xref: /openbmc/linux/drivers/usb/gadget/legacy/ncm.c (revision bc5aa3a0)
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 = DYNAMIC */
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 const struct usb_descriptor_header *otg_desc[2];
73 
74 /* string IDs are assigned dynamically */
75 static struct usb_string strings_dev[] = {
76 	[USB_GADGET_MANUFACTURER_IDX].s = "",
77 	[USB_GADGET_PRODUCT_IDX].s = DRIVER_DESC,
78 	[USB_GADGET_SERIAL_IDX].s = "",
79 	{  } /* end of list */
80 };
81 
82 static struct usb_gadget_strings stringtab_dev = {
83 	.language	= 0x0409,	/* en-us */
84 	.strings	= strings_dev,
85 };
86 
87 static struct usb_gadget_strings *dev_strings[] = {
88 	&stringtab_dev,
89 	NULL,
90 };
91 
92 static struct usb_function_instance *f_ncm_inst;
93 static struct usb_function *f_ncm;
94 
95 /*-------------------------------------------------------------------------*/
96 
97 static int ncm_do_config(struct usb_configuration *c)
98 {
99 	int status;
100 
101 	/* FIXME alloc iConfiguration string, set it in c->strings */
102 
103 	if (gadget_is_otg(c->cdev->gadget)) {
104 		c->descriptors = otg_desc;
105 		c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
106 	}
107 
108 	f_ncm = usb_get_function(f_ncm_inst);
109 	if (IS_ERR(f_ncm)) {
110 		status = PTR_ERR(f_ncm);
111 		return status;
112 	}
113 
114 	status = usb_add_function(c, f_ncm);
115 	if (status < 0) {
116 		usb_put_function(f_ncm);
117 		return status;
118 	}
119 
120 	return 0;
121 }
122 
123 static struct usb_configuration ncm_config_driver = {
124 	/* .label = f(hardware) */
125 	.label			= "CDC Ethernet (NCM)",
126 	.bConfigurationValue	= 1,
127 	/* .iConfiguration = DYNAMIC */
128 	.bmAttributes		= USB_CONFIG_ATT_SELFPOWER,
129 };
130 
131 /*-------------------------------------------------------------------------*/
132 
133 static int gncm_bind(struct usb_composite_dev *cdev)
134 {
135 	struct usb_gadget	*gadget = cdev->gadget;
136 	struct f_ncm_opts	*ncm_opts;
137 	int			status;
138 
139 	f_ncm_inst = usb_get_function_instance("ncm");
140 	if (IS_ERR(f_ncm_inst))
141 		return PTR_ERR(f_ncm_inst);
142 
143 	ncm_opts = container_of(f_ncm_inst, struct f_ncm_opts, func_inst);
144 
145 	gether_set_qmult(ncm_opts->net, qmult);
146 	if (!gether_set_host_addr(ncm_opts->net, host_addr))
147 		pr_info("using host ethernet address: %s", host_addr);
148 	if (!gether_set_dev_addr(ncm_opts->net, dev_addr))
149 		pr_info("using self ethernet address: %s", dev_addr);
150 
151 	/* Allocate string descriptor numbers ... note that string
152 	 * contents can be overridden by the composite_dev glue.
153 	 */
154 
155 	status = usb_string_ids_tab(cdev, strings_dev);
156 	if (status < 0)
157 		goto fail;
158 	device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id;
159 	device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id;
160 
161 	if (gadget_is_otg(gadget) && !otg_desc[0]) {
162 		struct usb_descriptor_header *usb_desc;
163 
164 		usb_desc = usb_otg_descriptor_alloc(gadget);
165 		if (!usb_desc)
166 			goto fail;
167 		usb_otg_descriptor_init(gadget, usb_desc);
168 		otg_desc[0] = usb_desc;
169 		otg_desc[1] = NULL;
170 	}
171 
172 	status = usb_add_config(cdev, &ncm_config_driver,
173 				ncm_do_config);
174 	if (status < 0)
175 		goto fail1;
176 
177 	usb_composite_overwrite_options(cdev, &coverwrite);
178 	dev_info(&gadget->dev, "%s\n", DRIVER_DESC);
179 
180 	return 0;
181 
182 fail1:
183 	kfree(otg_desc[0]);
184 	otg_desc[0] = NULL;
185 fail:
186 	usb_put_function_instance(f_ncm_inst);
187 	return status;
188 }
189 
190 static int gncm_unbind(struct usb_composite_dev *cdev)
191 {
192 	if (!IS_ERR_OR_NULL(f_ncm))
193 		usb_put_function(f_ncm);
194 	if (!IS_ERR_OR_NULL(f_ncm_inst))
195 		usb_put_function_instance(f_ncm_inst);
196 	kfree(otg_desc[0]);
197 	otg_desc[0] = NULL;
198 
199 	return 0;
200 }
201 
202 static struct usb_composite_driver ncm_driver = {
203 	.name		= "g_ncm",
204 	.dev		= &device_desc,
205 	.strings	= dev_strings,
206 	.max_speed	= USB_SPEED_HIGH,
207 	.bind		= gncm_bind,
208 	.unbind		= gncm_unbind,
209 };
210 
211 module_usb_composite_driver(ncm_driver);
212 
213 MODULE_DESCRIPTION(DRIVER_DESC);
214 MODULE_AUTHOR("Yauheni Kaliuta");
215 MODULE_LICENSE("GPL");
216