From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtpbguseast2.qq.com (smtpbguseast2.qq.com [54.204.34.130]) (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 E15A542049C for ; Tue, 4 Aug 2026 07:08:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=54.204.34.130 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785827304; cv=none; b=qW2hi9ArgZP789jm3r3MmHUiNgOfmxdnfzQQvMnuQ0/LXJHwKbDBVfdO9ItAMkZQ8S1eKfPYYydHe7jeTN7X02/IiMmZZJNOgZ9uYdmeS2Cf6VRFflTPs5jWkDVeJ3zITUET57DdZmPvfx0Bpf7hRdxIAaThSlroOQj7gc+sOBk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785827304; c=relaxed/simple; bh=K/757+Xj0f49RBIji9eGvyrhKhuwaqAYgLFSnBCNHpI=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References; b=cjFFCFBIW64ib9tOy35FlDXh77yPvOGDgsfdbGfdT+BlieIZMLFw1AkI0cbgY8dgJvHnWa8KyElc+QjGCloD5F+t0WuCmKeadSg1o/dZNWVX/mA5n11wNIcbyzZvbUGs7crigATMBq2/jvRnSq5PMkQugLKfKLxJiNy2g64jWUw= 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=MY4uZyhS; arc=none smtp.client-ip=54.204.34.130 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="MY4uZyhS" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=airkyi.com; s=altu2504; t=1785827283; bh=fH6u5h4xpDz1C8ZdGsVLKRX5KFIbcVXaaz97fyPxnmA=; h=From:To:Subject:Date:Message-Id; b=MY4uZyhSi0TWs9wHY7ElZgdIRNi+oTTYdxvP4wULKub1RCvUu9Vq3YlGTWUJBHfz0 5VvG7zFNCjT4gOZV4/yCg5CID/81+gl+6PBJ6ULfu1AaMgBEwnwqPKfYd5tnvRg74j jz0cbtw4haW5KiiBs2mAh76AGyTIg0JscpFaGAt8= X-QQ-mid: esmtpsz19t1785827282t0f0d09eb X-QQ-Originating-IP: UacgRZcbWfS4e/DkD9DWOSe5Fguk5twcxO1gmhIpdfM= Received: from DESKTOP-8BT1A2O.localdomain ( [61.154.14.86]) by bizesmtp.qq.com (ESMTP) with id ; Tue, 04 Aug 2026 15:07:58 +0800 (CST) X-QQ-SSF: 0000000000000000000000000000000 X-QQ-GoodBg: 0 X-BIZMAIL-ID: 1834984709830205392 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 v6 2/7] drm/bridge: Implement generic USB Type-C DP HPD bridge Date: Tue, 4 Aug 2026 15:07:25 +0800 Message-Id: <20260804070730.68-3-kernel@airkyi.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20260804070730.68-1-kernel@airkyi.com> References: <20260804070730.68-1-kernel@airkyi.com> X-QQ-SENDSIZE: 520 Feedback-ID: esmtpsz:airkyi.com:qybglogicsvrgz:qybglogicsvrgz6b-0 X-QQ-XMAILINFO: NRLj+a+1JRyJfsg4lbGBEPFbqVZcVfOunMNL29MAr9VNNLXA5jHkmjey z5N06wXoDOpIp5jQqhYvDXNHe+kdyx2WRIQXN/ST0fCQozkwxvpxSjf4R4oUFrSzcU7qoEC 3jCEKc/py9ZwkFDggWuGENqJzA8cguCLEvHvE7LA1XeSKU6ZYnE27mWxCCFIqD/oDP3SIPi ED8s/PvibD8SoYRVfDKv0yI4Z+uDTS2BUMQxqIWiU7yuFg5D7f+jZb3jnFDkS4ML+rR6TQ1 KzgeF0x1EQVa8lKp6iCOlEjE3bw+T9IBoUyn0lBh50z5D8I8PgbJkAYAzAeGWrO7HRRhRMf dx/6QB54YvhRJWhMEslIi9fOqksakhGP6m5HEdVPdn8pBmM6wtEWivrSiT8NMvFXoB2T5MK LffAmEhsPalGUOYICE+R+OoJ66MVTRnf6F7L3eD86diB8KMyEzn09SyaRhcMgtVe0YPjHrf spPeTSj0Slzl5aRpSr33ToLjv33f1Y5NOxX6GbsfAq/oNLsBFK5E7QggTMmXkeMAm9tUKpO GEWFp+iPgzgxK+BMMci3TQYwIFqL5YhoUAr3Ope9xcbwjLIGYVXJA6ZAAN5Q7uznXjIAiOv pYa5nrUb0hXSUZU5yFcNQL8c77OKByK+4yKWBMyxHH7zzdWlh17T38lwfSM0HcYdgD/Elif Kj3WhpxVZyNQWUShfvNPocW4jK0ds/wTn9jLATbUi6laI6zJX7Z8Hc7MtGKEXR4tFGEFnWe VxF5HUh7M2LNlwNnoA3O1uR0aHYPTiMqDMyBXN0xexlUIteA7ONZyumJSd3ASAl0UaOhqdi 3IIWliDcMxe12qzqK/78cG7xpJsnlK/BFO/7t5ckISxhJClKome192m+/AbShJLg9OCO6u5 5GSvij76+F1HwRqlMfCdNljZnYRDm6r1vGlUaEtMOf1smk3BSZ/XeYnsbUyrV88IVO/CYQZ dqMfZhv/ycIZjsluSNFmWZGPtgdzol8tbGpNmNN82Td506HBj9WegEd0eMznxW+4ZU2b/NY b05Uhpqj9DcBFZSD0QqviZ60/iYoxQZec7M2kmWc1+UN5MVBNUuHdEcg6467U= 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 --- Changes in v6: - Avoid duplicate registration of the same DisplayPort HPD bridge. (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 | 67 +++++++++++++++++++ 3 files changed, 78 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..682bc192e093 --- /dev/null +++ b/drivers/gpu/drm/bridge/aux-hpd-typec-dp-bridge.c @@ -0,0 +1,67 @@ +// 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); + struct device_node *np; + + 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) { + np = to_of_node(alt->dev.parent->fwnode); + if (!drm_dev_has_dp_hpd_bridge(alt->dev.parent->parent, np)) + drm_dp_hpd_bridge_register(alt->dev.parent->parent, np); + } + + 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