RE: [PATCH] iio: adc: ltc2309: Add read delay support for LTC2305

[Jones, Carlos jr]

> On Fri, Mar 27, 2026 at 11:41:59AM +0800, Carlos Jones Jr wrote:
> > The LTC2305 requires a minimum 1.6μs delay between the I2C write
> > operation (channel selection) and the subsequent read operation to
> > allow the chip to process the command and prepare the result. While
> > not explicitly documented in the datasheet, this timing requirement
> > was identified by the hardware designer as necessary for reliable
> > operation.
> >
> > This extends the existing LTC2305 support (commit 8625d418d24b
> > ("iio: adc: ltc2309: add support for ltc2305")) with the missing
> > inter-transaction delay.
> >
> > Add a read_delay_us field to chip_info to support chip-specific timing
> > requirements. Use fsleep() to implement the delay, with LTC2305 set to
> > 2μs (1.6μs requirement rounded up). LTC2309 does not require
> > additional delay beyond inherent I2C bus timing.
> 
> > Also optimize chip_info structure with __counted_by_ptr() annotation
> > and field reordering to minimize padding.
> 
> This should be a separate patch.
> Please, always split the change to logical pieces.
> 
> --
> With Best Regards,
> Andy Shevchenko
> 

Thanks for the review, Andy. I'll keep this in mind.