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author | 2023-02-21 18:24:12 -0800 | |
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committer | 2023-02-21 18:24:12 -0800 | |
commit | 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch) | |
tree | cc5c2d0a898769fd59549594fedb3ee6f84e59a0 /Documentation/driver-api/media/drivers/pxa_camera.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/driver-api/media/drivers/pxa_camera.rst')
-rw-r--r-- | Documentation/driver-api/media/drivers/pxa_camera.rst | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/Documentation/driver-api/media/drivers/pxa_camera.rst b/Documentation/driver-api/media/drivers/pxa_camera.rst new file mode 100644 index 000000000..46919919b --- /dev/null +++ b/Documentation/driver-api/media/drivers/pxa_camera.rst @@ -0,0 +1,194 @@ +.. SPDX-License-Identifier: GPL-2.0 + +PXA-Camera Host Driver +====================== + +Author: Robert Jarzmik <robert.jarzmik@free.fr> + +Constraints +----------- + +a) Image size for YUV422P format + All YUV422P images are enforced to have width x height % 16 = 0. + This is due to DMA constraints, which transfers only planes of 8 byte + multiples. + + +Global video workflow +--------------------- + +a) QCI stopped + Initially, the QCI interface is stopped. + When a buffer is queued, start_streaming is called and the QCI starts. + +b) QCI started + More buffers can be queued while the QCI is started without halting the + capture. The new buffers are "appended" at the tail of the DMA chain, and + smoothly captured one frame after the other. + + Once a buffer is filled in the QCI interface, it is marked as "DONE" and + removed from the active buffers list. It can be then requeud or dequeued by + userland application. + + Once the last buffer is filled in, the QCI interface stops. + +c) Capture global finite state machine schema + +.. code-block:: none + + +----+ +---+ +----+ + | DQ | | Q | | DQ | + | v | v | v + +-----------+ +------------------------+ + | STOP | | Wait for capture start | + +-----------+ Q +------------------------+ + +-> | QCI: stop | ------------------> | QCI: run | <------------+ + | | DMA: stop | | DMA: stop | | + | +-----------+ +-----> +------------------------+ | + | / | | + | / +---+ +----+ | | + |capture list empty / | Q | | DQ | | QCI Irq EOF | + | / | v | v v | + | +--------------------+ +----------------------+ | + | | DMA hotlink missed | | Capture running | | + | +--------------------+ +----------------------+ | + | | QCI: run | +-----> | QCI: run | <-+ | + | | DMA: stop | / | DMA: run | | | + | +--------------------+ / +----------------------+ | Other | + | ^ /DMA still | | channels | + | | capture list / running | DMA Irq End | not | + | | not empty / | | finished | + | | / v | yet | + | +----------------------+ +----------------------+ | | + | | Videobuf released | | Channel completed | | | + | +----------------------+ +----------------------+ | | + +-- | QCI: run | | QCI: run | --+ | + | DMA: run | | DMA: run | | + +----------------------+ +----------------------+ | + ^ / | | + | no overrun / | overrun | + | / v | + +--------------------+ / +----------------------+ | + | Frame completed | / | Frame overran | | + +--------------------+ <-----+ +----------------------+ restart frame | + | QCI: run | | QCI: stop | --------------+ + | DMA: run | | DMA: stop | + +--------------------+ +----------------------+ + + Legend: - each box is a FSM state + - each arrow is the condition to transition to another state + - an arrow with a comment is a mandatory transition (no condition) + - arrow "Q" means : a buffer was enqueued + - arrow "DQ" means : a buffer was dequeued + - "QCI: stop" means the QCI interface is not enabled + - "DMA: stop" means all 3 DMA channels are stopped + - "DMA: run" means at least 1 DMA channel is