state_decode(bp->state),
+		   sp->q_bcount,sp->q_count);
+	spin_unlock_irqrestore(&sp->list_lock,irq_flags);
+}
+
+static void pvr2_buffer_wipe(struct pvr2_buffer *bp)
+{
+	if (bp->state == pvr2_buffer_state_queued) {
+		usb_kill_urb(bp->purb);
+	}
+}
+
+static int pvr2_buffer_init(struct pvr2_buffer *bp,
+			    struct pvr2_stream *sp,
+			    unsigned int id)
+{
+	memset(bp,0,sizeof(*bp));
+	bp->signature = BUFFER_SIG;
+	bp->id = id;
+	pvr2_trace(PVR2_TRACE_BUF_POOL,
+		   "/*---TRACE_FLOW---*/ bufferInit     %p stream=%p",bp,sp);
+	bp->stream = sp;
+	bp->state = pvr2_buffer_state_none;
+	INIT_LIST_HEAD(&bp->list_overhead);
+	bp->purb = usb_alloc_urb(0,GFP_KERNEL);
+	if (! bp->purb) return -ENOMEM;
+#ifdef SANITY_CHECK_BUFFERS
+	pvr2_buffer_describe(bp,"create");
+#endif
+	return 0;
+}
+
+static void pvr2_buffer_done(struct pvr2_buffer *bp)
+{
+#ifdef SANITY_CHECK_BUFFERS
+	pvr2_buffer_describe(bp,"delete");
+#endif
+	pvr2_buffer_wipe(bp);
+	pvr2_buffer_set_none(bp);
+	bp->signature = 0;
+	bp->stream = 0;
+	if (bp->purb) usb_free_urb(bp->purb);
+	pvr2_trace(PVR2_TRACE_BUF_POOL,"/*---TRACE_FLOW---*/"
+		   " bufferDone     %p",bp);
+}
+
+static int pvr2_stream_buffer_count(struct pvr2_stream *sp,unsigned int cnt)
+{
+	int ret;
+	unsigned int scnt;
+
+	/* Allocate buffers pointer array in multiples of 32 entries */
+	if (cnt == sp->buffer_total_count) return 0;
+
+	pvr2_trace(PVR2_TRACE_BUF_POOL,
+		   "/*---TRACE_FLOW---*/ poolResize    "
+		   " stream=%p cur=%d adj=%+d",
+		   sp,
+		   sp->buffer_total_count,
+		   cnt-sp->buffer_total_count);
+
+	scnt = cnt & ~0x1f;
+	if (cnt > scnt) scnt += 0x20;
+
+	if (cnt > sp->buffer_total_count) {
+		if (scnt > sp->buffer_slot_count) {
+			struct pvr2_buffer **nb;
+			nb = kmalloc(scnt * sizeof(*nb),GFP_KERNEL);
+			if (!nb) return -ENOMEM;
+			if (sp->buffer_slot_count) {
+				memcpy(nb,sp->buffers,
+				       sp->buffer_slot_count * sizeof(*nb));
+				kfree(sp->buffers);
+			}
+			sp->buffers = nb;
+			sp->buffer_slot_count = scnt;
+		}
+		while (sp->buffer_total_count < cnt) {
+			struct pvr2_buffer *bp;
+			bp = kmalloc(sizeof(*bp),GFP_KERNEL);
+			if (!bp) return -ENOMEM;
+			ret = pvr2_buffer_init(bp,sp,sp->buffer_total_count);
+			if (ret) {
+				kfree(bp);
+				return -ENOMEM;
+			}
+			sp->buffers[sp->buffer_total_count] = bp;
+			(sp->buffer_total_count)++;
+			pvr2_buffer_set_idle(bp);
+		}
+	} else {
+		while (sp->buffer_total_count > cnt) {
+			struct pvr2_buffer *bp;
+			bp = sp->buffers[sp->buffer_total_count - 1];
+			/* Paranoia */
+			sp->buffers[sp->buffer_total_count - 1] = 0;
+			(sp->buffer_total_count)--;
+			pvr2_buffer_done(bp);
+			kfree(bp);
+		}
+		if (scnt < sp->buffer_slot_count) {
+			struct pvr2_buffer **nb = 0;
+			if (scnt) {
+				nb = kmalloc(scnt * sizeof(*nb),GFP_KERNEL);
+				if (!nb) return -ENOMEM;
+				memcpy(nb,sp->buffers,scnt * sizeof(*nb));
+			}
+			kfree(sp->buffers);
