aboutsummaryrefslogtreecommitdiff
path: root/Documentation/usb/gadget_printer.rst
diff options
context:
space:
mode:
authorLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
committerLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
commit5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch)
treecc5c2d0a898769fd59549594fedb3ee6f84e59a0 /Documentation/usb/gadget_printer.rst
downloadlinux-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/usb/gadget_printer.rst')
-rw-r--r--Documentation/usb/gadget_printer.rst523
1 files changed, 523 insertions, 0 deletions
diff --git a/Documentation/usb/gadget_printer.rst b/Documentation/usb/gadget_printer.rst
new file mode 100644
index 000000000..e611a6d91
--- /dev/null
+++ b/Documentation/usb/gadget_printer.rst
@@ -0,0 +1,523 @@
+===============================
+Linux USB Printer Gadget Driver
+===============================
+
+06/04/2007
+
+Copyright (C) 2007 Craig W. Nadler <craig@nadler.us>
+
+
+
+General
+=======
+
+This driver may be used if you are writing printer firmware using Linux as
+the embedded OS. This driver has nothing to do with using a printer with
+your Linux host system.
+
+You will need a USB device controller and a Linux driver for it that accepts
+a gadget / "device class" driver using the Linux USB Gadget API. After the
+USB device controller driver is loaded then load the printer gadget driver.
+This will present a printer interface to the USB Host that your USB Device
+port is connected to.
+
+This driver is structured for printer firmware that runs in user mode. The
+user mode printer firmware will read and write data from the kernel mode
+printer gadget driver using a device file. The printer returns a printer status
+byte when the USB HOST sends a device request to get the printer status. The
+user space firmware can read or write this status byte using a device file
+/dev/g_printer . Both blocking and non-blocking read/write calls are supported.
+
+
+
+
+Howto Use This Driver
+=====================
+
+To load the USB device controller driver and the printer gadget driver. The
+following example uses the Netchip 2280 USB device controller driver::
+
+ modprobe net2280
+ modprobe g_printer
+
+
+The follow command line parameter can be used when loading the printer gadget
+(ex: modprobe g_printer idVendor=0x0525 idProduct=0xa4a8 ):
+
+idVendor
+ This is the Vendor ID used in the device descriptor. The default is
+ the Netchip vendor id 0x0525. YOU MUST CHANGE TO YOUR OWN VENDOR ID
+ BEFORE RELEASING A PRODUCT. If you plan to release a product and don't
+ already have a Vendor ID please see www.usb.org for details on how to
+ get one.
+
+idProduct
+ This is the Product ID used in the device descriptor. The default
+ is 0xa4a8, you should change this to an ID that's not used by any of
+ your other USB products if you have any. It would be a good idea to
+ start numbering your products starting with say 0x0001.
+
+bcdDevice
+ This is the version number of your product. It would be a good idea
+ to put your firmware version here.
+
+iManufacturer
+ A string containing the name of the Vendor.
+
+iProduct
+ A string containing the Product Name.
+
+iSerialNum
+ A string containing the Serial Number. This should be changed for
+ each unit of your product.
+
+iPNPstring
+ The PNP ID string used for this printer. You will want to set
+ either on the command line or hard code the PNP ID string used for
+ your printer product.
+
+qlen
+ The number of 8k buffers to use per endpoint. The default is 10, you
+ should tune this for your product. You may also want to tune the
+ size of each buffer for your product.
+
+
+
+
+Using The Example Code
+======================
+
+This example code talks to stdout, instead of a print engine.
+
+To compile the test code below:
+
+1) save it to a file called prn_example.c
+2) compile the code with the follow command::
+
+ gcc prn_example.c -o prn_example
+
+
+
+To read printer data from the host to stdout::
+
+ # prn_example -read_data
+
+
+To write printer data from a file (data_file) to the host::
+
+ # cat data_file | prn_example -write_data
+
+
+To get the current printer status for the gadget driver:::
+
+ # prn_example -get_status
+
+ Printer status is:
+ Printer is NOT Selected
+ Paper is Out
+ Printer OK
+
+
+To set printer to Selected/On-line::
+
+ # prn_example -selected
+
+
+To set printer to Not Selected/Off-line::
+
+ # prn_example -not_selected
+
+
+To set paper status to paper out::
+
+ # prn_example -paper_out
+
+
+To set paper status to paper loaded::
+
+ # prn_example -paper_loaded
+
+
+To set error status to printer OK::
+
+ # prn_example -no_error
+
+
+To set error status to ERROR::
+
+ # prn_example -error
+
+
+
+
+Example Code
+============
+
+::
+
+
+ #include <stdio.h>
+ #include <stdlib.h>
+ #include <fcntl.h>
+ #include <linux/poll.h>
+ #include <sys/ioctl.h>
+ #include <linux/usb/g_printer.h>
+
+ #define PRINTER_FILE "/dev/g_printer"
+ #define BUF_SIZE 512
+
+
+ /*
+ * 'usage()' - Show program usage.
