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>
---
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-subdev.c | 65 ++++++++++++++++++++++++++
include/media/v4l2-common.h | 6 ++-
include/media/v4l2-dev.h | 18 ++++++-
include/media/v4l2-subdev.h | 16 ++++++-
11 files changed, 166 insertions(+), 30 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-subdev.c b/drivers/media/video/v4l2-subdev.c
new file mode 100644
index 0000000..f016376
--- /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-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
--
1.7.1
--
To unsubscribe from this list: send the line "unsubscribe linux-media" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
