1 // SPDX-License-Identifier: GPL-2.0
3 USB Driver layer for GSM modems
9 History: see the git log.
13 This driver exists because the "normal" serial driver doesn't work too well
14 with GSM modems. Issues:
15 - data loss -- one single Receive URB is not nearly enough
16 - controlling the baud rate doesn't make sense
20 #define DRIVER_DESC "USB Driver for GSM modems"
22 #include <linux/kernel.h>
23 #include <linux/jiffies.h>
24 #include <linux/errno.h>
25 #include <linux/slab.h>
26 #include <linux/tty.h>
27 #include <linux/tty_flip.h>
28 #include <linux/module.h>
29 #include <linux/bitops.h>
30 #include <linux/uaccess.h>
31 #include <linux/usb.h>
32 #include <linux/usb/serial.h>
33 #include <linux/serial.h>
37 * Generate DTR/RTS signals on the port using the SET_CONTROL_LINE_STATE request
40 static int usb_wwan_send_setup(struct usb_serial_port *port)
42 struct usb_serial *serial = port->serial;
43 struct usb_wwan_port_private *portdata;
48 portdata = usb_get_serial_port_data(port);
50 if (portdata->dtr_state)
52 if (portdata->rts_state)
55 ifnum = serial->interface->cur_altsetting->desc.bInterfaceNumber;
57 res = usb_autopm_get_interface(serial->interface);
61 res = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
62 0x22, 0x21, val, ifnum, NULL, 0,
63 USB_CTRL_SET_TIMEOUT);
65 usb_autopm_put_interface(port->serial->interface);
70 void usb_wwan_dtr_rts(struct usb_serial_port *port, int on)
72 struct usb_wwan_port_private *portdata;
73 struct usb_wwan_intf_private *intfdata;
75 intfdata = usb_get_serial_data(port->serial);
77 if (!intfdata->use_send_setup)
80 portdata = usb_get_serial_port_data(port);
82 portdata->rts_state = on;
83 portdata->dtr_state = on;
85 usb_wwan_send_setup(port);
87 EXPORT_SYMBOL(usb_wwan_dtr_rts);
89 int usb_wwan_tiocmget(struct tty_struct *tty)
91 struct usb_serial_port *port = tty->driver_data;
93 struct usb_wwan_port_private *portdata;
95 portdata = usb_get_serial_port_data(port);
97 value = ((portdata->rts_state) ? TIOCM_RTS : 0) |
98 ((portdata->dtr_state) ? TIOCM_DTR : 0) |
99 ((portdata->cts_state) ? TIOCM_CTS : 0) |
100 ((portdata->dsr_state) ? TIOCM_DSR : 0) |
101 ((portdata->dcd_state) ? TIOCM_CAR : 0) |
102 ((portdata->ri_state) ? TIOCM_RNG : 0);
106 EXPORT_SYMBOL(usb_wwan_tiocmget);
108 int usb_wwan_tiocmset(struct tty_struct *tty,
109 unsigned int set, unsigned int clear)
111 struct usb_serial_port *port = tty->driver_data;
112 struct usb_wwan_port_private *portdata;
113 struct usb_wwan_intf_private *intfdata;
115 portdata = usb_get_serial_port_data(port);
116 intfdata = usb_get_serial_data(port->serial);
118 if (!intfdata->use_send_setup)
121 /* FIXME: what locks portdata fields ? */
123 portdata->rts_state = 1;
125 portdata->dtr_state = 1;
127 if (clear & TIOCM_RTS)
128 portdata->rts_state = 0;
129 if (clear & TIOCM_DTR)
130 portdata->dtr_state = 0;
131 return usb_wwan_send_setup(port);
133 EXPORT_SYMBOL(usb_wwan_tiocmset);
135 int usb_wwan_get_serial_info(struct tty_struct *tty,
136 struct serial_struct *ss)
