1 // SPDX-License-Identifier: GPL-2.0+
4 * functions for manipulating drivers
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>
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>
21 #include "comedidev.h"
22 #include "comedi_internal.h"
24 struct comedi_driver *comedi_drivers;
25 /* protects access to comedi_drivers */
26 DEFINE_MUTEX(comedi_drivers_list_lock);
29 * comedi_set_hw_dev() - Set hardware device associated with COMEDI device
30 * @dev: COMEDI device.
31 * @hw_dev: Hardware device.
33 * For automatically configured COMEDI devices (resulting from a call to
34 * comedi_auto_config() or one of its wrappers from the low-level COMEDI
35 * driver), comedi_set_hw_dev() is called automatically by the COMEDI core
36 * to associate the COMEDI device with the hardware device. It can also be
37 * called directly by "legacy" low-level COMEDI drivers that rely on the
38 * %COMEDI_DEVCONFIG ioctl to configure the hardware as long as the hardware
39 * has a &struct device.
41 * If @dev->hw_dev is NULL, it gets a reference to @hw_dev and sets
42 * @dev->hw_dev, otherwise, it does nothing. Calling it multiple times
43 * with the same hardware device is not considered an error. If it gets
44 * a reference to the hardware device, it will be automatically 'put' when
45 * the device is detached from COMEDI.
47 * Returns 0 if @dev->hw_dev was NULL or the same as @hw_dev, otherwise
50 int comedi_set_hw_dev(struct comedi_device *dev, struct device *hw_dev)
52 if (hw_dev == dev->hw_dev)
56 dev->hw_dev = get_device(hw_dev);
59 EXPORT_SYMBOL_GPL(comedi_set_hw_dev);
61 static void comedi_clear_hw_dev(struct comedi_device *dev)
63 put_device(dev->hw_dev);
68 * comedi_alloc_devpriv() - Allocate memory for the device private data
69 * @dev: COMEDI device.
70 * @size: Size of the memory to allocate.
72 * The allocated memory is zero-filled. @dev->private points to it on
73 * return. The memory will be automatically freed when the COMEDI device is
76 * Returns a pointer to the allocated memory, or NULL on failure.
78 void *comedi_alloc_devpriv(struct comedi_device *dev, size_t size)
80 dev->private = kzalloc(size, GFP_KERNEL);
83 EXPORT_SYMBOL_GPL(comedi_alloc_devpriv);
86 * comedi_alloc_subdevices() - Allocate subdevices for COMEDI device
87 * @dev: COMEDI device.
88 * @num_subdevices: Number of subdevices to allocate.
90 * Allocates and initializes an array of &struct comedi_subdevice for the
91 * COMEDI device. If successful, sets @dev->subdevices to point to the
92 * first one and @dev->n_subdevices to the number.
94 * Returns 0 on success, -EINVAL if @num_subdevices is < 1, or -ENOMEM if
95 * failed to allocate the memory.
97 int comedi_alloc_subdevices(struct comedi_device *dev, int num_subdevices)
99 struct comedi_subdevice *s;
102 if (num_subdevices < 1)
105 s = kcalloc(num_subdevices, sizeof(*s), GFP_KERNEL);
109 dev->n_subdevices = num_subdevices;
111 for (i = 0; i < num_subdevices; ++i) {
112 s = &dev->subdevices[i];
115 s->async_dma_dir = DMA_NONE;
116 spin_lock_init(&s->spin_lock);
121 EXPORT_SYMBOL_GPL(comedi_alloc_subdevices);
124 * comedi_alloc_subdev_readback() - Allocate memory for the subdevice readback
125 * @s: COMEDI subdevice.
127 * This is called by low-level COMEDI drivers to allocate an array to record
128 * the last values written to a subdevice's analog output channels (at least
129 * by the %INSN_WRITE instruction), to allow them to be read back by an
130 * %INSN_READ instruction. It also provides a default handler for the
131 * %INSN_READ instruction unless one has already been set.
133 * On success, @s->readback points to the first element of the array, which
134 * is zero-filled. The low-level driver is responsible for updating its
135 * contents. @s->insn_read will be set to comedi_readback_insn_read()
136 * unless it is already non-NULL.
138 * Returns 0 on success, -EINVAL if the subdevice has no channels, or
139 * -ENOMEM on allocation failure.
