Resistive 4.3" touchscreen (ads7846) with kernel 3.18.21-custom

Previous Topic Next Topic
 
classic Classic list List threaded Threaded
4 messages Options
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Resistive 4.3" touchscreen (ads7846) with kernel 3.18.21-custom

fred
Hi,

We have a couple of system that use the following combination:
Yocto 1.6 (Daisy) with kernel 3.5.7-custom + 4.3" resistive display on
chestnut43 expansion board.

We now want to upgrade those systems to yocto 1.8 (fido) with kernel
3.18.21-custom and keep the same hardware.

The LCD screen is working but the touch functionality is not.

Even if the kernel use the device tree blob
"omap3-overo-chestnut43.dtb", the driver for the capacitive display is
loaded at startup (ft5x06) instead of the driver for the resistive
touchscreen (ads7846). I tried to remove the module "edt_ft5x06" and
start the right one (ads7846), I received no error message but nothing
happens.

When I look in dmesg (dmesg | grep ads), I get these messages only:

[    0.691925] of_get_named_gpiod_flags: can't parse 'gpio' property of
node '/ads7846-reg[0]'
[    0.692565] ads7846-reg: 3300 mV
[    4.435333] ads7846-reg: disabling

Did anyone try this touchscreen driver (ads7846) with this kernel
(3.18.21) ?
Is the device tree for the chestnut missing something?

Thanks

Fred


------------------------------------------------------------------------------
What NetFlow Analyzer can do for you? Monitors network bandwidth and traffic
patterns at an interface-level. Reveals which users, apps, and protocols are
consuming the most bandwidth. Provides multi-vendor support for NetFlow,
J-Flow, sFlow and other flows. Make informed decisions using capacity planning
reports.http://sdm.link/zohodev2dev
_______________________________________________
gumstix-users mailing list
[hidden email]
https://lists.sourceforge.net/lists/listinfo/gumstix-users
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: Resistive 4.3" touchscreen (ads7846) with kernel 3.18.21-custom

fred
Hi again everyone.

I solved this issue. There was a problem with the device tree for the
arbor43c that was disabling the ads7846 driver.

If anyone else face this issue, I included the patch I did in this
email. Maybe it should be included in the gumstix patches as well?

I tested this patch with an chestnut43 with resistive display and a
arbor43c with a capacitive display and both were working.

Thanks

Fred

On 07/13/2016 03:20 PM, Fred Lamer wrote:

> Hi,
>
> We have a couple of system that use the following combination:
> Yocto 1.6 (Daisy) with kernel 3.5.7-custom + 4.3" resistive display on
> chestnut43 expansion board.
>
> We now want to upgrade those systems to yocto 1.8 (fido) with kernel
> 3.18.21-custom and keep the same hardware.
>
> The LCD screen is working but the touch functionality is not.
>
> Even if the kernel use the device tree blob
> "omap3-overo-chestnut43.dtb", the driver for the capacitive display is
> loaded at startup (ft5x06) instead of the driver for the resistive
> touchscreen (ads7846). I tried to remove the module "edt_ft5x06" and
> start the right one (ads7846), I received no error message but nothing
> happens.
>
> When I look in dmesg (dmesg | grep ads), I get these messages only:
>
> [    0.691925] of_get_named_gpiod_flags: can't parse 'gpio' property of
> node '/ads7846-reg[0]'
> [    0.692565] ads7846-reg: 3300 mV
> [    4.435333] ads7846-reg: disabling
>
> Did anyone try this touchscreen driver (ads7846) with this kernel
> (3.18.21) ?
> Is the device tree for the chestnut missing something?
>
> Thanks
>
> Fred
>
>
> ------------------------------------------------------------------------------
> What NetFlow Analyzer can do for you? Monitors network bandwidth and traffic
> patterns at an interface-level. Reveals which users, apps, and protocols are
> consuming the most bandwidth. Provides multi-vendor support for NetFlow,
> J-Flow, sFlow and other flows. Make informed decisions using capacity planning
> reports.http://sdm.link/zohodev2dev
> _______________________________________________
> gumstix-users mailing list
> [hidden email]
> https://lists.sourceforge.net/lists/listinfo/gumstix-users

------------------------------------------------------------------------------
What NetFlow Analyzer can do for you? Monitors network bandwidth and traffic
patterns at an interface-level. Reveals which users, apps, and protocols are
consuming the most bandwidth. Provides multi-vendor support for NetFlow,
J-Flow, sFlow and other flows. Make informed decisions using capacity planning
reports.http://sdm.link/zohodev2dev
_______________________________________________
gumstix-users mailing list
[hidden email]
https://lists.sourceforge.net/lists/listinfo/gumstix-users

0001-update-device-tree-for-touch-lcd43-on-chesnut.patch (2K) Download Attachment
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: Resistive 4.3" touchscreen (ads7846) with kernel 3.18.21-custom

Andrew C. Smith
Hi,

I just came across this post.  Wanted to clarify something.  The reason why the arbor43c device tree is disabling the ads7846 driver is because the arbor43c is meant for a capacitive touch (hence the "c" in the name) which uses the ft5x06 driver.  This patch information is definitely helpful for users wishing to use a resistive screen with their Overo.  Just please be aware that the stock device trees are intended for a specific board.


Thanks,

Andrew
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: Resistive 4.3" touchscreen (ads7846) with kernel 3.18.21-custom

fred
I'm sorry I made a mistake. The problem was not only in the arbor43c device tree, it was in the "/arch/arm/boot/dts/omap3-overo-common-lcd43.dtsi" file. This file is common for all lcd43 screen (resistive and capacitive). This file was disabling mcspi1, therefore disabling the touch controller for the resistive touch screen... This code should probably not be in the common file if you want to support both touchscreen?

Thanks

Fred
Loading...