From patchwork Mon Dec 20 22:28:27 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Rajat Jain X-Patchwork-Id: 12688771 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 57AEBC433FE for ; Mon, 20 Dec 2021 22:29:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232376AbhLTW3T (ORCPT ); Mon, 20 Dec 2021 17:29:19 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55154 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231994AbhLTW3T (ORCPT ); Mon, 20 Dec 2021 17:29:19 -0500 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0A690C061574 for ; Mon, 20 Dec 2021 14:29:19 -0800 (PST) Received: by mail-yb1-xb49.google.com with SMTP id y125-20020a25dc83000000b005c2326bf744so21749924ybe.21 for ; Mon, 20 Dec 2021 14:29:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=9UuDXITW1KrM/sWxwU0TyE+d+hZlmw/w1FKu5Oyb/q4=; b=fZw86D1BWHuZP4RxtxDxnaCCxsagtJrFMd6YBokfA5gnPUOx+mdKCFO2CPdGXHjzRY K8S3Qt9iWc/+NPnBwp171AXqai5CQuQ+JKIyoZdJa87GbwqZGn3yjPabB65h4ZJTLtzy EU53FSmSwU6Zzj0i0i1jeK3eglYBoBJpTR+s6x/YNxbiUUCLwcklw+RAVvZrLxF58HlG B0ZrSDngjvX6EC/6PL0U+CC1m50p0o4xUVhe0cecxM7z7rUd0eYz2BS6I0UH+1ZZq+Yh 3mmGvvpvpfb63JeNrz9GMiXMhhZDiff4ykTyweePTVgJr8AMbAC/EuNFj8+s/4k40HZP JK7g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=9UuDXITW1KrM/sWxwU0TyE+d+hZlmw/w1FKu5Oyb/q4=; b=76kPWgP1cg+b/PferNGS0+UTS+EnIgViK87eEM5zoPRO4Gw4w5gmj6bFzAtSbdkEKz E0puwFEzEFAJ0R6COjN7AbS9ZYyBAZIuZ+5pF2f81DQytPQx7xi1uvHFwwZV3eC9ytX1 H21F05EFW51wBji4ZakxXSa07WsmdyL+y39nY7dgjwDKWRCBb0uBNSaqhwsOe+G3eKML Owga/sNhxKJcjZPCQ0+PWQVzHPBT8z4ntOwXTRJD8JE5Vs8P53ad0MbGnkoru84NX5hF 1VxHE/k2ZrwNQosMCEIWNsnDZ1uYF43Pv+JuP/A71XxCsXyeucBODhiMPYiUlnQZHUg/ 2mFA== X-Gm-Message-State: AOAM533m89GR1quxi953e1KEA0RBBIVe/EWzuKAmJIVHjT5+40eUSG5H HWglx5KsN3I+G2LjLQ80kKJQMG2u9r0p X-Google-Smtp-Source: ABdhPJzTPAZpg2o0uGAee3Z+/CvVGLXMTpfWCUxW+vE7w+4I67zte7EhtUv2ROwivNRBGHb08MPmaM3yfIGR X-Received: from rajat2.mtv.corp.google.com ([2620:15c:202:201:f6d7:6572:2e42:ea7d]) (user=rajatja job=sendgmr) by 2002:a25:868b:: with SMTP id z11mr396357ybk.395.1640039358271; Mon, 20 Dec 2021 14:29:18 -0800 (PST) Date: Mon, 20 Dec 2021 14:28:27 -0800 In-Reply-To: <20211220222828.2625444-1-rajatja@google.com> Message-Id: <20211220222828.2625444-2-rajatja@google.com> Mime-Version: 1.0 References: <20211220222828.2625444-1-rajatja@google.com> X-Mailer: git-send-email 2.34.1.307.g9b7440fafd-goog Subject: [PATCH v3 2/3] platform/chrome: Add driver for ChromeOS privacy-screen From: Rajat Jain To: Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , Hans de Goede , David Airlie , Daniel Vetter , Benson Leung , Henrique de Moraes Holschuh , Mark Gross , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, ibm-acpi-devel@lists.sourceforge.net, platform-driver-x86@vger.kernel.org, gwendal@google.com, seanpaul@google.com, marcheu@google.com, dtor@google.com Cc: Rajat Jain , rajatxjain@gmail.com Precedence: bulk List-ID: X-Mailing-List: platform-driver-x86@vger.kernel.org This adds the ACPI driver for the ChromeOS privacy screen that is present on some chromeos devices. Note that ideally, we'd want this privacy screen driver to be probed BEFORE the drm probe in order to avoid a drm probe deferral: https://hansdegoede.livejournal.com/25948.html In practise, I found that ACPI drivers are bound to their devices AFTER the drm probe on chromebooks. So on chromebooks with privacy-screen, this patch along with the other one in this series results in a probe deferral of about 250ms for i915 driver. However, it did not result