xref: /openbmc/linux/drivers/usb/gadget/legacy/serial.c (revision 9cfc5c90)
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 /*-------------------------------------------------------------------------*/
31 USB_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 
47 static 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 
55 static struct usb_gadget_strings stringtab_dev = {
56 	.language	= 0x0409,	/* en-us */
57 	.strings	= strings_dev,
58 };
59 
60 static struct usb_gadget_strings *dev_strings[] = {
61 	&stringtab_dev,
62 	NULL,
63 };
64 
65 static 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 
81 static const struct usb_descriptor_header *otg_desc[2];
82 
83 /*-------------------------------------------------------------------------*/
84 
85 /* Module */
86 MODULE_DESCRIPTION(GS_VERSION_NAME);
87 MODULE_AUTHOR("Al Borchers");
88 MODULE_AUTHOR("David Brownell");
89 MODULE_LICENSE("GPL");
90 
91 static bool use_acm = true;
92 module_param(use_acm, bool, 0);
93 MODULE_PARM_DESC(use_acm, "Use CDC ACM, default=yes");
94 
95 static bool use_obex = false;
96 module_param(use_obex, bool, 0);
97 MODULE_PARM_DESC(use_obex, "Use CDC OBEX, default=no");
98 
99 static unsigned n_ports = 1;
100 module_param(n_ports, uint, 0);
101 MODULE_PARM_DESC(n_ports, "number of ports to create, default=1");
102 
103 /*-------------------------------------------------------------------------*/
104 
105 static 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 
112 static struct usb_function_instance *fi_serial[MAX_U_SERIAL_PORTS];
113 static struct usb_function *f_serial[MAX_U_SERIAL_PORTS];
114 
115 static 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 
146 err_add_func:
147 	usb_put_function(f_serial[i]);
148 err_get_func:
149 	usb_put_function_instance(fi_serial[i]);
150 
151 fail:
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 	}
159 out:
160 	return ret;
161 }
162 
163 static 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;
215 fail1:
216 	kfree(otg_desc[0]);
217 	otg_desc[0] = NULL;
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 
231 	kfree(otg_desc[0]);
232 	otg_desc[0] = NULL;
233 
234 	return 0;
235 }
236 
237 static 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 
246 static 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 }
274 module_init(init);
275 
276 static void __exit cleanup(void)
277 {
278 	usb_composite_unregister(&gserial_driver);
279 }
280 module_exit(cleanup);
281