1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3 * comedidev.h
4 * header file for kernel-only structures, variables, and constants
5 *
6 * COMEDI - Linux Control and Measurement Device Interface
7 * Copyright (C) 1997-2000 David A. Schleef <ds@schleef.org>
8 */
9
10 #ifndef _COMEDIDEV_H
11 #define _COMEDIDEV_H
12
13 #include <linux/dma-mapping.h>
14 #include <linux/mutex.h>
15 #include <linux/spinlock_types.h>
16 #include <linux/rwsem.h>
17 #include <linux/kref.h>
18
19 #include "comedi.h"
20
21 #define COMEDI_VERSION(a, b, c) (((a) << 16) + ((b) << 8) + (c))
22 #define COMEDI_VERSION_CODE COMEDI_VERSION(COMEDI_MAJORVERSION, \
23 COMEDI_MINORVERSION, COMEDI_MICROVERSION)
24 #define COMEDI_RELEASE VERSION
25
26 #define COMEDI_NUM_BOARD_MINORS 0x30
27
28 /**
29 * struct comedi_subdevice - Working data for a COMEDI subdevice
30 * @device: COMEDI device to which this subdevice belongs. (Initialized by
31 * comedi_alloc_subdevices().)
32 * @index: Index of this subdevice within device's array of subdevices.
33 * (Initialized by comedi_alloc_subdevices().)
34 * @type: Type of subdevice from &enum comedi_subdevice_type. (Initialized by
35 * the low-level driver.)
36 * @n_chan: Number of channels the subdevice supports. (Initialized by the
37 * low-level driver.)
38 * @subdev_flags: Various "SDF" flags indicating aspects of the subdevice to
39 * the COMEDI core and user application. (Initialized by the low-level
40 * driver.)
41 * @len_chanlist: Maximum length of a channel list if the subdevice supports
42 * asynchronous acquisition commands. (Optionally initialized by the
43 * low-level driver, or changed from 0 to 1 during post-configuration.)
44 * @private: Private data pointer which is either set by the low-level driver
45 * itself, or by a call to comedi_alloc_spriv() which allocates storage.
46 * In the latter case, the storage is automatically freed after the
47 * low-level driver's "detach" handler is called for the device.
48 * (Initialized by the low-level driver.)
49 * @async: Pointer to &struct comedi_async id the subdevice supports
50 * asynchronous acquisition commands. (Allocated and initialized during
51 * post-configuration if needed.)
52 * @lock: Pointer to a file object that performed a %COMEDI_LOCK ioctl on the
53 * subdevice. (Initially NULL.)
54 * @busy: Pointer to a file object that is performing an asynchronous
55 * acquisition command on the subdevice. (Initially NULL.)
56 * @runflags: Internal flags for use by COMEDI core, mostly indicating whether
57 * an asynchronous acquisition command is running.
58 * @spin_lock: Generic spin-lock for use by the COMEDI core and the low-level
59 * driver. (Initialized by comedi_alloc_subdevices().)
60 * @io_bits: Bit-mask indicating the channel directions for a DIO subdevice
61 * with no more than 32 channels. A '1' at a bit position indicates the
62 * corresponding channel is configured as an output. (Initialized by the
63 * low-level driver for a DIO subdevice. Forced to all-outputs during
64 * post-configuration for a digital output subdevice.)
65 * @maxdata: If non-zero, this is the maximum raw data value of each channel.
66 * If zero, the maximum data value is channel-specific. (Initialized by
67 * the low-level driver.)
68 * @maxdata_list: If the maximum data value is channel-specific, this points
69 * to an array of maximum data values indexed by channel index.
70 * (Initialized by the low-level driver.)
71 * @range_table: If non-NULL, this points to a COMEDI range table for the
72 * subdevice. If NULL, the range table is channel-specific. (Initialized
73 * by the low-level driver, will be set to an "invalid" range table during
74 * post-configuration if @range_table and @range_table_list are both
75 * NULL.)
76 * @range_table_list: If the COMEDI range table is channel-specific, this
77 * points to an array of pointers to COMEDI range tables indexed by
78 * channel number. (Initialized by the low-level driver.)
79 * @chanlist: Not used.
80 * @insn_read: Optional pointer to a handler for the %INSN_READ instruction.
81 * (Initialized by the low-level driver, or set to a default handler
82 * during post-configuration.)
83 * @insn_write: Optional pointer to a handler for the %INSN_WRITE instruction.
84 * (Initialized by the low-level driver, or set to a default handler
85 * during post-configuration.)
86 * @insn_bits: Optional pointer to a handler for the %INSN_BITS instruction
87 * for a digital input, digital output or digital input/output subdevice.
88 * (Initialized by the low-level driver, or set to a default handler
89 * during post-configuration.)
90 * @insn_config: Optional pointer to a handler for the %INSN_CONFIG
91 * instruction. (Initialized by the low-level driver, or set to a default
92 * handler during post-configuration.)
93 * @do_cmd: If the subdevice supports asynchronous acquisition commands, this
94 * points to a handler to set it up in hardware. (Initialized by the
95 * low-level driver.)
96 * @do_cmdtest: If the subdevice supports asynchronous acquisition commands,
97 * this points to a handler used to check and possibly tweak a prospective
98 * acquisition command without setting it up in hardware. (Initialized by
99 * the low-level driver.)
100 * @poll: If the subdevice supports asynchronous acquisition commands, this
101 * is an optional pointer to a handler for the %COMEDI_POLL ioctl which
102 * instructs the low-level driver to synchronize buffers. (Initialized by
103 * the low-level driver if needed.)
104 * @cancel: If the subdevice supports asynchronous acquisition commands, this
105 * points to a handler used to terminate a running command. (Initialized
106 * by the low-level driver.)
107 * @buf_change: If the subdevice supports asynchronous acquisition commands,
108 * this is an optional pointer to a handler that is called when the data
109 * buffer for handling asynchronous commands is allocated or reallocated.
