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>

7 files changed, 2156 insertions, 0 deletions

diff --git a/Documentation/usb/gadget_printer.txt b/Documentation/usb/gadget_printer.txt
new file mode 100644
index 00000000000..ad995bf0db4
--- /dev/null
+++ b/Documentation/usb/gadget_printer.txt
@@ -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);
+}
diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
index e706882a8e6..8a88f24270b 100644
--- a/drivers/usb/gadget/Kconfig
+++ b/drivers/usb/gadget/Kconfig
@@ -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.
diff --git a/drivers/usb/gadget/Makefile b/drivers/usb/gadget/Makefile
index 904e57bf611..c3aab80b6c7 100644
--- a/drivers/usb/gadget/Makefile
+++ b/drivers/usb/gadget/Makefile
@@ -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
 
diff --git a/drivers/usb/gadget/printer.c b/drivers/usb/gadget/printer.c
new file mode 100644
index 00000000000..9fdabc8fcac
--- /dev/null
+++ b/drivers/usb/gadget/printer.c
@@ -0,0 +1,1592 @@
+/*
+ * printer.c -- Printer gadget driver
+ *
+ * Copyright (C) 2003-2005 David Brownell
+ * Copyright (C) 2006 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
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/ioport.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/smp_lock.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/timer.h>
+#include <linux/list.h>
+#include <linux/interrupt.h>
+#include <linux/utsname.h>
+#include <linux/device.h>
+#include <linux/moduleparam.h>
+#include <linux/fs.h>
+#include <linux/poll.h>
+#include <linux/types.h>
+#include <linux/ctype.h>
+#include <linux/cdev.h>
+
+#include <asm/byteorder.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <asm/system.h>
+#include <linux/uaccess.h>
+#include <asm/unaligned.h>
+
+#include <linux/usb/ch9.h>
+#include <linux/usb/gadget.h>
+#include <linux/usb/g_printer.h>
+
+#include "gadget_chips.h"
+
+#define DRIVER_DESC		"Printer Gadget"
+#define DRIVER_VERSION		"2007 OCT 06"
+
+static const char shortname [] = "printer";
+static const char driver_desc [] = DRIVER_DESC;
+
+static dev_t g_printer_devno;
+
+static struct class *usb_gadget_class;
+
+/*-------------------------------------------------------------------------*/
+
+struct printer_dev {
+	spinlock_t		lock;		/* lock this structure */
+	/* lock buffer lists during read/write calls */
+	spinlock_t		lock_printer_io;
+	struct usb_gadget	*gadget;
+	struct usb_request	*req;		/* for control responses */
+	u8			config;
+	s8			interface;
+	struct usb_ep		*in_ep, *out_ep;
+	const struct usb_endpoint_descriptor
+				*in, *out;
+	struct list_head	rx_reqs;	/* List of free RX structs */
+	struct list_head	rx_reqs_active;	/* List of Active RX xfers */
+	struct list_head	rx_buffers;	/* List of completed xfers */
+	/* wait until there is data to be read. */
+	wait_queue_head_t	rx_wait;
+	struct list_head	tx_reqs;	/* List of free TX structs */
+	struct list_head	tx_reqs_active; /* List of Active TX xfers */
+	/* Wait until there are write buffers available to use. */
+	wait_queue_head_t	tx_wait;
+	/* Wait until all write buffers have been sent. */
+	wait_queue_head_t	tx_flush_wait;
+	struct usb_request	*current_rx_req;
+	size_t			current_rx_bytes;
+	u8			*current_rx_buf;
+	u8			printer_status;
+	u8			reset_printer;
+	struct class_device	*printer_class_dev;
+	struct cdev		printer_cdev;
+	struct device		*pdev;
+	u8			printer_cdev_open;
+	wait_queue_head_t	wait;
+};
+
+static struct printer_dev usb_printer_gadget;
+
+/*-------------------------------------------------------------------------*/
+
+/* DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
+ * Instead:  allocate your own, using normal USB-IF procedures.
+ */
+
+/* Thanks to NetChip Technologies for donating this product ID.
