Hi, Am 11.10.23 um 21:00 schrieb Werner Sembach:
From: Christoffer Sandberg <cs@xxxxxxxxx> Implement per-key keyboard backlight in the leds sysfs interface for several TUXEDO devices using the ite8291 controller. There are however some known short comings: - The sysfs leds interface does only allow to write one key at a time. The controller however can only update row wise or the whole keyboard at once (whole keyboard update is currently not implemented). This means that even when you want to updated a whole row, the whole row is actually updated once for each key. So you actually write up to 18x as much as would be required. - When you want to update the brightness of the whole keyboard you have to write 126 sysfs entries, which inherently is somewhat slow, especially when using a slider that is live updating the brightness. - While the controller manages up to 126 leds, not all are actually populated. However the unused are not grouped at the end but also in between. To not have dead sysfs entries, this would require manual testing for each implemented device to see which leds are used and some kind of bitmap in the driver to sort out the unconnected ones. - It is not communicated to userspace which led entry controls which key exactly Co-developed-by: Werner Sembach <wse@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Werner Sembach <wse@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Christoffer Sandberg <cs@xxxxxxxxx>
The first time I submit a whole module, so please let me know if it made any mistakes e.g. I'm unsure if I need add myself explicitly as a maintainer, if MODULE_AUTHOR has to be a human, or if i have to split this up into smaller junks.
Also please let me know if i somehow misinterpreted the current API and the shortcomings can actually be avoided.
I have not yet looked deeply into triggers, but one idea i had is to only have one kbd_backlight by default that just makes the whole keyboard the same color and brightness. In addition to that a trigger per_key_control, that, when set, adds 125*3 subleds to write the whole keyboard in rainbow colors with a single echo to multi_intensity.
The keyboard also supports hardware color effects like color cycle, which continuously and smoothly cycles through up to 7 colors. Could this also be implemented with a trigger? That trigger would need to add a new entry nr_colors and also respectively additional subleds or additional multi_intensity_* entries.
An additional though I had was that it would be nice if the driver could somehow communicate the physical location of the key to the userspace for UIs to automatically generate a keyboard view to graphically set individual colors.
Kind regards, Werner Sembach
