On Wed, Jan 28, 2026 at 11:11:33AM +0100, Krzysztof Kozlowski wrote:
On 23/01/2026 12:11, tessolveupstream@gmail.com wrote:
quoted
On 20-01-2026 20:01, Krzysztof Kozlowski wrote:
quoted
On 20/01/2026 13:50, Sudarshan Shetty wrote:
quoted
Update the gpio-backlight binding to support configurations that require
more than one GPIO for enabling/disabling the backlight.
Why? Which devices need it? How a backlight would have three enable
GPIOs? I really do not believe, so you need to write proper hardware
justification.
To clarify our hardware setup:
the panel requires one GPIO for the backlight enable signal, and it
also has a PWM input. Since the QCS615 does not provide a PWM controller
for this use case, the PWM input is connected to a GPIO that is driven
high to provide a constant 100% duty cycle, as explained in the link
below.
https://lore.kernel.org/all/20251028061636.724667-1-tessolveupstream@gmail.com/T/#m93ca4e5c7bf055715ed13316d91f0cd544244cf5 (local)
That's not an enable gpio, but PWM.
You write bindings for this device, not for something else - like your
board.
Sudarshan: I believe at one point the intent was to model this hardware
as a pwm-backlight (using enables GPIOs to drive the enable pin)
attached to a pwm-gpio (to drive the PWM pin). Did this approach work?
Daniel.