> Create a device node named subdevX for every registered subdev.
>
> As the device node is registered before the subdev core::s_config
> function is called, return -EGAIN on open until initialization
> completes.
The only reason we have s_config is for old i2c drivers that need to be
supported in pre-2.6.26 kernels in the mercurial repository.
I'm thinking that we should get rid of that legacy support in the git
tree. It hurts my eyes every time I see that code.
Not a blocker for this patch series, but if others agree that we should
get rid of the legacy support then I can work on that.
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> Signed-off-by: Vimarsh Zutshi <vimarsh.zutshi@xxxxxxxxx>
> ---
> drivers/media/video/Makefile | 2 +-
> drivers/media/video/v4l2-common.c | 3 ++
> drivers/media/video/v4l2-dev.c | 5 +++
> drivers/media/video/v4l2-device.c | 27 +++++++++++++++-
> drivers/media/video/v4l2-subdev.c | 65
> +++++++++++++++++++++++++++++++++++++
> include/media/v4l2-dev.h | 3 +-
> include/media/v4l2-subdev.h | 10 ++++++
> 7 files changed, 112 insertions(+), 3 deletions(-)
> create mode 100644 drivers/media/video/v4l2-subdev.c
>
> diff --git a/drivers/media/video/Makefile b/drivers/media/video/Makefile
> index cc93859..c9c07e5 100644
> --- a/drivers/media/video/Makefile
> +++ b/drivers/media/video/Makefile
> @@ -11,7 +11,7 @@ stkwebcam-objs := stk-webcam.o stk-sensor.o
> omap2cam-objs := omap24xxcam.o omap24xxcam-dma.o
>
> videodev-objs := v4l2-dev.o v4l2-ioctl.o v4l2-device.o v4l2-fh.o \
> - v4l2-event.o
> + v4l2-event.o v4l2-subdev.o
>
> # V4L2 core modules
>
> diff --git a/drivers/media/video/v4l2-common.c
> b/drivers/media/video/v4l2-common.c
> index 4e53b0b..3032aa3 100644
> --- a/drivers/media/video/v4l2-common.c
> +++ b/drivers/media/video/v4l2-common.c
> @@ -871,6 +871,7 @@ struct v4l2_subdev *v4l2_i2c_new_subdev_board(struct
> v4l2_device *v4l2_dev,
>
> /* Register with the v4l2_device which increases the module's
> use count as well. */
> + sd->initialized = 0;
> if (v4l2_device_register_subdev(v4l2_dev, sd))
> sd = NULL;
> /* Decrease the module use count to match the first try_module_get. */
> @@ -885,6 +886,8 @@ struct v4l2_subdev *v4l2_i2c_new_subdev_board(struct
> v4l2_device *v4l2_dev,
> if (err && err != -ENOIOCTLCMD) {
> v4l2_device_unregister_subdev(sd);
> sd = NULL;
> + } else {
> + sd->initialized = 1;
> }
> }
>
> diff --git a/drivers/media/video/v4l2-dev.c
> b/drivers/media/video/v4l2-dev.c
> index 0ca7ec9..5a9e9df 100644
> --- a/drivers/media/video/v4l2-dev.c
> +++ b/drivers/media/video/v4l2-dev.c
> @@ -401,6 +401,8 @@ static int get_index(struct video_device *vdev)
> * %VFL_TYPE_VBI - Vertical blank data (undecoded)
> *
> * %VFL_TYPE_RADIO - A radio card
> + *
> + * %VFL_TYPE_SUBDEV - A subdevice
> */
> static int __video_register_device(struct video_device *vdev, int type,
> int nr,
> int warn_if_nr_in_use)
> @@ -439,6 +441,9 @@ static int __video_register_device(struct video_device
> *vdev, int type, int nr,
> case VFL_TYPE_RADIO:
> name_base = "radio";
> break;
> + case VFL_TYPE_SUBDEV:
> + name_base = "subdev";
> + break;
> default:
> printk(KERN_ERR "%s called with unknown type: %d\n",
> __func__, type);
> diff --git a/drivers/media/video/v4l2-device.c
> b/drivers/media/video/v4l2-device.c
> index 5a7dc4a..685fa82 100644
> --- a/drivers/media/video/v4l2-device.c
> +++ b/drivers/media/video/v4l2-device.c
> @@ -115,18 +115,40 @@ EXPORT_SYMBOL_GPL(v4l2_device_unregister);
> int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
> struct v4l2_subdev *sd)
> {
> + struct video_device *vdev;
> + int ret;
> +
> /* 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;
> spin_lock(&v4l2_dev->lock);
> list_add_tail(&sd->list, &v4l2_dev->subdevs);
> spin_unlock(&v4l2_dev->lock);
> - return 0;
> +
> + /* Register the device node. */
> + vdev = &sd->devnode;
> + snprintf(vdev->name, sizeof(vdev->name), "subdev");
Hmm, perhaps we should be more creative here. For example:
snprintf(vdev->name, sizeof(vdev->name), "subdev %s", sd->name);
> + vdev->parent = v4l2_dev->dev;
> + vdev->fops = &v4l2_subdev_fops;
> + vdev->release = video_device_release_empty;
> + ret = video_register_device(vdev, VFL_TYPE_SUBDEV, -1);
> + if (ret < 0) {
> + spin_lock(&v4l2_dev->lock);
> + list_del(&sd->list);
> + spin_unlock(&v4l2_dev->lock);
> + sd->v4l2_dev = NULL;
> + module_put(sd->owner);
You can just call v4l2_device_unregister_subdev(sd) here. The call
to video_unregister_device will know that the registration failed and will
just return.
