xref: /linux/drivers/usb/atm/xusbatm.c (revision 5fd54ace4721fc5ce2bb5aef6318fcf17f421460)
1 // SPDX-License-Identifier: GPL-2.0+
2 /******************************************************************************
3  *  xusbatm.c -	dumb usbatm-based driver for modems initialized in userspace
4  *
5  *  Copyright (C) 2005 Duncan Sands, Roman Kagan (rkagan % mail ! ru)
6  *
7  *  This program is free software; you can redistribute it and/or modify it
8  *  under the terms of the GNU General Public License as published by the Free
9  *  Software Foundation; either version 2 of the License, or (at your option)
10  *  any later version.
11  *
12  *  This program is distributed in the hope that it will be useful, but WITHOUT
13  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
15  *  more details.
16  *
17  *  You should have received a copy of the GNU General Public License along with
18  *  this program; if not, write to the Free Software Foundation, Inc., 59
19  *  Temple Place - Suite 330, Boston, MA  02111-1307, USA.
20  *
21  ******************************************************************************/
22 
23 #include <linux/module.h>
24 #include <linux/etherdevice.h>		/* for eth_random_addr() */
25 
26 #include "usbatm.h"
27 
28 
29 #define XUSBATM_DRIVERS_MAX	8
30 
31 #define XUSBATM_PARM(name, type, parmtype, desc) \
32 	static type name[XUSBATM_DRIVERS_MAX]; \
33 	static unsigned int num_##name; \
34 	module_param_array(name, parmtype, &num_##name, 0444); \
35 	MODULE_PARM_DESC(name, desc)
36 
37 XUSBATM_PARM(vendor, unsigned short, ushort, "USB device vendor");
38 XUSBATM_PARM(product, unsigned short, ushort, "USB device product");
39 
40 XUSBATM_PARM(rx_endpoint, unsigned char, byte, "rx endpoint number");
41 XUSBATM_PARM(tx_endpoint, unsigned char, byte, "tx endpoint number");
42 XUSBATM_PARM(rx_padding, unsigned char, byte, "rx padding (default 0)");
43 XUSBATM_PARM(tx_padding, unsigned char, byte, "tx padding (default 0)");
44 XUSBATM_PARM(rx_altsetting, unsigned char, byte, "rx altsetting (default 0)");
45 XUSBATM_PARM(tx_altsetting, unsigned char, byte, "rx altsetting (default 0)");
46 
47 static const char xusbatm_driver_name[] = "xusbatm";
48 
49 static struct usbatm_driver xusbatm_drivers[XUSBATM_DRIVERS_MAX];
50 static struct usb_device_id xusbatm_usb_ids[XUSBATM_DRIVERS_MAX + 1];
51 static struct usb_driver xusbatm_usb_driver;
52 
53 static struct usb_interface *xusbatm_find_intf(struct usb_device *usb_dev, int altsetting, u8 ep)
54 {
55 	struct usb_host_interface *alt;
56 	struct usb_interface *intf;
57 	int i, j;
58 
59 	for (i = 0; i < usb_dev->actconfig->desc.bNumInterfaces; i++)
60 		if ((intf = usb_dev->actconfig->interface[i]) && (alt = usb_altnum_to_altsetting(intf, altsetting)))
61 			for (j = 0; j < alt->desc.bNumEndpoints; j++)
62 				if (alt->endpoint[j].desc.bEndpointAddress == ep)
63 					return intf;
64 	return NULL;
65 }
66 
67 static int xusbatm_capture_intf(struct usbatm_data *usbatm, struct usb_device *usb_dev,
68 		struct usb_interface *intf, int altsetting, int claim)
69 {
70 	int ifnum = intf->altsetting->desc.bInterfaceNumber;
71 	int ret;
72 
73 	if (claim && (ret = usb_driver_claim_interface(&xusbatm_usb_driver, intf, usbatm))) {
74 		usb_err(usbatm, "%s: failed to claim interface %2d (%d)!\n", __func__, ifnum, ret);
75 		return ret;
76 	}
77 	ret = usb_set_interface(usb_dev, ifnum, altsetting);
78 	if (ret) {
79 		usb_err(usbatm, "%s: altsetting %2d for interface %2d failed (%d)!\n", __func__, altsetting, ifnum, ret);
80 		return ret;
81 	}
82 	return 0;
83 }
84 
85 static void xusbatm_release_intf(struct usb_device *usb_dev, struct usb_interface *intf, int claimed)
86 {
87 	if (claimed) {
88 		usb_set_intfdata(intf, NULL);
89 		usb_driver_release_interface(&xusbatm_usb_driver, intf);
90 	}
91 }
92 
93 static int xusbatm_bind(struct usbatm_data *usbatm,
94 			struct usb_interface *intf, const struct usb_device_id *id)
95 {
96 	struct usb_device *usb_dev = interface_to_usbdev(intf);
97 	int drv_ix = id - xusbatm_usb_ids;
98 	int rx_alt = rx_altsetting[drv_ix];
99 	int tx_alt = tx_altsetting[drv_ix];
100 	struct usb_interface *rx_intf = xusbatm_find_intf(usb_dev, rx_alt, rx_endpoint[drv_ix]);
101 	struct usb_interface *tx_intf = xusbatm_find_intf(usb_dev, tx_alt, tx_endpoint[drv_ix]);
