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, 200 insertions, 0 deletions

diff --git a/drivers/media/video/ivtv/ivtv-udma.c b/drivers/media/video/ivtv/ivtv-udma.c
new file mode 100644
index 00000000000..bd642e1aafc
--- /dev/null
+++ b/drivers/media/video/ivtv/ivtv-udma.c
@@ -0,0 +1,200 @@
+/*
+    User DMA
+
+    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-udma.h"
+
+void ivtv_udma_get_page_info(struct ivtv_dma_page_info *dma_page, unsigned long first, unsigned long size)
+{
+	dma_page->uaddr = first & PAGE_MASK;
+	dma_page->offset = first & ~PAGE_MASK;
+	dma_page->tail = 1 + ((first+size-1) & ~PAGE_MASK);
+	dma_page->first = (first & PAGE_MASK) >> PAGE_SHIFT;
+	dma_page->last = ((first+size-1) & PAGE_MASK) >> PAGE_SHIFT;
+	dma_page->page_count = dma_page->last - dma_page->first + 1;
+	if (dma_page->page_count == 1) dma_page->tail -= dma_page->offset;
+}
+
+int ivtv_udma_fill_sg_list (struct ivtv_user_dma *dma, struct ivtv_dma_page_info *dma_page, int map_offset)
+{
+	int i, offset;
+
+	offset = dma_page->offset;
+
+	/* Fill SG Array with new values */
+	for (i = 0; i < dma_page->page_count; i++) {
+		if (i == dma_page->page_count - 1) {
+			dma->SGlist[map_offset].length = dma_page->tail;
+		}
+		else {
+			dma->SGlist[map_offset].length = PAGE_SIZE - offset;
+		}
+		dma->SGlist[map_offset].offset = offset;
+		dma->SGlist[map_offset].page = dma->map[map_offset];
+		offset = 0;
+		map_offset++;
+	}
+	return map_offset;
+}
+
+void ivtv_udma_fill_sg_array (struct ivtv_user_dma *dma, u32 buffer_offset, u32 buffer_offset_2, u32 split) {
+	int i;
+	struct scatterlist *sg;
+
+	for (i = 0, sg = dma->SGlist; i < dma->SG_length; i++, sg++) {
+		dma->SGarray[i].size = cpu_to_le32(sg_dma_len(sg));
+		dma->SGarray[i].src = cpu_to_le32(sg_dma_address(sg));
+		dma->SGarray[i].dst = cpu_to_le32(buffer_offset);
+		buffer_offset += sg_dma_len(sg);
+
+		split -= sg_dma_len(sg);
+		if (split == 0)
+			buffer_offset = buffer_offset_2;
+	}
+}
+
+/* User DMA Buffers */
+void ivtv_udma_alloc(struct ivtv *itv)
+{
+	if (itv->udma.SG_handle == 0) {
+		/* Map DMA Page Array Buffer */
+		itv->udma.SG_handle = pci_map_single(itv->dev, itv->udma.SGarray,
+			   sizeof(itv->udma.SGarray), PCI_DMA_TODEVICE);
+		ivtv_udma_sync_for_cpu(itv);
+	}
+}
+
+int ivtv_udma_setup(struct ivtv *itv, unsigned long ivtv_dest_addr,
+		       void __user *userbuf, int size_in_bytes)
+{
+	struct ivtv_dma_page_info user_dma;
+	struct ivtv_user_dma *dma = &itv->udma;
+	int err;
+
+	IVTV_DEBUG_DMA("ivtv_udma_setup, dst: 0x%08x\n", (unsigned int)ivtv_dest_addr);
+
+	/* Still in USE */
+	if (dma->SG_length || dma->page_count) {
+		IVTV_DEBUG_WARN("ivtv_udma_setup: SG_length %d page_count %d still full?\n",
