3 * header file for kernel-only structures, variables, and constants
5 * COMEDI - Linux Control and Measurement Device Interface
6 * Copyright (C) 1997-2000 David A. Schleef <ds@schleef.org>
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
22 #include <linux/dma-mapping.h>
23 #include <linux/mutex.h>
24 #include <linux/spinlock_types.h>
25 #include <linux/rwsem.h>
26 #include <linux/kref.h>
30 #define COMEDI_VERSION(a, b, c) (((a) << 16) + ((b) << 8) + (c))
31 #define COMEDI_VERSION_CODE COMEDI_VERSION(COMEDI_MAJORVERSION, \
32 COMEDI_MINORVERSION, COMEDI_MICROVERSION)
33 #define COMEDI_RELEASE VERSION
35 #define COMEDI_NUM_BOARD_MINORS 0x30
38 * struct comedi_subdevice - Working data for a COMEDI subdevice
39 * @device: COMEDI device to which this subdevice belongs. (Initialized by
40 * comedi_alloc_subdevices().)
41 * @index: Index of this subdevice within device's array of subdevices.
42 * (Initialized by comedi_alloc_subdevices().)
43 * @type: Type of subdevice from &enum comedi_subdevice_type. (Initialized by
44 * the low-level driver.)
45 * @n_chan: Number of channels the subdevice supports. (Initialized by the
47 * @subdev_flags: Various "SDF" flags indicating aspects of the subdevice to
48 * the COMEDI core and user application. (Initialized by the low-level
50 * @len_chanlist: Maximum length of a channel list if the subdevice supports
51 * asynchronous acquisition commands. (Optionally initialized by the
52 * low-level driver, or changed from 0 to 1 during post-configuration.)
53 * @private: Private data pointer which is either set by the low-level driver
54 * itself, or by a call to comedi_alloc_spriv() which allocates storage.
55 * In the latter case, the storage is automatically freed after the
56 * low-level driver's "detach" handler is called for the device.
57 * (Initialized by the low-level driver.)
58 * @async: Pointer to &struct comedi_async id the subdevice supports
59 * asynchronous acquisition commands. (Allocated and initialized during
60 * post-configuration if needed.)
61 * @lock: Pointer to a file object that performed a %COMEDI_LOCK ioctl on the
62 * subdevice. (Initially NULL.)
63 * @busy: Pointer to a file object that is performing an asynchronous
64 * acquisition command on the subdevice. (Initially NULL.)
65 * @runflags: Internal flags for use by COMEDI core, mostly indicating whether
66 * an asynchronous acquisition command is running.
67 * @spin_lock: Generic spin-lock for use by the COMEDI core and the low-level
68 * driver. (Initialized by comedi_alloc_subdevices().)
69 * @io_bits: Bit-mask indicating the channel directions for a DIO subdevice
70 * with no more than 32 channels. A '1' at a bit position indicates the
71 * corresponding channel is configured as an output. (Initialized by the
72 * low-level driver for a DIO subdevice. Forced to all-outputs during
73 * post-configuration for a digital output subdevice.)
74 * @maxdata: If non-zero, this is the maximum raw data value of each channel.
75 * If zero, the maximum data value is channel-specific. (Initialized by
76 * the low-level driver.)
77 * @maxdata_list: If the maximum data value is channel-specific, this points
78 * to an array of maximum data values indexed by channel index.
79 * (Initialized by the low-level driver.)
80 * @range_table: If non-NULL, this points to a COMEDI range table for the
81 * subdevice. If NULL, the range table is channel-specific. (Initialized
82 * by the low-level driver, will be set to an "invalid" range table during
83 * post-configuration if @range_table and @range_table_list are both
85 * @range_table_list: If the COMEDI range table is channel-specific, this
86 * points to an array of pointers to COMEDI range tables indexed by
87 * channel number. (Initialized by the low-level driver.)
88 * @chanlist: Not used.
89 * @insn_read: Optional pointer to a handler for the %INSN_READ instruction.
90 * (Initialized by the low-level driver, or set to a default handler
91 * during post-configuration.)
92 * @insn_write: Optional pointer to a handler for the %INSN_WRITE instruction.
93 * (Initialized by the low-level driver, or set to a default handler
94 * during post-configuration.)
95 * @insn_bits: Optional pointer to a handler for the %INSN_BITS instruction
96 * for a digital input, digital output or digital input/output subdevice.
97 * (Initialized by the low-level driver, or set to a default handler
98 * during post-configuration.)
99 * @insn_config: Optional pointer to a handler for the %INSN_CONFIG
100 * instruction. (Initialized by the low-level driver, or set to a default
101 * handler during post-configuration.)
102 * @do_cmd: If the subdevice supports asynchronous acquisition commands, this
103 * points to a handler to set it up in hardware. (Initialized by the
105 * @do_cmdtest: If the subdevice supports asynchronous acquisition commands,
106 * this points to a handler used to check and possibly tweak a prospective
107 * acquisition command without setting it up in hardware. (Initialized by
108 * the low-level driver.)
