lkml.org 
[lkml]   [2017]   [Mar]   [31]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 1/2] gpio: Add a driver for Cadence GPIO controller
On Thu, 30 Mar 2017 18:26:01 +0100
Simon Hatliff <hatliff@cadence.com> wrote:


> > Another solution would be to write 0xffffffff into CDNS_GPIO_OUTPUT_EN
> > at probe time so that each time CDNS_GPIO_DIRECTION_MODE is modified to
> > set a pin in output mode, the CDNS_GPIO_OUTPUT_EN is already correctly
> > configured.
> > Simon, would that work? Is there a good reason to keep a bit in
> > CDNS_GPIO_OUTPUT_EN set to 0 when the GPIO is in input mode (power
> > consumption?)?
> If direction_mode is set to input then output_en is ignored so this
> should work. The hardware defaults to output mode, so as long as you
> set all pins to input mode before you set all output_en bits there
> should be no negative effect.

Okay, I'll try something like that, except I'll probably keep already
output-enabled in their existing state to avoid modifying bootloader's
GPIO settings.

Thanks for the feedback.

Boris

\
 
 \ /
  Last update: 2017-03-31 15:30    [W:0.084 / U:0.124 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site