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1/*
2 * UART driver for the Greybus "generic" UART module.
3 *
4 * Copyright 2014 Google Inc.
5 * Copyright 2014 Linaro Ltd.
6 *
7 * Released under the GPLv2 only.
8 *
9 * Heavily based on drivers/usb/class/cdc-acm.c and
10 * drivers/usb/serial/usb-serial.c.
11 */
12#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13
14#include <linux/kernel.h>
15#include <linux/errno.h>
16#include <linux/module.h>
17#include <linux/sched.h>
18#include <linux/wait.h>
19#include <linux/slab.h>
20#include <linux/uaccess.h>
21#include <linux/mutex.h>
22#include <linux/tty.h>
23#include <linux/serial.h>
24#include <linux/tty_driver.h>
25#include <linux/tty_flip.h>
26#include <linux/serial.h>
27#include <linux/idr.h>
28#include <linux/fs.h>
29#include <linux/kdev_t.h>
30#include <linux/kfifo.h>
31#include <linux/workqueue.h>
32#include <linux/completion.h>
33
34#include "greybus.h"
35#include "gbphy.h"
36
37#define GB_NUM_MINORS 16 /* 16 is is more than enough */
38#define GB_NAME "ttyGB"
39
40#define GB_UART_WRITE_FIFO_SIZE PAGE_SIZE
41#define GB_UART_WRITE_ROOM_MARGIN 1 /* leave some space in fifo */
42#define GB_UART_FIRMWARE_CREDITS 4096
43#define GB_UART_CREDIT_WAIT_TIMEOUT_MSEC 10000
44
45struct gb_tty_line_coding {
46 __le32 rate;
47 __u8 format;
48 __u8 parity;
49 __u8 data_bits;
50 __u8 flow_control;
51};
52
53struct gb_tty {
54 struct gbphy_device *gbphy_dev;
55 struct tty_port port;
56 void *buffer;
57 size_t buffer_payload_max;
58 struct gb_connection *connection;
59 u16 cport_id;
60 unsigned int minor;
61 unsigned char clocal;
62 bool disconnected;
63 spinlock_t read_lock;
64 spinlock_t write_lock;
65 struct async_icount iocount;
66 struct async_icount oldcount;
67 wait_queue_head_t wioctl;
68 struct mutex mutex;
69 u8 ctrlin; /* input control lines */
70 u8 ctrlout; /* output control lines */
71 struct gb_tty_line_coding line_coding;
72 struct work_struct tx_work;
73 struct kfifo write_fifo;
74 bool close_pending;
75 unsigned int credits;
76 struct completion credits_complete;
77};
78
79static struct tty_driver *gb_tty_driver;
80static DEFINE_IDR(tty_minors);
81static DEFINE_MUTEX(table_lock);
82
83static int gb_uart_receive_data_handler(struct gb_operation *op)
84{
85 struct gb_connection *connection = op->connection;
86 struct gb_tty *gb_tty = gb_connection_get_data(connection);
87 struct tty_port *port = &gb_tty->port;
88 struct gb_message *request = op->request;
89 struct gb_uart_recv_data_request *receive_data;
90 u16 recv_data_size;
91 int count;
92 unsigned long tty_flags = TTY_NORMAL;
93
94 if (request->payload_size < sizeof(*receive_data)) {
95 dev_err(&gb_tty->gbphy_dev->dev,
96 "short receive-data request received (%zu < %zu)\n",
97 request->payload_size, sizeof(*receive_data));
98 return -EINVAL;
99 }
100
101 receive_data = op->request->payload;
102 recv_data_size = le16_to_cpu(receive_data->size);
103
104 if (recv_data_size != request->payload_size - sizeof(*receive_data)) {
105 dev_err(&gb_tty->gbphy_dev->dev,
106 "malformed receive-data request received (%u != %zu)\n",
107 recv_data_size,
108 request->payload_size - sizeof(*receive_data));
109 return -EINVAL;
110 }
111
112 if (!recv_data_size)
113 return -EINVAL;
114
115 if (receive_data->flags) {
116 if (receive_data->flags & GB_UART_RECV_FLAG_BREAK)
117 tty_flags = TTY_BREAK;
118 else if (receive_data->flags & GB_UART_RECV_FLAG_PARITY)
119 tty_flags = TTY_PARITY;
120 else if (receive_data->flags & GB_UART_RECV_FLAG_FRAMING)
