Commit | Line | Data |
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c1dca562 DB |
1 | /* |
2 | * u_serial.c - utilities for USB gadget "serial port"/TTY support | |
3 | * | |
4 | * Copyright (C) 2003 Al Borchers (alborchers@steinerpoint.com) | |
5 | * Copyright (C) 2008 David Brownell | |
6 | * Copyright (C) 2008 by Nokia Corporation | |
7 | * | |
8 | * This code also borrows from usbserial.c, which is | |
9 | * Copyright (C) 1999 - 2002 Greg Kroah-Hartman (greg@kroah.com) | |
10 | * Copyright (C) 2000 Peter Berger (pberger@brimson.com) | |
11 | * Copyright (C) 2000 Al Borchers (alborchers@steinerpoint.com) | |
12 | * | |
13 | * This software is distributed under the terms of the GNU General | |
14 | * Public License ("GPL") as published by the Free Software Foundation, | |
15 | * either version 2 of that License or (at your option) any later version. | |
16 | */ | |
17 | ||
18 | /* #define VERBOSE_DEBUG */ | |
19 | ||
20 | #include <linux/kernel.h> | |
1e413943 | 21 | #include <linux/sched.h> |
c1dca562 DB |
22 | #include <linux/interrupt.h> |
23 | #include <linux/device.h> | |
24 | #include <linux/delay.h> | |
25 | #include <linux/tty.h> | |
26 | #include <linux/tty_flip.h> | |
5a0e3ad6 | 27 | #include <linux/slab.h> |
f940fcd8 | 28 | #include <linux/export.h> |
3249ca22 | 29 | #include <linux/module.h> |
c1dca562 DB |
30 | |
31 | #include "u_serial.h" | |
32 | ||
33 | ||
34 | /* | |
35 | * This component encapsulates the TTY layer glue needed to provide basic | |
36 | * "serial port" functionality through the USB gadget stack. Each such | |
37 | * port is exposed through a /dev/ttyGS* node. | |
38 | * | |
19b10a88 SAS |
39 | * After this module has been loaded, the individual TTY port can be requested |
40 | * (gserial_alloc_line()) and it will stay available until they are removed | |
41 | * (gserial_free_line()). Each one may be connected to a USB function | |
42 | * (gserial_connect), or disconnected (with gserial_disconnect) when the USB | |
43 | * host issues a config change event. Data can only flow when the port is | |
44 | * connected to the host. | |
c1dca562 DB |
45 | * |
46 | * A given TTY port can be made available in multiple configurations. | |
47 | * For example, each one might expose a ttyGS0 node which provides a | |
48 | * login application. In one case that might use CDC ACM interface 0, | |
49 | * while another configuration might use interface 3 for that. The | |
50 | * work to handle that (including descriptor management) is not part | |
51 | * of this component. | |
52 | * | |
53 | * Configurations may expose more than one TTY port. For example, if | |
54 | * ttyGS0 provides login service, then ttyGS1 might provide dialer access | |
55 | * for a telephone or fax link. And ttyGS2 might be something that just | |
56 | * needs a simple byte stream interface for some messaging protocol that | |
57 | * is managed in userspace ... OBEX, PTP, and MTP have been mentioned. | |
58 | */ | |
59 | ||
937ef73d DB |
60 | #define PREFIX "ttyGS" |
61 | ||
c1dca562 DB |
62 | /* |
63 | * gserial is the lifecycle interface, used by USB functions | |
64 | * gs_port is the I/O nexus, used by the tty driver | |
65 | * tty_struct links to the tty/filesystem framework | |
66 | * | |
67 | * gserial <---> gs_port ... links will be null when the USB link is | |
1f1ba11b DB |
68 | * inactive; managed by gserial_{connect,disconnect}(). each gserial |
69 | * instance can wrap its own USB control protocol. | |
c1dca562 DB |
70 | * gserial->ioport == usb_ep->driver_data ... gs_port |
71 | * gs_port->port_usb ... gserial | |
72 | * | |
73 | * gs_port <---> tty_struct ... links will be null when the TTY file | |
74 | * isn't opened; managed by gs_open()/gs_close() | |
75 | * gserial->port_tty ... tty_struct | |
76 | * tty_struct->driver_data ... gserial | |
77 | */ | |
78 | ||
79 | /* RX and TX queues can buffer QUEUE_SIZE packets before they hit the | |
80 | * next layer of buffering. For TX that's a circular buffer; for RX | |
81 | * consider it a NOP. A third layer is provided by the TTY code. | |
82 | */ | |
83 | #define QUEUE_SIZE 16 | |
84 | #define WRITE_BUF_SIZE 8192 /* TX only */ | |
85 | ||
86 | /* circular buffer */ | |
87 | struct gs_buf { | |
88 | unsigned buf_size; | |
89 | char *buf_buf; | |
90 | char *buf_get; | |
91 | char *buf_put; | |
92 | }; | |
93 | ||
94 | /* | |
95 | * The port structure holds info for each port, one for each minor number | |
96 | * (and thus for each /dev/ node). | |
97 | */ | |
98 | struct gs_port { | |
266e37ef | 99 | struct tty_port port; |
c1dca562 DB |
100 | spinlock_t port_lock; /* guard port_* access */ |
101 | ||
102 | struct gserial *port_usb; | |
c1dca562 | 103 | |
c1dca562 DB |
104 | bool openclose; /* open/close in progress */ |
105 | u8 port_num; | |
106 | ||
c1dca562 | 107 | struct list_head read_pool; |
28609d40 JS |
108 | int read_started; |
109 | int read_allocated; | |
937ef73d DB |
110 | struct list_head read_queue; |
111 | unsigned n_read; | |
c1dca562 DB |
112 | struct tasklet_struct push; |
113 | ||
114 | struct list_head write_pool; | |
28609d40 JS |
115 | int write_started; |
116 | int write_allocated; | |
c1dca562 DB |
117 | struct gs_buf port_write_buf; |
118 | wait_queue_head_t drain_wait; /* wait while writes drain */ | |
119 | ||
120 | /* REVISIT this state ... */ | |
121 | struct usb_cdc_line_coding port_line_coding; /* 8-N-1 etc */ | |
122 | }; | |
123 | ||
c1dca562 DB |
124 | static struct portmaster { |
125 | struct mutex lock; /* protect open/close */ | |
126 | struct gs_port *port; | |
19b10a88 | 127 | } ports[MAX_U_SERIAL_PORTS]; |
c1dca562 DB |
128 | |
129 | #define GS_CLOSE_TIMEOUT 15 /* seconds */ | |
130 | ||
131 | ||
132 | ||
133 | #ifdef VERBOSE_DEBUG | |
ea0e6276 | 134 | #ifndef pr_vdebug |
c1dca562 DB |
135 | #define pr_vdebug(fmt, arg...) \ |
136 | pr_debug(fmt, ##arg) | |
ea0e6276 | 137 | #endif /* pr_vdebug */ |
c1dca562 | 138 | #else |
ea0e6276 | 139 | #ifndef pr_vdebig |
c1dca562 DB |
140 | #define pr_vdebug(fmt, arg...) \ |
141 | ({ if (0) pr_debug(fmt, ##arg); }) | |
