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 
8 #include <linux/module.h>
9 #include <linux/etherdevice.h>		/* for eth_random_addr() */
10 
11 #include "usbatm.h"
12 
13 
14 #define XUSBATM_DRIVERS_MAX	8
15 
16 #define XUSBATM_PARM(name, type, parmtype, desc) \
17 	static type name[XUSBATM_DRIVERS_MAX]; \
18 	static unsigned int num_##name; \
19 	module_param_array(name, parmtype, &num_##name, 0444); \
20 	MODULE_PARM_DESC(name, desc)
21 
22 XUSBATM_PARM(vendor, unsigned short, ushort, "USB device vendor");
23 XUSBATM_PARM(product, unsigned short, ushort, "USB device product");
24 
25 XUSBATM_PARM(rx_endpoint, unsigned char, byte, "rx endpoint number");
26 XUSBATM_PARM(tx_endpoint, unsigned char, byte, "tx endpoint number");
27 XUSBATM_PARM(rx_padding, unsigned char, byte, "rx padding (default 0)");
28 XUSBATM_PARM(tx_padding, unsigned char, byte, "tx padding (default 0)");
29 XUSBATM_PARM(rx_altsetting, unsigned char, byte, "rx altsetting (default 0)");
30 XUSBATM_PARM(tx_altsetting, unsigned char, byte, "rx altsetting (default 0)");
31 
32 static const char xusbatm_driver_name[] = "xusbatm";
33 
34 static struct usbatm_driver xusbatm_drivers[XUSBATM_DRIVERS_MAX];
35 static struct usb_device_id xusbatm_usb_ids[XUSBATM_DRIVERS_MAX + 1];
36 static struct usb_driver xusbatm_usb_driver;
37 
xusbatm_find_intf(struct usb_device * usb_dev,int altsetting,u8 ep)38 static struct usb_interface *xusbatm_find_intf(struct usb_device *usb_dev, int altsetting, u8 ep)
39 {
40 	struct usb_host_interface *alt;
41 	struct usb_interface *intf;
42 	int i, j;
43 
44 	for (i = 0; i < usb_dev->actconfig->desc.bNumInterfaces; i++)
45 		if ((intf = usb_dev->actconfig->interface[i]) && (alt = usb_altnum_to_altsetting(intf, altsetting)))
46 			for (j = 0; j < alt->desc.bNumEndpoints; j++)
47 				if (alt->endpoint[j].desc.bEndpointAddress == ep)
48 					return intf;
49 	return NULL;
50 }
51 
xusbatm_capture_intf(struct usbatm_data * usbatm,struct usb_device * usb_dev,struct usb_interface * intf,int altsetting,int claim)52 static int xusbatm_capture_intf(struct usbatm_data *usbatm, struct usb_device *usb_dev,
53 		struct usb_interface *intf, int altsetting, int claim)
54 {
55 	int ifnum = intf->altsetting->desc.bInterfaceNumber;
56 	int ret;
57 
58 	if (claim && (ret = usb_driver_claim_interface(&xusbatm_usb_driver, intf, usbatm))) {
59 		usb_err(usbatm, "%s: failed to claim interface %2d (%d)!\n", __func__, ifnum, ret);
60 		return ret;
61 	}
62 	ret = usb_set_interface(usb_dev, ifnum, altsetting);
63 	if (ret) {
64 		usb_err(usbatm, "%s: altsetting %2d for interface %2d failed (%d)!\n", __func__, altsetting, ifnum, ret);
65 		return ret;
66 	}
67 	return 0;
68 }
69 
xusbatm_release_intf(struct usb_device * usb_dev,struct usb_interface * intf,int claimed)70 static void xusbatm_release_intf(struct usb_device *usb_dev, struct usb_interface *intf, int claimed)
71 {
72 	if (claimed) {
73 		usb_set_intfdata(intf, NULL);
74 		usb_driver_release_interface(&xusbatm_usb_driver, intf);
75 	}
76 }
77 
xusbatm_bind(struct usbatm_data * usbatm,struct usb_interface * intf,const struct usb_device_id * id)78 static int xusbatm_bind(struct usbatm_data *usbatm,
79 			struct usb_interface *intf, const struct usb_device_id *id)
80 {
81 	struct usb_device *usb_dev = interface_to_usbdev(intf);
82 	int drv_ix = id - xusbatm_usb_ids;
83 	int rx_alt = rx_altsetting[drv_ix];
84 	int tx_alt = tx_altsetting[drv_ix];
85 	struct usb_interface *rx_intf = xusbatm_find_intf(usb_dev, rx_alt, rx_endpoint[drv_ix]);
86 	struct usb_interface *tx_intf = xusbatm_find_intf(usb_dev, tx_alt, tx_endpoint[drv_ix]);
87 	int ret;
88 
89 	usb_dbg(usbatm, "%s: binding driver %d: vendor %04x product %04x"
90 		" rx: ep %02x padd %d alt %2d tx: ep %02x padd %d alt %2d\n",
91 		__func__, drv_ix, vendor[drv_ix], product[drv_ix],
92 		rx_endpoint[drv_ix], rx_padding[drv_ix], rx_alt,
93 		tx_endpoint[drv_ix], tx_padding[drv_ix], tx_alt);
94 
95 	if (!rx_intf || !tx_intf) {
96 		if (!rx_intf)
97 			usb_dbg(usbatm, "%s: no interface contains endpoint %02x in altsetting %2d\n",