141 int comedi_alloc_subdev_readback(struct comedi_subdevice *s)
146 s->readback = kcalloc(s->n_chan, sizeof(*s->readback), GFP_KERNEL);
151 s->insn_read = comedi_readback_insn_read;
155 EXPORT_SYMBOL_GPL(comedi_alloc_subdev_readback);
157 static void comedi_device_detach_cleanup(struct comedi_device *dev)
160 struct comedi_subdevice *s;
162 if (dev->subdevices) {
163 for (i = 0; i < dev->n_subdevices; i++) {
164 s = &dev->subdevices[i];
165 if (comedi_can_auto_free_spriv(s))
167 comedi_free_subdevice_minor(s);
169 comedi_buf_alloc(dev, s, 0);
174 kfree(dev->subdevices);
175 dev->subdevices = NULL;
176 dev->n_subdevices = 0;
183 dev->board_name = NULL;
184 dev->board_ptr = NULL;
188 dev->ioenabled = false;
190 dev->read_subdev = NULL;
191 dev->write_subdev = NULL;
194 comedi_clear_hw_dev(dev);
197 void comedi_device_detach(struct comedi_device *dev)
199 comedi_device_cancel_all(dev);
200 down_write(&dev->attach_lock);
201 dev->attached = false;
204 dev->driver->detach(dev);
205 comedi_device_detach_cleanup(dev);
206 up_write(&dev->attach_lock);
209 static int poll_invalid(struct comedi_device *dev, struct comedi_subdevice *s)
214 int insn_inval(struct comedi_device *dev, struct comedi_subdevice *s,
215 struct comedi_insn *insn, unsigned int *data)
221 * comedi_readback_insn_read() - A generic (*insn_read) for subdevice readback.
222 * @dev: COMEDI device.
223 * @s: COMEDI subdevice.
224 * @insn: COMEDI instruction.
225 * @data: Pointer to return the readback data.
227 * Handles the %INSN_READ instruction for subdevices that use the readback
228 * array allocated by comedi_alloc_subdev_readback(). It may be used
229 * directly as the subdevice's handler (@s->insn_read) or called via a
232 * @insn->n is normally 1, which will read a single value. If higher, the
233 * same element of the readback array will be read multiple times.
235 * Returns @insn->n on success, or -EINVAL if @s->readback is NULL.
237 int comedi_readback_insn_read(struct comedi_device *dev,
238 struct comedi_subdevice *s,
239 struct comedi_insn *insn,
242 unsigned int chan = CR_CHAN(insn->chanspec);
248 for (i = 0; i < insn->n; i++)
249 data[i] = s->readback[chan];
253 EXPORT_SYMBOL_GPL(comedi_readback_insn_read);
256 * comedi_timeout() - Busy-wait for a driver condition to occur
257 * @dev: COMEDI device.
258 * @s: COMEDI subdevice.
259 * @insn: COMEDI instruction.
260 * @cb: Callback to check for the condition.
261 * @context: Private context from the driver.
263 * Busy-waits for up to a second (%COMEDI_TIMEOUT_MS) for the condition or
264 * some error (other than -EBUSY) to occur. The parameters @dev, @s, @insn,
265 * and @context are passed to the callback function, which returns -EBUSY to
266 * continue waiting or some other value to stop waiting (generally 0 if the
267 * condition occurred, or some error value).
269 * Returns -ETIMEDOUT if timed out, otherwise the return value from the
272 int comedi_timeout(struct comedi_device *dev,
273 struct comedi_subdevice *s,
274 struct comedi_insn *insn,
275 int (*cb)(struct comedi_device *dev,
276 struct comedi_subdevice *s,
277 struct comedi_insn *insn,
278 unsigned long context),
279 unsigned long context)
281 unsigned long timeout = jiffies + msecs_to_jiffies(COMEDI_TIMEOUT_MS);
284 while (time_before(jiffies, timeout)) {
285 ret = cb(dev, s, insn, context);
287 return ret; /* success (0) or non EBUSY errno */
292 EXPORT_SYMBOL_GPL(comedi_timeout);
295 * comedi_dio_insn_config() - Boilerplate (*insn_config) for DIO subdevices
296 * @dev: COMEDI device.
297 * @s: COMEDI subdevice.
298 * @insn: COMEDI instruction.
299 * @data: Instruction parameters and return data.
