linux/drivers/usb/gadget/legacy/tcm_usb_gadget.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/* Target based USB-Gadget
   3 *
   4 * UAS protocol handling, target callbacks, configfs handling,
   5 * BBB (USB Mass Storage Class Bulk-Only (BBB) and Transport protocol handling.
   6 *
   7 * Author: Sebastian Andrzej Siewior <bigeasy at linutronix dot de>
   8 */
   9#include <linux/kernel.h>
  10#include <linux/module.h>
  11#include <linux/types.h>
  12#include <linux/string.h>
  13#include <linux/configfs.h>
  14#include <linux/ctype.h>
  15#include <linux/usb/ch9.h>
  16#include <linux/usb/composite.h>
  17#include <linux/usb/gadget.h>
  18#include <linux/usb/storage.h>
  19#include <scsi/scsi_tcq.h>
  20#include <target/target_core_base.h>
  21#include <target/target_core_fabric.h>
  22#include <asm/unaligned.h>
  23
  24#include "u_tcm.h"
  25
  26USB_GADGET_COMPOSITE_OPTIONS();
  27
  28#define UAS_VENDOR_ID   0x0525  /* NetChip */
  29#define UAS_PRODUCT_ID  0xa4a5  /* Linux-USB File-backed Storage Gadget */
  30
  31static struct usb_device_descriptor usbg_device_desc = {
  32        .bLength =              sizeof(usbg_device_desc),
  33        .bDescriptorType =      USB_DT_DEVICE,
  34        /* .bcdUSB = DYNAMIC */
  35        .bDeviceClass =         USB_CLASS_PER_INTERFACE,
  36        .idVendor =             cpu_to_le16(UAS_VENDOR_ID),
  37        .idProduct =            cpu_to_le16(UAS_PRODUCT_ID),
  38        .bNumConfigurations =   1,
  39};
  40
  41#define USB_G_STR_CONFIG USB_GADGET_FIRST_AVAIL_IDX
  42
  43static struct usb_string        usbg_us_strings[] = {
  44        [USB_GADGET_MANUFACTURER_IDX].s = "Target Manufacturer",
  45        [USB_GADGET_PRODUCT_IDX].s      = "Target Product",
  46        [USB_GADGET_SERIAL_IDX].s       = "000000000001",
  47        [USB_G_STR_CONFIG].s            = "default config",
  48        { },
  49};
  50
  51static struct usb_gadget_strings usbg_stringtab = {
  52        .language = 0x0409,
  53        .strings = usbg_us_strings,
  54};
  55
  56static struct usb_gadget_strings *usbg_strings[] = {
  57        &usbg_stringtab,
  58        NULL,
  59};
  60
  61static struct usb_function_instance *fi_tcm;
  62static struct usb_function *f_tcm;
  63
  64static int guas_unbind(struct usb_composite_dev *cdev)
  65{
  66        if (!IS_ERR_OR_NULL(f_tcm))
  67                usb_put_function(f_tcm);
  68
  69        return 0;
  70}
  71
  72static int tcm_do_config(struct usb_configuration *c)
  73{
  74        int status;
  75
  76        f_tcm = usb_get_function(fi_tcm);
  77        if (IS_ERR(f_tcm))
  78                return PTR_ERR(f_tcm);
  79
  80        status = usb_add_function(c, f_tcm);
  81        if (status < 0) {
  82                usb_put_function(f_tcm);
  83                return status;
  84        }
  85
  86        return 0;
  87}
  88
  89static struct usb_configuration usbg_config_driver = {
  90        .label                  = "Linux Target",
  91        .bConfigurationValue    = 1,
  92        .bmAttributes           = USB_CONFIG_ATT_SELFPOWER,
  93};
  94
  95static int usbg_attach(struct usb_function_instance *f);
  96static void usbg_detach(struct usb_function_instance *f);
  97
  98static int usb_target_bind(struct usb_composite_dev *cdev)
  99{
 100        int ret;
 101
 102        ret = usb_string_ids_tab(cdev, usbg_us_strings);
 103        if (ret)
 104                return ret;
 105
 106        usbg_device_desc.iManufacturer =
 107                usbg_us_strings[USB_GADGET_MANUFACTURER_IDX].id;
 108        usbg_device_desc.iProduct = usbg_us_strings[USB_GADGET_PRODUCT_IDX].id;
 109        usbg_device_desc.iSerialNumber =
 110                usbg_us_strings[USB_GADGET_SERIAL_IDX].id;
 111        usbg_config_driver.iConfiguration =
 112                usbg_us_strings[USB_G_STR_CONFIG].id;
 113
 114        ret = usb_add_config(cdev, &usbg_config_driver, tcm_do_config);
 115        if (ret)
 116                return ret;
 117        usb_composite_overwrite_options(cdev, &coverwrite);
 118        return 0;
 119}
 120
 121static struct usb_composite_driver usbg_driver = {
 122        .name           = "g_target",
 123        .dev            = &usbg_device_desc,
 124        .strings        = usbg_strings,
 125        .max_speed      = USB_SPEED_SUPER,
 126        .bind           = usb_target_bind,
 127        .unbind         = guas_unbind,
 128};
 129
 130static int usbg_attach(struct usb_function_instance *f)
 131{
 132        return usb_composite_probe(&usbg_driver);
 133}
 134
 135static void usbg_detach(struct usb_function_instance *f)
 136{
 137        usb_composite_unregister(&usbg_driver);
 138}
 139
 140static int __init usb_target_gadget_init(void)
 141{
 142        struct f_tcm_opts *tcm_opts;
 143
 144        fi_tcm = usb_get_function_instance("tcm");
 145        if (IS_ERR(fi_tcm))
 146                return PTR_ERR(fi_tcm);
 147
 148        tcm_opts = container_of(fi_tcm, struct f_tcm_opts, func_inst);
 149        mutex_lock(&tcm_opts->dep_lock);
 150        tcm_opts->tcm_register_callback = usbg_attach;
 151        tcm_opts->tcm_unregister_callback = usbg_detach;
 152        tcm_opts->dependent = THIS_MODULE;
 153        tcm_opts->can_attach = true;
 154        tcm_opts->has_dep = true;
 155        mutex_unlock(&tcm_opts->dep_lock);
 156
 157        fi_tcm->set_inst_name(fi_tcm, "tcm-legacy");
 158
 159        return 0;
 160}
 161module_init(usb_target_gadget_init);
 162
 163static void __exit usb_target_gadget_exit(void)
 164{
 165        if (!IS_ERR_OR_NULL(fi_tcm))
 166                usb_put_function_instance(fi_tcm);
 167
 168}
 169module_exit(usb_target_gadget_exit);
 170
 171MODULE_AUTHOR("Sebastian Andrzej Siewior <bigeasy@linutronix.de>");
 172MODULE_DESCRIPTION("usb-gadget fabric");
 173MODULE_LICENSE("GPL v2");
 174