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From: Pavel Machek <pavel@ucw.cz>
To: Hans de Goede <hdegoede@redhat.com>
Cc: Yauhen Kharuzhy <jekhor@gmail.com>,
	linux-kernel@vger.kernel.org, linux-leds@vger.kernel.org
Subject: Re: [PATCH v2 1/2] leds: Add Intel Cherry Trail Whiskey Cove PMIC LEDs
Date: Thu, 14 Feb 2019 00:38:06 +0100	[thread overview]
Message-ID: <20190213233806.GA11867@amd> (raw)
In-Reply-To: <42078a81-e32e-81b7-528f-d1adb60d31c3@redhat.com>

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Hi!


> >Agreed.
> >
> >>I believe it would be best to add a custom "mode" attribute
> >>to the led classdev, with "manual" and "on-when-charging"
> >>modes, this would then control bits 0-1 of reg 0x5e1f and
> >>by default these bits should be left as is when the driver
> >>loads.
> >
> >No. This is not first hardware when we have something like this, and
> >we need something generic here.
> >
> >One possibility would be magic "hardware drives this led"
> >trigger. Hmm? (Jacek disliked this idea before, but maybe we can
> >convince him).
> >
> >Generic "is this driven by hardware or not" attribute might be
> >possible, too... but its interaction with triggers/brightness/etc
> >would be confusing.
> 
> In this case the interaction is not that tricky, but it will
> likely be different per led controller, so I do not think that
> we can ever come up with a truely generic solution.
> 
> Basically the charge led has 3 states:
> 
> 1) Off
> 2) On
> 3) On when charging
> 
> And then when on it has 4 patterns:
> 
> 1) Permanently off (so still not really on)
> 2) Permanently on
> 3) Blinking
> 4) Breathing

Ok, so you don't really need to support _both_ off methods.

Still sounds like a normal LED, with special "yoga-charging" and
"yoga-breathing" triggers. (All the normal triggers should still work,
too.)

> These 4 patterns can be selected when on, independent
> of being perma-on or ondemand-on

Yeah, but we don't really want to expose that to userspace.

> >>As for the 0x5e20 settings, I believe another custom
> >>sysfs attribute, called "breathing" would be a good idea to
> >>export the breathing functionality.
> >
> >We have "pattern" trigger that can do this kind of stuff in
> >software. But I'm not sure if this is worth supporting.
> 
> The problem is that any changes made are permanent, they
> survice reboots and the default is Breathing, so we need
> a way to restore that which does not involve removing
> the internal battery of these devices.

Wow. Now that's a broken hardware.

Anyway, in such case I'd propose having rmmod/reboot/poweroff hook
that just sets it to breathing. No need to expose it to userspace.

Thanks,
									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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  reply	other threads:[~2019-02-13 23:38 UTC|newest]

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-12 20:58 [PATCH v2 0/2] Intel Cherry Trail Whiskey Cove LEDs support Yauhen Kharuzhy
2019-02-12 20:59 ` [PATCH v2 1/2] leds: Add Intel Cherry Trail Whiskey Cove PMIC LEDs Yauhen Kharuzhy
2019-02-13 22:43   ` Hans de Goede
2019-02-13 23:07     ` Pavel Machek
2019-02-13 23:25       ` Hans de Goede
2019-02-13 23:38         ` Pavel Machek [this message]
2019-02-14  9:57           ` Hans de Goede
2019-02-14 11:14             ` Pavel Machek
2019-02-14 11:31               ` Hans de Goede
2019-02-14 12:28                 ` Pavel Machek
2019-02-15 21:41                   ` Jacek Anaszewski
2019-02-15 23:26                     ` Pavel Machek
2019-02-14 21:46                 ` Jacek Anaszewski
2019-02-14 23:03                   ` Pavel Machek
2019-02-15  7:27                     ` Yauhen Kharuzhy
2019-02-15 21:43                       ` Jacek Anaszewski
2019-02-16 11:26                         ` Yauhen Kharuzhy
2019-02-15 11:27                     ` Hans de Goede
2019-02-15 13:02                       ` Pavel Machek
2019-02-15 21:42                       ` Jacek Anaszewski
2019-02-15 22:26                         ` Hans de Goede
2019-02-15 22:31                           ` Jacek Anaszewski
2019-02-15 23:14                             ` Hans de Goede
2019-02-16 17:02                               ` Jacek Anaszewski
2019-02-16 19:01                                 ` Hans de Goede
2019-02-16 19:37                                   ` Pavel Machek
2019-02-16 20:55                                     ` Hans de Goede
2019-02-17  0:08                                       ` Pavel Machek
2019-02-17 14:10                                         ` Hans de Goede
2019-02-17 17:45                                           ` Pavel Machek
2019-02-18 11:12                                             ` Hans de Goede
2019-02-18 21:59                                               ` Jacek Anaszewski
2019-02-16 21:54                                     ` Jacek Anaszewski
2019-02-16 22:03                                       ` Hans de Goede
2019-02-17 12:40                                         ` Jacek Anaszewski
2019-02-14 11:28             ` Pavel Machek
2019-02-14 21:34             ` Yauhen Kharuzhy
2019-02-14  6:55     ` Yauhen Kharuzhy
2019-02-14 10:04     ` Hans de Goede
2019-02-12 20:59 ` [PATCH v2 2/2] mfd: Add leds MFD cell for intel_soc_pmic_chtwc Yauhen Kharuzhy
2019-02-13 21:24   ` Jacek Anaszewski
2019-03-20  9:56   ` Lee Jones
2019-03-20  9:57     ` Lee Jones
2019-04-21 19:28 ` [PATCH v2 0/2] Intel Cherry Trail Whiskey Cove LEDs support Hans de Goede
2019-04-24 18:32   ` Yauhen Kharuzhy

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