109 * @poll: If the subdevice supports asynchronous acquisition commands, this
110 * is an optional pointer to a handler for the %COMEDI_POLL ioctl which
111 * instructs the low-level driver to synchronize buffers. (Initialized by
112 * the low-level driver if needed.)
113 * @cancel: If the subdevice supports asynchronous acquisition commands, this
114 * points to a handler used to terminate a running command. (Initialized
115 * by the low-level driver.)
116 * @buf_change: If the subdevice supports asynchronous acquisition commands,
117 * this is an optional pointer to a handler that is called when the data
118 * buffer for handling asynchronous commands is allocated or reallocated.
119 * (Initialized by the low-level driver if needed.)
120 * @munge: If the subdevice supports asynchronous acquisition commands and
121 * uses DMA to transfer data from the hardware to the acquisition buffer,
122 * this points to a function used to "munge" the data values from the
123 * hardware into the format expected by COMEDI. (Initialized by the
124 * low-level driver if needed.)
125 * @async_dma_dir: If the subdevice supports asynchronous acquisition commands
126 * and uses DMA to transfer data from the hardware to the acquisition
127 * buffer, this sets the DMA direction for the buffer. (initialized to
128 * %DMA_NONE by comedi_alloc_subdevices() and changed by the low-level
129 * driver if necessary.)
130 * @state: Handy bit-mask indicating the output states for a DIO or digital
131 * output subdevice with no more than 32 channels. (Initialized by the
133 * @class_dev: If the subdevice supports asynchronous acquisition commands,
134 * this points to a sysfs comediX_subdY device where X is the minor device
135 * number of the COMEDI device and Y is the subdevice number. The minor
136 * device number for the sysfs device is allocated dynamically in the
137 * range 48 to 255. This is used to allow the COMEDI device to be opened
138 * with a different default read or write subdevice. (Allocated during
139 * post-configuration if needed.)
140 * @minor: If @class_dev is set, this is its dynamically allocated minor
141 * device number. (Set during post-configuration if necessary.)
142 * @readback: Optional pointer to memory allocated by
143 * comedi_alloc_subdev_readback() used to hold the values written to
144 * analog output channels so they can be read back. The storage is
145 * automatically freed after the low-level driver's "detach" handler is
146 * called for the device. (Initialized by the low-level driver.)
148 * This is the main control structure for a COMEDI subdevice. If the subdevice
149 * supports asynchronous acquisition commands, additional information is stored
150 * in the &struct comedi_async pointed to by @async.
152 * Most of the subdevice is initialized by the low-level driver's "attach" or
153 * "auto_attach" handlers but parts of it are initialized by
154 * comedi_alloc_subdevices(), and other parts are initialized during
155 * post-configuration on return from that handler.
157 * A low-level driver that sets @insn_bits for a digital input, digital output,
158 * or DIO subdevice may leave @insn_read and @insn_write uninitialized, in
159 * which case they will be set to a default handler during post-configuration
160 * that uses @insn_bits to emulate the %INSN_READ and %INSN_WRITE instructions.
162 struct comedi_subdevice {
163 struct comedi_device *device;
168 int len_chanlist; /* maximum length of channel/gain list */
172 struct comedi_async *async;
177 spinlock_t spin_lock;
179 unsigned int io_bits;
181 unsigned int maxdata; /* if maxdata==0, use list */
182 const unsigned int *maxdata_list; /* list is channel specific */
184 const struct comedi_lrange *range_table;
185 const struct comedi_lrange *const *range_table_list;
187 unsigned int *chanlist; /* driver-owned chanlist (not used) */
189 int (*insn_read)(struct comedi_device *, struct comedi_subdevice *,
190 struct comedi_insn *, unsigned int *);
191 int (*insn_write)(struct comedi_device *, struct comedi_subdevice *,
192 struct comedi_insn *, unsigned int *);
193 int (*insn_bits)(struct comedi_device *, struct comedi_subdevice *,
194 struct comedi_insn *, unsigned int *);
195 int (*insn_config)(struct comedi_device *, struct comedi_subdevice *,
196 struct comedi_insn *, unsigned int *);
198 int (*do_cmd)(struct comedi_device *, struct comedi_subdevice *);
199 int (*do_cmdtest)(struct comedi_device *, struct comedi_subdevice *,
200 struct comedi_cmd *);
201 int (*poll)(struct comedi_device *, struct comedi_subdevice *);
202 int (*cancel)(struct comedi_device *, struct comedi_subdevice *);
204 /* called when the buffer changes */
205 int (*buf_change)(struct comedi_device *, struct comedi_subdevice *);
207 void (*munge)(struct comedi_device *dev, struct comedi_subdevice *s,
208 void *data, unsigned int num_bytes,
209 unsigned int start_chan_index);
210 enum dma_data_direction async_dma_dir;
214 struct device *class_dev;
217 unsigned int *readback;
221 * struct comedi_buf_page - Describe a page of a COMEDI buffer
222 * @virt_addr: Kernel address of page.
223 * @dma_addr: DMA address of page if in DMA coherent memory.