138 struct usb_serial_port *port = tty->driver_data;
140 ss->line = port->minor;
141 ss->port = port->port_number;
142 ss->baud_base = tty_get_baud_rate(port->port.tty);
143 ss->close_delay = port->port.close_delay / 10;
144 ss->closing_wait = port->port.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
145 ASYNC_CLOSING_WAIT_NONE :
146 port->port.closing_wait / 10;
149 EXPORT_SYMBOL(usb_wwan_get_serial_info);
151 int usb_wwan_set_serial_info(struct tty_struct *tty,
152 struct serial_struct *ss)
154 struct usb_serial_port *port = tty->driver_data;
155 unsigned int closing_wait, close_delay;
158 close_delay = ss->close_delay * 10;
159 closing_wait = ss->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
160 ASYNC_CLOSING_WAIT_NONE : ss->closing_wait * 10;
162 mutex_lock(&port->port.mutex);
164 if (!capable(CAP_SYS_ADMIN)) {
165 if ((close_delay != port->port.close_delay) ||
166 (closing_wait != port->port.closing_wait))
169 retval = -EOPNOTSUPP;
171 port->port.close_delay = close_delay;
172 port->port.closing_wait = closing_wait;
175 mutex_unlock(&port->port.mutex);
178 EXPORT_SYMBOL(usb_wwan_set_serial_info);
180 int usb_wwan_write(struct tty_struct *tty, struct usb_serial_port *port,
181 const unsigned char *buf, int count)
183 struct usb_wwan_port_private *portdata;
184 struct usb_wwan_intf_private *intfdata;
187 struct urb *this_urb = NULL; /* spurious */
191 portdata = usb_get_serial_port_data(port);
192 intfdata = usb_get_serial_data(port->serial);
194 dev_dbg(&port->dev, "%s: write (%d chars)\n", __func__, count);
198 for (i = 0; left > 0 && i < N_OUT_URB; i++) {
200 if (todo > OUT_BUFLEN)
203 this_urb = portdata->out_urbs[i];
204 if (test_and_set_bit(i, &portdata->out_busy)) {
205 if (time_before(jiffies,
206 portdata->tx_start_time[i] + 10 * HZ))
208 usb_unlink_urb(this_urb);
211 dev_dbg(&port->dev, "%s: endpoint %d buf %d\n", __func__,
212 usb_pipeendpoint(this_urb->pipe), i);
214 err = usb_autopm_get_interface_async(port->serial->interface);
216 clear_bit(i, &portdata->out_busy);
221 memcpy(this_urb->transfer_buffer, buf, todo);
222 this_urb->transfer_buffer_length = todo;
224 spin_lock_irqsave(&intfdata->susp_lock, flags);
225 if (intfdata->suspended) {
226 usb_anchor_urb(this_urb, &portdata->delayed);
227 spin_unlock_irqrestore(&intfdata->susp_lock, flags);
229 intfdata->in_flight++;
230 spin_unlock_irqrestore(&intfdata->susp_lock, flags);
231 err = usb_submit_urb(this_urb, GFP_ATOMIC);
234 "%s: submit urb %d failed: %d\n",
236 clear_bit(i, &portdata->out_busy);
237 spin_lock_irqsave(&intfdata->susp_lock, flags);
238 intfdata->in_flight--;
239 spin_unlock_irqrestore(&intfdata->susp_lock,
241 usb_autopm_put_interface_async(port->serial->interface);
246 portdata->tx_start_time[i] = jiffies;
252 dev_dbg(&port->dev, "%s: wrote (did %d)\n", __func__, count);
255 EXPORT_SYMBOL(usb_wwan_write);
257 static void usb_wwan_indat_callback(struct urb *urb)
261 struct usb_serial_port *port;
263 unsigned char *data = urb->transfer_buffer;
264 int status = urb->status;
