USB: add Printer Gadget Driver

G_PRINTER: Adds a USB printer gadget driver for use in printer firmware.

This adds a USB printer gadget driver for use in printer firmware.
The printer gadget channels data between the USB host and a userspace
program driving the print engine. The user space program reads and
writes the device file /dev/g_printer to receive or send printer data.
It can use ioctl calls to the device file to get or set printer status.

Signed-off-by: Craig W. Nadler <craig@nadler.us>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Craig W. Nadler 2007-11-11 15:00:15 -08:00 committed by Greg Kroah-Hartman
parent 676d3aa16f
commit 25a010c8c1
7 changed files with 2156 additions and 0 deletions

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@ -0,0 +1,510 @@
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);
}

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@ -548,6 +548,20 @@ config USB_MIDI_GADGET
Say "y" to link the driver statically, or "m" to build a
dynamically linked module called "g_midi".
config USB_G_PRINTER
tristate "Printer Gadget"
help
The Printer Gadget channels data between the USB host and a
userspace program driving the print engine. The user space
program reads and writes the device file /dev/g_printer to
receive or send printer data. It can use ioctl calls to
the device file to get or set printer status.
Say "y" to link the driver statically, or "m" to build a
dynamically linked module called "g_printer".
For more information, see Documentation/usb/gadget_printer.txt
which includes sample code for accessing the device file.
# put drivers that need isochronous transfer support (for audio
# or video class gadget drivers), or specific hardware, here.

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@ -28,6 +28,8 @@ g_midi-objs := gmidi.o usbstring.o config.o epautoconf.o
gadgetfs-objs := inode.o
g_file_storage-objs := file_storage.o usbstring.o config.o \
epautoconf.o
g_printer-objs := printer.o usbstring.o config.o \
epautoconf.o
ifeq ($(CONFIG_USB_ETH_RNDIS),y)
g_ether-objs += rndis.o
@ -38,5 +40,6 @@ obj-$(CONFIG_USB_ETH) += g_ether.o
obj-$(CONFIG_USB_GADGETFS) += gadgetfs.o
obj-$(CONFIG_USB_FILE_STORAGE) += g_file_storage.o
obj-$(CONFIG_USB_G_SERIAL) += g_serial.o
obj-$(CONFIG_USB_G_PRINTER) += g_printer.o
obj-$(CONFIG_USB_MIDI_GADGET) += g_midi.o

1592
drivers/usb/gadget/printer.c Normal file

File diff suppressed because it is too large Load diff

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@ -3,4 +3,5 @@ unifdef-y += cdc.h
unifdef-y += ch9.h
unifdef-y += gadgetfs.h
unifdef-y += midi.h
unifdef-y += g_printer.h

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@ -0,0 +1,31 @@
/*
* g_printer.h -- Header file for USB Printer gadget driver
*
* Copyright (C) 2007 Craig W. Nadler
*
* 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
*/
#define PRINTER_NOT_ERROR 0x08
#define PRINTER_SELECTED 0x10
#define PRINTER_PAPER_EMPTY 0x20
/* The 'g' code is also used by gadgetfs ioctl requests.
* Don't add any colliding codes to either driver, and keep
* them in unique ranges (size 0x20 for now).
*/
#define GADGET_GET_PRINTER_STATUS _IOR('g', 0x21, unsigned char)
#define GADGET_SET_PRINTER_STATUS _IOWR('g', 0x22, unsigned char)

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@ -59,6 +59,11 @@ struct usb_gadgetfs_event {
};
/* The 'g' code is also used by printer gadget ioctl requests.
* Don't add any colliding codes to either driver, and keep
* them in unique ranges (size 0x20 for now).
*/
/* endpoint ioctls */
/* IN transfers may be reported to the gadget driver as complete