[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 <[e-mail]>
Signed-off-by: Hans Verkuil <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/platform/vimc/Makefile

···
-vimc-objs := vimc-core.o vimc-capture.o vimc-common.o vimc-sensor.o
+vimc-objs := vimc-core.o
+vimc_capture-objs := vimc-capture.o
+vimc_common-objs := vimc-common.o
+vimc_sensor-objs := vimc-sensor.o
 
-obj-$(CONFIG_VIDEO_VIMC) += vimc.o
+obj-$(CONFIG_VIDEO_VIMC) += vimc.o vimc_capture.o vimc_common.o vimc_sensor.o

drivers/media/platform/vimc/vimc-capture.c

···
  *
  */
 
+#include <linux/component.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
 #include <media/v4l2-ioctl.h>
 #include <media/videobuf2-core.h>
 #include <media/videobuf2-vmalloc.h>
 
-#include "vimc-capture.h"
+#include "vimc-common.h"
+
+#define VIMC_CAP_DRV_NAME "vimc-capture"
 
 struct vimc_cap_device {
 	struct vimc_ent_device ved;
 	struct video_device vdev;
+	struct device *dev;
 	struct v4l2_pix_format format;
 	struct vb2_queue queue;
 	struct list_head buf_list;
···
 
 	vimc_cap_try_fmt_vid_cap(file, priv, f);
 
-	dev_dbg(vcap->vdev.v4l2_dev->dev, "%s: format update: "
+	dev_dbg(vcap->dev, "%s: format update: "
 		"old:%dx%d (0x%x, %d, %d, %d, %d) "
 		"new:%dx%d (0x%x, %d, %d, %d, %d)\n", vcap->vdev.name,
 		/* old */
···
 	unsigned long size = vcap->format.sizeimage;
 
 	if (vb2_plane_size(vb, 0) < size) {
-		dev_err(vcap->vdev.v4l2_dev->dev,
-			"%s: buffer too small (%lu < %lu)\n",
+		dev_err(vcap->dev, "%s: buffer too small (%lu < %lu)\n",
 			vcap->vdev.name, vb2_plane_size(vb, 0), size);
 		return -EINVAL;
 	}
···
 	.link_validate		= vimc_link_validate,
 };
 
-static void vimc_cap_destroy(struct vimc_ent_device *ved)
+static void vimc_cap_comp_unbind(struct device *comp, struct device *master,
+				 void *master_data)
 {
+	struct vimc_ent_device *ved = dev_get_drvdata(comp);
 	struct vimc_cap_device *vcap = container_of(ved, struct vimc_cap_device,
 						    ved);
 
···
 	vb2_buffer_done(&vimc_buf->vb2.vb2_buf, VB2_BUF_STATE_DONE);
 }
 
-struct vimc_ent_device *vimc_cap_create(struct v4l2_device *v4l2_dev,
-					const char *const name,
-					u16 num_pads,
-					const unsigned long *pads_flag)
+static int vimc_cap_comp_bind(struct device *comp, struct device *master,
+			      void *master_data)
 {
+	struct v4l2_device *v4l2_dev = master_data;
+	struct vimc_platform_data *pdata = comp->platform_data;
 	const struct vimc_pix_map *vpix;
 	struct vimc_cap_device *vcap;
 	struct video_device *vdev;
 	struct vb2_queue *q;
 	int ret;
 
-	/*
-	 * Check entity configuration params
-	 * NOTE: we only support a single sink pad
-	 */
-	if (!name || num_pads != 1 || !pads_flag ||
-	    !(pads_flag[0] & MEDIA_PAD_FL_SINK))
-		return ERR_PTR(-EINVAL);
-
 	/* Allocate the vimc_cap_device struct */
 	vcap = kzalloc(sizeof(*vcap), GFP_KERNEL);
 	if (!vcap)
-		return ERR_PTR(-ENOMEM);
+		return -ENOMEM;
 
 	/* Allocate the pads */
-	vcap->ved.pads = vimc_pads_init(num_pads, pads_flag);
+	vcap->ved.pads =
+		vimc_pads_init(1, (const unsigned long[1]) {MEDIA_PAD_FL_SINK});
 	if (IS_ERR(vcap->ved.pads)) {
 		ret = PTR_ERR(vcap->ved.pads);
 		goto err_free_vcap;
 	}
 
 	/* Initialize the media entity */
-	vcap->vdev.entity.name = name;
+	vcap->vdev.entity.name = pdata->entity_name;
 	vcap->vdev.entity.function = MEDIA_ENT_F_IO_V4L;
 	ret = media_entity_pads_init(&vcap->vdev.entity,
-				     num_pads, vcap->ved.pads);
+				     1, vcap->ved.pads);
 	if (ret)
 		goto err_clean_pads;
 