110 * (Initialized by the low-level driver if needed.)
111 * @munge: If the subdevice supports asynchronous acquisition commands and
112 * uses DMA to transfer data from the hardware to the acquisition buffer,
113 * this points to a function used to "munge" the data values from the
114 * hardware into the format expected by COMEDI. (Initialized by the
115 * low-level driver if needed.)
116 * @async_dma_dir: If the subdevice supports asynchronous acquisition commands
117 * and uses DMA to transfer data from the hardware to the acquisition
118 * buffer, this sets the DMA direction for the buffer. (initialized to
119 * %DMA_NONE by comedi_alloc_subdevices() and changed by the low-level
120 * driver if necessary.)
121 * @state: Handy bit-mask indicating the output states for a DIO or digital
122 * output subdevice with no more than 32 channels. (Initialized by the
123 * low-level driver.)
124 * @class_dev: If the subdevice supports asynchronous acquisition commands,
125 * this points to a sysfs comediX_subdY device where X is the minor device
126 * number of the COMEDI device and Y is the subdevice number. The minor
127 * device number for the sysfs device is allocated dynamically in the
128 * range 48 to 255. This is used to allow the COMEDI device to be opened
129 * with a different default read or write subdevice. (Allocated during
130 * post-configuration if needed.)
131 * @minor: If @class_dev is set, this is its dynamically allocated minor
132 * device number. (Set during post-configuration if necessary.)
133 * @readback: Optional pointer to memory allocated by
134 * comedi_alloc_subdev_readback() used to hold the values written to
135 * analog output channels so they can be read back. The storage is
136 * automatically freed after the low-level driver's "detach" handler is
137 * called for the device. (Initialized by the low-level driver.)
138 *
139 * This is the main control structure for a COMEDI subdevice. If the subdevice
140 * supports asynchronous acquisition commands, additional information is stored
141 * in the &struct comedi_async pointed to by @async.
142 *
143 * Most of the subdevice is initialized by the low-level driver's "attach" or
144 * "auto_attach" handlers but parts of it are initialized by
145 * comedi_alloc_subdevices(), and other parts are initialized during
146 * post-configuration on return from that handler.
147 *
148 * A low-level driver that sets @insn_bits for a digital input, digital output,
149 * or DIO subdevice may leave @insn_read and @insn_write uninitialized, in
150 * which case they will be set to a default handler during post-configuration
151 * that uses @insn_bits to emulate the %INSN_READ and %INSN_WRITE instructions.
152 */
153 struct comedi_subdevice {
154 struct comedi_device *device;
155 int index;
156 int type;
157 int n_chan;
158 int subdev_flags;
159 int len_chanlist; /* maximum length of channel/gain list */
160
161 void *private;
162
163 struct comedi_async *async;
164
165 void *lock;
166 void *busy;
167 unsigned int runflags;
168 spinlock_t spin_lock; /* generic spin-lock for COMEDI and drivers */
169
170 unsigned int io_bits;
171
172 unsigned int maxdata; /* if maxdata==0, use list */
173 const unsigned int *maxdata_list; /* list is channel specific */
174
175 const struct comedi_lrange *range_table;
176 const struct comedi_lrange *const *range_table_list;
177
178 unsigned int *chanlist; /* driver-owned chanlist (not used) */
179
180 int (*insn_read)(struct comedi_device *dev, struct comedi_subdevice *s,
181 struct comedi_insn *insn, unsigned int *data);
182 int (*insn_write)(struct comedi_device *dev, struct comedi_subdevice *s,
183 struct comedi_insn *insn, unsigned int *data);
184 int (*insn_bits)(struct comedi_device *dev, struct comedi_subdevice *s,
185 struct comedi_insn *insn, unsigned int *data);
186 int (*insn_config)(struct comedi_device *dev,
187 struct comedi_subdevice *s,
188 struct comedi_insn *insn,
189 unsigned int *data);
190
191 int (*do_cmd)(struct comedi_device *dev, struct comedi_subdevice *s);
192 int (*do_cmdtest)(struct comedi_device *dev,
193 struct comedi_subdevice *s,
194 struct comedi_cmd *cmd);
195 int (*poll)(struct comedi_device *dev, struct comedi_subdevice *s);
196 int (*cancel)(struct comedi_device *dev, struct comedi_subdevice *s);
197
198 /* called when the buffer changes */
199 int (*buf_change)(struct comedi_device *dev,
200 struct comedi_subdevice *s);
201
202 void (*munge)(struct comedi_device *dev, struct comedi_subdevice *s,
203 void *data, unsigned int num_bytes,
204 unsigned int start_chan_index);
205 enum dma_data_direction async_dma_dir;
206
207 unsigned int state;
208
209 struct device *class_dev;
210 int minor;
211
212 unsigned int *readback;
213 };
214
215 /**
216 * struct comedi_buf_page - Describe a page of a COMEDI buffer
217 * @virt_addr: Kernel address of page.
218 * @dma_addr: DMA address of page if in DMA coherent memory.
219 */
220 struct comedi_buf_page {
221 void *virt_addr;
222 dma_addr_t dma_addr;
223 };
224
225 /**
226 * struct comedi_buf_map - Describe pages in a COMEDI buffer
227 * @dma_hw_dev: Low-level hardware &struct device pointer copied from the
228 * COMEDI device's hw_dev member.
229 * @page_list: Pointer to array of &struct comedi_buf_page, one for each
230 * page in the buffer.
231 * @n_pages: Number of pages in the buffer.
232 * @dma_dir: DMA direction used to allocate pages of DMA coherent memory,
233 * or %DMA_NONE if pages allocated from regular memory.
234 * @refcount: &struct kref reference counter used to free the buffer.
235 *
236 * A COMEDI data buffer is allocated as individual pages, either in
237 * conventional memory or DMA coherent memory, depending on the attached,
238 * low-level hardware device. (The buffer pages also get mapped into the
239 * kernel's contiguous virtual address space pointed to by the 'prealloc_buf'
240 * member of &struct comedi_async.)
