From patchwork Mon Dec 6 06:34:51 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Kai-Heng Feng X-Patchwork-Id: 1563829 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: bilbo.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=canonical.com header.i=@canonical.com header.a=rsa-sha256 header.s=20210705 header.b=AB1qhWKl; dkim-atps=neutral Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lists.ubuntu.com (client-ip=91.189.94.19; helo=huckleberry.canonical.com; envelope-from=kernel-team-bounces@lists.ubuntu.com; receiver=) Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by bilbo.ozlabs.org (Postfix) with ESMTPS id 4J6tww00NRz9sRN for ; Mon, 6 Dec 2021 17:35:59 +1100 (AEDT) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.86_2) (envelope-from ) id 1mu7bH-000847-Mt; Mon, 06 Dec 2021 06:35:47 +0000 Received: from smtp-relay-canonical-1.internal ([10.131.114.174] helo=smtp-relay-canonical-1.canonical.com) by huckleberry.canonical.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1mu7bF-00082Z-Bf for kernel-team@lists.ubuntu.com; Mon, 06 Dec 2021 06:35:45 +0000 Received: from localhost.localdomain (unknown [10.101.196.174]) (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 smtp-relay-canonical-1.canonical.com (Postfix) with ESMTPSA id 0F4D2404AB for ; Mon, 6 Dec 2021 06:35:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=canonical.com; s=20210705; t=1638772545; bh=g2f8xuTl9vgCq/QiFYld8qN5yXBiSaqCFAUX/Vv7niE=; h=From:To:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=AB1qhWKlMFczhUPhDqLOcabKuqVWv3RsSxJGCFCc77+bzQzoffwkyAYnGfmmZcjHM 5qnwj0KcCChafnU58F9vqEt4Z+ww2JPMAYTwBE+gsLziiSg4Ov1eVjJhr0ecCXEC0Q HlCGWgRjbfiuaWMA17IMqVRwUq1CpUERVLaSW883/9FPaN9IYCHNe2gvP+Ncl4Bzw0 CTX8A9KFD2Z1iFSKAdigyKJ+lNKI1JakwroG26nKSydOAhgj44vpUFNUtgfnSMEvJV 5m9AcZfcw3P7vnPcvgwVWTdOb62fkVklyT9KoJasI7oZbXbPXyRR3gAOcacDaMtB72 z5rcX/7p9Aa/w== From: Kai-Heng Feng To: kernel-team@lists.ubuntu.com Subject: [OEM-5.14] [PATCH 1/4] platform/x86: Add driver for ACPI WMAA EC-based backlight control Date: Mon, 6 Dec 2021 14:34:51 +0800 Message-Id: <20211206063457.1522003-2-kai.heng.feng@canonical.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20211206063457.1522003-1-kai.heng.feng@canonical.com> References: <20211206063457.1522003-1-kai.heng.feng@canonical.com> MIME-Version: 1.0 X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.20 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: "kernel-team" From: Daniel Dadap BugLink: https://bugs.launchpad.net/bugs/1953286 A number of upcoming notebook computer designs drive the internal display panel's backlight PWM through the Embedded Controller (EC). This EC-based backlight control can be plumbed through to an ACPI "WMAA" method interface, which in turn can be wrapped by WMI with the GUID handle 603E9613-EF25-4338-A3D0-C46177516DB7. Add a new driver, aliased to the WMAA WMI GUID, to expose a sysfs backlight class driver to control backlight levels on systems with EC-driven backlights. Signed-off-by: Daniel Dadap Reviewed-by: Thomas Weißschuh Link: https://lore.kernel.org/r/20210903003838.15797-1-ddadap@nvidia.com Reviewed-by: Hans de Goede Signed-off-by: Hans de Goede (backported from commit ad62cd93198bde6644ecb5ff8f6f4c5394b5821a) Signed-off-by: Kai-Heng Feng --- MAINTAINERS | 6 + drivers/platform/x86/Kconfig | 16 ++ drivers/platform/x86/Makefile | 1 + drivers/platform/x86/wmaa-backlight-wmi.c | 205 ++++++++++++++++++++++ 4 files changed, 228 insertions(+) create mode 100644 drivers/platform/x86/wmaa-backlight-wmi.c diff --git a/MAINTAINERS b/MAINTAINERS index 507b61efaaba9..9d22d199d61a1 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -20037,6 +20037,12 @@ L: linux-wireless@vger.kernel.org S: Odd fixes F: drivers/net/wireless/wl3501* +WMAA BACKLIGHT DRIVER +M: Daniel Dadap +L: platform-driver-x86@vger.kernel.org +S: Supported +F: drivers/platform/x86/wmaa-backlight-wmi.c + WOLFSON MICROELECTRONICS DRIVERS L: patches@opensource.cirrus.com S: Supported diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig index c51f6ada29759..516b812a4fd79 100644 --- a/drivers/platform/x86/Kconfig +++ b/drivers/platform/x86/Kconfig @@ -113,6 +113,22 @@ config PEAQ_WMI help Say Y here if you want to support WMI-based hotkeys on PEAQ 2-in-1s. +config WMAA_BACKLIGHT_WMI + tristate "ACPI WMAA Backlight Driver" + depends on ACPI_WMI + depends on BACKLIGHT_CLASS_DEVICE + help + This driver provides a sysfs backlight interface for notebook + systems which expose the WMAA ACPI method and an associated WMI + wrapper to drive LCD backlight levels through the Embedded Controller + (EC). + + Say Y or M here if you want to control the backlight on a notebook + system with an EC-driven backlight using the ACPI WMAA method. + + If you choose to compile this driver as a module the module will be + called wmaa-backlight-wmi. + config XIAOMI_WMI tristate "Xiaomi WMI key driver" depends on ACPI_WMI diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile index 7ee369aab10d0..109c1714237dd 100644 --- a/drivers/platform/x86/Makefile +++ b/drivers/platform/x86/Makefile @@ -14,6 +14,7 @@ obj-$(CONFIG_INTEL_WMI_SBL_FW_UPDATE) += intel-wmi-sbl-fw-update.o obj-$(CONFIG_INTEL_WMI_THUNDERBOLT) += intel-wmi-thunderbolt.o obj-$(CONFIG_MXM_WMI) += mxm-wmi.o obj-$(CONFIG_PEAQ_WMI) += peaq-wmi.o +obj-$(CONFIG_WMAA_BACKLIGHT_WMI) += wmaa-backlight-wmi.o obj-$(CONFIG_XIAOMI_WMI) += xiaomi-wmi.o obj-$(CONFIG_GIGABYTE_WMI) += gigabyte-wmi.o diff --git a/drivers/platform/x86/wmaa-backlight-wmi.c b/drivers/platform/x86/wmaa-backlight-wmi.c new file mode 100644 index 0000000000000..f5c4f8337c2c0 --- /dev/null +++ b/drivers/platform/x86/wmaa-backlight-wmi.c @@ -0,0 +1,205 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2020, NVIDIA CORPORATION. All rights reserved. + */ + +#include +#include +#include +#include +#include +#include + +/** + * enum wmaa_method - WMI method IDs for ACPI WMAA + * @WMAA_METHOD_LEVEL: Get or set the brightness level, + * or get the maximum brightness level. + * @WMAA_METHOD_SOURCE: Get the source for backlight control. + */ +enum wmaa_method { + WMAA_METHOD_LEVEL = 1, + WMAA_METHOD_SOURCE = 2, + WMAA_METHOD_MAX +}; + +/** + * enum wmaa_mode - Operation mode for ACPI WMAA method + * @WMAA_MODE_GET: Get the current brightness level or source. + * @WMAA_MODE_SET: Set the brightness level. + * @WMAA_MODE_GET_MAX_LEVEL: Get the maximum brightness level. This is only + * valid when the WMI method is %WMAA_METHOD_LEVEL. + */ +enum wmaa_mode { + WMAA_MODE_GET = 0, + WMAA_MODE_SET = 1, + WMAA_MODE_GET_MAX_LEVEL = 2, + WMAA_MODE_MAX +}; + +/** + * enum wmaa_source - Backlight brightness control source identification + * @WMAA_SOURCE_GPU: Backlight brightness is controlled by the GPU. + * @WMAA_SOURCE_EC: Backlight brightness is controlled by the system's + * Embedded Controller (EC). + * @WMAA_SOURCE_AUX: Backlight brightness is controlled over the DisplayPort + * AUX channel. + */ +enum wmaa_source { + WMAA_SOURCE_GPU = 1, + WMAA_SOURCE_EC = 2, + WMAA_SOURCE_AUX = 3, + WMAA_SOURCE_MAX +}; + +/** + * struct wmaa_args - arguments for the ACPI WMAA method + * @mode: Pass in an &enum wmaa_mode value to select between getting or + * setting a value. + * @val: In parameter for value to set when operating in %WMAA_MODE_SET + * mode. Not used in %WMAA_MODE_GET or %WMAA_MODE_GET_MAX_LEVEL mode. + * @ret: Out parameter returning retrieved value when operating in + * %WMAA_MODE_GET or %WMAA_MODE_GET_MAX_LEVEL mode. Not used in + * %WMAA_MODE_SET mode. + * @ignored: Padding; not used. The ACPI method expects a 24 byte params struct. + * + * This is the parameters structure for the ACPI WMAA method as wrapped by WMI. + * The value passed in to @val or