+			sp->buffers = nb;
+			sp->buffer_slot_count = scnt;
+		}
+	}
+	return 0;
+}
+
+static int pvr2_stream_achieve_buffer_count(struct pvr2_stream *sp)
+{
+	struct pvr2_buffer *bp;
+	unsigned int cnt;
+
+	if (sp->buffer_total_count == sp->buffer_target_count) return 0;
+
+	pvr2_trace(PVR2_TRACE_BUF_POOL,
+		   "/*---TRACE_FLOW---*/"
+		   " poolCheck      stream=%p cur=%d tgt=%d",
+		   sp,sp->buffer_total_count,sp->buffer_target_count);
+
+	if (sp->buffer_total_count < sp->buffer_target_count) {
+		return pvr2_stream_buffer_count(sp,sp->buffer_target_count);
+	}
+
+	cnt = 0;
+	while ((sp->buffer_total_count - cnt) > sp->buffer_target_count) {
+		bp = sp->buffers[sp->buffer_total_count - (cnt + 1)];
+		if (bp->state != pvr2_buffer_state_idle) break;
+		cnt++;
+	}
+	if (cnt) {
+		pvr2_stream_buffer_count(sp,sp->buffer_total_count - cnt);
+	}
+
+	return 0;
+}
+
+static void pvr2_stream_internal_flush(struct pvr2_stream *sp)
+{
+	struct list_head *lp;
+	struct pvr2_buffer *bp1;
+	while ((lp = sp->queued_list.next) != &sp->queued_list) {
+		bp1 = list_entry(lp,struct pvr2_buffer,list_overhead);
+		pvr2_buffer_wipe(bp1);
+		/* At this point, we should be guaranteed that no
+		   completion callback may happen on this buffer.  But it's
+		   possible that it might have completed after we noticed
+		   it but before we wiped it.  So double check its status
+		   here first. */
+		if (bp1->state != pvr2_buffer_state_queued) continue;
+		pvr2_buffer_set_idle(bp1);
+	}
+	if (sp->buffer_total_count != sp->buffer_target_count) {
+		pvr2_stream_achieve_buffer_count(sp);
+	}
+}
+
+static void pvr2_stream_init(struct pvr2_stream *sp)
+{
+	spin_lock_init(&sp->list_lock);
+	mutex_init(&sp->mutex);
+	INIT_LIST_HEAD(&sp->queued_list);
+	INIT_LIST_HEAD(&sp->ready_list);
+	INIT_LIST_HEAD(&sp->idle_list);
+}
+
+static void pvr2_stream_done(struct pvr2_stream *sp)
+{
+	mutex_lock(&sp->mutex); do {
+		pvr2_stream_internal_flush(sp);
+		pvr2_stream_buffer_count(sp,0);
+	} while (0); mutex_unlock(&sp->mutex);
+}
+
+static void buffer_complete(struct urb *urb, struct pt_regs *regs)
+{
+	struct pvr2_buffer *bp = urb->context;
+	struct pvr2_stream *sp;
+	unsigned long irq_flags;
+	BUFFER_CHECK(bp);
+	sp = bp->stream;
+	bp->used_count = 0;
+	bp->status = 0;
+	pvr2_trace(PVR2_TRACE_BUF_FLOW,
+		   "/*---TRACE_FLOW---*/ bufferComplete %p stat=%d cnt=%d",
+		   bp,urb->status,urb->actual_length);
+	spin_lock_irqsave(&sp->list_lock,irq_flags);
+	if ((!(urb->status)) ||
+	    (urb->status == -ENOENT) ||
+	    (urb->status == -ECONNRESET) ||
+	    (urb->status == -ESHUTDOWN)) {
+		bp->used_count = urb->actual_length;
+		if (sp->fail_count) {
+			pvr2_trace(PVR2_TRACE_TOLERANCE,
+				   "stream %p transfer ok"
+				   " - fail count reset",sp);
+			sp->fail_count = 0;
+		}
+	} else if (sp->fail_count < sp->fail_tolerance) {
+		// We can tolerate this error, because we're below the
+		// threshold...
