Messages in this thread | | | Date | Fri, 8 Apr 2022 12:18:06 +0100 | From | Mark Brown <> | Subject | Re: [PATCH 5/5] drm/solomon: Add SSD130x OLED displays SPI support |
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On Thu, Apr 07, 2022 at 10:02:04PM +0200, Javier Martinez Canillas wrote: > The ssd130x driver only provides the core support for these devices but it > does not have any bus transport logic. Add a driver to interface over SPI. > > There is a difference in the communication protocol when using 4-wire SPI > instead of I2C. For the latter, a control byte that contains a D/C# field > has to be sent. This field tells the controller whether the data has to be > written to the command register or to the graphics display data memory. > > But for 4-wire SPI that control byte is not used, instead a real D/C# line > must be pulled HIGH for commands data and LOW for graphics display data. > > For this reason the standard SPI regmap can't be used and a custom .write > bus handler is needed.
Acked-by: Mark Brown <broonie@kernel.org> [unhandled content-type:application/pgp-signature] | |