From: Chaoyi Chen <chaoyi.chen@rock-chips.com>
Several USB-C controller drivers have already implemented the DP HPD
bridge function provided by aux-hpd-bridge.c, but there are still
some USB-C controller driver that have not yet implemented it.
This patch implements a generic DP HPD bridge based on aux-hpd-bridge.c,
so that other USB-C controller drivers don't need to implement it again.
Signed-off-by: Chaoyi Chen <chaoyi.chen@rock-chips.com>
---
Changes in v8:
- Merge generic DP HPD bridge into one module.
drivers/gpu/drm/bridge/Kconfig | 5 +-
drivers/gpu/drm/bridge/Makefile | 8 +++-
drivers/gpu/drm/bridge/aux-hpd-bridge.c | 23 ++++++++-
drivers/gpu/drm/bridge/aux-hpd-bridge.h | 13 +++++
.../gpu/drm/bridge/aux-hpd-typec-dp-bridge.c | 47 +++++++++++++++++++
5 files changed, 93 insertions(+), 3 deletions(-)
create mode 100644 drivers/gpu/drm/bridge/aux-hpd-bridge.h
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..17257b223a28 100644
--- a/drivers/gpu/drm/bridge/Kconfig
+++ b/drivers/gpu/drm/bridge/Kconfig
@@ -23,13 +23,16 @@ config DRM_AUX_BRIDGE
build bridges chain.
config DRM_AUX_HPD_BRIDGE
- tristate
+ tristate "AUX HPD bridge support"
depends on DRM_BRIDGE && OF
select AUXILIARY_BUS
help
Simple bridge that terminates the bridge chain and provides HPD
support.
+ Specifically, if you want a default Type-C DisplayPort HPD bridge for
+ each port of the Type-C controller, say Y here.
+
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..2998937444bc 100644
--- a/drivers/gpu/drm/bridge/Makefile
+++ b/drivers/gpu/drm/bridge/Makefile
@@ -1,6 +1,12 @@
# SPDX-License-Identifier: GPL-2.0
obj-$(CONFIG_DRM_AUX_BRIDGE) += aux-bridge.o
-obj-$(CONFIG_DRM_AUX_HPD_BRIDGE) += aux-hpd-bridge.o
+
+hpd-bridge-y := aux-hpd-bridge.o
+ifneq ($(CONFIG_TYPEC),)
+hpd-bridge-y += aux-hpd-typec-dp-bridge.o
+endif
+obj-$(CONFIG_DRM_AUX_HPD_BRIDGE) += hpd-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-bridge.c b/drivers/gpu/drm/bridge/aux-hpd-bridge.c
index 2e9c702c7087..11ad6dc776c7 100644
--- a/drivers/gpu/drm/bridge/aux-hpd-bridge.c
+++ b/drivers/gpu/drm/bridge/aux-hpd-bridge.c
@@ -12,6 +12,8 @@
#include <drm/drm_bridge.h>
#include <drm/bridge/aux-bridge.h>
+#include "aux-hpd-bridge.h"
+
static DEFINE_IDA(drm_aux_hpd_bridge_ida);
struct drm_aux_hpd_bridge_data {
@@ -204,7 +206,26 @@ static struct auxiliary_driver drm_aux_hpd_bridge_drv = {
.id_table = drm_aux_hpd_bridge_table,
.probe = drm_aux_hpd_bridge_probe,
};
-module_auxiliary_driver(drm_aux_hpd_bridge_drv);
+
+static int drm_aux_hpd_bridge_mod_init(void)
+{
+ int ret;
+
+ ret = auxiliary_driver_register(&drm_aux_hpd_bridge_drv);
+ if (ret)
+ return ret;
+
+ return drm_aux_hpd_typec_dp_bridge_init();
+}
+
+static void drm_aux_hpd_bridge_mod_exit(void)
+{
+ drm_aux_hpd_typec_dp_bridge_exit();
+ auxiliary_driver_unregister(&drm_aux_hpd_bridge_drv);
+}
+
+module_init(drm_aux_hpd_bridge_mod_init);
+module_exit(drm_aux_hpd_bridge_mod_exit);
MODULE_AUTHOR("Dmitry Baryshkov <dmitry.baryshkov@linaro.org>");
MODULE_DESCRIPTION("DRM HPD bridge");
diff --git a/drivers/gpu/drm/bridge/aux-hpd-bridge.h b/drivers/gpu/drm/bridge/aux-hpd-bridge.h
new file mode 100644
index 000000000000..69364731c2f1
--- /dev/null
+++ b/drivers/gpu/drm/bridge/aux-hpd-bridge.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef AUX_HPD_BRIDGE_H
+#define AUX_HPD_BRIDGE_H
+
+#if IS_REACHABLE(CONFIG_TYPEC)
+int drm_aux_hpd_typec_dp_bridge_init(void);
+void drm_aux_hpd_typec_dp_bridge_exit(void);
+#else
+static inline int drm_aux_hpd_typec_dp_bridge_init(void) { return 0; }
+static inline void drm_aux_hpd_typec_dp_bridge_exit(void) { }
+#endif /* IS_REACHABLE(CONFIG_TYPEC) */
+
+#endif /* AUX_HPD_BRIDGE_H */
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..6f2a1fca0fc5
--- /dev/null
+++ b/drivers/gpu/drm/bridge/aux-hpd-typec-dp-bridge.c
@@ -0,0 +1,47 @@
+// SPDX-License-Identifier: GPL-2.0+
+#include <linux/of.h>
+#include <linux/usb/typec_altmode.h>
+#include <linux/usb/typec_dp.h>
+#include <linux/usb/typec_notify.h>
+
+#include <drm/bridge/aux-bridge.h>
+
+#include "aux-hpd-bridge.h"
+
+#if IS_REACHABLE(CONFIG_TYPEC)
+static int drm_typec_bus_event(struct notifier_block *nb,
+ unsigned long action, void *data)
+{
+ struct typec_altmode *alt = (struct typec_altmode *)data;
+
+ if (action != TYPEC_ALTMODE_REGISTERED)
+ goto done;
+
+ if (is_typec_partner(&alt->dev) || alt->svid != USB_TYPEC_DP_SID)
+ 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 = {
+ .notifier_call = drm_typec_bus_event,
+};
+
+int drm_aux_hpd_typec_dp_bridge_init(void)
+{
+ return typec_altmode_register_notify(&drm_typec_event_nb);
+}
+
+void drm_aux_hpd_typec_dp_bridge_exit(void)
+{
+ typec_altmode_unregister_notify(&drm_typec_event_nb);
+}
+#endif
--
2.49.0On Wed, Oct 29, 2025 at 03:14:28PM +0800, Chaoyi Chen wrote:
> From: Chaoyi Chen <chaoyi.chen@rock-chips.com>
>
> Several USB-C controller drivers have already implemented the DP HPD
> bridge function provided by aux-hpd-bridge.c, but there are still
> some USB-C controller driver that have not yet implemented it.
