Merge branch 'for-2.6.21' of master.kernel.org:/pub/scm/linux/kernel/git/davej/agpgart
[linux-2.6] / drivers / usb / serial / generic.c
1 /*
2  * USB Serial Converter Generic functions
3  *
4  * Copyright (C) 1999 - 2002 Greg Kroah-Hartman (greg@kroah.com)
5  *
6  *      This program is free software; you can redistribute it and/or
7  *      modify it under the terms of the GNU General Public License version
8  *      2 as published by the Free Software Foundation.
9  *
10  */
11
12 #include <linux/kernel.h>
13 #include <linux/errno.h>
14 #include <linux/slab.h>
15 #include <linux/tty.h>
16 #include <linux/tty_flip.h>
17 #include <linux/module.h>
18 #include <linux/moduleparam.h>
19 #include <linux/usb.h>
20 #include <linux/usb/serial.h>
21 #include <asm/uaccess.h>
22
23
24 static int debug;
25
26 #ifdef CONFIG_USB_SERIAL_GENERIC
27
28 static int generic_probe(struct usb_interface *interface,
29                          const struct usb_device_id *id);
30
31 static __u16 vendor  = 0x05f9;
32 static __u16 product = 0xffff;
33
34 module_param(vendor, ushort, 0);
35 MODULE_PARM_DESC(vendor, "User specified USB idVendor");
36
37 module_param(product, ushort, 0);
38 MODULE_PARM_DESC(product, "User specified USB idProduct");
39
40 static struct usb_device_id generic_device_ids[2]; /* Initially all zeroes. */
41
42 /* we want to look at all devices, as the vendor/product id can change
43  * depending on the command line argument */
44 static struct usb_device_id generic_serial_ids[] = {
45         {.driver_info = 42},
46         {}
47 };
48
49 static struct usb_driver generic_driver = {
50         .name =         "usbserial_generic",
51         .probe =        generic_probe,
52         .disconnect =   usb_serial_disconnect,
53         .id_table =     generic_serial_ids,
54         .no_dynamic_id =        1,
55 };
56
57 /* All of the device info needed for the Generic Serial Converter */
58 struct usb_serial_driver usb_serial_generic_device = {
59         .driver = {
60                 .owner =        THIS_MODULE,
61                 .name =         "generic",
62         },
63         .id_table =             generic_device_ids,
64         .usb_driver =           &generic_driver,
65         .num_interrupt_in =     NUM_DONT_CARE,
66         .num_bulk_in =          NUM_DONT_CARE,
67         .num_bulk_out =         NUM_DONT_CARE,
68         .num_ports =            1,
69         .shutdown =             usb_serial_generic_shutdown,
70         .throttle =             usb_serial_generic_throttle,
71         .unthrottle =           usb_serial_generic_unthrottle,
72 };
73
74 static int generic_probe(struct usb_interface *interface,
75                                const struct usb_device_id *id)
76 {
77         const struct usb_device_id *id_pattern;
78
79         id_pattern = usb_match_id(interface, generic_device_ids);
80         if (id_pattern != NULL)
81                 return usb_serial_probe(interface, id);
82         return -ENODEV;
83 }
84 #endif
85
86 int usb_serial_generic_register (int _debug)
87 {
88         int retval = 0;
89
90         debug = _debug;
91 #ifdef CONFIG_USB_SERIAL_GENERIC
92         generic_device_ids[0].idVendor = vendor;
93         generic_device_ids[0].idProduct = product;
94         generic_device_ids[0].match_flags = USB_DEVICE_ID_MATCH_VENDOR | USB_DEVICE_ID_MATCH_PRODUCT;
95
96         /* register our generic driver with ourselves */
97         retval = usb_serial_register (&usb_serial_generic_device);
98         if (retval)
99                 goto exit;
100         retval = usb_register(&generic_driver);
101         if (retval)
102                 usb_serial_deregister(&usb_serial_generic_device);
103 exit:
104 #endif
105         return retval;
106 }
107
108 void usb_serial_generic_deregister (void)
109 {
110 #ifdef CONFIG_USB_SERIAL_GENERIC
111         /* remove our generic driver */
112         usb_deregister(&generic_driver);
113         usb_serial_deregister (&usb_serial_generic_device);
114 #endif
115 }
116
117 int usb_serial_generic_open (struct usb_serial_port *port, struct file *filp)
118 {
119         struct usb_serial *serial = port->serial;
120         int result = 0;
121         unsigned long flags;
122
123         dbg("%s - port %d", __FUNCTION__, port->number);
124
125         /* force low_latency on so that our tty_push actually forces the data through, 
126            otherwise it is scheduled, and with high data rates (like with OHCI) data
127            can get lost. */
128         if (port->tty)
129                 port->tty->low_latency = 1;
130
131         /* clear the throttle flags */
132         spin_lock_irqsave(&port->lock, flags);
133         port->throttled = 0;
134         port->throttle_req = 0;
135         spin_unlock_irqrestore(&port->lock, flags);
136
137         /* if we have a bulk endpoint, start reading from it */
138         if (serial->num_bulk_in) {
139                 /* Start reading from the device */
140                 usb_fill_bulk_urb (port->read_urb, serial->dev,
141                                    usb_rcvbulkpipe(serial->dev, port->bulk_in_endpointAddress),
142                                    port->read_urb->transfer_buffer,
143                                    port->read_urb->transfer_buffer_length,
144                                    ((serial->type->read_bulk_callback) ?
