1 // SPDX-License-Identifier: GPL-2.0+
3 * serial.c -- USB gadget serial driver
5 * Copyright (C) 2003 Al Borchers (alborchers@steinerpoint.com)
6 * Copyright (C) 2008 by David Brownell
7 * Copyright (C) 2008 by Nokia Corporation
10 #include <linux/kernel.h>
11 #include <linux/device.h>
12 #include <linux/module.h>
13 #include <linux/tty.h>
14 #include <linux/tty_flip.h>
21 #define GS_VERSION_STR "v2.4"
22 #define GS_VERSION_NUM 0x2400
24 #define GS_LONG_NAME "Gadget Serial"
25 #define GS_VERSION_NAME GS_LONG_NAME " " GS_VERSION_STR
27 /*-------------------------------------------------------------------------*/
28 USB_GADGET_COMPOSITE_OPTIONS();
30 /* Thanks to NetChip Technologies for donating this product ID.
32 * DO NOT REUSE THESE IDs with a protocol-incompatible driver!! Ever!!
33 * Instead: allocate your own, using normal USB-IF procedures.
35 #define GS_VENDOR_ID 0x0525 /* NetChip */
36 #define GS_PRODUCT_ID 0xa4a6 /* Linux-USB Serial Gadget */
37 #define GS_CDC_PRODUCT_ID 0xa4a7 /* ... as CDC-ACM */
38 #define GS_CDC_OBEX_PRODUCT_ID 0xa4a9 /* ... as CDC-OBEX */
40 /* string IDs are assigned dynamically */
42 #define STRING_DESCRIPTION_IDX USB_GADGET_FIRST_AVAIL_IDX
44 static struct usb_string strings_dev[] = {
45 [USB_GADGET_MANUFACTURER_IDX].s = "",
46 [USB_GADGET_PRODUCT_IDX].s = GS_VERSION_NAME,
47 [USB_GADGET_SERIAL_IDX].s = "",
48 [STRING_DESCRIPTION_IDX].s = NULL /* updated; f(use_acm) */,
52 static struct usb_gadget_strings stringtab_dev = {
53 .language = 0x0409, /* en-us */
54 .strings = strings_dev,
57 static struct usb_gadget_strings *dev_strings[] = {
62 static struct usb_device_descriptor device_desc = {
63 .bLength = USB_DT_DEVICE_SIZE,
64 .bDescriptorType = USB_DT_DEVICE,
65 /* .bcdUSB = DYNAMIC */
66 /* .bDeviceClass = f(use_acm) */
69 /* .bMaxPacketSize0 = f(hardware) */
70 .idVendor = cpu_to_le16(GS_VENDOR_ID),
71 /* .idProduct = f(use_acm) */
72 .bcdDevice = cpu_to_le16(GS_VERSION_NUM),
73 /* .iManufacturer = DYNAMIC */
74 /* .iProduct = DYNAMIC */
75 .bNumConfigurations = 1,
78 static const struct usb_descriptor_header *otg_desc[2];
80 /*-------------------------------------------------------------------------*/
83 MODULE_DESCRIPTION(GS_VERSION_NAME);
84 MODULE_AUTHOR("Al Borchers");
85 MODULE_AUTHOR("David Brownell");
86 MODULE_LICENSE("GPL");
88 static bool use_acm = true;
89 module_param(use_acm, bool, 0);
90 MODULE_PARM_DESC(use_acm, "Use CDC ACM, default=yes");
92 static bool use_obex = false;
93 module_param(use_obex, bool, 0);
94 MODULE_PARM_DESC(use_obex, "Use CDC OBEX, default=no");
96 static unsigned n_ports = 1;
97 module_param(n_ports, uint, 0);
98 MODULE_PARM_DESC(n_ports, "number of ports to create, default=1");
100 /*-------------------------------------------------------------------------*/
102 static struct usb_configuration serial_config_driver = {
103 /* .label = f(use_acm) */
104 /* .bConfigurationValue = f(use_acm) */
105 /* .iConfiguration = DYNAMIC */
106 .bmAttributes = USB_CONFIG_ATT_SELFPOWER,
109 static struct usb_function_instance *fi_serial[MAX_U_SERIAL_PORTS];
110 static struct usb_function *f_serial[MAX_U_SERIAL_PORTS];
112 static int serial_register_ports(struct usb_composite_dev *cdev,
