From: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
To: Conor Dooley <conor.dooley@microchip.com>
Cc: Thierry Reding <thierry.reding@gmail.com>,
Rob Herring <robh+dt@kernel.org>,
Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
Daire McNamara <daire.mcnamara@microchip.com>,
devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-pwm@vger.kernel.org, linux-riscv@lists.infradead.org
Subject: Re: [PATCH v10 3/4] pwm: add microchip soft ip corePWM driver
Date: Fri, 30 Sep 2022 11:13:16 +0200 [thread overview]
Message-ID: <20220930091316.kdkf4oeu6uvxzqa6@pengutronix.de> (raw)
In-Reply-To: <Yyh8v+MtHuc0LLf0@wendy>
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On Mon, Sep 19, 2022 at 03:29:19PM +0100, Conor Dooley wrote:
> Hey Uwe,
>
> On Mon, Sep 19, 2022 at 03:50:08PM +0200, Uwe Kleine-König wrote:
> > On Mon, Sep 19, 2022 at 01:53:56PM +0100, Conor Dooley wrote:
> > > Because I was running into conflicts between the reporting here and some
> > > of the checks that I have added to prevent the PWM being put into an
> > > invalid state. On boot both negedge and posedge will be zero & this was
> > > preventing me from setting the period at all.
> >
> > I don't understood that.
>
> On startup, (negedge == posedge) is true as both are zero, but the reset
> values for prescale and period are actually 0x8. If on reset I try to
> set a small period, say "echo 1000 > period" apply() returns -EINVAL
> because of a check in the pwm core in pwm_apply_state() as I am
> attempting to set the period to lower than the out-of-reset duty cycle.
You're supposed to keep the period for pwm#1 untouched while configuring
pwm#0 only if pwm#1 already has a consumer. So if pwm#1 isn't requested,
you can change the period for pwm#0.
Best regards
Uwe
--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | https://www.pengutronix.de/ |
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next prev parent reply other threads:[~2022-09-30 9:13 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-24 9:12 [PATCH v10 0/4] Microchip soft ip corePWM driver Conor Dooley
2022-08-24 9:12 ` [PATCH v10 1/4] dt-bindings: pwm: fix microchip corePWM's pwm-cells Conor Dooley
2022-08-24 9:12 ` [PATCH v10 2/4] riscv: dts: fix the icicle's #pwm-cells Conor Dooley
2022-09-14 19:59 ` Uwe Kleine-König
2022-09-15 7:03 ` Conor.Dooley
2022-08-24 9:12 ` [PATCH v10 3/4] pwm: add microchip soft ip corePWM driver Conor Dooley
2022-09-15 7:21 ` Uwe Kleine-König
2022-09-19 12:53 ` Conor Dooley
2022-09-19 13:50 ` Uwe Kleine-König
2022-09-19 14:29 ` Conor Dooley
2022-09-30 7:11 ` Conor Dooley
2022-09-30 9:13 ` Uwe Kleine-König [this message]
2022-09-30 9:45 ` Conor Dooley
2022-09-30 13:39 ` Uwe Kleine-König
2022-09-30 13:49 ` Conor Dooley
2022-09-30 14:06 ` Uwe Kleine-König
2022-08-24 9:12 ` [PATCH v10 4/4] MAINTAINERS: add pwm to PolarFire SoC entry Conor Dooley
2022-09-14 20:01 ` Uwe Kleine-König
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