Add linux-next specific files for 20110831
[linux-2.6/next.git] / drivers / usb / serial / generic.c
blobe4db5ad2bc55f1c37f2da2b15c086534e98248c7
1 /*
2 * USB Serial Converter Generic functions
4 * Copyright (C) 2010 Johan Hovold (jhovold@gmail.com)
5 * Copyright (C) 1999 - 2002 Greg Kroah-Hartman (greg@kroah.com)
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License version
9 * 2 as published by the Free Software Foundation.
13 #include <linux/kernel.h>
14 #include <linux/errno.h>
15 #include <linux/slab.h>
16 #include <linux/sysrq.h>
17 #include <linux/tty.h>
18 #include <linux/tty_flip.h>
19 #include <linux/module.h>
20 #include <linux/moduleparam.h>
21 #include <linux/usb.h>
22 #include <linux/usb/serial.h>
23 #include <linux/uaccess.h>
24 #include <linux/kfifo.h>
25 #include <linux/serial.h>
27 static int debug;
29 #ifdef CONFIG_USB_SERIAL_GENERIC
31 static int generic_probe(struct usb_interface *interface,
32 const struct usb_device_id *id);
34 static __u16 vendor = 0x05f9;
35 static __u16 product = 0xffff;
37 module_param(vendor, ushort, 0);
38 MODULE_PARM_DESC(vendor, "User specified USB idVendor");
40 module_param(product, ushort, 0);
41 MODULE_PARM_DESC(product, "User specified USB idProduct");
43 static struct usb_device_id generic_device_ids[2]; /* Initially all zeroes. */
45 /* we want to look at all devices, as the vendor/product id can change
46 * depending on the command line argument */
47 static const struct usb_device_id generic_serial_ids[] = {
48 {.driver_info = 42},
52 static struct usb_driver generic_driver = {
53 .name = "usbserial_generic",
54 .probe = generic_probe,
55 .disconnect = usb_serial_disconnect,
56 .id_table = generic_serial_ids,
57 .no_dynamic_id = 1,
60 /* All of the device info needed for the Generic Serial Converter */
61 struct usb_serial_driver usb_serial_generic_device = {
62 .driver = {
63 .owner = THIS_MODULE,
64 .name = "generic",
66 .id_table = generic_device_ids,
67 .usb_driver = &generic_driver,
68 .num_ports = 1,
69 .disconnect = usb_serial_generic_disconnect,
70 .release = usb_serial_generic_release,
71 .throttle = usb_serial_generic_throttle,
72 .unthrottle = usb_serial_generic_unthrottle,
73 .resume = usb_serial_generic_resume,
76 static int generic_probe(struct usb_interface *interface,
77 const struct usb_device_id *id)
79 const struct usb_device_id *id_pattern;
81 id_pattern = usb_match_id(interface, generic_device_ids);
82 if (id_pattern != NULL)
83 return usb_serial_probe(interface, id);
84 return -ENODEV;
86 #endif
88 int usb_serial_generic_register(int _debug)
90 int retval = 0;
92 debug = _debug;
93 #ifdef CONFIG_USB_SERIAL_GENERIC
94 generic_device_ids[0].idVendor = vendor;
95 generic_device_ids[0].idProduct = product;
96 generic_device_ids[0].match_flags =
97 USB_DEVICE_ID_MATCH_VENDOR | USB_DEVICE_ID_MATCH_PRODUCT;
99 /* register our generic driver with ourselves */
100 retval = usb_serial_register(&usb_serial_generic_device);
101 if (retval)
102 goto exit;
103 retval = usb_register(&generic_driver);
104 if (retval)
105 usb_serial_deregister(&usb_serial_generic_device);
106 exit:
107 #endif
108 return retval;
111 void usb_serial_generic_deregister(void)
113 #ifdef CONFIG_USB_SERIAL_GENERIC
114 /* remove our generic driver */
115 usb_deregister(&generic_driver);
116 usb_serial_deregister(&usb_serial_generic_device);
117 #endif
120 int usb_serial_generic_open(struct tty_struct *tty, struct usb_serial_port *port)
122 int result = 0;
123 unsigned long flags;
125 dbg("%s - port %d", __func__, port->number);
127 /* clear the throttle flags */
128 spin_lock_irqsave(&port->lock, flags);
