diff mbox series

[3/9] drm/connector: Add drm_connector_find_by_fwnode() function (v2)

Message ID 20210503154647.142551-4-hdegoede@redhat.com (mailing list archive)
State New, archived
Headers show
Series drm + usb-type-c: Add support for out-of-band hotplug notification (v2) | expand

Commit Message

Hans de Goede May 3, 2021, 3:46 p.m. UTC
Add a function to find a connector based on a fwnode.

This will be used by the new drm_connector_oob_hotplug_event()
function which is added by the next patch in this patch-set.

Changes in v2:
- Complete rewrite to use a global connector list in drm_connector.c
  rather then using a class-dev-iter in drm_sysfs.c

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/gpu/drm/drm_connector.c     | 50 +++++++++++++++++++++++++++++
 drivers/gpu/drm/drm_crtc_internal.h |  1 +
 include/drm/drm_connector.h         |  8 +++++
 3 files changed, 59 insertions(+)

Comments

Andy Shevchenko May 4, 2021, 8 a.m. UTC | #1
On Monday, May 3, 2021, Hans de Goede <hdegoede@redhat.com> wrote:

> Add a function to find a connector based on a fwnode.
>
> This will be used by the new drm_connector_oob_hotplug_event()
> function which is added by the next patch in this patch-set.
>
> Changes in v2:
> - Complete rewrite to use a global connector list in drm_connector.c
>   rather then using a class-dev-iter in drm_sysfs.c
>
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
>  drivers/gpu/drm/drm_connector.c     | 50 +++++++++++++++++++++++++++++
>  drivers/gpu/drm/drm_crtc_internal.h |  1 +
>  include/drm/drm_connector.h         |  8 +++++
>  3 files changed, 59 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_
> connector.c
> index 87c68563e6c3..ef759d6add81 100644
> --- a/drivers/gpu/drm/drm_connector.c
> +++ b/drivers/gpu/drm/drm_connector.c
> @@ -66,6 +66,14 @@
>   * support can instead use e.g. drm_helper_hpd_irq_event().
>   */
>
> +/*
> + * Global connector list for drm_connector_find_by_fwnode().
> + * Note drm_connector_[un]register() first take connector->lock and then
> + * take the connector_list_lock.
> + */
> +static DEFINE_MUTEX(connector_list_lock);
> +static LIST_HEAD(connector_list);
> +
>  struct drm_conn_prop_enum_list {
>         int type;
>         const char *name;
> @@ -267,6 +275,7 @@ int drm_connector_init(struct drm_device *dev,
>                 goto out_put_type_id;
>         }
>
> +       INIT_LIST_HEAD(&connector->global_connector_list_entry);
>         INIT_LIST_HEAD(&connector->probed_modes);
>         INIT_LIST_HEAD(&connector->modes);
>         mutex_init(&connector->mutex);
> @@ -540,6 +549,9 @@ int drm_connector_register(struct drm_connector
> *connector)
>                 drm_privacy_screen_register_notifier(connector->privacy_
> screen,
>                                            &connector->privacy_screen_
> notifier);
>
> +       mutex_lock(&connector_list_lock);
> +       list_add_tail(&connector->global_connector_list_entry,
> &connector_list);
> +       mutex_unlock(&connector_list_lock);
>         goto unlock;
>
>  err_debugfs:
> @@ -568,6 +580,10 @@ void drm_connector_unregister(struct drm_connector
> *connector)
>                 return;
>         }
>
> +       mutex_lock(&connector_list_lock);
> +       list_del_init(&connector->global_connector_list_entry);
> +       mutex_unlock(&connector_list_lock);
> +
>         if (connector->privacy_screen)
>                 drm_privacy_screen_unregister_notifier(
>                                         connector->privacy_screen,
> @@ -2676,6 +2692,40 @@ int drm_mode_getconnector(struct drm_device *dev,
> void *data,
>         return ret;
>  }
>
> +/**
> + * drm_connector_find_by_fwnode - Find a connector based on the
> associated fwnode
> + * @fwnode: fwnode for which to find the matching drm_connector
> + *
> + * This functions looks up a drm_connector based on its associated
> fwnode. When
> + * a connector is found a reference to the connector is returned. The
> caller must
> + * call drm_connector_put() to release this reference when it is done
> with the
> + * connector.
> + *
> + * Returns: A reference to the found connector or an ERR_PTR().
> + */
> +struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle
> *fwnode)
> +{
> +       struct drm_connector *connector, *found = ERR_PTR(-ENODEV);
> +
> +       if (!fwnode)
> +               return ERR_PTR(-ENODEV);
> +
> +       mutex_lock(&connector_list_lock);
> +
> +       list_for_each_entry(connector, &connector_list,
> global_connector_list_entry) {
> +               if (connector->fwnode == fwnode ||
> +                   (connector->fwnode && connector->fwnode->secondary ==
> fwnode)) {
> +                       drm_connector_get(connector);
> +                       found = connector;
> +                       break;
> +               }
> +       }
> +
> +       mutex_unlock(&connector_list_lock);
> +
> +       return found;



If I am not mistaken you can replace this with

return list_entry_is_head();

call and remove additional Boolean variable.


