diff options
author | 2023-02-21 18:24:12 -0800 | |
---|---|---|
committer | 2023-02-21 18:24:12 -0800 | |
commit | 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch) | |
tree | cc5c2d0a898769fd59549594fedb3ee6f84e59a0 /Documentation/userspace-api/media/v4l/standard.rst | |
download | linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.zip |
Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted
Pull networking updates from Jakub Kicinski:
"Core:
- Add dedicated kmem_cache for typical/small skb->head, avoid having
to access struct page at kfree time, and improve memory use.
- Introduce sysctl to set default RPS configuration for new netdevs.
- Define Netlink protocol specification format which can be used to
describe messages used by each family and auto-generate parsers.
Add tools for generating kernel data structures and uAPI headers.
- Expose all net/core sysctls inside netns.
- Remove 4s sleep in netpoll if carrier is instantly detected on
boot.
- Add configurable limit of MDB entries per port, and port-vlan.
- Continue populating drop reasons throughout the stack.
- Retire a handful of legacy Qdiscs and classifiers.
Protocols:
- Support IPv4 big TCP (TSO frames larger than 64kB).
- Add IP_LOCAL_PORT_RANGE socket option, to control local port range
on socket by socket basis.
- Track and report in procfs number of MPTCP sockets used.
- Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
manager.
- IPv6: don't check net.ipv6.route.max_size and rely on garbage
collection to free memory (similarly to IPv4).
- Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).
- ICMP: add per-rate limit counters.
- Add support for user scanning requests in ieee802154.
- Remove static WEP support.
- Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
reporting.
- WiFi 7 EHT channel puncturing support (client & AP).
BPF:
- Add a rbtree data structure following the "next-gen data structure"
precedent set by recently added linked list, that is, by using
kfunc + kptr instead of adding a new BPF map type.
- Expose XDP hints via kfuncs with initial support for RX hash and
timestamp metadata.
- Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
better support decap on GRE tunnel devices not operating in collect
metadata.
- Improve x86 JIT's codegen for PROBE_MEM runtime error checks.
- Remove the need for trace_printk_lock for bpf_trace_printk and
bpf_trace_vprintk helpers.
- Extend libbpf's bpf_tracing.h support for tracing arguments of
kprobes/uprobes and syscall as a special case.
- Significantly reduce the search time for module symbols by
livepatch and BPF.
- Enable cpumasks to be used as kptrs, which is useful for tracing
programs tracking which tasks end up running on which CPUs in
different time intervals.
- Add support for BPF trampoline on s390x and riscv64.
- Add capability to export the XDP features supported by the NIC.
- Add __bpf_kfunc tag for marking kernel functions as kfuncs.
- Add cgroup.memory=nobpf kernel parameter option to disable BPF
memory accounting for container environments.
Netfilter:
- Remove the CLUSTERIP target. It has been marked as obsolete for
years, and we still have WARN splats wrt races of the out-of-band
/proc interface installed by this target.
- Add 'destroy' commands to nf_tables. They are identical to the
existing 'delete' commands, but do not return an error if the
referenced object (set, chain, rule...) did not exist.
Driver API:
- Improve cpumask_local_spread() locality to help NICs set the right
IRQ affinity on AMD platforms.
- Separate C22 and C45 MDIO bus transactions more clearly.
- Introduce new DCB table to control DSCP rewrite on egress.
- Support configuration of Physical Layer Collision Avoidance (PLCA)
Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
shared medium Ethernet.
- Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
preemption of low priority frames by high priority frames.
- Add support for controlling MACSec offload using netlink SET.
- Rework devlink instance refcounts to allow registration and
de-registration under the instance lock. Split the code into
multiple files, drop some of the unnecessarily granular locks and
factor out common parts of netlink operation handling.
- Add TX frame aggregation parameters (for USB drivers).
- Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
messages with notifications for debug.
- Allow offloading of UDP NEW connections via act_ct.
- Add support for per action HW stats in TC.
- Support hardware miss to TC action (continue processing in SW from
a specific point in the action chain).