ea0e6276 | 142 | #endif /* pr_vdebug */ |
c1dca562 DB |
143 | #endif |
144 | ||
145 | /*-------------------------------------------------------------------------*/ | |
146 | ||
147 | /* Circular Buffer */ | |
148 | ||
149 | /* | |
150 | * gs_buf_alloc | |
151 | * | |
152 | * Allocate a circular buffer and all associated memory. | |
153 | */ | |
154 | static int gs_buf_alloc(struct gs_buf *gb, unsigned size) | |
155 | { | |
156 | gb->buf_buf = kmalloc(size, GFP_KERNEL); | |
157 | if (gb->buf_buf == NULL) | |
158 | return -ENOMEM; | |
159 | ||
160 | gb->buf_size = size; | |
161 | gb->buf_put = gb->buf_buf; | |
162 | gb->buf_get = gb->buf_buf; | |
163 | ||
164 | return 0; | |
165 | } | |
166 | ||
167 | /* | |
168 | * gs_buf_free | |
169 | * | |
170 | * Free the buffer and all associated memory. | |
171 | */ | |
172 | static void gs_buf_free(struct gs_buf *gb) | |
173 | { | |
174 | kfree(gb->buf_buf); | |
175 | gb->buf_buf = NULL; | |
176 | } | |
177 | ||
178 | /* | |
179 | * gs_buf_clear | |
180 | * | |
181 | * Clear out all data in the circular buffer. | |
182 | */ | |
183 | static void gs_buf_clear(struct gs_buf *gb) | |
184 | { | |
185 | gb->buf_get = gb->buf_put; | |
186 | /* equivalent to a get of all data available */ | |
187 | } | |
188 | ||
189 | /* | |
190 | * gs_buf_data_avail | |
191 | * | |
1f1ba11b | 192 | * Return the number of bytes of data written into the circular |
c1dca562 DB |
193 | * buffer. |
194 | */ | |
195 | static unsigned gs_buf_data_avail(struct gs_buf *gb) | |
196 | { | |
197 | return (gb->buf_size + gb->buf_put - gb->buf_get) % gb->buf_size; | |
198 | } | |
199 | ||
200 | /* | |
201 | * gs_buf_space_avail | |
202 | * | |
203 | * Return the number of bytes of space available in the circular | |
204 | * buffer. | |
205 | */ | |
206 | static unsigned gs_buf_space_avail(struct gs_buf *gb) | |
207 | { | |
208 | return (gb->buf_size + gb->buf_get - gb->buf_put - 1) % gb->buf_size; | |
209 | } | |
210 | ||
211 | /* | |
212 | * gs_buf_put | |
213 | * | |
214 | * Copy data data from a user buffer and put it into the circular buffer. | |
215 | * Restrict to the amount of space available. | |
216 | * | |
217 | * Return the number of bytes copied. | |
218 | */ | |
219 | static unsigned | |
220 | gs_buf_put(struct gs_buf *gb, const char *buf, unsigned count) | |
221 | { | |
222 | unsigned len; | |
223 | ||
224 | len = gs_buf_space_avail(gb); | |
225 | if (count > len) | |
226 | count = len; | |
227 | ||
228 | if (count == 0) | |
229 | return 0; | |
230 | ||
231 | len = gb->buf_buf + gb->buf_size - gb->buf_put; | |
232 | if (count > len) { | |
233 | memcpy(gb->buf_put, buf, len); | |
234 | memcpy(gb->buf_buf, buf+len, count - len); | |
235 | gb->buf_put = gb->buf_buf + count - len; | |
236 | } else { | |
237 | memcpy(gb->buf_put, buf, count); | |
238 | if (count < len) | |
239 | gb->buf_put += count; | |
240 | else /* count == len */ | |
241 | gb->buf_put = gb->buf_buf; | |
242 | } | |
243 | ||
244 | return count; | |
245 | } | |
246 | ||
247 | /* | |
248 | * gs_buf_get | |
249 | * | |
250 | * Get data from the circular buffer and copy to the given buffer. | |
251 | * Restrict to the amount of data available. | |
252 | * | |
253 | * Return the number of bytes copied. | |
254 | */ | |
255 | static unsigned | |
256 | gs_buf_get(struct gs_buf *gb, char *buf, unsigned count) | |
257 | { | |
258 | unsigned len; | |
259 | ||
260 | len = gs_buf_data_avail(gb); | |
261 | if (count > len) | |
262 | count = len; | |
263 | ||
264 | if (count == 0) | |
265 | return 0; | |
266 | ||
267 | len = gb->buf_buf + gb->buf_size - gb->buf_get; | |
268 | if (count > len) { | |
269 | memcpy(buf, gb->buf_get, len); | |
270 | memcpy(buf+len, gb->buf_buf, count - len); | |
271 | gb->buf_get = gb->buf_buf + count - len; | |
272 | } else { | |
273 | memcpy(buf, gb->buf_get, count); | |
274 | if (count < len) | |
275 | gb->buf_get += count; | |
276 | else /* count == len */ | |
277 | gb->buf_get = gb->buf_buf; | |
278 | } | |
279 | ||
280 | return count; | |
281 | } | |
282 | ||
283 | /*-------------------------------------------------------------------------*/ | |
284 | ||
285 | /* I/O glue between TTY (upper) and USB function (lower) driver layers */ | |
286 | ||
287 | /* | |
288 | * gs_alloc_req | |
289 | * | |
290 | * Allocate a usb_request and its buffer. Returns a pointer to the | |
291 | * usb_request or NULL if there is an error. | |
292 | */ | |
1f1ba11b | 293 | struct usb_request * |
c1dca562 DB |
294 | gs_alloc_req(struct usb_ep *ep, unsigned len, gfp_t kmalloc_flags) |
295 | { | |
296 | struct usb_request *req; | |
297 | ||
298 | req = usb_ep_alloc_request(ep, kmalloc_flags); | |
299 | ||
300 | if (req != NULL) { | |
301 | req->length = len; | |
302 | req->buf = kmalloc(len, kmalloc_flags); | |
303 | if (req->buf == NULL) { | |
304 | usb_ep_free_request(ep, req); | |
305 | return NULL; | |
306 | } | |
307 | } | |
308 | ||
309 | return req; | |
310 | } | |
3249ca22 | 311 | EXPORT_SYMBOL_GPL(gs_alloc_req); |
c1dca562 DB |
312 | |
313 | /* | |
314 | * gs_free_req | |
315 | * | |
316 | * Free a usb_request and its buffer. | |
317 | */ | |
1f1ba11b | 318 | void gs_free_req(struct usb_ep *ep, struct usb_request *req) |
c1dca562 DB |
319 | { |
320 | kfree(req->buf); | |
321 | usb_ep_free_request(ep, req); | |
322 | } | |
3249ca22 | 323 | EXPORT_SYMBOL_GPL(gs_free_req); |
c1dca562 DB |
324 | |
325 | /* | |
326 | * gs_send_packet | |
327 | * | |
328 | * If there is data to send, a packet is built in the given | |
329 | * buffer and the size is returned. If there is no data to | |
330 | * send, 0 is returned. | |
331 | * | |
332 | * Called with port_lock held. | |
333 | */ | |
334 | static unsigned | |
335 | gs_send_packet(struct gs_port *port, char *packet, unsigned size) | |
336 | { | |
337 | unsigned len; | |
338 | ||
339 | len = gs_buf_data_avail(&port->port_write_buf); | |
340 | if (len < size) | |
341 | size = len; | |
342 | if (size != 0) | |
343 | size = gs_buf_get(&port->port_write_buf, packet, size); | |
344 | return size; | |
345 | } | |
