1 | // SPDX-License-Identifier: GPL-2.0+ |
2 | /* |
3 | * module/drivers.c |
4 | * functions for manipulating drivers |
5 | * |
6 | * COMEDI - Linux Control and Measurement Device Interface |
7 | * Copyright (C) 1997-2000 David A. Schleef <ds@schleef.org> |
8 | * Copyright (C) 2002 Frank Mori Hess <fmhess@users.sourceforge.net> |
9 | */ |
10 | |
11 | #include <linux/device.h> |
12 | #include <linux/module.h> |
13 | #include <linux/errno.h> |
14 | #include <linux/kernel.h> |
15 | #include <linux/ioport.h> |
16 | #include <linux/slab.h> |
17 | #include <linux/dma-direction.h> |
18 | #include <linux/interrupt.h> |
19 | #include <linux/firmware.h> |
20 | #include <linux/comedi/comedidev.h> |
21 | #include "comedi_internal.h" |
22 | |
23 | struct comedi_driver *comedi_drivers; |
24 | /* protects access to comedi_drivers */ |
25 | DEFINE_MUTEX(comedi_drivers_list_lock); |
26 | |
27 | /** |
28 | * comedi_set_hw_dev() - Set hardware device associated with COMEDI device |
29 | * @dev: COMEDI device. |
30 | * @hw_dev: Hardware device. |
31 | * |
32 | * For automatically configured COMEDI devices (resulting from a call to |
33 | * comedi_auto_config() or one of its wrappers from the low-level COMEDI |
34 | * driver), comedi_set_hw_dev() is called automatically by the COMEDI core |
35 | * to associate the COMEDI device with the hardware device. It can also be |
36 | * called directly by "legacy" low-level COMEDI drivers that rely on the |
37 | * %COMEDI_DEVCONFIG ioctl to configure the hardware as long as the hardware |
38 | * has a &struct device. |
39 | * |
40 | * If @dev->hw_dev is NULL, it gets a reference to @hw_dev and sets |
41 | * @dev->hw_dev, otherwise, it does nothing. Calling it multiple times |
42 | * with the same hardware device is not considered an error. If it gets |
43 | * a reference to the hardware device, it will be automatically 'put' when |
44 | * the device is detached from COMEDI. |
45 | * |
46 | * Returns 0 if @dev->hw_dev was NULL or the same as @hw_dev, otherwise |
47 | * returns -EEXIST. |
48 | */ |
49 | int comedi_set_hw_dev(struct comedi_device *dev, struct device *hw_dev) |
50 | { |
51 | if (hw_dev == dev->hw_dev) |
52 | return 0; |
53 | if (dev->hw_dev) |
54 | return -EEXIST; |
55 | dev->hw_dev = get_device(dev: hw_dev); |
56 | return 0; |
57 | } |
58 | EXPORT_SYMBOL_GPL(comedi_set_hw_dev); |
59 | |
60 | static void comedi_clear_hw_dev(struct comedi_device *dev) |
61 | { |
62 | put_device(dev: dev->hw_dev); |
63 | dev->hw_dev = NULL; |
64 | } |
65 | |
66 | /** |
67 | * comedi_alloc_devpriv() - Allocate memory for the device private data |
68 | * @dev: COMEDI device. |
69 | * @size: Size of the memory to allocate. |
70 | * |
71 | * The allocated memory is zero-filled. @dev->private points to it on |
72 | * return. The memory will be automatically freed when the COMEDI device is |
73 | * "detached". |
74 | * |
75 | * Returns a pointer to the allocated memory, or NULL on failure. |
76 | */ |
77 | void *comedi_alloc_devpriv(struct comedi_device *dev, size_t size) |
78 | { |
79 | dev->private = kzalloc(size, GFP_KERNEL); |
80 | return dev->private; |
81 | } |
82 | EXPORT_SYMBOL_GPL(comedi_alloc_devpriv); |
83 | |
84 | /** |
85 | * comedi_alloc_subdevices() - Allocate subdevices for COMEDI device |
86 | * @dev: COMEDI device. |
87 | * @num_subdevices: Number of subdevices to allocate. |
88 | * |
89 | * Allocates and initializes an array of &struct comedi_subdevice for the |
90 | * COMEDI device. If successful, sets @dev->subdevices to point to the |
91 | * first one and @dev->n_subdevices to the number. |
92 | * |
93 | * Returns 0 on success, -EINVAL if @num_subdevices is < 1, or -ENOMEM if |
94 | * failed to allocate the memory. |
95 | */ |
96 | int 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(n: num_subdevices, size: 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 | } |
120 | EXPORT_SYMBOL_GPL(comedi_alloc_subdevices); |
121 | |
122 | /** |
123 | * comedi_alloc_subdev_readback() - Allocate memory for the subdevice readback |
