xref: /openbmc/linux/drivers/usb/gadget/legacy/serial.c (revision 4f3db074)
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 /*-------------------------------------------------------------------------*/
32 USB_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 
48 static 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 
56 static struct usb_gadget_strings stringtab_dev = {
57 	.language	= 0x0409,	/* en-us */
58 	.strings	= strings_dev,
59 };
60 
61 static struct usb_gadget_strings *dev_strings[] = {
62 	&stringtab_dev,
63 	NULL,
64 };
65 
66 static 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 
82 static 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 
92 static const struct usb_descriptor_header *otg_desc[] = {
93 	(struct usb_descriptor_header *) &otg_descriptor,
94 	NULL,
95 };
96 
97 /*-------------------------------------------------------------------------*/
98 
99 /* Module */
100 MODULE_DESCRIPTION(GS_VERSION_NAME);
101 MODULE_AUTHOR("Al Borchers");
102 MODULE_AUTHOR("David Brownell");
103 MODULE_LICENSE("GPL");
104 
105 static bool use_acm = true;
106 module_param(use_acm, bool, 0);
107 MODULE_PARM_DESC(use_acm, "Use CDC ACM, default=yes");
108 
109 static bool use_obex = false;
110 module_param(use_obex, bool, 0);
111 MODULE_PARM_DESC(use_obex, "Use CDC OBEX, default=no");
112 
113 static unsigned n_ports = 1;
114 module_param(n_ports, uint, 0);
115 MODULE_PARM_DESC(n_ports, "number of ports to create, default=1");
116 
117 /*-------------------------------------------------------------------------*/
118 
119 static 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 
126 static struct usb_function_instance *fi_serial[MAX_U_SERIAL_PORTS];
127 static struct usb_function *f_serial[MAX_U_SERIAL_PORTS];
128 
129 static 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 
160 err_add_func:
161 	usb_put_function(f_serial[i]);
162 err_get_func:
163 	usb_put_function_instance(fi_serial[i]);
164 
165 fail:
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 	}
173 out:
174 	return ret;
175 }
176 
177 static int __init 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 
218 fail:
219 	return status;
220 }
221 
222 static 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 
233 static __refdata 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 
242 static 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 }
270 module_init(init);
271 
272 static void __exit cleanup(void)
273 {
274 	usb_composite_unregister(&gserial_driver);
275 }
276 module_exit(cleanup);
277