On 11/15/22 05:41, Richard Fitzgerald wrote: > On 15/11/2022 11:03, Charles Keepax wrote: >> On Mon, Nov 14, 2022 at 10:13:07AM -0600, Pierre-Louis Bossart wrote: >>> >>> >>> On 11/14/22 04:29, Charles Keepax wrote: >>>> Provide stub functions when CONFIG_SOUNDWIRE is not set for functions >>>> that are quite likely to be used from common code on devices supporting >>>> multiple control buses. >>> >>> So far this case has been covered by splitting SoundWire related code >>> away from, say I2C, and with a clear 'depends on SOUNDWIRE'. This is the >>> case for rt5682, max98373, etc. >>> >>> Is this not good enough? >>> >>> I am not against this patch, just wondering if allowing code for >>> different interfaces to be part of the same file will lead to confusions >>> with e.g. register offsets or functionality exposed with different >>> registers. >>> >> >> I guess this is a bit of a grey area this one. Both work, I guess >> the reason I was leaning this way is that in order to avoid a >> circular dependency if I put all the soundwire DAI handling into >> the soundwire code then I have to duplicate the snd_soc_dai_driver >> structure into both the sdw and i2c specific code (worth noting >> the I2S DAIs are still usable when the part is sdw to the host). But >> there are also downsides to this approach in that it will likely have >> some small impact on driver size when soundwire is not built in. >> > > I think we should just add the stubs. Other subsystems use stubs to help > with code that references stuff that might not be available. > > Splitting all the soundwire-specifics out into a separate module works > for simple chips that are either I2S or soundwire. but can get messy for > a complex codec. I used the separate file method for CS42L42, but for a > driver I'm working on I abandoned that and put both DAIs in the core > code. I didn't notice the missing stubs because my defconfig that was > intended to omit soundwire apparently has something that is selecting > it anyway. It would be good if you could look into this, I don't see any 'select SOUNDWIRE'. I agree the premise of the split was that the device is used in one mode of the other, I am not sure however what the a 'complex codec' would change. It's likely that we will see a second level within a SoundWire device to deal with independent 'functions', but I don't quite see how this would matter. That said, I don't write codec drivers so I am not going to lay on the tracks over 2 stubs. We can revisit the sdw.h split as well later. Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
