[alsa-devel] [PATCH] cs4270: add support for slave mode configurations

[Daniel Mack]

On Wed, Feb 25, 2009 at 03:34:45PM +0000, Mark Brown wrote:
> On Wed, Feb 25, 2009 at 02:37:21PM +0100, Daniel Mack wrote:
> 
> >  	reg = snd_soc_read(codec, CS4270_MODE);
> >  	reg &= ~(CS4270_MODE_SPEED_MASK | CS4270_MODE_DIV_MASK);
> > -	reg |= cs4270_mode_ratios[i].speed_mode | cs4270_mode_ratios[i].mclk;
> > +	reg |= cs4270_mode_ratios[i].mclk;
> > +
> > +	if (cs4270->slave_mode)
> > +		reg |= CS4270_MODE_SLAVE;
> > +	else
> > +		reg |= cs4270_mode_ratios[i].speed_mode;
> 
> Shouldn't this be clearing MODE_SLAVE if it's in master mode? 

MODE_SLAVE is unset by the CS4270_MODE_SPEED_MASK mask:

#define CS4270_MODE_SPEED_MASK	0x30
#define CS4270_MODE_SLAVE	0x30

> Since
> we're doing a read/modify/write here it'd probably just be as easy to
> set or clear the bit when setting the DAI format rather than storing the
> data and setting it here.

I though so too, but the problem is that the bits that select the speed
mode are the same that select the slave mode. Hence, if I write to the
register in set_dai_fmt(), I'd have to add a special case in the other
part again. Doing it this looked much cleaner to me. Does that make
sense?

Daniel