2 * USB Serial Converter Generic functions
4 * Copyright (C) 2010 - 2013 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.
12 #include <linux/kernel.h>
13 #include <linux/errno.h>
14 #include <linux/slab.h>
15 #include <linux/sysrq.h>
16 #include <linux/tty.h>
17 #include <linux/tty_flip.h>
18 #include <linux/module.h>
19 #include <linux/moduleparam.h>
20 #include <linux/usb.h>
21 #include <linux/usb/serial.h>
22 #include <linux/uaccess.h>
23 #include <linux/kfifo.h>
24 #include <linux/serial.h>
26 #ifdef CONFIG_USB_SERIAL_GENERIC
28 static __u16 vendor = 0x05f9;
29 static __u16 product = 0xffff;
31 module_param(vendor, ushort, 0);
32 MODULE_PARM_DESC(vendor, "User specified USB idVendor");
34 module_param(product, ushort, 0);
35 MODULE_PARM_DESC(product, "User specified USB idProduct");
37 static struct usb_device_id generic_device_ids[2]; /* Initially all zeroes. */
39 struct usb_serial_driver usb_serial_generic_device = {
44 .id_table = generic_device_ids,
46 .throttle = usb_serial_generic_throttle,
47 .unthrottle = usb_serial_generic_unthrottle,
48 .resume = usb_serial_generic_resume,
51 static struct usb_serial_driver * const serial_drivers[] = {
52 &usb_serial_generic_device, NULL
57 int usb_serial_generic_register(void)
61 #ifdef CONFIG_USB_SERIAL_GENERIC
62 generic_device_ids[0].idVendor = vendor;
63 generic_device_ids[0].idProduct = product;
64 generic_device_ids[0].match_flags =
65 USB_DEVICE_ID_MATCH_VENDOR | USB_DEVICE_ID_MATCH_PRODUCT;
67 retval = usb_serial_register_drivers(serial_drivers,
68 "usbserial_generic", generic_device_ids);
73 void usb_serial_generic_deregister(void)
75 #ifdef CONFIG_USB_SERIAL_GENERIC
76 usb_serial_deregister_drivers(serial_drivers);
80 int usb_serial_generic_open(struct tty_struct *tty, struct usb_serial_port *port)
85 spin_lock_irqsave(&port->lock, flags);
87 port->throttle_req = 0;
88 spin_unlock_irqrestore(&port->lock, flags);
90 if (port->bulk_in_size)
91 result = usb_serial_generic_submit_read_urbs(port, GFP_KERNEL);
95 EXPORT_SYMBOL_GPL(usb_serial_generic_open);
97 void usb_serial_generic_close(struct usb_serial_port *port)
102 if (port->bulk_out_size) {
103 for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i)
104 usb_kill_urb(port->write_urbs[i]);
106 spin_lock_irqsave(&port->lock, flags);
107 kfifo_reset_out(&port->write_fifo);
108 spin_unlock_irqrestore(&port->lock, flags);
110 if (port->bulk_in_size) {
111 for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i)
112 usb_kill_urb(port->read_urbs[i]);
115 EXPORT_SYMBOL_GPL(usb_serial_generic_close);
117 int usb_serial_generic_prepare_write_buffer(struct usb_serial_port *port,
118 void *dest, size_t size)
120 return kfifo_out_locked(&port->write_fifo, dest, size, &port->lock);
124 * usb_serial_generic_write_start - start writing buffered data
125 * @port: usb-serial port
126 * @mem_flags: flags to use for memory allocations
128 * Serialised using USB_SERIAL_WRITE_BUSY flag.
130 * Return: Zero on success or if busy, otherwise a negative errno value.
