dm thin metadata: fix __udivdi3 undefined on 32-bit
[linux/fpc-iii.git] / drivers / staging / comedi / drivers.c
blob1f398d06f4ee8b966523f1ca78b9369a3ff6d9c1
1 /*
2 * module/drivers.c
3 * functions for manipulating drivers
5 * COMEDI - Linux Control and Measurement Device Interface
6 * Copyright (C) 1997-2000 David A. Schleef <ds@schleef.org>
7 * Copyright (C) 2002 Frank Mori Hess <fmhess@users.sourceforge.net>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
20 #include <linux/device.h>
21 #include <linux/module.h>
22 #include <linux/errno.h>
23 #include <linux/kernel.h>
24 #include <linux/ioport.h>
25 #include <linux/slab.h>
26 #include <linux/dma-direction.h>
27 #include <linux/interrupt.h>
28 #include <linux/firmware.h>
30 #include "comedidev.h"
31 #include "comedi_internal.h"
33 struct comedi_driver *comedi_drivers;
34 /* protects access to comedi_drivers */
35 DEFINE_MUTEX(comedi_drivers_list_lock);
37 /**
38 * comedi_set_hw_dev() - Set hardware device associated with COMEDI device
39 * @dev: COMEDI device.
40 * @hw_dev: Hardware device.
42 * For automatically configured COMEDI devices (resulting from a call to
43 * comedi_auto_config() or one of its wrappers from the low-level COMEDI
44 * driver), comedi_set_hw_dev() is called automatically by the COMEDI core
45 * to associate the COMEDI device with the hardware device. It can also be
46 * called directly by "legacy" low-level COMEDI drivers that rely on the
47 * %COMEDI_DEVCONFIG ioctl to configure the hardware as long as the hardware
48 * has a &struct device.
50 * If @dev->hw_dev is NULL, it gets a reference to @hw_dev and sets
51 * @dev->hw_dev, otherwise, it does nothing. Calling it multiple times
52 * with the same hardware device is not considered an error. If it gets
53 * a reference to the hardware device, it will be automatically 'put' when
54 * the device is detached from COMEDI.
56 * Returns 0 if @dev->hw_dev was NULL or the same as @hw_dev, otherwise
57 * returns -EEXIST.
59 int comedi_set_hw_dev(struct comedi_device *dev, struct device *hw_dev)
61 if (hw_dev == dev->hw_dev)
62 return 0;
63 if (dev->hw_dev)
64 return -EEXIST;
65 dev->hw_dev = get_device(hw_dev);
66 return 0;
68 EXPORT_SYMBOL_GPL(comedi_set_hw_dev);
70 static void comedi_clear_hw_dev(struct comedi_device *dev)
72 put_device(dev->hw_dev);
73 dev->hw_dev = NULL;
76 /**
77 * comedi_alloc_devpriv() - Allocate memory for the device private data
78 * @dev: COMEDI device.
79 * @size: Size of the memory to allocate.
81 * The allocated memory is zero-filled. @dev->private points to it on
82 * return. The memory will be automatically freed when the COMEDI device is
83 * "detached".
85 * Returns a pointer to the allocated memory, or NULL on failure.
87 void *comedi_alloc_devpriv(struct comedi_device *dev, size_t size)
89 dev->private = kzalloc(size, GFP_KERNEL);
90 return dev->private;
92 EXPORT_SYMBOL_GPL(comedi_alloc_devpriv);
94 /**
95 * comedi_alloc_subdevices() - Allocate subdevices for COMEDI device
96 * @dev: COMEDI device.
97 * @num_subdevices: Number of subdevices to allocate.
99 * Allocates and initializes an array of &struct comedi_subdevice for the
100 * COMEDI device. If successful, sets @dev->subdevices to point to the
101 * first one and @dev->n_subdevices to the number.
103 * Returns 0 on success, -EINVAL if @num_subdevices is < 1, or -ENOMEM if
104 * failed to allocate the memory.
106 int comedi_alloc_subdevices(struct comedi_device *dev, int num_subdevices)
108 struct comedi_subdevice *s;
109 int i;
111 if (num_subdevices < 1)
112 return -EINVAL;
114 s = kcalloc(num_subdevices, sizeof(*s), GFP_KERNEL);
115 if (!s)
116 return -ENOMEM;
117 dev->subdevices = s;
118 dev->n_subdevices = num_subdevices;
120 for (i = 0; i < num_subdevices; ++i) {
121 s = &dev->subdevices[i];
122 s->device = dev;
123 s->index = i;
124 s->async_dma_dir = DMA_NONE;
125 spin_lock_init(&s->spin_lock);
126 s->minor = -1;
128 return 0;
130 EXPORT_SYMBOL_GPL(comedi_alloc_subdevices);
133 * comedi_alloc_subdev_readback() - Allocate memory for the subdevice readback
134 * @s: COMEDI subdevice.