124 | * @s: COMEDI subdevice. |
125 | * |
126 | * This is called by low-level COMEDI drivers to allocate an array to record |
127 | * the last values written to a subdevice's analog output channels (at least |
128 | * by the %INSN_WRITE instruction), to allow them to be read back by an |
129 | * %INSN_READ instruction. It also provides a default handler for the |
130 | * %INSN_READ instruction unless one has already been set. |
131 | * |
132 | * On success, @s->readback points to the first element of the array, which |
133 | * is zero-filled. The low-level driver is responsible for updating its |
134 | * contents. @s->insn_read will be set to comedi_readback_insn_read() |
135 | * unless it is already non-NULL. |
136 | * |
137 | * Returns 0 on success, -EINVAL if the subdevice has no channels, or |
138 | * -ENOMEM on allocation failure. |
139 | */ |
140 | int comedi_alloc_subdev_readback(struct comedi_subdevice *s) |
141 | { |
142 | if (!s->n_chan) |
143 | return -EINVAL; |
144 | |
145 | s->readback = kcalloc(n: s->n_chan, size: 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 | } |
154 | EXPORT_SYMBOL_GPL(comedi_alloc_subdev_readback); |
155 | |
156 | static 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(objp: s->private); |
168 | comedi_free_subdevice_minor(s); |
169 | if (s->async) { |
170 | comedi_buf_alloc(dev, s, new_size: 0); |
171 | kfree(objp: s->async); |
172 | } |
173 | kfree(objp: s->readback); |
174 | } |
175 | kfree(objp: dev->subdevices); |
176 | dev->subdevices = NULL; |
177 | dev->n_subdevices = 0; |
178 | } |
179 | kfree(objp: dev->private); |
180 | if (!IS_ERR(ptr: dev->pacer)) |
181 | kfree(objp: dev->pacer); |
182 | dev->private = NULL; |
183 | dev->pacer = NULL; |
184 | dev->driver = NULL; |
185 | dev->board_name = NULL; |
186 | dev->board_ptr = NULL; |
187 | dev->mmio = NULL; |
188 | dev->iobase = 0; |
189 | dev->iolen = 0; |
190 | dev->ioenabled = false; |
191 | dev->irq = 0; |
192 | dev->read_subdev = NULL; |
193 | dev->write_subdev = NULL; |
194 | dev->open = NULL; |
195 | dev->close = NULL; |
196 | comedi_clear_hw_dev(dev); |
197 | } |
198 | |
199 | void comedi_device_detach(struct comedi_device *dev) |
200 | { |
201 | lockdep_assert_held(&dev->mutex); |
202 | comedi_device_cancel_all(dev); |
203 | down_write(sem: &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(sem: &dev->attach_lock); |
210 | } |
211 | |
212 | static int poll_invalid(struct comedi_device *dev, struct comedi_subdevice *s) |
213 | { |
214 | return -EINVAL; |
215 | } |
216 | |
217 | static int insn_device_inval(struct comedi_device *dev, |
218 | struct comedi_insn *insn, unsigned int *data) |
219 | { |
220 | return -EINVAL; |
221 | } |
222 | |
223 | static 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 | |
230 | int 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 readback |
244 | * array allocated by comedi_alloc_subdev_readback(). It may be used |
245 | * directly as the subdevice's handler (@s->insn_read) or called via a |
246 | * wrapper. |
247 | * |
248 | * @insn->n is normally 1, which will read a single value. If higher, the |
249 | * 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 | */ |
253 | int 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 | } |
269 | EXPORT_SYMBOL_GPL(comedi_readback_insn_read); |
270 | |
271 | /** |
272 | * comedi_timeout() - Busy-wait for a driver condition to occur |
273 | * @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 or |
280 | * some error (other than -EBUSY) to occur. The parameters @dev, @s, @insn, |
281 | * and @context are passed to the callback function, which returns -EBUSY to |
282 | * continue waiting or some other value to stop waiting (generally 0 if the |
283 | * condition occurred, or some error value). |
284 | * |
285 | * Returns -ETIMEDOUT if timed out, otherwise the return value from the |
286 | * callback function. |
287 | */ |
288 | int 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 | } |
