Merge tag 'usb-4.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb
[sfrench/cifs-2.6.git] / drivers / usb / serial / omninet.c
1 /*
2  * USB ZyXEL omni.net LCD PLUS driver
3  *
4  *      This program is free software; you can redistribute it and/or
5  *      modify it under the terms of the GNU General Public License version
6  *      2 as published by the Free Software Foundation.
7  *
8  * See Documentation/usb/usb-serial.txt for more information on using this
9  * driver
10  *
11  * Please report both successes and troubles to the author at omninet@kroah.com
12  */
13
14 #include <linux/kernel.h>
15 #include <linux/errno.h>
16 #include <linux/slab.h>
17 #include <linux/tty.h>
18 #include <linux/tty_driver.h>
19 #include <linux/tty_flip.h>
20 #include <linux/module.h>
21 #include <linux/uaccess.h>
22 #include <linux/usb.h>
23 #include <linux/usb/serial.h>
24
25 #define DRIVER_AUTHOR "Alessandro Zummo"
26 #define DRIVER_DESC "USB ZyXEL omni.net LCD PLUS Driver"
27
28 #define ZYXEL_VENDOR_ID         0x0586
29 #define ZYXEL_OMNINET_ID        0x1000
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 void omninet_write_bulk_callback(struct urb *urb);
36 static int  omninet_write(struct tty_struct *tty, struct usb_serial_port *port,
37                                 const unsigned char *buf, int count);
38 static int  omninet_write_room(struct tty_struct *tty);
39 static void omninet_disconnect(struct usb_serial *serial);
40 static int omninet_attach(struct usb_serial *serial);
41 static int omninet_port_probe(struct usb_serial_port *port);
42 static int omninet_port_remove(struct usb_serial_port *port);
43
44 static const struct usb_device_id id_table[] = {
45         { USB_DEVICE(ZYXEL_VENDOR_ID, ZYXEL_OMNINET_ID) },
46         { USB_DEVICE(ZYXEL_VENDOR_ID, BT_IGNITIONPRO_ID) },
47         { }                                             /* Terminating entry */
48 };
49 MODULE_DEVICE_TABLE(usb, id_table);
50
51 static struct usb_serial_driver zyxel_omninet_device = {
52         .driver = {
53                 .owner =        THIS_MODULE,
54                 .name =         "omninet",
55         },
56         .description =          "ZyXEL - omni.net lcd plus usb",
57         .id_table =             id_table,
58         .num_ports =            1,
59         .attach =               omninet_attach,
60         .port_probe =           omninet_port_probe,
61         .port_remove =          omninet_port_remove,
62         .write =                omninet_write,
63         .write_room =           omninet_write_room,
64         .write_bulk_callback =  omninet_write_bulk_callback,
65         .process_read_urb =     omninet_process_read_urb,
66         .disconnect =           omninet_disconnect,
67 };
68
69 static struct usb_serial_driver * const serial_drivers[] = {
70         &zyxel_omninet_device, NULL
71 };
72
73
74 /*
75  * The protocol.
76  *
77  * The omni.net always exchange 64 bytes of data with the host. The first
78  * four bytes are the control header.
79  *
80  * oh_seq is a sequence number. Don't know if/how it's used.
81  * oh_len is the length of the data bytes in the packet.
82  * oh_xxx Bit-mapped, related to handshaking and status info.
83  *      I normally set it to 0x03 in transmitted frames.
84  *      7: Active when the TA is in a CONNECTed state.
85  *      6: unknown
86  *      5: handshaking, unknown
87  *      4: handshaking, unknown
88  *      3: unknown, usually 0
89  *      2: unknown, usually 0
90  *      1: handshaking, unknown, usually set to 1 in transmitted frames
91  *      0: handshaking, unknown, usually set to 1 in transmitted frames
92  * oh_pad Probably a pad byte.
93  *
94  * After the header you will find data bytes if oh_len was greater than zero.