300 * @mask: io_bits mask for grouped channels, or 0 for single channel.
302 * If @mask is 0, it is replaced with a single-bit mask corresponding to the
303 * channel number specified by @insn->chanspec. Otherwise, @mask
304 * corresponds to a group of channels (which should include the specified
305 * channel) that are always configured together as inputs or outputs.
307 * Partially handles the %INSN_CONFIG_DIO_INPUT, %INSN_CONFIG_DIO_OUTPUTS,
308 * and %INSN_CONFIG_DIO_QUERY instructions. The first two update
309 * @s->io_bits to record the directions of the masked channels. The last
310 * one sets @data[1] to the current direction of the group of channels
311 * (%COMEDI_INPUT) or %COMEDI_OUTPUT) as recorded in @s->io_bits.
313 * The caller is responsible for updating the DIO direction in the hardware
314 * registers if this function returns 0.
316 * Returns 0 for a %INSN_CONFIG_DIO_INPUT or %INSN_CONFIG_DIO_OUTPUT
317 * instruction, @insn->n (> 0) for a %INSN_CONFIG_DIO_QUERY instruction, or
318 * -EINVAL for some other instruction.
320 int comedi_dio_insn_config(struct comedi_device *dev,
321 struct comedi_subdevice *s,
322 struct comedi_insn *insn,
326 unsigned int chan_mask = 1 << CR_CHAN(insn->chanspec);
332 case INSN_CONFIG_DIO_INPUT:
336 case INSN_CONFIG_DIO_OUTPUT:
340 case INSN_CONFIG_DIO_QUERY:
341 data[1] = (s->io_bits & mask) ? COMEDI_OUTPUT : COMEDI_INPUT;
350 EXPORT_SYMBOL_GPL(comedi_dio_insn_config);
353 * comedi_dio_update_state() - Update the internal state of DIO subdevices
354 * @s: COMEDI subdevice.
355 * @data: The channel mask and bits to update.
357 * Updates @s->state which holds the internal state of the outputs for DIO
358 * or DO subdevices (up to 32 channels). @data[0] contains a bit-mask of
359 * the channels to be updated. @data[1] contains a bit-mask of those
360 * channels to be set to '1'. The caller is responsible for updating the
361 * outputs in hardware according to @s->state. As a minimum, the channels
362 * in the returned bit-mask need to be updated.
364 * Returns @mask with non-existent channels removed.
366 unsigned int comedi_dio_update_state(struct comedi_subdevice *s,
369 unsigned int chanmask = (s->n_chan < 32) ? ((1 << s->n_chan) - 1)
371 unsigned int mask = data[0] & chanmask;
372 unsigned int bits = data[1];
376 s->state |= (bits & mask);
381 EXPORT_SYMBOL_GPL(comedi_dio_update_state);
384 * comedi_bytes_per_scan_cmd() - Get length of asynchronous command "scan" in
386 * @s: COMEDI subdevice.
387 * @cmd: COMEDI command.
389 * Determines the overall scan length according to the subdevice type and the
390 * number of channels in the scan for the specified command.
392 * For digital input, output or input/output subdevices, samples for
393 * multiple channels are assumed to be packed into one or more unsigned
394 * short or unsigned int values according to the subdevice's %SDF_LSAMPL
395 * flag. For other types of subdevice, samples are assumed to occupy a
396 * whole unsigned short or unsigned int according to the %SDF_LSAMPL flag.
398 * Returns the overall scan length in bytes.
400 unsigned int comedi_bytes_per_scan_cmd(struct comedi_subdevice *s,
401 struct comedi_cmd *cmd)
403 unsigned int num_samples;
404 unsigned int bits_per_sample;
409 case COMEDI_SUBD_DIO:
410 bits_per_sample = 8 * comedi_bytes_per_sample(s);
411 num_samples = DIV_ROUND_UP(cmd->scan_end_arg, bits_per_sample);
414 num_samples = cmd->scan_end_arg;
417 return comedi_samples_to_bytes(s, num_samples);
419 EXPORT_SYMBOL_GPL(comedi_bytes_per_scan_cmd);
422 * comedi_bytes_per_scan() - Get length of asynchronous command "scan" in bytes
423 * @s: COMEDI subdevice.
425 * Determines the overall scan length according to the subdevice type and the
426 * number of channels in the scan for the current command.