121 tty_flags = TTY_FRAME;
122
123 /* overrun is special, not associated with a char */
124 if (receive_data->flags & GB_UART_RECV_FLAG_OVERRUN)
125 tty_insert_flip_char(port, 0, TTY_OVERRUN);
126 }
127 count = tty_insert_flip_string_fixed_flag(port, receive_data->data,
128 tty_flags, recv_data_size);
129 if (count != recv_data_size) {
130 dev_err(&gb_tty->gbphy_dev->dev,
131 "UART: RX 0x%08x bytes only wrote 0x%08x\n",
132 recv_data_size, count);
133 }
134 if (count)
135 tty_flip_buffer_push(port);
136 return 0;
137}
138
139static int gb_uart_serial_state_handler(struct gb_operation *op)
140{
141 struct gb_connection *connection = op->connection;
142 struct gb_tty *gb_tty = gb_connection_get_data(connection);
143 struct gb_message *request = op->request;
144 struct gb_uart_serial_state_request *serial_state;
145
146 if (request->payload_size < sizeof(*serial_state)) {
147 dev_err(&gb_tty->gbphy_dev->dev,
148 "short serial-state event received (%zu < %zu)\n",
149 request->payload_size, sizeof(*serial_state));
150 return -EINVAL;
151 }
152
153 serial_state = request->payload;
154 gb_tty->ctrlin = serial_state->control;
155
156 return 0;
157}
158
159static int gb_uart_receive_credits_handler(struct gb_operation *op)
160{
161 struct gb_connection *connection = op->connection;
162 struct gb_tty *gb_tty = gb_connection_get_data(connection);
163 struct gb_message *request = op->request;
164 struct gb_uart_receive_credits_request *credit_request;
165 unsigned long flags;
166 unsigned int incoming_credits;
167 int ret = 0;
168
169 if (request->payload_size < sizeof(*credit_request)) {
170 dev_err(&gb_tty->gbphy_dev->dev,
171 "short receive_credits event received (%zu < %zu)\n",
172 request->payload_size,
173 sizeof(*credit_request));
174 return -EINVAL;
175 }
176
177 credit_request = request->payload;
178 incoming_credits = le16_to_cpu(credit_request->count);
179
180 spin_lock_irqsave(&gb_tty->write_lock, flags);
181 gb_tty->credits += incoming_credits;
182 if (gb_tty->credits > GB_UART_FIRMWARE_CREDITS) {
183 gb_tty->credits -= incoming_credits;
184 ret = -EINVAL;
185 }
186 spin_unlock_irqrestore(&gb_tty->write_lock, flags);
187
188 if (ret) {
189 dev_err(&gb_tty->gbphy_dev->dev,
190 "invalid number of incoming credits: %d\n",
191 incoming_credits);
192 return ret;
193 }
194
195 if (!gb_tty->close_pending)
196 schedule_work(&gb_tty->tx_work);
197
198 /*
199 * the port the tty layer may be waiting for credits
200 */
201 tty_port_tty_wakeup(&gb_tty->port);
202
203 if (gb_tty->credits == GB_UART_FIRMWARE_CREDITS)
204 complete(&gb_tty->credits_complete);
205
206 return ret;
207}
208
209static int gb_uart_request_handler(struct gb_operation *op)
210{
211 struct gb_connection *connection = op->connection;
212 struct gb_tty *gb_tty = gb_connection_get_data(connection);
213 int type = op->type;
214 int ret;
215
216 switch (type) {
217 case GB_UART_TYPE_RECEIVE_DATA:
218 ret = gb_uart_receive_data_handler(op);
219 break;
220 case GB_UART_TYPE_SERIAL_STATE:
221 ret = gb_uart_serial_state_handler(op);
222 break;
223 case GB_UART_TYPE_RECEIVE_CREDITS:
224 ret = gb_uart_receive_credits_handler(op);
225 break;
226 default:
227 dev_err(&gb_tty->gbphy_dev->dev,
228 "unsupported unsolicited request: 0x%02x\n", type);
229 ret = -EINVAL;
230 }
231
232 return ret;
233}
234
235static void gb_uart_tx_write_work(struct work_struct *work)
236{
237 struct gb_uart_send_data_request *request;
238 struct gb_tty *gb_tty;
239 unsigned long flags;
240 unsigned int send_size;
