media: subdev: add active state to struct v4l2_subdev

Add a new 'active_state' field to struct v4l2_subdev to which we can
store the active state of a subdev. This will place the subdev
configuration into a known place, allowing us to use the state directly
from the v4l2 framework, thus simplifying the drivers.

Also add functions v4l2_subdev_init_finalize() and
v4l2_subdev_cleanup(), which will allocate and free the active state.
The functions are named in a generic way so that they can be also used
for other subdev initialization work.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Reviewed-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
index a1494999352b8ed123b4f7d522094d48339c765f..5ac447b3038ca7e34477a66842d398cc71a5391f 100644 (file)
--- a/drivers/media/v4l2-core/v4l2-subdev.c
+++ b/drivers/media/v4l2-core/v4l2-subdev.c
@@ -906,6 +906,27 @@ void __v4l2_subdev_state_free(struct v4l2_subdev_state *state)
 }
 EXPORT_SYMBOL_GPL(__v4l2_subdev_state_free);
 
+int v4l2_subdev_init_finalize(struct v4l2_subdev *sd)
+{
+       struct v4l2_subdev_state *state;
+
+       state = __v4l2_subdev_state_alloc(sd);
+       if (IS_ERR(state))
+               return PTR_ERR(state);
+
+       sd->active_state = state;
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(v4l2_subdev_init_finalize);
+
+void v4l2_subdev_cleanup(struct v4l2_subdev *sd)
+{
+       __v4l2_subdev_state_free(sd->active_state);
+       sd->active_state = NULL;
+}
+EXPORT_SYMBOL_GPL(v4l2_subdev_cleanup);
+
 #endif /* CONFIG_MEDIA_CONTROLLER */
 
 void v4l2_subdev_init(struct v4l2_subdev *sd, const struct v4l2_subdev_ops *ops)

diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
index ac3bcc54ea0701bd1305cd58aeb5415c13d69eef..d0d0e4caf89330cfa20959c74883d19bb109a6a3 100644 (file)
--- a/include/media/v4l2-subdev.h
+++ b/include/media/v4l2-subdev.h
@@ -645,6 +645,9 @@ struct v4l2_subdev_ir_ops {
  * This structure only needs to be passed to the pad op if the 'which' field
  * of the main argument is set to %V4L2_SUBDEV_FORMAT_TRY. For
  * %V4L2_SUBDEV_FORMAT_ACTIVE it is safe to pass %NULL.
+ *
+ * Note: This struct is also used in active state, and the 'try' prefix is
+ * historical and to be removed.
  */
 struct v4l2_subdev_pad_config {
        struct v4l2_mbus_framefmt try_fmt;
@@ -885,6 +888,9 @@ struct v4l2_subdev_platform_data {
  * @subdev_notifier: A sub-device notifier implicitly registered for the sub-
  *                  device using v4l2_async_register_subdev_sensor().
  * @pdata: common part of subdevice platform data
+ * @active_state: Active state for the subdev (NULL for subdevs tracking the
+ *               state internally). Initialized by calling
+ *               v4l2_subdev_init_finalize().
  *
  * Each instance of a subdev driver should create this struct, either
  * stand-alone or embedded in a larger struct.
@@ -916,6 +922,19 @@ struct v4l2_subdev {
        struct v4l2_async_notifier *notifier;
        struct v4l2_async_notifier *subdev_notifier;
        struct v4l2_subdev_platform_data *pdata;
+
+       /*
+        * The fields below are private, and should only be accessed via
+        * appropriate functions.
+        */
+
+       /*
+        * TODO: active_state should most likely be changed from a pointer to an
+        * embedded field. For the time being it's kept as a pointer to more
+        * easily catch uses of active_state in the cases where the driver
+        * doesn't support it.
+        */
+       struct v4l2_subdev_state *active_state;
 };
 
 
@@ -1141,6 +1160,45 @@ struct v4l2_subdev_state *__v4l2_subdev_state_alloc(struct v4l2_subdev *sd);
  */
 void __v4l2_subdev_state_free(struct v4l2_subdev_state *state);
 
+/**
+ * v4l2_subdev_init_finalize() - Finalizes the initialization of the subdevice
+ * @sd: The subdev
+ *
+ * This function finalizes the initialization of the subdev, including
+ * allocation of the active state for the subdev.
+ *
+ * This function must be called by the subdev drivers that use the centralized
+ * active state, after the subdev struct has been initialized and
+ * media_entity_pads_init() has been called, but before registering the
+ * subdev.
+ *
+ * The user must call v4l2_subdev_cleanup() when the subdev is being removed.
+ */
+int v4l2_subdev_init_finalize(struct v4l2_subdev *sd);
+
+/**
+ * v4l2_subdev_cleanup() - Releases the resources allocated by the subdevice
+ * @sd: The subdevice
+ *
+ * This function will release the resources allocated in
+ * v4l2_subdev_init_finalize.
+ */
+void v4l2_subdev_cleanup(struct v4l2_subdev *sd);
+
+/**
+ * v4l2_subdev_get_active_state() - Returns the active subdev state for
+ *                                 subdevice
+ * @sd: The subdevice
+ *
+ * Returns the active state for the subdevice, or NULL if the subdev does not
+ * support active state.
+ */
+static inline struct v4l2_subdev_state *
+v4l2_subdev_get_active_state(struct v4l2_subdev *sd)
+{
+       return sd->active_state;
+}
+
 #endif /* CONFIG_MEDIA_CONTROLLER */
 
 /**