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1// SPDX-License-Identifier: GPL-2.0+2/*3 * module/drivers.c4 * functions for manipulating drivers5 *6 * COMEDI - Linux Control and Measurement Device Interface7 * 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 device29 * @dev: COMEDI device.30 * @hw_dev: Hardware device.31 *32 * For automatically configured COMEDI devices (resulting from a call to33 * comedi_auto_config() or one of its wrappers from the low-level COMEDI34 * driver), comedi_set_hw_dev() is called automatically by the COMEDI core35 * to associate the COMEDI device with the hardware device. It can also be36 * called directly by "legacy" low-level COMEDI drivers that rely on the37 * %COMEDI_DEVCONFIG ioctl to configure the hardware as long as the hardware38 * has a &struct device.39 *40 * If @dev->hw_dev is NULL, it gets a reference to @hw_dev and sets41 * @dev->hw_dev, otherwise, it does nothing. Calling it multiple times42 * with the same hardware device is not considered an error. If it gets43 * a reference to the hardware device, it will be automatically 'put' when44 * the device is detached from COMEDI.45 *46 * Returns 0 if @dev->hw_dev was NULL or the same as @hw_dev, otherwise47 * 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(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->hw_dev);63 dev->hw_dev = NULL;64}65 66/**67 * comedi_alloc_devpriv() - Allocate memory for the device private data68 * @dev: COMEDI device.69 * @size: Size of the memory to allocate.70 *71 * The allocated memory is zero-filled. @dev->private points to it on72 * return. The memory will be automatically freed when the COMEDI device is73 * "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 device86 * @dev: COMEDI device.87 * @num_subdevices: Number of subdevices to allocate.88 *89 * Allocates and initializes an array of &struct comedi_subdevice for the90 * COMEDI device. If successful, sets @dev->subdevices to point to the91 * first one and @dev->n_subdevices to the number.92 *93 * Returns 0 on success, -EINVAL if @num_subdevices is < 1, or -ENOMEM if94 * 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 readback124 * @s: COMEDI subdevice.125 *126 * This is called by low-level COMEDI drivers to allocate an array to record127 * the last values written to a subdevice's analog output channels (at least128 * by the %INSN_WRITE instruction), to allow them to be read back by an129 * %INSN_READ instruction. It also provides a default handler for the130 * %INSN_READ instruction unless one has already been set.131 *132 * On success, @s->readback points to the first element of the array, which133 * is zero-filled. The low-level driver is responsible for updating its134 * 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, or138 * -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(&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(s->private);168 comedi_free_subdevice_minor(s);169 if (s->async) {170 comedi_buf_alloc(dev, s, 0);171 kfree(s->async);172 }173 kfree(s->readback);174 }175 kfree(dev->subdevices);176 dev->subdevices = NULL;177 dev->n_subdevices = 0;178 }179 kfree(dev->private);180 if (!IS_ERR(dev->pacer))181 kfree(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(struct comedi_device *dev)200{201 lockdep_assert_held(&dev->mutex);202 comedi_device_cancel_all(dev);203 down_write(&dev->attach_lock);204 dev->attached = false;205 dev->detach_count++;206 if (dev->driver)207 dev->driver->detach(dev);208 comedi_device_detach_cleanup(dev);209 up_write(&dev->attach_lock);210}211 212static int poll_invalid(struct comedi_device *dev, struct comedi_subdevice *s)213{214 return -EINVAL;215}216 217static int insn_device_inval(struct comedi_device *dev,218 struct comedi_insn *insn, unsigned int *data)219{220 return -EINVAL;221}222 223static unsigned int get_zero_valid_routes(struct comedi_device *dev,224 unsigned int n_pairs,225 unsigned int *pair_data)226{227 return 0;228}229 230int insn_inval(struct comedi_device *dev, struct comedi_subdevice *s,231 struct comedi_insn *insn, unsigned int *data)232{233 return -EINVAL;234}235 236/**237 * comedi_readback_insn_read() - A generic (*insn_read) for subdevice readback.238 * @dev: COMEDI device.239 * @s: COMEDI subdevice.240 * @insn: COMEDI instruction.241 * @data: Pointer to return the readback data.242 *243 * Handles the %INSN_READ instruction for subdevices that use the readback244 * array allocated by comedi_alloc_subdev_readback(). It may be used245 * directly as the subdevice's handler (@s->insn_read) or called via a246 * wrapper.247 *248 * @insn->n is normally 1, which will read a single value. If higher, the249 * same element of the readback array will be read multiple times.250 *251 * Returns @insn->n on success, or -EINVAL if @s->readback is NULL.252 */253int comedi_readback_insn_read(struct comedi_device *dev,254 struct comedi_subdevice *s,255 struct comedi_insn *insn,256 unsigned int *data)257{258 unsigned int chan = CR_CHAN(insn->chanspec);259 int i;260 261 if (!s->readback)262 return -EINVAL;263 264 for (i = 0; i < insn->n; i++)265 data[i] = s->readback[chan];266 267 return insn->n;268}269EXPORT_SYMBOL_GPL(comedi_readback_insn_read);270 271/**272 * comedi_timeout() - Busy-wait for a driver condition to occur273 * @dev: COMEDI device.274 * @s: COMEDI subdevice.275 * @insn: COMEDI instruction.276 * @cb: Callback to check for the condition.277 * @context: Private context from the driver.278 *279 * Busy-waits for up to a second (%COMEDI_TIMEOUT_MS) for the condition or280 * some error (other than -EBUSY) to occur. The parameters @dev, @s, @insn,281 * and @context are passed to the callback function, which returns -EBUSY to282 * continue waiting or some other value to stop waiting (generally 0 if the283 * condition occurred, or some error value).284 *285 * Returns -ETIMEDOUT if timed out, otherwise the return value from the286 * callback function.287 */288int comedi_timeout(struct comedi_device *dev,289 struct comedi_subdevice *s,290 struct comedi_insn *insn,291 int (*cb)(struct comedi_device *dev,292 struct comedi_subdevice *s,293 struct comedi_insn *insn,294 unsigned long context),295 unsigned long context)296{297 unsigned long timeout = jiffies + msecs_to_jiffies(COMEDI_TIMEOUT_MS);298 int ret;299 300 while (time_before(jiffies, timeout)) {301 ret = cb(dev, s, insn, context);302 if (ret != -EBUSY)303 return ret; /* success (0) or non EBUSY errno */304 cpu_relax();305 }306 return -ETIMEDOUT;307}308EXPORT_SYMBOL_GPL(comedi_timeout);309 310/**311 * comedi_dio_insn_config() - Boilerplate (*insn_config) for DIO subdevices312 * @dev: COMEDI device.313 * @s: COMEDI subdevice.314 * @insn: COMEDI instruction.315 * @data: Instruction parameters and return data.316 * @mask: io_bits mask for grouped channels, or 0 for single channel.317 *318 * If @mask is 0, it is replaced with a single-bit mask corresponding to the319 * channel number specified by @insn->chanspec. Otherwise, @mask320 * corresponds to a group of channels (which should include the specified321 * channel) that are always configured together as inputs or outputs.322 *323 * Partially handles the %INSN_CONFIG_DIO_INPUT, %INSN_CONFIG_DIO_OUTPUTS,324 * and %INSN_CONFIG_DIO_QUERY instructions. The first two update325 * @s->io_bits to record the directions of the masked channels. The last326 * one sets @data[1] to the current direction of the group of channels327 * (%COMEDI_INPUT) or %COMEDI_OUTPUT) as recorded in @s->io_bits.328 *329 * The caller is responsible for updating the DIO direction in the hardware330 * registers if this function returns 0.331 *332 * Returns 0 for a %INSN_CONFIG_DIO_INPUT or %INSN_CONFIG_DIO_OUTPUT333 * instruction, @insn->n (> 0) for a %INSN_CONFIG_DIO_QUERY instruction, or334 * -EINVAL for some other instruction.335 */336int comedi_dio_insn_config(struct comedi_device *dev,337 struct comedi_subdevice *s,338 struct comedi_insn *insn,339 unsigned int *data,340 unsigned int mask)341{342 unsigned int chan_mask = 1 << CR_CHAN(insn->chanspec);343 344 if (!mask)345 mask = chan_mask;346 347 switch (data[0]) {348 case INSN_CONFIG_DIO_INPUT:349 s->io_bits &= ~mask;350 break;351 352 case INSN_CONFIG_DIO_OUTPUT:353 s->io_bits |= mask;354 break;355 356 case INSN_CONFIG_DIO_QUERY:357 data[1] = (s->io_bits & mask) ? COMEDI_OUTPUT : COMEDI_INPUT;358 return insn->n;359 360 default:361 return -EINVAL;362 }363 364 return 0;365}366EXPORT_SYMBOL_GPL(comedi_dio_insn_config);367 368/**369 * comedi_dio_update_state() - Update the internal state of DIO subdevices370 * @s: COMEDI subdevice.371 * @data: The channel mask and bits to update.372 *373 * Updates @s->state which holds the internal state of the outputs for DIO374 * or DO subdevices (up to 32 channels). @data[0] contains a bit-mask of375 * the channels to be updated. @data[1] contains a bit-mask of those376 * channels to be set to '1'. The caller is responsible for updating the377 * outputs in hardware according to @s->state. As a minimum, the channels378 * in the returned bit-mask need to be updated.379 *380 * Returns @mask with non-existent channels removed.381 */382unsigned int comedi_dio_update_state(struct comedi_subdevice *s,383 unsigned int *data)384{385 unsigned int chanmask = (s->n_chan < 32) ? ((1 << s->n_chan) - 1)386 : 0xffffffff;387 unsigned int mask = data[0] & chanmask;388 unsigned int bits = data[1];389 390 if (mask) {391 s->state &= ~mask;392 s->state |= (bits & mask);393 }394 395 return mask;396}397EXPORT_SYMBOL_GPL(comedi_dio_update_state);398 399/**400 * comedi_bytes_per_scan_cmd() - Get length of asynchronous command "scan" in401 * bytes402 * @s: COMEDI subdevice.403 * @cmd: COMEDI command.404 *405 * Determines the overall scan length according to the subdevice type and the406 * number of channels in the scan for the specified command.407 *408 * For digital input, output or input/output subdevices, samples for409 * multiple channels are assumed to be packed into one or more unsigned410 * short or unsigned int values according to the subdevice's %SDF_LSAMPL411 * flag. For other types of subdevice, samples are assumed to occupy a412 * whole unsigned short or unsigned int according to the %SDF_LSAMPL flag.413 *414 * Returns the overall scan length in bytes.415 */416unsigned int comedi_bytes_per_scan_cmd(struct comedi_subdevice *s,417 struct comedi_cmd *cmd)418{419 unsigned int num_samples;420 unsigned int bits_per_sample;421 422 switch (s->type) {423 case COMEDI_SUBD_DI:424 case COMEDI_SUBD_DO:425 case COMEDI_SUBD_DIO:426 bits_per_sample = 8 * comedi_bytes_per_sample(s);427 num_samples = DIV_ROUND_UP(cmd->scan_end_arg, bits_per_sample);428 break;429 default:430 num_samples = cmd->scan_end_arg;431 break;432 }433 return comedi_samples_to_bytes(s, num_samples);434}435EXPORT_SYMBOL_GPL(comedi_bytes_per_scan_cmd);436 437/**438 * comedi_bytes_per_scan() - Get length of asynchronous command "scan" in bytes439 * @s: COMEDI subdevice.440 *441 * Determines the overall scan length according to the subdevice type and the442 * number of channels in the scan for the current command.443 *444 * For digital input, output or input/output subdevices, samples for445 * multiple channels are assumed to be packed into one or more unsigned446 * short or unsigned int values according to the subdevice's %SDF_LSAMPL447 * flag. For other types of subdevice, samples are assumed to occupy a448 * whole unsigned short or unsigned int according to the %SDF_LSAMPL flag.449 *450 * Returns the overall scan length in bytes.451 */452unsigned int comedi_bytes_per_scan(struct comedi_subdevice *s)453{454 struct comedi_cmd *cmd = &s->async->cmd;455 456 return comedi_bytes_per_scan_cmd(s, cmd);457}458EXPORT_SYMBOL_GPL(comedi_bytes_per_scan);459 460static unsigned int __comedi_nscans_left(struct comedi_subdevice *s,461 unsigned int nscans)462{463 struct comedi_async *async = s->async;464 struct comedi_cmd *cmd = &async->cmd;465 466 if (cmd->stop_src == TRIG_COUNT) {467 unsigned int scans_left = 0;468 469 if (async->scans_done < cmd->stop_arg)470 scans_left = cmd->stop_arg - async->scans_done;471 472 if (nscans > scans_left)473 nscans = scans_left;474 }475 return nscans;476}477 478/**479 * comedi_nscans_left() - Return the number of scans left in the command480 * @s: COMEDI subdevice.481 * @nscans: The expected number of scans or 0 for all available scans.482 *483 * If @nscans is 0, it is set to the number of scans available in the484 * async buffer.485 *486 * If the async command has a stop_src of %TRIG_COUNT, the @nscans will be487 * checked against the number of scans remaining to complete the command.488 *489 * The return value will then be either the expected number of scans or the490 * number of scans