linux/drivers/usb/gadget/legacy/printer.c
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   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * printer.c -- Printer gadget driver
   4 *
   5 * Copyright (C) 2003-2005 David Brownell
   6 * Copyright (C) 2006 Craig W. Nadler
   7 */
   8
   9#include <linux/module.h>
  10#include <linux/kernel.h>
  11#include <asm/byteorder.h>
  12
  13#include <linux/usb/ch9.h>
  14#include <linux/usb/composite.h>
  15#include <linux/usb/gadget.h>
  16#include <linux/usb/g_printer.h>
  17
  18USB_GADGET_COMPOSITE_OPTIONS();
  19
  20#define DRIVER_DESC             "Printer Gadget"
  21#define DRIVER_VERSION          "2015 FEB 17"
  22
  23static const char shortname [] = "printer";
  24static const char driver_desc [] = DRIVER_DESC;
  25
  26#include "u_printer.h"
  27
  28/*-------------------------------------------------------------------------*/
  29
  30/* DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
  31 * Instead:  allocate your own, using normal USB-IF procedures.
  32 */
  33
  34/* Thanks to NetChip Technologies for donating this product ID.
  35 */
  36#define PRINTER_VENDOR_NUM      0x0525          /* NetChip */
  37#define PRINTER_PRODUCT_NUM     0xa4a8          /* Linux-USB Printer Gadget */
  38
  39/* Some systems will want different product identifiers published in the
  40 * device descriptor, either numbers or strings or both.  These string
  41 * parameters are in UTF-8 (superset of ASCII's 7 bit characters).
  42 */
  43
  44module_param_named(iSerialNum, coverwrite.serial_number, charp, S_IRUGO);
  45MODULE_PARM_DESC(iSerialNum, "1");
  46
  47static char *iPNPstring;
  48module_param(iPNPstring, charp, S_IRUGO);
  49MODULE_PARM_DESC(iPNPstring, "MFG:linux;MDL:g_printer;CLS:PRINTER;SN:1;");
  50
  51/* Number of requests to allocate per endpoint, not used for ep0. */
  52static unsigned qlen = 10;
  53module_param(qlen, uint, S_IRUGO|S_IWUSR);
  54
  55#define QLEN    qlen
  56
  57static struct usb_function_instance *fi_printer;
  58static struct usb_function *f_printer;
  59
  60/*-------------------------------------------------------------------------*/
  61
  62/*
  63 * DESCRIPTORS ... most are static, but strings and (full) configuration
  64 * descriptors are built on demand.
  65 */
  66
  67static struct usb_device_descriptor device_desc = {
  68        .bLength =              sizeof device_desc,
  69        .bDescriptorType =      USB_DT_DEVICE,
  70        /* .bcdUSB = DYNAMIC */
  71        .bDeviceClass =         USB_CLASS_PER_INTERFACE,
  72        .bDeviceSubClass =      0,
  73        .bDeviceProtocol =      0,
  74        .idVendor =             cpu_to_le16(PRINTER_VENDOR_NUM),
  75        .idProduct =            cpu_to_le16(PRINTER_PRODUCT_NUM),
  76        .bNumConfigurations =   1
  77};
  78
  79static const struct usb_descriptor_header *otg_desc[2];
  80
  81/*-------------------------------------------------------------------------*/
  82
  83/* descriptors that are built on-demand */
  84
  85static char                             product_desc [40] = DRIVER_DESC;
  86static char                             serial_num [40] = "1";
  87static char                             *pnp_string =
  88        "MFG:linux;MDL:g_printer;CLS:PRINTER;SN:1;";
  89
  90/* static strings, in UTF-8 */
  91static struct usb_string                strings [] = {
  92        [USB_GADGET_MANUFACTURER_IDX].s = "",
  93        [USB_GADGET_PRODUCT_IDX].s = product_desc,
  94        [USB_GADGET_SERIAL_IDX].s =     serial_num,
  95        {  }            /* end of list */
  96};
  97
  98static struct usb_gadget_strings        stringtab_dev = {
  99        .language       = 0x0409,       /* en-us */
 100        .strings        = strings,
 101};
 102
 103static struct usb_gadget_strings *dev_strings[] = {
 104        &stringtab_dev,
 105        NULL,
 106};
 107
 108static struct usb_configuration printer_cfg_driver = {
 109        .label                  = "printer",
 110        .bConfigurationValue    = 1,
