Messages in this thread | | | Date | Thu, 14 Jan 2021 19:05:09 +0100 | From | Uwe Kleine-König <> | Subject | Re: [PATCH v5 2/7] pwm: pca9685: Support hardware readout |
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Hello Clemens,
On Thu, Jan 14, 2021 at 06:16:22PM +0100, Clemens Gruber wrote: > On Mon, Jan 11, 2021 at 09:35:32PM +0100, Uwe Kleine-König wrote: > > My position here is: A consumer should disable a PWM before calling > > pwm_put. The driver should however not enforce this and so should not > > modify the hardware state in .free(). > > > > Also .probe should not change the PWM configuration. > > I see. This would also allow PWMs initialized in the bootloader (e.g. > backlights) to stay on between the bootloader and Linux and avoid > flickering. > > If no one objects, I would then no longer reset period and duty cycles > in the driver (and for our projects, reset them in the bootloader code > to avoid leaving PWMs on after a kernel panic and watchdog reset, etc.) > > And if there is no pre-known state of the registers, we actually need > the .get_state function fully implemented.
This sounds right.
Thanks Uwe
-- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | https://www.pengutronix.de/ | [unhandled content-type:application/pgp-signature] | |