linux-kernel - Re: [PATCH v8 7/8] pwm: pca9685: Restrict period change for enabled PWMs

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Message-ID: <20210417154617.uamygwgvfs5qopek@pengutronix.de>
Date:   Sat, 17 Apr 2021 17:46:17 +0200
From:   Uwe Kleine-König <u.kleine-koenig@...gutronix.de>
To:     Clemens Gruber <clemens.gruber@...ruber.com>
Cc:     linux-pwm@...r.kernel.org,
        Thierry Reding <thierry.reding@...il.com>,
        Sven Van Asbroeck <TheSven73@...il.com>,
        devicetree@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v8 7/8] pwm: pca9685: Restrict period change for enabled
 PWMs

On Mon, Apr 12, 2021 at 03:27:44PM +0200, Clemens Gruber wrote:
> Previously, the last used PWM channel could change the global prescale
> setting, even if other channels are already in use.
> 
> Fix it by only allowing the first enabled PWM to change the global
> chip-wide prescale setting. If there is more than one channel in use,
> the prescale settings resulting from the chosen periods must match.
> 
> GPIOs do not count as enabled PWMs as they are not using the prescaler
> and can't change it.
> 
> Signed-off-by: Clemens Gruber <clemens.gruber@...ruber.com>

I think this patch could be a tad simpler (by just counting the number
of enabled channels instead of maintaining a bitmap). Still this is
beneficial, so:

Acked-by: Uwe Kleine-König <u.kleine-koenig@...gutronix.de>

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |

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