 111        .bmAttributes           = USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER,
 112};
 113
 114static int printer_do_config(struct usb_configuration *c)
 115{
 116        struct usb_gadget       *gadget = c->cdev->gadget;
 117        int                     status = 0;
 118
 119        usb_ep_autoconfig_reset(gadget);
 120
 121        usb_gadget_set_selfpowered(gadget);
 122
 123        if (gadget_is_otg(gadget)) {
 124                printer_cfg_driver.descriptors = otg_desc;
 125                printer_cfg_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
 126        }
 127
 128        f_printer = usb_get_function(fi_printer);
 129        if (IS_ERR(f_printer))
 130                return PTR_ERR(f_printer);
 131
 132        status = usb_add_function(c, f_printer);
 133        if (status < 0)
 134                usb_put_function(f_printer);
 135
 136        return status;
 137}
 138
 139static int printer_bind(struct usb_composite_dev *cdev)
 140{
 141        struct f_printer_opts *opts;
 142        int ret;
 143
 144        fi_printer = usb_get_function_instance("printer");
 145        if (IS_ERR(fi_printer))
 146                return PTR_ERR(fi_printer);
 147
 148        opts = container_of(fi_printer, struct f_printer_opts, func_inst);
 149        opts->minor = 0;
 150        opts->q_len = QLEN;
 151        if (iPNPstring) {
 152                opts->pnp_string = kstrdup(iPNPstring, GFP_KERNEL);
 153                if (!opts->pnp_string) {
 154                        ret = -ENOMEM;
 155                        goto fail_put_func_inst;
 156                }
 157                opts->pnp_string_allocated = true;
 158                /*
 159                 * we don't free this memory in case of error
 160                 * as printer cleanup func will do this for us
 161                 */
 162        } else {
 163                opts->pnp_string = pnp_string;
 164        }
 165
 166        ret = usb_string_ids_tab(cdev, strings);
 167        if (ret < 0)
 168                goto fail_put_func_inst;
 169
 170        device_desc.iManufacturer = strings[USB_GADGET_MANUFACTURER_IDX].id;
 171        device_desc.iProduct = strings[USB_GADGET_PRODUCT_IDX].id;
 172        device_desc.iSerialNumber = strings[USB_GADGET_SERIAL_IDX].id;
 173
 174        if (gadget_is_otg(cdev->gadget) && !otg_desc[0]) {
 175                struct usb_descriptor_header *usb_desc;
 176
 177                usb_desc = usb_otg_descriptor_alloc(cdev->gadget);
 178                if (!usb_desc) {
 179                        ret = -ENOMEM;
 180                        goto fail_put_func_inst;
 181                }
 182                usb_otg_descriptor_init(cdev->gadget, usb_desc);
 183                otg_desc[0] = usb_desc;
 184                otg_desc[1] = NULL;
 185        }
 186
 187        ret = usb_add_config(cdev, &printer_cfg_driver, printer_do_config);
 188        if (ret)
 189                goto fail_free_otg_desc;
 190
 191        usb_composite_overwrite_options(cdev, &coverwrite);
 192        return ret;
 193
 194fail_free_otg_desc:
 195        kfree(otg_desc[0]);
 196        otg_desc[0] = NULL;
 197fail_put_func_inst:
 198        usb_put_function_instance(fi_printer);
 199        return ret;
 200}
 201
 202static int printer_unbind(struct usb_composite_dev *cdev)
 203{
 204        usb_put_function(f_printer);
 205        usb_put_function_instance(fi_printer);
 206
 207        kfree(otg_desc[0]);
 208        otg_desc[0] = NULL;
 209
 210        return 0;
 211}
 212
 213static struct usb_composite_driver printer_driver = {
 214        .name           = shortname,
 215        .dev            = &device_desc,
 216        .strings        = dev_strings,
 217        .max_speed      = USB_SPEED_SUPER,
 218        .bind           = printer_bind,
 219        .unbind         = printer_unbind,
 220};
 221
 222module_usb_composite_driver(printer_driver);
 223
 224MODULE_DESCRIPTION(DRIVER_DESC);
 225MODULE_AUTHOR("Craig Nadler");
 226MODULE_LICENSE("GPL");
 227