From nobody Sat Feb 7 07:24:17 2026 Received: from smtpbguseast1.qq.com (smtpbguseast1.qq.com [54.204.34.129]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C1C3FD531; Mon, 19 Jan 2026 07:31:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=54.204.34.129 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768807905; cv=none; b=ANilEigZgwncsn6Bq8uJxSZNqbju4AoTUwZAKNvYQUthiKhPBuceOe1Fs0QmZGcGW9lDJVZpQkh0MnA0X0qVlNKYQyRGQ86U7oDKEseVLHzKycdrm2xSwmktXhulm2BzOlWGev7ucG2RZgSveqTaQGH7X3sxhU2l4Y7xsjB8grw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768807905; c=relaxed/simple; bh=xUSsOkydNp3uq6fFe9PAhbwC4yfTInu6czge2AyPPYU=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References; b=aUEIjTJ5v7/Wvq1cG1OOTJfq+yvHcTCN8fDEgYZlbm6qdMNwCOFCu96NLOSTTQNXFMmZ7ZMKB4IG4Sx6riHLACwsHBvUHnUonyFYf1yqxsfwPXyIr3Urc59IOtf6IdtXmoIT7v1t+w4Er4vOt/uYKpahJfB4dYONm7sgQyqKFOg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=airkyi.com; spf=pass smtp.mailfrom=airkyi.com; dkim=pass (1024-bit key) header.d=airkyi.com header.i=@airkyi.com header.b=Uod0nkml; arc=none smtp.client-ip=54.204.34.129 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=airkyi.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=airkyi.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=airkyi.com header.i=@airkyi.com header.b="Uod0nkml" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=airkyi.com; s=altu2504; t=1768807881; bh=OToeNz4t2oXNHYHV6Pu5IF6zpl5lN3hD9z93ek1ZgZE=; h=From:To:Subject:Date:Message-Id; b=Uod0nkmlqrXZXPZM1MWByTE0PC8pIyG5YgyEI/z17ut/xvkX9m/SV/mq9el3oCB4S Azv0JWd7g5IzWtE+MksM3y4939LHss4DBhOt8iAzb+16g5D2NH1Jv3H5Ej3oO4C5K+ LWhOvLGWcVtBhXdrXBFayjLPIwMfj1TekSEbqVoQ= 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: OWPUhxQsoeAVwkVaQIEGSKwwgKCxK/fD5g== X-QQ-RECHKSPAM: 0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" 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. =20 +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 =20 diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makef= ile 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-$(CONFIG_DRM_AUX_BRIDGE) +=3D aux-bridge.o obj-$(CONFIG_DRM_AUX_HPD_BRIDGE) +=3D aux-hpd-bridge.o +obj-$(CONFIG_DRM_AUX_HPD_TYPEC_BRIDGE) +=3D aux-hpd-typec-dp-bridge.o obj-$(CONFIG_DRM_CHIPONE_ICN6211) +=3D chipone-icn6211.o obj-$(CONFIG_DRM_CHRONTEL_CH7033) +=3D chrontel-ch7033.o obj-$(CONFIG_DRM_CROS_EC_ANX7688) +=3D 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 =3D (struct device *)data; + struct typec_altmode *alt =3D to_typec_altmode(dev); + + if (action !=3D 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 =3D=3D 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 =3D { + .notifier_call =3D 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"); --=20 2.51.1