[alsa-devel] Juli - function of specific GPIOs?

Takashi Iwai tiwai at suse.de
Mon Jan 21 16:54:53 CET 2008


At Fri, 18 Jan 2008 22:41:51 +0100,
Pavel Hofman wrote:
> 
> Hi Takashi,
> 
> Sorry for distracting you from the constant struggle with HDA.
> 
> I would like to provide complete support for the ESI Juli@ card.
> Informing the ADC (AK5385) about current sample rate via the dedicated
> GPIOs is fairly simple, as well as the monitoring features (DIGOUT, 
> DIGIN, ANAIN, MUTE + volume control of the remaining DACs).
> 
> However, I do not understand functions of the GPIO_FREQ_XXKHZ and
> GPIO_MULTI_XX GPIOs. The card's user manual says the card can detect
> incoming SPDIF rate. AK4114 can either read the rate from the input data
> in professional format only, or detect it by comparing external clock 
> with the input rate. The AK4114 external clock pin does go to the Xilinx 
> CPLD. The GPIOs lead to the CPLD too. Do they in some way control the 
> CPLD to provide AK4114 with external clock so that AK4114 can provide 
> correct input rate data through its registers?

Sorry, I have little idea about Juli (and all ESI boards).  The
datasheet was given only to Jaroslav (cc'ed) at that time.


Takashi


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