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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 BBC97CA0EEB for ; Fri, 22 Aug 2025 12:59:33 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 28A2610EB0D; Fri, 22 Aug 2025 12:59:33 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=foss.st.com header.i=@foss.st.com header.b="Nfs7u0K7"; dkim-atps=neutral Received: from mx07-00178001.pphosted.com (mx07-00178001.pphosted.com [185.132.182.106]) by gabe.freedesktop.org (Postfix) with ESMTPS id 5FCB310EB0A for ; Fri, 22 Aug 2025 12:59:32 +0000 (UTC) Received: from pps.filterd (m0369458.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 57MB4cNS006702; Fri, 22 Aug 2025 14:59:21 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=foss.st.com; h= cc:content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s=selector1; bh= eJVEVHQF5pr9BGboWJab/5hf088ZC2OEhk357P8nepk=; b=Nfs7u0K7OlORz/Pc D6Sp9pLBly1bVFLlKKcXt7nNlZ5eXZOoOd/qZd4N+VnZuxcjgEGKSBv/03cE56zg s84BseNPmH/f+YN7NSapfJKf+23PI0iJ600LKTygRkXTD61x4zSjNS+nVdEanN4X 8UkYHvd8+MLYSy7DR2s0f/KcAiDAUmDmoD4YLeuK6xE/njAeRga+/hPk3wUdKicd AYGrS4YgsgAXP51YZsHDT0rzu8Wcl0w8TW0adxRh5IV844+RUSm3e2z6rKjqHfg4 Gfe46MB+fUE/+Psv+l70rV0hwLzDDvCaflRKi6JueVyZ40yvhK7L5Sd3om1Vs46U 5/8iOA== Received: from beta.dmz-ap.st.com (beta.dmz-ap.st.com [138.198.100.35]) by mx07-00178001.pphosted.com (PPS) with ESMTPS id 48nj3v88b7-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 22 Aug 2025 14:59:21 +0200 (MEST) Received: from euls16034.sgp.st.com (euls16034.sgp.st.com [10.75.44.20]) by beta.dmz-ap.st.com (STMicroelectronics) with ESMTP id 880E04002D; Fri, 22 Aug 2025 14:57:35 +0200 (CEST) Received: from Webmail-eu.st.com (shfdag1node3.st.com [10.75.129.71]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id 967FE5EFA17; Fri, 22 Aug 2025 14:56:34 +0200 (CEST) Received: from [10.48.87.178] (10.48.87.178) by SHFDAG1NODE3.st.com (10.75.129.71) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.39; Fri, 22 Aug 2025 14:56:33 +0200 Message-ID: <6bc77ea8-c664-45ff-886a-aefc79767253@foss.st.com> Date: Fri, 22 Aug 2025 14:56:33 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 08/13] drm/stm: ltdc: handle lvds pixel clock To: Raphael Gallais-Pou , Philippe Cornu , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Rob Herring , "Krzysztof Kozlowski" , Conor Dooley , "Maxime Coquelin" , Alexandre Torgue , Catalin Marinas , Will Deacon , Christophe Roullier CC: , , , , References: <20250821-drm-misc-next-v4-0-7060500f8fd3@foss.st.com> <20250821-drm-misc-next-v4-8-7060500f8fd3@foss.st.com> Content-Language: en-US From: Yannick FERTRE In-Reply-To: <20250821-drm-misc-next-v4-8-7060500f8fd3@foss.st.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.48.87.178] X-ClientProxiedBy: EQNCAS1NODE4.st.com (10.75.129.82) To SHFDAG1NODE3.st.com (10.75.129.71) X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1099,Hydra:6.1.9,FMLib:17.12.80.40 definitions=2025-08-22_04,2025-08-20_03,2025-03-28_01 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Hi Raphael, Thanks for the patch. Acked-by: Yannick Fertre Le 21/08/2025 à 13:08, Raphael Gallais-Pou a écrit : > From: Yannick Fertre > > Handle LVDS pixel clock. > > The LTDC operates with multiple clock domains for register access, > requiring all clocks to be provided during read/write operations. This > imposes a dependency between the LVDS and LTDC to access correctly all > LTDC registers. And because both IPs' pixel rates must be synchronized, > the LTDC has to handle the LVDS clock. > > Signed-off-by: Yannick Fertre > Signed-off-by: Raphael Gallais-Pou > --- > drivers/gpu/drm/stm/ltdc.c | 22 +++++++++++++++++++++- > drivers/gpu/drm/stm/ltdc.h | 1 + > 2 files changed, 22 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c > index 17548dd3484a0a3e1015c58c752b80f8892a0ff7..f84a9a8590f0653e422798ff61804d7c3966caef 100644 > --- a/drivers/gpu/drm/stm/ltdc.c > +++ b/drivers/gpu/drm/stm/ltdc.c > @@ -837,6 +837,12 @@ ltdc_crtc_mode_valid(struct drm_crtc *crtc, > int target_max = target + CLK_TOLERANCE_HZ; > int result; > > + if (ldev->lvds_clk) { > + result = clk_round_rate(ldev->lvds_clk, target); > + drm_dbg_driver(crtc->dev, "lvds pixclk rate target %d, available %d\n", > + target, result); > + } > + > result = clk_round_rate(ldev->pixel_clk, target); > > DRM_DEBUG_DRIVER("clk rate target %d, available %d\n", target, result); > @@ -1878,6 +1884,8 @@ void ltdc_suspend(struct drm_device *ddev) > clk_disable_unprepare(ldev->pixel_clk); > if (ldev->bus_clk) > clk_disable_unprepare(ldev->bus_clk); > + if (ldev->lvds_clk) > + clk_disable_unprepare(ldev->lvds_clk); > } > > int ltdc_resume(struct drm_device *ddev) > @@ -1895,8 +1903,16 @@ int ltdc_resume(struct drm_device *ddev) > > if (ldev->bus_clk) { > ret = clk_prepare_enable(ldev->bus_clk); > - if (ret) > + if (ret) { > drm_err(ddev, "failed to enable bus clock (%d)\n", ret); > + return ret; > + } > + } > + > + if (ldev->lvds_clk) { > + ret = clk_prepare_enable(ldev->lvds_clk); > + if (ret) > + drm_err(ddev, "failed to prepare lvds clock\n"); > } > > return ret; > @@ -1981,6 +1997,10 @@ int ltdc_load(struct drm_device *ddev) > } > } > > + ldev->lvds_clk = devm_clk_get(dev, "lvds"); > + if (IS_ERR(ldev->lvds_clk)) > + ldev->lvds_clk = NULL; > + > rstc = devm_reset_control_get_exclusive(dev, NULL); > > mutex_init(&ldev->err_lock); > diff --git a/drivers/gpu/drm/stm/ltdc.h b/drivers/gpu/drm/stm/ltdc.h > index ddfa8ae61a7ba5dc446fae647562d0ec8e6953e1..17b51a7ce28eee5de6d24ca943ca3b1f48695dfd 100644 > --- a/drivers/gpu/drm/stm/ltdc.h > +++ b/drivers/gpu/drm/stm/ltdc.h > @@ -48,6 +48,7 @@ struct ltdc_device { > void __iomem *regs; > struct regmap *regmap; > struct clk *pixel_clk; /* lcd pixel clock */ > + struct clk *lvds_clk; /* lvds pixel clock */ > struct clk *bus_clk; /* bus clock */ > struct mutex err_lock; /* protecting error_status */ > struct ltdc_caps caps; >