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 8A0D6CA5FFE for ; Mon, 19 Jan 2026 07:32:46 +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:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:MIME-Version:Content-Type: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=OToeNz4t2oXNHYHV6Pu5IF6zpl5lN3hD9z93ek1ZgZE=; b=iD9xC61Y0bQTBkyfnUOiYMyhnE U70PfsiuhGzOcvQA1CsCZ7V5h1XZajuLBG56Ivhkuvw8u9ZBrJ8XNkhA1wk1APQtdLjtrZHC1Tn2N krs7IUi7tSuejewTs64c4Eg16I7moBSXw6PQ1aaS0S+D9HXDOWNNcGQjMnGcAMCoer0eiLtkJYKpD Ai5MGxcsgxUGUNIgvcBZsFD5w3+8hE1tf5Q8NAPAqFhSNFpm3oiYu2DswiU+IGHpS0x7krRIZOssS 25yUbT98fQhVYfIcCWikgIJbnJcG2kA1tDe+1JagtznkFlUAYFdNUfyfeodn8RGRDHhbbi9k5di3e HmQRPhuA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vhjkS-00000001Twl-2NbJ; Mon, 19 Jan 2026 07:32:29 +0000 Received: from smtpbgau1.qq.com ([54.206.16.166]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vhjk8-00000001TnJ-2TrG; Mon, 19 Jan 2026 07:32:22 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=airkyi.com; s=altu2504; t=1768807882; bh=OToeNz4t2oXNHYHV6Pu5IF6zpl5lN3hD9z93ek1ZgZE=; h=From:To:Subject:Date:Message-Id; b=CEqf9qZKhHkvHdqnXSKGB6T42SEfONJ3IHCjbAeXKMNZfyvIchxRcTojKRaPK/3nv MCHcGkg9whpckgfsdx3g5JFzvwT/Cwb6cJJFKkcln0RUcnDqynIPWKSbqIdBGqBii4 r6p4Kp+1BWuuoQxDOvWHe69E+hOtqqsntgcrlQzE= X-QQ-mid: esmtpsz17t1768807880t0b5bc7d4 X-QQ-Originating-IP: rUc8iNV8fJzPqcaO9ExsW47sRe4cqZbnD2CD0yEkQV4= Received: from DESKTOP-8BT1A2O.localdomain ( [58.22.7.114]) by bizesmtp.qq.com (ESMTP) with id ; Mon, 19 Jan 2026 15:31:11 +0800 (CST) X-QQ-SSF: 0000000000000000000000000000000 X-QQ-GoodBg: 0 X-BIZMAIL-ID: 8138520730138124000 From: Chaoyi Chen To: Heikki Krogerus , Greg Kroah-Hartman , Dmitry Baryshkov , Peter Chen , Luca Ceresoli , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Vinod Koul , Kishon Vijay Abraham I , Heiko Stuebner , Sandy Huang , Andy Yan , Yubing Zhang , Frank Wang , Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Amit Sunil Dhamne , Chaoyi Chen , Dragan Simic , Johan Jonker , Diederik de Haas , Peter Robinson Cc: linux-usb@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-phy@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, dri-devel@lists.freedesktop.org Subject: [PATCH v14 1/9] drm/bridge: Implement generic USB Type-C DP HPD bridge Date: Mon, 19 Jan 2026 15:30:52 +0800 Message-Id: <20260119073100.143-2-kernel@airkyi.