1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * module/drivers.c
4 * functions for manipulating drivers
5 *
6 * COMEDI - Linux Control and Measurement Device Interface
7 * Copyright (C) 1997-2000 David A. Schleef <ds@schleef.org>
8 * Copyright (C) 2002 Frank Mori Hess <fmhess@users.sourceforge.net>
9 */
10
11#include <linux/device.h>
12#include <linux/module.h>
13#include <linux/errno.h>
14#include <linux/kernel.h>
15#include <linux/ioport.h>
16#include <linux/slab.h>
17#include <linux/dma-direction.h>
18#include <linux/interrupt.h>
19#include <linux/firmware.h>
20#include <linux/comedi/comedidev.h>
21#include "comedi_internal.h"
22
23struct comedi_driver *comedi_drivers;
24/* protects access to comedi_drivers */
25DEFINE_MUTEX(comedi_drivers_list_lock);
26
27/**
28 * comedi_set_hw_dev() - Set hardware device associated with COMEDI device
29 * @dev: COMEDI device.
30 * @hw_dev: Hardware device.
31 *
32 * For automatically configured COMEDI devices (resulting from a call to
33 * comedi_auto_config() or one of its wrappers from the low-level COMEDI
34 * driver), comedi_set_hw_dev() is called automatically by the COMEDI core
35 * to associate the COMEDI device with the hardware device. It can also be
36 * called directly by "legacy" low-level COMEDI drivers that rely on the
37 * %COMEDI_DEVCONFIG ioctl to configure the hardware as long as the hardware
38 * has a &struct device.
39 *
40 * If @dev->hw_dev is NULL, it gets a reference to @hw_dev and sets
41 * @dev->hw_dev, otherwise, it does nothing. Calling it multiple times
42 * with the same hardware device is not considered an error. If it gets
43 * a reference to the hardware device, it will be automatically 'put' when
44 * the device is detached from COMEDI.
45 *
46 * Returns 0 if @dev->hw_dev was NULL or the same as @hw_dev, otherwise
47 * returns -EEXIST.
48 */
49int comedi_set_hw_dev(struct comedi_device *dev, struct device *hw_dev)
50{
51 if (hw_dev == dev->hw_dev)
52 return 0;
53 if (dev->hw_dev)
54 return -EEXIST;
55 dev->hw_dev = get_device(dev: hw_dev);
56 return 0;
57}
58EXPORT_SYMBOL_GPL(comedi_set_hw_dev);
59
60static void comedi_clear_hw_dev(struct comedi_device *dev)
61{
62 put_device(dev: dev->hw_dev);
63 dev->hw_dev = NULL;
64}
65
66/**
67 * comedi_alloc_devpriv() - Allocate memory for the device private data
68 * @dev: COMEDI device.
69 * @size: Size of the memory to allocate.
70 *
71 * The allocated memory is zero-filled. @dev->private points to it on
72 * return. The memory will be automatically freed when the COMEDI device is
73 * "detached".
74 *
75 * Returns a pointer to the allocated memory, or NULL on failure.
76 */
77void *comedi_alloc_devpriv(struct comedi_device *dev, size_t size)
78{
79 dev->private = kzalloc(size, GFP_KERNEL);
80 return dev->private;
81}
82EXPORT_SYMBOL_GPL(comedi_alloc_devpriv);
83
84/**
85 * comedi_alloc_subdevices() - Allocate subdevices for COMEDI device
86 * @dev: COMEDI device.
87 * @num_subdevices: Number of subdevices to allocate.
88 *
89 * Allocates and initializes an array of &struct comedi_subdevice for the
90 * COMEDI device. If successful, sets @dev->subdevices to point to the
91 * first one and @dev->n_subdevices to the number.
92 *
93 * Returns 0 on success, -EINVAL if @num_subdevices is < 1, or -ENOMEM if
94 * failed to allocate the memory.
95 */
96int comedi_alloc_subdevices(struct comedi_device *dev, int num_subdevices)
97{
98 struct comedi_subdevice *s;
99 int i;
100
101 if (num_subdevices < 1)
102 return -EINVAL;
103
104 s = kcalloc(num_subdevices, sizeof(*s), GFP_KERNEL);
105 if (!s)
106 return -ENOMEM;
107 dev->subdevices = s;
108 dev->n_subdevices = num_subdevices;
109
110 for (i = 0; i < num_subdevices; ++i) {
111 s = &dev->subdevices[i];
112 s->device = dev;
113 s->index = i;
114 s->async_dma_dir = DMA_NONE;
115 spin_lock_init(&s->spin_lock);
116 s->minor = -1;
117 }
118 return 0;
119}
120EXPORT_SYMBOL_GPL(comedi_alloc_subdevices);
121
122/**
123 * comedi_alloc_subdev_readback() - Allocate memory for the subdevice readback
124 * @s: COMEDI subdevice.
125 *
126 * This is called by low-level COMEDI drivers to allocate an array to record
127 * the last values written to a subdevice's analog output channels (at least
128 * by the %INSN_WRITE instruction), to allow them to be read back by an
129 * %INSN_READ instruction. It also provides a default handler for the
130 * %INSN_READ instruction unless one has already been set.
131 *
132 * On success, @s->readback points to the first element of the array, which
133 * is zero-filled. The low-level driver is responsible for updating its
134 * contents. @s->insn_read will be set to comedi_readback_insn_read()
135 * unless it is already non-NULL.
136 *
137 * Returns 0 on success, -EINVAL if the subdevice has no channels, or
138 * -ENOMEM on allocation failure.
