2 * USB Serial Converter Generic functions
4 * Copyright (C) 2010 - 2011 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>
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
[] = {
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
,
60 /* All of the device info needed for the Generic Serial Converter */
61 struct usb_serial_driver usb_serial_generic_device
= {
66 .id_table
= generic_device_ids
,
67 .usb_driver
= &generic_driver
,
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
);
88 int usb_serial_generic_register(int _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
);
103 retval
= usb_register(&generic_driver
);
105 usb_serial_deregister(&usb_serial_generic_device
);
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
);
120 int usb_serial_generic_open(struct tty_struct
*tty
, struct usb_serial_port
*port
)
125 dbg("%s - port %d", __func__
, port
->number
);
127 /* clear the throttle flags */
128 spin_lock_irqsave(&port
->lock
, flags
);
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_urbs(port
, GFP_KERNEL
);
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
;
147 dbg("%s - port %d", __func__
, port
->number
);
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 for (i
= 0; i
< ARRAY_SIZE(port
->read_urbs
); ++i
)
162 usb_kill_urb(port
->read_urbs
[i
]);
167 void usb_serial_generic_close(struct usb_serial_port
*port
)
169 dbg("%s - port %d", __func__
, port
->number
);
170 generic_cleanup(port
);
172 EXPORT_SYMBOL_GPL(usb_serial_generic_close
);
174 int usb_serial_generic_prepare_write_buffer(struct usb_serial_port
*port
,
175 void *dest
, size_t size
)
177 return kfifo_out_locked(&port
->write_fifo
, dest
, size
, &port
->lock
);
181 * usb_serial_generic_write_start - kick off an URB write
182 * @port: Pointer to the &struct usb_serial_port data
184 * Returns zero on success, or a negative errno value
186 static int usb_serial_generic_write_start(struct usb_serial_port
*port
)
193 if (test_and_set_bit_lock(USB_SERIAL_WRITE_BUSY
, &port
->flags
))
196 spin_lock_irqsave(&port
->lock
, flags
);
197 if (!port
->write_urbs_free
|| !kfifo_len(&port
->write_fifo
)) {
198 clear_bit_unlock(USB_SERIAL_WRITE_BUSY
, &port
->flags
);
199 spin_unlock_irqrestore(&port
->lock
, flags
);
202 i
= (int)find_first_bit(&port
->write_urbs_free
,
203 ARRAY_SIZE(port
->write_urbs
));
204 spin_unlock_irqrestore(&port
->lock
, flags
);
206 urb
= port
->write_urbs
[i
];
207 count
= port
->serial
->type
->prepare_write_buffer(port
,
208 urb
->transfer_buffer
,
209 port
->bulk_out_size
);
210 urb
->transfer_buffer_length
= count
;
211 usb_serial_debug_data(debug
, &port
->dev
, __func__
, count
,
212 urb
->transfer_buffer
);
213 spin_lock_irqsave(&port
->lock
, flags
);
214 port
->tx_bytes
+= count
;
215 spin_unlock_irqrestore(&port
->lock
, flags
);
217 clear_bit(i
, &port
->write_urbs_free
);
218 result
= usb_submit_urb(urb
, GFP_ATOMIC
);
220 dev_err(&port
->dev
, "%s - error submitting urb: %d\n",
222 set_bit(i
, &port
->write_urbs_free
);
223 spin_lock_irqsave(&port
->lock
, flags
);
224 port
->tx_bytes
-= count
;
225 spin_unlock_irqrestore(&port
->lock
, flags
);
227 clear_bit_unlock(USB_SERIAL_WRITE_BUSY
, &port
->flags
);
231 /* Try sending off another urb, unless in irq context (in which case
232 * there will be no free urb). */
236 clear_bit_unlock(USB_SERIAL_WRITE_BUSY
, &port
->flags
);
242 * usb_serial_generic_write - generic write function for serial USB devices
243 * @tty: Pointer to &struct tty_struct for the device
244 * @port: Pointer to the &usb_serial_port structure for the device
245 * @buf: Pointer to the data to write
246 * @count: Number of bytes to write
248 * Returns the number of characters actually written, which may be anything
249 * from zero to @count. If an error occurs, it returns the negative errno
