On Monday 12 July 2010 17:25:49 Laurent Pinchart wrote:
> 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.
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> Signed-off-by: Vimarsh Zutshi <vimarsh.zutshi@xxxxxxxxx>
Acked-by: Hans Verkuil <hverkuil@xxxxxxxxx>
Note: on Friday I hope to post a patch that removes the VTX support. This was
scheduled for removal in 2.6.35, but I never got around to that, so I hope
to remove it in 2.6.36 instead. That change will clash with this patch though
since the VTX type is removed.
It may (or may not) be a good idea to use the freed range of minors for these
new subdev nodes.
Regards,
Hans
> ---
> Documentation/video4linux/v4l2-framework.txt | 18 +++++++
> drivers/media/radio/radio-si4713.c | 2 +-
> drivers/media/video/Makefile | 2 +-
> drivers/media/video/soc_camera.c | 2 +-
> drivers/media/video/v4l2-common.c | 15 +++++-
> drivers/media/video/v4l2-dev.c | 27 ++++------
> drivers/media/video/v4l2-device.c | 25 +++++++++-
> drivers/media/video/v4l2-ioctl.c | 2 +-
> drivers/media/video/v4l2-subdev.c | 65 ++++++++++++++++++++++++++
> include/media/v4l2-common.h | 6 ++-
> include/media/v4l2-dev.h | 18 ++++++-
> include/media/v4l2-ioctl.h | 3 +
> include/media/v4l2-subdev.h | 16 ++++++-
> 13 files changed, 170 insertions(+), 31 deletions(-)
> create mode 100644 drivers/media/video/v4l2-subdev.c
>
> diff --git a/Documentation/video4linux/v4l2-framework.txt b/Documentation/video4linux/v4l2-framework.txt
> index e831aac..164bb0f 100644
> --- a/Documentation/video4linux/v4l2-framework.txt
> +++ b/Documentation/video4linux/v4l2-framework.txt
> @@ -314,6 +314,24 @@ controlled through GPIO pins. This distinction is only relevant when setting
> up the device, but once the subdev is registered it is completely transparent.
>
>
> +V4L2 sub-device userspace API
> +-----------------------------
> +
> +Beside exposing a kernel API through the v4l2_subdev_ops structure, V4L2
> +sub-devices can also be controlled directly by userspace applications.
> +
> +When a sub-device is registered, a device node named v4l-subdevX can be created
> +in /dev. If the sub-device supports direct userspace configuration it must set
> +the V4L2_SUBDEV_FL_HAS_DEVNODE flag before being registered.
> +
> +For I2C and SPI sub-devices, the v4l2_device driver can disable registration of
> +the device node if it wants to control the sub-device on its own. In that case
> +it must set the v4l2_i2c_new_subdev_board or v4l2_spi_new_subdev enable_devnode
> +argument to 0. Setting the argument to 1 will only enable device node
> +registration if the sub-device driver has set the V4L2_SUBDEV_FL_HAS_DEVNODE
> +flag.