308 | EXPORT_SYMBOL_GPL(comedi_timeout); |
309 | |
310 | /** |
311 | * comedi_dio_insn_config() - Boilerplate (*insn_config) for DIO subdevices |
312 | * @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 the |
319 | * channel number specified by @insn->chanspec. Otherwise, @mask |
320 | * corresponds to a group of channels (which should include the specified |
321 | * 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 update |
325 | * @s->io_bits to record the directions of the masked channels. The last |
326 | * one sets @data[1] to the current direction of the group of channels |
327 | * (%COMEDI_INPUT) or %COMEDI_OUTPUT) as recorded in @s->io_bits. |
328 | * |
329 | * The caller is responsible for updating the DIO direction in the hardware |
330 | * registers if this function returns 0. |
331 | * |
332 | * Returns 0 for a %INSN_CONFIG_DIO_INPUT or %INSN_CONFIG_DIO_OUTPUT |
333 | * instruction, @insn->n (> 0) for a %INSN_CONFIG_DIO_QUERY instruction, or |
334 | * -EINVAL for some other instruction. |
335 | */ |
336 | int 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 | } |
366 | EXPORT_SYMBOL_GPL(comedi_dio_insn_config); |
367 | |
368 | /** |
369 | * comedi_dio_update_state() - Update the internal state of DIO subdevices |
370 | * @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 DIO |
374 | * or DO subdevices (up to 32 channels). @data[0] contains a bit-mask of |
375 | * the channels to be updated. @data[1] contains a bit-mask of those |
376 | * channels to be set to '1'. The caller is responsible for updating the |
377 | * outputs in hardware according to @s->state. As a minimum, the channels |
378 | * in the returned bit-mask need to be updated. |
379 | * |
380 | * Returns @mask with non-existent channels removed. |
381 | */ |
382 | unsigned 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 | } |
397 | EXPORT_SYMBOL_GPL(comedi_dio_update_state); |
398 | |
399 | /** |
400 | * comedi_bytes_per_scan_cmd() - Get length of asynchronous command "scan" in |
401 | * bytes |
402 | * @s: COMEDI subdevice. |
403 | * @cmd: COMEDI command. |
404 | * |
405 | * Determines the overall scan length according to the subdevice type and the |
406 | * number of channels in the scan for the specified command. |
407 | * |
408 | * For digital input, output or input/output subdevices, samples for |
409 | * multiple channels are assumed to be packed into one or more unsigned |
410 | * short or unsigned int values according to the subdevice's %SDF_LSAMPL |
411 | * flag. For other types of subdevice, samples are assumed to occupy a |
412 | * whole unsigned short or unsigned int according to the %SDF_LSAMPL flag. |
413 | * |
414 | * Returns the overall scan length in bytes. |
415 | */ |
416 | unsigned 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, nsamples: num_samples); |
434 | } |
435 | EXPORT_SYMBOL_GPL(comedi_bytes_per_scan_cmd); |
436 | |
437 | /** |
438 | * comedi_bytes_per_scan() - Get length of asynchronous command "scan" in bytes |
439 | * @s: COMEDI subdevice. |
440 | * |
441 | * Determines the overall scan length according to the subdevice type and the |
442 | * number of channels in the scan for the current command. |
443 | * |
444 | * For digital input, output or input/output subdevices, samples for |
445 | * multiple channels are assumed to be packed into one or more unsigned |
446 | * short or unsigned int values according to the subdevice's %SDF_LSAMPL |
447 | * flag. For other types of subdevice, samples are assumed to occupy a |
448 | * whole unsigned short or unsigned int according to the %SDF_LSAMPL flag. |
449 | * |
450 | * Returns the overall scan length in bytes. |
451 | */ |
452 | unsigned 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 | } |
458 | EXPORT_SYMBOL_GPL(comedi_bytes_per_scan); |
459 | |
460 | static 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 command |
480 | * @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 the |
484 | * async buffer. |
485 | * |