252 int usb_serial_generic_write(struct tty_struct
*tty
,
253 struct usb_serial_port
*port
, const unsigned char *buf
, int count
)
257 dbg("%s - port %d", __func__
, port
->number
);
259 /* only do something if we have a bulk out endpoint */
260 if (!port
->bulk_out_size
)
266 count
= kfifo_in_locked(&port
->write_fifo
, buf
, count
, &port
->lock
);
267 result
= usb_serial_generic_write_start(port
);
273 EXPORT_SYMBOL_GPL(usb_serial_generic_write
);
275 int usb_serial_generic_write_room(struct tty_struct
*tty
)
277 struct usb_serial_port
*port
= tty
->driver_data
;
281 dbg("%s - port %d", __func__
, port
->number
);
283 if (!port
->bulk_out_size
)
286 spin_lock_irqsave(&port
->lock
, flags
);
287 room
= kfifo_avail(&port
->write_fifo
);
288 spin_unlock_irqrestore(&port
->lock
, flags
);
290 dbg("%s - returns %d", __func__
, room
);
294 int usb_serial_generic_chars_in_buffer(struct tty_struct
*tty
)
296 struct usb_serial_port
*port
= tty
->driver_data
;
300 dbg("%s - port %d", __func__
, port
->number
);
302 if (!port
->bulk_out_size
)
305 spin_lock_irqsave(&port
->lock
, flags
);
306 chars
= kfifo_len(&port
->write_fifo
) + port
->tx_bytes
;
307 spin_unlock_irqrestore(&port
->lock
, flags
);
309 dbg("%s - returns %d", __func__
, chars
);
313 static int usb_serial_generic_submit_read_urb(struct usb_serial_port
*port
,
314 int index
, gfp_t mem_flags
)
318 if (!test_and_clear_bit(index
, &port
->read_urbs_free
))
321 dbg("%s - port %d, urb %d\n", __func__
, port
->number
, index
);
323 res
= usb_submit_urb(port
->read_urbs
[index
], mem_flags
);
327 "%s - usb_submit_urb failed: %d\n",
330 set_bit(index
, &port
->read_urbs_free
);
337 int usb_serial_generic_submit_read_urbs(struct usb_serial_port
*port
,
343 dbg("%s - port %d", __func__
, port
->number
);
345 for (i
= 0; i
< ARRAY_SIZE(port
->read_urbs
); ++i
) {
346 res
= usb_serial_generic_submit_read_urb(port
, i
, mem_flags
);
354 usb_kill_urb(port
->read_urbs
[i
]);
358 EXPORT_SYMBOL_GPL(usb_serial_generic_submit_read_urbs
);
360 void usb_serial_generic_process_read_urb(struct urb
*urb
)
362 struct usb_serial_port
*port
= urb
->context
;
363 struct tty_struct
*tty
;
364 char *ch
= (char *)urb
->transfer_buffer
;
367 if (!urb
->actual_length
)
370 tty
= tty_port_tty_get(&port
->port
);
374 /* The per character mucking around with sysrq path it too slow for
375 stuff like 3G modems, so shortcircuit it in the 99.9999999% of cases
376 where the USB serial is not a console anyway */
377 if (!port
->port
.console
|| !port
->sysrq
)
378 tty_insert_flip_string(tty
, ch
, urb
->actual_length
);
380 for (i
= 0; i
< urb
->actual_length
; i
++, ch
++) {
381 if (!usb_serial_handle_sysrq_char(port
, *ch
))
382 tty_insert_flip_char(tty
, *ch
, TTY_NORMAL
);
385 tty_flip_buffer_push(tty
);
388 EXPORT_SYMBOL_GPL(usb_serial_generic_process_read_urb
);
390 void usb_serial_generic_read_bulk_callback(struct urb
*urb
)
392 struct usb_serial_port
*port
= urb
->context
;
393 unsigned char *data
= urb
->transfer_buffer
;
397 for (i
= 0; i
< ARRAY_SIZE(port
->read_urbs
); ++i
) {
398 if (urb
== port
->read_urbs
[i
])
401 set_bit(i
, &port
->read_urbs_free
);
403 dbg("%s - port %d, urb %d, len %d\n", __func__
, port
->number
, i
,
406 dbg("%s - non-zero urb status: %d\n", __func__
, urb
->status
);
410 usb_serial_debug_data(debug
, &port
->dev
, __func__
,
411 urb
->actual_length
, data
);
412 port
->serial
->type
->process_read_urb(urb
);
414 /* Throttle the device if requested by tty */
415 spin_lock_irqsave(&port
->lock
, flags
);
416 port
->throttled
= port
->throttle_req
;
417 if (!port
->throttled
) {
418 spin_unlock_irqrestore(&port
->lock
, flags
);
419 usb_serial_generic_submit_read_urb(port
, i
, GFP_ATOMIC
);
421 spin_unlock_irqrestore(&port