139 */
140int comedi_alloc_subdev_readback(struct comedi_subdevice *s)
141{
142 if (!s->n_chan)
143 return -EINVAL;
144
145 s->readback = kcalloc(s->n_chan, sizeof(*s->readback), GFP_KERNEL);
146 if (!s->readback)
147 return -ENOMEM;
148
149 if (!s->insn_read)
150 s->insn_read = comedi_readback_insn_read;
151
152 return 0;
153}
154EXPORT_SYMBOL_GPL(comedi_alloc_subdev_readback);
155
156static void comedi_device_detach_cleanup(struct comedi_device *dev)
157{
158 int i;
159 struct comedi_subdevice *s;
160
161 lockdep_assert_held_write(&dev->attach_lock);
162 lockdep_assert_held(&dev->mutex);
163 if (dev->subdevices) {
164 for (i = 0; i < dev->n_subdevices; i++) {
165 s = &dev->subdevices[i];
166 if (comedi_can_auto_free_spriv(s))
167 kfree(objp: s->private);
168 comedi_free_subdevice_minor(s);
169 if (s->async) {
170 comedi_buf_alloc(dev, s, new_size: 0);
171 kfree(objp: s->async);
172 }
173 kfree(objp: s->readback);
174 }
175 kfree(objp: dev->subdevices);
176 dev->subdevices = NULL;
177 dev->n_subdevices = 0;
178 }
179 kfree(objp: dev->private);
180 if (!IS_ERR(ptr: dev->pacer))
181 kfree(objp: dev->pacer);
182 dev->private = NULL;
183 dev->pacer = NULL;
184 dev->driver = NULL;
185 dev->board_name = NULL;
186 dev->board_ptr = NULL;
187 dev->mmio = NULL;
188 dev->iobase = 0;
189 dev->iolen = 0;
190 dev->ioenabled = false;
191 dev->irq = 0;
192 dev->read_subdev = NULL;
193 dev->write_subdev = NULL;
194 dev->open = NULL;
195 dev->close = NULL;
196 comedi_clear_hw_dev(dev);
197}
198
199void comedi_device_detach_locked(struct comedi_device *dev)
200{
201 lockdep_assert_held_write(&dev->attach_lock);
202 lockdep_assert_held(&dev->mutex);
203 comedi_device_cancel_all(dev);
204 dev->attached = false;
205 dev->detach_count++;
206 if (dev->driver)
207 dev->driver->detach(dev);
208 comedi_device_detach_cleanup(dev);
209}
210
211void comedi_device_detach(struct comedi_device *dev)
212{
213 lockdep_assert_held(&dev->mutex);
214 down_write(sem: &dev->attach_lock);
215 comedi_device_detach_locked(dev);
216 up_write(sem: &dev->attach_lock);
217}
218
219static int poll_invalid(struct comedi_device *dev, struct comedi_subdevice *s)
220{
221 return -EINVAL;
222}
223
224static int insn_device_inval(struct comedi_device *dev,
225 struct comedi_insn *insn, unsigned int *data)
226{
227 return -EINVAL;
228}
229
230static unsigned int get_zero_valid_routes(struct comedi_device *dev,
231 unsigned int n_pairs,
232 unsigned int *pair_data)
233{
234 return 0;
235}
236
237int insn_inval(struct comedi_device *dev, struct comedi_subdevice *s,
238 struct comedi_insn *insn, unsigned int *data)
239{
240 return -EINVAL;
241}
242
243/**
244 * comedi_readback_insn_read() - A generic (*insn_read) for subdevice readback.
245 * @dev: COMEDI device.
246 * @s: COMEDI subdevice.
247 * @insn: COMEDI instruction.
248 * @data: Pointer to return the readback data.
249 *
250 * Handles the %INSN_READ instruction for subdevices that use the readback
251 * array allocated by comedi_alloc_subdev_readback(). It may be used
252 * directly as the subdevice's handler (@s->insn_read) or called via a
253 * wrapper.
254 *
255 * @insn->n is normally 1, which will read a single value. If higher, the
256 * same element of the readback array will be read multiple times.
257 *
258 * Returns @insn->n on success, or -EINVAL if @s->readback is NULL.
259 */
260int comedi_readback_insn_read(struct comedi_device *dev,
261 struct comedi_subdevice *s,
262 struct comedi_insn *insn,
263 unsigned int *data)
264{
265 unsigned int chan = CR_CHAN(insn->chanspec);
266 int i;
267
268 if (!s->readback)
269 return -EINVAL;
270
271 for (i = 0; i < insn->n; i++)
272 data[i] = s->readback[chan];
273
274 return insn->n;
275}
276EXPORT_SYMBOL_GPL(comedi_readback_insn_read);
277
278/**
279 * comedi_timeout() - Busy-wait for a driver condition to occur
280 * @dev: COMEDI device.
281 * @s: COMEDI subdevice.
282 * @insn: COMEDI instruction.
283 * @cb: Callback to check for the condition.
284 * @context: Private context from the driver.
285 *
286 * Busy-waits for up to a second (%COMEDI_TIMEOUT_MS) for the condition or
287 * some error (other than -EBUSY) to occur. The parameters @dev, @s, @insn,
288 * and @context are passed to the callback function, which returns -EBUSY to
289 * continue waiting or some other value to stop waiting (generally 0 if the
290 * condition occurred, or some error value).
291 *
292 * Returns -ETIMEDOUT if timed out, otherwise the return value from the
293 * callback function.
294 */
295int comedi_timeout(struct comedi_device *dev,
296 struct comedi_subdevice *s,
297 struct comedi_insn *insn,
298 int (*cb)(struct comedi_device *dev,
299 struct comedi_subdevice *s,
300 struct comedi_insn *insn,
301 unsigned long context),
302 unsigned long context)
303{
304 unsigned long timeout = jiffies + msecs_to_jiffies(COMEDI_TIMEOUT_MS);
305 int ret;
306
307 while (time_before(jiffies, timeout)) {
308 ret = cb(dev, s, insn, context);
309 if (ret != -EBUSY)
310 return ret; /* success (0) or non EBUSY errno */
311 cpu_relax();
312 }
313 return -ETIMEDOUT;
314}
315EXPORT_SYMBOL_GPL(comedi_timeout);
316
317/**
318 * comedi_dio_insn_config() - Boilerplate (*insn_config) for DIO subdevices
319 * @dev: COMEDI device.