129 port->throttled = 0;
130 port->throttle_req = 0;
131 spin_unlock_irqrestore(&port->lock, flags);
133 /* if we have a bulk endpoint, start reading from it */
134 if (port->bulk_in_size)
135 result = usb_serial_generic_submit_read_urb(port, GFP_KERNEL);
137 return result;
139 EXPORT_SYMBOL_GPL(usb_serial_generic_open);
141 static void generic_cleanup(struct usb_serial_port *port)
143 struct usb_serial *serial = port->serial;
144 unsigned long flags;
145 int i;
147 dbg("%s - port %d", __func__, port->number);
149 if (serial->dev) {
150 /* shutdown any bulk transfers that might be going on */
151 if (port->bulk_out_size) {
152 usb_kill_urb(port->write_urb);
153 for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i)
154 usb_kill_urb(port->write_urbs[i]);
156 spin_lock_irqsave(&port->lock, flags);
157 kfifo_reset_out(&port->write_fifo);
158 spin_unlock_irqrestore(&port->lock, flags);
160 if (port->bulk_in_size)
161 usb_kill_urb(port->read_urb);
165 void usb_serial_generic_close(struct usb_serial_port *port)
167 dbg("%s - port %d", __func__, port->number);
168 generic_cleanup(port);
170 EXPORT_SYMBOL_GPL(usb_serial_generic_close);
172 int usb_serial_generic_prepare_write_buffer(struct usb_serial_port *port,
173 void *dest, size_t size)
175 return kfifo_out_locked(&port->write_fifo, dest, size, &port->lock);
179 * usb_serial_generic_write_start - kick off an URB write
180 * @port: Pointer to the &struct usb_serial_port data
182 * Returns zero on success, or a negative errno value
184 static int usb_serial_generic_write_start(struct usb_serial_port *port)
186 struct urb *urb;
187 int count, result;
188 unsigned long flags;
189 int i;
191 if (test_and_set_bit_lock(USB_SERIAL_WRITE_BUSY, &port->flags))
192 return 0;
193 retry:
194 spin_lock_irqsave(&port->lock, flags);
195 if (!port->write_urbs_free || !kfifo_len(&port->write_fifo)) {
196 clear_bit_unlock(USB_SERIAL_WRITE_BUSY, &port->flags);
197 spin_unlock_irqrestore(&port->lock, flags);
198 return 0;
200 i = (int)find_first_bit(&port->write_urbs_free,
201 ARRAY_SIZE(port->write_urbs));
202 spin_unlock_irqrestore(&port->lock, flags);
204 urb = port->write_urbs[i];
205 count = port->serial->type->prepare_write_buffer(port,
206 urb->transfer_buffer,
207 port->bulk_out_size);
208 urb->transfer_buffer_length = count;
209 usb_serial_debug_data(debug, &port->dev, __func__, count,
210 urb->transfer_buffer);
211 spin_lock_irqsave(&port->lock, flags);
212 port->tx_bytes += count;
213 spin_unlock_irqrestore(&port->lock, flags);
215 clear_bit(i, &port->write_urbs_free);
216 result = usb_submit_urb(urb, GFP_ATOMIC);
217 if (result) {
218 dev_err(&port->dev, "%s - error submitting urb: %d\n",
219 __func__, result);
220 set_bit(i, &port->write_urbs_free);
221 spin_lock_irqsave(&port->lock, flags);
222 port->tx_bytes -= count;
223 spin_unlock_irqrestore(&port->lock, flags);
225 clear_bit_unlock(USB_SERIAL_WRITE_BUSY, &port->flags);
226 return result;
229 /* Try sending off another urb, unless in irq context (in which case
230 * there will be no free urb). */
231 if (!in_irq())
232 goto retry;
234 clear_bit_unlock(USB_SERIAL_WRITE_BUSY, &port->flags);
236 return 0;
240 * usb_serial_generic_write - generic write function for serial USB devices
241 * @tty: Pointer to &struct tty_struct for the device
242 * @port: Pointer to the &usb_serial_port structure for the device
243 * @buf: Pointer to the data to write
244 * @count: Number of bytes to write
246 * Returns the number of characters actually written, which may be anything
247 * from zero to @count. If an error occurs, it returns the negative errno
248 * value.