241 *
242 * The buffer is normally freed when the COMEDI device is detached from the
243 * low-level driver (which may happen due to device removal), but if it happens
244 * to be mmapped at the time, the pages cannot be freed until the buffer has
245 * been munmapped. That is what the reference counter is for. (The virtual
246 * address space pointed by 'prealloc_buf' is freed when the COMEDI device is
247 * detached.)
248 */
249 struct comedi_buf_map {
250 struct device *dma_hw_dev;
251 struct comedi_buf_page *page_list;
252 unsigned int n_pages;
253 enum dma_data_direction dma_dir;
254 struct kref refcount;
255 };
256
257 /**
258 * struct comedi_async - Control data for asynchronous COMEDI commands
259 * @prealloc_buf: Kernel virtual address of allocated acquisition buffer.
260 * @prealloc_bufsz: Buffer size (in bytes).
261 * @buf_map: Map of buffer pages.
262 * @max_bufsize: Maximum allowed buffer size (in bytes).
263 * @buf_write_count: "Write completed" count (in bytes, modulo 2**32).
264 * @buf_write_alloc_count: "Allocated for writing" count (in bytes,
265 * modulo 2**32).
266 * @buf_read_count: "Read completed" count (in bytes, modulo 2**32).
267 * @buf_read_alloc_count: "Allocated for reading" count (in bytes,
268 * modulo 2**32).
269 * @buf_write_ptr: Buffer position for writer.
270 * @buf_read_ptr: Buffer position for reader.
271 * @cur_chan: Current position in chanlist for scan (for those drivers that
272 * use it).
273 * @scans_done: The number of scans completed.
274 * @scan_progress: Amount received or sent for current scan (in bytes).
275 * @munge_chan: Current position in chanlist for "munging".
276 * @munge_count: "Munge" count (in bytes, modulo 2**32).
277 * @munge_ptr: Buffer position for "munging".
278 * @events: Bit-vector of events that have occurred.
279 * @cmd: Details of comedi command in progress.
280 * @wait_head: Task wait queue for file reader or writer.
281 * @cb_mask: Bit-vector of events that should wake waiting tasks.
282 * @inttrig: Software trigger function for command, or NULL.
283 *
284 * Note about the ..._count and ..._ptr members:
285 *
286 * Think of the _Count values being integers of unlimited size, indexing
287 * into a buffer of infinite length (though only an advancing portion
288 * of the buffer of fixed length prealloc_bufsz is accessible at any
289 * time). Then:
290 *
291 * Buf_Read_Count <= Buf_Read_Alloc_Count <= Munge_Count <=
292 * Buf_Write_Count <= Buf_Write_Alloc_Count <=
293 * (Buf_Read_Count + prealloc_bufsz)
294 *
295 * (Those aren't the actual members, apart from prealloc_bufsz.) When the
296 * buffer is reset, those _Count values start at 0 and only increase in value,
297 * maintaining the above inequalities until the next time the buffer is
298 * reset. The buffer is divided into the following regions by the inequalities:
299 *
300 * [0, Buf_Read_Count):
301 * old region no longer accessible
302 *
303 * [Buf_Read_Count, Buf_Read_Alloc_Count):
304 * filled and munged region allocated for reading but not yet read
305 *
306 * [Buf_Read_Alloc_Count, Munge_Count):
307 * filled and munged region not yet allocated for reading
308 *
309 * [Munge_Count, Buf_Write_Count):
310 * filled region not yet munged
311 *
312 * [Buf_Write_Count, Buf_Write_Alloc_Count):
313 * unfilled region allocated for writing but not yet written
314 *
315 * [Buf_Write_Alloc_Count, Buf_Read_Count + prealloc_bufsz):
316 * unfilled region not yet allocated for writing
317 *
318 * [Buf_Read_Count + prealloc_bufsz, infinity):
319 * unfilled region not yet accessible
320 *
321 * Data needs to be written into the buffer before it can be read out,
322 * and may need to be converted (or "munged") between the two
323 * operations. Extra unfilled buffer space may need to allocated for
324 * writing (advancing Buf_Write_Alloc_Count) before new data is written.
325 * After writing new data, the newly filled space needs to be released
326 * (advancing Buf_Write_Count). This also results in the new data being
327 * "munged" (advancing Munge_Count). Before data is read out of the
328 * buffer, extra space may need to be allocated for reading (advancing
329 * Buf_Read_Alloc_Count). After the data has been read out, the space
330 * needs to be released (advancing Buf_Read_Count).
331 *
332 * The actual members, buf_read_count, buf_read_alloc_count,
333 * munge_count, buf_write_count, and buf_write_alloc_count take the
334 * value of the corresponding capitalized _Count values modulo 2^32
335 * (UINT_MAX+1). Subtracting a "higher" _count value from a "lower"
336 * _count value gives the same answer as subtracting a "higher" _Count
337 * value from a lower _Count value because prealloc_bufsz < UINT_MAX+1.
338 * The modulo operation is done implicitly.
339 *
340 * The buf_read_ptr, munge_ptr, and buf_write_ptr members take the value
341 * of the corresponding capitalized _Count values modulo prealloc_bufsz.
342 * These correspond to byte indices in the physical buffer. The modulo
343 * operation is done by subtracting prealloc_bufsz when the value
344 * exceeds prealloc_bufsz (assuming prealloc_bufsz plus the increment is
345 * less than or equal to UINT_MAX).
