V4L/DVB (5345): ivtv driver for Conexant cx23416/cx23415 MPEG encoder/decoder

It took three core maintainers, over four years of work, eight new i2c
modules, eleven new V4L2 ioctls, three new DVB video ioctls, a Sliced
VBI API, a new MPEG encoder API, an enhanced DVB video MPEG decoding
API, major YUV/OSD contributions from Ian and John, web/wiki/svn/trac
support from Axel Thimm, (hardware) support from Hauppauge, support and
assistance from the v4l-dvb people and the many, many users of ivtv to
finally make it possible to merge this driver into the kernel.
Thank you all!

Signed-off-by: Kevin Thayer <nufan_wfk@yahoo.com>
Signed-off-by: Chris Kennedy <c@groovy.org>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: John P Harvey <john.p.harvey@btinternet.com>
Signed-off-by: Ian Armstrong <ian@iarmst.demon.co.uk>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

1 files changed, 262 insertions, 0 deletions

diff --git a/drivers/media/video/ivtv/ivtv-queue.c b/drivers/media/video/ivtv/ivtv-queue.c
new file mode 100644
index 000000000000..ccfcef1ad91a
--- /dev/null
+++ b/drivers/media/video/ivtv/ivtv-queue.c
@@ -0,0 +1,262 @@
+/*
+    buffer queues.
+    Copyright (C) 2003-2004  Kevin Thayer <nufan_wfk at yahoo.com>
+    Copyright (C) 2004  Chris Kennedy <c@groovy.org>
+    Copyright (C) 2005-2007  Hans Verkuil <hverkuil@xs4all.nl>
+
+    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, 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 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 "ivtv-driver.h"
+#include "ivtv-streams.h"
+#include "ivtv-queue.h"
+#include "ivtv-mailbox.h"
+
+int ivtv_buf_copy_from_user(struct ivtv_stream *s, struct ivtv_buffer *buf, const char __user *src, int copybytes)
+{
+	if (s->buf_size - buf->bytesused < copybytes)
+		copybytes = s->buf_size - buf->bytesused;
+	if (copy_from_user(buf->buf + buf->bytesused, src, copybytes)) {
+		return -EFAULT;
+	}
+	buf->bytesused += copybytes;
+	return copybytes;
+}
+
+void ivtv_buf_swap(struct ivtv_buffer *buf)
+{
+	int i;
+
+	for (i = 0; i < buf->bytesused; i += 4)
+		swab32s((u32 *)(buf->buf + i));
+}
+
+void ivtv_queue_init(struct ivtv_queue *q)
+{
+	INIT_LIST_HEAD(&q->list);
+	q->buffers = 0;
+	q->length = 0;
+	q->bytesused = 0;
+}
+
+void ivtv_enqueue(struct ivtv_stream *s, struct ivtv_buffer *buf, struct ivtv_queue *q)
+{
+	unsigned long flags = 0;
+
+	/* clear the buffer if it is going to be enqueued to the free queue */
+	if (q == &s->q_free) {
+		buf->bytesused = 0;
+		buf->readpos = 0;
+		buf->b_flags = 0;
+	}
+	spin_lock_irqsave(&s->qlock, flags);
+	list_add_tail(&buf->list, &q->list);
+	q->buffers++;
+	q->length += s->buf_size;
+	q->bytesused += buf->bytesused - buf->readpos;
+	spin_unlock_irqrestore(&s->qlock, flags);
+}
+
+struct ivtv_buffer *ivtv_dequeue(struct ivtv_stream *s, struct ivtv_queue *q)
+{
+	struct ivtv_buffer *buf = NULL;
+	unsigned long flags = 0;
+
+	spin_lock_irqsave(&s->qlock, flags);
+	if (!list_empty(&q->list)) {
+		buf = list_entry(q->list.next, struct ivtv_buffer, list);
+		list_del_init(q->list.next);
+		q->buffers--;
+		q->length -= s->buf_size;
+		q->bytesused -= buf->bytesused - buf->readpos;
+	}
+	spin_unlock_irqrestore(&s->qlock, flags);
+	return buf;
+}
+
+static void ivtv_queue_move_buf(struct ivtv_stream *s, struct ivtv_queue *from,
+		struct ivtv_queue *to, int clear, int full)
+{
+	struct ivtv_buffer *buf = list_entry(from->list.next, struct ivtv_buffer, list);
+
+	list_move_tail(from->list.next, &to->list);
+	from->buffers--;
+	from->length -= s->buf_size;
+	from->bytesused -= buf->bytesused - buf->readpos;
+	/* special handling for q_free */
+	if (clear)
+		buf->bytesused = buf->readpos = buf->b_flags = 0;
+	else if (full) {
+		/* special handling for stolen buffers, assume
+		   all bytes are used. */
+		buf->bytesused = s->buf_size;
+		buf->readpos = buf->b_flags = 0;
+	}
+	to->buffers++;
+	to->length += s->buf_size;
+	to->bytesused += buf->bytesused - buf->readpos;
+}
+
+/* Move 'needed_bytes' worth of buffers from queue 'from' into queue 'to'.
+   If 'needed_bytes' == 0, then move all buffers from 'from' into 'to'.
+   If 'steal' != NULL, then buffers may also taken from that queue if
+   needed.
+
+   The buffer is automatically cleared if it goes to the free queue. It is