- Warn if old Wireless Extension user space interface is used with
modern cfg80211/mac80211 drivers. Do not support Wireless
Extensions for Wi-Fi 7 devices at all. Everyone should switch to
using nl80211 interface instead.
- Improve the CAN bit timing configuration. Use extack to return
error messages directly to user space, update the SJW handling,
including the definition of a new default value that will benefit
CAN-FD controllers, by increasing their oscillator tolerance.
New hardware / drivers:
- Ethernet:
- nVidia BlueField-3 support (control traffic driver)
- Ethernet support for imx93 SoCs
- Motorcomm yt8531 gigabit Ethernet PHY
- onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
- Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
- Amlogic gxl MDIO mux
- WiFi:
- RealTek RTL8188EU (rtl8xxxu)
- Qualcomm Wi-Fi 7 devices (ath12k)
- CAN:
- Renesas R-Car V4H
Drivers:
- Bluetooth:
- Set Per Platform Antenna Gain (PPAG) for Intel controllers.
- Ethernet NICs:
- Intel (1G, igc):
- support TSN / Qbv / packet scheduling features of i226 model
- Intel (100G, ice):
- use GNSS subsystem instead of TTY
- multi-buffer XDP support
- extend support for GPIO pins to E823 devices
- nVidia/Mellanox:
- update the shared buffer configuration on PFC commands
- implement PTP adjphase function for HW offset control
- TC support for Geneve and GRE with VF tunnel offload
- more efficient crypto key management method
- multi-port eswitch support
- Netronome/Corigine:
- add DCB IEEE support
- support IPsec offloading for NFP3800
- Freescale/NXP (enetc):
- support XDP_REDIRECT for XDP non-linear buffers
- improve reconfig, avoid link flap and waiting for idle
- support MAC Merge layer
- Other NICs:
- sfc/ef100: add basic devlink support for ef100
- ionic: rx_push mode operation (writing descriptors via MMIO)
- bnxt: use the auxiliary bus abstraction for RDMA
- r8169: disable ASPM and reset bus in case of tx timeout
- cpsw: support QSGMII mode for J721e CPSW9G
- cpts: support pulse-per-second output
- ngbe: add an mdio bus driver
- usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
- r8152: handle devices with FW with NCM support
- amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
- virtio-net: support multi buffer XDP
- virtio/vsock: replace virtio_vsock_pkt with sk_buff
- tsnep: XDP support
- Ethernet high-speed switches:
- nVidia/Mellanox (mlxsw):
- add support for latency TLV (in FW control messages)
- Microchip (sparx5):
- separate explicit and implicit traffic forwarding rules, make
the implicit rules always active
- add support for egress DSCP rewrite
- IS0 VCAP support (Ingress Classification)
- IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
etc.)
- ES2 VCAP support (Egress Access Control)
- support for Per-Stream Filtering and Policing (802.1Q,
8.6.5.1)
- Ethernet embedded switches:
- Marvell (mv88e6xxx):
- add MAB (port auth) offload support
- enable PTP receive for mv88e6390
- NXP (ocelot):
- support MAC Merge layer
- support for the the vsc7512 internal copper phys
- Microchip:
- lan9303: convert to PHYLINK
- lan966x: support TC flower filter statistics
- lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
- lan937x: support Credit Based Shaper configuration
- ksz9477: support Energy Efficient Ethernet
- other:
- qca8k: convert to regmap read/write API, use bulk operations
- rswitch: Improve TX timestamp accuracy
- Intel WiFi (iwlwifi):
- EHT (Wi-Fi 7) rate reporting
- STEP equalizer support: transfer some STEP (connection to radio
on platforms with integrated wifi) related parameters from the
BIOS to the firmware.
