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/cdc.h>
33 #include <linux/usb/serial.h>
34 #include <linux/serial.h>
38 * Generate DTR/RTS signals on the port using the SET_CONTROL_LINE_STATE request
41 static int usb_wwan_send_setup(struct usb_serial_port *port)
43 struct usb_serial *serial = port->serial;
44 struct usb_wwan_port_private *portdata;
49 portdata = usb_get_serial_port_data(port);
51 if (portdata->dtr_state)
52 val |= USB_CDC_CTRL_DTR;
53 if (portdata->rts_state)
54 val |= USB_CDC_CTRL_RTS;
56 ifnum = serial->interface->cur_altsetting->desc.bInterfaceNumber;
58 res = usb_autopm_get_interface(serial->interface);
62 res = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
63 USB_CDC_REQ_SET_CONTROL_LINE_STATE,
64 USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
65 val, ifnum, NULL, 0, USB_CTRL_SET_TIMEOUT);
67 usb_autopm_put_interface(port->serial->interface);
72 void usb_wwan_dtr_rts(struct usb_serial_port *port, int on)
74 struct usb_wwan_port_private *portdata;
75 struct usb_wwan_intf_private *intfdata;
77 intfdata = usb_get_serial_data(port->serial);
79 if (!intfdata->use_send_setup)
82 portdata = usb_get_serial_port_data(port);
84 portdata->rts_state = on;
85 portdata->dtr_state = on;
87 usb_wwan_send_setup(port);
89 EXPORT_SYMBOL(usb_wwan_dtr_rts);
91 int usb_wwan_tiocmget(struct tty_struct *tty)
93 struct usb_serial_port *port = tty->driver_data;
95 struct usb_wwan_port_private *portdata;
97 portdata = usb_get_serial_port_data(port);
99 value = ((portdata->rts_state) ? TIOCM_RTS : 0) |
100 ((portdata->dtr_state) ? TIOCM_DTR : 0) |
101 ((portdata->cts_state) ? TIOCM_CTS : 0) |
102 ((portdata->dsr_state) ? TIOCM_DSR : 0) |
103 ((portdata->dcd_state) ? TIOCM_CAR : 0) |
104 ((portdata->ri_state) ? TIOCM_RNG : 0);
108 EXPORT_SYMBOL(usb_wwan_tiocmget);
110 int usb_wwan_tiocmset(struct tty_struct *tty,
111 unsigned int set, unsigned int clear)
113 struct usb_serial_port *port = tty->driver_data;
114 struct usb_wwan_port_private *portdata;
115 struct usb_wwan_intf_private *intfdata;
117 portdata = usb_get_serial_port_data(port);
118 intfdata = usb_get_serial_data(port->serial);
120 if (!intfdata->use_send_setup)
123 /* FIXME: what locks portdata fields ? */
125 portdata->rts_state = 1;
127 portdata->dtr_state = 1;
129 if (clear & TIOCM_RTS)
130 portdata->rts_state = 0;
131 if (clear & TIOCM_DTR)
132 portdata->dtr_state = 0;
133 return usb_wwan_send_setup(port);
135 EXPORT_SYMBOL(usb_wwan_tiocmset);
137 int usb_wwan_write(struct tty_struct *tty, struct usb_serial_port *port,
138 const unsigned char *buf, int count)
140 struct usb_wwan_port_private *portdata;
141 struct usb_wwan_intf_private *intfdata;
144 struct urb *this_urb = NULL; /* spurious */
148 portdata = usb_get_serial_port_data(port);
149 intfdata = usb_get_serial_data(port->serial);
151 dev_dbg(&port->dev, "%s: write (%d chars)\n", __func__, count);
154 for (i = 0; left > 0 && i < N_OUT_URB; i++) {
156 if (todo > OUT_BUFLEN)
159 this_urb = portdata->out_urbs[i];
160 if (test_and_set_bit(i, &portdata->out_busy)) {
161 if (time_before(jiffies,
162 portdata->tx_start_time[i] + 10 * HZ))
164 usb_unlink_urb(this_urb);
167 dev_dbg(&port->dev, "%s: endpoint %d buf %d\n", __func__,
168 usb_pipeendpoint(this_urb->pipe), i);
170 err = usb_autopm_get_interface_async(port->serial->interface);
172 clear_bit(i, &portdata->out_busy);
