Commit 64229b84 authored by Louis Chauvet's avatar Louis Chauvet Committed by Luca Ceresoli
Browse files

drm/vkms: Allow to attach connectors and encoders via configfs 



Create a default subgroup at
/config/vkms/connectors/connector/possible_encoders that will contain
symbolic links to the possible encoders for the connector.

Tested-by: default avatarMark Yacoub <markyacoub@google.com>
Reviewed-by: default avatarLouis Chauvet <louis.chauvet@bootlin.com>
Reviewed-by: default avatarHarry Wentland <harry.wentland@amd.com>
Reviewed-by: default avatarLuca Ceresoli <luca.ceresoli@bootlin.com>
Signed-off-by: default avatarLouis Chauvet <louis.chauvet@bootlin.com>
Co-developed-by: default avatarJosé Expósito <jose.exposito89@gmail.com>
Signed-off-by: default avatarJosé Expósito <jose.exposito89@gmail.com>
Link: https://lore.kernel.org/r/20251016175618.10051-12-jose.exposito89@gmail.com


Signed-off-by: default avatarLuca Ceresoli <luca.ceresoli@bootlin.com>
parent 272acbca

Documentation/gpu/vkms.rst

+2 −0
Original line number Diff line number Diff line
@@ -112,6 +112,7 @@ To finish the configuration, link the different pipeline items:: 


  sudo ln -s /config/vkms/my-vkms/crtcs/crtc0 /config/vkms/my-vkms/planes/plane0/possible_crtcs

  sudo ln -s /config/vkms/my-vkms/crtcs/crtc0 /config/vkms/my-vkms/encoders/encoder0/possible_crtcs

  sudo ln -s /config/vkms/my-vkms/encoders/encoder0 /config/vkms/my-vkms/connectors/connector0/possible_encoders



Since at least one primary plane is required, make sure to set the right type::
@@ -129,6 +130,7 @@ And removing the top level directory and its subdirectories:: 


  sudo rm /config/vkms/my-vkms/planes/*/possible_crtcs/*

  sudo rm /config/vkms/my-vkms/encoders/*/possible_crtcs/*

  sudo rm /config/vkms/my-vkms/connectors/*/possible_encoders/*

  sudo rmdir /config/vkms/my-vkms/planes/*

  sudo rmdir /config/vkms/my-vkms/crtcs/*

  sudo rmdir /config/vkms/my-vkms/encoders/*

drivers/gpu/drm/vkms/vkms_configfs.c

+62 −0
Original line number Diff line number Diff line
@@ -88,11 +88,14 @@ struct vkms_configfs_encoder { 
 *

 * @group: Top level configuration group that represents a connector.

 * Initialized when a new directory is created under "/config/vkms/connectors"

 * @possible_encoders_group: Default subgroup of @group at

 * "connector/possible_encoders"

 * @dev: The vkms_configfs_device this connector belongs to

 * @config: Configuration of the VKMS connector

 */

struct vkms_configfs_connector {

	struct config_group group;

	struct config_group possible_encoders_group;

	struct vkms_configfs_device *dev;

	struct vkms_config_connector *config;

};
@@ -126,6 +129,10 @@ struct vkms_configfs_connector { 
	container_of(to_config_group((item)), struct vkms_configfs_connector, \

		     group)



#define connector_possible_encoders_item_to_vkms_configfs_connector(item) \

	container_of(to_config_group((item)), struct vkms_configfs_connector, \

		     possible_encoders_group)



static ssize_t crtc_writeback_show(struct config_item *item, char *page)

{

	struct vkms_configfs_crtc *crtc;
@@ -528,6 +535,55 @@ static const struct config_item_type connector_item_type = { 
	.ct_owner	= THIS_MODULE,

};



static int connector_possible_encoders_allow_link(struct config_item *src,

						  struct config_item *target)

{

	struct vkms_configfs_connector *connector;

	struct vkms_configfs_encoder *encoder;

	int ret;



	if (target->ci_type != &encoder_item_type)

		return -EINVAL;



	connector = connector_possible_encoders_item_to_vkms_configfs_connector(src);

	encoder = encoder_item_to_vkms_configfs_encoder(target);



	scoped_guard(mutex, &connector->dev->lock) {

		if (connector->dev->enabled)

			return -EBUSY;



		ret = vkms_config_connector_attach_encoder(connector->config,

							   encoder->config);

	}



	return ret;

}



static void connector_possible_encoders_drop_link(struct config_item *src,

						  struct config_item *target)

{

	struct vkms_configfs_connector *connector;

	struct vkms_configfs_encoder *encoder;



	connector = connector_possible_encoders_item_to_vkms_configfs_connector(src);

	encoder = encoder_item_to_vkms_configfs_encoder(target);



	scoped_guard(mutex, &connector->dev->lock) {

		vkms_config_connector_detach_encoder(connector->config,

						     encoder->config);

	}

}



static struct configfs_item_operations connector_possible_encoders_item_operations = {

	.allow_link	= connector_possible_encoders_allow_link,

	.drop_link	= connector_possible_encoders_drop_link,

};



static const struct config_item_type connector_possible_encoders_group_type = {

	.ct_item_ops	= &connector_possible_encoders_item_operations,

	.ct_owner	= THIS_MODULE,

};



static struct config_group *make_connector_group(struct config_group *group,

						 const char *name)

{
@@ -554,6 +610,12 @@ static struct config_group *make_connector_group(struct config_group *group, 


		config_group_init_type_name(&connector->group, name,

					    &connector_item_type);



		config_group_init_type_name(&connector->possible_encoders_group,

					    "possible_encoders",

					    &connector_possible_encoders_group_type);

		configfs_add_default_group(&connector->possible_encoders_group,

					   &connector->group);

	}



	return &connector->group;