98 				__func__, rx_endpoint[drv_ix], rx_alt);
99 		if (!tx_intf)
100 			usb_dbg(usbatm, "%s: no interface contains endpoint %02x in altsetting %2d\n",
101 				__func__, tx_endpoint[drv_ix], tx_alt);
102 		return -ENODEV;
103 	}
104 
105 	if ((rx_intf != intf) && (tx_intf != intf))
106 		return -ENODEV;
107 
108 	if ((rx_intf == tx_intf) && (rx_alt != tx_alt)) {
109 		usb_err(usbatm, "%s: altsettings clash on interface %2d (%2d vs %2d)!\n", __func__,
110 				rx_intf->altsetting->desc.bInterfaceNumber, rx_alt, tx_alt);
111 		return -EINVAL;
112 	}
113 
114 	usb_dbg(usbatm, "%s: rx If#=%2d; tx If#=%2d\n", __func__,
115 			rx_intf->altsetting->desc.bInterfaceNumber,
116 			tx_intf->altsetting->desc.bInterfaceNumber);
117 
118 	ret = xusbatm_capture_intf(usbatm, usb_dev, rx_intf, rx_alt, rx_intf != intf);
119 	if (ret)
120 		return ret;
121 
122 	if ((tx_intf != rx_intf) && (ret = xusbatm_capture_intf(usbatm, usb_dev, tx_intf, tx_alt, tx_intf != intf))) {
123 		xusbatm_release_intf(usb_dev, rx_intf, rx_intf != intf);
124 		return ret;
125 	}
126 
127 	return 0;
128 }
129 
xusbatm_unbind(struct usbatm_data * usbatm,struct usb_interface * intf)130 static void xusbatm_unbind(struct usbatm_data *usbatm,
131 			   struct usb_interface *intf)
132 {
133 	struct usb_device *usb_dev = interface_to_usbdev(intf);
134 	int i;
135 
136 	usb_dbg(usbatm, "%s entered\n", __func__);
137 
138 	for (i = 0; i < usb_dev->actconfig->desc.bNumInterfaces; i++) {
139 		struct usb_interface *cur_intf = usb_dev->actconfig->interface[i];
140 
141 		if (cur_intf && (usb_get_intfdata(cur_intf) == usbatm)) {
142 			usb_set_intfdata(cur_intf, NULL);
143 			usb_driver_release_interface(&xusbatm_usb_driver, cur_intf);
144 		}
145 	}
146 }
147 
xusbatm_atm_start(struct usbatm_data * usbatm,struct atm_dev * atm_dev)148 static int xusbatm_atm_start(struct usbatm_data *usbatm,
149 			     struct atm_dev *atm_dev)
150 {
151 	atm_dbg(usbatm, "%s entered\n", __func__);
152 
153 	/* use random MAC as we've no way to get it from the device */
154 	eth_random_addr(atm_dev->esi);
155 
156 	return 0;
157 }
158 
159 
xusbatm_usb_probe(struct usb_interface * intf,const struct usb_device_id * id)160 static int xusbatm_usb_probe(struct usb_interface *intf,
161 			     const struct usb_device_id *id)
162 {
163 	return usbatm_usb_probe(intf, id,
164 				xusbatm_drivers + (id - xusbatm_usb_ids));
165 }
166 
167 static struct usb_driver xusbatm_usb_driver = {
168 	.name		= xusbatm_driver_name,
169 	.probe		= xusbatm_usb_probe,
170 	.disconnect	= usbatm_usb_disconnect,
171 	.id_table	= xusbatm_usb_ids
172 };
173 
xusbatm_init(void)174 static int __init xusbatm_init(void)
175 {
176 	int i;
177 
178 	if (!num_vendor ||
179 	    num_vendor != num_product ||
180 	    num_vendor != num_rx_endpoint ||
181 	    num_vendor != num_tx_endpoint) {
182 		pr_warn("xusbatm: malformed module parameters\n");
183 		return -EINVAL;
184 	}
185 
186 	for (i = 0; i < num_vendor; i++) {
187 		rx_endpoint[i] |= USB_DIR_IN;
188 		tx_endpoint[i] &= USB_ENDPOINT_NUMBER_MASK;
189 
190 		xusbatm_usb_ids[i].match_flags	= USB_DEVICE_ID_MATCH_DEVICE;
191 		xusbatm_usb_ids[i].idVendor	= vendor[i];
192 		xusbatm_usb_ids[i].idProduct	= product[i];
193 
194 		xusbatm_drivers[i].driver_name	= xusbatm_driver_name;
195 		xusbatm_drivers[i].bind		= xusbatm_bind;
196 		xusbatm_drivers[i].unbind	= xusbatm_unbind;
197 		xusbatm_drivers[i].atm_start	= xusbatm_atm_start;
198 		xusbatm_drivers[i].bulk_in	= rx_endpoint[i];
199 		xusbatm_drivers[i].bulk_out	= tx_endpoint[i];
200 		xusbatm_drivers[i].rx_padding	= rx_padding[i];
201 		xusbatm_drivers[i].tx_padding	= tx_padding[i];
202 	}
203 
204 	return usb_register(&xusbatm_usb_driver);
205 }
206 module_init(xusbatm_init);
207 
xusbatm_exit(void)208 static void __exit xusbatm_exit(void)
209 {
210 	usb_deregister(&xusbatm_usb_driver);
211 }
212 module_exit(xusbatm_exit);
213 
214 MODULE_AUTHOR("Roman Kagan, Duncan Sands");
215 MODULE_DESCRIPTION("Driver for USB ADSL modems initialized in userspace");
216 MODULE_LICENSE("GPL");
217