> +
> +
> I2C sub-device drivers
> ----------------------
>
> diff --git a/drivers/media/radio/radio-si4713.c b/drivers/media/radio/radio-si4713.c
> index 13554ab..58dd199 100644
> --- a/drivers/media/radio/radio-si4713.c
> +++ b/drivers/media/radio/radio-si4713.c
> @@ -292,7 +292,7 @@ static int radio_si4713_pdriver_probe(struct platform_device *pdev)
> }
>
> sd = v4l2_i2c_new_subdev_board(&rsdev->v4l2_dev, adapter, "si4713_i2c",
> - pdata->subdev_board_info, NULL);
> + pdata->subdev_board_info, NULL, 0);
> if (!sd) {
> dev_err(&pdev->dev, "Cannot get v4l2 subdevice\n");
> rval = -ENODEV;
> 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/soc_camera.c b/drivers/media/video/soc_camera.c
> index 475757b..10fae27 100644
> --- a/drivers/media/video/soc_camera.c
> +++ b/drivers/media/video/soc_camera.c
> @@ -895,7 +895,7 @@ static int soc_camera_init_i2c(struct soc_camera_device *icd,
> icl->board_info->platform_data = icd;
>
> subdev = v4l2_i2c_new_subdev_board(&ici->v4l2_dev, adap,
> - icl->module_name, icl->board_info, NULL);
> + icl->module_name, icl->board_info, NULL, 0);
> if (!subdev)
> goto ei2cnd;
>
> diff --git a/drivers/media/video/v4l2-common.c b/drivers/media/video/v4l2-common.c
> index bbda421..4265562 100644
> --- a/drivers/media/video/v4l2-common.c
> +++ b/drivers/media/video/v4l2-common.c
> @@ -838,7 +838,8 @@ EXPORT_SYMBOL_GPL(v4l2_i2c_subdev_init);
> /* Load an i2c sub-device. */
> struct v4l2_subdev *v4l2_i2c_new_subdev_board(struct v4l2_device *v4l2_dev,
> struct i2c_adapter *adapter, const char *module_name,
> - struct i2c_board_info *info, const unsigned short *probe_addrs)
> + struct i2c_board_info *info, const unsigned short *probe_addrs,
> + int enable_devnode)
> {
> struct v4l2_subdev *sd = NULL;
> struct i2c_client *client;
> @@ -868,9 +869,12 @@ struct v4l2_subdev *v4l2_i2c_new_subdev_board(struct v4l2_device *v4l2_dev,
> if (!try_module_get(client->driver->driver.owner))
> goto error;
> sd = i2c_get_clientdata(client);
> + if (!enable_devnode)
> + sd->flags &= ~V4L2_SUBDEV_FL_HAS_DEVNODE;
>
> /* 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 +889,8 @@ 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;
> }
> }
>
> @@ -911,7 +917,7 @@ struct v4l2_subdev *v4l2_i2c_new_subdev(struct v4l2_device *v4l2_dev,
> info.addr = addr;
>
> return v4l2_i2c_new_subdev_board(v4l2_dev, adapter, module_name,
> - &info, probe_addrs);
> + &info, probe_addrs, 0);
> }
> EXPORT_SYMBOL_GPL(v4l2_i2c_new_subdev);
>
> @@ -981,7 +987,8 @@ void v4l2_spi_subdev_init(struct v4l2_subdev *sd, struct spi_device *spi,
> EXPORT_SYMBOL_GPL(v4l2_spi_subdev_init);
>
> struct v4l2_subdev *v4l2_spi_new_subdev(struct v4l2_device *v4l2_dev,
> - struct spi_master *master, struct spi_board_info *info)
> + struct spi_master *master, struct spi_board_info *info,
> + int enable_devnode)
> {
> struct v4l2_subdev *sd = NULL;
> struct spi_device *spi = NULL;
> @@ -1000,6 +1007,8 @@ struct v4l2_subdev *v4l2_spi_new_subdev(struct v4l2_device *v4l2_dev,
> goto error;
>
> sd = spi_get_drvdata(spi);
> + if (!enable_devnode)
> + sd->flags &= ~V4L2_SUBDEV_FL_HAS_DEVNODE;
>
> /* Register with the v4l2_device which increases the module's
> use count as well. */
> diff --git a/drivers/media/video/v4l2-dev.c b/drivers/media/video/v4l2-dev.c
> index 0ca7ec9..bcd47a0 100644
> --- a/drivers/media/video/v4l2-dev.c
> +++ b/drivers/media/video/v4l2-dev.c
> @@ -376,13 +376,14 @@ static int get_index(struct video_device *vdev)
> }
>
> /**
> - * video_register_device - register video4linux devices
> + * __video_register_device - register video4linux devices
> * @vdev: video device structure we want to register
> * @type: type of device to register
> * @nr: which device node number (0 == /dev/video0, 1 == /dev/video1, ...
> * -1 == first free)
> * @warn_if_nr_in_use: warn if the desired device node number
> * was already in use and another number was chosen instead.
