From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: [PATCH v5 2/3] platform/chrome: Add Wilco EC keyboard backlight LEDs support Date: Sat, 6 Apr 2019 10:41:57 +0200 Message-ID: <20190406084157.GA27043@amd> References: <20190404171007.160878-1-ncrews@chromium.org> <20190404171007.160878-2-ncrews@chromium.org> <20190405201534.GA4426@roeck-us.net> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="BXVAT5kNtrzKuDFl" Return-path: Content-Disposition: inline In-Reply-To: <20190405201534.GA4426@roeck-us.net> Sender: linux-kernel-owner@vger.kernel.org To: Guenter Roeck Cc: Nick Crews , 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 List-Id: linux-leds@vger.kernel.org --BXVAT5kNtrzKuDFl Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri 2019-04-05 13:15:34, Guenter Roeck wrote: > On Thu, Apr 04, 2019 at 11:10:08AM -0600, 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 > >=20 > > 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. > >=20 > > 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. > >=20 > > Since the EC will never change the backlight level of its own accord, > > we don't need to implement a brightness_get() method. > >=20 > > v5 changes: > > -Rename the LED device to "platform::kbd_backlight", to > > denote that this is the built-in system keyboard. > >=20 >=20 > NACK. Please keep it as it is, it is okay. > Per Documentation/leds/leds-class.txt, LED devices are named > "devicename:colour:function" You failed to follow threads explaining this is being changed, even when I pointed you at them. What you are doing here is not helpful. > This document also states "The naming scheme above leaves scope > for further attributes should they be needed". It does not permit, > however, to redefine one of the fields to mean "location", much less > the declaration that a devicename of "platform" shall refer to an > "internal" backlight, or that there shall be no more than one > "internal" backlight in a given system. "platform" is as good devicename as "wilco" or "chromeos". Pavel --=20 (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo= g.html --BXVAT5kNtrzKuDFl Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAlyoZlUACgkQMOfwapXb+vIzTgCdGkShC0MeKZrta+HxTkQUi6AB H04AnRnwkj3XaficTFJiKbidp2+kFc+i =ui1D -----END PGP SIGNATURE----- --BXVAT5kNtrzKuDFl--