From mboxrd@z Thu Jan 1 00:00:00 1970 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C1D90C44520 for ; Fri, 17 Jul 2026 12:19:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=PazjzQ9/RAMBhl8ZObuStg+aPYI7SBm0oUOl0yW6hLs=; b=BwLuT4E8cta2bbTK7sTWPk0zFg pFSRXpk0qGdTtYxVOgz8KLuVTkUPKmXAboTsQkg+R57oIgz1izabYCyaT/4yrTPhoGWZz3b3E6bEc Jk2ghrUJ5aoHKpNyiIcrKcotvwUyfbfvRVgdTvZgUeeqsnzWm/BGRK4laE4K0M9VKmJ95fjj7YkyO FMbAco3clnnQ9uln8yspmdvhLLw5Tw0a1YTzG2UO/9GEp9iHXIYZcQq9tnl+LE82nrY41YtN+LyBd 45lttHOKYGjmZuY+WqaIoBo+nZ0+9W9akwg229Mm/4xmrgHKSxtFKlYfh9aS+CFpVJ+X0AEZnfdZK oAOugqhw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wkhX3-00000002GaT-0RIr; Fri, 17 Jul 2026 12:19:09 +0000 Received: from mail11.truemail.it ([217.194.8.81]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wkhWz-00000002GYf-3Fli for linux-arm-kernel@lists.infradead.org; Fri, 17 Jul 2026 12:19:08 +0000 Received: from francesco-nb.. (unknown [178.82.120.96]) by mail11.truemail.it (Postfix) with ESMTPA id 58EC9228C8; Fri, 17 Jul 2026 14:18:59 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=dolcini.it; s=default; t=1784290740; bh=PazjzQ9/RAMBhl8ZObuStg+aPYI7SBm0oUOl0yW6hLs=; h=From:To:Subject; b=sm61I0gxuOE+Ck67P8NErrRE02PHdi7FDQo8FiyUzhiCDIbot3migWkACx8gMhy8P DV/wfx1yAJp/waYlAOJEvqkeX9vD7E5/ghbiPuOah8BNFCJISrVevO/c2ew/gJyS/n 78PCwcQaQy0Gx4pXCk7MAzQJBRfrxg2Buiw7CclfJRjI5KVjRn5Tmxgv9F55TMs+Tt BxfxgqSK3rieJ3dtY5rMYaabs4GKFDCTEAyJXCZg7Oy7ONlVuvD/NlsA6q5eozF0l9 Lo0o76Omnq95LmKSR8tonwHkvhgX+0Zw/z/mDbv6whJOsbAYqv9PqYdyzOepYJS/pu C4VwK0SW0db6A== From: Francesco Dolcini To: Marek Vasut , Stefan Agner , David Airlie , Simona Vetter , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Frank Li , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam Cc: Francesco Dolcini , dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, imx@lists.linux.dev, linux-arm-kernel@lists.infradead.org Subject: [PATCH v1 2/4] drm: mxsfb: Allow optional LCDIF interface format override Date: Fri, 17 Jul 2026 14:18:44 +0200 Message-ID: <20260717121847.488148-3-francesco@dolcini.it> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260717121847.488148-1-francesco@dolcini.it> References: <20260717121847.488148-1-francesco@dolcini.it> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260717_051906_794044_60874E4A X-CRM114-Status: GOOD ( 17.47 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Francesco Dolcini LCDIF programs LCD_DATABUS_WIDTH from the selected media bus format. The format reported by the downstream panel or bridge describes the display input, but it does not describe how the LCDIF data pins are physically wired on the board. These can differ. For example, a 16-bit LCDIF bus can be connected to a 24-bit display by wiring the available color bits to the corresponding display inputs. In that case, using the display's 24-bit format to configure LCDIF selects the wrong data-bus mode and changes the assignment of color bits on the LCD_DATA pins. Read the optional interface-pix-fmt