path: root/Documentation/video4linux
diff options
authorLinus Torvalds <>2013-07-13 12:09:57 -0700
committerLinus Torvalds <>2013-07-13 12:09:57 -0700
commit858655116bfc722837e3aec0909b8e9d08f96996 (patch)
treeef9171d51ffcd01e40d1131d62be32e5a7d371dc /Documentation/video4linux
parent239dab4636f7f5f971ac39b5ca84254cff112cac (diff)
parent1b2c14b44adcb7836528640bfdc40bf7499d987d (diff)
Merge branch 'v4l_for_linus' of git://
Pull media updates from Mauro Carvalho Chehab: "This series contain: - new i2c video drivers: ml86v7667 (video decoder), ths8200 (video encoder) - a new video driver for EasyCap cards based on Fushicai USBTV007 - Improved support for OF and embedded systems, with V4L2 async initialization and a better support for clocks - API cleanups on the ioctls used by the v4l2 debug tool - Lots of cleanups - As usual, several driver improvements and new cards additions - Revert two changesets that change the minimal symbol rate for stv0399, as request by Manu - Update MAINTAINERS and other files to point to my new e-mail" * 'v4l_for_linus' of git:// (378 commits) MAINTAINERS & ABI: Update to point to my new email [media] stb0899: restore minimal rate to 5Mbauds [media] exynos4-is: Correct colorspace handling at FIMC-LITE [media] exynos4-is: Set valid initial format on FIMC.n subdevs [media] exynos4-is: Set valid initial format on FIMC-IS-ISP subdev pads [media] exynos4-is: Fix format propagation on FIMC-IS-ISP subdev [media] exynos4-is: Set valid initial format at FIMC-LITE [media] exynos4-is: Fix format propagation on FIMC-LITE.n subdevs [media] MAINTAINERS: Update S5P/Exynos FIMC driver entry [media] Documentation: Update driver's directory in video4linux/fimc.txt [media] exynos4-is: Change fimc-is firmware file names [media] exynos4-is: Add support for Exynos5250 MIPI-CSIS [media] exynos4-is: Add Exynos5250 SoC support to fimc-lite driver [media] exynos4-is: Drop drvdata handling in fimc-lite for non-dt platforms [media] media: i2c: tvp514x: remove manual setting of subdev name [media] media: i2c: tvp7002: remove manual setting of subdev name [media] mem2mem: set missing v4l2_dev pointer [media] wl128x: add missing struct v4l2_device [media] tvp514x: Fix init seqeunce [media] saa7134: Fix sparse warnings by adding __user annotation ...
Diffstat (limited to 'Documentation/video4linux')
5 files changed, 106 insertions, 28 deletions
diff --git a/Documentation/video4linux/CARDLIST.bttv b/Documentation/video4linux/CARDLIST.bttv
index 581f666a76cf..f14475011fea 100644
--- a/Documentation/video4linux/CARDLIST.bttv
+++ b/Documentation/video4linux/CARDLIST.bttv
@@ -160,3 +160,6 @@
159 -> ProVideo PV183 [1830:1540,1831:1540,1832:1540,1833:1540,1834:1540,1835:1540,1836:1540,1837:1540]
160 -> Tongwei Video Technology TD-3116 [f200:3116]
161 -> Aposonic W-DVR [0279:0228]
+162 -> Adlink MPG24
+163 -> Bt848 Capture 14MHz
+164 -> CyberVision CV06 (SV)
diff --git a/Documentation/video4linux/CARDLIST.saa7134 b/Documentation/video4linux/CARDLIST.saa7134
index b3ad68309109..8df17d063499 100644
--- a/Documentation/video4linux/CARDLIST.saa7134
+++ b/Documentation/video4linux/CARDLIST.saa7134
@@ -190,3 +190,4 @@
189 -> Kworld PC150-U [17de:a134]
190 -> Asus My Cinema PS3-100 [1043:48cd]
191 -> Hawell HW-9004V1
+192 -> AverMedia AverTV Satellite Hybrid+FM A706 [1461:2055]
diff --git a/Documentation/video4linux/CARDLIST.tuner b/Documentation/video4linux/CARDLIST.tuner
index 5b83a3ff15c2..ac8862184962 100644
--- a/Documentation/video4linux/CARDLIST.tuner
+++ b/Documentation/video4linux/CARDLIST.tuner
@@ -86,6 +86,6 @@ tuner=85 - Philips FQ1236 MK5
tuner=86 - Tena TNF5337 MFD
tuner=87 - Xceive 4000 tuner
tuner=88 - Xceive 5000C tuner
-tuner=89 - Sony PAL+SECAM (BTF-PG472Z)
-tuner=90 - Sony NTSC-M-JP (BTF-PK467Z)
-tuner=91 - Sony NTSC-M (BTF-PB463Z)
+tuner=89 - Sony BTF-PG472Z PAL/SECAM
+tuner=90 - Sony BTF-PK467Z NTSC-M-JP
+tuner=91 - Sony BTF-PB463Z NTSC-M
diff --git a/Documentation/video4linux/fimc.txt b/Documentation/video4linux/fimc.txt
index 25f4d3402722..e51f1b5b7324 100644
--- a/Documentation/video4linux/fimc.txt
+++ b/Documentation/video4linux/fimc.txt
@@ -1,6 +1,6 @@
Samsung S5P/EXYNOS4 FIMC driver
-Copyright (C) 2012 Samsung Electronics Co., Ltd.