> + }
> +
> + return ret;
> }
> EXPORT_SYMBOL_GPL(v4l2_device_register_subdev);
>
> @@ -135,10 +157,13 @@ void v4l2_device_unregister_subdev(struct
> v4l2_subdev *sd)
> /* return if it isn't registered */
> if (sd == NULL || sd->v4l2_dev == NULL)
> return;
> +
> spin_lock(&sd->v4l2_dev->lock);
> list_del(&sd->list);
> spin_unlock(&sd->v4l2_dev->lock);
> sd->v4l2_dev = NULL;
> +
> module_put(sd->owner);
> + video_unregister_device(&sd->devnode);
> }
> EXPORT_SYMBOL_GPL(v4l2_device_unregister_subdev);
> diff --git a/drivers/media/video/v4l2-subdev.c
> b/drivers/media/video/v4l2-subdev.c
> new file mode 100644
> index 0000000..a048161
> --- /dev/null
> +++ b/drivers/media/video/v4l2-subdev.c
> @@ -0,0 +1,65 @@
> +/*
> + * V4L2 subdevice support.
> + *
> + * Copyright (C) 2009 Laurent Pinchart
2009 -> 2010
Might be wrong elsewhere as well.
> <laurent.pinchart@xxxxxxxxxxxxxxxx>
> + *
> + * 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/videodev2.h>
> +
> +#include <media/v4l2-device.h>
> +#include <media/v4l2-ioctl.h>
> +
> +static int subdev_open(struct file *file)
> +{
> + struct video_device *vdev = video_devdata(file);
> + struct v4l2_subdev *sd = vdev_to_v4l2_subdev(vdev);
> +
> + if (!sd->initialized)
> + return -EAGAIN;
> +
> + return 0;
> +}
> +
> +static int subdev_close(struct file *file)
> +{
> + return 0;
> +}
> +
> +static long subdev_do_ioctl(struct file *file, unsigned int cmd, void
> *arg)
> +{
> + switch (cmd) {
> + default:
> + return -ENOIOCTLCMD;
> + }
> +
> + return 0;
> +}
> +
> +static long subdev_ioctl(struct file *file, unsigned int cmd,
> + unsigned long arg)
> +{
> + return video_usercopy(file, cmd, arg, subdev_do_ioctl);
> +}
> +
> +const struct v4l2_file_operations v4l2_subdev_fops = {
> + .owner = THIS_MODULE,
> + .open = subdev_open,
> + .unlocked_ioctl = subdev_ioctl,
> + .release = subdev_close,
> +};
> diff --git a/include/media/v4l2-dev.h b/include/media/v4l2-dev.h
> index bebe44b..eee1e2b 100644
> --- a/include/media/v4l2-dev.h
> +++ b/include/media/v4l2-dev.h
> @@ -22,7 +22,8 @@
> #define VFL_TYPE_VBI 1
> #define VFL_TYPE_RADIO 2
> #define VFL_TYPE_VTX 3
> -#define VFL_TYPE_MAX 4
> +#define VFL_TYPE_SUBDEV 4
> +#define VFL_TYPE_MAX 5
>
> struct v4l2_ioctl_callbacks;
> struct video_device;
> diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
> index 6088316..00010bd 100644
> --- a/include/media/v4l2-subdev.h
> +++ b/include/media/v4l2-subdev.h
> @@ -22,6 +22,7 @@
> #define _V4L2_SUBDEV_H
>
> #include <media/v4l2-common.h>
> +#include <media/v4l2-dev.h>
> #include <media/v4l2-mediabus.h>
>
> /* generic v4l2_device notify callback notification values */
> @@ -421,8 +422,16 @@ struct v4l2_subdev {
> u32 grp_id;
> /* pointer to private data */
> void *priv;
> + /* subdev device node */
> + struct video_device devnode;
> + unsigned int initialized;
> };
>
> +#define vdev_to_v4l2_subdev(vdev) \
> + container_of(vdev, struct v4l2_subdev, devnode)
> +
> +extern const struct v4l2_file_operations v4l2_subdev_fops;
> +
> static inline void v4l2_set_subdevdata(struct v4l2_subdev *sd, void *p)
> {
> sd->priv = p;
> @@ -444,6 +453,7 @@ static inline void v4l2_subdev_init(struct v4l2_subdev
> *sd,
> sd->name[0] = '\0';
> sd->grp_id = 0;
> sd->priv = NULL;
> + sd->initialized = 0;
> }
>
> /* Call an ops of a v4l2_subdev, doing the right checks against
> --
> 1.7.1
>
> --
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>
Reviewed-by: Hans Verkuil <hverkuil@xxxxxxxxx>
--
Hans Verkuil - video4linux developer - sponsored by TANDBERG, part of Cisco
--
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