fsl, imx-parallel-display Question

fsl, imx-parallel-display Question

[Adam Ford]

I am trying to use a parallel LCD with an i.MX6Q board using the
device tree, but I was hoping to do it in the device tree itself
instead of modifying the "panel-simple" driver that most imx6q devices
appear to use.  I have an omap product with the LCD, and I was hoping
to just re-use the panel timings, etc.

I found imx6q-tx6q-1010-comtft.dts didn't use "panel-simple", but
using that as an example doesn't work, for me yet I can get it working
with "panel-simple"

Looking at the driver for parallel-display.c, I states that "port at 1"
is the output port which is consistent with most of the boards that
use "panel-simple" but imx6q-tx6q-1010-comtft.dts does not have this.
The other thing I noticed is that "panel-simple" devices have an gpio
enable which I need, but but imx6q-tx6q-1010-comtft.dts does not have
this either.

Is "panel-simple" the only solution, or is there a way to integrate
the display info into the device tree and keep the enable-gpios stuff?
 Is imx6q-tx6q-1010-comtft.dts doing something wrong?

adam

fsl, imx-parallel-display Question

[Lothar Waßmann]

Hi,

On Tue, 2 May 2017 08:55:20 -0500 Adam Ford wrote:
> I am trying to use a parallel LCD with an i.MX6Q board using the
> device tree, but I was hoping to do it in the device tree itself
> instead of modifying the "panel-simple" driver that most imx6q devices
> appear to use.  I have an omap product with the LCD, and I was hoping
> to just re-use the panel timings, etc.
> 
> I found imx6q-tx6q-1010-comtft.dts didn't use "panel-simple", but
> using that as an example doesn't work, for me yet I can get it working
> with "panel-simple"
> 
> Looking at the driver for parallel-display.c, I states that "port at 1"
> is the output port which is consistent with most of the boards that
> use "panel-simple" but imx6q-tx6q-1010-comtft.dts does not have this.
> The other thing I noticed is that "panel-simple" devices have an gpio
> enable which I need, but but imx6q-tx6q-1010-comtft.dts does not have
> this either.
> 
> Is "panel-simple" the only solution, or is there a way to integrate
> the display info into the device tree and keep the enable-gpios stuff?
>  Is imx6q-tx6q-1010-comtft.dts doing something wrong?
> 
You can specify the display timings in the 'display-timings' subnode of
the display at di0 node. The active timing can be selected by setting the
'native-mode' property appropriately.


Lothar Wa?mann

fsl, imx-parallel-display Question

[Lucas Stach]

Am Dienstag, den 02.05.2017, 08:55 -0500 schrieb Adam Ford:
> I am trying to use a parallel LCD with an i.MX6Q board using the
> device tree, but I was hoping to do it in the device tree itself
> instead of modifying the "panel-simple" driver that most imx6q devices
> appear to use.  I have an omap product with the LCD, and I was hoping
> to just re-use the panel timings, etc.
> 
> I found imx6q-tx6q-1010-comtft.dts didn't use "panel-simple", but
> using that as an example doesn't work, for me yet I can get it working
> with "panel-simple"
> 
> Looking at the driver for parallel-display.c, I states that "port at 1"
> is the output port which is consistent with most of the boards that
> use "panel-simple" but imx6q-tx6q-1010-comtft.dts does not have this.
> The other thing I noticed is that "panel-simple" devices have an gpio
> enable which I need, but but imx6q-tx6q-1010-comtft.dts does not have
> this either.
> 
> Is "panel-simple" the only solution, or is there a way to integrate
> the display info into the device tree and keep the enable-gpios stuff?

Please use the panel-simple option. It's the agreed solution to describe
the panels in DT and is the only option that is acceptable if you ever
try to upstream your DT.

>  Is imx6q-tx6q-1010-comtft.dts doing something wrong?

It's using the deprecated way of describing the attached panel, by
putting the timings in the DT. This is not acceptable for new DTs, so
please don't try to replicate this.

Regards,
Lucas