[media] vimc: Subdevices as modules

Change the core structure for adding subdevices in the topology.
Instead of calling the specific create function for each subdevice,
inject a child platform_device with the driver's name.
Each type of node in the topology (sensor, capture, debayer, scaler)
will register a platform_driver with the corresponding name through the
component subsystem.
Implementing a new subdevice type doesn't require vimc-core to be altered.

This facilitates future implementation of dynamic entities, where
hotpluging an entity in the topology is just a matter of
registering/unregistering a platform_device in the system.
It also facilitates other implementations of different nodes without
touching the core code and remove the need of a header file for each
type of node.

Signed-off-by: Helen Koike <helen.koike@collabora.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

1 files changed, 20 insertions, 9 deletions

diff --git a/drivers/media/platform/vimc/vimc-common.h b/drivers/media/platform/vimc/vimc-common.h
index fb3463c06185..a9c1cfdc0dff 100644
--- a/drivers/media/platform/vimc/vimc-common.h
+++ b/drivers/media/platform/vimc/vimc-common.h
@@ -1,5 +1,5 @@
 /*
- * vimc-ccommon.h Virtual Media Controller Driver
+ * vimc-common.h Virtual Media Controller Driver
  *
  * Copyright (C) 2015-2017 Helen Koike <helen.fornazier@gmail.com>
  *
@@ -54,6 +54,21 @@ do {									\
 } while (0)
 
 /**
+ * struct vimc_platform_data - platform data to components
+ *
+ * @entity_name:        The name of the entity to be created
+ *
+ * Board setup code will often provide additional information using the device's
+ * platform_data field to hold additional information.
+ * When injecting a new platform_device in the component system the core needs
+ * to provide to the corresponding submodules the name of the entity that should
+ * be used when registering the subdevice in the Media Controller system.
+ */
+struct vimc_platform_data {
+        char entity_name[32];
+};
+
+/**
  * struct vimc_pix_map - maps media bus code with v4l2 pixel format
  *
  * @code:               media bus format code defined by MEDIA_BUS_FMT_* macros
@@ -74,7 +89,6 @@ struct vimc_pix_map {
  *
  * @ent:                the pointer to struct media_entity for the node
  * @pads:               the list of pads of the node
- * @destroy:            callback to destroy the node
  * @process_frame:      callback send a frame to that node
  * @vdev_get_format:    callback that returns the current format a pad, used
  *                      only when is_media_entity_v4l2_video_device(ent) returns
@@ -91,7 +105,6 @@ struct vimc_pix_map {
 struct vimc_ent_device {
         struct media_entity *ent;
         struct media_pad *pads;
-        void (*destroy)(struct vimc_ent_device *);
         void (*process_frame)(struct vimc_ent_device *ved,
                               struct media_pad *sink, const void *frame);
         void (*vdev_get_format)(struct vimc_ent_device *ved,
@@ -176,7 +189,6 @@ const struct vimc_pix_map *vimc_pix_map_by_pixelformat(u32 pixelformat);
  * @num_pads:   number of pads to initialize
  * @pads_flag:  flags to use in each pad
  * @sd_ops:     pointer to &struct v4l2_subdev_ops.
- * @sd_destroy: callback to destroy the node
  *
  * Helper function initialize and register the struct vimc_ent_device and struct
  * v4l2_subdev which represents a subdev node in the topology
@@ -188,14 +200,13 @@ int vimc_ent_sd_register(struct vimc_ent_device *ved,
                          u32 function,
                          u16 num_pads,
                          const unsigned long *pads_flag,
-                         const struct v4l2_subdev_ops *sd_ops,
-                         void (*sd_destroy)(struct vimc_ent_device *));
+                         const struct v4l2_subdev_ops *sd_ops);
 
 /**
- * vimc_ent_sd_register - initialize and register a subdev node
+ * vimc_ent_sd_unregister - cleanup and unregister a subdev node
  *
- * @ved:        the vimc_ent_device struct to be initialize
- * @sd:         the v4l2_subdev struct to be initialize and registered
+ * @ved:        the vimc_ent_device struct to be cleaned up
+ * @sd:         the v4l2_subdev struct to be unregistered
  *
  * Helper function cleanup and unregister the struct vimc_ent_device and struct
  * v4l2_subdev which represents a subdev node in the topology