From: Andy Shevchenko <andriy.shevchenko@intel.com>
To: Carlos Jones Jr <carlosjr.jones@analog.com>
Cc: "Jonathan Cameron" <jic23@kernel.org>,
"David Lechner" <dlechner@baylibre.com>,
"Michael Hennerich" <Michael.Hennerich@analog.com>,
"Liam Beguin" <liambeguin@gmail.com>,
"Nuno Sá" <nuno.sa@analog.com>,
"Andy Shevchenko" <andy@kernel.org>,
"Jorge Marques" <jorge.marques@analog.com>,
linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] iio: adc: ltc2309: Add read delay support for LTC2305
Date: Fri, 27 Mar 2026 11:34:37 +0200 [thread overview]
Message-ID: <acZPLXhC9PWNIpeN@ashevche-desk.local> (raw)
In-Reply-To: <20260327034159.15545-1-carlosjr.jones@analog.com>
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
next prev parent reply other threads:[~2026-03-27 9:34 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-27 3:41 Carlos Jones Jr
2026-03-27 9:34 ` Andy Shevchenko [this message]
2026-03-30 4:18 ` Jones, Carlos jr
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