From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtpbgeu2.qq.com (smtpbgeu2.qq.com [18.194.254.142]) (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 5EAC333263F for ; Thu, 30 Jul 2026 01:35:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=18.194.254.142 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785375324; cv=none; b=pLd66oYL1sQQb2SUOIXIcOxiErnPBCaDTyFItAY76Fzfp1V9zZ//TKpKRu0BWcicw2wE54s75WkudVtIWBPKeC0EqnYKpjAtuEDs4CIKH7YeGnTZpUByCG+6/JLOdr3FHsmSKtS7bOMfta1XbWXPn/8MfzAJmSXqZdecbtp5hbw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785375324; c=relaxed/simple; bh=///koveLgSYQ3co5Rva11qmxtNoHRf76E85yHsSEBGA=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References; b=I8S5B85EeuzbSG/hV+5e3WLzdGCxeTkQCkJM3/BuZxyR3j806pn7lxldPeDbK7+U2ieO5EgELM8iCE6pzfsphJPlRDq5xRUzgGjDdbmKjYWDMfG/PEijo0HJ0q47P4XmKmGl5AJCzU2OhjN4qHQxEF/ed7qgQQvHsNy7lB5CUzk= 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=Q9MK5VZU; arc=none smtp.client-ip=18.194.254.142 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="Q9MK5VZU" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=airkyi.com; s=altu2504; t=1785375251; bh=43+X27qI/TbPuXwMFgfhd3B71pHWvOwE8wu/TMq6zqY=; h=From:To:Subject:Date:Message-Id; b=Q9MK5VZU34zjg+oOHYmoQVyYqLs55B/WN+jxlN0PCBYe0g//Lb4SP8bJceTwgEXvJ zH0hLLe+I/otggQ+07mtbXdfxy4Gixd2mzEK5v5rkmJt7VtqjIh1EoxHOqUv1pmt8w WATGuK92riA4v0S8UL50teB4sOt+t1iRbVSE31CQ= X-QQ-mid: esmtpgz16t1785375250t19b9e41f X-QQ-Originating-IP: dTfTdJtp/NTG1QBfdY8GFurBKpZo3du5oXip7OFw00A= Received: from DESKTOP-8BT1A2O.localdomain ( [61.154.14.86]) by bizesmtp.qq.com (ESMTP) with id ; Thu, 30 Jul 2026 09:34:02 +0800 (CST) X-QQ-SSF: 0000000000000000000000000000000 X-QQ-GoodBg: 0 X-BIZMAIL-ID: 12002367343437877311 From: Chaoyi Chen To: Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Luca Ceresoli , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Sandy Huang , =?UTF-8?q?Heiko=20St=C3=BCbner?= , Andy Yan , Vinod Koul , Chaoyi Chen , Sebastian Reichel , Nicolas Frattaroli , Heikki Krogerus Cc: linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, linux-phy@lists.infradead.org Subject: [PATCH v5 1/6] drm/bridge: Implement generic USB Type-C DP HPD bridge Date: Thu, 30 Jul 2026 09:33:44 +0800 Message-Id: <20260730013349.51-2-kernel@airkyi.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20260730013349.51-1-kernel@airkyi.com> References: <20260730013349.51-1-kernel@airkyi.com> X-QQ-SENDSIZE: 520 Feedback-ID: esmtpgz:airkyi.com:qybglogicsvrgz:qybglogicsvrgz6b-0 X-QQ-XMAILINFO: MB5+LsFw85NoydBFfA2/oqOn3niG02j2mE1z+W+Bc5ZAk05yLepVPVOQ IR0biSq5blFIgP9I9R7djSwe8YDJTSbDFuT14Y4MgGAUrJlVXJ7THhkf1E40HOaZiAaSiRQ VMtqL0MHuf6G8gkAm9yOiCAq3gI8ryyTBJandvt38IojQi/uXvJS1Gy9k6xrOIPQGw0DY7u b1PMSUL0T2DQUTpvb4DQ49AKns03teWBbwWlMZ+hZDqF9nYcTwVBeMeYpm4YtXtt0ZbmoHZ IzMxtjk2m9+FzAk4LI+xBq+YIs/Gwj9r6hJ2XalNmvD7IR0bqkl05b7T3KFfDLpiM0lGMBg UjcyAPiV4GuvIdjdSgGs0mlHEZ1b7m/stBRoCGK0z0Qx8/PRi+5yOMeGzL2RSFMT1lhbvnU S7uJfJ38hPAIp+caBvG2QG2ZlbyZffYCXB2EaAe4nAAY5L51PJBveRMNyg47o8kAbsoDfuU 4cLAcZeRulJu/sjSMX82PFKxSP1A7Z9Z2qmCdoPbBIA2WDLjNIshT7Qkw7gTpTb+PenxDV2 KNBXE7d6lGih9TQJps4s+kNCpsBECXHTpr8XPAeH4rbFVZPOksRrTBHdCQRNz1WBgYolS1/ uRZFD8/7M1RngUHq/x9mSA5cIRJ3PO5IKUSjjhHWefBKf/5Spc09s8EE+4dHZic7sHFsEJs tj+2n4nLGO+m1OE9cC3OZHwLVkHlDm1nD+by+yWBW0cBIvjbHZuIEsBv81wOlQdQStnHKOY anR2SJrNKMFywiIcdptIlkwEZK6DuqShbrjzbCYBwnZn/9CLvGaHZoscOkgkQoB1EH7HV2r dbTKB+GASfvLCW+foMGe1MVEt7I9//CTWidiSVNe04o6csLsT202X8oGOKT/h7s3TLZxyuZ uM8llwnhziNHmNNkqfma5VyTTFB/9hc1Rx2NMjaZDi4F+bBABzTejVbq69e02USXNnu+Ss8 AT84X/ECS/8SgMsp8Dfz3kfy6I7k9aDaEzdZLOOfDEqjC0Oz6imQObmNWMDpk5OTbfgZyPo PNnbQdb9XWHGOEwe/23vzkA5SX8wLraUnw489piXqfuW3ZsafNsg8RXp5a730= X-QQ-XMRINFO: NS+P29fieYNwqS3WCnRCOn9D1NpZuCnCRA== X-QQ-RECHKSPAM: 0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: 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 Reviewed-by: Nicolas Frattaroli --- (no changes since v5) Changes in v4: - Scan the entire typec_bus and attempt to register the hpd bridge, so as not to miss devices that were already added during initialization. (no changes since v3) Changes in v2: - Add copyright text. - Remove useless goto. --- drivers/gpu/drm/bridge/Kconfig | 10 +++ drivers/gpu/drm/bridge/Makefile | 1 + .../gpu/drm/bridge/aux-hpd-typec-dp-bridge.c | 64 +++++++++++++++++++ 3 files changed, 75 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 4a57d49b4c6d..9739b2a19758 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 15cc821d85b7..d88a9e1ccc9a 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..43af3ea20f20 --- /dev/null +++ b/drivers/gpu/drm/bridge/aux-hpd-typec-dp-bridge.c @@ -0,0 +1,64 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2026 Rockchip Electronics Co., Ltd. + * + * Author: Chaoyi Chen + */ +#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) + return NOTIFY_OK; + + /* + * 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)); + + return NOTIFY_OK; +} + +static struct notifier_block drm_typec_event_nb = { + .notifier_call = drm_typec_bus_event, +}; + +static int check_device_already_added(struct device *dev, void *data) +{ + drm_typec_bus_event(NULL, BUS_NOTIFY_ADD_DEVICE, dev); + return 0; +} + +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); + /* + * Before module initialization, some devices may have already been added. + * Register the HPD bridge for these devices. + */ + bus_for_each_dev(&typec_bus, NULL, NULL, check_device_already_added); + return 0; +} + +module_init(drm_aux_hpd_typec_dp_bridge_module_init); +module_exit(drm_aux_hpd_typec_dp_bridge_module_exit); + +MODULE_AUTHOR("Chaoyi Chen "); +MODULE_DESCRIPTION("DRM TYPEC DP HPD BRIDGE"); +MODULE_LICENSE("GPL"); -- 2.53.0