486 | * If the async command has a stop_src of %TRIG_COUNT, the @nscans will be |
487 | * 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 the |
490 | * number of scans remaining to complete the command, whichever is fewer. |
491 | */ |
492 | unsigned 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 | } |
502 | EXPORT_SYMBOL_GPL(comedi_nscans_left); |
503 | |
504 | /** |
505 | * comedi_nsamples_left() - Return the number of samples left in the command |
506 | * @s: COMEDI subdevice. |
507 | * @nsamples: The expected number of samples. |
508 | * |
509 | * Returns the number of samples remaining to complete the command, or the |
510 | * specified expected number of samples (@nsamples), whichever is fewer. |
511 | */ |
512 | unsigned 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, nscans: 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, nbytes: async->scan_progress); |
529 | |
530 | if (samples_left < nsamples) |
531 | return samples_left; |
532 | return nsamples; |
533 | } |
534 | EXPORT_SYMBOL_GPL(comedi_nsamples_left); |
535 | |
536 | /** |
537 | * comedi_inc_scan_progress() - Update scan progress in asynchronous command |
538 | * @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, reduce |
543 | * it modulo the scan length in bytes and set the "end of scan" asynchronous |
544 | * event flag (%COMEDI_CB_EOS) to be processed later. |
545 | */ |
546 | void 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, nbytes: 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 | else |
566 | async->scans_done = UINT_MAX; |
567 | |
568 | async->scan_progress %= scan_length; |
569 | async->events |= COMEDI_CB_EOS; |
570 | } |
571 | } |
572 | EXPORT_SYMBOL_GPL(comedi_inc_scan_progress); |
573 | |
574 | /** |
575 | * comedi_handle_events() - Handle events and possibly stop acquisition |
576 | * @dev: COMEDI device. |
577 | * @s: COMEDI subdevice. |
578 | * |
579 | * Handles outstanding asynchronous acquisition event flags associated |
580 | * with the subdevice. Call the subdevice's @s->cancel() handler if the |
581 | * "end of acquisition", "error" or "overflow" event flags are set in order |
582 | * to stop the acquisition at the driver level. |
583 | * |
584 | * Calls comedi_event() to further process the event flags, which may mark |
585 | * the asynchronous command as no longer running, possibly terminated with |
586 | * an error, and may wake up tasks. |
587 | * |
588 | * Return a bit-mask of the handled events. |
589 | */ |
590 | unsigned 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 | } |
605 | EXPORT_SYMBOL_GPL(comedi_handle_events); |
606 | |
607 | static 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 | |
642 | static 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(size: 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, new_size: 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 | |
691 | static 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 | else |
714 | 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 */ |
751 | static 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(sem: &dev->attach_lock); |
760 | dev->attached = true; |
761 | up_write(sem: &dev->attach_lock); |
762 | return 0; |
763 | } |
764 | |
765 | /* |
766 | * Generic recognize function for drivers that register their supported |
767 | * board names. |
768 | * |
769 | * 'driv->board_name' points to a 'const char *' member within the |
770 | * zeroth element of an array of some private board information |
771 | * structure, say 'struct foo_board' containing a member 'const char |
772 | * *board_name' that is initialized to point to a board name string that |
773 | * is one of the candidates matched against this function's 'name' |
774 | * parameter. |
775 | * |
776 | * 'driv->offset' is the size of the private board information |
777 | * structure, say 'sizeof(struct foo_board)', and 'driv->num_names' is |
778 | * the length of the array of private board information structures. |
779 | * |
