* Question about SND_SOC_DAIFMT_xB_xF
@ 2014-07-31 2:01 Kuninori Morimoto
2014-07-31 7:42 ` Lars-Peter Clausen
0 siblings, 1 reply; 3+ messages in thread
From: Kuninori Morimoto @ 2014-07-31 2:01 UTC (permalink / raw)
To: Mark Brown; +Cc: Linux-ALSA, Simon, Liam Girdwood, Kuninori Morimoto
Hi Mark
I would like to ask you about SND_SOC_DAIFMT_xB_xF.
Are these flags for based on "required format" ? or "default HW behavior" ?
For example, if some data format requests that data is sent from "rising edge",
but HW send data from "falling edge" in default setting.
This case, HW should use inverted edge.
Then, should HW send it by SND_SOC_DAIFMT_NB_NF (= based on required format) ?
or SND_SOC_DAIFMT_NB_IF (= based on default HW behavior) ?
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: Question about SND_SOC_DAIFMT_xB_xF
2014-07-31 2:01 Question about SND_SOC_DAIFMT_xB_xF Kuninori Morimoto
@ 2014-07-31 7:42 ` Lars-Peter Clausen
2014-07-31 7:45 ` Kuninori Morimoto
0 siblings, 1 reply; 3+ messages in thread
From: Lars-Peter Clausen @ 2014-07-31 7:42 UTC (permalink / raw)
To: Kuninori Morimoto, Mark Brown
Cc: Linux-ALSA, Simon, Liam Girdwood, Kuninori Morimoto
On 07/31/2014 04:01 AM, Kuninori Morimoto wrote:
> r example, if some data format requests that data is sent from "rising edge",
> but HW send data from "falling edge" in default setting.
> This case, HW should use inverted edge.
> Then, should HW send it by SND_SOC_DAIFMT_NB_NF (= based on required format) ?
> or SND_SOC_DAIFMT_NB_IF (= based on default HW behavior) ?
The same set of settings passed to snd_soc_dai_set_fmt() must for all
drivers result in the same waveforms. Otherwise interoperability is pretty
hard to archive. This means the clock invert settings are always be relative
to the selected DAI format (I2S, LJ, RJ, ...). The hardware default of the
specific IP that the driver was written for does not matter in this case.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: Question about SND_SOC_DAIFMT_xB_xF
2014-07-31 7:42 ` Lars-Peter Clausen
@ 2014-07-31 7:45 ` Kuninori Morimoto
0 siblings, 0 replies; 3+ messages in thread
From: Kuninori Morimoto @ 2014-07-31 7:45 UTC (permalink / raw)
To: Lars-Peter Clausen
Cc: Linux-ALSA, Mark Brown, Kuninori Morimoto, Simon, Liam Girdwood
Hi Lars
> > r example, if some data format requests that data is sent from "rising edge",
> > but HW send data from "falling edge" in default setting.
> > This case, HW should use inverted edge.
> > Then, should HW send it by SND_SOC_DAIFMT_NB_NF (= based on required format) ?
> > or SND_SOC_DAIFMT_NB_IF (= based on default HW behavior) ?
>
> The same set of settings passed to snd_soc_dai_set_fmt() must for all
> drivers result in the same waveforms. Otherwise interoperability is pretty
> hard to archive. This means the clock invert settings are always be relative
> to the selected DAI format (I2S, LJ, RJ, ...). The hardware default of the
> specific IP that the driver was written for does not matter in this case.
OK, I see
Thank you for your explain
Best regards
---
Kuninori Morimoto
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2014-07-31 7:45 UTC | newest]
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2014-07-31 2:01 Question about SND_SOC_DAIFMT_xB_xF Kuninori Morimoto
2014-07-31 7:42 ` Lars-Peter Clausen
2014-07-31 7:45 ` Kuninori Morimoto
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