[PATCH v4] gpio: mxc_gpio: fix reading state of GPIO pins in output mode

Fabio Estevam festevam at gmail.com
Mon Sep 2 19:46:17 CEST 2024


On Wed, Aug 28, 2024 at 10:09 AM Tomas Paukrt <tomaspaukrt at email.cz> wrote:
>
> The PSR register works correctly for GPIO pins in input mode,
> but always returns 0 for GPIO pins in output mode unless the SION
> bit is set.
>
> The DR register should be used for GPIO pins in output mode
> to allow correct getting of previously set output value.
>
> Please note that the Linux gpio-mxc driver and the NXP U-Boot mxc_gpio
> driver already use the DR register for all GPIO pins in output mode:
>
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=442b2494b17d1a4f0a14721580271eb23ebffd42
> https://github.com/nxp-imx/uboot-imx/commit/4afc3f90943c6b117f79b66d2cd04e64f437b0c2
>
> Signed-off-by: Tomas Paukrt <tomaspaukrt at email.cz>

Applied, thanks.


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