in any user noticeable delay of splash screen in my personal experience. In future if this probe deferral turns out to be an issue, we can consider turning this ACPI driver into something that is probed earlier than the drm drivers. Signed-off-by: Rajat Jain --- v3: * Renamed everything chromeos_priv_scrn_* to chromeos_privacy_screen_* (and added line breaks to accommodate longer names within 80 chars) * Cleanup / Added few comments * Use the newly added drm_privacy_screen_get_drvdata() * Provide the cleanup function chromeos_privacy_screen_remove() v2: * Reword the commit log * Make the Kconfig into a tristate * Reorder the patches in the series. drivers/platform/chrome/Kconfig | 11 ++ drivers/platform/chrome/Makefile | 1 + .../platform/chrome/chromeos_privacy_screen.c | 152 ++++++++++++++++++ 3 files changed, 164 insertions(+) create mode 100644 drivers/platform/chrome/chromeos_privacy_screen.c diff --git a/drivers/platform/chrome/Kconfig b/drivers/platform/chrome/Kconfig index ccc23d8686e8..75e93efd669f 100644 --- a/drivers/platform/chrome/Kconfig +++ b/drivers/platform/chrome/Kconfig @@ -243,6 +243,17 @@ config CROS_USBPD_NOTIFY To compile this driver as a module, choose M here: the module will be called cros_usbpd_notify. +config CHROMEOS_PRIVACY_SCREEN + tristate "ChromeOS Privacy Screen support" + depends on ACPI + depends on DRM + select DRM_PRIVACY_SCREEN + help + This driver provides the support needed for the in-built electronic + privacy screen that is present on some ChromeOS devices. When enabled, + this should probably always be built into the kernel to avoid or + minimize drm probe deferral. + source "drivers/platform/chrome/wilco_ec/Kconfig" endif # CHROMEOS_PLATFORMS diff --git a/drivers/platform/chrome/Makefile b/drivers/platform/chrome/Makefile index f901d2e43166..5d4be9735d9d 100644 --- a/drivers/platform/chrome/Makefile +++ b/drivers/platform/chrome/Makefile @@ -4,6 +4,7 @@ CFLAGS_cros_ec_trace.o:= -I$(src) obj-$(CONFIG_CHROMEOS_LAPTOP) += chromeos_laptop.o +obj-$(CONFIG_CHROMEOS_PRIVACY_SCREEN) += chromeos_privacy_screen.o obj-$(CONFIG_CHROMEOS_PSTORE) += chromeos_pstore.o obj-$(CONFIG_CHROMEOS_TBMC) += chromeos_tbmc.o obj-$(CONFIG_CROS_EC) += cros_ec.o diff --git a/drivers/platform/chrome/chromeos_privacy_screen.c b/drivers/platform/chrome/chromeos_privacy_screen.c new file mode 100644 index 000000000000..07c9f257c723 --- /dev/null +++ b/drivers/platform/chrome/chromeos_privacy_screen.c @@ -0,0 +1,152 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * ChromeOS Privacy Screen support + * + * Copyright (C) 2022 Google LLC + * + * This is the Chromeos privacy screen provider, present on certain chromebooks, + * represented by a GOOG0010 device in the ACPI. This ACPI device, if present, + * will cause the i915 drm driver to probe defer until this driver registers + * the privacy-screen. + */ + +#include +#include + +/* + * The DSM (Device Specific Method) constants below are the agreed API with + * the firmware team, on how to control privacy screen using ACPI methods. + */ +#define PRIV_SCRN_DSM_REVID 1 /* DSM version */ +#define PRIV_SCRN_DSM_FN_GET_STATUS 1 /* Get privacy screen status */ +#define PRIV_SCRN_DSM_FN_ENABLE 2 /* Enable privacy screen */ +#define PRIV_SCRN_DSM_FN_DISABLE 3 /* Disable privacy screen */ + +static const guid_t chromeos_privacy_screen_dsm_guid = + GUID_INIT(0xc7033113, 0x8720, 0x4ceb, + 0x90, 0x90, 0x9d, 0x52, 0xb3, 0xe5, 0x2d, 0x73); + +static void +chromeos_privacy_screen_get_hw_state(struct