>
> This patch implements a generic DP HPD bridge based on aux-hpd-bridge.c,
> so that other USB-C controller drivers don't need to implement it again.
This doesn't describe the problem that you are trying to solve.
>
> Signed-off-by: Chaoyi Chen <chaoyi.chen@rock-chips.com>
> ---
>
> Changes in v8:
> - Merge generic DP HPD bridge into one module.
>
> drivers/gpu/drm/bridge/Kconfig | 5 +-
> drivers/gpu/drm/bridge/Makefile | 8 +++-
> drivers/gpu/drm/bridge/aux-hpd-bridge.c | 23 ++++++++-
> drivers/gpu/drm/bridge/aux-hpd-bridge.h | 13 +++++
> .../gpu/drm/bridge/aux-hpd-typec-dp-bridge.c | 47 +++++++++++++++++++
> 5 files changed, 93 insertions(+), 3 deletions(-)
> create mode 100644 drivers/gpu/drm/bridge/aux-hpd-bridge.h
> 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..17257b223a28 100644
> --- a/drivers/gpu/drm/bridge/Kconfig
> +++ b/drivers/gpu/drm/bridge/Kconfig
> @@ -23,13 +23,16 @@ config DRM_AUX_BRIDGE
> build bridges chain.
>
> config DRM_AUX_HPD_BRIDGE
> - tristate
> + tristate "AUX HPD bridge support"
Why? No, this is supposed to be selected by other drivers. Users don't
know an wouldn't know what is this.
> depends on DRM_BRIDGE && OF
> select AUXILIARY_BUS
> help
> Simple bridge that terminates the bridge chain and provides HPD
> support.
>
> + Specifically, if you want a default Type-C DisplayPort HPD bridge for
> + each port of the Type-C controller, say Y here.
> +
> 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..2998937444bc 100644
> --- a/drivers/gpu/drm/bridge/Makefile
> +++ b/drivers/gpu/drm/bridge/Makefile
> @@ -1,6 +1,12 @@
> # SPDX-License-Identifier: GPL-2.0
> obj-$(CONFIG_DRM_AUX_BRIDGE) += aux-bridge.o
> -obj-$(CONFIG_DRM_AUX_HPD_BRIDGE) += aux-hpd-bridge.o
> +
> +hpd-bridge-y := aux-hpd-bridge.o
> +ifneq ($(CONFIG_TYPEC),)
> +hpd-bridge-y += aux-hpd-typec-dp-bridge.o
> +endif
> +obj-$(CONFIG_DRM_AUX_HPD_BRIDGE) += hpd-bridge.o
> +
> obj-$(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-bridge.c b/drivers/gpu/drm/bridge/aux-hpd-bridge.c
> index 2e9c702c7087..11ad6dc776c7 100644
> --- a/drivers/gpu/drm/bridge/aux-hpd-bridge.c
> +++ b/drivers/gpu/drm/bridge/aux-hpd-bridge.c
> @@ -12,6 +12,8 @@
> #include <drm/drm_bridge.h>
> #include <drm/bridge/aux-bridge.h>
>
> +#include "aux-hpd-bridge.h"
> +
> static DEFINE_IDA(drm_aux_hpd_bridge_ida);
>
> struct drm_aux_hpd_bridge_data {
> @@ -204,7 +206,26 @@ static struct auxiliary_driver drm_aux_hpd_bridge_drv = {
> .id_table = drm_aux_hpd_bridge_table,
> .probe = drm_aux_hpd_bridge_probe,
> };
> -module_auxiliary_driver(drm_aux_hpd_bridge_drv);
> +
> +static int drm_aux_hpd_bridge_mod_init(void)
> +{
> + int ret;
> +
> + ret = auxiliary_driver_register(&drm_aux_hpd_bridge_drv);
> + if (ret)
> + return ret;
> +
> + return drm_aux_hpd_typec_dp_bridge_init();
> +}
> +
> +static void drm_aux_hpd_bridge_mod_exit(void)
> +{
> + drm_aux_hpd_typec_dp_bridge_exit();
> + auxiliary_driver_unregister(&drm_aux_hpd_bridge_drv);
> +}
> +
> +module_init(drm_aux_hpd_bridge_mod_init);
> +module_exit(drm_aux_hpd_bridge_mod_exit);
>
> MODULE_AUTHOR("Dmitry Baryshkov <dmitry.baryshkov@linaro.org>");
> MODULE_DESCRIPTION("DRM HPD bridge");
> diff --git a/drivers/gpu/drm/bridge/aux-hpd-bridge.h b/drivers/gpu/drm/bridge/aux-hpd-bridge.h
> new file mode 100644
> index 000000000000..69364731c2f1
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/aux-hpd-bridge.h
> @@ -0,0 +1,13 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +#ifndef AUX_HPD_BRIDGE_H
> +#define AUX_HPD_BRIDGE_H
> +
> +#if IS_REACHABLE(CONFIG_TYPEC)
> +int drm_aux_hpd_typec_dp_bridge_init(void);
> +void drm_aux_hpd_typec_dp_bridge_exit(void);
> +#else
> +static inline int drm_aux_hpd_typec_dp_bridge_init(void) { return 0; }
> +static inline void drm_aux_hpd_typec_dp_bridge_exit(void) { }
> +#endif /* IS_REACHABLE(CONFIG_TYPEC) */
> +
> +#endif /* AUX_HPD_BRIDGE_H */
> 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..6f2a1fca0fc5
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/aux-hpd-typec-dp-bridge.c
> @@ -0,0 +1,47 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +#include <linux/of.h>
> +#include <linux/usb/typec_altmode.h>
> +#include <linux/usb/typec_dp.h>
> +#include <linux/usb/typec_notify.h>
> +
> +#include <drm/bridge/aux-bridge.h>
> +
> +#include "aux-hpd-bridge.h"
> +
> +#if IS_REACHABLE(CONFIG_TYPEC)
> +static int drm_typec_bus_event(struct notifier_block *nb,
> + unsigned long action, void *data)
> +{
This feels like this should be a part of the Type-C subsystem rather
than DRM.