132 int usb_serial_generic_write_start(struct usb_serial_port *port,
140 if (test_and_set_bit_lock(USB_SERIAL_WRITE_BUSY, &port->flags))
143 spin_lock_irqsave(&port->lock, flags);
144 if (!port->write_urbs_free || !kfifo_len(&port->write_fifo)) {
145 clear_bit_unlock(USB_SERIAL_WRITE_BUSY, &port->flags);
146 spin_unlock_irqrestore(&port->lock, flags);
149 i = (int)find_first_bit(&port->write_urbs_free,
150 ARRAY_SIZE(port->write_urbs));
151 spin_unlock_irqrestore(&port->lock, flags);
153 urb = port->write_urbs[i];
154 count = port->serial->type->prepare_write_buffer(port,
155 urb->transfer_buffer,
156 port->bulk_out_size);
157 urb->transfer_buffer_length = count;
158 usb_serial_debug_data(&port->dev, __func__, count, urb->transfer_buffer);
159 spin_lock_irqsave(&port->lock, flags);
160 port->tx_bytes += count;
161 spin_unlock_irqrestore(&port->lock, flags);
163 clear_bit(i, &port->write_urbs_free);
164 result = usb_submit_urb(urb, mem_flags);
166 dev_err_console(port, "%s - error submitting urb: %d\n",
168 set_bit(i, &port->write_urbs_free);
169 spin_lock_irqsave(&port->lock, flags);
170 port->tx_bytes -= count;
171 spin_unlock_irqrestore(&port->lock, flags);
173 clear_bit_unlock(USB_SERIAL_WRITE_BUSY, &port->flags);
177 goto retry; /* try sending off another urb */
179 EXPORT_SYMBOL_GPL(usb_serial_generic_write_start);
182 * usb_serial_generic_write - generic write function
183 * @tty: tty for the port
184 * @port: usb-serial port
185 * @buf: data to write
186 * @count: number of bytes to write
188 * Return: The number of characters buffered, which may be anything from
189 * zero to @count, or a negative errno value.
191 int usb_serial_generic_write(struct tty_struct *tty,
192 struct usb_serial_port *port, const unsigned char *buf, int count)
196 if (!port->bulk_out_size)
202 count = kfifo_in_locked(&port->write_fifo, buf, count, &port->lock);
203 result = usb_serial_generic_write_start(port, GFP_ATOMIC);
209 EXPORT_SYMBOL_GPL(usb_serial_generic_write);
211 int usb_serial_generic_write_room(struct tty_struct *tty)
213 struct usb_serial_port *port = tty->driver_data;
217 if (!port->bulk_out_size)
220 spin_lock_irqsave(&port->lock, flags);
221 room = kfifo_avail(&port->write_fifo);
222 spin_unlock_irqrestore(&port->lock, flags);
224 dev_dbg(&port->dev, "%s - returns %d\n", __func__, room);
228 int usb_serial_generic_chars_in_buffer(struct tty_struct *tty)
230 struct usb_serial_port *port = tty->driver_data;
234 if (!port->bulk_out_size)
237 spin_lock_irqsave(&port->lock, flags);
238 chars = kfifo_len(&port->write_fifo) + port->tx_bytes;
239 spin_unlock_irqrestore(&port->lock, flags);
241 dev_dbg(&port->dev, "%s - returns %d\n", __func__, chars);
244 EXPORT_SYMBOL_GPL(usb_serial_generic_chars_in_buffer);
246 void usb_serial_generic_wait_until_sent(struct tty_struct *tty, long timeout)
248 struct usb_serial_port *port = tty->driver_data;
250 unsigned long period;
251 unsigned long expire;
253 bps = tty_get_baud_rate(tty);
257 * Use a poll-period of roughly the time it takes to send one
258 * character or at least one jiffy.
260 period = max_t(unsigned long, (10 * HZ / bps), 1);
262 period = min_t(unsigned long, period, timeout);
264 dev_dbg(&port->dev, "%s - timeout = %u ms, period = %u ms\n",
265 __func__, jiffies_to_msecs(timeout),
266 jiffies_to_msecs(period));
267 expire = jiffies + timeout;
268 while (!port->serial->type->tx_empty(port)) {
269 schedule_timeout_interruptible(period);
270 if (signal_pending(current))
272 if (timeout && time_after(jiffies, expire))
276 EXPORT_SYMBOL_GPL(usb_serial_generic_wait_until_sent);
278 static int usb_serial_generic_submit_read_urb(struct usb_serial_port *port,
279 int index, gfp_t mem_flags)
283 if (!test_and_clear_bit(index, &port->read_urbs_free))
286 dev_dbg(&port->dev, "%s - urb %d\n", __func__, index);
288 res = usb_submit_urb(port->read_urbs[index], mem_flags);
290 if (res != -EPERM && res != -ENODEV) {
292 "%s - usb_submit_urb failed: %d\n",
295 set_bit(index, &port->read_urbs_free);
302 int usb_serial_generic_submit_read_urbs(struct usb_serial_port *port,
308 for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i) {
309 res = usb_serial_generic_submit_read_urb(port, i, mem_flags);
317 usb_kill_urb(port->read_urbs[i]);
321 EXPORT_SYMBOL_GPL(usb_serial_generic_submit_read_urbs);
323 void usb_serial_generic_process_read_urb(struct urb *urb)
325 struct usb_serial_port *port = urb->context;
326 char *ch = (char *)urb->transfer_buffer;
329 if (!urb->actual_length)
332 * The per character mucking around with sysrq path it too slow for
333 * stuff like 3G modems, so shortcircuit it in the 99.9999999% of
334 * cases where the USB serial is not a console anyway.