+		(sp->fail_count)++;
+		pvr2_trace(PVR2_TRACE_TOLERANCE,
+			   "stream %p ignoring error %d"
+			   " - fail count increased to %u",
+			   sp,urb->status,sp->fail_count);
+	} else {
+		bp->status = urb->status;
+	}
+	spin_unlock_irqrestore(&sp->list_lock,irq_flags);
+	pvr2_buffer_set_ready(bp);
+	if (sp && sp->callback_func) {
+		sp->callback_func(sp->callback_data);
+	}
+}
+
+struct pvr2_stream *pvr2_stream_create(void)
+{
+	struct pvr2_stream *sp;
+	sp = kmalloc(sizeof(*sp),GFP_KERNEL);
+	if (!sp) return sp;
+	memset(sp,0,sizeof(*sp));
+	pvr2_trace(PVR2_TRACE_INIT,"pvr2_stream_create: sp=%p",sp);
+	pvr2_stream_init(sp);
+	return sp;
+}
+
+void pvr2_stream_destroy(struct pvr2_stream *sp)
+{
+	if (!sp) return;
+	pvr2_trace(PVR2_TRACE_INIT,"pvr2_stream_destroy: sp=%p",sp);
+	pvr2_stream_done(sp);
+	kfree(sp);
+}
+
+void pvr2_stream_setup(struct pvr2_stream *sp,
+		       struct usb_device *dev,
+		       int endpoint,
+		       unsigned int tolerance)
+{
+	mutex_lock(&sp->mutex); do {
+		pvr2_stream_internal_flush(sp);
+		sp->dev = dev;
+		sp->endpoint = endpoint;
+		sp->fail_tolerance = tolerance;
+	} while(0); mutex_unlock(&sp->mutex);
+}
+
+void pvr2_stream_set_callback(struct pvr2_stream *sp,
+			      pvr2_stream_callback func,
+			      void *data)
+{
+	unsigned long irq_flags;
+	mutex_lock(&sp->mutex); do {
+		spin_lock_irqsave(&sp->list_lock,irq_flags);
+		sp->callback_data = data;
+		sp->callback_func = func;
+		spin_unlock_irqrestore(&sp->list_lock,irq_flags);
+	} while(0); mutex_unlock(&sp->mutex);
+}
+
+/* Query / set the nominal buffer count */
+int pvr2_stream_get_buffer_count(struct pvr2_stream *sp)
+{
+	return sp->buffer_target_count;
+}
+
+int pvr2_stream_set_buffer_count(struct pvr2_stream *sp,unsigned int cnt)
+{
+	int ret;
+	if (sp->buffer_target_count == cnt) return 0;
+	mutex_lock(&sp->mutex); do {
+		sp->buffer_target_count = cnt;
+		ret = pvr2_stream_achieve_buffer_count(sp);
+	} while(0); mutex_unlock(&sp->mutex);
+	return ret;
+}
+
+struct pvr2_buffer *pvr2_stream_get_idle_buffer(struct pvr2_stream *sp)
+{
+	struct list_head *lp = sp->idle_list.next;
+	if (lp == &sp->idle_list) return 0;
+	return list_entry(lp,struct pvr2_buffer,list_overhead);
+}
+
+struct pvr2_buffer *pvr2_stream_get_ready_buffer(struct pvr2_stream *sp)
+{
+	struct list_head *lp = sp->ready_list.next;
+	if (lp == &sp->ready_list) return 0;
+	return list_entry(lp,struct pvr2_buffer,list_overhead);
+}
+
+struct pvr2_buffer *pvr2_stream_get_buffer(struct pvr2_stream *sp,int id)
+{
+	if (id < 0) return 0;
+	if (id >= sp->buffer_total_count) return 0;
+	return sp->buffers[id];
+}
+
+int pvr2_stream_get_ready_count(struct pvr2_stream *sp)
+{
+	return sp->r_count;
+}
+
+int pvr2_stream_get_idle_count(struct pvr2_stream *sp)
+{
+	return sp->i_count;
+}
+
+void pvr2_stream_flush(struct pvr2_stream *sp)
+{
+	mutex_lock(&sp->mutex); do {
+		pvr2_stream_internal_flush(sp);
+	} while(0); mutex_unlock(&sp->mutex);
+}
+
+void pvr2_stream_kill(struct pvr2_stream *sp)
+{
+	struct pvr2_buffer *bp;