> + struct typec_altmode *alt = (struct typec_altmode *)data;
> +
> + if (action != TYPEC_ALTMODE_REGISTERED)
> + goto done;
> +
> + if (is_typec_partner(&alt->dev) || alt->svid != USB_TYPEC_DP_SID)
> + 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 = {
> + .notifier_call = drm_typec_bus_event,
> +};
> +
> +int drm_aux_hpd_typec_dp_bridge_init(void)
> +{
> + return typec_altmode_register_notify(&drm_typec_event_nb);
> +}
> +
> +void drm_aux_hpd_typec_dp_bridge_exit(void)
> +{
> + typec_altmode_unregister_notify(&drm_typec_event_nb);
> +}
> +#endif
> --
> 2.49.0
>
--
With best wishes
Dmitry
On 11/3/2025 12:00 PM, Dmitry Baryshkov wrote: > On Wed, Oct 29, 2025 at 03:14:28PM +0800, Chaoyi Chen wrote: >> From: Chaoyi Chen <chaoyi.chen@rock-chips.com> >> >> Several USB-C controller drivers have already implemented the DP HPD >> bridge function provided by aux-hpd-bridge.c, but there are still >> some USB-C controller driver that have not yet implemented it. >> >> This patch implements a generic DP HPD bridge based on aux-hpd-bridge.c, >> so that other USB-C controller drivers don't need to implement it again. > This doesn't describe the problem that you are trying to solve. > >> Signed-off-by: Chaoyi Chen <chaoyi.chen@rock-chips.com> >> --- >> >> Changes in v8: >> - Merge generic DP HPD bridge into one module. >> >> drivers/gpu/drm/bridge/Kconfig | 5 +- >> drivers/gpu/drm/bridge/Makefile | 8 +++- >> drivers/gpu/drm/bridge/aux-hpd-bridge.c | 23 ++++++++- >> drivers/gpu/drm/bridge/aux-hpd-bridge.h | 13 +++++ >> .../gpu/drm/bridge/aux-hpd-typec-dp-bridge.c | 47 +++++++++++++++++++ >> 5 files changed, 93 insertions(+), 3 deletions(-) >> create mode 100644 drivers/gpu/drm/bridge/aux-hpd-bridge.h >> 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..17257b223a28 100644 >> --- a/drivers/gpu/drm/bridge/Kconfig >> +++ b/drivers/gpu/drm/bridge/Kconfig >> @@ -23,13 +23,16 @@ config DRM_AUX_BRIDGE >> build bridges chain. >> >> config DRM_AUX_HPD_BRIDGE >> - tristate >> + tristate "AUX HPD bridge support" > Why? No, this is supposed to be selected by other drivers. Users don't > know an wouldn't know what is this. > Sorry, I might have misunderstood you point. In v7, I added a new DRM_AUX_TYPEC_DP_HPD_BRIDGE module to select DRM_AUX_HPD_BRIDGE. This seems to fit the "selected by other drivers" scenario, but I think you might not want to expose any information to the users. And the other one is what Heikki said: +if DRM_AUX_HPD_BRIDGE + +config DRM_AUX_HPD_TYPEC_BRIDGE + tristate + depends on TYPEC || !TYPEC + default TYPEC + +endif /* DRM_AUX_HPD_BRIDGE */ + menu "Display Interface Bridges" depends on DRM && DRM_BRIDGE If I understand correctly, in this scenario we need to select DRM_AUX_HPD_BRIDGE in the DP driver. When Type-C is available, DRM_AUX_HPD_TYPEC_BRIDGE will be selected automatically. Is the method mentioned by Heikki what you want? Thank you. -- Best, Chaoyi
On 11/3/2025 12:00 PM, Dmitry Baryshkov wrote:
> On Wed, Oct 29, 2025 at 03:14:28PM +0800, Chaoyi Chen wrote:
>> From: Chaoyi Chen <chaoyi.chen@rock-chips.com>
>>
>> Several USB-C controller drivers have already implemented the DP HPD
>> bridge function provided by aux-hpd-bridge.c, but there are still
>> some USB-C controller driver that have not yet implemented it.
>>
>> This patch implements a generic DP HPD bridge based on aux-hpd-bridge.c,
>> so that other USB-C controller drivers don't need to implement it again.
> This doesn't describe the problem that you are trying to solve.
I'll try to describe the information more accurately. Thank you.
>
>> Signed-off-by: Chaoyi Chen <chaoyi.chen@rock-chips.com>
>> ---
>>
>> Changes in v8:
>> - Merge generic DP HPD bridge into one module.
>>
>> drivers/gpu/drm/bridge/Kconfig | 5 +-
>> drivers/gpu/drm/bridge/Makefile | 8 +++-
>> drivers/gpu/drm/bridge/aux-hpd-bridge.c | 23 ++++++++-
>> drivers/gpu/drm/bridge/aux-hpd-bridge.h | 13 +++++
>> .../gpu/drm/bridge/aux-hpd-typec-dp-bridge.c | 47 +++++++++++++++++++
>> 5 files changed, 93 insertions(+), 3 deletions(-)
>> create mode 100644 drivers/gpu/drm/bridge/aux-hpd-bridge.h
>> 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..17257b223a28 100644
>> --- a/drivers/gpu/drm/bridge/Kconfig
>> +++ b/drivers/gpu/drm/bridge/Kconfig
>> @@ -23,13 +23,16 @@ config DRM_AUX_BRIDGE
>> build bridges chain.
>>
>> config DRM_AUX_HPD_BRIDGE
>> - tristate
>> + tristate "AUX HPD bridge support"
> Why? No, this is supposed to be selected by other drivers. Users don't
> know an wouldn't know what is this.
In v7, I implemented an additional module for selecting this option. But Heikki believes that it would be better to merge the two modules into one.
>
>> depends on DRM_BRIDGE && OF
>> select AUXILIARY_BUS
>> help
>> Simple bridge that terminates the bridge chain and provides HPD
>> support.
>>
>> + Specifically, if you want a default Type-C DisplayPort HPD bridge for
>> + each port of the Type-C controller, say Y here.
