On Monday, May 3, 2021, Hans de Goede <hdegoede@redhat.com> wrote:

> Add a fwnode pointer to struct drm_connector and register an acpi_bus_type
> for the connectors with the ACPI subsystem (when CONFIG_ACPI is enabled).
>
> The adding of the fwnode pointer allows drivers to associate a fwnode
> that represents a connector with that connector.
>
> When the new fwnode pointer points to an ACPI-companion, then the new
> acpi_bus_type will cause the ACPI subsys to bind the device instantiated
> for the connector with the fwnode by calling acpi_bind_one(). This will
> result in a firmware_node symlink under /sys/class/card#-<connecter-name>/
> which helps to verify that the fwnode-s and connectors are properly
> matched.
>
> Co-authored-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>



Official tag is Co-developed-by


> Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
>  drivers/gpu/drm/drm_sysfs.c | 37 +++++++++++++++++++++++++++++++++++++
>  include/drm/drm_connector.h |  2 ++
>  2 files changed, 39 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_sysfs.c b/drivers/gpu/drm/drm_sysfs.c
> index 553024bcda8a..12cc649c44f0 100644
> --- a/drivers/gpu/drm/drm_sysfs.c
> +++ b/drivers/gpu/drm/drm_sysfs.c
> @@ -10,6 +10,7 @@
>   * Copyright (c) 2003-2004 IBM Corp.
>   */
>
> +#include <linux/acpi.h>
>  #include <linux/device.h>
>  #include <linux/err.h>
>  #include <linux/export.h>
> @@ -56,6 +57,39 @@ static struct device_type drm_sysfs_device_connector = {
>
>  struct class *drm_class;
>
> +#ifdef CONFIG_ACPI
> +static bool drm_connector_acpi_bus_match(struct device *dev)
> +{
> +       return dev->type == &drm_sysfs_device_connector;
> +}
> +
> +static struct acpi_device *drm_connector_acpi_find_companion(struct
> device *dev)
> +{
> +       struct drm_connector *connector = to_drm_connector(dev);
> +
> +       return to_acpi_device_node(connector->fwnode);
> +}
> +
> +static struct acpi_bus_type drm_connector_acpi_bus = {
> +       .name = "drm_connector",
> +       .match = drm_connector_acpi_bus_match,
> +       .find_companion = drm_connector_acpi_find_companion,
> +};
> +
> +static void drm_sysfs_acpi_register(void)
> +{
> +       register_acpi_bus_type(&drm_connector_acpi_bus);
> +}
> +
> +static void drm_sysfs_acpi_unregister(void)
> +{
> +       unregister_acpi_bus_type(&drm_connector_acpi_bus);
> +}
> +#else
> +static void drm_sysfs_acpi_register(void) { }
> +static void drm_sysfs_acpi_unregister(void) { }
> +#endif
> +
>  static char *drm_devnode(struct device *dev, umode_t *mode)
>  {
>         return kasprintf(GFP_KERNEL, "dri/%s", dev_name(dev));
> @@ -89,6 +123,8 @@ int drm_sysfs_init(void)
>         }
>
>         drm_class->devnode = drm_devnode;
> +
> +       drm_sysfs_acpi_register();
>         return 0;
>  }
>
> @@ -101,6 +137,7 @@ void drm_sysfs_destroy(void)
>  {
>         if (IS_ERR_OR_NULL(drm_class))
>                 return;
> +       drm_sysfs_acpi_unregister();
>         class_remove_file(drm_class, &class_attr_version.attr);
>         class_destroy(drm_class);
>         drm_class = NULL;
> diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
> index 0261801af62c..d20bfd7576ed 100644
> --- a/include/drm/drm_connector.h
> +++ b/include/drm/drm_connector.h
> @@ -1254,6 +1254,8 @@ struct drm_connector {
>         struct device *kdev;
>         /** @attr: sysfs attributes */
>         struct device_attribute *attr;
> +       /** @fwnode: associated fwnode supplied by platform firmware */
> +       struct fwnode_handle *fwnode;
>
>         /**
>          * @head:
> --
> 2.31.1
>
>

-- 
With Best Regards,
Andy Shevchenko