336 if (!port->port.console || !port->sysrq) {
337 tty_insert_flip_string(&port->port, ch, urb->actual_length);
339 for (i = 0; i < urb->actual_length; i++, ch++) {
340 if (!usb_serial_handle_sysrq_char(port, *ch))
341 tty_insert_flip_char(&port->port, *ch, TTY_NORMAL);
344 tty_flip_buffer_push(&port->port);
346 EXPORT_SYMBOL_GPL(usb_serial_generic_process_read_urb);
348 void usb_serial_generic_read_bulk_callback(struct urb *urb)
350 struct usb_serial_port *port = urb->context;
351 unsigned char *data = urb->transfer_buffer;
353 bool stopped = false;
354 int status = urb->status;
357 for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i) {
358 if (urb == port->read_urbs[i])
362 dev_dbg(&port->dev, "%s - urb %d, len %d\n", __func__, i,
366 usb_serial_debug_data(&port->dev, __func__, urb->actual_length,
368 port->serial->type->process_read_urb(urb);
373 dev_dbg(&port->dev, "%s - urb stopped: %d\n",
378 dev_err(&port->dev, "%s - urb stopped: %d\n",
383 dev_dbg(&port->dev, "%s - nonzero urb status: %d\n",
389 * Make sure URB processing is done before marking as free to avoid
390 * racing with unthrottle() on another CPU. Matches the barriers
391 * implied by the test_and_clear_bit() in
392 * usb_serial_generic_submit_read_urb().
394 smp_mb__before_atomic();
395 set_bit(i, &port->read_urbs_free);
397 * Make sure URB is marked as free before checking the throttled flag
398 * to avoid racing with unthrottle() on another CPU. Matches the
399 * smp_mb() in unthrottle().
401 smp_mb__after_atomic();
406 /* Throttle the device if requested by tty */
407 spin_lock_irqsave(&port->lock, flags);
408 port->throttled = port->throttle_req;
409 if (!port->throttled) {
410 spin_unlock_irqrestore(&port->lock, flags);
411 usb_serial_generic_submit_read_urb(port, i, GFP_ATOMIC);
413 spin_unlock_irqrestore(&port->lock, flags);
416 EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback);
418 void usb_serial_generic_write_bulk_callback(struct urb *urb)
421 struct usb_serial_port *port = urb->context;
422 int status = urb->status;
425 for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i) {
426 if (port->write_urbs[i] == urb)
429 spin_lock_irqsave(&port->lock, flags);
430 port->tx_bytes -= urb->transfer_buffer_length;
431 set_bit(i, &port->write_urbs_free);
432 spin_unlock_irqrestore(&port->lock, flags);
440 dev_dbg(&port->dev, "%s - urb stopped: %d\n",
444 dev_err_console(port, "%s - urb stopped: %d\n",
448 dev_err_console(port, "%s - nonzero urb status: %d\n",
454 usb_serial_generic_write_start(port, GFP_ATOMIC);
455 usb_serial_port_softint(port);
457 EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback);
459 void usb_serial_generic_throttle(struct tty_struct *tty)
461 struct usb_serial_port *port = tty->driver_data;
464 spin_lock_irqsave(&port->lock, flags);
465 port->throttle_req = 1;
466 spin_unlock_irqrestore(&port->lock, flags);
468 EXPORT_SYMBOL_GPL(usb_serial_generic_throttle);
470 void usb_serial_generic_unthrottle(struct tty_struct *tty)
472 struct usb_serial_port *port = tty->driver_data;
475 spin_lock_irq(&port->lock);
476 was_throttled = port->throttled;
477 port->throttled = port->throttle_req = 0;
478 spin_unlock_irq(&port->lock);
481 * Matches the smp_mb__after_atomic() in
482 * usb_serial_generic_read_bulk_callback().
487 usb_serial_generic_submit_read_urbs(port, GFP_KERNEL);
489 EXPORT_SYMBOL_GPL(usb_serial_generic_unthrottle);
491 static bool usb_serial_generic_msr_changed(struct tty_struct *tty,
492 unsigned long arg, struct async_icount *cprev)
494 struct usb_serial_port *port = tty->driver_data;
495 struct async_icount cnow;
500 * Use tty-port initialised flag to detect all hangups including the
501 * one generated at USB-device disconnect.