> +}
> +
>
>  /**
>   * DOC: Tile group
> diff --git a/drivers/gpu/drm/drm_crtc_internal.h
> b/drivers/gpu/drm/drm_crtc_internal.h
> index 54d4cf1233e9..6e28fc00a740 100644
> --- a/drivers/gpu/drm/drm_crtc_internal.h
> +++ b/drivers/gpu/drm/drm_crtc_internal.h
> @@ -185,6 +185,7 @@ int drm_connector_set_obj_prop(struct drm_mode_object
> *obj,
>  int drm_connector_create_standard_properties(struct drm_device *dev);
>  const char *drm_get_connector_force_name(enum drm_connector_force force);
>  void drm_connector_free_work_fn(struct work_struct *work);
> +struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle
> *fwnode);
>
>  /* IOCTL */
>  int drm_connector_property_set_ioctl(struct drm_device *dev,
> diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
> index d20bfd7576ed..ae377354e48e 100644
> --- a/include/drm/drm_connector.h
> +++ b/include/drm/drm_connector.h
> @@ -1267,6 +1267,14 @@ struct drm_connector {
>          */
>         struct list_head head;
>
> +       /**
> +        * @global_connector_list_entry:
> +        *
> +        * Connector entry in the global connector-list, used by
> +        * drm_connector_find_by_fwnode().
> +        */
> +       struct list_head global_connector_list_entry;
> +
>         /** @base: base KMS object */
>         struct drm_mode_object base;
>
> --
> 2.31.1
>
>
Hans de Goede May 4, 2021, 11:53 a.m. UTC | #2
Hi,

On 5/4/21 10:00 AM, Andy Shevchenko wrote:
> 
> 
> On Monday, May 3, 2021, Hans de Goede <hdegoede@redhat.com <mailto:hdegoede@redhat.com>> wrote:
> 
>     Add a function to find a connector based on a fwnode.
> 
>     This will be used by the new drm_connector_oob_hotplug_event()
>     function which is added by the next patch in this patch-set.
> 
>     Changes in v2:
>     - Complete rewrite to use a global connector list in drm_connector.c
>       rather then using a class-dev-iter in drm_sysfs.c
> 
>     Signed-off-by: Hans de Goede <hdegoede@redhat.com <mailto:hdegoede@redhat.com>>
>     ---
>      drivers/gpu/drm/drm_connector.c     | 50 +++++++++++++++++++++++++++++
>      drivers/gpu/drm/drm_crtc_internal.h |  1 +
>      include/drm/drm_connector.h         |  8 +++++
>      3 files changed, 59 insertions(+)
> 
>     diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
>     index 87c68563e6c3..ef759d6add81 100644
>     --- a/drivers/gpu/drm/drm_connector.c
>     +++ b/drivers/gpu/drm/drm_connector.c
>     @@ -66,6 +66,14 @@
>       * support can instead use e.g. drm_helper_hpd_irq_event().
>       */
> 
>     +/*
>     + * Global connector list for drm_connector_find_by_fwnode().
>     + * Note drm_connector_[un]register() first take connector->lock and then
>     + * take the connector_list_lock.
>     + */
>     +static DEFINE_MUTEX(connector_list_lock);
>     +static LIST_HEAD(connector_list);
>     +
>      struct drm_conn_prop_enum_list {
>             int type;
>             const char *name;
>     @@ -267,6 +275,7 @@ int drm_connector_init(struct drm_device *dev,
>                     goto out_put_type_id;
>             }
> 
>     +       INIT_LIST_HEAD(&connector->global_connector_list_entry);
>             INIT_LIST_HEAD(&connector->probed_modes);
>             INIT_LIST_HEAD(&connector->modes);
>             mutex_init(&connector->mutex);
>     @@ -540,6 +549,9 @@ int drm_connector_register(struct drm_connector *connector)
>                     drm_privacy_screen_register_notifier(connector->privacy_screen,
>                                                &connector->privacy_screen_notifier);
> 
>     +       mutex_lock(&connector_list_lock);
>     +       list_add_tail(&connector->global_connector_list_entry, &connector_list);
>     +       mutex_unlock(&connector_list_lock);
>             goto unlock;
> 
>      err_debugfs:
>     @@ -568,6 +580,10 @@ void drm_connector_unregister(struct drm_connector *connector)
>                     return;
>             }
> 
>     +       mutex_lock(&connector_list_lock);
>     +       list_del_init(&connector->global_connector_list_entry);
>     +       mutex_unlock(&connector_list_lock);
>     +
>             if (connector->privacy_screen)
>                     drm_privacy_screen_unregister_notifier(
>                                             connector->privacy_screen,
>     @@ -2676,6 +2692,40 @@ int drm_mode_getconnector(struct drm_device *dev, void *data,
>             return ret;
>      }
> 
>     +/**
>     + * drm_connector_find_by_fwnode - Find a connector based on the associated fwnode
>     + * @fwnode: fwnode for which to find the matching drm_connector
>     + *
>     + * This functions looks up a drm_connector based on its associated fwnode. When
>     + * a connector is found a reference to the connector is returned. The caller must
>     + * call drm_connector_put() to release this reference when it is done with the
>     + * connector.
>     + *
>     + * Returns: A reference to the found connector or an ERR_PTR().
>     + */
>     +struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
>     +{
>     +       struct drm_connector *connector, *found = ERR_PTR(-ENODEV);
>     +
>     +       if (!fwnode)
>     +               return ERR_PTR(-ENODEV);
>     +
>     +       mutex_lock(&connector_list_lock);
>     +
>     +       list_for_each_entry(connector, &connector_list, global_connector_list_entry) {
>     +               if (connector->fwnode == fwnode ||
>     +                   (connector->fwnode && connector->fwnode->secondary == fwnode)) {
>     +                       drm_connector_get(connector);
>     +                       found = connector;
>     +                       break;
>     +               }
>     +       }
>     +
>     +       mutex_unlock(&connector_list_lock);
>     +
>     +       return found;
> 
> 
> 
> If I am not mistaken you can replace this with
> 
> return list_entry_is_head();
> 
> call and remove additional Boolean variable.

