From patchwork Mon Jun 1 06:51:58 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sam Ravnborg X-Patchwork-Id: 188690 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, EXCUSE_4, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 95E55C433DF for ; Mon, 1 Jun 2020 06:52:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 70A9C2076B for ; Mon, 1 Jun 2020 06:52:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="FB8sUWHt" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726072AbgFAGw1 (ORCPT ); Mon, 1 Jun 2020 02:52:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44864 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725283AbgFAGw0 (ORCPT ); Mon, 1 Jun 2020 02:52:26 -0400 Received: from mail-lj1-x244.google.com (mail-lj1-x244.google.com [IPv6:2a00:1450:4864:20::244]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 53759C061A0E; Sun, 31 May 2020 23:52:26 -0700 (PDT) Received: by mail-lj1-x244.google.com with SMTP id e4so6770184ljn.4; Sun, 31 May 2020 23:52:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=wgQFgo3RHYwmcB8tP1uDfvnC0G/9E3cMrWKRfBK9IL8=; b=FB8sUWHtOWot1aPy7v97jwE2MCN9TFsZ8Uzu9Z2YTCLVknO+bXcp3uJkdWR2fGuHs8 ZWssNLxEldBQUfhYGP9t1ThPGqRMwdelU3gewbV3Rftyl9AAetV3O4zpyk8PPHf2QCZ5 xNA7J6x6lk8QJrfOpVkNWjPfi3sXMAl1cVzqbbZurLhdkXvGsIh4A0AabGXW0yNUB/uu AvlqROHPpoYOwtV2h4TlIO7iJWcsAqfKczoGhIiw+uX3BsBm5DnRLmSy3/fbwWyY1CwX l45bKiFfSZbWa14DxgOYoXGnnpi4EinY4CzhASM382I0RrBG1IO9r1D5wH2KlqfmYfqM j2dA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :in-reply-to:references:mime-version:content-transfer-encoding; bh=wgQFgo3RHYwmcB8tP1uDfvnC0G/9E3cMrWKRfBK9IL8=; b=r8BqBsMM5xOmC6HYXFbxDGiYX4whgaKQdC26B33pRpDdY0sUkI+P7rj9ybGgKI2ozu U06kB9ZAUjuwBTjWt2gISITUQYVDJPVejJdde31QEGotqbhgu+oulLPHfW5Opw+InL6J TTi69+X1jDA9gkfVLYeWAPQuZnucA26RmtfB5ldi2SUPXcysb1CpPkFCjeRU+YJ9+BSv FhVpOWM7F6tzEFJfrxYTFPp+CtnG3Gz3XAB0BtkAYw2MPItobaMj1myIh4/lLnMJHJVo 1XjqQn0KT4ZmmIO7wTckdVo5bWJEROAM2XQ3X9CB4WykDV37m27QXqbSCGFQLYBiDKLO ByrA== X-Gm-Message-State: AOAM532vktNhY4dVcGtBNOfHQbxfiQWtN5aU27yFPNxYufdh0RkAIorv 8nsG9TLTPXip8ND8TzH5ndc= X-Google-Smtp-Source: ABdhPJzYtFLljsRs6Mh3pY4A40UVOWi60Y4AkVBMEcmu4THO7pQ00+38XavNrIHuVeGK1VbdGJyydg== X-Received: by 2002:a2e:9b4a:: with SMTP id o10mr5192012ljj.278.1590994344766; Sun, 31 May 2020 23:52:24 -0700 (PDT) Received: from saturn.lan ([2a00:fd00:805f:db00:281d:a604:434c:a58d]) by smtp.gmail.com with ESMTPSA id e13sm2540462ljl.117.2020.05.31.23.52.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 31 May 2020 23:52:24 -0700 (PDT) From: Sam Ravnborg To: dri-devel@lists.freedesktop.org, Jingoo Han , Lee Jones , Daniel Thompson Cc: Andy Gross , Bartlomiej Zolnierkiewicz , Bjorn Andersson , Daniel Vetter , David Airlie , Emil Velikov , Jonathan Corbet , linux-arm-msm@vger.kernel.org, linux-pwm@vger.kernel.org, Maarten Lankhorst , Maxime Ripard , Michael Hennerich , patches@opensource.cirrus.com, Support Opensource , Thierry Reding , Thomas Zimmermann , Uwe Kleine-Konig , Peter Ujfalusi , Tomi Valkeinen , Sam Ravnborg Subject: [PATCH v3 04/13] backlight: improve backlight_properties documentation Date: Mon, 1 Jun 2020 08:51:58 +0200 Message-Id: <20200601065207.492614-5-sam@ravnborg.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200601065207.492614-1-sam@ravnborg.org> References: <20200601065207.492614-1-sam@ravnborg.org> MIME-Version: 1.0 Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org Improve the documentation for backlight_properties and adapt it to kernel-doc style. v2: - Added into for each field (Daniel) - Re-written some parts to explain what to do, rather than what not to do. Partly based on suggestions from the review (Daniel) Signed-off-by: Sam Ravnborg Cc: Lee Jones Cc: Daniel Thompson Cc: Jingoo Han Reviewed-by: Daniel Thompson --- include/linux/backlight.h | 96 ++++++++++++++++++++++++++++++++++----- 1 file changed, 85 insertions(+), 11 