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From: Hans de Goede <hdegoede@redhat.com>
To: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
	Maxime Ripard <mripard@kernel.org>,
	Thomas Zimmermann <tzimmermann@suse.de>,
	Jani Nikula <jani.nikula@linux.intel.com>,
	Lyude <lyude@redhat.com>,
	Joonas Lahtinen <joonas.lahtinen@linux.intel.com>,
	Rodrigo Vivi <rodrigo.vivi@intel.com>,
	Imre Deak <imre.deak@intel.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Guenter Roeck <linux@roeck-us.net>,
	Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: Hans de Goede <hdegoede@redhat.com>,
	Daniel Vetter <daniel@ffwll.ch>, David Airlie <airlied@linux.ie>,
	intel-gfx <intel-gfx@lists.freedesktop.org>,
	dri-devel@lists.freedesktop.org, linux-usb@vger.kernel.org
Subject: [PATCH 4/8] drm/connector: Add support for out-of-band hotplug notification (v3)
Date: Tue, 17 Aug 2021 23:51:57 +0200	[thread overview]
Message-ID: <20210817215201.795062-5-hdegoede@redhat.com> (raw)
In-Reply-To: <20210817215201.795062-1-hdegoede@redhat.com>

Add a new drm_connector_oob_hotplug_event() function and
oob_hotplug_event drm_connector_funcs member.

On some hardware a hotplug event notification may come from outside the
display driver / device. An example of this is some USB Type-C setups
where the hardware muxes the DisplayPort data and aux-lines but does
not pass the altmode HPD status bit to the GPU's DP HPD pin.

In cases like this the new drm_connector_oob_hotplug_event() function can
be used to report these out-of-band events.

Changes in v2:
- Make drm_connector_oob_hotplug_event() take a fwnode as argument and
  have it call drm_connector_find_by_fwnode() internally. This allows
  making drm_connector_find_by_fwnode() a drm-internal function and
  avoids code outside the drm subsystem potentially holding on the
  a drm_connector reference for a longer period.

Changes in v3:
- Drop the data argument to the drm_connector_oob_hotplug_event
  function since it is not used atm. This can be re-added later when
  a use for it actually arises.

Tested-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/gpu/drm/drm_connector.c | 27 +++++++++++++++++++++++++++
 include/drm/drm_connector.h     |  9 +++++++++
 2 files changed, 36 insertions(+)

diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index 7d72bcefa4d6..e0a30e0ee86a 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -2595,6 +2595,33 @@ struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
 	return found;
 }
 
+/**
+ * drm_connector_oob_hotplug_event - Report out-of-band hotplug event to connector
+ * @connector: connector to report the event on
+ *
+ * On some hardware a hotplug event notification may come from outside the display
+ * driver / device. An example of this is some USB Type-C setups where the hardware
+ * muxes the DisplayPort data and aux-lines but does not pass the altmode HPD
+ * status bit to the GPU's DP HPD pin.
+ *
+ * This function can be used to report these out-of-band events after obtaining
+ * a drm_connector reference through calling drm_connector_find_by_fwnode().
+ */
+void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
+{
+	struct drm_connector *connector;
+
+	connector = drm_connector_find_by_fwnode(connector_fwnode);
+	if (IS_ERR(connector))
+		return;
+
+	if (connector->funcs->oob_hotplug_event)
+		connector->funcs->oob_hotplug_event(connector);
+
+	drm_connector_put(connector);
+}
+EXPORT_SYMBOL(drm_connector_oob_hotplug_event);
+
 
 /**
  * DOC: Tile group
diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index 8132c48b56ae..79fa34e5ccdb 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -1084,6 +1084,14 @@ struct drm_connector_funcs {
 	 */
 	void (*atomic_print_state)(struct drm_printer *p,
 				   const struct drm_connector_state *state);
+
+	/**
+	 * @oob_hotplug_event:
+	 *
+	 * This will get called when a hotplug-event for a drm-connector
+	 * has been received from a source outside the display driver / device.
+	 */
+	void (*oob_hotplug_event)(struct drm_connector *connector);
 };
 
 /**
@@ -1666,6 +1674,7 @@ drm_connector_is_unregistered(struct drm_connector *connector)
 		DRM_CONNECTOR_UNREGISTERED;
 }
 
+void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode);
 const char *drm_get_connector_type_name(unsigned int connector_type);
 const char *drm_get_connector_status_name(enum drm_connector_status status);
 const char *drm_get_subpixel_order_name(enum subpixel_order order);
-- 
2.31.1


  parent reply	other threads:[~2021-08-17 21:52 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-17 21:51 [PATCH 0/8] drm + usb-type-c: Add support for out-of-band hotplug notification (v4 resend) Hans de Goede
2021-08-17 21:51 ` [PATCH 1/8] drm/connector: Give connector sysfs devices there own device_type Hans de Goede
2021-08-18 21:35   ` Lyude Paul
2021-08-17 21:51 ` [PATCH 2/8] drm/connector: Add a fwnode pointer to drm_connector and register with ACPI (v2) Hans de Goede
2021-08-17 21:51 ` [PATCH 3/8] drm/connector: Add drm_connector_find_by_fwnode() function (v3) Hans de Goede
2021-08-17 21:51 ` Hans de Goede [this message]
2021-08-17 21:51 ` [PATCH 5/8] drm/i915: Associate ACPI connector nodes with connector entries (v2) Hans de Goede
2021-08-17 21:51 ` [PATCH 6/8] drm/i915/dp: Add support for out-of-bound hotplug events Hans de Goede
2021-08-17 21:52 ` [PATCH 7/8] usb: typec: altmodes/displayport: Make dp_altmode_notify() more generic Hans de Goede
2021-08-17 21:52 ` [PATCH 8/8] usb: typec: altmodes/displayport: Notify drm subsys of hotplug events Hans de Goede
2021-09-16  3:20   ` Stephen Boyd
2021-09-16 13:17     ` Hans de Goede
2021-09-24 23:29       ` Stephen Boyd
2021-08-18 22:03 ` [PATCH 0/8] drm + usb-type-c: Add support for out-of-band hotplug notification (v4 resend) Lyude Paul
  -- strict thread matches above, loose matches on Subject: below --
2021-06-04 19:48 [PATCH 0/8] drm + usb-type-c: Add support for out-of-band hotplug notification (v4) Hans de Goede
2021-06-04 19:48 ` [PATCH 4/8] drm/connector: Add support for out-of-band hotplug notification (v3) Hans de Goede
2021-05-05 16:24 [PATCH 0/8] drm + usb-type-c: " Hans de Goede
2021-05-05 16:24 ` [PATCH 4/8] drm/connector: " Hans de Goede

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