241 int ret;
242
243 gb_tty = container_of(work, struct gb_tty, tx_work);
244 request = gb_tty->buffer;
245
246 while (1) {
247 if (gb_tty->close_pending)
248 break;
249
250 spin_lock_irqsave(&gb_tty->write_lock, flags);
251 send_size = gb_tty->buffer_payload_max;
252 if (send_size > gb_tty->credits)
253 send_size = gb_tty->credits;
254
255 send_size = kfifo_out_peek(&gb_tty->write_fifo,
256 &request->data[0],
257 send_size);
258 if (!send_size) {
259 spin_unlock_irqrestore(&gb_tty->write_lock, flags);
260 break;
261 }
262
263 gb_tty->credits -= send_size;
264 spin_unlock_irqrestore(&gb_tty->write_lock, flags);
265
266 request->size = cpu_to_le16(send_size);
267 ret = gb_operation_sync(gb_tty->connection,
268 GB_UART_TYPE_SEND_DATA,
269 request, sizeof(*request) + send_size,
270 NULL, 0);
271 if (ret) {
272 dev_err(&gb_tty->gbphy_dev->dev,
273 "send data error: %d\n", ret);
274 spin_lock_irqsave(&gb_tty->write_lock, flags);
275 gb_tty->credits += send_size;
276 spin_unlock_irqrestore(&gb_tty->write_lock, flags);
277 if (!gb_tty->close_pending)
278 schedule_work(work);
279 return;
280 }
281
282 spin_lock_irqsave(&gb_tty->write_lock, flags);
283 ret = kfifo_out(&gb_tty->write_fifo, &request->data[0],
284 send_size);
285 spin_unlock_irqrestore(&gb_tty->write_lock, flags);
286
287 tty_port_tty_wakeup(&gb_tty->port);
288 }
289}
290
291static int send_line_coding(struct gb_tty *tty)
292{
293 struct gb_uart_set_line_coding_request request;
294
295 memcpy(&request, &tty->line_coding,
296 sizeof(tty->line_coding));
297 return gb_operation_sync(tty->connection, GB_UART_TYPE_SET_LINE_CODING,
298 &request, sizeof(request), NULL, 0);
299}
300
301static int send_control(struct gb_tty *gb_tty, u8 control)
302{
303 struct gb_uart_set_control_line_state_request request;
304
305 request.control = control;
306 return gb_operation_sync(gb_tty->connection,
307 GB_UART_TYPE_SET_CONTROL_LINE_STATE,
308 &request, sizeof(request), NULL, 0);
309}
310
311static int send_break(struct gb_tty *gb_tty, u8 state)
312{
313 struct gb_uart_set_break_request request;
314
315 if ((state != 0) && (state != 1)) {
316 dev_err(&gb_tty->gbphy_dev->dev,
317 "invalid break state of %d\n", state);
318 return -EINVAL;
319 }
320
321 request.state = state;
322 return gb_operation_sync(gb_tty->connection, GB_UART_TYPE_SEND_BREAK,
323 &request, sizeof(request), NULL, 0);
324}
325
326static int gb_uart_wait_for_all_credits(struct gb_tty *gb_tty)
327{
328 int ret;
329
330 if (gb_tty->credits == GB_UART_FIRMWARE_CREDITS)
331 return 0;
332
333 ret = wait_for_completion_timeout(&gb_tty->credits_complete,
334 msecs_to_jiffies(GB_UART_CREDIT_WAIT_TIMEOUT_MSEC));
335 if (!ret) {
336 dev_err(&gb_tty->gbphy_dev->dev,
337 "time out waiting for credits\n");
338 return -ETIMEDOUT;
339 }
340
341 return 0;
342}
343
344static int gb_uart_flush(struct gb_tty *gb_tty, u8 flags)
345{
346 struct gb_uart_serial_flush_request request;
347
348 request.flags = flags;
349 return gb_operation_sync(gb_tty->connection, GB_UART_TYPE_FLUSH_FIFOS,
350 &request, sizeof(request), NULL, 0);
351}
352
353static struct gb_tty *get_gb_by_minor(unsigned int minor)
354{
355 struct gb_tty *gb_tty;
356
357 mutex_lock(&table_lock);
358 gb_tty = idr_find(&tty_minors, minor);
359 if (gb_tty) {
360 mutex_lock(&gb_tty->mutex);
361 if (gb_tty->disconnected) {
362 mutex_unlock(&gb_tty->mutex);
363 gb_tty = NULL;
364 } else {
365 tty_port_get(&gb_tty->port);
366 mutex_unlock(&gb_tty->mutex);
367 }
368 }
369 mutex_unlock(&table_lock);
