1/*
2 * serial.c -- USB gadget serial driver
3 *
4 * Copyright (C) 2003 Al Borchers (alborchers@steinerpoint.com)
5 * Copyright (C) 2008 by David Brownell
6 * Copyright (C) 2008 by Nokia Corporation
7 *
8 * This software is distributed under the terms of the GNU General
9 * Public License ("GPL") as published by the Free Software Foundation,
10 * either version 2 of that License or (at your option) any later version.
11 */
12
13#include <linux/kernel.h>
14#include <linux/device.h>
15#include <linux/module.h>
16#include <linux/tty.h>
17#include <linux/tty_flip.h>
18
19#include "u_serial.h"
20#include "gadget_chips.h"
21
22
23/* Defines */
24
25#define GS_VERSION_STR			"v2.4"
26#define GS_VERSION_NUM			0x2400
27
28#define GS_LONG_NAME			"Gadget Serial"
29#define GS_VERSION_NAME			GS_LONG_NAME " " GS_VERSION_STR
30
31/*-------------------------------------------------------------------------*/
32USB_GADGET_COMPOSITE_OPTIONS();
33
34/* Thanks to NetChip Technologies for donating this product ID.
35*
36* DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
37* Instead:  allocate your own, using normal USB-IF procedures.
38*/
39#define GS_VENDOR_ID			0x0525	/* NetChip */
40#define GS_PRODUCT_ID			0xa4a6	/* Linux-USB Serial Gadget */
41#define GS_CDC_PRODUCT_ID		0xa4a7	/* ... as CDC-ACM */
42#define GS_CDC_OBEX_PRODUCT_ID		0xa4a9	/* ... as CDC-OBEX */
43
44/* string IDs are assigned dynamically */
45
46#define STRING_DESCRIPTION_IDX		USB_GADGET_FIRST_AVAIL_IDX
47
48static struct usb_string strings_dev[] = {
49	[USB_GADGET_MANUFACTURER_IDX].s = "",
50	[USB_GADGET_PRODUCT_IDX].s = GS_VERSION_NAME,
51	[USB_GADGET_SERIAL_IDX].s = "",
52	[STRING_DESCRIPTION_IDX].s = NULL /* updated; f(use_acm) */,
53	{  } /* end of list */
54};
55
56static struct usb_gadget_strings stringtab_dev = {
57	.language	= 0x0409,	/* en-us */
58	.strings	= strings_dev,
59};
60
61static struct usb_gadget_strings *dev_strings[] = {
62	&stringtab_dev,
63	NULL,
64};
65
66static struct usb_device_descriptor device_desc = {
67	.bLength =		USB_DT_DEVICE_SIZE,
68	.bDescriptorType =	USB_DT_DEVICE,
69	.bcdUSB =		cpu_to_le16(0x0200),
70	/* .bDeviceClass = f(use_acm) */
71	.bDeviceSubClass =	0,
72	.bDeviceProtocol =	0,
73	/* .bMaxPacketSize0 = f(hardware) */
74	.idVendor =		cpu_to_le16(GS_VENDOR_ID),
75	/* .idProduct =	f(use_acm) */
76	.bcdDevice = cpu_to_le16(GS_VERSION_NUM),
77	/* .iManufacturer = DYNAMIC */
78	/* .iProduct = DYNAMIC */
79	.bNumConfigurations =	1,
80};
81
82static struct usb_otg_descriptor otg_descriptor = {
83	.bLength =		sizeof otg_descriptor,
84	.bDescriptorType =	USB_DT_OTG,
85
86	/* REVISIT SRP-only hardware is possible, although
87	 * it would not be called "OTG" ...