225 struct comedi_buf_page {
231 * struct comedi_buf_map - Describe pages in a COMEDI buffer
232 * @dma_hw_dev: Low-level hardware &struct device pointer copied from the
233 * COMEDI device's hw_dev member.
234 * @page_list: Pointer to array of &struct comedi_buf_page, one for each
235 * page in the buffer.
236 * @n_pages: Number of pages in the buffer.
237 * @dma_dir: DMA direction used to allocate pages of DMA coherent memory,
238 * or %DMA_NONE if pages allocated from regular memory.
239 * @refcount: &struct kref reference counter used to free the buffer.
241 * A COMEDI data buffer is allocated as individual pages, either in
242 * conventional memory or DMA coherent memory, depending on the attached,
243 * low-level hardware device. (The buffer pages also get mapped into the
244 * kernel's contiguous virtual address space pointed to by the 'prealloc_buf'
245 * member of &struct comedi_async.)
247 * The buffer is normally freed when the COMEDI device is detached from the
248 * low-level driver (which may happen due to device removal), but if it happens
249 * to be mmapped at the time, the pages cannot be freed until the buffer has
250 * been munmapped. That is what the reference counter is for. (The virtual
251 * address space pointed by 'prealloc_buf' is freed when the COMEDI device is
254 struct comedi_buf_map {
255 struct device *dma_hw_dev;
256 struct comedi_buf_page *page_list;
257 unsigned int n_pages;
258 enum dma_data_direction dma_dir;
259 struct kref refcount;
263 * struct comedi_async - Control data for asynchronous COMEDI commands
264 * @prealloc_buf: Kernel virtual address of allocated acquisition buffer.
265 * @prealloc_bufsz: Buffer size (in bytes).
266 * @buf_map: Map of buffer pages.
267 * @max_bufsize: Maximum allowed buffer size (in bytes).
268 * @buf_write_count: "Write completed" count (in bytes, modulo 2**32).
269 * @buf_write_alloc_count: "Allocated for writing" count (in bytes,
271 * @buf_read_count: "Read completed" count (in bytes, modulo 2**32).
272 * @buf_read_alloc_count: "Allocated for reading" count (in bytes,
274 * @buf_write_ptr: Buffer position for writer.
275 * @buf_read_ptr: Buffer position for reader.
276 * @cur_chan: Current position in chanlist for scan (for those drivers that
278 * @scans_done: The number of scans completed.
279 * @scan_progress: Amount received or sent for current scan (in bytes).
280 * @munge_chan: Current position in chanlist for "munging".
281 * @munge_count: "Munge" count (in bytes, modulo 2**32).
282 * @munge_ptr: Buffer position for "munging".
283 * @events: Bit-vector of events that have occurred.
284 * @cmd: Details of comedi command in progress.
285 * @wait_head: Task wait queue for file reader or writer.
286 * @cb_mask: Bit-vector of events that should wake waiting tasks.
287 * @inttrig: Software trigger function for command, or NULL.
289 * Note about the ..._count and ..._ptr members:
291 * Think of the _Count values being integers of unlimited size, indexing
292 * into a buffer of infinite length (though only an advancing portion
293 * of the buffer of fixed length prealloc_bufsz is accessible at any
296 * Buf_Read_Count <= Buf_Read_Alloc_Count <= Munge_Count <=
297 * Buf_Write_Count <= Buf_Write_Alloc_Count <=
298 * (Buf_Read_Count + prealloc_bufsz)
300 * (Those aren't the actual members, apart from prealloc_bufsz.) When the
301 * buffer is reset, those _Count values start at 0 and only increase in value,
302 * maintaining the above inequalities until the next time the buffer is
303 * reset. The buffer is divided into the following regions by the inequalities:
305 * [0, Buf_Read_Count):
306 * old region no longer accessible
308 * [Buf_Read_Count, Buf_Read_Alloc_Count):
309 * filled and munged region allocated for reading but not yet read
311 * [Buf_Read_Alloc_Count, Munge_Count):
312 * filled and munged region not yet allocated for reading
314 * [Munge_Count, Buf_Write_Count):
315 * filled region not yet munged
317 * [Buf_Write_Count, Buf_Write_Alloc_Count):
318 * unfilled region allocated for writing but not yet written
320 * [Buf_Write_Alloc_Count, Buf_Read_Count + prealloc_bufsz):
321 * unfilled region not yet allocated for writing
323 * [Buf_Read_Count + prealloc_bufsz, infinity):
324 * unfilled region not yet accessible
326 * Data needs to be written into the buffer before it can be read out,
327 * and may need to be converted (or "munged") between the two
328 * operations. Extra unfilled buffer space may need to allocated for
329 * writing (advancing Buf_Write_Alloc_Count) before new data is written.
330 * After writing new data, the newly filled space needs to be released
331 * (advancing Buf_Write_Count). This also results in the new data being
332 * "munged" (advancing Munge_Count). Before data is read out of the
333 * buffer, extra space may need to be allocated for reading (advancing
334 * Buf_Read_Alloc_Count). After the data has been read out, the space
335 * needs to be released (advancing Buf_Read_Count).
