On 02/21/2017 04:03 PM, Lucas Stach wrote:
I am fighting to enable ldb in Linux 4.9.7. In barebox the SAME
device-tree is modified by barebox to enable/disable the ldb or hdmi
depending on what is found.
During Linux bootup with HDMI only, it works with no hassle.
If booting with ldb it does not start the ldb driver registration due to
a panel/bridge missing.
In the config of linux kernel I have (as imx_v6_v7_defconfig) all drm
and simple panel enabled.
What is missing???
During last week I was able to activate/deactivate the hdmi and ldb
nodes from internal device-tree of Barebox and everything is working great.
Barebox is working without it, so I suppose it was working in Linux
kernel too...
No, Linux does not support DT defined modes in the panel. You need a
panel with a proper compatible and driver.
See drivers/gpu/drm/panel. For most LVDS panels simple-panel is what you
want to use.
I see. The main issue here, I have a bunch of display-timings (3
actually) and they are working in Barebox setting the ldb timings in ldb
node in the device-tree.
The same behaviour cannot be done in Linux?
in panel-simple there is a function named: panel_simple_get_modes() and
it looks for edid eeprom on each panel, then add the fixed mode
hardcoded in the module. Is there a clean way to add the
timing-definition of the ldb module to this procedure?
Nobody has never had a multiple display-timing definitions in a
device-tree and added those timings to the panel?
I cannot believe.
In barebox all display-timings are correctly added to the ldb device
drivers, and I am wondering Linux does not do the same.
Due to this limitiation of the Linux Kernel, in my board
device_initcall() I will try to change the compatibility string to match
a hardcoded timing in the panel-simple.c hardcoded timing.
i.e.:
panel {
compatible = "simple-panel", "auo,b101aw03";
...
to:
panel {
compatible = "simple-panel", "ampire,am800480r3tmqwa1h";
...
so Linux can be happy and register a framebuffer...
Is there a of_ utility in barebox to achieve this kind of stuff??
That is change a compatibility string *MODIFYING ONLY A VALUE*
(ampire,...) and leave the "simple-panel" untouched?
Regards,
--
Eurek s.r.l. |
Electronic Engineering | http://www.eurek.it
via Celletta 8/B, 40026 Imola, Italy | Phone: +39-(0)542-609120
p.iva 00690621206 - c.f. 04020030377 | Fax: +39-(0)542-609212
_______________________________________________
barebox mailing list
barebox@xxxxxxxxxxxxxxxxxxx
http://lists.infradead.org/mailman/listinfo/barebox