property from the LCDIF node and use it to select the media bus format used to configure LCDIF. This allows the LCDIF bus mode to describe the physical interface independently of the downstream display format. When the optional property is absent, continue using the format reported by the downstream display device, preserving the existing behavior. This follows the same approach already implemented in drivers/gpu/drm/imx/ipuv3/parallel-display.c. Signed-off-by: Francesco Dolcini --- drivers/gpu/drm/mxsfb/mxsfb_drv.c | 16 ++++++++++++++++ drivers/gpu/drm/mxsfb/mxsfb_drv.h | 2 ++ drivers/gpu/drm/mxsfb/mxsfb_kms.c | 8 ++++++++ 3 files changed, 26 insertions(+) diff --git a/drivers/gpu/drm/mxsfb/mxsfb_drv.c b/drivers/gpu/drm/mxsfb/mxsfb_drv.c index 9b8fbda85d28..edf347968fd2 100644 --- a/drivers/gpu/drm/mxsfb/mxsfb_drv.c +++ b/drivers/gpu/drm/mxsfb/mxsfb_drv.c @@ -12,7 +12,9 @@ #include #include #include +#include #include +#include #include #include #include @@ -209,7 +211,10 @@ static int mxsfb_load(struct drm_device *drm, const struct mxsfb_devdata *devdata) { struct platform_device *pdev = to_platform_device(drm->dev); + struct device_node *np = pdev->dev.of_node; struct mxsfb_drm_private *mxsfb; + u32 bus_format = 0; + const char *fmt; int ret; mxsfb = devm_kzalloc(&pdev->dev, sizeof(*mxsfb), GFP_KERNEL); @@ -236,6 +241,17 @@ static int mxsfb_load(struct drm_device *drm, if (IS_ERR(mxsfb->clk_disp_axi)) mxsfb->clk_disp_axi = NULL; + ret = of_property_read_string(np, "interface-pix-fmt", &fmt); + if (!ret) { + if (!strcmp(fmt, "rgb24")) + bus_format = MEDIA_BUS_FMT_RGB888_1X24; + else if (!strcmp(fmt, "rgb565")) + bus_format = MEDIA_BUS_FMT_RGB565_1X16; + else if (!strcmp(fmt, "rgb666")) + bus_format = MEDIA_BUS_FMT_RGB666_1X18; + } + mxsfb->bus_format = bus_format; + ret = dma_set_mask_and_coherent(drm->dev, DMA_BIT_MASK(32)); if (ret) return ret; diff --git a/drivers/gpu/drm/mxsfb/mxsfb_drv.h b/drivers/gpu/drm/mxsfb/mxsfb_drv.h index d160d921b25f..f64800f06a69 100644 --- a/drivers/gpu/drm/mxsfb/mxsfb_drv.h +++ b/drivers/gpu/drm/mxsfb/mxsfb_drv.h @@ -46,6 +46,8 @@ struct mxsfb_drm_private { struct drm_connector *connector; struct drm_bridge *bridge; + u32 bus_format; + bool crc_active; }; diff --git a/drivers/gpu/drm/mxsfb/mxsfb_kms.c b/drivers/gpu/drm/mxsfb/mxsfb_kms.c index d8ebebc5314b..8b482727aed5 100644 --- a/drivers/gpu/drm/mxsfb/mxsfb_kms.c +++ b/drivers/gpu/drm/mxsfb/mxsfb_kms.c @@ -386,6 +386,14 @@ static void mxsfb_crtc_atomic_enable(struct drm_crtc *crtc, if (!bus_format) bus_format = MEDIA_BUS_FMT_RGB888_1X24; + /* + * Prefer bus format set via optional "interface-pix-fmt" DT property, + * over panel or next bridge bus format. This is necessary to support + * 24bit DPI panels connected to a 18bit interface, for example. + */ + if (mxsfb->bus_format) + bus_format = mxsfb->bus_format; + mxsfb_crtc_mode_set_nofb(mxsfb, bridge_state, bus_format); /* Write cur_buf as well to avoid an initial corrupt frame */ -- 2.47.3