+ */
+
+ static void
+ usage(const char *option) /* I - Option string or NULL */
+ {
+ if (option) {
+ fprintf(stderr,"prn_example: Unknown option \"%s\"!\n",
+ option);
+ }
+
+ fputs("\n", stderr);
+ fputs("Usage: prn_example -[options]\n", stderr);
+ fputs("Options:\n", stderr);
+ fputs("\n", stderr);
+ fputs("-get_status Get the current printer status.\n", stderr);
+ fputs("-selected Set the selected status to selected.\n", stderr);
+ fputs("-not_selected Set the selected status to NOT selected.\n",
+ stderr);
+ fputs("-error Set the error status to error.\n", stderr);
+ fputs("-no_error Set the error status to NO error.\n", stderr);
+ fputs("-paper_out Set the paper status to paper out.\n", stderr);
+ fputs("-paper_loaded Set the paper status to paper loaded.\n",
+ stderr);
+ fputs("-read_data Read printer data from driver.\n", stderr);
+ fputs("-write_data Write printer sata to driver.\n", stderr);
+ fputs("-NB_read_data (Non-Blocking) Read printer data from driver.\n",
+ stderr);
+ fputs("\n\n", stderr);
+
+ exit(1);
+ }
+
+
+ static int
+ read_printer_data()
+ {
+ struct pollfd fd[1];
+
+ /* Open device file for printer gadget. */
+ fd[0].fd = open(PRINTER_FILE, O_RDWR);
+ if (fd[0].fd < 0) {
+ printf("Error %d opening %s\n", fd[0].fd, PRINTER_FILE);
+ close(fd[0].fd);
+ return(-1);
+ }
+
+ fd[0].events = POLLIN | POLLRDNORM;
+
+ while (1) {
+ static char buf[BUF_SIZE];
+ int bytes_read;
+ int retval;
+
+ /* Wait for up to 1 second for data. */
+ retval = poll(fd, 1, 1000);
+
+ if (retval && (fd[0].revents & POLLRDNORM)) {
+
+ /* Read data from printer gadget driver. */
+ bytes_read = read(fd[0].fd, buf, BUF_SIZE);
+
+ if (bytes_read < 0) {
+ printf("Error %d reading from %s\n",
+ fd[0].fd, PRINTER_FILE);
+ close(fd[0].fd);
+ return(-1);
+ } else if (bytes_read > 0) {
+ /* Write data to standard OUTPUT (stdout). */
+ fwrite(buf, 1, bytes_read, stdout);
+ fflush(stdout);
+ }
+
+ }
+
+ }
+
+ /* Close the device file. */
+ close(fd[0].fd);
+
+ return 0;
+ }
+
+
+ static int
+ write_printer_data()
+ {
+ struct pollfd fd[1];
+
+ /* Open device file for printer gadget. */
+ fd[0].fd = open (PRINTER_FILE, O_RDWR);
+ if (fd[0].fd < 0) {
+ printf("Error %d opening %s\n", fd[0].fd, PRINTER_FILE);
+ close(fd[0].fd);
+ return(-1);
+ }
+
+ fd[0].events = POLLOUT | POLLWRNORM;
+
+ while (1) {
+ int retval;
+ static char buf[BUF_SIZE];
+ /* Read data from standard INPUT (stdin). */
+ int bytes_read = fread(buf, 1, BUF_SIZE, stdin);
+
+ if (!bytes_read) {
+ break;
+ }
+
+ while (bytes_read) {
+
+ /* Wait for up to 1 second to sent data. */
+ retval = poll(fd, 1, 1000);
+
+ /* Write data to printer gadget driver. */
+ if (retval && (fd[0].revents & POLLWRNORM)) {
+ retval = write(fd[0].fd, buf, bytes_read);
+ if (retval < 0) {
+ printf("Error %d writing to %s\n",
+ fd[0].fd,
+ PRINTER_FILE);
+ close(fd[0].fd);
+ return(-1);
+ } else {
+ bytes_read -= retval;
+ }
+
+ }
+
+ }
+
+ }
+
+ /* Wait until the data has been sent. */
+ fsync(fd[0].fd);
+
+ /* Close the device file. */
+ close(fd[0].fd);
+
+ return 0;
+ }
+
+
+ static int
+ read_NB_printer_data()
+ {
+ int fd;
+ static char buf[BUF_SIZE];
+ int bytes_read;
+
+ /* Open device file for printer gadget. */
+ fd = open(PRINTER_FILE, O_RDWR|O_NONBLOCK);
+ if (fd < 0) {
+ printf("Error %d opening %s\n", fd, PRINTER_FILE);
+ close(fd);
+ return(-1);
+ }
+
+ while (1) {
+ /* Read data from printer gadget driver. */
+ bytes_read = read(fd, buf, BUF_SIZE);
+ if (bytes_read <= 0) {
+ break;
+ }
