Re: [PATCH 2/2] ASoC: cs35l45: Adds support for SYNC bus

[Ricardo Rivera-Matos <rriveram@opensource.cirrus.com>]

On 8/11/26 12:24 PM, Mark Brown wrote:
> On Tue, Aug 11, 2026 at 05:06:03PM +0000, Ricardo Rivera-Matos wrote:
>> Adds support for the multidevice synchronization (SYNC) bus.
>> The SYNC bus is an opaque one wire bus that is shared between
>> Cirrus devices. Initial support only includes software (SW)
>> data packets.
> 
> Given this description...
> 
>> +	SOC_SINGLE_BOOL_EXT("SYNC Enable", 0, cs35l45_sync_en_get, cs35l45_sync_en_put),
>> +	SOC_SINGLE("SYNC LSW RX Enable", CS35L45_SYNC_TX_RX_ENABLES,
>> +			CS35L45_SYNC_LSW_RX_EN_SHIFT, 1, 0),
>> +	SOC_SINGLE("SYNC LSW TX Enable", CS35L45_SYNC_TX_RX_ENABLES,
>> +			CS35L45_SYNC_LSW_TX_EN_SHIFT, 1, 0),
>> +	SOC_SINGLE("SYNC SW RX Enable", CS35L45_SYNC_TX_RX_ENABLES,
>> +			CS35L45_SYNC_SW_RX_EN_SHIFT, 1, 0),
>> +	SOC_SINGLE("SYNC SW TX Enable", CS35L45_SYNC_TX_RX_ENABLES,
>> +			CS35L45_SYNC_SW_TX_EN_SHIFT, 1, 0),
> 
> ...it's not clear to me why this would be user controllable.

This can be use-case dependent. An example that comes to mind is keeping 
similar transducers linked during a posture switch.

That is to say, on a four speaker system in landscape orientation, two 
particular amps are acting as linked tweeters and two amps are acting as 
unlinked woofers. When rotated into portrait orientation the linking 
over the SYNC bus needs to be reconfigured to match the new pairings in 
the portrait use-case.

Ricardo