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>
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_urb(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 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
)
191 if (test_and_set_bit_lock(USB_SERIAL_WRITE_BUSY
, &port
->flags
))
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
);
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 result
= usb_submit_urb(urb
, GFP_ATOMIC
);
213 dev_err(&port
->dev
, "%s - error submitting urb: %d\n",
215 clear_bit_unlock(USB_SERIAL_WRITE_BUSY
, &port
->flags
);
218 clear_bit(i
, &port
->write_urbs_free
);
220 spin_lock_irqsave(&port
->lock
, flags
);
221 port
->tx_bytes
+= count
;
222 spin_unlock_irqrestore(&port
->lock
, flags
);
224 /* Try sending off another urb, unless in irq context (in which case
225 * there will be no free urb). */
229 clear_bit_unlock(USB_SERIAL_WRITE_BUSY
, &port
->flags
);
235 * usb_serial_generic_write - generic write function for serial USB devices
236 * @tty: Pointer to &struct tty_struct for the device
237 * @port: Pointer to the &usb_serial_port structure for the device
238 * @buf: Pointer to the data to write
239 * @count: Number of bytes to write
241 * Returns the number of characters actually written, which may be anything
242 * from zero to @count. If an error occurs, it returns the negative errno
245 int usb_serial_generic_write(struct tty_struct
*tty
,
246 struct usb_serial_port
*port
, const unsigned char *buf
, int count
)
250 dbg("%s - port %d", __func__
, port
->number
);
252 /* only do something if we have a bulk out endpoint */
253 if (!port
->bulk_out_size
)
259 count
= kfifo_in_locked(&port
->write_fifo
, buf
, count
, &port
->lock
);
260 result
= usb_serial_generic_write_start(port
);
266 EXPORT_SYMBOL_GPL(usb_serial_generic_write
);
268 int usb_serial_generic_write_room(struct tty_struct
*tty
)
270 struct usb_serial_port
*port
= tty
->driver_data
;
274 dbg("%s - port %d", __func__
, port
->number
);
276 if (!port
->bulk_out_size
)
279 spin_lock_irqsave(&port
->lock
, flags
);
280 room
= kfifo_avail(&port
->write_fifo
);
281 spin_unlock_irqrestore(&port
->lock
, flags
);
283 dbg("%s - returns %d", __func__
, room
);
287 int usb_serial_generic_chars_in_buffer(struct tty_struct
*tty
)
289 struct usb_serial_port
*port
= tty
->driver_data
;
293 dbg("%s - port %d", __func__
, port
->number
);
295 if (!port
->bulk_out_size
)
298 spin_lock_irqsave(&port
->lock
, flags
);
299 chars
= kfifo_len(&port
->write_fifo
) + port
->tx_bytes
;
300 spin_unlock_irqrestore(&port
->lock
, flags
);
302 dbg("%s - returns %d", __func__
, chars
);
306 int usb_serial_generic_submit_read_urb(struct usb_serial_port
*port
,
311 result
= usb_submit_urb(port
->read_urb
, mem_flags
);
312 if (result
&& result
!= -EPERM
) {
313 dev_err(&port
->dev
, "%s - error submitting urb: %d\n",
318 EXPORT_SYMBOL_GPL(usb_serial_generic_submit_read_urb
);
320 void usb_serial_generic_process_read_urb(struct urb
*urb
)
322 struct usb_serial_port
*port
= urb
->context
;
323 struct tty_struct
*tty
;
324 char *ch
= (char *)urb
->transfer_buffer
;
327 if (!urb
->actual_length
)
330 tty
= tty_port_tty_get(&port
->port
);
334 /* The per character mucking around with sysrq path it too slow for
335 stuff like 3G modems, so shortcircuit it in the 99.9999999% of cases
336 where the USB serial is not a console anyway */
337 if (!port
->port
.console
|| !port
->sysrq
)
338 tty_insert_flip_string(tty
, ch
, urb
->actual_length
);
340 for (i
= 0; i
< urb
->actual_length
; i
++, ch
++) {
341 if (!usb_serial_handle_sysrq_char(tty
, port
, *ch
))
342 tty_insert_flip_char(tty
, *ch
, TTY_NORMAL
);
345 tty_flip_buffer_push(tty
);
348 EXPORT_SYMBOL_GPL(usb_serial_generic_process_read_urb
);
350 void usb_serial_generic_read_bulk_callback(struct urb
*urb
)
352 struct usb_serial_port
*port
= urb
->context
