Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0
2
3/***************************************************************************
4 * copyright : (C) 2001, 2002 by Frank Mori Hess
5 ***************************************************************************/
6
7#define dev_fmt(fmt) KBUILD_MODNAME ": " fmt
8
9#include "ibsys.h"
10#include <linux/delay.h>
11#include <linux/kthread.h>
12#include <linux/vmalloc.h>
13
14/*
15 * IBCAC
16 * Return to the controller active state from the
17 * controller standby state, i.e., turn ATN on. Note
18 * that in order to enter the controller active state
19 * from the controller idle state, ibsic must be called.
20 * If sync is non-zero, attempt to take control synchronously.
21 * If fallback_to_async is non-zero, try to take control asynchronously
22 * if synchronous attempt fails.
23 */
24int ibcac(struct gpib_board *board, int sync, int fallback_to_async)
25{
26 int status = ibstatus(board);
27 int retval;
28
29 if ((status & CIC) == 0)
30 return -EINVAL;
31
32 if (status & ATN)
33 return 0;
34
35 if (sync && (status & LACS) == 0)
36 /*
37 * tcs (take control synchronously) can only possibly work when
38 * controller is listener. Error code also needs to be -ETIMEDOUT
39 * or it will giveout without doing fallback.
40 */
41 retval = -ETIMEDOUT;
42 else
43 retval = board->interface->take_control(board, sync);
44
45 if (retval < 0 && fallback_to_async) {
46 if (sync && retval == -ETIMEDOUT)
47 retval = board->interface->take_control(board, 0);
48 }
49 board->interface->update_status(board, 0);
50
51 return retval;
52}
53
54/*
55 * After ATN is asserted, it should cause any connected devices
56 * to start listening for command bytes and leave acceptor idle state.
57 * So if ATN is asserted and neither NDAC or NRFD are asserted,
58 * then there are no devices and ibcmd should error out immediately.
59 * Some gpib hardware sees itself asserting NDAC/NRFD when it
60 * is controller in charge, in which case this check will
61 * do nothing useful (but shouldn't cause any harm either).
62 * Drivers that don't need this check (ni_usb for example) may
63 * set the skip_check_for_command_acceptors flag in their
64 * gpib_interface_struct to avoid useless overhead.
65 */
66static int check_for_command_acceptors(struct gpib_board *board)
67{
68 int lines;
69
70 if (board->interface->skip_check_for_command_acceptors)
71 return 0;
72 if (!board->interface->line_status)
73 return 0;
74
75 udelay(2); // allow time for devices to respond to ATN if it was just asserted
76
77 lines = board->interface->line_status(board);
78 if (lines < 0)
79 return lines;
80
81 if ((lines & VALID_NRFD) && (lines & VALID_NDAC)) {
82 if ((lines & BUS_NRFD) == 0 && (lines & BUS_NDAC) == 0)
83 return -ENOTCONN;
84 }
85
86 return 0;
87}
88
89/*
90 * IBCMD
91 * Write cnt command bytes from buf to the GPIB. The
92 * command operation terminates only on I/O complete.
93 *
94 * NOTE:
95 * 1. Prior to beginning the command, the interface is
96 * placed in the controller active state.
97 * 2. Before calling ibcmd for the first time, ibsic
98 * must be called to initialize the GPIB and enable
99 * the interface to leave the controller idle state.
100 */
101int ibcmd(struct gpib_board *board, u8 *buf, size_t length, size_t *bytes_written)
102{
103 ssize_t ret = 0;
104 int status;
105
106 *bytes_written = 0;
107
108 status = ibstatus(board);
109
110 if ((status & CIC) == 0)
111 return -EINVAL;
112
113 os_start_timer(board, board->usec_timeout);
114
115 ret = ibcac(board, 1, 1);
116 if (ret == 0) {
117 ret = check_for_command_acceptors(board);
118 if (ret == 0)
119 ret = board->interface->command(board, buf, length, bytes_written);
120 }
121
122 os_remove_timer(board);
123
124 if (io_timed_out(board))
125 ret = -ETIMEDOUT;
126
127 return ret;
128}
129
130/*
131 * IBGTS
132 * Go to the controller standby state from the controller
133 * active state, i.e., turn ATN off.
