media: vimc: Collapse component structure into a single monolithic driver

vimc uses Component API to split the driver into functional components.
The real hardware resembles a monolith structure than component and
component structure added a level of complexity making it hard to
maintain without adding any real benefit.

The sensor is one vimc component that would makes sense to be a separate
module to closely align with the real hardware. It would be easier to
collapse vimc into single monolithic driver first and then split the
sensor off as a separate module.

Collapse it into a single monolithic driver removing the Component API.
This patch removes the component API and makes minimal changes to the
code base preserving the functional division of the code structure.
Preserving the functional structure allows us to split the sensor off
as a separate module in the future.

Major design elements in this change are:
- Use existing struct vimc_ent_config and struct vimc_pipeline_config
  to drive the initialization of the functional components.
- Make vimc_device and vimc_ent_config global by moving them to
  vimc-common.h
- Add two new hooks add and rm to initialize and register, unregister
  and free subdevs.
- All component API is now gone and bind and unbind hooks are modified
  to do "add" and "rm" with minimal changes to just add and rm subdevs.
- vimc-core's bind and unbind are now register and unregister.
- Add a new field to vimc_device structure for saving the pointers to
  struct vimc_ent_device(s) subdevs create in their "add" hooks. These
  get used to create links and removing the subdevs. vimc-core allocates
  this array which sized to number of entries in the topology defined in
  the vimc_pipeline_config structure.
- vimc-core invokes "add" hooks from its vimc_register_devices().
  The "add" hooks remain the same and register subdevs. They don't
  create platform devices of their own and use vimc's pdev.dev as
  their reference device. Each "add" hook returns pointer to its struct
  vimc_ent_device. This is saved in the vimc_device ent_devs array.
- vimc-core invokes "rm" hooks from its unregister to unregister subdevs
  and cleanup.
- vimc-core invokes "add" and "rm" hooks with pointer to struct vimc_device
  and the corresponding vimc_ent_device saved in the ent_devs.

The following configure and stream test works on all devices.

media-ctl -d platform:vimc -V '"Sensor A":0[fmt:SBGGR8_1X8/640x480]'
media-ctl -d platform:vimc -V '"Debayer A":0[fmt:SBGGR8_1X8/640x480]'
media-ctl -d platform:vimc -V '"Sensor B":0[fmt:SBGGR8_1X8/640x480]'
media-ctl -d platform:vimc -V '"Debayer B":0[fmt:SBGGR8_1X8/640x480]'

v4l2-ctl -z platform:vimc -d "RGB/YUV Capture" -v width=1920,height=1440
v4l2-ctl -z platform:vimc -d "Raw Capture 0" -v pixelformat=BA81
v4l2-ctl -z platform:vimc -d "Raw Capture 1" -v pixelformat=BA81

v4l2-ctl --stream-mmap --stream-count=100 -d /dev/video1
v4l2-ctl --stream-mmap --stream-count=100 -d /dev/video2
v4l2-ctl --stream-mmap --stream-count=100 -d /dev/video3

Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Acked-by: Helen Koike <helen.koike@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

1 files changed, 87 insertions, 129 deletions

diff --git a/drivers/media/platform/vimc/vimc-core.c b/drivers/media/platform/vimc/vimc-core.c
index 571c55aa0e16..6e3e5c91ae39 100644
--- a/drivers/media/platform/vimc/vimc-core.c
+++ b/drivers/media/platform/vimc/vimc-core.c
@@ -5,7 +5,6 @@
  * Copyright (C) 2015-2017 Helen Koike <helen.fornazier@gmail.com>
  */
 
-#include <linux/component.h>
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
@@ -24,29 +23,6 @@
 	.flags = link_flags,					\
 }
 
-struct vimc_device {
-	/* The platform device */
-	struct platform_device pdev;
-
-	/* The pipeline configuration */
-	const struct vimc_pipeline_config *pipe_cfg;
-
-	/* The Associated media_device parent */
-	struct media_device mdev;
-
-	/* Internal v4l2 parent device*/
-	struct v4l2_device v4l2_dev;
-
-	/* Subdevices */
-	struct platform_device **subdevs;
-};
-
-/* Structure which describes individual configuration for each entity */
-struct vimc_ent_config {
-	const char *name;
-	const char *drv;
-};
-
 /* Structure which describes links between entities */
 struct vimc_ent_link {
 	unsigned int src_ent;
@@ -68,43 +44,52 @@ struct vimc_pipeline_config {
  * Topology Configuration
  */
 