Found is not a boolean, it is a pointer to the found connector (or ERR_PTR(-ENODEV)).

Regards,

Hans


>  
> 
>     +}
>     +
> 
>      /**
>       * DOC: Tile group
>     diff --git a/drivers/gpu/drm/drm_crtc_internal.h b/drivers/gpu/drm/drm_crtc_internal.h
>     index 54d4cf1233e9..6e28fc00a740 100644
>     --- a/drivers/gpu/drm/drm_crtc_internal.h
>     +++ b/drivers/gpu/drm/drm_crtc_internal.h
>     @@ -185,6 +185,7 @@ int drm_connector_set_obj_prop(struct drm_mode_object *obj,
>      int drm_connector_create_standard_properties(struct drm_device *dev);
>      const char *drm_get_connector_force_name(enum drm_connector_force force);
>      void drm_connector_free_work_fn(struct work_struct *work);
>     +struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode);
> 
>      /* IOCTL */
>      int drm_connector_property_set_ioctl(struct drm_device *dev,
>     diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
>     index d20bfd7576ed..ae377354e48e 100644
>     --- a/include/drm/drm_connector.h
>     +++ b/include/drm/drm_connector.h
>     @@ -1267,6 +1267,14 @@ struct drm_connector {
>              */
>             struct list_head head;
> 
>     +       /**
>     +        * @global_connector_list_entry:
>     +        *
>     +        * Connector entry in the global connector-list, used by
>     +        * drm_connector_find_by_fwnode().
>     +        */
>     +       struct list_head global_connector_list_entry;
>     +
>             /** @base: base KMS object */
>             struct drm_mode_object base;
>      
>     -- 
>     2.31.1
> 
> 
> 
> -- 
> With Best Regards,
> Andy Shevchenko
> 
>
Andy Shevchenko May 4, 2021, 12:35 p.m. UTC | #3
On Tue, May 4, 2021 at 2:53 PM Hans de Goede <hdegoede@redhat.com> wrote:
> On 5/4/21 10:00 AM, Andy Shevchenko wrote:
> > On Monday, May 3, 2021, Hans de Goede <hdegoede@redhat.com <mailto:hdegoede@redhat.com>> wrote:

...

> >     +struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
> >     +{
> >     +       struct drm_connector *connector, *found = ERR_PTR(-ENODEV);
> >     +
> >     +       if (!fwnode)
> >     +               return ERR_PTR(-ENODEV);
> >     +
> >     +       mutex_lock(&connector_list_lock);
> >     +
> >     +       list_for_each_entry(connector, &connector_list, global_connector_list_entry) {
> >     +               if (connector->fwnode == fwnode ||
> >     +                   (connector->fwnode && connector->fwnode->secondary == fwnode)) {
> >     +                       drm_connector_get(connector);
> >     +                       found = connector;
> >     +                       break;
> >     +               }
> >     +       }
> >     +
> >     +       mutex_unlock(&connector_list_lock);
> >     +
> >     +       return found;
> >
> > If I am not mistaken you can replace this with
> >
> > return list_entry_is_head();
> >
> > call and remove additional Boolean variable.
>
> Found is not a boolean, it is a pointer to the found connector (or ERR_PTR(-ENODEV)).

