From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 519D313B2A4; Thu, 9 May 2024 04:25:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715228705; cv=none; b=B23VMRlZOTbwabkP3FZq/xwy/4LUBm+kF4tV1Si/acbkeZJgzeSkJWhX7yi82zQ1WUUOHgOmTW5Ererycybb1tcA3AKua3XNJXEkfy94JWWI9eIUbpgRz0ayTfjaKA8Cb2us3DRllICJe6CnH5KwIi44/q9Ynb9O+8dnfvB7wJQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715228705; c=relaxed/simple; bh=6HMpt//iy5ul/2zvPh0UXT6YXRvV0LGvSjzXl6xMbJU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=i1L4Xzieg5FnY7q13dmJqnvLRDxXV9L5LcmodkR+Y4Gr3NOcqslYWErV/ewKWBdFynhh/ihGW5paD29PiCKGPCK0NU51JcP4i6mkZUjmbJVde7Dp63nn6CRso1rQ/tnm2az5j35SWaZL8wH8V70+bbVkh2XQI+NJeoRvb5+qOeg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=mkK1WhgX; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="mkK1WhgX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A5983C116B1; Thu, 9 May 2024 04:25:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1715228705; bh=6HMpt//iy5ul/2zvPh0UXT6YXRvV0LGvSjzXl6xMbJU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=mkK1WhgXxEb58hvEtKOpPilq6s7ovX1CgptaWZkaoVON9UAOv+HG3ayV5TSUxLODp UTlP3JhwsnoC40fipbLtTPEvUdiJgPn83VJJIEsjtZzj0NYaS7lk/8Nj/dUWW0cFtz 8rlCCcyd7XSmKtEtd1gsT1+6lVduhuqOnuB3+mGqYfGTATi1UMaCurYP3xms6fgFNi hJCz+LJfNZgrTPjezaP3RKzs55KapM0oDls4UWdkjwV8v46k8EcR7eTvYaRq8Kpud+ lcrHYLjmR/Wd1ikuGDSJ1If8w3hdJnHCKWaI0WO3eDL6mLGAOc86BTlzFOn25wPyv7 qFCqaS5cE/RTA== Date: Thu, 9 May 2024 12:25:01 +0800 From: Tzung-Bi Shih To: Thomas =?iso-8859-1?Q?Wei=DFschuh?= Cc: Mario Limonciello , Lee Jones , Benson Leung , Guenter Roeck , chrome-platform@lists.linux.dev, linux-kernel@vger.kernel.org, Dustin Howett Subject: Re: [PATCH] platform/chrome: cros_kbd_led_backlight: enable probing through EC_FEATURE_PWM_KEYB Message-ID: References: <20240505-cros_ec-kbd-led-framework-v1-1-bfcca69013d2@weissschuh.net> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Mon, May 06, 2024 at 07:38:09PM +0200, Thomas Weißschuh wrote: > On 2024-05-05 08:42:21+0000, Mario Limonciello wrote: > > On 5/5/2024 04:41, Thomas Weißschuh wrote: > > > The ChromeOS EC used in Framework laptops supports the standard cros > > > keyboard backlight protocol. > > > However the firmware on these laptops don't implement the ACPI ID > > > GOOG0002 that is recognized by cros_kbd_led_backlight and they also > > > don't use device tree. If implementing ACPI ID GOOG0002 is not an option, how about adding a new ACPI ID? For the new ACPI ID, it can use EC PWM for setting the brightness. > > Something I'd wonder is if the GOOG0002 ACPI ID can go away entirely with > > this type of change. Presumably the Chromebooks with ChromeOS EC /also/ > > advertise EC_FEATURE_PWM_KEYB. > > Sounds good to me in general. It would make the code cleaner. > > But I have no idea how CrOS kernels are set up in general. > If they are not using CONFIG_MFD_CROS_EC_DEV for some reason that > wouldn't work. > > If the CrOS folks agree with that aproach I'll be happy to implement it. I would say NO as some existing devices (with legacy firmware and kernel) may rely on it.