1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * cdc2.c -- CDC Composite driver, with ECM and ACM support
4  *
5  * Copyright (C) 2008 David Brownell
6  * Copyright (C) 2008 Nokia Corporation
7  */
8 
9 #include <linux/kernel.h>
10 #include <linux/module.h>
11 
12 #include "u_ether.h"
13 #include "u_serial.h"
14 #include "u_ecm.h"
15 
16 
17 #define DRIVER_DESC		"CDC Composite Gadget"
18 #define DRIVER_VERSION		"King Kamehameha Day 2008"
19 
20 /*-------------------------------------------------------------------------*/
21 
22 /* DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
23  * Instead:  allocate your own, using normal USB-IF procedures.
24  */
25 
26 /* Thanks to NetChip Technologies for donating this product ID.
27  * It's for devices with only this composite CDC configuration.
28  */
29 #define CDC_VENDOR_NUM		0x0525	/* NetChip */
30 #define CDC_PRODUCT_NUM		0xa4aa	/* CDC Composite: ECM + ACM */
31 
32 USB_GADGET_COMPOSITE_OPTIONS();
33 
34 USB_ETHERNET_MODULE_PARAMETERS();
35 
36 /*-------------------------------------------------------------------------*/
37 
38 static struct usb_device_descriptor device_desc = {
39 	.bLength =		sizeof device_desc,
40 	.bDescriptorType =	USB_DT_DEVICE,
41 
42 	/* .bcdUSB = DYNAMIC */
43 
44 	.bDeviceClass =		USB_CLASS_COMM,
45 	.bDeviceSubClass =	0,
46 	.bDeviceProtocol =	0,
47 	/* .bMaxPacketSize0 = f(hardware) */
48 
49 	/* Vendor and product id can be overridden by module parameters.  */
50 	.idVendor =		cpu_to_le16(CDC_VENDOR_NUM),
51 	.idProduct =		cpu_to_le16(CDC_PRODUCT_NUM),
52 	/* .bcdDevice = f(hardware) */
53 	/* .iManufacturer = DYNAMIC */
54 	/* .iProduct = DYNAMIC */
55 	/* NO SERIAL NUMBER */
56 	.bNumConfigurations =	1,
57 };
58 
59 static const struct usb_descriptor_header *otg_desc[2];
60 
61 /* string IDs are assigned dynamically */
62 static struct usb_string strings_dev[] = {
63 	[USB_GADGET_MANUFACTURER_IDX].s = "",
64 	[USB_GADGET_PRODUCT_IDX].s = DRIVER_DESC,
65 	[USB_GADGET_SERIAL_IDX].s = "",
66 	{  } /* end of list */
67 };
68 
69 static struct usb_gadget_strings stringtab_dev = {
70 	.language	= 0x0409,	/* en-us */
71 	.strings	= strings_dev,
72 };
73 
74 static struct usb_gadget_strings *dev_strings[] = {
75 	&stringtab_dev,
76 	NULL,
77 };
78 
79 /*-------------------------------------------------------------------------*/
80 static struct usb_function *f_acm;
81 static struct usb_function_instance *fi_serial;
82 
83 static struct usb_function *f_ecm;
84 static struct usb_function_instance *fi_ecm;
85 
86 /*
87  * We _always_ have both CDC ECM and CDC ACM functions.
