Received: by 2002:a05:6a10:9848:0:0:0:0 with SMTP id x8csp165925pxf; Tue, 30 Mar 2021 23:29:50 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzofcpWViDa3OnfZWP2JAIxvGmOFRupn+Kn1sBY9v18tHZsokDMG3q6TSk30qiPEgzqAH9l X-Received: by 2002:a17:906:8a65:: with SMTP id hy5mr1913757ejc.250.1617172190188; Tue, 30 Mar 2021 23:29:50 -0700 (PDT) ARC-Seal: i=2; a=rsa-sha256; t=1617172190; cv=pass; d=google.com; s=arc-20160816; b=O5ZaFEFGJ/q6VNUsmXlYog9+jjZx72f6mKScTiaLMoQMF4rnd77rIyjquROIxGfXPq YqLYiron9CBARxFDk1oR3Sg+MN0q/5IT2BO08amdAGxmSkiriV3HiLtvAsWZn005VbCG zoWG5rOzeKIhWzedfo3XddWm9m9ArnjHo5L0GqdqCgcz7T2sQf4CZ+A9JkFIbEa4IPaN pkVUKH1cuw5n6afnNnpvyGiQhSQWB0WOFLE4uEpPu8B5kHOnsTieS49DRa+r/15eouY0 nKYPJ40yEqcMEK2k8mSlHrj1Dwp40n7VGWX0YdRFmat4blj0+QKra9S/tBt4wwnhb6sG eNTA== ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:mime-version:content-transfer-encoding :user-agent:references:in-reply-to:date:cc:to:from:subject :message-id:dkim-signature; bh=tBt/ruS7lh8NOOOpmI+FclqGUQGGd65x43UcEp+R+rs=; b=sqT32O985khXwkQwwinImowjH/BzYoVV6O7zk9HL9DNwcOGog5jE0ojyFS/qqKKqWE kWM6O6AntDxpTf2PG3fVm72PYOAbZflU9NO1GuEGguEOSA0fxNVmpgsEqaY0fcskQMcs 7X9rI7Tvdj38d3h6pILWj9cWyzz5WvU0bSHtg4qxknSOGL2ZL+AUbZSlmsFgoHcbF30b KKDhnXiIxLXPjKKbbbfBoHHawSekI36AFm9FWHKpelNRFqVSfsrlWjPePbKIWWe1ndPU TCUhjYfjKAEenYoKjn0PVfh8etE8n46DTzm79UaIbmoRRm3LH9RxUKPGclVlTpKrbUhL ytgw== ARC-Authentication-Results: i=2; mx.google.com; dkim=pass header.i=@nxp.com header.s=selector2 header.b=Wh4Hk4g2; arc=pass (i=1 spf=pass spfdomain=nxp.com dkim=pass dkdomain=nxp.com dmarc=pass fromdomain=nxp.com); spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=nxp.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id q2si1004068edw.238.2021.03.30.23.29.27; Tue, 30 Mar 2021 23:29:50 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@nxp.com header.s=selector2 header.b=Wh4Hk4g2; arc=pass (i=1 spf=pass spfdomain=nxp.com dkim=pass dkdomain=nxp.com dmarc=pass fromdomain=nxp.com); spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=nxp.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233803AbhCaG2A (ORCPT + 99 others); Wed, 31 Mar 2021 02:28:00 -0400 Received: from mail-eopbgr00080.outbound.protection.outlook.com ([40.107.0.80]:19614 "EHLO EUR02-AM5-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S231315AbhCaG1l (ORCPT ); Wed, 31 Mar 2021 02:27:41 -0400 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=d0DMb6FaW/4UFgJv4iGZwRVwN2IeIHhPzxkrAwb45a/DPgsLTR6DfyzrTmQW/XGJejIqaCzDyNIaq4m9evtYvdHIGu8wz7KT2QCfVUV/GZywH/FgGtJDUmHD6YCdeYsP3bqTJOqRYh24QgqU3c2+vDL+pVaJgAEf6r7qUxlFL/SZbEc3qUQJyOVQyzAhBQAhHiegRIH0pDHf6PbkiEpXuBGqAYk7pfITELijA9hI+oTgcCxRc34zhVtCNjrvHFLOEFcJgPVkM0/hOKkFnTJbasTSfcTqogUUU085v2eIMZOT2W3T9kc0HY4zDYpRuLScZDqJ9iMIGJGKx24QiXCAMA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=tBt/ruS7lh8NOOOpmI+FclqGUQGGd65x43UcEp+R+rs=; b=Q3LMO2b1ADG47eudK6yK6Pn7G/zNtZcxO12lLhM3kRyKzHATm+0R/LTkVk3iLajxelSFQm1CD/WCMDSktrxfDZRGT50b1S7XtqEsB/XqgZIp1HmsAPId3Gs5R2MDsvqF0lP+wQesCdSV1+5E58WWnVX+bMfN9n9zT/zwdee4b/vjtg6w/bqDcGzvSp3dCsBXMHWz4DZFx7dpBdS6XURNA3+6LZO+UdJc7BkXfZppQc46SfTYhSXA32hQTPA5zPhDUJUCjZ5EC/ieAIbQwOcX4UousOj3ODAVVK+DNX+MryOCwV0EcZqfpH5pTzIgRrmKKW0v223AYXT+jG6ZesAlew== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nxp.com; dmarc=pass action=none header.from=nxp.com; dkim=pass header.d=nxp.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nxp.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=tBt/ruS7lh8NOOOpmI+FclqGUQGGd65x43UcEp+R+rs=; b=Wh4Hk4g2UsGjV7ZPMBX51JdnAUanF2+h2Vn+cO9mWkxeZpg3fX6OOrwbLH/H0Aq9ZB5GEM89JRLhwJhg35jsTSzn+MZtSk8LBY4Ojq1wlljjbR2IHXeyyXl1bxw0jqpsQnDCChsYp3EB4omGMrvqfoTrKgiDXKteoUcQGDAZgMw= Authentication-Results: linaro.org; dkim=none (message not signed) header.d=none;linaro.org; dmarc=none action=none header.from=nxp.com; Received: from VI1PR04MB3983.eurprd04.prod.outlook.com (2603:10a6:803:4c::16) by VI1PR04MB6142.eurprd04.prod.outlook.com (2603:10a6:803:fe::10) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3977.30; Wed, 31 Mar 2021 06:27:35 +0000 Received: from VI1PR04MB3983.eurprd04.prod.outlook.com ([fe80::3ce1:4759:5c33:514c]) by VI1PR04MB3983.eurprd04.prod.outlook.com ([fe80::3ce1:4759:5c33:514c%5]) with mapi id 15.20.3977.033; Wed, 31 Mar 2021 06:27:35 +0000 Message-ID: <8905aad5ba0a37d1c889cfe612b785817d0f1193.camel@nxp.com> Subject: Re: [PATCH v6 12/14] drm/bridge: imx: Add LDB support for i.MX8qxp From: Liu Ying To: Robert Foss Cc: dri-devel , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , "moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE" , linux-kernel , linux-media , David Airlie , Daniel Vetter , Rob Herring , shawnguo@kernel.org, s.hauer@pengutronix.de, kernel@pengutronix.de, Fabio Estevam , linux-imx@nxp.com, Mauro Carvalho Chehab , Andrzej Hajda , Neil Armstrong , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , kishon@ti.com, Vinod Koul , lee.jones@linaro.org Date: Wed, 31 Mar 2021 14:25:57 +0800 In-Reply-To: References: <1615952569-4711-1-git-send-email-victor.liu@nxp.com> <1615952569-4711-13-git-send-email-victor.liu@nxp.com> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.36.4-0ubuntu1 Content-Transfer-Encoding: 7bit X-Originating-IP: [119.31.174.66] X-ClientProxiedBy: MA1PR01CA0127.INDPRD01.PROD.OUTLOOK.COM (2603:1096:a00:35::21) To VI1PR04MB3983.eurprd04.prod.outlook.com (2603:10a6:803:4c::16) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from blueberry (119.31.174.66) by MA1PR01CA0127.INDPRD01.PROD.OUTLOOK.COM (2603:1096:a00:35::21) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3999.26 via Frontend Transport; Wed, 31 Mar 2021 06:27:28 +0000 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-HT: Tenant X-MS-Office365-Filtering-Correlation-Id: 98a1227c-ed96-4243-0162-08d8f40e128f X-MS-TrafficTypeDiagnostic: VI1PR04MB6142: X-MS-Exchange-Transport-Forked: True X-Microsoft-Antispam-PRVS: X-MS-Oob-TLC-OOBClassifiers: OLM:5797; X-MS-Exchange-SenderADCheck: 1 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:VI1PR04MB3983.eurprd04.prod.outlook.com;PTR:;CAT:NONE;SFS:(4636009)(366004)(966005)(52116002)(36756003)(5660300002)(186003)(66556008)(66946007)(66476007)(45080400002)(8676002)(498600001)(83380400001)(6666004)(6496006)(7416002)(26005)(6916009)(38100700001)(4326008)(2906002)(8936002)(16526019)(6486002)(956004)(2616005)(54906003)(86362001);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData: =?utf-8?B?TXZWeDZvakZXSHVwWnJaS0dEUW5hOG94ZnliN0xQdWFSVmRnNUpDTEdhbGts?= =?utf-8?B?Tjhoc2hmVHJrQ2dYWXVJUFRlK0NFT1pMQzJiemVPdUpRYW1sZHlXU2k0SVNM?= =?utf-8?B?UjF5dldCSzhBL241c3AwZ012YVpJVXp2dmNQczJuSlBaVmt2TElJTWFhR2Yv?= =?utf-8?B?WUVYUVN1QUtTdWROeFpIRkg0blJYbDNEZzBId0ZsQUNUOUs5bnI5amEwMHVH?= =?utf-8?B?elUxRkM2QWkvem1UZE9uUVZnOWt5N3Q0WEtnMS91NHZVODB3UDhVRVpGcWhH?= =?utf-8?B?NHNyc0ZqRk1oV0FVQ3dUTk93QzRWM1BkUlBjci9aaktTZXFaT0dKY1ArYkJE?= =?utf-8?B?U3dNRDBtTDdCeDdMakhmSk9hVG85SEE5ZGpFTERxNSt0eVlpQnIrK3AyWFNk?= =?utf-8?B?bVBXQXh4dm1mNUFoc2Yway8yMDVMQnNSaDFnUHJmeDZ4aitTekptbjlkdlBG?= =?utf-8?B?NUo2SlJhcWdvcS9uM1JaK1hUL1JvWGtkQ21RVXNuOEJ6Y0s5KzUwK1Fnd1Zp?= =?utf-8?B?c2ZWaHYyMEtPRXJXRTQwc3UzWjRBRTdyeGU5VkJzY0dZWkprV0F4a3p6eVVP?= =?utf-8?B?aXFmMW1teTk3NldVYVUxV0dKRW8zMDVDRlM4SjFmMUszdlQySUxkMFVYLzVV?= =?utf-8?B?dk91QjFaYjQ4VzczV3ZTRExYTDlVUkxGTkQ5RkhXUHZUNEVzL2t3dHpFaWFT?= =?utf-8?B?SmVzbmNEUkwwTE90eC9KR1V6dkVkaFIvMjk2U0h5ejVYODd6Q2tzZzI0N0E2?= =?utf-8?B?LzhCcUxqS1hldERrUWkvOXpWZkdiUHY5YTdyckkxTmt3MDZiSlNpbVg1Z1Mv?= =?utf-8?B?STlIS09yczl3OHNNYU9EMjlSc1ZlYVN0SzFKb1g1RDFBQldSamV2encvZEdi?= =?utf-8?B?cTFDQjhmSU1mVmJUV0EvMTQ5RGNxTFljMU5QUmhvZ2QwV0czS0Z3dWJVQ1RF?= =?utf-8?B?d0FpZ3R3LzJiYXRmcDc3S2xyV2tKb3BxNXlsSE5YaVljckVFbG4wQ2hHV3NW?= =?utf-8?B?anl2TjRqMmdmTVlERC82WFh2eHg3LzNWTnQ2MjA3ZW14Y2s4akZHMWRsUmJo?= =?utf-8?B?NjZSL3hOSjluelJnUURpV0xBUDBqNmhpNXc2SHhqWW0rNkxCRWRwT1VqeXNE?= =?utf-8?B?OUdpUUVVc0wwelRHQy91ZE9zOG96VmN6d2NNTHhPWEp0dHdEeGVRYkJWeEZS?= =?utf-8?B?b3BuZnMzUE9iSldlazV0Z2pzVlc4elhmenhBM01adURsdnV1YnMyZ2lQSW1H?= =?utf-8?B?RGFqcUVRMGZhM3VKYmZQTmR6dkFoRGlvRXo3aXM5Y1NEaHRHYmR2MGtrRmtK?= =?utf-8?B?MHE1bEtBZUJ4R2paK2JUQjRKcHJjV01EN0F3VlkzQzVtR0I1aERreGN5aEJo?