134 */
135
136int ibgts(struct gpib_board *board)
137{
138 int status = ibstatus(board);
139 int retval;
140
141 if ((status & CIC) == 0)
142 return -EINVAL;
143
144 retval = board->interface->go_to_standby(board); /* go to standby */
145
146 board->interface->update_status(board, 0);
147
148 return retval;
149}
150
151static int autospoll_wait_should_wake_up(struct gpib_board *board)
152{
153 int retval;
154
155 mutex_lock(&board->big_gpib_mutex);
156
157 retval = board->master && board->autospollers > 0 &&
158 !atomic_read(&board->stuck_srq) &&
159 test_and_clear_bit(SRQI_NUM, &board->status);
160
161 mutex_unlock(&board->big_gpib_mutex);
162 return retval;
163}
164
165static int autospoll_thread(void *board_void)
166{
167 struct gpib_board *board = board_void;
168 int retval = 0;
169
170 dev_dbg(board->gpib_dev, "entering autospoll thread\n");
171
172 while (1) {
173 wait_event_interruptible(board->wait,
174 kthread_should_stop() ||
175 autospoll_wait_should_wake_up(board));
176 dev_dbg(board->gpib_dev, "autospoll wait satisfied\n");
177 if (kthread_should_stop())
178 break;
179
180 mutex_lock(&board->big_gpib_mutex);
181 /* make sure we are still good after we have lock */
182 if (board->autospollers <= 0 || board->master == 0) {
183 mutex_unlock(&board->big_gpib_mutex);
184 continue;
185 }
186 mutex_unlock(&board->big_gpib_mutex);
187
188 if (try_module_get(board->provider_module)) {
189 retval = autopoll_all_devices(board);
190 module_put(board->provider_module);
191 } else {
192 dev_err(board->gpib_dev, "try_module_get() failed!\n");
193 }
194 if (retval <= 0) {
195 dev_err(board->gpib_dev, "stuck SRQ\n");
196
197 atomic_set(&board->stuck_srq, 1); // XXX could be better
198 set_bit(SRQI_NUM, &board->status);
199 }
200 }
201 return retval;
202}
203
204int ibonline(struct gpib_board *board)
205{
206 int retval;
207
208 if (board->online)
209 return -EBUSY;
210 if (!board->interface)
211 return -ENODEV;
212 retval = gpib_allocate_board(board);
213 if (retval < 0)
214 return retval;
215
216 board->dev = NULL;
217 board->local_ppoll_mode = 0;
218 retval = board->interface->attach(board, &board->config);
219 if (retval < 0) {
220 board->interface->detach(board);
221 return retval;
222 }
223 /*
224 * nios2nommu on 2.6.11 uclinux kernel has weird problems
225 * with autospoll thread causing huge slowdowns
226 */
227#ifndef CONFIG_NIOS2
228 board->autospoll_task = kthread_run(&autospoll_thread, board,
229 "gpib%d_autospoll_kthread", board->minor);
230 if (IS_ERR(board->autospoll_task)) {
231 dev_err(board->gpib_dev, "failed to create autospoll thread\n");
232 board->interface->detach(board);
233 return PTR_ERR(board->autospoll_task);
234 }
235#endif
236 board->online = 1;
237 dev_dbg(board->gpib_dev, "board online\n");
238
239 return 0;
240}
241
242/* XXX need to make sure board is generally not in use (grab board lock?) */
243int iboffline(struct gpib_board *board)
244{
245 int retval;
246
247 if (board->online == 0)
248 return 0;
249 if (!board->interface)
250 return -ENODEV;
251
252 if (board->autospoll_task && !IS_ERR(board->autospoll_task)) {
253 retval = kthread_stop(board->autospoll_task);
254 if (retval)
255 dev_err(board->gpib_dev, "kthread_stop returned %i\n", retval);
256 board->autospoll_task = NULL;
257 }
258
259 board->interface->detach(board);
260 gpib_deallocate_board(board);
261 board->online = 0;
262 dev_dbg(board->gpib_dev, "board offline\n");
263
264 return 0;
265}
266
267/*
268 * IBLINES
269 * Poll the GPIB control lines and return their status in buf.
270 *
271 * LSB (bits 0-7) - VALID lines mask (lines that can be monitored).
272 * Next LSB (bits 8-15) - STATUS lines mask (lines that are currently set).