Ah, perhaps giving a better name? `match` ?

And to the initial topic, it's either an additional variable or
additional branch in this case. I think additional branch (taking into
account the length of the line or amount of lines) doesn't buy us
anything.

> >     +}
diff mbox series

Patch

diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index 87c68563e6c3..ef759d6add81 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -66,6 +66,14 @@ 
  * support can instead use e.g. drm_helper_hpd_irq_event().
  */
 
+/*
+ * Global connector list for drm_connector_find_by_fwnode().
+ * Note drm_connector_[un]register() first take connector->lock and then
+ * take the connector_list_lock.
+ */
+static DEFINE_MUTEX(connector_list_lock);
+static LIST_HEAD(connector_list);
+
 struct drm_conn_prop_enum_list {
 	int type;
 	const char *name;
@@ -267,6 +275,7 @@  int drm_connector_init(struct drm_device *dev,
 		goto out_put_type_id;
 	}
 
+	INIT_LIST_HEAD(&connector->global_connector_list_entry);
 	INIT_LIST_HEAD(&connector->probed_modes);
 	INIT_LIST_HEAD(&connector->modes);
 	mutex_init(&connector->mutex);
@@ -540,6 +549,9 @@  int drm_connector_register(struct drm_connector *connector)
 		drm_privacy_screen_register_notifier(connector->privacy_screen,
 					   &connector->privacy_screen_notifier);
 
+	mutex_lock(&connector_list_lock);
+	list_add_tail(&connector->global_connector_list_entry, &connector_list);
+	mutex_unlock(&connector_list_lock);
 	goto unlock;
 
 err_debugfs:
@@ -568,6 +580,10 @@  void drm_connector_unregister(struct drm_connector *connector)
 		return;
 	}
 
+	mutex_lock(&connector_list_lock);
+	list_del_init(&connector->global_connector_list_entry);
+	mutex_unlock(&connector_list_lock);
+
 	if (connector->privacy_screen)
 		drm_privacy_screen_unregister_notifier(
 					connector->privacy_screen,
@@ -2676,6 +2692,40 @@  int drm_mode_getconnector(struct drm_device *dev, void *data,
 	return ret;
 }
 
+/**
+ * drm_connector_find_by_fwnode - Find a connector based on the associated fwnode
+ * @fwnode: fwnode for which to find the matching drm_connector
+ *
+ * This functions looks up a drm_connector based on its associated fwnode. When
+ * a connector is found a reference to the connector is returned. The caller must
+ * call drm_connector_put() to release this reference when it is done with the
+ * connector.
+ *
+ * Returns: A reference to the found connector or an ERR_PTR().
+ */
+struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
+{
+	struct drm_connector *connector, *found = ERR_PTR(-ENODEV);
+
+	if (!fwnode)
+		return ERR_PTR(-ENODEV);
+
+	mutex_lock(&connector_list_lock);
+
+	list_for_each_entry(connector, &connector_list, global_connector_list_entry) {
+		if (connector->fwnode == fwnode ||
+		    (connector->fwnode && connector->fwnode->secondary == fwnode)) {
+			drm_connector_get(connector);
+			found = connector;
+			break;
+		}
+	}
+
+	mutex_unlock(&connector_list_lock);
+
+	return found;
+}
+
 
 /**
  * DOC: Tile group
diff --git a/drivers/gpu/drm/drm_crtc_internal.h b/drivers/gpu/drm/drm_crtc_internal.h
index 54d4cf1233e9..6e28fc00a740 100644
--- a/drivers/gpu/drm/drm_crtc_internal.h
+++ b/drivers/gpu/drm/drm_crtc_internal.h
@@ -185,6 +185,7 @@  int drm_connector_set_obj_prop(struct drm_mode_object *obj,
 int drm_connector_create_standard_properties(struct drm_device *dev);
 const char *drm_get_connector_force_name(enum drm_connector_force force);
 void drm_connector_free_work_fn(struct work_struct *work);
+struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode);
 
 /* IOCTL */
 int drm_connector_property_set_ioctl(struct drm_device *dev,
diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index d20bfd7576ed..ae377354e48e 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -1267,6 +1267,14 @@  struct drm_connector {
 	 */
 	struct list_head head;
 
+	/**
+	 * @global_connector_list_entry:
+	 *
+	 * Connector entry in the global connector-list, used by
+	 * drm_connector_find_by_fwnode().
+	 */
+	struct list_head global_connector_list_entry;
+
 	/** @base: base KMS object */
 	struct drm_mode_object base;