->lock
, flags
);
423 EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback
);
425 void usb_serial_generic_write_bulk_callback(struct urb
*urb
)
428 struct usb_serial_port
*port
= urb
->context
;
429 int status
= urb
->status
;
432 dbg("%s - port %d", __func__
, port
->number
);
434 for (i
= 0; i
< ARRAY_SIZE(port
->write_urbs
); ++i
)
435 if (port
->write_urbs
[i
] == urb
)
438 spin_lock_irqsave(&port
->lock
, flags
);
439 port
->tx_bytes
-= urb
->transfer_buffer_length
;
440 set_bit(i
, &port
->write_urbs_free
);
441 spin_unlock_irqrestore(&port
->lock
, flags
);
444 dbg("%s - non-zero urb status: %d", __func__
, status
);
446 spin_lock_irqsave(&port
->lock
, flags
);
447 kfifo_reset_out(&port
->write_fifo
);
448 spin_unlock_irqrestore(&port
->lock
, flags
);
450 usb_serial_generic_write_start(port
);
453 usb_serial_port_softint(port
);
455 EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback
);
457 void usb_serial_generic_throttle(struct tty_struct
*tty
)
459 struct usb_serial_port
*port
= tty
->driver_data
;
462 dbg("%s - port %d", __func__
, port
->number
);
464 /* Set the throttle request flag. It will be picked up
465 * by usb_serial_generic_read_bulk_callback(). */
466 spin_lock_irqsave(&port
->lock
, flags
);
467 port
->throttle_req
= 1;
468 spin_unlock_irqrestore(&port
->lock
, flags
);
470 EXPORT_SYMBOL_GPL(usb_serial_generic_throttle
);
472 void usb_serial_generic_unthrottle(struct tty_struct
*tty
)
474 struct usb_serial_port
*port
= tty
->driver_data
;
477 dbg("%s - port %d", __func__
, port
->number
);
479 /* Clear the throttle flags */
480 spin_lock_irq(&port
->lock
);
481 was_throttled
= port
->throttled
;
482 port
->throttled
= port
->throttle_req
= 0;
483 spin_unlock_irq(&port
->lock
);
486 usb_serial_generic_submit_read_urbs(port
, GFP_KERNEL
);
488 EXPORT_SYMBOL_GPL(usb_serial_generic_unthrottle
);
490 #ifdef CONFIG_MAGIC_SYSRQ
491 int usb_serial_handle_sysrq_char(struct usb_serial_port
*port
, unsigned int ch
)
493 if (port
->sysrq
&& port
->port
.console
) {
494 if (ch
&& time_before(jiffies
, port
->sysrq
)) {
504 int usb_serial_handle_sysrq_char(struct usb_serial_port
*port
, unsigned int ch
)
509 EXPORT_SYMBOL_GPL(usb_serial_handle_sysrq_char
);
511 int usb_serial_handle_break(struct usb_serial_port
*port
)
514 port
->sysrq
= jiffies
+ HZ
*5;
520 EXPORT_SYMBOL_GPL(usb_serial_handle_break
);
523 * usb_serial_handle_dcd_change - handle a change of carrier detect state
524 * @port: usb_serial_port structure for the open port
525 * @tty: tty_struct structure for the port
526 * @status: new carrier detect status, nonzero if active
528 void usb_serial_handle_dcd_change(struct usb_serial_port
*usb_port
,
529 struct tty_struct
*tty
, unsigned int status
)
531 struct tty_port
*port
= &usb_port
->port
;
533 dbg("%s - port %d, status %d", __func__
, usb_port
->number
, status
);
536 wake_up_interruptible(&port
->open_wait
);
537 else if (tty
&& !C_CLOCAL(tty
))
540 EXPORT_SYMBOL_GPL(usb_serial_handle_dcd_change
);
542 int usb_serial_generic_resume(struct usb_serial
*serial
)
544 struct usb_serial_port
*port
;
547 for (i
= 0; i
< serial
->num_ports
; i
++) {
548 port
= serial
->port
[i
];
549 if (!test_bit(ASYNCB_INITIALIZED
, &port
->port
.flags
))
552 if (port
->bulk_in_size
) {
553 r
= usb_serial_generic_submit_read_urbs(port
,
559 if (port
->bulk_out_size
) {
560 r
= usb_serial_generic_write_start(port
);
568 EXPORT_SYMBOL_GPL(usb_serial_generic_resume
);
570 void usb_serial_generic_disconnect(struct usb_serial
*serial
)
576 /* stop reads and writes on all ports */
577 for (i
= 0; i
< serial
->num_ports
; ++i
)
578 generic_cleanup(serial
->port
[i
]);
580 EXPORT_SYMBOL_GPL(usb_serial_generic_disconnect
);
582 void usb_serial_generic_release(struct usb_serial
*serial
)