145                                      serial->type->read_bulk_callback :
146                                      usb_serial_generic_read_bulk_callback),
147                                    port);
148                 result = usb_submit_urb(port->read_urb, GFP_KERNEL);
149                 if (result)
150                         dev_err(&port->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result);
151         }
152
153         return result;
154 }
155 EXPORT_SYMBOL_GPL(usb_serial_generic_open);
156
157 static void generic_cleanup (struct usb_serial_port *port)
158 {
159         struct usb_serial *serial = port->serial;
160
161         dbg("%s - port %d", __FUNCTION__, port->number);
162
163         if (serial->dev) {
164                 /* shutdown any bulk reads that might be going on */
165                 if (serial->num_bulk_out)
166                         usb_kill_urb(port->write_urb);
167                 if (serial->num_bulk_in)
168                         usb_kill_urb(port->read_urb);
169         }
170 }
171
172 void usb_serial_generic_close (struct usb_serial_port *port, struct file * filp)
173 {
174         dbg("%s - port %d", __FUNCTION__, port->number);
175         generic_cleanup (port);
176 }
177
178 int usb_serial_generic_write(struct usb_serial_port *port, const unsigned char *buf, int count)
179 {
180         struct usb_serial *serial = port->serial;
181         int result;
182         unsigned char *data;
183
184         dbg("%s - port %d", __FUNCTION__, port->number);
185
186         if (count == 0) {
187                 dbg("%s - write request of 0 bytes", __FUNCTION__);
188                 return (0);
189         }
190
191         /* only do something if we have a bulk out endpoint */
192         if (serial->num_bulk_out) {
193                 spin_lock_bh(&port->lock);
194                 if (port->write_urb_busy) {
195                         spin_unlock_bh(&port->lock);
196                         dbg("%s - already writing", __FUNCTION__);
197                         return 0;
198                 }
199                 port->write_urb_busy = 1;
200                 spin_unlock_bh(&port->lock);
201
202                 count = (count > port->bulk_out_size) ? port->bulk_out_size : count;
203
204                 memcpy (port->write_urb->transfer_buffer, buf, count);
205                 data = port->write_urb->transfer_buffer;
206                 usb_serial_debug_data(debug, &port->dev, __FUNCTION__, count, data);
207
208                 /* set up our urb */
209                 usb_fill_bulk_urb (port->write_urb, serial->dev,
210                                    usb_sndbulkpipe (serial->dev,
211                                                     port->bulk_out_endpointAddress),
212                                    port->write_urb->transfer_buffer, count,
213                                    ((serial->type->write_bulk_callback) ? 