337 * The actual members, buf_read_count, buf_read_alloc_count,
338 * munge_count, buf_write_count, and buf_write_alloc_count take the
339 * value of the corresponding capitalized _Count values modulo 2^32
340 * (UINT_MAX+1). Subtracting a "higher" _count value from a "lower"
341 * _count value gives the same answer as subtracting a "higher" _Count
342 * value from a lower _Count value because prealloc_bufsz < UINT_MAX+1.
343 * The modulo operation is done implicitly.
345 * The buf_read_ptr, munge_ptr, and buf_write_ptr members take the value
346 * of the corresponding capitalized _Count values modulo prealloc_bufsz.
347 * These correspond to byte indices in the physical buffer. The modulo
348 * operation is done by subtracting prealloc_bufsz when the value
349 * exceeds prealloc_bufsz (assuming prealloc_bufsz plus the increment is
350 * less than or equal to UINT_MAX).
352 struct comedi_async {
354 unsigned int prealloc_bufsz;
355 struct comedi_buf_map *buf_map;
356 unsigned int max_bufsize;
357 unsigned int buf_write_count;
358 unsigned int buf_write_alloc_count;
359 unsigned int buf_read_count;
360 unsigned int buf_read_alloc_count;
361 unsigned int buf_write_ptr;
362 unsigned int buf_read_ptr;
363 unsigned int cur_chan;
364 unsigned int scans_done;
365 unsigned int scan_progress;
366 unsigned int munge_chan;
367 unsigned int munge_count;
368 unsigned int munge_ptr;
370 struct comedi_cmd cmd;
371 wait_queue_head_t wait_head;
372 unsigned int cb_mask;
373 int (*inttrig)(struct comedi_device *dev, struct comedi_subdevice *s,
378 * enum comedi_cb - &struct comedi_async callback "events"
379 * @COMEDI_CB_EOS: end-of-scan
380 * @COMEDI_CB_EOA: end-of-acquisition/output
381 * @COMEDI_CB_BLOCK: data has arrived, wakes up read() / write()
382 * @COMEDI_CB_EOBUF: DEPRECATED: end of buffer
383 * @COMEDI_CB_ERROR: card error during acquisition
384 * @COMEDI_CB_OVERFLOW: buffer overflow/underflow
385 * @COMEDI_CB_ERROR_MASK: events that indicate an error has occurred
386 * @COMEDI_CB_CANCEL_MASK: events that will cancel an async command
389 COMEDI_CB_EOS = BIT(0),
390 COMEDI_CB_EOA = BIT(1),
391 COMEDI_CB_BLOCK = BIT(2),
392 COMEDI_CB_EOBUF = BIT(3),
393 COMEDI_CB_ERROR = BIT(4),
394 COMEDI_CB_OVERFLOW = BIT(5),
396 COMEDI_CB_ERROR_MASK = (COMEDI_CB_ERROR | COMEDI_CB_OVERFLOW),
397 COMEDI_CB_CANCEL_MASK = (COMEDI_CB_EOA | COMEDI_CB_ERROR_MASK)
401 * struct comedi_driver - COMEDI driver registration
402 * @driver_name: Name of driver.
403 * @module: Owning module.
404 * @attach: The optional "attach" handler for manually configured COMEDI
406 * @detach: The "detach" handler for deconfiguring COMEDI devices.
407 * @auto_attach: The optional "auto_attach" handler for automatically
408 * configured COMEDI devices.
409 * @num_names: Optional number of "board names" supported.
410 * @board_name: Optional pointer to a pointer to a board name. The pointer
411 * to a board name is embedded in an element of a driver-defined array
412 * of static, read-only board type information.
413 * @offset: Optional size of each element of the driver-defined array of
414 * static, read-only board type information, i.e. the offset between each
415 * pointer to a board name.
417 * This is used with comedi_driver_register() and comedi_driver_unregister() to
418 * register and unregister a low-level COMEDI driver with the COMEDI core.
420 * If @num_names is non-zero, @board_name should be non-NULL, and @offset
421 * should be at least sizeof(*board_name). These are used by the handler for
422 * the %COMEDI_DEVCONFIG ioctl to match a hardware device and its driver by
423 * board name. If @num_names is zero, the %COMEDI_DEVCONFIG ioctl matches a
424 * hardware device and its driver by driver name. This is only useful if the
425 * @attach handler is set. If @num_names is non-zero, the driver's @attach
426 * handler will be called with the COMEDI device structure's board_ptr member
427 * pointing to the matched pointer to a board name within the driver's private
428 * array of static, read-only board type information.
430 struct comedi_driver {
432 struct comedi_driver *next; /* Next in list of COMEDI drivers. */
434 const char *driver_name;
435 struct module *module;
436 int (*attach)(struct comedi_device *, struct comedi_devconfig *);
437 void (*detach)(struct comedi_device *);
438 int (*auto_attach)(struct comedi_device *, unsigned long);
439 unsigned int num_names;
440 const char *const *board_name;
445 * struct comedi_device - Working data for a COMEDI device
446 * @use_count: Number of open file objects.
447 * @driver: Low-level COMEDI driver attached to this COMEDI device.