177 memcpy(this_urb->transfer_buffer, buf, todo);
178 this_urb->transfer_buffer_length = todo;
180 spin_lock_irqsave(&intfdata->susp_lock, flags);
181 if (intfdata->suspended) {
182 usb_anchor_urb(this_urb, &portdata->delayed);
183 spin_unlock_irqrestore(&intfdata->susp_lock, flags);
185 intfdata->in_flight++;
186 spin_unlock_irqrestore(&intfdata->susp_lock, flags);
187 err = usb_submit_urb(this_urb, GFP_ATOMIC);
190 "%s: submit urb %d failed: %d\n",
192 clear_bit(i, &portdata->out_busy);
193 spin_lock_irqsave(&intfdata->susp_lock, flags);
194 intfdata->in_flight--;
195 spin_unlock_irqrestore(&intfdata->susp_lock,
197 usb_autopm_put_interface_async(port->serial->interface);
202 portdata->tx_start_time[i] = jiffies;
208 dev_dbg(&port->dev, "%s: wrote (did %d)\n", __func__, count);
211 EXPORT_SYMBOL(usb_wwan_write);
213 static void usb_wwan_indat_callback(struct urb *urb)
217 struct usb_serial_port *port;
219 unsigned char *data = urb->transfer_buffer;
220 int status = urb->status;
222 endpoint = usb_pipeendpoint(urb->pipe);
227 dev_dbg(dev, "%s: nonzero status: %d on endpoint %02x.\n",
228 __func__, status, endpoint);
230 /* don't resubmit on fatal errors */
231 if (status == -ESHUTDOWN || status == -ENOENT)
234 if (urb->actual_length) {
235 tty_insert_flip_string(&port->port, data,
237 tty_flip_buffer_push(&port->port);
239 dev_dbg(dev, "%s: empty read urb received\n", __func__);
241 /* Resubmit urb so we continue receiving */
242 err = usb_submit_urb(urb, GFP_ATOMIC);
244 if (err != -EPERM && err != -ENODEV) {
245 dev_err(dev, "%s: resubmit read urb failed. (%d)\n",
247 /* busy also in error unless we are killed */
248 usb_mark_last_busy(port->serial->dev);
251 usb_mark_last_busy(port->serial->dev);
255 static void usb_wwan_outdat_callback(struct urb *urb)
257 struct usb_serial_port *port;
258 struct usb_wwan_port_private *portdata;
259 struct usb_wwan_intf_private *intfdata;
264 intfdata = usb_get_serial_data(port->serial);
266 usb_serial_port_softint(port);
267 usb_autopm_put_interface_async(port->serial->interface);
268 portdata = usb_get_serial_port_data(port);
269 spin_lock_irqsave(&intfdata->susp_lock, flags);
270 intfdata->in_flight--;
271 spin_unlock_irqrestore(&intfdata->susp_lock, flags);
273 for (i = 0; i < N_OUT_URB; ++i) {
274 if (portdata->out_urbs[i] == urb) {
275 smp_mb__before_atomic();
276 clear_bit(i, &portdata->out_busy);
282 unsigned int usb_wwan_write_room(struct tty_struct *tty)
284 struct usb_serial_port *port = tty->driver_data;
285 struct usb_wwan_port_private *portdata;
287 unsigned int data_len = 0;
288 struct urb *this_urb;
290 portdata = usb_get_serial_port_data(port);
292 for (i = 0; i < N_OUT_URB; i++) {
293 this_urb = portdata->out_urbs[i];
294 if (this_urb && !test_bit(i, &portdata->out_busy))
295 data_len += OUT_BUFLEN;
298 dev_dbg(&port->dev, "%s: %u\n", __func__, data_len);
301 EXPORT_SYMBOL(usb_wwan_write_room);
303 unsigned int usb_wwan_chars_in_buffer(struct tty_struct *tty)
305 struct usb_serial_port *port = tty->driver_data;
306 struct usb_wwan_port_private *portdata;
308 unsigned int data_len = 0;
309 struct urb *this_urb;
311 portdata = usb_get_serial_port_data(port);
313 for (i = 0; i < N_OUT_URB; i++) {
314 this_urb = portdata->out_urbs[i];
315 /* FIXME: This locking is insufficient as this_urb may
316 go unused during the test */
317 if (this_urb && test_bit(i, &portdata->out_busy))
