[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, 69 insertions, 30 deletions

diff --git a/drivers/media/platform/vimc/vimc-capture.c b/drivers/media/platform/vimc/vimc-capture.c
index 359f59efb44e..14cb32e21130 100644
--- a/drivers/media/platform/vimc/vimc-capture.c
+++ b/drivers/media/platform/vimc/vimc-capture.c
@@ -15,15 +15,21 @@
  *
  */
 
+#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;
@@ -131,7 +137,7 @@ static int vimc_cap_s_fmt_vid_cap(struct file *file, void *priv,
 
         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 */
@@ -309,8 +315,7 @@ static int vimc_cap_buffer_prepare(struct vb2_buffer *vb)
         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;
         }
@@ -335,8 +340,10 @@ static const struct media_entity_operations vimc_cap_mops = {
         .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);
 
@@ -385,42 +392,35 @@ static void vimc_cap_process_frame(struct vimc_ent_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;
 
@@ -441,9 +441,8 @@ struct vimc_ent_device *vimc_cap_create(struct v4l2_device *v4l2_dev,
 
         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;
         }
 
@@ -459,10 +458,11 @@ struct vimc_ent_device *vimc_cap_create(struct v4l2_device *v4l2_dev,
                                  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;
@@ -475,19 +475,18 @@ struct vimc_ent_device *vimc_cap_create(struct v4l2_device *v4l2_dev,
         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);
@@ -498,5 +497,45 @@ err_clean_pads:
 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 <helen.fornazier@gmail.com>");
+MODULE_LICENSE("GPL");