250 int usb_serial_generic_write(struct tty_struct *tty,
251 struct usb_serial_port *port, const unsigned char *buf, int count)
253 int result;
255 dbg("%s - port %d", __func__, port->number);
257 /* only do something if we have a bulk out endpoint */
258 if (!port->bulk_out_size)
259 return -ENODEV;
261 if (!count)
262 return 0;
264 count = kfifo_in_locked(&port->write_fifo, buf, count, &port->lock);
265 result = usb_serial_generic_write_start(port);
266 if (result)
267 return result;
269 return count;
271 EXPORT_SYMBOL_GPL(usb_serial_generic_write);
273 int usb_serial_generic_write_room(struct tty_struct *tty)
275 struct usb_serial_port *port = tty->driver_data;
276 unsigned long flags;
277 int room;
279 dbg("%s - port %d", __func__, port->number);
281 if (!port->bulk_out_size)
282 return 0;
284 spin_lock_irqsave(&port->lock, flags);
285 room = kfifo_avail(&port->write_fifo);
286 spin_unlock_irqrestore(&port->lock, flags);
288 dbg("%s - returns %d", __func__, room);
289 return room;
292 int usb_serial_generic_chars_in_buffer(struct tty_struct *tty)
294 struct usb_serial_port *port = tty->driver_data;
295 unsigned long flags;
296 int chars;
298 dbg("%s - port %d", __func__, port->number);
300 if (!port->bulk_out_size)
301 return 0;
303 spin_lock_irqsave(&port->lock, flags);
304 chars = kfifo_len(&port->write_fifo) + port->tx_bytes;
305 spin_unlock_irqrestore(&port->lock, flags);
307 dbg("%s - returns %d", __func__, chars);
308 return chars;
311 int usb_serial_generic_submit_read_urb(struct usb_serial_port *port,
312 gfp_t mem_flags)
314 int result;
316 result = usb_submit_urb(port->read_urb, mem_flags);
317 if (result && result != -EPERM) {
318 dev_err(&port->dev, "%s - error submitting urb: %d\n",
319 __func__, result);
321 return result;
323 EXPORT_SYMBOL_GPL(usb_serial_generic_submit_read_urb);
325 void usb_serial_generic_process_read_urb(struct urb *urb)
327 struct usb_serial_port *port = urb->context;
328 struct tty_struct *tty;
329 char *ch = (char *)urb->transfer_buffer;
330 int i;
332 if (!urb->actual_length)
333 return;
335 tty = tty_port_tty_get(&port->port);
336 if (!tty)
337 return;
339 /* The per character mucking around with sysrq path it too slow for
340 stuff like 3G modems, so shortcircuit it in the 99.9999999% of cases
341 where the USB serial is not a console anyway */
342 if (!port->port.console || !port->sysrq)
343 tty_insert_flip_string(tty, ch, urb->actual_length);
344 else {
345 for (i = 0; i < urb->actual_length; i++, ch++) {
346 if (!usb_serial_handle_sysrq_char(port, *ch))
347 tty_insert_flip_char(tty, *ch, TTY_NORMAL);
350 tty_flip_buffer_push(tty);
351 tty_kref_put(tty);
353 EXPORT_SYMBOL_GPL(usb_serial_generic_process_read_urb);
355 void usb_serial_generic_read_bulk_callback(struct urb *urb)
357 struct usb_serial_port *port = urb->context;
358 unsigned char *data = urb->transfer_buffer;
359 int status = urb->status;
360 unsigned long flags;
362 dbg("%s - port %d", __func__, port->number);
364 if (unlikely(status != 0)) {
365 dbg("%s - nonzero read bulk status received: %d",
366 __func__, status);
367 return;
370 usb_serial_debug_data(debug, &port->dev, __func__,
371 urb->actual_length, data);
372 port->serial->type->process_read_urb(urb);
374 /* Throttle the device if requested by tty */
375 spin_lock_irqsave(&port->lock, flags);
376 port->throttled = port->throttle_req;
377 if (!port->throttled) {
378 spin_unlock_irqrestore(&port->lock, flags);
379 usb_serial_generic_submit_read_urb(port, GFP_ATOMIC);
380 } else
381 spin_unlock_irqrestore(&port->lock, flags);
383 EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback);
385 void usb_serial_generic_write_bulk_callback(struct urb *urb)
387 unsigned long flags;
388 struct usb_serial_port *port = urb->context;
389 int status = urb->status;
390 int i;
392 dbg("%s - port %d", __func__, port->number);