+Copyright (C) 2012 - 2013 Samsung Electronics Co., Ltd.
The FIMC (Fully Interactive Mobile Camera) device available in Samsung
@@ -10,7 +10,7 @@ data from LCD controller (FIMD) through the SoC internal writeback data
path. There are multiple FIMC instances in the SoCs (up to 4), having
slightly different capabilities, like pixel alignment constraints, rotator
availability, LCD writeback support, etc. The driver is located at
-drivers/media/platform/s5p-fimc directory.
+drivers/media/platform/exynos4-is directory.
1. Supported SoCs
@@ -36,21 +36,21 @@ Not currently supported:
- media device driver
- drivers/media/platform/s5p-fimc/fimc-mdevice.[ch]
+ drivers/media/platform/exynos4-is/media-dev.[ch]
- camera capture video device driver
- drivers/media/platform/s5p-fimc/fimc-capture.c
+ drivers/media/platform/exynos4-is/fimc-capture.c
- MIPI-CSI2 receiver subdev
- drivers/media/platform/s5p-fimc/mipi-csis.[ch]
+ drivers/media/platform/exynos4-is/mipi-csis.[ch]
- video post-processor (mem-to-mem)
- drivers/media/platform/s5p-fimc/fimc-core.c
+ drivers/media/platform/exynos4-is/fimc-core.c
- common files
- drivers/media/platform/s5p-fimc/fimc-core.h
- drivers/media/platform/s5p-fimc/fimc-reg.h
- drivers/media/platform/s5p-fimc/regs-fimc.h
+ drivers/media/platform/exynos4-is/fimc-core.h
+ drivers/media/platform/exynos4-is/fimc-reg.h
+ drivers/media/platform/exynos4-is/regs-fimc.h
4. User space interfaces
@@ -143,7 +143,8 @@ or retrieve the information from /dev/media? with help of the media-ctl tool:
6. Platform support
-The machine code (plat-s5p and arch/arm/mach-*) must select following options
+The machine code (arch/arm/plat-samsung and arch/arm/mach-*) must select
+following options:
CONFIG_S5P_DEV_FIMC0 mandatory
diff --git a/Documentation/video4linux/v4l2-framework.txt b/Documentation/video4linux/v4l2-framework.txt
index a300b283a1a0..6c4866b49eb5 100644
--- a/Documentation/video4linux/v4l2-framework.txt
+++ b/Documentation/video4linux/v4l2-framework.txt
@@ -246,7 +246,6 @@ 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_dbg_chip_ident *chip);
int (*log_status)(struct v4l2_subdev *sd);
int (*init)(struct v4l2_subdev *sd, u32 val);
@@ -326,8 +325,27 @@ that width, height and the media bus pixel code are equal on both source and
sink of the link. Subdev drivers are also free to use this function to
perform the checks mentioned above in addition to their own checks.
-A device (bridge) driver needs to register the v4l2_subdev with the
+There are currently two ways to register subdevices with the V4L2 core. The
+first (traditional) possibility is to have subdevices registered by bridge
+drivers. This can be done when the bridge driver has the complete information
+about subdevices connected to it and knows exactly when to register them. This
+is typically the case for internal subdevices, like video data processing units
+within SoCs or complex PCI(e) boards, camera sensors in USB cameras or connected
+to SoCs, which pass information about them to bridge drivers, usually in their
+platform data.
+There are however also situations where subdevices have to be registered
+asynchronously to bridge devices. An example of such a configuration is a Device
+Tree based system where information about subdevices is made available to the
+system independently from the bridge devices, e.g. when subdevices are defined
+in DT as I2C device nodes. The API used in this second case is described further
+Using one or the other registration method only affects the probing process, the
+run-time bridge-subdevice interaction is in both cases the same.
+In the synchronous case a device (bridge) driver needs to register the
+v4l2_subdev with the v4l2_device:
int err = v4l2_device_register_subdev(v4l2_dev, sd);
@@ -346,24 +364,24 @@ Afterwards the subdev module can be unloaded and sd->dev == NULL.
You can call an ops function either directly:
- err = sd->ops->core->g_chip_ident(sd, &chip);
+ err = sd->ops->core->g_std(sd, &norm);
but it is better and easier to use this macro:
- err = v4l2_subdev_call(sd, core, g_chip_ident, &chip);
+ err = v4l2_subdev_call(sd, core, g_std, &norm);
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.
+is NULL, -ENOIOCTLCMD if either subdev->core or subdev->core->g_std is
+NULL, or the actual result of the subdev->ops->core->g_std ops.
