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authorHans Verkuil <hverkuil@xs4all.nl>2007-01-23 00:27:47 +0300
committerMauro Carvalho Chehab <mchehab@infradead.org>2007-02-21 18:34:48 +0300
commita63ad325c337ba634824cefe54f7ac52ee554b72 (patch)
tree2d53a0a03b048d83ec5dd09e0ea4933cbf8d3448 /Documentation/video4linux
parent5cc1dd8c3d8f80dbdce4d2e981a5e452af4b4529 (diff)
downloadlinux-a63ad325c337ba634824cefe54f7ac52ee554b72.tar.xz
V4L/DVB (5119): Various cx2341x documentation updates/fixes.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Diffstat (limited to 'Documentation/video4linux')
-rw-r--r--Documentation/video4linux/cx2341x/fw-dma.txt16
-rw-r--r--Documentation/video4linux/cx2341x/fw-encoder-api.txt10
-rw-r--r--Documentation/video4linux/cx2341x/fw-memory.txt4
3 files changed, 18 insertions, 12 deletions
diff --git a/Documentation/video4linux/cx2341x/fw-dma.txt b/Documentation/video4linux/cx2341x/fw-dma.txt
index 8123e262d5b6..be52b6fd1e9a 100644
--- a/Documentation/video4linux/cx2341x/fw-dma.txt
+++ b/Documentation/video4linux/cx2341x/fw-dma.txt
@@ -22,6 +22,8 @@ urged to choose a smaller block size and learn the scatter-gather technique.
Mailbox #10 is reserved for DMA transfer information.
+Note: the hardware expects little-endian data ('intel format').
+
Flow
====
@@ -64,7 +66,7 @@ addresses are the physical memory location of the target DMA buffer.
Each S-G array element is a struct of three 32-bit words. The first word is
the source address, the second is the destination address. Both take up the
-entire 32 bits. The lowest 16 bits of the third word is the transfer byte
+entire 32 bits. The lowest 18 bits of the third word is the transfer byte
count. The high-bit of the third word is the "last" flag. The last-flag tells
the card to raise the DMA_DONE interrupt. From hard personal experience, if
you forget to set this bit, the card will still "work" but the stream will
@@ -78,8 +80,8 @@ Array Element:
- 32-bit Source Address
- 32-bit Destination Address
-- 16-bit reserved (high bit is the last flag)
-- 16-bit byte count
+- 14-bit reserved (high bit is the last flag)
+- 18-bit byte count
DMA Transfer Status
===================
@@ -87,8 +89,8 @@ DMA Transfer Status
Register 0x0004 holds the DMA Transfer Status:
Bit
-4 Scatter-Gather array error
-3 DMA write error
-2 DMA read error
-1 write completed
0 read completed
+1 write completed
+2 DMA read error
+3 DMA write error
+4 Scatter-Gather array error
diff --git a/Documentation/video4linux/cx2341x/fw-encoder-api.txt b/Documentation/video4linux/cx2341x/fw-encoder-api.txt
index fe02bdb84598..e499cc07fe3d 100644
--- a/Documentation/video4linux/cx2341x/fw-encoder-api.txt
+++ b/Documentation/video4linux/cx2341x/fw-encoder-api.txt
@@ -498,12 +498,14 @@ Name CX2341X_ENC_GET_PREV_DMA_INFO_MB_9
Enum 203/0xCB
Description
Returns information on the previous DMA transfer in conjunction with
- bit 27 of the interrupt mask. Uses mailbox 9.
+ bit 27 or 18 of the interrupt mask. Uses mailbox 9.
Result[0]
Status bits:
- Bit 0 set indicates transfer complete
- Bit 2 set indicates transfer error
- Bit 4 set indicates linked list error
+ 0 read completed
+ 1 write completed
+ 2 DMA read error
+ 3 DMA write error
+ 4 Scatter-Gather array error
Result[1]
DMA type
Result[2]
diff --git a/Documentation/video4linux/cx2341x/fw-memory.txt b/Documentation/video4linux/cx2341x/fw-memory.txt
index d445e457fc1b..9d736fe8de66 100644
--- a/Documentation/video4linux/cx2341x/fw-memory.txt
+++ b/Documentation/video4linux/cx2341x/fw-memory.txt
@@ -1,6 +1,8 @@
This document describes the cx2341x memory map and documents some of the register
space.
+Note: the memory long words are little-endian ('intel format').
+
Warning! This information was figured out from searching through the memory and
registers, this information may not be correct and is certainly not complete, and
was not derived from anything more than searching through the memory space with
@@ -67,7 +69,7 @@ DMA Registers 0x000-0xff:
0x84 - first write linked list reg, for pci memory addr
0x88 - first write linked list reg, for length of buffer in memory addr
(|0x80000000 or this for last link)
- 0x8c-0xcc - rest of write linked list reg, 8 sets of 3 total, DMA goes here
+ 0x8c-0xdc - rest of write linked list reg, 8 sets of 3 total, DMA goes here
from linked list addr in reg 0x0c, firmware must push through or
something.
0xe0 - first (and only) read linked list reg, for pci memory addr