[DEV][PATCH] KCAL - Advanced color control for Qualcomm MDSS 8x10/8x26/8974/8084/8939

[savoca]

Hello! If you're keen on custom kernels, especially for Nexus devices, you've probably heard the term Color/Gamma Control thrown around a bit. A once *very* device dependent feature now made available for the following chipsets:

8x10
8974 v1.0
8x26 v1.0
8x26 v2.0, 8926 v1.0
8926 v2.0
8974 v2.0
8974 v3.0 (Pro)
8084 v1.0
8084 v1.1
8994 v1.0
8916 v1.0
8939 v1.0
8092 v1.0

Color calibration allows you to use an app (or root shell) to manipulate the following post-processing features of the Qualcomm MDSS:

RGB Multipliers (Polynomial Color Correction)
Display Color Inversion (Inverse Gamma Correction)
Hue/Saturation/Value/Contrast Manipulation (Picture Adjustment)

Too confusing? Here's a video demonstration by @Andromjb:

Sysfs paths/variables:

/sys/devices/platform/kcal_ctrl.0/kcal - (0-256 0-256 0-256) - Controls R/G/B Multipliers
/sys/devices/platform/kcal_ctrl.0/kcal_min - (0-256) - Controls minimum RGB Multiplier value
/sys/devices/platform/kcal_ctrl.0/kcal_enable - (0-1) - Enables/Disables RGB Multiplier Control
/sys/devices/platform/kcal_ctrl.0/kcal_invert - (0-1) - Enables/Disables Display Inversion Mode
/sys/devices/platform/kcal_ctrl.0/kcal_sat - (224-383 or 128) - Controls saturation intensity - use 128 for grayscale mode
/sys/devices/platform/kcal_ctrl.0/kcal_hue - (0-1536) - Controls display hue - may have issues with msm8x26 in the higher values
/sys/devices/platform/kcal_ctrl.0/kcal_val - (128-383) - Controls display value
/sys/devices/platform/kcal_ctrl.0/kcal_cont - (128-383) - Controls display contrast

Link your favorite kernel developer back to this thread and ask them to add support!

KCAL for MDP5
https://github.com/savoca/kcal/commits/mdp5

KCAL for MDP3 (Only supports RGB multipliers):
https://github.com/savoca/kcal/commits/mdp3

And finally, an app to control your display - available for free here:
http://downloads.codefi.re/savoca/kcal

Thank you to LG for the display inversion control and code reference, also thank you to @faux123 for insight/reference with MDP3 RGB multipliers and @eng.stk for testing on APQ8084

 

[BlackSoulxxx]

Deleted

 

[neobuddy89]

Great work @savoca
How to check MDSS_MDP_HW_REV? Any idea which is for Hammerhead and Shamu?

 

[mosabajaj]

great

 

[FantasticalX]

It is will works on lollipop branch?

 

[franciscofranco]

Looks great to me. I'll give it a whirl on Shamu. Thanks!

 

[flar2]

Sweet. I'll try it on HTC m8 and Nexus 6 this week.

 

[djvita]

msm8960?

any support for first gen krait?

 

[franciscofranco]

On Shamu I can't get anything to work besides the usual RGB and inverted.

 

[DerRomtester]

Works great on bacon thank you

 

[savoca]

On Shamu I can't get anything to work besides the usual RGB and inverted.

Sweet. I'll try it on HTC m8 and Nexus 6 this week.

Sat/Hue/Val/Cont use the picture adjustment feature, and on APQ8084 and beyond it's been moved to a 2nd version of Qcom's picture adjustment. I don't have any of those devices so I didn't attempt to add support - but here's a blind patch you can try to add support or use for reference:
https://github.com/savoca/kernel-msm/commit/7dbc9ba0fd18279cde564c1631e52b448b39fc98
(This patch is assuming the scaling for PA v2 is the same as v1, it's very possible that has changed - but again, no device in hand, not much I can find out)

Great work @savoca
How to check MDSS_MDP_HW_REV? Any idea which is for Hammerhead and Shamu?

First code block in the OP has a reference list. :good:

 

[GalaticStryder]

I'll try to add it on my G2 kernel, let's see how good is this...
+1 savoca :good:

 

[Snepsts]

Looks like for newer Qualcomms, good work! Unfortunately my device is back on APQ8064T, but always nice to see innovation for all devices!

 

[drive2droad]

Well i have a Redmi 1S with a Qualcomm Snapdragon 400 chipset , i know this might be stupid to ask but will it work ??

 

[eng.stk]

@savoca I merged your patches on shamu, at least RGB, invert and so on work echo values.
Can't test your app, it crashes when opening...

 

[Tommy-Geenexus]

any support for first gen krait?

Anything released before msm8974 doesn't use MDSS display driver and can't be supported.

 

[savoca]

@savoca I merged your patches on shamu, at least RGB, invert and so on work echo values.
Can't test your app, it crashes when opening...

Check this post for info on HW_REV_103 (APQ8084) - you can test the patch there.

As for the app, never happened to me - I'd gladly accept a log.

 

[eng.stk]

Check this post for info on HW_REV_103 (APQ8084) - you can test the patch there.

As for the app, never happened to me - I'd gladly accept a log.

Sorry mate I added a log but was on .log and now I put .txt so xda upload doesn't derp it

I added the said patch also, but would like to test with the app.

 

[savoca]

Sorry mate I added a log but was on .log and now I put .txt so xda upload doesn't derp it

I added the said patch also, but would like to test with the app.

Are you using a ROM with support for RGB calibration? If so the selinux/contexts it may hold with the kcal sysfs path could prevent the app from using them. You can either pull all references to kcal out of the ramdisk, or use a root shell for now.

I'd also like to hear your results on pa_v2 control with N6.

 

[neobuddy89]

@savoca

Tested. Works great.
One thing.. on click on "Restore" ... Gamma value for RED autosets to 86 instead of 256.