1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * USB ZyXEL omni.net driver
4 *
5 * Copyright (C) 2013,2017 Johan Hovold <johan@kernel.org>
6 *
7 * See Documentation/usb/usb-serial.rst for more information on using this
8 * driver
9 *
10 * Please report both successes and troubles to the author at omninet@kroah.com
11 */
12
13 #include <linux/kernel.h>
14 #include <linux/errno.h>
15 #include <linux/slab.h>
16 #include <linux/tty.h>
17 #include <linux/tty_driver.h>
18 #include <linux/tty_flip.h>
19 #include <linux/module.h>
20 #include <linux/uaccess.h>
21 #include <linux/usb.h>
22 #include <linux/usb/serial.h>
23
24 #define DRIVER_AUTHOR "Alessandro Zummo"
25 #define DRIVER_DESC "USB ZyXEL omni.net Driver"
26
27 #define ZYXEL_VENDOR_ID 0x0586
28 #define ZYXEL_OMNINET_ID 0x1000
29 #define ZYXEL_OMNI_56K_PLUS_ID 0x1500
30 /* This one seems to be a re-branded ZyXEL device */
31 #define BT_IGNITIONPRO_ID 0x2000
32
33 /* function prototypes */
34 static void omninet_process_read_urb(struct urb *urb);
35 static int omninet_prepare_write_buffer(struct usb_serial_port *port,
36 void *buf, size_t count);
37 static int omninet_calc_num_ports(struct usb_serial *serial,
38 struct usb_serial_endpoints *epds);
39 static int omninet_port_probe(struct usb_serial_port *port);
40 static void omninet_port_remove(struct usb_serial_port *port);
41
42 static const struct usb_device_id id_table[] = {
43 { USB_DEVICE(ZYXEL_VENDOR_ID, ZYXEL_OMNINET_ID) },
44 { USB_DEVICE(ZYXEL_VENDOR_ID, ZYXEL_OMNI_56K_PLUS_ID) },
45 { USB_DEVICE(ZYXEL_VENDOR_ID, BT_IGNITIONPRO_ID) },
46 { } /* Terminating entry */
47 };
48 MODULE_DEVICE_TABLE(usb, id_table);
49
50 static struct usb_serial_driver zyxel_omninet_device = {
51 .driver = {
52 .owner = THIS_MODULE,
53 .name = "omninet",
54 },
55 .description = "ZyXEL - omni.net usb",
56 .id_table = id_table,
57 .num_bulk_out = 2,
58 .calc_num_ports = omninet_calc_num_ports,
59 .port_probe = omninet_port_probe,
60 .port_remove = omninet_port_remove,
61 .process_read_urb = omninet_process_read_urb,
62 .prepare_write_buffer = omninet_prepare_write_buffer,
63 };
64
65 static struct usb_serial_driver * const serial_drivers[] = {
66 &zyxel_omninet_device, NULL
67 };
68
69
70 /*
71 * The protocol.
72 *
73 * The omni.net always exchange 64 bytes of data with the host. The first
74 * four bytes are the control header.
75 *
76 * oh_seq is a sequence number. Don't know if/how it's used.
77 * oh_len is the length of the data bytes in the packet.
78 * oh_xxx Bit-mapped, related to handshaking and status info.
79 * I normally set it to 0x03 in transmitted frames.
80 * 7: Active when the TA is in a CONNECTed state.
81 * 6: unknown
82 * 5: handshaking, unknown
83 * 4: handshaking, unknown
84 * 3: unknown, usually 0
85 * 2: unknown, usually 0
86 * 1: handshaking, unknown, usually set to 1 in transmitted frames
87 * 0: handshaking, unknown, usually set to 1 in transmitted frames
88 * oh_pad Probably a pad byte.
89 *
90 * After the header you will find data bytes if oh_len was greater than zero.
91 */
92 struct omninet_header {
93 __u8 oh_seq;
94 __u8 oh_len;
95 __u8 oh_xxx;
96 __u8 oh_pad;
97 };
98
99 struct omninet_data {
100 __u8 od_outseq; /* Sequence number for bulk_out URBs */
101 };
102
omninet_calc_num_ports(struct usb_serial * serial,struct usb_serial_endpoints * epds)103 static int omninet_calc_num_ports(struct usb_serial *serial,
104 struct usb_serial_endpoints *epds)
105 {
106 /* We need only the second bulk-out for our single-port device. */
107 epds->bulk_out[0] = epds->bulk_out[1];
108 epds->num_bulk_out = 1;
109
110 return 1;
111 }
112
omninet_port_probe(struct usb_serial_port * port)113 static int omninet_port_probe(struct usb_serial_port *port)
114 {
115 struct omninet_data *od;
116
117 od = kzalloc(sizeof(*od), GFP_KERNEL);
118 if (!od)
119 return -ENOMEM;
120
121 usb_set_serial_port_data(port, od);
122
123 return 0;
124 }
125
omninet_port_remove(struct usb_serial_port * port)126 static void omninet_port_remove(struct usb_serial_port *port)
127 {
128 struct omninet_data *od;
129
130 od = usb_get_serial_port_data(port);
131 kfree(od);
132 }
133
134 #define OMNINET_HEADERLEN 4
135 #define OMNINET_BULKOUTSIZE 64
136 #define OMNINET_PAYLOADSIZE (OMNINET_BULKOUTSIZE - OMNINET_HEADERLEN)
137
omninet_process_read_urb(struct urb * urb)138 static void omninet_process_read_urb(struct urb *urb)
139 {
140 struct usb_serial_port *port = urb->context;
141 const struct omninet_header *hdr = urb->transfer_buffer;
142 const unsigned char *data;
143 size_t data_len;
144
145 if (urb->actual_length <= OMNINET_HEADERLEN || !hdr->oh_len)
146 return;
147
148 data = (char *)urb->transfer_buffer + OMNINET_HEADERLEN;
149 data_len = min_t(size_t, urb->actual_length - OMNINET_HEADERLEN,
150 hdr->oh_len);
151 tty_insert_flip_string(&port->port, data, data_len);
152 tty_flip_buffer_push(&port->port);
153 }
154
omninet_prepare_write_buffer(struct usb_serial_port * port,void * buf,size_t count)155 static int omninet_prepare_write_buffer(struct usb_serial_port *port,
156 void *buf, size_t count)
157 {
158 struct omninet_data *od = usb_get_serial_port_data(port);
159 struct omninet_header *header = buf;
160
161 count = min_t(size_t, count, OMNINET_PAYLOADSIZE);
162
163 count = kfifo_out_locked(&port->write_fifo, buf + OMNINET_HEADERLEN,
164 count, &port->lock);
165
166 header->oh_seq = od->od_outseq++;
167 header->oh_len = count;
168 header->oh_xxx = 0x03;
169 header->oh_pad = 0x00;
170
171 /* always 64 bytes */
172 return OMNINET_BULKOUTSIZE;
173 }
174
175 module_usb_serial_driver(serial_drivers, id_table);
176
177 MODULE_AUTHOR(DRIVER_AUTHOR);
178 MODULE_DESCRIPTION(DRIVER_DESC);
179 MODULE_LICENSE("GPL v2");
180