266 endpoint = usb_pipeendpoint(urb->pipe);
271 dev_dbg(dev, "%s: nonzero status: %d on endpoint %02x.\n",
272 __func__, status, endpoint);
274 /* don't resubmit on fatal errors */
275 if (status == -ESHUTDOWN || status == -ENOENT)
278 if (urb->actual_length) {
279 tty_insert_flip_string(&port->port, data,
281 tty_flip_buffer_push(&port->port);
283 dev_dbg(dev, "%s: empty read urb received\n", __func__);
285 /* Resubmit urb so we continue receiving */
286 err = usb_submit_urb(urb, GFP_ATOMIC);
288 if (err != -EPERM && err != -ENODEV) {
289 dev_err(dev, "%s: resubmit read urb failed. (%d)\n",
291 /* busy also in error unless we are killed */
292 usb_mark_last_busy(port->serial->dev);
295 usb_mark_last_busy(port->serial->dev);
299 static void usb_wwan_outdat_callback(struct urb *urb)
301 struct usb_serial_port *port;
302 struct usb_wwan_port_private *portdata;
303 struct usb_wwan_intf_private *intfdata;
308 intfdata = usb_get_serial_data(port->serial);
310 usb_serial_port_softint(port);
311 usb_autopm_put_interface_async(port->serial->interface);
312 portdata = usb_get_serial_port_data(port);
313 spin_lock_irqsave(&intfdata->susp_lock, flags);
314 intfdata->in_flight--;
315 spin_unlock_irqrestore(&intfdata->susp_lock, flags);
317 for (i = 0; i < N_OUT_URB; ++i) {
318 if (portdata->out_urbs[i] == urb) {
319 smp_mb__before_atomic();
320 clear_bit(i, &portdata->out_busy);
326 int usb_wwan_write_room(struct tty_struct *tty)
328 struct usb_serial_port *port = tty->driver_data;
329 struct usb_wwan_port_private *portdata;
332 struct urb *this_urb;
334 portdata = usb_get_serial_port_data(port);
336 for (i = 0; i < N_OUT_URB; i++) {
337 this_urb = portdata->out_urbs[i];
338 if (this_urb && !test_bit(i, &portdata->out_busy))
339 data_len += OUT_BUFLEN;
342 dev_dbg(&port->dev, "%s: %d\n", __func__, data_len);
345 EXPORT_SYMBOL(usb_wwan_write_room);
347 int usb_wwan_chars_in_buffer(struct tty_struct *tty)
349 struct usb_serial_port *port = tty->driver_data;
350 struct usb_wwan_port_private *portdata;
353 struct urb *this_urb;
355 portdata = usb_get_serial_port_data(port);
357 for (i = 0; i < N_OUT_URB; i++) {
358 this_urb = portdata->out_urbs[i];
359 /* FIXME: This locking is insufficient as this_urb may
360 go unused during the test */
361 if (this_urb && test_bit(i, &portdata->out_busy))
362 data_len += this_urb->transfer_buffer_length;
364 dev_dbg(&port->dev, "%s: %d\n", __func__, data_len);
367 EXPORT_SYMBOL(usb_wwan_chars_in_buffer);
369 int usb_wwan_open(struct tty_struct *tty, struct usb_serial_port *port)
371 struct usb_wwan_port_private *portdata;
372 struct usb_wwan_intf_private *intfdata;
373 struct usb_serial *serial = port->serial;
377 portdata = usb_get_serial_port_data(port);
378 intfdata = usb_get_serial_data(serial);
380 if (port->interrupt_in_urb) {
381 err = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
383 dev_err(&port->dev, "%s: submit int urb failed: %d\n",
388 /* Start reading from the IN endpoint */
389 for (i = 0; i < N_IN_URB; i++) {
390 urb = portdata->in_urbs[i];