346 */
347 struct comedi_async {
348 void *prealloc_buf;
349 unsigned int prealloc_bufsz;
350 struct comedi_buf_map *buf_map;
351 unsigned int max_bufsize;
352 unsigned int buf_write_count;
353 unsigned int buf_write_alloc_count;
354 unsigned int buf_read_count;
355 unsigned int buf_read_alloc_count;
356 unsigned int buf_write_ptr;
357 unsigned int buf_read_ptr;
358 unsigned int cur_chan;
359 unsigned int scans_done;
360 unsigned int scan_progress;
361 unsigned int munge_chan;
362 unsigned int munge_count;
363 unsigned int munge_ptr;
364 unsigned int events;
365 struct comedi_cmd cmd;
366 wait_queue_head_t wait_head;
367 unsigned int cb_mask;
368 int (*inttrig)(struct comedi_device *dev, struct comedi_subdevice *s,
369 unsigned int x);
370 };
371
372 /**
373 * enum comedi_cb - &struct comedi_async callback "events"
374 * @COMEDI_CB_EOS: end-of-scan
375 * @COMEDI_CB_EOA: end-of-acquisition/output
376 * @COMEDI_CB_BLOCK: data has arrived, wakes up read() / write()
377 * @COMEDI_CB_EOBUF: DEPRECATED: end of buffer
378 * @COMEDI_CB_ERROR: card error during acquisition
379 * @COMEDI_CB_OVERFLOW: buffer overflow/underflow
380 * @COMEDI_CB_ERROR_MASK: events that indicate an error has occurred
381 * @COMEDI_CB_CANCEL_MASK: events that will cancel an async command
382 */
383 enum comedi_cb {
384 COMEDI_CB_EOS = BIT(0),
385 COMEDI_CB_EOA = BIT(1),
386 COMEDI_CB_BLOCK = BIT(2),
387 COMEDI_CB_EOBUF = BIT(3),
388 COMEDI_CB_ERROR = BIT(4),
389 COMEDI_CB_OVERFLOW = BIT(5),
390 /* masks */
391 COMEDI_CB_ERROR_MASK = (COMEDI_CB_ERROR | COMEDI_CB_OVERFLOW),
392 COMEDI_CB_CANCEL_MASK = (COMEDI_CB_EOA | COMEDI_CB_ERROR_MASK)
393 };
394
395 /**
396 * struct comedi_driver - COMEDI driver registration
397 * @driver_name: Name of driver.
398 * @module: Owning module.
399 * @attach: The optional "attach" handler for manually configured COMEDI
400 * devices.
401 * @detach: The "detach" handler for deconfiguring COMEDI devices.
402 * @auto_attach: The optional "auto_attach" handler for automatically
403 * configured COMEDI devices.
404 * @num_names: Optional number of "board names" supported.
405 * @board_name: Optional pointer to a pointer to a board name. The pointer
406 * to a board name is embedded in an element of a driver-defined array
407 * of static, read-only board type information.
408 * @offset: Optional size of each element of the driver-defined array of
409 * static, read-only board type information, i.e. the offset between each
410 * pointer to a board name.
411 *
412 * This is used with comedi_driver_register() and comedi_driver_unregister() to
413 * register and unregister a low-level COMEDI driver with the COMEDI core.
414 *
415 * If @num_names is non-zero, @board_name should be non-NULL, and @offset
416 * should be at least sizeof(*board_name). These are used by the handler for
417 * the %COMEDI_DEVCONFIG ioctl to match a hardware device and its driver by
418 * board name. If @num_names is zero, the %COMEDI_DEVCONFIG ioctl matches a
419 * hardware device and its driver by driver name. This is only useful if the
420 * @attach handler is set. If @num_names is non-zero, the driver's @attach
421 * handler will be called with the COMEDI device structure's board_ptr member
422 * pointing to the matched pointer to a board name within the driver's private
423 * array of static, read-only board type information.
424 *
425 * The @detach handler has two roles. If a COMEDI device was successfully
426 * configured by the @attach or @auto_attach handler, it is called when the
427 * device is being deconfigured (by the %COMEDI_DEVCONFIG ioctl, or due to
428 * unloading of the driver, or due to device removal). It is also called when
429 * the @attach or @auto_attach handler returns an error. Therefore, the
430 * @attach or @auto_attach handlers can defer clean-up on error until the
431 * @detach handler is called. If the @attach or @auto_attach handlers free
432 * any resources themselves, they must prevent the @detach handler from
433 * freeing the same resources. The @detach handler must not assume that all
434 * resources requested by the @attach or @auto_attach handler were
435 * successfully allocated.
436 */
437 struct comedi_driver {
438 /* private: */
439 struct comedi_driver *next; /* Next in list of COMEDI drivers. */
440 /* public: */
441 const char *driver_name;
442 struct module *module;
443 int (*attach)(struct comedi_device *dev, struct comedi_devconfig *it);
444 void (*detach)(struct comedi_device *dev);
445 int (*auto_attach)(struct comedi_device *dev, unsigned long context);
446 unsigned int num_names;
447 const char *const *board_name;
448 int offset;
449 };
450
451 /**
452 * struct comedi_device - Working data for a COMEDI device
453 * @use_count: Number of open file objects.
454 * @driver: Low-level COMEDI driver attached to this COMEDI device.
455 * @pacer: Optional pointer to a dynamically allocated acquisition pacer
456 * control. It is freed automatically after the COMEDI device is
457 * detached from the low-level driver.
458 * @private: Optional pointer to private data allocated by the low-level
459 * driver. It is freed automatically after the COMEDI device is
460 * detached from the low-level driver.
461 * @class_dev: Sysfs comediX device.
462 * @minor: Minor device number of COMEDI char device (0-47).
463 * @detach_count: Counter incremented every time the COMEDI device is detached.
464 * Used for checking a previous attachment is still valid.
465 * @hw_dev: Optional pointer to the low-level hardware &struct device. It is
466 * required for automatically configured COMEDI devices and optional for
467 * COMEDI devices configured by the %COMEDI_DEVCONFIG ioctl, although
468 * the bus-specific COMEDI functions only work if it is set correctly.
469 * It is also passed to dma_alloc_coherent() for COMEDI subdevices that
470 * have their 'async_dma_dir' member set to something other than
471 * %DMA_NONE.