+			   dma->SG_length, dma->page_count);
+		return -EBUSY;
+	}
+
+	ivtv_udma_get_page_info(&user_dma, (unsigned long)userbuf, size_in_bytes);
+
+	if (user_dma.page_count <= 0) {
+		IVTV_DEBUG_WARN("ivtv_udma_setup: Error %d page_count from %d bytes %d offset\n",
+			   user_dma.page_count, size_in_bytes, user_dma.offset);
+		return -EINVAL;
+	}
+
+	/* Get user pages for DMA Xfer */
+	down_read(&current->mm->mmap_sem);
+	err = get_user_pages(current, current->mm,
+			user_dma.uaddr, user_dma.page_count, 0, 1, dma->map, NULL);
+	up_read(&current->mm->mmap_sem);
+
+	if (user_dma.page_count != err) {
+		IVTV_DEBUG_WARN("failed to map user pages, returned %d instead of %d\n",
+			   err, user_dma.page_count);
+		return -EINVAL;
+	}
+
+	dma->page_count = user_dma.page_count;
+
+	/* Fill SG List with new values */
+	ivtv_udma_fill_sg_list(dma, &user_dma, 0);
+
+	/* Map SG List */
+	dma->SG_length = pci_map_sg(itv->dev, dma->SGlist, dma->page_count, PCI_DMA_TODEVICE);
+
+	/* Fill SG Array with new values */
+	ivtv_udma_fill_sg_array (dma, ivtv_dest_addr, 0, -1);
+
+	/* Tag SG Array with Interrupt Bit */
+	dma->SGarray[dma->SG_length - 1].size |= cpu_to_le32(0x80000000);
+
+	ivtv_udma_sync_for_device(itv);
+	return dma->page_count;
+}
+
+void ivtv_udma_unmap(struct ivtv *itv)
+{
+	struct ivtv_user_dma *dma = &itv->udma;
+	int i;
+
+	IVTV_DEBUG_INFO("ivtv_unmap_user_dma\n");
+
+	/* Nothing to free */
+	if (dma->page_count == 0)
+		return;
+
+	/* Unmap Scatterlist */
+	if (dma->SG_length) {
+		pci_unmap_sg(itv->dev, dma->SGlist, dma->page_count, PCI_DMA_TODEVICE);
+		dma->SG_length = 0;
+	}
+	/* sync DMA */
+	ivtv_udma_sync_for_cpu(itv);
+
+	/* Release User Pages */
+	for (i = 0; i < dma->page_count; i++) {
+		put_page(dma->map[i]);
+	}
+	dma->page_count = 0;
+}
+
+void ivtv_udma_free(struct ivtv *itv)
+{
+	/* Unmap SG Array */
+	if (itv->udma.SG_handle) {
+		pci_unmap_single(itv->dev, itv->udma.SG_handle,
+			 sizeof(itv->udma.SGarray), PCI_DMA_TODEVICE);
+	}
+
+	/* Unmap Scatterlist */
+	if (itv->udma.SG_length) {
+		pci_unmap_sg(itv->dev, itv->udma.SGlist, itv->udma.page_count, PCI_DMA_TODEVICE);
+	}
+}
+
+void ivtv_udma_start(struct ivtv *itv)
+{
+	IVTV_DEBUG_DMA("start UDMA\n");
+	write_reg(itv->udma.SG_handle, IVTV_REG_DECDMAADDR);
+	write_reg_sync(read_reg(IVTV_REG_DMAXFER) | 0x01, IVTV_REG_DMAXFER);
+	set_bit(IVTV_F_I_DMA, &itv->i_flags);
+	set_bit(IVTV_F_I_UDMA, &itv->i_flags);
+}
+
+void ivtv_udma_prepare(struct ivtv *itv)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&itv->dma_reg_lock, flags);
+	if (!test_bit(IVTV_F_I_DMA, &itv->i_flags))
+		ivtv_udma_start(itv);
+	else
+		set_bit(IVTV_F_I_UDMA_PENDING, &itv->i_flags);
+	spin_unlock_irqrestore(&itv->dma_reg_lock, flags);
+}