88	 */
89	.bmAttributes =		USB_OTG_SRP | USB_OTG_HNP,
90};
91
92static const struct usb_descriptor_header *otg_desc[] = {
93	(struct usb_descriptor_header *) &otg_descriptor,
94	NULL,
95};
96
97/*-------------------------------------------------------------------------*/
98
99/* Module */
100MODULE_DESCRIPTION(GS_VERSION_NAME);
101MODULE_AUTHOR("Al Borchers");
102MODULE_AUTHOR("David Brownell");
103MODULE_LICENSE("GPL");
104
105static bool use_acm = true;
106module_param(use_acm, bool, 0);
107MODULE_PARM_DESC(use_acm, "Use CDC ACM, default=yes");
108
109static bool use_obex = false;
110module_param(use_obex, bool, 0);
111MODULE_PARM_DESC(use_obex, "Use CDC OBEX, default=no");
112
113static unsigned n_ports = 1;
114module_param(n_ports, uint, 0);
115MODULE_PARM_DESC(n_ports, "number of ports to create, default=1");
116
117/*-------------------------------------------------------------------------*/
118
119static struct usb_configuration serial_config_driver = {
120	/* .label = f(use_acm) */
121	/* .bConfigurationValue = f(use_acm) */
122	/* .iConfiguration = DYNAMIC */
123	.bmAttributes	= USB_CONFIG_ATT_SELFPOWER,
124};
125
126static struct usb_function_instance *fi_serial[MAX_U_SERIAL_PORTS];
127static struct usb_function *f_serial[MAX_U_SERIAL_PORTS];
128
129static int serial_register_ports(struct usb_composite_dev *cdev,
130		struct usb_configuration *c, const char *f_name)
131{
132	int i;
133	int ret;
134
135	ret = usb_add_config_only(cdev, c);
136	if (ret)
137		goto out;
138
139	for (i = 0; i < n_ports; i++) {
140
141		fi_serial[i] = usb_get_function_instance(f_name);
142		if (IS_ERR(fi_serial[i])) {
143			ret = PTR_ERR(fi_serial[i]);
144			goto fail;
145		}
146
147		f_serial[i] = usb_get_function(fi_serial[i]);
148		if (IS_ERR(f_serial[i])) {
149			ret = PTR_ERR(f_serial[i]);
150			goto err_get_func;
151		}
152
153		ret = usb_add_function(c, f_serial[i]);
154		if (ret)
155			goto err_add_func;
156	}
157
158	return 0;
159
160err_add_func:
161	usb_put_function(f_serial[i]);
162err_get_func:
163	usb_put_function_instance(fi_serial[i]);
164
165fail:
166	i--;
167	while (i >= 0) {
168		usb_remove_function(c, f_serial[i]);
169		usb_put_function(f_serial[i]);
170		usb_put_function_instance(fi_serial[i]);
171		i--;
172	}
173out:
174	return ret;
175}
176
177static int gs_bind(struct usb_composite_dev *cdev)
178{
179	int			status;
180
181	/* Allocate string descriptor numbers ... note that string
182	 * contents can be overridden by the composite_dev glue.
183	 */
184
185	status = usb_string_ids_tab(cdev, strings_dev);
186	if (status < 0)
187		goto fail;
188	device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id;
189	device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id;
190	status = strings_dev[STRING_DESCRIPTION_IDX].id;
191	serial_config_driver.iConfiguration = status;
192
193	if (gadget_is_otg(cdev->gadget)) {
194		serial_config_driver.descriptors = otg_desc;
195		serial_config_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
196	}
197
198	/* register our configuration */
199	if (use_acm) {
200		status  = serial_register_ports(cdev, &serial_config_driver,
201				"acm");
202		usb_ep_autoconfig_reset(cdev->gadget);
203	} else if (use_obex)
204		status = serial_register_ports(cdev, &serial_config_driver,
205				"obex");
206	else {
207		status = serial_register_ports(cdev, &serial_config_driver,
208				"gser");
209	}
210	if (status < 0)
211		goto fail;
212
213	usb_composite_overwrite_options(cdev, &coverwrite);
214	INFO(cdev, "%s\n", GS_VERSION_NAME);
215
216	return 0;
217
218fail:
219	return status;
220}
221
222static int gs_unbind(struct usb_composite_dev *cdev)
223{
224	int i;
225
226	for (i = 0; i < n_ports; i++) {
227		usb_put_function(f_serial[i]);
228		usb_put_function_instance(fi_serial[i]);
229	}
230	return 0;
231}
232
233static struct usb_composite_driver gserial_driver = {
234	.name		= "g_serial",
235	.dev		= &device_desc,
236	.strings	= dev_strings,
237	.max_speed	= USB_SPEED_SUPER,
238	.bind		= gs_bind,
239	.unbind		= gs_unbind,
240};
241
242static int __init init(void)
243{
244	/* We *could* export two configs; that'd be much cleaner...
245	 * but neither of these product IDs was defined that way.
246	 */
247	if (use_acm) {
248		serial_config_driver.label = "CDC ACM config";
249		serial_config_driver.bConfigurationValue = 2;
250		device_desc.bDeviceClass = USB_CLASS_COMM;
251		device_desc.idProduct =
252				cpu_to_le16(GS_CDC_PRODUCT_ID);
253	} else if (use_obex) {
254		serial_config_driver.label = "CDC OBEX config";
255		serial_config_driver.bConfigurationValue = 3;
256		device_desc.bDeviceClass = USB_CLASS_COMM;
257		device_desc.idProduct =
258			cpu_to_le16(GS_CDC_OBEX_PRODUCT_ID);
259	} else {
260		serial_config_driver.label = "Generic Serial config";
261		serial_config_driver.bConfigurationValue = 1;
262		device_desc.bDeviceClass = USB_CLASS_VENDOR_SPEC;
263		device_desc.idProduct =
264				cpu_to_le16(GS_PRODUCT_ID);
265	}
266	strings_dev[STRING_DESCRIPTION_IDX].s = serial_config_driver.label;
267
268	return usb_composite_probe(&gserial_driver);
269}
270module_init(init);
271
272static void __exit cleanup(void)
273{
274	usb_composite_unregister(&gserial_driver);
275}
276module_exit(cleanup);
277