Re: em28xx: Terratec Grabby no sound

2010-12-27 Thread Florian Klink 

Hi Mauro,

with the help of Bernd Spaeth, I finally managed to get the Terratec 
Grabby

working by using

mplayer -v -tv
driver=v4l2:input=0:device=/dev/video1:alsa:adevice=hw.2,0:audiorate=48000:forceaudio:immediatemode=0
tv://

and your patch

diff --git a/drivers/media/video/em28xx/em28xx-cards.c
b/drivers/media/video/em28xx/em28xx-cards.c
index e7efb4b..6e80376 100644
--- a/drivers/media/video/em28xx/em28xx-cards.c
+++ b/drivers/media/video/em28xx/em28xx-cards.c
@@ -1621,11 +1621,11 @@ struct em28xx_board em28xx_boards[] = {
 .input = { {
 .type = EM28XX_VMUX_COMPOSITE1,
 .vmux = SAA7115_COMPOSITE0,
- .amux = EM28XX_AMUX_VIDEO2,
+ .amux = EM28XX_AMUX_LINE_IN,
 }, {
 .type = EM28XX_VMUX_SVIDEO,
 .vmux = SAA7115_SVIDEO3,
- .amux = EM28XX_AMUX_VIDEO2,
+ .amux = EM28XX_AMUX_LINE_IN,
 } },
 },
 [EM2860_BOARD_TERRATEC_AV350] = {

Working video and audio!

I wasn't able to test it with s-video, only composite.

But I think it's still safe to commit the patch, because s-video is 
only

another video input, the audio output stays the same.

Florian

On Tue, 09 Nov 2010 08:56:32 -0200, Mauro Carvalho Chehab wrote:


Em 26-10-2010 10:58, Florian Klink escreveu:

Hi,


The sound comes from alsa device. Several em28xx types provide
standard USB audio. So, snd-usb-audio handles it. That's why you 
need

alsa:adevice=hw.2,0:forceaudio at mplayer.

... but thats my problem. sound doesn't appear inside mplayer, even
with the command line options set to use the external alsa device.
However, arecord -D hw:2,0 -r 32000 -c 2 -f S16_LE | aplay - plays
the sound, but only before mplayer tried to access the sound card
Have you tried my patch? If you're using 
alsa:adevice=hw.2,0:forceaudio
at mplayer, you should not be running arecord/aplay. You need to use 
one

solution or the other.


When trying to play sound with arecord again after mplayer tried to
access it, I have to re-plug the card to get it playing sound over
arecord again, video only seems to not break it. There is no error
message or something in arecord when it's not playing anything, just
silence and the same command line output. Is there maybe anything 
with

the sample format S16_LE or something that confuses mplayer/the
driver/whatever? Strange problem... mplayer output (mplayer -v -tv

driver=v4l2:input=0:device=/dev/video1:alsa:adevice=hw.2,0:forceaudio
tv://): http://pastebin.com/yTV300iG [1] Florian -- To unsubscribe 
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Re: em28xx: Terratec Grabby no sound

2010-11-09 Thread Mauro Carvalho Chehab 
Em 26-10-2010 10:58, Florian Klink escreveu:
 Hi,
 
 The sound comes from alsa device. Several em28xx types provide
 standard USB audio. So,
 snd-usb-audio handles it. That's why you need
 alsa:adevice=hw.2,0:forceaudio at mplayer.
 
 ... but thats my problem.
 sound doesn't appear inside mplayer, even with the command line options set 
 to use the external alsa device. However, arecord -D hw:2,0 -r 32000 -c 2 
 -f S16_LE | aplay - plays the sound, but only before mplayer tried to access 
 the sound card

Have you tried my patch?

If you're using alsa:adevice=hw.2,0:forceaudio at mplayer, you should not be 
running arecord/aplay. You need
to use one solution or the other.
 
 When trying to play sound with arecord again after mplayer tried to access 
 it, I have to re-plug the card to get it playing sound over arecord again, 
 video only seems to not break it. There is no error message or something in 
 arecord when it's not playing anything, just silence and the same command 
 line output.
 
 Is there maybe anything with the sample format S16_LE or something that 
 confuses mplayer/the driver/whatever?
 
