2 * Author: Thomas Ingleby <thomas.c.ingleby@intel.com>
3 * Author: Brendan Le Foll <brendan.le.foll@intel.com>
4 * Copyright (c) 2014 Intel Corporation.
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:
14 * The above copyright notice and this permission notice shall be
15 * included in all copies or substantial portions of the Software.
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.
26 #include "mraa_internal.h"
38 #define SYSFS_CLASS_GPIO "/sys/class/gpio"
43 mraa_gpio_get_valfp(mraa_gpio_context dev)
46 sprintf(bu, SYSFS_CLASS_GPIO "/gpio%d/value", dev->pin);
47 dev->value_fp = open(bu, O_RDWR);
48 if (dev->value_fp == -1) {
49 return MRAA_ERROR_INVALID_RESOURCE;
56 mraa_gpio_init(int pin)
59 syslog(LOG_ERR, "gpio: platform not initialised");
62 if (pin < 0 || pin > plat->phy_pin_count) {
63 syslog(LOG_ERR, "gpio: pin %i beyond platform definition", pin);
66 if (plat->pins[pin].capabilites.gpio != 1) {
67 syslog(LOG_ERR, "gpio: pin %i not capable of gpio", pin);
70 if (plat->pins[pin].gpio.mux_total > 0) {
71 if (mraa_setup_mux_mapped(plat->pins[pin].gpio) != MRAA_SUCCESS) {
72 syslog(LOG_ERR, "gpio: unable to setup muxes");
77 mraa_gpio_context r = mraa_gpio_init_raw(plat->pins[pin].gpio.pinmap);
79 syslog(LOG_CRIT, "gpio: mraa_gpio_init_raw(%d) returned error", pin);
84 if (advance_func->gpio_init_post != NULL) {
85 mraa_result_t ret = advance_func->gpio_init_post(r);
86 if (ret != MRAA_SUCCESS) {
95 mraa_gpio_init_raw(int pin)
97 if (advance_func->gpio_init_pre != NULL) {
98 if (advance_func->gpio_init_pre(pin) != MRAA_SUCCESS)
108 mraa_gpio_context dev = (mraa_gpio_context) malloc(sizeof(struct _gpio));
110 syslog(LOG_CRIT, "gpio: Failed to allocate memory for context");
114 memset(dev, 0, sizeof(struct _gpio));
116 dev->isr_value_fp = -1;
120 // then check to make sure the pin is exported.
121 char directory[MAX_SIZE];
122 snprintf(directory, MAX_SIZE, SYSFS_CLASS_GPIO "/gpio%d/", dev->pin);
124 if (stat(directory, &dir) == 0 && S_ISDIR(dir.st_mode)) {
125 dev->owner = 0; // Not Owner
127 int export = open(SYSFS_CLASS_GPIO "/export", O_WRONLY);
129 syslog(LOG_ERR, "gpio: Failed to open export for writing");
133 length = snprintf(bu, sizeof(bu), "%d", dev->pin);
134 if (write(export, bu, length*sizeof(char)) == -1) {
135 syslog(LOG_ERR, "gpio: Failed to write to export");
149 mraa_gpio_wait_interrupt(int fd)
154 // setup poll on POLLPRI
156 pfd.events = POLLPRI;
158 // do an initial read to clear interupt
162 return MRAA_ERROR_INVALID_RESOURCE;
165 // Wait for it forever or until pthread_cancel
166 // poll is a cancelable point like sleep()
167 int x = poll (&pfd, 1, -1);