448 * @pacer: Optional pointer to a dynamically allocated acquisition pacer
449 * control. It is freed automatically after the COMEDI device is
450 * detached from the low-level driver.
451 * @private: Optional pointer to private data allocated by the low-level
452 * driver. It is freed automatically after the COMEDI device is
453 * detached from the low-level driver.
454 * @class_dev: Sysfs comediX device.
455 * @minor: Minor device number of COMEDI char device (0-47).
456 * @detach_count: Counter incremented every time the COMEDI device is detached.
457 * Used for checking a previous attachment is still valid.
458 * @hw_dev: Optional pointer to the low-level hardware &struct device. It is
459 * required for automatically configured COMEDI devices and optional for
460 * COMEDI devices configured by the %COMEDI_DEVCONFIG ioctl, although
461 * the bus-specific COMEDI functions only work if it is set correctly.
462 * It is also passed to dma_alloc_coherent() for COMEDI subdevices that
463 * have their 'async_dma_dir' member set to something other than
465 * @board_name: Pointer to a COMEDI board name or a COMEDI driver name. When
466 * the low-level driver's "attach" handler is called by the handler for
467 * the %COMEDI_DEVCONFIG ioctl, it either points to a matched board name
468 * string if the 'num_names' member of the &struct comedi_driver is
469 * non-zero, otherwise it points to the low-level driver name string.
470 * When the low-lever driver's "auto_attach" handler is called for an
471 * automatically configured COMEDI device, it points to the low-level
472 * driver name string. The low-level driver is free to change it in its
473 * "attach" or "auto_attach" handler if it wishes.
474 * @board_ptr: Optional pointer to private, read-only board type information in
475 * the low-level driver. If the 'num_names' member of the &struct
476 * comedi_driver is non-zero, the handler for the %COMEDI_DEVCONFIG ioctl
477 * will point it to a pointer to a matched board name string within the
478 * driver's private array of static, read-only board type information when
479 * calling the driver's "attach" handler. The low-level driver is free to
481 * @attached: Flag indicating that the COMEDI device is attached to a low-level
483 * @ioenabled: Flag used to indicate that a PCI device has been enabled and
484 * its regions requested.
485 * @spinlock: Generic spin-lock for use by the low-level driver.
486 * @mutex: Generic mutex for use by the COMEDI core module.
487 * @attach_lock: &struct rw_semaphore used to guard against the COMEDI device
488 * being detached while an operation is in progress. The down_write()
489 * operation is only allowed while @mutex is held and is used when
490 * changing @attached and @detach_count and calling the low-level driver's
491 * "detach" handler. The down_read() operation is generally used without
493 * @refcount: &struct kref reference counter for freeing COMEDI device.
494 * @n_subdevices: Number of COMEDI subdevices allocated by the low-level
495 * driver for this device.
496 * @subdevices: Dynamically allocated array of COMEDI subdevices.
497 * @mmio: Optional pointer to a remapped MMIO region set by the low-level
499 * @iobase: Optional base of an I/O port region requested by the low-level
501 * @iolen: Length of I/O port region requested at @iobase.
502 * @irq: Optional IRQ number requested by the low-level driver.
503 * @read_subdev: Optional pointer to a default COMEDI subdevice operated on by
504 * the read() file operation. Set by the low-level driver.
505 * @write_subdev: Optional pointer to a default COMEDI subdevice operated on by
506 * the write() file operation. Set by the low-level driver.
507 * @async_queue: Storage for fasync_helper().
508 * @open: Optional pointer to a function set by the low-level driver to be
509 * called when @use_count changes from 0 to 1.
510 * @close: Optional pointer to a function set by the low-level driver to be
511 * called when @use_count changed from 1 to 0.
513 * This is the main control data structure for a COMEDI device (as far as the
514 * COMEDI core is concerned). There are two groups of COMEDI devices -
515 * "legacy" devices that are configured by the handler for the
516 * %COMEDI_DEVCONFIG ioctl, and automatically configured devices resulting
517 * from a call to comedi_auto_config() as a result of a bus driver probe in
518 * a low-level COMEDI driver. The "legacy" COMEDI devices are allocated
519 * during module initialization if the "comedi_num_legacy_minors" module
520 * parameter is non-zero and use minor device numbers from 0 to
521 * comedi_num_legacy_minors minus one. The automatically configured COMEDI
522 * devices are allocated on demand and use minor device numbers from
523 * comedi_num_legacy_minors to 47.
