Hello, On Fri, Mar 02, 2018 at 03:26:32PM -0700, Richard Wilbur wrote: > On Mar 1, 2018, at 20:30, Luke Kenneth Casson Leighton <l...@lkcl.net> wrote: > > > Sent from my iPhone > > On Thu, Mar 1, 2018 at 9:46 PM, Richard Wilbur <richard.wil...@gmail.com> > > wrote: > >> It looks to me like the fastest way to test the GPIO lines connected > >> on the micro-desktop board to VESA_SCL and VESA_SDA would simply be to > >> connect a VGA monitor to the micro-desktop and make sure it is > >> properly detected and a test image looks right on it. > > > > yep, pretty much... with one slight fly in the ointment: the SCL and > > SDA lines are straight GPIO and will need a bit-banging I2C linux > > kernel driver. once that's configured, doing i2cdetect _should_ be > > enough to test the circuit, although scanning the data and running > > read-edid on it would be awesome and amazing: it would mean being able > > to *really* do proper VESA detection. > > Is someone already working on that? Sounds like we need the device > tree for the micro-desktop to be populated. If we did it for > micro-desktop v1.7 it would be something to build off for > micro-desktop v1.8 and also a good place to begin for the laptop.
I'm not actively working on any of this, but I'm interested in the devicetree side of things. > From what I'm hearing, once the device tree is ready we could work on > "automagically" configuring the VESA DDC driver to bit-bang the > correct GPIO pins. Does the bit-banging VESA DDC driver exist already? > (I wrote a bit-banging I2C driver in VxWorks at a previous position so > the topic is not foreign.) Mainline Linux has a driver for I2C-over-GPIO. It's been there since 2.6.22, albeit initially without devicetree support, which came in 3.4. There's also a generic devicetree binding for I2C-over-GPIO in Linux's Documentation/devicetree/bindings directory. > If none of this is underway I'll continue mapping things out so we can > create the device tree for the micro-desktop. If I remember correctly > we also should create a device tree for the DS-113 v2.7.4 and v2.7.5? What is DS-113? > I'd be happy to work on that if you think that is the highest priority > right now. It sounds like it will help both testing and deployment. Thanks, Jonathan Neuschäfer : https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/i2c/busses/i2c-gpio.c : https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/i2c/i2c-gpio.txt _______________________________________________ arm-netbook mailing list firstname.lastname@example.org http://lists.phcomp.co.uk/mailman/listinfo/arm-netbook Send large attachments to arm-netb...@files.phcomp.co.uk