These two messages are related to the remotevision mx subject.
Sorry about the re-posting.
IMO the way that bt848 handles the gpio is similar to bt878. If so, then the
info in there must help.
A "gpio scanner" would be great to discover the wired pins, althought the
card spec is always better.
Regards
Gleicon S. Moraes --
gleicon@xxxxxxxxxxxx - gleicon@xxxxxxxxxx
http://videodog.cjb.net
http://planeta.terra.com.br/informatica/gleicon/
--- Begin Message ---
I've mananged to borrow a bt878 card with an external 4067 multiplexer (
16input-1output, 4bit channel selection).
The 4 address lines from the 4067 are connected to the GPIO[0:3] (pins
86-83). How can I control this thru the bttv driver (0.7.x)?
By looking at the bttv-card.c code it looks like I need something like the
following:
// I'm ignoring the fact this runs on top AUDIO stuff,
// VIDIOCSAUDIO is used to set the current channel
// VIDIOCGAUDIO is used to read the current channel
// flags (stuct video_audio) constains the channel
{
name: "bt878 + 16channel mux (4067)"
video_inputs: 4,
pll: PLL_28,
audio_hook: external4067_muxsel
}
void external4067_muxsel(struct bttv *btv, struct video_audio *v, int set){
int data;
int input
data=btread(BT848_GPIO_DATA);
if(set){ // set mode, caused by VIDIOCSAUDIO
//v->flags contaings the channel (4bit) from the user
if((v->flags<16)&&(v->flags>=0))
data&=v->flags;
}else{ //read mode, caused by VIDIOCGAUDIO
v->flags=data&0x000F; //only return the [3:0] bits
}
btwrite(data,BT848_GPIO_DATA);
}
What does btread(BT848_GPIO_DATA) give me? Do I just set bit 0 to TRUE to
set the GPIO pin to TRUE? I'll try the code after I get some sleep.
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--- End Message ---
--- Begin Message ---
On Mon, 2001-09-17 at 23:11, Robert D. wrote:
> The 4 address lines from the 4067 are connected to the GPIO[0:3] (pins
> 86-83). How can I control this thru the bttv driver (0.7.x)?
> ...
> What does btread(BT848_GPIO_DATA) give me? Do I just set bit 0 to TRUE
to
> set the GPIO pin to TRUE?
>
Yes, that's it. I am doing the same with a similar board, which makes
intensive use of the GPIOs.
> I'll try the code after I get some sleep.
Good Luck,
Miguel
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--- End Message ---