214                                      serial->type->write_bulk_callback :
215                                      usb_serial_generic_write_bulk_callback), port);
216
217                 /* send the data out the bulk port */
218                 port->write_urb_busy = 1;
219                 result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
220                 if (result) {
221                         dev_err(&port->dev, "%s - failed submitting write urb, error %d\n", __FUNCTION__, result);
222                         /* don't have to grab the lock here, as we will retry if != 0 */
223                         port->write_urb_busy = 0;
224                 } else
225                         result = count;
226
227                 return result;
228         }
229
230         /* no bulk out, so return 0 bytes written */
231         return 0;
232 }
233
234 int usb_serial_generic_write_room (struct usb_serial_port *port)
235 {
236         struct usb_serial *serial = port->serial;
237         int room = 0;
238
239         dbg("%s - port %d", __FUNCTION__, port->number);
240
241         if (serial->num_bulk_out) {
242                 if (!(port->write_urb_busy))
243                         room = port->bulk_out_size;
244         }
245
246         dbg("%s - returns %d", __FUNCTION__, room);
247         return (room);
248 }
249
250 int usb_serial_generic_chars_in_buffer (struct usb_serial_port *port)
251 {
252         struct usb_serial *serial = port->serial;
253         int chars = 0;
254
255         dbg("%s - port %d", __FUNCTION__, port->number);
256
257         if (serial->num_bulk_out) {
258                 if (port->write_urb_busy)
259                         chars = port->write_urb->transfer_buffer_length;
260         }
261
262         dbg("%s - returns %d", __FUNCTION__, chars);
263         return (chars);
264 }
265
266 /* Push data to tty layer and resubmit the bulk read URB */
267 static void flush_and_resubmit_read_urb (struct usb_serial_port *port)
268 {
269         struct usb_serial *serial = port->serial;
270         struct urb *urb = port->read_urb;
271         struct tty_struct *tty = port->tty;
272         int result;
273
274         /* Push data to tty */
275         if (tty && urb->actual_length) {
276                 tty_buffer_request_room(tty, urb->actual_length);
277                 tty_insert_flip_string(tty, urb->transfer_buffer, urb->actual_length);
278                 tty_flip_buffer_push(tty); /* is this allowed from an URB callback ? */
279         }
280
281         /* Continue reading from device */
282         usb_fill_bulk_urb (port->read_urb, serial->dev,
283                            usb_rcvbulkpipe (serial->dev,
284                                             port->bulk_in_endpointAddress),
285                            port->read_urb->transfer_buffer,
286                            port->read_urb->transfer_buffer_length,
287                            ((serial->type->read_bulk_callback) ? 
288                              serial->type->read_bulk_callback : 
289                              usb_serial_generic_read_bulk_callback), port);
290         result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
291         if (result)
292                 dev_err(&port->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result);
293 }
294
295 void usb_serial_generic_read_bulk_callback (struct urb *urb)
296 {
297         struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
298         unsigned char *data = urb->transfer_buffer;
299         int is_throttled;
300         unsigned long flags;
301
302         dbg("%s - port %d", __FUNCTION__, port->number);
303
304         if (urb->status) {
305                 dbg("%s - nonzero read bulk status received: %d", __FUNCTION__, urb->status);
306                 return;
307         }
308
309         usb_serial_debug_data(debug, &port->dev, __FUNCTION__, urb->actual_length, data);
310
311         /* Throttle the device if requested by tty */
312         if (urb->actual_length) {
313                 spin_lock_irqsave(&port->lock, flags);
314                 is_throttled = port->throttled = port->throttle_req;
315                 spin_unlock_irqrestore(&port->lock, flags);
316                 if (is_throttled) {
317                         /* Let the received data linger in the read URB;
318                          * usb_serial_generic_unthrottle() will pick it
319                          * up later. */
320                         dbg("%s - throttling device", __FUNCTION__);
321                         return;
322                 }
323         }
324
325         /* Handle data and continue reading from device */
326         flush_and_resubmit_read_urb(port);
327 }
328 EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback);
329
330 void usb_serial_generic_write_bulk_callback (struct urb *urb)
331 {
332         struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
333
334         dbg("%s - port %d", __FUNCTION__, port->number);
335
336         port->write_urb_busy = 0;
337         if (urb->status) {
338                 dbg("%s - nonzero write bulk status received: %d", __FUNCTION__, urb->status);
339                 return;
340         }
341
342         usb_serial_port_softint(port);
343 }
344 EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback);
345
346 void usb_serial_generic_throttle (struct usb_serial_port *port)
347 {
348         unsigned long flags;
349
350         dbg("%s - port %d", __FUNCTION__, port->number);
351
352         /* Set the throttle request flag. It will be picked up
353          * by usb_serial_generic_read_bulk_callback(). */
354         spin_lock_irqsave(&port->lock, flags);
355         port->throttle_req = 1;
356         spin_unlock_irqrestore(&port->lock, flags);
357 }
358
359 void usb_serial_generic_unthrottle (struct usb_serial_port *port)
360 {
361         int was_throttled;
362         unsigned long flags;
363
364         dbg("%s - port %d", __FUNCTION__, port->number);
365
366         /* Clear the throttle flags */
367         spin_lock_irqsave(&port->lock, flags);
368         was_throttled = port->throttled;
369         port->throttled = port->throttle_req = 0;
370         spin_unlock_irqrestore(&port->lock, flags);
371
372         if (was_throttled) {
373                 /* Handle pending data and resume reading from device */
374                 flush_and_resubmit_read_urb(port);
375         }
376 }
377
378 void usb_serial_generic_shutdown (struct usb_serial *serial)
379 {
380         int i;
381
382         dbg("%s", __FUNCTION__);
383
384         /* stop reads and writes on all ports */
385         for (i=0; i < serial->num_ports; ++i) {
386                 generic_cleanup(serial->port[i]);
387         }
388 }
389