deletions(-) diff --git a/include/linux/backlight.h b/include/linux/backlight.h index b6c1ab6c922a..69a20da03035 100644 --- a/include/linux/backlight.h +++ b/include/linux/backlight.h @@ -117,28 +117,102 @@ struct backlight_ops { int (*check_fb)(struct backlight_device *bd, struct fb_info *info); }; -/* This structure defines all the properties of a backlight */ +/** + * struct backlight_properties - backlight properties + * + * This structure defines all the properties of a backlight. + */ struct backlight_properties { - /* Current User requested brightness (0 - max_brightness) */ + /** + * @brightness: The current brightness requested by the user. + * + * The backlight core makes sure the range is (0 to max_brightness) + * when the brightness is set via the sysfs attribute: + * /sys/class/backlight//brightness. + * + * This value can be set in the backlight_properties passed + * to devm_backlight_device_register() to set a default brightness + * value. + */ int brightness; - /* Maximal value for brightness (read-only) */ + + /** + * @max_brightness: The maximum brightness value. + * + * This value must be set in the backlight_properties passed to + * devm_backlight_device_register() and shall not be modified by the + * driver after registration. + */ int max_brightness; - /* Current FB Power mode (0: full on, 1..3: power saving - modes; 4: full off), see FB_BLANK_XXX */ + + /** + * @power: The current power mode. + * + * User space can configure the power mode using the sysfs + * attribute: /sys/class/backlight//bl_power + * When the power property is updated update_status() is called. + * + * The possible values are: (0: full on, 1 to 3: power saving + * modes; 4: full off), see FB_BLANK_XXX. + * + * When the backlight device is enabled @power is set + * to FB_BLANK_UNBLANK. When the backlight device is disabled + * @power is set to FB_BLANK_POWERDOWN. + */ int power; - /* FB Blanking active? (values as for power) */ - /* Due to be removed, please use (state & BL_CORE_FBBLANK) */ + + /** + * @fb_blank: The power state from the FBIOBLANK ioclt. + * + * When the FBIOBLANK ioctl is called fb_blank is set to the + * blank parameter and the update_status() operation is called. + * + * When the backlight device is enabled @fb_blank is set + * to FB_BLANK_UNBLANK. When the backlight device is disabled + * @fb_blank is set to FB_BLANK_POWERDOWN. + * + * Backlight drivers should avoid using this property. It has been + * replaced by state & BL_CORE_FBLANK (although most drivers should + * use backlight_is_blank() as the preferred means to get the blank + * state). + * + * fb_blank is deprecated and will be removed. + */ int fb_blank; - /* Backlight type */ + + /** + * @type: The type of backlight supported. + * + * The backlight type allows userspace to make appropriate + * policy desicions based on the backlight type. + * + * This value must be set in the backlight_properties + * passed to devm_backlight_device_register(). + */ enum backlight_type type; - /* Flags used to signal drivers of state changes */ + + /** + * @state: The state of the backlight core. + * + * The state is a bitmask. BL_CORE_FBBLANK is set when the display + * is expected to be blank. BL_CORE_SUSPENDED is set when the + * driver is suspended. + * + * backlight drivers are excpected to use backlight_is_blank() + * in their update_status() operation rather than reading the + * state property. + * + * The state is maintained by the core and drivers may not modify it. + */ unsigned int state; - /* Type of the brightness scale (linear, non-linear, ...) */ - enum backlight_scale scale; #define BL_CORE_SUSPENDED (1 << 0) /* backlight is suspended */ #define BL_CORE_FBBLANK (1 << 1) /* backlight is under an fb blank event */ + /** + * @scale: The type of the brightness scale. + */ + enum backlight_scale scale; }; struct backlight_device {