 Strange problem...
 
 mplayer output (mplayer -v -tv 
 driver=v4l2:input=0:device=/dev/video1:alsa:adevice=hw.2,0:forceaudio tv://):
 http://pastebin.com/yTV300iG
 
 Florian
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Re: em28xx: Terratec Grabby no sound

2010-10-25 Thread Mauro Carvalho Chehab 
Em 25-10-2010 15:24, Florian Klink escreveu:
 Hi,
 
 I recently bought a Terratec Grabby. The device has a S-Video and 3 Cinch
 cables (sound left, sound right, video). I want to record some video
 cassettes with it. (with a cinch-scart adapter).
 
 I checked the signal, there is audio and video on it.
 
 When I try to play the capture device with e.g. mplayer, I see no
 sound, even with various options.
 
 I can hear sound only by doing arecord -D hw:2,0 -r 32000 -c 2 -f S16_LE |
 aplay -, but as soon as mplayer is starting, I can't hear anything
 anymore.
 
 ...which means that using alsa as the sound device with mplayer doesn't
 work either.
 
 Am I missing something?

Maybe the amux is wrong. The only way to know for sure is to check the used 
GPIO's,
via a USB snoop dump. Please take a look at linuxtv.org Wiki (search for 
usbsnoop).
After getting the dump, please parse it and send me.

 
 I checked the source code, Terratec Grabby support was introduced with
 4557af9c5338605c85fe54f5ebba3d4b14a60ab8:
 
 -
 diff --git a/drivers/media/video/em28xx/em28xx-cards.c 
 b/drivers/media/video/em28xx/em28xx-cards.c
 index 7cb93fb..b4c78f2 100644
 --- a/drivers/media/video/em28xx/em28xx-cards.c
 +++ b/drivers/media/video/em28xx/em28xx-cards.c
 @@ -1347,6 +1347,22 @@ struct em28xx_board em28xx_boards[] = {
  .amux = EM28XX_AMUX_VIDEO,
  } },
  },
 +[EM2860_BOARD_TERRATEC_GRABBY] = {
 +.name= Terratec Grabby,
 +.vchannels   = 2,
 +.tuner_type  = TUNER_ABSENT,
 +.decoder = EM28XX_SAA711X,
 +.xclk= EM28XX_XCLK_FREQUENCY_12MHZ,
 +.input   = { {
 +.type = EM28XX_VMUX_COMPOSITE1,
 +.vmux = SAA7115_COMPOSITE0,
 +.amux = EM28XX_AMUX_VIDEO2,
 +}, {
 +.type = EM28XX_VMUX_SVIDEO,
 +.vmux = SAA7115_SVIDEO3,
 +.amux = EM28XX_AMUX_VIDEO2,
 +} },
 +},
  };
  const unsigned int em28xx_bcount = ARRAY_SIZE(em28xx_boards);
 
 @@ -1410,6 +1426,8 @@ struct usb_device_id em28xx_id_table[] = {
  .driver_info = EM2870_BOARD_TERRATEC_XS },
  { USB_DEVICE(0x0ccd, 0x0047),
  .driver_info = EM2880_BOARD_TERRATEC_PRODIGY_XS },
 +{ USB_DEVICE(0x0ccd, 0x0096),
 +.driver_info = EM2860_BOARD_TERRATEC_GRABBY },
  { USB_DEVICE(0x185b, 0x2870),
  .driver_info = EM2870_BOARD_COMPRO_VIDEOMATE },
  { USB_DEVICE(0x185b, 0x2041),
 diff --git a/drivers/media/video/em28xx/em28xx.h 
 b/drivers/media/video/em28xx/em28xx.h
 index e801f78..fa2fb41 100644
 --- a/drivers/media/video/em28xx/em28xx.h
 +++ b/drivers/media/video/em28xx/em28xx.h
 @@ -103,6 +103,7 @@
  #define EM2860_BOARD_EASYCAP  64
  #define EM2820_BOARD_IODATA_GVMVP_SZ  65
  #define EM2880_BOARD_EMPIRE_DUAL_TV  66
 +#define EM2860_BOARD_TERRATEC_GRABBY  67
 
  /* Limits minimum and default number of buffers */
  #define EM28XX_MIN_BUF 4
 -
 
 Is there maybe a wrong amux set? Which one could it be?
 Is sound-usb-audio somehow conflicting with em28xx module?
 
 I hope you have an idea what is wrong here!
 
 Florian Klink
 

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Re: em28xx: Terratec Grabby no sound

2010-10-25 Thread Mauro Carvalho Chehab 
Em 25-10-2010 18:24, Florian Klink escreveu:
 Hi Mauro,
 
 thanks for your answer!

