1/*
2  USB Driver layer for GSM modems
3
4  Copyright (C) 2005  Matthias Urlichs <smurf@smurf.noris.de>
5
6  This driver is free software; you can redistribute it and/or modify
7  it under the terms of Version 2 of the GNU General Public License as
8  published by the Free Software Foundation.
9
10  Portions copied from the Keyspan driver by Hugh Blemings <hugh@blemings.org>
11
12  History: see the git log.
13
14  Work sponsored by: Sigos GmbH, Germany <info@sigos.de>
15
16  This driver exists because the "normal" serial driver doesn't work too well
17  with GSM modems. Issues:
18  - data loss -- one single Receive URB is not nearly enough
19  - controlling the baud rate doesn't make sense
20*/
21
22#define DRIVER_AUTHOR "Matthias Urlichs <smurf@smurf.noris.de>"
23#define DRIVER_DESC "USB Driver for GSM modems"
24
25#include <linux/kernel.h>
26#include <linux/jiffies.h>
27#include <linux/errno.h>
28#include <linux/slab.h>
29#include <linux/tty.h>
30#include <linux/tty_flip.h>
31#include <linux/module.h>
32#include <linux/bitops.h>
33#include <linux/uaccess.h>
34#include <linux/usb.h>
35#include <linux/usb/serial.h>
36#include <linux/serial.h>
37#include "usb-wwan.h"
38
39void usb_wwan_dtr_rts(struct usb_serial_port *port, int on)
40{
41	struct usb_wwan_port_private *portdata;
42	struct usb_wwan_intf_private *intfdata;
43
44	intfdata = usb_get_serial_data(port->serial);
45
46	if (!intfdata->send_setup)
47		return;
48
49	portdata = usb_get_serial_port_data(port);
50	/* FIXME: locking */
51	portdata->rts_state = on;
52	portdata->dtr_state = on;
53
54	intfdata->send_setup(port);
55}
56EXPORT_SYMBOL(usb_wwan_dtr_rts);
57
58int usb_wwan_tiocmget(struct tty_struct *tty)
59{
60	struct usb_serial_port *port = tty->driver_data;
61	unsigned int value;
62	struct usb_wwan_port_private *portdata;
63
64	portdata = usb_get_serial_port_data(port);
65
66	value = ((portdata->rts_state) ? TIOCM_RTS : 0) |
67	    ((portdata->dtr_state) ? TIOCM_DTR : 0) |
68	    ((portdata->cts_state) ? TIOCM_CTS : 0) |
69	    ((portdata->dsr_state) ? TIOCM_DSR : 0) |
70	    ((portdata->dcd_state) ? TIOCM_CAR : 0) |
71	    ((portdata->ri_state) ? TIOCM_RNG : 0);
72
73	return value;
74}
75EXPORT_SYMBOL(usb_wwan_tiocmget);
76
77int usb_wwan_tiocmset(struct tty_struct *tty,
78		      unsigned int set, unsigned int clear)
79{
80	struct usb_serial_port *port = tty->driver_data;
81	struct usb_wwan_port_private *portdata;
82	struct usb_wwan_intf_private *intfdata;
83
84	portdata = usb_get_serial_port_data(port);
85	intfdata = usb_get_serial_data(port->serial);
86
87	if (!intfdata->send_setup)
88		return -EINVAL;
89
90	/* FIXME: what locks portdata fields ? */
91	if (set & TIOCM_RTS)
92		portdata->rts_state = 1;
93	if (set & TIOCM_DTR)
94		portdata->dtr_state = 1;
95
96	if (clear & TIOCM_RTS)
97		portdata->rts_state = 0;
98	if (clear & TIOCM_DTR)
99		portdata->dtr_state = 0;
100	return intfdata->send_setup(port);
101}
102EXPORT_SYMBOL(usb_wwan_tiocmset);
103
104static int get_serial_info(struct usb_serial_port *port,
105			   struct serial_struct __user *retinfo)
106{
107	struct serial_struct tmp;
108