346 | ||
347 | /* | |
348 | * gs_start_tx | |
349 | * | |
350 | * This function finds available write requests, calls | |
351 | * gs_send_packet to fill these packets with data, and | |
352 | * continues until either there are no more write requests | |
353 | * available or no more data to send. This function is | |
354 | * run whenever data arrives or write requests are available. | |
355 | * | |
356 | * Context: caller owns port_lock; port_usb is non-null. | |
357 | */ | |
358 | static int gs_start_tx(struct gs_port *port) | |
359 | /* | |
360 | __releases(&port->port_lock) | |
361 | __acquires(&port->port_lock) | |
362 | */ | |
363 | { | |
364 | struct list_head *pool = &port->write_pool; | |
365 | struct usb_ep *in = port->port_usb->in; | |
366 | int status = 0; | |
367 | bool do_tty_wake = false; | |
368 | ||
369 | while (!list_empty(pool)) { | |
370 | struct usb_request *req; | |
371 | int len; | |
372 | ||
28609d40 JS |
373 | if (port->write_started >= QUEUE_SIZE) |
374 | break; | |
375 | ||
c1dca562 DB |
376 | req = list_entry(pool->next, struct usb_request, list); |
377 | len = gs_send_packet(port, req->buf, in->maxpacket); | |
378 | if (len == 0) { | |
379 | wake_up_interruptible(&port->drain_wait); | |
380 | break; | |
381 | } | |
382 | do_tty_wake = true; | |
383 | ||
384 | req->length = len; | |
385 | list_del(&req->list); | |
2e251341 | 386 | req->zero = (gs_buf_data_avail(&port->port_write_buf) == 0); |
c1dca562 | 387 | |
937ef73d DB |
388 | pr_vdebug(PREFIX "%d: tx len=%d, 0x%02x 0x%02x 0x%02x ...\n", |
389 | port->port_num, len, *((u8 *)req->buf), | |
c1dca562 | 390 | *((u8 *)req->buf+1), *((u8 *)req->buf+2)); |
c1dca562 DB |
391 | |
392 | /* Drop lock while we call out of driver; completions | |
393 | * could be issued while we do so. Disconnection may | |
394 | * happen too; maybe immediately before we queue this! | |
395 | * | |
396 | * NOTE that we may keep sending data for a while after | |
397 | * the TTY closed (dev->ioport->port_tty is NULL). | |
398 | */ | |
399 | spin_unlock(&port->port_lock); | |
400 | status = usb_ep_queue(in, req, GFP_ATOMIC); | |
401 | spin_lock(&port->port_lock); | |
402 | ||
403 | if (status) { | |
404 | pr_debug("%s: %s %s err %d\n", | |
405 | __func__, "queue", in->name, status); | |
406 | list_add(&req->list, pool); | |
407 | break; | |
408 | } | |
409 | ||
28609d40 JS |
410 | port->write_started++; |
411 | ||
c1dca562 DB |
412 | /* abort immediately after disconnect */ |
413 | if (!port->port_usb) | |
414 | break; | |
415 | } | |
416 | ||
35f95fd7 JS |
417 | if (do_tty_wake && port->port.tty) |
418 | tty_wakeup(port->port.tty); | |
c1dca562 DB |
419 | return status; |
420 | } | |
421 | ||
c1dca562 DB |
422 | /* |
423 | * Context: caller owns port_lock, and port_usb is set | |
424 | */ | |
425 | static unsigned gs_start_rx(struct gs_port *port) | |
426 | /* | |
427 | __releases(&port->port_lock) | |
428 | __acquires(&port->port_lock) | |
429 | */ | |
430 | { | |
431 | struct list_head *pool = &port->read_pool; | |
432 | struct usb_ep *out = port->port_usb->out; | |
c1dca562 DB |
433 | |
434 | while (!list_empty(pool)) { | |
435 | struct usb_request *req; | |
436 | int status; | |
437 | struct tty_struct *tty; | |
438 | ||
937ef73d | 439 | /* no more rx if closed */ |
35f95fd7 | 440 | tty = port->port.tty; |
937ef73d | 441 | if (!tty) |
c1dca562 DB |
442 | break; |
443 | ||
28609d40 JS |
444 | if (port->read_started >= QUEUE_SIZE) |
445 | break; | |
446 | ||
c1dca562 DB |
447 | req = list_entry(pool->next, struct usb_request, list); |
448 | list_del(&req->list); | |
449 | req->length = out->maxpacket; | |
450 | ||
451 | /* drop lock while we call out; the controller driver | |
452 | * may need to call us back (e.g. for disconnect) | |
453 | */ | |
454 | spin_unlock(&port->port_lock); | |
455 | status = usb_ep_queue(out, req, GFP_ATOMIC); | |
456 | spin_lock(&port->port_lock); | |
457 | ||
458 | if (status) { | |
459 | pr_debug("%s: %s %s err %d\n", | |
460 | __func__, "queue", out->name, status); | |
461 | list_add(&req->list, pool); | |
462 | break; | |
463 | } | |
28609d40 | 464 | port->read_started++; |
c1dca562 DB |
465 | |
466 | /* abort immediately after disconnect */ | |
467 | if (!port->port_usb) | |
468 | break; | |
469 | } | |
28609d40 | 470 | return port->read_started; |
c1dca562 DB |
471 | } |
472 | ||
937ef73d DB |
473 | /* |
474 | * RX tasklet takes data out of the RX queue and hands it up to the TTY | |
475 | * layer until it refuses to take any more data (or is throttled back). | |
476 | * Then it issues reads for any further data. | |
477 | * | |
478 | * If the RX queue becomes full enough that no usb_request is queued, | |
479 | * the OUT endpoint may begin NAKing as soon as its FIFO fills up. | |
480 | * So QUEUE_SIZE packets plus however many the FIFO holds (usually two) | |
481 | * can be buffered before the TTY layer's buffers (currently 64 KB). | |
482 | */ | |
483 | static void gs_rx_push(unsigned long _port) | |
c1dca562 | 484 | { |
937ef73d DB |
485 | struct gs_port *port = (void *)_port; |
486 | struct tty_struct *tty; | |
487 | struct list_head *queue = &port->read_queue; | |
488 | bool disconnect = false; | |
489 | bool do_push = false; | |
c1dca562 | 490 | |
937ef73d DB |
491 | /* hand any queued data to the tty */ |
492 | spin_lock_irq(&port->port_lock); | |
35f95fd7 | 493 | tty = port->port.tty; |
937ef73d DB |
494 | while (!list_empty(queue)) { |
495 | struct usb_request *req; | |
c1dca562 | 496 | |
937ef73d | 497 | req = list_first_entry(queue, struct usb_request, list); |
c1dca562 | 498 | |
937ef73d DB |
499 | /* discard data if tty was closed */ |
500 | if (!tty) | |
501 | goto recycle; | |
c1dca562 | 502 | |
937ef73d DB |
503 | /* leave data queued if tty was rx throttled */ |
504 | if (test_bit(TTY_THROTTLED, &tty->flags)) | |
505 | break; | |
506 | ||
507 | switch (req->status) { | |
508 | case -ESHUTDOWN: | |
509 | disconnect = true; | |
510 | pr_vdebug(PREFIX "%d: shutdown\n", port->port_num); | |
511 | break; | |
512 | ||
513 | default: | |
