xref: /openbmc/linux/drivers/usb/gadget/legacy/ncm.c (revision d7a3d85e)
1 /*
2  * ncm.c -- NCM gadget driver
3  *
4  * Copyright (C) 2010 Nokia Corporation
5  * Contact: Yauheni Kaliuta <yauheni.kaliuta@nokia.com>
6  *
7  * The driver borrows from ether.c which is:
8  *
9  * Copyright (C) 2003-2005,2008 David Brownell
10  * Copyright (C) 2003-2004 Robert Schwebel, Benedikt Spranger
11  * Copyright (C) 2008 Nokia Corporation
12  *
13  * This program is free software; you can redistribute it and/or modify
14  * it under the terms of the GNU General Public License as published by
15  * the Free Software Foundation; either version 2 of the License, or
16  * (at your option) any later version.
17  */
18 
19 /* #define DEBUG */
20 /* #define VERBOSE_DEBUG */
21 
22 #include <linux/kernel.h>
23 #include <linux/module.h>
24 #include <linux/usb/composite.h>
25 
26 #include "u_ether.h"
27 #include "u_ncm.h"
28 
29 #define DRIVER_DESC		"NCM Gadget"
30 
31 /*-------------------------------------------------------------------------*/
32 
33 /* DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
34  * Instead:  allocate your own, using normal USB-IF procedures.
35  */
36 
37 /* Thanks to NetChip Technologies for donating this product ID.
38  * It's for devices with only CDC Ethernet configurations.
39  */
40 #define CDC_VENDOR_NUM		0x0525	/* NetChip */
41 #define CDC_PRODUCT_NUM		0xa4a1	/* Linux-USB Ethernet Gadget */
42 
43 /*-------------------------------------------------------------------------*/
44 USB_GADGET_COMPOSITE_OPTIONS();
45 
46 USB_ETHERNET_MODULE_PARAMETERS();
47 
48 static struct usb_device_descriptor device_desc = {
49 	.bLength =		sizeof device_desc,
50 	.bDescriptorType =	USB_DT_DEVICE,
51 
52 	.bcdUSB =		cpu_to_le16 (0x0200),
53 
54 	.bDeviceClass =		USB_CLASS_COMM,
55 	.bDeviceSubClass =	0,
56 	.bDeviceProtocol =	0,
57 	/* .bMaxPacketSize0 = f(hardware) */
58 
59 	/* Vendor and product id defaults change according to what configs
60 	 * we support.  (As does bNumConfigurations.)  These values can
61 	 * also be overridden by module parameters.
62 	 */
63 	.idVendor =		cpu_to_le16 (CDC_VENDOR_NUM),
64 	.idProduct =		cpu_to_le16 (CDC_PRODUCT_NUM),
65 	/* .bcdDevice = f(hardware) */
66 	/* .iManufacturer = DYNAMIC */
67 	/* .iProduct = DYNAMIC */
68 	/* NO SERIAL NUMBER */
69 	.bNumConfigurations =	1,
70 };
71 
72 static struct usb_otg_descriptor otg_descriptor = {
73 	.bLength =		sizeof otg_descriptor,
74 	.bDescriptorType =	USB_DT_OTG,
75 
76 	/* REVISIT SRP-only hardware is possible, although
77 	 * it would not be called "OTG" ...
