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 .name = "omninet",
53 },
54 .description = "ZyXEL - omni.net usb",
55 .id_table = id_table,
56 .num_bulk_out = 2,
57 .calc_num_ports = omninet_calc_num_ports,
58 .port_probe = omninet_port_probe,
59 .port_remove = omninet_port_remove,
60 .process_read_urb = omninet_process_read_urb,
61 .prepare_write_buffer = omninet_prepare_write_buffer,
62 };
63
64 static struct usb_serial_driver * const serial_drivers[] = {
65 &zyxel_omninet_device, NULL
66 };
67
68
69 /*
70 * The protocol.
71 *
72 * The omni.net always exchange 64 bytes of data with the host. The first
73 * four bytes are the control header.
74 *
75 * oh_seq is a sequence number. Don't know if/how it's used.
76 * oh_len is the length of the data bytes in the packet.
77 * oh_xxx Bit-mapped, related to handshaking and status info.
78 * I normally set it to 0x03 in transmitted frames.
79 * 7: Active when the TA is in a CONNECTed state.
80 * 6: unknown
81 * 5: handshaking, unknown
82 * 4: handshaking, unknown
83 * 3: unknown, usually 0
84 * 2: unknown, usually 0
85 * 1: handshaking, unknown, usually set to 1 in transmitted frames
86 * 0: handshaking, unknown, usually set to 1 in transmitted frames
87 * oh_pad Probably a pad byte.
88 *
89 * After the header you will find data bytes if oh_len was greater than zero.
90 */
91 struct omninet_header {
92 __u8 oh_seq;
93 __u8 oh_len;
94 __u8 oh_xxx;
95 __u8 oh_pad;
96 };
97
98 struct omninet_data {
99 __u8 od_outseq; /* Sequence number for bulk_out URBs */
100 };
101
omninet_calc_num_ports(struct usb_serial * serial,struct usb_serial_endpoints * epds)102 static int omninet_calc_num_ports(struct usb_serial *serial,
103 struct usb_serial_endpoints *epds)
104 {
105 /* We need only the second bulk-out for our single-port device. */
106 epds->bulk_out[0] = epds->bulk_out[1];
107 epds->num_bulk_out = 1;
108
109 return 1;
110 }
111
omninet_port_probe(struct usb_serial_port * port)112 static int omninet_port_probe(struct usb_serial_port *port)
113 {
114 struct omninet_data *od;
115
116 od = kzalloc(sizeof(*od), GFP_KERNEL);
117 if (!od)
118 return -ENOMEM;
119
120 usb_set_serial_port_data(port, od);
121
122 return 0;
123 }
124
omninet_port_remove(struct usb_serial_port * port)125 static void omninet_port_remove(struct usb_serial_port *port)
126 {
127 struct omninet_data *od;
128
129 od = usb_get_serial_port_data(port);
130 kfree(od);
131 }
132
133 #define OMNINET_HEADERLEN 4
134 #define OMNINET_BULKOUTSIZE 64
135 #define OMNINET_PAYLOADSIZE (OMNINET_BULKOUTSIZE - OMNINET_HEADERLEN)
136
omninet_process_read_urb(struct urb * urb)137 static void omninet_process_read_urb(struct urb *urb)
138 {
139 struct usb_serial_port *port = urb->context;
140 const struct omninet_header *hdr = urb->transfer_buffer;
141 const unsigned char *data;
142 size_t data_len;
143
144 if (urb->actual_length <= OMNINET_HEADERLEN || !hdr->oh_len)
145 return;
146
147 data = (char *)urb->transfer_buffer + OMNINET_HEADERLEN;
148 data_len = min_t(size_t, urb->actual_length - OMNINET_HEADERLEN,
149 hdr->oh_len);
150 tty_insert_flip_string(&port->port, data, data_len);
151 tty_flip_buffer_push(&port->port);
152 }
153
omninet_prepare_write_buffer(struct usb_serial_port * port,void * buf,size_t count)154 static int omninet_prepare_write_buffer(struct usb_serial_port *port,
155 void *buf, size_t count)
156 {
157 struct omninet_data *od = usb_get_serial_port_data(port);
158 struct omninet_header *header = buf;
159
160 count = min_t(size_t, count, OMNINET_PAYLOADSIZE);
161
162 count = kfifo_out_locked(&port->write_fifo, buf + OMNINET_HEADERLEN,
163 count, &port->lock);
164
165 header->oh_seq = od->od_outseq++;
166 header->oh_len = count;
167 header->oh_xxx = 0x03;
168 header->oh_pad = 0x00;
169
170 /* always 64 bytes */
171 return OMNINET_BULKOUTSIZE;
172 }
173
174 module_usb_serial_driver(serial_drivers, id_table);
175
176 MODULE_AUTHOR(DRIVER_AUTHOR);
177 MODULE_DESCRIPTION(DRIVER_DESC);
178 MODULE_LICENSE("GPL v2");
179