I'm c/c the mailing list, as this info may be useful for the others.
It would be nice to have this added to wiki, but I won't have time for it,
unfortunately.
 
 Maybe the amux is wrong. The only way to know for sure is to check
 the used GPIO's,
 via a USB snoop dump. Please take a look at linuxtv.org Wiki (search
 for usbsnoop).
 After getting the dump, please parse it and send me.
 
 I did the usbsnooping and hope I did the parsing right (At least the log
 file shrinked from 100MB to some KB, and there are plenty of EM28XX
 strings inside ;-))
 
 You can get it here: http://pastebin.com/SXKfLUny

There are a few things that are relevant:

First of all, GPIO's. They enable/disable parts of the board:

$ grep GPIO /tmp/dump
em28xx_write_reg(dev, EM28XX_R08_GPIO, 0xff);
em28xx_read_reg(dev, EM28XX_R08_GPIO);  /* read 0xff */
em28xx_write_reg(dev, EM28XX_R08_GPIO, 0xfd);
em28xx_read_reg(dev, EM28XX_R08_GPIO);  /* read 0xfd */
em28xx_write_reg(dev, EM28XX_R08_GPIO, 0xfd);
em28xx_read_reg(dev, EM28XX_R08_GPIO);  /* read 0xfd */
em28xx_write_reg(dev, EM28XX_R08_GPIO, 0x7d);
em28xx_write_reg(dev, EM28XX_R08_GPIO, 0x2a);
em28xx_write_reg(dev, EM28XX_R08_GPIO, 0x2a);

Currently, they're not touched for this device. Perhaps, we might need to 
initialize 
them to 0xfd for capture mode, and 0x2a for sleep mode.

In this specific case, maybe it is just safe to keep it as-is, as I suspect 
that GPIO's
are not used on this device. I may be wrong, though. A simple test will tell.

The audio entries are related to the ac97 chip.

The driver will basically run this code:

amux = EM28XX_AMUX_VIDEO2;  /* from Terratec Grabby entry, at 
em28xx-cards.c */

static struct em28xx_vol_table inputs[] = {
{ EM28XX_AMUX_VIDEO,AC97_VIDEO_VOL   },
{ EM28XX_AMUX_LINE_IN,  AC97_LINEIN_VOL  },
{ EM28XX_AMUX_PHONE,AC97_PHONE_VOL   },
{ EM28XX_AMUX_MIC,  AC97_MIC_VOL },
{ EM28XX_AMUX_CD,   AC97_CD_VOL  },
{ EM28XX_AMUX_AUX,  AC97_AUX_VOL },
{ EM28XX_AMUX_PCM_OUT,  AC97_PCM_OUT_VOL },

if (amux == inputs[i].mux)
ret = em28xx_write_ac97(dev, inputs[i].reg, 0x0808);
/* Put the volume in 50% */
else
ret = em28xx_write_ac97(dev, inputs[i].reg, 0x8000);
/* Mute the volume */   

Any mixer entry equal or bigger than 0x8000 is muted.