393 err = usb_submit_urb(urb, GFP_KERNEL);
396 "%s: submit read urb %d failed: %d\n",
401 spin_lock_irq(&intfdata->susp_lock);
402 if (++intfdata->open_ports == 1)
403 serial->interface->needs_remote_wakeup = 1;
404 spin_unlock_irq(&intfdata->susp_lock);
405 /* this balances a get in the generic USB serial code */
406 usb_autopm_put_interface(serial->interface);
410 EXPORT_SYMBOL(usb_wwan_open);
412 static void unbusy_queued_urb(struct urb *urb,
413 struct usb_wwan_port_private *portdata)
417 for (i = 0; i < N_OUT_URB; i++) {
418 if (urb == portdata->out_urbs[i]) {
419 clear_bit(i, &portdata->out_busy);
425 void usb_wwan_close(struct usb_serial_port *port)
428 struct usb_serial *serial = port->serial;
429 struct usb_wwan_port_private *portdata;
430 struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial);
433 portdata = usb_get_serial_port_data(port);
436 * Need to take susp_lock to make sure port is not already being
437 * resumed, but no need to hold it due to initialized
439 spin_lock_irq(&intfdata->susp_lock);
440 if (--intfdata->open_ports == 0)
441 serial->interface->needs_remote_wakeup = 0;
442 spin_unlock_irq(&intfdata->susp_lock);
445 urb = usb_get_from_anchor(&portdata->delayed);
448 unbusy_queued_urb(urb, portdata);
449 usb_autopm_put_interface_async(serial->interface);
452 for (i = 0; i < N_IN_URB; i++)
453 usb_kill_urb(portdata->in_urbs[i]);
454 for (i = 0; i < N_OUT_URB; i++)
455 usb_kill_urb(portdata->out_urbs[i]);
456 usb_kill_urb(port->interrupt_in_urb);
458 usb_autopm_get_interface_no_resume(serial->interface);
460 EXPORT_SYMBOL(usb_wwan_close);
462 static struct urb *usb_wwan_setup_urb(struct usb_serial_port *port,
464 int dir, void *ctx, char *buf, int len,
465 void (*callback) (struct urb *))
467 struct usb_serial *serial = port->serial;
468 struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial);
471 urb = usb_alloc_urb(0, GFP_KERNEL); /* No ISO */
475 usb_fill_bulk_urb(urb, serial->dev,
476 usb_sndbulkpipe(serial->dev, endpoint) | dir,
477 buf, len, callback, ctx);
479 if (intfdata->use_zlp && dir == USB_DIR_OUT)
480 urb->transfer_flags |= URB_ZERO_PACKET;
485 int usb_wwan_port_probe(struct usb_serial_port *port)
487 struct usb_wwan_port_private *portdata;
492 if (!port->bulk_in_size || !port->bulk_out_size)
495 portdata = kzalloc(sizeof(*portdata), GFP_KERNEL);
499 init_usb_anchor(&portdata->delayed);
501 for (i = 0; i < N_IN_URB; i++) {
502 buffer = (u8 *)__get_free_page(GFP_KERNEL);
505 portdata->in_buffer[i] = buffer;
507 urb = usb_wwan_setup_urb(port, port->bulk_in_endpointAddress,
510 usb_wwan_indat_callback);
511 portdata->in_urbs[i] = urb;
514 for (i = 0; i < N_OUT_URB; i++) {
515 buffer = kmalloc(OUT_BUFLEN, GFP_KERNEL);
517 goto bail_out_error2;
518 portdata->out_buffer[i] = buffer;
520 urb = usb_wwan_setup_urb(port, port->bulk_out_endpointAddress,
523 usb_wwan_outdat_callback);
524 portdata->out_urbs[i] = urb;
527 usb_set_serial_port_data(port, portdata);
532 for (i = 0; i < N_OUT_URB; i++) {
533 usb_free_urb(portdata->out_urbs[i]);