273 *
274 */
275int iblines(const struct gpib_board *board, short *lines)
276{
277 int retval;
278
279 *lines = 0;
280 if (!board->interface->line_status)
281 return 0;
282 retval = board->interface->line_status(board);
283 if (retval < 0)
284 return retval;
285 *lines = retval;
286 return 0;
287}
288
289/*
290 * IBRD
291 * Read up to 'length' bytes of data from the GPIB into buf. End
292 * on detection of END (EOI and or EOS) and set 'end_flag'.
293 *
294 * NOTE:
295 * 1. The interface is placed in the controller standby
296 * state prior to beginning the read.
297 * 2. Prior to calling ibrd, the intended devices as well
298 * as the interface board itself must be addressed by
299 * calling ibcmd.
300 */
301
302int ibrd(struct gpib_board *board, u8 *buf, size_t length, int *end_flag, size_t *nbytes)
303{
304 ssize_t ret = 0;
305 int retval;
306 size_t bytes_read;
307
308 *nbytes = 0;
309 *end_flag = 0;
310 if (length == 0)
311 return 0;
312
313 if (board->master) {
314 retval = ibgts(board);
315 if (retval < 0)
316 return retval;
317 }
318 /*
319 * XXX resetting timer here could cause timeouts take longer than they should,
320 * since read_ioctl calls this
321 * function in a loop, there is probably a similar problem with writes/commands
322 */
323 os_start_timer(board, board->usec_timeout);
324
325 do {
326 ret = board->interface->read(board, buf, length - *nbytes, end_flag, &bytes_read);
327 if (ret < 0)
328 goto ibrd_out;
329
330 buf += bytes_read;
331 *nbytes += bytes_read;
332 if (need_resched())
333 schedule();
334 } while (ret == 0 && *nbytes > 0 && *nbytes < length && *end_flag == 0);
335ibrd_out:
336 os_remove_timer(board);
337
338 return ret;
339}
340
341/*
342 * IBRPP
343 * Conduct a parallel poll and return the byte in buf.
344 *
345 * NOTE:
346 * 1. Prior to conducting the poll the interface is placed
347 * in the controller active state.
348 */
349int ibrpp(struct gpib_board *board, u8 *result)
350{
351 int retval = 0;
352
353 os_start_timer(board, board->usec_timeout);
354 retval = ibcac(board, 1, 1);
355 if (retval)
356 return -1;
357
358 retval = board->interface->parallel_poll(board, result);
359
360 os_remove_timer(board);
361 return retval;
362}
363
364int ibppc(struct gpib_board *board, u8 configuration)
365{
366 configuration &= 0x1f;
367 board->interface->parallel_poll_configure(board, configuration);
368 board->parallel_poll_configuration = configuration;
369
370 return 0;
371}
372
373int ibrsv2(struct gpib_board *board, u8 status_byte, int new_reason_for_service)
374{
375 int board_status = ibstatus(board);
376 const unsigned int MSS = status_byte & request_service_bit;
377
378 if ((board_status & CIC))
379 return -EINVAL;
380
381 if (MSS == 0 && new_reason_for_service)
382 return -EINVAL;
383
384 if (board->interface->serial_poll_response2) {
385 board->interface->serial_poll_response2(board, status_byte, new_reason_for_service);
386 // fall back on simpler serial_poll_response if the behavior would be the same
387 } else if (board->interface->serial_poll_response &&
388 (MSS == 0 || (MSS && new_reason_for_service))) {
389 board->interface->serial_poll_response(board, status_byte);
390 } else {
391 return -EOPNOTSUPP;
392 }
393
394 return 0;
395}
396
397/*
398 * IBSIC
399 * Send IFC for at least 100 microseconds.
400 *
401 * NOTE:
402 * 1. Ibsic must be called prior to the first call to
403 * ibcmd in order to initialize the bus and enable the
404 * interface to leave the controller idle state.
405 */
406int ibsic(struct gpib_board *board, unsigned int usec_duration)
407{
408 if (board->master == 0)
409 return -EINVAL;
410
411 if (usec_duration < 100)
412 usec_duration = 100;
413 if (usec_duration > 1000)
414 usec_duration = 1000;
415
416 dev_dbg(board->gpib_dev, "sending interface clear, delay = %ius\n", usec_duration);
417 board->interface->interface_clear(board, 1);
418 udelay(usec_duration);
419 board->interface->interface_clear(board, 0);
420
421 return 0;
422}
423
424int ibrsc(struct gpib_board *board, int request_control)
425{
426 int retval;
427
428 if (!board->interface->request_system_control)
429 return -EPERM;
430
431 retval = board->interface->request_system_control(board, request_control);
432
433 if (retval)
434 return retval;
435
436 board->master = request_control != 0;
437
438 return 0;
439}
440
441/*
442 * IBSRE
443 * Send REN true if v is non-zero or false if v is zero.