136 * This is called by low-level COMEDI drivers to allocate an array to record
137 * the last values written to a subdevice's analog output channels (at least
138 * by the %INSN_WRITE instruction), to allow them to be read back by an
139 * %INSN_READ instruction. It also provides a default handler for the
140 * %INSN_READ instruction unless one has already been set.
142 * On success, @s->readback points to the first element of the array, which
143 * is zero-filled. The low-level driver is responsible for updating its
144 * contents. @s->insn_read will be set to comedi_readback_insn_read()
145 * unless it is already non-NULL.
147 * Returns 0 on success, -EINVAL if the subdevice has no channels, or
148 * -ENOMEM on allocation failure.
150 int comedi_alloc_subdev_readback(struct comedi_subdevice *s)
152 if (!s->n_chan)
153 return -EINVAL;
155 s->readback = kcalloc(s->n_chan, sizeof(*s->readback), GFP_KERNEL);
156 if (!s->readback)
157 return -ENOMEM;
159 if (!s->insn_read)
160 s->insn_read = comedi_readback_insn_read;
162 return 0;
164 EXPORT_SYMBOL_GPL(comedi_alloc_subdev_readback);
166 static void comedi_device_detach_cleanup(struct comedi_device *dev)
168 int i;
169 struct comedi_subdevice *s;
171 if (dev->subdevices) {
172 for (i = 0; i < dev->n_subdevices; i++) {
173 s = &dev->subdevices[i];
174 if (comedi_can_auto_free_spriv(s))
175 kfree(s->private);
176 comedi_free_subdevice_minor(s);
177 if (s->async) {
178 comedi_buf_alloc(dev, s, 0);
179 kfree(s->async);
181 kfree(s->readback);
183 kfree(dev->subdevices);
184 dev->subdevices = NULL;
185 dev->n_subdevices = 0;
187 kfree(dev->private);
188 kfree(dev->pacer);
189 dev->private = NULL;
190 dev->pacer = NULL;
191 dev->driver = NULL;
192 dev->board_name = NULL;
193 dev->board_ptr = NULL;
194 dev->mmio = NULL;
195 dev->iobase = 0;
196 dev->iolen = 0;
197 dev->ioenabled = false;
198 dev->irq = 0;
199 dev->read_subdev = NULL;
200 dev->write_subdev = NULL;
201 dev->open = NULL;
202 dev->close = NULL;
203 comedi_clear_hw_dev(dev);
206 void comedi_device_detach(struct comedi_device *dev)
208 comedi_device_cancel_all(dev);
209 down_write(&dev->attach_lock);
210 dev->attached = false;
211 dev->detach_count++;
212 if (dev->driver)
213 dev->driver->detach(dev);
214 comedi_device_detach_cleanup(dev);
215 up_write(&dev->attach_lock);
218 static int poll_invalid(struct comedi_device *dev, struct comedi_subdevice *s)
220 return -EINVAL;
223 int insn_inval(struct comedi_device *dev, struct comedi_subdevice *s,
224 struct comedi_insn *insn, unsigned int *data)
226 return -EINVAL;
230 * comedi_readback_insn_read() - A generic (*insn_read) for subdevice readback.
231 * @dev: COMEDI device.
232 * @s: COMEDI subdevice.
233 * @insn: COMEDI instruction.
234 * @data: Pointer to return the readback data.
236 * Handles the %INSN_READ instruction for subdevices that use the readback
237 * array allocated by comedi_alloc_subdev_readback(). It may be used
238 * directly as the subdevice's handler (@s->insn_read) or called via a
239 * wrapper.
241 * @insn->n is normally 1, which will read a single value. If higher, the
242 * same element of the readback array will be read multiple times.
244 * Returns @insn->n on success, or -EINVAL if @s->readback is NULL.
246 int comedi_readback_insn_read(struct comedi_device *dev,
247 struct comedi_subdevice *s,
248 struct comedi_insn *insn,
249 unsigned int *data)
251 unsigned int chan = CR_CHAN(insn->chanspec);
252 int i;
254 if (!s->readback)
255 return -EINVAL;
257 for (i = 0; i < insn->n; i++)
258 data[i] = s->readback[chan];
260 return insn->n;
262 EXPORT_SYMBOL_GPL(comedi_readback_insn_read);
265 * comedi_timeout() - Busy-wait for a driver condition to occur
266 * @dev: COMEDI device.
267 * @s: COMEDI subdevice.
268 * @insn: COMEDI instruction.
269 * @cb: Callback to check for the condition.
270 * @context: Private context from the driver.
272 * Busy-waits for up to a second (%COMEDI_TIMEOUT_MS) for the condition or
273 * some error (other than -EBUSY) to occur. The parameters @dev, @s, @insn,
274 * and @context are passed to the callback function, which returns -EBUSY to
275 * continue waiting or some other value to stop waiting (generally 0 if the
276 * condition occurred, or some error value).
278 * Returns -ETIMEDOUT if timed out, otherwise the return value from the
279 * callback function.