472 * @board_name: Pointer to a COMEDI board name or a COMEDI driver name. When
473 * the low-level driver's "attach" handler is called by the handler for
474 * the %COMEDI_DEVCONFIG ioctl, it either points to a matched board name
475 * string if the 'num_names' member of the &struct comedi_driver is
476 * non-zero, otherwise it points to the low-level driver name string.
477 * When the low-lever driver's "auto_attach" handler is called for an
478 * automatically configured COMEDI device, it points to the low-level
479 * driver name string. The low-level driver is free to change it in its
480 * "attach" or "auto_attach" handler if it wishes.
481 * @board_ptr: Optional pointer to private, read-only board type information in
482 * the low-level driver. If the 'num_names' member of the &struct
483 * comedi_driver is non-zero, the handler for the %COMEDI_DEVCONFIG ioctl
484 * will point it to a pointer to a matched board name string within the
485 * driver's private array of static, read-only board type information when
486 * calling the driver's "attach" handler. The low-level driver is free to
487 * change it.
488 * @attached: Flag indicating that the COMEDI device is attached to a low-level
489 * driver.
490 * @ioenabled: Flag used to indicate that a PCI device has been enabled and
491 * its regions requested.
492 * @spinlock: Generic spin-lock for use by the low-level driver.
493 * @mutex: Generic mutex for use by the COMEDI core module.
494 * @attach_lock: &struct rw_semaphore used to guard against the COMEDI device
495 * being detached while an operation is in progress. The down_write()
496 * operation is only allowed while @mutex is held and is used when
497 * changing @attached and @detach_count and calling the low-level driver's
498 * "detach" handler. The down_read() operation is generally used without
499 * holding @mutex.
500 * @refcount: &struct kref reference counter for freeing COMEDI device.
501 * @n_subdevices: Number of COMEDI subdevices allocated by the low-level
502 * driver for this device.
503 * @subdevices: Dynamically allocated array of COMEDI subdevices.
504 * @mmio: Optional pointer to a remapped MMIO region set by the low-level
505 * driver.
506 * @iobase: Optional base of an I/O port region requested by the low-level
507 * driver.
508 * @iolen: Length of I/O port region requested at @iobase.
509 * @irq: Optional IRQ number requested by the low-level driver.
510 * @read_subdev: Optional pointer to a default COMEDI subdevice operated on by
511 * the read() file operation. Set by the low-level driver.
512 * @write_subdev: Optional pointer to a default COMEDI subdevice operated on by
513 * the write() file operation. Set by the low-level driver.
514 * @async_queue: Storage for fasync_helper().
515 * @open: Optional pointer to a function set by the low-level driver to be
516 * called when @use_count changes from 0 to 1.
517 * @close: Optional pointer to a function set by the low-level driver to be
518 * called when @use_count changed from 1 to 0.
519 * @insn_device_config: Optional pointer to a handler for all sub-instructions
520 * except %INSN_DEVICE_CONFIG_GET_ROUTES of the %INSN_DEVICE_CONFIG
521 * instruction. If this is not initialized by the low-level driver, a
522 * default handler will be set during post-configuration.
523 * @get_valid_routes: Optional pointer to a handler for the
524 * %INSN_DEVICE_CONFIG_GET_ROUTES sub-instruction of the
525 * %INSN_DEVICE_CONFIG instruction set. If this is not initialized by the
526 * low-level driver, a default handler that copies zero routes back to the
527 * user will be used.
528 *
529 * This is the main control data structure for a COMEDI device (as far as the
530 * COMEDI core is concerned). There are two groups of COMEDI devices -
531 * "legacy" devices that are configured by the handler for the
532 * %COMEDI_DEVCONFIG ioctl, and automatically configured devices resulting
533 * from a call to comedi_auto_config() as a result of a bus driver probe in
534 * a low-level COMEDI driver. The "legacy" COMEDI devices are allocated
535 * during module initialization if the "comedi_num_legacy_minors" module
536 * parameter is non-zero and use minor device numbers from 0 to
537 * comedi_num_legacy_minors minus one. The automatically configured COMEDI
538 * devices are allocated on demand and use minor device numbers from
539 * comedi_num_legacy_minors to 47.
540 */
541 struct comedi_device {
542 int use_count;
543 struct comedi_driver *driver;
544 struct comedi_8254 *pacer;
545 void *private;
546
547 struct device *class_dev;
548 int minor;
549 unsigned int detach_count;
550 struct device *hw_dev;
551
552 const char *board_name;
553 const void *board_ptr;
554 unsigned int attached:1;
555 unsigned int ioenabled:1;
556 spinlock_t spinlock; /* generic spin-lock for low-level driver */
557 struct mutex mutex; /* generic mutex for COMEDI core */
558 struct rw_semaphore attach_lock;
559 struct kref refcount;
560
561 int n_subdevices;
562 struct comedi_subdevice *subdevices;
563
564 /* dumb */
565 void __iomem *mmio;
566 unsigned long iobase;
567 unsigned long iolen;
568 unsigned int irq;
569
570 struct comedi_subdevice *read_subdev;
571 struct comedi_subdevice *write_subdev;
572
573 struct fasync_struct *async_queue;
574
575 int (*open)(struct comedi_device *dev);
576 void (*close)(struct comedi_device *dev);
577 int (*insn_device_config)(struct comedi_device *dev,
578 struct comedi_insn *insn, unsigned int *data);
579 unsigned int (*get_valid_routes)(struct comedi_device *dev,
580 unsigned int n_pairs,
581 unsigned int *pair_data);
582 };
583
584 /*
585 * function prototypes
586 */
587
588 void comedi_event(struct comedi_device *dev, struct comedi_subdevice *s);
589
590 struct comedi_device *comedi_dev_get_from_minor(unsigned int minor);
591 int comedi_dev_put(struct comedi_device *dev);
592
593 bool comedi_is_subdevice_running(struct comedi_subdevice *s);
594
595 void *comedi_alloc_spriv(struct comedi_subdevice *s, size_t size);
596 void comedi_set_spriv_auto_free(struct comedi_subdevice *s);
597
598 int comedi_check_chanlist(struct comedi_subdevice *s,
599 int n,
600 unsigned int *chanlist);
601
602 /* range stuff */
603
604 #define RANGE(a, b) {(a) * 1e6, (b) * 1e6, 0}
605 #define RANGE_ext(a, b) {(a) * 1e6, (b) * 1e6, RF_EXTERNAL}
606 #define RANGE_mA(a, b) {(a) * 1e6, (b) * 1e6, UNIT_mA}
607 #define RANGE_unitless(a, b) {(a) * 1e6, (b) * 1e6, 0}
608 #define BIP_RANGE(a) {-(a) * 1e6, (a) * 1e6, 0}
609 #define UNI_RANGE(a) {0, (a) * 1e6, 0}
610
611 extern const struct comedi_lrange range_bipolar10;
612 extern const struct comedi_lrange range_bipolar5;
613 extern const struct comedi_lrange range_bipolar2_5;
614 extern const struct comedi_lrange range_unipolar10;
615 extern const struct comedi_lrange range_unipolar5;
616 extern const struct comedi_lrange range_unipolar2_5;
617 extern const struct comedi_lrange range_0_20mA;
618 extern const struct comedi_lrange range_4_20mA;
619 extern const struct comedi_lrange range_0_32mA;
620 extern const struct comedi_lrange range_unknown;
621
622 #define range_digital range_unipolar5
623
624 /**
625 * struct comedi_lrange - Describes a COMEDI range table
626 * @length: Number of entries in the range table.