514 | /* presumably a transient fault */ | |
515 | pr_warning(PREFIX "%d: unexpected RX status %d\n", | |
516 | port->port_num, req->status); | |
517 | /* FALLTHROUGH */ | |
518 | case 0: | |
519 | /* normal completion */ | |
520 | break; | |
521 | } | |
522 | ||
523 | /* push data to (open) tty */ | |
524 | if (req->actual) { | |
525 | char *packet = req->buf; | |
526 | unsigned size = req->actual; | |
527 | unsigned n; | |
528 | int count; | |
529 | ||
530 | /* we may have pushed part of this packet already... */ | |
531 | n = port->n_read; | |
532 | if (n) { | |
533 | packet += n; | |
534 | size -= n; | |
535 | } | |
536 | ||
537 | count = tty_insert_flip_string(tty, packet, size); | |
538 | if (count) | |
539 | do_push = true; | |
540 | if (count != size) { | |
541 | /* stop pushing; TTY layer can't handle more */ | |
542 | port->n_read += count; | |
543 | pr_vdebug(PREFIX "%d: rx block %d/%d\n", | |
544 | port->port_num, | |
545 | count, req->actual); | |
546 | break; | |
547 | } | |
548 | port->n_read = 0; | |
549 | } | |
550 | recycle: | |
551 | list_move(&req->list, &port->read_pool); | |
28609d40 | 552 | port->read_started--; |
937ef73d DB |
553 | } |
554 | ||
44a0c019 JP |
555 | /* Push from tty to ldisc; without low_latency set this is handled by |
556 | * a workqueue, so we won't get callbacks and can hold port_lock | |
937ef73d | 557 | */ |
50238299 | 558 | if (tty && do_push) |
937ef73d | 559 | tty_flip_buffer_push(tty); |
937ef73d DB |
560 | |
561 | ||
562 | /* We want our data queue to become empty ASAP, keeping data | |
563 | * in the tty and ldisc (not here). If we couldn't push any | |
564 | * this time around, there may be trouble unless there's an | |
565 | * implicit tty_unthrottle() call on its way... | |
566 | * | |
567 | * REVISIT we should probably add a timer to keep the tasklet | |
568 | * from starving ... but it's not clear that case ever happens. | |
569 | */ | |
570 | if (!list_empty(queue) && tty) { | |
571 | if (!test_bit(TTY_THROTTLED, &tty->flags)) { | |
572 | if (do_push) | |
573 | tasklet_schedule(&port->push); | |
574 | else | |
575 | pr_warning(PREFIX "%d: RX not scheduled?\n", | |
576 | port->port_num); | |
577 | } | |
578 | } | |
579 | ||
580 | /* If we're still connected, refill the USB RX queue. */ | |
581 | if (!disconnect && port->port_usb) | |
582 | gs_start_rx(port); | |
583 | ||
584 | spin_unlock_irq(&port->port_lock); | |
585 | } | |
586 | ||
587 | static void gs_read_complete(struct usb_ep *ep, struct usb_request *req) | |
588 | { | |
589 | struct gs_port *port = ep->driver_data; | |
590 | ||
591 | /* Queue all received data until the tty layer is ready for it. */ | |
592 | spin_lock(&port->port_lock); | |
593 | list_add_tail(&req->list, &port->read_queue); | |
594 | tasklet_schedule(&port->push); | |
c1dca562 DB |
595 | spin_unlock(&port->port_lock); |
596 | } | |
597 | ||
598 | static void gs_write_complete(struct usb_ep *ep, struct usb_request *req) | |
599 | { | |
600 | struct gs_port *port = ep->driver_data; | |
601 | ||
602 | spin_lock(&port->port_lock); | |
603 | list_add(&req->list, &port->write_pool); | |
28609d40 | 604 | port->write_started--; |
c1dca562 DB |
605 | |
606 | switch (req->status) { | |
607 | default: | |
608 | /* presumably a transient fault */ | |
609 | pr_warning("%s: unexpected %s status %d\n", | |
610 | __func__, ep->name, req->status); | |
611 | /* FALL THROUGH */ | |
612 | case 0: | |
613 | /* normal completion */ | |
614 | gs_start_tx(port); | |
615 | break; | |
616 | ||
617 | case -ESHUTDOWN: | |
618 | /* disconnect */ | |
619 | pr_vdebug("%s: %s shutdown\n", __func__, ep->name); | |
620 | break; | |
621 | } | |
622 | ||
623 | spin_unlock(&port->port_lock); | |
624 | } | |
625 | ||
28609d40 JS |
626 | static void gs_free_requests(struct usb_ep *ep, struct list_head *head, |
627 | int *allocated) | |
c1dca562 DB |
628 | { |
629 | struct usb_request *req; | |
630 | ||
631 | while (!list_empty(head)) { | |
632 | req = list_entry(head->next, struct usb_request, list); | |
633 | list_del(&req->list); | |
634 | gs_free_req(ep, req); | |
28609d40 JS |
635 | if (allocated) |
636 | (*allocated)--; | |
c1dca562 DB |
637 | } |
638 | } | |
639 | ||
640 | static int gs_alloc_requests(struct usb_ep *ep, struct list_head *head, | |
28609d40 JS |
641 | void (*fn)(struct usb_ep *, struct usb_request *), |
642 | int *allocated) | |
c1dca562 DB |
643 | { |
644 | int i; | |
645 | struct usb_request *req; | |
28609d40 | 646 | int n = allocated ? QUEUE_SIZE - *allocated : QUEUE_SIZE; |
c1dca562 DB |
647 | |
648 | /* Pre-allocate up to QUEUE_SIZE transfers, but if we can't | |
649 | * do quite that many this time, don't fail ... we just won't | |
650 | * be as speedy as we might otherwise be. | |
651 | */ | |
28609d40 | 652 | for (i = 0; i < n; i++) { |
c1dca562 DB |
653 | req = gs_alloc_req(ep, ep->maxpacket, GFP_ATOMIC); |
654 | if (!req) | |
655 | return list_empty(head) ? -ENOMEM : 0; | |
656 | req->complete = fn; | |
657 | list_add_tail(&req->list, head); | |
28609d40 JS |
658 | if (allocated) |
659 | (*allocated)++; | |
c1dca562 DB |
660 | } |
661 | return 0; | |
662 | } | |
663 | ||
664 | /** | |
665 | * gs_start_io - start USB I/O streams | |
666 | * @dev: encapsulates endpoints to use | |
667 | * Context: holding port_lock; port_tty and port_usb are non-null | |
668 | * | |
669 | * We only start I/O when something is connected to both sides of | |
670 | * this port. If nothing is listening on the host side, we may | |
671 | * be pointlessly filling up our TX buffers and FIFO. | |
672 | */ | |
673 | static int gs_start_io(struct gs_port *port) | |
674 | { | |
675 | struct list_head *head = &port->read_pool; | |
676 | struct usb_ep *ep = port->port_usb->out; | |
677 | int status; | |
678 | unsigned started; | |
679 | ||
680 | /* Allocate RX and TX I/O buffers. We can't easily do this much | |
681 | * earlier (with GFP_KERNEL) because the requests are coupled to | |
682 | * endpoints, as are the packet sizes we'll be using. Different | |
683 | * configurations may use different endpoints with a given port; | |