;
353 unsigned char *data
= urb
->transfer_buffer
;
354 int status
= urb
->status
;
357 dbg("%s - port %d", __func__
, port
->number
);
359 if (unlikely(status
!= 0)) {
360 dbg("%s - nonzero read bulk status received: %d",
365 usb_serial_debug_data(debug
, &port
->dev
, __func__
,
366 urb
->actual_length
, data
);
367 port
->serial
->type
->process_read_urb(urb
);
369 /* Throttle the device if requested by tty */
370 spin_lock_irqsave(&port
->lock
, flags
);
371 port
->throttled
= port
->throttle_req
;
372 if (!port
->throttled
) {
373 spin_unlock_irqrestore(&port
->lock
, flags
);
374 usb_serial_generic_submit_read_urb(port
, GFP_ATOMIC
);
376 spin_unlock_irqrestore(&port
->lock
, flags
);
378 EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback
);
380 void usb_serial_generic_write_bulk_callback(struct urb
*urb
)
383 struct usb_serial_port
*port
= urb
->context
;
384 int status
= urb
->status
;
387 dbg("%s - port %d", __func__
, port
->number
);
389 for (i
= 0; i
< ARRAY_SIZE(port
->write_urbs
); ++i
)
390 if (port
->write_urbs
[i
] == urb
)
393 spin_lock_irqsave(&port
->lock
, flags
);
394 port
->tx_bytes
-= urb
->transfer_buffer_length
;
395 set_bit(i
, &port
->write_urbs_free
);
396 spin_unlock_irqrestore(&port
->lock
, flags
);
399 dbg("%s - non-zero urb status: %d", __func__
, status
);
401 spin_lock_irqsave(&port
->lock
, flags
);
402 kfifo_reset_out(&port
->write_fifo
);
403 spin_unlock_irqrestore(&port
->lock
, flags
);
405 usb_serial_generic_write_start(port
);
408 usb_serial_port_softint(port
);
410 EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback
);
412 void usb_serial_generic_throttle(struct tty_struct
*tty
)
414 struct usb_serial_port
*port
= tty
->driver_data
;
417 dbg("%s - port %d", __func__
, port
->number
);
419 /* Set the throttle request flag. It will be picked up
420 * by usb_serial_generic_read_bulk_callback(). */
421 spin_lock_irqsave(&port
->lock
, flags
);
422 port
->throttle_req
= 1;
423 spin_unlock_irqrestore(&port
->lock
, flags
);
425 EXPORT_SYMBOL_GPL(usb_serial_generic_throttle
);
427 void usb_serial_generic_unthrottle(struct tty_struct
*tty
)
429 struct usb_serial_port
*port
= tty
->driver_data
;
432 dbg("%s - port %d", __func__
, port
->number
);
434 /* Clear the throttle flags */
435 spin_lock_irq(&port
->lock
);
436 was_throttled
= port
->throttled
;
437 port
->throttled
= port
->throttle_req
= 0;
438 spin_unlock_irq(&port
->lock
);
441 usb_serial_generic_submit_read_urb(port
, GFP_KERNEL
);
443 EXPORT_SYMBOL_GPL(usb_serial_generic_unthrottle
);
445 #ifdef CONFIG_MAGIC_SYSRQ
446 int usb_serial_handle_sysrq_char(struct tty_struct
*tty
,
447 struct usb_serial_port
*port
, unsigned int ch
)
449 if (port
->sysrq
&& port
->port
.console
) {
450 if (ch
&& time_before(jiffies
, port
->sysrq
)) {
451 handle_sysrq(ch
, tty
);
460 int usb_serial_handle_sysrq_char(struct tty_struct
*tty
,
461 struct usb_serial_port
*port
, unsigned int ch
)
466 EXPORT_SYMBOL_GPL(usb_serial_handle_sysrq_char
);
468 int usb_serial_handle_break(struct usb_serial_port
*port
)
471 port
->sysrq
= jiffies
+ HZ
*5;
477 EXPORT_SYMBOL_GPL(usb_serial_handle_break
);
479 int usb_serial_generic_resume(struct usb_serial
*serial
)
481 struct usb_serial_port
*port
;
484 for (i
= 0; i
< serial
->num_ports
; i
++) {
485 port
= serial
->port
[i
];
486 if (!test_bit(ASYNCB_INITIALIZED
, &port
->port
.flags
))
489 if (port
->read_urb
) {
490 r
= usb_submit_urb(port
->read_urb
, GFP_NOIO
);
495 if (port
->bulk_out_size
) {
496 r
= usb_serial_generic_write_start(port
);
504 EXPORT_SYMBOL_GPL(usb_serial_generic_resume
);
506 void usb_serial_generic_disconnect(struct usb_serial
*serial
)
512 /* stop reads and writes on all ports */
513 for (i
= 0; i
< serial
->num_ports
; ++i
)
514 generic_cleanup(serial
->port
[i
]);
517 void usb_serial_generic_release(struct usb_serial
*serial
)