627 * @range: Array of &struct comedi_krange, one for each range.
628 *
629 * Each element of @range[] describes the minimum and maximum physical range
630 * range and the type of units. Typically, the type of unit is %UNIT_volt
631 * (i.e. volts) and the minimum and maximum are in millionths of a volt.
632 * There may also be a flag that indicates the minimum and maximum are merely
633 * scale factors for an unknown, external reference.
634 */
635 struct comedi_lrange {
636 int length;
637 struct comedi_krange range[];
638 };
639
640 /**
641 * comedi_range_is_bipolar() - Test if subdevice range is bipolar
642 * @s: COMEDI subdevice.
643 * @range: Index of range within a range table.
644 *
645 * Tests whether a range is bipolar by checking whether its minimum value
646 * is negative.
647 *
648 * Assumes @range is valid. Does not work for subdevices using a
649 * channel-specific range table list.
650 *
651 * Return:
652 * %true if the range is bipolar.
653 * %false if the range is unipolar.
654 */
655 static inline bool comedi_range_is_bipolar(struct comedi_subdevice *s,
656 unsigned int range)
657 {
658 return s->range_table->range[range].min < 0;
659 }
660
661 /**
662 * comedi_range_is_unipolar() - Test if subdevice range is unipolar
663 * @s: COMEDI subdevice.
664 * @range: Index of range within a range table.
665 *
666 * Tests whether a range is unipolar by checking whether its minimum value
667 * is at least 0.
668 *
669 * Assumes @range is valid. Does not work for subdevices using a
670 * channel-specific range table list.
671 *
672 * Return:
673 * %true if the range is unipolar.
674 * %false if the range is bipolar.
675 */
676 static inline bool comedi_range_is_unipolar(struct comedi_subdevice *s,
677 unsigned int range)
678 {
679 return s->range_table->range[range].min >= 0;
680 }
681
682 /**
683 * comedi_range_is_external() - Test if subdevice range is external
684 * @s: COMEDI subdevice.
685 * @range: Index of range within a range table.
686 *
687 * Tests whether a range is externally reference by checking whether its
688 * %RF_EXTERNAL flag is set.
689 *
690 * Assumes @range is valid. Does not work for subdevices using a
691 * channel-specific range table list.
692 *
693 * Return:
694 * %true if the range is external.
695 * %false if the range is internal.
696 */
697 static inline bool comedi_range_is_external(struct comedi_subdevice *s,
698 unsigned int range)
699 {
700 return !!(s->range_table->range[range].flags & RF_EXTERNAL);
701 }
702
703 /**
704 * comedi_chan_range_is_bipolar() - Test if channel-specific range is bipolar
705 * @s: COMEDI subdevice.
706 * @chan: The channel number.
707 * @range: Index of range within a range table.
708 *
709 * Tests whether a range is bipolar by checking whether its minimum value
710 * is negative.
711 *
712 * Assumes @chan and @range are valid. Only works for subdevices with a
713 * channel-specific range table list.
714 *
715 * Return:
716 * %true if the range is bipolar.
717 * %false if the range is unipolar.
718 */
719 static inline bool comedi_chan_range_is_bipolar(struct comedi_subdevice *s,
720 unsigned int chan,
721 unsigned int range)
722 {
723 return s->range_table_list[chan]->range[range].min < 0;
724 }
725
726 /**
727 * comedi_chan_range_is_unipolar() - Test if channel-specific range is unipolar
728 * @s: COMEDI subdevice.
729 * @chan: The channel number.
730 * @range: Index of range within a range table.
731 *
732 * Tests whether a range is unipolar by checking whether its minimum value
733 * is at least 0.
734 *
735 * Assumes @chan and @range are valid. Only works for subdevices with a
736 * channel-specific range table list.
737 *
738 * Return:
739 * %true if the range is unipolar.
740 * %false if the range is bipolar.
741 */
742 static inline bool comedi_chan_range_is_unipolar(struct comedi_subdevice *s,
743 unsigned int chan,
744 unsigned int range)
745 {
746 return s->range_table_list[chan]->range[range].min >= 0;
747 }
748
749 /**
750 * comedi_chan_range_is_external() - Test if channel-specific range is external
751 * @s: COMEDI subdevice.
752 * @chan: The channel number.
753 * @range: Index of range within a range table.
754 *
755 * Tests whether a range is externally reference by checking whether its
756 * %RF_EXTERNAL flag is set.