320 * @s: COMEDI subdevice.
321 * @insn: COMEDI instruction.
322 * @data: Instruction parameters and return data.
323 * @mask: io_bits mask for grouped channels, or 0 for single channel.
324 *
325 * If @mask is 0, it is replaced with a single-bit mask corresponding to the
326 * channel number specified by @insn->chanspec. Otherwise, @mask
327 * corresponds to a group of channels (which should include the specified
328 * channel) that are always configured together as inputs or outputs.
329 *
330 * Partially handles the %INSN_CONFIG_DIO_INPUT, %INSN_CONFIG_DIO_OUTPUTS,
331 * and %INSN_CONFIG_DIO_QUERY instructions. The first two update
332 * @s->io_bits to record the directions of the masked channels. The last
333 * one sets @data[1] to the current direction of the group of channels
334 * (%COMEDI_INPUT) or %COMEDI_OUTPUT) as recorded in @s->io_bits.
335 *
336 * The caller is responsible for updating the DIO direction in the hardware
337 * registers if this function returns 0.
338 *
339 * Returns 0 for a %INSN_CONFIG_DIO_INPUT or %INSN_CONFIG_DIO_OUTPUT
340 * instruction, @insn->n (> 0) for a %INSN_CONFIG_DIO_QUERY instruction, or
341 * -EINVAL for some other instruction.
342 */
343int comedi_dio_insn_config(struct comedi_device *dev,
344 struct comedi_subdevice *s,
345 struct comedi_insn *insn,
346 unsigned int *data,
347 unsigned int mask)
348{
349 unsigned int chan = CR_CHAN(insn->chanspec);
350
351 if (!mask && chan < 32)
352 mask = 1U << chan;
353
354 switch (data[0]) {
355 case INSN_CONFIG_DIO_INPUT:
356 s->io_bits &= ~mask;
357 break;
358
359 case INSN_CONFIG_DIO_OUTPUT:
360 s->io_bits |= mask;
361 break;
362
363 case INSN_CONFIG_DIO_QUERY:
364 data[1] = (s->io_bits & mask) ? COMEDI_OUTPUT : COMEDI_INPUT;
365 return insn->n;
366
367 default:
368 return -EINVAL;
369 }
370
371 return 0;
372}
373EXPORT_SYMBOL_GPL(comedi_dio_insn_config);
374
375/**
376 * comedi_dio_update_state() - Update the internal state of DIO subdevices
377 * @s: COMEDI subdevice.
378 * @data: The channel mask and bits to update.
379 *
380 * Updates @s->state which holds the internal state of the outputs for DIO
381 * or DO subdevices (up to 32 channels). @data[0] contains a bit-mask of
382 * the channels to be updated. @data[1] contains a bit-mask of those
383 * channels to be set to '1'. The caller is responsible for updating the
384 * outputs in hardware according to @s->state. As a minimum, the channels
385 * in the returned bit-mask need to be updated.
386 *
387 * Returns @mask with non-existent channels removed.
388 */
389unsigned int comedi_dio_update_state(struct comedi_subdevice *s,
390 unsigned int *data)
391{
392 unsigned int chanmask = (s->n_chan < 32) ? ((1U << s->n_chan) - 1)
393 : 0xffffffff;
394 unsigned int mask = data[0] & chanmask;
395 unsigned int bits = data[1];
396
397 if (mask) {
398 s->state &= ~mask;
399 s->state |= (bits & mask);
400 }
401
402 return mask;
403}
404EXPORT_SYMBOL_GPL(comedi_dio_update_state);
405
406/**
407 * comedi_bytes_per_scan_cmd() - Get length of asynchronous command "scan" in
408 * bytes
409 * @s: COMEDI subdevice.
410 * @cmd: COMEDI command.
411 *
412 * Determines the overall scan length according to the subdevice type and the
413 * number of channels in the scan for the specified command.
414 *
415 * For digital input, output or input/output subdevices, samples for
416 * multiple channels are assumed to be packed into one or more unsigned
417 * short or unsigned int values according to the subdevice's %SDF_LSAMPL
418 * flag. For other types of subdevice, samples are assumed to occupy a
419 * whole unsigned short or unsigned int according to the %SDF_LSAMPL flag.
420 *
421 * Returns the overall scan length in bytes.
422 */
423unsigned int comedi_bytes_per_scan_cmd(struct comedi_subdevice *s,
424 struct comedi_cmd *cmd)
425{
426 unsigned int num_samples;
427 unsigned int bits_per_sample;
428
429 switch (s->type) {
430 case COMEDI_SUBD_DI:
431 case COMEDI_SUBD_DO:
432 case COMEDI_SUBD_DIO:
433 bits_per_sample = 8 * comedi_bytes_per_sample(s);
434 num_samples = DIV_ROUND_UP(cmd->scan_end_arg, bits_per_sample);
435 break;
436 default:
437 num_samples = cmd->scan_end_arg;
438 break;
439 }
440 return comedi_samples_to_bytes(s, nsamples: num_samples);
441}
442EXPORT_SYMBOL_GPL(comedi_bytes_per_scan_cmd);
443
444static unsigned int _comedi_bytes_per_scan(struct comedi_subdevice *s)
445{
446 struct comedi_cmd *cmd = &s->async->cmd;
447
448 return comedi_bytes_per_scan_cmd(s, cmd);
449}
450
451/**
452 * comedi_bytes_per_scan() - Get length of asynchronous command "scan" in bytes
453 * @s: COMEDI subdevice.
454 *
455 * Determines the overall scan length according to the subdevice type and the
456 * number of channels in the scan for the current command.