102 	int ret;
103 
104 	usb_dbg(usbatm, "%s: binding driver %d: vendor %04x product %04x"
105 		" rx: ep %02x padd %d alt %2d tx: ep %02x padd %d alt %2d\n",
106 		__func__, drv_ix, vendor[drv_ix], product[drv_ix],
107 		rx_endpoint[drv_ix], rx_padding[drv_ix], rx_alt,
108 		tx_endpoint[drv_ix], tx_padding[drv_ix], tx_alt);
109 
110 	if (!rx_intf || !tx_intf) {
111 		if (!rx_intf)
112 			usb_dbg(usbatm, "%s: no interface contains endpoint %02x in altsetting %2d\n",
113 				__func__, rx_endpoint[drv_ix], rx_alt);
114 		if (!tx_intf)
115 			usb_dbg(usbatm, "%s: no interface contains endpoint %02x in altsetting %2d\n",
116 				__func__, tx_endpoint[drv_ix], tx_alt);
117 		return -ENODEV;
118 	}
119 
120 	if ((rx_intf != intf) && (tx_intf != intf))
121 		return -ENODEV;
122 
123 	if ((rx_intf == tx_intf) && (rx_alt != tx_alt)) {
124 		usb_err(usbatm, "%s: altsettings clash on interface %2d (%2d vs %2d)!\n", __func__,
125 				rx_intf->altsetting->desc.bInterfaceNumber, rx_alt, tx_alt);
126 		return -EINVAL;
127 	}
128 
129 	usb_dbg(usbatm, "%s: rx If#=%2d; tx If#=%2d\n", __func__,
130 			rx_intf->altsetting->desc.bInterfaceNumber,
131 			tx_intf->altsetting->desc.bInterfaceNumber);
132 
133 	ret = xusbatm_capture_intf(usbatm, usb_dev, rx_intf, rx_alt, rx_intf != intf);
134 	if (ret)
135 		return ret;
136 
137 	if ((tx_intf != rx_intf) && (ret = xusbatm_capture_intf(usbatm, usb_dev, tx_intf, tx_alt, tx_intf != intf))) {
138 		xusbatm_release_intf(usb_dev, rx_intf, rx_intf != intf);
139 		return ret;
140 	}
141 
142 	return 0;
143 }
144 
145 static void xusbatm_unbind(struct usbatm_data *usbatm,
146 			   struct usb_interface *intf)
147 {
148 	struct usb_device *usb_dev = interface_to_usbdev(intf);
149 	int i;
150 
151 	usb_dbg(usbatm, "%s entered\n", __func__);
152 
153 	for (i = 0; i < usb_dev->actconfig->desc.bNumInterfaces; i++) {
154 		struct usb_interface *cur_intf = usb_dev->actconfig->interface[i];
155 
156 		if (cur_intf && (usb_get_intfdata(cur_intf) == usbatm)) {
157 			usb_set_intfdata(cur_intf, NULL);
158 			usb_driver_release_interface(&xusbatm_usb_driver, cur_intf);
159 		}
160 	}
161 }
162 
163 static int xusbatm_atm_start(struct usbatm_data *usbatm,
164 			     struct atm_dev *atm_dev)
165 {
166 	atm_dbg(usbatm, "%s entered\n", __func__);
167 
168 	/* use random MAC as we've no way to get it from the device */
169 	eth_random_addr(atm_dev->esi);
170 
171 	return 0;
172 }
173 
174 
175 static int xusbatm_usb_probe(struct usb_interface *intf,
176 			     const struct usb_device_id *id)
177 {
178 	return usbatm_usb_probe(intf, id,
179 				xusbatm_drivers + (id - xusbatm_usb_ids));
180 }
181 
182 static struct usb_driver xusbatm_usb_driver = {
183 	.name		= xusbatm_driver_name,
184 	.probe		= xusbatm_usb_probe,
185 	.disconnect	= usbatm_usb_disconnect,
186 	.id_table	= xusbatm_usb_ids
187 };
188 
189 static int __init xusbatm_init(void)
190 {
191 	int i;
192 
193 	if (!num_vendor ||
194 	    num_vendor != num_product ||
195 	    num_vendor != num_rx_endpoint ||
196 	    num_vendor != num_tx_endpoint) {
197 		printk(KERN_WARNING "xusbatm: malformed module parameters\n");
198 		return -EINVAL;
199 	}
200 
201 	for (i = 0; i < num_vendor; i++) {
202 		rx_endpoint[i] |= USB_DIR_IN;
203 		tx_endpoint[i] &= USB_ENDPOINT_NUMBER_MASK;
204 
205 		xusbatm_usb_ids[i].match_flags	= USB_DEVICE_ID_MATCH_DEVICE;
206 		xusbatm_usb_ids[i].idVendor	= vendor[i];
207 		xusbatm_usb_ids[i].idProduct	= product[i];
208 
209 		xusbatm_drivers[i].driver_name	= xusbatm_driver_name;
210 		xusbatm_drivers[i].bind		= xusbatm_bind;
211 		xusbatm_drivers[i].unbind	= xusbatm_unbind;
212 		xusbatm_drivers[i].atm_start	= xusbatm_atm_start;
213 		xusbatm_drivers[i].bulk_in	= rx_endpoint[i];
214 		xusbatm_drivers[i].bulk_out	= tx_endpoint[i];
215 		xusbatm_drivers[i].rx_padding	= rx_padding[i];
216 		xusbatm_drivers[i].tx_padding	= tx_padding[i];
217 	}
218 
219 	return usb_register(&xusbatm_usb_driver);
220 }
221 module_init(xusbatm_init);
222 
223 static void __exit xusbatm_exit(void)
224 {
225 	usb_deregister(&xusbatm_usb_driver);
226 }
227 module_exit(xusbatm_exit);
228 
229 MODULE_AUTHOR("Roman Kagan, Duncan Sands");
230 MODULE_DESCRIPTION("Driver for USB ADSL modems initialized in userspace");
231 MODULE_LICENSE("GPL");
232