> + * @owner: module that owns the video device node
> *
> * The registration code assigns minor numbers and device node numbers
> * based on the requested type and registers the new device node with
> @@ -401,9 +402,11 @@ 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)
> +int __video_register_device(struct video_device *vdev, int type, int nr,
> + int warn_if_nr_in_use, struct module *owner)
> {
> int i = 0;
> int ret;
> @@ -439,6 +442,9 @@ 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 = "v4l-subdev";
> + break;
> default:
> printk(KERN_ERR "%s called with unknown type: %d\n",
> __func__, type);
> @@ -525,7 +531,7 @@ static int __video_register_device(struct video_device *vdev, int type, int nr,
> vdev->cdev->ops = &v4l2_unlocked_fops;
> else
> vdev->cdev->ops = &v4l2_fops;
> - vdev->cdev->owner = vdev->fops->owner;
> + vdev->cdev->owner = owner;
> ret = cdev_add(vdev->cdev, MKDEV(VIDEO_MAJOR, vdev->minor), 1);
> if (ret < 0) {
> printk(KERN_ERR "%s: cdev_add failed\n", __func__);
> @@ -574,18 +580,7 @@ cleanup:
> vdev->minor = -1;
> return ret;
> }
> -
> -int video_register_device(struct video_device *vdev, int type, int nr)
> -{
> - return __video_register_device(vdev, type, nr, 1);
> -}
> -EXPORT_SYMBOL(video_register_device);
> -
> -int video_register_device_no_warn(struct video_device *vdev, int type, int nr)
> -{
> - return __video_register_device(vdev, type, nr, 0);
> -}
> -EXPORT_SYMBOL(video_register_device_no_warn);
> +EXPORT_SYMBOL(__video_register_device);
>
> /**
> * video_unregister_device - unregister a video4linux device
> diff --git a/drivers/media/video/v4l2-device.c b/drivers/media/video/v4l2-device.c
> index 5a7dc4a..b287aaa 100644
> --- a/drivers/media/video/v4l2-device.c
> +++ b/drivers/media/video/v4l2-device.c
> @@ -115,18 +115,38 @@ 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 = 0;
> +
> /* 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;
> + strlcpy(vdev->name, sd->name, sizeof(vdev->name));
> + vdev->parent = v4l2_dev->dev;
> + vdev->fops = &v4l2_subdev_fops;
> + vdev->release = video_device_release_empty;
> + if (sd->flags & V4L2_SUBDEV_FL_HAS_DEVNODE) {
> + ret = __video_register_device(vdev, VFL_TYPE_SUBDEV, -1, 1,
> + sd->owner);
> + if (ret < 0)
> + v4l2_device_unregister_subdev(sd);
> + }
> +
> + return ret;
> }
> EXPORT_SYMBOL_GPL(v4l2_device_register_subdev);
>
> @@ -135,10 +155,13 @@ 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-ioctl.c b/drivers/media/video/v4l2-ioctl.c
> index 486eaba..e49ace8 100644
> --- a/drivers/media/video/v4l2-ioctl.c
> +++ b/drivers/media/video/v4l2-ioctl.c
> @@ -412,7 +412,7 @@ static unsigned long cmd_input_size(unsigned int cmd)
> }
> }
>
> -static long
> +long
> __video_usercopy(struct file *file, unsigned int cmd, unsigned long arg,
> v4l2_kioctl func)
> {
> diff --git a/drivers/media/video/v4l2-subdev.c b/drivers/media/video/v4l2-subdev.c
> new file mode 100644
> index 0000000..424c9c2
> --- /dev/null
> +++ b/drivers/media/video/v4l2-subdev.c
> @@ -0,0 +1,65 @@
> +/*
> + * V4L2 subdevice support.
> + *
> + * Copyright (C) 2010 Laurent Pinchart <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-common.h b/include/media/v4l2-common.h
> index 6fc3d7a..496d158 100644
> --- a/include/media/v4l2-common.h
> +++ b/include/media/v4l2-common.h
> @@ -148,7 +148,8 @@ struct i2c_board_info;
>
> struct v4l2_subdev *v4l2_i2c_new_subdev_board(struct v4l2_device *v4l2_dev,
> struct i2c_adapter *adapter, const char *module_name,
> - struct i2c_board_info *info, const unsigned short *probe_addrs);
> + struct i2c_board_info *info, const unsigned short *probe_addrs,
> + int enable_devnode);
>
> /* Initialize an v4l2_subdev with data from an i2c_client struct */
> void v4l2_i2c_subdev_init(struct v4l2_subdev *sd, struct i2c_client *client,
> @@ -181,7 +182,8 @@ struct spi_device;
> /* Load an spi module and return an initialized v4l2_subdev struct.
