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 3BE9ACA0FE7 for ; Thu, 21 Aug 2025 15:30:07 +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:CC:To:In-Reply-To:References :Message-ID:Content-Transfer-Encoding:Content-Type:MIME-Version:Subject:Date: From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=uVfCJbInqjmalxCX55tfF2G5Qmv+BXNDRy6gsYqLKtg=; b=RQwXvpBNB9CC5td7bFxx2BiTsD AFCUpuj70oY4CzOEXR6Yit4UXfu60pQcBTFey87qKYE6NylnTpUhlzdUE5Bf70H7NVynxtIv/SbI7 lrus9M5CYbm3/EsrCCltBQwhGwSzfTGLEvcEpnmKOTHAdxF0jYc7JB5joWPKlnqOaZpUcM04/qqir DtTJ8I6tbGuEJZIIahQfOCVqunhM2AA6Q/T3iJZOmAB2heTwOiPLh0VmNy681gvG8khzCJVBEA20r 3V90Bchj/F9QJXtEN/mDhQ2BXa4qDzZ63KYmhgkMXc5q2uYw4zt0TXSUFO5V/pBethqd7RdtIFAnR WSxJeWTw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1up7Em-0000000HM7A-3pRQ; Thu, 21 Aug 2025 15:30:00 +0000 Received: from mx07-00178001.pphosted.com ([185.132.182.106]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1up3Dc-0000000GiM5-0Dpp for linux-arm-kernel@lists.infradead.org; Thu, 21 Aug 2025 11:12:34 +0000 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 57LAJcpq012185; Thu, 21 Aug 2025 13:12:20 +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= uVfCJbInqjmalxCX55tfF2G5Qmv+BXNDRy6gsYqLKtg=; b=3GEp5mHQGqeJ2OHk 8qXUT3pMhnigUDyMC3rO0TZ28BtYYqUOaM9TMOVTQwYLorOg2LgTKFuiYFKIVlos W2NH2Z1zuZkBSZ4tWuw/TEtLcrIBp6K6PSjJJDk/7KXpo5WW5SYsfibIvXibUAPC gnbDBC2BxBH34hViCqCS+KtJd0z/NkPl3W2hOk6HK9TzU9q4GLy7+GXd5aOnS1ou cnyp712S3TtSa1DIvleQMDHgZBWrsBrQY7zjZYuE5zNqvpGVwNtYIW9A1bKVbrc3 sUKEH/sdT4CkxDFoRHL2Y4cZ7jJb9mA0hb9r7C3Y7ITyjMEBN2vOlCWpKddQ0eyv YwkoCA== 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 48nj3v3n8f-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 21 Aug 2025 13:12:20 +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 AE11340055; Thu, 21 Aug 2025 13:10:56 +0200 (CEST) Received: from Webmail-eu.st.com (shfdag1node2.st.com [10.75.129.70]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id 6303974EF09; Thu, 21 Aug 2025 13:09:58 +0200 (CEST) Received: from localhost (10.252.7.99) by SHFDAG1NODE2.st.com (10.75.129.70) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.39; Thu, 21 Aug 2025 13:09:58 +0200 From: Raphael Gallais-Pou Date: Thu, 21 Aug 2025 13:08:58 +0200 Subject: [PATCH v4 08/13] drm/stm: ltdc: handle lvds pixel clock MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-ID: <20250821-drm-misc-next-v4-8-7060500f8fd3@foss.st.com> References: <20250821-drm-misc-next-v4-0-7060500f8fd3@foss.st.com> In-Reply-To: <20250821-drm-misc-next-v4-0-7060500f8fd3@foss.st.com> To: Yannick Fertre , 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: , , , , X-Mailer: b4 0.14.2 X-Originating-IP: [10.252.7.99] X-ClientProxiedBy: SHFCAS1NODE2.st.com (10.75.129.73) To SHFDAG1NODE2.st.com (10.75.129.70) 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=2025-08-21_03,2025-08-20_03,2025-03-28_01 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250821_041232_411178_7E89158F X-CRM114-Status: GOOD ( 14.68 ) 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: 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; -- 2.25.1