= =?utf-8?B?MmxXbU5pMGVvb0lPYm5qZmlUUVdVaDkxaUtNSGhiMzc3elhuVVMwZFlsZlVx?= =?utf-8?B?eCs0SWVnbmFyU1BVT2cxVnJ1MTBGb0VjQWxqSGFLV1duTGY2RHJ5ZXJMVE52?= =?utf-8?B?WFFHODRVd0J3cXhxOWsza2NOalNFcC9VVVJVcWpXQzlaZTVNTFFldlU3aDhI?= =?utf-8?B?R3VkbkZxM1EyaGpPcjdHMTZJbnNWajJyajlHMkZMSFl1dklWcGdjSDhOb05Q?= =?utf-8?B?dDNlOGpmYWRDWVhSeGRJYlYvRDRHUnVGTWdXSTlvaU1iWW1JWUVZc2ZzcTcr?= =?utf-8?B?eEJMcTdndzMvdWlKaldjQzJZejY0anlVNlJwOGpsb2w0L1VOWDFUU2pVREFO?= =?utf-8?Q?lVa6Vxh18xeiwghoSBzSJ7ueSqVPg5nNb5HGkHd?= X-OriginatorOrg: nxp.com X-MS-Exchange-CrossTenant-Network-Message-Id: 98a1227c-ed96-4243-0162-08d8f40e128f X-MS-Exchange-CrossTenant-AuthSource: VI1PR04MB3983.eurprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 31 Mar 2021 06:27:35.7372 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 686ea1d3-bc2b-4c6f-a92c-d99c5c301635 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: NF05LJoQOAFybIYYyW+5T4KSP2ePEIalAVtiLyRnvQJ5SwdoJ/Uzk/V5IN/0uIDvV/tDdJvRBltozqgXkDHRug== X-MS-Exchange-Transport-CrossTenantHeadersStamped: VI1PR04MB6142 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2021-03-30 at 11:54 +0200, Robert Foss wrote: > Hey Liu, > > checkpatch --strict lists some nit and a warning. With those fixed > feel free to add my r-b. > > On Wed, 17 Mar 2021 at 04:57, Liu Ying wrote: > > This patch adds a drm bridge driver for i.MX8qxp LVDS display bridge(LDB) > > which is officially named as pixel mapper. The LDB has two channels. > > Each of them supports up to 24bpp parallel input color format and can map > > the input to VESA or JEIDA standards. The two channels cannot be used > > simultaneously, that is to say, the user should pick one of them to use. > > Two LDB channels from two LDB instances can work together in LDB split > > mode to support a dual link LVDS display. The channel indexes have to be > > different. Channel0 outputs odd pixels and channel1 outputs even pixels. > > This patch supports the LDB single mode and split mode. > > > > Signed-off-by: Liu Ying > > --- > > Note that this patch depends on the patch 'phy: Add LVDS configuration options', > > which has already been sent with the following series to add Mixel combo PHY > > found in i.MX8qxp: > > https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.spinics.net%2Flists%2Farm-kernel%2Fmsg879957.html&data=04%7C01%7Cvictor.liu%40nxp.com%7C7c4f1092633c4687fb3108d8f361ddfd%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C637526948949839014%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=iNr6RU0xrhcW8epwIPPJDpayjWxfmWsSjCju3XIcmPM%3D&reserved=0 > > > > v5->v6: > > * No change. > > > > v4->v5: > > * Link with the imx-ldb-helper