428 * For digital input, output or input/output subdevices, samples for
429 * multiple channels are assumed to be packed into one or more unsigned
430 * short or unsigned int values according to the subdevice's %SDF_LSAMPL
431 * flag. For other types of subdevice, samples are assumed to occupy a
432 * whole unsigned short or unsigned int according to the %SDF_LSAMPL flag.
434 * Returns the overall scan length in bytes.
436 unsigned int comedi_bytes_per_scan(struct comedi_subdevice *s)
438 struct comedi_cmd *cmd = &s->async->cmd;
440 return comedi_bytes_per_scan_cmd(s, cmd);
442 EXPORT_SYMBOL_GPL(comedi_bytes_per_scan);
444 static unsigned int __comedi_nscans_left(struct comedi_subdevice *s,
447 struct comedi_async *async = s->async;
448 struct comedi_cmd *cmd = &async->cmd;
450 if (cmd->stop_src == TRIG_COUNT) {
451 unsigned int scans_left = 0;
453 if (async->scans_done < cmd->stop_arg)
454 scans_left = cmd->stop_arg - async->scans_done;
456 if (nscans > scans_left)
463 * comedi_nscans_left() - Return the number of scans left in the command
464 * @s: COMEDI subdevice.
465 * @nscans: The expected number of scans or 0 for all available scans.
467 * If @nscans is 0, it is set to the number of scans available in the
470 * If the async command has a stop_src of %TRIG_COUNT, the @nscans will be
471 * checked against the number of scans remaining to complete the command.
473 * The return value will then be either the expected number of scans or the
474 * number of scans remaining to complete the command, whichever is fewer.
476 unsigned int comedi_nscans_left(struct comedi_subdevice *s,
480 unsigned int nbytes = comedi_buf_read_n_available(s);
482 nscans = nbytes / comedi_bytes_per_scan(s);
484 return __comedi_nscans_left(s, nscans);
486 EXPORT_SYMBOL_GPL(comedi_nscans_left);
489 * comedi_nsamples_left() - Return the number of samples left in the command
490 * @s: COMEDI subdevice.
491 * @nsamples: The expected number of samples.
493 * Returns the number of samples remaining to complete the command, or the
494 * specified expected number of samples (@nsamples), whichever is fewer.
496 unsigned int comedi_nsamples_left(struct comedi_subdevice *s,
497 unsigned int nsamples)
499 struct comedi_async *async = s->async;
500 struct comedi_cmd *cmd = &async->cmd;
501 unsigned long long scans_left;
502 unsigned long long samples_left;
504 if (cmd->stop_src != TRIG_COUNT)
507 scans_left = __comedi_nscans_left(s, cmd->stop_arg);
511 samples_left = scans_left * cmd->scan_end_arg -
512 comedi_bytes_to_samples(s, async->scan_progress);
514 if (samples_left < nsamples)
518 EXPORT_SYMBOL_GPL(comedi_nsamples_left);
521 * comedi_inc_scan_progress() - Update scan progress in asynchronous command
522 * @s: COMEDI subdevice.
523 * @num_bytes: Amount of data in bytes to increment scan progress.
525 * Increments the scan progress by the number of bytes specified by @num_bytes.
526 * If the scan progress reaches or exceeds the scan length in bytes, reduce
527 * it modulo the scan length in bytes and set the "end of scan" asynchronous
528 * event flag (%COMEDI_CB_EOS) to be processed later.
530 void comedi_inc_scan_progress(struct comedi_subdevice *s,
531 unsigned int num_bytes)
533 struct comedi_async *async = s->async;
534 struct comedi_cmd *cmd = &async->cmd;
535 unsigned int scan_length = comedi_bytes_per_scan(s);
537 /* track the 'cur_chan' for non-SDF_PACKED subdevices */
538 if (!(s->subdev_flags & SDF_PACKED)) {
539 async->cur_chan += comedi_bytes_to_samples(s, num_bytes);
540 async->cur_chan %= cmd->chanlist_len;
543 async->scan_progress += num_bytes;
544 if (async->scan_progress >= scan_length) {
545 unsigned int nscans = async->scan_progress / scan_length;
547 if (async->scans_done < (UINT_MAX - nscans))
548 async->scans_done += nscans;
550 async->scans_done = UINT_MAX;
552 async->scan_progress %= scan_length;
553 async->events |= COMEDI_CB_EOS;
556 EXPORT_SYMBOL_GPL(comedi_inc_scan_progress);
559 * comedi_handle_events() - Handle events and possibly stop acquisition
560 * @dev: COMEDI device.
