1 /*
2  * Author: Brendan Le Foll <brendan.le.foll@intel.com>
3  * Author: Thomas Ingleby <thomas.c.ingleby@intel.com>
4  * Copyright (c) 2014-2016 Intel Corporation.
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining
7  * a copy of this software and associated documentation files (the
8  * "Software"), to deal in the Software without restriction, including
9  * without limitation the rights to use, copy, modify, merge, publish,
10  * distribute, sublicense, and/or sell copies of the Software, and to
11  * permit persons to whom the Software is furnished to do so, subject to
12  * the following conditions:
13  *
14  * The above copyright notice and this permission notice shall be
15  * included in all copies or substantial portions of the Software.
16  *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
18  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
19  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
20  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
21  * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
22  * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
23  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
24  */
25 
26 #define _GNU_SOURCE
27 #if !defined(_XOPEN_SOURCE) || _XOPEN_SOURCE < 600
28 #define _XOPEN_SOURCE 600 /* Get nftw() and S_IFSOCK declarations */
29 #endif
30 
31 #include <stddef.h>
32 #include <stdlib.h>
33 #include <sched.h>
34 #include <string.h>
35 #include <pwd.h>
36 #include <glob.h>
37 #include <ftw.h>
38 #include <dirent.h>
39 #include <sys/stat.h>
40 #include <fcntl.h>
41 #include <string.h>
42 #include <stdio.h>
43 
44 #include "mraa_internal.h"
45 #include "gpio.h"
46 #include "version.h"
47 
48 #define IIO_DEVICE_WILDCARD "iio:device*"
49 mraa_board_t* plat = NULL;
50 mraa_iio_info_t* plat_iio = NULL;
51 
52 static char* platform_name = NULL;
53 static char* platform_long_name = NULL;
54 
55 static int num_i2c_devices = 0;
56 static int num_iio_devices = 0;
57 
58 const char*
mraa_get_version()59 mraa_get_version()
60 {
61     return gVERSION;
62 }
63 
64 mraa_result_t
mraa_set_log_level(int level)65 mraa_set_log_level(int level)
66 {
67     if (level <= 7 && level >= 0) {
68         setlogmask(LOG_UPTO(level));
69         syslog(LOG_DEBUG, "Loglevel %d is set", level);
70         return MRAA_SUCCESS;
71     }
72     syslog(LOG_NOTICE, "Invalid loglevel %d requested", level);
73     return MRAA_ERROR_INVALID_PARAMETER;
74 }
75 
76 
77 #if (defined SWIGPYTHON) || (defined SWIG)
78 mraa_result_t
79 #else
80 mraa_result_t __attribute__((constructor))
81 #endif
mraa_init()82 mraa_init()
83 {
84     if (plat != NULL) {
85         return MRAA_ERROR_PLATFORM_ALREADY_INITIALISED;
86     }
87 
88     uid_t proc_euid = geteuid();
89     struct passwd* proc_user = getpwuid(proc_euid);
90 
91 #ifdef DEBUG
92     setlogmask(LOG_UPTO(LOG_DEBUG));
93 #else
94     setlogmask(LOG_UPTO(LOG_NOTICE));
95 #endif
96 
97     openlog("libmraa", LOG_CONS | LOG_PID | LOG_NDELAY, LOG_LOCAL1);
98     syslog(LOG_NOTICE, "libmraa version %s initialised by user '%s' with EUID %d",
99            mraa_get_version(), (proc_user != NULL) ? proc_user->pw_name : "<unknown>", proc_euid);
100 
101 #ifdef SWIGPYTHON
102     // Initialise python threads, this allows use to grab the GIL when we are
103     // required to do so
104     Py_InitializeEx(0);
105     PyEval_InitThreads();
106 #endif
107 
108     mraa_platform_t platform_type;
109 #if defined(X86PLAT)
110     // Use runtime x86 platform detection
111     platform_type = mraa_x86_platform();
112 #elif defined(ARMPLAT)
113     // Use runtime ARM platform detection
114     platform_type = mraa_arm_platform();
115 #else
116 #error mraa_ARCH NOTHING