684 | * and high speed vs full speed changes packet sizes too. | |
685 | */ | |
28609d40 JS |
686 | status = gs_alloc_requests(ep, head, gs_read_complete, |
687 | &port->read_allocated); | |
c1dca562 DB |
688 | if (status) |
689 | return status; | |
690 | ||
691 | status = gs_alloc_requests(port->port_usb->in, &port->write_pool, | |
28609d40 | 692 | gs_write_complete, &port->write_allocated); |
c1dca562 | 693 | if (status) { |
28609d40 | 694 | gs_free_requests(ep, head, &port->read_allocated); |
c1dca562 DB |
695 | return status; |
696 | } | |
697 | ||
698 | /* queue read requests */ | |
937ef73d | 699 | port->n_read = 0; |
c1dca562 DB |
700 | started = gs_start_rx(port); |
701 | ||
702 | /* unblock any pending writes into our circular buffer */ | |
703 | if (started) { | |
35f95fd7 | 704 | tty_wakeup(port->port.tty); |
c1dca562 | 705 | } else { |
28609d40 JS |
706 | gs_free_requests(ep, head, &port->read_allocated); |
707 | gs_free_requests(port->port_usb->in, &port->write_pool, | |
708 | &port->write_allocated); | |
937ef73d | 709 | status = -EIO; |
c1dca562 DB |
710 | } |
711 | ||
937ef73d | 712 | return status; |
c1dca562 DB |
713 | } |
714 | ||
715 | /*-------------------------------------------------------------------------*/ | |
716 | ||
717 | /* TTY Driver */ | |
718 | ||
719 | /* | |
720 | * gs_open sets up the link between a gs_port and its associated TTY. | |
721 | * That link is broken *only* by TTY close(), and all driver methods | |
722 | * know that. | |
723 | */ | |
724 | static int gs_open(struct tty_struct *tty, struct file *file) | |
725 | { | |
726 | int port_num = tty->index; | |
727 | struct gs_port *port; | |
728 | int status; | |
729 | ||
c1dca562 DB |
730 | do { |
731 | mutex_lock(&ports[port_num].lock); | |
732 | port = ports[port_num].port; | |
733 | if (!port) | |
734 | status = -ENODEV; | |
735 | else { | |
736 | spin_lock_irq(&port->port_lock); | |
737 | ||
738 | /* already open? Great. */ | |
266e37ef | 739 | if (port->port.count) { |
c1dca562 | 740 | status = 0; |
266e37ef | 741 | port->port.count++; |
c1dca562 DB |
742 | |
743 | /* currently opening/closing? wait ... */ | |
744 | } else if (port->openclose) { | |
745 | status = -EBUSY; | |
746 | ||
747 | /* ... else we do the work */ | |
748 | } else { | |
749 | status = -EAGAIN; | |
750 | port->openclose = true; | |
751 | } | |
752 | spin_unlock_irq(&port->port_lock); | |
753 | } | |
754 | mutex_unlock(&ports[port_num].lock); | |
755 | ||
756 | switch (status) { | |
757 | default: | |
758 | /* fully handled */ | |
759 | return status; | |
760 | case -EAGAIN: | |
761 | /* must do the work */ | |
762 | break; | |
763 | case -EBUSY: | |
764 | /* wait for EAGAIN task to finish */ | |
765 | msleep(1); | |
766 | /* REVISIT could have a waitchannel here, if | |
767 | * concurrent open performance is important | |
768 | */ | |
769 | break; | |
770 | } | |
771 | } while (status != -EAGAIN); | |
772 | ||
773 | /* Do the "real open" */ | |
774 | spin_lock_irq(&port->port_lock); | |
775 | ||
776 | /* allocate circular buffer on first open */ | |
777 | if (port->port_write_buf.buf_buf == NULL) { | |
778 | ||
779 | spin_unlock_irq(&port->port_lock); | |
780 | status = gs_buf_alloc(&port->port_write_buf, WRITE_BUF_SIZE); | |
781 | spin_lock_irq(&port->port_lock); | |
782 | ||
783 | if (status) { | |
784 | pr_debug("gs_open: ttyGS%d (%p,%p) no buffer\n", | |
785 | port->port_num, tty, file); | |
786 | port->openclose = false; | |
787 | goto exit_unlock_port; | |
788 | } | |
789 | } | |
790 | ||
791 | /* REVISIT if REMOVED (ports[].port NULL), abort the open | |
792 | * to let rmmod work faster (but this way isn't wrong). | |
793 | */ | |
794 | ||
795 | /* REVISIT maybe wait for "carrier detect" */ | |
796 | ||
797 | tty->driver_data = port; | |
35f95fd7 | 798 | port->port.tty = tty; |
c1dca562 | 799 | |
266e37ef | 800 | port->port.count = 1; |
c1dca562 DB |
801 | port->openclose = false; |
802 | ||
c1dca562 DB |
803 | /* if connected, start the I/O stream */ |
804 | if (port->port_usb) { | |
1f1ba11b DB |
805 | struct gserial *gser = port->port_usb; |
806 | ||
c1dca562 DB |
807 | pr_debug("gs_open: start ttyGS%d\n", port->port_num); |
808 | gs_start_io(port); | |
809 | ||
1f1ba11b DB |
810 | if (gser->connect) |
811 | gser->connect(gser); | |
c1dca562 DB |
812 | } |
813 | ||
814 | pr_debug("gs_open: ttyGS%d (%p,%p)\n", port->port_num, tty, file); | |
815 | ||
816 | status = 0; | |
817 | ||
818 | exit_unlock_port: | |
819 | spin_unlock_irq(&port->port_lock); | |
820 | return status; | |
821 | } | |
822 | ||
823 | static int gs_writes_finished(struct gs_port *p) | |
824 | { | |
825 | int cond; | |
826 | ||
827 | /* return true on disconnect or empty buffer */ | |
828 | spin_lock_irq(&p->port_lock); | |
829 | cond = (p->port_usb == NULL) || !gs_buf_data_avail(&p->port_write_buf); | |
830 | spin_unlock_irq(&p->port_lock); | |
831 | ||
832 | return cond; | |
833 | } | |
834 | ||
835 | static void gs_close(struct tty_struct *tty, struct file *file) | |
836 | { | |
837 | struct gs_port *port = tty->driver_data; | |
1f1ba11b | 838 | struct gserial *gser; |
c1dca562 DB |
839 | |
840 | spin_lock_irq(&port->port_lock); | |
841 | ||
266e37ef JS |
842 | if (port->port.count != 1) { |
843 | if (port->port.count == 0) | |
c1dca562 DB |
844 | WARN_ON(1); |
845 | else | |
266e37ef | 846 | --port->port.count; |
c1dca562 DB |
847 | goto exit; |
848 | } | |
849 | ||
850 | pr_debug("gs_close: ttyGS%d (%p,%p) ...\n", port->port_num, tty, file); | |
851 | ||
852 | /* mark port as closing but in use; we can drop port lock | |
853 | * and sleep if necessary | |
854 | */ | |
855 | port->openclose = true; | |
266e37ef | 856 | port->port.count = 0; |
c1dca562 | 857 | |
1f1ba11b DB |
858 | gser = port->port_usb; |
859 | if (gser && gser->disconnect) | |
860 | gser->disconnect(gser); | |
c1dca562 DB |
861 | |
862 | /* wait for circular write buffer to drain, disconnect, or at | |
863 | * most GS_CLOSE_TIMEOUT seconds; then discard the rest | |
864 | */ | |
1f1ba11b | 865 | if (gs_buf_data_avail(&port->port_write_buf) > 0 && gser) { |