It is also possible to call all or a subset of the sub-devices:
- v4l2_device_call_all(v4l2_dev, 0, core, g_chip_ident, &chip);
+ v4l2_device_call_all(v4l2_dev, 0, core, g_std, &norm);
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(v4l2_dev, 0, core, g_chip_ident, &chip);
+ err = v4l2_device_call_until_err(v4l2_dev, 0, core, g_std, &norm);
Any error except -ENOIOCTLCMD will exit the loop with that error. If no
errors (except -ENOIOCTLCMD) occurred, then 0 is returned.
@@ -394,6 +412,30 @@ controlled through GPIO pins. This distinction is only relevant when setting
up the device, but once the subdev is registered it is completely transparent.
+In the asynchronous case subdevice probing can be invoked independently of the
+bridge driver availability. The subdevice driver then has to verify whether all
+the requirements for a successful probing are satisfied. This can include a
+check for a master clock availability. If any of the conditions aren't satisfied
+the driver might decide to return -EPROBE_DEFER to request further reprobing
+attempts. Once all conditions are met the subdevice shall be registered using
+the v4l2_async_register_subdev() function. Unregistration is performed using
+the v4l2_async_unregister_subdev() call. Subdevices registered this way are
+stored in a global list of subdevices, ready to be picked up by bridge drivers.
+Bridge drivers in turn have to register a notifier object with an array of
+subdevice descriptors that the bridge device needs for its operation. This is
+performed using the v4l2_async_notifier_register() call. To unregister the
+notifier the driver has to call v4l2_async_notifier_unregister(). The former of
+the two functions takes two arguments: a pointer to struct v4l2_device and a
+pointer to struct v4l2_async_notifier. The latter contains a pointer to an array
+of pointers to subdevice descriptors of type struct v4l2_async_subdev type. The
+V4L2 core will then use these descriptors to match asynchronously registered
+subdevices to them. If a match is detected the .bound() notifier callback is
+called. After all subdevices have been located the .complete() callback is
+called. When a subdevice is removed from the system the .unbind() method is
+called. All three callbacks are optional.
V4L2 sub-device userspace API
@@ -575,9 +617,13 @@ of the video device exits.
The default video_device_release() callback just calls kfree to free the
allocated memory.
+There is also a video_device_release_empty() function that does nothing
+(is empty) and can be used if the struct is embedded and there is nothing
+to do when it is released.
You should also set these fields:
-- v4l2_dev: set to the v4l2_device parent device.
+- v4l2_dev: must be set to the v4l2_device parent device.
- name: set to something descriptive and unique.
@@ -614,15 +660,16 @@ You should also set these fields:
If you want to have a separate priority state per (group of) device node(s),
then you can point it to your own struct v4l2_prio_state.
-- parent: you only set this if v4l2_device was registered with NULL as
+- dev_parent: you only set this if v4l2_device was registered with NULL as
the parent device struct. This only happens in cases where one hardware
device has multiple PCI devices that all share the same v4l2_device core.
The cx88 driver is an example of this: one core v4l2_device struct, but
- it is used by both an raw video PCI device (cx8800) and a MPEG PCI device
- (cx8802). Since the v4l2_device cannot be associated with a particular
- PCI device it is setup without a parent device. But when the struct
- video_device is setup you do know which parent PCI device to use.
+ it is used by both a raw video PCI device (cx8800) and a MPEG PCI device
+ (cx8802). Since the v4l2_device cannot be associated with two PCI devices
+ at the same time it is setup without a parent device. But when the struct
+ video_device is initialized you *do* know which parent PCI device to use and
+ so you set dev_device to the correct PCI device.
- flags: optional. Set to V4L2_FL_USE_FH_PRIO if you want to let the framework
handle the VIDIOC_G/S_PRIORITY ioctls. This requires that you use struct
@@ -1061,3 +1108,29 @@ available event type is 'class base + 1'.
An example on how the V4L2 events may be used can be found in the OMAP
3 ISP driver (drivers/media/platform/omap3isp).
+V4L2 clocks
+Many subdevices, like camera sensors, TV decoders and encoders, need a clock
+signal to be supplied by the system. Often this clock is supplied by the
+respective bridge device. The Linux kernel provides a Common Clock Framework for
+this purpose. However, it is not (yet) available on all architectures. Besides,
+the nature of the multi-functional (clock, data + synchronisation, I2C control)
+connection of subdevices to the system might impose special requirements on the
+clock API usage. E.g. V4L2 has to support clock provider driver unregistration
+while a subdevice driver is holding a reference to the clock. For these reasons
+a V4L2 clock helper API has been developed and is provided to bridge and
+subdevice drivers.
+The API consists of two parts: two functions to register and unregister a V4L2
+clock source: v4l2_clk_register() and v4l2_clk_unregister() and calls to control
+a clock object, similar to the respective generic clock API calls:
+v4l2_clk_get(), v4l2_clk_put(), v4l2_clk_enable(), v4l2_clk_disable(),
+v4l2_clk_get_rate(), and v4l2_clk_set_rate(). Clock suppliers have to provide
+clock operations that will be called when clock users invoke respective API
+It is expected that once the CCF becomes available on all relevant
+architectures this API will be removed.