linux/drivers/comedi/drivers/ni_routes.c
<<
>>
Prefs
   1// SPDX-License-Identifier: GPL-2.0+
   2/* vim: set ts=8 sw=8 noet tw=80 nowrap: */
   3/*
   4 *  comedi/drivers/ni_routes.c
   5 *  Route information for NI boards.
   6 *
   7 *  COMEDI - Linux Control and Measurement Device Interface
   8 *  Copyright (C) 2016 Spencer E. Olson <olsonse@umich.edu>
   9 *
  10 *  This program is free software; you can redistribute it and/or modify
  11 *  it under the terms of the GNU General Public License as published by
  12 *  the Free Software Foundation; either version 2 of the License, or
  13 *  (at your option) any later version.
  14 *
  15 *  This program is distributed in the hope that it will be useful,
  16 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 *  GNU General Public License for more details.
  19 */
  20
  21#include <linux/module.h>
  22#include <linux/slab.h>
  23#include <linux/bsearch.h>
  24#include <linux/sort.h>
  25
  26#include "../comedi.h"
  27
  28#include "ni_routes.h"
  29#include "ni_routing/ni_route_values.h"
  30#include "ni_routing/ni_device_routes.h"
  31
  32/*
  33 * This is defined in ni_routing/ni_route_values.h:
  34 * #define B(x) ((x) - NI_NAMES_BASE)
  35 */
  36
  37/*
  38 * These are defined in ni_routing/ni_route_values.h to identify clearly
  39 * elements of the table that were set.  In other words, entries that are zero
  40 * are invalid.  To get the value to use for the register, one must mask out the
  41 * high bit.
  42 *
  43 * #define V(x) ((x) | 0x80)
  44 *
  45 * #define UNMARK(x)    ((x) & (~(0x80)))
  46 *
  47 */
  48
  49/* Helper for accessing data. */
  50#define RVi(table, src, dest)   ((table)[(dest) * NI_NUM_NAMES + (src)])
  51
  52/*
  53 * Find the route values for a device family.
  54 */
  55static const u8 *ni_find_route_values(const char *device_family)
  56{
  57        const u8 *rv = NULL;
  58        int i;
  59
  60        for (i = 0; ni_all_route_values[i]; ++i) {
  61                if (memcmp(ni_all_route_values[i]->family, device_family,
  62                           strnlen(device_family, 30)) == 0) {
  63                        rv = &ni_all_route_values[i]->register_values[0][0];
  64                        break;
  65                }
  66        }
  67        return rv;
  68}
  69
  70/*
  71 * Find the valid routes for a board.
  72 */
  73static const struct ni_device_routes *
  74ni_find_valid_routes(const char *board_name)
  75{
  76        const struct ni_device_routes *dr = NULL;
  77        int i;
  78
  79        for (i = 0; ni_device_routes_list[i]; ++i) {
  80                if (memcmp(ni_device_routes_list[i]->device, board_name,
  81                           strnlen(board_name, 30)) == 0) {
  82                        dr = ni_device_routes_list[i];
  83                        break;
  84                }
  85        }
  86        return dr;
  87}
  88
  89/*
  90 * Find the proper route_values and ni_device_routes tables for this particular
  91 * device.  Possibly try an alternate board name if device routes not found
  92 * for the actual board name.
  93 *
  94 * Return: -ENODATA if either was not found; 0 if both were found.
  95 */
  96static int ni_find_device_routes(const char *device_family,
  97                                 const char *board_name,
  98                                 const char *alt_board_name,
  99                                 struct ni_route_tables *tables)
 100{
 101        const struct ni_device_routes *dr;
 102        const u8 *rv;
 103
 104        /* First, find the register_values table for this device family */
 105        rv = ni_find_route_values(device_family);
 106
 107        /* Second, find the set of routes valid for this device. */
 108        dr = ni_find_valid_routes(board_name);
 109        if (!dr && alt_board_name)
 110                dr = ni_find_valid_routes(alt_board_name);
 111
 112        tables->route_values = rv;
 113        tables->valid_routes = dr;
 114
 115        if (!rv || !dr)
 116                return -ENODATA;
 117
 118        return 0;
 119}
 120
 121/**
 122 * ni_assign_device_routes() - Assign the proper lookup table for NI signal
 123 *                             routing to the specified NI device.
 124 * @device_family: Device family name (determines route values).