$ grep 97 dump
em28xx_read_ac97(dev, AC97_VENDOR_ID1); /* read 0x0x8384 */
em28xx_read_ac97(dev, AC97_VENDOR_ID2); /* read 0x0x7652 */
em28xx_write_ac97(dev, AC97_LINEIN_VOL, 0x0808);
em28xx_write_ac97(dev, AC97_VIDEO_VOL, 0x9010);
em28xx_write_ac97(dev, AC97_AUX_VOL, 0x9010);
em28xx_write_ac97(dev, AC97_MIC_VOL, 0x9010);
em28xx_write_ac97(dev, AC97_RECORD_GAIN, 0x);
em28xx_write_ac97(dev, AC97_RECORD_GAIN, 0x);
em28xx_write_ac97(dev, AC97_RECORD_GAIN, 0x8000);
em28xx_write_ac97(dev, AC97_RECORD_GAIN, 0x8000);
em28xx_write_ac97(dev, AC97_POWER_DOWN_CTRL, 0x4200);
em28xx_write_ac97(dev, AC97_RECORD_SELECT, 0x0505);
em28xx_write_ac97(dev, AC97_EXT_AUD_CTRL, 0x0031);
em28xx_write_ac97(dev, AC97_PCM_IN_SRATE, 0xbb80);
em28xx_write_ac97(dev, AC97_LINEIN_VOL, 0x0808);
em28xx_write_ac97(dev, AC97_VIDEO_VOL, 0x9010);
em28xx_write_ac97(dev, AC97_AUX_VOL, 0x9010);
em28xx_write_ac97(dev, AC97_MIC_VOL, 0x9010);
em28xx_write_ac97(dev, AC97_RECORD_GAIN, 0x8000);
em28xx_write_ac97(dev, AC97_RECORD_GAIN, 0x8000);
em28xx_write_ac97(dev, AC97_RECORD_GAIN, 0x8000);
em28xx_write_ac97(dev, AC97_LINEIN_VOL, 0x0808);
em28xx_write_ac97(dev, AC97_VIDEO_VOL, 0x9010);
em28xx_write_ac97(dev, AC97_AUX_VOL, 0x9010);
em28xx_write_ac97(dev, AC97_MIC_VOL, 0x9010);
em28xx_write_ac97(dev, AC97_RECORD_GAIN, 0x);
em28xx_write_ac97(dev, AC97_RECORD_GAIN, 0x);
em28xx_write_ac97(dev, AC97_LINEIN_VOL, 0x0808);
em28xx_write_ac97(dev, AC97_VIDEO_VOL, 0x9010);
em28xx_write_ac97(dev, AC97_AUX_VOL, 0x9010);
em28xx_write_ac97(dev, AC97_MIC_VOL, 0x9010);
em28xx_write_ac97(dev, AC97_RECORD_GAIN, 0x);
em28xx_write_ac97(dev, AC97_RECORD_GAIN, 0x);
em28xx_write_ac97(dev, AC97_RECORD_GAIN, 0x8000);
em28xx_write_ac97(dev, AC97_RECORD_GAIN, 0x8000);
em28xx_write_ac97(dev, AC97_POWER_DOWN_CTRL, 0x4200);
em28xx_write_ac97(dev, AC97_RECORD_SELECT, 0x0505);
em28xx_write_ac97(dev, AC97_EXT_AUD_CTRL, 0x0031);
em28xx_write_ac97(dev, AC97_PCM_IN_SRATE, 0xbb80);
em28xx_write_ac97(dev, AC97_LINEIN_VOL, 0x0808);
em28xx_write_ac97(dev, AC97_VIDEO_VOL, 0x9010);
em28xx_write_ac97(dev, AC97_AUX_VOL, 0x9010);
em28xx_write_ac97(dev, AC97_MIC_VOL, 0x9010);
em28xx_write_ac97(dev, AC97_RECORD_GAIN, 0x8000);
em28xx_write_ac97(dev, AC97_RECORD_GAIN, 0x8000);
em28xx_write_ac97(dev, AC97_RECORD_GAIN, 0x8000);
em28xx_write_ac97(dev, AC97_LINEIN_VOL, 0x0808);
em28xx_write_ac97(dev, AC97_VIDEO_VOL, 0x9010);
em28xx_write_ac97(dev, AC97_AUX_VOL, 0x9010);
em28xx_write_ac97(dev,

Re: em28xx: Terratec Grabby no sound

2010-10-25 Thread Florian Klink 

Hi,

I'm not very familiar with mailing lists, sorry!

Patched em28xx-cards.c, but no luck with
mplayer -v -tv driver=v4l2:input=0:device=/dev/video1:forceaudio tv://
(/dev/video0 is webcam). I'm able to see the video, but still no sound 
in mplayer


playing the sound with arecord works (i think it goes over the 
snd-usb-audio module,
but don't know why some mplayer -v -tv 
driver=v4l2:input=0:device=/dev/video1:alsa:adevice=hw.2,0:forceaudio 
tv:// magic won't do the job.


And shouldn't the sound go over v4l, too?

Florian



On Mon, 25 Oct 2010 18:51:15 -0200, Mauro Carvalho Chehab 
mche...@redhat.com wrote:

Em 25-10-2010 18:24, Florian Klink escreveu:

Hi Mauro,

thanks for your answer!


I'm c/c the mailing list, as this info may be useful for the others.
It would be nice to have this added to wiki, but I won't have time 
for it,

unfortunately.



Maybe the amux is wrong. The only way to know for sure is to check
the used GPIO's,
via a USB snoop dump. Please take a look at linuxtv.org Wiki 
(search

for usbsnoop).
After getting the dump, please parse it and send me.


