From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 C474F2576E for ; Sun, 12 May 2024 16:24:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715531047; cv=none; b=PmBoHvHTzlPxEtUKBwTLiZ3y7ZzJksQvtsk3XJ6aRfUZ0l8pAVDWdSJaDOY1d8rNk46wd+qAR2BAfYRHMZiiXpgzORbE8Cm/zUFtD74FXqfcLSKcvubbJUYc6LYk5OZdK36zeu6aZ4mQtGz+I6uav2BKmdauJWOlzUZAWVlwPZ0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715531047; c=relaxed/simple; bh=VSuYcVXARQhtCB32D2A1ORwhEPkNloYtX/BTRJ2D6H4=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=rNzBd4xWfLycFVhHNpG/G9J+jtap2W1JjPaec0UNkGL69IgTYlrdY1ykXHbB2gL4LVxA6HxHYUbThMq7d369nJMisQE3ALsqboYMscx8Zneh3/wafqQrwS9klXGqBR8jW+pLELuEG7a47BK3A1exUMrH2r4n35OnHL0txANSVs4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=Y7wCSuzd; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Y7wCSuzd" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1715531044; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=/ddAlNROTuHvvYZgc/WMbKnty1GcIypmkdCGPlRw7E4=; b=Y7wCSuzdJ2LxCUiylriYaI97GDFNeHG+/wmT7WouMn0yDKhA6VubYNeyv9Ny4bdceGKqF1 hf/FX8FQLpe6MAODsNVSUHTSheU8s1Vy8LEF9lcjtLCzuDZf7BPMhcXslSNbwhc78wLVzQ cK6ZRSZPhxsUPO/Yihhez3ToczepSfg= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-182-QrhKa4D0NU2ubF9vXlVbyg-1; Sun, 12 May 2024 12:24:00 -0400 X-MC-Unique: QrhKa4D0NU2ubF9vXlVbyg-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 7142B3801EC5; Sun, 12 May 2024 16:24:00 +0000 (UTC) Received: from localhost.localdomain (unknown [10.39.192.46]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4228D966; Sun, 12 May 2024 16:23:59 +0000 (UTC) From: Hans de Goede To: =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= , Andy Shevchenko , AceLan Kao Cc: Hans de Goede , Kai-Heng Feng , platform-driver-x86@vger.kernel.org Subject: [PATCH 0/2] platform/x86: Add new Dell UART backlight driver Date: Sun, 12 May 2024 18:23:50 +0200 Message-ID: <20240512162353.46693-1-hdegoede@redhat.com> Precedence: bulk X-Mailing-List: platform-driver-x86@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.1 Hi All, I recently learned that some Dell AIOs (1) use a backlight controller board connected to an UART. Canonical even submitted a driver for this in 2017: https://lkml.org/lkml/2017/10/26/78 This UART has a DELL0501 HID with CID set to PNP0501 so that the UART is still handled by 8250_pnp.c. Unfortunately there is no separate ACPI device with an UartSerialBusV2() resource to model the backlight-controller. An ACPI quirk has been merged recently to deal with this and create a serdev controller for the UART despite the missing UartSerialBusV2() resource: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=99b572e6136eab69a8c91d72cf8595b256e304b5 Patch 1 in this series adds a driver binding to the "dell-uart-backlight" device created by this quirk. This drivers creates a serdev-device for the DELL0501 serdev-controller and registers a serdev backlight driver which binds to this serdev-device. Patch 2 contains a small emulator for the UART attached backlight controller found on this Dell AOIs, I wrote and used this to develop the driver since I did not have access to such an AOI myself. This has been successfully tested by Roman Bogoyev (who originally reported the missing driver to me by email) on a Dell Inspiron 27 7000 (7790) and by Kai-Heng Feng on a newer Dell AOI model. Regards, Hans 1) All In One a monitor with a PC builtin Hans de Goede (2): platform/x86: Add new Dell UART backlight driver tools arch x86: Add dell-uart-backlight-emulator drivers/platform/x86/dell/Kconfig | 15 + drivers/platform/x86/dell/Makefile | 1 + .../platform/x86/dell/dell-uart-backlight.c | 409 ++++++++++++++++++ .../dell-uart-backlight-emulator/.gitignore | 1 + .../x86/dell-uart-backlight-emulator/Makefile | 19 + .../x86/dell-uart-backlight-emulator/README | 46 ++ .../dell-uart-backlight-emulator.c | 166 +++++++ 7 files changed, 657 insertions(+) create mode 100644 drivers/platform/x86/dell/dell-uart-backlight.c create mode 100644 tools/arch/x86/dell-uart-backlight-emulator/.gitignore create mode 100644 tools/arch/x86/dell-uart-backlight-emulator/Makefile create mode 100644 tools/arch/x86/dell-uart-backlight-emulator/README create mode 100644 tools/arch/x86/dell-uart-backlight-emulator/dell-uart-backlight-emulator.c -- 2.44.0