+
+ /* Write data to standard OUTPUT (stdout). */
+ fwrite(buf, 1, bytes_read, stdout);
+ fflush(stdout);
+ }
+
+ /* Close the device file. */
+ close(fd);
+
+ return 0;
+ }
+
+
+ static int
+ get_printer_status()
+ {
+ int retval;
+ int fd;
+
+ /* Open device file for printer gadget. */
+ fd = open(PRINTER_FILE, O_RDWR);
+ if (fd < 0) {
+ printf("Error %d opening %s\n", fd, PRINTER_FILE);
+ close(fd);
+ return(-1);
+ }
+
+ /* Make the IOCTL call. */
+ retval = ioctl(fd, GADGET_GET_PRINTER_STATUS);
+ if (retval < 0) {
+ fprintf(stderr, "ERROR: Failed to set printer status\n");
+ return(-1);
+ }
+
+ /* Close the device file. */
+ close(fd);
+
+ return(retval);
+ }
+
+
+ static int
+ set_printer_status(unsigned char buf, int clear_printer_status_bit)
+ {
+ int retval;
+ int fd;
+
+ retval = get_printer_status();
+ if (retval < 0) {
+ fprintf(stderr, "ERROR: Failed to get printer status\n");
+ return(-1);
+ }
+
+ /* Open device file for printer gadget. */
+ fd = open(PRINTER_FILE, O_RDWR);
+
+ if (fd < 0) {
+ printf("Error %d opening %s\n", fd, PRINTER_FILE);
+ close(fd);
+ return(-1);
+ }
+
+ if (clear_printer_status_bit) {
+ retval &= ~buf;
+ } else {
+ retval |= buf;
+ }
+
+ /* Make the IOCTL call. */
+ if (ioctl(fd, GADGET_SET_PRINTER_STATUS, (unsigned char)retval)) {
+ fprintf(stderr, "ERROR: Failed to set printer status\n");
+ return(-1);
+ }
+
+ /* Close the device file. */
+ close(fd);
+
+ return 0;
+ }
+
+
+ static int
+ display_printer_status()
+ {
+ char printer_status;
+
+ printer_status = get_printer_status();
+ if (printer_status < 0) {
+ fprintf(stderr, "ERROR: Failed to get printer status\n");
+ return(-1);
+ }
+
+ printf("Printer status is:\n");
+ if (printer_status & PRINTER_SELECTED) {
+ printf(" Printer is Selected\n");
+ } else {
+ printf(" Printer is NOT Selected\n");
+ }
+ if (printer_status & PRINTER_PAPER_EMPTY) {
+ printf(" Paper is Out\n");
+ } else {
+ printf(" Paper is Loaded\n");
+ }
+ if (printer_status & PRINTER_NOT_ERROR) {
+ printf(" Printer OK\n");
+ } else {
+ printf(" Printer ERROR\n");
+ }
+
+ return(0);
+ }
+
+
+ int
+ main(int argc, char *argv[])
+ {
+ int i; /* Looping var */
+ int retval = 0;
+
+ /* No Args */
+ if (argc == 1) {
+ usage(0);
+ exit(0);
+ }
+
+ for (i = 1; i < argc && !retval; i ++) {
+
+ if (argv[i][0] != '-') {
+ continue;
+ }
+
+ if (!strcmp(argv[i], "-get_status")) {
+ if (display_printer_status()) {
+ retval = 1;
+ }
+
+ } else if (!strcmp(argv[i], "-paper_loaded")) {
+ if (set_printer_status(PRINTER_PAPER_EMPTY, 1)) {
+ retval = 1;
+ }
+
+ } else if (!strcmp(argv[i], "-paper_out")) {
+ if (set_printer_status(PRINTER_PAPER_EMPTY, 0)) {
+ retval = 1;
+ }
+
+ } else if (!strcmp(argv[i], "-selected")) {
+ if (set_printer_status(PRINTER_SELECTED, 0)) {
+ retval = 1;
+ }
+
+ } else if (!strcmp(argv[i], "-not_selected")) {
+ if (set_printer_status(PRINTER_SELECTED, 1)) {
+ retval = 1;
+ }
+
+ } else if (!strcmp(argv[i], "-error")) {
+ if (set_printer_status(PRINTER_NOT_ERROR, 1)) {
+ retval = 1;
+ }
+
+ } else if (!strcmp(argv[i], "-no_error")) {
+ if (set_printer_status(PRINTER_NOT_ERROR, 0)) {
+ retval = 1;
+ }
+
+ } else if (!strcmp(argv[i], "-read_data")) {
+ if (read_printer_data()) {
+ retval = 1;
+ }
+
+ } else if (!strcmp(argv[i], "-write_data")) {
+ if (write_printer_data()) {
+ retval = 1;
+ }
+
+ } else if (!strcmp(argv[i], "-NB_read_data")) {
+ if (read_NB_printer_data()) {
+ retval = 1;
+ }
+
+ } else {
+ usage(argv[i]);
+ retval = 1;
+ }
+ }
+
+ exit(retval);
+ }