From 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Tue, 21 Feb 2023 18:24:12 -0800 Subject: Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 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(). ... --- Documentation/input/ff.rst | 265 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 265 insertions(+) create mode 100644 Documentation/input/ff.rst (limited to 'Documentation/input/ff.rst') diff --git a/Documentation/input/ff.rst b/Documentation/input/ff.rst new file mode 100644 index 000000000..5a1da42c3 --- /dev/null +++ b/Documentation/input/ff.rst @@ -0,0 +1,265 @@ +======================== +Force feedback for Linux +======================== + +:Author: Johann Deneux on 2001/04/22. +:Updated: Anssi Hannula on 2006/04/09. + +You may redistribute this file. Please remember to include shape.svg and +interactive.svg as well. + +Introduction +~~~~~~~~~~~~ + +This document describes how to use force feedback devices under Linux. The +goal is not to support these devices as if they were simple input-only devices +(as it is already the case), but to really enable the rendering of force +effects. +This document only describes the force feedback part of the Linux input +interface. Please read joydev/joystick.rst and input.rst before reading further +this document. + +Instructions to the user +~~~~~~~~~~~~~~~~~~~~~~~~ + +To enable force feedback, you have to: + +1. have your kernel configured with evdev and a driver that supports your + device. +2. make sure evdev module is loaded and /dev/input/event* device files are + created. + +Before you start, let me WARN you that some devices shake violently during the +initialisation phase. This happens for example with my "AVB Top Shot Pegasus". +To stop this annoying behaviour, move your joystick to its limits. Anyway, you +should keep a hand on your device, in order to avoid it to break down if +something goes wrong. + +If you have a serial iforce device, you need to start inputattach. See +joydev/joystick.rst for details. + +Does it work ? +-------------- + +There is an utility called fftest that will allow you to test the driver:: + + % fftest /dev/input/eventXX + +Instructions to the developer +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +All interactions are done using the event API. That is, you can use ioctl() +and write() on /dev/input/eventXX. +This information is subject to change. + +Querying device capabilities +---------------------------- + +:: + + #include + #include + + #define BITS_TO_LONGS(x) \ + (((x) + 8 * sizeof (unsigned long) - 1) / (8 * sizeof (unsigned long))) + unsigned long features[BITS_TO_LONGS(FF_CNT)]; + int ioctl(int file_descriptor, int request, unsigned long *features); + +"request" must be EVIOCGBIT(EV_FF, size of features array in bytes ) + +Returns the features supported by the device. features is a bitfield with the +following bits: + +- FF_CONSTANT can render constant force effects +- FF_PERIODIC can render periodic effects with the following waveforms: + + - FF_SQUARE square waveform + - FF_TRIANGLE triangle waveform + - FF_SINE sine waveform + - FF_SAW_UP sawtooth up waveform + - FF_SAW_DOWN sawtooth down waveform + - FF_CUSTOM custom waveform + +- FF_RAMP can render ramp effects +- FF_SPRING can simulate the presence of a spring +- FF_FRICTION can simulate friction +- FF_DAMPER can simulate damper effects +- FF_RUMBLE rumble effects +- FF_INERTIA can simulate inertia +- FF_GAIN gain is adjustable +- FF_AUTOCENTER autocenter is adjustable + +.. note:: + + - In most cases you should use FF_PERIODIC instead of FF_RUMBLE. All + devices that support FF_RUMBLE support FF_PERIODIC (square, triangle, + sine) and the other way around. + + - The exact syntax FF_CUSTOM is undefined for the time being as no driver + supports it yet. + +:: + + int ioctl(int fd, EVIOCGEFFECTS, int *n); + +Returns the number of effects the device can keep in its memory. + +Uploading effects to the device +------------------------------- + +:: + + #include + #include + + int ioctl(int file_descriptor, int request, struct ff_effect *effect); + +"request" must be EVIOCSFF. + +"effect" points to a structure describing the effect to upload. The effect is +uploaded, but not played. +The content of effect may be modified. In particular, its field "id" is set +to the unique id assigned by the driver. This data is required for performing +some operations (removing an effect, controlling the playback). +The "id" field must be set to -1 by the user in order to tell the driver to +allocate a new effect. + +Effects are file descriptor specific. + +See for a description of the ff_effect struct. You +should also find help in a few sketches, contained in files shape.svg +and interactive.svg: + +.. kernel-figure:: shape.svg + + Shape + +.. kernel-figure:: interactive.svg + + Interactive + + +Removing an effect from the device +---------------------------------- + +:: + + int ioctl(int fd, EVIOCRMFF, effect.id); + +This makes room for new effects in the device's memory. Note that this also +stops the effect if it was playing. + +Controlling the playback of effects +----------------------------------- + +Control of playing is done with write(). Below is an example: + +:: + + #include + #include + + struct input_event play; + struct input_event stop; + struct ff_effect effect; + int fd; + ... + fd = open("/dev/input/eventXX", O_RDWR); + ... + /* Play three times */ + play.type = EV_FF; + play.code = effect.id; + play.value = 3; + + write(fd, (const void*) &play, sizeof(play)); + ... + /* Stop an effect */ + stop.type = EV_FF; + stop.code = effect.id; + stop.value = 0; + + write(fd, (const void*) &stop, sizeof(stop)); + +Setting the gain +---------------- + +Not all devices have the same strength. Therefore, users should set a gain +factor depending on how strong they want effects to be. This setting is +persistent across access to the driver. + +:: + + /* Set the gain of the device + int gain; /* between 0 and 100 */ + struct input_event ie; /* structure used to communicate with the driver */ + + ie.type = EV_FF; + ie.code = FF_GAIN; + ie.value = 0xFFFFUL * gain / 100; + + if (write(fd, &ie, sizeof(ie)) == -1) + perror("set gain"); + +Enabling/Disabling autocenter +----------------------------- + +The autocenter feature quite disturbs the rendering of effects in my opinion, +and I think it should be an effect, which computation depends on the game +type. But you can enable it if you want. + +:: + + int autocenter; /* between 0 and 100 */ + struct input_event ie; + + ie.type = EV_FF; + ie.code = FF_AUTOCENTER; + ie.value = 0xFFFFUL * autocenter / 100; + + if (write(fd, &ie, sizeof(ie)) == -1) + perror("set auto-center"); + +A value of 0 means "no auto-center". + +Dynamic update of an effect +--------------------------- + +Proceed as if you wanted to upload a new effect, except that instead of +setting the id field to -1, you set it to the wanted effect id. +Normally, the effect is not stopped and restarted. However, depending on the +type of device, not all parameters can be dynamically updated. For example, +the direction of an effect cannot be updated with iforce devices. In this +case, the driver stops the effect, up-load it, and restart it. + +Therefore it is recommended to dynamically change direction while the effect +is playing only when it is ok to restart the effect with a replay count of 1. + +Information about the status of effects +--------------------------------------- + +Every time the status of an effect is changed, an event is sent. The values +and meanings of the fields of the event are as follows:: + + struct input_event { + /* When the status of the effect changed */ + struct timeval time; + + /* Set to EV_FF_STATUS */ + unsigned short type; + + /* Contains the id of the effect */ + unsigned short code; + + /* Indicates the status */ + unsigned int value; + }; + + FF_STATUS_STOPPED The effect stopped playing + FF_STATUS_PLAYING The effect started to play + +.. note:: + + - Status feedback is only supported by iforce driver. If you have + a really good reason to use this, please contact + linux-joystick@atrey.karlin.mff.cuni.cz or anssi.hannula@gmail.com + so that support for it can be added to the rest of the drivers. -- cgit v1.2.3