linux-kernel - Re: [PATCH 2/4] pwm: omap-dmtimer: Fix pwm enabling sequence

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Message-ID: <bac78775-4bee-7437-f5ef-3cf85997e7d1@ti.com>
Date:   Tue, 25 Feb 2020 10:32:20 +0530
From:   Lokesh Vutla <lokeshvutla@...com>
To:     Uwe Kleine-König <u.kleine-koenig@...gutronix.de>
CC:     Thierry Reding <thierry.reding@...il.com>,
        Tony Lindgren <tony@...mide.com>,
        Linux OMAP Mailing List <linux-omap@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>, <linux-pwm@...r.kernel.org>,
        Sekhar Nori <nsekhar@...com>
Subject: Re: [PATCH 2/4] pwm: omap-dmtimer: Fix pwm enabling sequence

Hi Uwe,

On 24/02/20 2:19 PM, Uwe Kleine-König wrote:
> On Mon, Feb 24, 2020 at 10:51:33AM +0530, Lokesh Vutla wrote:
>> To configure DM timer is pwm mode the following needs to be set in
>> OMAP_TIMER_CTRL_REG using set_pwm callback:
>> - Set toggle mode on PORTIMERPWM output pin
>> - Set trigger on overflow and match on PORTIMERPWM output pin.
>> - Set auto reload
>>
>> This is a one time configuration and needs to be set before the start of
>> the dm timer. But the current driver tries to set the same configuration
>> for every period/duty cycle update, which is not needed. So move the pwm
>> setup before enabling timer and do not update it in pwm_omap_dmtimer_config.
> 
> Is this change kind of moot with the conversion to .apply in the next
> patch?

Yes, but I didn't want to club it with the conversion to .apply as this is
functional change wrt to the existing driver.

Thanks and regards,
Lokesh