525 struct comedi_device {
527 struct comedi_driver *driver;
528 struct comedi_8254 *pacer;
531 struct device *class_dev;
533 unsigned int detach_count;
534 struct device *hw_dev;
536 const char *board_name;
537 const void *board_ptr;
542 struct rw_semaphore attach_lock;
543 struct kref refcount;
546 struct comedi_subdevice *subdevices;
550 unsigned long iobase;
554 struct comedi_subdevice *read_subdev;
555 struct comedi_subdevice *write_subdev;
557 struct fasync_struct *async_queue;
559 int (*open)(struct comedi_device *dev);
560 void (*close)(struct comedi_device *dev);
564 * function prototypes
567 void comedi_event(struct comedi_device *dev, struct comedi_subdevice *s);
569 struct comedi_device *comedi_dev_get_from_minor(unsigned minor);
570 int comedi_dev_put(struct comedi_device *dev);
572 bool comedi_is_subdevice_running(struct comedi_subdevice *s);
574 void *comedi_alloc_spriv(struct comedi_subdevice *s, size_t size);
575 void comedi_set_spriv_auto_free(struct comedi_subdevice *s);
577 int comedi_check_chanlist(struct comedi_subdevice *s,
579 unsigned int *chanlist);
583 #define RANGE(a, b) {(a)*1e6, (b)*1e6, 0}
584 #define RANGE_ext(a, b) {(a)*1e6, (b)*1e6, RF_EXTERNAL}
585 #define RANGE_mA(a, b) {(a)*1e6, (b)*1e6, UNIT_mA}
586 #define RANGE_unitless(a, b) {(a)*1e6, (b)*1e6, 0}
587 #define BIP_RANGE(a) {-(a)*1e6, (a)*1e6, 0}
588 #define UNI_RANGE(a) {0, (a)*1e6, 0}
590 extern const struct comedi_lrange range_bipolar10;
591 extern const struct comedi_lrange range_bipolar5;
592 extern const struct comedi_lrange range_bipolar2_5;
593 extern const struct comedi_lrange range_unipolar10;
594 extern const struct comedi_lrange range_unipolar5;
595 extern const struct comedi_lrange range_unipolar2_5;
596 extern const struct comedi_lrange range_0_20mA;
597 extern const struct comedi_lrange range_4_20mA;
598 extern const struct comedi_lrange range_0_32mA;
599 extern const struct comedi_lrange range_unknown;
601 #define range_digital range_unipolar5
604 #define GCC_ZERO_LENGTH_ARRAY
606 #define GCC_ZERO_LENGTH_ARRAY 0
610 * struct comedi_lrange - Describes a COMEDI range table
611 * @length: Number of entries in the range table.
612 * @range: Array of &struct comedi_krange, one for each range.
614 * Each element of @range[] describes the minimum and maximum physical range
615 * range and the type of units. Typically, the type of unit is %UNIT_volt
616 * (i.e. volts) and the minimum and maximum are in millionths of a volt.
617 * There may also be a flag that indicates the minimum and maximum are merely
618 * scale factors for an unknown, external reference.
620 struct comedi_lrange {
622 struct comedi_krange range[GCC_ZERO_LENGTH_ARRAY];
626 * comedi_range_is_bipolar() - Test if subdevice range is bipolar
627 * @s: COMEDI subdevice.
628 * @range: Index of range within a range table.
630 * Tests whether a range is bipolar by checking whether its minimum value
633 * Assumes @range is valid. Does not work for subdevices using a
634 * channel-specific range table list.
637 * %true if the range is bipolar.
638 * %false if the range is unipolar.
640 static inline bool comedi_range_is_bipolar(struct comedi_subdevice *s,
643 return s->range_table->range[range].min < 0;
647 * comedi_range_is_unipolar() - Test if subdevice range is unipolar
648 * @s: COMEDI subdevice.
649 * @range: Index of range within a range table.
651 * Tests whether a range is unipolar by checking whether its minimum value
654 * Assumes @range is valid. Does not work for subdevices using a
655 * channel-specific range table list.
658 * %true if the range is unipolar.
659 * %false if the range is bipolar.
661 static inline bool comedi_range_is_unipolar(struct comedi_subdevice *s,
664 return s->range_table->range[range].min >= 0;
668 * comedi_range_is_external() - Test if subdevice range is external
669 * @s: COMEDI subdevice.
670 * @range: Index of range within a range table.
672 * Tests whether a range is externally reference by checking whether its
673 * %RF_EXTERNAL flag is set.
675 * Assumes @range is valid. Does not work for subdevices using a
676 * channel-specific range table list.
679 * %true if the range is external.
680 * %false if the range is internal.
682 static inline bool comedi_range_is_external(struct comedi_subdevice *s,
685 return !!(s->range_table->range[range].flags & RF_EXTERNAL);
689 * comedi_chan_range_is_bipolar() - Test if channel-specific range is bipolar
690 * @s: COMEDI subdevice.
691 * @chan: The channel number.
692 * @range: Index of range within a range table.
694 * Tests whether a range is bipolar by checking whether its minimum value
697 * Assumes @chan and @range are valid. Only works for subdevices with a
698 * channel-specific range table list.
701 * %true if the range is bipolar.
702 * %false if the range is unipolar.
704 static inline bool comedi_chan_range_is_bipolar(struct comedi_subdevice *s,
708 return s->range_table_list[chan]->range[range].min < 0;
712 * comedi_chan_range_is_unipolar() - Test if channel-specific range is unipolar
713 * @s: COMEDI subdevice.
714 * @chan: The channel number.
715 * @range: Index of range within a range table.
717 * Tests whether a range is unipolar by checking whether its minimum value
720 * Assumes @chan and @range are valid. Only works for subdevices with a
721 * channel-specific range table list.