> The client_type argument is the name of the chip that's on the adapter. */
> struct v4l2_subdev *v4l2_spi_new_subdev(struct v4l2_device *v4l2_dev,
> - struct spi_master *master, struct spi_board_info *info);
> + struct spi_master *master, struct spi_board_info *info,
> + int enable_devnode);
>
> /* Initialize an v4l2_subdev with data from an spi_device struct */
> void v4l2_spi_subdev_init(struct v4l2_subdev *sd, struct spi_device *spi,
> diff --git a/include/media/v4l2-dev.h b/include/media/v4l2-dev.h
> index bebe44b..195fa56 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;
> @@ -98,15 +99,26 @@ struct video_device
> /* dev to video-device */
> #define to_video_device(cd) container_of(cd, struct video_device, dev)
>
> +int __must_check __video_register_device(struct video_device *vdev, int type,
> + int nr, int warn_if_nr_in_use, struct module *owner);
> +
> /* Register video devices. Note that if video_register_device fails,
> the release() callback of the video_device structure is *not* called, so
> the caller is responsible for freeing any data. Usually that means that
> you call video_device_release() on failure. */
> -int __must_check video_register_device(struct video_device *vdev, int type, int nr);
> +static inline int __must_check video_register_device(struct video_device *vdev,
> + int type, int nr)
> +{
> + return __video_register_device(vdev, type, nr, 1, vdev->fops->owner);
> +}
>
> /* Same as video_register_device, but no warning is issued if the desired
> device node number was already in use. */
> -int __must_check video_register_device_no_warn(struct video_device *vdev, int type, int nr);
> +static inline int __must_check video_register_device_no_warn(
> + struct video_device *vdev, int type, int nr)
> +{
> + return __video_register_device(vdev, type, nr, 0, vdev->fops->owner);
> +}
>
> /* Unregister video devices. Will do nothing if vdev == NULL or
> video_is_registered() returns false. */
> diff --git a/include/media/v4l2-ioctl.h b/include/media/v4l2-ioctl.h
> index 06daa6e..abb64d0 100644
> --- a/include/media/v4l2-ioctl.h
> +++ b/include/media/v4l2-ioctl.h
> @@ -316,6 +316,9 @@ extern long v4l2_compat_ioctl32(struct file *file, unsigned int cmd,
> unsigned long arg);
> #endif
>
> +extern long __video_usercopy(struct file *file, unsigned int cmd,
> + unsigned long arg, v4l2_kioctl func);
> +
> /* Include support for obsoleted stuff */
> extern long video_usercopy(struct file *file, unsigned int cmd,
> unsigned long arg, v4l2_kioctl func);
> diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
> index 6088316..dc0ccd3 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 */
> @@ -402,9 +403,11 @@ struct v4l2_subdev_ops {
> #define V4L2_SUBDEV_NAME_SIZE 32
>
> /* Set this flag if this subdev is a i2c device. */
> -#define V4L2_SUBDEV_FL_IS_I2C (1U << 0)
> +#define V4L2_SUBDEV_FL_IS_I2C (1U << 0)
> /* Set this flag if this subdev is a spi device. */
> -#define V4L2_SUBDEV_FL_IS_SPI (1U << 1)
> +#define V4L2_SUBDEV_FL_IS_SPI (1U << 1)
> +/* Set this flag if this subdev needs a device node. */
> +#define V4L2_SUBDEV_FL_HAS_DEVNODE (1U << 2)
>
> /* Each instance of a subdev driver should create this struct, either
> stand-alone or embedded in a larger struct.
> @@ -421,8 +424,16 @@ 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 +455,7 @@ static inline void v4l2_subdev_init(struct v4l2_subdev *sd,
> sd->name[0] = '\0';
> sd->grp_id = 0;
> sd->priv = NULL;
> + sd->initialized = 1;
> }
>
> /* Call an ops of a v4l2_subdev, doing the right checks against
>
--
Hans Verkuil - video4linux developer - sponsored by TANDBERG, part of Cisco
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