[alsa-devel] [PATCH 1/2] ASoC: Add driver for CLPS711X DAI interface

[Alexander Shiyan]

Четверг, 27 февраля 2014, 12:44 +09:00 от Mark Brown <broonie at kernel.org>:
> On Wed, Feb 26, 2014 at 08:05:41PM +0400, Alexander Shiyan wrote:
> 
> > +static int clps711x_dai_set_clkdiv(struct snd_soc_dai *dai, int div_id, int div)
> > +{
> > +	struct clps711x_dai *s = dev_get_drvdata(dai->dev);
> > +
> > +	s->div2 = div;
> > +
> > +	return 0;
> > +}
> 
> What is this divider and why does the machine driver need to manually
> configure it?

I'll think about it ...

> > +static int clps711x_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
> > +{
> > +	struct snd_soc_pcm_runtime *rtd = substream->private_data;
> > +	struct clps711x_dai *dai = snd_soc_platform_get_drvdata(rtd->platform);
> > +
> > +	switch (cmd) {
> > +	case SNDRV_PCM_TRIGGER_START:
> > +		atomic_set(&dai->running, 1);
> > +		hrtimer_start(&dai->hrt, ns_to_ktime(dai->reload),
> > +			      HRTIMER_MODE_REL);
> > +		break;
> 
> I'm wondering if the FIQ code can be shared with the i.MX FIQ code?  Not
> something that should block merging but it seems like it might be
> helpful for other platforms that need to use FIQ support.

This FIQ implementation and i.MX FIQ is totally different.
I am fully confident that we can not use any common features/calls.

> > +static int clps711x_pcm_silence(struct snd_pcm_substream *substream,
> > +				int channel, snd_pcm_uframes_t pos,
> > +				snd_pcm_uframes_t count)
> > +{
> > +	return 0;
> > +}
> 
> Omit empty functions.

So designed. I'll add a comment in the next version.

> > +#if defined(CONFIG_SND_CLPS711X_SOC_MODULE)
> > +irqreturn_t no_action(int irq, void *dev_id)
> > +{
> > +	return IRQ_NONE;
> > +}
> > +#endif
> 
> Eh?  Waht's this about?

In case using this driver as non-module, "no_action" handler is used
from kernel/irq/handle.c, but since it is not exported it cannot be used
in module case.
I'll remade this to use own empty handler always.

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