From nobody Mon Sep 15 07:54:13 2025 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 712C0C54EBE for ; Sat, 14 Jan 2023 01:00:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231250AbjANBAd (ORCPT ); Fri, 13 Jan 2023 20:00:33 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48966 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229536AbjANBA1 (ORCPT ); Fri, 13 Jan 2023 20:00:27 -0500 Received: from mail-il1-x12d.google.com (mail-il1-x12d.google.com [IPv6:2607:f8b0:4864:20::12d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D6D357A397 for ; Fri, 13 Jan 2023 17:00:26 -0800 (PST) Received: by mail-il1-x12d.google.com with SMTP id u8so11601676ilg.0 for ; Fri, 13 Jan 2023 17:00:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=Hef3HKJw/rh8LMbhGDXUzdaIfcIHyO7m2r48LhMzONQ=; b=Zy//f3JiIpMV+8UMCiYoIm2Tha3BaDlu356RKRLoiWjKY0XOKk1MGobKMcAb3ixLRP NTWR3wf4LAaxp+sYohOs90AIqfu+IbIiwZENwL6qTuSkmvefdO5/wxO41TBK72NB+D98 M+DP2helRU+IqSnOkn7f6AtZLOgt50oEQ6G5AGD+Hn8LwoXqLbCTb6oXLZmvJ7/cf9qL O64PgChaj6cl+I6HmfQUsM7eMJbM3bijQ1q48UKP8hql/nN+lQNIjR7EMMO2XbWkOh2A YoYWtMDDiaD5ek3wWbwMw4zh7x3h1dAQkDXvW6WzKotwUUR3S0KKZnawnoGK19YHesRw ct0w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=Hef3HKJw/rh8LMbhGDXUzdaIfcIHyO7m2r48LhMzONQ=; b=wYZhqbpracEMk+dCbDGI6LfT9oLkkNFAX2dICu+F/HN0mojEIQehkgmhMveGUTt30Y 1KWarpoicCuptPWBx2gukJ5rPJoCIVL694gY8/p+GD8tafsTGs/P6aeSPfZthkCLOIr0 4SoQ8MQX7HFRlbpoRDPpsHOdm39cqQkTpCIDcqz/ZpCKhOex5Vlau62b3bn0T4GFEvaY yOzsz7TF2o8oxHGyBS6dmYG6n39/+jnh89HmInMMCdIKNDEotK4P1voBkD2KBVGpi1yg j0YLKIZoVoTRNWM1Qdp3wOQwCsh7lnGZYscrj2goVAQ1dStzZ+O1aeadBA2FJSro4X3L 0msA== X-Gm-Message-State: AFqh2ko5084toAbGx7GiKhS9+BsChr362vrCmExwGIdCGnCKhTS/AAEU r6mWAKGqZLRcNY7a/AjrLLE= X-Google-Smtp-Source: AMrXdXsIIUYD+FJQRU22iUAfjjh4RjByOXA0IuTNMrw5Nv9J8+VQxZsV6IuZ/eXk5Q7x1+wwxbhfeA== X-Received: by 2002:a92:d186:0:b0:30d:b66e:e4e3 with SMTP id z6-20020a92d186000000b0030db66ee4e3mr10760510ilz.1.1673658026262; Fri, 13 Jan 2023 17:00:26 -0800 (PST) Received: from localhost ([2607:fea8:a2df:3d00::6463]) by smtp.gmail.com with ESMTPSA id 191-20020a021dc8000000b0039e07ca9ae5sm6566086jaj.113.2023.01.13.17.00.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 13 Jan 2023 17:00:25 -0800 (PST) From: Richard Acayan To: Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Daniel Vetter , Thierry Reding , Sam Ravnborg , Emil Velikov , Vinay Simha BN , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Cc: Daniel Mentz , Caleb Connolly , Richard Acayan Subject: [RFC PATCH v2 1/2] drm/dsi-mipi: Fix byte order of DCS set/get brightness Date: Fri, 13 Jan 2023 20:00:05 -0500 Message-Id: <20230114010006.50471-2-mailingradian@gmail.com> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230114010006.50471-1-mailingradian@gmail.com> References: <20230114010006.50471-1-mailingradian@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Daniel Mentz The MIPI DCS specification demands that brightness values are sent in big endian byte order. It also states that one parameter (i.e. one byte) shall be sent/received for 8 bit wide