117 #endif
118 
119     if (plat != NULL) {
120         plat->platform_type = platform_type;
121     } else {
122         platform_name = NULL;
123     }
124 
125 #if defined(USBPLAT)
126     // This is a platform extender so create null base platform if one doesn't already exist
127     if (plat == NULL) {
128         plat = (mraa_board_t*) calloc(1, sizeof(mraa_board_t));
129         if (plat != NULL) {
130             plat->platform_type = MRAA_NULL_PLATFORM;
131             plat->platform_name = "Unknown platform";
132         }
133     }
134     // Now detect sub platform
135     if (plat != NULL) {
136         mraa_platform_t usb_platform_type = mraa_usb_platform_extender(plat);
137         if (plat->platform_type == MRAA_UNKNOWN_PLATFORM && usb_platform_type != MRAA_UNKNOWN_PLATFORM) {
138             plat->platform_type = usb_platform_type;
139         } else {
140             return MRAA_ERROR_PLATFORM_NOT_INITIALISED;
141         }
142     }
143     if (plat == NULL) {
144         printf("mraa: FATAL error, failed to initialise platform\n");
145         return MRAA_ERROR_PLATFORM_NOT_INITIALISED;
146     }
147 #endif
148 
149     // Look for IIO devices
150     mraa_iio_detect();
151 
152     if (plat != NULL) {
153         int length = strlen(plat->platform_name) + 1;
154         if (mraa_has_sub_platform()) {
155             length += strlen(plat->sub_platform->platform_name);
156         }
157         platform_name = calloc(length, sizeof(char));
158         if (mraa_has_sub_platform()) {
159             snprintf(platform_name, length, "%s + %s", plat->platform_name, plat->sub_platform->platform_name);
160         } else {
161             strncpy(platform_name, plat->platform_name, length);
162         }
163     }
164 
165     syslog(LOG_NOTICE, "libmraa initialised for platform '%s' of type %d", mraa_get_platform_name(), mraa_get_platform_type());
166     return MRAA_SUCCESS;
167 }
168 
169 void
mraa_deinit()170 mraa_deinit()
171 {
172     if (plat != NULL) {
173         if (plat->pins != NULL) {
174             free(plat->pins);
175         }
176         mraa_board_t* sub_plat = plat->sub_platform;
177         if (sub_plat != NULL) {
178             if (sub_plat->pins != NULL) {
179                 free(sub_plat->pins);
180             }
181             free(sub_plat);
182         }
183         free(plat);
184 
185     }
186     if (plat_iio != NULL) {
187         free(plat_iio);
188     }
189     closelog();
190 }
191 
192 int
mraa_set_priority(const unsigned int priority)193 mraa_set_priority(const unsigned int priority)
194 {
195     struct sched_param sched_s;
196 
197     memset(&sched_s, 0, sizeof(struct sched_param));
198     if (priority > sched_get_priority_max(SCHED_RR)) {
199         sched_s.sched_priority = sched_get_priority_max(SCHED_RR);
200     } else {
201         sched_s.sched_priority = priority;
202     }
203 
204     return sched_setscheduler(0, SCHED_RR, &sched_s);
205 }
206 
207 static int
mraa_count_iio_devices(const char * path,const struct stat * sb,int flag,struct FTW * ftwb)208 mraa_count_iio_devices(const char* path, const struct stat* sb, int flag, struct FTW* ftwb)
209 {
210     // we are only interested in files with specific names
211     if (fnmatch(IIO_DEVICE_WILDCARD, basename(path), 0) == 0) {
212         num_iio_devices++;
213     }
214     return 0;
215 }
216 
217 mraa_result_t
mraa_iio_detect()218 mraa_iio_detect()
219 {
220     plat_iio = (mraa_iio_info_t*) calloc(1, sizeof(mraa_iio_info_t));
221     plat_iio->iio_device_count = num_iio_devices;
222     // Now detect IIO devices, linux only
223     // find how many iio devices we have if we haven't already