remaining to complete the command, whichever is fewer.491 */492unsigned int comedi_nscans_left(struct comedi_subdevice *s,493 unsigned int nscans)494{495 if (nscans == 0) {496 unsigned int nbytes = comedi_buf_read_n_available(s);497 498 nscans = nbytes / comedi_bytes_per_scan(s);499 }500 return __comedi_nscans_left(s, nscans);501}502EXPORT_SYMBOL_GPL(comedi_nscans_left);503 504/**505 * comedi_nsamples_left() - Return the number of samples left in the command506 * @s: COMEDI subdevice.507 * @nsamples: The expected number of samples.508 *509 * Returns the number of samples remaining to complete the command, or the510 * specified expected number of samples (@nsamples), whichever is fewer.511 */512unsigned int comedi_nsamples_left(struct comedi_subdevice *s,513 unsigned int nsamples)514{515 struct comedi_async *async = s->async;516 struct comedi_cmd *cmd = &async->cmd;517 unsigned long long scans_left;518 unsigned long long samples_left;519 520 if (cmd->stop_src != TRIG_COUNT)521 return nsamples;522 523 scans_left = __comedi_nscans_left(s, cmd->stop_arg);524 if (!scans_left)525 return 0;526 527 samples_left = scans_left * cmd->scan_end_arg -528 comedi_bytes_to_samples(s, async->scan_progress);529 530 if (samples_left < nsamples)531 return samples_left;532 return nsamples;533}534EXPORT_SYMBOL_GPL(comedi_nsamples_left);535 536/**537 * comedi_inc_scan_progress() - Update scan progress in asynchronous command538 * @s: COMEDI subdevice.539 * @num_bytes: Amount of data in bytes to increment scan progress.540 *541 * Increments the scan progress by the number of bytes specified by @num_bytes.542 * If the scan progress reaches or exceeds the scan length in bytes, reduce543 * it modulo the scan length in bytes and set the "end of scan" asynchronous544 * event flag (%COMEDI_CB_EOS) to be processed later.545 */546void comedi_inc_scan_progress(struct comedi_subdevice *s,547 unsigned int num_bytes)548{549 struct comedi_async *async = s->async;550 struct comedi_cmd *cmd = &async->cmd;551 unsigned int scan_length = comedi_bytes_per_scan(s);552 553 /* track the 'cur_chan' for non-SDF_PACKED subdevices */554 if (!(s->subdev_flags & SDF_PACKED)) {555 async->cur_chan += comedi_bytes_to_samples(s, num_bytes);556 async->cur_chan %= cmd->chanlist_len;557 }558 559 async->scan_progress += num_bytes;560 if (async->scan_progress >= scan_length) {561 unsigned int nscans = async->scan_progress / scan_length;562 563 if (async->scans_done < (UINT_MAX - nscans))564 async->scans_done += nscans;565 else566 async->scans_done = UINT_MAX;567 568 async->scan_progress %= scan_length;569 async->events |= COMEDI_CB_EOS;570 }571}572EXPORT_SYMBOL_GPL(comedi_inc_scan_progress);573 574/**575 * comedi_handle_events() - Handle events and possibly stop acquisition576 * @dev: COMEDI device.577 * @s: COMEDI subdevice.578 *579 * Handles outstanding asynchronous acquisition event flags associated580 * with the subdevice. Call the subdevice's @s->cancel() handler if the581 * "end of acquisition", "error" or "overflow" event flags are set in order582 * to stop the acquisition at the driver level.583 *584 * Calls comedi_event() to further process the event flags, which may mark585 * the asynchronous command as no longer running, possibly terminated with586 * an error, and may wake up tasks.587 *588 * Return a bit-mask of the handled events.589 */590unsigned int comedi_handle_events(struct comedi_device *dev,591 struct comedi_subdevice *s)592{593 unsigned int events = s->async->events;594 595 if (events == 0)596 return events;597 598 if ((events & COMEDI_CB_CANCEL_MASK) && s->cancel)599 s->cancel(dev, s);600 601 comedi_event(dev, s);602 603 return events;604}605EXPORT_SYMBOL_GPL(comedi_handle_events);606 607static int insn_rw_emulate_bits(struct comedi_device *dev,608 struct comedi_subdevice *s,609 struct comedi_insn *insn,610 unsigned int *data)611{612 struct comedi_insn _insn;613 unsigned int chan = CR_CHAN(insn->chanspec);614 unsigned int base_chan = (chan < 32) ? 0 : chan;615 unsigned int _data[2];616 int ret;617 618 memset(_data, 0, sizeof(_data));619 memset(&_insn, 0, sizeof(_insn));620 _insn.insn = INSN_BITS;621 _insn.chanspec = base_chan;622 _insn.n = 2;623 _insn.subdev = insn->subdev;624 625 if (insn->insn == INSN_WRITE) {626 if (!