281 int comedi_timeout(struct comedi_device *dev,
282 struct comedi_subdevice *s,
283 struct comedi_insn *insn,
284 int (*cb)(struct comedi_device *dev,
285 struct comedi_subdevice *s,
286 struct comedi_insn *insn,
287 unsigned long context),
288 unsigned long context)
290 unsigned long timeout = jiffies + msecs_to_jiffies(COMEDI_TIMEOUT_MS);
291 int ret;
293 while (time_before(jiffies, timeout)) {
294 ret = cb(dev, s, insn, context);
295 if (ret != -EBUSY)
296 return ret; /* success (0) or non EBUSY errno */
297 cpu_relax();
299 return -ETIMEDOUT;
301 EXPORT_SYMBOL_GPL(comedi_timeout);
304 * comedi_dio_insn_config() - Boilerplate (*insn_config) for DIO subdevices
305 * @dev: COMEDI device.
306 * @s: COMEDI subdevice.
307 * @insn: COMEDI instruction.
308 * @data: Instruction parameters and return data.
309 * @mask: io_bits mask for grouped channels, or 0 for single channel.
311 * If @mask is 0, it is replaced with a single-bit mask corresponding to the
312 * channel number specified by @insn->chanspec. Otherwise, @mask
313 * corresponds to a group of channels (which should include the specified
314 * channel) that are always configured together as inputs or outputs.
316 * Partially handles the %INSN_CONFIG_DIO_INPUT, %INSN_CONFIG_DIO_OUTPUTS,
317 * and %INSN_CONFIG_DIO_QUERY instructions. The first two update
318 * @s->io_bits to record the directions of the masked channels. The last
319 * one sets @data[1] to the current direction of the group of channels
320 * (%COMEDI_INPUT) or %COMEDI_OUTPUT) as recorded in @s->io_bits.
322 * The caller is responsible for updating the DIO direction in the hardware
323 * registers if this function returns 0.
325 * Returns 0 for a %INSN_CONFIG_DIO_INPUT or %INSN_CONFIG_DIO_OUTPUT
326 * instruction, @insn->n (> 0) for a %INSN_CONFIG_DIO_QUERY instruction, or
327 * -EINVAL for some other instruction.
329 int comedi_dio_insn_config(struct comedi_device *dev,
330 struct comedi_subdevice *s,
331 struct comedi_insn *insn,
332 unsigned int *data,
333 unsigned int mask)
335 unsigned int chan_mask = 1 << CR_CHAN(insn->chanspec);
337 if (!mask)
338 mask = chan_mask;
340 switch (data[0]) {
341 case INSN_CONFIG_DIO_INPUT:
342 s->io_bits &= ~mask;
343 break;
345 case INSN_CONFIG_DIO_OUTPUT:
346 s->io_bits |= mask;
347 break;
349 case INSN_CONFIG_DIO_QUERY:
350 data[1] = (s->io_bits & mask) ? COMEDI_OUTPUT : COMEDI_INPUT;
351 return insn->n;
353 default:
354 return -EINVAL;
357 return 0;
359 EXPORT_SYMBOL_GPL(comedi_dio_insn_config);
362 * comedi_dio_update_state() - Update the internal state of DIO subdevices
363 * @s: COMEDI subdevice.
364 * @data: The channel mask and bits to update.
366 * Updates @s->state which holds the internal state of the outputs for DIO
367 * or DO subdevices (up to 32 channels). @data[0] contains a bit-mask of
368 * the channels to be updated. @data[1] contains a bit-mask of those
369 * channels to be set to '1'. The caller is responsible for updating the
370 * outputs in hardware according to @s->state. As a minimum, the channels
371 * in the returned bit-mask need to be updated.
373 * Returns @mask with non-existent channels removed.
375 unsigned int comedi_dio_update_state(struct comedi_subdevice *s,
376 unsigned int *data)
378 unsigned int chanmask = (s->n_chan < 32) ? ((1 << s->n_chan) - 1)
379 : 0xffffffff;
380 unsigned int mask = data[0] & chanmask;
381 unsigned int bits = data[1];
383 if (mask) {
384 s->state &= ~mask;
385 s->state |= (bits & mask);
388 return mask;
390 EXPORT_SYMBOL_GPL(comedi_dio_update_state);
393 * comedi_bytes_per_scan() - Get length of asynchronous command "scan" in bytes
394 * @s: COMEDI subdevice.
396 * Determines the overall scan length according to the subdevice type and the
397 * number of channels in the scan.
399 * For digital input, output or input/output subdevices, samples for
400 * multiple channels are assumed to be packed into one or more unsigned
401 * short or unsigned int values according to the subdevice's %SDF_LSAMPL
402 * flag. For other types of subdevice, samples are assumed to occupy a
403 * whole unsigned short or unsigned int according to the %SDF_LSAMPL flag.
405 * Returns the overall scan length in bytes.
