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
22XUSBATM_PARM(vendor, unsigned short, ushort, "USB device vendor");
23XUSBATM_PARM(product, unsigned short, ushort, "USB device product");
24
25XUSBATM_PARM(rx_endpoint, unsigned char, byte, "rx endpoint number");
26XUSBATM_PARM(tx_endpoint, unsigned char, byte, "tx endpoint number");
27XUSBATM_PARM(rx_padding, unsigned char, byte, "rx padding (default 0)");
28XUSBATM_PARM(tx_padding, unsigned char, byte, "tx padding (default 0)");
29XUSBATM_PARM(rx_altsetting, unsigned char, byte, "rx altsetting (default 0)");
30XUSBATM_PARM(tx_altsetting, unsigned char, byte, "rx altsetting (default 0)");
31
32static const char xusbatm_driver_name[] = "xusbatm";
33
34static struct usbatm_driver xusbatm_drivers[XUSBATM_DRIVERS_MAX];
35static struct usb_device_id xusbatm_usb_ids[XUSBATM_DRIVERS_MAX + 1];
36static struct usb_driver xusbatm_usb_driver;
37
38static 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
52static 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
70static 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
78static 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
130static 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
148static 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
160static 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
167static 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
174static 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}
206module_init(xusbatm_init);
207
208static void __exit xusbatm_exit(void)
209{
210	usb_deregister(&xusbatm_usb_driver);
211}
212module_exit(xusbatm_exit);
213
214MODULE_AUTHOR("Roman Kagan, Duncan Sands");
215MODULE_DESCRIPTION("Driver for USB ADSL modems initialized in userspace");
216MODULE_LICENSE("GPL");
217