1 files changed, 253 insertions, 0 deletions

diff --git a/drivers/media/video/v4l2-device.c b/drivers/media/video/v4l2-device.c
new file mode 100644
index 00000000000..e6a2c3b302d
--- /dev/null
+++ b/drivers/media/video/v4l2-device.c
@@ -0,0 +1,253 @@
+/*
+    V4L2 device support.
+
+    Copyright (C) 2008  Hans Verkuil <hverkuil@xs4all.nl>
+
+    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.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/types.h>
+#include <linux/ioctl.h>
+#include <linux/i2c.h>
+#if defined(CONFIG_SPI)
+#include <linux/spi/spi.h>
+#endif
+#include <linux/videodev2.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-ctrls.h>
+
+int v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev)
+{
+        if (v4l2_dev == NULL)
+                return -EINVAL;
+
+        INIT_LIST_HEAD(&v4l2_dev->subdevs);
+        spin_lock_init(&v4l2_dev->lock);
+        mutex_init(&v4l2_dev->ioctl_lock);
+        v4l2_prio_init(&v4l2_dev->prio);
+        kref_init(&v4l2_dev->ref);
+        get_device(dev);
+        v4l2_dev->dev = dev;
+        if (dev == NULL) {
+                /* If dev == NULL, then name must be filled in by the caller */
+                WARN_ON(!v4l2_dev->name[0]);
+                return 0;
+        }
+
+        /* Set name to driver name + device name if it is empty. */
+        if (!v4l2_dev->name[0])
+                snprintf(v4l2_dev->name, sizeof(v4l2_dev->name), "%s %s",
+                        dev->driver->name, dev_name(dev));
+        if (!dev_get_drvdata(dev))
+                dev_set_drvdata(dev, v4l2_dev);
+        return 0;
+}
+EXPORT_SYMBOL_GPL(v4l2_device_register);
+
+static void v4l2_device_release(struct kref *ref)
+{
+        struct v4l2_device *v4l2_dev =
+                container_of(ref, struct v4l2_device, ref);
+
+        if (v4l2_dev->release)
+                v4l2_dev->release(v4l2_dev);
+}
+
+int v4l2_device_put(struct v4l2_device *v4l2_dev)
+{
+        return kref_put(&v4l2_dev->ref, v4l2_device_release);
+}
+EXPORT_SYMBOL_GPL(v4l2_device_put);
+
+int v4l2_device_set_name(struct v4l2_device *v4l2_dev, const char *basename,
+                                                atomic_t *instance)
+{
+        int num = atomic_inc_return(instance) - 1;
+        int len = strlen(basename);
+
+        if (basename[len - 1] >= '0' && basename[len - 1] <= '9')
+                snprintf(v4l2_dev->name, sizeof(v4l2_dev->name),
+                                "%s-%d", basename, num);
+        else
+                snprintf(v4l2_dev->name, sizeof(v4l2_dev->name),
+                                "%s%d", basename, num);
+        return num;
+}
+EXPORT_SYMBOL_GPL(v4l2_device_set_name);
+
+void v4l2_device_disconnect(struct v4l2_device *v4l2_dev)
+{
+        if (v4l2_dev->dev == NULL)
+                return;
+
+        if (dev_get_drvdata(v4l2_dev->dev) == v4l2_dev)
+                dev_set_drvdata(v4l2_dev->dev, NULL);
+        put_device(v4l2_dev->dev);
+        v4l2_dev->dev = NULL;
+}
+EXPORT_SYMBOL_GPL(v4l2_device_disconnect);
+
+void v4l2_device_unregister(struct v4l2_device *v4l2_dev)
+{
+        struct v4l2_subdev *sd, *next;
+
+        if (v4l2_dev == NULL)
+                return;
+        v4l2_device_disconnect(v4l2_dev);
+
+        /* Unregister subdevs */
+        list_for_each_entry_safe(sd, next, &v4l2_dev->subdevs, list) {
+                v4l2_device_unregister_subdev(sd);
+#if defined(CONFIG_I2C) || (defined(CONFIG_I2C_MODULE) && defined(MODULE))
+                if (sd->flags & V4L2_SUBDEV_FL_IS_I2C) {
+                        struct i2c_client *client = v4l2_get_subdevdata(sd);
+
+                        /* We need to unregister the i2c client explicitly.