+   also cleared if buffers need to be taken from the 'steal' queue and
+   the 'from' queue is the free queue.
+
+   When 'from' is q_free, then needed_bytes is compared to the total
+   available buffer length, otherwise needed_bytes is compared to the
+   bytesused value. For the 'steal' queue the total available buffer
+   length is always used.
+
+   -ENOMEM is returned if the buffers could not be obtained, 0 if all
+   buffers where obtained from the 'from' list and if non-zero then
+   the number of stolen buffers is returned. */
+int ivtv_queue_move(struct ivtv_stream *s, struct ivtv_queue *from, struct ivtv_queue *steal,
+		    struct ivtv_queue *to, int needed_bytes)
+{
+	unsigned long flags;
+	int rc = 0;
+	int from_free = from == &s->q_free;
+	int to_free = to == &s->q_free;
+	int bytes_available;
+
+	spin_lock_irqsave(&s->qlock, flags);
+	if (needed_bytes == 0) {
+		from_free = 1;
+		needed_bytes = from->length;
+	}
+
+	bytes_available = from_free ? from->length : from->bytesused;
+	bytes_available += steal ? steal->length : 0;
+
+	if (bytes_available < needed_bytes) {
+		spin_unlock_irqrestore(&s->qlock, flags);
+		return -ENOMEM;
+	}
+	if (from_free) {
+		u32 old_length = to->length;
+
+		while (to->length - old_length < needed_bytes) {
+			if (list_empty(&from->list))
+				from = steal;
+			if (from == steal)
+				rc++; 		/* keep track of 'stolen' buffers */
+			ivtv_queue_move_buf(s, from, to, 1, 0);
+		}
+	}
+	else {
+		u32 old_bytesused = to->bytesused;
+
+		while (to->bytesused - old_bytesused < needed_bytes) {
+			if (list_empty(&from->list))
+				from = steal;
+			if (from == steal)
+				rc++; 		/* keep track of 'stolen' buffers */
+			ivtv_queue_move_buf(s, from, to, to_free, rc);
+		}
+	}
+	spin_unlock_irqrestore(&s->qlock, flags);
+	return rc;
+}
+
+void ivtv_flush_queues(struct ivtv_stream *s)
+{
+	ivtv_queue_move(s, &s->q_io, NULL, &s->q_free, 0);
+	ivtv_queue_move(s, &s->q_full, NULL, &s->q_free, 0);
+	ivtv_queue_move(s, &s->q_dma, NULL, &s->q_free, 0);
+	ivtv_queue_move(s, &s->q_predma, NULL, &s->q_free, 0);
+}
+
+int ivtv_stream_alloc(struct ivtv_stream *s)
+{
+	struct ivtv *itv = s->itv;
+	int SGsize = sizeof(struct ivtv_SG_element) * s->buffers;
+	int i;
+
+	if (s->buffers == 0)
+		return 0;
+
+	IVTV_DEBUG_INFO("Allocate %s%s stream: %d x %d buffers (%dkB total)\n",
+		s->dma != PCI_DMA_NONE ? "DMA " : "",
+		s->name, s->buffers, s->buf_size, s->buffers * s->buf_size / 1024);
+
+	/* Allocate DMA SG Arrays */
+	if (s->dma != PCI_DMA_NONE) {
+		s->SGarray = (struct ivtv_SG_element *)kzalloc(SGsize, GFP_KERNEL);
+		if (s->SGarray == NULL) {
+			IVTV_ERR("Could not allocate SGarray for %s stream\n", s->name);
+			return -ENOMEM;
+		}
+		s->SG_length = 0;
+		s->SG_handle = pci_map_single(itv->dev, s->SGarray, SGsize, s->dma);
+		ivtv_stream_sync_for_cpu(s);
+	}
+
+	/* allocate stream buffers. Initially all buffers are in q_free. */
+	for (i = 0; i < s->buffers; i++) {
+		struct ivtv_buffer *buf = kzalloc(sizeof(struct ivtv_buffer), GFP_KERNEL);
+
+		if (buf == NULL)
+			break;
+		buf->buf = kmalloc(s->buf_size + 256, GFP_KERNEL);
+		if (buf->buf == NULL) {
+			kfree(buf);
+			break;
+		}
+		INIT_LIST_HEAD(&buf->list);
+		if (s->dma != PCI_DMA_NONE) {
+			buf->dma_handle = pci_map_single(s->itv->dev,
+				buf->buf, s->buf_size + 256, s->dma);
+			ivtv_buf_sync_for_cpu(s, buf);
+		}
+		ivtv_enqueue(s, buf, &s->q_free);
+	}
+	if (i == s->buffers)
+		return 0;
+	IVTV_ERR("Couldn't allocate buffers for %s stream\n", s->name);
+	ivtv_stream_free(s);
+	return -ENOMEM;
+}
+
+void ivtv_stream_free(struct ivtv_stream *s)
+{
+	struct ivtv_buffer *buf;
+
+	/* move all buffers to q_free */
+	ivtv_flush_queues(s);
+
+	/* empty q_free */
+	while ((buf = ivtv_dequeue(s, &s->q_free))) {
+		if (s->dma != PCI_DMA_NONE)
+			pci_unmap_single(s->itv->dev, buf->dma_handle,
+				s->buf_size + 256, s->dma);
+		kfree(buf->buf);
+		kfree(buf);
+	}
+
+	/* Free SG Array/Lists */
+	if (s->SGarray != NULL) {
+		if (s->SG_handle != IVTV_DMA_UNMAPPED) {
+			pci_unmap_single(s->itv->dev, s->SG_handle,
+				 sizeof(struct ivtv_SG_element) * s->buffers, PCI_DMA_TODEVICE);
+			s->SG_handle = IVTV_DMA_UNMAPPED;
+		}
+		s->SGarray = NULL;
+		s->SG_length = 0;
+	}
+}