780 | * If one of the board names in the array of private board information |
781 | * structures matches the name supplied to this function, the function |
782 | * returns a pointer to the pointer to the board name, otherwise it |
783 | * returns NULL. The return value ends up in the 'board_ptr' member of |
784 | * a 'struct comedi_device' that the low-level comedi driver's |
785 | * 'attach()' hook can convert to a point to a particular element of its |
786 | * array of private board information structures by subtracting the |
787 | * offset of the member that points to the board name. (No subtraction |
788 | * is required if the board name pointer is the first member of the |
789 | * private board information structure, which is generally the case.) |
790 | */ |
791 | static 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 | |
805 | static 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 device |
825 | * @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. Calls |
832 | * the callback function to upload the firmware to the device, them releases |
833 | * the firmware. |
834 | * |
835 | * Returns 0 on success, -EINVAL if @cb is NULL, or a negative error number |
836 | * from the firmware request or the callback function. |
837 | */ |
838 | int 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: &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 | } |
860 | EXPORT_SYMBOL_GPL(comedi_load_firmware); |
861 | |
862 | /** |
863 | * __comedi_request_region() - Request an I/O region for a legacy driver |
864 | * @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-zero |
869 | * address. |
870 | * |
871 | * Returns 0 on success, -EINVAL if @start is 0, or -EIO if the request |
872 | * fails. |
873 | */ |
874 | int __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 | } |
892 | EXPORT_SYMBOL_GPL(__comedi_request_region); |
893 | |
894 | /** |
895 | * comedi_request_region() - Request an I/O region for a legacy driver |
896 | * @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-zero |
901 | * address. |
902 | * |
903 | * On success, @dev->iobase is set to the base address of the region and |
904 | * @dev->iolen is set to its length. |
905 | * |
906 | * Returns 0 on success, -EINVAL if @start is 0, or -EIO if the request |
907 | * fails. |
908 | */ |
909 | int 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 | } |
922 | EXPORT_SYMBOL_GPL(comedi_request_region); |
923 | |
924 | /** |
925 | * comedi_legacy_detach() - A generic (*detach) function for legacy drivers |
926 | * @dev: COMEDI device. |
927 | * |
928 | * This is a simple, generic 'detach' handler for legacy COMEDI devices that |
929 | * just use a single I/O port region and possibly an IRQ and that don't need |
930 | * any special clean-up for their private device or subdevice storage. It |
931 | * 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 and |
934 | * @dev->iolen are both non-zero, the I/O port region will be released. |
935 | */ |
936 | void 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 | } |
948 | EXPORT_SYMBOL_GPL(comedi_legacy_detach); |
949 | |
950 | int 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(module: driv->module)) |
962 | continue; |
963 | if (driv->num_names) { |
964 | dev->board_ptr = comedi_recognize(driv, name: 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(module: 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(module: driv->module)) |
977 | continue; |
978 | comedi_report_boards(driv); |
979 | module_put(module: 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(module: driv->module); |
990 | ret = -EIO; |
991 | goto out; |
992 | } |
993 | dev->driver = driv; |
994 | dev->board_name = dev->board_ptr ? *(const char **)dev->board_ptr |
995 | : 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(module: driv->module); |
1002 | } |
1003 | /* On success, the driver module count has been incremented. */ |
1004 | out: |
1005 | mutex_unlock(lock: &comedi_drivers_list_lock); |
