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
21
22/* Defines */
23
24#define GS_VERSION_STR			"v2.4"
25#define GS_VERSION_NUM			0x2400
26
27#define GS_LONG_NAME			"Gadget Serial"
28#define GS_VERSION_NAME			GS_LONG_NAME " " GS_VERSION_STR
29
30/*-------------------------------------------------------------------------*/
31USB_GADGET_COMPOSITE_OPTIONS();
32
33/* Thanks to NetChip Technologies for donating this product ID.
34*
35* DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
36* Instead:  allocate your own, using normal USB-IF procedures.
37*/
38#define GS_VENDOR_ID			0x0525	/* NetChip */
39#define GS_PRODUCT_ID			0xa4a6	/* Linux-USB Serial Gadget */
40#define GS_CDC_PRODUCT_ID		0xa4a7	/* ... as CDC-ACM */
41#define GS_CDC_OBEX_PRODUCT_ID		0xa4a9	/* ... as CDC-OBEX */
42
43/* string IDs are assigned dynamically */
44
45#define STRING_DESCRIPTION_IDX		USB_GADGET_FIRST_AVAIL_IDX
46
47static struct usb_string strings_dev[] = {
48	[USB_GADGET_MANUFACTURER_IDX].s = "",
49	[USB_GADGET_PRODUCT_IDX].s = GS_VERSION_NAME,
50	[USB_GADGET_SERIAL_IDX].s = "",
51	[STRING_DESCRIPTION_IDX].s = NULL /* updated; f(use_acm) */,
52	{  } /* end of list */
53};
54
55static struct usb_gadget_strings stringtab_dev = {
56	.language	= 0x0409,	/* en-us */
57	.strings	= strings_dev,
58};
59
60static struct usb_gadget_strings *dev_strings[] = {
61	&stringtab_dev,
62	NULL,
63};
64
65static struct usb_device_descriptor device_desc = {
66	.bLength =		USB_DT_DEVICE_SIZE,
67	.bDescriptorType =	USB_DT_DEVICE,
68	.bcdUSB =		cpu_to_le16(0x0200),
69	/* .bDeviceClass = f(use_acm) */
70	.bDeviceSubClass =	0,
71	.bDeviceProtocol =	0,
72	/* .bMaxPacketSize0 = f(hardware) */
73	.idVendor =		cpu_to_le16(GS_VENDOR_ID),
74	/* .idProduct =	f(use_acm) */
75	.bcdDevice = cpu_to_le16(GS_VERSION_NUM),
76	/* .iManufacturer = DYNAMIC */
77	/* .iProduct = DYNAMIC */
78	.bNumConfigurations =	1,
79};
80
81static const struct usb_descriptor_header *otg_desc[2];
82
83/*-------------------------------------------------------------------------*/
84
85/* Module */
86MODULE_DESCRIPTION(GS_VERSION_NAME);
87MODULE_AUTHOR("Al Borchers");
88MODULE_AUTHOR("David Brownell");
89MODULE_LICENSE("GPL");
90
91static bool use_acm = true;
92module_param(use_acm, bool, 0);
93MODULE_PARM_DESC(use_acm, "Use CDC ACM, default=yes");
94
95static bool use_obex = false;
96module_param(use_obex, bool, 0);
97MODULE_PARM_DESC(use_obex, "Use CDC OBEX, default=no");
98
99static unsigned n_ports = 1;
100module_param(n_ports, uint, 0);
101MODULE_PARM_DESC(n_ports, "number of ports to create, default=1");
102
103/*-------------------------------------------------------------------------*/
104
105static struct usb_configuration serial_config_driver = {
106	/* .label = f(use_acm) */
107	/* .bConfigurationValue = f(use_acm) */
108	/* .iConfiguration = DYNAMIC */
109	.bmAttributes	= USB_CONFIG_ATT_SELFPOWER,
110};
111
112static struct usb_function_instance *fi_serial[MAX_U_SERIAL_PORTS];
113static struct usb_function *f_serial[MAX_U_SERIAL_PORTS];
114
115static int serial_register_ports(struct usb_composite_dev *cdev,
116		struct usb_configuration *c, const char *f_name)
117{
118	int i;
119	int ret;
120
121	ret = usb_add_config_only(cdev, c);
122	if (ret)
123		goto out;
124
125	for (i = 0; i < n_ports; i++) {
126
127		fi_serial[i] = usb_get_function_instance(f_name);
128		if (IS_ERR(fi_serial[i])) {
129			ret = PTR_ERR(fi_serial[i]);
130			goto fail;
131		}
132
133		f_serial[i] = usb_get_function(fi_serial[i]);
134		if (IS_ERR(f_serial[i])) {
135			ret = PTR_ERR(f_serial[i]);
136			goto err_get_func;
137		}
138
139		ret = usb_add_function(c, f_serial[i]);
140		if (ret)
141			goto err_add_func;
142	}
143
144	return 0;
145
146err_add_func:
147	usb_put_function(f_serial[i]);
148err_get_func:
149	usb_put_function_instance(fi_serial[i]);
150
151fail:
152	i--;
153	while (i >= 0) {
154		usb_remove_function(c, f_serial[i]);
155		usb_put_function(f_serial[i]);
156		usb_put_function_instance(fi_serial[i]);
157		i--;
158	}
159out:
160	return ret;
161}
162
163static int gs_bind(struct usb_composite_dev *cdev)
164{
165	int			status;
166
167	/* Allocate string descriptor numbers ... note that string
168	 * contents can be overridden by the composite_dev glue.