224     if (num_iio_devices == 0) {
225         if (nftw("/sys/bus/iio/devices", &mraa_count_iio_devices, 20, FTW_PHYS) == -1) {
226             return MRAA_ERROR_UNSPECIFIED;
227         }
228     }
229     char name[64], filepath[64];
230     int fd, len, i;
231     plat_iio->iio_device_count = num_iio_devices;
232     plat_iio->iio_devices = calloc(num_iio_devices, sizeof(struct _iio));
233     struct _iio* device;
234     for (i=0; i < num_iio_devices; i++) {
235         device = &plat_iio->iio_devices[i];
236         device->num = i;
237         snprintf(filepath, 64, "/sys/bus/iio/devices/iio:device%d/name", i);
238         fd = open(filepath, O_RDONLY);
239         if (fd != -1) {
240             len = read(fd, &name, 64);
241             if (len > 1) {
242                 // remove any trailing CR/LF symbols
243                 name[strcspn(name, "\r\n")] = '\0';
244                 len = strlen(name);
245                 // use strndup
246                 device->name = malloc((sizeof(char) * len) + sizeof(char));
247                 strncpy(device->name, name, len+1);
248             }
249             close(fd);
250         }
251     }
252     return MRAA_SUCCESS;
253 }
254 
255 
256 mraa_result_t
mraa_setup_mux_mapped(mraa_pin_t meta)257 mraa_setup_mux_mapped(mraa_pin_t meta)
258 {
259     int mi;
260 
261     for (mi = 0; mi < meta.mux_total; mi++) {
262         mraa_gpio_context mux_i;
263         mux_i = mraa_gpio_init_raw(meta.mux[mi].pin);
264         if (mux_i == NULL) {
265             return MRAA_ERROR_INVALID_HANDLE;
266         }
267         // this function will sometimes fail, however this is not critical as
268         // long as the write succeeds - Test case galileo gen2 pin2
269         mraa_gpio_dir(mux_i, MRAA_GPIO_OUT);
270         mraa_gpio_owner(mux_i, 0);
271 
272         if (mraa_gpio_write(mux_i, meta.mux[mi].value) != MRAA_SUCCESS) {
273             mraa_gpio_close(mux_i);
274             return MRAA_ERROR_INVALID_RESOURCE;
275         }
276         mraa_gpio_close(mux_i);
277     }
278 
279     return MRAA_SUCCESS;
280 }
281 
282 void
mraa_result_print(mraa_result_t result)283 mraa_result_print(mraa_result_t result)
284 {
285     switch (result) {
286         case MRAA_SUCCESS:
287             fprintf(stdout, "MRAA: SUCCESS\n");
288             break;
289         case MRAA_ERROR_FEATURE_NOT_IMPLEMENTED:
290             fprintf(stdout, "MRAA: Feature not implemented.\n");
291             break;
292         case MRAA_ERROR_FEATURE_NOT_SUPPORTED:
293             fprintf(stdout, "MRAA: Feature not supported by Hardware.\n");
294             break;
295         case MRAA_ERROR_INVALID_VERBOSITY_LEVEL:
296             fprintf(stdout, "MRAA: Invalid verbosity level.\n");
297             break;
298         case MRAA_ERROR_INVALID_PARAMETER:
299             fprintf(stdout, "MRAA: Invalid parameter.\n");
300             break;
301         case MRAA_ERROR_INVALID_HANDLE:
302             fprintf(stdout, "MRAA: Invalid Handle.\n");
303             break;
304         case MRAA_ERROR_NO_RESOURCES:
305             fprintf(stdout, "MRAA: No resources.\n");
306             break;
307         case MRAA_ERROR_INVALID_RESOURCE:
308             fprintf(stdout, "MRAA: Invalid resource.\n");
309             break;
310         case MRAA_ERROR_INVALID_QUEUE_TYPE:
311             fprintf(stdout, "MRAA: Invalid Queue Type.\n");
312             break;
313         case MRAA_ERROR_NO_DATA_AVAILABLE:
314             fprintf(stdout, "MRAA: No Data available.\n");
315             break;
316         case MRAA_ERROR_INVALID_PLATFORM:
317             fprintf(stdout, "MRAA: Platform not recognised.\n");
318             break;
319         case MRAA_ERROR_PLATFORM_NOT_INITIALISED:
320             fprintf(stdout, "MRAA: Platform not initialised.\n");
321             break;
322         case MRAA_ERROR_PLATFORM_ALREADY_INITIALISED:
323             fprintf(stdout, "MRAA: Platform already initialised.\n");
324             break;
325         case MRAA_ERROR_UNSPECIFIED:
326             fprintf(stdout, "MRAA: Unspecified Error.\n");
327             break;
328         default:
329             fprintf(stdout, "MRAA: Unrecognised error.\n");
330             break;
331     }
332 }
333 
334 
335 mraa_boolean_t
mraa_has_sub_platform()336 mraa_has_sub_platform()
337 {
338     return (plat != NULL) && (plat->sub_platform != NULL);
339 }
340 
341 mraa_boolean_t
mraa_pin_mode_test(int pin,mraa_pinmodes_t mode)342 mraa_pin_mode_test(int pin, mraa_pinmodes_t mode)
343 {
344     if (plat == NULL)
345         return 0;
346 
347     mraa_board_t* current_plat = plat;
348     if (mraa_is_sub_platform_id(pin)) {
349         current_plat = plat->sub_platform;
350         if (current_plat == NULL) {
351             syslog(LOG_ERR, "mraa_pin_mode_test: Sub platform Not Initialised");
352             return 0;
353         }
354         pin = mraa_get_sub_platform_index(pin);
355     }
356 
357     if (current_plat == NULL || current_plat->platform_type == MRAA_UNKNOWN_PLATFORM) {
358         return 0;
359     }
360     if (pin > (current_plat->phy_pin_count - 1) || pin < 0)
361         return 0;
362 
363     switch (mode) {
364         case MRAA_PIN_VALID:
365             if (current_plat->pins[pin].capabilites.valid == 1)
366                 return 1;
367             break;
368         case MRAA_PIN_GPIO:
369             if (current_plat->pins[pin].capabilites.gpio == 1)
370                 return 1;
371             break;
372         case MRAA_PIN_PWM:
373             if (current_plat->pins[pin].capabilites.pwm == 1)
374                 return 1;
375             break;
376         case MRAA_PIN_FAST_GPIO:
377             if (current_plat->pins[pin].capabilites.fast_gpio == 1)
378                 return 1;
379             break;
380         case MRAA_PIN_SPI:
381             if (current_plat->pins[pin].capabilites.spi == 1)
382                 return 1;
383             break;
384         case MRAA_PIN_I2C:
385             if (current_plat->pins[pin].capabilites.i2c == 1)
386                 return 1;
387             break;
388         case MRAA_PIN_AIO:
389             if (current_plat->pins[pin].capabilites.aio == 1)
390                 return 1;
391             break;
392         case MRAA_PIN_UART:
393             if (current_plat->pins[pin].capabilites.uart == 1)
394                 return 1;
395             break;
396         default:
397             syslog(LOG_NOTICE, "requested pinmode invalid");
398             break;
399     }
400     return 0;
401 }
402 
403 mraa_platform_t
mraa_get_platform_type()404 mraa_get_platform_type()
405 {
406     if (plat == NULL)
407         return MRAA_UNKNOWN_PLATFORM;
408     return plat->platform_type;
409 }
410 
411 int
mraa_get_platform_combined_type()412 mraa_get_platform_combined_type()
413 {
414     int type = mraa_get_platform_type();
415     int sub_type = mraa_has_sub_platform() ? plat->sub_platform->platform_type : MRAA_UNKNOWN_PLATFORM;
416     return type | (sub_type << 8);
417 }
418 
419 unsigned int
mraa_adc_raw_bits()420 mraa_adc_raw_bits()
421 {
422     if (plat == NULL)
423         return 0;
424 
425     if (plat->aio_count == 0)
426         return 0;
427 
428     return plat->adc_raw;
429 }
430 
431 unsigned int
mraa_get_platform_adc_raw_bits(uint8_t platform_offset)432 mraa_get_platform_adc_raw_bits(uint8_t platform_offset)
433 {
