linux-kernel - Re: [PATCH v2] power_supply: rt9455_charger: Properly notify userspace about charging events

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Message-ID: <20150709032751.GA13805@earth>
Date:	Thu, 9 Jul 2015 05:27:51 +0200
From:	Sebastian Reichel <sre@...nel.org>
To:	Anda-Maria Nicolae <anda-maria.nicolae@...el.com>
Cc:	k.kozlowski.k@...il.com, linux-pm@...r.kernel.org,
	linux-kernel@...r.kernel.org, devicetree@...r.kernel.org
Subject: Re: [PATCH v2] power_supply: rt9455_charger: Properly notify
 userspace about charging events

Hi,

On Tue, Jul 07, 2015 at 03:25:53PM +0300, Anda-Maria Nicolae wrote:
> Charging events this patch refers to are:
> - charger is connected to/disconnected from the power source
> - battery is reconnected to the charger, after it was absent.
> 
> When the charger is connected to/disconnected from the power source, CHRVPI
> interrupt occurs and PWR_RDY bit is either set or cleared. PWR_RDY bit is
> updated after 1-2 seconds CHRVPI interrupt has occurred.
> power_supply_changed() should be called after PWR_RDY bit is updated.
> /sys/class/power_supply/rt9455-charger/online file displays the value of
> PWR_RDY bit.
> This way, if the userspace is notified that a charging event has occurred
> and the userspace reads /sys/class/power_supply/rt9455-charger/online file,
> this file is properly updated when the userspace reads it.
> This is the reason why power_supply_changed() is called in
> rt9455_pwr_rdy_work_callback(), instead of being called in interrupt
> handler.
> 
> Since no interrupt is triggered when the battery is reconnected to the
> charger, the userspace is never notified that the battery is reconnected.
> This is why power_supply_changed() is called in
> rt9455_max_charging_time_work_callback(), so that the userspace is notified
> that the battery is reconnected.
> 
> Signed-off-by: Anda-Maria Nicolae <anda-maria.nicolae@...el.com>

Thanks, queued with Kzrysztof's Reviewed-By.

-- Sebastian

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