+ */
+#define PRINTER_VENDOR_NUM	0x0525		/* NetChip */
+#define PRINTER_PRODUCT_NUM	0xa4a8		/* Linux-USB Printer Gadget */
+
+/* Some systems will want different product identifers published in the
+ * device descriptor, either numbers or strings or both.  These string
+ * parameters are in UTF-8 (superset of ASCII's 7 bit characters).
+ */
+
+static ushort __initdata idVendor;
+module_param(idVendor, ushort, S_IRUGO);
+MODULE_PARM_DESC(idVendor, "USB Vendor ID");
+
+static ushort __initdata idProduct;
+module_param(idProduct, ushort, S_IRUGO);
+MODULE_PARM_DESC(idProduct, "USB Product ID");
+
+static ushort __initdata bcdDevice;
+module_param(bcdDevice, ushort, S_IRUGO);
+MODULE_PARM_DESC(bcdDevice, "USB Device version (BCD)");
+
+static char *__initdata iManufacturer;
+module_param(iManufacturer, charp, S_IRUGO);
+MODULE_PARM_DESC(iManufacturer, "USB Manufacturer string");
+
+static char *__initdata iProduct;
+module_param(iProduct, charp, S_IRUGO);
+MODULE_PARM_DESC(iProduct, "USB Product string");
+
+static char *__initdata iSerialNum;
+module_param(iSerialNum, charp, S_IRUGO);
+MODULE_PARM_DESC(iSerialNum, "1");
+
+static char *__initdata iPNPstring;
+module_param(iPNPstring, charp, S_IRUGO);
+MODULE_PARM_DESC(iPNPstring, "MFG:linux;MDL:g_printer;CLS:PRINTER;SN:1;");
+
+/* Number of requests to allocate per endpoint, not used for ep0. */
+static unsigned qlen = 10;
+module_param(qlen, uint, S_IRUGO|S_IWUSR);
+
+#define QLEN	qlen
+
+#ifdef CONFIG_USB_GADGET_DUALSPEED
+#define DEVSPEED	USB_SPEED_HIGH
+#else   /* full speed (low speed doesn't do bulk) */
+#define DEVSPEED        USB_SPEED_FULL
+#endif
+
+/*-------------------------------------------------------------------------*/
+
+#define xprintk(d, level, fmt, args...) \
+	printk(level "%s: " fmt, DRIVER_DESC, ## args)
+
+#ifdef DEBUG
+#define DBG(dev, fmt, args...) \
+	xprintk(dev, KERN_DEBUG, fmt, ## args)
+#else
+#define DBG(dev, fmt, args...) \
+	do { } while (0)
+#endif /* DEBUG */
+
+#ifdef VERBOSE
+#define VDBG(dev, fmt, args...) \
+	xprintk(dev, KERN_DEBUG, fmt, ## args)
+#else
+#define VDBG(dev, fmt, args...) \
+	do { } while (0)
+#endif /* VERBOSE */
+
+#define ERROR(dev, fmt, args...) \
+	xprintk(dev, KERN_ERR, fmt, ## args)
+#define WARN(dev, fmt, args...) \
+	xprintk(dev, KERN_WARNING, fmt, ## args)
+#define INFO(dev, fmt, args...) \
+	xprintk(dev, KERN_INFO, fmt, ## args)
+
+/*-------------------------------------------------------------------------*/
+
+/* USB DRIVER HOOKUP (to the hardware driver, below us), mostly
+ * ep0 implementation:  descriptors, config management, setup().
+ * also optional class-specific notification interrupt transfer.
+ */
+
+/*
+ * DESCRIPTORS ... most are static, but strings and (full) configuration
+ * descriptors are built on demand.
