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 __u16 vendor
= 0x05f9;
32 static __u16 product
= 0xffff;
34 module_param(vendor
, ushort
, 0);
35 MODULE_PARM_DESC(vendor
, "User specified USB idVendor");
37 module_param(product
, ushort
, 0);
38 MODULE_PARM_DESC(product
, "User specified USB idProduct");
40 static struct usb_device_id generic_device_ids
[2]; /* Initially all zeroes. */
42 /* All of the device info needed for the Generic Serial Converter */
43 struct usb_serial_driver usb_serial_generic_device
= {
48 .id_table
= generic_device_ids
,
50 .disconnect
= usb_serial_generic_disconnect
,
51 .release
= usb_serial_generic_release
,
52 .throttle
= usb_serial_generic_throttle
,
53 .unthrottle
= usb_serial_generic_unthrottle
,
54 .resume
= usb_serial_generic_resume
,
57 static struct usb_serial_driver
* const serial_drivers
[] = {
58 &usb_serial_generic_device
, NULL
63 int usb_serial_generic_register(int _debug
)
68 #ifdef CONFIG_USB_SERIAL_GENERIC
69 generic_device_ids
[0].idVendor
= vendor
;
70 generic_device_ids
[0].idProduct
= product
;
71 generic_device_ids
[0].match_flags
=
72 USB_DEVICE_ID_MATCH_VENDOR
| USB_DEVICE_ID_MATCH_PRODUCT
;
74 /* register our generic driver with ourselves */
75 retval
= usb_serial_register_drivers(serial_drivers
,
76 "usbserial_generic", generic_device_ids
);
81 void usb_serial_generic_deregister(void)
83 #ifdef CONFIG_USB_SERIAL_GENERIC
84 /* remove our generic driver */
85 usb_serial_deregister_drivers(serial_drivers
);
89 int usb_serial_generic_open(struct tty_struct
*tty
, struct usb_serial_port
*port
)
94 /* clear the throttle flags */
95 spin_lock_irqsave(&port
->lock
, flags
);
97 port
->throttle_req
= 0;
98 spin_unlock_irqrestore(&port
->lock
, flags
);
100 /* if we have a bulk endpoint, start reading from it */
101 if (port
->bulk_in_size
)
102 result
= usb_serial_generic_submit_read_urbs(port
, GFP_KERNEL
);
106 EXPORT_SYMBOL_GPL(usb_serial_generic_open
);
108 static void generic_cleanup(struct usb_serial_port
*port
)
110 struct usb_serial
*serial
= port
->serial
;
115 /* shutdown any bulk transfers that might be going on */
116 if (port
->bulk_out_size
) {
117 for (i
= 0; i
< ARRAY_SIZE(port
->write_urbs
); ++i
)
118 usb_kill_urb(port
->write_urbs
[i
]);
120 spin_lock_irqsave(&port
->lock
, flags
);
121 kfifo_reset_out(&port
->write_fifo
);
122 spin_unlock_irqrestore(&port
->lock
, flags
);
124 if (port
->bulk_in_size
) {
125 for (i
= 0; i
< ARRAY_SIZE(port
->read_urbs
); ++i
)
126 usb_kill_urb(port
->read_urbs
[i
]);
131 void usb_serial_generic_close(struct usb_serial_port
*port
)
133 generic_cleanup(port
);
135 EXPORT_SYMBOL_GPL(usb_serial_generic_close
);
137 int usb_serial_generic_prepare_write_buffer(struct usb_serial_port
*port
,
138 void *dest
, size_t size
)
140 return kfifo_out_locked(&port
->write_fifo
, dest
, size
, &port
->lock
);
144 * usb_serial_generic_write_start - kick off an URB write
145 * @port: Pointer to the &struct usb_serial_port data
147 * Returns zero on success, or a negative errno value
149 static int usb_serial_generic_write_start(struct usb_serial_port
*port
)
156 if (test_and_set_bit_lock(USB_SERIAL_WRITE_BUSY
, &port
->flags
))
159 spin_lock_irqsave(&port
->lock
, flags
);
160 if (!port
->write_urbs_free
|| !kfifo_len(&port
->write_fifo
)) {
161 clear_bit_unlock(USB_SERIAL_WRITE_BUSY
, &port
->flags
);
162 spin_unlock_irqrestore(&port
->lock
, flags
);
165 i
= (int)find_first_bit(&port
->write_urbs_free
,
166 ARRAY_SIZE(port
->write_urbs
));
167 spin_unlock_irqrestore(&port
->lock
, flags
);
169 urb
= port
->write_urbs
[i
];
170 count
= port
->serial
->type
->prepare_write_buffer(port
,
171 urb
->transfer_buffer
,
172 port
->bulk_out_size
);
173 urb
->transfer_buffer_length
= count
;
174 usb_serial_debug_data(debug
, &port
->dev
, __func__
, count
,
175 urb
->transfer_buffer
);
176 spin_lock_irqsave(&port
->lock
, flags
);
177 port
->tx_bytes
+= count
;
178 spin_unlock_irqrestore(&port
->lock
, flags
);