113 struct usb_configuration *c, const char *f_name)
118 ret = usb_add_config_only(cdev, c);
122 for (i = 0; i < n_ports; i++) {
124 fi_serial[i] = usb_get_function_instance(f_name);
125 if (IS_ERR(fi_serial[i])) {
126 ret = PTR_ERR(fi_serial[i]);
130 f_serial[i] = usb_get_function(fi_serial[i]);
131 if (IS_ERR(f_serial[i])) {
132 ret = PTR_ERR(f_serial[i]);
136 ret = usb_add_function(c, f_serial[i]);
144 usb_put_function(f_serial[i]);
146 usb_put_function_instance(fi_serial[i]);
151 usb_remove_function(c, f_serial[i]);
152 usb_put_function(f_serial[i]);
153 usb_put_function_instance(fi_serial[i]);
160 static int gs_bind(struct usb_composite_dev *cdev)
164 /* Allocate string descriptor numbers ... note that string
165 * contents can be overridden by the composite_dev glue.
168 status = usb_string_ids_tab(cdev, strings_dev);
171 device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id;
172 device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id;
173 status = strings_dev[STRING_DESCRIPTION_IDX].id;
174 serial_config_driver.iConfiguration = status;
176 if (gadget_is_otg(cdev->gadget)) {
178 struct usb_descriptor_header *usb_desc;
180 usb_desc = usb_otg_descriptor_alloc(cdev->gadget);
185 usb_otg_descriptor_init(cdev->gadget, usb_desc);
186 otg_desc[0] = usb_desc;
189 serial_config_driver.descriptors = otg_desc;
190 serial_config_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
193 /* register our configuration */
195 status = serial_register_ports(cdev, &serial_config_driver,
197 usb_ep_autoconfig_reset(cdev->gadget);
199 status = serial_register_ports(cdev, &serial_config_driver,
202 status = serial_register_ports(cdev, &serial_config_driver,
208 usb_composite_overwrite_options(cdev, &coverwrite);
209 INFO(cdev, "%s\n", GS_VERSION_NAME);
219 static int gs_unbind(struct usb_composite_dev *cdev)
223 for (i = 0; i < n_ports; i++) {
224 usb_put_function(f_serial[i]);
225 usb_put_function_instance(fi_serial[i]);
234 static struct usb_composite_driver gserial_driver = {
237 .strings = dev_strings,
238 .max_speed = USB_SPEED_SUPER,
243 static int __init init(void)
245 /* We *could* export two configs; that'd be much cleaner...
246 * but neither of these product IDs was defined that way.
249 serial_config_driver.label = "CDC ACM config";
250 serial_config_driver.bConfigurationValue = 2;
251 device_desc.bDeviceClass = USB_CLASS_COMM;
252 device_desc.idProduct =
253 cpu_to_le16(GS_CDC_PRODUCT_ID);
254 } else if (use_obex) {
255 serial_config_driver.label = "CDC OBEX config";
256 serial_config_driver.bConfigurationValue = 3;
257 device_desc.bDeviceClass = USB_CLASS_COMM;
258 device_desc.idProduct =
259 cpu_to_le16(GS_CDC_OBEX_PRODUCT_ID);
261 serial_config_driver.label = "Generic Serial config";
262 serial_config_driver.bConfigurationValue = 1;
263 device_desc.bDeviceClass = USB_CLASS_VENDOR_SPEC;
264 device_desc.idProduct =
265 cpu_to_le16(GS_PRODUCT_ID);
267 strings_dev[STRING_DESCRIPTION_IDX].s = serial_config_driver.label;
269 return usb_composite_probe(&gserial_driver);
273 static void __exit cleanup(void)
275 usb_composite_unregister(&gserial_driver);
277 module_exit(cleanup);