diff options
| -rw-r--r-- | Documentation/video4linux/v4l2-framework.txt | 362 | ||||
| -rw-r--r-- | drivers/media/video/Makefile | 2 | ||||
| -rw-r--r-- | drivers/media/video/v4l2-device.c | 86 | ||||
| -rw-r--r-- | drivers/media/video/v4l2-subdev.c | 108 | ||||
| -rw-r--r-- | include/media/v4l2-device.h | 109 | ||||
| -rw-r--r-- | include/media/v4l2-subdev.h | 188 |
6 files changed, 854 insertions, 1 deletions
diff --git a/Documentation/video4linux/v4l2-framework.txt b/Documentation/video4linux/v4l2-framework.txt new file mode 100644 index 00000000000..60eaf54e7ef --- /dev/null +++ b/Documentation/video4linux/v4l2-framework.txt @@ -0,0 +1,362 @@ +Overview of the V4L2 driver framework +===================================== + +This text documents the various structures provided by the V4L2 framework and +their relationships. + + +Introduction +------------ + +The V4L2 drivers tend to be very complex due to the complexity of the +hardware: most devices have multiple ICs, export multiple device nodes in +/dev, and create also non-V4L2 devices such as DVB, ALSA, FB, I2C and input +(IR) devices. + +Especially the fact that V4L2 drivers have to setup supporting ICs to +do audio/video muxing/encoding/decoding makes it more complex than most. +Usually these ICs are connected to the main bridge driver through one or +more I2C busses, but other busses can also be used. Such devices are +called 'sub-devices'. + +For a long time the framework was limited to the video_device struct for +creating V4L device nodes and video_buf for handling the video buffers +(note that this document does not discuss the video_buf framework). + +This meant that all drivers had to do the setup of device instances and +connecting to sub-devices themselves. Some of this is quite complicated +to do right and many drivers never did do it correctly. + +There is also a lot of common code that could never be refactored due to +the lack of a framework. + +So this framework sets up the basic building blocks that all drivers +need and this same framework should make it much easier to refactor +common code into utility functions shared by all drivers. + + +Structure of a driver +--------------------- + +All drivers have the following structure: + +1) A struct for each device instance containing the device state. + +2) A way of initializing and commanding sub-devices (if any). + +3) Creating V4L2 device nodes (/dev/videoX, /dev/vbiX, /dev/radioX and + /dev/vtxX) and keeping track of device-node specific data. + +4) Filehandle-specific structs containing per-filehandle data. + +This is a rough schematic of how it all relates: + + device instances + | + +-sub-device instances + | + \-V4L2 device nodes + | + \-filehandle instances + + +Structure of the framework +-------------------------- + +The framework closely resembles the driver structure: it has a v4l2_device +struct for the device instance data, a v4l2_subdev struct to refer to +sub-device instances, the video_device struct stores V4L2 device node data +and in the future a v4l2_fh struct will keep track of filehandle instances +(this is not yet implemented). + + +struct v4l2_device +------------------ + +Each device instance is represented by a struct v4l2_device (v4l2-device.h). +Very simple devices can just allocate this struct, but most of the time you +would embed this struct inside a larger struct. + +You must register the device instance: + + v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev); + +Registration will initialize the v4l2_device struct and link dev->driver_data +to v4l2_dev. Registration will also set v4l2_dev->name to a value derived from +dev (driver name followed by the bus_id, to be precise). You may change the +name after registration if you want. + +You unregister with: + + v4l2_device_unregister(struct v4l2_device *v4l2_dev); + +Unregistering will also automatically unregister all subdevs from the device. + +Sometimes you need to iterate over all devices registered by a specific +driver. This is usually the case if multiple device drivers use the same +hardware. E.g. the ivtvfb driver is a framebuffer driver that uses the ivtv +hardware. The same is true for alsa drivers for example. + +You can iterate over all registered devices as follows: + +static int callback(struct device *dev, void *p) +{ + struct v4l2_device *v4l2_dev = dev_get_drvdata(dev); + + /* test if this device was inited */ + if (v4l2_dev == NULL) + return 0; + ... + return 0; +} + +int iterate(void *p) +{ + struct device_driver *drv; + int err; + + /* Find driver 'ivtv' on the PCI bus. + pci_bus_type is a global. For USB busses use usb_bus_type. */ + drv = driver_find("ivtv", &pci_bus_type); + /* iterate over all ivtv device instances */ + err = driver_for_each_device(drv, NULL, p, callback); + put_driver(drv); + return err; +} + +Sometimes you need to keep a running counter of the device instance. This is +commonly used to map a device instance to an index of a module option array. + +The recommended approach is as follows: + +static atomic_t drv_instance = ATOMIC_INIT(0); + +static int __devinit drv_probe(struct pci_dev *dev, + const struct pci_device_id *pci_id) +{ + ... + state->instance = atomic_inc_return(&drv_instance) - 1; +} + + +struct v4l2_subdev +------------------ + +Many drivers need to communicate with sub-devices. These devices can do all +sort of tasks, but most commonly they handle audio and/or video muxing, +encoding or decoding. For webcams common sub-devices are sensors and camera +controllers. + +Usually these are I2C devices, but not necessarily. In order to provide the +driver with a consistent interface to these sub-devices the v4l2_subdev struct +(v4l2-subdev.h) was created. + +Each sub-device driver must have a v4l2_subdev struct. This struct can be +stand-alone for simple sub-devices or it might be embedded in a larger struct +if more state information needs to be stored. Usually there is a low-level +device struct (e.g. i2c_client) that contains the device data as setup +by the kernel. It is recommended to store that pointer in the private +data of v4l2_subdev using v4l2_set_subdevdata(). That makes it easy to go +from a v4l2_subdev to the actual low-level bus-specific device data. + +You also need a way to go from the low-level struct to v4l2_subdev. For the +common i2c_client struct the i2c_set_clientdata() call is used to store a +v4l2_subdev pointer, for other busses you may have to use other methods. + +From the bridge driver perspective you load the sub-device module and somehow +obtain the v4l2_subdev pointer. For i2c devices this is easy: you call +i2c_get_clientdata(). For other busses something similar needs to be done. +Helper functions exists for sub-devices on an I2C bus that do most of this +tricky work for you. + +Each v4l2_subdev contains function pointers that sub-device drivers can +implement (or leave NULL if it is not applicable). Since sub-devices can do +so many different things and you do not want to end up with a huge ops struct +of which only a handful of ops are commonly implemented, the function pointers +are sorted according to category and each category has its own ops struct. + +The top-level ops struct contains pointers to the category ops structs, which +may be NULL if the subdev driver does not support anything from that category. + +It looks like this: + +struct v4l2_subdev_core_ops { + int (*g_chip_ident)(struct v4l2_subdev *sd, struct v4l2_chip_ident *chip); + int (*log_status)(struct v4l2_subdev *sd); + int (*init)(struct v4l2_subdev *sd, u32 