(s->subdev_flags & SDF_WRITABLE))627 return -EINVAL;628 _data[0] = 1 << (chan - base_chan); /* mask */629 _data[1] = data[0] ? (1 << (chan - base_chan)) : 0; /* bits */630 }631 632 ret = s->insn_bits(dev, s, &_insn, _data);633 if (ret < 0)634 return ret;635 636 if (insn->insn == INSN_READ)637 data[0] = (_data[1] >> (chan - base_chan)) & 1;638 639 return 1;640}641 642static int __comedi_device_postconfig_async(struct comedi_device *dev,643 struct comedi_subdevice *s)644{645 struct comedi_async *async;646 unsigned int buf_size;647 int ret;648 649 lockdep_assert_held(&dev->mutex);650 if ((s->subdev_flags & (SDF_CMD_READ | SDF_CMD_WRITE)) == 0) {651 dev_warn(dev->class_dev,652 "async subdevices must support SDF_CMD_READ or SDF_CMD_WRITE\n");653 return -EINVAL;654 }655 if (!s->do_cmdtest) {656 dev_warn(dev->class_dev,657 "async subdevices must have a do_cmdtest() function\n");658 return -EINVAL;659 }660 if (!s->cancel)661 dev_warn(dev->class_dev,662 "async subdevices should have a cancel() function\n");663 664 async = kzalloc(sizeof(*async), GFP_KERNEL);665 if (!async)666 return -ENOMEM;667 668 init_waitqueue_head(&async->wait_head);669 s->async = async;670 671 async->max_bufsize = comedi_default_buf_maxsize_kb * 1024;672 buf_size = comedi_default_buf_size_kb * 1024;673 if (buf_size > async->max_bufsize)674 buf_size = async->max_bufsize;675 676 if (comedi_buf_alloc(dev, s, buf_size) < 0) {677 dev_warn(dev->class_dev, "Buffer allocation failed\n");678 return -ENOMEM;679 }680 if (s->buf_change) {681 ret = s->buf_change(dev, s);682 if (ret < 0)683 return ret;684 }685 686 comedi_alloc_subdevice_minor(s);687 688 return 0;689}690 691static int __comedi_device_postconfig(struct comedi_device *dev)692{693 struct comedi_subdevice *s;694 int ret;695 int i;696 697 lockdep_assert_held(&dev->mutex);698 if (!dev->insn_device_config)699 dev->insn_device_config = insn_device_inval;700 701 if (!dev->get_valid_routes)702 dev->get_valid_routes = get_zero_valid_routes;703 704 for (i = 0; i < dev->n_subdevices; i++) {705 s = &dev->subdevices[i];706 707 if (s->type == COMEDI_SUBD_UNUSED)708 continue;709 710 if (s->type == COMEDI_SUBD_DO) {711 if (s->n_chan < 32)712 s->io_bits = (1 << s->n_chan) - 1;713 else714 s->io_bits = 0xffffffff;715 }716 717 if (s->len_chanlist == 0)718 s->len_chanlist = 1;719 720 if (s->do_cmd) {721 ret = __comedi_device_postconfig_async(dev, s);722 if (ret)723 return ret;724 }725 726 if (!s->range_table && !s->range_table_list)727 s->range_table = &range_unknown;728 729 if (!s->insn_read && s->insn_bits)730 s->insn_read = insn_rw_emulate_bits;731 if (!s->insn_write && s->insn_bits)732 s->insn_write = insn_rw_emulate_bits;733 734 if (!s->insn_read)735 s->insn_read = insn_inval;736 if (!s->insn_write)737 s->insn_write = insn_inval;738 if (!s->insn_bits)739 s->insn_bits = insn_inval;740 if (!s->insn_config)741 s->insn_config = insn_inval;742 743 if (!s->poll)744 s->poll = poll_invalid;745 }746 747 return 0;748}749 750/* do a little post-config cleanup */751static int comedi_device_postconfig(struct comedi_device *dev)752{753 int ret;754 755 lockdep_assert_held(&dev->mutex);756 ret = __comedi_device_postconfig(dev);757 if (ret < 0)758 return ret;759 down_write(&dev->attach_lock);760 dev->attached = true;761 up_write(&dev->attach_lock);762 return 0;763}764 765/*766 * Generic recognize function for drivers that register their supported767 * board names.768 *769 * 'driv->board_name' points to a 'const char *' member within the770 * zeroth element of an array of some private board information771 * structure, say 'struct foo_board' containing a member 'const char772 * *board_name' that is initialized to point to a board name string that773 * is one of the candidates matched against this function's 'name'774 * parameter.775 *776 * 'driv->offset' is the size of the private board information777 * structure, say 'sizeof(struct foo_board)', and 'driv->num_names' is778 * the length of the array of private board information structures.779 *780 * If one of the board names in the array of private board information781 * structures matches the name supplied to this function, the function782 * returns a pointer to the pointer to the board name, otherwise