370 return gb_tty;
371}
372
373static int alloc_minor(struct gb_tty *gb_tty)
374{
375 int minor;
376
377 mutex_lock(&table_lock);
378 minor = idr_alloc(&tty_minors, gb_tty, 0, GB_NUM_MINORS, GFP_KERNEL);
379 mutex_unlock(&table_lock);
380 if (minor >= 0)
381 gb_tty->minor = minor;
382 return minor;
383}
384
385static void release_minor(struct gb_tty *gb_tty)
386{
387 int minor = gb_tty->minor;
388
389 gb_tty->minor = 0; /* Maybe should use an invalid value instead */
390 mutex_lock(&table_lock);
391 idr_remove(&tty_minors, minor);
392 mutex_unlock(&table_lock);
393}
394
395static int gb_tty_install(struct tty_driver *driver, struct tty_struct *tty)
396{
397 struct gb_tty *gb_tty;
398 int retval;
399
400 gb_tty = get_gb_by_minor(tty->index);
401 if (!gb_tty)
402 return -ENODEV;
403
404 retval = tty_standard_install(driver, tty);
405 if (retval)
406 goto error;
407
408 tty->driver_data = gb_tty;
409 return 0;
410error:
411 tty_port_put(&gb_tty->port);
412 return retval;
413}
414
415static int gb_tty_open(struct tty_struct *tty, struct file *file)
416{
417 struct gb_tty *gb_tty = tty->driver_data;
418
419 return tty_port_open(&gb_tty->port, tty, file);
420}
421
422static void gb_tty_close(struct tty_struct *tty, struct file *file)
423{
424 struct gb_tty *gb_tty = tty->driver_data;
425
426 tty_port_close(&gb_tty->port, tty, file);
427}
428
429static void gb_tty_cleanup(struct tty_struct *tty)
430{
431 struct gb_tty *gb_tty = tty->driver_data;
432
433 tty_port_put(&gb_tty->port);
434}
435
436static void gb_tty_hangup(struct tty_struct *tty)
437{
438 struct gb_tty *gb_tty = tty->driver_data;
439
440 tty_port_hangup(&gb_tty->port);
441}
442
443static int gb_tty_write(struct tty_struct *tty, const unsigned char *buf,
444 int count)
445{
446 struct gb_tty *gb_tty = tty->driver_data;
447
448 count = kfifo_in_spinlocked(&gb_tty->write_fifo, buf, count,
449 &gb_tty->write_lock);
450 if (count && !gb_tty->close_pending)
451 schedule_work(&gb_tty->tx_work);
452
453 return count;
454}
455
456static int gb_tty_write_room(struct tty_struct *tty)
457{
458 struct gb_tty *gb_tty = tty->driver_data;
459 unsigned long flags;
460 int room;
461
462 spin_lock_irqsave(&gb_tty->write_lock, flags);
463 room = kfifo_avail(&gb_tty->write_fifo);
464 spin_unlock_irqrestore(&gb_tty->write_lock, flags);
465
466 room -= GB_UART_WRITE_ROOM_MARGIN;
467 if (room < 0)
468 return 0;
469
470 return room;
471}
472
473static int gb_tty_chars_in_buffer(struct tty_struct *tty)
474{
475 struct gb_tty *gb_tty = tty->driver_data;
476 unsigned long flags;
477 int chars;
478
479 spin_lock_irqsave(&gb_tty->write_lock, flags);
480 chars = kfifo_len(&gb_tty->write_fifo);
481 if (gb_tty->credits < GB_UART_FIRMWARE_CREDITS)
482 chars += GB_UART_FIRMWARE_CREDITS - gb_tty->credits;
483 spin_unlock_irqrestore(&gb_tty->write_lock, flags);
484
485 return chars;
486}
487
488static int gb_tty_break_ctl(struct tty_struct *tty, int state)
489{
490 struct gb_tty *gb_tty = tty->driver_data;
491
492 return send_break(gb_tty, state ? 1 : 0);
493}
494
495static void gb_tty_set_termios(struct tty_struct *tty,
496 struct ktermios *termios_old)
497{
498 struct gb_tty *gb_tty = tty->driver_data;
499 struct ktermios *termios = &tty->termios;
500 struct gb_tty_line_coding newline;
501 u8 newctrl = gb_tty->ctrlout;
502
503 newline.rate = cpu_to_le32(tty_get_baud_rate(tty));
504 newline.format = termios->c_cflag & CSTOPB ?
505 GB_SERIAL_2_STOP_BITS : GB_SERIAL_1_STOP_BITS;
506 newline.parity = termios->c_cflag & PARENB ?