>> +
>> 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..2998937444bc 100644
>> --- a/drivers/gpu/drm/bridge/Makefile
>> +++ b/drivers/gpu/drm/bridge/Makefile
>> @@ -1,6 +1,12 @@
>> # SPDX-License-Identifier: GPL-2.0
>> obj-$(CONFIG_DRM_AUX_BRIDGE) += aux-bridge.o
>> -obj-$(CONFIG_DRM_AUX_HPD_BRIDGE) += aux-hpd-bridge.o
>> +
>> +hpd-bridge-y := aux-hpd-bridge.o
>> +ifneq ($(CONFIG_TYPEC),)
>> +hpd-bridge-y += aux-hpd-typec-dp-bridge.o
>> +endif
>> +obj-$(CONFIG_DRM_AUX_HPD_BRIDGE) += hpd-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-bridge.c b/drivers/gpu/drm/bridge/aux-hpd-bridge.c
>> index 2e9c702c7087..11ad6dc776c7 100644
>> --- a/drivers/gpu/drm/bridge/aux-hpd-bridge.c
>> +++ b/drivers/gpu/drm/bridge/aux-hpd-bridge.c
>> @@ -12,6 +12,8 @@
>> #include <drm/drm_bridge.h>
>> #include <drm/bridge/aux-bridge.h>
>>
>> +#include "aux-hpd-bridge.h"
>> +
>> static DEFINE_IDA(drm_aux_hpd_bridge_ida);
>>
>> struct drm_aux_hpd_bridge_data {
>> @@ -204,7 +206,26 @@ static struct auxiliary_driver drm_aux_hpd_bridge_drv = {
>> .id_table = drm_aux_hpd_bridge_table,
>> .probe = drm_aux_hpd_bridge_probe,
>> };
>> -module_auxiliary_driver(drm_aux_hpd_bridge_drv);
>> +
>> +static int drm_aux_hpd_bridge_mod_init(void)
>> +{
>> + int ret;
>> +
>> + ret = auxiliary_driver_register(&drm_aux_hpd_bridge_drv);
>> + if (ret)
>> + return ret;
>> +
>> + return drm_aux_hpd_typec_dp_bridge_init();
>> +}
>> +
>> +static void drm_aux_hpd_bridge_mod_exit(void)
>> +{
>> + drm_aux_hpd_typec_dp_bridge_exit();
>> + auxiliary_driver_unregister(&drm_aux_hpd_bridge_drv);
>> +}
>> +
>> +module_init(drm_aux_hpd_bridge_mod_init);
>> +module_exit(drm_aux_hpd_bridge_mod_exit);
>>
>> MODULE_AUTHOR("Dmitry Baryshkov <dmitry.baryshkov@linaro.org>");
>> MODULE_DESCRIPTION("DRM HPD bridge");
>> diff --git a/drivers/gpu/drm/bridge/aux-hpd-bridge.h b/drivers/gpu/drm/bridge/aux-hpd-bridge.h
>> new file mode 100644
>> index 000000000000..69364731c2f1
>> --- /dev/null
>> +++ b/drivers/gpu/drm/bridge/aux-hpd-bridge.h
>> @@ -0,0 +1,13 @@
>> +/* SPDX-License-Identifier: GPL-2.0-only */
>> +#ifndef AUX_HPD_BRIDGE_H
>> +#define AUX_HPD_BRIDGE_H
>> +
>> +#if IS_REACHABLE(CONFIG_TYPEC)
>> +int drm_aux_hpd_typec_dp_bridge_init(void);
>> +void drm_aux_hpd_typec_dp_bridge_exit(void);
>> +#else
>> +static inline int drm_aux_hpd_typec_dp_bridge_init(void) { return 0; }
>> +static inline void drm_aux_hpd_typec_dp_bridge_exit(void) { }
>> +#endif /* IS_REACHABLE(CONFIG_TYPEC) */
>> +
>> +#endif /* AUX_HPD_BRIDGE_H */
>> 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..6f2a1fca0fc5
>> --- /dev/null
>> +++ b/drivers/gpu/drm/bridge/aux-hpd-typec-dp-bridge.c
>> @@ -0,0 +1,47 @@
>> +// SPDX-License-Identifier: GPL-2.0+
>> +#include <linux/of.h>
>> +#include <linux/usb/typec_altmode.h>
>> +#include <linux/usb/typec_dp.h>
>> +#include <linux/usb/typec_notify.h>
>> +
>> +#include <drm/bridge/aux-bridge.h>
>> +
>> +#include "aux-hpd-bridge.h"
>> +
>> +#if IS_REACHABLE(CONFIG_TYPEC)
>> +static int drm_typec_bus_event(struct notifier_block *nb,
>> + unsigned long action, void *data)
>> +{
> This feels like this should be a part of the Type-C subsystem rather
> than DRM.
In v7, this used to be a part of the Type-C subsystem. I'm not sure what Heikki thinks about this.
>
>> + struct typec_altmode *alt = (struct typec_altmode *)data;
>> +
>> + if (action != TYPEC_ALTMODE_REGISTERED)
>> + goto done;
>> +
>> + if (is_typec_partner(&alt->dev) || alt->svid != USB_TYPEC_DP_SID)
>> + 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 = {
>> + .notifier_call = drm_typec_bus_event,
>> +};
>> +
>> +int drm_aux_hpd_typec_dp_bridge_init(void)
>> +{
>> + return typec_altmode_register_notify(&drm_typec_event_nb);
>> +}
>> +
>> +void drm_aux_hpd_typec_dp_bridge_exit(void)
>> +{
>> + typec_altmode_unregister_notify(&drm_typec_event_nb);
>> +}
>> +#endif
>> --
>> 2.49.0
>>
--
Best,
Chaoyi
> > > diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
> > > index a250afd8d662..17257b223a28 100644
> > > --- a/drivers/gpu/drm/bridge/Kconfig
> > > +++ b/drivers/gpu/drm/bridge/Kconfig
> > > @@ -23,13 +23,16 @@ config DRM_AUX_BRIDGE
> > > build bridges chain.
> > > config DRM_AUX_HPD_BRIDGE
> > > - tristate
> > > + tristate "AUX HPD bridge support"
> > Why? No, this is supposed to be selected by other drivers. Users don't
> > know an wouldn't know what is this.
>
> In v7, I implemented an additional module for selecting this option. But
> Heikki believes that it would be better to merge the two modules into one.
Like I said before, I was merely curious why not just squash the
support into that AUX_PD_HPD_BRIDGE. If that does not make sense, then
so be it - make it a "Display Interface Bridge" driver like you
originally proposed.
> > > depends on DRM_BRIDGE && OF
> > > select AUXILIARY_BUS
> > > help
> > > Simple bridge that terminates the bridge chain and provides HPD
> > > support.
> > > + Specifically, if you want a default Type-C DisplayPort HPD bridge for
> > > + each port of the Type-C controller, say Y here.
