diff options
Diffstat (limited to 'Documentation/video4linux/cx2341x')
| -rw-r--r-- | Documentation/video4linux/cx2341x/fw-dma.txt | 16 | ||||
| -rw-r--r-- | Documentation/video4linux/cx2341x/fw-encoder-api.txt | 10 | ||||
| -rw-r--r-- | Documentation/video4linux/cx2341x/fw-memory.txt | 4 |
3 files changed, 18 insertions, 12 deletions
diff --git a/Documentation/video4linux/cx2341x/fw-dma.txt b/Documentation/video4linux/cx2341x/fw-dma.txt index 8123e262d5b..be52b6fd1e9 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 fe02bdb8459..e499cc07fe3 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 d445e457fc1..9d736fe8de6 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 |