407 unsigned int comedi_bytes_per_scan(struct comedi_subdevice *s)
409 struct comedi_cmd *cmd = &s->async->cmd;
410 unsigned int num_samples;
411 unsigned int bits_per_sample;
413 switch (s->type) {
414 case COMEDI_SUBD_DI:
415 case COMEDI_SUBD_DO:
416 case COMEDI_SUBD_DIO:
417 bits_per_sample = 8 * comedi_bytes_per_sample(s);
418 num_samples = DIV_ROUND_UP(cmd->scan_end_arg, bits_per_sample);
419 break;
420 default:
421 num_samples = cmd->scan_end_arg;
422 break;
424 return comedi_samples_to_bytes(s, num_samples);
426 EXPORT_SYMBOL_GPL(comedi_bytes_per_scan);
428 static unsigned int __comedi_nscans_left(struct comedi_subdevice *s,
429 unsigned int nscans)
431 struct comedi_async *async = s->async;
432 struct comedi_cmd *cmd = &async->cmd;
434 if (cmd->stop_src == TRIG_COUNT) {
435 unsigned int scans_left = 0;
437 if (async->scans_done < cmd->stop_arg)
438 scans_left = cmd->stop_arg - async->scans_done;
440 if (nscans > scans_left)
441 nscans = scans_left;
443 return nscans;
447 * comedi_nscans_left() - Return the number of scans left in the command
448 * @s: COMEDI subdevice.
449 * @nscans: The expected number of scans or 0 for all available scans.
451 * If @nscans is 0, it is set to the number of scans available in the
452 * async buffer.
454 * If the async command has a stop_src of %TRIG_COUNT, the @nscans will be
455 * checked against the number of scans remaining to complete the command.
457 * The return value will then be either the expected number of scans or the
458 * number of scans remaining to complete the command, whichever is fewer.
460 unsigned int comedi_nscans_left(struct comedi_subdevice *s,
461 unsigned int nscans)
463 if (nscans == 0) {
464 unsigned int nbytes = comedi_buf_read_n_available(s);
466 nscans = nbytes / comedi_bytes_per_scan(s);
468 return __comedi_nscans_left(s, nscans);
470 EXPORT_SYMBOL_GPL(comedi_nscans_left);
473 * comedi_nsamples_left() - Return the number of samples left in the command
474 * @s: COMEDI subdevice.
475 * @nsamples: The expected number of samples.
477 * Returns the number of samples remaining to complete the command, or the
478 * specified expected number of samples (@nsamples), whichever is fewer.
480 unsigned int comedi_nsamples_left(struct comedi_subdevice *s,
481 unsigned int nsamples)
483 struct comedi_async *async = s->async;
484 struct comedi_cmd *cmd = &async->cmd;
486 if (cmd->stop_src == TRIG_COUNT) {
487 unsigned int scans_left = __comedi_nscans_left(s, cmd->stop_arg);
488 unsigned int scan_pos =
489 comedi_bytes_to_samples(s, async->scan_progress);
490 unsigned long long samples_left = 0;
492 if (scans_left) {
493 samples_left = ((unsigned long long)scans_left *
494 cmd->scan_end_arg) - scan_pos;
497 if (samples_left < nsamples)
498 nsamples = samples_left;
500 return nsamples;
502 EXPORT_SYMBOL_GPL(comedi_nsamples_left);
505 * comedi_inc_scan_progress() - Update scan progress in asynchronous command
506 * @s: COMEDI subdevice.
507 * @num_bytes: Amount of data in bytes to increment scan progress.
509 * Increments the scan progress by the number of bytes specified by @num_bytes.
510 * If the scan progress reaches or exceeds the scan length in bytes, reduce
511 * it modulo the scan length in bytes and set the "end of scan" asynchronous
512 * event flag (%COMEDI_CB_EOS) to be processed later.
514 void comedi_inc_scan_progress(struct comedi_subdevice *s,
515 unsigned int num_bytes)
517 struct comedi_async *async = s->async;
518 struct comedi_cmd *cmd = &async->cmd;
519 unsigned int scan_length = comedi_bytes_per_scan(s);
521 /* track the 'cur_chan' for non-SDF_PACKED subdevices */
522 if (!(s->subdev_flags & SDF_PACKED)) {
523 async->cur_chan += comedi_bytes_to_samples(s, num_bytes);
524 async->cur_chan %= cmd->chanlist_len;
527 async->scan_progress += num_bytes;
528 if (async->scan_progress >= scan_length) {
529 unsigned int nscans = async->scan_progress / scan_length;
531 if (async->scans_done < (UINT_MAX - nscans))
532 async->scans_done += nscans;
533 else
534 async->scans_done = UINT_MAX;
536 async->scan_progress %= scan_length;
537 async->events |= COMEDI_CB_EOS;
540 EXPORT_SYMBOL_GPL(comedi_inc_scan_progress);
543 * comedi_handle_events() - Handle events and possibly stop acquisition
544 * @dev: COMEDI device.
545 * @s: COMEDI subdevice.
