From mboxrd@z Thu Jan 1 00:00:00 1970 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 221CB3D3481 for ; Mon, 27 Jul 2026 06:44:50 +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=1785134694; cv=none; b=L1EgdYzTYlX4z192l3PLstMJBpIQmsq1V7hb4Ki/A9frUIQtqbj4e8t8w+fbawnmDaZBbr3RLJqNCH6g6QSL9VZVpC2UG7SD3/WvjCISTaCRlnWlq5MPFI1qa15ZwfOgPbhYR0KCbVOagNI9dAKd0IvkspRErm2rWN4GfGaBMSk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785134694; c=relaxed/simple; bh=UrSCFyN+ZyJEr3144rOkS9tvjOiOmkZjGRNtD1iZYKI=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References; b=FJTJsYVssK5UYepAXh4a/EGZrL+d5dxUBjd8JNbV+txOFyl4BFKsUgMLPaY/NriyMSaff36MTZ0/wJasjB5G29pSx/C/e5Bq+z3UcMasaXwqoGTEJCKBVpYeLXu4QIVcj09g8oawAZgcqMmAEqktcmclipmIGrT3QTH3fZuZ0T0= 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=rnWLpWum; 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="rnWLpWum" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=airkyi.com; s=altu2504; t=1785134675; bh=lOi4lTfSYq4gyPLa7vfMltbH7D8s9RIXzOfoY4QjKek=; h=From:To:Subject:Date:Message-Id; b=rnWLpWump30kpP2BCBUvipUS6uYpy+/N3kv7hPoZGm6Tdjgh3/5CeKBt73XSIbYsK AP/1vg4lblpi3322cDgzr388sCnDLkJk3vIxp3PKFkRGIhmfYtqwJRfM1q+ev/rl9m 74ryw0g7sDeABYLVCm5ibC77UcrbzN/ITC22Koz4= X-QQ-mid: esmtpgz10t1785134674t43ebba75 X-QQ-Originating-IP: r+MMC0cunT2/z7QaMAt4ARvLvBHI+zAjN8++dkZZD8Q= Received: from DESKTOP-8BT1A2O.localdomain ( [61.154.14.86]) by bizesmtp.qq.com (ESMTP) with id ; Mon, 27 Jul 2026 14:44:16 +0800 (CST) X-QQ-SSF: 0000000000000000000000000000000 X-QQ-GoodBg: 0 X-BIZMAIL-ID: 13742035455192945116 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 v4 1/5] drm/bridge: Implement generic USB Type-C DP HPD bridge Date: Mon, 27 Jul 2026 14:44:04 +0800 Message-Id: <20260727064408.101-2-kernel@airkyi.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20260727064408.101-1-kernel@airkyi.com> References: <20260727064408.101-1-kernel@airkyi.com> X-QQ-SENDSIZE: 520 Feedback-ID: esmtpgz:airkyi.com:qybglogicsvrgz:qybglogicsvrgz6b-0 X-QQ-XMAILINFO: MIXpHopat2IaDqYVhR+iMDxsSKO2UC9RjZYb/RBdNVBMVQR54HttDqKf 3bJ4O+B0iZeGOe74IrS522TfpaLB/1hp6dKnPX+j6tpyDlpRXhXghHHscpemO1lScVRcyAl JvRuyKW9tjJ1Jq9+Ocq7Rz3AdPTtTCQMJAfaENzui9D9BdGiQYE75FwhwPT67hZxjlO6oES n5oy3SHSS1xxvmm0N5iy/by1F9qatDCqlPz2UQGtj6VWzBQE5JATFhgeUkYuFgjkmq6tnG4 AhJ0+zexYwVpLrvJlkCotARqhJHx3BoafW+oQMEtzmm27Rd8XnanZJ0yYkUkKzjfGwCvDir XUV2FBv0ekOOBlMWByvaqqBJGHHd7C5xBVUn02mL3LTGu6VyPwDjwfIvEdGG/sFZE7Qodv7 XZUV5n6D1Y1cSKXGxpPD+3NKg3iClfXmcaw4lmPw03ny8iIL9VcO5SkTUhVp6MhvlzIVaqV 8+hpaJhA9RZpXapfn3o7nY7NhN4G6UOfd7pyJgoy6l58vZ3DR1dyzbq8DGC0I+k9AZSIYzZ z5ilkV4MGMM39MAkNh5EkxdYTufCfTL82qQRJvx7qtKjQJ/SKPSuhAGFUqar+TDeUa+EHXo OR+ozfrEKiftT0giRKgFpgCWDUyuZvYCIdsYj2Hk92U9g8osZavIrPz2yAxxw7Z95sYXr+2 kZdOBz153BJ8X8uILBpGE+faeCo/ZpmtHUrAKTIH4Cow1YN2fj4toV3CbCX+jnbKy2DCO0K AMva1EjNYKljj79dbvIqHqawaH0Bnbh3No7RirtjODJPA0RYnfH3vjfllprzJDmLn1QgV9R sKjmnn+2/AQhOw+H9bpRvfZrWkEDCmz9wHWsevKgCQ1ZNfZMBrvPPxo/4cQH4x2Zmt5a3Bq AYGQnBEKx8iYqjgb8K3bp6yBAK1rQ8ilFerqF/F68KeHIHpAB/w70QZeOF2QBNyT+HFQf3F GIrp+qgYLs8Q27P8hmVoFQC75RshtEdR9PWZ/75ueCTj3p4bZriLZTxnJEwZR0+mTG9sgVL +BWy9p+26+3oqZXH7UylYu+1+T4P4= X-QQ-XMRINFO: MSVp+SPm3vtSI1QTLgDHQqIV1w2oNKDqfg== 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 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