724 * %true if the range is unipolar.
725 * %false if the range is bipolar.
727 static inline bool comedi_chan_range_is_unipolar(struct comedi_subdevice *s,
731 return s->range_table_list[chan]->range[range].min >= 0;
735 * comedi_chan_range_is_external() - Test if channel-specific range is external
736 * @s: COMEDI subdevice.
737 * @chan: The channel number.
738 * @range: Index of range within a range table.
740 * Tests whether a range is externally reference by checking whether its
741 * %RF_EXTERNAL flag is set.
743 * Assumes @chan and @range are valid. Only works for subdevices with a
744 * channel-specific range table list.
747 * %true if the range is bipolar.
748 * %false if the range is unipolar.
750 static inline bool comedi_chan_range_is_external(struct comedi_subdevice *s,
754 return !!(s->range_table_list[chan]->range[range].flags & RF_EXTERNAL);
758 * comedi_offset_munge() - Convert between offset binary and 2's complement
759 * @s: COMEDI subdevice.
760 * @val: Value to be converted.
762 * Toggles the highest bit of a sample value to toggle between offset binary
763 * and 2's complement. Assumes that @s->maxdata is a power of 2 minus 1.
765 * Return: The converted value.
767 static inline unsigned int comedi_offset_munge(struct comedi_subdevice *s,
770 return val ^ s->maxdata ^ (s->maxdata >> 1);
774 * comedi_bytes_per_sample() - Determine subdevice sample size
775 * @s: COMEDI subdevice.
777 * The sample size will be 4 (sizeof int) or 2 (sizeof short) depending on
778 * whether the %SDF_LSAMPL subdevice flag is set or not.
780 * Return: The subdevice sample size.
782 static inline unsigned int comedi_bytes_per_sample(struct comedi_subdevice *s)
784 return s->subdev_flags & SDF_LSAMPL ? sizeof(int) : sizeof(short);
788 * comedi_sample_shift() - Determine log2 of subdevice sample size
789 * @s: COMEDI subdevice.
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. The log2 of the
793 * sample size will be 2 or 1 and can be used as the right operand of a
794 * bit-shift operator to multiply or divide something by the sample size.
796 * Return: log2 of the subdevice sample size.
798 static inline unsigned int comedi_sample_shift(struct comedi_subdevice *s)
800 return s->subdev_flags & SDF_LSAMPL ? 2 : 1;
804 * comedi_bytes_to_samples() - Convert a number of bytes to a number of samples
805 * @s: COMEDI subdevice.
806 * @nbytes: Number of bytes
808 * Return: The number of bytes divided by the subdevice sample size.
810 static inline unsigned int comedi_bytes_to_samples(struct comedi_subdevice *s,
813 return nbytes >> comedi_sample_shift(s);
817 * comedi_samples_to_bytes() - Convert a number of samples to a number of bytes
818 * @s: COMEDI subdevice.
819 * @nsamples: Number of samples.
821 * Return: The number of samples multiplied by the subdevice sample size.
822 * (Does not check for arithmetic overflow.)
824 static inline unsigned int comedi_samples_to_bytes(struct comedi_subdevice *s,
825 unsigned int nsamples)
827 return nsamples << comedi_sample_shift(s);
831 * comedi_check_trigger_src() - Trivially validate a comedi_cmd trigger source
832 * @src: Pointer to the trigger source to validate.
833 * @flags: Bitmask of valid %TRIG_* for the trigger.
835 * This is used in "step 1" of the do_cmdtest functions of comedi drivers
836 * to validate the comedi_cmd triggers. The mask of the @src against the
837 * @flags allows the userspace comedilib to pass all the comedi_cmd
838 * triggers as %TRIG_ANY and get back a bitmask of the valid trigger sources.
841 * 0 if trigger sources in *@src are all supported.
842 * -EINVAL if any trigger source in *@src is unsupported.
844 static inline int comedi_check_trigger_src(unsigned int *src,
847 unsigned int orig_src = *src;
849 *src = orig_src & flags;
850 if (*src == TRIG_INVALID || *src != orig_src)
856 * comedi_check_trigger_is_unique() - Make sure a trigger source is unique
857 * @src: The trigger source to check.
860 * 0 if no more than one trigger source is set.
861 * -EINVAL if more than one trigger source is set.
863 static inline int comedi_check_trigger_is_unique(unsigned int src)
865 /* this test is true if more than one _src bit is set */
866 if ((src & (src - 1)) != 0)
872 * comedi_check_trigger_arg_is() - Trivially validate a trigger argument
873 * @arg: Pointer to the trigger arg to validate.
874 * @val: The value the argument should be.
876 * Forces *@arg to be @val.
879 * 0 if *@arg was already @val.
880 * -EINVAL if *@arg differed from @val.
882 static inline int comedi_check_trigger_arg_is(unsigned int *arg,
893 * comedi_check_trigger_arg_min() - Trivially validate a trigger argument min
894 * @arg: Pointer to the trigger arg to validate.
895 * @val: The minimum value the argument should be.