- Qualcomm 802.11ax WiFi (ath11k):
- IPQ5018 support
- Fine Timing Measurement (FTM) responder role support
- channel 177 support
- MediaTek WiFi (mt76):
- per-PHY LED support
- mt7996: EHT (Wi-Fi 7) support
- Wireless Ethernet Dispatch (WED) reset support
- switch to using page pool allocator
- RealTek WiFi (rtw89):
- support new version of Bluetooth co-existance
- Mobile:
- rmnet: support TX aggregation"
* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
page_pool: add a comment explaining the fragment counter usage
net: ethtool: fix __ethtool_dev_mm_supported() implementation
ethtool: pse-pd: Fix double word in comments
xsk: add linux/vmalloc.h to xsk.c
sefltests: netdevsim: wait for devlink instance after netns removal
selftest: fib_tests: Always cleanup before exit
net/mlx5e: Align IPsec ASO result memory to be as required by hardware
net/mlx5e: TC, Set CT miss to the specific ct action instance
net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
net/mlx5: Refactor tc miss handling to a single function
net/mlx5: Kconfig: Make tc offload depend on tc skb extension
net/sched: flower: Support hardware miss to tc action
net/sched: flower: Move filter handle initialization earlier
net/sched: cls_api: Support hardware miss to tc action
net/sched: Rename user cookie and act cookie
sfc: fix builds without CONFIG_RTC_LIB
sfc: clean up some inconsistent indentings
net/mlx4_en: Introduce flexible array to silence overflow warning
net: lan966x: Fix possible deadlock inside PTP
net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
...
Diffstat (limited to 'Documentation/userspace-api/media/v4l/standard.rst')
-rw-r--r-- | Documentation/userspace-api/media/v4l/standard.rst | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/Documentation/userspace-api/media/v4l/standard.rst b/Documentation/userspace-api/media/v4l/standard.rst new file mode 100644 index 000000000..1f6678325 --- /dev/null +++ b/Documentation/userspace-api/media/v4l/standard.rst @@ -0,0 +1,185 @@ +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later + +.. _standard: + +*************** +Video Standards +*************** + +Video devices typically support one or more different video standards or +variations of standards. Each video input and output may support another +set of standards. This set is reported by the ``std`` field of struct +:c:type:`v4l2_input` and struct +:c:type:`v4l2_output` returned by the +:ref:`VIDIOC_ENUMINPUT` and +:ref:`VIDIOC_ENUMOUTPUT` ioctls, respectively. + +V4L2 defines one bit for each analog video standard currently in use +worldwide, and sets aside bits for driver defined standards, e. g. +hybrid standards to watch NTSC video tapes on PAL TVs and vice versa. +Applications can use the predefined bits to select a particular +standard, although presenting the user a menu of supported standards is +preferred. To enumerate and query the attributes of the supported +standards applications use the :ref:`VIDIOC_ENUMSTD` +ioctl. + +Many of the defined standards are actually just variations of a few +major standards. The hardware may in fact not distinguish between them, +or do so internal and switch automatically. Therefore enumerated +standards also contain sets of one or more standard bits. + +Assume a hypothetic tuner capable of demodulating B/PAL, G/PAL and I/PAL +signals. The first enumerated standard is a set of B and G/PAL, switched +automatically depending on the selected radio frequency in UHF or VHF +band. Enumeration gives a "PAL-B/G" or "PAL-I" choice. Similar a +Composite input may collapse standards, enumerating "PAL-B/G/H/I", +"NTSC-M" and "SECAM-D/K". [#f1]_ + +To query and select the standard used by the current video input or +output applications call the :ref:`VIDIOC_G_STD <VIDIOC_G_STD>` and +:ref:`VIDIOC_S_STD <VIDIOC_G_STD>` ioctl, respectively. The +*received* standard can be sensed with the +:ref:`VIDIOC_QUERYSTD` ioctl. + +.. note:: + + The parameter of all these ioctls is a pointer