Messages in this thread | | | Date | Fri, 31 Mar 2017 15:28:22 +0200 | From | Boris Brezillon <> | Subject | Re: [PATCH 1/2] gpio: Add a driver for Cadence GPIO controller |
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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
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