 125 * @board_name: Board name (determines set of routes).
 126 * @alt_board_name: Optional alternate board name to try on failure.
 127 * @tables: Pointer to assigned routing information.
 128 *
 129 * Finds the route values for the device family and the set of valid routes
 130 * for the board.  If valid routes could not be found for the actual board
 131 * name and an alternate board name has been specified, try that one.
 132 *
 133 * On failure, the assigned routing information may be partially filled
 134 * (for example, with the route values but not the set of valid routes).
 135 *
 136 * Return: -ENODATA if assignment was not successful; 0 if successful.
 137 */
 138int ni_assign_device_routes(const char *device_family,
 139                            const char *board_name,
 140                            const char *alt_board_name,
 141                            struct ni_route_tables *tables)
 142{
 143        memset(tables, 0, sizeof(struct ni_route_tables));
 144        return ni_find_device_routes(device_family, board_name, alt_board_name,
 145                                     tables);
 146}
 147EXPORT_SYMBOL_GPL(ni_assign_device_routes);
 148
 149/**
 150 * ni_count_valid_routes() - Count the number of valid routes.
 151 * @tables: Routing tables for which to count all valid routes.
 152 */
 153unsigned int ni_count_valid_routes(const struct ni_route_tables *tables)
 154{
 155        int total = 0;
 156        int i;
 157
 158        for (i = 0; i < tables->valid_routes->n_route_sets; ++i) {
 159                const struct ni_route_set *R = &tables->valid_routes->routes[i];
 160                int j;
 161
 162                for (j = 0; j < R->n_src; ++j) {
 163                        const int src  = R->src[j];
 164                        const int dest = R->dest;
 165                        const u8 *rv = tables->route_values;
 166
 167                        if (RVi(rv, B(src), B(dest)))
 168                                /* direct routing is valid */
 169                                ++total;
 170                        else if (channel_is_rtsi(dest) &&
 171                                 (RVi(rv, B(src), B(NI_RGOUT0)) ||
 172                                  RVi(rv, B(src), B(NI_RTSI_BRD(0))) ||
 173                                  RVi(rv, B(src), B(NI_RTSI_BRD(1))) ||
 174                                  RVi(rv, B(src), B(NI_RTSI_BRD(2))) ||
 175                                  RVi(rv, B(src), B(NI_RTSI_BRD(3))))) {
 176                                ++total;
 177                        }
 178                }
 179        }
 180        return total;
 181}
 182EXPORT_SYMBOL_GPL(ni_count_valid_routes);
 183
 184/**
 185 * ni_get_valid_routes() - Implements INSN_DEVICE_CONFIG_GET_ROUTES.
 186 * @tables:     pointer to relevant set of routing tables.
 187 * @n_pairs:    Number of pairs for which memory is allocated by the user.  If
 188 *              the user specifies '0', only the number of available pairs is
 189 *              returned.
 190 * @pair_data:  Pointer to memory allocated to return pairs back to user.  Each
 191 *              even, odd indexed member of this array will hold source,
 192 *              destination of a route pair respectively.
 193 *
 194 * Return: the number of valid routes if n_pairs == 0; otherwise, the number of
 195 *      valid routes copied.
 196 */
 197unsigned int ni_get_valid_routes(const struct ni_route_tables *tables,
 198                                 unsigned int n_pairs,
 199                                 unsigned int *pair_data)
 200{
 201        unsigned int n_valid = ni_count_valid_routes(tables);
 202        int i;
 203
 204        if (n_pairs == 0 || n_valid == 0)
 205                return n_valid;
 206
 207        if (!pair_data)
 208                return 0;
 209
 210        n_valid = 0;
 211
 212        for (i = 0; i < tables->valid_routes->n_route_sets; ++i) {
 213                const struct ni_route_set *R = &tables->valid_routes->routes[i];
 214                int j;
 215
 216                for (j = 0; j < R->n_src; ++j) {
 217                        const int src  = R->src[j];
 218                        const int dest = R->dest;
 219                        bool valid = false;
 220                        const u8 *rv = tables->route_values;
 221
 222                        if (RVi(rv, B(src), B(dest)))
 223                                /* direct routing is valid */
 224                                valid = true;
 225                        else if (channel_is_rtsi(dest) &&
 226                                 (RVi(rv, B(src), B(NI_RGOUT0)) ||
 227                                  RVi(rv, B(src), B(NI_RTSI_BRD(0))) ||
 228                                  RVi(rv, B(src), B(NI_RTSI_BRD(1))) ||
 229                                  RVi(rv, B(src), B(NI_RTSI_BRD(2))) ||
 230                                  RVi(rv, B(src), B(NI_RTSI_BRD(3))))) {
 231                                /* indirect routing also valid */
 232                                valid = true;
 233                        }
 234
 235                        if (valid) {
 236                                pair_data[2 * n_valid] = src;
 237                                pair_data[2 * n_valid + 1] = dest;
 238                                ++n_valid;
 239                        }
 240
 241                        if (n_valid >= n_pairs)
 242                                return n_valid;
 243                }
 244        }
 245        return n_valid;
 246}
 247EXPORT_SYMBOL_GPL(ni_get_valid_routes);
 248
 249/**
 250 * List of NI global signal names that, as destinations, are only routeable
 251 * indirectly through the *_arg elements of the comedi_cmd structure.