> > > +
> > > 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..2998937444bc 100644
> > > --- a/drivers/gpu/drm/bridge/Makefile
> > > +++ b/drivers/gpu/drm/bridge/Makefile
> > > @@ -1,6 +1,12 @@
> > > # SPDX-License-Identifier: GPL-2.0
> > > obj-$(CONFIG_DRM_AUX_BRIDGE) += aux-bridge.o
> > > -obj-$(CONFIG_DRM_AUX_HPD_BRIDGE) += aux-hpd-bridge.o
> > > +
> > > +hpd-bridge-y := aux-hpd-bridge.o
> > > +ifneq ($(CONFIG_TYPEC),)
> > > +hpd-bridge-y += aux-hpd-typec-dp-bridge.o
> > > +endif
> > > +obj-$(CONFIG_DRM_AUX_HPD_BRIDGE) += hpd-bridge.o
> > > +
> > > obj-$(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-bridge.c b/drivers/gpu/drm/bridge/aux-hpd-bridge.c
> > > index 2e9c702c7087..11ad6dc776c7 100644
> > > --- a/drivers/gpu/drm/bridge/aux-hpd-bridge.c
> > > +++ b/drivers/gpu/drm/bridge/aux-hpd-bridge.c
> > > @@ -12,6 +12,8 @@
> > > #include <drm/drm_bridge.h>
> > > #include <drm/bridge/aux-bridge.h>
> > > +#include "aux-hpd-bridge.h"
> > > +
> > > static DEFINE_IDA(drm_aux_hpd_bridge_ida);
> > > struct drm_aux_hpd_bridge_data {
> > > @@ -204,7 +206,26 @@ static struct auxiliary_driver drm_aux_hpd_bridge_drv = {
> > > .id_table = drm_aux_hpd_bridge_table,
> > > .probe = drm_aux_hpd_bridge_probe,
> > > };
> > > -module_auxiliary_driver(drm_aux_hpd_bridge_drv);
> > > +
> > > +static int drm_aux_hpd_bridge_mod_init(void)
> > > +{
> > > + int ret;
> > > +
> > > + ret = auxiliary_driver_register(&drm_aux_hpd_bridge_drv);
> > > + if (ret)
> > > + return ret;
> > > +
> > > + return drm_aux_hpd_typec_dp_bridge_init();
> > > +}
> > > +
> > > +static void drm_aux_hpd_bridge_mod_exit(void)
> > > +{
> > > + drm_aux_hpd_typec_dp_bridge_exit();
> > > + auxiliary_driver_unregister(&drm_aux_hpd_bridge_drv);
> > > +}
> > > +
> > > +module_init(drm_aux_hpd_bridge_mod_init);
> > > +module_exit(drm_aux_hpd_bridge_mod_exit);
> > > MODULE_AUTHOR("Dmitry Baryshkov <dmitry.baryshkov@linaro.org>");
> > > MODULE_DESCRIPTION("DRM HPD bridge");
> > > diff --git a/drivers/gpu/drm/bridge/aux-hpd-bridge.h b/drivers/gpu/drm/bridge/aux-hpd-bridge.h
> > > new file mode 100644
> > > index 000000000000..69364731c2f1
> > > --- /dev/null
> > > +++ b/drivers/gpu/drm/bridge/aux-hpd-bridge.h
> > > @@ -0,0 +1,13 @@
> > > +/* SPDX-License-Identifier: GPL-2.0-only */
> > > +#ifndef AUX_HPD_BRIDGE_H
> > > +#define AUX_HPD_BRIDGE_H
> > > +
> > > +#if IS_REACHABLE(CONFIG_TYPEC)
> > > +int drm_aux_hpd_typec_dp_bridge_init(void);
> > > +void drm_aux_hpd_typec_dp_bridge_exit(void);
> > > +#else
> > > +static inline int drm_aux_hpd_typec_dp_bridge_init(void) { return 0; }
> > > +static inline void drm_aux_hpd_typec_dp_bridge_exit(void) { }
> > > +#endif /* IS_REACHABLE(CONFIG_TYPEC) */
> > > +
> > > +#endif /* AUX_HPD_BRIDGE_H */
> > > 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..6f2a1fca0fc5
> > > --- /dev/null
> > > +++ b/drivers/gpu/drm/bridge/aux-hpd-typec-dp-bridge.c
> > > @@ -0,0 +1,47 @@
> > > +// SPDX-License-Identifier: GPL-2.0+
> > > +#include <linux/of.h>
> > > +#include <linux/usb/typec_altmode.h>
> > > +#include <linux/usb/typec_dp.h>
> > > +#include <linux/usb/typec_notify.h>
> > > +
> > > +#include <drm/bridge/aux-bridge.h>
> > > +
> > > +#include "aux-hpd-bridge.h"
> > > +
> > > +#if IS_REACHABLE(CONFIG_TYPEC)
> > > +static int drm_typec_bus_event(struct notifier_block *nb,
> > > + unsigned long action, void *data)
> > > +{
> > This feels like this should be a part of the Type-C subsystem rather
> > than DRM.
>
> In v7, this used to be a part of the Type-C subsystem. I'm not sure what
> Heikki thinks about this.
Your original proposal of making the entire TYPEC subsystem depend on
DRM is _not_ going to happen. In general, if I've now understood this
correctly, this thing probable should be a "display interface bridge
driver", similar to what you proposed in the previous version.
Note also that you could make it selected automatically, so there is
no need for user selectable option if that's the preference. Kconfig
and Makefile gives you options on how to do that. For example, maybe
this Kconfig works (or does not, but something like it will):
diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
index a250afd8d662..7487024ba2ce 100644
--- a/drivers/gpu/drm/bridge/Kconfig
+++ b/drivers/gpu/drm/bridge/Kconfig
@@ -30,6 +30,15 @@ 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
+
+endif /* DRM_AUX_HPD_BRIDGE */
+
menu "Display Interface Bridges"
depends on DRM && DRM_BRIDGE
thanks,
--
heikki
On 11/3/2025 9:48 PM, Heikki Krogerus wrote:
>>>> diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
>>>> index a250afd8d662..17257b223a28 100644
>>>> --- a/drivers/gpu/drm/bridge/Kconfig
>>>> +++ b/drivers/gpu/drm/bridge/Kconfig
>>>> @@ -23,13 +23,16 @@ config DRM_AUX_BRIDGE
>>>> build bridges chain.
>>>> config DRM_AUX_HPD_BRIDGE
>>>> - tristate
>>>> + tristate "AUX HPD bridge support"
>>> Why? No, this is supposed to be selected by other drivers. Users don't
>>> know an wouldn't know what is this.
>> In v7, I implemented an additional module for selecting this option. But
>> Heikki believes that it would be better to merge the two modules into one.
> Like I said before, I was merely curious why not just squash the
> support into that AUX_PD_HPD_BRIDGE. If that does not make sense, then
> so be it - make it a "Display Interface Bridge" driver like you
> originally proposed.
Yes, it is.
>>>> depends on DRM_BRIDGE && OF
>>>> select AUXILIARY_BUS
>>>> help
>>>> Simple bridge that terminates the bridge chain and provides HPD
>>>> support.
>>>> + Specifically, if you want a default Type-C DisplayPort HPD bridge for
>>>> + each port of the Type-C controller, say Y here.