it783 * returns NULL. The return value ends up in the 'board_ptr' member of784 * a 'struct comedi_device' that the low-level comedi driver's785 * 'attach()' hook can convert to a point to a particular element of its786 * array of private board information structures by subtracting the787 * offset of the member that points to the board name. (No subtraction788 * is required if the board name pointer is the first member of the789 * private board information structure, which is generally the case.)790 */791static void *comedi_recognize(struct comedi_driver *driv, const char *name)792{793 char **name_ptr = (char **)driv->board_name;794 int i;795 796 for (i = 0; i < driv->num_names; i++) {797 if (strcmp(*name_ptr, name) == 0)798 return name_ptr;799 name_ptr = (void *)name_ptr + driv->offset;800 }801 802 return NULL;803}804 805static void comedi_report_boards(struct comedi_driver *driv)806{807 unsigned int i;808 const char *const *name_ptr;809 810 pr_info("comedi: valid board names for %s driver are:\n",811 driv->driver_name);812 813 name_ptr = driv->board_name;814 for (i = 0; i < driv->num_names; i++) {815 pr_info(" %s\n", *name_ptr);816 name_ptr = (const char **)((char *)name_ptr + driv->offset);817 }818 819 if (driv->num_names == 0)820 pr_info(" %s\n", driv->driver_name);821}822 823/**824 * comedi_load_firmware() - Request and load firmware for a device825 * @dev: COMEDI device.826 * @device: Hardware device.827 * @name: The name of the firmware image.828 * @cb: Callback to the upload the firmware image.829 * @context: Private context from the driver.830 *831 * Sends a firmware request for the hardware device and waits for it. Calls832 * the callback function to upload the firmware to the device, them releases833 * the firmware.834 *835 * Returns 0 on success, -EINVAL if @cb is NULL, or a negative error number836 * from the firmware request or the callback function.837 */838int comedi_load_firmware(struct comedi_device *dev,839 struct device *device,840 const char *name,841 int (*cb)(struct comedi_device *dev,842 const u8 *data, size_t size,843 unsigned long context),844 unsigned long context)845{846 const struct firmware *fw;847 int ret;848 849 if (!cb)850 return -EINVAL;851 852 ret = request_firmware(&fw, name, device);853 if (ret == 0) {854 ret = cb(dev, fw->data, fw->size, context);855 release_firmware(fw);856 }857 858 return min(ret, 0);859}860EXPORT_SYMBOL_GPL(comedi_load_firmware);861 862/**863 * __comedi_request_region() - Request an I/O region for a legacy driver864 * @dev: COMEDI device.865 * @start: Base address of the I/O region.866 * @len: Length of the I/O region.867 *868 * Requests the specified I/O port region which must start at a non-zero869 * address.870 *871 * Returns 0 on success, -EINVAL if @start is 0, or -EIO if the request872 * fails.873 */874int __comedi_request_region(struct comedi_device *dev,875 unsigned long start, unsigned long len)876{877 if (!start) {878 dev_warn(dev->class_dev,879 "%s: a I/O base address must be specified\n",880 dev->board_name);881 return -EINVAL;882 }883 884 if (!request_region(start, len, dev->board_name)) {885 dev_warn(dev->class_dev, "%s: I/O port conflict (%#lx,%lu)\n",886 dev->board_name, start, len);887 return -EIO;888 }889 890 return 0;891}892EXPORT_SYMBOL_GPL(__comedi_request_region);893 894/**895 * comedi_request_region() - Request an I/O region for a legacy driver896 * @dev: COMEDI device.897 * @start: Base address of the I/O region.898 * @len: Length of the I/O region.899 *900 * Requests the specified I/O port region which must start at a non-zero901 * address.902 *903 * On success, @dev->iobase is set to the base address of the region and904 * @dev->iolen is set to its length.905 *906 * Returns 0 on success, -EINVAL if @start is 0, or -EIO if the request907 * fails.908 */909int comedi_request_region(struct comedi_device *dev,910 unsigned long start, unsigned long len)911{912 int ret;913 914 ret = __comedi_request_region(dev, start, len);915 if (ret == 0) {916 dev->iobase = start;917 dev->iolen = len;918 }919 920 return ret;921}922EXPORT_SYMBOL_GPL(comedi_request_region);923 924/**925 * comedi_legacy_detach() - A generic (*detach) function for legacy drivers926 * @dev: COMEDI device.927 *928 * This