Re: [PATCH RFC 1/2] dt-bindings: regmap: add common schema for no-sequential-read

Mark Brown <[email protected]> Wed, 22 Jul 2026 14:59:12 +0100

Newsgroups	dev.linux.lists.driver-core,org.kernel.vger.linux-devicetree,org.kernel.vger.linux-kernel
Message-ID	<[email protected]>

On Wed, Jul 22, 2026 at 10:42:46AM +0200, Richard Leitner wrote:
> Introduce a common regmap dt-binding schema with an optional boolean
> property no-sequential-read to describe hardware integrations where
> reading multiple consecutive registers in a single operation is not
> reliable and registers must be read individually.

> A typical case are imaging sensors used on vendor-provided camera
> modules whose bus integration does not support reads that advance across
> consecutive register addresses. In such cases, single-register reads
> work, but bulk reads do not. This restriction is a property of the
> concrete hardware integration, not of the chip itself. It therefore
> cannot be identified from the device driver and duplicating firmware
> parsing in each affected driver does not scale.

No, this should not be a DT property.  We should discover this through
the bus, just like we do currently for the various I2C quirks that are
advertied by the I2C subsystem.

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