returned by @ret will be a brightness value + * when the WMI method ID is %WMAA_METHOD_LEVEL, or an &enum wmaa_source value + * when the WMI method ID is %WMAA_METHOD_SOURCE. + */ +struct wmaa_args { + u32 mode; + u32 val; + u32 ret; + u32 ignored[3]; +}; + +/** + * wmi_call_wmaa() - helper function for calling ACPI WMAA via its WMI wrapper + * @w: Pointer to the struct wmi_device identified by %WMAA_WMI_GUID + * @id: The method ID for the ACPI WMAA method (e.g. %WMAA_METHOD_LEVEL or + * %WMAA_METHOD_SOURCE) + * @mode: The operation to perform on the ACPI WMAA method (e.g. %WMAA_MODE_SET + * or %WMAA_MODE_GET) + * @val: Pointer to a value passed in by the caller when @mode is + * %WMAA_MODE_SET, or a value passed out to the caller when @mode is + * %WMAA_MODE_GET or %WMAA_MODE_GET_MAX_LEVEL. + * + * Returns 0 on success, or a negative error number on failure. + */ +static int wmi_call_wmaa(struct wmi_device *w, enum wmaa_method id, enum wmaa_mode mode, u32 *val) +{ + struct wmaa_args args = { + .mode = mode, + .val = 0, + .ret = 0, + }; + struct acpi_buffer buf = { (acpi_size)sizeof(args), &args }; + acpi_status status; + + if (id < WMAA_METHOD_LEVEL || id >= WMAA_METHOD_MAX || + mode < WMAA_MODE_GET || mode >= WMAA_MODE_MAX) + return -EINVAL; + + if (mode == WMAA_MODE_SET) + args.val = *val; + + status = wmidev_evaluate_method(w, 0, id, &buf, &buf); + if (ACPI_FAILURE(status)) { + dev_err(&w->dev, "ACPI WMAA failed: %s\n", + acpi_format_exception(status)); + return -EIO; + } + + if (mode != WMAA_MODE_SET) + *val = args.ret; + + return 0; +} + +static int wmaa_backlight_update_status(struct backlight_device *bd) +{ + struct wmi_device *wdev = bl_get_data(bd); + + return wmi_call_wmaa(wdev, WMAA_METHOD_LEVEL, WMAA_MODE_SET, + &bd->props.brightness); +} + +static int wmaa_backlight_get_brightness(struct backlight_device *bd) +{ + struct wmi_device *wdev = bl_get_data(bd); + u32 level; + int ret; + + ret = wmi_call_wmaa(wdev, WMAA_METHOD_LEVEL, WMAA_MODE_GET, &level); + if (ret < 0) + return ret; + + return level; +} + +static const struct backlight_ops wmaa_backlight_ops = { + .update_status = wmaa_backlight_update_status, + .get_brightness = wmaa_backlight_get_brightness, +}; + +static int wmaa_backlight_wmi_probe(struct wmi_device *wdev, const void *ctx) +{ + struct backlight_properties props = {}; + struct backlight_device *bdev; + u32 source; + int ret; + + ret = wmi_call_wmaa(wdev, WMAA_METHOD_SOURCE, WMAA_MODE_GET, &source); + if (ret) + return ret; + + /* + * This driver is only to be used when brightness control is handled + * by the EC; otherwise, the GPU driver(s) should control brightness. + */ + if (source != WMAA_SOURCE_EC) + return -ENODEV; + + /* + * Identify this backlight device as a firmware device so that it can + * be prioritized over any exposed GPU-driven raw device(s). + */ + props.type = BACKLIGHT_FIRMWARE; + + ret = wmi_call_wmaa(wdev, WMAA_METHOD_LEVEL, WMAA_MODE_GET_MAX_LEVEL, + &props.max_brightness); + if (ret) + return ret; + + ret = wmi_call_wmaa(wdev, WMAA_METHOD_LEVEL, WMAA_MODE_GET, + &props.brightness); + if (ret) + return ret; + + bdev = devm_backlight_device_register(&wdev->dev, "wmaa_backlight", + &wdev->dev, wdev, + &wmaa_backlight_ops, &props); + return PTR_ERR_OR_ZERO(bdev); +} + +#define WMAA_WMI_GUID "603E9613-EF25-4338-A3D0-C46177516DB7" + +static const struct wmi_device_id wmaa_backlight_wmi_id_table[] = { + { .guid_string = WMAA_WMI_GUID }, + { } +}; +MODULE_DEVICE_TABLE(wmi, wmaa_backlight_wmi_id_table); + +static struct wmi_driver wmaa_backlight_wmi_driver = { + .driver = { + .name = "wmaa-backlight", + }, + .probe = wmaa_backlight_wmi_probe, + .id_table = wmaa_backlight_wmi_id_table, +}; +module_wmi_driver(wmaa_backlight_wmi_driver); + +MODULE_AUTHOR("Daniel Dadap "); +MODULE_DESCRIPTION("WMAA Backlight WMI driver"); +MODULE_LICENSE("GPL");