Messages in this thread | | | Date | Fri, 23 Nov 2018 11:25:38 +0100 | From | Uwe Kleine-König <> | Subject | Re: [PATCH v2] pwm: kconfig: enable kona pwm to be built for cygnus arch |
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Hello Clément,
On Fri, Nov 23, 2018 at 10:31:18AM +0100, Clément Péron wrote: > On Thu, 22 Nov 2018 at 21:05, Uwe Kleine-König > <u.kleine-koenig@pengutronix.de> wrote: > > Related to this driver I have a set of questions: If the disable > > callback completed, does the hardware still drive the pin? If yes, would > > it be possible to disable the pin driver such that the pin gets high-Z? > > If yes, how? > > The output pin type is configured with the bit "21:16 PWMOUT_TYPE RW > default 0x3F" in the Control register > PWM_CONTROL_TYPE_SHIFT macro in the driver > Datasheets says : "When set to 1 the PWM Output signal will have a > push/pull type.When set to 0 the PWM Output signal will have an open > drain output type.Recommend to leave it push/pull type." > > In the driver we actually set push/pull mode for all channels : > /* Set push/pull for all channels */ > for (chan = 0; chan < kp->chip.npwm; chan++) > value |= (1 << PWM_CONTROL_TYPE_SHIFT(chan));
So if disabling the output driver was part of the requirements for .disable the bcm-kona driver could not implement this for both inverted and uninverted PWMs. (At least not without resorting to pinmuxing.)
Thanks Uwe
-- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ |
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