503 if (!tty_port_initialized(&port->port))
506 spin_lock_irqsave(&port->lock, flags);
507 cnow = port->icount; /* atomic copy*/
508 spin_unlock_irqrestore(&port->lock, flags);
510 ret = ((arg & TIOCM_RNG) && (cnow.rng != cprev->rng)) ||
511 ((arg & TIOCM_DSR) && (cnow.dsr != cprev->dsr)) ||
512 ((arg & TIOCM_CD) && (cnow.dcd != cprev->dcd)) ||
513 ((arg & TIOCM_CTS) && (cnow.cts != cprev->cts));
520 int usb_serial_generic_tiocmiwait(struct tty_struct *tty, unsigned long arg)
522 struct usb_serial_port *port = tty->driver_data;
523 struct async_icount cnow;
527 spin_lock_irqsave(&port->lock, flags);
528 cnow = port->icount; /* atomic copy */
529 spin_unlock_irqrestore(&port->lock, flags);
531 ret = wait_event_interruptible(port->port.delta_msr_wait,
532 usb_serial_generic_msr_changed(tty, arg, &cnow));
533 if (!ret && !tty_port_initialized(&port->port))
538 EXPORT_SYMBOL_GPL(usb_serial_generic_tiocmiwait);
540 int usb_serial_generic_get_icount(struct tty_struct *tty,
541 struct serial_icounter_struct *icount)
543 struct usb_serial_port *port = tty->driver_data;
544 struct async_icount cnow;
547 spin_lock_irqsave(&port->lock, flags);
548 cnow = port->icount; /* atomic copy */
549 spin_unlock_irqrestore(&port->lock, flags);
551 icount->cts = cnow.cts;
552 icount->dsr = cnow.dsr;
553 icount->rng = cnow.rng;
554 icount->dcd = cnow.dcd;
555 icount->tx = cnow.tx;
556 icount->rx = cnow.rx;
557 icount->frame = cnow.frame;
558 icount->parity = cnow.parity;
559 icount->overrun = cnow.overrun;
560 icount->brk = cnow.brk;
561 icount->buf_overrun = cnow.buf_overrun;
565 EXPORT_SYMBOL_GPL(usb_serial_generic_get_icount);
567 #ifdef CONFIG_MAGIC_SYSRQ
568 int usb_serial_handle_sysrq_char(struct usb_serial_port *port, unsigned int ch)
570 if (port->sysrq && port->port.console) {
571 if (ch && time_before(jiffies, port->sysrq)) {
581 int usb_serial_handle_sysrq_char(struct usb_serial_port *port, unsigned int ch)
586 EXPORT_SYMBOL_GPL(usb_serial_handle_sysrq_char);
588 int usb_serial_handle_break(struct usb_serial_port *port)
591 port->sysrq = jiffies + HZ*5;
597 EXPORT_SYMBOL_GPL(usb_serial_handle_break);
600 * usb_serial_handle_dcd_change - handle a change of carrier detect state
601 * @port: usb-serial port
602 * @tty: tty for the port
603 * @status: new carrier detect status, nonzero if active
605 void usb_serial_handle_dcd_change(struct usb_serial_port *usb_port,
606 struct tty_struct *tty, unsigned int status)
608 struct tty_port *port = &usb_port->port;
610 dev_dbg(&usb_port->dev, "%s - status %d\n", __func__, status);
613 struct tty_ldisc *ld = tty_ldisc_ref(tty);
616 if (ld->ops->dcd_change)
617 ld->ops->dcd_change(tty, status);
623 wake_up_interruptible(&port->open_wait);
624 else if (tty && !C_CLOCAL(tty))
627 EXPORT_SYMBOL_GPL(usb_serial_handle_dcd_change);
629 int usb_serial_generic_resume(struct usb_serial *serial)
631 struct usb_serial_port *port;
634 for (i = 0; i < serial->num_ports; i++) {
635 port = serial->port[i];
636 if (!tty_port_initialized(&port->port))
639 if (port->bulk_in_size) {
640 r = usb_serial_generic_submit_read_urbs(port,
646 if (port->bulk_out_size) {
647 r = usb_serial_generic_write_start(port, GFP_NOIO);
655 EXPORT_SYMBOL_GPL(usb_serial_generic_resume);