318 data_len += this_urb->transfer_buffer_length;
320 dev_dbg(&port->dev, "%s: %u\n", __func__, data_len);
323 EXPORT_SYMBOL(usb_wwan_chars_in_buffer);
325 int usb_wwan_open(struct tty_struct *tty, struct usb_serial_port *port)
327 struct usb_wwan_port_private *portdata;
328 struct usb_wwan_intf_private *intfdata;
329 struct usb_serial *serial = port->serial;
333 portdata = usb_get_serial_port_data(port);
334 intfdata = usb_get_serial_data(serial);
336 if (port->interrupt_in_urb) {
337 err = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
339 dev_err(&port->dev, "%s: submit int urb failed: %d\n",
344 /* Start reading from the IN endpoint */
345 for (i = 0; i < N_IN_URB; i++) {
346 urb = portdata->in_urbs[i];
349 err = usb_submit_urb(urb, GFP_KERNEL);
352 "%s: submit read urb %d failed: %d\n",
357 spin_lock_irq(&intfdata->susp_lock);
358 if (++intfdata->open_ports == 1)
359 serial->interface->needs_remote_wakeup = 1;
360 spin_unlock_irq(&intfdata->susp_lock);
361 /* this balances a get in the generic USB serial code */
362 usb_autopm_put_interface(serial->interface);
366 EXPORT_SYMBOL(usb_wwan_open);
368 static void unbusy_queued_urb(struct urb *urb,
369 struct usb_wwan_port_private *portdata)
373 for (i = 0; i < N_OUT_URB; i++) {
374 if (urb == portdata->out_urbs[i]) {
375 clear_bit(i, &portdata->out_busy);
381 void usb_wwan_close(struct usb_serial_port *port)
384 struct usb_serial *serial = port->serial;
385 struct usb_wwan_port_private *portdata;
386 struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial);
389 portdata = usb_get_serial_port_data(port);
392 * Need to take susp_lock to make sure port is not already being
393 * resumed, but no need to hold it due to the tty-port initialized
396 spin_lock_irq(&intfdata->susp_lock);
397 if (--intfdata->open_ports == 0)
398 serial->interface->needs_remote_wakeup = 0;
399 spin_unlock_irq(&intfdata->susp_lock);
402 urb = usb_get_from_anchor(&portdata->delayed);
405 unbusy_queued_urb(urb, portdata);
406 usb_autopm_put_interface_async(serial->interface);
409 for (i = 0; i < N_IN_URB; i++)
410 usb_kill_urb(portdata->in_urbs[i]);
411 for (i = 0; i < N_OUT_URB; i++)
412 usb_kill_urb(portdata->out_urbs[i]);
413 usb_kill_urb(port->interrupt_in_urb);
415 usb_autopm_get_interface_no_resume(serial->interface);
417 EXPORT_SYMBOL(usb_wwan_close);
419 static struct urb *usb_wwan_setup_urb(struct usb_serial_port *port,
421 int dir, void *ctx, char *buf, int len,
422 void (*callback) (struct urb *))
424 struct usb_serial *serial = port->serial;
425 struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial);
428 urb = usb_alloc_urb(0, GFP_KERNEL); /* No ISO */
432 usb_fill_bulk_urb(urb, serial->dev,
433 usb_sndbulkpipe(serial->dev, endpoint) | dir,
434 buf, len, callback, ctx);
436 if (intfdata->use_zlp && dir == USB_DIR_OUT)
437 urb->transfer_flags |= URB_ZERO_PACKET;
442 int usb_wwan_port_probe(struct usb_serial_port *port)
444 struct usb_wwan_port_private *portdata;
449 if (!port->bulk_in_size || !port->bulk_out_size)
452 portdata = kzalloc(sizeof(*portdata), GFP_KERNEL);
456 init_usb_anchor(&portdata->delayed);
458 for (i = 0; i < N_IN_URB; i++) {
459 buffer = (u8 *)__get_free_page(GFP_KERNEL);
462 portdata->in_buffer[i] = buffer;
464 urb = usb_wwan_setup_urb(port, port->bulk_in_endpointAddress,
467 usb_wwan_indat_callback);
468 portdata->in_urbs[i] = urb;
471 for (i = 0; i < N_OUT_URB; i++) {