···
 
 	ret = vb2_queue_init(q);
 	if (ret) {
-		dev_err(vcap->vdev.v4l2_dev->dev,
-			"%s: vb2 queue init failed (err=%d)\n",
-			vcap->vdev.name, ret);
+		dev_err(comp, "%s: vb2 queue init failed (err=%d)\n",
+			pdata->entity_name, ret);
 		goto err_clean_m_ent;
 	}
 
···
 				 vcap->format.height;
 
 	/* Fill the vimc_ent_device struct */
-	vcap->ved.destroy = vimc_cap_destroy;
 	vcap->ved.ent = &vcap->vdev.entity;
 	vcap->ved.process_frame = vimc_cap_process_frame;
 	vcap->ved.vdev_get_format = vimc_cap_get_format;
+	dev_set_drvdata(comp, &vcap->ved);
+	vcap->dev = comp;
 
 	/* Initialize the video_device struct */
 	vdev = &vcap->vdev;
···
 	vdev->queue = q;
 	vdev->v4l2_dev = v4l2_dev;
 	vdev->vfl_dir = VFL_DIR_RX;
-	strlcpy(vdev->name, name, sizeof(vdev->name));
+	strlcpy(vdev->name, pdata->entity_name, sizeof(vdev->name));
 	video_set_drvdata(vdev, &vcap->ved);
 
 	/* Register the video_device with the v4l2 and the media framework */
 	ret = video_register_device(vdev, VFL_TYPE_GRABBER, -1);
 	if (ret) {
-		dev_err(vcap->vdev.v4l2_dev->dev,
-			"%s: video register failed (err=%d)\n",
+		dev_err(comp, "%s: video register failed (err=%d)\n",
 			vcap->vdev.name, ret);
 		goto err_release_queue;
 	}
 
-	return &vcap->ved;
+	return 0;
 
 err_release_queue:
 	vb2_queue_release(q);
···
 err_free_vcap:
 	kfree(vcap);
 
-	return ERR_PTR(ret);
+	return ret;
 }
+
+static const struct component_ops vimc_cap_comp_ops = {
+	.bind = vimc_cap_comp_bind,
+	.unbind = vimc_cap_comp_unbind,
+};
+
+static int vimc_cap_probe(struct platform_device *pdev)
+{
+	return component_add(&pdev->dev, &vimc_cap_comp_ops);
+}
+
+static int vimc_cap_remove(struct platform_device *pdev)
+{
+	component_del(&pdev->dev, &vimc_cap_comp_ops);
+
+	return 0;
+}
+
+static struct platform_driver vimc_cap_pdrv = {
+	.probe		= vimc_cap_probe,
+	.remove		= vimc_cap_remove,
+	.driver		= {
+		.name	= VIMC_CAP_DRV_NAME,
+	},
+};
+
+static const struct platform_device_id vimc_cap_driver_ids[] = {
+	{
+		.name           = VIMC_CAP_DRV_NAME,
+	},
+	{ }
+};
+
+module_platform_driver(vimc_cap_pdrv);
+
+MODULE_DEVICE_TABLE(platform, vimc_cap_driver_ids);
+
+MODULE_DESCRIPTION("Virtual Media Controller Driver (VIMC) Capture");
+MODULE_AUTHOR("Helen Mae Koike Fornazier <[e-mail]>");
+MODULE_LICENSE("GPL");

drivers/media/platform/vimc/vimc-capture.h

···
-/*
- * vimc-capture.h Virtual Media Controller Driver
- *
- * Copyright (C) 2015-2017 Helen Koike <[e-mail]>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- */
-
-#ifndef _VIMC_CAPTURE_H_
-#define _VIMC_CAPTURE_H_
-
-#include "vimc-common.h"
-
-struct vimc_ent_device *vimc_cap_create(struct v4l2_device *v4l2_dev,
-					const char *const name,
-					u16 num_pads,
-					const unsigned long *pads_flag);
-
-#endif

drivers/media/platform/vimc/vimc-common.c

···
  *
  */
 
+#include <linux/init.h>
+#include <linux/module.h>
+
 #include "vimc-common.h"
 
 static const struct vimc_pix_map vimc_pix_map_list[] = {
···
 
 	return &vimc_pix_map_list[i];
 }
+EXPORT_SYMBOL_GPL(vimc_pix_map_by_index);
 
 const struct vimc_pix_map *vimc_pix_map_by_code(u32 code)
 {
···
 	}
 	return NULL;
 }
+EXPORT_SYMBOL_GPL(vimc_pix_map_by_code);
 
 const struct vimc_pix_map *vimc_pix_map_by_pixelformat(u32 pixelformat)
 {
···
 	}
 	return NULL;
 }
+EXPORT_SYMBOL_GPL(vimc_pix_map_by_pixelformat);
 
 int vimc_propagate_frame(struct media_pad *src, const void *frame)
 {
···
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(vimc_propagate_frame);
 
