// SPDX-License-Identifier: GPL-2.0+
/*
 * 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 <asm/byteorder.h>

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

USB_GADGET_COMPOSITE_OPTIONS();

#define DRIVER_DESC             "Printer Gadget"
#define DRIVER_VERSION          "2015 FEB 17"

static const char shortname [] = "printer";

#include "u_printer.h"

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

/* 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 identifiers 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).
 */

module_param_named(iSerialNum, coverwrite.serial_number, charp, S_IRUGO);
MODULE_PARM_DESC(iSerialNum, "1");

static char *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);
MODULE_PARM_DESC(qlen, "The number of 8k buffers to use per endpoint");

#define QLEN    qlen

static struct usb_function_instance *fi_printer;
static struct usb_function *f_printer;

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

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

static struct usb_device_descriptor device_desc = {
        .bLength =              sizeof device_desc,
        .bDescriptorType =      USB_DT_DEVICE,
        /* .bcdUSB = DYNAMIC */
        .bDeviceClass =         USB_CLASS_PER_INTERFACE,
        .bDeviceSubClass =      0,
        .bDeviceProtocol =      0,
        .idVendor =             cpu_to_le16(PRINTER_VENDOR_NUM),
        .idProduct =            cpu_to_le16(PRINTER_PRODUCT_NUM),
        .bNumConfigurations =   1
};

static const struct usb_descriptor_header *otg_desc[2];

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

/* descriptors that are built on-demand */

static char                             product_desc [40] = DRIVER_DESC;
static char                             serial_num [40] = "1";
static char                             *pnp_string =
        "MFG:linux;MDL:g_printer;CLS:PRINTER;SN:1;";

/* static strings, in UTF-8 */
static struct usb_string                strings [] = {
        [USB_GADGET_MANUFACTURER_IDX].s = "",
        [USB_GADGET_PRODUCT_IDX].s = product_desc,
        [USB_GADGET_SERIAL_IDX].s =     serial_num,
        {  }            /* end of list */
};

static struct usb_gadget_strings        stringtab_dev = {
        .language       = 0x0409,       /* en-us */
        .strings        = strings,
};

static struct usb_gadget_strings *dev_strings[] = {
        &stringtab_dev,
        NULL,
};

static struct usb_configuration printer_cfg_driver = {
        .label                  = "printer",
        .bConfigurationValue    = 1,
        .bmAttributes           = USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER,
};

static int printer_do_config(struct usb_configuration *c)
{
        struct usb_gadget       *gadget = c->cdev->gadget;
        int                     status = 0;

        usb_ep_autoconfig_reset(gadget);

        usb_gadget_set_selfpowered(gadget);

        if (gadget_is_otg(gadget)) {
                printer_cfg_driver.descriptors = otg_desc;
                printer_cfg_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
        }

        f_printer = usb_get_function(fi_printer);
        if (IS_ERR(f_printer))
                return PTR_ERR(f_printer);

        status = usb_add_function(c, f_printer);
        if (status < 0)
                usb_put_function(f_printer);

        return status;
}

static int printer_bind(struct usb_composite_dev *cdev)
{
        struct f_printer_opts *opts;
        int ret;

        fi_printer = usb_get_function_instance("printer");
        if (IS_ERR(fi_printer))
                return PTR_ERR(fi_printer);

        opts = container_of(fi_printer, struct f_printer_opts, func_inst);
        opts->minor = 0;
        opts->q_len = QLEN;
        if (iPNPstring) {
                opts->pnp_string = kstrdup(iPNPstring, GFP_KERNEL);
                if (!opts->pnp_string) {
                        ret = -ENOMEM;
                        goto fail_put_func_inst;
                }
                opts->pnp_string_allocated = true;
                /*
                 * we don't free this memory in case of error
                 * as printer cleanup func will do this for us
                 */
        } else {
                opts->pnp_string = pnp_string;
        }

        ret = usb_string_ids_tab(cdev, strings);
        if (ret < 0)
                goto fail_put_func_inst;

        device_desc.iManufacturer = strings[USB_GADGET_MANUFACTURER_IDX].id;
        device_desc.iProduct = strings[USB_GADGET_PRODUCT_IDX].id;
        device_desc.iSerialNumber = strings[USB_GADGET_SERIAL_IDX].id;

        if (gadget_is_otg(cdev->gadget) && !otg_desc[0]) {
                struct usb_descriptor_header *usb_desc;

                usb_desc = usb_otg_descriptor_alloc(cdev->gadget);
                if (!usb_desc) {
                        ret = -ENOMEM;
                        goto fail_put_func_inst;
                }
                usb_otg_descriptor_init(cdev->gadget, usb_desc);
                otg_desc[0] = usb_desc;
                otg_desc[1] = NULL;
        }

        ret = usb_add_config(cdev, &printer_cfg_driver, printer_do_config);
        if (ret)
                goto fail_free_otg_desc;

        usb_composite_overwrite_options(cdev, &coverwrite);
        return ret;

fail_free_otg_desc:
        kfree(otg_desc[0]);
        otg_desc[0] = NULL;
fail_put_func_inst:
        usb_put_function_instance(fi_printer);
        return ret;
}

static int printer_unbind(struct usb_composite_dev *cdev)
{
        usb_put_function(f_printer);
        usb_put_function_instance(fi_printer);

        kfree(otg_desc[0]);
        otg_desc[0] = NULL;

        return 0;
}

static struct usb_composite_driver printer_driver = {
        .name           = shortname,
        .dev            = &device_desc,
        .strings        = dev_strings,
        .max_speed      = USB_SPEED_SUPER,
        .bind           = printer_bind,
        .unbind         = printer_unbind,
};

module_usb_composite_driver(printer_driver);

MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_AUTHOR("Craig Nadler");
MODULE_LICENSE("GPL");