561 * @s: COMEDI subdevice.
563 * Handles outstanding asynchronous acquisition event flags associated
564 * with the subdevice. Call the subdevice's @s->cancel() handler if the
565 * "end of acquisition", "error" or "overflow" event flags are set in order
566 * to stop the acquisition at the driver level.
568 * Calls comedi_event() to further process the event flags, which may mark
569 * the asynchronous command as no longer running, possibly terminated with
570 * an error, and may wake up tasks.
572 * Return a bit-mask of the handled events.
574 unsigned int comedi_handle_events(struct comedi_device *dev,
575 struct comedi_subdevice *s)
577 unsigned int events = s->async->events;
582 if ((events & COMEDI_CB_CANCEL_MASK) && s->cancel)
585 comedi_event(dev, s);
589 EXPORT_SYMBOL_GPL(comedi_handle_events);
591 static int insn_rw_emulate_bits(struct comedi_device *dev,
592 struct comedi_subdevice *s,
593 struct comedi_insn *insn,
596 struct comedi_insn _insn;
597 unsigned int chan = CR_CHAN(insn->chanspec);
598 unsigned int base_chan = (chan < 32) ? 0 : chan;
599 unsigned int _data[2];
602 memset(_data, 0, sizeof(_data));
603 memset(&_insn, 0, sizeof(_insn));
604 _insn.insn = INSN_BITS;
605 _insn.chanspec = base_chan;
607 _insn.subdev = insn->subdev;
609 if (insn->insn == INSN_WRITE) {
610 if (!(s->subdev_flags & SDF_WRITABLE))
612 _data[0] = 1 << (chan - base_chan); /* mask */
613 _data[1] = data[0] ? (1 << (chan - base_chan)) : 0; /* bits */
616 ret = s->insn_bits(dev, s, &_insn, _data);
620 if (insn->insn == INSN_READ)
621 data[0] = (_data[1] >> (chan - base_chan)) & 1;
626 static int __comedi_device_postconfig_async(struct comedi_device *dev,
627 struct comedi_subdevice *s)
629 struct comedi_async *async;
630 unsigned int buf_size;
633 if ((s->subdev_flags & (SDF_CMD_READ | SDF_CMD_WRITE)) == 0) {
634 dev_warn(dev->class_dev,
635 "async subdevices must support SDF_CMD_READ or SDF_CMD_WRITE\n");
638 if (!s->do_cmdtest) {
639 dev_warn(dev->class_dev,
640 "async subdevices must have a do_cmdtest() function\n");
644 dev_warn(dev->class_dev,
645 "async subdevices should have a cancel() function\n");
647 async = kzalloc(sizeof(*async), GFP_KERNEL);
651 init_waitqueue_head(&async->wait_head);
654 async->max_bufsize = comedi_default_buf_maxsize_kb * 1024;
655 buf_size = comedi_default_buf_size_kb * 1024;
656 if (buf_size > async->max_bufsize)
657 buf_size = async->max_bufsize;
659 if (comedi_buf_alloc(dev, s, buf_size) < 0) {
660 dev_warn(dev->class_dev, "Buffer allocation failed\n");
664 ret = s->buf_change(dev, s);
669 comedi_alloc_subdevice_minor(s);
674 static int __comedi_device_postconfig(struct comedi_device *dev)
676 struct comedi_subdevice *s;
680 for (i = 0; i < dev->n_subdevices; i++) {
681 s = &dev->subdevices[i];
683 if (s->type == COMEDI_SUBD_UNUSED)
686 if (s->type == COMEDI_SUBD_DO) {
688 s->io_bits = (1 << s->n_chan) - 1;
690 s->io_bits = 0xffffffff;
693 if (s->len_chanlist == 0)
697 ret = __comedi_device_postconfig_async(dev, s);
702 if (!s->range_table && !s->range_table_list)
703 s->range_table = &range_unknown;
705 if (!s->insn_read && s->insn_bits)
706 s->insn_read = insn_rw_emulate_bits;
707 if (!s->insn_write && s->insn_bits)
708 s->insn_write = insn_rw_emulate_bits;
711 s->insn_read = insn_inval;
713 s->insn_write = insn_inval;
715 s->insn_bits = insn_inval;
717 s->insn_config = insn_inval;
720 s->poll = poll_invalid;
726 /* do a little post-config cleanup */
727 static int comedi_device_postconfig(struct comedi_device *dev)
731 ret = __comedi_device_postconfig(dev);
734 down_write(&dev->attach_lock);
735 dev->attached = true;
736 up_write(&dev->attach_lock);
741 * Generic recognize function for drivers that register their supported
744 * 'driv->board_name' points to a 'const char *' member within the
745 * zeroth element of an array of some private board information
746 * structure, say 'struct foo_board' containing a member 'const char
747 * *board_name' that is initialized to point to a board name string that
748 * is one of the candidates matched against this function's 'name'
751 * 'driv->offset' is the size of the private board information
752 * structure, say 'sizeof(struct foo_board)', and 'driv->num_names' is
753 * the length of the array of private board information structures.