180 clear_bit(i
, &port
->write_urbs_free
);
181 result
= usb_submit_urb(urb
, GFP_ATOMIC
);
183 dev_err_console(port
, "%s - error submitting urb: %d\n",
185 set_bit(i
, &port
->write_urbs_free
);
186 spin_lock_irqsave(&port
->lock
, flags
);
187 port
->tx_bytes
-= count
;
188 spin_unlock_irqrestore(&port
->lock
, flags
);
190 clear_bit_unlock(USB_SERIAL_WRITE_BUSY
, &port
->flags
);
194 /* Try sending off another urb, unless in irq context (in which case
195 * there will be no free urb). */
199 clear_bit_unlock(USB_SERIAL_WRITE_BUSY
, &port
->flags
);
205 * usb_serial_generic_write - generic write function for serial USB devices
206 * @tty: Pointer to &struct tty_struct for the device
207 * @port: Pointer to the &usb_serial_port structure for the device
208 * @buf: Pointer to the data to write
209 * @count: Number of bytes to write
211 * Returns the number of characters actually written, which may be anything
212 * from zero to @count. If an error occurs, it returns the negative errno
215 int usb_serial_generic_write(struct tty_struct
*tty
,
216 struct usb_serial_port
*port
, const unsigned char *buf
, int count
)
220 /* only do something if we have a bulk out endpoint */
221 if (!port
->bulk_out_size
)
227 count
= kfifo_in_locked(&port
->write_fifo
, buf
, count
, &port
->lock
);
228 result
= usb_serial_generic_write_start(port
);
234 EXPORT_SYMBOL_GPL(usb_serial_generic_write
);
236 int usb_serial_generic_write_room(struct tty_struct
*tty
)
238 struct usb_serial_port
*port
= tty
->driver_data
;
242 if (!port
->bulk_out_size
)
245 spin_lock_irqsave(&port
->lock
, flags
);
246 room
= kfifo_avail(&port
->write_fifo
);
247 spin_unlock_irqrestore(&port
->lock
, flags
);
249 dev_dbg(&port
->dev
, "%s - returns %d\n", __func__
, room
);
253 int usb_serial_generic_chars_in_buffer(struct tty_struct
*tty
)
255 struct usb_serial_port
*port
= tty
->driver_data
;
259 if (!port
->bulk_out_size
)
262 spin_lock_irqsave(&port
->lock
, flags
);
263 chars
= kfifo_len(&port
->write_fifo
) + port
->tx_bytes
;
264 spin_unlock_irqrestore(&port
->lock
, flags
);
266 dev_dbg(&port
->dev
, "%s - returns %d\n", __func__
, chars
);
270 static int usb_serial_generic_submit_read_urb(struct usb_serial_port
*port
,
271 int index
, gfp_t mem_flags
)
275 if (!test_and_clear_bit(index
, &port
->read_urbs_free
))
278 dev_dbg(&port
->dev
, "%s - port %d, urb %d\n", __func__
,
279 port
->number
, index
);
281 res
= usb_submit_urb(port
->read_urbs
[index
], mem_flags
);
285 "%s - usb_submit_urb failed: %d\n",
288 set_bit(index
, &port
->read_urbs_free
);
295 int usb_serial_generic_submit_read_urbs(struct usb_serial_port
*port
,
301 for (i
= 0; i
< ARRAY_SIZE(port
->read_urbs
); ++i
) {
302 res
= usb_serial_generic_submit_read_urb(port
, i
, mem_flags
);
310 usb_kill_urb(port
->read_urbs
[i
]);
314 EXPORT_SYMBOL_GPL(usb_serial_generic_submit_read_urbs
);
316 void usb_serial_generic_process_read_urb(struct urb
*urb
)
318 struct usb_serial_port
*port
= urb
->context
;
319 struct tty_struct
*tty
;
320 char *ch
= (char *)urb
->transfer_buffer
;
323 if (!urb
->actual_length
)
326 tty
= tty_port_tty_get(&port
->port
);
330 /* The per character mucking around with sysrq path it too slow for
331 stuff like 3G modems, so shortcircuit it in the 99.9999999% of cases
332 where the USB serial is not a console anyway */
333 if (!port
->port
.console
|| !port
->sysrq
)
334 tty_insert_flip_string(tty
, ch
, urb
->actual_length
);
336 for (i
= 0; i
< urb
->actual_length
; i
++, ch
++) {
337 if (!usb_serial_handle_sysrq_char(port
, *ch
))
338 tty_insert_flip_char(tty
, *ch
, TTY_NORMAL
);
341 tty_flip_buffer_push(tty
);
344 EXPORT_SYMBOL_GPL(usb_serial_generic_process_read_urb
);
346 void usb_serial_generic_read_bulk_callback(struct urb
*urb
)
348 struct usb_serial_port
*port
= urb
->context
;
349 unsigned char *data
= urb
->transfer_buffer
;
353 for (i
= 0; i
< ARRAY_SIZE(port
->read_urbs
); ++i
) {
354 if (urb
== port
->read_urbs
[i
])
357 set_bit(i
, &port