757 *
758 * Assumes @chan and @range are valid. Only works for subdevices with a
759 * channel-specific range table list.
760 *
761 * Return:
762 * %true if the range is bipolar.
763 * %false if the range is unipolar.
764 */
765 static inline bool comedi_chan_range_is_external(struct comedi_subdevice *s,
766 unsigned int chan,
767 unsigned int range)
768 {
769 return !!(s->range_table_list[chan]->range[range].flags & RF_EXTERNAL);
770 }
771
772 /**
773 * comedi_offset_munge() - Convert between offset binary and 2's complement
774 * @s: COMEDI subdevice.
775 * @val: Value to be converted.
776 *
777 * Toggles the highest bit of a sample value to toggle between offset binary
778 * and 2's complement. Assumes that @s->maxdata is a power of 2 minus 1.
779 *
780 * Return: The converted value.
781 */
782 static inline unsigned int comedi_offset_munge(struct comedi_subdevice *s,
783 unsigned int val)
784 {
785 return val ^ s->maxdata ^ (s->maxdata >> 1);
786 }
787
788 /**
789 * comedi_bytes_per_sample() - Determine subdevice sample size
790 * @s: COMEDI subdevice.
791 *
792 * The sample size will be 4 (sizeof int) or 2 (sizeof short) depending on
793 * whether the %SDF_LSAMPL subdevice flag is set or not.
794 *
795 * Return: The subdevice sample size.
796 */
797 static inline unsigned int comedi_bytes_per_sample(struct comedi_subdevice *s)
798 {
799 return s->subdev_flags & SDF_LSAMPL ? sizeof(int) : sizeof(short);
800 }
801
802 /**
803 * comedi_sample_shift() - Determine log2 of subdevice sample size
804 * @s: COMEDI subdevice.
805 *
806 * The sample size will be 4 (sizeof int) or 2 (sizeof short) depending on
807 * whether the %SDF_LSAMPL subdevice flag is set or not. The log2 of the
808 * sample size will be 2 or 1 and can be used as the right operand of a
809 * bit-shift operator to multiply or divide something by the sample size.
810 *
811 * Return: log2 of the subdevice sample size.
812 */
813 static inline unsigned int comedi_sample_shift(struct comedi_subdevice *s)
814 {
815 return s->subdev_flags & SDF_LSAMPL ? 2 : 1;
816 }
817
818 /**
819 * comedi_bytes_to_samples() - Convert a number of bytes to a number of samples
820 * @s: COMEDI subdevice.
821 * @nbytes: Number of bytes
822 *
823 * Return: The number of bytes divided by the subdevice sample size.
824 */
825 static inline unsigned int comedi_bytes_to_samples(struct comedi_subdevice *s,
826 unsigned int nbytes)
827 {
828 return nbytes >> comedi_sample_shift(s);
829 }
830
831 /**
832 * comedi_samples_to_bytes() - Convert a number of samples to a number of bytes
833 * @s: COMEDI subdevice.
834 * @nsamples: Number of samples.
835 *
836 * Return: The number of samples multiplied by the subdevice sample size.
837 * (Does not check for arithmetic overflow.)
838 */
839 static inline unsigned int comedi_samples_to_bytes(struct comedi_subdevice *s,
840 unsigned int nsamples)
841 {
842 return nsamples << comedi_sample_shift(s);
843 }
844
845 /**
846 * comedi_check_trigger_src() - Trivially validate a comedi_cmd trigger source
847 * @src: Pointer to the trigger source to validate.
848 * @flags: Bitmask of valid %TRIG_* for the trigger.
849 *
850 * This is used in "step 1" of the do_cmdtest functions of comedi drivers
851 * to validate the comedi_cmd triggers. The mask of the @src against the
852 * @flags allows the userspace comedilib to pass all the comedi_cmd
853 * triggers as %TRIG_ANY and get back a bitmask of the valid trigger sources.
854 *
855 * Return:
856 * 0 if trigger sources in *@src are all supported.
857 * -EINVAL if any trigger source in *@src is unsupported.
858 */
859 static inline int comedi_check_trigger_src(unsigned int *src,
860 unsigned int flags)
861 {
862 unsigned int orig_src = *src;
863
864 *src = orig_src & flags;
865 if (*src == TRIG_INVALID || *src != orig_src)
866 return -EINVAL;
867 return 0;
868 }
869
870 /**
871 * comedi_check_trigger_is_unique() - Make sure a trigger source is unique
872 * @src: The trigger source to check.
873 *
874 * Return:
875 * 0 if no more than one trigger source is set.
876 * -EINVAL if more than one trigger source is set.
877 */
878 static inline int comedi_check_trigger_is_unique(unsigned int src)
879 {
880 /* this test is true if more than one _src bit is set */
881 if ((src & (src - 1)) != 0)
882 return -EINVAL;
883 return 0;
884 }
885
886 /**
887 * comedi_check_trigger_arg_is() - Trivially validate a trigger argument
888 * @arg: Pointer to the trigger arg to validate.
889 * @val: The value the argument should be.
890 *
891 * Forces *@arg to be @val.
892 *
893 * Return:
894 * 0 if *@arg was already @val.
895 * -EINVAL if *@arg differed from @val.
896 */
897 static inline int comedi_check_trigger_arg_is(unsigned int *arg,
898 unsigned int val)
899 {
900 if (*arg != val) {
901 *arg = val;
902 return -EINVAL;
903 }
904 return 0;
905 }
906
907 /**
908 * comedi_check_trigger_arg_min() - Trivially validate a trigger argument min
909 * @arg: Pointer to the trigger arg to validate.
910 * @val: The minimum value the argument should be.
911 *
912 * Forces *@arg to be at least @val, setting it to @val if necessary.
913 *
914 * Return:
915 * 0 if *@arg was already at least @val.
916 * -EINVAL if *@arg was less than @val.