78 	 */
79 	.bmAttributes =		USB_OTG_SRP | USB_OTG_HNP,
80 };
81 
82 static const struct usb_descriptor_header *otg_desc[] = {
83 	(struct usb_descriptor_header *) &otg_descriptor,
84 	NULL,
85 };
86 
87 /* string IDs are assigned dynamically */
88 static struct usb_string strings_dev[] = {
89 	[USB_GADGET_MANUFACTURER_IDX].s = "",
90 	[USB_GADGET_PRODUCT_IDX].s = DRIVER_DESC,
91 	[USB_GADGET_SERIAL_IDX].s = "",
92 	{  } /* end of list */
93 };
94 
95 static struct usb_gadget_strings stringtab_dev = {
96 	.language	= 0x0409,	/* en-us */
97 	.strings	= strings_dev,
98 };
99 
100 static struct usb_gadget_strings *dev_strings[] = {
101 	&stringtab_dev,
102 	NULL,
103 };
104 
105 static struct usb_function_instance *f_ncm_inst;
106 static struct usb_function *f_ncm;
107 
108 /*-------------------------------------------------------------------------*/
109 
110 static int ncm_do_config(struct usb_configuration *c)
111 {
112 	int status;
113 
114 	/* FIXME alloc iConfiguration string, set it in c->strings */
115 
116 	if (gadget_is_otg(c->cdev->gadget)) {
117 		c->descriptors = otg_desc;
118 		c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
119 	}
120 
121 	f_ncm = usb_get_function(f_ncm_inst);
122 	if (IS_ERR(f_ncm)) {
123 		status = PTR_ERR(f_ncm);
124 		return status;
125 	}
126 
127 	status = usb_add_function(c, f_ncm);
128 	if (status < 0) {
129 		usb_put_function(f_ncm);
130 		return status;
131 	}
132 
133 	return 0;
134 }
135 
136 static struct usb_configuration ncm_config_driver = {
137 	/* .label = f(hardware) */
138 	.label			= "CDC Ethernet (NCM)",
139 	.bConfigurationValue	= 1,
140 	/* .iConfiguration = DYNAMIC */
141 	.bmAttributes		= USB_CONFIG_ATT_SELFPOWER,
142 };
143 
144 /*-------------------------------------------------------------------------*/
145 
146 static int gncm_bind(struct usb_composite_dev *cdev)
147 {
148 	struct usb_gadget	*gadget = cdev->gadget;
149 	struct f_ncm_opts	*ncm_opts;
150 	int			status;
151 
152 	f_ncm_inst = usb_get_function_instance("ncm");
153 	if (IS_ERR(f_ncm_inst))
154 		return PTR_ERR(f_ncm_inst);
155 
156 	ncm_opts = container_of(f_ncm_inst, struct f_ncm_opts, func_inst);
157 
158 	gether_set_qmult(ncm_opts->net, qmult);
159 	if (!gether_set_host_addr(ncm_opts->net, host_addr))
160 		pr_info("using host ethernet address: %s", host_addr);
161 	if (!gether_set_dev_addr(ncm_opts->net, dev_addr))
162 		pr_info("using self ethernet address: %s", dev_addr);
163 
164 	/* Allocate string descriptor numbers ... note that string
165 	 * contents can be overridden by the composite_dev glue.
166 	 */
167 
168 	status = usb_string_ids_tab(cdev, strings_dev);
169 	if (status < 0)
170 		goto fail;
171 	device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id;
172 	device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id;
173 
174 	status = usb_add_config(cdev, &ncm_config_driver,
175 				ncm_do_config);
176 	if (status < 0)
177 		goto fail;
178 
179 	usb_composite_overwrite_options(cdev, &coverwrite);
180 	dev_info(&gadget->dev, "%s\n", DRIVER_DESC);
181 
182 	return 0;
183 
184 fail:
185 	usb_put_function_instance(f_ncm_inst);
186 	return status;
187 }
188 
189 static int gncm_unbind(struct usb_composite_dev *cdev)
190 {
191 	if (!IS_ERR_OR_NULL(f_ncm))
192 		usb_put_function(f_ncm);
193 	if (!IS_ERR_OR_NULL(f_ncm_inst))
194 		usb_put_function_instance(f_ncm_inst);
195 	return 0;
196 }
197 
198 static struct usb_composite_driver ncm_driver = {
199 	.name		= "g_ncm",
200 	.dev		= &device_desc,
201 	.strings	= dev_strings,
202 	.max_speed	= USB_SPEED_HIGH,
203 	.bind		= gncm_bind,
204 	.unbind		= gncm_unbind,
205 };
206 
207 module_usb_composite_driver(ncm_driver);
208 
209 MODULE_DESCRIPTION(DRIVER_DESC);
210 MODULE_AUTHOR("Yauheni Kaliuta");
211 MODULE_LICENSE("GPL");
212