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 */ 152struct 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 */ 219struct 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 */ 248struct 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 */ 346struct 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 */ 382enum 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 */ 436struct 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 */ 540struct 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 587void comedi_event(struct comedi_device *dev, struct comedi_subdevice *s); 588 589struct comedi_device *comedi_dev_get_from_minor(unsigned int minor); 590int comedi_dev_put(struct comedi_device *dev); 591 592bool comedi_is_subdevice_running(struct comedi_subdevice *s); 593 594void *comedi_alloc_spriv(struct comedi_subdevice *s, size_t size); 595void comedi_set_spriv_auto_free(struct comedi_subdevice *s); 596 597int 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 610extern const struct comedi_lrange range_bipolar10; 611extern const struct comedi_lrange range_bipolar5; 612extern const struct comedi_lrange range_bipolar2_5; 613extern const struct comedi_lrange range_unipolar10; 614extern const struct comedi_lrange range_unipolar5; 615extern const struct comedi_lrange range_unipolar2_5; 616extern const struct comedi_lrange range_0_20mA; 617extern const struct comedi_lrange range_4_20mA; 618extern const struct comedi_lrange range_0_32mA; 619extern 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 */ 634struct 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 */ 654static 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 */ 675static 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 */ 696static 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 */ 718static 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 */ 741static 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 */ 764static 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 */ 781static 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 */ 796static 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 */ 812static 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 */ 824static 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 */ 838static 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 */ 858static 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 */ 877static 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 */ 896static 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 */ 917static 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 */ 938static 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 */ 954int 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 */ 966static 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 971unsigned int comedi_buf_write_alloc(struct comedi_subdevice *s, unsigned int n); 972unsigned int comedi_buf_write_free(struct comedi_subdevice *s, unsigned int n); 973 974unsigned int comedi_buf_read_n_available(struct comedi_subdevice *s); 975unsigned int comedi_buf_read_alloc(struct comedi_subdevice *s, unsigned int n); 976unsigned int comedi_buf_read_free(struct comedi_subdevice *s, unsigned int n); 977 978unsigned int comedi_buf_write_samples(struct comedi_subdevice *s, 979 const void *data, unsigned int nsamples); 980unsigned 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 987int 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 994unsigned int comedi_handle_events(struct comedi_device *dev, 995 struct comedi_subdevice *s); 996 997int 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); 1001unsigned int comedi_dio_update_state(struct comedi_subdevice *s, 1002 unsigned int *data); 1003unsigned int comedi_bytes_per_scan_cmd(struct comedi_subdevice *s, 1004 struct comedi_cmd *cmd); 1005unsigned int comedi_bytes_per_scan(struct comedi_subdevice *s); 1006unsigned int comedi_nscans_left(struct comedi_subdevice *s, 1007 unsigned int nscans); 1008unsigned int comedi_nsamples_left(struct comedi_subdevice *s, 1009 unsigned int nsamples); 1010void comedi_inc_scan_progress(struct comedi_subdevice *s, 1011 unsigned int num_bytes); 1012 1013void *comedi_alloc_devpriv(struct comedi_device *dev, size_t size); 1014int comedi_alloc_subdevices(struct comedi_device *dev, int num_subdevices); 1015int comedi_alloc_subdev_readback(struct comedi_subdevice *s); 1016 1017int comedi_readback_insn_read(struct comedi_device *dev, 1018 struct comedi_subdevice *s, 1019 struct comedi_insn *insn, unsigned int *data); 1020 1021int 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 1028int __comedi_request_region(struct comedi_device *dev, 1029 unsigned long start, unsigned long len); 1030int comedi_request_region(struct comedi_device *dev, 1031 unsigned long start, unsigned long len); 1032void comedi_legacy_detach(struct comedi_device *dev); 1033 1034int comedi_auto_config(struct device *hardware_device, 1035 struct comedi_driver *driver, unsigned long context); 1036void comedi_auto_unconfig(struct device *hardware_device); 1037 1038int comedi_driver_register(struct comedi_driver *driver); 1039void 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