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Diffstat (limited to 'Documentation/video4linux/cx2341x/fw-memory.txt')
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diff --git a/Documentation/video4linux/cx2341x/fw-memory.txt b/Documentation/video4linux/cx2341x/fw-memory.txt new file mode 100644 index 000000000..9d736fe8d --- /dev/null +++ b/Documentation/video4linux/cx2341x/fw-memory.txt @@ -0,0 +1,139 @@ +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 +commands like: + + ivtvctl -O min=0x02000000,max=0x020000ff + +So take this as is, I'm always searching for more stuff, it's a large +register space :-). + +Memory Map +========== + +The cx2341x exposes its entire 64M memory space to the PCI host via the PCI BAR0 +(Base Address Register 0). The addresses here are offsets relative to the +address held in BAR0. + +0x00000000-0x00ffffff Encoder memory space +0x00000000-0x0003ffff Encode.rom + ???-??? MPEG buffer(s) + ???-??? Raw video capture buffer(s) + ???-??? Raw audio capture buffer(s) + ???-??? Display buffers (6 or 9) + +0x01000000-0x01ffffff Decoder memory space +0x01000000-0x0103ffff Decode.rom + ???-??? MPEG buffers(s) +0x0114b000-0x0115afff Audio.rom (deprecated?) + +0x02000000-0x0200ffff Register Space + +Registers +========= + +The registers occupy the 64k space starting at the 0x02000000 offset from BAR0. +All of these registers are 32 bits wide. + +DMA Registers 0x000-0xff: + + 0x00 - Control: + 0=reset/cancel, 1=read, 2=write, 4=stop + 0x04 - DMA status: + 1=read busy, 2=write busy, 4=read error, 8=write error, 16=link list error + 0x08 - pci DMA pointer for read link list + 0x0c - pci DMA pointer for write link list + 0x10 - read/write DMA enable: + 1=read enable, 2=write enable + 0x14 - always 0xffffffff, if set any lower instability occurs, 0x00 crashes + 0x18 - ?? + 0x1c - always 0x20 or 32, smaller values slow down DMA transactions + 0x20 - always value of 0x780a010a + 0x24-0x3c - usually just random values??? + 0x40 - Interrupt status + 0x44 - Write a bit here and shows up in Interrupt status 0x40 + 0x48 - Interrupt Mask + 0x4C - always value of 0xfffdffff, + if changed to 0xffffffff DMA write interrupts break. + 0x50 - always 0xffffffff + 0x54 - always 0xffffffff (0x4c, 0x50, 0x54 seem like interrupt masks, are + 3 processors on chip, Java ones, VPU, SPU, APU, maybe these are the + interrupt masks???). + 0x60-0x7C - random values + 0x80 - first write linked list reg, for Encoder Memory addr + 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-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 + 0xe4 - first (and only) read linked list reg, for Decoder memory addr + 0xe8 - first (and only) read linked list reg, for length of buffer + 0xec-0xff - Nothing seems to be in these registers, 0xec-f4 are 0x00000000. + +Memory locations for Encoder Buffers 0x700-0x7ff: + +These registers show offsets of memory locations pertaining to each +buffer area used for encoding, have to shift them by <<1 first. + +0x07F8: Encoder SDRAM refresh +0x07FC: Encoder SDRAM pre-charge + +Memory locations for Decoder Buffers 0x800-0x8ff: + +These registers show offsets of memory locations pertaining to each +buffer area used for decoding, have to shift them by <<1 first. + +0x08F8: Decoder SDRAM refresh +0x08FC: Decoder SDRAM pre-charge + +Other memory locations: + +0x2800: Video Display Module control +0x2D00: AO (audio output?) control +0x2D24: Bytes Flushed +0x7000: LSB I2C write clock bit (inverted) +0x7004: LSB I2C write data bit (inverted) +0x7008: LSB I2C read clock bit +0x700c: LSB I2C read data bit +0x9008: GPIO get input state +0x900c: GPIO set output state +0x9020: GPIO direction (Bit7 (GPIO 0..7) - 0:input, 1:output) +0x9050: SPU control +0x9054: Reset HW blocks +0x9058: VPU control +0xA018: Bit6: interrupt pending? +0xA064: APU command + + +Interrupt Status Register +========================= + +The definition of the bits in the interrupt status register 0x0040, and the +interrupt mask 0x0048. If a bit is cleared in the mask, then we want our ISR to +execute. + +Bit +31 Encoder Start Capture +30 Encoder EOS +29 Encoder VBI capture +28 Encoder Video Input Module reset event +27 Encoder DMA complete +24 Decoder audio mode change detection event (through event notification) +22 Decoder data request +20 Decoder DMA complete +19 Decoder VBI re-insertion +18 Decoder DMA err (linked-list bad) + +Missing +Encoder API call completed +Decoder API call completed +Encoder API post(?) +Decoder API post(?) +Decoder VTRACE event |