534 kfree(portdata->out_buffer[i]);
537 for (i = 0; i < N_IN_URB; i++) {
538 usb_free_urb(portdata->in_urbs[i]);
539 free_page((unsigned long)portdata->in_buffer[i]);
545 EXPORT_SYMBOL_GPL(usb_wwan_port_probe);
547 int usb_wwan_port_remove(struct usb_serial_port *port)
550 struct usb_wwan_port_private *portdata;
552 portdata = usb_get_serial_port_data(port);
553 usb_set_serial_port_data(port, NULL);
555 for (i = 0; i < N_IN_URB; i++) {
556 usb_free_urb(portdata->in_urbs[i]);
557 free_page((unsigned long)portdata->in_buffer[i]);
559 for (i = 0; i < N_OUT_URB; i++) {
560 usb_free_urb(portdata->out_urbs[i]);
561 kfree(portdata->out_buffer[i]);
568 EXPORT_SYMBOL(usb_wwan_port_remove);
571 static void stop_urbs(struct usb_serial *serial)
574 struct usb_serial_port *port;
575 struct usb_wwan_port_private *portdata;
577 for (i = 0; i < serial->num_ports; ++i) {
578 port = serial->port[i];
579 portdata = usb_get_serial_port_data(port);
582 for (j = 0; j < N_IN_URB; j++)
583 usb_kill_urb(portdata->in_urbs[j]);
584 for (j = 0; j < N_OUT_URB; j++)
585 usb_kill_urb(portdata->out_urbs[j]);
586 usb_kill_urb(port->interrupt_in_urb);
590 int usb_wwan_suspend(struct usb_serial *serial, pm_message_t message)
592 struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial);
594 spin_lock_irq(&intfdata->susp_lock);
595 if (PMSG_IS_AUTO(message)) {
596 if (intfdata->in_flight) {
597 spin_unlock_irq(&intfdata->susp_lock);
601 intfdata->suspended = 1;
602 spin_unlock_irq(&intfdata->susp_lock);
608 EXPORT_SYMBOL(usb_wwan_suspend);
610 /* Caller must hold susp_lock. */
611 static int usb_wwan_submit_delayed_urbs(struct usb_serial_port *port)
613 struct usb_serial *serial = port->serial;
614 struct usb_wwan_intf_private *data = usb_get_serial_data(serial);
615 struct usb_wwan_port_private *portdata;
620 portdata = usb_get_serial_port_data(port);
623 urb = usb_get_from_anchor(&portdata->delayed);
627 err = usb_submit_urb(urb, GFP_ATOMIC);
629 dev_err(&port->dev, "%s: submit urb failed: %d\n",
632 unbusy_queued_urb(urb, portdata);
633 usb_autopm_put_interface_async(serial->interface);
645 int usb_wwan_resume(struct usb_serial *serial)
648 struct usb_serial_port *port;
649 struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial);
650 struct usb_wwan_port_private *portdata;
655 spin_lock_irq(&intfdata->susp_lock);
656 for (i = 0; i < serial->num_ports; i++) {
657 port = serial->port[i];
659 if (!tty_port_initialized(&port->port))
662 portdata = usb_get_serial_port_data(port);
664 if (port->interrupt_in_urb) {
665 err = usb_submit_urb(port->interrupt_in_urb,
669 "%s: submit int urb failed: %d\n",
675 err = usb_wwan_submit_delayed_urbs(port);
679 for (j = 0; j < N_IN_URB; j++) {
680 urb = portdata->in_urbs[j];
681 err = usb_submit_urb(urb, GFP_ATOMIC);
684 "%s: submit read urb %d failed: %d\n",
690 intfdata->suspended = 0;
691 spin_unlock_irq(&intfdata->susp_lock);
698 EXPORT_SYMBOL(usb_wwan_resume);
701 MODULE_AUTHOR(DRIVER_AUTHOR);
702 MODULE_DESCRIPTION(DRIVER_DESC);
703 MODULE_LICENSE("GPL v2");