summaryrefslogtreecommitdiff
path: root/Documentation/media
diff options
context:
space:
mode:
authorMauro Carvalho Chehab <mchehab@s-opensource.com>2016-07-18 16:42:17 (GMT)
committerMauro Carvalho Chehab <mchehab@s-opensource.com>2016-07-18 16:42:17 (GMT)
commit290bbbfe872c7a5aa54bf34c31447496182553a8 (patch)
tree6834f480e5a40f8cffce4e13dc51059d5c7493e0 /Documentation/media
parentf8eb496f4cadb392f03f329bf586a8134174a502 (diff)
downloadlinux-290bbbfe872c7a5aa54bf34c31447496182553a8.tar.xz
[media] cx2341x.rst: add contents of fw-memory.txt
Convert the content to ReST and add it at the cx231xx.rst file. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Diffstat (limited to 'Documentation/media')
-rw-r--r--Documentation/media/v4l-drivers/cx2341x.rst151
1 files changed, 151 insertions, 0 deletions
diff --git a/Documentation/media/v4l-drivers/cx2341x.rst b/Documentation/media/v4l-drivers/cx2341x.rst
index ca2f15c..ed7e536 100644
--- a/Documentation/media/v4l-drivers/cx2341x.rst
+++ b/Documentation/media/v4l-drivers/cx2341x.rst
@@ -1,6 +1,157 @@
The cx2341x driver
==================
+Memory at cx2341x chips
+-----------------------
+
+This section 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:
+
+ .. code-block:: none
+
+ 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.
+
+.. code-block:: none
+
+ 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.
+
+.. code-block:: none
+
+ 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
+- bit 30 Encoder EOS
+- bit 29 Encoder VBI capture
+- bit 28 Encoder Video Input Module reset event
+- bit 27 Encoder DMA complete
+- bit 24 Decoder audio mode change detection event (through event notification)
+- bit 22 Decoder data request
+- bit 20 Decoder DMA complete
+- bit 19 Decoder VBI re-insertion
+- bit 18 Decoder DMA err (linked-list bad)
+
+Missing documentation
+---------------------
+
+- Encoder API post(?)
+- Decoder API post(?)
+- Decoder VTRACE event
+
+
How to call the firmware API
----------------------------