472 buffer = kmalloc(OUT_BUFLEN, GFP_KERNEL);
474 goto bail_out_error2;
475 portdata->out_buffer[i] = buffer;
477 urb = usb_wwan_setup_urb(port, port->bulk_out_endpointAddress,
480 usb_wwan_outdat_callback);
481 portdata->out_urbs[i] = urb;
484 usb_set_serial_port_data(port, portdata);
489 for (i = 0; i < N_OUT_URB; i++) {
490 usb_free_urb(portdata->out_urbs[i]);
491 kfree(portdata->out_buffer[i]);
494 for (i = 0; i < N_IN_URB; i++) {
495 usb_free_urb(portdata->in_urbs[i]);
496 free_page((unsigned long)portdata->in_buffer[i]);
502 EXPORT_SYMBOL_GPL(usb_wwan_port_probe);
504 void usb_wwan_port_remove(struct usb_serial_port *port)
507 struct usb_wwan_port_private *portdata;
509 portdata = usb_get_serial_port_data(port);
510 usb_set_serial_port_data(port, NULL);
512 for (i = 0; i < N_IN_URB; i++) {
513 usb_free_urb(portdata->in_urbs[i]);
514 free_page((unsigned long)portdata->in_buffer[i]);
516 for (i = 0; i < N_OUT_URB; i++) {
517 usb_free_urb(portdata->out_urbs[i]);
518 kfree(portdata->out_buffer[i]);
523 EXPORT_SYMBOL(usb_wwan_port_remove);
526 static void stop_urbs(struct usb_serial *serial)
529 struct usb_serial_port *port;
530 struct usb_wwan_port_private *portdata;
532 for (i = 0; i < serial->num_ports; ++i) {
533 port = serial->port[i];
534 portdata = usb_get_serial_port_data(port);
537 for (j = 0; j < N_IN_URB; j++)
538 usb_kill_urb(portdata->in_urbs[j]);
539 for (j = 0; j < N_OUT_URB; j++)
540 usb_kill_urb(portdata->out_urbs[j]);
541 usb_kill_urb(port->interrupt_in_urb);
545 int usb_wwan_suspend(struct usb_serial *serial, pm_message_t message)
547 struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial);
549 spin_lock_irq(&intfdata->susp_lock);
550 if (PMSG_IS_AUTO(message)) {
551 if (intfdata->in_flight) {
552 spin_unlock_irq(&intfdata->susp_lock);
556 intfdata->suspended = 1;
557 spin_unlock_irq(&intfdata->susp_lock);
563 EXPORT_SYMBOL(usb_wwan_suspend);
565 /* Caller must hold susp_lock. */
566 static int usb_wwan_submit_delayed_urbs(struct usb_serial_port *port)
568 struct usb_serial *serial = port->serial;
569 struct usb_wwan_intf_private *data = usb_get_serial_data(serial);
570 struct usb_wwan_port_private *portdata;
575 portdata = usb_get_serial_port_data(port);
578 urb = usb_get_from_anchor(&portdata->delayed);
582 err = usb_submit_urb(urb, GFP_ATOMIC);
584 dev_err(&port->dev, "%s: submit urb failed: %d\n",
587 unbusy_queued_urb(urb, portdata);
588 usb_autopm_put_interface_async(serial->interface);
600 int usb_wwan_resume(struct usb_serial *serial)
603 struct usb_serial_port *port;
604 struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial);
605 struct usb_wwan_port_private *portdata;
610 spin_lock_irq(&intfdata->susp_lock);
611 for (i = 0; i < serial->num_ports; i++) {
612 port = serial->port[i];
614 if (!tty_port_initialized(&port->port))
617 portdata = usb_get_serial_port_data(port);
619 if (port->interrupt_in_urb) {
620 err = usb_submit_urb(port->interrupt_in_urb,
624 "%s: submit int urb failed: %d\n",
630 err = usb_wwan_submit_delayed_urbs(port);
634 for (j = 0; j < N_IN_URB; j++) {
635 urb = portdata->in_urbs[j];
636 err = usb_submit_urb(urb, GFP_ATOMIC);
639 "%s: submit read urb %d failed: %d\n",
645 intfdata->suspended = 0;
646 spin_unlock_irq(&intfdata->susp_lock);
653 EXPORT_SYMBOL(usb_wwan_resume);
656 MODULE_AUTHOR(DRIVER_AUTHOR);
657 MODULE_DESCRIPTION(DRIVER_DESC);
658 MODULE_LICENSE("GPL v2");