917 */
918 static inline int comedi_check_trigger_arg_min(unsigned int *arg,
919 unsigned int val)
920 {
921 if (*arg < val) {
922 *arg = val;
923 return -EINVAL;
924 }
925 return 0;
926 }
927
928 /**
929 * comedi_check_trigger_arg_max() - Trivially validate a trigger argument max
930 * @arg: Pointer to the trigger arg to validate.
931 * @val: The maximum value the argument should be.
932 *
933 * Forces *@arg to be no more than @val, setting it to @val if necessary.
934 *
935 * Return:
936 * 0 if*@arg was already no more than @val.
937 * -EINVAL if *@arg was greater than @val.
938 */
939 static inline int comedi_check_trigger_arg_max(unsigned int *arg,
940 unsigned int val)
941 {
942 if (*arg > val) {
943 *arg = val;
944 return -EINVAL;
945 }
946 return 0;
947 }
948
949 /*
950 * Must set dev->hw_dev if you wish to dma directly into comedi's buffer.
951 * Also useful for retrieving a previously configured hardware device of
952 * known bus type. Set automatically for auto-configured devices.
953 * Automatically set to NULL when detaching hardware device.
954 */
955 int comedi_set_hw_dev(struct comedi_device *dev, struct device *hw_dev);
956
957 /**
958 * comedi_buf_n_bytes_ready - Determine amount of unread data in buffer
959 * @s: COMEDI subdevice.
960 *
961 * Determines the number of bytes of unread data in the asynchronous
962 * acquisition data buffer for a subdevice. The data in question might not
963 * have been fully "munged" yet.
964 *
965 * Returns: The amount of unread data in bytes.
966 */
967 static inline unsigned int comedi_buf_n_bytes_ready(struct comedi_subdevice *s)
968 {
969 return s->async->buf_write_count - s->async->buf_read_count;
970 }
971
972 unsigned int comedi_buf_write_alloc(struct comedi_subdevice *s, unsigned int n);
973 unsigned int comedi_buf_write_free(struct comedi_subdevice *s, unsigned int n);
974
975 unsigned int comedi_buf_read_n_available(struct comedi_subdevice *s);
976 unsigned int comedi_buf_read_alloc(struct comedi_subdevice *s, unsigned int n);
977 unsigned int comedi_buf_read_free(struct comedi_subdevice *s, unsigned int n);
978
979 unsigned int comedi_buf_write_samples(struct comedi_subdevice *s,
980 const void *data, unsigned int nsamples);
981 unsigned int comedi_buf_read_samples(struct comedi_subdevice *s,
982 void *data, unsigned int nsamples);
983
984 /* drivers.c - general comedi driver functions */
985
986 #define COMEDI_TIMEOUT_MS 1000
987
988 int comedi_timeout(struct comedi_device *dev, struct comedi_subdevice *s,
989 struct comedi_insn *insn,
990 int (*cb)(struct comedi_device *dev,
991 struct comedi_subdevice *s,
992 struct comedi_insn *insn, unsigned long context),
993 unsigned long context);
994
995 unsigned int comedi_handle_events(struct comedi_device *dev,
996 struct comedi_subdevice *s);
997
998 int comedi_dio_insn_config(struct comedi_device *dev,
999 struct comedi_subdevice *s,
1000 struct comedi_insn *insn, unsigned int *data,
1001 unsigned int mask);
1002 unsigned int comedi_dio_update_state(struct comedi_subdevice *s,
1003 unsigned int *data);
1004 unsigned int comedi_bytes_per_scan_cmd(struct comedi_subdevice *s,
1005 struct comedi_cmd *cmd);
1006 unsigned int comedi_bytes_per_scan(struct comedi_subdevice *s);
1007 unsigned int comedi_nscans_left(struct comedi_subdevice *s,
1008 unsigned int nscans);
1009 unsigned int comedi_nsamples_left(struct comedi_subdevice *s,
1010 unsigned int nsamples);
1011 void comedi_inc_scan_progress(struct comedi_subdevice *s,
1012 unsigned int num_bytes);
1013
1014 void *comedi_alloc_devpriv(struct comedi_device *dev, size_t size);
1015 int comedi_alloc_subdevices(struct comedi_device *dev, int num_subdevices);
1016 int comedi_alloc_subdev_readback(struct comedi_subdevice *s);
1017
1018 int comedi_readback_insn_read(struct comedi_device *dev,
1019 struct comedi_subdevice *s,
1020 struct comedi_insn *insn, unsigned int *data);
1021
1022 int comedi_load_firmware(struct comedi_device *dev, struct device *hw_dev,
1023 const char *name,
1024 int (*cb)(struct comedi_device *dev,
1025 const u8 *data, size_t size,
1026 unsigned long context),
1027 unsigned long context);
1028
1029 int __comedi_request_region(struct comedi_device *dev,
1030 unsigned long start, unsigned long len);
1031 int comedi_request_region(struct comedi_device *dev,
1032 unsigned long start, unsigned long len);
1033 void comedi_legacy_detach(struct comedi_device *dev);
1034
1035 int comedi_auto_config(struct device *hardware_device,
1036 struct comedi_driver *driver, unsigned long context);
1037 void comedi_auto_unconfig(struct device *hardware_device);
1038
1039 int comedi_driver_register(struct comedi_driver *driver);
1040 void comedi_driver_unregister(struct comedi_driver *driver);
1041
1042 /**
1043 * module_comedi_driver() - Helper macro for registering a comedi driver
1044 * @__comedi_driver: comedi_driver struct
1045 *
1046 * Helper macro for comedi drivers which do not do anything special in module
1047 * init/exit. This eliminates a lot of boilerplate. Each module may only use
1048 * this macro once, and calling it replaces module_init() and module_exit().
1049 */
1050 #define module_comedi_driver(__comedi_driver) \
1051 module_driver(__comedi_driver, comedi_driver_register, \
1052 comedi_driver_unregister)
1053
1054 #endif /* _COMEDIDEV_H */