> I saw the thread 'Adding an SPI device to the Minnowboard' from late > 2013 and 'SPI support on minnowboard v1' from Aug 2014. > > Darren Hart notes: > Ultimately we want to do things like this without board files by using > the _DSD mechanisms introduced by the ACPI 5.1 specification last week > > I just wanted to confirm the ACPI mechanism is not the recommended way > yet, and that using low-speed-spidev.c as a template is still the way to go.
The answer to that will depend on what kernel you are intending to target. Kernel's with ACPI 5.1 _DSD support, I think you'd want to push on that. Older kernels without that, likely spidev or a more targeted driver. > Additional q: > How do you tell the SPI controller that you have an active-high instead > of the usual active-low device? Is it correct to do a bitwise or with > SPI_CS_HIGH (0x4) with your SPI_MODE in your spi_board_info struct, like: > .mode = SPI_MODE_0 | SPI_CS_HIGH That should work, but take my statement with a grain of salt as I haven't tried it with a device. - John 'Warthog9' Hawley _______________________________________________ elinux-MinnowBoard mailing list [email protected] http://lists.elinux.org/mailman/listinfo/elinux-minnowboard
