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