 252 */
 253static const int NI_CMD_DESTS[] = {
 254        NI_AI_SampleClock,
 255        NI_AI_StartTrigger,
 256        NI_AI_ConvertClock,
 257        NI_AO_SampleClock,
 258        NI_AO_StartTrigger,
 259        NI_DI_SampleClock,
 260        NI_DO_SampleClock,
 261};
 262
 263/**
 264 * ni_is_cmd_dest() - Determine whether the given destination is only
 265 *                    configurable via a comedi_cmd struct.
 266 * @dest: Destination to test.
 267 */
 268bool ni_is_cmd_dest(int dest)
 269{
 270        int i;
 271
 272        for (i = 0; i < ARRAY_SIZE(NI_CMD_DESTS); ++i)
 273                if (NI_CMD_DESTS[i] == dest)
 274                        return true;
 275        return false;
 276}
 277EXPORT_SYMBOL_GPL(ni_is_cmd_dest);
 278
 279/* **** BEGIN Routes sort routines **** */
 280static int _ni_sort_destcmp(const void *va, const void *vb)
 281{
 282        const struct ni_route_set *a = va;
 283        const struct ni_route_set *b = vb;
 284
 285        if (a->dest < b->dest)
 286                return -1;
 287        else if (a->dest > b->dest)
 288                return 1;
 289        return 0;
 290}
 291
 292static int _ni_sort_srccmp(const void *vsrc0, const void *vsrc1)
 293{
 294        const int *src0 = vsrc0;
 295        const int *src1 = vsrc1;
 296
 297        if (*src0 < *src1)
 298                return -1;
 299        else if (*src0 > *src1)
 300                return 1;
 301        return 0;
 302}
 303
 304/**
 305 * ni_sort_device_routes() - Sort the list of valid device signal routes in
 306 *                           preparation for use.
 307 * @valid_routes:       pointer to ni_device_routes struct to sort.
 308 */
 309void ni_sort_device_routes(struct ni_device_routes *valid_routes)
 310{
 311        unsigned int n;
 312
 313        /* 1. Count and set the number of ni_route_set objects. */
 314        valid_routes->n_route_sets = 0;
 315        while (valid_routes->routes[valid_routes->n_route_sets].dest != 0)
 316                ++valid_routes->n_route_sets;
 317
 318        /* 2. sort all ni_route_set objects by destination. */
 319        sort(valid_routes->routes, valid_routes->n_route_sets,
 320             sizeof(struct ni_route_set), _ni_sort_destcmp, NULL);
 321
 322        /* 3. Loop through each route_set for sorting. */
 323        for (n = 0; n < valid_routes->n_route_sets; ++n) {
 324                struct ni_route_set *rs = &valid_routes->routes[n];
 325
 326                /* 3a. Count and set the number of sources. */
 327                rs->n_src = 0;
 328                while (rs->src[rs->n_src])
 329                        ++rs->n_src;
 330
 331                /* 3a. Sort sources. */
 332                sort(valid_routes->routes[n].src, valid_routes->routes[n].n_src,
 333                     sizeof(int), _ni_sort_srccmp, NULL);
 334        }
 335}
 336EXPORT_SYMBOL_GPL(ni_sort_device_routes);
 337
 338/* sort all valid device signal routes in prep for use */
 339static void ni_sort_all_device_routes(void)
 340{
 341        unsigned int i;
 342
 343        for (i = 0; ni_device_routes_list[i]; ++i)
 344                ni_sort_device_routes(ni_device_routes_list[i]);
 345}
 346
 347/* **** BEGIN Routes search routines **** */
 348static int _ni_bsearch_destcmp(const void *vkey, const void *velt)
 349{
 350        const int *key = vkey;
 351        const struct ni_route_set *elt = velt;
 352
 353        if (*key < elt->dest)
 354                return -1;
 355        else if (*key > elt->dest)
 356                return 1;
 357        return 0;
 358}
 359
 360static int _ni_bsearch_srccmp(const void *vkey, const void *velt)
 361{
 362        const int *key = vkey;
 363        const int *elt = velt;
 364
 365        if (*key < *elt)
 366                return -1;
 367        else if (*key > *elt)
 368                return 1;
 369        return 0;
 370}
 371
 372/**
 373 * ni_find_route_set() - Finds the proper route set with the specified
 374 *                       destination.