+	mutex_lock(&sp->mutex); do {
+		pvr2_stream_internal_flush(sp);
+		while ((bp = pvr2_stream_get_ready_buffer(sp)) != 0) {
+			pvr2_buffer_set_idle(bp);
+		}
+		if (sp->buffer_total_count != sp->buffer_target_count) {
+			pvr2_stream_achieve_buffer_count(sp);
+		}
+	} while(0); mutex_unlock(&sp->mutex);
+}
+
+int pvr2_buffer_queue(struct pvr2_buffer *bp)
+{
+#undef SEED_BUFFER
+#ifdef SEED_BUFFER
+	unsigned int idx;
+	unsigned int val;
+#endif
+	int ret = 0;
+	struct pvr2_stream *sp;
+	if (!bp) return -EINVAL;
+	sp = bp->stream;
+	mutex_lock(&sp->mutex); do {
+		pvr2_buffer_wipe(bp);
+		if (!sp->dev) {
+			ret = -EIO;
+			break;
+		}
+		pvr2_buffer_set_queued(bp);
+#ifdef SEED_BUFFER
+		for (idx = 0; idx < (bp->max_count) / 4; idx++) {
+			val = bp->id << 24;
+			val |= idx;
+			((unsigned int *)(bp->ptr))[idx] = val;
+		}
+#endif
+		bp->status = -EINPROGRESS;
+		usb_fill_bulk_urb(bp->purb,      // struct urb *urb
+				  sp->dev,       // struct usb_device *dev
+				  // endpoint (below)
+				  usb_rcvbulkpipe(sp->dev,sp->endpoint),
+				  bp->ptr,       // void *transfer_buffer
+				  bp->max_count, // int buffer_length
+				  buffer_complete,
+				  bp);
+		usb_submit_urb(bp->purb,GFP_KERNEL);
+	} while(0); mutex_unlock(&sp->mutex);
+	return ret;
+}
+
+int pvr2_buffer_idle(struct pvr2_buffer *bp)
+{
+	struct pvr2_stream *sp;
+	if (!bp) return -EINVAL;
+	sp = bp->stream;
+	mutex_lock(&sp->mutex); do {
+		pvr2_buffer_wipe(bp);
+		pvr2_buffer_set_idle(bp);
+		if (sp->buffer_total_count != sp->buffer_target_count) {
+			pvr2_stream_achieve_buffer_count(sp);
+		}
+	} while(0); mutex_unlock(&sp->mutex);
+	return 0;
+}
+
+int pvr2_buffer_set_buffer(struct pvr2_buffer *bp,void *ptr,unsigned int cnt)
+{
+	int ret = 0;
+	unsigned long irq_flags;
+	struct pvr2_stream *sp;
+	if (!bp) return -EINVAL;
+	sp = bp->stream;
+	mutex_lock(&sp->mutex); do {
+		spin_lock_irqsave(&sp->list_lock,irq_flags);
+		if (bp->state != pvr2_buffer_state_idle) {
+			ret = -EPERM;
+		} else {
+			bp->ptr = ptr;
+			bp->stream->i_bcount -= bp->max_count;
+			bp->max_count = cnt;
+			bp->stream->i_bcount += bp->max_count;
+			pvr2_trace(PVR2_TRACE_BUF_FLOW,
+				   "/*---TRACE_FLOW---*/ bufferPool    "
+				   " %8s cap cap=%07d cnt=%02d",
+				   pvr2_buffer_state_decode(
+					   pvr2_buffer_state_idle),
+				   bp->stream->i_bcount,bp->stream->i_count);
+		}
+		spin_unlock_irqrestore(&sp->list_lock,irq_flags);
+	} while(0); mutex_unlock(&sp->mutex);
+	return ret;
+}
+
+unsigned int pvr2_buffer_get_count(struct pvr2_buffer *bp)
+{
+	return bp->used_count;
+}
+
+int pvr2_buffer_get_status(struct pvr2_buffer *bp)
+{
+	return bp->status;
+}
+
+enum pvr2_buffer_state pvr2_buffer_get_state(struct pvr2_buffer *bp)
+{
+	return bp->state;
+}
+
+int pvr2_buffer_get_id(struct pvr2_buffer *bp)
+{
+	return bp->id;
+}
+
+
+/*
+  Stuff for Emacs to see, in order to encourage consistent editing style:
+  *** Local Variables: ***
+  *** mode: c ***
+  *** fill-column: 75 ***
+  *** tab-width: 8 ***
+  *** c-basic-offset: 8 ***
+  *** End: ***
+  */