444 */
445int ibsre(struct gpib_board *board, int enable)
446{
447 if (board->master == 0)
448 return -EINVAL;
449
450 board->interface->remote_enable(board, enable); /* set or clear REN */
451 if (!enable)
452 usleep_range(100, 150);
453
454 return 0;
455}
456
457/*
458 * IBPAD
459 * change the GPIB address of the interface board. The address
460 * must be 0 through 30. ibonl resets the address to PAD.
461 */
462int ibpad(struct gpib_board *board, unsigned int addr)
463{
464 if (addr > MAX_GPIB_PRIMARY_ADDRESS)
465 return -EINVAL;
466
467 board->pad = addr;
468 if (board->online)
469 board->interface->primary_address(board, board->pad);
470 dev_dbg(board->gpib_dev, "set primary addr to %i\n", board->pad);
471 return 0;
472}
473
474/*
475 * IBSAD
476 * change the secondary GPIB address of the interface board.
477 * The address must be 0 through 30, or negative disables. ibonl resets the
478 * address to SAD.
479 */
480int ibsad(struct gpib_board *board, int addr)
481{
482 if (addr > MAX_GPIB_SECONDARY_ADDRESS)
483 return -EINVAL;
484 board->sad = addr;
485 if (board->online) {
486 if (board->sad >= 0)
487 board->interface->secondary_address(board, board->sad, 1);
488 else
489 board->interface->secondary_address(board, 0, 0);
490 }
491 dev_dbg(board->gpib_dev, "set secondary addr to %i\n", board->sad);
492
493 return 0;
494}
495
496/*
497 * IBEOS
498 * Set the end-of-string modes for I/O operations to v.
499 *
500 */
501int ibeos(struct gpib_board *board, int eos, int eosflags)
502{
503 int retval;
504
505 if (eosflags & ~EOS_MASK)
506 return -EINVAL;
507 if (eosflags & REOS) {
508 retval = board->interface->enable_eos(board, eos, eosflags & BIN);
509 } else {
510 board->interface->disable_eos(board);
511 retval = 0;
512 }
513 return retval;
514}
515
516int ibstatus(struct gpib_board *board)
517{
518 return general_ibstatus(board, NULL, 0, 0, NULL);
519}
520
521int general_ibstatus(struct gpib_board *board, const struct gpib_status_queue *device,
522 int clear_mask, int set_mask, struct gpib_descriptor *desc)
523{
524 int status = 0;
525 short line_status;
526
527 if (board->private_data) {
528 status = board->interface->update_status(board, clear_mask);
529 /*
530 * XXX should probably stop having drivers use TIMO bit in
531 * board->status to avoid confusion
532 */
533 status &= ~TIMO;
534 /* get real SRQI status if we can */
535 if (iblines(board, &line_status) == 0) {
536 if ((line_status & VALID_SRQ)) {
537 if ((line_status & BUS_SRQ))
538 status |= SRQI;
539 else
540 status &= ~SRQI;
541 }
542 }
543 }
544 if (device)
545 if (num_status_bytes(device))
546 status |= RQS;
547
548 if (desc) {
549 if (set_mask & CMPL)
550 atomic_set(&desc->io_in_progress, 0);
551 else if (clear_mask & CMPL)
552 atomic_set(&desc->io_in_progress, 1);
553
554 if (atomic_read(&desc->io_in_progress))
555 status &= ~CMPL;
556 else
557 status |= CMPL;
558 }
559 if (num_gpib_events(&board->event_queue))
560 status |= EVENT;
561 else
562 status &= ~EVENT;
563
564 return status;
565}
566
567struct wait_info {
568 struct gpib_board *board;
569 struct timer_list timer;
570 int timed_out;
571 unsigned long usec_timeout;
572};
573
574static void wait_timeout(struct timer_list *t)
575{
576 struct wait_info *winfo = timer_container_of(winfo, t, timer);
577
578 winfo->timed_out = 1;
579 wake_up_interruptible(&winfo->board->wait);
580}
581
582static void init_wait_info(struct wait_info *winfo)
583{
584 winfo->board = NULL;
585 winfo->timed_out = 0;
586 timer_setup_on_stack(&winfo->timer, wait_timeout, 0);
587}
588
589static int wait_satisfied(struct wait_info *winfo, struct gpib_status_queue *status_queue,
590 int wait_mask, int *status, struct gpib_descriptor *desc)
591{
592 struct gpib_board *board = winfo->board;
593 int temp_status;
594
595 if (mutex_lock_interruptible(&board->big_gpib_mutex))
596 return -ERESTARTSYS;
597
598 temp_status = general_ibstatus(board, status_queue, 0, 0, desc);
599
600 mutex_unlock(&board->big_gpib_mutex);
601
602 if (winfo->timed_out)
603 temp_status |= TIMO;
604 else
605 temp_status &= ~TIMO;
606 if (wait_mask & temp_status) {
607 *status = temp_status;
608 return 1;
609 }
610// XXX does wait for END work?