755 * If one of the board names in the array of private board information
756 * structures matches the name supplied to this function, the function
757 * returns a pointer to the pointer to the board name, otherwise it
758 * returns NULL. The return value ends up in the 'board_ptr' member of
759 * a 'struct comedi_device' that the low-level comedi driver's
760 * 'attach()' hook can convert to a point to a particular element of its
761 * array of private board information structures by subtracting the
762 * offset of the member that points to the board name. (No subtraction
763 * is required if the board name pointer is the first member of the
764 * private board information structure, which is generally the case.)
766 static void *comedi_recognize(struct comedi_driver *driv, const char *name)
768 char **name_ptr = (char **)driv->board_name;
771 for (i = 0; i < driv->num_names; i++) {
772 if (strcmp(*name_ptr, name) == 0)
774 name_ptr = (void *)name_ptr + driv->offset;
780 static void comedi_report_boards(struct comedi_driver *driv)
783 const char *const *name_ptr;
785 pr_info("comedi: valid board names for %s driver are:\n",
788 name_ptr = driv->board_name;
789 for (i = 0; i < driv->num_names; i++) {
790 pr_info(" %s\n", *name_ptr);
791 name_ptr = (const char **)((char *)name_ptr + driv->offset);
794 if (driv->num_names == 0)
795 pr_info(" %s\n", driv->driver_name);
799 * comedi_load_firmware() - Request and load firmware for a device
800 * @dev: COMEDI device.
801 * @device: Hardware device.
802 * @name: The name of the firmware image.
803 * @cb: Callback to the upload the firmware image.
804 * @context: Private context from the driver.
806 * Sends a firmware request for the hardware device and waits for it. Calls
807 * the callback function to upload the firmware to the device, them releases
810 * Returns 0 on success, -EINVAL if @cb is NULL, or a negative error number
811 * from the firmware request or the callback function.
813 int comedi_load_firmware(struct comedi_device *dev,
814 struct device *device,
816 int (*cb)(struct comedi_device *dev,
817 const u8 *data, size_t size,
818 unsigned long context),
819 unsigned long context)
821 const struct firmware *fw;
827 ret = maybe_reject_firmware(&fw, name, device);
829 ret = cb(dev, fw->data, fw->size, context);
830 release_firmware(fw);
833 return ret < 0 ? ret : 0;
835 EXPORT_SYMBOL_GPL(comedi_load_firmware);
838 * __comedi_request_region() - Request an I/O region for a legacy driver
839 * @dev: COMEDI device.
840 * @start: Base address of the I/O region.
841 * @len: Length of the I/O region.
843 * Requests the specified I/O port region which must start at a non-zero
846 * Returns 0 on success, -EINVAL if @start is 0, or -EIO if the request
849 int __comedi_request_region(struct comedi_device *dev,
850 unsigned long start, unsigned long len)
853 dev_warn(dev->class_dev,
854 "%s: a I/O base address must be specified\n",
859 if (!request_region(start, len, dev->board_name)) {
860 dev_warn(dev->class_dev, "%s: I/O port conflict (%#lx,%lu)\n",
861 dev->board_name, start, len);
867 EXPORT_SYMBOL_GPL(__comedi_request_region);
870 * comedi_request_region() - Request an I/O region for a legacy driver
871 * @dev: COMEDI device.
872 * @start: Base address of the I/O region.
873 * @len: Length of the I/O region.
