xref: /openbmc/linux/drivers/usb/gadget/legacy/ncm.c (revision e27d4b30)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * ncm.c -- NCM gadget driver
4  *
5  * Copyright (C) 2010 Nokia Corporation
6  * Contact: Yauheni Kaliuta <yauheni.kaliuta@nokia.com>
7  *
8  * The driver borrows from ether.c which is:
9  *
10  * Copyright (C) 2003-2005,2008 David Brownell
11  * Copyright (C) 2003-2004 Robert Schwebel, Benedikt Spranger
12  * Copyright (C) 2008 Nokia Corporation
13  */
14 
15 /* #define DEBUG */
16 /* #define VERBOSE_DEBUG */
17 
18 #include <linux/kernel.h>
19 #include <linux/module.h>
20 #include <linux/usb/composite.h>
21 
22 #include "u_ether.h"
23 #include "u_ncm.h"
24 
25 #define DRIVER_DESC		"NCM Gadget"
26 
27 /*-------------------------------------------------------------------------*/
28 
29 /* DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
30  * Instead:  allocate your own, using normal USB-IF procedures.
31  */
32 
33 /* Thanks to NetChip Technologies for donating this product ID.
34  * It's for devices with only CDC Ethernet configurations.
35  */
36 #define CDC_VENDOR_NUM		0x0525	/* NetChip */
37 #define CDC_PRODUCT_NUM		0xa4a1	/* Linux-USB Ethernet Gadget */
38 
39 /*-------------------------------------------------------------------------*/
40 USB_GADGET_COMPOSITE_OPTIONS();
41 
42 USB_ETHERNET_MODULE_PARAMETERS();
43 
44 static struct usb_device_descriptor device_desc = {
45 	.bLength =		sizeof device_desc,
46 	.bDescriptorType =	USB_DT_DEVICE,
47 
48 	/* .bcdUSB = DYNAMIC */
49 
50 	.bDeviceClass =		USB_CLASS_COMM,
51 	.bDeviceSubClass =	0,
52 	.bDeviceProtocol =	0,
53 	/* .bMaxPacketSize0 = f(hardware) */
54 
55 	/* Vendor and product id defaults change according to what configs
56 	 * we support.  (As does bNumConfigurations.)  These values can
57 	 * also be overridden by module parameters.
58 	 */
59 	.idVendor =		cpu_to_le16 (CDC_VENDOR_NUM),
60 	.idProduct =		cpu_to_le16 (CDC_PRODUCT_NUM),
61 	/* .bcdDevice = f(hardware) */
62 	/* .iManufacturer = DYNAMIC */
63 	/* .iProduct = DYNAMIC */
64 	/* NO SERIAL NUMBER */
65 	.bNumConfigurations =	1,
66 };
67 
68 static const struct usb_descriptor_header *otg_desc[2];
69 
70 /* string IDs are assigned dynamically */
71 static struct usb_string strings_dev[] = {
72 	[USB_GADGET_MANUFACTURER_IDX].s = "",
73 	[USB_GADGET_PRODUCT_IDX].s = DRIVER_DESC,
74 	[USB_GADGET_SERIAL_IDX].s = "",
75 	{  } /* end of list */
76 };
77 
78 static struct usb_gadget_strings stringtab_dev = {
79 	.language	= 0x0409,	/* en-us */
80 	.strings	= strings_dev,
81 };
82 
83 static struct usb_gadget_strings *dev_strings[] = {
84 	&stringtab_dev,
85 	NULL,
86 };
87 
88 static struct usb_function_instance *f_ncm_inst;
89 static struct usb_function *f_ncm;
90 
91 /*-------------------------------------------------------------------------*/
92 
ncm_do_config(struct usb_configuration * c)93 static int ncm_do_config(struct usb_configuration *c)
94 {
95 	int status;
96 
97 	/* FIXME alloc iConfiguration string, set it in c->strings */
98 
99 	if (gadget_is_otg(c->cdev->gadget)) {
100 		c->descriptors = otg_desc;
101 		c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
102 	}
103 
104 	f_ncm = usb_get_function(f_ncm_inst);
105 	if (IS_ERR(f_ncm))
106 		return PTR_ERR(f_ncm);
107 
108 	status = usb_add_function(c, f_ncm);
109 	if (status < 0) {
110 		usb_put_function(f_ncm);
111 		return status;
112 	}
113 
114 	return 0;
115 }
116 
117 static struct usb_configuration ncm_config_driver = {
118 	/* .label = f(hardware) */
119 	.label			= "CDC Ethernet (NCM)",
120 	.bConfigurationValue	= 1,
121 	/* .iConfiguration = DYNAMIC */
122 	.bmAttributes		= USB_CONFIG_ATT_SELFPOWER,
123 };
124 
125 /*-------------------------------------------------------------------------*/
126 
gncm_bind(struct usb_composite_dev * cdev)127 static int gncm_bind(struct usb_composite_dev *cdev)
128 {
129 	struct usb_gadget	*gadget = cdev->gadget;
130 	struct f_ncm_opts	*ncm_opts;
131 	int			status;
132 
133 	f_ncm_inst = usb_get_function_instance("ncm");
134 	if (IS_ERR(f_ncm_inst))
135 		return PTR_ERR(f_ncm_inst);
136 
137 	ncm_opts = container_of(f_ncm_inst, struct f_ncm_opts, func_inst);
138 
139 	gether_set_qmult(ncm_opts->net, qmult);
140 	if (!gether_set_host_addr(ncm_opts->net, host_addr))
141 		pr_info("using host ethernet address: %s", host_addr);
142 	if (!gether_set_dev_addr(ncm_opts->net, dev_addr))
143 		pr_info("using self ethernet address: %s", dev_addr);
144 
145 	/* Allocate string descriptor numbers ... note that string
146 	 * contents can be overridden by the composite_dev glue.
147 	 */
148 
149 	status = usb_string_ids_tab(cdev, strings_dev);
150 	if (status < 0)
151 		goto fail;
152 	device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id;
153 	device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id;
154 
155 	if (gadget_is_otg(gadget) && !otg_desc[0]) {
156 		struct usb_descriptor_header *usb_desc;
157 
158 		usb_desc = usb_otg_descriptor_alloc(gadget);
159 		if (!usb_desc) {
160 			status = -ENOMEM;
161 			goto fail;
162 		}
163 		usb_otg_descriptor_init(gadget, usb_desc);
164 		otg_desc[0] = usb_desc;
165 		otg_desc[1] = NULL;
166 	}
167 
168 	status = usb_add_config(cdev, &ncm_config_driver,
169 				ncm_do_config);
170 	if (status < 0)
171 		goto fail1;
172 
173 	usb_composite_overwrite_options(cdev, &coverwrite);
174 	dev_info(&gadget->dev, "%s\n", DRIVER_DESC);
175 
176 	return 0;
177 
178 fail1:
179 	kfree(otg_desc[0]);
180 	otg_desc[0] = NULL;
181 fail:
182 	usb_put_function_instance(f_ncm_inst);
183 	return status;
184 }
185 
gncm_unbind(struct usb_composite_dev * cdev)186 static int gncm_unbind(struct usb_composite_dev *cdev)
187 {
188 	if (!IS_ERR_OR_NULL(f_ncm))
189 		usb_put_function(f_ncm);
190 	if (!IS_ERR_OR_NULL(f_ncm_inst))
191 		usb_put_function_instance(f_ncm_inst);
192 	kfree(otg_desc[0]);
193 	otg_desc[0] = NULL;
194 
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_SUPER,
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