to a + :ref:`v4l2_std_id <v4l2-std-id>` type (a standard set), *not* an + index into the standard enumeration. Drivers must implement all video + standard ioctls when the device has one or more video inputs or outputs. + +Special rules apply to devices such as USB cameras where the notion of +video standards makes little sense. More generally for any capture or +output device which is: + +- incapable of capturing fields or frames at the nominal rate of the + video standard, or + +- that does not support the video standard formats at all. + +Here the driver shall set the ``std`` field of struct +:c:type:`v4l2_input` and struct +:c:type:`v4l2_output` to zero and the :ref:`VIDIOC_G_STD <VIDIOC_G_STD>`, +:ref:`VIDIOC_S_STD <VIDIOC_G_STD>`, :ref:`VIDIOC_QUERYSTD` and :ref:`VIDIOC_ENUMSTD` ioctls +shall return the ``ENOTTY`` error code or the ``EINVAL`` error code. + +Applications can make use of the :ref:`input-capabilities` and +:ref:`output-capabilities` flags to determine whether the video +standard ioctls can be used with the given input or output. + +Example: Information about the current video standard +===================================================== + +.. code-block:: c + + v4l2_std_id std_id; + struct v4l2_standard standard; + + if (-1 == ioctl(fd, VIDIOC_G_STD, &std_id)) { + /* Note when VIDIOC_ENUMSTD always returns ENOTTY this + is no video device or it falls under the USB exception, + and VIDIOC_G_STD returning ENOTTY is no error. */ + + perror("VIDIOC_G_STD"); + exit(EXIT_FAILURE); + } + + memset(&standard, 0, sizeof(standard)); + standard.index = 0; + + while (0 == ioctl(fd, VIDIOC_ENUMSTD, &standard)) { + if (standard.id & std_id) { + printf("Current video standard: %s\\n", standard.name); + exit(EXIT_SUCCESS); + } + + standard.index++; + } + + /* EINVAL indicates the end of the enumeration, which cannot be + empty unless this device falls under the USB exception. */ + + if (errno == EINVAL || standard.index == 0) { + perror("VIDIOC_ENUMSTD"); + exit(EXIT_FAILURE); + } + +Example: Listing the video standards supported by the current input +=================================================================== + +.. code-block:: c + + struct v4l2_input input; + struct v4l2_standard standard; + + memset(&input, 0, sizeof(input)); + + if (-1 == ioctl(fd, VIDIOC_G_INPUT, &input.index)) { + perror("VIDIOC_G_INPUT"); + exit(EXIT_FAILURE); + } + + if (-1 == ioctl(fd, VIDIOC_ENUMINPUT, &input)) { + perror("VIDIOC_ENUM_INPUT"); + exit(EXIT_FAILURE); + } + + printf("Current input %s supports:\\n", input.name); + + memset(&standard, 0, sizeof(standard)); + standard.index = 0; + + while (0 == ioctl(fd, VIDIOC_ENUMSTD, &standard)) { + if (standard.id & input.std) + printf("%s\\n", standard.name); + + standard.index++; + } + + /* EINVAL indicates the end of the enumeration, which cannot be + empty unless this device falls under the USB exception. */ + + if (errno != EINVAL || standard.index == 0) { + perror("VIDIOC_ENUMSTD"); + exit(EXIT_FAILURE); + } + +Example: Selecting a new video standard +======================================= + +.. code-block:: c + + struct v4l2_input input; + v4l2_std_id std_id; + + memset(&input, 0, sizeof(input)); + + if (-1 == ioctl(fd, VIDIOC_G_INPUT, &input.index)) { + perror("VIDIOC_G_INPUT"); + exit(EXIT_FAILURE); + } + + if (-1 == ioctl(fd, VIDIOC_ENUMINPUT, &input)) { + perror("VIDIOC_ENUM_INPUT"); + exit(EXIT_FAILURE); + } + + if (0 == (input.std & V4L2_STD_PAL_BG)) { + fprintf(stderr, "Oops. B/G PAL is not supported.\\n"); + exit(EXIT_FAILURE); + } + + /* Note this is also supposed to work when only B + or G/PAL is supported. */ + + std_id = V4L2_STD_PAL_BG; + + if (-1 == ioctl(fd, VIDIOC_S_STD, &std_id)) { + perror("VIDIOC_S_STD"); + exit(EXIT_FAILURE); + } + +.. [#f1] + Some users are already confused by technical terms PAL, NTSC and + SECAM. There is no point asking them to distinguish between B, G, D, + or K when the software or hardware can do that automatically. |