From patchwork Fri Jul 31 20:21:53 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Dadap X-Patchwork-Id: 11695427 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 168A013B1 for ; Fri, 31 Jul 2020 20:20:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ECBA62087C for ; Fri, 31 Jul 2020 20:20:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="HUpoRwQh" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726862AbgGaUU4 (ORCPT ); Fri, 31 Jul 2020 16:20:56 -0400 Received: from hqnvemgate24.nvidia.com ([216.228.121.143]:9297 "EHLO hqnvemgate24.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725767AbgGaUU4 (ORCPT ); Fri, 31 Jul 2020 16:20:56 -0400 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate24.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Fri, 31 Jul 2020 13:19:21 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Fri, 31 Jul 2020 13:20:55 -0700 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Fri, 31 Jul 2020 13:20:55 -0700 Received: from lenny.nvidia.com (10.124.1.5) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Fri, 31 Jul 2020 20:20:54 +0000 From: Daniel Dadap To: , , CC: , , , Daniel Dadap Subject: [PATCH v2 1/2] platform/x86: Add driver for ACPI WMAA EC-based backlight control Date: Fri, 31 Jul 2020 15:21:53 -0500 Message-ID: <20200731202154.11382-1-ddadap@nvidia.com> X-Mailer: git-send-email 2.18.4 In-Reply-To: References: X-NVConfidentiality: public MIME-Version: 1.0 X-Originating-IP: [10.124.1.5] X-ClientProxiedBy: HQMAIL111.nvidia.com (172.20.187.18) To HQMAIL107.nvidia.com (172.20.187.13) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1596226761; bh=QYPn+58ugcma5pLegDt+y+Mv2vxHRLN5WGqcb8nKEac=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:X-NVConfidentiality:MIME-Version: X-Originating-IP:X-ClientProxiedBy:Content-Type; b=HUpoRwQhCbX5TlZCSCFWrfwlRgZvfaMIQnFkZkkhuFlla/N4FgWK0GqLoy4Y+8fYO iPyXBsDJKQj6WA+o/OUKz0Bcd7CTK2tXlCXJhkKRdL5iht0Sp4nkN+UxYGVkK5DRDw ai1vZtp73eurOtcUg3REd8/PFVRjDk5iSxb43DYUN8GvshTfJc3datMXKdxojakEFP 45wu4Bl/BFiY3LTMB7UGvhhfbWkMmdpY9uO2wQ8ObZpxqqq8+kM/14ie0GkRaEj8PI W8Zq4DactJ1P3WQzNPAAzP5h5S1yVT0N2k+n0z2AbgAxD3+WQW7jyDeeoOK7sVSuAN srOoyDiiMjRvQ== Sender: platform-driver-x86-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: platform-driver-x86@vger.kernel.org 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: Aaron Plattner Signed-off-by: Daniel Dadap --- MAINTAINERS | 6 + drivers/platform/x86/Kconfig | 11 ++ drivers/platform/x86/Makefile | 2 + drivers/platform/x86/wmaa-backlight-wmi.c | 188 ++++++++++++++++++++++ 4 files changed, 207 insertions(+) create mode 100644 drivers/platform/x86/wmaa-backlight-wmi.c diff --git a/MAINTAINERS b/MAINTAINERS index eeff55560759..e5ce6544a3c8 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -18249,6 +18249,12 @@ 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 T: git https://github.com/CirrusLogic/linux-drivers.git diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig index 0ad7ad8cf8e1..db342e480aa9 100644 --- a/drivers/platform/x86/Kconfig +++ b/drivers/platform/x86/Kconfig @@ -1368,6 +1368,17 @@ config INTEL_TELEMETRY directly via debugfs files. Various tools may use this interface for SoC state monitoring. +config WMAA_BACKLIGHT_WMI + tristate "ACPI WMAA Backlight Driver" + depends on ACPI_WMI + depends on ACPI + 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 system's + Embedded Controller. + endif # X86_PLATFORM_DEVICES config PMC_ATOM diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile index 53408d965874..fb6e16d62031 100644 --- a/drivers/platform/x86/Makefile +++ b/drivers/platform/x86/Makefile @@ -146,3 +146,5 @@ obj-$(CONFIG_INTEL_TELEMETRY) += intel_telemetry_core.o \ intel_telemetry_pltdrv.o \ intel_telemetry_debugfs.o obj-$(CONFIG_PMC_ATOM) += pmc_atom.o + +obj-$(CONFIG_WMAA_BACKLIGHT_WMI) += wmaa-backlight-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 000000000000..65117082787d --- /dev/null +++ b/drivers/platform/x86/wmaa-backlight-wmi.c @@ -0,0 +1,188 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * WMAA Backlight WMI driver + * + * Copyright (c) 2020, NVIDIA CORPORATION. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include + +MODULE_AUTHOR("Aaron Plattner "); +MODULE_AUTHOR("Daniel Dadap "); +MODULE_DESCRIPTION("WMAA Backlight WMI driver"); +MODULE_LICENSE("GPL v2"); + +#define WMAA_WMI_GUID "603E9613-EF25-4338-A3D0-C46177516DB7" + +MODULE_ALIAS("wmi:"WMAA_WMI_GUID); + +struct wmi_wmaa_priv { + struct backlight_device *backlight; +}; + +enum wmaa_method { + WMAA_BRIGHTNESS_LEVEL = 1, + WMAA_BRIGHTNESS_SOURCE = 2, +}; + +enum wmaa_get_or_set { + WMAA_GET = 0, + WMAA_SET = 1, + WMAA_GET_MAX = 2, // for WMAA_BRIGHTNESS_LEVEL only +}; + +enum wmaa_source { + WMAA_SOURCE_CLEAR = 0, + WMAA_SOURCE_GPU = 1, + WMAA_SOURCE_EC = 2, + WMAA_SOURCE_AUX = 3, + WMAA_SOURCE_COUNT +}; + +struct wmaa_args { + u32 set; + u32 val; + u32 ret; + u32 ignored[3]; +}; + +static const struct wmi_device_id wmaa_backlight_wmi_id_table[] = { + { .guid_string = WMAA_WMI_GUID }, + { }, +}; + +static struct wmi_device *wdev; + +static int wmi_call_wmaa(enum wmaa_method method, enum wmaa_get_or_set set, + u32 *val) +{ + struct wmaa_args args = { + .set = set, + .val = 0, + .ret = 0, + }; + struct acpi_buffer buf = { (acpi_size)sizeof(args), &args }; + acpi_status status; + + if (set == WMAA_SET) + args.val = *val; + + status = wmidev_evaluate_method(wdev, 0, method, &buf, &buf); + if (ACPI_FAILURE(status)) { + pr_err("ACPI WMAA failed with %s\n", + acpi_format_exception(status)); + return -EIO; + } + + if (set != WMAA_SET) + *val = args.ret; + + return 0; +} + +static int wmaa_get_brightness(u32 *level) +{ + return wmi_call_wmaa(WMAA_BRIGHTNESS_LEVEL, WMAA_GET, level); +} + +static int wmaa_set_brightness(u32 level) +{ + return wmi_call_wmaa(WMAA_BRIGHTNESS_LEVEL, WMAA_SET, &level); +} + +static int wmaa_backlight_update_status(struct backlight_device *bd) +{ + return wmaa_set_brightness(bd->props.brightness); +} + +static int wmaa_backlight_get_brightness(struct backlight_device *bd) +{ + u32 level; + int ret = wmaa_get_brightness(&level); + + WARN_ON(ret != 0); + return ret == 0 ? level : 0; +} + +static const struct backlight_ops wmaa_backlight_ops = { + .update_status = wmaa_backlight_update_status, + .get_brightness = wmaa_backlight_get_brightness, +}; + +static int wmaa_get_max_brightness(u32 *level) +{ + return wmi_call_wmaa(WMAA_BRIGHTNESS_LEVEL, WMAA_GET_MAX, level); +} + +static int wmaa_get_brightness_source(u32 *source) +{ + return wmi_call_wmaa(WMAA_BRIGHTNESS_SOURCE, WMAA_GET, source); +} + +static int wmaa_backlight_wmi_probe(struct wmi_device *w, const void *ctx) +{ + struct wmi_wmaa_priv *priv; + struct backlight_properties props = {0}; + u32 source; + + priv = devm_kmalloc(&w->dev, sizeof(*priv), GFP_KERNEL); + if(!priv) + return -ENOMEM; + + wdev = w; + + if (wmaa_get_brightness_source(&source)) + return -EINVAL; + if (source != WMAA_SOURCE_EC) + return -ENODEV; + + // Register a backlight handler + props.type = BACKLIGHT_PLATFORM; + if (wmaa_get_max_brightness(&props.max_brightness) || + wmaa_get_brightness(&props.brightness)) + return -EINVAL; + + priv->backlight = backlight_device_register("wmaa_backlight", + NULL, NULL, &wmaa_backlight_ops, &props); + if (IS_ERR(priv->backlight)) + return PTR_ERR(priv->backlight); + + dev_set_drvdata(&w->dev, priv); + + return 0; +} + +static int wmaa_backlight_wmi_remove(struct wmi_device *wdev) +{ + struct wmi_wmaa_priv *priv = dev_get_drvdata(&wdev->dev); + + backlight_device_unregister(priv->backlight); + + return 0; +} + +static struct wmi_driver wmaa_backlight_wmi_driver = { + .driver = { + .name = "wmaa-backlight", + }, + .probe = wmaa_backlight_wmi_probe, + .remove = wmaa_backlight_wmi_remove, + .id_table = wmaa_backlight_wmi_id_table, +}; + +module_wmi_driver(wmaa_backlight_wmi_driver);