897 * Forces *@arg to be at least @val, setting it to @val if necessary.
900 * 0 if *@arg was already at least @val.
901 * -EINVAL if *@arg was less than @val.
903 static inline int comedi_check_trigger_arg_min(unsigned int *arg,
914 * comedi_check_trigger_arg_max() - Trivially validate a trigger argument max
915 * @arg: Pointer to the trigger arg to validate.
916 * @val: The maximum value the argument should be.
918 * Forces *@arg to be no more than @val, setting it to @val if necessary.
921 * 0 if*@arg was already no more than @val.
922 * -EINVAL if *@arg was greater than @val.
924 static inline int comedi_check_trigger_arg_max(unsigned int *arg,
935 * Must set dev->hw_dev if you wish to dma directly into comedi's buffer.
936 * Also useful for retrieving a previously configured hardware device of
937 * known bus type. Set automatically for auto-configured devices.
938 * Automatically set to NULL when detaching hardware device.
940 int comedi_set_hw_dev(struct comedi_device *dev, struct device *hw_dev);
943 * comedi_buf_n_bytes_ready - Determine amount of unread data in buffer
944 * @s: COMEDI subdevice.
946 * Determines the number of bytes of unread data in the asynchronous
947 * acquisition data buffer for a subdevice. The data in question might not
948 * have been fully "munged" yet.
950 * Returns: The amount of unread data in bytes.
952 static inline unsigned int comedi_buf_n_bytes_ready(struct comedi_subdevice *s)
954 return s->async->buf_write_count - s->async->buf_read_count;
957 unsigned int comedi_buf_write_alloc(struct comedi_subdevice *s, unsigned int n);
958 unsigned int comedi_buf_write_free(struct comedi_subdevice *s, unsigned int n);
960 unsigned int comedi_buf_read_n_available(struct comedi_subdevice *s);
961 unsigned int comedi_buf_read_alloc(struct comedi_subdevice *s, unsigned int n);
962 unsigned int comedi_buf_read_free(struct comedi_subdevice *s, unsigned int n);
964 unsigned int comedi_buf_write_samples(struct comedi_subdevice *s,
965 const void *data, unsigned int nsamples);
966 unsigned int comedi_buf_read_samples(struct comedi_subdevice *s,
967 void *data, unsigned int nsamples);
969 /* drivers.c - general comedi driver functions */
971 #define COMEDI_TIMEOUT_MS 1000
973 int comedi_timeout(struct comedi_device *, struct comedi_subdevice *,
974 struct comedi_insn *,
975 int (*cb)(struct comedi_device *, struct comedi_subdevice *,
976 struct comedi_insn *, unsigned long context),
977 unsigned long context);
979 unsigned int comedi_handle_events(struct comedi_device *dev,
980 struct comedi_subdevice *s);
982 int comedi_dio_insn_config(struct comedi_device *, struct comedi_subdevice *,
983 struct comedi_insn *, unsigned int *data,
985 unsigned int comedi_dio_update_state(struct comedi_subdevice *,
987 unsigned int comedi_bytes_per_scan(struct comedi_subdevice *s);
988 unsigned int comedi_nscans_left(struct comedi_subdevice *s,
989 unsigned int nscans);
990 unsigned int comedi_nsamples_left(struct comedi_subdevice *s,
991 unsigned int nsamples);
992 void comedi_inc_scan_progress(struct comedi_subdevice *s,
993 unsigned int num_bytes);
995 void *comedi_alloc_devpriv(struct comedi_device *, size_t);
996 int comedi_alloc_subdevices(struct comedi_device *, int);
997 int comedi_alloc_subdev_readback(struct comedi_subdevice *);
999 int comedi_readback_insn_read(struct comedi_device *, struct comedi_subdevice *,
1000 struct comedi_insn *, unsigned int *data);
1002 int comedi_load_firmware(struct comedi_device *, struct device *,
1004 int (*cb)(struct comedi_device *,
1005 const u8 *data, size_t size,
1006 unsigned long context),
1007 unsigned long context);
1009 int __comedi_request_region(struct comedi_device *,
1010 unsigned long start, unsigned long len);
1011 int comedi_request_region(struct comedi_device *,
1012 unsigned long start, unsigned long len);
1013 void comedi_legacy_detach(struct comedi_device *);
1015 int comedi_auto_config(struct device *, struct comedi_driver *,
1016 unsigned long context);
1017 void comedi_auto_unconfig(struct device *);
1019 int comedi_driver_register(struct comedi_driver *);
1020 void comedi_driver_unregister(struct comedi_driver *);
1023 * module_comedi_driver() - Helper macro for registering a comedi driver
1024 * @__comedi_driver: comedi_driver struct
1026 * Helper macro for comedi drivers which do not do anything special in module
1027 * init/exit. This eliminates a lot of boilerplate. Each module may only use
1028 * this macro once, and calling it replaces module_init() and module_exit().
1030 #define module_comedi_driver(__comedi_driver) \
1031 module_driver(__comedi_driver, comedi_driver_register, \
1032 comedi_driver_unregister)
1034 #endif /* _COMEDIDEV_H */