still running + +DMA usage +--------- + +a) DMA flow + - first buffer queued for capture + Once a first buffer is queued for capture, the QCI is started, but data + transfer is not started. On "End Of Frame" interrupt, the irq handler + starts the DMA chain. + - capture of one videobuffer + The DMA chain starts transferring data into videobuffer RAM pages. + When all pages are transferred, the DMA irq is raised on "ENDINTR" status + - finishing one videobuffer + The DMA irq handler marks the videobuffer as "done", and removes it from + the active running queue + Meanwhile, the next videobuffer (if there is one), is transferred by DMA + - finishing the last videobuffer + On the DMA irq of the last videobuffer, the QCI is stopped. + +b) DMA prepared buffer will have this structure + +.. code-block:: none + + +------------+-----+---------------+-----------------+ + | desc-sg[0] | ... | desc-sg[last] | finisher/linker | + +------------+-----+---------------+-----------------+ + +This structure is pointed by dma->sg_cpu. +The descriptors are used as follows: + +- desc-sg[i]: i-th descriptor, transferring the i-th sg + element to the video buffer scatter gather +- finisher: has ddadr=DADDR_STOP, dcmd=ENDIRQEN +- linker: has ddadr= desc-sg[0] of next video buffer, dcmd=0 + +For the next schema, let's assume d0=desc-sg[0] .. dN=desc-sg[N], +"f" stands for finisher and "l" for linker. +A typical running chain is : + +.. code-block:: none + + Videobuffer 1 Videobuffer 2 + +---------+----+---+ +----+----+----+---+ + | d0 | .. | dN | l | | d0 | .. | dN | f | + +---------+----+-|-+ ^----+----+----+---+ + | | + +----+ + +After the chaining is finished, the chain looks like : + +.. code-block:: none + + Videobuffer 1 Videobuffer 2 Videobuffer 3 + +---------+----+---+ +----+----+----+---+ +----+----+----+---+ + | d0 | .. | dN | l | | d0 | .. | dN | l | | d0 | .. | dN | f | + +---------+----+-|-+ ^----+----+----+-|-+ ^----+----+----+---+ + | | | | + +----+ +----+ + new_link + +c) DMA hot chaining timeslice issue + +As DMA chaining is done while DMA _is_ running, the linking may be done +while the DMA jumps from one Videobuffer to another. On the schema, that +would be a problem if the following sequence is encountered : + +- DMA chain is Videobuffer1 + Videobuffer2 +- pxa_videobuf_queue() is called to queue Videobuffer3 +- DMA controller finishes Videobuffer2, and DMA stops + +.. code-block:: none + + => + Videobuffer 1 Videobuffer 2 + +---------+----+---+ +----+----+----+---+ + | d0 | .. | dN | l | | d0 | .. | dN | f | + +---------+----+-|-+ ^----+----+----+-^-+ + | | | + +----+ +-- DMA DDADR loads DDADR_STOP + +- pxa_dma_add_tail_buf() is called, the Videobuffer2 "finisher" is + replaced by a "linker" to Videobuffer3 (creation of new_link) +- pxa_videobuf_queue() finishes +- the DMA irq handler is called, which terminates Videobuffer2 +- Videobuffer3 capture is not scheduled on DMA chain (as it stopped !!!) + +.. code-block:: none + + Videobuffer 1 Videobuffer 2 Videobuffer 3 + +---------+----+---+ +----+----+----+---+ +----+----+----+---+ + | d0 | .. | dN | l | | d0 | .. | dN | l | | d0 | .. | dN | f | + +---------+----+-|-+ ^----+----+----+-|-+ ^----+----+----+---+ + | | | | + +----+ +----+ + new_link + DMA DDADR still is DDADR_STOP + +- pxa_camera_check_link_miss() is called + This checks if the DMA is finished and a buffer is still on the + pcdev->capture list. If that's the case, the capture will be restarted, + and Videobuffer3 is scheduled on DMA chain. +- the DMA irq handler finishes + +.. note:: + + If DMA stops just after pxa_camera_check_link_miss() reads DDADR() + value, we have the guarantee that the DMA irq handler will be called back + when the DMA will finish the buffer, and pxa_camera_check_link_miss() will + be called again, to reschedule Videobuffer3. |