-static const struct vimc_ent_config ent_config[] = {
+static struct vimc_ent_config ent_config[] = {
 	{
 		.name = "Sensor A",
-		.drv = "vimc-sensor",
+		.add = vimc_sen_add,
+		.rm = vimc_sen_rm,
 	},
 	{
 		.name = "Sensor B",
-		.drv = "vimc-sensor",
+		.add = vimc_sen_add,
+		.rm = vimc_sen_rm,
 	},
 	{
 		.name = "Debayer A",
-		.drv = "vimc-debayer",
+		.add = vimc_deb_add,
+		.rm = vimc_deb_rm,
 	},
 	{
 		.name = "Debayer B",
-		.drv = "vimc-debayer",
+		.add = vimc_deb_add,
+		.rm = vimc_deb_rm,
 	},
 	{
 		.name = "Raw Capture 0",
-		.drv = "vimc-capture",
+		.add = vimc_cap_add,
+		.rm = vimc_cap_rm,
 	},
 	{
 		.name = "Raw Capture 1",
-		.drv = "vimc-capture",
+		.add = vimc_cap_add,
+		.rm = vimc_cap_rm,
 	},
 	{
-		.name = "RGB/YUV Input",
 		/* TODO: change this to vimc-input when it is implemented */
-		.drv = "vimc-sensor",
+		.name = "RGB/YUV Input",
+		.add = vimc_sen_add,
+		.rm = vimc_sen_rm,
 	},
 	{
 		.name = "Scaler",
-		.drv = "vimc-scaler",
+		.add = vimc_sca_add,
+		.rm = vimc_sca_rm,
 	},
 	{
 		.name = "RGB/YUV Capture",
-		.drv = "vimc-capture",
+		.add = vimc_cap_add,
+		.rm = vimc_cap_rm,
 	},
 };
 
@@ -127,7 +112,7 @@ static const struct vimc_ent_link ent_links[] = {
 	VIMC_ENT_LINK(7, 1, 8, 0, MEDIA_LNK_FL_ENABLED | MEDIA_LNK_FL_IMMUTABLE),
 };
 
-static const struct vimc_pipeline_config pipe_cfg = {
+static struct vimc_pipeline_config pipe_cfg = {
 	.ents		= ent_config,
 	.num_ents	= ARRAY_SIZE(ent_config),
 	.links		= ent_links,
@@ -136,6 +121,14 @@ static const struct vimc_pipeline_config pipe_cfg = {
 
 /* -------------------------------------------------------------------------- */
 
+static void vimc_rm_links(struct vimc_device *vimc)
+{
+	unsigned int i;
+
+	for (i = 0; i < vimc->pipe_cfg->num_ents; i++)
+		media_entity_remove_links(vimc->ent_devs[i]->ent);
+}
+
 static int vimc_create_links(struct vimc_device *vimc)
 {
 	unsigned int i;
@@ -144,32 +137,58 @@ static int vimc_create_links(struct vimc_device *vimc)
 	/* 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]);
+			vimc->ent_devs[link->src_ent];
 		struct vimc_ent_device *ved_sink =
-			platform_get_drvdata(vimc->subdevs[link->sink_ent]);
+			vimc->ent_devs[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;
+			goto err_rm_links;
 	}
 
 	return 0;
+
+err_rm_links:
+	vimc_rm_links(vimc);
+	return ret;
 }
 
-static int vimc_comp_bind(struct device *master)
+static int vimc_add_subdevs(struct vimc_device *vimc)
 {
-	struct vimc_device *vimc = container_of(to_platform_device(master),
-						struct vimc_device, pdev);
-	int ret;
+	unsigned int i;
+	struct vimc_ent_device *ved;
+
+	for (i = 0; i < vimc->pipe_cfg->num_ents; i++) {
+		dev_dbg(&vimc->pdev.dev, "new entity for %s\n",
+			vimc->pipe_cfg->ents[i].name);
+		ved = vimc->pipe_cfg->ents[i].add(vimc,
+					vimc->pipe_cfg->ents[i].name);
+		if (!ved) {
+			dev_err(&vimc->pdev.dev, "add new entity for %s\n",
+				vimc->pipe_cfg->ents[i].name);
+			return -EINVAL;
+		}
+		vimc->ent_devs[i] = ved;
+	}
+	return 0;
+}
+
+static void vimc_rm_subdevs(struct vimc_device *vimc)
+{
+	unsigned int i;
 
