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/utsname.h>
15 #include <linux/device.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 /*-------------------------------------------------------------------------*/
32 
33 /*
34  * Kbuild is not very cooperative with respect to linking separately
35  * compiled library objects into one module.  So for now we won't use
36  * separate compilation ... ensuring init/exit sections work to shrink
37  * the runtime footprint, and giving us at least some parts of what
38  * a "gcc --combine ... part1.c part2.c part3.c ... " build would.
39  */
40 #include "composite.c"
41 #include "usbstring.c"
42 #include "config.c"
43 #include "epautoconf.c"
44 
45 #include "f_acm.c"
46 #include "f_obex.c"
47 #include "f_serial.c"
48 #include "u_serial.c"
49 
50 /*-------------------------------------------------------------------------*/
51 
52 /* Thanks to NetChip Technologies for donating this product ID.
53 *
54 * DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
55 * Instead:  allocate your own, using normal USB-IF procedures.
56 */
57 #define GS_VENDOR_ID			0x0525	/* NetChip */
58 #define GS_PRODUCT_ID			0xa4a6	/* Linux-USB Serial Gadget */
59 #define GS_CDC_PRODUCT_ID		0xa4a7	/* ... as CDC-ACM */
60 #define GS_CDC_OBEX_PRODUCT_ID		0xa4a9	/* ... as CDC-OBEX */
61 
62 /* string IDs are assigned dynamically */
63 
64 #define STRING_MANUFACTURER_IDX		0
65 #define STRING_PRODUCT_IDX		1
66 #define STRING_DESCRIPTION_IDX		2
67 
68 static char manufacturer[50];
69 
70 static struct usb_string strings_dev[] = {
71 	[STRING_MANUFACTURER_IDX].s = manufacturer,
72 	[STRING_PRODUCT_IDX].s = GS_VERSION_NAME,
73 	[STRING_DESCRIPTION_IDX].s = NULL /* updated; f(use_acm) */,
74 	{  } /* end of list */
75 };
76 
77 static struct usb_gadget_strings stringtab_dev = {
78 	.language	= 0x0409,	/* en-us */
79 	.strings	= strings_dev,
80 };
81 
82 static struct usb_gadget_strings *dev_strings[] = {
83 	&stringtab_dev,
84 	NULL,
85 };
86 
87 static struct usb_device_descriptor device_desc = {
88 	.bLength =		USB_DT_DEVICE_SIZE,
89 	.bDescriptorType =	USB_DT_DEVICE,
90 	.bcdUSB =		cpu_to_le16(0x0200),
91 	/* .bDeviceClass = f(use_acm) */
92 	.bDeviceSubClass =	0,
93 	.bDeviceProtocol =	0,
94 	/* .bMaxPacketSize0 = f(hardware) */
95 	.idVendor =		cpu_to_le16(GS_VENDOR_ID),
96 	/* .idProduct =	f(use_acm) */
97 	/* .bcdDevice = f(hardware) */
98 	/* .iManufacturer = DYNAMIC */
99 	/* .iProduct = DYNAMIC */
100 	.bNumConfigurations =	1,
101 };
102 
103 static struct usb_otg_descriptor otg_descriptor = {
104 	.bLength =		sizeof otg_descriptor,
105 	.bDescriptorType =	USB_DT_OTG,
106 
107 	/* REVISIT SRP-only hardware is possible, although
108 	 * it would not be called "OTG" ...
109 	 */
110 	.bmAttributes =		USB_OTG_SRP | USB_OTG_HNP,
111 };
112 
113 static const struct usb_descriptor_header *otg_desc[] = {
114 	(struct usb_descriptor_header *) &otg_descriptor,
115 	NULL,
116 };
117 
118 /*-------------------------------------------------------------------------*/
119 
120 /* Module */
121 MODULE_DESCRIPTION(GS_VERSION_NAME);
122 MODULE_AUTHOR("Al Borchers");
123 MODULE_AUTHOR("David Brownell");
124 MODULE_LICENSE("GPL");
125 
126 static int use_acm = true;
127 module_param(use_acm, bool, 0);
128 MODULE_PARM_DESC(use_acm, "Use CDC ACM, default=yes");
129 
130 static int use_obex = false;
131 module_param(use_obex, bool, 0);
132 MODULE_PARM_DESC(use_obex, "Use CDC OBEX, default=no");
133 
134 static unsigned n_ports = 1;
135 module_param(n_ports, uint, 0);
136 MODULE_PARM_DESC(n_ports, "number of ports to create, default=1");
137 
138 /*-------------------------------------------------------------------------*/
139 
serial_bind_config(struct usb_configuration * c)140 static int __init serial_bind_config(struct usb_configuration *c)
141 {
142 	unsigned i;
143 	int status = 0;
144 
145 	for (i = 0; i < n_ports && status == 0; i++) {
146 		if (use_acm)
147 			status = acm_bind_config(c, i);
148 		else if (use_obex)
149 			status = obex_bind_config(c, i);
150 		else
151 			status = gser_bind_config(c, i);
152 	}
153 	return status;
154 }
155 
156 static struct usb_configuration serial_config_driver = {
157 	/* .label = f(use_acm) */
158 	/* .bConfigurationValue = f(use_acm) */
159 	/* .iConfiguration = DYNAMIC */
160 	.bmAttributes	= USB_CONFIG_ATT_SELFPOWER,
161 };
162 
gs_bind(struct usb_composite_dev * cdev)163 static int __init gs_bind(struct usb_composite_dev *cdev)
164 {
165 	int			gcnum;
166 	struct usb_gadget	*gadget = cdev->gadget;
167 	int			status;
168 
169 	status = gserial_setup(cdev->gadget, n_ports);
170 	if (status < 0)
171 		return status;
172 
173 	/* Allocate string descriptor numbers ... note that string
174 	 * contents can be overridden by the composite_dev glue.