 /* Helper function to allocate and initialize pads */
 struct media_pad *vimc_pads_init(u16 num_pads, const unsigned long *pads_flag)
···
 
 	return pads;
 }
+EXPORT_SYMBOL_GPL(vimc_pads_init);
 
 int vimc_pipeline_s_stream(struct media_entity *ent, int enable)
 {
···
 		/* Start the stream in the subdevice direct connected */
 		pad = media_entity_remote_pad(&ent->pads[i]);
 
-		/*
-		 * if this is a raw node from vimc-core, then there is
-		 * nothing to activate
-		 * TODO: remove this when there are no more raw nodes in the
-		 * core and return error instead
-		 */
-		if (pad->entity->obj_type == MEDIA_ENTITY_TYPE_BASE)
-			continue;
+		if (!is_media_entity_v4l2_subdev(pad->entity))
+			return -EINVAL;
 
 		sd = media_entity_to_v4l2_subdev(pad->entity);
 		ret = v4l2_subdev_call(sd, video, s_stream, enable);
···
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(vimc_pipeline_s_stream);
 
 static int vimc_get_mbus_format(struct media_pad *pad,
 				struct v4l2_subdev_format *fmt)
···
 {
 	struct v4l2_subdev_format source_fmt, sink_fmt;
 	int ret;
-
-	/*
-	 * if it is a raw node from vimc-core, ignore the link for now
-	 * TODO: remove this when there are no more raw nodes in the
-	 * core and return error instead
-	 */
-	if (link->source->entity->obj_type == MEDIA_ENTITY_TYPE_BASE)
-		return 0;
 
 	ret = vimc_get_mbus_format(link->source, &source_fmt);
 	if (ret)
···
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(vimc_link_validate);
 
 static const struct media_entity_operations vimc_ent_sd_mops = {
 	.link_validate = vimc_link_validate,
···
 			 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)
 {
 	int ret;
 
···
 		return PTR_ERR(ved->pads);
 
 	/* Fill the vimc_ent_device struct */
-	ved->destroy = sd_destroy;
 	ved->ent = &sd->entity;
 
 	/* Initialize the subdev */
···
 	vimc_pads_cleanup(ved->pads);
 	return ret;
 }
+EXPORT_SYMBOL_GPL(vimc_ent_sd_register);
 
 void vimc_ent_sd_unregister(struct vimc_ent_device *ved, struct v4l2_subdev *sd)
 {
···
 	media_entity_cleanup(ved->ent);
 	vimc_pads_cleanup(ved->pads);
 }
+EXPORT_SYMBOL_GPL(vimc_ent_sd_unregister);
+
+MODULE_DESCRIPTION("Virtual Media Controller Driver (VIMC) Common");
+MODULE_AUTHOR("Helen Koike <[e-mail]>");
+MODULE_LICENSE("GPL");

drivers/media/platform/vimc/vimc-common.h

···
 /*
- * vimc-ccommon.h Virtual Media Controller Driver
+ * vimc-common.h Virtual Media Controller Driver
  *
  * Copyright (C) 2015-2017 Helen Koike <[e-mail]>
  *
···
 } 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
···
  *
  * @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
···
 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,
···
  * @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
···
 			 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

drivers/media/platform/vimc/vimc-core.c

···
  *
  */
 
+#include <linux/component.h>
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <media/media-device.h>
 #include <media/v4l2-device.h>
 
-#include "vimc-capture.h"
 #include "vimc-common.h"
-#include "vimc-sensor.h"
 
 #define VIMC_PDEV_NAME "vimc"
 #define VIMC_MDEV_MODEL_NAME "VIMC MDEV"
···
 }
 
 struct vimc_device {
-	/*
-	 * The pipeline configuration
-	 * (filled before calling vimc_device_register)
-	 */
+	/* The platform device */
+	struct platform_device pdev;
+
+	/* The pipeline configuration */
 	const struct vimc_pipeline_config *pipe_cfg;
 
 	/* The Associated media_device parent */
···
 	/* Internal v4l2 parent device*/
 	struct v4l2_device v4l2_dev;
 
-	/* Internal topology */
-	struct vimc_ent_device **ved;
-};
-
-/**
- * enum vimc_ent_node - Select the functionality of a node in the topology
- * @VIMC_ENT_NODE_SENSOR:	A node of type SENSOR simulates a camera sensor
- *				generating internal images in bayer format and
- *				propagating those images through the pipeline
- * @VIMC_ENT_NODE_CAPTURE:	A node of type CAPTURE is a v4l2 video_device
- *				that exposes the received image from the
- *				pipeline to the user space
- * @VIMC_ENT_NODE_INPUT:	A node of type INPUT is a v4l2 video_device that
- *				receives images from the user space and
- *				propagates them through the pipeline
- * @VIMC_ENT_NODE_DEBAYER:	A node type DEBAYER expects to receive a frame
- *				in bayer format converts it to RGB
- * @VIMC_ENT_NODE_SCALER:	A node of type SCALER scales the received image
- *				by a given multiplier
- *
- * This enum is used in the entity configuration struct to allow the definition
- * of a custom topology specifying the role of each node on it.
- */
-enum vimc_ent_node {
-	VIMC_ENT_NODE_SENSOR,
-	VIMC_ENT_NODE_CAPTURE,
-	VIMC_ENT_NODE_INPUT,
-	VIMC_ENT_NODE_DEBAYER,
-	VIMC_ENT_NODE_SCALER,
+	/* Subdevices */
+	struct platform_device **subdevs;
 };
 