I did the usbsnooping and hope I did the parsing right (At least the 
log

file shrinked from 100MB to some KB, and there are plenty of EM28XX
strings inside ;-))

You can get it here: http://pastebin.com/SXKfLUny


There are a few things that are relevant:

First of all, GPIO's. They enable/disable parts of the board:

$ grep GPIO /tmp/dump
em28xx_write_reg(dev, EM28XX_R08_GPIO, 0xff);
em28xx_read_reg(dev, EM28XX_R08_GPIO);  /* read 0xff */
em28xx_write_reg(dev, EM28XX_R08_GPIO, 0xfd);
em28xx_read_reg(dev, EM28XX_R08_GPIO);  /* read 0xfd */
em28xx_write_reg(dev, EM28XX_R08_GPIO, 0xfd);
em28xx_read_reg(dev, EM28XX_R08_GPIO);  /* read 0xfd */
em28xx_write_reg(dev, EM28XX_R08_GPIO, 0x7d);
em28xx_write_reg(dev, EM28XX_R08_GPIO, 0x2a);
em28xx_write_reg(dev, EM28XX_R08_GPIO, 0x2a);

Currently, they're not touched for this device. Perhaps, we might
need to initialize
them to 0xfd for capture mode, and 0x2a for sleep mode.

In this specific case, maybe it is just safe to keep it as-is, as I
suspect that GPIO's
are not used on this device. I may be wrong, though. A simple test 
will tell.


The audio entries are related to the ac97 chip.

The driver will basically run this code:

amux = EM28XX_AMUX_VIDEO2;  /* from Terratec Grabby entry, at
em28xx-cards.c */

static struct em28xx_vol_table inputs[] = {
{ EM28XX_AMUX_VIDEO,AC97_VIDEO_VOL   },
{ EM28XX_AMUX_LINE_IN,  AC97_LINEIN_VOL  },
{ EM28XX_AMUX_PHONE,AC97_PHONE_VOL   },
{ EM28XX_AMUX_MIC,  AC97_MIC_VOL },
{ EM28XX_AMUX_CD,   AC97_CD_VOL  },
{ EM28XX_AMUX_AUX,  AC97_AUX_VOL },
{ EM28XX_AMUX_PCM_OUT,  AC97_PCM_OUT_VOL },

if (amux == inputs[i].mux)
ret = em28xx_write_ac97(dev, inputs[i].reg, 0x0808);
/* Put the
volume in 50% */
else
ret = em28xx_write_ac97(dev, inputs[i].reg, 0x8000);
/* Mute the
volume */

Any mixer entry equal or bigger than 0x8000 is muted.


$ grep 97 dump
em28xx_read_ac97(dev, AC97_VENDOR_ID1); /* read 0x0x8384 */
em28xx_read_ac97(dev, AC97_VENDOR_ID2); /* read 0x0x7652 */
em28xx_write_ac97(dev, AC97_LINEIN_VOL, 0x0808);
em28xx_write_ac97(dev, AC97_VIDEO_VOL, 0x9010);
em28xx_write_ac97(dev, AC97_AUX_VOL, 0x9010);
em28xx_write_ac97(dev, AC97_MIC_VOL, 0x9010);
em28xx_write_ac97(dev, AC97_RECORD_GAIN, 0x);
em28xx_write_ac97(dev, AC97_RECORD_GAIN, 0x);
em28xx_write_ac97(dev, AC97_RECORD_GAIN, 0x8000);
em28xx_write_ac97(dev, AC97_RECORD_GAIN, 0x8000);
em28xx_write_ac97(dev, AC97_POWER_DOWN_CTRL, 0x4200);
em28xx_write_ac97(dev, AC97_RECORD_SELECT, 0x0505);
em28xx_write_ac97(dev, AC97_EXT_AUD_CTRL, 0x0031);
em28xx_write_ac97(dev, AC97_PCM_IN_SRATE, 0xbb80);
em28xx_write_ac97(dev, AC97_LINEIN_VOL, 0x0808);
em28xx_write_ac97(dev, AC97_VIDEO_VOL, 0x9010);
em28xx_write_ac97(dev, AC97_AUX_VOL, 0x9010);
em28xx_write_ac97(dev, AC97_MIC_VOL, 0x9010);
em28xx_write_ac97(dev, AC97_RECORD_GAIN, 0x8000);
em28xx_write_ac97(dev, AC97_RECORD_GAIN, 0x8000);
em28xx_write_ac97(dev, AC97_RECORD_GAIN, 0x8000);
em28xx_write_ac97(dev, AC97_LINEIN_VOL, 0x0808);
em28xx_write_ac97(dev, AC97_VIDEO_VOL, 0x9010);
em28xx_write_ac97(dev, AC97_AUX_VOL, 0x9010);
em28xx_write_ac97(dev, AC97_MIC_VOL, 0x9010);
em28xx_write_ac97(dev, AC97_RECORD_GAIN, 0x);
em28xx_write_ac97(dev, AC97_RECORD_GAIN, 0x);
em28xx_write_ac97(dev, AC97_LINEIN_VOL, 0x0808);
em28xx_write_ac97(dev, AC97_VIDEO_VOL, 0x9010);
em28xx_write_ac97(dev, AC97_AUX_VOL, 0x9010);
em28xx_write_ac97(dev, AC97_MIC_VOL, 0x9010);
em28xx_write_ac97(dev, AC97_RECORD_GAIN, 0x);
em28xx_write_ac97(dev, AC97_RECORD_GAIN, 0x);
em28xx_write_ac97(dev, AC97_RECORD_GAIN, 0x8000);
em28xx_write_ac97(dev, AC97_RECORD_GAIN, 0x8000);
em28xx_write_ac97(dev, AC97_POWER_DOWN_CTRL, 0x4200);
em28xx_write_ac97(dev, AC97_RECORD_SELECT, 0x0505);