875 * Requests the specified I/O port region which must start at a non-zero
878 * On success, @dev->iobase is set to the base address of the region and
879 * @dev->iolen is set to its length.
881 * Returns 0 on success, -EINVAL if @start is 0, or -EIO if the request
884 int comedi_request_region(struct comedi_device *dev,
885 unsigned long start, unsigned long len)
889 ret = __comedi_request_region(dev, start, len);
897 EXPORT_SYMBOL_GPL(comedi_request_region);
900 * comedi_legacy_detach() - A generic (*detach) function for legacy drivers
901 * @dev: COMEDI device.
903 * This is a simple, generic 'detach' handler for legacy COMEDI devices that
904 * just use a single I/O port region and possibly an IRQ and that don't need
905 * any special clean-up for their private device or subdevice storage. It
906 * can also be called by a driver-specific 'detach' handler.
908 * If @dev->irq is non-zero, the IRQ will be freed. If @dev->iobase and
909 * @dev->iolen are both non-zero, the I/O port region will be released.
911 void comedi_legacy_detach(struct comedi_device *dev)
914 free_irq(dev->irq, dev);
917 if (dev->iobase && dev->iolen) {
918 release_region(dev->iobase, dev->iolen);
923 EXPORT_SYMBOL_GPL(comedi_legacy_detach);
925 int comedi_device_attach(struct comedi_device *dev, struct comedi_devconfig *it)
927 struct comedi_driver *driv;
933 mutex_lock(&comedi_drivers_list_lock);
934 for (driv = comedi_drivers; driv; driv = driv->next) {
935 if (!try_module_get(driv->module))
937 if (driv->num_names) {
938 dev->board_ptr = comedi_recognize(driv, it->board_name);
941 } else if (strcmp(driv->driver_name, it->board_name) == 0) {
944 module_put(driv->module);
947 /* recognize has failed if we get here */
948 /* report valid board names before returning error */
949 for (driv = comedi_drivers; driv; driv = driv->next) {
950 if (!try_module_get(driv->module))
952 comedi_report_boards(driv);
953 module_put(driv->module);
959 /* driver does not support manual configuration */
960 dev_warn(dev->class_dev,
961 "driver '%s' does not support attach using comedi_config\n",
963 module_put(driv->module);
968 dev->board_name = dev->board_ptr ? *(const char **)dev->board_ptr
969 : dev->driver->driver_name;
970 ret = driv->attach(dev, it);
972 ret = comedi_device_postconfig(dev);
974 comedi_device_detach(dev);
975 module_put(driv->module);
977 /* On success, the driver module count has been incremented. */
979 mutex_unlock(&comedi_drivers_list_lock);
984 * comedi_auto_config() - Create a COMEDI device for a hardware device
985 * @hardware_device: Hardware device.
986 * @driver: COMEDI low-level driver for the hardware device.
987 * @context: Driver context for the auto_attach handler.
989 * Allocates a new COMEDI device for the hardware device and calls the
990 * low-level driver's 'auto_attach' handler to set-up the hardware and
991 * allocate the COMEDI subdevices. Additional "post-configuration" setting
992 * up is performed on successful return from the 'auto_attach' handler.
993 * If the 'auto_attach' handler fails, the low-level driver's 'detach'
994 * handler will be called as part of the clean-up.
996 * This is usually called from a wrapper function in a bus-specific COMEDI
997 * module, which in turn is usually called from a bus device 'probe'
998 * function in the low-level driver.
1000 * Returns 0 on success, -EINVAL if the parameters are invalid or the
1001 * post-configuration determines the driver has set the COMEDI device up
1002 * incorrectly, -ENOMEM if failed to allocate memory, -EBUSY if run out of
1003 * COMEDI minor device numbers, or some negative error number returned by
1004 * the driver's 'auto_attach' handler.
