On Tue, Aug 9, 2011 at 5:54 PM, Kim Phillips <kim.phill...@freescale.com> wrote: > On Tue, 9 Aug 2011 17:31:29 -0500 Joe Hershberger <joe.hershber...@ni.com> > wrote: > >> + /* Update the local output buffer soft copy */ >> + gpio_output_value[ctrlr] = >> + (gpio_output_value[ctrlr] & ~lineMask) | (value ? lineMask : >> 0); > > what's the use of having a local output buffer soft copy? I don't > see it being used anywhere.
It's used in the line you quoted. If other lines on the same controller are configured for open-collector, but are externally pulled low, then using the DAT register instead of the soft copy will force those to be actively grounded. To avoid this, I use a soft-copy. -Joe _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