109	if (!retinfo)
110		return -EFAULT;
111
112	memset(&tmp, 0, sizeof(tmp));
113	tmp.line            = port->minor;
114	tmp.port            = port->port_number;
115	tmp.baud_base       = tty_get_baud_rate(port->port.tty);
116	tmp.close_delay	    = port->port.close_delay / 10;
117	tmp.closing_wait    = port->port.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
118				 ASYNC_CLOSING_WAIT_NONE :
119				 port->port.closing_wait / 10;
120
121	if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
122		return -EFAULT;
123	return 0;
124}
125
126static int set_serial_info(struct usb_serial_port *port,
127			   struct serial_struct __user *newinfo)
128{
129	struct serial_struct new_serial;
130	unsigned int closing_wait, close_delay;
131	int retval = 0;
132
133	if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
134		return -EFAULT;
135
136	close_delay = new_serial.close_delay * 10;
137	closing_wait = new_serial.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
138			ASYNC_CLOSING_WAIT_NONE : new_serial.closing_wait * 10;
139
140	mutex_lock(&port->port.mutex);
141
142	if (!capable(CAP_SYS_ADMIN)) {
143		if ((close_delay != port->port.close_delay) ||
144		    (closing_wait != port->port.closing_wait))
145			retval = -EPERM;
146		else
147			retval = -EOPNOTSUPP;
148	} else {
149		port->port.close_delay  = close_delay;
150		port->port.closing_wait = closing_wait;
151	}
152
153	mutex_unlock(&port->port.mutex);
154	return retval;
155}
156
157int usb_wwan_ioctl(struct tty_struct *tty,
158		   unsigned int cmd, unsigned long arg)
159{
160	struct usb_serial_port *port = tty->driver_data;
161
162	dev_dbg(&port->dev, "%s cmd 0x%04x\n", __func__, cmd);
163
164	switch (cmd) {
165	case TIOCGSERIAL:
166		return get_serial_info(port,
167				       (struct serial_struct __user *) arg);
168	case TIOCSSERIAL:
169		return set_serial_info(port,
170				       (struct serial_struct __user *) arg);
171	default:
172		break;
173	}
174
175	dev_dbg(&port->dev, "%s arg not supported\n", __func__);
176
177	return -ENOIOCTLCMD;
178}
179EXPORT_SYMBOL(usb_wwan_ioctl);
180
181int usb_wwan_write(struct tty_struct *tty, struct usb_serial_port *port,
182		   const unsigned char *buf, int count)
183{
184	struct usb_wwan_port_private *portdata;
185	struct usb_wwan_intf_private *intfdata;
186	int i;
187	int left, todo;
188	struct urb *this_urb = NULL;	/* spurious */
189	int err;
190	unsigned long flags;
191
192	portdata = usb_get_serial_port_data(port);
193	intfdata = usb_get_serial_data(port->serial);
194
195	dev_dbg(&port->dev, "%s: write (%d chars)\n", __func__, count);
196
197	i = 0;
198	left = count;
199	for (i = 0; left > 0 && i < N_OUT_URB; i++) {
200		todo = left;
201		if (todo > OUT_BUFLEN)
202			todo = OUT_BUFLEN;
203
204		this_urb = portdata->out_urbs[i];
205		if (test_and_set_bit(i, &portdata->out_busy)) {
206			if (time_before(jiffies,
207					portdata->tx_start_time[i] + 10 * HZ))
208				continue;
209			usb_unlink_urb(this_urb);
210			continue;
211		}
212		dev_dbg(&port->dev, "%s: endpoint %d buf %d\n", __func__,
213			usb_pipeendpoint(this_urb->pipe), i);
214
