From patchwork Fri Jul 3 18:45:30 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sam Ravnborg X-Patchwork-Id: 1322606 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=linux-pwm-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=ravnborg.org Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=aUrQbKZd; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 49z3nx57TJz9sPF for ; Sat, 4 Jul 2020 04:46:13 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726831AbgGCSqN (ORCPT ); Fri, 3 Jul 2020 14:46:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54372 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726236AbgGCSqM (ORCPT ); Fri, 3 Jul 2020 14:46:12 -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 7DF41C061794; Fri, 3 Jul 2020 11:46:12 -0700 (PDT) Received: by mail-lj1-x244.google.com with SMTP id f5so22205755ljj.10; Fri, 03 Jul 2020 11:46:12 -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=nbqgxv/h5SeSHOXMolpp1BPamIvzkqESgLDvhPwqMhU=; b=aUrQbKZdkhxD1Dd4uBn5ucmlkFRreyu98hbK7o3nUJZwjsPOawXWWS3FA7FkPHM25i t+C8U4CEYx2Yg5LL/Vs9FGMuAvPEf1RTdiSrn8EvyIxw0IQmpmxWlfxR5tK5D36ezspC VqkBZ7eiUJKfCW88KNSRS0JtIBAGLD+KKpPMpyDTOFfUI3wCZx+MfDnHO+YMtMp9i4fN Ym/N7AHLblWfueGGKW8aszqrB0bYioGSbtVSsrZUvIdOTEhWfUqmBaNpQS3xmKxDUouD ar0ODZlYti3Y9E2NBZ9hkIJC24AyseEOkN1Vjxc+BfGlvVCtCHe8yNYEqFXWa0z/3Zbx aNmQ== 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=nbqgxv/h5SeSHOXMolpp1BPamIvzkqESgLDvhPwqMhU=; b=kLai0/cagnB1bgrhXAinzdYjWMaxlkOxCzCP2sUtuJL/RT90yvzjp9axlqV6uH2Ust kXQvbFcN8qWEy2zYjxtSJlbUHXiiIL9xyII7uxnYnNLRwFtPR6H1nIplZSr1Oj8Xja3P n5F/wTnt5EFXre9HyFGp0vrNelGqJ9+he4X9qG/M3hbJ/LCXVQgiReEyaF5Cz4ZpVzpH MUY09NDT+YbZH6D2J2DufxJjySnozKHM1mdsHmOgwLb51K11N28Lm+w9yVz6Av5VCY+v /HCN9RYanlk7YK6qzTjnHZm1b31de2ZEg518L2BEqNNN683gf+dfvr9tS9rBvlopsIVh HVQA== X-Gm-Message-State: AOAM533cJPoUV6dotGr1KA/B2yAKNItN9IZmWFPvtNSk+DsCp5iXBXXC LAPYrMFiyDe1tF5EZWcBTUU= X-Google-Smtp-Source: ABdhPJyB2KLbGvSFYJK9M08dD+WetXzOuCGvcnziBRnn8Uhx16R3/LsaKsRHnGUZi1/20iEoXXzyoQ== X-Received: by 2002:a2e:8804:: with SMTP id x4mr20595944ljh.56.1593801971005; Fri, 03 Jul 2020 11:46:11 -0700 (PDT) Received: from saturn.lan ([2a00:fd00:805f:db00:4025:a614:1d5c:b7bc]) by smtp.gmail.com with ESMTPSA id h22sm4404224ljg.1.2020.07.03.11.46.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 03 Jul 2020 11:46:10 -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 v4 04/20] backlight: improve backlight_properties documentation Date: Fri, 3 Jul 2020 20:45:30 +0200 Message-Id: <20200703184546.144664-5-sam@ravnborg.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200703184546.144664-1-sam@ravnborg.org> References: <20200703184546.144664-1-sam@ravnborg.org> MIME-Version: 1.0 Sender: linux-pwm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pwm@vger.kernel.org Improve the documentation for backlight_properties and adapt it to kernel-doc style. v3: - Added missing '@' in kernel-doc 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 Reviewed-by: Daniel Thompson Reviewed-by: Emil Velikov Cc: Lee Jones Cc: Daniel Thompson Cc: Jingoo Han --- 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 dfb43ee02ea0..10518b00b059 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 {