is a simple, generic 'detach' handler for legacy COMEDI devices that929 * just use a single I/O port region and possibly an IRQ and that don't need930 * any special clean-up for their private device or subdevice storage. It931 * can also be called by a driver-specific 'detach' handler.932 *933 * If @dev->irq is non-zero, the IRQ will be freed. If @dev->iobase and934 * @dev->iolen are both non-zero, the I/O port region will be released.935 */936void comedi_legacy_detach(struct comedi_device *dev)937{938 if (dev->irq) {939 free_irq(dev->irq, dev);940 dev->irq = 0;941 }942 if (dev->iobase && dev->iolen) {943 release_region(dev->iobase, dev->iolen);944 dev->iobase = 0;945 dev->iolen = 0;946 }947}948EXPORT_SYMBOL_GPL(comedi_legacy_detach);949 950int comedi_device_attach(struct comedi_device *dev, struct comedi_devconfig *it)951{952 struct comedi_driver *driv;953 int ret;954 955 lockdep_assert_held(&dev->mutex);956 if (dev->attached)957 return -EBUSY;958 959 mutex_lock(&comedi_drivers_list_lock);960 for (driv = comedi_drivers; driv; driv = driv->next) {961 if (!try_module_get(driv->module))962 continue;963 if (driv->num_names) {964 dev->board_ptr = comedi_recognize(driv, it->board_name);965 if (dev->board_ptr)966 break;967 } else if (strcmp(driv->driver_name, it->board_name) == 0) {968 break;969 }970 module_put(driv->module);971 }972 if (!driv) {973 /* recognize has failed if we get here */974 /* report valid board names before returning error */975 for (driv = comedi_drivers; driv; driv = driv->next) {976 if (!try_module_get(driv->module))977 continue;978 comedi_report_boards(driv);979 module_put(driv->module);980 }981 ret = -EIO;982 goto out;983 }984 if (!driv->attach) {985 /* driver does not support manual configuration */986 dev_warn(dev->class_dev,987 "driver '%s' does not support attach using comedi_config\n",988 driv->driver_name);989 module_put(driv->module);990 ret = -EIO;991 goto out;992 }993 dev->driver = driv;994 dev->board_name = dev->board_ptr ? *(const char **)dev->board_ptr995 : dev->driver->driver_name;996 ret = driv->attach(dev, it);997 if (ret >= 0)998 ret = comedi_device_postconfig(dev);999 if (ret < 0) {1000 comedi_device_detach(dev);1001 module_put(driv->module);1002 }1003 /* On success, the driver module count has been incremented. */1004out:1005 mutex_unlock(&comedi_drivers_list_lock);1006 return ret;1007}1008 1009/**1010 * comedi_auto_config() - Create a COMEDI device for a hardware device1011 * @hardware_device: Hardware device.1012 * @driver: COMEDI low-level driver for the hardware device.1013 * @context: Driver context for the auto_attach handler.1014 *1015 * Allocates a new COMEDI device for the hardware device and calls the1016 * low-level driver's 'auto_attach' handler to set-up the hardware and1017 * allocate the COMEDI subdevices. Additional "post-configuration" setting1018 * up is performed on successful return from the 'auto_attach' handler.1019 * If the 'auto_attach' handler fails, the low-level driver's 'detach'1020 * handler will be called as part of the clean-up.1021 *1022 * This is usually called from a wrapper function in a bus-specific COMEDI1023 * module, which in turn is usually called from a bus device 'probe'1024 * function in the low-level driver.1025 *1026 * Returns 0 on success, -EINVAL if the parameters are invalid or the1027 * post-configuration determines the driver has set the COMEDI device up1028 * incorrectly, -ENOMEM if failed to allocate memory, -EBUSY if run out of1029 * COMEDI minor device numbers, or some negative error number returned by1030 * the driver's 'auto_attach' handler.1031 */1032int comedi_auto_config(struct device *hardware_device,1033 struct comedi_driver *driver, unsigned long context)1034{1035 struct comedi_device *dev;1036 int ret;1037 1038 if (!hardware_device) {1039 pr_warn("BUG! %s called with NULL hardware_device\n", __func__);1040 return -EINVAL;1041 }1042 if (!driver) {1043 dev_warn(hardware_device,1044 "BUG! %s called with NULL comedi driver\n", __func__);1045 return -EINVAL;1046 }1047 1048 if (!driver->auto_attach) {1049 dev_warn(hardware_device,1050 "BUG! comedi driver '%s' has no auto_attach handler\n",1051 driver->driver_name);1052 return -EINVAL;1053 }1054 1055 dev = comedi_alloc_board_minor(hardware_device);1056 if (IS_ERR(dev)) {1057 dev_warn(hardware_device,1058 "driver '%s' could not create device.