547 * Handles outstanding asynchronous acquisition event flags associated
548 * with the subdevice. Call the subdevice's @s->cancel() handler if the
549 * "end of acquisition", "error" or "overflow" event flags are set in order
550 * to stop the acquisition at the driver level.
552 * Calls comedi_event() to further process the event flags, which may mark
553 * the asynchronous command as no longer running, possibly terminated with
554 * an error, and may wake up tasks.
556 * Return a bit-mask of the handled events.
558 unsigned int comedi_handle_events(struct comedi_device *dev,
559 struct comedi_subdevice *s)
561 unsigned int events = s->async->events;
563 if (events == 0)
564 return events;
566 if (events & COMEDI_CB_CANCEL_MASK)
567 s->cancel(dev, s);
569 comedi_event(dev, s);
571 return events;
573 EXPORT_SYMBOL_GPL(comedi_handle_events);
575 static int insn_rw_emulate_bits(struct comedi_device *dev,
576 struct comedi_subdevice *s,
577 struct comedi_insn *insn, unsigned int *data)
579 struct comedi_insn new_insn;
580 int ret;
581 static const unsigned channels_per_bitfield = 32;
583 unsigned chan = CR_CHAN(insn->chanspec);
584 const unsigned base_bitfield_channel =
585 (chan < channels_per_bitfield) ? 0 : chan;
586 unsigned int new_data[2];
588 memset(new_data, 0, sizeof(new_data));
589 memset(&new_insn, 0, sizeof(new_insn));
590 new_insn.insn = INSN_BITS;
591 new_insn.chanspec = base_bitfield_channel;
592 new_insn.n = 2;
593 new_insn.subdev = insn->subdev;
595 if (insn->insn == INSN_WRITE) {
596 if (!(s->subdev_flags & SDF_WRITABLE))
597 return -EINVAL;
598 new_data[0] = 1 << (chan - base_bitfield_channel); /* mask */
599 new_data[1] = data[0] ? (1 << (chan - base_bitfield_channel))
600 : 0; /* bits */
603 ret = s->insn_bits(dev, s, &new_insn, new_data);
604 if (ret < 0)
605 return ret;
607 if (insn->insn == INSN_READ)
608 data[0] = (new_data[1] >> (chan - base_bitfield_channel)) & 1;
610 return 1;
613 static int __comedi_device_postconfig_async(struct comedi_device *dev,
614 struct comedi_subdevice *s)
616 struct comedi_async *async;
617 unsigned int buf_size;
618 int ret;
620 if ((s->subdev_flags & (SDF_CMD_READ | SDF_CMD_WRITE)) == 0) {
621 dev_warn(dev->class_dev,
622 "async subdevices must support SDF_CMD_READ or SDF_CMD_WRITE\n");
623 return -EINVAL;
625 if (!s->do_cmdtest) {
626 dev_warn(dev->class_dev,
627 "async subdevices must have a do_cmdtest() function\n");
628 return -EINVAL;
631 async = kzalloc(sizeof(*async), GFP_KERNEL);
632 if (!async)
633 return -ENOMEM;
635 init_waitqueue_head(&async->wait_head);
636 s->async = async;
638 async->max_bufsize = comedi_default_buf_maxsize_kb * 1024;
639 buf_size = comedi_default_buf_size_kb * 1024;
640 if (buf_size > async->max_bufsize)
641 buf_size = async->max_bufsize;
643 if (comedi_buf_alloc(dev, s, buf_size) < 0) {
644 dev_warn(dev->class_dev, "Buffer allocation failed\n");
645 return -ENOMEM;
647 if (s->buf_change) {
648 ret = s->buf_change(dev, s);
649 if (ret < 0)
650 return ret;
653 comedi_alloc_subdevice_minor(s);
655 return 0;
658 static int __comedi_device_postconfig(struct comedi_device *dev)
660 struct comedi_subdevice *s;
661 int ret;
662 int i;
664 for (i = 0; i < dev->n_subdevices; i++) {
665 s = &dev->subdevices[i];
667 if (s->type == COMEDI_SUBD_UNUSED)
668 continue;
670 if (s->type == COMEDI_SUBD_DO) {
671 if (s->n_chan < 32)
672 s->io_bits = (1 << s->n_chan) - 1;
673 else
674 s->io_bits = 0xffffffff;
677 if (s->len_chanlist == 0)
678 s->len_chanlist = 1;
680 if (s->do_cmd) {
681 ret = __comedi_device_postconfig_async(dev, s);
682 if (ret)
683 return ret;
686 if (!s->range_table && !s->range_table_list)
687 s->range_table = &range_unknown;
689 if (!s->insn_read && s->insn_bits)
690 s->insn_read = insn_rw_emulate_bits;
691 if (!s->insn_write && s->insn_bits)
692 s->insn_write = insn_rw_emulate_bits;
694 if (!s->insn_read)
695 s->insn_read = insn_inval;
696 if (!s->insn_write)
697 s->insn_write = insn_inval;
698 if (!s->insn_bits)
699 s->insn_bits = insn_inval;
700 if (!s->insn_config)
701 s->insn_config = insn_inval;
703 if (!s->poll)
704 s->poll = poll_invalid;
707 return 0;
710 /* do a little post-config cleanup */
711 static int comedi_device_postconfig(struct comedi_device *dev)
713 int ret;
715 ret = __comedi_device_postconfig(dev);
716 if (ret < 0)
717 return ret;
718 down_write(&dev->attach_lock);
719 dev->attached = true;
720 up_write(&dev->attach_lock);
721 return 0;
725 * Generic recognize function for drivers that register their supported
726 * board names.