drm_privacy_screen + *drm_privacy_screen) +{ + union acpi_object *obj; + acpi_handle handle; + struct device *privacy_screen = + drm_privacy_screen_get_drvdata(drm_privacy_screen); + + handle = acpi_device_handle(to_acpi_device(privacy_screen)); + obj = acpi_evaluate_dsm(handle, &chromeos_privacy_screen_dsm_guid, + PRIV_SCRN_DSM_REVID, + PRIV_SCRN_DSM_FN_GET_STATUS, NULL); + if (!obj) { + dev_err(privacy_screen, + "_DSM failed to get privacy-screen state\n"); + return; + } + + if (obj->type != ACPI_TYPE_INTEGER) + dev_err(privacy_screen, + "Bad _DSM to get privacy-screen state\n"); + else if (obj->integer.value == 1) + drm_privacy_screen->hw_state = drm_privacy_screen->sw_state = + PRIVACY_SCREEN_ENABLED; + else + drm_privacy_screen->hw_state = drm_privacy_screen->sw_state = + PRIVACY_SCREEN_DISABLED; + + ACPI_FREE(obj); +} + +static int +chromeos_privacy_screen_set_sw_state(struct drm_privacy_screen + *drm_privacy_screen, + enum drm_privacy_screen_status state) +{ + union acpi_object *obj = NULL; + acpi_handle handle; + struct device *privacy_screen = + drm_privacy_screen_get_drvdata(drm_privacy_screen); + + handle = acpi_device_handle(to_acpi_device(privacy_screen)); + + if (state == PRIVACY_SCREEN_DISABLED) { + obj = acpi_evaluate_dsm(handle, + &chromeos_privacy_screen_dsm_guid, + PRIV_SCRN_DSM_REVID, + PRIV_SCRN_DSM_FN_DISABLE, NULL); + } else if (state == PRIVACY_SCREEN_ENABLED) { + obj = acpi_evaluate_dsm(handle, + &chromeos_privacy_screen_dsm_guid, + PRIV_SCRN_DSM_REVID, + PRIV_SCRN_DSM_FN_ENABLE, NULL); + } else { + dev_err(privacy_screen, + "Bad attempt to set privacy-screen status to %u\n", + state); + return -EINVAL; + } + + if (!obj) { + dev_err(privacy_screen, + "_DSM failed to set privacy-screen state\n"); + return -EIO; + } + + drm_privacy_screen->hw_state = drm_privacy_screen->sw_state = state; + ACPI_FREE(obj); + return 0; +} + +static const struct drm_privacy_screen_ops chromeos_privacy_screen_ops = { + .get_hw_state = chromeos_privacy_screen_get_hw_state, + .set_sw_state = chromeos_privacy_screen_set_sw_state, +}; + +static int chromeos_privacy_screen_add(struct acpi_device *adev) +{ + struct drm_privacy_screen *drm_privacy_screen = + drm_privacy_screen_register(&adev->dev, + &chromeos_privacy_screen_ops, + &adev->dev); + + if (IS_ERR(drm_privacy_screen)) { + dev_err(&adev->dev, "Error registering privacy-screen\n"); + return PTR_ERR(drm_privacy_screen); + } + + adev->driver_data = drm_privacy_screen; + dev_info(&adev->dev, "registered privacy-screen '%s'\n", + dev_name(&drm_privacy_screen->dev)); + + return 0; +} + +static int chromeos_privacy_screen_remove(struct acpi_device *adev) +{ + struct drm_privacy_screen *drm_privacy_screen = acpi_driver_data(adev); + drm_privacy_screen_unregister(drm_privacy_screen); + return 0; +} + +static const struct acpi_device_id chromeos_privacy_screen_device_ids[] = { + {"GOOG0010", 0}, /* Google's electronic privacy screen for eDP-1 */ + {} +}; +MODULE_DEVICE_TABLE(acpi, chromeos_privacy_screen_device_ids); + +static struct acpi_driver chromeos_privacy_screen_driver = { + .name = "chromeos_privacy_screen_drvr", + .class = "ChromeOS", + .ids = chromeos_privacy_screen_device_ids, + .ops = { + .add = chromeos_privacy_screen_add, + .remove = chromeos_privacy_screen_remove, + }, +}; + +module_acpi_driver(chromeos_privacy_screen_driver); +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("ChromeOS ACPI Privacy Screen driver"); +MODULE_AUTHOR("Rajat Jain ");