+ */
+
+#define STRING_MANUFACTURER		1
+#define STRING_PRODUCT			2
+#define STRING_SERIALNUM		3
+
+/* holds our biggest descriptor */
+#define USB_DESC_BUFSIZE		256
+#define USB_BUFSIZE			8192
+
+/* This device advertises one configuration. */
+#define DEV_CONFIG_VALUE		1
+#define	PRINTER_INTERFACE		0
+
+static struct usb_device_descriptor device_desc = {
+	.bLength =		sizeof device_desc,
+	.bDescriptorType =	USB_DT_DEVICE,
+	.bcdUSB =		__constant_cpu_to_le16(0x0200),
+	.bDeviceClass =		USB_CLASS_PER_INTERFACE,
+	.bDeviceSubClass =	0,
+	.bDeviceProtocol =	0,
+	.idVendor =		__constant_cpu_to_le16(PRINTER_VENDOR_NUM),
+	.idProduct =		__constant_cpu_to_le16(PRINTER_PRODUCT_NUM),
+	.iManufacturer =	STRING_MANUFACTURER,
+	.iProduct =		STRING_PRODUCT,
+	.iSerialNumber =	STRING_SERIALNUM,
+	.bNumConfigurations =	1
+};
+
+static struct usb_otg_descriptor otg_desc = {
+	.bLength =		sizeof otg_desc,
+	.bDescriptorType =	USB_DT_OTG,
+	.bmAttributes =		USB_OTG_SRP
+};
+
+static struct usb_config_descriptor config_desc = {
+	.bLength =		sizeof config_desc,
+	.bDescriptorType =	USB_DT_CONFIG,
+
+	/* compute wTotalLength on the fly */
+	.bNumInterfaces =	1,
+	.bConfigurationValue =	DEV_CONFIG_VALUE,
+	.iConfiguration =	0,
+	.bmAttributes =		USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER,
+	.bMaxPower =		1	/* Self-Powered */
+};
+
+static struct usb_interface_descriptor intf_desc = {
+	.bLength =		sizeof intf_desc,
+	.bDescriptorType =	USB_DT_INTERFACE,
+	.bInterfaceNumber =	PRINTER_INTERFACE,
+	.bNumEndpoints =	2,
+	.bInterfaceClass =	USB_CLASS_PRINTER,
+	.bInterfaceSubClass =	1,	/* Printer Sub-Class */
+	.bInterfaceProtocol =	2,	/* Bi-Directional */
+	.iInterface =		0
+};
+
+static struct usb_endpoint_descriptor fs_ep_in_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+	.bEndpointAddress =	USB_DIR_IN,
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK
+};
+
+static struct usb_endpoint_descriptor fs_ep_out_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+	.bEndpointAddress =	USB_DIR_OUT,
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK
+};
+
+static const struct usb_descriptor_header *fs_printer_function [11] = {
+	(struct usb_descriptor_header *) &otg_desc,
+	(struct usb_descriptor_header *) &intf_desc,
+	(struct usb_descriptor_header *) &fs_ep_in_desc,
+	(struct usb_descriptor_header *) &fs_ep_out_desc,
+	NULL
+};
+
+#ifdef	CONFIG_USB_GADGET_DUALSPEED
+
+/*
+ * usb 2.0 devices need to expose both high speed and full speed
+ * descriptors, unless they only run at full speed.
+ */
+
+static struct usb_endpoint_descriptor hs_ep_in_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize =	__constant_cpu_to_le16(512)
+};
+
+static struct usb_endpoint_descriptor hs_ep_out_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
+	.wMaxPacketSize =	__constant_cpu_to_le16(512)
+};
+
+static struct usb_qualifier_descriptor dev_qualifier = {
+	.bLength =		sizeof dev_qualifier,
+	.bDescriptorType =	USB_DT_DEVICE_QUALIFIER,
+	.bcdUSB =		__constant_cpu_to_le16(0x0200),
+	.bDeviceClass =		USB_CLASS_PRINTER,
+	.bNumConfigurations =	1
+};
+
+static const struct usb_descriptor_header *hs_printer_function [11] = {
+	(struct usb_descriptor_header *) &otg_desc,
+	(struct usb_descriptor_header *) &intf_desc,
+	(struct usb_descriptor_header *) &hs_ep_in_desc,