728 * 'driv->board_name' points to a 'const char *' member within the
729 * zeroth element of an array of some private board information
730 * structure, say 'struct foo_board' containing a member 'const char
731 * *board_name' that is initialized to point to a board name string that
732 * is one of the candidates matched against this function's 'name'
733 * parameter.
735 * 'driv->offset' is the size of the private board information
736 * structure, say 'sizeof(struct foo_board)', and 'driv->num_names' is
737 * the length of the array of private board information structures.
739 * If one of the board names in the array of private board information
740 * structures matches the name supplied to this function, the function
741 * returns a pointer to the pointer to the board name, otherwise it
742 * returns NULL. The return value ends up in the 'board_ptr' member of
743 * a 'struct comedi_device' that the low-level comedi driver's
744 * 'attach()' hook can convert to a point to a particular element of its
745 * array of private board information structures by subtracting the
746 * offset of the member that points to the board name. (No subtraction
747 * is required if the board name pointer is the first member of the
748 * private board information structure, which is generally the case.)
750 static void *comedi_recognize(struct comedi_driver *driv, const char *name)
752 char **name_ptr = (char **)driv->board_name;
753 int i;
755 for (i = 0; i < driv->num_names; i++) {
756 if (strcmp(*name_ptr, name) == 0)
757 return name_ptr;
758 name_ptr = (void *)name_ptr + driv->offset;
761 return NULL;
764 static void comedi_report_boards(struct comedi_driver *driv)
766 unsigned int i;
767 const char *const *name_ptr;
769 pr_info("comedi: valid board names for %s driver are:\n",
770 driv->driver_name);
772 name_ptr = driv->board_name;
773 for (i = 0; i < driv->num_names; i++) {
774 pr_info(" %s\n", *name_ptr);
775 name_ptr = (const char **)((char *)name_ptr + driv->offset);
778 if (driv->num_names == 0)
779 pr_info(" %s\n", driv->driver_name);
783 * comedi_load_firmware() - Request and load firmware for a device
784 * @dev: COMEDI device.
785 * @device: Hardware device.
786 * @name: The name of the firmware image.
787 * @cb: Callback to the upload the firmware image.
788 * @context: Private context from the driver.
790 * Sends a firmware request for the hardware device and waits for it. Calls
791 * the callback function to upload the firmware to the device, them releases
792 * the firmware.
794 * Returns 0 on success, -EINVAL if @cb is NULL, or a negative error number
795 * from the firmware request or the callback function.
797 int comedi_load_firmware(struct comedi_device *dev,
798 struct device *device,
799 const char *name,
800 int (*cb)(struct comedi_device *dev,
801 const u8 *data, size_t size,
802 unsigned long context),
803 unsigned long context)
805 const struct firmware *fw;
806 int ret;
808 if (!cb)
809 return -EINVAL;
811 ret = request_firmware(&fw, name, device);
812 if (ret == 0) {
813 ret = cb(dev, fw->data, fw->size, context);
814 release_firmware(fw);
817 return ret < 0 ? ret : 0;
819 EXPORT_SYMBOL_GPL(comedi_load_firmware);
822 * __comedi_request_region() - Request an I/O region for a legacy driver
823 * @dev: COMEDI device.
824 * @start: Base address of the I/O region.
825 * @len: Length of the I/O region.
827 * Requests the specified I/O port region which must start at a non-zero
828 * address.
830 * Returns 0 on success, -EINVAL if @start is 0, or -EIO if the request
831 * fails.
833 int __comedi_request_region(struct comedi_device *dev,
834 unsigned long start, unsigned long len)
836 if (!start) {
837 dev_warn(dev->class_dev,
838 "%s: a I/O base address must be specified\n",
839 dev->board_name);
840 return -EINVAL;
843 if (!request_region(start, len, dev->board_name)) {
844 dev_warn(dev->class_dev, "%s: I/O port conflict (%#lx,%lu)\n",
845 dev->board_name, start, len);
846 return -EIO;
849 return 0;
851 EXPORT_SYMBOL_GPL(__comedi_request_region);
854 * comedi_request_region() - Request an I/O region for a legacy driver
855 * @dev: COMEDI device.
856 * @start: Base address of the I/O region.
857 * @len: Length of the I/O region.
