Hi Stephen, On 1 February 2016 at 17:17, Stephen Warren <swar...@wwwdotorg.org> wrote: > On 02/01/2016 05:05 PM, Simon Glass wrote: >> >> Hi Stephen, >> >> On 1 February 2016 at 17:00, Stephen Warren <swar...@wwwdotorg.org> wrote: >>> >>> On 01/30/2016 04:37 PM, Simon Glass wrote: >>>> >>>> >>>> This series moves these two drivers over to use driver model for video. >>>> >>>> This involves the following steps: >>>> - Sync up some device tree files with Linux >>>> - Implement a proper PWM driver >>>> - Clean up and unify the driver code >>>> - Modify the existing drivers to work with driver model >>>> >>>> The tegra20 display driver uses device tree bindings invented in 2011 >>>> before >>>> Linux had this or anyone was able to agree a standard. It seems possible >>>> to >>>> move it to the new bindings (like tegra124) except for the issue of time >>>> delays between stages. It isn't clear how this should work, and Linux >>>> implements this by including all LCD definitions in the kernel source >>>> code, >>>> and not using any delays. This causes strange display artifacts on the >>>> display when starting up, but perhaps is harmless to the display. Future >>>> work will sync up the device tree more for seaboard, and thus tidy this >>>> up >>>> for nvidia boards. >>>> >>>> A bug in the keyboard driver is also fixed by this series. The series is >>>> tested on seaboard and nyan-big, the two boards I have which support a >>>> display. >>>> >>>> This series is available at u-boot-dm/tegra-working. >>> >>> >>> >>> This changes the name of the output device from "lcd" to "vidconsole". >>> Anyone who doesn't reset their environment to default when switching to >>> this >>> new U-Boot will lose their display output because of this. Is there any >>> way >>> to maintain compatibility? >> >> >> I could not think of one other than an egregious hack. It will >> certainly bite someone. Perhaps a hack that detects 'lcd' in the >> stdout env variable and prints a warning would be useful? > > > Can't the two drivers just respond to the same device name. Presumably a > build would only have one or the other compiled in?
I don't want to use 'lcd' for 'vidconsole' since 'vidconsole' is supposed to work for both LCD and video devices. The idea is to merge them. The only way I could think of to make it work was hack in stdio.c to automatically change 'lcd' to vidconsole. I was not brave enough to attempt that, but it might work. What do you think? > > Or perhaps we can add a hook in the board-specific initialization code which > re-writes the environment after loading it? > > Printing a message would be useful if the user has a serial console plugged > in, which will not always be the case. It is not possible on Paz00 (likely > the most widely used T20 device) for example without taking the case apart > and soldering to a very tiny connector; I expect almost nobody has done > that. Is that the shield thing? I'd really like to attempt that solder if there are instructions somewhere. Regards, Simon _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
