Issue 458: use new panel driver model

Reported by Nikolaus Schaller, Jul 23, 2013

The latest (3.10) DSS panel driver is quite generic so that the 
board file only defines which panel to use and some GPIOs to be 
controlled as well as a delay after power on/off:

http://git.neil.brown.name/?p=gta04.git;a=blob;f=drivers/video/omap2/
displays/panel-generic-dpi.c;h=97363f73368323353b245b5a46c0a065b8788f
b7;hb=refs/heads/mainline

This is sufficient for the GTA04b2 and GTA04b3 panel, so that we 
should finally remove our own panel drivers.

Only the GTA04 (GTA02) TPO display needs special code to send SPI 
data to the controller.

Comment 1 by Nikolaus Schaller, Jul 28, 2013

Labels: Milestone:3.10

Comment 2 by Nikolaus Schaller, Aug 7, 2013

Owner: hns

Comment 3 by Nikolaus Schaller, Aug 28, 2013

Wasn't difficult...

Status: Fixed

Comment 4 by Nikolaus Schaller, Sep 1, 2013

Reopened since this type of drivers is no longer supported in 3.12 
kernel!

I.e. we have to rewrite all panel drivers (TPO028, COM37, LQ070) to 
the "new panel model".

Labels: Type:Critical Priority:High ~~Type:Enhancement~~ ~~Priority:Low~~
Status: Accepted
Summary: use new panel driver model

Comment 5 by Nikolaus Schaller, Sep 1, 2013

Labels: Milestone:3.12 ~~Milestone:3.10~~

Comment 6 by Nikolaus Schaller, Sep 2, 2013

It appears that we have to do (can start on 3.11 kernel):

1. configure "new display model DISPLAY_PANEL_DPI"
2. use "panel-dpi" driver
3. use struct panel_dpi_platform_data in the platform data
4. move display config from the driver to the board file (referenced 
by struct panel_dpi_platform_data)
5. specify the enable/disable and backlight GPIOs

A problem may arise with the polarity of the enable GPIO

Comment 7 by Nikolaus Schaller, Sep 2, 2013

Ok,
* code for boardfile and defconfig fixed
* compiles well with 3.11-rc7
* but display does not work - kernel reports that it has no displays

For 3.12 code see:
https://git.kernel.org/cgit/linux/kernel/git/tomba/linux.git/commit/?
h=3.12/dss-legacy-removal&id=c78fb21decade8511b252ab8d60f8c93315e
b271

Comment 8 by Nikolaus Schaller, Sep 10, 2013

Finally works fine on 3.11. On 3.12 there is some other bug 
(framebuffer allocation) preventing testing.

Status: Fixed

Letux Kernel