+	(struct usb_descriptor_header *) &hs_ep_out_desc,
+	NULL
+};
+
+/* maxpacket and other transfer characteristics vary by speed. */
+#define ep_desc(g, hs, fs) (((g)->speed == USB_SPEED_HIGH)?(hs):(fs))
+
+#else
+
+/* if there's no high speed support, maxpacket doesn't change. */
+#define ep_desc(g, hs, fs) (((void)(g)), (fs))
+
+#endif	/* !CONFIG_USB_GADGET_DUALSPEED */
+
+/*-------------------------------------------------------------------------*/
+
+/* descriptors that are built on-demand */
+
+static char				manufacturer [50];
+static char				product_desc [40] = DRIVER_DESC;
+static char				serial_num [40] = "1";
+static char				pnp_string [1024] =
+	"XXMFG:linux;MDL:g_printer;CLS:PRINTER;SN:1;";
+
+/* static strings, in UTF-8 */
+static struct usb_string		strings [] = {
+	{ STRING_MANUFACTURER,	manufacturer, },
+	{ STRING_PRODUCT,	product_desc, },
+	{ STRING_SERIALNUM,	serial_num, },
+	{  }		/* end of list */
+};
+
+static struct usb_gadget_strings	stringtab = {
+	.language	= 0x0409,	/* en-us */
+	.strings	= strings,
+};
+
+/*-------------------------------------------------------------------------*/
+
+static struct usb_request *
+printer_req_alloc(struct usb_ep *ep, unsigned len, gfp_t gfp_flags)
+{
+	struct usb_request	*req;
+
+	req = usb_ep_alloc_request(ep, gfp_flags);
+
+	if (req != NULL) {
+		req->length = len;
+		req->buf = kmalloc(len, gfp_flags);
+		if (req->buf == NULL) {
+			usb_ep_free_request(ep, req);
+			return NULL;
+		}
+	}
+
+	return req;
+}
+
+static void
+printer_req_free(struct usb_ep *ep, struct usb_request *req)
+{
+	if (ep != NULL && req != NULL) {
+		kfree(req->buf);
+		usb_ep_free_request(ep, req);
+	}
+}
+
+/*-------------------------------------------------------------------------*/
+
+static void rx_complete(struct usb_ep *ep, struct usb_request *req)
+{
+	struct printer_dev	*dev = ep->driver_data;
+	int			status = req->status;
+	unsigned long		flags;
+
+	spin_lock_irqsave(&dev->lock, flags);
+
+	list_del_init(&req->list);	/* Remode from Active List */
+
+	switch (status) {
+
+	/* normal completion */
+	case 0:
+		list_add_tail(&req->list, &dev->rx_buffers);
+		wake_up_interruptible(&dev->rx_wait);
+		DBG(dev, "G_Printer : rx length %d\n", req->actual);
+		break;
+
+	/* software-driven interface shutdown */
+	case -ECONNRESET:		/* unlink */
+	case -ESHUTDOWN:		/* disconnect etc */
+		VDBG(dev, "rx shutdown, code %d\n", status);
+		list_add(&req->list, &dev->rx_reqs);
+		break;
+
+	/* for hardware automagic (such as pxa) */
+	case -ECONNABORTED:		/* endpoint reset */
+		DBG(dev, "rx %s reset\n", ep->name);
+		list_add(&req->list, &dev->rx_reqs);
+		break;
+
+	/* data overrun */
+	case -EOVERFLOW:
+		/* FALLTHROUGH */
+
+	default:
+		DBG(dev, "rx status %d\n", status);
+		list_add(&req->list, &dev->rx_reqs);
+		break;
+	}
+	spin_unlock_irqrestore(&dev->lock, flags);
+}
+
+static void tx_complete(struct usb_ep *ep, struct usb_request *req)
+{
+	struct printer_dev	*dev = ep->driver_data;
+
+	switch (req->status) {
+	default:
+		VDBG(dev, "tx err %d\n", req->status);
+		/* FALLTHROUGH */
+	case -ECONNRESET:		/* unlink */
+	case -ESHUTDOWN:		/* disconnect etc */
+		break;
+	case 0:
+		break;
+	}
+
+	spin_lock(&dev->lock);
+	/* Take the request struct off the active list and put it on the
+	 * free list.