457 *
458 * For digital input, output or input/output subdevices, samples for
459 * multiple channels are assumed to be packed into one or more unsigned
460 * short or unsigned int values according to the subdevice's %SDF_LSAMPL
461 * flag. For other types of subdevice, samples are assumed to occupy a
462 * whole unsigned short or unsigned int according to the %SDF_LSAMPL flag.
463 *
464 * Returns the overall scan length in bytes.
465 */
466unsigned int comedi_bytes_per_scan(struct comedi_subdevice *s)
467{
468 unsigned int num_bytes;
469
470 if (comedi_get_is_subdevice_running(s)) {
471 num_bytes = _comedi_bytes_per_scan(s);
472 comedi_put_is_subdevice_running(s);
473 } else {
474 /* Use nomimal, single sample scan length. */
475 num_bytes = comedi_samples_to_bytes(s, nsamples: 1);
476 }
477 return num_bytes;
478}
479EXPORT_SYMBOL_GPL(comedi_bytes_per_scan);
480
481static unsigned int __comedi_nscans_left(struct comedi_subdevice *s,
482 unsigned int nscans)
483{
484 struct comedi_async *async = s->async;
485 struct comedi_cmd *cmd = &async->cmd;
486
487 if (cmd->stop_src == TRIG_COUNT) {
488 unsigned int scans_left = 0;
489
490 if (async->scans_done < cmd->stop_arg)
491 scans_left = cmd->stop_arg - async->scans_done;
492
493 if (nscans > scans_left)
494 nscans = scans_left;
495 }
496 return nscans;
497}
498
499static unsigned int _comedi_nscans_left(struct comedi_subdevice *s,
500 unsigned int nscans)
501{
502 if (nscans == 0) {
503 unsigned int nbytes = _comedi_buf_read_n_available(s);
504
505 nscans = nbytes / _comedi_bytes_per_scan(s);
506 }
507 return __comedi_nscans_left(s, nscans);
508}
509
510/**
511 * comedi_nscans_left() - Return the number of scans left in the command
512 * @s: COMEDI subdevice.
513 * @nscans: The expected number of scans or 0 for all available scans.
514 *
515 * If @nscans is 0, it is set to the number of scans available in the
516 * async buffer.
517 *
518 * If the async command has a stop_src of %TRIG_COUNT, the @nscans will be
519 * checked against the number of scans remaining to complete the command.
520 *
521 * The return value will then be either the expected number of scans or the
522 * number of scans remaining to complete the command, whichever is fewer.
523 */
524unsigned int comedi_nscans_left(struct comedi_subdevice *s,
525 unsigned int nscans)
526{
527 if (comedi_get_is_subdevice_running(s)) {
528 nscans = _comedi_nscans_left(s, nscans);
529 comedi_put_is_subdevice_running(s);
530 } else {
531 nscans = 0;
532 }
533 return nscans;
534}
535EXPORT_SYMBOL_GPL(comedi_nscans_left);
536
537static unsigned int _comedi_nsamples_left(struct comedi_subdevice *s,
538 unsigned int nsamples)
539{
540 struct comedi_async *async = s->async;
541 struct comedi_cmd *cmd = &async->cmd;
542 unsigned long long scans_left;
543 unsigned long long samples_left;
544
545 if (cmd->stop_src != TRIG_COUNT)
546 return nsamples;
547
548 scans_left = __comedi_nscans_left(s, nscans: cmd->stop_arg);
549 if (!scans_left)
550 return 0;
551
552 samples_left = scans_left * cmd->scan_end_arg -
553 comedi_bytes_to_samples(s, nbytes: async->scan_progress);
554
555 if (samples_left < nsamples)
556 return samples_left;
557 return nsamples;
558}
559
560/**
561 * comedi_nsamples_left() - Return the number of samples left in the command
562 * @s: COMEDI subdevice.
563 * @nsamples: The expected number of samples.
564 *
565 * Returns the number of samples remaining to complete the command, or the
566 * specified expected number of samples (@nsamples), whichever is fewer.
567 */
568unsigned int comedi_nsamples_left(struct comedi_subdevice *s,
569 unsigned int nsamples)
570{
571 if (comedi_get_is_subdevice_running(s)) {
572 nsamples = _comedi_nsamples_left(s, nsamples);
573 comedi_put_is_subdevice_running(s);
574 } else {
575 nsamples = 0;
576 }
577 return nsamples;
578}
579EXPORT_SYMBOL_GPL(comedi_nsamples_left);
580
581void _comedi_inc_scan_progress(struct comedi_subdevice *s,
582 unsigned int num_bytes)
583{
584 struct comedi_async *async = s->async;
585 struct comedi_cmd *cmd = &async->cmd;
586 unsigned int scan_length = _comedi_bytes_per_scan(s);
587
588 /* track the 'cur_chan' for non-SDF_PACKED subdevices */
589 if (!(s->subdev_flags & SDF_PACKED)) {
590 async->cur_chan += comedi_bytes_to_samples(s, nbytes: num_bytes);
591 async->cur_chan %= cmd->chanlist_len;
592 }
593
594 async->scan_progress += num_bytes;
595 if (async->scan_progress >= scan_length) {
596 unsigned int nscans = async->scan_progress / scan_length;
597
598 if (async->scans_done < (UINT_MAX - nscans))
599 async->scans_done += nscans;
600 else
601 async->scans_done = UINT_MAX;
602
603 async->scan_progress %= scan_length;
604 async->events |= COMEDI_CB_EOS;
605 }
606}
607
608/**
609 * comedi_inc_scan_progress() - Update scan progress in asynchronous command
610 * @s: COMEDI subdevice.
611 * @num_bytes: Amount of data in bytes to increment scan progress.
612 *
613 * Increments the scan progress by the number of bytes specified by @num_bytes.