859 * Requests the specified I/O port region which must start at a non-zero
860 * address.
862 * On success, @dev->iobase is set to the base address of the region and
863 * @dev->iolen is set to its length.
865 * Returns 0 on success, -EINVAL if @start is 0, or -EIO if the request
866 * fails.
868 int comedi_request_region(struct comedi_device *dev,
869 unsigned long start, unsigned long len)
871 int ret;
873 ret = __comedi_request_region(dev, start, len);
874 if (ret == 0) {
875 dev->iobase = start;
876 dev->iolen = len;
879 return ret;
881 EXPORT_SYMBOL_GPL(comedi_request_region);
884 * comedi_legacy_detach() - A generic (*detach) function for legacy drivers
885 * @dev: COMEDI device.
887 * This is a simple, generic 'detach' handler for legacy COMEDI devices that
888 * just use a single I/O port region and possibly an IRQ and that don't need
889 * any special clean-up for their private device or subdevice storage. It
890 * can also be called by a driver-specific 'detach' handler.
892 * If @dev->irq is non-zero, the IRQ will be freed. If @dev->iobase and
893 * @dev->iolen are both non-zero, the I/O port region will be released.
895 void comedi_legacy_detach(struct comedi_device *dev)
897 if (dev->irq) {
898 free_irq(dev->irq, dev);
899 dev->irq = 0;
901 if (dev->iobase && dev->iolen) {
902 release_region(dev->iobase, dev->iolen);
903 dev->iobase = 0;
904 dev->iolen = 0;
907 EXPORT_SYMBOL_GPL(comedi_legacy_detach);
909 int comedi_device_attach(struct comedi_device *dev, struct comedi_devconfig *it)
911 struct comedi_driver *driv;
912 int ret;
914 if (dev->attached)
915 return -EBUSY;
917 mutex_lock(&comedi_drivers_list_lock);
918 for (driv = comedi_drivers; driv; driv = driv->next) {
919 if (!try_module_get(driv->module))
920 continue;
921 if (driv->num_names) {
922 dev->board_ptr = comedi_recognize(driv, it->board_name);
923 if (dev->board_ptr)
924 break;
925 } else if (strcmp(driv->driver_name, it->board_name) == 0) {
926 break;
928 module_put(driv->module);
930 if (!driv) {
931 /* recognize has failed if we get here */
932 /* report valid board names before returning error */
933 for (driv = comedi_drivers; driv; driv = driv->next) {
934 if (!try_module_get(driv->module))
935 continue;
936 comedi_report_boards(driv);
937 module_put(driv->module);
939 ret = -EIO;
940 goto out;
942 if (!driv->attach) {
943 /* driver does not support manual configuration */
944 dev_warn(dev->class_dev,
945 "driver '%s' does not support attach using comedi_config\n",
946 driv->driver_name);
947 module_put(driv->module);
948 ret = -EIO;
949 goto out;
951 dev->driver = driv;
952 dev->board_name = dev->board_ptr ? *(const char **)dev->board_ptr
953 : dev->driver->driver_name;
954 ret = driv->attach(dev, it);
955 if (ret >= 0)
956 ret = comedi_device_postconfig(dev);
957 if (ret < 0) {
958 comedi_device_detach(dev);
959 module_put(driv->module);
961 /* On success, the driver module count has been incremented. */
962 out:
963 mutex_unlock(&comedi_drivers_list_lock);
964 return ret;
968 * comedi_auto_config() - Create a COMEDI device for a hardware device
969 * @hardware_device: Hardware device.
970 * @driver: COMEDI low-level driver for the hardware device.
971 * @context: Driver context for the auto_attach handler.
973 * Allocates a new COMEDI device for the hardware device and calls the
974 * low-level driver's 'auto_attach' handler to set-up the hardware and
975 * allocate the COMEDI subdevices. Additional "post-configuration" setting
976 * up is performed on successful return from the 'auto_attach' handler.
977 * If the 'auto_attach' handler fails, the low-level driver's 'detach'
978 * handler will be called as part of the clean-up.
980 * This is usually called from a wrapper function in a bus-specific COMEDI
981 * module, which in turn is usually called from a bus device 'probe'
982 * function in the low-level driver.
984 * Returns 0 on success, -EINVAL if the parameters are invalid or the
985 * post-configuration determines the driver has set the COMEDI device up
986 * incorrectly, -ENOMEM if failed to allocate memory, -EBUSY if run out of
987 * COMEDI minor device numbers, or some negative error number returned by
988 * the driver's 'auto_attach' handler.