 /* Structure which describes individual configuration for each entity */
 struct vimc_ent_config {
 	const char *name;
-	size_t pads_qty;
-	const unsigned long *pads_flag;
-	enum vimc_ent_node node;
+	const char *drv;
 };
 
 /* Structure which describes links between entities */
···
 static const struct vimc_ent_config ent_config[] = {
 	{
 		.name = "Sensor A",
-		.pads_qty = 1,
-		.pads_flag = (const unsigned long[]){MEDIA_PAD_FL_SOURCE},
-		.node = VIMC_ENT_NODE_SENSOR,
+		.drv = "vimc-sensor",
 	},
 	{
 		.name = "Sensor B",
-		.pads_qty = 1,
-		.pads_flag = (const unsigned long[]){MEDIA_PAD_FL_SOURCE},
-		.node = VIMC_ENT_NODE_SENSOR,
+		.drv = "vimc-sensor",
 	},
 	{
 		.name = "Debayer A",
-		.pads_qty = 2,
-		.pads_flag = (const unsigned long[]){MEDIA_PAD_FL_SINK,
-						     MEDIA_PAD_FL_SOURCE},
-		.node = VIMC_ENT_NODE_DEBAYER,
+		.drv = "vimc-debayer",
 	},
 	{
 		.name = "Debayer B",
-		.pads_qty = 2,
-		.pads_flag = (const unsigned long[]){MEDIA_PAD_FL_SINK,
-						     MEDIA_PAD_FL_SOURCE},
-		.node = VIMC_ENT_NODE_DEBAYER,
+		.drv = "vimc-debayer",
 	},
 	{
 		.name = "Raw Capture 0",
-		.pads_qty = 1,
-		.pads_flag = (const unsigned long[]){MEDIA_PAD_FL_SINK},
-		.node = VIMC_ENT_NODE_CAPTURE,
+		.drv = "vimc-capture",
 	},
 	{
 		.name = "Raw Capture 1",
-		.pads_qty = 1,
-		.pads_flag = (const unsigned long[]){MEDIA_PAD_FL_SINK},
-		.node = VIMC_ENT_NODE_CAPTURE,
+		.drv = "vimc-capture",
 	},
 	{
 		.name = "RGB/YUV Input",
-		.pads_qty = 1,
-		.pads_flag = (const unsigned long[]){MEDIA_PAD_FL_SOURCE},
-		.node = VIMC_ENT_NODE_INPUT,
+		/* TODO: change this to vimc-input when it is implemented */
+		.drv = "vimc-sensor",
 	},
 	{
 		.name = "Scaler",
-		.pads_qty = 2,
-		.pads_flag = (const unsigned long[]){MEDIA_PAD_FL_SINK,
-						     MEDIA_PAD_FL_SOURCE},
-		.node = VIMC_ENT_NODE_SCALER,
+		.drv = "vimc-scaler",
 	},
 	{
 		.name = "RGB/YUV Capture",
-		.pads_qty = 1,
-		.pads_flag = (const unsigned long[]){MEDIA_PAD_FL_SINK},
-		.node = VIMC_ENT_NODE_CAPTURE,
+		.drv = "vimc-capture",
 	},
 };
 