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20260119073100.143-1-kernel@airkyi.com> References: <20260119073100.143-1-kernel@airkyi.com> X-QQ-SENDSIZE: 520 Feedback-ID: esmtpsz:airkyi.com:qybglogicsvrgz:qybglogicsvrgz6b-0 X-QQ-XMAILINFO: MX+1SEN3H+wAprBSZyZpYvfjKkAEBXBia0if9pIIpzZeNUhkW9+SP97a mpTDPni3mqcTf8sBrRpWuHTIku36nfifeJkZQT4B/cLvHz/RPIZUHa4N6FZY2SRnfLKITXi aNsT9Z+duZYNV95ckbW6ZXZglg8ErHQJOaAw1jAANIRi/oWxCmiQHD6snPCiwdaYuzeBLka ge0CuTpYa9Lyg1GrN05qnOB3xX1Nd6tOL2Ojum42OqdnO+s6d+rfny8kyiJpitjGCxNVNJs Yog5Jt2TIeQPFcsJLw1exxo/HSigjjXGgpMVimGGJaiQmcMA7X+Z8rQa7elud+Pcl62chC2 ZxYaTzvmua9Y/0hLTvNcHKbffbGrKm1v3/woG9NmBV5aXXL6gJu8Qr/Y+7O1cUmtzYemUi3 KzCWzjtaaWYbcbVEkRd3MOgIs+A9N8aRfiqKtWfCYy02YLps3c4woqwTuh/9ftaGvTfHzPU WB6W/L7Kx4WrYkrDUUvPpI9JHCUQHJ090F2gWprqRIGSjH16JopWVv7wYovm4Sq9YTzTZTc JyAgFB8HhIuOc8eNyHB0F0pWLLqlr8rtMKrimJe0dl8y+KSjxYhmd0aepHi70nLnwdGMgIi JdMD/hKl6hehuS/aCBPr2v6M5by4oPtw1mCdNaBVvHJVwOi1HKdiLajbK8FF0v4UBX8DtDm eJiLHP5f2bKJxzgeabf92W0qE8MpRG8jMqETY4Uh744UacHdinRyM0Riuq3vw7DeTZzzFEs TsJVkNBv14pQTK9O+qCIQQMh2SwrbA8C5oqty+WDXlSFPe5GsOf05gfP89R/LBAV3UZGqHD FveOvQP79CqDHsPWL45A0g7PbNIeitHCLHSAmfSN/Eaq/IzTBfFpbkE+I7Ls15ceIdoVwwg bHqu24N9N/EY29LBQ5xNYaWls9fD07xTIIeGm2fdlXzvz8+uPxm+84hohCWN7Otj6jgsqvq tyGij7eswwtv+Rmrg/3L6fNNCNoMdfjEN7g53+oxHBzGrETMooM6L9x3kZByyFRL4ulR4+q gQ3NFHxA== X-QQ-XMRINFO: Mp0Kj//9VHAxzExpfF+O8yhSrljjwrznVg== X-QQ-RECHKSPAM: 0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260118_233210_445261_9D205AC9 X-CRM114-Status: GOOD ( 21.53 ) 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: Chaoyi Chen The HPD function of Type-C DP is implemented through drm_connector_oob_hotplug_event(). For embedded DP, it is required that the DRM connector fwnode corresponds to the Type-C port fwnode. To describe the relationship between the DP controller and the Type-C port device, we usually using drm_bridge to build a bridge chain. Now several USB-C controller drivers have already implemented the DP HPD bridge function provided by aux-hpd-bridge.c, it will build a DP HPD bridge on USB-C connector port device. But this requires the USB-C controller driver to manually register the HPD bridge. If the driver does not implement this feature, the bridge will not be create. So this patch implements a generic DP HPD bridge based on aux-hpd-bridge.c. It will monitor Type-C bus events, and when a Type-C port device containing the DP svid is registered, it will create an HPD bridge for it without the need for the USB-C controller driver to implement it. Signed-off-by: Chaoyi Chen Reviewed-by: Heikki Krogerus --- (no changes since v14) Changes in v13: - Only register drm dp hpd bridge for typec port altmode device. (no changes since v12) Changes in v11: - Switch to using typec bus notifiers. (no changes since v10) Changes in v9: - Remove the exposed DRM_AUX_HPD_BRIDGE option, and select DRM_AUX_HPD_TYPEC_BRIDGE when it is available. - Add more commit comment about problem background. Changes in v8: - Merge generic DP HPD bridge into one module. --- drivers/gpu/drm/bridge/Kconfig | 10 ++++ drivers/gpu/drm/bridge/Makefile | 1 + .../gpu/drm/bridge/aux-hpd-typec-dp-bridge.c | 49 +++++++++++++++++++ 3 files changed, 60 insertions(+) create mode 100644 drivers/gpu/drm/bridge/aux-hpd-typec-dp-bridge.c diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig index a250afd8d662..559487aa09a9 100644 --- a/drivers/gpu/drm/bridge/Kconfig +++ b/drivers/gpu/drm/bridge/Kconfig @@ -30,6 +30,16 @@ config DRM_AUX_HPD_BRIDGE Simple bridge that terminates the bridge chain and provides HPD support. +if DRM_AUX_HPD_BRIDGE +config DRM_AUX_HPD_TYPEC_BRIDGE + tristate + depends on TYPEC || !TYPEC + default TYPEC + help + Simple bridge that terminates the bridge chain and provides HPD + support. It build bridge on each USB-C connector device node. +endif + menu "Display Interface Bridges" depends on DRM && DRM_BRIDGE diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile index c7dc03182e59..a3a0393d2e72 100644 --- a/drivers/gpu/drm/bridge/Makefile +++ b/drivers/gpu/drm/bridge/Makefile @@ -1,6 +1,7 @@ # SPDX-License-Identifier: GPL-2.0 obj-$(CONFIG_DRM_AUX_BRIDGE) += aux-bridge.o obj-$(CONFIG_DRM_AUX_HPD_BRIDGE) += aux-hpd-bridge.o +obj-$(CONFIG_DRM_AUX_HPD_TYPEC_BRIDGE) += aux-hpd-typec-dp-bridge.o obj-$(CONFIG_DRM_CHIPONE_ICN6211) += chipone-icn6211.o obj-$(CONFIG_DRM_CHRONTEL_CH7033) += chrontel-ch7033.o obj-$(CONFIG_DRM_CROS_EC_ANX7688) += cros-ec-anx7688.o diff --git a/drivers/gpu/drm/bridge/aux-hpd-typec-dp-bridge.c b/drivers/gpu/drm/bridge/aux-hpd-typec-dp-bridge.c new file mode 100644 index 000000000000..d915e0fb0668 --- /dev/null +++ b/drivers/gpu/drm/bridge/aux-hpd-typec-dp-bridge.c @@ -0,0 +1,49 @@ +// SPDX-License-Identifier: GPL-2.0+ +#include +#include +#include + +#include + +static int drm_typec_bus_event(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct device *dev = (struct device *)data; + struct typec_altmode *alt = to_typec_altmode(dev); + + if (action != BUS_NOTIFY_ADD_DEVICE) + goto done; + + /* + * alt->dev.parent->parent : USB-C controller device + * alt->dev.parent : USB-C connector device + */ + if (is_typec_port_altmode(&alt->dev) && alt->svid == USB_TYPEC_DP_SID) + drm_dp_hpd_bridge_register(alt->dev.parent->parent, + to_of_node(alt->dev.parent->fwnode)); + +done: + return NOTIFY_OK; +} + +static struct notifier_block drm_typec_event_nb = { + .notifier_call = drm_typec_bus_event, +}; + +static void drm_aux_hpd_typec_dp_bridge_module_exit(void) +{ + bus_unregister_notifier(&typec_bus, &drm_typec_event_nb); +} + +static int __init drm_aux_hpd_typec_dp_bridge_module_init(void) +{ + bus_register_notifier(&typec_bus, &drm_typec_event_nb); + + return 0; +} + +module_init(drm_aux_hpd_typec_dp_bridge_module_init); +module_exit(drm_aux_hpd_typec_dp_bridge_module_exit); + +MODULE_DESCRIPTION("DRM TYPEC DP HPD BRIDGE"); +MODULE_LICENSE("GPL"); -- 2.51.1