values, and two parameters shall be used for values that are between 9 and 16 bits wide. Fixes: 1a9d759331b8 ("drm/dsi: Implement DCS set/get display brightness") Signed-off-by: Daniel Mentz Change-Id: I24306e21ec6a5ff48ea121d977419a81d5b44152 Link: https://android.googlesource.com/kernel/msm/+/754affd62d0ee268c686c53= 169b1dbb7deac8550 [richard: fix 16-bit brightness_get] [richard: use separate functions instead of switch/case] Signed-off-by: Richard Acayan --- drivers/gpu/drm/drm_mipi_dsi.c | 52 ++++++++++++++++++++++++++++++++++ include/drm/drm_mipi_dsi.h | 4 +++ 2 files changed, 56 insertions(+) diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c index 497ef4b6a90a..4bc15fbd009d 100644 --- a/drivers/gpu/drm/drm_mipi_dsi.c +++ b/drivers/gpu/drm/drm_mipi_dsi.c @@ -1224,6 +1224,58 @@ int mipi_dsi_dcs_get_display_brightness(struct mipi_= dsi_device *dsi, } EXPORT_SYMBOL(mipi_dsi_dcs_get_display_brightness); =20 +/** + * mipi_dsi_dcs_set_display_brightness_large() - sets the 16-bit brightnes= s value + * of the display + * @dsi: DSI peripheral device + * @brightness: brightness value + * + * Return: 0 on success or a negative error code on failure. + */ +int mipi_dsi_dcs_set_display_brightness_large(struct mipi_dsi_device *dsi, + u16 brightness) +{ + u8 payload[2] =3D { brightness >> 8, brightness & 0xff }; + ssize_t err; + + err =3D mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_DISPLAY_BRIGHTNESS, + payload, sizeof(payload)); + if (err < 0) + return err; + + return 0; +} +EXPORT_SYMBOL(mipi_dsi_dcs_set_display_brightness_large); + +/** + * mipi_dsi_dcs_get_display_brightness_large() - gets the current 16-bit + * brightness value of the display + * @dsi: DSI peripheral device + * @brightness: brightness value + * + * Return: 0 on success or a negative error code on failure. + */ +int mipi_dsi_dcs_get_display_brightness_large(struct mipi_dsi_device *dsi, + u16 *brightness) +{ + u8 brightness_be[2]; + ssize_t err; + + err =3D mipi_dsi_dcs_read(dsi, MIPI_DCS_GET_DISPLAY_BRIGHTNESS, + brightness_be, sizeof(brightness_be)); + if (err <=3D 0) { + if (err =3D=3D 0) + err =3D -ENODATA; + + return err; + } + + *brightness =3D (brightness_be[0] << 8) | brightness_be[1]; + + return 0; +} +EXPORT_SYMBOL(mipi_dsi_dcs_get_display_brightness_large); + static int mipi_dsi_drv_probe(struct device *dev) { struct mipi_dsi_driver *drv =3D to_mipi_dsi_driver(dev->driver); diff --git a/include/drm/drm_mipi_dsi.h b/include/drm/drm_mipi_dsi.h index 4f503d99f668..16f30975b22b 100644 --- a/include/drm/drm_mipi_dsi.h +++ b/include/drm/drm_mipi_dsi.h @@ -296,6 +296,10 @@ int mipi_dsi_dcs_set_display_brightness(struct mipi_ds= i_device *dsi, u16 brightness); int mipi_dsi_dcs_get_display_brightness(struct mipi_dsi_device *dsi, u16 *brightness); +int mipi_dsi_dcs_set_display_brightness_large(struct mipi_dsi_device *dsi, + u16 brightness); +int mipi_dsi_dcs_get_display_brightness_large(struct mipi_dsi_device *dsi, + u16 *brightness); =20 /** * mipi_dsi_generic_write_seq - transmit data using a generic write packet --=20 2.39.0