[PATCH 0/1] auxdisplay: Add I2C gpio expander example

From: Ralf Schlatterbeck
Date: Wed Jan 06 2021 - 06:38:21 EST


The Hitachi HD44780 is often used together with a PCF8574 based I2C
I/O expander. It was non-obvious to me that the existing parallel
connected version of the auxdisplay driver can already handle this
configuration with appropriate device tree magic. This patch documents
the necessary incantations in an example.

That this is not only non-obvious to me is documented by at least two
I2C kernel implementations for the display out there.

Thanks to Geert Uytterhoeven for pointing out how this is done.
Thanks to Miguel Ojeda for extensively commenting on my previous patch.

.../bindings/auxdisplay/hit,hd44780.yaml | 31 ++++++++++++++++++-
1 file changed, 30 insertions(+), 1 deletion(-)

Ralf
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