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