990 int comedi_auto_config(struct device *hardware_device,
991 struct comedi_driver *driver, unsigned long context)
993 struct comedi_device *dev;
994 int ret;
996 if (!hardware_device) {
997 pr_warn("BUG! comedi_auto_config called with NULL hardware_device\n");
998 return -EINVAL;
1000 if (!driver) {
1001 dev_warn(hardware_device,
1002 "BUG! comedi_auto_config called with NULL comedi driver\n");
1003 return -EINVAL;
1006 if (!driver->auto_attach) {
1007 dev_warn(hardware_device,
1008 "BUG! comedi driver '%s' has no auto_attach handler\n",
1009 driver->driver_name);
1010 return -EINVAL;
1013 dev = comedi_alloc_board_minor(hardware_device);
1014 if (IS_ERR(dev)) {
1015 dev_warn(hardware_device,
1016 "driver '%s' could not create device.\n",
1017 driver->driver_name);
1018 return PTR_ERR(dev);
1020 /* Note: comedi_alloc_board_minor() locked dev->mutex. */
1022 dev->driver = driver;
1023 dev->board_name = dev->driver->driver_name;
1024 ret = driver->auto_attach(dev, context);
1025 if (ret >= 0)
1026 ret = comedi_device_postconfig(dev);
1027 mutex_unlock(&dev->mutex);
1029 if (ret < 0) {
1030 dev_warn(hardware_device,
1031 "driver '%s' failed to auto-configure device.\n",
1032 driver->driver_name);
1033 comedi_release_hardware_device(hardware_device);
1034 } else {
1036 * class_dev should be set properly here
1037 * after a successful auto config
1039 dev_info(dev->class_dev,
1040 "driver '%s' has successfully auto-configured '%s'.\n",
1041 driver->driver_name, dev->board_name);
1043 return ret;
1045 EXPORT_SYMBOL_GPL(comedi_auto_config);
1048 * comedi_auto_unconfig() - Unconfigure auto-allocated COMEDI device
1049 * @hardware_device: Hardware device previously passed to
1050 * comedi_auto_config().
1052 * Cleans up and eventually destroys the COMEDI device allocated by
1053 * comedi_auto_config() for the same hardware device. As part of this
1054 * clean-up, the low-level COMEDI driver's 'detach' handler will be called.
1055 * (The COMEDI device itself will persist in an unattached state if it is
1056 * still open, until it is released, and any mmapped buffers will persist
1057 * until they are munmapped.)
1059 * This is usually called from a wrapper module in a bus-specific COMEDI
1060 * module, which in turn is usually set as the bus device 'remove' function
1061 * in the low-level COMEDI driver.
1063 void comedi_auto_unconfig(struct device *hardware_device)
1065 if (!hardware_device)
1066 return;
1067 comedi_release_hardware_device(hardware_device);
1069 EXPORT_SYMBOL_GPL(comedi_auto_unconfig);
1072 * comedi_driver_register() - Register a low-level COMEDI driver
1073 * @driver: Low-level COMEDI driver.
1075 * The low-level COMEDI driver is added to the list of registered COMEDI
1076 * drivers. This is used by the handler for the "/proc/comedi" file and is
1077 * also used by the handler for the %COMEDI_DEVCONFIG ioctl to configure
1078 * "legacy" COMEDI devices (for those low-level drivers that support it).
1080 * Returns 0.
1082 int comedi_driver_register(struct comedi_driver *driver)
1084 mutex_lock(&comedi_drivers_list_lock);
1085 driver->next = comedi_drivers;
1086 comedi_drivers = driver;
1087 mutex_unlock(&comedi_drivers_list_lock);
1089 return 0;
1091 EXPORT_SYMBOL_GPL(comedi_driver_register);
1094 * comedi_driver_unregister() - Unregister a low-level COMEDI driver
1095 * @driver: Low-level COMEDI driver.
1097 * The low-level COMEDI driver is removed from the list of registered COMEDI
1098 * drivers. Detaches any COMEDI devices attached to the driver, which will
1099 * result in the low-level driver's 'detach' handler being called for those
1100 * devices before this function returns.
1102 void comedi_driver_unregister(struct comedi_driver *driver)
1104 struct comedi_driver *prev;
1105 int i;
1107 /* unlink the driver */
1108 mutex_lock(&comedi_drivers_list_lock);
1109 if (comedi_drivers == driver) {
1110 comedi_drivers = driver->next;
1111 } else {
1112 for (prev = comedi_drivers; prev->next; prev = prev->next) {
1113 if (prev->next == driver) {
1114 prev->next = driver->next;
1115 break;
1119 mutex_unlock(&comedi_drivers_list_lock);
1121 /* check for devices using this driver */
1122 for (i = 0; i < COMEDI_NUM_BOARD_MINORS; i++) {
1123 struct comedi_device *dev = comedi_dev_get_from_minor(i);
1125 if (!dev)
1126 continue;
1128 mutex_lock(&dev->mutex);
1129 if (dev->attached && dev->driver == driver) {
1130 if (dev->use_count)
1131 dev_warn(dev->class_dev,
1132 "BUG! detaching device with use_count=%d\n",
1133 dev->use_count);
1134 comedi_device_detach(dev);
1136 mutex_unlock(&dev->mutex);
1137 comedi_dev_put(dev);
1140 EXPORT_SYMBOL_GPL(comedi_driver_unregister);