507 (termios->c_cflag & PARODD ? 1 : 2) +
508 (termios->c_cflag & CMSPAR ? 2 : 0) : 0;
509
510 switch (termios->c_cflag & CSIZE) {
511 case CS5:
512 newline.data_bits = 5;
513 break;
514 case CS6:
515 newline.data_bits = 6;
516 break;
517 case CS7:
518 newline.data_bits = 7;
519 break;
520 case CS8:
521 default:
522 newline.data_bits = 8;
523 break;
524 }
525
526 /* FIXME: needs to clear unsupported bits in the termios */
527 gb_tty->clocal = ((termios->c_cflag & CLOCAL) != 0);
528
529 if (C_BAUD(tty) == B0) {
530 newline.rate = gb_tty->line_coding.rate;
531 newctrl &= ~(GB_UART_CTRL_DTR | GB_UART_CTRL_RTS);
532 } else if (termios_old && (termios_old->c_cflag & CBAUD) == B0) {
533 newctrl |= (GB_UART_CTRL_DTR | GB_UART_CTRL_RTS);
534 }
535
536 if (newctrl != gb_tty->ctrlout) {
537 gb_tty->ctrlout = newctrl;
538 send_control(gb_tty, newctrl);
539 }
540
541 if (C_CRTSCTS(tty) && C_BAUD(tty) != B0)
542 newline.flow_control |= GB_SERIAL_AUTO_RTSCTS_EN;
543 else
544 newline.flow_control &= ~GB_SERIAL_AUTO_RTSCTS_EN;
545
546 if (memcmp(&gb_tty->line_coding, &newline, sizeof(newline))) {
547 memcpy(&gb_tty->line_coding, &newline, sizeof(newline));
548 send_line_coding(gb_tty);
549 }
550}
551
552static int gb_tty_tiocmget(struct tty_struct *tty)
553{
554 struct gb_tty *gb_tty = tty->driver_data;
555
556 return (gb_tty->ctrlout & GB_UART_CTRL_DTR ? TIOCM_DTR : 0) |
557 (gb_tty->ctrlout & GB_UART_CTRL_RTS ? TIOCM_RTS : 0) |
558 (gb_tty->ctrlin & GB_UART_CTRL_DSR ? TIOCM_DSR : 0) |
559 (gb_tty->ctrlin & GB_UART_CTRL_RI ? TIOCM_RI : 0) |
560 (gb_tty->ctrlin & GB_UART_CTRL_DCD ? TIOCM_CD : 0) |
561 TIOCM_CTS;
562}
563
564static int gb_tty_tiocmset(struct tty_struct *tty, unsigned int set,
565 unsigned int clear)
566{
567 struct gb_tty *gb_tty = tty->driver_data;
568 u8 newctrl = gb_tty->ctrlout;
569
570 set = (set & TIOCM_DTR ? GB_UART_CTRL_DTR : 0) |
571 (set & TIOCM_RTS ? GB_UART_CTRL_RTS : 0);
572 clear = (clear & TIOCM_DTR ? GB_UART_CTRL_DTR : 0) |
573 (clear & TIOCM_RTS ? GB_UART_CTRL_RTS : 0);
574
575 newctrl = (newctrl & ~clear) | set;
576 if (gb_tty->ctrlout == newctrl)
577 return 0;
578
579 gb_tty->ctrlout = newctrl;
580 return send_control(gb_tty, newctrl);
581}
582
583static void gb_tty_throttle(struct tty_struct *tty)
584{
585 struct gb_tty *gb_tty = tty->driver_data;
586 unsigned char stop_char;
587 int retval;
588
589 if (I_IXOFF(tty)) {
590 stop_char = STOP_CHAR(tty);
591 retval = gb_tty_write(tty, &stop_char, 1);
592 if (retval <= 0)
593 return;
594 }
595
596 if (tty->termios.c_cflag & CRTSCTS) {
597 gb_tty->ctrlout &= ~GB_UART_CTRL_RTS;
598 retval = send_control(gb_tty, gb_tty->ctrlout);
599 }
600}
601
602static void gb_tty_unthrottle(struct tty_struct *tty)
603{
604 struct gb_tty *gb_tty = tty->driver_data;
605 unsigned char start_char;
606 int retval;
607
608 if (I_IXOFF(tty)) {
609 start_char = START_CHAR(tty);
610 retval = gb_tty_write(tty, &start_char, 1);
611 if (retval <= 0)
612 return;
613 }
614
615 if (tty->termios.c_cflag & CRTSCTS) {
616 gb_tty->ctrlout |= GB_UART_CTRL_RTS;
617 retval = send_control(gb_tty, gb_tty->ctrlout);
618 }
619}
620
621static int get_serial_info(struct gb_tty *gb_tty,
622 struct serial_struct __user *info)
623{
624 struct serial_struct tmp;
625
626 memset(&tmp, 0, sizeof(tmp));
627 tmp.flags = ASYNC_LOW_LATENCY | ASYNC_SKIP_TEST;
628 tmp.type = PORT_16550A;
629 tmp.line = gb_tty->minor;
630 tmp.xmit_fifo_size = 16;
631 tmp.baud_base = 9600;
632 tmp.close_delay = gb_tty->port.close_delay / 10;
633 tmp.closing_wait = gb_tty->port.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
634 ASYNC_CLOSING_WAIT_NONE : gb_tty->port.closing_wait / 10;
635
636 if (copy_to_user(info, &tmp, sizeof(tmp)))
637 return -EFAULT;
638 return 0;
639}
640