c1dca562 DB |
866 | spin_unlock_irq(&port->port_lock); |
867 | wait_event_interruptible_timeout(port->drain_wait, | |
868 | gs_writes_finished(port), | |
869 | GS_CLOSE_TIMEOUT * HZ); | |
870 | spin_lock_irq(&port->port_lock); | |
1f1ba11b | 871 | gser = port->port_usb; |
c1dca562 DB |
872 | } |
873 | ||
874 | /* Iff we're disconnected, there can be no I/O in flight so it's | |
875 | * ok to free the circular buffer; else just scrub it. And don't | |
876 | * let the push tasklet fire again until we're re-opened. | |
877 | */ | |
1f1ba11b | 878 | if (gser == NULL) |
c1dca562 DB |
879 | gs_buf_free(&port->port_write_buf); |
880 | else | |
881 | gs_buf_clear(&port->port_write_buf); | |
882 | ||
c1dca562 | 883 | tty->driver_data = NULL; |
35f95fd7 | 884 | port->port.tty = NULL; |
c1dca562 DB |
885 | |
886 | port->openclose = false; | |
887 | ||
888 | pr_debug("gs_close: ttyGS%d (%p,%p) done!\n", | |
889 | port->port_num, tty, file); | |
890 | ||
3d5ea59d | 891 | wake_up_interruptible(&port->port.close_wait); |
c1dca562 DB |
892 | exit: |
893 | spin_unlock_irq(&port->port_lock); | |
894 | } | |
895 | ||
896 | static int gs_write(struct tty_struct *tty, const unsigned char *buf, int count) | |
897 | { | |
898 | struct gs_port *port = tty->driver_data; | |
899 | unsigned long flags; | |
900 | int status; | |
901 | ||
902 | pr_vdebug("gs_write: ttyGS%d (%p) writing %d bytes\n", | |
903 | port->port_num, tty, count); | |
904 | ||
905 | spin_lock_irqsave(&port->port_lock, flags); | |
906 | if (count) | |
907 | count = gs_buf_put(&port->port_write_buf, buf, count); | |
908 | /* treat count == 0 as flush_chars() */ | |
909 | if (port->port_usb) | |
910 | status = gs_start_tx(port); | |
911 | spin_unlock_irqrestore(&port->port_lock, flags); | |
912 | ||
913 | return count; | |
914 | } | |
915 | ||
916 | static int gs_put_char(struct tty_struct *tty, unsigned char ch) | |
917 | { | |
918 | struct gs_port *port = tty->driver_data; | |
919 | unsigned long flags; | |
920 | int status; | |
921 | ||
bfa346ad | 922 | pr_vdebug("gs_put_char: (%d,%p) char=0x%x, called from %pf\n", |
c1dca562 DB |
923 | port->port_num, tty, ch, __builtin_return_address(0)); |
924 | ||
925 | spin_lock_irqsave(&port->port_lock, flags); | |
926 | status = gs_buf_put(&port->port_write_buf, &ch, 1); | |
927 | spin_unlock_irqrestore(&port->port_lock, flags); | |
928 | ||
929 | return status; | |
930 | } | |
931 | ||
932 | static void gs_flush_chars(struct tty_struct *tty) | |
933 | { | |
934 | struct gs_port *port = tty->driver_data; | |
935 | unsigned long flags; | |
936 | ||
937 | pr_vdebug("gs_flush_chars: (%d,%p)\n", port->port_num, tty); | |
938 | ||
939 | spin_lock_irqsave(&port->port_lock, flags); | |
940 | if (port->port_usb) | |
941 | gs_start_tx(port); | |
942 | spin_unlock_irqrestore(&port->port_lock, flags); | |
943 | } | |
944 | ||
945 | static int gs_write_room(struct tty_struct *tty) | |
946 | { | |
947 | struct gs_port *port = tty->driver_data; | |
948 | unsigned long flags; | |
949 | int room = 0; | |
950 | ||
951 | spin_lock_irqsave(&port->port_lock, flags); | |
952 | if (port->port_usb) | |
953 | room = gs_buf_space_avail(&port->port_write_buf); | |
954 | spin_unlock_irqrestore(&port->port_lock, flags); | |
955 | ||
956 | pr_vdebug("gs_write_room: (%d,%p) room=%d\n", | |
957 | port->port_num, tty, room); | |
958 | ||
959 | return room; | |
960 | } | |
961 | ||
962 | static int gs_chars_in_buffer(struct tty_struct *tty) | |
963 | { | |
964 | struct gs_port *port = tty->driver_data; | |
965 | unsigned long flags; | |
966 | int chars = 0; | |
967 | ||
968 | spin_lock_irqsave(&port->port_lock, flags); | |
969 | chars = gs_buf_data_avail(&port->port_write_buf); | |
970 | spin_unlock_irqrestore(&port->port_lock, flags); | |
971 | ||
972 | pr_vdebug("gs_chars_in_buffer: (%d,%p) chars=%d\n", | |
973 | port->port_num, tty, chars); | |
974 | ||
975 | return chars; | |
976 | } | |
977 | ||
978 | /* undo side effects of setting TTY_THROTTLED */ | |
979 | static void gs_unthrottle(struct tty_struct *tty) | |
980 | { | |
981 | struct gs_port *port = tty->driver_data; | |
982 | unsigned long flags; | |
c1dca562 DB |
983 | |
984 | spin_lock_irqsave(&port->port_lock, flags); | |
937ef73d DB |
985 | if (port->port_usb) { |
986 | /* Kickstart read queue processing. We don't do xon/xoff, | |
987 | * rts/cts, or other handshaking with the host, but if the | |
988 | * read queue backs up enough we'll be NAKing OUT packets. | |
989 | */ | |
990 | tasklet_schedule(&port->push); | |
991 | pr_vdebug(PREFIX "%d: unthrottle\n", port->port_num); | |
992 | } | |
c1dca562 | 993 | spin_unlock_irqrestore(&port->port_lock, flags); |
c1dca562 DB |
994 | } |
995 | ||
1f1ba11b DB |
996 | static int gs_break_ctl(struct tty_struct *tty, int duration) |
997 | { | |
998 | struct gs_port *port = tty->driver_data; | |
999 | int status = 0; | |
1000 | struct gserial *gser; | |
1001 | ||
1002 | pr_vdebug("gs_break_ctl: ttyGS%d, send break (%d) \n", | |
1003 | port->port_num, duration); | |
1004 | ||
1005 | spin_lock_irq(&port->port_lock); | |
1006 | gser = port->port_usb; | |
1007 | if (gser && gser->send_break) | |
1008 | status = gser->send_break(gser, duration); | |
1009 | spin_unlock_irq(&port->port_lock); | |
1010 | ||
1011 | return status; | |
1012 | } | |
1013 | ||
c1dca562 DB |
1014 | static const struct tty_operations gs_tty_ops = { |
1015 | .open = gs_open, | |
1016 | .close = gs_close, | |
1017 | .write = gs_write, | |
1018 | .put_char = gs_put_char, | |
1019 | .flush_chars = gs_flush_chars, | |
1020 | .write_room = gs_write_room, | |
1021 | .chars_in_buffer = gs_chars_in_buffer, | |
1022 | .unthrottle = gs_unthrottle, | |
1f1ba11b | 1023 | .break_ctl = gs_break_ctl, |
c1dca562 DB |
1024 | }; |
1025 | ||
1026 | /*-------------------------------------------------------------------------*/ | |
1027 | ||
1028 | static struct tty_driver *gs_tty_driver; | |
1029 | ||
c3c04b29 | 1030 | static int |
c1dca562 DB |
1031 | gs_port_alloc(unsigned port_num, struct usb_cdc_line_coding *coding) |