···
 
 /* -------------------------------------------------------------------------- */
 
-static void vimc_device_unregister(struct vimc_device *vimc)
-{
-	unsigned int i;
-
-	media_device_unregister(&vimc->mdev);
-	/* Cleanup (only initialized) entities */
-	for (i = 0; i < vimc->pipe_cfg->num_ents; i++) {
-		if (vimc->ved[i] && vimc->ved[i]->destroy)
-			vimc->ved[i]->destroy(vimc->ved[i]);
-
-		vimc->ved[i] = NULL;
-	}
-	v4l2_device_unregister(&vimc->v4l2_dev);
-	media_device_cleanup(&vimc->mdev);
-}
-
-/*
- * TODO: remove this function when all the
- * entities specific code are implemented
- */
-static void vimc_raw_destroy(struct vimc_ent_device *ved)
-{
-	media_device_unregister_entity(ved->ent);
-
-	media_entity_cleanup(ved->ent);
-
-	vimc_pads_cleanup(ved->pads);
-
-	kfree(ved->ent);
-
-	kfree(ved);
-}
-
-/*
- * TODO: remove this function when all the
- * entities specific code are implemented
- */
-static struct vimc_ent_device *vimc_raw_create(struct v4l2_device *v4l2_dev,
-					       const char *const name,
-					       u16 num_pads,
-					       const unsigned long *pads_flag)
-{
-	struct vimc_ent_device *ved;
-	int ret;
-
-	/* Allocate the main ved struct */
-	ved = kzalloc(sizeof(*ved), GFP_KERNEL);
-	if (!ved)
-		return ERR_PTR(-ENOMEM);
-
-	/* Allocate the media entity */
-	ved->ent = kzalloc(sizeof(*ved->ent), GFP_KERNEL);
-	if (!ved->ent) {
-		ret = -ENOMEM;
-		goto err_free_ved;
-	}
-
-	/* Allocate the pads */
-	ved->pads = vimc_pads_init(num_pads, pads_flag);
-	if (IS_ERR(ved->pads)) {
-		ret = PTR_ERR(ved->pads);
-		goto err_free_ent;
-	}
-
-	/* Initialize the media entity */
-	ved->ent->name = name;
-	ved->ent->function = MEDIA_ENT_F_V4L2_SUBDEV_UNKNOWN;
-	ret = media_entity_pads_init(ved->ent, num_pads, ved->pads);
-	if (ret)
-		goto err_cleanup_pads;
-
-	/* Register the media entity */
-	ret = media_device_register_entity(v4l2_dev->mdev, ved->ent);
-	if (ret)
-		goto err_cleanup_entity;
-
-	/* Fill out the destroy function and return */
-	ved->destroy = vimc_raw_destroy;
-	return ved;
-
-err_cleanup_entity:
-	media_entity_cleanup(ved->ent);
-err_cleanup_pads:
-	vimc_pads_cleanup(ved->pads);
-err_free_ent:
-	kfree(ved->ent);
-err_free_ved:
-	kfree(ved);
-
-	return ERR_PTR(ret);
-}
-
-static int vimc_device_register(struct vimc_device *vimc)
+static int vimc_create_links(struct vimc_device *vimc)
 {
 	unsigned int i;
 	int ret;
 
-	/* Allocate memory for the vimc_ent_devices pointers */
-	vimc->ved = devm_kcalloc(vimc->mdev.dev, vimc->pipe_cfg->num_ents,
-				 sizeof(*vimc->ved), GFP_KERNEL);
-	if (!vimc->ved)
-		return -ENOMEM;
+	/* Initialize the links between entities */
+	for (i = 0; i < vimc->pipe_cfg->num_links; i++) {
+		const struct vimc_ent_link *link = &vimc->pipe_cfg->links[i];
+		/*
+		 * TODO: Check another way of retrieving ved struct without
+		 * relying on platform_get_drvdata
+		 */
+		struct vimc_ent_device *ved_src =
+			platform_get_drvdata(vimc->subdevs[link->src_ent]);
+		struct vimc_ent_device *ved_sink =
+			platform_get_drvdata(vimc->subdevs[link->sink_ent]);
 
-	/* Link the media device within the v4l2_device */
-	vimc->v4l2_dev.mdev = &vimc->mdev;
+		ret = media_create_pad_link(ved_src->ent, link->src_pad,
+					    ved_sink->ent, link->sink_pad,
+					    link->flags);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int vimc_comp_bind(struct device *master)
+{
+	struct vimc_device *vimc = container_of(to_platform_device(master),
+						struct vimc_device, pdev);
+	int ret;
+
+	dev_dbg(master, "bind");
 
 	/* Register the v4l2 struct */
 	ret = v4l2_device_register(vimc->mdev.dev, &vimc->v4l2_dev);
···
 		return ret;
 	}
 
-	/* Initialize entities */
-	for (i = 0; i < vimc->pipe_cfg->num_ents; i++) {
-		struct vimc_ent_device *(*create_func)(struct v4l2_device *,
-						       const char *const,
-						       u16,
-						       const unsigned long *);
+	/* Bind subdevices */
+	ret = component_bind_all(master, &vimc->v4l2_dev);
+	if (ret)
+		goto err_v4l2_unregister;
 
-		/* Register the specific node */
-		switch (vimc->pipe_cfg->ents[i].node) {
-		case VIMC_ENT_NODE_SENSOR:
-			create_func = vimc_sen_create;
-			break;
-
-		case VIMC_ENT_NODE_CAPTURE:
-			create_func = vimc_cap_create;
-			break;
-
-		/* TODO: Instantiate the specific topology node */
-		case VIMC_ENT_NODE_INPUT:
-		case VIMC_ENT_NODE_DEBAYER:
-		case VIMC_ENT_NODE_SCALER:
-		default:
-			/*
-			 * TODO: remove this when all the entities specific
-			 * code are implemented
-			 */
-			create_func = vimc_raw_create;
-			break;
-		}
-
-		vimc->ved[i] = create_func(&vimc->v4l2_dev,
-					   vimc->pipe_cfg->ents[i].name,
-					   vimc->pipe_cfg->ents[i].pads_qty,
-					   vimc->pipe_cfg->ents[i].pads_flag);
-		if (IS_ERR(vimc->ved[i])) {
-			ret = PTR_ERR(vimc->ved[i]);
-			vimc->ved[i] = NULL;
-			goto err;
-		}
-	}
-
-	/* Initialize the links between entities */
-	for (i = 0; i < vimc->pipe_cfg->num_links; i++) {
-		const struct vimc_ent_link *link = &vimc->pipe_cfg->links[i];
-
-		ret = media_create_pad_link(vimc->ved[link->src_ent]->ent,
-					    link->src_pad,
-					    vimc->ved[link->sink_ent]->ent,
-					    link->sink_pad,
-					    link->flags);
-		if (ret)
-			goto err;
-	}
+	/* Initialize links */
+	ret = vimc_create_links(vimc);
+	if (ret)
+		goto err_comp_unbind_all;
 