1006 | return ret; |
1007 | } |
1008 | |
1009 | /** |
1010 | * comedi_auto_config() - Create a COMEDI device for a hardware device |
1011 | * @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 the |
1016 | * low-level driver's 'auto_attach' handler to set-up the hardware and |
1017 | * allocate the COMEDI subdevices. Additional "post-configuration" setting |
1018 | * 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 COMEDI |
1023 | * 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 the |
1027 | * post-configuration determines the driver has set the COMEDI device up |
1028 | * incorrectly, -ENOMEM if failed to allocate memory, -EBUSY if run out of |
1029 | * COMEDI minor device numbers, or some negative error number returned by |
1030 | * the driver's 'auto_attach' handler. |
1031 | */ |
1032 | int 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(ptr: dev)) { |
1057 | dev_warn(hardware_device, |
1058 | "driver '%s' could not create device.\n" , |
1059 | driver->driver_name); |
1060 | return PTR_ERR(ptr: 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(lock: &dev->mutex); |
1076 | comedi_release_hardware_device(hardware_device); |
1077 | } else { |
1078 | /* |
1079 | * class_dev should be set properly here |
1080 | * after a successful auto config |
1081 | */ |
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(lock: &dev->mutex); |
1086 | } |
1087 | return ret; |
1088 | } |
1089 | EXPORT_SYMBOL_GPL(comedi_auto_config); |
1090 | |
1091 | /** |
1092 | * comedi_auto_unconfig() - Unconfigure auto-allocated COMEDI device |
1093 | * @hardware_device: Hardware device previously passed to |
1094 | * comedi_auto_config(). |
1095 | * |
1096 | * Cleans up and eventually destroys the COMEDI device allocated by |
1097 | * comedi_auto_config() for the same hardware device. As part of this |
1098 | * 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 is |
1100 | * still open, until it is released, and any mmapped buffers will persist |
1101 | * until they are munmapped.) |
1102 | * |
1103 | * This is usually called from a wrapper module in a bus-specific COMEDI |
1104 | * module, which in turn is usually set as the bus device 'remove' function |
1105 | * in the low-level COMEDI driver. |
1106 | */ |
1107 | void comedi_auto_unconfig(struct device *hardware_device) |
1108 | { |
1109 | if (!hardware_device) |
1110 | return; |
1111 | comedi_release_hardware_device(hardware_device); |
1112 | } |
1113 | EXPORT_SYMBOL_GPL(comedi_auto_unconfig); |
1114 | |
1115 | /** |
1116 | * comedi_driver_register() - Register a low-level COMEDI driver |
1117 | * @driver: Low-level COMEDI driver. |
1118 | * |
1119 | * The low-level COMEDI driver is added to the list of registered COMEDI |
1120 | * drivers. This is used by the handler for the "/proc/comedi" file and is |
1121 | * also used by the handler for the %COMEDI_DEVCONFIG ioctl to configure |
1122 | * "legacy" COMEDI devices (for those low-level drivers that support it). |
1123 | * |
1124 | * Returns 0. |
1125 | */ |
1126 | int 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(lock: &comedi_drivers_list_lock); |
1132 | |
1133 | return 0; |
1134 | } |
1135 | EXPORT_SYMBOL_GPL(comedi_driver_register); |
1136 | |
1137 | /** |
1138 | * comedi_driver_unregister() - Unregister a low-level COMEDI driver |
1139 | * @driver: Low-level COMEDI driver. |
1140 | * |
1141 | * The low-level COMEDI driver is removed from the list of registered COMEDI |
1142 | * drivers. Detaches any COMEDI devices attached to the driver, which will |
1143 | * result in the low-level driver's 'detach' handler being called for those |
1144 | * devices before this function returns. |
1145 | */ |
1146 | void 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(lock: &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(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(lock: &dev->mutex); |
1181 | comedi_dev_put(dev); |
1182 | } |
1183 | } |
1184 | EXPORT_SYMBOL_GPL(comedi_driver_unregister); |
1185 | |