1032 | { | |
1033 | struct gs_port *port; | |
19b10a88 SAS |
1034 | int ret = 0; |
1035 | ||
1036 | mutex_lock(&ports[port_num].lock); | |
1037 | if (ports[port_num].port) { | |
1038 | ret = -EBUSY; | |
1039 | goto out; | |
1040 | } | |
c1dca562 DB |
1041 | |
1042 | port = kzalloc(sizeof(struct gs_port), GFP_KERNEL); | |
19b10a88 SAS |
1043 | if (port == NULL) { |
1044 | ret = -ENOMEM; | |
1045 | goto out; | |
1046 | } | |
c1dca562 | 1047 | |
266e37ef | 1048 | tty_port_init(&port->port); |
c1dca562 | 1049 | spin_lock_init(&port->port_lock); |
c1dca562 DB |
1050 | init_waitqueue_head(&port->drain_wait); |
1051 | ||
1052 | tasklet_init(&port->push, gs_rx_push, (unsigned long) port); | |
1053 | ||
1054 | INIT_LIST_HEAD(&port->read_pool); | |
937ef73d | 1055 | INIT_LIST_HEAD(&port->read_queue); |
c1dca562 DB |
1056 | INIT_LIST_HEAD(&port->write_pool); |
1057 | ||
1058 | port->port_num = port_num; | |
1059 | port->port_line_coding = *coding; | |
1060 | ||
1061 | ports[port_num].port = port; | |
19b10a88 SAS |
1062 | out: |
1063 | mutex_unlock(&ports[port_num].lock); | |
1064 | return ret; | |
c1dca562 DB |
1065 | } |
1066 | ||
1067 | static int gs_closed(struct gs_port *port) | |
1068 | { | |
1069 | int cond; | |
1070 | ||
1071 | spin_lock_irq(&port->port_lock); | |
266e37ef | 1072 | cond = (port->port.count == 0) && !port->openclose; |
c1dca562 DB |
1073 | spin_unlock_irq(&port->port_lock); |
1074 | return cond; | |
1075 | } | |
1076 | ||
19b10a88 SAS |
1077 | static void gserial_free_port(struct gs_port *port) |
1078 | { | |
1079 | tasklet_kill(&port->push); | |
1080 | /* wait for old opens to finish */ | |
1081 | wait_event(port->port.close_wait, gs_closed(port)); | |
1082 | WARN_ON(port->port_usb != NULL); | |
1083 | tty_port_destroy(&port->port); | |
1084 | kfree(port); | |
1085 | } | |
1086 | ||
1087 | void gserial_free_line(unsigned char port_num) | |
c1dca562 | 1088 | { |
c1dca562 DB |
1089 | struct gs_port *port; |
1090 | ||
19b10a88 SAS |
1091 | mutex_lock(&ports[port_num].lock); |
1092 | if (WARN_ON(!ports[port_num].port)) { | |
1093 | mutex_unlock(&ports[port_num].lock); | |
ac90e365 | 1094 | return; |
19b10a88 SAS |
1095 | } |
1096 | port = ports[port_num].port; | |
1097 | ports[port_num].port = NULL; | |
1098 | mutex_unlock(&ports[port_num].lock); | |
ac90e365 | 1099 | |
19b10a88 SAS |
1100 | gserial_free_port(port); |
1101 | tty_unregister_device(gs_tty_driver, port_num); | |
1102 | } | |
1103 | EXPORT_SYMBOL_GPL(gserial_free_line); | |
937ef73d | 1104 | |
19b10a88 SAS |
1105 | int gserial_alloc_line(unsigned char *line_num) |
1106 | { | |
1107 | struct usb_cdc_line_coding coding; | |
1108 | struct device *tty_dev; | |
1109 | int ret; | |
1110 | int port_num; | |
c1dca562 | 1111 | |
19b10a88 SAS |
1112 | coding.dwDTERate = cpu_to_le32(9600); |
1113 | coding.bCharFormat = 8; | |
1114 | coding.bParityType = USB_CDC_NO_PARITY; | |
1115 | coding.bDataBits = USB_CDC_1_STOP_BITS; | |
c1dca562 | 1116 | |
19b10a88 SAS |
1117 | for (port_num = 0; port_num < MAX_U_SERIAL_PORTS; port_num++) { |
1118 | ret = gs_port_alloc(port_num, &coding); | |
1119 | if (ret == -EBUSY) | |
1120 | continue; | |
1121 | if (ret) | |
1122 | return ret; | |
1123 | break; | |
c1dca562 | 1124 | } |
19b10a88 SAS |
1125 | if (ret) |
1126 | return ret; | |
c1dca562 | 1127 | |
19b10a88 | 1128 | /* ... and sysfs class devices, so mdev/udev make /dev/ttyGS* */ |
c1dca562 | 1129 | |
19b10a88 SAS |
1130 | tty_dev = tty_port_register_device(&ports[port_num].port->port, |
1131 | gs_tty_driver, port_num, NULL); | |
1132 | if (IS_ERR(tty_dev)) { | |
1133 | struct gs_port *port; | |
1134 | pr_err("%s: failed to register tty for port %d, err %ld\n", | |
1135 | __func__, port_num, PTR_ERR(tty_dev)); | |
1136 | ||
1137 | ret = PTR_ERR(tty_dev); | |
1138 | port = ports[port_num].port; | |
1139 | ports[port_num].port = NULL; | |
1140 | gserial_free_port(port); | |
1141 | goto err; | |
1142 | } | |
1143 | *line_num = port_num; | |
1144 | err: | |
1145 | return ret; | |
c1dca562 | 1146 | } |
19b10a88 | 1147 | EXPORT_SYMBOL_GPL(gserial_alloc_line); |
c1dca562 DB |
1148 | |
1149 | /** | |
1150 | * gserial_connect - notify TTY I/O glue that USB link is active | |
1151 | * @gser: the function, set up with endpoints and descriptors | |
1152 | * @port_num: which port is active | |
1153 | * Context: any (usually from irq) | |
1154 | * | |
1155 | * This is called activate endpoints and let the TTY layer know that | |
1156 | * the connection is active ... not unlike "carrier detect". It won't | |
1157 | * necessarily start I/O queues; unless the TTY is held open by any | |
1158 | * task, there would be no point. However, the endpoints will be | |
1159 | * activated so the USB host can perform I/O, subject to basic USB | |
1160 | * hardware flow control. | |
1161 | * | |
1162 | * Caller needs to have set up the endpoints and USB function in @dev | |
1163 | * before calling this, as well as the appropriate (speed-specific) | |
19b10a88 SAS |
1164 | * endpoint descriptors, and also have allocate @port_num by calling |
1165 | * @gserial_alloc_line(). | |
c1dca562 DB |
1166 | * |
1167 | * Returns negative errno or zero. | |
1168 | * On success, ep->driver_data will be overwritten. | |
1169 | */ | |
1170 | int gserial_connect(struct gserial *gser, u8 port_num) | |
1171 | { | |
1172 | struct gs_port *port; | |
1173 | unsigned long flags; | |
1174 | int status; | |
1175 | ||
19b10a88 | 1176 | if (port_num >= MAX_U_SERIAL_PORTS) |
c1dca562 DB |
1177 | return -ENXIO; |
1178 | ||
c1dca562 | 1179 | port = ports[port_num].port; |
19b10a88 SAS |
1180 | if (!port) { |
1181 | pr_err("serial line %d not allocated.\n", port_num); | |
1182 | return -EINVAL; | |
1183 | } | |
1184 | if (port->port_usb) { | |
1185 | pr_err("serial line %d is in use.\n", port_num); | |
1186 | return -EBUSY; | |
1187 | } | |
c1dca562 DB |
1188 | |
1189 | /* activate the endpoints */ | |
72c973dd | 1190 | status = usb_ep_enable(gser->in); |
c1dca562 DB |
1191 | if (status < 0) |
1192 | return status; | |
1193 | gser->in->driver_data = port; | |
