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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/input/gameport-programming.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/input/gameport-programming.rst')
-rw-r--r-- | Documentation/input/gameport-programming.rst | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/Documentation/input/gameport-programming.rst b/Documentation/input/gameport-programming.rst new file mode 100644 index 000000000..7d7063ad0 --- /dev/null +++ b/Documentation/input/gameport-programming.rst @@ -0,0 +1,233 @@ +~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +Programming gameport drivers +~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +A basic classic gameport +~~~~~~~~~~~~~~~~~~~~~~~~ + +If the gameport doesn't provide more than the inb()/outb() functionality, +the code needed to register it with the joystick drivers is simple:: + + struct gameport gameport; + + gameport.io = MY_IO_ADDRESS; + gameport_register_port(&gameport); + +Make sure struct gameport is initialized to 0 in all other fields. The +gameport generic code will take care of the rest. + +If your hardware supports more than one io address, and your driver can +choose which one to program the hardware to, starting from the more exotic +addresses is preferred, because the likelihood of clashing with the standard +0x201 address is smaller. + +E.g. if your driver supports addresses 0x200, 0x208, 0x210 and 0x218, then +0x218 would be the address of first choice. + +If your hardware supports a gameport address that is not mapped to ISA io +space (is above 0x1000), use that one, and don't map the ISA mirror. + +Also, always request_region() on the whole io space occupied by the +gameport. Although only one ioport is really used, the gameport usually +occupies from one to sixteen addresses in the io space. + +Please also consider enabling the gameport on the card in the ->open() +callback if the io is mapped to ISA space - this way it'll occupy the io +space only when something really is using it. Disable it again in the +->close() callback. You also can select the io address in the ->open() +callback, so that it doesn't fail if some of the possible addresses are +already occupied by other gameports. + +Memory mapped gameport +~~~~~~~~~~~~~~~~~~~~~~ + +When a gameport can be accessed through MMIO, this way is preferred, because +it is faster, allowing more reads per second. Registering such a gameport +isn't as easy as a basic IO one, but not so much complex:: + + struct gameport gameport; + + void my_trigger(struct gameport *gameport) + { + my_mmio = 0xff; + } + + unsigned char my_read(struct gameport *gameport) + { + return my_mmio; + } + + gameport.read = my_read; + gameport.trigger = my_trigger; + gameport_register_port(&gameport); + +.. _gameport_pgm_cooked_mode: + +Cooked mode gameport +~~~~~~~~~~~~~~~~~~~~ + +There are gameports that can report the axis values as numbers, that means +the driver doesn't have to measure them the old way - an ADC is built into +the gameport. To register a cooked gameport:: + + struct gameport gameport; + + int my_cooked_read(struct gameport *gameport, int *axes, int *buttons) + { + int i; + + for (i = 0; i < 4; i++) + axes[i] = my_mmio[i]; + buttons[0] = my_mmio[4]; + } + + int my_open(struct gameport *gameport, int mode) + { + return -(mode != GAMEPORT_MODE_COOKED); + } + + gameport.cooked_read = my_cooked_read; + gameport.open = my_open; + gameport.fuzz = 8; + gameport_register_port(&gameport); + +The only confusing thing here is the fuzz value. Best determined by +experimentation, it is the amount of noise in the ADC data. Perfect +gameports can set this to zero, most common have fuzz between 8 and 32. +See analog.c and input.c for handling of fuzz - the fuzz value determines +the size of a gaussian filter window that is used to eliminate the noise +in the data. + +More complex gameports +~~~~~~~~~~~~~~~~~~~~~~ + +Gameports can support both raw and cooked modes. In that case combine either +examples 1+2 or 1+3. Gameports can support internal calibration - see below, +and also lightning.c and analog.c on how that works. If your driver supports +more than one gameport instance simultaneously, use the ->private member of +the gameport struct to point to your data. + +Unregistering a gameport +~~~~~~~~~~~~~~~~~~~~~~~~ + +Simple:: + + gameport_unregister_port(&gameport); + +The gameport structure +~~~~~~~~~~~~~~~~~~~~~~ + +:: + + struct gameport { + + void *port_data; + +A private pointer for free use in the gameport driver. (Not the joystick +driver!) + +:: + + char name[32]; + +Driver's name as set by driver calling gameport_set_name(). Informational +purpose only. + +:: + + char phys[32]; + +gameport's physical name/description as set by driver calling gameport_set_phys(). +Informational purpose only. + +:: + + int io; + +I/O address for use with raw mode. You have to either set this, or ->read() +to some value if your gameport supports raw mode. + +:: + + int speed; + +Raw mode speed of the gameport reads in thousands of reads per second. + +:: + + int fuzz; + +If the gameport supports cooked mode, this should be set to a value that +represents the amount of noise in the data. See +:ref:`gameport_pgm_cooked_mode`. + +:: + + void (*trigger)(struct gameport *); + +Trigger. This function should trigger the ns558 oneshots. If set to NULL, +outb(0xff, io) will be used. + +:: + + unsigned char (*read)(struct gameport *); + +Read the buttons and ns558 oneshot bits. If set to NULL, inb(io) will be +used instead. + +:: + + int (*cooked_read)(struct gameport *, int *axes, int *buttons); + +If the gameport supports cooked mode, it should point this to its cooked +read function. It should fill axes[0..3] with four values of the joystick axes +and buttons[0] with four bits representing the buttons. + +:: + + int (*calibrate)(struct gameport *, int *axes, int *max); + +Function for calibrating the ADC hardware. When called, axes[0..3] should be +pre-filled by cooked data by the caller, max[0..3] should be pre-filled with +expected maximums for each axis. The calibrate() function should set the +sensitivity of the ADC hardware so that the maximums fit in its range and +recompute the axes[] values to match the new sensitivity or re-read them from +the hardware so that they give valid values. + +:: + + int (*open)(struct gameport *, int mode); + +Open() serves two purposes. First a driver either opens the port in raw or +in cooked mode, the open() callback can decide which modes are supported. +Second, resource allocation can happen here. The port can also be enabled +here. Prior to this call, other fields of the gameport struct (namely the io +member) need not to be valid. + +:: + + void (*close)(struct gameport *); + +Close() should free the resources allocated by open, possibly disabling the +gameport. + +:: + + struct timer_list poll_timer; + unsigned int poll_interval; /* in msecs */ + spinlock_t timer_lock; + unsigned int poll_cnt; + void (*poll_handler)(struct gameport *); + struct gameport *parent, *child; + struct gameport_driver *drv; + struct mutex drv_mutex; /* protects serio->drv so attributes can pin driver */ + struct device dev; + struct list_head node; + +For internal use by the gameport layer. + +:: + + }; + +Enjoy! |