 375 * @destination: Destination of which to search for the route set.
 376 * @valid_routes: Pointer to device routes within which to search.
 377 *
 378 * Return: NULL if no route_set is found with the specified @destination;
 379 *      otherwise, a pointer to the route_set if found.
 380 */
 381const struct ni_route_set *
 382ni_find_route_set(const int destination,
 383                  const struct ni_device_routes *valid_routes)
 384{
 385        return bsearch(&destination, valid_routes->routes,
 386                       valid_routes->n_route_sets, sizeof(struct ni_route_set),
 387                       _ni_bsearch_destcmp);
 388}
 389EXPORT_SYMBOL_GPL(ni_find_route_set);
 390
 391/**
 392 * ni_route_set_has_source() - Determines whether the given source is in
 393 *                             included given route_set.
 394 *
 395 * Return: true if found; false otherwise.
 396 */
 397bool ni_route_set_has_source(const struct ni_route_set *routes,
 398                             const int source)
 399{
 400        if (!bsearch(&source, routes->src, routes->n_src, sizeof(int),
 401                     _ni_bsearch_srccmp))
 402                return false;
 403        return true;
 404}
 405EXPORT_SYMBOL_GPL(ni_route_set_has_source);
 406
 407/**
 408 * ni_lookup_route_register() - Look up a register value for a particular route
 409 *                              without checking whether the route is valid for
 410 *                              the particular device.
 411 * @src:        global-identifier for route source
 412 * @dest:       global-identifier for route destination
 413 * @tables:     pointer to relevant set of routing tables.
 414 *
 415 * Return: -EINVAL if the specified route is not valid for this device family.
 416 */
 417s8 ni_lookup_route_register(int src, int dest,
 418                            const struct ni_route_tables *tables)
 419{
 420        s8 regval;
 421
 422        /*
 423         * Be sure to use the B() macro to subtract off the NI_NAMES_BASE before
 424         * indexing into the route_values array.
 425         */
 426        src = B(src);
 427        dest = B(dest);
 428        if (src < 0 || src >= NI_NUM_NAMES || dest < 0 || dest >= NI_NUM_NAMES)
 429                return -EINVAL;
 430        regval = RVi(tables->route_values, src, dest);
 431        if (!regval)
 432                return -EINVAL;
 433        /* mask out the valid-value marking bit */
 434        return UNMARK(regval);
 435}
 436EXPORT_SYMBOL_GPL(ni_lookup_route_register);
 437
 438/**
 439 * ni_route_to_register() - Validates and converts the specified signal route
 440 *                          (src-->dest) to the value used at the appropriate
 441 *                          register.
 442 * @src:        global-identifier for route source
 443 * @dest:       global-identifier for route destination
 444 * @tables:     pointer to relevant set of routing tables.
 445 *
 446 * Generally speaking, most routes require the first six bits and a few require
 447 * 7 bits.  Special handling is given for the return value when the route is to
 448 * be handled by the RTSI sub-device.  In this case, the returned register may
 449 * not be sufficient to define the entire route path, but rather may only
 450 * indicate the intermediate route.  For example, if the route must go through
 451 * the RGOUT0 pin, the (src->RGOUT0) register value will be returned.
 452 * Similarly, if the route must go through the NI_RTSI_BRD lines, the BIT(6)
 453 * will be set:
 454 *
 455 * if route does not need RTSI_BRD lines:
 456 *   bits 0:7 : register value
 457 *              for a route that must go through RGOUT0 pin, this will be equal
 458 *              to the (src->RGOUT0) register value.