88  */
cdc_do_config(struct usb_configuration * c)89 static int cdc_do_config(struct usb_configuration *c)
90 {
91 	int	status;
92 
93 	if (gadget_is_otg(c->cdev->gadget)) {
94 		c->descriptors = otg_desc;
95 		c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
96 	}
97 
98 	f_ecm = usb_get_function(fi_ecm);
99 	if (IS_ERR(f_ecm)) {
100 		status = PTR_ERR(f_ecm);
101 		goto err_get_ecm;
102 	}
103 
104 	status = usb_add_function(c, f_ecm);
105 	if (status)
106 		goto err_add_ecm;
107 
108 	f_acm = usb_get_function(fi_serial);
109 	if (IS_ERR(f_acm)) {
110 		status = PTR_ERR(f_acm);
111 		goto err_get_acm;
112 	}
113 
114 	status = usb_add_function(c, f_acm);
115 	if (status)
116 		goto err_add_acm;
117 	return 0;
118 
119 err_add_acm:
120 	usb_put_function(f_acm);
121 err_get_acm:
122 	usb_remove_function(c, f_ecm);
123 err_add_ecm:
124 	usb_put_function(f_ecm);
125 err_get_ecm:
126 	return status;
127 }
128 
129 static struct usb_configuration cdc_config_driver = {
130 	.label			= "CDC Composite (ECM + ACM)",
131 	.bConfigurationValue	= 1,
132 	/* .iConfiguration = DYNAMIC */
133 	.bmAttributes		= USB_CONFIG_ATT_SELFPOWER,
134 };
135 
136 /*-------------------------------------------------------------------------*/
137 
cdc_bind(struct usb_composite_dev * cdev)138 static int cdc_bind(struct usb_composite_dev *cdev)
139 {
140 	struct usb_gadget	*gadget = cdev->gadget;
141 	struct f_ecm_opts	*ecm_opts;
142 	int			status;
143 
144 	if (!can_support_ecm(cdev->gadget)) {
145 		dev_err(&gadget->dev, "controller '%s' not usable\n",
146 				gadget->name);
147 		return -EINVAL;
148 	}
149 
150 	fi_ecm = usb_get_function_instance("ecm");
151 	if (IS_ERR(fi_ecm))
152 		return PTR_ERR(fi_ecm);
153 
154 	ecm_opts = container_of(fi_ecm, struct f_ecm_opts, func_inst);
155 
156 	gether_set_qmult(ecm_opts->net, qmult);
157 	if (!gether_set_host_addr(ecm_opts->net, host_addr))
158 		pr_info("using host ethernet address: %s", host_addr);
159 	if (!gether_set_dev_addr(ecm_opts->net, dev_addr))
160 		pr_info("using self ethernet address: %s", dev_addr);
161 
162 	fi_serial = usb_get_function_instance("acm");
163 	if (IS_ERR(fi_serial)) {
164 		status = PTR_ERR(fi_serial);
165 		goto fail;
166 	}
167 
168 	/* Allocate string descriptor numbers ... note that string
169 	 * contents can be overridden by the composite_dev glue.
170 	 */
171 
172 	status = usb_string_ids_tab(cdev, strings_dev);
173 	if (status < 0)
174 		goto fail1;
175 	device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id;
176 	device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id;
177 
178 	if (gadget_is_otg(gadget) && !otg_desc[0]) {
179 		struct usb_descriptor_header *usb_desc;
180 
181 		usb_desc = usb_otg_descriptor_alloc(gadget);
182 		if (!usb_desc) {
183 			status = -ENOMEM;
184 			goto fail1;
185 		}
186 		usb_otg_descriptor_init(gadget, usb_desc);
187 		otg_desc[0] = usb_desc;
188 		otg_desc[1] = NULL;
189 	}
190 
191 	/* register our configuration */
192 	status = usb_add_config(cdev, &cdc_config_driver, cdc_do_config);
193 	if (status < 0)
194 		goto fail2;
195 
196 	usb_composite_overwrite_options(cdev, &coverwrite);
197 	dev_info(&gadget->dev, "%s, version: " DRIVER_VERSION "\n",
198 			DRIVER_DESC);
199 
200 	return 0;
201 
202 fail2:
203 	kfree(otg_desc[0]);
204 	otg_desc[0] = NULL;
205 fail1:
206 	usb_put_function_instance(fi_serial);
207 fail:
208 	usb_put_function_instance(fi_ecm);
209 	return status;
210 }
211 
cdc_unbind(struct usb_composite_dev * cdev)212 static int cdc_unbind(struct usb_composite_dev *cdev)
213 {
214 	usb_put_function(f_acm);
215 	usb_put_function_instance(fi_serial);
216 	if (!IS_ERR_OR_NULL(f_ecm))
217 		usb_put_function(f_ecm);
218 	if (!IS_ERR_OR_NULL(fi_ecm))
219 		usb_put_function_instance(fi_ecm);
220 	kfree(otg_desc[0]);
221 	otg_desc[0] = NULL;
222 
223 	return 0;
224 }
225 
226 static struct usb_composite_driver cdc_driver = {
227 	.name		= "g_cdc",
228 	.dev		= &device_desc,
229 	.strings	= dev_strings,
230 	.max_speed	= USB_SPEED_SUPER,
231 	.bind		= cdc_bind,
232 	.unbind		= cdc_unbind,
233 };
234 
235 module_usb_composite_driver(cdc_driver);
236 
237 MODULE_DESCRIPTION(DRIVER_DESC);
238 MODULE_AUTHOR("David Brownell");
239 MODULE_LICENSE("GPL");
240