215		err = usb_autopm_get_interface_async(port->serial->interface);
216		if (err < 0) {
217			clear_bit(i, &portdata->out_busy);
218			break;
219		}
220
221		/* send the data */
222		memcpy(this_urb->transfer_buffer, buf, todo);
223		this_urb->transfer_buffer_length = todo;
224
225		spin_lock_irqsave(&intfdata->susp_lock, flags);
226		if (intfdata->suspended) {
227			usb_anchor_urb(this_urb, &portdata->delayed);
228			spin_unlock_irqrestore(&intfdata->susp_lock, flags);
229		} else {
230			intfdata->in_flight++;
231			spin_unlock_irqrestore(&intfdata->susp_lock, flags);
232			err = usb_submit_urb(this_urb, GFP_ATOMIC);
233			if (err) {
234				dev_err(&port->dev,
235					"%s: submit urb %d failed: %d\n",
236					__func__, i, err);
237				clear_bit(i, &portdata->out_busy);
238				spin_lock_irqsave(&intfdata->susp_lock, flags);
239				intfdata->in_flight--;
240				spin_unlock_irqrestore(&intfdata->susp_lock,
241						       flags);
242				usb_autopm_put_interface_async(port->serial->interface);
243				break;
244			}
245		}
246
247		portdata->tx_start_time[i] = jiffies;
248		buf += todo;
249		left -= todo;
250	}
251
252	count -= left;
253	dev_dbg(&port->dev, "%s: wrote (did %d)\n", __func__, count);
254	return count;
255}
256EXPORT_SYMBOL(usb_wwan_write);
257
258static void usb_wwan_indat_callback(struct urb *urb)
259{
260	int err;
261	int endpoint;
262	struct usb_serial_port *port;
263	struct device *dev;
264	unsigned char *data = urb->transfer_buffer;
265	int status = urb->status;
266
267	endpoint = usb_pipeendpoint(urb->pipe);
268	port = urb->context;
269	dev = &port->dev;
270
271	if (status) {
272		dev_dbg(dev, "%s: nonzero status: %d on endpoint %02x.\n",
273			__func__, status, endpoint);
274	} else {
275		if (urb->actual_length) {
276			tty_insert_flip_string(&port->port, data,
277					urb->actual_length);
278			tty_flip_buffer_push(&port->port);
279		} else
280			dev_dbg(dev, "%s: empty read urb received\n", __func__);
281	}
282	/* Resubmit urb so we continue receiving */
283	err = usb_submit_urb(urb, GFP_ATOMIC);
284	if (err) {
285		if (err != -EPERM) {
286			dev_err(dev, "%s: resubmit read urb failed. (%d)\n",
287				__func__, err);
288			/* busy also in error unless we are killed */
289			usb_mark_last_busy(port->serial->dev);
290		}
291	} else {
292		usb_mark_last_busy(port->serial->dev);
293	}
294}
295
296static void usb_wwan_outdat_callback(struct urb *urb)
297{
298	struct usb_serial_port *port;
299	struct usb_wwan_port_private *portdata;
300	struct usb_wwan_intf_private *intfdata;
301	int i;
302
303	port = urb->context;
304	intfdata = usb_get_serial_data(port->serial);
305
306	usb_serial_port_softint(port);
307	usb_autopm_put_interface_async(port->serial->interface);
308	portdata = usb_get_serial_port_data(port);
309	spin_lock(&intfdata->susp_lock);
310	intfdata->in_flight--;
311	spin_unlock(&intfdata->susp_lock);
312
313	for (i = 0; i < N_OUT_URB; ++i) {
314		if (portdata->out_urbs[i] == urb) {
315			smp_mb__before_atomic();
316			clear_bit(i, &portdata->out_busy);
317			break;
318		}
319	}
320}
321
322int usb_wwan_write_room(struct tty_struct *tty)
323{