169	 */
170
171	status = usb_string_ids_tab(cdev, strings_dev);
172	if (status < 0)
173		goto fail;
174	device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id;
175	device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id;
176	status = strings_dev[STRING_DESCRIPTION_IDX].id;
177	serial_config_driver.iConfiguration = status;
178
179	if (gadget_is_otg(cdev->gadget)) {
180		if (!otg_desc[0]) {
181			struct usb_descriptor_header *usb_desc;
182
183			usb_desc = usb_otg_descriptor_alloc(cdev->gadget);
184			if (!usb_desc) {
185				status = -ENOMEM;
186				goto fail;
187			}
188			usb_otg_descriptor_init(cdev->gadget, usb_desc);
189			otg_desc[0] = usb_desc;
190			otg_desc[1] = NULL;
191		}
192		serial_config_driver.descriptors = otg_desc;
193		serial_config_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
194	}
195
196	/* register our configuration */
197	if (use_acm) {
198		status  = serial_register_ports(cdev, &serial_config_driver,
199				"acm");
200		usb_ep_autoconfig_reset(cdev->gadget);
201	} else if (use_obex)
202		status = serial_register_ports(cdev, &serial_config_driver,
203				"obex");
204	else {
205		status = serial_register_ports(cdev, &serial_config_driver,
206				"gser");
207	}
208	if (status < 0)
209		goto fail1;
210
211	usb_composite_overwrite_options(cdev, &coverwrite);
212	INFO(cdev, "%s\n", GS_VERSION_NAME);
213
214	return 0;
215fail1:
216	kfree(otg_desc[0]);
217	otg_desc[0] = NULL;
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
231	kfree(otg_desc[0]);
232	otg_desc[0] = NULL;
233
234	return 0;
235}
236
237static struct usb_composite_driver gserial_driver = {
238	.name		= "g_serial",
239	.dev		= &device_desc,
240	.strings	= dev_strings,
241	.max_speed	= USB_SPEED_SUPER,
242	.bind		= gs_bind,
243	.unbind		= gs_unbind,
244};
245
246static int __init init(void)
247{
248	/* We *could* export two configs; that'd be much cleaner...
249	 * but neither of these product IDs was defined that way.
250	 */
251	if (use_acm) {
252		serial_config_driver.label = "CDC ACM config";
253		serial_config_driver.bConfigurationValue = 2;
254		device_desc.bDeviceClass = USB_CLASS_COMM;
255		device_desc.idProduct =
256				cpu_to_le16(GS_CDC_PRODUCT_ID);
257	} else if (use_obex) {
258		serial_config_driver.label = "CDC OBEX config";
259		serial_config_driver.bConfigurationValue = 3;
260		device_desc.bDeviceClass = USB_CLASS_COMM;
261		device_desc.idProduct =
262			cpu_to_le16(GS_CDC_OBEX_PRODUCT_ID);
263	} else {
264		serial_config_driver.label = "Generic Serial config";
265		serial_config_driver.bConfigurationValue = 1;
266		device_desc.bDeviceClass = USB_CLASS_VENDOR_SPEC;
267		device_desc.idProduct =
268				cpu_to_le16(GS_PRODUCT_ID);
269	}
270	strings_dev[STRING_DESCRIPTION_IDX].s = serial_config_driver.label;
271
272	return usb_composite_probe(&gserial_driver);
273}
274module_init(init);
275
276static void __exit cleanup(void)
277{
278	usb_composite_unregister(&gserial_driver);
279}
280module_exit(cleanup);
281