[alsa-devel] [PATCH v3 2/3] ARM: ep93xx: add AC97 platform support

[Ryan Mallon]

On 10/15/2010 10:46 AM, H Hartley Sweeten wrote:
> On Thursday, October 14, 2010 7:49 AM, Mika Westerberg wrote:

>> +void __init ep93xx_register_ac97(void)
>> +{
>> +	/*
>> +	 * Make sure that the AC97 pins are not used by I2S.
>> +	 */
>> +	ep93xx_devcfg_clear_bits(EP93XX_SYSCON_DEVCFG_I2SONAC97);
> 
> This is fine for now.
> 
> Eventually some thought should go into a proper iomux to prevent
> loading drivers with conflicting pin requirements.  Currently, depending
> on the configuration, this could break if a user should try to use the
> ac97 and i2s audio at the same time (I2SONAC97 mode).  But, the same
> problem already exists if a user tries using spi and i2s audio (I2SONSSP
> mode).

I initially suggested this also, since we have acquire/release functions
for some other drivers, but I now think this is fine as is. It's highly
unlikely that a board is going to have both I2S and AC97 audio. We can
change this later if such a board shows up, no need to make the code
more complicated for hypothetical boards :-).

~Ryan

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