614 * If the scan progress reaches or exceeds the scan length in bytes, reduce
615 * it modulo the scan length in bytes and set the "end of scan" asynchronous
616 * event flag (%COMEDI_CB_EOS) to be processed later.
617 */
618void comedi_inc_scan_progress(struct comedi_subdevice *s,
619 unsigned int num_bytes)
620{
621 if (comedi_get_is_subdevice_running(s)) {
622 _comedi_inc_scan_progress(s, num_bytes);
623 comedi_put_is_subdevice_running(s);
624 }
625}
626EXPORT_SYMBOL_GPL(comedi_inc_scan_progress);
627
628static unsigned int _comedi_handle_events(struct comedi_device *dev,
629 struct comedi_subdevice *s)
630{
631 unsigned int events = s->async->events;
632
633 if (events == 0)
634 return events;
635
636 if ((events & COMEDI_CB_CANCEL_MASK) && s->cancel)
637 s->cancel(dev, s);
638
639 _comedi_event(dev, s);
640
641 return events;
642}
643
644/**
645 * comedi_handle_events() - Handle events and possibly stop acquisition
646 * @dev: COMEDI device.
647 * @s: COMEDI subdevice.
648 *
649 * Handles outstanding asynchronous acquisition event flags associated
650 * with the subdevice. Call the subdevice's @s->cancel() handler if the
651 * "end of acquisition", "error" or "overflow" event flags are set in order
652 * to stop the acquisition at the driver level.
653 *
654 * Calls comedi_event() to further process the event flags, which may mark
655 * the asynchronous command as no longer running, possibly terminated with
656 * an error, and may wake up tasks.
657 *
658 * Return a bit-mask of the handled events.
659 */
660unsigned int comedi_handle_events(struct comedi_device *dev,
661 struct comedi_subdevice *s)
662{
663 unsigned int events;
664
665 if (comedi_get_is_subdevice_running(s)) {
666 events = _comedi_handle_events(dev, s);
667 comedi_put_is_subdevice_running(s);
668 } else {
669 events = 0;
670 }
671 return events;
672}
673EXPORT_SYMBOL_GPL(comedi_handle_events);
674
675static int insn_rw_emulate_bits(struct comedi_device *dev,
676 struct comedi_subdevice *s,
677 struct comedi_insn *insn,
678 unsigned int *data)
679{
680 struct comedi_insn _insn;
681 unsigned int chan = CR_CHAN(insn->chanspec);
682 unsigned int base_chan = (chan < 32) ? 0 : chan;
683 unsigned int _data[2];
684 unsigned int i;
685 int ret;
686
687 memset(_data, 0, sizeof(_data));
688 memset(&_insn, 0, sizeof(_insn));
689 _insn.insn = INSN_BITS;
690 _insn.chanspec = base_chan;
691 _insn.n = 2;
692 _insn.subdev = insn->subdev;
693
694 if (insn->insn == INSN_WRITE) {
695 if (!(s->subdev_flags & SDF_WRITABLE))
696 return -EINVAL;
697 _data[0] = 1U << (chan - base_chan); /* mask */
698 }
699 for (i = 0; i < insn->n; i++) {
700 if (insn->insn == INSN_WRITE)
701 _data[1] = data[i] ? _data[0] : 0; /* bits */
702
703 ret = s->insn_bits(dev, s, &_insn, _data);
704 if (ret < 0)
705 return ret;
706
707 if (insn->insn == INSN_READ)
708 data[i] = (_data[1] >> (chan - base_chan)) & 1;
709 }
710
711 return insn->n;
712}
713
714static int __comedi_device_postconfig_async(struct comedi_device *dev,
715 struct comedi_subdevice *s)
716{
717 struct comedi_async *async;
718 unsigned int buf_size;
719 int ret;
720
721 lockdep_assert_held(&dev->mutex);
722 if ((s->subdev_flags & (SDF_CMD_READ | SDF_CMD_WRITE)) == 0) {
723 dev_warn(dev->class_dev,
724 "async subdevices must support SDF_CMD_READ or SDF_CMD_WRITE\n");
725 return -EINVAL;
726 }
727 if (!s->do_cmdtest) {
728 dev_warn(dev->class_dev,
729 "async subdevices must have a do_cmdtest() function\n");
730 return -EINVAL;
731 }
732 if (!s->cancel)
733 dev_warn(dev->class_dev,
734 "async subdevices should have a cancel() function\n");
735
736 async = kzalloc(sizeof(*async), GFP_KERNEL);
737 if (!async)
738 return -ENOMEM;
739
740 init_waitqueue_head(&async->wait_head);
741 init_completion(x: &async->run_complete);
742 s->async = async;
743
744 async->max_bufsize = comedi_default_buf_maxsize_kb * 1024;
745 buf_size = comedi_default_buf_size_kb * 1024;
746 if (buf_size > async->max_bufsize)
747 buf_size = async->max_bufsize;
748
749 if (comedi_buf_alloc(dev, s, new_size: buf_size) < 0) {
750 dev_warn(dev->class_dev, "Buffer allocation failed\n");
751 return -ENOMEM;
752 }
753 if (s->buf_change) {
754 ret = s->buf_change(dev, s);
755 if (ret < 0)
756 return ret;
757 }
758
759 comedi_alloc_subdevice_minor(s);
760
761 return 0;
762}
763
764static int __comedi_device_postconfig(struct comedi_device *dev)
765{
766 struct comedi_subdevice *s;
767 int ret;
768 int i;
769
770 lockdep_assert_held(&dev->mutex);
771 if (!dev->insn_device_config)
772 dev->insn_device_config = insn_device_inval;
773
774 if (!dev->get_valid_routes)
775 dev->get_valid_routes = get_zero_valid_routes;
776
777 for (i = 0; i < dev->n_subdevices; i++) {
778 s = &dev->subdevices[i];
779
780 if (s->type == COMEDI_SUBD_UNUSED)
781 continue;
782
783 if (s->type == COMEDI_SUBD_DO) {
784 if (s->n_chan < 32)
785 s->io_bits = (1U << s->n_chan) - 1;
786 else
787 s->io_bits = 0xffffffff;