val); + ... +}; + +struct v4l2_subdev_tuner_ops { + ... +}; + +struct v4l2_subdev_audio_ops { + ... +}; + +struct v4l2_subdev_video_ops { + ... +}; + +struct v4l2_subdev_ops { + const struct v4l2_subdev_core_ops *core; + const struct v4l2_subdev_tuner_ops *tuner; + const struct v4l2_subdev_audio_ops *audio; + const struct v4l2_subdev_video_ops *video; +}; + +The core ops are common to all subdevs, the other categories are implemented +depending on the sub-device. E.g. a video device is unlikely to support the +audio ops and vice versa. + +This setup limits the number of function pointers while still making it easy +to add new ops and categories. + +A sub-device driver initializes the v4l2_subdev struct using: + + v4l2_subdev_init(subdev, &ops); + +Afterwards you need to initialize subdev->name with a unique name and set the +module owner. This is done for you if you use the i2c helper functions. + +A device (bridge) driver needs to register the v4l2_subdev with the +v4l2_device: + + int err = v4l2_device_register_subdev(device, subdev); + +This can fail if the subdev module disappeared before it could be registered. +After this function was called successfully the subdev->dev field points to +the v4l2_device. + +You can unregister a sub-device using: + + v4l2_device_unregister_subdev(subdev); + +Afterwards the subdev module can be unloaded and subdev->dev == NULL. + +You can call an ops function either directly: + + err = subdev->ops->core->g_chip_ident(subdev, &chip); + +but it is better and easier to use this macro: + + err = v4l2_subdev_call(subdev, core, g_chip_ident, &chip); + +The macro will to the right NULL pointer checks and returns -ENODEV if subdev +is NULL, -ENOIOCTLCMD if either subdev->core or subdev->core->g_chip_ident is +NULL, or the actual result of the subdev->ops->core->g_chip_ident ops. + +It is also possible to call all or a subset of the sub-devices: + + v4l2_device_call_all(dev, 0, core, g_chip_ident, &chip); + +Any subdev that does not support this ops is skipped and error results are +ignored. If you want to check for errors use this: + + err = v4l2_device_call_until_err(dev, 0, core, g_chip_ident, &chip); + +Any error except -ENOIOCTLCMD will exit the loop with that error. If no +errors (except -ENOIOCTLCMD) occured, then 0 is returned. + +The second argument to both calls is a group ID. If 0, then all subdevs are +called. If non-zero, then only those whose group ID match that value will +be called. Before a bridge driver registers a subdev it can set subdev->grp_id +to whatever value it wants (it's 0 by default). This value is owned by the +bridge driver and the sub-device driver will never modify or use it. + +The group ID gives the bridge driver more control how callbacks are called. +For example, there may be multiple audio chips on a board, each capable of +changing the volume. But usually only one will actually be used when the +user want to change the volume. You can set the group ID for that subdev to +e.g. AUDIO_CONTROLLER and specify that as the group ID value when calling +v4l2_device_call_all(). That ensures that it will only go to the subdev +that needs it. + +The advantage of using v4l2_subdev is that it is a generic struct and does +not contain any knowledge about the underlying hardware. So a driver might +contain several subdevs that use an I2C bus, but also a subdev that is +controlled through GPIO pins. This distinction is only relevant when setting +up the device, but once the subdev is registered it is completely transparent. + + +I2C sub-device drivers +---------------------- + +Since these drivers are so common, special helper functions are available to +ease the use of these drivers (v4l2-common.h). + +The recommended method of adding v4l2_subdev support to an I2C driver is to +embed the v4l2_subdev struct into the state struct that is created for each +I2C device instance. Very simple devices have no state struct and in that case +you can just create a v4l2_subdev directly. + +A typical state struct would look like this (where 'chipname' is replaced by +the name of the chip): + +struct chipname_state { + struct v4l2_subdev sd; + ... /* additional state fields */ +}; + +Initialize the v4l2_subdev struct as follows: + + v4l2_i2c_subdev_init(&state->sd, client, subdev_ops); + +This function will fill in all the fields of v4l2_subdev and ensure that the +v4l2_subdev and i2c_client both point to one another. + +You should also add a helper inline function to go from a v4l2_subdev pointer +to a chipname_state struct: + +static inline struct chipname_state *to_state(struct v4l2_subdev *sd) +{ + return container_of(sd, struct chipname_state, sd); +} + +Use this to go from the v4l2_subdev struct to the i2c_client struct: + + struct i2c_client *client = v4l2_get_subdevdata(sd); + +And this to go from an i2c_client to a v4l2_subdev struct: + + struct v4l2_subdev *sd = i2c_get_clientdata(client); + +Finally you need to make a command function to make driver->command() +call the right subdev_ops functions: + +static int subdev_command(struct i2c_client *client, unsigned cmd, void *arg) +{ + return v4l2_subdev_command(i2c_get_clientdata(client), cmd, arg); +} + +If driver->command is never used then you can leave this out. Eventually the +driver->command usage should be removed from v4l. + +Make sure to call v4l2_device_unregister_subdev(sd) when the remove() callback +is called. This will unregister the sub-device from the bridge driver. It is +safe to call this even if the sub-device was never registered. + + +The bridge driver also has some helper functions it can use: + +struct v4l2_subdev *sd = v4l2_i2c_new_subdev(adapter, "module_foo", "chipid", 0x36); + +This loads the given module (can be NULL if no module needs to be loaded) and +calls i2c_new_device() with the given i2c_adapter and chip/address arguments. +If all goes well, then it registers the subdev with the v4l2_device. It gets +the v4l2_device by calling i2c_get_adapdata(adapter), so you should make sure +that adapdata is set to v4l2_device when you setup the i2c_adapter in your +driver. + +You can also use v4l2_i2c_new_probed_subdev() which is very similar to +v4l2_i2c_new_subdev(), except that it has an array of possible I2C addresses +that it should probe. Internally it calls i2c_new_probed_device(). + +Both functions return NULL if something went wrong. + + +struct video_device +------------------- + +Not yet documented. diff --git a/drivers/media/video/Makefile b/drivers/media/video/Makefile index 492ab3dce71..84a2be0cbbe 100644 --- a/drivers/media/video/Makefile +++ b/drivers/media/video/Makefile @@ -10,7 +10,7 @@ stkwebcam-objs := stk-webcam.o stk-sensor.o omap2cam-objs := omap24xxcam.o omap24xxcam-dma.o -videodev-objs := v4l2-dev.o v4l2-ioctl.o +videodev-objs := v4l2-dev.o v4l2-ioctl.o v4l2-device.o v4l2-subdev.o obj-$(CONFIG_VIDEO_DEV) += videodev.o v4l2-compat-ioctl32.o v4l2-int-device.o diff --git a/drivers/media/video/v4l2-device.c b/drivers/media/video/v4l2-device.c new file mode 100644 index 00000000000..9eefde03159 --- /dev/null +++ b/drivers/media/video/v4l2-device.c @@ -0,0 +1,86 @@ +/* + 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> +#include <linux/videodev2.h> +#include <media/v4l2-device.h> + +int v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev) +{ + if (dev == NULL || v4l2_dev == NULL) + return -EINVAL; + /* Warn if we apparently re-register a device */ + WARN_ON(dev_get_drvdata(dev)); + INIT_LIST_HEAD(&v4l2_dev->subdevs); + spin_lock_init(&v4l2_dev->lock); + v4l2_dev->dev = dev; + snprintf(v4l2_dev->name, sizeof(v4l2_dev->name), "%s %s", + dev->driver->name, dev->bus_id); + dev_set_drvdata(dev, v4l2_dev); + return 0; +} +EXPORT_SYMBOL_GPL(v4l2_device_register); + +void v4l2_device_unregister(struct v4l2_device *v4l2_dev) +{ + struct v4l2_subdev *sd, *next; + + if (v4l2_dev == NULL || v4l2_dev->dev == NULL) + return; + dev_set_drvdata(v4l2_dev->dev, NULL); + /* unregister subdevs */ + list_for_each_entry_safe(sd, next, &v4l2_dev->subdevs, list) + v4l2_device_unregister_subdev(sd); + + v4l2_dev->dev = NULL; +} +EXPORT_SYMBOL_GPL(v4l2_device_unregister); + +int v4l2_device_register_subdev(struct v4l2_device *dev, struct v4l2_subdev *sd) +{ + /* Check for valid input */ + if (dev == NULL || sd == NULL || !sd->name[0]) + return -EINVAL; + /* Warn if we apparently re-register a subdev */ + WARN_ON(sd->dev); + if (!try_module_get(sd->owner)) + return -ENODEV; + sd->dev = dev; + spin_lock(&dev->lock); + list_add_tail(&sd->list, &dev->subdevs); + spin_unlock(&dev->lock); + return 0; +} +EXPORT_SYMBOL_GPL(v4l2_device_register_subdev); + +void v4l2_device_unregister_subdev(struct v4l2_subdev *sd) +{ + /* return if it isn't registered */ + if (sd == NULL || sd->dev == NULL) + return; + spin_lock(&sd->dev->lock); + list_del(&sd->list); + spin_unlock(&sd->dev->lock); + sd->dev = NULL; + module_put(sd->owner); +} +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 00000000000..fe1f01c970a --- /dev/null +++ b/drivers/media/video/v4l2-subdev.c @@ -0,0 +1,108 @@ +/* + V4L2 sub-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> +#include <linux/videodev2.h> +#include <media/v4l2-subdev.h> + +int v4l2_subdev_command(struct v4l2_subdev *sd, unsigned cmd, void *arg) +{ + switch (cmd) { + case VIDIOC_QUERYCTRL: + return v4l2_subdev_call(sd, core, querymenu, arg); + case VIDIOC_G_CTRL: + return v4l2_subdev_call(sd, core, g_ctrl, arg); + case VIDIOC_S_CTRL: + return v4l2_subdev_call(sd, core, s_ctrl, arg); + case VIDIOC_QUERYMENU: + return v4l2_subdev_call(sd, core, queryctrl, arg); + case VIDIOC_LOG_STATUS: + return v4l2_subdev_call(sd, core, log_status); + case VIDIOC_G_CHIP_IDENT: + return v4l2_subdev_call(sd, core, g_chip_ident, arg); + case VIDIOC_INT_S_STANDBY: + return v4l2_subdev_call(sd, core, s_standby, *(u32 *)arg); + case VIDIOC_INT_RESET: + return v4l2_subdev_call(sd, core, reset, *(u32 *)arg); + case VIDIOC_INT_S_GPIO: + return v4l2_subdev_call(sd, core, s_gpio, *(u32 *)arg); + case VIDIOC_INT_INIT: + return v4l2_subdev_call(sd, core, init, *(u32 *)arg); +#ifdef CONFIG_VIDEO_ADV_DEBUG + case VIDIOC_DBG_G_REGISTER: + return v4l2_subdev_call(sd, core, g_register, arg); + case VIDIOC_DBG_S_REGISTER: + return v4l2_subdev_call(sd, core, s_register, arg); +#endif + + case VIDIOC_INT_S_TUNER_MODE: + return v4l2_subdev_call(sd, tuner, s_mode, *(enum v4l2_tuner_type *)arg); + case AUDC_SET_RADIO: + return v4l2_subdev_call(sd, tuner, s_radio); + case VIDIOC_S_TUNER: + return v4l2_subdev_call(sd, tuner, s_tuner, arg); + case VIDIOC_G_TUNER: + return v4l2_subdev_call(sd, tuner, g_tuner, arg); + case VIDIOC_S_STD: + return v4l2_subdev_call(sd, tuner, s_std, *(v4l2_std_id *)arg); + case VIDIOC_S_FREQUENCY: + return v4l2_subdev_call(sd, tuner, s_frequency, arg); + case VIDIOC_G_FREQUENCY: + return v4l2_subdev_call(sd, tuner, g_frequency, arg); + case TUNER_SET_TYPE_ADDR: + return v4l2_subdev_call(sd, tuner, s_type_addr, arg); + case TUNER_SET_CONFIG: + return v4l2_subdev_call(sd, tuner, s_config, arg); + + case VIDIOC_INT_AUDIO_CLOCK_FREQ: + return v4l2_subdev_call(sd, audio, s_clock_freq, *(u32 *)arg); + case VIDIOC_INT_S_AUDIO_ROUTING: + return v4l2_subdev_call(sd, audio, s_routing, arg); + case VIDIOC_INT_I2S_CLOCK_FREQ: + return v4l2_subdev_call(sd, audio, s_i2s_clock_freq, *(u32 *)arg); + + case VIDIOC_INT_S_VIDEO_ROUTING: + return v4l2_subdev_call(sd, video, s_routing, arg); + case VIDIOC_INT_S_CRYSTAL_FREQ: + return v4l2_subdev_call(sd, video, s_crystal_freq, arg); + case VIDIOC_INT_DECODE_VBI_LINE: + return v4l2_subdev_call(sd, video, decode_vbi_line, arg); + case VIDIOC_INT_S_VBI_DATA: + return v4l2_subdev_call(sd, video, s_vbi_data, arg); + case VIDIOC_INT_G_VBI_DATA: + return v4l2_subdev_call(sd, video, g_vbi_data, arg); + case VIDIOC_S_FMT: + return v4l2_subdev_call(sd, video, s_fmt, arg); + case VIDIOC_G_FMT: + return v4l2_subdev_call(sd, video, g_fmt, arg); + case VIDIOC_INT_S_STD_OUTPUT: + return v4l2_subdev_call(sd, video, s_std_output, *(v4l2_std_id *)arg); + case VIDIOC_STREAMON: + return v4l2_subdev_call(sd, video, s_stream, 1); + case VIDIOC_STREAMOFF: + return v4l2_subdev_call(sd, video, s_stream, 0); + + default: + return v4l2_subdev_call(sd, core, ioctl, cmd, arg); + } +} +EXPORT_SYMBOL_GPL(v4l2_subdev_command); diff --git a/include/media/v4l2-device.h b/include/media/v4l2-device.h new file mode 100644 index 00000000000..97b283a0428 --- /dev/null +++ b/include/media/v4l2-device.h @@ -0,0 +1,109 @@ +/* + V4L2 device support header. + + 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 + */ + +#ifndef _V4L2_DEVICE_H +#define _V4L2_DEVICE_H + +#include <media/v4l2-subdev.h> + +/* Each instance of a V4L2 device should create the v4l2_device struct, + either stand-alone or embedded in a larger struct. + + It allows easy access to sub-devices (see v4l2-subdev.h) and provides + basic V4L2 device-level support. + */ + +#define V4L2_DEVICE_NAME_SIZE (BUS_ID_SIZE + 16) + +struct v4l2_device { + /* dev->driver_data points to this struct */ + struct device *dev; + /* used to keep track of the registered subdevs */ + struct list_head subdevs; + /* lock this struct; can be used by the driver as well if this + struct is embedded into a larger struct. */ + spinlock_t lock; + /* unique device name, by default the driver name + bus ID */ + char name[V4L2_DEVICE_NAME_SIZE]; +}; + +/* Initialize v4l2_dev and make dev->driver_data point to v4l2_dev */ +int __must_check v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev); +/* Set v4l2_dev->dev->driver_data to NULL and unregister all sub-devices */ +void v4l2_device_unregister(struct v4l2_device *v4l2_dev); + +/* Register a subdev with a v4l2 device. While registered the subdev module + is marked as in-use. An error is returned if the module is no longer + loaded when you attempt to register it. */ +int __must_check v4l2_device_register_subdev(struct v4l2_device *dev, struct v4l2_subdev *sd); +/* Unregister a subdev with a v4l2 device. Can also be called if the subdev + wasn't registered. In that case it will do nothing. */ +void v4l2_device_unregister_subdev(struct v4l2_subdev *sd); + +/* Iterate over all subdevs. */ +#define v4l2_device_for_each_subdev(sd, dev) \ + list_for_each_entry(sd, &(dev)->subdevs, list) + +/* Call the specified callback for all subdevs matching the condition. + Ignore any errors. Note that you cannot add or delete a subdev + while walking the subdevs list. */ +#define __v4l2_device_call_subdevs(dev, cond, o, f, args...) \ + do { \ + struct v4l2_subdev *sd; \ + \ + list_for_each_entry(sd, &(dev)->subdevs, list) \ + if ((cond) && sd->ops->o && sd->ops->o->f) \ + sd->ops->o->f(sd , ##args); \ + } while (0) + +/* Call the specified callback for all subdevs matching the condition. + If the callback returns an error other than 0 or -ENOIOCTLCMD, then + return with that error code. Note that you cannot add or delete a + subdev while walking the subdevs list. */ +#define __v4l2_device_call_subdevs_until_err(dev, cond, o, f, args...) \ +({ \ + struct v4l2_subdev *sd; \ + int err = 0; \ + \ + list_for_each_entry(sd, &(dev)->subdevs, list) { \ + if ((cond) && sd->ops->o && sd->ops->o->f) \ + err = sd->ops->o->f(sd , ##args); \ + if (err && err != -ENOIOCTLCMD) \ + break; \ + } \ + (err == -ENOIOCTLCMD) ? 