->read_urbs_free
);
359 dev_dbg(&port
->dev
, "%s - port %d, urb %d, len %d\n",
360 __func__
, port
->number
, i
, urb
->actual_length
);
363 dev_dbg(&port
->dev
, "%s - non-zero urb status: %d\n",
364 __func__
, urb
->status
);
368 usb_serial_debug_data(debug
, &port
->dev
, __func__
,
369 urb
->actual_length
, data
);
370 port
->serial
->type
->process_read_urb(urb
);
372 /* Throttle the device if requested by tty */
373 spin_lock_irqsave(&port
->lock
, flags
);
374 port
->throttled
= port
->throttle_req
;
375 if (!port
->throttled
) {
376 spin_unlock_irqrestore(&port
->lock
, flags
);
377 usb_serial_generic_submit_read_urb(port
, i
, GFP_ATOMIC
);
379 spin_unlock_irqrestore(&port
->lock
, flags
);
381 EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback
);
383 void usb_serial_generic_write_bulk_callback(struct urb
*urb
)
386 struct usb_serial_port
*port
= urb
->context
;
387 int status
= urb
->status
;
390 for (i
= 0; i
< ARRAY_SIZE(port
->write_urbs
); ++i
)
391 if (port
->write_urbs
[i
] == urb
)
394 spin_lock_irqsave(&port
->lock
, flags
);
395 port
->tx_bytes
-= urb
->transfer_buffer_length
;
396 set_bit(i
, &port
->write_urbs_free
);
397 spin_unlock_irqrestore(&port
->lock
, flags
);
400 dev_dbg(&port
->dev
, "%s - non-zero urb status: %d\n",
403 spin_lock_irqsave(&port
->lock
, flags
);
404 kfifo_reset_out(&port
->write_fifo
);
405 spin_unlock_irqrestore(&port
->lock
, flags
);
407 usb_serial_generic_write_start(port
);
410 usb_serial_port_softint(port
);
412 EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback
);
414 void usb_serial_generic_throttle(struct tty_struct
*tty
)
416 struct usb_serial_port
*port
= tty
->driver_data
;
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 /* Clear the throttle flags */
433 spin_lock_irq(&port
->lock
);
434 was_throttled
= port
->throttled
;
435 port
->throttled
= port
->throttle_req
= 0;
436 spin_unlock_irq(&port
->lock
);
439 usb_serial_generic_submit_read_urbs(port
, GFP_KERNEL
);
441 EXPORT_SYMBOL_GPL(usb_serial_generic_unthrottle
);
443 #ifdef CONFIG_MAGIC_SYSRQ
444 int usb_serial_handle_sysrq_char(struct usb_serial_port
*port
, unsigned int ch
)
446 if (port
->sysrq
&& port
->port
.console
) {
447 if (ch
&& time_before(jiffies
, port
->sysrq
)) {
457 int usb_serial_handle_sysrq_char(struct usb_serial_port
*port
, unsigned int ch
)
462 EXPORT_SYMBOL_GPL(usb_serial_handle_sysrq_char
);
464 int usb_serial_handle_break(struct usb_serial_port
*port
)
467 port
->sysrq
= jiffies
+ HZ
*5;
473 EXPORT_SYMBOL_GPL(usb_serial_handle_break
);
476 * usb_serial_handle_dcd_change - handle a change of carrier detect state
477 * @port: usb_serial_port structure for the open port
478 * @tty: tty_struct structure for the port
479 * @status: new carrier detect status, nonzero if active
481 void usb_serial_handle_dcd_change(struct usb_serial_port
*usb_port
,
482 struct tty_struct
*tty
, unsigned int status
)
484 struct tty_port
*port
= &usb_port
->port
;
486 dev_dbg(&usb_port
->dev
, "%s - port %d, status %d\n", __func__
,
487 usb_port
->number
, status
);
490 wake_up_interruptible(&port
->open_wait
);
491 else if (tty
&& !C_CLOCAL(tty
))
494 EXPORT_SYMBOL_GPL(usb_serial_handle_dcd_change
);
496 int usb_serial_generic_resume(struct usb_serial
*serial
)
498 struct usb_serial_port
*port
;
501 for (i
= 0; i
< serial
->num_ports
; i
++) {
502 port
= serial
->port
[i
];
503 if (!test_bit(ASYNCB_INITIALIZED
, &port
->port
.flags
))
506 if (port
->bulk_in_size
) {
507 r
= usb_serial_generic_submit_read_urbs(port
,
513 if (port
->bulk_out_size
) {
514 r
= usb_serial_generic_write_start(port
);
522 EXPORT_SYMBOL_GPL(usb_serial_generic_resume
);
524 void usb_serial_generic_disconnect(struct usb_serial
*serial
)
528 /* stop reads and writes on all ports */
529 for (i
= 0; i
< serial
->num_ports
; ++i
)
530 generic_cleanup(serial
->port
[i
]);
532 EXPORT_SYMBOL_GPL(usb_serial_generic_disconnect
);
534 void usb_serial_generic_release(struct usb_serial
*serial
)