[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, 158 insertions, 247 deletions

diff --git a/drivers/media/platform/vimc/vimc-core.c b/drivers/media/platform/vimc/vimc-core.c
index afc79e2f3029..51c0eee61ca6 100644
--- a/drivers/media/platform/vimc/vimc-core.c
+++ b/drivers/media/platform/vimc/vimc-core.c
@@ -15,15 +15,14 @@
  *
  */
 
+#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"
@@ -37,10 +36,10 @@
 }
 
 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 */
@@ -49,43 +48,14 @@ struct vimc_device {
 	/* 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 */
@@ -112,60 +82,40 @@ struct vimc_pipeline_config {
 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",
 	},
 };
 
@@ -197,111 +147,40 @@ static const struct vimc_pipeline_config pipe_cfg = {
 
 /* -------------------------------------------------------------------------- */
 
-static void vimc_device_unregister(struct vimc_device *vimc)
+static int vimc_create_links(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 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]);
+
+		ret = media_create_pad_link(ved_src->ent, link->src_pad,
+					    ved_sink->ent, link->sink_pad,
+					    link->flags);
+		if (ret)
+			return ret;
 	}
 
-	/* 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);
+	return 0;
 }
 
-static int vimc_device_register(struct vimc_device *vimc)
+static int vimc_comp_bind(struct device *master)
 {
-	unsigned int i;
+	struct vimc_device *vimc = container_of(to_platform_device(master),
+						struct vimc_device, pdev);
 	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;
-
-	/* Link the media device within the v4l2_device */
-	vimc->v4l2_dev.mdev = &vimc->mdev;
+	dev_dbg(master, "bind");
 
 	/* Register the v4l2 struct */
 	ret = v4l2_device_register(vimc->mdev.dev, &vimc->v4l2_dev);
@@ -311,66 +190,22 @@ static int vimc_device_register(struct vimc_device *vimc)
 		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 *);
-
-		/* 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];
+	/* Bind subdevices */
+	ret = component_bind_all(master, &vimc->v4l2_dev);
+	if (ret)
+		goto err_v4l2_unregister;
 
-		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*/
@@ -379,32 +214,106 @@ static int vimc_device_register(struct vimc_device *vimc)
 		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,
@@ -412,28 +321,27 @@ static int vimc_probe(struct platform_device *pdev)
 	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;
 }
@@ -442,9 +350,12 @@ static void vimc_dev_release(struct device *dev)
 {
 }
 
-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 = {
@@ -459,29 +370,29 @@ static int __init vimc_init(void)
 {
 	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);