324	struct usb_serial_port *port = tty->driver_data;
325	struct usb_wwan_port_private *portdata;
326	int i;
327	int data_len = 0;
328	struct urb *this_urb;
329
330	portdata = usb_get_serial_port_data(port);
331
332	for (i = 0; i < N_OUT_URB; i++) {
333		this_urb = portdata->out_urbs[i];
334		if (this_urb && !test_bit(i, &portdata->out_busy))
335			data_len += OUT_BUFLEN;
336	}
337
338	dev_dbg(&port->dev, "%s: %d\n", __func__, data_len);
339	return data_len;
340}
341EXPORT_SYMBOL(usb_wwan_write_room);
342
343int usb_wwan_chars_in_buffer(struct tty_struct *tty)
344{
345	struct usb_serial_port *port = tty->driver_data;
346	struct usb_wwan_port_private *portdata;
347	int i;
348	int data_len = 0;
349	struct urb *this_urb;
350
351	portdata = usb_get_serial_port_data(port);
352
353	for (i = 0; i < N_OUT_URB; i++) {
354		this_urb = portdata->out_urbs[i];
355		/* FIXME: This locking is insufficient as this_urb may
356		   go unused during the test */
357		if (this_urb && test_bit(i, &portdata->out_busy))
358			data_len += this_urb->transfer_buffer_length;
359	}
360	dev_dbg(&port->dev, "%s: %d\n", __func__, data_len);
361	return data_len;
362}
363EXPORT_SYMBOL(usb_wwan_chars_in_buffer);
364
365int usb_wwan_open(struct tty_struct *tty, struct usb_serial_port *port)
366{
367	struct usb_wwan_port_private *portdata;
368	struct usb_wwan_intf_private *intfdata;
369	struct usb_serial *serial = port->serial;
370	int i, err;
371	struct urb *urb;
372
373	portdata = usb_get_serial_port_data(port);
374	intfdata = usb_get_serial_data(serial);
375
376	if (port->interrupt_in_urb) {
377		err = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
378		if (err) {
379			dev_err(&port->dev, "%s: submit int urb failed: %d\n",
380				__func__, err);
381		}
382	}
383
384	/* Start reading from the IN endpoint */
385	for (i = 0; i < N_IN_URB; i++) {
386		urb = portdata->in_urbs[i];
387		if (!urb)
388			continue;
389		err = usb_submit_urb(urb, GFP_KERNEL);
390		if (err) {
391			dev_err(&port->dev,
392				"%s: submit read urb %d failed: %d\n",
393				__func__, i, err);
394		}
395	}
396
397	spin_lock_irq(&intfdata->susp_lock);
398	if (++intfdata->open_ports == 1)
399		serial->interface->needs_remote_wakeup = 1;
400	spin_unlock_irq(&intfdata->susp_lock);
401	/* this balances a get in the generic USB serial code */
402	usb_autopm_put_interface(serial->interface);
403
404	return 0;
405}
406EXPORT_SYMBOL(usb_wwan_open);
407
408static void unbusy_queued_urb(struct urb *urb,
409					struct usb_wwan_port_private *portdata)
410{
411	int i;
412
413	for (i = 0; i < N_OUT_URB; i++) {
414		if (urb == portdata->out_urbs[i]) {
415			clear_bit(i, &portdata->out_busy);
416			break;
417		}
418	}
419}
420
421void usb_wwan_close(struct usb_serial_port *port)
422{
423	int i;
424	struct usb_serial *serial = port->serial;
425	struct usb_wwan_port_private *portdata;
426	struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial);
427	struct urb *urb;
428
429	portdata = usb_get_serial_port_data(port);
430
431	/*
432	 * Need to take susp_lock to make sure port is not already being
433	 * resumed, but no need to hold it due to ASYNC_INITIALIZED.