175 	 */
176 
177 	/* device description: manufacturer, product */
178 	snprintf(manufacturer, sizeof manufacturer, "%s %s with %s",
179 		init_utsname()->sysname, init_utsname()->release,
180 		gadget->name);
181 	status = usb_string_id(cdev);
182 	if (status < 0)
183 		goto fail;
184 	strings_dev[STRING_MANUFACTURER_IDX].id = status;
185 
186 	device_desc.iManufacturer = status;
187 
188 	status = usb_string_id(cdev);
189 	if (status < 0)
190 		goto fail;
191 	strings_dev[STRING_PRODUCT_IDX].id = status;
192 
193 	device_desc.iProduct = status;
194 
195 	/* config description */
196 	status = usb_string_id(cdev);
197 	if (status < 0)
198 		goto fail;
199 	strings_dev[STRING_DESCRIPTION_IDX].id = status;
200 
201 	serial_config_driver.iConfiguration = status;
202 
203 	/* set up other descriptors */
204 	gcnum = usb_gadget_controller_number(gadget);
205 	if (gcnum >= 0)
206 		device_desc.bcdDevice = cpu_to_le16(GS_VERSION_NUM | gcnum);
207 	else {
208 		/* this is so simple (for now, no altsettings) that it
209 		 * SHOULD NOT have problems with bulk-capable hardware.
210 		 * so warn about unrcognized controllers -- don't panic.
211 		 *
212 		 * things like configuration and altsetting numbering
213 		 * can need hardware-specific attention though.
214 		 */
215 		pr_warning("gs_bind: controller '%s' not recognized\n",
216 			gadget->name);
217 		device_desc.bcdDevice =
218 			cpu_to_le16(GS_VERSION_NUM | 0x0099);
219 	}
220 
221 	if (gadget_is_otg(cdev->gadget)) {
222 		serial_config_driver.descriptors = otg_desc;
223 		serial_config_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP;
224 	}
225 
226 	/* register our configuration */
227 	status = usb_add_config(cdev, &serial_config_driver,
228 			serial_bind_config);
229 	if (status < 0)
230 		goto fail;
231 
232 	INFO(cdev, "%s\n", GS_VERSION_NAME);
233 
234 	return 0;
235 
236 fail:
237 	gserial_cleanup();
238 	return status;
239 }
240 
241 static struct usb_composite_driver gserial_driver = {
242 	.name		= "g_serial",
243 	.dev		= &device_desc,
244 	.strings	= dev_strings,
245 };
246 
init(void)247 static int __init init(void)
248 {
249 	/* We *could* export two configs; that'd be much cleaner...
250 	 * but neither of these product IDs was defined that way.
251 	 */
252 	if (use_acm) {
253 		serial_config_driver.label = "CDC ACM config";
254 		serial_config_driver.bConfigurationValue = 2;
255 		device_desc.bDeviceClass = USB_CLASS_COMM;
256 		device_desc.idProduct =
257 				cpu_to_le16(GS_CDC_PRODUCT_ID);
258 	} else if (use_obex) {
259 		serial_config_driver.label = "CDC OBEX config";
260 		serial_config_driver.bConfigurationValue = 3;
261 		device_desc.bDeviceClass = USB_CLASS_COMM;
262 		device_desc.idProduct =
263 			cpu_to_le16(GS_CDC_OBEX_PRODUCT_ID);
264 	} else {
265 		serial_config_driver.label = "Generic Serial config";
266 		serial_config_driver.bConfigurationValue = 1;
267 		device_desc.bDeviceClass = USB_CLASS_VENDOR_SPEC;
268 		device_desc.idProduct =
269 				cpu_to_le16(GS_PRODUCT_ID);
270 	}
271 	strings_dev[STRING_DESCRIPTION_IDX].s = serial_config_driver.label;
272 
273 	return usb_composite_probe(&gserial_driver, gs_bind);
274 }
275 module_init(init);
276 
cleanup(void)277 static void __exit cleanup(void)
278 {
279 	usb_composite_unregister(&gserial_driver);
280 	gserial_cleanup();
281 }
282 module_exit(cleanup);
283