-	dev_dbg(master, "bind");
+	for (i = 0; i < vimc->pipe_cfg->num_ents; i++)
+		if (vimc->ent_devs[i])
+			vimc->pipe_cfg->ents[i].rm(vimc, vimc->ent_devs[i]);
+}
+
+static int vimc_register_devices(struct vimc_device *vimc)
+{
+	int ret;
 
 	/* Register the v4l2 struct */
 	ret = v4l2_device_register(vimc->mdev.dev, &vimc->v4l2_dev);
@@ -179,22 +198,30 @@ static int vimc_comp_bind(struct device *master)
 		return ret;
 	}
 
-	/* Bind subdevices */
-	ret = component_bind_all(master, &vimc->v4l2_dev);
-	if (ret)
+	/* allocate ent_devs */
+	vimc->ent_devs = kmalloc_array(vimc->pipe_cfg->num_ents,
+				       sizeof(*vimc->ent_devs),
+				       GFP_KERNEL);
+	if (!vimc->ent_devs)
 		goto err_v4l2_unregister;
 
+	/* Invoke entity config hooks to initialize and register subdevs */
+	ret = vimc_add_subdevs(vimc);
+	if (ret)
+		/* remove sundevs that got added */
+		goto err_rm_subdevs;
+
 	/* Initialize links */
 	ret = vimc_create_links(vimc);
 	if (ret)
-		goto err_comp_unbind_all;
+		goto err_rm_subdevs;
 
 	/* 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);
-		goto err_comp_unbind_all;
+		goto err_rm_subdevs;
 	}
 
 	/* Expose all subdev's nodes*/
@@ -211,98 +238,32 @@ static int vimc_comp_bind(struct device *master)
 err_mdev_unregister:
 	media_device_unregister(&vimc->mdev);
 	media_device_cleanup(&vimc->mdev);
-err_comp_unbind_all:
-	component_unbind_all(master, NULL);
+err_rm_subdevs:
+	vimc_rm_subdevs(vimc);
+	kfree(vimc->ent_devs);
 err_v4l2_unregister:
 	v4l2_device_unregister(&vimc->v4l2_dev);
 
 	return ret;
 }
 
-static void vimc_comp_unbind(struct device *master)
+static void vimc_unregister(struct vimc_device *vimc)
 {
-	struct vimc_device *vimc = container_of(to_platform_device(master),
-						struct vimc_device, pdev);
-
-	dev_dbg(master, "unbind");
-
 	media_device_unregister(&vimc->mdev);
 	media_device_cleanup(&vimc->mdev);
-	component_unbind_all(master, NULL);
 	v4l2_device_unregister(&vimc->v4l2_dev);
+	kfree(vimc->ent_devs);
 }
 
-static int vimc_comp_compare(struct device *comp, void *data)
-{
-	return comp == data;
-}
-
-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);
-
-		strscpy(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 (IS_ERR(vimc->subdevs[i])) {
-			match = ERR_CAST(vimc->subdevs[i]);
-			while (--i >= 0)
-				platform_device_unregister(vimc->subdevs[i]);
-
-			return match;
-		}
-
-		component_match_add(&vimc->pdev.dev, &match, vimc_comp_compare,
-				    &vimc->subdevs[i]->dev);
-	}
-
-	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 = container_of(pdev, struct vimc_device, pdev);
-	struct component_match *match = NULL;
 	int ret;
 
 	dev_dbg(&pdev->dev, "probe");
 
 	memset(&vimc->mdev, 0, sizeof(vimc->mdev));
 
-	/* 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;
-
-	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;
 
@@ -314,12 +275,9 @@ static int vimc_probe(struct platform_device *pdev)
 	vimc->mdev.dev = &pdev->dev;
 	media_device_init(&vimc->mdev);
 
-	/* Add self to the component system */
-	ret = component_master_add_with_match(&pdev->dev, &vimc_comp_ops,
-					      match);
+	ret = vimc_register_devices(vimc);
 	if (ret) {
 		media_device_cleanup(&vimc->mdev);
-		vimc_rm_subdevs(vimc);
 		return ret;
 	}
 
@@ -332,8 +290,8 @@ static int vimc_remove(struct platform_device *pdev)
 
 	dev_dbg(&pdev->dev, "remove");
 
-	component_master_del(&pdev->dev, &vimc_comp_ops);
 	vimc_rm_subdevs(vimc);
+	vimc_unregister(vimc);
 
 	return 0;
 }