tcm_usb_gadget.c

  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 <linux/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");