611 return 0;
612}
613
614/* install timer interrupt handler */
615static void start_wait_timer(struct wait_info *winfo)
616/* Starts the timeout task */
617{
618 winfo->timed_out = 0;
619
620 if (winfo->usec_timeout > 0)
621 mod_timer(&winfo->timer, jiffies + usec_to_jiffies(winfo->usec_timeout));
622}
623
624static void remove_wait_timer(struct wait_info *winfo)
625{
626 timer_delete_sync(&winfo->timer);
627 timer_destroy_on_stack(&winfo->timer);
628}
629
630/*
631 * IBWAIT
632 * Check or wait for a GPIB event to occur. The mask argument
633 * is a bit vector corresponding to the status bit vector. It
634 * has a bit set for each condition which can terminate the wait
635 * If the mask is 0 then
636 * no condition is waited for.
637 */
638int ibwait(struct gpib_board *board, int wait_mask, int clear_mask, int set_mask,
639 int *status, unsigned long usec_timeout, struct gpib_descriptor *desc)
640{
641 int retval = 0;
642 struct gpib_status_queue *status_queue;
643 struct wait_info winfo;
644
645 if (desc->is_board)
646 status_queue = NULL;
647 else
648 status_queue = get_gpib_status_queue(board, desc->pad, desc->sad);
649
650 if (wait_mask == 0) {
651 *status = general_ibstatus(board, status_queue, clear_mask, set_mask, desc);
652 return 0;
653 }
654
655 mutex_unlock(&board->big_gpib_mutex);
656
657 init_wait_info(&winfo);
658 winfo.board = board;
659 winfo.usec_timeout = usec_timeout;
660 start_wait_timer(&winfo);
661
662 if (wait_event_interruptible(board->wait, wait_satisfied(&winfo, status_queue,
663 wait_mask, status, desc))) {
664 dev_dbg(board->gpib_dev, "wait interrupted\n");
665 retval = -ERESTARTSYS;
666 }
667 remove_wait_timer(&winfo);
668
669 if (retval)
670 return retval;
671 if (mutex_lock_interruptible(&board->big_gpib_mutex))
672 return -ERESTARTSYS;
673
674 /* make sure we only clear status bits that we are reporting */
675 if (*status & clear_mask || set_mask)
676 general_ibstatus(board, status_queue, *status & clear_mask, set_mask, NULL);
677
678 return 0;
679}
680
681/*
682 * IBWRT
683 * Write cnt bytes of data from buf to the GPIB. The write
684 * operation terminates only on I/O complete.
685 *
686 * NOTE:
687 * 1. Prior to beginning the write, the interface is
688 * placed in the controller standby state.
689 * 2. Prior to calling ibwrt, the intended devices as
690 * well as the interface board itself must be
691 * addressed by calling ibcmd.
692 */
693int ibwrt(struct gpib_board *board, u8 *buf, size_t cnt, int send_eoi, size_t *bytes_written)
694{
695 int ret = 0;
696 int retval;
697
698 if (cnt == 0)
699 return 0;
700
701 if (board->master) {
702 retval = ibgts(board);
703 if (retval < 0)
704 return retval;
705 }
706 os_start_timer(board, board->usec_timeout);
707 ret = board->interface->write(board, buf, cnt, send_eoi, bytes_written);
708
709 if (io_timed_out(board))
710 ret = -ETIMEDOUT;
711
712 os_remove_timer(board);
713
714 return ret;
715}
716