From: Mark Brown <broonie@kernel.org>
To: Chris Packham <chris.packham@alliedtelesis.co.nz>
Cc: robh+dt@kernel.org, mark.rutland@arm.com,
Hamish Martin <hamish.martin@alliedtelesis.co.nz>,
linux-spi@vger.kernel.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/3] spi: SPI bus multiplexer
Date: Fri, 12 Apr 2019 09:29:13 +0100 [thread overview]
Message-ID: <20190412082913.GA6909@sirena.org.uk> (raw)
In-Reply-To: <20190412050213.17698-1-chris.packham@alliedtelesis.co.nz>
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On Fri, Apr 12, 2019 at 05:02:10PM +1200, Chris Packham wrote:
> Unfortunately recent changes have stopped my hacks from working. I've
> tried adapting cs-gpios to work with my particular hardware but I came
> to the realisation that the current cs-gpios support assumes a 1:1
> mapping of gpio to SPI device whereas my hardware used the state of the
> gpio selecting the device i.e. a 1:2 mapping.
> This is my attempt to implement a driver to deal with this. One nice
> property is that it is pretty much self contained. The only change to
> the core SPI infrastructure is exposing a function I needed to lookup
> the spi_controller instance.
Why not implement the device that demuxes the GPIOs you're using for
chip select as a GPIO controller? Presumably it might get used for
things other than chip selects.
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next prev parent reply other threads:[~2019-04-12 8:29 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-12 5:02 [PATCH 0/3] spi: SPI bus multiplexer Chris Packham
2019-04-12 5:02 ` [PATCH 1/3] dt-bindings: spi: Add spi-mux-gpio Chris Packham
2019-04-29 21:37 ` Rob Herring
2020-01-13 3:43 ` Chris Packham
2019-04-12 5:02 ` [PATCH 2/3] spi: Make of_find_spi_controller_by_node visible Chris Packham
2019-04-12 5:02 ` [PATCH 3/3] spi: Add SPI bus gpio multiplexer Chris Packham
2019-04-12 8:29 ` Mark Brown [this message]
2019-04-28 22:28 ` [PATCH 0/3] spi: SPI bus multiplexer Chris Packham
2019-05-02 2:45 ` Mark Brown
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