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From: Pavel Machek <pavel@ucw.cz>
To: Nick Crews <ncrews@chromium.org>
Cc: enric.balletbo@collabora.com, bleung@chromium.org,
	linux-leds@vger.kernel.org, jacek.anaszewski@gmail.com,
	alexandre.belloni@bootlin.com, a.zummo@towertech.it,
	linux-rtc@vger.kernel.org, linux-kernel@vger.kernel.org,
	dlaurie@chromium.org, sjg@google.com, groeck@google.com,
	dtor@google.com
Subject: Re: [PATCH v5 2/3] platform/chrome: Add Wilco EC keyboard backlight LEDs support
Date: Thu, 4 Apr 2019 21:52:10 +0200	[thread overview]
Message-ID: <20190404195210.GC29984@amd> (raw)
In-Reply-To: <20190404171007.160878-2-ncrews@chromium.org>

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On Thu 2019-04-04 11:10:08, Nick Crews wrote:
> The EC is in charge of controlling the keyboard backlight on
> the Wilco platform. We expose a standard LED class device at
> /sys/class/leds/platform::kbd_backlight. This driver is modeled
> after the standard Chrome OS keyboard backlight driver at
> drivers/platform/chrome/cros_kbd_led_backlight.c
> 
> Some Wilco devices do not support a keyboard backlight. This
> is checked via wilco_ec_keyboard_leds_exist() in the core driver,
> and a platform_device will only be registered by the core if
> a backlight is supported.
> 
> After an EC reset the backlight could be in a non-PWM mode.
> Earlier in the boot sequence the BIOS should send a command to
> the EC to set the brightness, so things **should** be set up,
> but we double check in probe() as we query the initial brightness.
> If not set up, then set the brightness to 0.
> 
> Since the EC will never change the backlight level of its own accord,
> we don't need to implement a brightness_get() method.
...
> Signed-off-by: Nick Crews <ncrews@chromium.org>
> Acked-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>

Acked-by: Pavel Machek <pavel@ucw.cz>

-- 
(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:[~2019-04-04 19:52 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-04-04 17:10 [PATCH v5 1/3] platform/chrome: wilco_ec: Standardize mailbox interface Nick Crews
2019-04-04 17:10 ` [PATCH v5 2/3] platform/chrome: Add Wilco EC keyboard backlight LEDs support Nick Crews
2019-04-04 19:52   ` Pavel Machek [this message]
2019-04-05 20:15   ` Guenter Roeck
2019-04-06  8:41     ` Pavel Machek
2019-04-07 21:46       ` Dmitry Torokhov
2019-04-07 22:18         ` Pavel Machek
2019-04-07 22:26           ` Dmitry Torokhov
2019-04-08  9:41             ` Keyboard backlight LED naming was " Pavel Machek
2019-04-08 13:31               ` Guenter Roeck
2019-04-04 17:10 ` [PATCH v5 3/3] platform/chrome: Standardize Chrome OS keyboard backlight name Nick Crews
2019-04-04 17:36   ` Guenter Roeck
2019-04-04 17:43     ` Dmitry Torokhov
2019-04-04 18:41       ` Nick Crews
2019-04-04 18:55         ` Dmitry Torokhov
2019-04-04 18:59           ` Pavel Machek
2019-04-04 19:05             ` Dmitry Torokhov
2019-04-04 19:19               ` Pavel Machek
2019-04-04 19:59                 ` Dmitry Torokhov
2019-04-04 20:06                   ` Pavel Machek
2019-04-04 20:13                     ` Dmitry Torokhov
2019-04-04 20:20                       ` Pavel Machek
2019-04-04 20:26                         ` Dmitry Torokhov
2019-04-04 20:42                           ` Pavel Machek
2019-04-04 21:48                             ` Dmitry Torokhov
2019-04-04 22:05                               ` Pavel Machek
2019-04-04 22:42                                 ` Guenter Roeck
2019-04-05  8:42                                   ` Enric Balletbo i Serra
2019-04-05 20:00                                     ` Jacek Anaszewski
2019-04-06  9:53                                       ` Pavel Machek
2019-04-06 14:15                                         ` Jacek Anaszewski
2019-04-06 22:17                                           ` Pavel Machek
2019-04-07 22:01                                       ` Dmitry Torokhov
2019-04-08 20:01                                         ` Jacek Anaszewski
2019-04-04 18:56         ` Pavel Machek
2019-04-08 23:58   ` Nick Crews

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