1194 | ||
72c973dd | 1195 | status = usb_ep_enable(gser->out); |
c1dca562 DB |
1196 | if (status < 0) |
1197 | goto fail_out; | |
1198 | gser->out->driver_data = port; | |
1199 | ||
1200 | /* then tell the tty glue that I/O can work */ | |
1201 | spin_lock_irqsave(&port->port_lock, flags); | |
1202 | gser->ioport = port; | |
1203 | port->port_usb = gser; | |
1204 | ||
1205 | /* REVISIT unclear how best to handle this state... | |
1206 | * we don't really couple it with the Linux TTY. | |
1207 | */ | |
1208 | gser->port_line_coding = port->port_line_coding; | |
1209 | ||
1210 | /* REVISIT if waiting on "carrier detect", signal. */ | |
1211 | ||
1f1ba11b DB |
1212 | /* if it's already open, start I/O ... and notify the serial |
1213 | * protocol about open/close status (connect/disconnect). | |
c1dca562 | 1214 | */ |
266e37ef | 1215 | if (port->port.count) { |
c1dca562 DB |
1216 | pr_debug("gserial_connect: start ttyGS%d\n", port->port_num); |
1217 | gs_start_io(port); | |
1f1ba11b DB |
1218 | if (gser->connect) |
1219 | gser->connect(gser); | |
1220 | } else { | |
1221 | if (gser->disconnect) | |
1222 | gser->disconnect(gser); | |
c1dca562 DB |
1223 | } |
1224 | ||
1225 | spin_unlock_irqrestore(&port->port_lock, flags); | |
1226 | ||
1227 | return status; | |
1228 | ||
1229 | fail_out: | |
1230 | usb_ep_disable(gser->in); | |
1231 | gser->in->driver_data = NULL; | |
1232 | return status; | |
1233 | } | |
3249ca22 | 1234 | EXPORT_SYMBOL_GPL(gserial_connect); |
c1dca562 DB |
1235 | /** |
1236 | * gserial_disconnect - notify TTY I/O glue that USB link is inactive | |
1237 | * @gser: the function, on which gserial_connect() was called | |
1238 | * Context: any (usually from irq) | |
1239 | * | |
1240 | * This is called to deactivate endpoints and let the TTY layer know | |
1241 | * that the connection went inactive ... not unlike "hangup". | |
1242 | * | |
1243 | * On return, the state is as if gserial_connect() had never been called; | |
1244 | * there is no active USB I/O on these endpoints. | |
1245 | */ | |
1246 | void gserial_disconnect(struct gserial *gser) | |
1247 | { | |
1248 | struct gs_port *port = gser->ioport; | |
1249 | unsigned long flags; | |
1250 | ||
1251 | if (!port) | |
1252 | return; | |
1253 | ||
1254 | /* tell the TTY glue not to do I/O here any more */ | |
1255 | spin_lock_irqsave(&port->port_lock, flags); | |
1256 | ||
1257 | /* REVISIT as above: how best to track this? */ | |
1258 | port->port_line_coding = gser->port_line_coding; | |
1259 | ||
1260 | port->port_usb = NULL; | |
1261 | gser->ioport = NULL; | |
266e37ef | 1262 | if (port->port.count > 0 || port->openclose) { |
c1dca562 | 1263 | wake_up_interruptible(&port->drain_wait); |
35f95fd7 JS |
1264 | if (port->port.tty) |
1265 | tty_hangup(port->port.tty); | |
c1dca562 DB |
1266 | } |
1267 | spin_unlock_irqrestore(&port->port_lock, flags); | |
1268 | ||
1269 | /* disable endpoints, aborting down any active I/O */ | |
1270 | usb_ep_disable(gser->out); | |
1271 | gser->out->driver_data = NULL; | |
1272 | ||
1273 | usb_ep_disable(gser->in); | |
1274 | gser->in->driver_data = NULL; | |
1275 | ||
1276 | /* finally, free any unused/unusable I/O buffers */ | |
1277 | spin_lock_irqsave(&port->port_lock, flags); | |
266e37ef | 1278 | if (port->port.count == 0 && !port->openclose) |
c1dca562 | 1279 | gs_buf_free(&port->port_write_buf); |
28609d40 JS |
1280 | gs_free_requests(gser->out, &port->read_pool, NULL); |
1281 | gs_free_requests(gser->out, &port->read_queue, NULL); | |
1282 | gs_free_requests(gser->in, &port->write_pool, NULL); | |
1283 | ||
1284 | port->read_allocated = port->read_started = | |
1285 | port->write_allocated = port->write_started = 0; | |
1286 | ||
c1dca562 DB |
1287 | spin_unlock_irqrestore(&port->port_lock, flags); |
1288 | } | |
3249ca22 SAS |
1289 | EXPORT_SYMBOL_GPL(gserial_disconnect); |
1290 | ||
19b10a88 SAS |
1291 | int userial_init(void) |
1292 | { | |
1293 | unsigned i; | |
1294 | int status; | |
1295 | ||
1296 | gs_tty_driver = alloc_tty_driver(MAX_U_SERIAL_PORTS); | |
1297 | if (!gs_tty_driver) | |
1298 | return -ENOMEM; | |
1299 | ||
1300 | gs_tty_driver->driver_name = "g_serial"; | |
1301 | gs_tty_driver->name = PREFIX; | |
1302 | /* uses dynamically assigned dev_t values */ | |
1303 | ||
1304 | gs_tty_driver->type = TTY_DRIVER_TYPE_SERIAL; | |
1305 | gs_tty_driver->subtype = SERIAL_TYPE_NORMAL; | |
1306 | gs_tty_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV; | |
1307 | gs_tty_driver->init_termios = tty_std_termios; | |
1308 | ||
1309 | /* 9600-8-N-1 ... matches defaults expected by "usbser.sys" on | |
1310 | * MS-Windows. Otherwise, most of these flags shouldn't affect | |
1311 | * anything unless we were to actually hook up to a serial line. | |
1312 | */ | |
1313 | gs_tty_driver->init_termios.c_cflag = | |
1314 | B9600 | CS8 | CREAD | HUPCL | CLOCAL; | |
1315 | gs_tty_driver->init_termios.c_ispeed = 9600; | |
1316 | gs_tty_driver->init_termios.c_ospeed = 9600; | |
1317 | ||
1318 | tty_set_operations(gs_tty_driver, &gs_tty_ops); | |
1319 | for (i = 0; i < MAX_U_SERIAL_PORTS; i++) | |
1320 | mutex_init(&ports[i].lock); | |
1321 | ||
1322 | /* export the driver ... */ | |
1323 | status = tty_register_driver(gs_tty_driver); | |
1324 | if (status) { | |
1325 | pr_err("%s: cannot register, err %d\n", | |
1326 | __func__, status); | |
1327 | goto fail; | |
1328 | } | |
1329 | ||
1330 | pr_debug("%s: registered %d ttyGS* device%s\n", __func__, | |
1331 | MAX_U_SERIAL_PORTS, | |
1332 | (MAX_U_SERIAL_PORTS == 1) ? "" : "s"); | |
1333 | ||
1334 | return status; | |
1335 | fail: | |
1336 | put_tty_driver(gs_tty_driver); | |
1337 | gs_tty_driver = NULL; | |
1338 | return status; | |
1339 | } | |
1340 | module_init(userial_init); | |
1341 | ||
1342 | static void userial_cleanup(void) | |
1343 | { | |
1344 | tty_unregister_driver(gs_tty_driver); | |
1345 | put_tty_driver(gs_tty_driver); | |
1346 | gs_tty_driver = NULL; | |
1347 | } | |
1348 | module_exit(userial_cleanup); | |
1349 | ||
3249ca22 | 1350 | MODULE_LICENSE("GPL"); |