+                           We cannot rely on i2c_del_adapter to always
+                           unregister clients for us, since if the i2c bus
+                           is a platform bus, then it is never deleted. */
+                        if (client)
+                                i2c_unregister_device(client);
+                        continue;
+                }
+#endif
+#if defined(CONFIG_SPI)
+                if (sd->flags & V4L2_SUBDEV_FL_IS_SPI) {
+                        struct spi_device *spi = v4l2_get_subdevdata(sd);
+
+                        if (spi)
+                                spi_unregister_device(spi);
+                        continue;
+                }
+#endif
+        }
+}
+EXPORT_SYMBOL_GPL(v4l2_device_unregister);
+
+int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
+                                struct v4l2_subdev *sd)
+{
+#if defined(CONFIG_MEDIA_CONTROLLER)
+        struct media_entity *entity = &sd->entity;
+#endif
+        int err;
+
+        /* Check for valid input */
+        if (v4l2_dev == NULL || sd == NULL || !sd->name[0])
+                return -EINVAL;
+
+        /* Warn if we apparently re-register a subdev */
+        WARN_ON(sd->v4l2_dev != NULL);
+
+        if (!try_module_get(sd->owner))
+                return -ENODEV;
+
+        sd->v4l2_dev = v4l2_dev;
+        if (sd->internal_ops && sd->internal_ops->registered) {
+                err = sd->internal_ops->registered(sd);
+                if (err) {
+                        module_put(sd->owner);
+                        return err;
+                }
+        }
+
+        /* This just returns 0 if either of the two args is NULL */
+        err = v4l2_ctrl_add_handler(v4l2_dev->ctrl_handler, sd->ctrl_handler);
+        if (err) {
+                if (sd->internal_ops && sd->internal_ops->unregistered)
+                        sd->internal_ops->unregistered(sd);
+                module_put(sd->owner);
+                return err;
+        }
+
+#if defined(CONFIG_MEDIA_CONTROLLER)
+        /* Register the entity. */
+        if (v4l2_dev->mdev) {
+                err = media_device_register_entity(v4l2_dev->mdev, entity);
+                if (err < 0) {
+                        if (sd->internal_ops && sd->internal_ops->unregistered)
+                                sd->internal_ops->unregistered(sd);
+                        module_put(sd->owner);
+                        return err;
+                }
+        }
+#endif
+
+        spin_lock(&v4l2_dev->lock);
+        list_add_tail(&sd->list, &v4l2_dev->subdevs);
+        spin_unlock(&v4l2_dev->lock);
+
+        return 0;
+}
+EXPORT_SYMBOL_GPL(v4l2_device_register_subdev);
+
+int v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev)
+{
+        struct video_device *vdev;
+        struct v4l2_subdev *sd;
+        int err;
+
+        /* Register a device node for every subdev marked with the
+         * V4L2_SUBDEV_FL_HAS_DEVNODE flag.
+         */
+        list_for_each_entry(sd, &v4l2_dev->subdevs, list) {
+                if (!(sd->flags & V4L2_SUBDEV_FL_HAS_DEVNODE))
+                        continue;
+
+                vdev = &sd->devnode;
+                strlcpy(vdev->name, sd->name, sizeof(vdev->name));
+                vdev->v4l2_dev = v4l2_dev;
+                vdev->fops = &v4l2_subdev_fops;
+                vdev->release = video_device_release_empty;
+                vdev->ctrl_handler = sd->ctrl_handler;
+                err = __video_register_device(vdev, VFL_TYPE_SUBDEV, -1, 1,
+                                              sd->owner);
+                if (err < 0)
+                        return err;
+#if defined(CONFIG_MEDIA_CONTROLLER)
+                sd->entity.v4l.major = VIDEO_MAJOR;
+                sd->entity.v4l.minor = vdev->minor;
+#endif
+        }
+        return 0;
+}
+EXPORT_SYMBOL_GPL(v4l2_device_register_subdev_nodes);
+
+void v4l2_device_unregister_subdev(struct v4l2_subdev *sd)
+{
+        struct v4l2_device *v4l2_dev;
+
+        /* return if it isn't registered */
+        if (sd == NULL || sd->v4l2_dev == NULL)
+                return;
+
+        v4l2_dev = sd->v4l2_dev;
+
+        spin_lock(&v4l2_dev->lock);
+        list_del(&sd->list);
+        spin_unlock(&v4l2_dev->lock);
+
+        if (sd->internal_ops && sd->internal_ops->unregistered)
+                sd->internal_ops->unregistered(sd);
+        sd->v4l2_dev = NULL;
+
+#if defined(CONFIG_MEDIA_CONTROLLER)
+        if (v4l2_dev->mdev)
+                media_device_unregister_entity(&sd->entity);
+#endif
+        video_unregister_device(&sd->devnode);
+        module_put(sd->owner);
+}
+EXPORT_SYMBOL_GPL(v4l2_device_unregister_subdev);