path: root/drivers/usb/gadget/function/f_printer.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * f_printer.c - USB printer function driver
 *
 * Copied from drivers/usb/gadget/legacy/printer.c,
 * which was:
 *
 * printer.c -- Printer gadget driver
 *
 * Copyright (C) 2003-2005 David Brownell
 * Copyright (C) 2006 Craig W. Nadler
 */

#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/mutex.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/idr.h>
#include <linux/timer.h>
#include <linux/list.h>
#include <linux/interrupt.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 <linux/kref.h>

#include <asm/byteorder.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/uaccess.h>
#include <linux/unaligned.h>

#include <linux/usb/ch9.h>
#include <linux/usb/composite.h>
#include <linux/usb/gadget.h>
#include <linux/usb/g_printer.h>

#include "u_printer.h"

#define PRINTER_MINORS		4
#define GET_DEVICE_ID		0
#define GET_PORT_STATUS		1
#define SOFT_RESET		2

#define DEFAULT_Q_LEN		10 /* same as legacy g_printer gadget */

static int major, minors;
static const struct class usb_gadget_class = {
	.name = "usb_printer_gadget",
};

static DEFINE_IDA(printer_ida);
static DEFINE_MUTEX(printer_ida_lock); /* protects access do printer_ida */

/*-------------------------------------------------------------------------*/

struct printer_dev {
	spinlock_t		lock;		/* lock this structure */
	/* lock buffer lists during read/write calls */
	struct mutex		lock_printer_io;
	struct usb_gadget	*gadget;
	s8			interface;
	struct usb_ep		*in_ep, *out_ep;
	struct kref             kref;
	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;
	int			minor;
	struct cdev		printer_cdev;
	u8			printer_cdev_open;
	wait_queue_head_t	wait;
	unsigned		q_len;
	char			**pnp_string;	/* We don't own memory! */
	struct usb_function	function;
};

static inline struct printer_dev *func_to_printer(struct usb_function *f)
{
	return container_of(f, struct printer_dev, function);
}

/*-------------------------------------------------------------------------*/

/*
 * DESCRIPTORS ... most are static, but strings and (full) configuration
 * descriptors are built on demand.
 */

/* holds our biggest descriptor */
#define USB_DESC_BUFSIZE		256
#define USB_BUFSIZE			8192

static struct usb_interface_descriptor intf_desc = {
	.bLength =		sizeof(intf_desc),
	.bDescriptorType =	USB_DT_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 struct usb_descriptor_header *fs_printer_function[] = {
	(struct usb_descriptor_header *) &intf_desc,
	(struct usb_descriptor_header *) &fs_ep_in_desc,
	(struct usb_descriptor_header *) &fs_ep_out_desc,
	NULL
};

/*
 * 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 =	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 =	cpu_to_le16(512)
};

static struct usb_descriptor_header *hs_printer_function[] = {
	(struct usb_descriptor_header *) &intf_desc,
	(struct usb_descriptor_header *) &hs_ep_in_desc,
	(struct usb_descriptor_header *) &hs_ep_out_desc,
	NULL
};

/*
 * Added endpoint descriptors for 3.0 devices
 */

static struct usb_endpoint_descriptor ss_ep_in_desc = {
	.bLength =              USB_DT_ENDPOINT_SIZE,
	.bDescriptorType =      USB_DT_ENDPOINT,
	.bmAttributes =         USB_ENDPOINT_XFER_BULK,
	.wMaxPacketSize =       cpu_to_le16(1024),
};

static struct usb_ss_ep_comp_descriptor ss_ep_in_comp_desc = {
	.bLength =              sizeof(ss_ep_in_comp_desc),
	.bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
};

static struct usb_endpoint_descriptor ss_ep_out_desc = {
	.bLength =              USB_DT_ENDPOINT_SIZE,
	.bDescriptorType =      USB_DT_ENDPOINT,
	.bmAttributes =         USB_ENDPOINT_XFER_BULK,
	.wMaxPacketSize =       cpu_to_le16(1024),
};

static struct usb_ss_ep_comp_descriptor ss_ep_out_comp_desc = {
	.bLength =              sizeof(ss_ep_out_comp_desc),
	.bDescriptorType =      USB_DT_SS_ENDPOINT_COMP,
};

static struct usb_descriptor_header *ss_printer_function[] = {
	(struct usb_descriptor_header *) &intf_desc,
	(struct usb_descriptor_header *) &ss_ep_in_desc,
	(struct usb_descriptor_header *) &ss_ep_in_comp_desc,
	(struct usb_descriptor_header *) &ss_ep_out_desc,
	(struct usb_descriptor_header *) &ss_ep_out_comp_desc,
	NULL
};

/* maxpacket and other transfer characteristics vary by speed. */
static inline struct usb_endpoint_descriptor *ep_desc(struct usb_gadget *gadget,
					struct usb_endpoint_descript