Re: em28xx: Terratec Grabby no sound

2010-10-25 Thread Mauro Carvalho Chehab 
Em 25-10-2010 20:06, Florian Klink escreveu:
 Hi,
 
 I'm not very familiar with mailing lists, sorry!
 
 Patched em28xx-cards.c, but no luck with
 mplayer -v -tv driver=v4l2:input=0:device=/dev/video1:forceaudio tv://
 (/dev/video0 is webcam). I'm able to see the video, but still no sound in 
 mplayer
 
 playing the sound with arecord works (i think it goes over the snd-usb-audio 
 module,
 but don't know why some mplayer -v -tv 
 driver=v4l2:input=0:device=/dev/video1:alsa:adevice=hw.2,0:forceaudio tv:// 
 magic won't do the job.
 
 And shouldn't the sound go over v4l, too?

The sound comes from alsa device. Several em28xx types provide standard USB 
audio. So,
snd-usb-audio handles it. That's why you need alsa:adevice=hw.2,0:forceaudio at 
mplayer.

 
 Florian
 
 
 
 On Mon, 25 Oct 2010 18:51:15 -0200, Mauro Carvalho Chehab 
 mche...@redhat.com wrote:
 Em 25-10-2010 18:24, Florian Klink escreveu:
 Hi Mauro,

 thanks for your answer!

 I'm c/c the mailing list, as this info may be useful for the others.
 It would be nice to have this added to wiki, but I won't have time for it,
 unfortunately.

 Maybe the amux is wrong. The only way to know for sure is to check
 the used GPIO's,
 via a USB snoop dump. Please take a look at linuxtv.org Wiki (search
 for usbsnoop).
 After getting the dump, please parse it and send me.

 I did the usbsnooping and hope I did the parsing right (At least the log
 file shrinked from 100MB to some KB, and there are plenty of EM28XX
 strings inside ;-))

 You can get it here: http://pastebin.com/SXKfLUny

 There are a few things that are relevant:

 First of all, GPIO's. They enable/disable parts of the board:

 $ grep GPIO /tmp/dump
 em28xx_write_reg(dev, EM28XX_R08_GPIO, 0xff);
 em28xx_read_reg(dev, EM28XX_R08_GPIO);/* read 0xff */
 em28xx_write_reg(dev, EM28XX_R08_GPIO, 0xfd);
 em28xx_read_reg(dev, EM28XX_R08_GPIO);/* read 0xfd */
 em28xx_write_reg(dev, EM28XX_R08_GPIO, 0xfd);
 em28xx_read_reg(dev, EM28XX_R08_GPIO);/* read 0xfd */
 em28xx_write_reg(dev, EM28XX_R08_GPIO, 0x7d);
 em28xx_write_reg(dev, EM28XX_R08_GPIO, 0x2a);
 em28xx_write_reg(dev, EM28XX_R08_GPIO, 0x2a);

 Currently, they're not touched for this device. Perhaps, we might
 need to initialize
 them to 0xfd for capture mode, and 0x2a for sleep mode.