641static int set_serial_info(struct gb_tty *gb_tty,
642 struct serial_struct __user *newinfo)
643{
644 struct serial_struct new_serial;
645 unsigned int closing_wait;
646 unsigned int close_delay;
647 int retval = 0;
648
649 if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
650 return -EFAULT;
651
652 close_delay = new_serial.close_delay * 10;
653 closing_wait = new_serial.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
654 ASYNC_CLOSING_WAIT_NONE : new_serial.closing_wait * 10;
655
656 mutex_lock(&gb_tty->port.mutex);
657 if (!capable(CAP_SYS_ADMIN)) {
658 if ((close_delay != gb_tty->port.close_delay) ||
659 (closing_wait != gb_tty->port.closing_wait))
660 retval = -EPERM;
661 else
662 retval = -EOPNOTSUPP;
663 } else {
664 gb_tty->port.close_delay = close_delay;
665 gb_tty->port.closing_wait = closing_wait;
666 }
667 mutex_unlock(&gb_tty->port.mutex);
668 return retval;
669}
670
671static int wait_serial_change(struct gb_tty *gb_tty, unsigned long arg)
672{
673 int retval = 0;
674 DECLARE_WAITQUEUE(wait, current);
675 struct async_icount old;
676 struct async_icount new;
677
678 if (!(arg & (TIOCM_DSR | TIOCM_RI | TIOCM_CD)))
679 return -EINVAL;
680
681 do {
682 spin_lock_irq(&gb_tty->read_lock);
683 old = gb_tty->oldcount;
684 new = gb_tty->iocount;
685 gb_tty->oldcount = new;
686 spin_unlock_irq(&gb_tty->read_lock);
687
688 if ((arg & TIOCM_DSR) && (old.dsr != new.dsr))
689 break;
690 if ((arg & TIOCM_CD) && (old.dcd != new.dcd))
691 break;
692 if ((arg & TIOCM_RI) && (old.rng != new.rng))
693 break;
694
695 add_wait_queue(&gb_tty->wioctl, &wait);
696 set_current_state(TASK_INTERRUPTIBLE);
697 schedule();
698 remove_wait_queue(&gb_tty->wioctl, &wait);
699 if (gb_tty->disconnected) {
700 if (arg & TIOCM_CD)
701 break;
702 retval = -ENODEV;
703 } else if (signal_pending(current)) {
704 retval = -ERESTARTSYS;
705 }
706 } while (!retval);
707
708 return retval;
709}
710
711static int gb_tty_get_icount(struct tty_struct *tty,
712 struct serial_icounter_struct *icount)
713{
714 struct gb_tty *gb_tty = tty->driver_data;
715
716 icount->dsr = gb_tty->iocount.dsr;
717 icount->rng = gb_tty->iocount.rng;
718 icount->dcd = gb_tty->iocount.dcd;
719 icount->frame = gb_tty->iocount.frame;
720 icount->overrun = gb_tty->iocount.overrun;
721 icount->parity = gb_tty->iocount.parity;
722 icount->brk = gb_tty->iocount.brk;
723
724 return 0;
725}
726
727static int gb_tty_ioctl(struct tty_struct *tty, unsigned int cmd,
728 unsigned long arg)
729{
730 struct gb_tty *gb_tty = tty->driver_data;
731
732 switch (cmd) {
733 case TIOCGSERIAL:
734 return get_serial_info(gb_tty,
735 (struct serial_struct __user *)arg);
736 case TIOCSSERIAL:
737 return set_serial_info(gb_tty,
738 (struct serial_struct __user *)arg);
739 case TIOCMIWAIT:
740 return wait_serial_change(gb_tty, arg);
741 }
742
743 return -ENOIOCTLCMD;
744}
745
746static void gb_tty_dtr_rts(struct tty_port *port, int on)
747{
748 struct gb_tty *gb_tty;
749 u8 newctrl;
750
751 gb_tty = container_of(port, struct gb_tty, port);
752 newctrl = gb_tty->ctrlout;
753
754 if (on)
755 newctrl |= (GB_UART_CTRL_DTR | GB_UART_CTRL_RTS);
756 else
757 newctrl &= ~(GB_UART_CTRL_DTR | GB_UART_CTRL_RTS);
758
759 gb_tty->ctrlout = newctrl;
760 send_control(gb_tty, newctrl);
761}
762
763static int gb_tty_port_activate(struct tty_port *port,
764 struct tty_struct *tty)
765{
766 struct gb_tty *gb_tty;
767
768 gb_tty = container_of(port, struct gb_tty, port);
769
770 return gbphy_runtime_get_sync(gb_tty->gbphy_dev);
771}
772
773static void gb_tty_port_shutdown(struct tty_port *port)
774{
775 struct gb_tty *gb_tty;
776 unsigned long flags;
777 int ret;
778
779 gb_tty = container_of(port, struct gb_tty, port);
780
781 gb_tty->close_pending = true;
782
783 cancel_work_sync(&gb_tty->tx_work);