788 }
789
790 if (s->len_chanlist == 0)
791 s->len_chanlist = 1;
792
793 if (s->do_cmd) {
794 ret = __comedi_device_postconfig_async(dev, s);
795 if (ret)
796 return ret;
797 }
798
799 if (!s->range_table && !s->range_table_list)
800 s->range_table = &range_unknown;
801
802 if (!s->insn_read && s->insn_bits)
803 s->insn_read = insn_rw_emulate_bits;
804 if (!s->insn_write && s->insn_bits)
805 s->insn_write = insn_rw_emulate_bits;
806
807 if (!s->insn_read)
808 s->insn_read = insn_inval;
809 if (!s->insn_write)
810 s->insn_write = insn_inval;
811 if (!s->insn_bits)
812 s->insn_bits = insn_inval;
813 if (!s->insn_config)
814 s->insn_config = insn_inval;
815
816 if (!s->poll)
817 s->poll = poll_invalid;
818 }
819
820 return 0;
821}
822
823/* do a little post-config cleanup */
824static int comedi_device_postconfig(struct comedi_device *dev)
825{
826 int ret;
827
828 lockdep_assert_held(&dev->mutex);
829 ret = __comedi_device_postconfig(dev);
830 if (ret < 0)
831 return ret;
832 down_write(sem: &dev->attach_lock);
833 dev->attached = true;
834 up_write(sem: &dev->attach_lock);
835 return 0;
836}
837
838/*
839 * Generic recognize function for drivers that register their supported
840 * board names.
841 *
842 * 'driv->board_name' points to a 'const char *' member within the
843 * zeroth element of an array of some private board information
844 * structure, say 'struct foo_board' containing a member 'const char
845 * *board_name' that is initialized to point to a board name string that
846 * is one of the candidates matched against this function's 'name'
847 * parameter.
848 *
849 * 'driv->offset' is the size of the private board information
850 * structure, say 'sizeof(struct foo_board)', and 'driv->num_names' is
851 * the length of the array of private board information structures.
852 *
853 * If one of the board names in the array of private board information
854 * structures matches the name supplied to this function, the function
855 * returns a pointer to the pointer to the board name, otherwise it
856 * returns NULL. The return value ends up in the 'board_ptr' member of
857 * a 'struct comedi_device' that the low-level comedi driver's
858 * 'attach()' hook can convert to a point to a particular element of its
859 * array of private board information structures by subtracting the
860 * offset of the member that points to the board name. (No subtraction
861 * is required if the board name pointer is the first member of the
862 * private board information structure, which is generally the case.)
863 */
864static void *comedi_recognize(struct comedi_driver *driv, const char *name)
865{
866 char **name_ptr = (char **)driv->board_name;
867 int i;
868
869 for (i = 0; i < driv->num_names; i++) {
870 if (strcmp(*name_ptr, name) == 0)
871 return name_ptr;
872 name_ptr = (void *)name_ptr + driv->offset;
873 }
874
875 return NULL;
876}
877
878static void comedi_report_boards(struct comedi_driver *driv)
879{
880 unsigned int i;
881 const char *const *name_ptr;
882
883 pr_info("comedi: valid board names for %s driver are:\n",
884 driv->driver_name);
885
886 name_ptr = driv->board_name;
887 for (i = 0; i < driv->num_names; i++) {
888 pr_info(" %s\n", *name_ptr);
889 name_ptr = (const char **)((char *)name_ptr + driv->offset);
890 }
891
892 if (driv->num_names == 0)
893 pr_info(" %s\n", driv->driver_name);
894}
895
896/**
897 * comedi_load_firmware() - Request and load firmware for a device
898 * @dev: COMEDI device.
899 * @device: Hardware device.
900 * @name: The name of the firmware image.
901 * @cb: Callback to the upload the firmware image.
902 * @context: Private context from the driver.
903 *
904 * Sends a firmware request for the hardware device and waits for it. Calls
905 * the callback function to upload the firmware to the device, them releases
906 * the firmware.
907 *
908 * Returns 0 on success, -EINVAL if @cb is NULL, or a negative error number
909 * from the firmware request or the callback function.
910 */
911int comedi_load_firmware(struct comedi_device *dev,
912 struct device *device,
913 const char *name,
914 int (*cb)(struct comedi_device *dev,
915 const u8 *data, size_t size,
916 unsigned long context),
917 unsigned long context)
918{
919 const struct firmware *fw;
920 int ret;
921
922 if (!cb)
923 return -EINVAL;
924
925 ret = request_firmware(fw: &fw, name, device);
926 if (ret == 0) {
927 ret = cb(dev, fw->data, fw->size, context);
928 release_firmware(fw);
929 }
930
931 return min(ret, 0);
932}
933EXPORT_SYMBOL_GPL(comedi_load_firmware);
934
935/**
936 * __comedi_request_region() - Request an I/O region for a legacy driver
937 * @dev: COMEDI device.
938 * @start: Base address of the I/O region.
939 * @len: Length of the I/O region.
940 *
941 * Requests the specified I/O port region which must start at a non-zero
942 * address.
943 *
944 * Returns 0 on success, -EINVAL if @start is 0, or -EIO if the request
945 * fails.