434     if (platform_offset == MRAA_MAIN_PLATFORM_OFFSET)
435         return mraa_adc_raw_bits();
436     else {
437         if (!mraa_has_sub_platform())
438             return 0;
439 
440         if (plat->sub_platform->aio_count == 0)
441             return 0;
442 
443         return plat->sub_platform->adc_raw;
444     }
445 }
446 
447 
448 unsigned int
mraa_adc_supported_bits()449 mraa_adc_supported_bits()
450 {
451     if (plat == NULL)
452         return 0;
453 
454     if (plat->aio_count == 0)
455         return 0;
456 
457     return plat->adc_supported;
458 }
459 
460 unsigned int
mraa_get_platform_adc_supported_bits(int platform_offset)461 mraa_get_platform_adc_supported_bits(int platform_offset)
462 {
463     if (platform_offset == MRAA_MAIN_PLATFORM_OFFSET)
464         return mraa_adc_supported_bits();
465     else {
466         if (!mraa_has_sub_platform())
467             return 0;
468 
469         if (plat->sub_platform->aio_count == 0)
470             return 0;
471 
472         return plat->sub_platform->adc_supported;
473     }
474 }
475 
476 const char*
mraa_get_platform_name()477 mraa_get_platform_name()
478 {
479     return platform_name;
480 }
481 
482 const char*
mraa_get_platform_version(int platform_offset)483 mraa_get_platform_version(int platform_offset)
484 {
485     if (plat == NULL) {
486         return NULL;
487     }
488     if (platform_offset == MRAA_MAIN_PLATFORM_OFFSET) {
489         return plat->platform_version;
490     } else {
491         return plat->sub_platform->platform_version;
492     }
493 }
494 
495 int
mraa_get_i2c_bus_count()496 mraa_get_i2c_bus_count()
497 {
498     if (plat == NULL) {
499         return -1;
500     }
501     return plat->i2c_bus_count;
502 }
503 
504 int
mraa_get_i2c_bus_id(unsigned i2c_bus)505 mraa_get_i2c_bus_id(unsigned i2c_bus)
506 {
507     if (plat == NULL) {
508         return -1;
509     }
510 
511     if (i2c_bus >= plat->i2c_bus_count) {
512         return -1;
513     }
514 
515     return plat->i2c_bus[i2c_bus].bus_id;
516 }
517 
518 unsigned int
mraa_get_pin_count()519 mraa_get_pin_count()
520 {
521     if (plat == NULL) {
522         return 0;
523     }
524     return plat->phy_pin_count;
525 }
526 
527 unsigned int
mraa_get_platform_pin_count(uint8_t platform_offset)528 mraa_get_platform_pin_count(uint8_t platform_offset)
529 {
530     if (platform_offset == MRAA_MAIN_PLATFORM_OFFSET)
531         return mraa_get_pin_count();
532     else {
533         if (mraa_has_sub_platform())
534            return plat->sub_platform->phy_pin_count;
535         else
536            return 0;
537     }
538 }
539 
540 
541 char*
mraa_get_pin_name(int pin)542 mraa_get_pin_name(int pin)
543 {
544     if (plat == NULL)
545         return 0;
546 
547     mraa_board_t* current_plat = plat;
548     if (mraa_is_sub_platform_id(pin)) {
549         current_plat = plat->sub_platform;
550         if (current_plat == NULL) {
551             syslog(LOG_ERR, "mraa_get_pin_name: Sub platform Not Initialised");
552             return 0;
553         }
554         pin = mraa_get_sub_platform_index(pin);
555     }
556 
557     if (pin > (current_plat->phy_pin_count - 1) || pin < 0)
558         return NULL;
559     return (char*) current_plat->pins[pin].name;
560 }
561 
562 int
mraa_get_default_i2c_bus(uint8_t platform_offset)563 mraa_get_default_i2c_bus(uint8_t platform_offset)
564 {
565     if (plat == NULL)
566         return -1;
567     if (platform_offset == MRAA_MAIN_PLATFORM_OFFSET) {
568         return plat->def_i2c_bus;
569     } else {
570         if (mraa_has_sub_platform())
571            return plat->sub_platform->def_i2c_bus;
572         else
573            return -1;
574     }
575 }
576 
577 