0 : err; \ +}) + +/* Call the specified callback for all subdevs matching grp_id (if 0, then + match them all). Ignore any errors. Note that you cannot add or delete + a subdev while walking the subdevs list. */ +#define v4l2_device_call_all(dev, grp_id, o, f, args...) \ + __v4l2_device_call_subdevs(dev, \ + !(grp_id) || sd->grp_id == (grp_id), o, f , ##args) + +/* Call the specified callback for all subdevs matching grp_id (if 0, then + match them all). If the callback returns an error other than 0 or + -ENOIOCTLCMD, then return with that error code. Note that you cannot + add or delete a subdev while walking the subdevs list. */ +#define v4l2_device_call_until_err(dev, grp_id, o, f, args...) \ + __v4l2_device_call_subdevs_until_err(dev, \ + !(grp_id) || sd->grp_id == (grp_id), o, f , ##args) + +#endif diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h new file mode 100644 index 00000000000..bc9e0fbf282 --- /dev/null +++ b/include/media/v4l2-subdev.h @@ -0,0 +1,188 @@ +/* + V4L2 sub-device support header. + + 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 + */ + +#ifndef _V4L2_SUBDEV_H +#define _V4L2_SUBDEV_H + +#include <media/v4l2-common.h> + +struct v4l2_device; +struct v4l2_subdev; +struct tuner_setup; + +/* Sub-devices are devices that are connected somehow to the main bridge + device. These devices are usually audio/video muxers/encoders/decoders or + sensors and webcam controllers. + + Usually these devices are controlled through an i2c bus, but other busses + may also be used. + + The v4l2_subdev struct provides a way of accessing these devices in a + generic manner. Most operations that these sub-devices support fall in + a few categories: core ops, audio ops, video ops and tuner ops. + + More categories can be added if needed, although this should remain a + limited set (no more than approx. 8 categories). + + Each category has its own set of ops that subdev drivers can implement. + + A subdev driver can leave the pointer to the category ops NULL if + it does not implement them (e.g. an audio subdev will generally not + implement the video category ops). The exception is the core category: + this must always be present. + + These ops are all used internally so it is no problem to change, remove + or add ops or move ops from one to another category. Currently these + ops are based on the original ioctls, but since ops are not limited to + one argument there is room for improvement here once all i2c subdev + drivers are converted to use these ops. + */ + +/* Core ops: it is highly recommended to implement at least these ops: + + g_chip_ident + log_status + g_register + s_register + + This provides basic debugging support. + + The ioctl ops is meant for generic ioctl-like commands. Depending on + the use-case it might be better to use subdev-specific ops (currently + not yet implemented) since ops provide proper type-checking. + */ +struct v4l2_subdev_core_ops { + int (*g_chip_ident)(struct v4l2_subdev *sd, struct v4l2_chip_ident *chip); + int (*log_status)(struct v4l2_subdev *sd); + int (*init)(struct v4l2_subdev *sd, u32 val); + int (*s_standby)(struct v4l2_subdev *sd, u32 standby); + int (*reset)(struct v4l2_subdev *sd, u32 val); + int (*s_gpio)(struct v4l2_subdev *sd, u32 val); + int (*queryctrl)(struct v4l2_subdev *sd, struct v4l2_queryctrl *qc); + int (*g_ctrl)(struct v4l2_subdev *sd, struct v4l2_control *ctrl); + int (*s_ctrl)(struct v4l2_subdev *sd, struct v4l2_control *ctrl); + int (*querymenu)(struct v4l2_subdev *sd, struct v4l2_querymenu *qm); + int (*ioctl)(struct v4l2_subdev *sd, int cmd, void *arg); +#ifdef CONFIG_VIDEO_ADV_DEBUG + int (*g_register)(struct v4l2_subdev *sd, struct v4l2_register *reg); + int (*s_register)(struct v4l2_subdev *sd, struct v4l2_register *reg); +#endif +}; + +struct v4l2_subdev_tuner_ops { + int (*s_mode)(struct v4l2_subdev *sd, enum v4l2_tuner_type); + int (*s_radio)(struct v4l2_subdev *sd); + int (*s_frequency)(struct v4l2_subdev *sd, struct v4l2_frequency *freq); + int (*g_frequency)(struct v4l2_subdev *sd, struct v4l2_frequency *freq); + int (*g_tuner)(struct v4l2_subdev *sd, struct v4l2_tuner *vt); + int (*s_tuner)(struct v4l2_subdev *sd, struct v4l2_tuner *vt); + int (*s_std)(struct v4l2_subdev *sd, v4l2_std_id norm); + int (*s_type_addr)(struct v4l2_subdev *sd, struct tuner_setup *type); + int (*s_config)(struct v4l2_subdev *sd, const struct v4l2_priv_tun_config *config); +}; + +struct v4l2_subdev_audio_ops { + int (*s_clock_freq)(struct v4l2_subdev *sd, u32 freq); + int (*s_i2s_clock_freq)(struct v4l2_subdev *sd, u32 freq); + int (*s_routing)(struct v4l2_subdev *sd, const struct v4l2_routing *route); +}; + +struct v4l2_subdev_video_ops { + int (*s_routing)(struct v4l2_subdev *sd, const struct v4l2_routing *route); + int (*s_crystal_freq)(struct v4l2_subdev *sd, struct v4l2_crystal_freq *freq); + int (*decode_vbi_line)(struct v4l2_subdev *sd, struct v4l2_decode_vbi_line *vbi_line); + int (*s_vbi_data)(struct v4l2_subdev *sd, const struct v4l2_sliced_vbi_data *vbi_data); + int (*g_vbi_data)(struct v4l2_subdev *sd, struct v4l2_sliced_vbi_data *vbi_data); + int (*s_std_output)(struct v4l2_subdev *sd, v4l2_std_id std); + int (*s_stream)(struct v4l2_subdev *sd, int enable); + int (*s_fmt)(struct v4l2_subdev *sd, struct v4l2_format *fmt); + int (*g_fmt)(struct v4l2_subdev *sd, struct v4l2_format *fmt); +}; + +struct v4l2_subdev_ops { + const struct v4l2_subdev_core_ops *core; + const struct v4l2_subdev_tuner_ops *tuner; + const struct v4l2_subdev_audio_ops *audio; + const struct v4l2_subdev_video_ops *video; +}; + +#define V4L2_SUBDEV_NAME_SIZE 32 + +/* Each instance of a subdev driver should create this struct, either + stand-alone or embedded in a larger struct. + */ +struct v4l2_subdev { + struct list_head list; + struct module *owner; + struct v4l2_device *dev; + const struct v4l2_subdev_ops *ops; + /* name must be unique */ + char name[V4L2_SUBDEV_NAME_SIZE]; + /* can be used to group similar subdevs, value is driver-specific */ + u32 grp_id; + /* pointer to private data */ + void *priv; +}; + +static inline void v4l2_set_subdevdata(struct v4l2_subdev *sd, void *p) +{ + sd->priv = p; +} + +static inline void *v4l2_get_subdevdata(const struct v4l2_subdev *sd) +{ + return sd->priv; +} + +/* Convert an ioctl-type command to the proper v4l2_subdev_ops function call. + This is used by subdev modules that can be called by both old-style ioctl + commands and through the v4l2_subdev_ops. + + The ioctl API of the subdev driver can call this function to call the + right ops based on the ioctl cmd and arg. + + Once all subdev drivers have been converted and all drivers no longer + use the ioctl interface, then this function can be removed. + */ +int v4l2_subdev_command(struct v4l2_subdev *sd, unsigned cmd, void *arg); + +static inline void v4l2_subdev_init(struct v4l2_subdev *sd, + const struct v4l2_subdev_ops *ops) +{ + INIT_LIST_HEAD(&sd->list); + /* ops->core MUST be set */ + BUG_ON(!ops || !ops->core); + sd->ops = ops; + sd->dev = NULL; + sd->name[0] = '\0'; + sd->grp_id = 0; + sd->priv = NULL; +} + +/* Call an ops of a v4l2_subdev, doing the right checks against + NULL pointers. + + Example: err = v4l2_subdev_call(sd, core, g_chip_ident, &chip); + */ +#define v4l2_subdev_call(sd, o, f, args...) \ + (!(sd) ? -ENODEV : (((sd) && (sd)->ops->o && (sd)->ops->o->f) ? \ + (sd)->ops->o->f((sd) , ##args) : -ENOIOCTLCMD)) + +#endif |