[U-Boot] [PATCH V3] imx: mx25: Remove SION bit in all pin-mux that are safe
Stefano Babic
sbabic at denx.de
Sun Feb 4 10:14:10 UTC 2018
On 25/01/2018 14:06, Michael Trimarchi wrote:
> SION bit should be used in the situation that we need
> to read back the value of a pin and should not be set by
> default macro.
>
> We get some malfunction as raised by following thread
>
> https://www.spinics.net/lists/linux-usb/msg162574.html
>
> As reported by this application note:
> https://www.nxp.com/docs/en/application-note/AN5078.pdf
>
> The software input on (SION) bit is an option to force an input
> path to be active regardless of the value driven by the
> corresponding module. It is used when the nature direction
> of a pin depending on selected alternative function is an output,
> but it is needed to read the real logic value on a pin.
>
> The SION bit can be used in:
> • Loopback: the module of a selected alternative function drives
> the pad and also receives the pad value as an input
> • GPIO capture: the module of a selected alternative function
> drives the pin and the value is captured by the GPIO
>
> SION bit is not necessary when the pin is configured as a peripheral
> apart specific silicon bug. If an application needs to have this
> set, this should be done in board file or in dts file
>
> Signed-off-by: Michael Trimarchi <michael at amarulasolutions.com>
Applied to u-boot-imx, thanks !
Best regards,
Stefano Babic
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