 	/* Register the media device */
 	ret = media_device_register(&vimc->mdev);
 	if (ret) {
 		dev_err(vimc->mdev.dev,
 			"media device register failed (err=%d)\n", ret);
-		return ret;
+		goto err_comp_unbind_all;
 	}
 
 	/* Expose all subdev's nodes*/
···
 		dev_err(vimc->mdev.dev,
 			"vimc subdev nodes registration failed (err=%d)\n",
 			ret);
-		goto err;
+		goto err_mdev_unregister;
 	}
 
 	return 0;
 
-err:
-	/* Destroy the so far created topology */
-	vimc_device_unregister(vimc);
+err_mdev_unregister:
+	media_device_unregister(&vimc->mdev);
+err_comp_unbind_all:
+	component_unbind_all(master, NULL);
+err_v4l2_unregister:
+	v4l2_device_unregister(&vimc->v4l2_dev);
 
 	return ret;
 }
 
+static void vimc_comp_unbind(struct device *master)
+{
+	struct vimc_device *vimc = container_of(to_platform_device(master),
+						struct vimc_device, pdev);
+
+	dev_dbg(master, "unbind");
+
+	media_device_unregister(&vimc->mdev);
+	component_unbind_all(master, NULL);
+	v4l2_device_unregister(&vimc->v4l2_dev);
+}
+
+static int vimc_comp_compare(struct device *comp, void *data)
+{
+	const struct platform_device *pdev = to_platform_device(comp);
+	const char *name = data;
+
+	return !strcmp(pdev->dev.platform_data, name);
+}
+
+static struct component_match *vimc_add_subdevs(struct vimc_device *vimc)
+{
+	struct component_match *match = NULL;
+	struct vimc_platform_data pdata;
+	int i;
+
+	for (i = 0; i < vimc->pipe_cfg->num_ents; i++) {
+		dev_dbg(&vimc->pdev.dev, "new pdev for %s\n",
+			vimc->pipe_cfg->ents[i].drv);
+
+		strlcpy(pdata.entity_name, vimc->pipe_cfg->ents[i].name,
+			sizeof(pdata.entity_name));
+
+		vimc->subdevs[i] = platform_device_register_data(&vimc->pdev.dev,
+						vimc->pipe_cfg->ents[i].drv,
+						PLATFORM_DEVID_AUTO,
+						&pdata,
+						sizeof(pdata));
+		if (!vimc->subdevs[i]) {
+			while (--i >= 0)
+				platform_device_unregister(vimc->subdevs[i]);
+
+			return ERR_PTR(-ENOMEM);
+		}
+
+		component_match_add(&vimc->pdev.dev, &match, vimc_comp_compare,
+				    (void *)vimc->pipe_cfg->ents[i].name);
+	}
+
+	return match;
+}
+
+static void vimc_rm_subdevs(struct vimc_device *vimc)
+{
+	unsigned int i;
+
+	for (i = 0; i < vimc->pipe_cfg->num_ents; i++)
+		platform_device_unregister(vimc->subdevs[i]);
+}
+
+static const struct component_master_ops vimc_comp_ops = {
+	.bind = vimc_comp_bind,
+	.unbind = vimc_comp_unbind,
+};
+
 static int vimc_probe(struct platform_device *pdev)
 {
-	struct vimc_device *vimc;
+	struct vimc_device *vimc = container_of(pdev, struct vimc_device, pdev);
+	struct component_match *match = NULL;
 	int ret;
 
-	/* Prepare the vimc topology structure */
+	dev_dbg(&pdev->dev, "probe");
 
-	/* Allocate memory for the vimc structure */
-	vimc = kzalloc(sizeof(*vimc), GFP_KERNEL);
-	if (!vimc)
+	/* Create platform_device for each entity in the topology*/
+	vimc->subdevs = devm_kcalloc(&vimc->pdev.dev, vimc->pipe_cfg->num_ents,
+				     sizeof(*vimc->subdevs), GFP_KERNEL);
+	if (!vimc->subdevs)
 		return -ENOMEM;
 
