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Thu, 04 Dec 2025 14:31:30 +0800 (CST) X-QQ-SSF: 0000000000000000000000000000000 X-QQ-GoodBg: 0 X-BIZMAIL-ID: 9830896031001290684 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: [RESEND PATCH v11 03/11] drm/bridge: Implement generic USB Type-C DP HPD bridge Date: Thu, 4 Dec 2025 14:31:01 +0800 Message-Id: <20251204063109.104-4-kernel@airkyi.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20251204063109.104-1-kernel@airkyi.com> References: <20251204063109.104-1-kernel@airkyi.com> X-QQ-SENDSIZE: 520 Feedback-ID: esmtpsz:airkyi.com:qybglogicsvrgz:qybglogicsvrgz6b-0 X-QQ-XMAILINFO: OCzxluqIaPHWaE3FMcAg8ojbsDmsMtBFoQudEX3P7mvMCeV8G7JBLpTa hGYydDbw9jkuKual2t8lXq9Gf8d3VUG+FSUNgxeoBTJGVncxKurmQ82M7FNnDQHmWv31/YO GgdxSuqf95lkGdT3sbhBfNWXm0ESIF1JTEMP18Lv/H2anX5r7yQUuavyDLHy4wS12zENdkq cewnBYwd1+VhgEAtzwVYcH+p7MyaCnHaybi/yGQX//RsutU4R6ETMC2E3hTNIdz4IJ6D1dx 0+2QJWWzydR/8dI7zaCb/swF0s/D7ZySvw5sZj06wAXJcAHFzXFzvnQJK1uZKiB8TxL0P09 W4cOb1fSKXr3AcWW1Bi6hbUgCHo5tBiy6sQ1FysSXY2y2WqrxrnrqponnSG5qnQFc1NTzgv Y1U6DWrFHOJIwZvT4rBokj56N2Ek5uYEC5Y345HceUbqttqM3HIM3q2eV8JGYvCfr7kIvjG /3HBd+Pv7+mYmDT6x31l9Yh/DIXNPynxhoNYLL/ydrzvit00hIdWK+wxlqKYskx1iaB6cIj LqCP/C9Wu9gGxIxpc/D++aJcDpaIy2l1uHra9nRcEn1PfclQSvoM6/vknVMUkuVd4qejfQ8 7XU26BzNh9QqUnzsFiM+ZwbRu1WhM5N1C6HAD878ZVu+XExXaj0ZWzLHQSdRpCPElwsnusr 5Ucn4uBln8ByvV+E4+IHDPeOmuFdkll2zK5+UMEbMAc7ixrAlrfSY+HsJA1n8fLpK2TEVrE HHWUDMDoIaeuAEGWgI3hvxn5e4n7+vd291osY/cOYM0ne2klID28J0Bt85nCi1PPCpFSjEk FlVaoQa9SkZpJCldxKG2//8XHpFbB0hPucmI7BheObRp0tccbd5md9OGnJUYpDeO4Lut6wi KRlDgmWA/pZIfaW856R88eBiZa/glVIJADQBJHYZCFgkDPnjU4HPNdLctHEnd8xXi3YcPZl O/DquZ4junyyan98LuWv4kMpYg/U34+6Mg15sBlvvA01D9jnnU1/6IBSMBXMfBwSJpbPEkn uN0A8L85AO5+ItuxYSxubFoMmvx68= X-QQ-XMRINFO: NI4Ajvh11aEj8Xl/2s1/T8w= 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 --- 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 | 51 +++++++++++++++++++ 3 files changed, 62 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..94be3d5f69e9 --- /dev/null +++ b/drivers/gpu/drm/bridge/aux-hpd-typec-dp-bridge.c @@ -0,0 +1,51 @@ +// 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; + + if (is_typec_partner_altmode(&alt->dev) || alt->svid !=3D USB_TYPEC_DP_SI= D) + goto done; + + /* + * alt->dev.parent->parent : USB-C controller device + * alt->dev.parent : USB-C connector device + */ + 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