578 mraa_boolean_t
mraa_file_exist(const char * filename)579 mraa_file_exist(const char* filename)
580 {
581     glob_t results;
582     results.gl_pathc = 0;
583     glob(filename, 0, NULL, &results);
584     int file_found = results.gl_pathc == 1;
585     globfree(&results);
586     return file_found;
587 }
588 
589 mraa_boolean_t
mraa_file_contains(const char * filename,const char * content)590 mraa_file_contains(const char* filename, const char* content)
591 {
592     mraa_boolean_t found = 0;
593     if ((filename == NULL) || (content == NULL)) {
594         return 0;
595     }
596 
597     char* file = mraa_file_unglob(filename);
598     if (file != NULL) {
599         size_t len = 1024;
600         char* line = calloc(len, sizeof(char));
601         if (line == NULL) {
602             free(file);
603             return 0;
604         }
605         FILE* fh = fopen(file, "r");
606         if (fh == NULL) {
607             free(file);
608             free(line);
609             return 0;
610         }
611         while ((getline(&line, &len, fh) != -1) && (found == 0)) {
612             if (strstr(line, content)) {
613                 found = 1;
614                 break;
615             }
616         }
617         fclose(fh);
618         free(file);
619         free(line);
620     }
621     return found;
622 }
623 
624 mraa_boolean_t
mraa_file_contains_both(const char * filename,const char * content,const char * content2)625 mraa_file_contains_both(const char* filename, const char* content, const char* content2)
626 {
627     mraa_boolean_t found = 0;
628     if ((filename == NULL) || (content == NULL)) {
629         return 0;
630     }
631 
632     char* file = mraa_file_unglob(filename);
633     if (file != NULL) {
634         size_t len = 1024;
635         char* line = calloc(len, sizeof(char));
636         if (line == NULL) {
637             free(file);
638             return 0;
639         }
640         FILE* fh = fopen(file, "r");
641         if (fh == NULL) {
642             free(file);
643             free(line);
644             return 0;
645         }
646         while ((getline(&line, &len, fh) != -1) && (found == 0)) {
647             if (strstr(line, content) && strstr(line, content2)) {
648                 found = 1;
649                 break;
650             }
651         }
652         fclose(fh);
653         free(file);
654         free(line);
655     }
656     return found;
657 }
658 
659 char*
mraa_file_unglob(const char * filename)660 mraa_file_unglob(const char* filename)
661 {
662     glob_t results;
663     char* res = NULL;
664     results.gl_pathc = 0;
665     glob(filename, 0, NULL, &results);
666     if (results.gl_pathc == 1)
667         res = strdup(results.gl_pathv[0]);
668     globfree(&results);
669     return res;
670 }
671 
672 mraa_boolean_t
mraa_link_targets(const char * filename,const char * targetname)673 mraa_link_targets(const char* filename, const char* targetname)
674 {
675     int size = 100;
676     int nchars = 0;
677     char* buffer = NULL;
678     while (nchars == 0) {
679         buffer = (char*) realloc(buffer, size);
680         if (buffer == NULL)
681             return 0;
682         nchars = readlink(filename, buffer, size);
683         if (nchars < 0) {
684             free(buffer);
685             return 0;
686         } else {
687             buffer[nchars] = '\0';
688         }
689         if (nchars >= size) {
690             size *= 2;
691             nchars = 0;
692         }
693     }
694     if (strstr(buffer, targetname)) {
695         free(buffer);
696         return 1;
697     } else {
698         free(buffer);
699         return 0;
700     }
701 }
702 
703 static int