\n",1059 driver->driver_name);1060 return PTR_ERR(dev);1061 }1062 /* Note: comedi_alloc_board_minor() locked dev->mutex. */1063 lockdep_assert_held(&dev->mutex);1064 1065 dev->driver = driver;1066 dev->board_name = dev->driver->driver_name;1067 ret = driver->auto_attach(dev, context);1068 if (ret >= 0)1069 ret = comedi_device_postconfig(dev);1070 1071 if (ret < 0) {1072 dev_warn(hardware_device,1073 "driver '%s' failed to auto-configure device.\n",1074 driver->driver_name);1075 mutex_unlock(&dev->mutex);1076 comedi_release_hardware_device(hardware_device);1077 } else {1078 /*1079 * class_dev should be set properly here1080 * after a successful auto config1081 */1082 dev_info(dev->class_dev,1083 "driver '%s' has successfully auto-configured '%s'.\n",1084 driver->driver_name, dev->board_name);1085 mutex_unlock(&dev->mutex);1086 }1087 return ret;1088}1089EXPORT_SYMBOL_GPL(comedi_auto_config);1090 1091/**1092 * comedi_auto_unconfig() - Unconfigure auto-allocated COMEDI device1093 * @hardware_device: Hardware device previously passed to1094 * comedi_auto_config().1095 *1096 * Cleans up and eventually destroys the COMEDI device allocated by1097 * comedi_auto_config() for the same hardware device. As part of this1098 * clean-up, the low-level COMEDI driver's 'detach' handler will be called.1099 * (The COMEDI device itself will persist in an unattached state if it is1100 * still open, until it is released, and any mmapped buffers will persist1101 * until they are munmapped.)1102 *1103 * This is usually called from a wrapper module in a bus-specific COMEDI1104 * module, which in turn is usually set as the bus device 'remove' function1105 * in the low-level COMEDI driver.1106 */1107void comedi_auto_unconfig(struct device *hardware_device)1108{1109 if (!hardware_device)1110 return;1111 comedi_release_hardware_device(hardware_device);1112}1113EXPORT_SYMBOL_GPL(comedi_auto_unconfig);1114 1115/**1116 * comedi_driver_register() - Register a low-level COMEDI driver1117 * @driver: Low-level COMEDI driver.1118 *1119 * The low-level COMEDI driver is added to the list of registered COMEDI1120 * drivers. This is used by the handler for the "/proc/comedi" file and is1121 * also used by the handler for the %COMEDI_DEVCONFIG ioctl to configure1122 * "legacy" COMEDI devices (for those low-level drivers that support it).1123 *1124 * Returns 0.1125 */1126int comedi_driver_register(struct comedi_driver *driver)1127{1128 mutex_lock(&comedi_drivers_list_lock);1129 driver->next = comedi_drivers;1130 comedi_drivers = driver;1131 mutex_unlock(&comedi_drivers_list_lock);1132 1133 return 0;1134}1135EXPORT_SYMBOL_GPL(comedi_driver_register);1136 1137/**1138 * comedi_driver_unregister() - Unregister a low-level COMEDI driver1139 * @driver: Low-level COMEDI driver.1140 *1141 * The low-level COMEDI driver is removed from the list of registered COMEDI1142 * drivers. Detaches any COMEDI devices attached to the driver, which will1143 * result in the low-level driver's 'detach' handler being called for those1144 * devices before this function returns.1145 */1146void comedi_driver_unregister(struct comedi_driver *driver)1147{1148 struct comedi_driver *prev;1149 int i;1150 1151 /* unlink the driver */1152 mutex_lock(&comedi_drivers_list_lock);1153 if (comedi_drivers == driver) {1154 comedi_drivers = driver->next;1155 } else {1156 for (prev = comedi_drivers; prev->next; prev = prev->next) {1157 if (prev->next == driver) {1158 prev->next = driver->next;1159 break;1160 }1161 }1162 }1163 mutex_unlock(&comedi_drivers_list_lock);1164 1165 /* check for devices using this driver */1166 for (i = 0; i < COMEDI_NUM_BOARD_MINORS; i++) {1167 struct comedi_device *dev = comedi_dev_get_from_minor(i);1168 1169 if (!dev)1170 continue;1171 1172 mutex_lock(&dev->mutex);1173 if (dev->attached && dev->driver == driver) {1174 if (dev->use_count)1175 dev_warn(dev->class_dev,1176 "BUG! detaching device with use_count=%d\n",1177 dev->use_count);1178 comedi_device_detach(dev);1179 }1180 mutex_unlock(&dev->mutex);1181 comedi_dev_put(dev);1182 }1183}1184EXPORT_SYMBOL_GPL(comedi_driver_unregister);1185