>>>> +
>>>> 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..2998937444bc 100644
>>>> --- a/drivers/gpu/drm/bridge/Makefile
>>>> +++ b/drivers/gpu/drm/bridge/Makefile
>>>> @@ -1,6 +1,12 @@
>>>> # SPDX-License-Identifier: GPL-2.0
>>>> obj-$(CONFIG_DRM_AUX_BRIDGE) += aux-bridge.o
>>>> -obj-$(CONFIG_DRM_AUX_HPD_BRIDGE) += aux-hpd-bridge.o
>>>> +
>>>> +hpd-bridge-y := aux-hpd-bridge.o
>>>> +ifneq ($(CONFIG_TYPEC),)
>>>> +hpd-bridge-y += aux-hpd-typec-dp-bridge.o
>>>> +endif
>>>> +obj-$(CONFIG_DRM_AUX_HPD_BRIDGE) += hpd-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-bridge.c b/drivers/gpu/drm/bridge/aux-hpd-bridge.c
>>>> index 2e9c702c7087..11ad6dc776c7 100644
>>>> --- a/drivers/gpu/drm/bridge/aux-hpd-bridge.c
>>>> +++ b/drivers/gpu/drm/bridge/aux-hpd-bridge.c
>>>> @@ -12,6 +12,8 @@
>>>> #include <drm/drm_bridge.h>
>>>> #include <drm/bridge/aux-bridge.h>
>>>> +#include "aux-hpd-bridge.h"
>>>> +
>>>> static DEFINE_IDA(drm_aux_hpd_bridge_ida);
>>>> struct drm_aux_hpd_bridge_data {
>>>> @@ -204,7 +206,26 @@ static struct auxiliary_driver drm_aux_hpd_bridge_drv = {
>>>> .id_table = drm_aux_hpd_bridge_table,
>>>> .probe = drm_aux_hpd_bridge_probe,
>>>> };
>>>> -module_auxiliary_driver(drm_aux_hpd_bridge_drv);
>>>> +
>>>> +static int drm_aux_hpd_bridge_mod_init(void)
>>>> +{
>>>> + int ret;
>>>> +
>>>> + ret = auxiliary_driver_register(&drm_aux_hpd_bridge_drv);
>>>> + if (ret)
>>>> + return ret;
>>>> +
>>>> + return drm_aux_hpd_typec_dp_bridge_init();
>>>> +}
>>>> +
>>>> +static void drm_aux_hpd_bridge_mod_exit(void)
>>>> +{
>>>> + drm_aux_hpd_typec_dp_bridge_exit();
>>>> + auxiliary_driver_unregister(&drm_aux_hpd_bridge_drv);
>>>> +}
>>>> +
>>>> +module_init(drm_aux_hpd_bridge_mod_init);
>>>> +module_exit(drm_aux_hpd_bridge_mod_exit);
>>>> MODULE_AUTHOR("Dmitry Baryshkov <dmitry.baryshkov@linaro.org>");
>>>> MODULE_DESCRIPTION("DRM HPD bridge");
>>>> diff --git a/drivers/gpu/drm/bridge/aux-hpd-bridge.h b/drivers/gpu/drm/bridge/aux-hpd-bridge.h
>>>> new file mode 100644
>>>> index 000000000000..69364731c2f1
>>>> --- /dev/null
>>>> +++ b/drivers/gpu/drm/bridge/aux-hpd-bridge.h
>>>> @@ -0,0 +1,13 @@
>>>> +/* SPDX-License-Identifier: GPL-2.0-only */
>>>> +#ifndef AUX_HPD_BRIDGE_H
>>>> +#define AUX_HPD_BRIDGE_H
>>>> +
>>>> +#if IS_REACHABLE(CONFIG_TYPEC)
>>>> +int drm_aux_hpd_typec_dp_bridge_init(void);
>>>> +void drm_aux_hpd_typec_dp_bridge_exit(void);
>>>> +#else
>>>> +static inline int drm_aux_hpd_typec_dp_bridge_init(void) { return 0; }
>>>> +static inline void drm_aux_hpd_typec_dp_bridge_exit(void) { }
>>>> +#endif /* IS_REACHABLE(CONFIG_TYPEC) */
>>>> +
>>>> +#endif /* AUX_HPD_BRIDGE_H */
>>>> 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..6f2a1fca0fc5
>>>> --- /dev/null
>>>> +++ b/drivers/gpu/drm/bridge/aux-hpd-typec-dp-bridge.c
>>>> @@ -0,0 +1,47 @@
>>>> +// SPDX-License-Identifier: GPL-2.0+
>>>> +#include <linux/of.h>
>>>> +#include <linux/usb/typec_altmode.h>
>>>> +#include <linux/usb/typec_dp.h>
>>>> +#include <linux/usb/typec_notify.h>
>>>> +
>>>> +#include <drm/bridge/aux-bridge.h>
>>>> +
>>>> +#include "aux-hpd-bridge.h"
>>>> +
>>>> +#if IS_REACHABLE(CONFIG_TYPEC)
>>>> +static int drm_typec_bus_event(struct notifier_block *nb,
>>>> + unsigned long action, void *data)
>>>> +{
>>> This feels like this should be a part of the Type-C subsystem rather
>>> than DRM.
>> In v7, this used to be a part of the Type-C subsystem. I'm not sure what
>> Heikki thinks about this.
> Your original proposal of making the entire TYPEC subsystem depend on
> DRM is _not_ going to happen. In general, if I've now understood this
> correctly, this thing probable should be a "display interface bridge
> driver", similar to what you proposed in the previous version.
>
> Note also that you could make it selected automatically, so there is
> no need for user selectable option if that's the preference. Kconfig
> and Makefile gives you options on how to do that. For example, maybe
> this Kconfig works (or does not, but something like it will):
>
> diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig
> index a250afd8d662..7487024ba2ce 100644
> --- a/drivers/gpu/drm/bridge/Kconfig
> +++ b/drivers/gpu/drm/bridge/Kconfig
> @@ -30,6 +30,15 @@ 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
> +
> +endif /* DRM_AUX_HPD_BRIDGE */
> +
> menu "Display Interface Bridges"
> depends on DRM && DRM_BRIDGE
Thank you for your code. I think both of your points make sense. So choosing the approach you mentioned now (similar to v7) might be a reasonable compromise.
>
>
>
> thanks,
>
--
Best,
Chaoyi
Wed, Oct 29, 2025 at 03:14:28PM +0800, Chaoyi Chen kirjoitti:
> From: Chaoyi Chen <chaoyi.chen@rock-chips.com>
>
> Several USB-C controller drivers have already implemented the DP HPD
> bridge function provided by aux-hpd-bridge.c, but there are still
> some USB-C controller driver that have not yet implemented it.
>
> This patch implements a generic DP HPD bridge based on aux-hpd-bridge.c,
> so that other USB-C controller drivers don't need to implement it again.
>
> Signed-off-by: Chaoyi Chen <chaoyi.chen@rock-chips.com>
> ---
>
> Changes in v8:
> - Merge generic DP HPD bridge into one module.