784
785 spin_lock_irqsave(&gb_tty->write_lock, flags);
786 kfifo_reset_out(&gb_tty->write_fifo);
787 spin_unlock_irqrestore(&gb_tty->write_lock, flags);
788
789 if (gb_tty->credits == GB_UART_FIRMWARE_CREDITS)
790 goto out;
791
792 ret = gb_uart_flush(gb_tty, GB_SERIAL_FLAG_FLUSH_TRANSMITTER);
793 if (ret) {
794 dev_err(&gb_tty->gbphy_dev->dev,
795 "error flushing transmitter: %d\n", ret);
796 }
797
798 gb_uart_wait_for_all_credits(gb_tty);
799
800out:
801 gb_tty->close_pending = false;
802
803 gbphy_runtime_put_autosuspend(gb_tty->gbphy_dev);
804}
805
806static const struct tty_operations gb_ops = {
807 .install = gb_tty_install,
808 .open = gb_tty_open,
809 .close = gb_tty_close,
810 .cleanup = gb_tty_cleanup,
811 .hangup = gb_tty_hangup,
812 .write = gb_tty_write,
813 .write_room = gb_tty_write_room,
814 .ioctl = gb_tty_ioctl,
815 .throttle = gb_tty_throttle,
816 .unthrottle = gb_tty_unthrottle,
817 .chars_in_buffer = gb_tty_chars_in_buffer,
818 .break_ctl = gb_tty_break_ctl,
819 .set_termios = gb_tty_set_termios,
820 .tiocmget = gb_tty_tiocmget,
821 .tiocmset = gb_tty_tiocmset,
822 .get_icount = gb_tty_get_icount,
823};
824
825static const struct tty_port_operations gb_port_ops = {
826 .dtr_rts = gb_tty_dtr_rts,
827 .activate = gb_tty_port_activate,
828 .shutdown = gb_tty_port_shutdown,
829};
830
831static int gb_uart_probe(struct gbphy_device *gbphy_dev,
832 const struct gbphy_device_id *id)
833{
834 struct gb_connection *connection;
835 size_t max_payload;
836 struct gb_tty *gb_tty;
837 struct device *tty_dev;
838 int retval;
839 int minor;
840
841 gb_tty = kzalloc(sizeof(*gb_tty), GFP_KERNEL);
842 if (!gb_tty)
843 return -ENOMEM;
844
845 connection = gb_connection_create(gbphy_dev->bundle,
846 le16_to_cpu(gbphy_dev->cport_desc->id),
847 gb_uart_request_handler);
848 if (IS_ERR(connection)) {
849 retval = PTR_ERR(connection);
850 goto exit_tty_free;
851 }
852
853 max_payload = gb_operation_get_payload_size_max(connection);
854 if (max_payload < sizeof(struct gb_uart_send_data_request)) {
855 retval = -EINVAL;
856 goto exit_connection_destroy;
857 }
858
859 gb_tty->buffer_payload_max = max_payload -
860 sizeof(struct gb_uart_send_data_request);
861
862 gb_tty->buffer = kzalloc(gb_tty->buffer_payload_max, GFP_KERNEL);
863 if (!gb_tty->buffer) {
864 retval = -ENOMEM;
865 goto exit_connection_destroy;
866 }
867
868 INIT_WORK(&gb_tty->tx_work, gb_uart_tx_write_work);
869
870 retval = kfifo_alloc(&gb_tty->write_fifo, GB_UART_WRITE_FIFO_SIZE,
871 GFP_KERNEL);
872 if (retval)
873 goto exit_buf_free;
874
875 gb_tty->credits = GB_UART_FIRMWARE_CREDITS;
876 init_completion(&gb_tty->credits_complete);
877
878 minor = alloc_minor(gb_tty);
879 if (minor < 0) {
880 if (minor == -ENOSPC) {
881 dev_err(&gbphy_dev->dev,
882 "no more free minor numbers\n");
883 retval = -ENODEV;
884 } else {
885 retval = minor;
886 }
887 goto exit_kfifo_free;
888 }
889
890 gb_tty->minor = minor;
891 spin_lock_init(&gb_tty->write_lock);
892 spin_lock_init(&gb_tty->read_lock);
893 init_waitqueue_head(&gb_tty->wioctl);
894 mutex_init(&gb_tty->mutex);
895
896 tty_port_init(&gb_tty->port);
897 gb_tty->port.ops = &gb_port_ops;
898
899 gb_tty->connection = connection;
900 gb_tty->gbphy_dev = gbphy_dev;
901 gb_connection_set_data(connection, gb_tty);
902 gb_gbphy_set_data(gbphy_dev, gb_tty);
903
904 retval = gb_connection_enable_tx(connection);
905 if (retval)
906 goto exit_release_minor;
907
908 send_control(gb_tty, gb_tty->ctrlout);
909
910 /* initialize the uart to be 9600n81 */
911 gb_tty->line_coding.rate = cpu_to_le32(9600);
912 gb_tty->line_coding.format = GB_SERIAL_1_STOP_BITS;
913 gb_tty->line_coding.parity = GB_SERIAL_NO_PARITY;
914 gb_tty->line_coding.data_bits = 8;
915 send_line_coding(gb_tty);