169 // do a final read to clear interupt
176 mraa_gpio_interrupt_handler(void* arg)
178 mraa_gpio_context dev = (mraa_gpio_context) arg;
181 // open gpio value with open(3)
183 sprintf(bu, SYSFS_CLASS_GPIO "/gpio%d/value", dev->pin);
184 int fp = open(bu, O_RDONLY);
186 syslog(LOG_ERR, "gpio: failed to open gpio%d/value", dev->pin);
189 dev->isr_value_fp = fp;
192 ret = mraa_gpio_wait_interrupt(dev->isr_value_fp);
193 if (ret == MRAA_SUCCESS) {
194 pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
196 // In order to call a python object (all python functions are objects) we
197 // need to aquire the GIL (Global Interpreter Lock). This may not always be
198 // nessecary but especially if doing IO (like print()) python will segfault
199 // if we do not hold a lock on the GIL
200 PyGILState_STATE gilstate = PyGILState_Ensure();
203 arglist = Py_BuildValue("(i)", dev->isr_args);
204 if (arglist == NULL) {
205 syslog(LOG_ERR, "gpio: Py_BuildValue NULL");
207 ret = PyEval_CallObject((PyObject*)dev->isr, arglist);
209 syslog(LOG_ERR, "gpio: PyEval_CallObject failed");
216 PyGILState_Release (gilstate);
218 dev->isr(dev->isr_args);
220 pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
222 // we must have got an error code so die nicely
223 pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
224 close(dev->isr_value_fp);
225 dev->isr_value_fp = -1;
232 mraa_gpio_edge_mode(mraa_gpio_context dev, gpio_edge_t mode)
234 if (dev->value_fp != -1) {
235 close(dev->value_fp);
239 char filepath[MAX_SIZE];
240 snprintf(filepath, MAX_SIZE, SYSFS_CLASS_GPIO "/gpio%d/edge", dev->pin);
242 int edge = open(filepath, O_RDWR);
244 syslog(LOG_ERR, "gpio: Failed to open edge for writing");
245 return MRAA_ERROR_INVALID_RESOURCE;
251 case MRAA_GPIO_EDGE_NONE:
252 length = snprintf(bu, sizeof(bu), "none");
254 case MRAA_GPIO_EDGE_BOTH:
255 length = snprintf(bu, sizeof(bu), "both");
257 case MRAA_GPIO_EDGE_RISING:
258 length = snprintf(bu, sizeof(bu), "rising");
260 case MRAA_GPIO_EDGE_FALLING:
261 length = snprintf(bu, sizeof(bu), "falling");
265 return MRAA_ERROR_FEATURE_NOT_IMPLEMENTED;
267 if (write(edge, bu, length*sizeof(char)) == -1) {
268 syslog(LOG_ERR, "gpio: Failed to write to edge");
270 return MRAA_ERROR_INVALID_RESOURCE;
278 mraa_gpio_isr(mraa_gpio_context dev, gpio_edge_t mode, void (*fptr)(void *), void * args)
280 // we only allow one isr per mraa_gpio_context
281 if (dev->thread_id != 0) {
282 return MRAA_ERROR_NO_RESOURCES;
285 if (MRAA_SUCCESS != mraa_gpio_edge_mode(dev, mode)) {
286 return MRAA_ERROR_UNSPECIFIED;
290 dev->isr_args = args;
291 pthread_create (&dev->thread_id, NULL, mraa_gpio_interrupt_handler, (void *) dev);