-	/* Set the pipeline configuration struct */
-	vimc->pipe_cfg = &pipe_cfg;
+	match = vimc_add_subdevs(vimc);
+	if (IS_ERR(match))
+		return PTR_ERR(match);
+
+	/* Link the media device within the v4l2_device */
+	vimc->v4l2_dev.mdev = &vimc->mdev;
 
 	/* Initialize media device */
 	strlcpy(vimc->mdev.model, VIMC_MDEV_MODEL_NAME,
···
 	vimc->mdev.dev = &pdev->dev;
 	media_device_init(&vimc->mdev);
 
-	/* Create vimc topology */
-	ret = vimc_device_register(vimc);
+	/* Add self to the component system */
+	ret = component_master_add_with_match(&pdev->dev, &vimc_comp_ops,
+					      match);
 	if (ret) {
-		dev_err(vimc->mdev.dev,
-			"vimc device registration failed (err=%d)\n", ret);
+		media_device_cleanup(&vimc->mdev);
+		vimc_rm_subdevs(vimc);
 		kfree(vimc);
 		return ret;
 	}
-
-	/* Link the topology object with the platform device object */
-	platform_set_drvdata(pdev, vimc);
 
 	return 0;
 }
 
 static int vimc_remove(struct platform_device *pdev)
 {
-	struct vimc_device *vimc = platform_get_drvdata(pdev);
+	struct vimc_device *vimc = container_of(pdev, struct vimc_device, pdev);
 
-	/* Destroy all the topology */
-	vimc_device_unregister(vimc);
-	kfree(vimc);
+	dev_dbg(&pdev->dev, "remove");
+
+	component_master_del(&pdev->dev, &vimc_comp_ops);
+	vimc_rm_subdevs(vimc);
 
 	return 0;
 }
···
 {
 }
 
-static struct platform_device vimc_pdev = {
-	.name		= VIMC_PDEV_NAME,
-	.dev.release	= vimc_dev_release,
+static struct vimc_device vimc_dev = {
+	.pipe_cfg = &pipe_cfg,
+	.pdev = {
+		.name = VIMC_PDEV_NAME,
+		.dev.release = vimc_dev_release,
+	}
 };
 
 static struct platform_driver vimc_pdrv = {
···
 {
 	int ret;
 
-	ret = platform_device_register(&vimc_pdev);
+	ret = platform_device_register(&vimc_dev.pdev);
 	if (ret) {
-		dev_err(&vimc_pdev.dev,
+		dev_err(&vimc_dev.pdev.dev,
 			"platform device registration failed (err=%d)\n", ret);
 		return ret;
 	}
 
 	ret = platform_driver_register(&vimc_pdrv);
 	if (ret) {
-		dev_err(&vimc_pdev.dev,
+		dev_err(&vimc_dev.pdev.dev,
 			"platform driver registration failed (err=%d)\n", ret);
-
-		platform_device_unregister(&vimc_pdev);
+		platform_driver_unregister(&vimc_pdrv);
+		return ret;
 	}
 
-	return ret;
+	return 0;
 }
 
 static void __exit vimc_exit(void)
 {
 	platform_driver_unregister(&vimc_pdrv);
 
-	platform_device_unregister(&vimc_pdev);
+	platform_device_unregister(&vimc_dev.pdev);
 }
 
 module_init(vimc_init);

drivers/media/platform/vimc/vimc-sensor.c

···
  *
  */
 
+#include <linux/component.h>
 #include <linux/freezer.h>
 #include <linux/kthread.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
 #include <linux/v4l2-mediabus.h>
 #include <linux/vmalloc.h>
 #include <media/v4l2-subdev.h>
 #include <media/v4l2-tpg.h>
 
-#include "vimc-sensor.h"
+#include "vimc-common.h"
+
+#define VIMC_SEN_DRV_NAME "vimc-sensor"
 
 struct vimc_sen_device {
 	struct vimc_ent_device ved;
 	struct v4l2_subdev sd;
+	struct device *dev;
 	struct tpg_data tpg;
 	struct task_struct *kthread_sen;
 	u8 *frame;
···
 	/* Set the new format */
 	vimc_sen_adjust_fmt(&fmt->format);
 
-	dev_dbg(vsen->sd.v4l2_dev->mdev->dev, "%s: format update: "
+	dev_dbg(vsen->dev, "%s: format update: "
 		"old:%dx%d (0x%x, %d, %d, %d, %d) "
 		"new:%dx%d (0x%x, %d, %d, %d, %d)\n", vsen->sd.name,
 		/* old */
···
 		vsen->kthread_sen = kthread_run(vimc_sen_tpg_thread, vsen,
 					"%s-sen", vsen->sd.v4l2_dev->name);
 		if (IS_ERR(vsen->kthread_sen)) {
-			dev_err(vsen->sd.v4l2_dev->dev,
-				"%s: kernel_thread() failed\n",	vsen->sd.name);
+			dev_err(vsen->dev, "%s: kernel_thread() failed\n",
+				vsen->sd.name);
 			vfree(vsen->frame);
 			vsen->frame = NULL;
 			return PTR_ERR(vsen->kthread_sen);
···
 	.video = &vimc_sen_video_ops,
 };
 