394 for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i)
395 if (port->write_urbs[i] == urb)
396 break;
398 spin_lock_irqsave(&port->lock, flags);
399 port->tx_bytes -= urb->transfer_buffer_length;
400 set_bit(i, &port->write_urbs_free);
401 spin_unlock_irqrestore(&port->lock, flags);
403 if (status) {
404 dbg("%s - non-zero urb status: %d", __func__, status);
406 spin_lock_irqsave(&port->lock, flags);
407 kfifo_reset_out(&port->write_fifo);
408 spin_unlock_irqrestore(&port->lock, flags);
409 } else {
410 usb_serial_generic_write_start(port);
413 usb_serial_port_softint(port);
415 EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback);
417 void usb_serial_generic_throttle(struct tty_struct *tty)
419 struct usb_serial_port *port = tty->driver_data;
420 unsigned long flags;
422 dbg("%s - port %d", __func__, port->number);
424 /* Set the throttle request flag. It will be picked up
425 * by usb_serial_generic_read_bulk_callback(). */
426 spin_lock_irqsave(&port->lock, flags);
427 port->throttle_req = 1;
428 spin_unlock_irqrestore(&port->lock, flags);
430 EXPORT_SYMBOL_GPL(usb_serial_generic_throttle);
432 void usb_serial_generic_unthrottle(struct tty_struct *tty)
434 struct usb_serial_port *port = tty->driver_data;
435 int was_throttled;
437 dbg("%s - port %d", __func__, port->number);
439 /* Clear the throttle flags */
440 spin_lock_irq(&port->lock);
441 was_throttled = port->throttled;
442 port->throttled = port->throttle_req = 0;
443 spin_unlock_irq(&port->lock);
445 if (was_throttled)
446 usb_serial_generic_submit_read_urb(port, GFP_KERNEL);
448 EXPORT_SYMBOL_GPL(usb_serial_generic_unthrottle);
450 #ifdef CONFIG_MAGIC_SYSRQ
451 int usb_serial_handle_sysrq_char(struct usb_serial_port *port, unsigned int ch)
453 if (port->sysrq && port->port.console) {
454 if (ch && time_before(jiffies, port->sysrq)) {
455 handle_sysrq(ch);
456 port->sysrq = 0;
457 return 1;
459 port->sysrq = 0;
461 return 0;
463 #else
464 int usb_serial_handle_sysrq_char(struct usb_serial_port *port, unsigned int ch)
466 return 0;
468 #endif
469 EXPORT_SYMBOL_GPL(usb_serial_handle_sysrq_char);
471 int usb_serial_handle_break(struct usb_serial_port *port)
473 if (!port->sysrq) {
474 port->sysrq = jiffies + HZ*5;
475 return 1;
477 port->sysrq = 0;
478 return 0;
480 EXPORT_SYMBOL_GPL(usb_serial_handle_break);
483 * usb_serial_handle_dcd_change - handle a change of carrier detect state
484 * @port: usb_serial_port structure for the open port
485 * @tty: tty_struct structure for the port
486 * @status: new carrier detect status, nonzero if active
488 void usb_serial_handle_dcd_change(struct usb_serial_port *usb_port,
489 struct tty_struct *tty, unsigned int status)
491 struct tty_port *port = &usb_port->port;
493 dbg("%s - port %d, status %d", __func__, usb_port->number, status);
495 if (status)
496 wake_up_interruptible(&port->open_wait);
497 else if (tty && !C_CLOCAL(tty))
498 tty_hangup(tty);
500 EXPORT_SYMBOL_GPL(usb_serial_handle_dcd_change);
502 int usb_serial_generic_resume(struct usb_serial *serial)
504 struct usb_serial_port *port;
505 int i, c = 0, r;
507 for (i = 0; i < serial->num_ports; i++) {
508 port = serial->port[i];
509 if (!test_bit(ASYNCB_INITIALIZED, &port->port.flags))
510 continue;
512 if (port->read_urb) {
513 r = usb_submit_urb(port->read_urb, GFP_NOIO);
514 if (r < 0)
515 c++;
518 if (port->bulk_out_size) {
519 r = usb_serial_generic_write_start(port);
520 if (r < 0)
521 c++;
525 return c ? -EIO : 0;
527 EXPORT_SYMBOL_GPL(usb_serial_generic_resume);
529 void usb_serial_generic_disconnect(struct usb_serial *serial)
531 int i;
533 dbg("%s", __func__);
535 /* stop reads and writes on all ports */
536 for (i = 0; i < serial->num_ports; ++i)
537 generic_cleanup(serial->port[i]);
539 EXPORT_SYMBOL_GPL(usb_serial_generic_disconnect);
541 void usb_serial_generic_release(struct usb_serial *serial)
543 dbg("%s", __func__);