Commit f0d17227 authored by Mauro Carvalho Chehab's avatar Mauro Carvalho Chehab
Browse files

[media] cx88.rst: add contents of hauppauge-wintv-cx88-ir.txt 



Import the contents of hauppauge-wintv-cx88-ir.txt, after
converted to ReST into cx88.rst file.

Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@s-opensource.com>
parent 2b8de4ea

Documentation/media/v4l-drivers/cx88.rst

+62 −0
Original line number Diff line number Diff line
@@ -98,3 +98,65 @@ MO_OUTPUT_FORMAT (0x310164) 
0x47 is the sync byte for MPEG-2 transport stream packets.

Datasheet incorrectly states to use 47 decimal. 188 is the length.

All DVB compliant frontends output packets with this start code.



Hauppauge WinTV cx88 IR information

-----------------------------------



The controls for the mux are GPIO [0,1] for source, and GPIO 2 for muting.



====== ======== =================================================

GPIO0  GPIO1

====== ======== =================================================

  0        0    TV Audio

  1        0    FM radio

  0        1    Line-In

  1        1    Mono tuner bypass or CD passthru (tuner specific)

====== ======== =================================================



GPIO 16(I believe) is tied to the IR port (if present).





From the data sheet:



- Register 24'h20004  PCI Interrupt Status

 - bit [18]  IR_SMP_INT Set when 32 input samples have been collected over

 - gpio[16] pin into GP_SAMPLE register.



What's missing from the data sheet:



- Setup 4KHz sampling rate (roughly 2x oversampled; good enough for our RC5

  compat remote)

- set register 0x35C050 to  0xa80a80

- enable sampling

- set register 0x35C054 to 0x5

- enable the IRQ bit 18 in the interrupt mask register (and

  provide for a handler)



GP_SAMPLE register is at 0x35C058



Bits are then right shifted into the GP_SAMPLE register at the specified

rate; you get an interrupt when a full DWORD is received.

You need to recover the actual RC5 bits out of the (oversampled) IR sensor

bits. (Hint: look for the 0/1and 1/0 crossings of the RC5 bi-phase data)  An

actual raw RC5 code will span 2-3 DWORDS, depending on the actual alignment.



I'm pretty sure when no IR signal is present the receiver is always in a

marking state(1); but stray light, etc can cause intermittent noise values

as well.  Remember, this is a free running sample of the IR receiver state

over time, so don't assume any sample starts at any particular place.



Additional info

~~~~~~~~~~~~~~~



This data sheet (google search) seems to have a lovely description of the

RC5 basics:

http://www.atmel.com/dyn/resources/prod_documents/doc2817.pdf



This document has more data:

http://www.nenya.be/beor/electronics/rc5.htm



This document has a  how to decode a bi-phase data stream:

http://www.ee.washington.edu/circuit_archive/text/ir_decode.txt



This document has still more info:

http://www.xs4all.nl/~sbp/knowledge/ir/rc5.htm

Documentation/video4linux/cx88/hauppauge-wintv-cx88-ir.txt

deleted100644 → 0
+0 −54
Original line number Diff line number Diff line 
The controls for the mux are GPIO [0,1] for source, and GPIO 2 for muting.



GPIO0  GPIO1

  0        0    TV Audio

  1        0    FM radio

  0        1    Line-In

  1        1    Mono tuner bypass or CD passthru (tuner specific)



GPIO 16(i believe) is tied to the IR port (if present).



------------------------------------------------------------------------------------



>From the data sheet:

 Register 24'h20004  PCI Interrupt Status

  bit [18]  IR_SMP_INT Set when 32 input samples have been collected over

  gpio[16] pin into GP_SAMPLE register.



What's missing from the data sheet:



Setup 4KHz sampling rate (roughly 2x oversampled; good enough for our RC5

compat remote)

set register 0x35C050 to  0xa80a80



enable sampling

set register 0x35C054 to 0x5



Of course, enable the IRQ bit 18 in the interrupt mask register .(and

provide for a handler)



GP_SAMPLE register is at 0x35C058



Bits are then right shifted into the GP_SAMPLE register at the specified

rate; you get an interrupt when a full DWORD is received.

You need to recover the actual RC5 bits out of the (oversampled) IR sensor

bits. (Hint: look for the 0/1and 1/0 crossings of the RC5 bi-phase data)  An

actual raw RC5 code will span 2-3 DWORDS, depending on the actual alignment.



I'm pretty sure when no IR signal is present the receiver is always in a

marking state(1); but stray light, etc can cause intermittent noise values

as well.  Remember, this is a free running sample of the IR receiver state

over time, so don't assume any sample starts at any particular place.



http://www.atmel.com/dyn/resources/prod_documents/doc2817.pdf

This data sheet (google search) seems to have a lovely description of the

RC5 basics



http://www.nenya.be/beor/electronics/rc5.htm  and more data



http://www.ee.washington.edu/circuit_archive/text/ir_decode.txt

and even a reference to how to decode a bi-phase data stream.



http://www.xs4all.nl/~sbp/knowledge/ir/rc5.htm

still more info

Documentation/video4linux/hauppauge-wintv-cx88-ir.txt

deleted100644 → 0
+0 −54
Original line number Diff line number Diff line 
The controls for the mux are GPIO [0,1] for source, and GPIO 2 for muting.



GPIO0  GPIO1

  0        0    TV Audio

  1        0    FM radio

  0        1    Line-In

  1        1    Mono tuner bypass or CD passthru (tuner specific)



GPIO 16(i believe) is tied to the IR port (if present).



------------------------------------------------------------------------------------



>From the data sheet:

 Register 24'h20004  PCI Interrupt Status

  bit [18]  IR_SMP_INT Set when 32 input samples have been collected over

  gpio[16] pin into GP_SAMPLE register.



What's missing from the data sheet:



Setup 4KHz sampling rate (roughly 2x oversampled; good enough for our RC5

compat remote)

set register 0x35C050 to  0xa80a80



enable sampling

set register 0x35C054 to 0x5



Of course, enable the IRQ bit 18 in the interrupt mask register .(and

provide for a handler)



GP_SAMPLE register is at 0x35C058



Bits are then right shifted into the GP_SAMPLE register at the specified

rate; you get an interrupt when a full DWORD is received.

You need to recover the actual RC5 bits out of the (oversampled) IR sensor

bits. (Hint: look for the 0/1and 1/0 crossings of the RC5 bi-phase data)  An

actual raw RC5 code will span 2-3 DWORDS, depending on the actual alignment.



I'm pretty sure when no IR signal is present the receiver is always in a

marking state(1); but stray light, etc can cause intermittent noise values

as well.  Remember, this is a free running sample of the IR receiver state

over time, so don't assume any sample starts at any particular place.



http://www.atmel.com/dyn/resources/prod_documents/doc2817.pdf

This data sheet (google search) seems to have a lovely description of the

RC5 basics



http://www.nenya.be/beor/electronics/rc5.htm and more data



http://www.ee.washington.edu/circuit_archive/text/ir_decode.txt

and even a reference to how to decode a bi-phase data stream.



http://www.xs4all.nl/~sbp/knowledge/ir/rc5.htm

still more info

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