Enable de-ghosting for RGB matrix on the IS31L3733

[donicrosby]

Description

Currently RGB matrixes for the IS31L3733 have ghosting issues with the LEDs. Any LEDs used as indicators or just plain off in the matrix glow faintly which isn't ideal. I have added a option to be set in a keyboards config.h that allows for makers and users to enable the on-chip resistors for all of the drivers on the board so that this ghosting is eliminated.

I have set the default value to allow for ghosting (0 ohm resistor) so as to stay backwards compatible and not cause power issues with older boards.

The datasheet recommends enabling the 32k ohm resistor as it is only on during the blanking time so there shouldn't be any dimming with the LEDs when they are on. If you want me to set that as the default (would make sense that you wouldn't want ghosting on the matrix) I can do that as well.

Types of Changes

• Core
• Bugfix
• New feature
• Enhancement/optimization
• Keyboard (addition or update)
• Keymap/layout/userspace (addition or update)
• Documentation

Issues Fixed or Closed by This PR

None

Checklist

• My code follows the code style of this project: C, Python
• I have read the PR Checklist document and have made the appropriate changes.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• I have tested the changes and verified that they work and don't break anything (as well as I can manage).

[donicrosby]

Would it be wise to update all of the ISSI RGB drivers that have on-chip pull-up/down resistors follow the same syntax and the documentation is updated to reflect that?

[drashna]

Would it be wise to update all of the ISSI RGB drivers that have on-chip pull-up/down resistors follow the same syntax and the documentation is updated to reflect that?

Yeah, I think it would be worth adding to all of the controllers that support it.