On Fri, Dec 13, 2024 at 06:32:50PM +0100, J. Neuschäfer via B4 Relay wrote:
> From: "J. Neuschäfer" <j.ne@xxxxxxxxxx>
>
> The Fairchild MM74HC595 and other compatible parts have a latch clock
> input (also known as storage register clock input), which must be
> clocked once in order to apply any value that was serially shifted in.
>
> This patch adds driver support for using a GPIO that connects to the
> latch clock.
>
> Signed-off-by: J. Neuschäfer <j.ne@xxxxxxxxxx>
I just noticed that this feature is unnecessary for my use-case:
The 74HC595 doesn't have a chip-select input, but if the rising-edge
triggered latch clock input is reinterpreted as an active-low chip
select, it does the right thing.
_ _ _ _
shift clock ____| |_| |_..._| |_| |_________
latch clock * trigger
___ ________
chip select# |___________________|
-- jn