+	 */
+	list_del_init(&req->list);
+	list_add(&req->list, &dev->tx_reqs);
+	wake_up_interruptible(&dev->tx_wait);
+	if (likely(list_empty(&dev->tx_reqs_active)))
+		wake_up_interruptible(&dev->tx_flush_wait);
+
+	spin_unlock(&dev->lock);
+}
+
+/*-------------------------------------------------------------------------*/
+
+static int
+printer_open(struct inode *inode, struct file *fd)
+{
+	struct printer_dev	*dev;
+	unsigned long		flags;
+	int			ret = -EBUSY;
+
+	dev = container_of(inode->i_cdev, struct printer_dev, printer_cdev);
+
+	spin_lock_irqsave(&dev->lock, flags);
+
+	if (!dev->printer_cdev_open) {
+		dev->printer_cdev_open = 1;
+		fd->private_data = dev;
+		ret = 0;
+		/* Change the printer status to show that it's on-line. */
+		dev->printer_status |= PRINTER_SELECTED;
+	}
+
+	spin_unlock_irqrestore(&dev->lock, flags);
+
+	DBG(dev, "printer_open returned %x\n", ret);
+
+	return ret;
+}
+
+static int
+printer_close(struct inode *inode, struct file *fd)
+{
+	struct printer_dev	*dev = fd->private_data;
+	unsigned long		flags;
+
+	spin_lock_irqsave(&dev->lock, flags);
+	dev->printer_cdev_open = 0;
+	fd->private_data = NULL;
+	/* Change printer status to show that the printer is off-line. */
+	dev->printer_status &= ~PRINTER_SELECTED;
+	spin_unlock_irqrestore(&dev->lock, flags);
+
+	DBG(dev, "printer_close\n");
+
+	return 0;
+}
+
+static ssize_t
+printer_read(struct file *fd, char __user *buf, size_t len, loff_t *ptr)
+{
+	struct printer_dev		*dev = fd->private_data;
+	unsigned long			flags;
+	size_t				size;
+	size_t				bytes_copied;
+	struct usb_request		*req;
+	/* This is a pointer to the current USB rx request. */
+	struct usb_request		*current_rx_req;
+	/* This is the number of bytes in the current rx buffer. */
+	size_t				current_rx_bytes;
+	/* This is a pointer to the current rx buffer. */
+	u8				*current_rx_buf;
+
+	if (len == 0)
+		return -EINVAL;
+
+	DBG(dev, "printer_read trying to read %d bytes\n", (int)len);
+
+	spin_lock(&dev->lock_printer_io);
+	spin_lock_irqsave(&dev->lock, flags);
+
+	/* We will use this flag later to check if a printer reset happened
+	 * after we turn interrupts back on.
+	 */
+	dev->reset_printer = 0;
+
+	while (likely(!list_empty(&dev->rx_reqs))) {
+		int error;
+
+		req = container_of(dev->rx_reqs.next,
+				struct usb_request, list);
+		list_del_init(&req->list);
+
+		/* The USB Host sends us whatever amount of data it wants to
+		 * so we always set the length field to the full USB_BUFSIZE.
+		 * If the amount of data is more than the read() caller asked
+		 * for it will be stored in the request buffer until it is
+		 * asked for by read().
+		 */
+		req->length = USB_BUFSIZE;
+		req->complete = rx_complete;
+
+		error = usb_ep_queue(dev->out_ep, req, GFP_ATOMIC);
+		if (error) {
+			DBG(dev, "rx submit --> %d\n", error);
+			list_add(&req->list, &dev->rx_reqs);
+			break;
+		} else {
+			list_add(&req->list, &dev->rx_reqs_active);
+		}
+	}
+
+	bytes_copied = 0;
+	current_rx_req = dev->current_rx_req;
+	current_rx_bytes = dev->current_rx_bytes;
+	current_rx_buf = dev->current_rx_buf;
+	dev->current_rx_req = NULL;
+	dev->current_rx_bytes = 0;
+	dev->current_rx_buf = NULL;
+
+	/* Check if there is any data in the read buffers. Please note that
+	 * current_rx_bytes is the number of bytes in the current rx buffer.
+	 * If it is zero then check if there are any other rx_buffers that
+	 * are on the completed list. We are only out of data if all rx
+	 * buffers are empty.
+	 */
+	if ((current_rx_bytes == 0) &&
+			(likely(list_empty(&dev->rx_buffers)))) {
+		/* Turn interrupts back on before sleeping. */
+		spin_u