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 6921BD4A5F4 for ; Mon, 19 Jan 2026 07:36:36 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id B03A310E37C; Mon, 19 Jan 2026 07:36:35 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (1024-bit key; unprotected) header.d=airkyi.com header.i=@airkyi.com header.b="EHdZYKlI"; dkim-atps=neutral Received: from smtp-usa2.onexmail.com (smtp-usa2.onexmail.com [35.173.142.173]) by gabe.freedesktop.org (Postfix) with ESMTPS id 5C47110E37C for ; Mon, 19 Jan 2026 07:36:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=airkyi.com; s=altu2504; t=1768808173; bh=OToeNz4t2oXNHYHV6Pu5IF6zpl5lN3hD9z93ek1ZgZE=; h=From:To:Subject:Date:Message-Id; b=EHdZYKlIwvJPzgeuHzTkDhHljyMBILjksEiWvm0SnKZLmM+i9+3kXTUsJ1B9nOPO4 9P8QQTDNZZtK3beAes3RtafAf/8Cc/o47ug/x+WwODww1/f8onKvCj95v+xRlpD7LZ hURse9KjfK0a3ZgaHz+pOus5TWipc2nTttd7ZwZI= 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: MpO6L0LObisW8Yg5hLugK0yDZFBsBGtj4cPe6Y73tqqyvJWLAF/sn5jj ylz34Sp8F02sUm4dHwcu0+VFl/HZ4qG0PptTbIFvXa0HejnVM6yUrC+IC1yXizZeIS3GrIW bLcWrOxrMu1NZnH6pqwu4oeUDq/nToD8c0+p3+JpqoWDImaCGnxCAN1GJa5r3pl8VJBW/Tr I87HVW2VgK7jUkIge+ZaBmzRM/ByDMemGj20UFvfF+SLJLskIZQcV2AkdGVxzNYm31K/ruI +A4qgwuQtOa7UN5zSiGy3+7D6hMGK3w98hGgjwJipXR7Ggb+tzuppnjnX6Es8+rTFgwKgXn dlATZawxBFJN/E8bOwv3sXm1fluXCnSOn6xvjvumXTy/eS5jBZbnWolphv9ngrwx5skqkEW 4Ke9i51qam8B+PmAS6Hli6P41NgFk+0L2UO1TDEk1NTL8rjuoGkLKo2u2w4Zd0wA0FH7Ezf jV/O8UQG+UydkdpemZPB6ruOkYUcMcQUX6t5ykTwGn/8Ehgj1XN0bTLX2wt2Cn4GIu76XUe USWKYwnIBU2EqbJkF816AsgTq46lln8RoKPD6Qa3xOsF+PYOPzpoLf2Kh350gDk5Sauhwbn tPswknTHN4Z/BeweD+FUFCXImk0AxAIJ1o4el4LsHsMk3dPhieGyh7yXxopQfOwtf+4KPC2 bxnGqH5C4TDeU1mCblvrdEXeZBiisuJJPkRiiO6BqlO2lhkaBvjQSISjSCb9+d+ZkO1LOoS +ugVIffPi9MdG5PrjR5bsQyDuYNY4pqYzN92BUJpql9wp/w97bf6WUdkVTk7kJm4jg11bk5 QMPwk8QX7Nwkx2BTJC43zYxUtc9j4PJPbiIVZKQwgndj+BTqnZshnV0FOoGLEEyaN8RmOei g57OhbzyGYKxiHnfktu2y44YNkPFSAcYalvzcDJM4imLvatEEh46h1+T4pKNe1w+u/WWw++ dH1rt7JANact5oepw49Nn78ywoyrDIzy27md2lx4YEBCl7arh5IxCAQAFayK9/iPTbLSjAG tHT0BDqg== X-QQ-XMRINFO: MSVp+SPm3vtSI1QTLgDHQqIV1w2oNKDqfg== X-QQ-RECHKSPAM: 0 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" 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