On 02/01/2016 05:28 PM, Simon Glass wrote:
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?
That sounds like it should work. Isn't that simply:
#if SOMETHING
if (!strcmp(foo, "lcd"))
foo = "vidconsole";
#endif
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.
It's the Toshiba AC100 laptop. There's some information at
https://ac100.grandou.net/doku.php (and numerous other places if you
search Google for the model number.)
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