On Sun, 2009-07-12 at 17:36 +0530, Ravi A wrote:
> On Sat, Jul 11, 2009 at 9:43 PM, Andy Walls<[email protected]> wrote:
>
> > Ravi,
> >
> > I have added a change here:
> >
> > http://linuxtv.org/hg/~awalls/ivtv
> >
> > to the cx25840 module. The change ensures that the Video and Aux PLLs
> > for CX2584x chips run close to 400 MHz, the center frequency of the
> > VCOs. The change is essentially what the cx18 driver does for it's
> > integrated A/V core.
> >
> > Please see if you get reliable audio with the CX25841 on your board with
> > this change.
> >
> > Regards,
> > Andy
> >
>
> Hi Andy,
>
> The audio still does not work consistently with this version. Let me
> know if there is any way I can check whether the new settings got
> applied.
Well, if you conpiled the modules with the CONFIG_ADV_DEBUG (?) option,
then you can use v4l2-dbg to look at the registers of the chips.
Something like this will show you the change is in effect:
$ su - root
# v4l2-dbg -d /dev/video0 -S
host0: cx23416 revision 0x00000000
i2c 0x1b: wm8775 revision 0x00000000
i2c 0x44: cx25843 revision 0x00008433
# v4l2-dbg -d /dev/video0 -c cx25840 --list-registers=min=0x110,max=0x113
ioctl: VIDIOC_DBG_G_REGISTER
00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F
00000110: 0c 74 76 01
^^^^^^^^^^^
|
Indicator of the change, when set to line-in at 48 ksps.
Here's my guess at the audio processing chain on your card:
+----------+
+---------------+
| Sel0 |<--------------------------------------| GPIO14
|
| Sel1 |<--------------------------------------| GPIO15
|
| | |
|
(FM AF L)---->| 74HC4052 | |
|
(FM AF R)---->| | +----------------+------------|I2C Data &
CLK |
| Dual 4:1 | V V |
|
| Mux | +------+ +--------------+ |
|
Line-in L --->| | |WM8739| | CX25841 | | CX23416
|
Line-in R --->| |---->|Analog|----->|I2S Data In | |
|
| |---->|to I2S|------|I2S Clock | |
|
White Conn?-->| | |Audio | | I2S Data Out |--->|I2S Data In
|
| | +------+ | I2S Clock |----|I2S Clock
|
+----------+ | | |
|
Tuner SIF ---------------------------------->|SIF In |
+---------------+
| |
+--------------+
I realize your card doesn't have FM radio audio, but variants of it with
the same PCB do have FM.
The above picutre is just my guess. Without having the card in hand,
it's hard to actaully trace the wiring. So let's look at where thing
could be going wrong for Line-in audio:
1. I could be setting the 74HC4052 dual 4:1 multiplexer wrong. The
datasheet is here:
http://www.datasheetcatalog.com/datasheets_pdf/7/4/H/C/74HC4052.shtml
So if you could trace how line-in L & R run over to the chip, that would
eliminate an unknown.
2. I could be using the wrong GPIO pins from the CX23416 for controlling
the 74HC4052 mux. Floating GPIO pins for driving the mux selection
would explain why sometimes audio works and sometimes doesn't. The best
thing to do is to trace the selection inputs from the 74HC4052 back to
the CX23416's BGA and figure out which balls in the grid are driving
those lines. An alternative would be to begin experimenting with pairs
of GPIO pins in the ivtv-cards.c entry for your card, or use ivtv-ctl to
manipulate GPIO pins interactively to see when audio works (or you
change the state of the select pins on the 74HC4052 mux.
3. The WM8739 does actually have a volume control internally, that we
are not explicitly setting - I'm using whatever the WM8739 module does
by default. v4l2-dbg could be used to set the WM8739 volume control
registers manually to see if that makes audio work.
The datasheet is here:
http://dl.ivtvdriver.org/datasheets/audio/WM8739.pdf
4. The baseband audio processing in the CX25841 could not be working or
have it's volume set too low. The volume controls available with
v4l2-ctl should let you set the volume and mute of this device. If
you're interested, the datasheet is here:
http://dl.ivtvdriver.org/datasheets/video/cx25840.pdf
Sections 3.24 and 3.25 show the chip's audio processing capabilities.
I2S audio shoudl be coming in through Sample Rate Convertor (SRC) 1,
passing through a baseband processing path and exiting through SRC3 to
the CX23416. AC97 audio isn't used, and I'm fairly sure nor is
Ancillary mode audio.
So what do you feel like looking at first? I'd at least like you to
verify my overall block diagaram as best you can by visually inspecting
the traces on the board. (My diagram amounts to 1 big assumption right
now.)
Regards,
Andy
> Regards
> Ravi
>
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