95  */
96 struct omninet_header {
97         __u8    oh_seq;
98         __u8    oh_len;
99         __u8    oh_xxx;
100         __u8    oh_pad;
101 };
102
103 struct omninet_data {
104         __u8    od_outseq;      /* Sequence number for bulk_out URBs */
105 };
106
107 static int omninet_attach(struct usb_serial *serial)
108 {
109         /* The second bulk-out endpoint is used for writing. */
110         if (serial->num_bulk_out < 2) {
111                 dev_err(&serial->interface->dev, "missing endpoints\n");
112                 return -ENODEV;
113         }
114
115         return 0;
116 }
117
118 static int omninet_port_probe(struct usb_serial_port *port)
119 {
120         struct omninet_data *od;
121
122         od = kzalloc(sizeof(*od), GFP_KERNEL);
123         if (!od)
124                 return -ENOMEM;
125
126         usb_set_serial_port_data(port, od);
127
128         return 0;
129 }
130
131 static int omninet_port_remove(struct usb_serial_port *port)
132 {
133         struct omninet_data *od;
134
135         od = usb_get_serial_port_data(port);
136         kfree(od);
137
138         return 0;
139 }
140
141 #define OMNINET_HEADERLEN       4
142 #define OMNINET_BULKOUTSIZE     64
143 #define OMNINET_PAYLOADSIZE     (OMNINET_BULKOUTSIZE - OMNINET_HEADERLEN)
144
145 static void omninet_process_read_urb(struct urb *urb)
146 {
147         struct usb_serial_port *port = urb->context;
148         const struct omninet_header *hdr = urb->transfer_buffer;
149         const unsigned char *data;
150         size_t data_len;
151
152         if (urb->actual_length <= OMNINET_HEADERLEN || !hdr->oh_len)
153                 return;
154
155         data = (char *)urb->transfer_buffer + OMNINET_HEADERLEN;
156         data_len = min_t(size_t, urb->actual_length - OMNINET_HEADERLEN,
157                                                                 hdr->oh_len);
158         tty_insert_flip_string(&port->port, data, data_len);
159         tty_flip_buffer_push(&port->port);
160 }
161
162 static int omninet_write(struct tty_struct *tty, struct usb_serial_port *port,
163                                         const unsigned char *buf, int count)
164 {
165         struct usb_serial *serial = port->serial;
166         struct usb_serial_port *wport = serial->port[1];
167
168         struct omninet_data *od = usb_get_serial_port_data(port);
169         struct omninet_header *header = (struct omninet_header *)
170                                         wport->write_urb->transfer_buffer;
171
172         int                     result;
173
174         if (count == 0) {
175                 dev_dbg(&port->dev, "%s - write request of 0 bytes\n", __func__);
176                 return 0;
177         }
178
179         if (!test_and_clear_bit(0, &port->write_urbs_free)) {
180                 dev_dbg(&port->dev, "%s - already writing\n", __func__);
181                 return 0;
182         }
183
184         count = (count > OMNINET_PAYLOADSIZE) ? OMNINET_PAYLOADSIZE : count;
185
186         memcpy(wport->write_urb->transfer_buffer + OMNINET_HEADERLEN,
187                                                                 buf, count);
188
189         usb_serial_debug_data(&port->dev, __func__, count,
190                               wport->write_urb->transfer_buffer);
191
192         header->oh_seq  = od->od_outseq++;
193         header->oh_len  = count;
194         header->oh_xxx  = 0x03;
195         header->oh_pad  = 0x00;
196
197         /* send the data out the bulk port, always 64 bytes */
198         wport->write_urb->transfer_buffer_length = OMNINET_BULKOUTSIZE;
199
200         result = usb_submit_urb(wport->write_urb, GFP_ATOMIC);
201         if (result) {
202                 set_bit(0, &wport->write_urbs_free);
203                 dev_err_console(port,
204                         "%s - failed submitting write urb, error %d\n",
205                         __func__, result);
206         } else
207                 result = count;
208
209         return result;
210 }
211
212
213 static int omninet_write_room(struct tty_struct *tty)
214 {
215         struct usb_serial_port *port = tty->driver_data;
216         struct usb_serial       *serial = port->serial;
217         struct usb_serial_port  *wport  = serial->port[1];
218
219         int room = 0; /* Default: no room */
220
221         if (test_bit(0, &wport->write_urbs_free))
222                 room = wport->bulk_out_size - OMNINET_HEADERLEN;
223
224         dev_dbg(&port->dev, "%s - returns %d\n", __func__, room);
225
226         return room;
227 }
228
229 static void omninet_write_bulk_callback(struct urb *urb)
230 {
231 /*      struct omninet_header   *header = (struct omninet_header  *)
232                                                 urb->transfer_buffer; */
233         struct usb_serial_port  *port   =  urb->context;
234         int status = urb->status;
235
236         set_bit(0, &port->write_urbs_free);
237         if (status) {
238                 dev_dbg(&port->dev, "%s - nonzero write bulk status received: %d\n",
239                         __func__, status);
240                 return;
241         }
242
243         usb_serial_port_softint(port);
244 }
245
246
247 static void omninet_disconnect(struct usb_serial *serial)
248 {
249         struct usb_serial_port *wport = serial->port[1];
250
251         usb_kill_urb(wport->write_urb);
252 }
253
254 module_usb_serial_driver(serial_drivers, id_table);
255
256 MODULE_AUTHOR(DRIVER_AUTHOR);
257 MODULE_DESCRIPTION(DRIVER_DESC);
258 MODULE_LICENSE("GPL");