>
> drivers/gpu/drm/bridge/Kconfig | 5 +-
> drivers/gpu/drm/bridge/Makefile | 8 +++-
> drivers/gpu/drm/bridge/aux-hpd-bridge.c | 23 ++++++++-
> drivers/gpu/drm/bridge/aux-hpd-bridge.h | 13 +++++
> .../gpu/drm/bridge/aux-hpd-typec-dp-bridge.c | 47 +++++++++++++++++++
> 5 files changed, 93 insertions(+), 3 deletions(-)
> create mode 100644 drivers/gpu/drm/bridge/aux-hpd-bridge.h
> 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..17257b223a28 100644
> --- a/drivers/gpu/drm/bridge/Kconfig
> +++ b/drivers/gpu/drm/bridge/Kconfig
> @@ -23,13 +23,16 @@ config DRM_AUX_BRIDGE
> build bridges chain.
>
> config DRM_AUX_HPD_BRIDGE
> - tristate
> + tristate "AUX HPD bridge support"
Don't you now need:
depends on TYPEC || !TYPEC
> depends on DRM_BRIDGE && OF
> select AUXILIARY_BUS
> help
> Simple bridge that terminates the bridge chain and provides HPD
> support.
>
> + Specifically, if you want a default Type-C DisplayPort HPD bridge for
> + each port of the Type-C controller, say Y here.
> +
> 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..2998937444bc 100644
> --- a/drivers/gpu/drm/bridge/Makefile
> +++ b/drivers/gpu/drm/bridge/Makefile
> @@ -1,6 +1,12 @@
> # SPDX-License-Identifier: GPL-2.0
> obj-$(CONFIG_DRM_AUX_BRIDGE) += aux-bridge.o
> -obj-$(CONFIG_DRM_AUX_HPD_BRIDGE) += aux-hpd-bridge.o
> +
> +hpd-bridge-y := aux-hpd-bridge.o
> +ifneq ($(CONFIG_TYPEC),)
> +hpd-bridge-y += aux-hpd-typec-dp-bridge.o
> +endif
> +obj-$(CONFIG_DRM_AUX_HPD_BRIDGE) += hpd-bridge.o
> +
> obj-$(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-bridge.c b/drivers/gpu/drm/bridge/aux-hpd-bridge.c
> index 2e9c702c7087..11ad6dc776c7 100644
> --- a/drivers/gpu/drm/bridge/aux-hpd-bridge.c
> +++ b/drivers/gpu/drm/bridge/aux-hpd-bridge.c
> @@ -12,6 +12,8 @@
> #include <drm/drm_bridge.h>
> #include <drm/bridge/aux-bridge.h>
>
> +#include "aux-hpd-bridge.h"
> +
> static DEFINE_IDA(drm_aux_hpd_bridge_ida);
>
> struct drm_aux_hpd_bridge_data {
> @@ -204,7 +206,26 @@ static struct auxiliary_driver drm_aux_hpd_bridge_drv = {
> .id_table = drm_aux_hpd_bridge_table,
> .probe = drm_aux_hpd_bridge_probe,
> };
> -module_auxiliary_driver(drm_aux_hpd_bridge_drv);
> +
> +static int drm_aux_hpd_bridge_mod_init(void)
> +{
> + int ret;
> +
> + ret = auxiliary_driver_register(&drm_aux_hpd_bridge_drv);
> + if (ret)
> + return ret;
> +
> + return drm_aux_hpd_typec_dp_bridge_init();
> +}
> +
> +static void drm_aux_hpd_bridge_mod_exit(void)
> +{
> + drm_aux_hpd_typec_dp_bridge_exit();
> + auxiliary_driver_unregister(&drm_aux_hpd_bridge_drv);
> +}
> +
> +module_init(drm_aux_hpd_bridge_mod_init);
> +module_exit(drm_aux_hpd_bridge_mod_exit);
>
> MODULE_AUTHOR("Dmitry Baryshkov <dmitry.baryshkov@linaro.org>");
> MODULE_DESCRIPTION("DRM HPD bridge");
> diff --git a/drivers/gpu/drm/bridge/aux-hpd-bridge.h b/drivers/gpu/drm/bridge/aux-hpd-bridge.h
> new file mode 100644
> index 000000000000..69364731c2f1
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/aux-hpd-bridge.h
> @@ -0,0 +1,13 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +#ifndef AUX_HPD_BRIDGE_H
> +#define AUX_HPD_BRIDGE_H
> +
> +#if IS_REACHABLE(CONFIG_TYPEC)
> +int drm_aux_hpd_typec_dp_bridge_init(void);
> +void drm_aux_hpd_typec_dp_bridge_exit(void);
> +#else
> +static inline int drm_aux_hpd_typec_dp_bridge_init(void) { return 0; }
> +static inline void drm_aux_hpd_typec_dp_bridge_exit(void) { }
> +#endif /* IS_REACHABLE(CONFIG_TYPEC) */
> +
> +#endif /* AUX_HPD_BRIDGE_H */
> 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..6f2a1fca0fc5
> --- /dev/null
> +++ b/drivers/gpu/drm/bridge/aux-hpd-typec-dp-bridge.c
> @@ -0,0 +1,47 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +#include <linux/of.h>
> +#include <linux/usb/typec_altmode.h>
> +#include <linux/usb/typec_dp.h>
> +#include <linux/usb/typec_notify.h>
> +
> +#include <drm/bridge/aux-bridge.h>
> +
> +#include "aux-hpd-bridge.h"
> +
> +#if IS_REACHABLE(CONFIG_TYPEC)
You don't need that. You should not use ifdefs in .c files.
> +static int drm_typec_bus_event(struct notifier_block *nb,
> + unsigned long action, void *data)
> +{
> + struct typec_altmode *alt = (struct typec_altmode *)data;
> +
> + if (action != TYPEC_ALTMODE_REGISTERED)
> + goto done;
> +
> + if (is_typec_partner(&alt->dev) || alt->svid != USB_TYPEC_DP_SID)
> + 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 = {
> + .notifier_call = drm_typec_bus_event,
> +};
> +
> +int drm_aux_hpd_typec_dp_bridge_init(void)
> +{
> + return typec_altmode_register_notify(&drm_typec_event_nb);
> +}
> +
> +void drm_aux_hpd_typec_dp_bridge_exit(void)
> +{
> + typec_altmode_unregister_notify(&drm_typec_event_nb);
> +}
> +#endif
> --
> 2.49.0
--
heikki
On 10/31/2025 9:58 PM, Heikki Krogerus wrote:
> Wed, Oct 29, 2025 at 03:14:28PM +0800, Chaoyi Chen kirjoitti:
>> From: Chaoyi Chen <chaoyi.chen@rock-chips.com>
>>
>> Several USB-C controller drivers have already implemented the DP HPD
>> bridge function provided by aux-hpd-bridge.c, but there are still
>> some USB-C controller driver that have not yet implemented it.