mraa_count_i2c_files(const char * path,const struct stat * sb,int flag,struct FTW * ftwb)704 mraa_count_i2c_files(const char* path, const struct stat* sb, int flag, struct FTW* ftwb)
705 {
706     switch (sb->st_mode & S_IFMT) {
707         case S_IFLNK:
708             num_i2c_devices++;
709             break;
710     }
711     return 0;
712 }
713 
714 int
mraa_find_i2c_bus(const char * devname,int startfrom)715 mraa_find_i2c_bus(const char* devname, int startfrom)
716 {
717     char path[64];
718     int fd;
719     int i = startfrom;
720     int ret = -1;
721 
722     // because feeding mraa_find_i2c_bus result back into the function is
723     // useful treat -1 as 0
724     if (startfrom < 0) {
725         startfrom = 0;
726     }
727 
728     // find how many i2c buses we have if we haven't already
729     if (num_i2c_devices == 0) {
730         if (nftw("/sys/class/i2c-dev/", &mraa_count_i2c_files, 20, FTW_PHYS) == -1) {
731             return -1;
732         }
733     }
734 
735     // i2c devices are numbered numerically so 0 must exist otherwise there is
736     // no i2c-dev loaded
737     if (mraa_file_exist("/sys/class/i2c-dev/i2c-0")) {
738         for (i; i < num_i2c_devices; i++) {
739             off_t size, err;
740             snprintf(path, 64, "/sys/class/i2c-dev/i2c-%u/name", i);
741             fd = open(path, O_RDONLY);
742             if (fd < 0) {
743                 break;
744             }
745             size = lseek(fd, 0, SEEK_END);
746             if (size < 0) {
747                 syslog(LOG_WARNING, "mraa: failed to seek i2c filename file");
748                 close(fd);
749                 break;
750             }
751             err = lseek(fd, 0, SEEK_SET);
752             if (err < 0) {
753                 syslog(LOG_WARNING, "mraa: failed to seek i2c filename file");
754                 close(fd);
755                 break;
756             }
757             char* value = malloc(size);
758             if (value == NULL) {
759                 syslog(LOG_ERR, "mraa: failed to allocate memory for i2c file");
760                 close(fd);
761                 break;
762             }
763             ssize_t r = read(fd, value, size);
764             if (r > 0) {
765                 if (strcasestr(value, devname) != NULL) {
766                     free(value);
767                     close(fd);
768                     return i;
769                 }
770             } else {
771                 syslog(LOG_ERR, "mraa: sysfs i2cdev failed");
772             }
773             free(value);
774             close(fd);
775         }
776     } else {
777         syslog(LOG_WARNING, "mraa: no i2c-dev detected, load i2c-dev");
778     }
779 
780     return ret;
781 }
782 
783 mraa_boolean_t
mraa_is_sub_platform_id(int pin_or_bus)784 mraa_is_sub_platform_id(int pin_or_bus)
785 {
786     return (pin_or_bus & MRAA_SUB_PLATFORM_MASK) != 0;
787 }
788 
789 int
mraa_get_sub_platform_id(int pin_or_bus)790 mraa_get_sub_platform_id(int pin_or_bus)
791 {
792     return pin_or_bus | MRAA_SUB_PLATFORM_MASK;
793 }
794 
795 int
mraa_get_sub_platform_index(int pin_or_bus)796 mraa_get_sub_platform_index(int pin_or_bus)
797 {
798     return pin_or_bus & (~MRAA_SUB_PLATFORM_MASK);
799 }
800 
801 int
mraa_get_iio_device_count()802 mraa_get_iio_device_count()
803 {
804     return plat_iio->iio_device_count;
805 }
806 
807 int
mraa_find_iio_device(const char * devicename)808 mraa_find_iio_device(const char* devicename)
809 {
810     int i = 0;
811     for (i; i < plat_iio->iio_device_count; i++) {
812 #if 0
813         // compare with devices array
814         if (!strcmp() {
815         }
816 #endif
817     }
818     return 0;
819 }
820