946 */
947int __comedi_request_region(struct comedi_device *dev,
948 unsigned long start, unsigned long len)
949{
950 if (!start) {
951 dev_warn(dev->class_dev,
952 "%s: a I/O base address must be specified\n",
953 dev->board_name);
954 return -EINVAL;
955 }
956
957 if (!request_region(start, len, dev->board_name)) {
958 dev_warn(dev->class_dev, "%s: I/O port conflict (%#lx,%lu)\n",
959 dev->board_name, start, len);
960 return -EIO;
961 }
962
963 return 0;
964}
965EXPORT_SYMBOL_GPL(__comedi_request_region);
966
967/**
968 * comedi_request_region() - Request an I/O region for a legacy driver
969 * @dev: COMEDI device.
970 * @start: Base address of the I/O region.
971 * @len: Length of the I/O region.
972 *
973 * Requests the specified I/O port region which must start at a non-zero
974 * address.
975 *
976 * On success, @dev->iobase is set to the base address of the region and
977 * @dev->iolen is set to its length.
978 *
979 * Returns 0 on success, -EINVAL if @start is 0, or -EIO if the request
980 * fails.
981 */
982int comedi_request_region(struct comedi_device *dev,
983 unsigned long start, unsigned long len)
984{
985 int ret;
986
987 ret = __comedi_request_region(dev, start, len);
988 if (ret == 0) {
989 dev->iobase = start;
990 dev->iolen = len;
991 }
992
993 return ret;
994}
995EXPORT_SYMBOL_GPL(comedi_request_region);
996
997/**
998 * comedi_legacy_detach() - A generic (*detach) function for legacy drivers
999 * @dev: COMEDI device.
1000 *
1001 * This is a simple, generic 'detach' handler for legacy COMEDI devices that
1002 * just use a single I/O port region and possibly an IRQ and that don't need
1003 * any special clean-up for their private device or subdevice storage. It
1004 * can also be called by a driver-specific 'detach' handler.
1005 *
1006 * If @dev->irq is non-zero, the IRQ will be freed. If @dev->iobase and
1007 * @dev->iolen are both non-zero, the I/O port region will be released.
1008 */
1009void comedi_legacy_detach(struct comedi_device *dev)
1010{
1011 if (dev->irq) {
1012 free_irq(dev->irq, dev);
1013 dev->irq = 0;
1014 }
1015 if (dev->iobase && dev->iolen) {
1016 release_region(dev->iobase, dev->iolen);
1017 dev->iobase = 0;
1018 dev->iolen = 0;
1019 }
1020}
1021EXPORT_SYMBOL_GPL(comedi_legacy_detach);
1022
1023int comedi_device_attach(struct comedi_device *dev, struct comedi_devconfig *it)
1024{
1025 struct comedi_driver *driv;
1026 int ret;
1027
1028 lockdep_assert_held(&dev->mutex);
1029 if (dev->attached)
1030 return -EBUSY;
1031
1032 mutex_lock(&comedi_drivers_list_lock);
1033 for (driv = comedi_drivers; driv; driv = driv->next) {
1034 if (!try_module_get(module: driv->module))
1035 continue;
1036 if (driv->num_names) {
1037 dev->board_ptr = comedi_recognize(driv, name: it->board_name);
1038 if (dev->board_ptr)
1039 break;
1040 } else if (strcmp(driv->driver_name, it->board_name) == 0) {
1041 break;
1042 }
1043 module_put(module: driv->module);
1044 }
1045 if (!driv) {
1046 /* recognize has failed if we get here */
1047 /* report valid board names before returning error */
1048 for (driv = comedi_drivers; driv; driv = driv->next) {
1049 if (!try_module_get(module: driv->module))
1050 continue;
1051 comedi_report_boards(driv);
1052 module_put(module: driv->module);
1053 }
1054 ret = -EIO;
1055 goto out;
1056 }
1057 if (!driv->attach) {
1058 /* driver does not support manual configuration */
1059 dev_warn(dev->class_dev,
1060 "driver '%s' does not support attach using comedi_config\n",
1061 driv->driver_name);
1062 module_put(module: driv->module);
1063 ret = -EIO;
1064 goto out;
1065 }
1066 dev->driver = driv;
1067 dev->board_name = dev->board_ptr ? *(const char **)dev->board_ptr
1068 : dev->driver->driver_name;
1069 ret = driv->attach(dev, it);
1070 if (ret >= 0)
1071 ret = comedi_device_postconfig(dev);
1072 if (ret < 0) {
1073 comedi_device_detach(dev);
1074 module_put(module: driv->module);
1075 }
1076 /* On success, the driver module count has been incremented. */
1077out:
1078 mutex_unlock(lock: &comedi_drivers_list_lock);
1079 return ret;
1080}
1081
1082/**
1083 * comedi_auto_config() - Create a COMEDI device for a hardware device
1084 * @hardware_device: Hardware device.
1085 * @driver: COMEDI low-level driver for the hardware device.
1086 * @context: Driver context for the auto_attach handler.
1087 *
1088 * Allocates a new COMEDI device for the hardware device and calls the
1089 * low-level driver's 'auto_attach' handler to set-up the hardware and
1090 * allocate the COMEDI subdevices. Additional "post-configuration" setting
1091 * up is performed on successful return from the 'auto_attach' handler.
1092 * If the 'auto_attach' handler fails, the low-level driver's 'detach'
1093 * handler will be called as part of the clean-up.
1094 *
1095 * This is usually called from a wrapper function in a bus-specific COMEDI
1096 * module, which in turn is usually called from a bus device 'probe'
1097 * function in the low-level driver.
1098 *
1099 * Returns 0 on success, -EINVAL if the parameters are invalid or the
1100 * post-configuration determines the driver has set the COMEDI device up
1101 * incorrectly, -ENOMEM if failed to allocate memory, -EBUSY if run out of
1102 * COMEDI minor device numbers, or some negative error number returned by
1103 * the driver's 'auto_attach' handler.