object. (Robert) > > * Correspondingly, rename 'imx8qxp-ldb.c' to 'imx8qxp-ldb-drv.c'. > > > > v3->v4: > > * No change. > > > > v2->v3: > > * No change. > > > > v1->v2: > > * Drop unnecessary DT validation. > > * Use of_graph_get_endpoint_by_regs() and of_graph_get_remote_endpoint() to > > get the input remote endpoint in imx8qxp_ldb_set_di_id(). > > * Avoid using companion_port OF node after putting it in > > imx8qxp_ldb_parse_dt_companion(). > > * Mention i.MX8qxp LDB official name 'pixel mapper' in the bridge driver > > and Kconfig help message. > > > > drivers/gpu/drm/bridge/imx/Kconfig | 9 + > > drivers/gpu/drm/bridge/imx/Makefile | 3 + > > drivers/gpu/drm/bridge/imx/imx8qxp-ldb-drv.c | 720 +++++++++++++++++++++++++++ > > 3 files changed, 732 insertions(+) > > create mode 100644 drivers/gpu/drm/bridge/imx/imx8qxp-ldb-drv.c > > [...] > > + > > +static int imx8qxp_ldb_probe(struct platform_device *pdev) > > +{ > > + struct device *dev = &pdev->dev; > > + struct imx8qxp_ldb *imx8qxp_ldb; > > + struct imx8qxp_ldb_channel *imx8qxp_ldb_ch; > > + struct ldb *ldb; > > + struct ldb_channel *ldb_ch; > > + int ret, i; > > + > > + imx8qxp_ldb = devm_kzalloc(dev, sizeof(*imx8qxp_ldb), GFP_KERNEL); > > + if (!imx8qxp_ldb) > > + return -ENOMEM; > > + > > + imx8qxp_ldb->clk_pixel = devm_clk_get(dev, "pixel"); > > + if (IS_ERR(imx8qxp_ldb->clk_pixel)) { > > + ret = PTR_ERR(imx8qxp_ldb->clk_pixel); > > + if (ret != -EPROBE_DEFER) > > + DRM_DEV_ERROR(dev, > > + "failed to get pixel clock: %d\n", ret); > > + return ret; > > + } > > + > > + imx8qxp_ldb->clk_bypass = devm_clk_get(dev, "bypass"); > > + if (IS_ERR(imx8qxp_ldb->clk_bypass)) { > > + ret = PTR_ERR(imx8qxp_ldb->clk_bypass); > > + if (ret != -EPROBE_DEFER) > > + DRM_DEV_ERROR(dev, > > + "failed to get bypass clock: %d\n", ret); > > + return ret; > > + } > > + > > + imx8qxp_ldb->dev = dev; > > + > > + ldb = &imx8qxp_ldb->base; > > + ldb->dev = dev; > > + ldb->ctrl_reg = 0xe0; > > + > > + for (i = 0; i < MAX_LDB_CHAN_NUM; i++) > > + ldb->channel[i] = &imx8qxp_ldb->channel[i].base; > > + > > + ret = ldb_init_helper(ldb); > > + if (ret) > > + return ret; > > + > > + if (ldb->available_ch_cnt == 0) { > > + DRM_DEV_DEBUG_DRIVER(dev, "no available channel\n"); > > + return 0; > > + } else if (ldb->available_ch_cnt > 1) { > > + DRM_DEV_ERROR(dev, "invalid available channel number(%u)\n", > > + ldb->available_ch_cnt); > > + return -ENOTSUPP; > > + } > > WARNING: ENOTSUPP is not a SUSV4 error code, prefer EOPNOTSUPP > #683: FILE: drivers/gpu/drm/bridge/imx/imx8qxp-ldb-drv.c:625: > + return -ENOTSUPP; > > Maybe -EINVAL is a better return value. Will use -EINVAL in the next version. Liu Ying