1006 int comedi_auto_config(struct device *hardware_device,
1007 struct comedi_driver *driver, unsigned long context)
1009 struct comedi_device *dev;
1012 if (!hardware_device) {
1013 pr_warn("BUG! %s called with NULL hardware_device\n", __func__);
1017 dev_warn(hardware_device,
1018 "BUG! %s called with NULL comedi driver\n", __func__);
1022 if (!driver->auto_attach) {
1023 dev_warn(hardware_device,
1024 "BUG! comedi driver '%s' has no auto_attach handler\n",
1025 driver->driver_name);
1029 dev = comedi_alloc_board_minor(hardware_device);
1031 dev_warn(hardware_device,
1032 "driver '%s' could not create device.\n",
1033 driver->driver_name);
1034 return PTR_ERR(dev);
1036 /* Note: comedi_alloc_board_minor() locked dev->mutex. */
1038 dev->driver = driver;
1039 dev->board_name = dev->driver->driver_name;
1040 ret = driver->auto_attach(dev, context);
1042 ret = comedi_device_postconfig(dev);
1043 mutex_unlock(&dev->mutex);
1046 dev_warn(hardware_device,
1047 "driver '%s' failed to auto-configure device.\n",
1048 driver->driver_name);
1049 comedi_release_hardware_device(hardware_device);
1052 * class_dev should be set properly here
1053 * after a successful auto config
1055 dev_info(dev->class_dev,
1056 "driver '%s' has successfully auto-configured '%s'.\n",
1057 driver->driver_name, dev->board_name);
1061 EXPORT_SYMBOL_GPL(comedi_auto_config);
1064 * comedi_auto_unconfig() - Unconfigure auto-allocated COMEDI device
1065 * @hardware_device: Hardware device previously passed to
1066 * comedi_auto_config().
1068 * Cleans up and eventually destroys the COMEDI device allocated by
1069 * comedi_auto_config() for the same hardware device. As part of this
1070 * clean-up, the low-level COMEDI driver's 'detach' handler will be called.
1071 * (The COMEDI device itself will persist in an unattached state if it is
1072 * still open, until it is released, and any mmapped buffers will persist
1073 * until they are munmapped.)
1075 * This is usually called from a wrapper module in a bus-specific COMEDI
1076 * module, which in turn is usually set as the bus device 'remove' function
1077 * in the low-level COMEDI driver.
1079 void comedi_auto_unconfig(struct device *hardware_device)
1081 if (!hardware_device)
1083 comedi_release_hardware_device(hardware_device);
1085 EXPORT_SYMBOL_GPL(comedi_auto_unconfig);
1088 * comedi_driver_register() - Register a low-level COMEDI driver
1089 * @driver: Low-level COMEDI driver.
1091 * The low-level COMEDI driver is added to the list of registered COMEDI
1092 * drivers. This is used by the handler for the "/proc/comedi" file and is
1093 * also used by the handler for the %COMEDI_DEVCONFIG ioctl to configure
1094 * "legacy" COMEDI devices (for those low-level drivers that support it).
1098 int comedi_driver_register(struct comedi_driver *driver)
1100 mutex_lock(&comedi_drivers_list_lock);
1101 driver->next = comedi_drivers;
1102 comedi_drivers = driver;
1103 mutex_unlock(&comedi_drivers_list_lock);
1107 EXPORT_SYMBOL_GPL(comedi_driver_register);
1110 * comedi_driver_unregister() - Unregister a low-level COMEDI driver
1111 * @driver: Low-level COMEDI driver.
1113 * The low-level COMEDI driver is removed from the list of registered COMEDI
1114 * drivers. Detaches any COMEDI devices attached to the driver, which will
1115 * result in the low-level driver's 'detach' handler being called for those
1116 * devices before this function returns.
1118 void comedi_driver_unregister(struct comedi_driver *driver)
1120 struct comedi_driver *prev;
1123 /* unlink the driver */
1124 mutex_lock(&comedi_drivers_list_lock);
1125 if (comedi_drivers == driver) {
1126 comedi_drivers = driver->next;
1128 for (prev = comedi_drivers; prev->next; prev = prev->next) {
1129 if (prev->next == driver) {
1130 prev->next = driver->next;
1135 mutex_unlock(&comedi_drivers_list_lock);
1137 /* check for devices using this driver */
1138 for (i = 0; i < COMEDI_NUM_BOARD_MINORS; i++) {
1139 struct comedi_device *dev = comedi_dev_get_from_minor(i);
1144 mutex_lock(&dev->mutex);
1145 if (dev->attached && dev->driver == driver) {
1147 dev_warn(dev->class_dev,
1148 "BUG! detaching device with use_count=%d\n",
1150 comedi_device_detach(dev);
1152 mutex_unlock(&dev->mutex);
1153 comedi_dev_put(dev);
1156 EXPORT_SYMBOL_GPL(comedi_driver_unregister);