 In this specific case, maybe it is just safe to keep it as-is, as I
 suspect that GPIO's
 are not used on this device. I may be wrong, though. A simple test will tell.

 The audio entries are related to the ac97 chip.

 The driver will basically run this code:

 amux = EM28XX_AMUX_VIDEO2; /* from Terratec Grabby entry, at
 em28xx-cards.c */

 static struct em28xx_vol_table inputs[] = {
 { EM28XX_AMUX_VIDEO, AC97_VIDEO_VOL   },
 { EM28XX_AMUX_LINE_IN,AC97_LINEIN_VOL  },
 { EM28XX_AMUX_PHONE,AC97_PHONE_VOL   },
 { EM28XX_AMUX_MIC,AC97_MIC_VOL },
 { EM28XX_AMUX_CD,AC97_CD_VOL  },
 { EM28XX_AMUX_AUX,AC97_AUX_VOL },
 { EM28XX_AMUX_PCM_OUT,AC97_PCM_OUT_VOL },

 if (amux == inputs[i].mux)
 ret = em28xx_write_ac97(dev, inputs[i].reg, 0x0808);/* 
 Put the
 volume in 50% */
 else
 ret = em28xx_write_ac97(dev, inputs[i].reg, 0x8000);/* 
 Mute the
 volume */

 Any mixer entry equal or bigger than 0x8000 is muted.


 $ grep 97 dump
 em28xx_read_ac97(dev, AC97_VENDOR_ID1);/* read 0x0x8384 */
 em28xx_read_ac97(dev, AC97_VENDOR_ID2);/* read 0x0x7652 */
 em28xx_write_ac97(dev, AC97_LINEIN_VOL, 0x0808);
 em28xx_write_ac97(dev, AC97_VIDEO_VOL, 0x9010);
 em28xx_write_ac97(dev, AC97_AUX_VOL, 0x9010);
 em28xx_write_ac97(dev, AC97_MIC_VOL, 0x9010);
 em28xx_write_ac97(dev, AC97_RECORD_GAIN, 0x);
 em28xx_write_ac97(dev, AC97_RECORD_GAIN, 0x);
 em28xx_write_ac97(dev, AC97_RECORD_GAIN, 0x8000);
 em28xx_write_ac97(dev, AC97_RECORD_GAIN, 0x8000);
 em28xx_write_ac97(dev, AC97_POWER_DOWN_CTRL, 0x4200);
 em28xx_write_ac97(dev, AC97_RECORD_SELECT, 0x0505);
 em28xx_write_ac97(dev, AC97_EXT_AUD_CTRL, 0x0031);
 em28xx_write_ac97(dev, AC97_PCM_IN_SRATE, 0xbb80);
 em28xx_write_ac97(dev, AC97_LINEIN_VOL, 0x0808);
 em28xx_write_ac97(dev, AC97_VIDEO_VOL, 0x9010);
 em28xx_write_ac97(dev, AC97_AUX_VOL, 0x9010);
 em28xx_write_ac97(dev, AC97_MIC_VOL, 0x9010);
 em28xx_write_ac97(dev, AC97_RECORD_GAIN, 0x8000);
 em28xx_write_ac97(dev, AC97_RECORD_GAIN, 0x8000);
 em28xx_write_ac97(dev, AC97_RECORD_GAIN, 0x8000);
 em28xx_write_ac97(dev, AC97_LINEIN_VOL, 0x0808);
 em28xx_write_ac97(dev, AC97_VIDEO_VOL, 0x9010);
 em28xx_write_ac97(dev, AC97_AUX_VOL, 0x9010);
 em28xx_write_ac97(dev, AC97_MIC_VOL, 0x9010);
 em28xx_write_ac97(dev, AC97_RECORD_GAIN, 0x);
 em28xx_write_ac97(dev, AC97_RECORD_GAIN, 0x);
 em28xx_write_ac97(dev, AC97_LINEIN_VOL, 0x0808);
 em28xx_write_ac97(dev, AC97_VIDEO_VOL, 0x9010);
 em28xx_write_ac97(dev, AC97_AUX_VOL, 0x9010);
 em28xx_write_ac97(dev, AC97_MIC_VOL, 0x9010);
 em28xx_write_ac97(dev, AC97_RECORD_GAIN, 0x);