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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/regulator.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/regulator.rst')
-rw-r--r-- | Documentation/driver-api/regulator.rst | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/Documentation/driver-api/regulator.rst b/Documentation/driver-api/regulator.rst new file mode 100644 index 000000000..b43c78eb2 --- /dev/null +++ b/Documentation/driver-api/regulator.rst @@ -0,0 +1,170 @@ +.. Copyright 2007-2008 Wolfson Microelectronics + +.. This documentation is free software; you can redistribute +.. it and/or modify it under the terms of the GNU General Public +.. License version 2 as published by the Free Software Foundation. + +================================= +Voltage and current regulator API +================================= + +:Author: Liam Girdwood +:Author: Mark Brown + +Introduction +============ + +This framework is designed to provide a standard kernel interface to +control voltage and current regulators. + +The intention is to allow systems to dynamically control regulator power +output in order to save power and prolong battery life. This applies to +both voltage regulators (where voltage output is controllable) and +current sinks (where current limit is controllable). + +Note that additional (and currently more complete) documentation is +available in the Linux kernel source under +``Documentation/power/regulator``. + +Glossary +-------- + +The regulator API uses a number of terms which may not be familiar: + +Regulator + + Electronic device that supplies power to other devices. Most regulators + can enable and disable their output and some can also control their + output voltage or current. + +Consumer + + Electronic device which consumes power provided by a regulator. These + may either be static, requiring only a fixed supply, or dynamic, + requiring active management of the regulator at runtime. + +Power Domain + + The electronic circuit supplied by a given regulator, including the + regulator and all consumer devices. The configuration of the regulator + is shared between all the components in the circuit. + +Power Management Integrated Circuit (PMIC) + + An IC which contains numerous regulators and often also other + subsystems. In an embedded system the primary PMIC is often equivalent + to a combination of the PSU and southbridge in a desktop system. + +Consumer driver interface +========================= + +This offers a similar API to the kernel clock framework. Consumer +drivers use `get <#API-regulator-get>`__ and +`put <#API-regulator-put>`__ operations to acquire and release +regulators. Functions are provided to `enable <#API-regulator-enable>`__ +and `disable <#API-regulator-disable>`__ the regulator and to get and +set the runtime parameters of the regulator. + +When requesting regulators consumers use symbolic names for their +supplies, such as "Vcc", which are mapped into actual regulator devices +by the machine interface. + +A stub version of this API is provided when the regulator framework is +not in use in order to minimise the need to use ifdefs. + +Enabling and disabling +---------------------- + +The regulator API provides reference counted enabling and disabling of +regulators. Consumer devices use the :c:func:`regulator_enable()` and +:c:func:`regulator_disable()` functions to enable and disable +regulators. Calls to the two functions must be balanced. + +Note that since multiple consumers may be using a regulator and machine +constraints may not allow the regulator to be disabled there is no +guarantee that calling :c:func:`regulator_disable()` will actually +cause the supply provided by the regulator to be disabled. Consumer +drivers should assume that the regulator may be enabled at all times. + +Configuration +------------- + +Some consumer devices may need to be able to dynamically configure their +supplies. For example, MMC drivers may need to select the correct +operating voltage for their cards. This may be done while the regulator +is enabled or disabled. + +The :c:func:`regulator_set_voltage()` and +:c:func:`regulator_set_current_limit()` functions provide the primary +interface for this. Both take ranges of voltages and currents, supporting +drivers that do not require a specific value (eg, CPU frequency scaling +normally permits the CPU to use a wider range of supply voltages at lower +frequencies but does not require that the supply voltage be lowered). Where +an exact value is required both minimum and maximum values should be +identical. + +Callbacks +--------- + +Callbacks may also be registered for events such as regulation failures. + +Regulator driver interface +========================== + +Drivers for regulator chips register the regulators with the regulator +core, providing operations structures to the core. A notifier interface +allows error conditions to be reported to the core. + +Registration should be triggered by explicit setup done by the platform, +supplying a struct regulator_init_data for the regulator +containing constraint and supply information. + +Machine interface +================= + +This interface provides a way to define how regulators are connected to +consumers on a given system and what the valid operating parameters are +for the system. + +Supplies +-------- + +Regulator supplies are specified using struct +:c:type:`regulator_consumer_supply`. This is done at driver registration +time as part of the machine constraints. + +Constraints +----------- + +As well as defining the connections the machine interface also provides +constraints defining the operations that clients are allowed to perform +and the parameters that may be set. This is required since generally +regulator devices will offer more flexibility than it is safe to use on +a given system, for example supporting higher supply voltages than the +consumers are rated for. + +This is done at driver registration time` by providing a +struct regulation_constraints. + +The constraints may also specify an initial configuration for the +regulator in the constraints, which is particularly useful for use with +static consumers. + +API reference +============= + +Due to limitations of the kernel documentation framework and the +existing layout of the source code the entire regulator API is +documented here. + +.. kernel-doc:: include/linux/regulator/consumer.h + :internal: + +.. kernel-doc:: include/linux/regulator/machine.h + :internal: + +.. kernel-doc:: include/linux/regulator/driver.h + :internal: + +.. kernel-doc:: drivers/regulator/core.c + :export: |