434	 */
435	spin_lock_irq(&intfdata->susp_lock);
436	if (--intfdata->open_ports == 0)
437		serial->interface->needs_remote_wakeup = 0;
438	spin_unlock_irq(&intfdata->susp_lock);
439
440	for (;;) {
441		urb = usb_get_from_anchor(&portdata->delayed);
442		if (!urb)
443			break;
444		unbusy_queued_urb(urb, portdata);
445		usb_autopm_put_interface_async(serial->interface);
446	}
447
448	for (i = 0; i < N_IN_URB; i++)
449		usb_kill_urb(portdata->in_urbs[i]);
450	for (i = 0; i < N_OUT_URB; i++)
451		usb_kill_urb(portdata->out_urbs[i]);
452	usb_kill_urb(port->interrupt_in_urb);
453
454	usb_autopm_get_interface_no_resume(serial->interface);
455}
456EXPORT_SYMBOL(usb_wwan_close);
457
458static struct urb *usb_wwan_setup_urb(struct usb_serial_port *port,
459				      int endpoint,
460				      int dir, void *ctx, char *buf, int len,
461				      void (*callback) (struct urb *))
462{
463	struct usb_serial *serial = port->serial;
464	struct urb *urb;
465
466	urb = usb_alloc_urb(0, GFP_KERNEL);	/* No ISO */
467	if (!urb)
468		return NULL;
469
470	usb_fill_bulk_urb(urb, serial->dev,
471			  usb_sndbulkpipe(serial->dev, endpoint) | dir,
472			  buf, len, callback, ctx);
473
474	return urb;
475}
476
477int usb_wwan_port_probe(struct usb_serial_port *port)
478{
479	struct usb_wwan_port_private *portdata;
480	struct urb *urb;
481	u8 *buffer;
482	int i;
483
484	if (!port->bulk_in_size || !port->bulk_out_size)
485		return -ENODEV;
486
487	portdata = kzalloc(sizeof(*portdata), GFP_KERNEL);
488	if (!portdata)
489		return -ENOMEM;
490
491	init_usb_anchor(&portdata->delayed);
492
493	for (i = 0; i < N_IN_URB; i++) {
494		buffer = (u8 *)__get_free_page(GFP_KERNEL);
495		if (!buffer)
496			goto bail_out_error;
497		portdata->in_buffer[i] = buffer;
498
499		urb = usb_wwan_setup_urb(port, port->bulk_in_endpointAddress,
500						USB_DIR_IN, port,
501						buffer, IN_BUFLEN,
502						usb_wwan_indat_callback);
503		portdata->in_urbs[i] = urb;
504	}
505
506	for (i = 0; i < N_OUT_URB; i++) {
507		buffer = kmalloc(OUT_BUFLEN, GFP_KERNEL);
508		if (!buffer)
509			goto bail_out_error2;
510		portdata->out_buffer[i] = buffer;
511
512		urb = usb_wwan_setup_urb(port, port->bulk_out_endpointAddress,
513						USB_DIR_OUT, port,
514						buffer, OUT_BUFLEN,
515						usb_wwan_outdat_callback);
516		portdata->out_urbs[i] = urb;
517	}
518
519	usb_set_serial_port_data(port, portdata);
520
521	return 0;
522
523bail_out_error2:
524	for (i = 0; i < N_OUT_URB; i++) {
525		usb_free_urb(portdata->out_urbs[i]);
526		kfree(portdata->out_buffer[i]);
527	}
528bail_out_error:
529	for (i = 0; i < N_IN_URB; i++) {
530		usb_free_urb(portdata->in_urbs[i]);
531		free_page((unsigned long)portdata->in_buffer[i]);
532	}
533	kfree(portdata);
534
535	return -ENOMEM;
536}
537EXPORT_SYMBOL_GPL(usb_wwan_port_probe);
538
539int usb_wwan_port_remove(struct usb_serial_port *port)
540{
541	int i;
542	struct usb_wwan_port_private *portdata;
543
544	portdata = usb_get_serial_port_data(port);
545	usb_set_serial_port_data(port, NULL);
546
547	for (i = 0; i < N_IN_URB; i++) {
548		usb_free_urb(portdata->in_urbs[i]);
549		free_page((unsigned long)portdata->in_buffer[i]);
550	}
551	for (i = 0; i < N_OUT_URB; i++) {
552		usb_free_urb(portdata->out_urbs[i]);
553		kfree(portdata->out_buffer[i]);
554	}
555
556	kfree(portdata);
557
558	return 0;
559}
560EXPORT_SYMBOL(usb_wwan_port_remove);