-static void vimc_sen_destroy(struct vimc_ent_device *ved)
+static void vimc_sen_comp_unbind(struct device *comp, struct device *master,
+				 void *master_data)
 {
+	struct vimc_ent_device *ved = dev_get_drvdata(comp);
 	struct vimc_sen_device *vsen =
 				container_of(ved, struct vimc_sen_device, ved);
 
···
 	kfree(vsen);
 }
 
-struct vimc_ent_device *vimc_sen_create(struct v4l2_device *v4l2_dev,
-					const char *const name,
-					u16 num_pads,
-					const unsigned long *pads_flag)
+static int vimc_sen_comp_bind(struct device *comp, struct device *master,
+			      void *master_data)
 {
+	struct v4l2_device *v4l2_dev = master_data;
+	struct vimc_platform_data *pdata = comp->platform_data;
 	struct vimc_sen_device *vsen;
-	unsigned int i;
 	int ret;
-
-	/* NOTE: a sensor node may be created with more then one pad */
-	if (!name || !num_pads || !pads_flag)
-		return ERR_PTR(-EINVAL);
-
-	/* check if all pads are sources */
-	for (i = 0; i < num_pads; i++)
-		if (!(pads_flag[i] & MEDIA_PAD_FL_SOURCE))
-			return ERR_PTR(-EINVAL);
 
 	/* Allocate the vsen struct */
 	vsen = kzalloc(sizeof(*vsen), GFP_KERNEL);
 	if (!vsen)
-		return ERR_PTR(-ENOMEM);
+		return -ENOMEM;
 
 	/* Initialize ved and sd */
-	ret = vimc_ent_sd_register(&vsen->ved, &vsen->sd, v4l2_dev, name,
-				   MEDIA_ENT_F_CAM_SENSOR, num_pads, pads_flag,
-				   &vimc_sen_ops, vimc_sen_destroy);
+	ret = vimc_ent_sd_register(&vsen->ved, &vsen->sd, v4l2_dev,
+				   pdata->entity_name,
+				   MEDIA_ENT_F_ATV_DECODER, 1,
+				   (const unsigned long[1]) {MEDIA_PAD_FL_SOURCE},
+				   &vimc_sen_ops);
 	if (ret)
 		goto err_free_vsen;
+
+	dev_set_drvdata(comp, &vsen->ved);
+	vsen->dev = comp;
 
 	/* Initialize the frame format */
 	vsen->mbus_format = fmt_default;
···
 	if (ret)
 		goto err_unregister_ent_sd;
 
-	return &vsen->ved;
+	return 0;
 
 err_unregister_ent_sd:
 	vimc_ent_sd_unregister(&vsen->ved,  &vsen->sd);
 err_free_vsen:
 	kfree(vsen);
 
-	return ERR_PTR(ret);
+	return ret;
 }
+
+static const struct component_ops vimc_sen_comp_ops = {
+	.bind = vimc_sen_comp_bind,
+	.unbind = vimc_sen_comp_unbind,
+};
+
+static int vimc_sen_probe(struct platform_device *pdev)
+{
+	return component_add(&pdev->dev, &vimc_sen_comp_ops);
+}
+
+static int vimc_sen_remove(struct platform_device *pdev)
+{
+	component_del(&pdev->dev, &vimc_sen_comp_ops);
+
+	return 0;
+}
+
+static struct platform_driver vimc_sen_pdrv = {
+	.probe		= vimc_sen_probe,
+	.remove		= vimc_sen_remove,
+	.driver		= {
+		.name	= VIMC_SEN_DRV_NAME,
+	},
+};
+
+static const struct platform_device_id vimc_sen_driver_ids[] = {
+	{
+		.name           = VIMC_SEN_DRV_NAME,
+	},
+	{ }
+};
+
+module_platform_driver(vimc_sen_pdrv);
+
+MODULE_DEVICE_TABLE(platform, vimc_sen_driver_ids);
+
+MODULE_DESCRIPTION("Virtual Media Controller Driver (VIMC) Sensor");
+MODULE_AUTHOR("Helen Mae Koike Fornazier <[e-mail]>");
+MODULE_LICENSE("GPL");

drivers/media/platform/vimc/vimc-sensor.h

···
-/*
- * vimc-sensor.h Virtual Media Controller Driver
- *
- * Copyright (C) 2015-2017 Helen Koike <[e-mail]>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- */
-
-#ifndef _VIMC_SENSOR_H_
-#define _VIMC_SENSOR_H_
-
-#include "vimc-common.h"
-
-struct vimc_ent_device *vimc_sen_create(struct v4l2_device *v4l2_dev,
-					const char *const name,
-					u16 num_pads,
-					const unsigned long *pads_flag);
-
-#endif