297 mraa_gpio_isr_exit(mraa_gpio_context dev)
299 mraa_result_t ret = MRAA_SUCCESS;
301 // wasting our time, there is no isr to exit from
302 if (dev->thread_id == 0 && dev->isr_value_fp == -1) {
306 // stop isr being useful
307 ret = mraa_gpio_edge_mode(dev, MRAA_GPIO_EDGE_NONE);
309 if ((dev->thread_id != 0)) {
310 if ((pthread_cancel(dev->thread_id) != 0) || (pthread_join(dev->thread_id, NULL) != 0)) {
311 ret = MRAA_ERROR_INVALID_HANDLE;
315 // close the filehandle in case it's still open
316 if (dev->isr_value_fp != -1) {
317 if (close(dev->isr_value_fp) != 0) {
318 ret = MRAA_ERROR_INVALID_PARAMETER;
323 // Dereference our Python call back function
327 // assume our thread will exit either way we just lost it's handle
329 dev->isr_value_fp = -1;
334 mraa_gpio_mode(mraa_gpio_context dev, gpio_mode_t mode)
336 if (advance_func->gpio_mode_replace != NULL)
337 return advance_func->gpio_mode_replace(dev,mode);
339 if (advance_func->gpio_mode_pre != NULL) {
340 mraa_result_t pre_ret = (advance_func->gpio_mode_pre(dev,mode));
341 if(pre_ret != MRAA_SUCCESS)
345 if (dev->value_fp != -1) {
346 close(dev->value_fp);
350 char filepath[MAX_SIZE];
351 snprintf(filepath, MAX_SIZE, SYSFS_CLASS_GPIO "/gpio%d/drive", dev->pin);
353 int drive = open(filepath, O_WRONLY);
355 syslog(LOG_ERR, "gpio: Failed to open drive for writing");
356 return MRAA_ERROR_INVALID_RESOURCE;
362 case MRAA_GPIO_STRONG:
363 length = snprintf(bu, sizeof(bu), "strong");
365 case MRAA_GPIO_PULLUP:
366 length = snprintf(bu, sizeof(bu), "pullup");
368 case MRAA_GPIO_PULLDOWN:
369 length = snprintf(bu, sizeof(bu), "pulldown");
372 length = snprintf(bu, sizeof(bu), "hiz");
376 return MRAA_ERROR_FEATURE_NOT_IMPLEMENTED;
378 if (write(drive, bu, length*sizeof(char)) == -1) {
379 syslog(LOG_ERR, "gpio: Failed to write to drive mode");
381 return MRAA_ERROR_INVALID_RESOURCE;
386 if (advance_func->gpio_mode_post != NULL)
387 return advance_func->gpio_mode_post(dev,mode);
392 mraa_gpio_dir(mraa_gpio_context dev, gpio_dir_t dir)
394 if (advance_func->gpio_dir_replace != NULL) {
395 return advance_func->gpio_dir_replace(dev,dir);
397 if (advance_func->gpio_dir_pre != NULL) {
398 mraa_result_t pre_ret = (advance_func->gpio_dir_pre(dev,dir));
399 if (pre_ret != MRAA_SUCCESS) {
405 return MRAA_ERROR_INVALID_HANDLE;
407 if (dev->value_fp != -1) {
408 close(dev->value_fp);
411 char filepath[MAX_SIZE];
412 snprintf(filepath, MAX_SIZE, SYSFS_CLASS_GPIO "/gpio%d/direction", dev->pin);
414 int direction = open(filepath, O_RDWR);
416 if (direction == -1) {
417 // Direction Failed to Open. If HIGH or LOW was passed will try and set
418 // If not fail as usual.