561
562#ifdef CONFIG_PM
563static void stop_urbs(struct usb_serial *serial)
564{
565	int i, j;
566	struct usb_serial_port *port;
567	struct usb_wwan_port_private *portdata;
568
569	for (i = 0; i < serial->num_ports; ++i) {
570		port = serial->port[i];
571		portdata = usb_get_serial_port_data(port);
572		if (!portdata)
573			continue;
574		for (j = 0; j < N_IN_URB; j++)
575			usb_kill_urb(portdata->in_urbs[j]);
576		for (j = 0; j < N_OUT_URB; j++)
577			usb_kill_urb(portdata->out_urbs[j]);
578		usb_kill_urb(port->interrupt_in_urb);
579	}
580}
581
582int usb_wwan_suspend(struct usb_serial *serial, pm_message_t message)
583{
584	struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial);
585
586	spin_lock_irq(&intfdata->susp_lock);
587	if (PMSG_IS_AUTO(message)) {
588		if (intfdata->in_flight) {
589			spin_unlock_irq(&intfdata->susp_lock);
590			return -EBUSY;
591		}
592	}
593	intfdata->suspended = 1;
594	spin_unlock_irq(&intfdata->susp_lock);
595
596	stop_urbs(serial);
597
598	return 0;
599}
600EXPORT_SYMBOL(usb_wwan_suspend);
601
602/* Caller must hold susp_lock. */
603static int usb_wwan_submit_delayed_urbs(struct usb_serial_port *port)
604{
605	struct usb_serial *serial = port->serial;
606	struct usb_wwan_intf_private *data = usb_get_serial_data(serial);
607	struct usb_wwan_port_private *portdata;
608	struct urb *urb;
609	int err_count = 0;
610	int err;
611
612	portdata = usb_get_serial_port_data(port);
613
614	for (;;) {
615		urb = usb_get_from_anchor(&portdata->delayed);
616		if (!urb)
617			break;
618
619		err = usb_submit_urb(urb, GFP_ATOMIC);
620		if (err) {
621			dev_err(&port->dev, "%s: submit urb failed: %d\n",
622					__func__, err);
623			err_count++;
624			unbusy_queued_urb(urb, portdata);
625			usb_autopm_put_interface_async(serial->interface);
626			continue;
627		}
628		data->in_flight++;
629	}
630
631	if (err_count)
632		return -EIO;
633
634	return 0;
635}
636
637int usb_wwan_resume(struct usb_serial *serial)
638{
639	int i, j;
640	struct usb_serial_port *port;
641	struct usb_wwan_intf_private *intfdata = usb_get_serial_data(serial);
642	struct usb_wwan_port_private *portdata;
643	struct urb *urb;
644	int err;
645	int err_count = 0;
646
647	spin_lock_irq(&intfdata->susp_lock);
648	for (i = 0; i < serial->num_ports; i++) {
649		port = serial->port[i];
650
651		if (!test_bit(ASYNCB_INITIALIZED, &port->port.flags))
652			continue;
653
654		portdata = usb_get_serial_port_data(port);
655
656		if (port->interrupt_in_urb) {
657			err = usb_submit_urb(port->interrupt_in_urb,
658					GFP_ATOMIC);
659			if (err) {
660				dev_err(&port->dev,
661					"%s: submit int urb failed: %d\n",
662					__func__, err);
663				err_count++;
664			}
665		}
666
667		err = usb_wwan_submit_delayed_urbs(port);
668		if (err)
669			err_count++;
670
671		for (j = 0; j < N_IN_URB; j++) {
672			urb = portdata->in_urbs[j];
673			err = usb_submit_urb(urb, GFP_ATOMIC);
674			if (err < 0) {
675				dev_err(&port->dev,
676					"%s: submit read urb %d failed: %d\n",
677					__func__, i, err);
678				err_count++;
679			}
680		}
681	}
682	intfdata->suspended = 0;
683	spin_unlock_irq(&intfdata->susp_lock);
684
685	if (err_count)
686		return -EIO;
687
688	return 0;
689}
690EXPORT_SYMBOL(usb_wwan_resume);
691#endif
692
693MODULE_AUTHOR(DRIVER_AUTHOR);
694MODULE_DESCRIPTION(DRIVER_DESC);
695MODULE_LICENSE("GPL");
696