916
917 retval = gb_connection_enable(connection);
918 if (retval)
919 goto exit_connection_disable;
920
921 tty_dev = tty_port_register_device(&gb_tty->port, gb_tty_driver, minor,
922 &gbphy_dev->dev);
923 if (IS_ERR(tty_dev)) {
924 retval = PTR_ERR(tty_dev);
925 goto exit_connection_disable;
926 }
927
928 gbphy_runtime_put_autosuspend(gbphy_dev);
929 return 0;
930
931exit_connection_disable:
932 gb_connection_disable(connection);
933exit_release_minor:
934 release_minor(gb_tty);
935exit_kfifo_free:
936 kfifo_free(&gb_tty->write_fifo);
937exit_buf_free:
938 kfree(gb_tty->buffer);
939exit_connection_destroy:
940 gb_connection_destroy(connection);
941exit_tty_free:
942 kfree(gb_tty);
943
944 return retval;
945}
946
947static void gb_uart_remove(struct gbphy_device *gbphy_dev)
948{
949 struct gb_tty *gb_tty = gb_gbphy_get_data(gbphy_dev);
950 struct gb_connection *connection = gb_tty->connection;
951 struct tty_struct *tty;
952 int ret;
953
954 ret = gbphy_runtime_get_sync(gbphy_dev);
955 if (ret)
956 gbphy_runtime_get_noresume(gbphy_dev);
957
958 mutex_lock(&gb_tty->mutex);
959 gb_tty->disconnected = true;
960
961 wake_up_all(&gb_tty->wioctl);
962 mutex_unlock(&gb_tty->mutex);
963
964 tty = tty_port_tty_get(&gb_tty->port);
965 if (tty) {
966 tty_vhangup(tty);
967 tty_kref_put(tty);
968 }
969
970 gb_connection_disable_rx(connection);
971 tty_unregister_device(gb_tty_driver, gb_tty->minor);
972
973 /* FIXME - free transmit / receive buffers */
974
975 gb_connection_disable(connection);
976 tty_port_destroy(&gb_tty->port);
977 gb_connection_destroy(connection);
978 release_minor(gb_tty);
979 kfifo_free(&gb_tty->write_fifo);
980 kfree(gb_tty->buffer);
981 kfree(gb_tty);
982}
983
984static int gb_tty_init(void)
985{
986 int retval = 0;
987
988 gb_tty_driver = tty_alloc_driver(GB_NUM_MINORS, 0);
989 if (IS_ERR(gb_tty_driver)) {
990 pr_err("Can not allocate tty driver\n");
991 retval = -ENOMEM;
992 goto fail_unregister_dev;
993 }
994
995 gb_tty_driver->driver_name = "gb";
996 gb_tty_driver->name = GB_NAME;
997 gb_tty_driver->major = 0;
998 gb_tty_driver->minor_start = 0;
999 gb_tty_driver->type = TTY_DRIVER_TYPE_SERIAL;
1000 gb_tty_driver->subtype = SERIAL_TYPE_NORMAL;
1001 gb_tty_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
1002 gb_tty_driver->init_termios = tty_std_termios;
1003 gb_tty_driver->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
1004 tty_set_operations(gb_tty_driver, &gb_ops);
1005
1006 retval = tty_register_driver(gb_tty_driver);
1007 if (retval) {
1008 pr_err("Can not register tty driver: %d\n", retval);
1009 goto fail_put_gb_tty;
1010 }
1011
1012 return 0;
1013
1014fail_put_gb_tty:
1015 put_tty_driver(gb_tty_driver);
1016fail_unregister_dev:
1017 return retval;
1018}
1019
1020static void gb_tty_exit(void)
1021{
1022 tty_unregister_driver(gb_tty_driver);
1023 put_tty_driver(gb_tty_driver);
1024 idr_destroy(&tty_minors);
1025}
1026
1027static const struct gbphy_device_id gb_uart_id_table[] = {
1028 { GBPHY_PROTOCOL(GREYBUS_PROTOCOL_UART) },
1029 { },
1030};
1031MODULE_DEVICE_TABLE(gbphy, gb_uart_id_table);
1032
1033static struct gbphy_driver uart_driver = {
1034 .name = "uart",
1035 .probe = gb_uart_probe,
1036 .remove = gb_uart_remove,
1037 .id_table = gb_uart_id_table,
1038};
1039
1040static int gb_uart_driver_init(void)
1041{
1042 int ret;
1043
1044 ret = gb_tty_init();
1045 if (ret)
1046 return ret;
1047
1048 ret = gb_gbphy_register(&uart_driver);
1049 if (ret) {
1050 gb_tty_exit();
1051 return ret;
1052 }
1053
1054 return 0;
1055}
1056module_init(gb_uart_driver_init);
1057
1058static void gb_uart_driver_exit(void)
1059{
1060 gb_gbphy_deregister(&uart_driver);
1061 gb_tty_exit();
1062}
1063
1064module_exit(gb_uart_driver_exit);
1065MODULE_LICENSE("GPL v2");