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/usb/gadget_serial.rst | 289 ++++++++++++++++++++++++++++++++++++ 1 file changed, 289 insertions(+) create mode 100644 Documentation/usb/gadget_serial.rst (limited to 'Documentation/usb/gadget_serial.rst') diff --git a/Documentation/usb/gadget_serial.rst b/Documentation/usb/gadget_serial.rst new file mode 100644 index 000000000..dce8bc1fb --- /dev/null +++ b/Documentation/usb/gadget_serial.rst @@ -0,0 +1,289 @@ +=============================== +Linux Gadget Serial Driver v2.0 +=============================== + +11/20/2004 + +(updated 8-May-2008 for v2.3) + + +License and Disclaimer +---------------------- +This program is free software; you can redistribute it and/or +modify it under the terms of the GNU General Public License as +published by the Free Software Foundation; either version 2 of +the License, or (at your option) any later version. + +This program is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public +License along with this program; if not, write to the Free +Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, +MA 02111-1307 USA. + +This document and the gadget serial driver itself are +Copyright (C) 2004 by Al Borchers (alborchers@steinerpoint.com). + +If you have questions, problems, or suggestions for this driver +please contact Al Borchers at alborchers@steinerpoint.com. + + +Prerequisites +------------- +Versions of the gadget serial driver are available for the +2.4 Linux kernels, but this document assumes you are using +version 2.3 or later of the gadget serial driver in a 2.6 +Linux kernel. + +This document assumes that you are familiar with Linux and +Windows and know how to configure and build Linux kernels, run +standard utilities, use minicom and HyperTerminal, and work with +USB and serial devices. It also assumes you configure the Linux +gadget and usb drivers as modules. + +With version 2.3 of the driver, major and minor device nodes are +no longer statically defined. Your Linux based system should mount +sysfs in /sys, and use "mdev" (in Busybox) or "udev" to make the +/dev nodes matching the sysfs /sys/class/tty files. + + + +Overview +-------- +The gadget serial driver is a Linux USB gadget driver, a USB device +side driver. It runs on a Linux system that has USB device side +hardware; for example, a PDA, an embedded Linux system, or a PC +with a USB development card. + +The gadget serial driver talks over USB to either a CDC ACM driver +or a generic USB serial driver running on a host PC:: + + Host + -------------------------------------- + | Host-Side CDC ACM USB Host | + | Operating | or | Controller | USB + | System | Generic USB | Driver |-------- + | (Linux or | Serial | and | | + | Windows) Driver USB Stack | | + -------------------------------------- | + | + | + | + Gadget | + -------------------------------------- | + | Gadget USB Periph. | | + | Device-Side | Gadget | Controller | | + | Linux | Serial | Driver |-------- + | Operating | Driver | and | + | System USB Stack | + -------------------------------------- + +On the device-side Linux system, the gadget serial driver looks +like a serial device. + +On the host-side system, the gadget serial device looks like a +CDC ACM compliant class device or a simple vendor specific device +with bulk in and bulk out endpoints, and it is treated similarly +to other serial devices. + +The host side driver can potentially be any ACM compliant driver +or any driver that can talk to a device with a simple bulk in/out +interface. Gadget serial has been tested with the Linux ACM driver, +the Windows usbser.sys ACM driver, and the Linux USB generic serial +driver. + +With the gadget serial driver and the host side ACM or generic +serial driver running, you should be able to communicate between +the host and the gadget side systems as if they were connected by a +serial cable. + +The gadget serial driver only provides simple unreliable data +communication. It does not yet handle flow control or many other +features of normal serial devices. + + +Installing the Gadget Serial Driver +----------------------------------- +To use the gadget serial driver you must configure the Linux gadget +side kernel for "Support for USB Gadgets", for a "USB Peripheral +Controller" (for example, net2280), and for the "Serial Gadget" +driver. All this are listed under "USB Gadget Support" when +configuring the kernel. Then rebuild and install the kernel or +modules. + +Then you must load the gadget serial driver. To load it as an +ACM device (recommended for interoperability), do this:: + + modprobe g_serial + +To load it as a vendor specific bulk in/out device, do this:: + + modprobe g_serial use_acm=0 + +This will also automatically load the underlying gadget peripheral +controller driver. This must be done each time you reboot the gadget +side Linux system. You can add this to the start up scripts, if +desired. + +Your system should use mdev (from busybox) or udev to make the +device nodes. After this gadget driver has been set up you should +then see a /dev/ttyGS0 node:: + + # ls -l /dev/ttyGS0 | cat + crw-rw---- 1 root root 253, 0 May 8 14:10 /dev/ttyGS0 + # + +Note that the major number (253, above) is system-specific. If +you need to create /dev nodes by hand, the right numbers to use +will be in the /sys/class/tty/ttyGS0/dev file. + +When you link this gadget driver early, perhaps even statically, +you may want to set up an /etc/inittab entry to run "getty" on it. +The /dev/ttyGS0 line should work like most any other serial port. + + +If gadget serial is loaded as an ACM device you will want to use +either the Windows or Linux ACM driver on the host side. If gadget +serial is loaded as a bulk in/out device, you will want to use the +Linux generic serial driver on the host side. Follow the appropriate +instructions below to install the host side driver. + + +Installing the Windows Host ACM Driver +-------------------------------------- +To use the Windows ACM driver you must have the "linux-cdc-acm.inf" +file (provided along this document) which supports all recent versions +of Windows. + +When the gadget serial driver is loaded and the USB device connected +to the Windows host with a USB cable, Windows should recognize the +gadget serial device and ask for a driver. Tell Windows to find the +driver in the folder that contains the "linux-cdc-acm.inf" file. + +For example, on Windows XP, when the gadget serial device is first +plugged in, the "Found New Hardware Wizard" starts up. Select +"Install from a list or specific location (Advanced)", then on the +next screen select "Include this location in the search" and enter the +path or browse to the folder containing the "linux-cdc-acm.inf" file. +Windows will complain that the Gadget Serial driver has not passed +Windows Logo testing, but select "Continue anyway" and finish the +driver installation. + +On Windows XP, in the "Device Manager" (under "Control Panel", +"System", "Hardware") expand the "Ports (COM & LPT)" entry and you +should see "Gadget Serial" listed as the driver for one of the COM +ports. + +To uninstall the Windows XP driver for "Gadget Serial", right click +on the "Gadget Serial" entry in the "Device Manager" and select +"Uninstall". + + +Installing the Linux Host ACM Driver +------------------------------------ +To use the Linux ACM driver you must configure the Linux host side +kernel for "Support for Host-side USB" and for "USB Modem (CDC ACM) +support". + +Once the gadget serial driver is loaded and the USB device connected +to the Linux host with a USB cable, the host system should recognize +the gadget serial device. For example, the command:: + + cat /sys/kernel/debug/usb/devices + +should show something like this::: + + T: Bus=01 Lev=01 Prnt=01 Port=01 Cnt=02 Dev#= 5 Spd=480 MxCh= 0 + D: Ver= 2.00 Cls=02(comm.) Sub=00 Prot=00 MxPS=64 #Cfgs= 1 + P: Vendor=0525 ProdID=a4a7 Rev= 2.01 + S: Manufacturer=Linux 2.6.8.1 with net2280 + S: Product=Gadget Serial + S: SerialNumber=0 + C:* #Ifs= 2 Cfg#= 2 Atr=c0 MxPwr= 2mA + I: If#= 0 Alt= 0 #EPs= 1 Cls=02(comm.) Sub=02 Prot=01 Driver=acm + E: Ad=83(I) Atr=03(Int.) MxPS= 8 Ivl=32ms + I: If#= 1 Alt= 0 #EPs= 2 Cls=0a(data ) Sub=00 Prot=00 Driver=acm + E: Ad=81(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms + E: Ad=02(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms + +If the host side Linux system is configured properly, the ACM driver +should be loaded automatically. The command "lsmod" should show the +"acm" module is loaded. + + +Installing the Linux Host Generic USB Serial Driver +--------------------------------------------------- +To use the Linux generic USB serial driver you must configure the +Linux host side kernel for "Support for Host-side USB", for "USB +Serial Converter support", and for the "USB Generic Serial Driver". + +Once the gadget serial driver is loaded and the USB device connected +to the Linux host with a USB cable, the host system should recognize +the gadget serial device. For example, the command:: + + cat /sys/kernel/debug/usb/devices + +should show something like this::: + + T: Bus=01 Lev=01 Prnt=01 Port=01 Cnt=02 Dev#= 6 Spd=480 MxCh= 0 + D: Ver= 2.00 Cls=ff(vend.) Sub=00 Prot=00 MxPS=64 #Cfgs= 1 + P: Vendor=0525 ProdID=a4a6 Rev= 2.01 + S: Manufacturer=Linux 2.6.8.1 with net2280 + S: Product=Gadget Serial + S: SerialNumber=0 + C:* #Ifs= 1 Cfg#= 1 Atr=c0 MxPwr= 2mA + I: If#= 0 Alt= 0 #EPs= 2 Cls=0a(data ) Sub=00 Prot=00 Driver=serial + E: Ad=81(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms + E: Ad=02(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms + +You must load the usbserial driver and explicitly set its parameters +to configure it to recognize the gadget serial device, like this:: + + echo 0x0525 0xA4A6 >/sys/bus/usb-serial/drivers/generic/new_id + +The legacy way is to use module parameters:: + + modprobe usbserial vendor=0x0525 product=0xA4A6 + +If everything is working, usbserial will print a message in the +system log saying something like "Gadget Serial converter now +attached to ttyUSB0". + + +Testing with Minicom or HyperTerminal +------------------------------------- +Once the gadget serial driver and the host driver are both installed, +and a USB cable connects the gadget device to the host, you should +be able to communicate over USB between the gadget and host systems. +You can use minicom or HyperTerminal to try this out. + +On the gadget side run "minicom -s" to configure a new minicom +session. Under "Serial port setup" set "/dev/ttygserial" as the +"Serial Device". Set baud rate, data bits, parity, and stop bits, +to 9600, 8, none, and 1--these settings mostly do not matter. +Under "Modem and dialing" erase all the modem and dialing strings. + +On a Linux host running the ACM driver, configure minicom similarly +but use "/dev/ttyACM0" as the "Serial Device". (If you have other +ACM devices connected, change the device name appropriately.) + +On a Linux host running the USB generic serial driver, configure +minicom similarly, but use "/dev/ttyUSB0" as the "Serial Device". +(If you have other USB serial devices connected, change the device +name appropriately.) + +On a Windows host configure a new HyperTerminal session to use the +COM port assigned to Gadget Serial. The "Port Settings" will be +set automatically when HyperTerminal connects to the gadget serial +device, so you can leave them set to the default values--these +settings mostly do not matter. + +With minicom configured and running on the gadget side and with +minicom or HyperTerminal configured and running on the host side, +you should be able to send data back and forth between the gadget +side and host side systems. Anything you type on the terminal +window on the gadget side should appear in the terminal window on +the host side and vice versa. -- cgit v1.2.3