420 case MRAA_GPIO_OUT_HIGH:
421 return mraa_gpio_write(dev, 1);
422 case MRAA_GPIO_OUT_LOW:
423 return mraa_gpio_write(dev, 0);
425 return MRAA_ERROR_INVALID_RESOURCE;
433 length = snprintf(bu, sizeof(bu), "out");
436 length = snprintf(bu, sizeof(bu), "in");
438 case MRAA_GPIO_OUT_HIGH:
439 length = snprintf(bu, sizeof(bu), "high");
441 case MRAA_GPIO_OUT_LOW:
442 length = snprintf(bu, sizeof(bu), "low");
446 return MRAA_ERROR_FEATURE_NOT_IMPLEMENTED;
449 if (write(direction, bu, length*sizeof(char)) == -1) {
451 return MRAA_ERROR_INVALID_RESOURCE;
455 if (advance_func->gpio_dir_post != NULL)
456 return advance_func->gpio_dir_post(dev,dir);
461 mraa_gpio_read(mraa_gpio_context dev)
466 if (dev->mmap_read != NULL)
467 return dev->mmap_read(dev);
469 if (dev->value_fp == -1) {
470 if (mraa_gpio_get_valfp(dev) != MRAA_SUCCESS) {
471 syslog(LOG_ERR, "gpio: Failed to get value file pointer");
476 // if value_fp is new this is pointless
477 lseek(dev->value_fp, 0, SEEK_SET);
480 if (read(dev->value_fp, bu, 2*sizeof(char)) != 2) {
481 syslog(LOG_ERR, "gpio: Failed to read a sensible value from sysfs");
484 lseek(dev->value_fp, 0, SEEK_SET);
486 return (int) strtol(bu, NULL, 10);
490 mraa_gpio_write(mraa_gpio_context dev, int value)
493 return MRAA_ERROR_INVALID_HANDLE;
495 if (dev->mmap_write != NULL)
496 return dev->mmap_write(dev,value);
498 if (advance_func->gpio_write_pre != NULL) {
499 mraa_result_t pre_ret = (advance_func->gpio_write_pre(dev,value));
500 if(pre_ret != MRAA_SUCCESS)
504 if (dev->value_fp == -1) {
505 if (mraa_gpio_get_valfp(dev) != MRAA_SUCCESS) {
506 return MRAA_ERROR_INVALID_RESOURCE;
510 if (lseek(dev->value_fp, 0, SEEK_SET) == -1) {
511 return MRAA_ERROR_INVALID_RESOURCE;
515 int length = snprintf(bu, sizeof(bu), "%d", value);
516 if (write(dev->value_fp, bu, length*sizeof(char)) == -1) {
517 return MRAA_ERROR_INVALID_HANDLE;
520 if (advance_func->gpio_write_post != NULL)
521 return advance_func->gpio_write_post(dev,value);
526 mraa_gpio_unexport_force(mraa_gpio_context dev)
528 int unexport = open(SYSFS_CLASS_GPIO "/unexport", O_WRONLY);
529 if (unexport == -1) {
530 syslog(LOG_ERR, "gpio: Failed to open unexport for writing");
531 return MRAA_ERROR_INVALID_RESOURCE;
535 int length = snprintf(bu, sizeof(bu), "%d", dev->pin);
536 if (write(unexport, bu, length*sizeof(char)) == -1) {
537 syslog(LOG_ERR, "gpio: Failed to write to unexport");
539 return MRAA_ERROR_INVALID_RESOURCE;
543 mraa_gpio_isr_exit(dev);
547 mraa_gpio_unexport(mraa_gpio_context dev)
550 return mraa_gpio_unexport_force(dev);
552 return MRAA_ERROR_INVALID_RESOURCE;
556 mraa_gpio_close(mraa_gpio_context dev)
558 mraa_result_t result = MRAA_SUCCESS;
560 if (advance_func->gpio_close_pre != NULL) {
561 result = advance_func->gpio_close_pre(dev);
564 if (dev->value_fp != -1) {
565 close(dev->value_fp);
567 mraa_gpio_unexport(dev);
573 mraa_gpio_owner(mraa_gpio_context dev, mraa_boolean_t own)
576 return MRAA_ERROR_INVALID_RESOURCE;
582 mraa_gpio_use_mmaped(mraa_gpio_context dev, mraa_boolean_t mmap_en)
584 if (advance_func->gpio_mmap_setup != NULL) {
585 return advance_func->gpio_mmap_setup(dev,mmap_en);
588 syslog(LOG_ERR, "gpio: mmap not implemented on this platform");
589 return MRAA_ERROR_FEATURE_NOT_IMPLEMENTED;
593 mraa_gpio_get_pin(mraa_gpio_context dev)
596 syslog(LOG_ERR, "gpio: context is invalid");
602 mraa_gpio_get_pin_raw(mraa_gpio_context dev)
605 syslog(LOG_ERR, "gpio: context is invalid");