Fabio Roger wrote:
>
> Hi
>
> I have a board with 8 video inputs based on 1 bt848a. I am able to get
> video from the first input.
>
> I've hacked the bttv-cards.c and added this into bttv_tvcards list:
> name: "New Card (bt848a)",
> video_inputs: 8,
> audio_inputs: 0,
> tuner: -1,
> svhs: -1,
> gpiomask: 0,
> muxsel: { 0, 1, 2, 3, 4, 5, 6, 7 },
> audiomux: { 0 },
> needs_tvaudio: 0,
> pll: PLL_28,
> tuner_type: -1,
>
> I want to know how can I find out the correct values, like gpiomask and
> muxsel. Is there some documentation about this?
well... I don't know about docs... but... you have the source luke ;)
from bttv-driver.c:
mux = bttv_tvcards[btv->type].muxsel[input] & 3;
muxsel is a mask array for the MUXSEL register of BT chip (3 bits) and
you (driver writer) have a choice of select a mask for each input
a little example:
muxsel: { 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3 },
this is for a card that owns a input multiplexer connected to BT pins
MUX1 and MUX2 and when you select from input 0 to 7 you are changing the
BT input multiplexer to MUX1 (mask 2) and when you select from input 8
to 15 you are selecting BT MUX2 (mask 3).
gpiomask is mainly used to mask the operations on GPIO register when
doing audio settings.
all values are hardware specific... you must know your hardware to
select some value.
Fernando Fuganti