1104 */
1105int comedi_auto_config(struct device *hardware_device,
1106 struct comedi_driver *driver, unsigned long context)
1107{
1108 struct comedi_device *dev;
1109 int ret;
1110
1111 if (!hardware_device) {
1112 pr_warn("BUG! %s called with NULL hardware_device\n", __func__);
1113 return -EINVAL;
1114 }
1115 if (!driver) {
1116 dev_warn(hardware_device,
1117 "BUG! %s called with NULL comedi driver\n", __func__);
1118 return -EINVAL;
1119 }
1120
1121 if (!driver->auto_attach) {
1122 dev_warn(hardware_device,
1123 "BUG! comedi driver '%s' has no auto_attach handler\n",
1124 driver->driver_name);
1125 return -EINVAL;
1126 }
1127
1128 dev = comedi_alloc_board_minor(hardware_device);
1129 if (IS_ERR(ptr: dev)) {
1130 dev_warn(hardware_device,
1131 "driver '%s' could not create device.\n",
1132 driver->driver_name);
1133 return PTR_ERR(ptr: dev);
1134 }
1135 /* Note: comedi_alloc_board_minor() locked dev->mutex. */
1136 lockdep_assert_held(&dev->mutex);
1137
1138 dev->driver = driver;
1139 dev->board_name = dev->driver->driver_name;
1140 ret = driver->auto_attach(dev, context);
1141 if (ret >= 0)
1142 ret = comedi_device_postconfig(dev);
1143
1144 if (ret < 0) {
1145 dev_warn(hardware_device,
1146 "driver '%s' failed to auto-configure device.\n",
1147 driver->driver_name);
1148 mutex_unlock(lock: &dev->mutex);
1149 comedi_release_hardware_device(hardware_device);
1150 } else {
1151 /*
1152 * class_dev should be set properly here
1153 * after a successful auto config
1154 */
1155 dev_info(dev->class_dev,
1156 "driver '%s' has successfully auto-configured '%s'.\n",
1157 driver->driver_name, dev->board_name);
1158 mutex_unlock(lock: &dev->mutex);
1159 }
1160 return ret;
1161}
1162EXPORT_SYMBOL_GPL(comedi_auto_config);
1163
1164/**
1165 * comedi_auto_unconfig() - Unconfigure auto-allocated COMEDI device
1166 * @hardware_device: Hardware device previously passed to
1167 * comedi_auto_config().
1168 *
1169 * Cleans up and eventually destroys the COMEDI device allocated by
1170 * comedi_auto_config() for the same hardware device. As part of this
1171 * clean-up, the low-level COMEDI driver's 'detach' handler will be called.
1172 * (The COMEDI device itself will persist in an unattached state if it is
1173 * still open, until it is released, and any mmapped buffers will persist
1174 * until they are munmapped.)
1175 *
1176 * This is usually called from a wrapper module in a bus-specific COMEDI
1177 * module, which in turn is usually set as the bus device 'remove' function
1178 * in the low-level COMEDI driver.
1179 */
1180void comedi_auto_unconfig(struct device *hardware_device)
1181{
1182 if (!hardware_device)
1183 return;
1184 comedi_release_hardware_device(hardware_device);
1185}
1186EXPORT_SYMBOL_GPL(comedi_auto_unconfig);
1187
1188/**
1189 * comedi_driver_register() - Register a low-level COMEDI driver
1190 * @driver: Low-level COMEDI driver.
1191 *
1192 * The low-level COMEDI driver is added to the list of registered COMEDI
1193 * drivers. This is used by the handler for the "/proc/comedi" file and is
1194 * also used by the handler for the %COMEDI_DEVCONFIG ioctl to configure
1195 * "legacy" COMEDI devices (for those low-level drivers that support it).
1196 *
1197 * Returns 0.
1198 */
1199int comedi_driver_register(struct comedi_driver *driver)
1200{
1201 mutex_lock(&comedi_drivers_list_lock);
1202 driver->next = comedi_drivers;
1203 comedi_drivers = driver;
1204 mutex_unlock(lock: &comedi_drivers_list_lock);
1205
1206 return 0;
1207}
1208EXPORT_SYMBOL_GPL(comedi_driver_register);
1209
1210/**
1211 * comedi_driver_unregister() - Unregister a low-level COMEDI driver
1212 * @driver: Low-level COMEDI driver.
1213 *
1214 * The low-level COMEDI driver is removed from the list of registered COMEDI
1215 * drivers. Detaches any COMEDI devices attached to the driver, which will
1216 * result in the low-level driver's 'detach' handler being called for those
1217 * devices before this function returns.
1218 */
1219void comedi_driver_unregister(struct comedi_driver *driver)
1220{
1221 struct comedi_driver *prev;
1222 int i;
1223
1224 /* unlink the driver */
1225 mutex_lock(&comedi_drivers_list_lock);
1226 if (comedi_drivers == driver) {
1227 comedi_drivers = driver->next;
1228 } else {
1229 for (prev = comedi_drivers; prev->next; prev = prev->next) {
1230 if (prev->next == driver) {
1231 prev->next = driver->next;
1232 break;
1233 }
1234 }
1235 }
1236 mutex_unlock(lock: &comedi_drivers_list_lock);
1237
1238 /* check for devices using this driver */
1239 for (i = 0; i < COMEDI_NUM_BOARD_MINORS; i++) {
1240 struct comedi_device *dev = comedi_dev_get_from_minor(minor: i);
1241
1242 if (!dev)
1243 continue;
1244
1245 mutex_lock(&dev->mutex);
1246 if (dev->attached && dev->driver == driver) {
1247 if (dev->use_count)
1248 dev_warn(dev->class_dev,
1249 "BUG! detaching device with use_count=%d\n",
1250 dev->use_count);
1251 comedi_device_detach(dev);
1252 }
1253 mutex_unlock(lock: &dev->mutex);
1254 comedi_dev_put(dev);
1255 }
1256}
1257EXPORT_SYMBOL_GPL(comedi_driver_unregister);
1258

source code of linux/drivers/comedi/drivers.c