>>
>> This patch implements a generic DP HPD bridge based on aux-hpd-bridge.c,
>> so that other USB-C controller drivers don't need to implement it again.
>>
>> Signed-off-by: Chaoyi Chen <chaoyi.chen@rock-chips.com>
>> ---
>>
>> Changes in v8:
>> - Merge generic DP HPD bridge into one module.
>>
>> drivers/gpu/drm/bridge/Kconfig | 5 +-
>> drivers/gpu/drm/bridge/Makefile | 8 +++-
>> drivers/gpu/drm/bridge/aux-hpd-bridge.c | 23 ++++++++-
>> drivers/gpu/drm/bridge/aux-hpd-bridge.h | 13 +++++
>> .../gpu/drm/bridge/aux-hpd-typec-dp-bridge.c | 47 +++++++++++++++++++
>> 5 files changed, 93 insertions(+), 3 deletions(-)
>> create mode 100644 drivers/gpu/drm/bridge/aux-hpd-bridge.h
>> 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..17257b223a28 100644
>> --- a/drivers/gpu/drm/bridge/Kconfig
>> +++ b/drivers/gpu/drm/bridge/Kconfig
>> @@ -23,13 +23,16 @@ config DRM_AUX_BRIDGE
>> build bridges chain.
>>
>> config DRM_AUX_HPD_BRIDGE
>> - tristate
>> + tristate "AUX HPD bridge support"
> Don't you now need:
>
> depends on TYPEC || !TYPEC
>
>> depends on DRM_BRIDGE && OF
>> select AUXILIARY_BUS
>> help
>> Simple bridge that terminates the bridge chain and provides HPD
>> support.
>>
>> + Specifically, if you want a default Type-C DisplayPort HPD bridge for
>> + each port of the Type-C controller, say Y here.
>> +
>> 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..2998937444bc 100644
>> --- a/drivers/gpu/drm/bridge/Makefile
>> +++ b/drivers/gpu/drm/bridge/Makefile
>> @@ -1,6 +1,12 @@
>> # SPDX-License-Identifier: GPL-2.0
>> obj-$(CONFIG_DRM_AUX_BRIDGE) += aux-bridge.o
>> -obj-$(CONFIG_DRM_AUX_HPD_BRIDGE) += aux-hpd-bridge.o
>> +
>> +hpd-bridge-y := aux-hpd-bridge.o
>> +ifneq ($(CONFIG_TYPEC),)
>> +hpd-bridge-y += aux-hpd-typec-dp-bridge.o
>> +endif
>> +obj-$(CONFIG_DRM_AUX_HPD_BRIDGE) += hpd-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-bridge.c b/drivers/gpu/drm/bridge/aux-hpd-bridge.c
>> index 2e9c702c7087..11ad6dc776c7 100644
>> --- a/drivers/gpu/drm/bridge/aux-hpd-bridge.c
>> +++ b/drivers/gpu/drm/bridge/aux-hpd-bridge.c
>> @@ -12,6 +12,8 @@
>> #include <drm/drm_bridge.h>
>> #include <drm/bridge/aux-bridge.h>
>>
>> +#include "aux-hpd-bridge.h"
>> +
>> static DEFINE_IDA(drm_aux_hpd_bridge_ida);
>>
>> struct drm_aux_hpd_bridge_data {
>> @@ -204,7 +206,26 @@ static struct auxiliary_driver drm_aux_hpd_bridge_drv = {
>> .id_table = drm_aux_hpd_bridge_table,
>> .probe = drm_aux_hpd_bridge_probe,
>> };
>> -module_auxiliary_driver(drm_aux_hpd_bridge_drv);
>> +
>> +static int drm_aux_hpd_bridge_mod_init(void)
>> +{
>> + int ret;
>> +
>> + ret = auxiliary_driver_register(&drm_aux_hpd_bridge_drv);
>> + if (ret)
>> + return ret;
>> +
>> + return drm_aux_hpd_typec_dp_bridge_init();
>> +}
>> +
>> +static void drm_aux_hpd_bridge_mod_exit(void)
>> +{
>> + drm_aux_hpd_typec_dp_bridge_exit();
>> + auxiliary_driver_unregister(&drm_aux_hpd_bridge_drv);
>> +}
>> +
>> +module_init(drm_aux_hpd_bridge_mod_init);
>> +module_exit(drm_aux_hpd_bridge_mod_exit);
>>
>> MODULE_AUTHOR("Dmitry Baryshkov <dmitry.baryshkov@linaro.org>");
>> MODULE_DESCRIPTION("DRM HPD bridge");
>> diff --git a/drivers/gpu/drm/bridge/aux-hpd-bridge.h b/drivers/gpu/drm/bridge/aux-hpd-bridge.h
>> new file mode 100644
>> index 000000000000..69364731c2f1
>> --- /dev/null
>> +++ b/drivers/gpu/drm/bridge/aux-hpd-bridge.h
>> @@ -0,0 +1,13 @@
>> +/* SPDX-License-Identifier: GPL-2.0-only */
>> +#ifndef AUX_HPD_BRIDGE_H
>> +#define AUX_HPD_BRIDGE_H
>> +
>> +#if IS_REACHABLE(CONFIG_TYPEC)
>> +int drm_aux_hpd_typec_dp_bridge_init(void);
>> +void drm_aux_hpd_typec_dp_bridge_exit(void);
>> +#else
>> +static inline int drm_aux_hpd_typec_dp_bridge_init(void) { return 0; }
>> +static inline void drm_aux_hpd_typec_dp_bridge_exit(void) { }
>> +#endif /* IS_REACHABLE(CONFIG_TYPEC) */
>> +
>> +#endif /* AUX_HPD_BRIDGE_H */
>> 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..6f2a1fca0fc5
>> --- /dev/null
>> +++ b/drivers/gpu/drm/bridge/aux-hpd-typec-dp-bridge.c
>> @@ -0,0 +1,47 @@
>> +// SPDX-License-Identifier: GPL-2.0+
>> +#include <linux/of.h>
>> +#include <linux/usb/typec_altmode.h>
>> +#include <linux/usb/typec_dp.h>
>> +#include <linux/usb/typec_notify.h>
>> +
>> +#include <drm/bridge/aux-bridge.h>
>> +
>> +#include "aux-hpd-bridge.h"
>> +
>> +#if IS_REACHABLE(CONFIG_TYPEC)
> You don't need that. You should not use ifdefs in .c files.
>
Oh yes, this should be handled by depend on. I will fix it in v9.
--
Best,
Chaoyi
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