 459 * else: * route is (src->RTSI_BRD(x), RTSI_BRD(x)->TRIGGER_LINE(i)) *
 460 *   bits 0:5 : zero
 461 *   bits 6   : set to 1
 462 *   bits 7:7 : zero
 463 *
 464 * Return: register value to be used for source at destination with special
 465 *      cases given above; Otherwise, -1 if the specified route is not valid for
 466 *      this particular device.
 467 */
 468s8 ni_route_to_register(const int src, const int dest,
 469                        const struct ni_route_tables *tables)
 470{
 471        const struct ni_route_set *routes =
 472                ni_find_route_set(dest, tables->valid_routes);
 473        const u8 *rv;
 474        s8 regval;
 475
 476        /* first check to see if source is listed with bunch of destinations. */
 477        if (!routes)
 478                return -1;
 479        /* 2nd, check to see if destination is in list of source's targets. */
 480        if (!ni_route_set_has_source(routes, src))
 481                return -1;
 482        /*
 483         * finally, check to see if we know how to route...
 484         * Be sure to use the B() macro to subtract off the NI_NAMES_BASE before
 485         * indexing into the route_values array.
 486         */
 487        rv = tables->route_values;
 488        regval = RVi(rv, B(src), B(dest));
 489
 490        /*
 491         * if we did not validate the route, we'll see if we can route through
 492         * one of the muxes
 493         */
 494        if (!regval && channel_is_rtsi(dest)) {
 495                regval = RVi(rv, B(src), B(NI_RGOUT0));
 496                if (!regval && (RVi(rv, B(src), B(NI_RTSI_BRD(0))) ||
 497                                RVi(rv, B(src), B(NI_RTSI_BRD(1))) ||
 498                                RVi(rv, B(src), B(NI_RTSI_BRD(2))) ||
 499                                RVi(rv, B(src), B(NI_RTSI_BRD(3)))))
 500                        regval = BIT(6);
 501        }
 502
 503        if (!regval)
 504                return -1;
 505        /* mask out the valid-value marking bit */
 506        return UNMARK(regval);
 507}
 508EXPORT_SYMBOL_GPL(ni_route_to_register);
 509
 510/**
 511 * ni_find_route_source() - Finds the signal source corresponding to a signal
 512 *                          route (src-->dest) of the specified routing register
 513 *                          value and the specified route destination on the
 514 *                          specified device.
 515 *
 516 * Note that this function does _not_ validate the source based on device
 517 * routes.
 518 *
 519 * Return: The NI signal value (e.g. NI_PFI(0) or PXI_Clk10) if found.
 520 *      If the source was not found (i.e. the register value is not
 521 *      valid for any routes to the destination), -EINVAL is returned.
 522 */
 523int ni_find_route_source(const u8 src_sel_reg_value, int dest,
 524                         const struct ni_route_tables *tables)
 525{
 526        int src;
 527
 528        if (!tables->route_values)
 529                return -EINVAL;
 530
 531        dest = B(dest); /* subtract NI names offset */
 532        /* ensure we are not going to under/over run the route value table */
 533        if (dest < 0 || dest >= NI_NUM_NAMES)
 534                return -EINVAL;
 535        for (src = 0; src < NI_NUM_NAMES; ++src)
 536                if (RVi(tables->route_values, src, dest) ==
 537                    V(src_sel_reg_value))
 538                        return src + NI_NAMES_BASE;
 539        return -EINVAL;
 540}
 541EXPORT_SYMBOL_GPL(ni_find_route_source);
 542
 543/* **** END Routes search routines **** */
 544
 545/* **** BEGIN simple module entry/exit functions **** */
 546static int __init ni_routes_module_init(void)
 547{
 548        ni_sort_all_device_routes();
 549        return 0;
 550}
 551
 552static void __exit ni_routes_module_exit(void)
 553{
 554}
 555
 556module_init(ni_routes_module_init);
 557module_exit(ni_routes_module_exit);
 558
 559MODULE_AUTHOR("Comedi https://www.comedi.org");
 560MODULE_DESCRIPTION("Comedi helper for routing signals-->terminals for NI");
 561MODULE_LICENSE("GPL");
 562/* **** END simple module entry/exit functions **** */
 563