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 %d to export", dev->pin);
149 mraa_gpio_wait_interrupt(int fd)
155 return MRAA_ERROR_INVALID_RESOURCE;
158 // setup poll on POLLPRI
160 pfd.events = POLLPRI;
162 // do an initial read to clear interrupt
163 lseek(fd, 0, SEEK_SET);
166 // Wait for it forever or until pthread_cancel
167 // poll is a cancelable point like sleep()
168 int x = poll(&pfd, 1, -1);
170 // do a final read to clear interrupt
177 mraa_gpio_interrupt_handler(void* arg)
179 mraa_gpio_context dev = (mraa_gpio_context) arg;
182 // open gpio value with open(3)
184 sprintf(bu, SYSFS_CLASS_GPIO "/gpio%d/value", dev->pin);
185 int fp = open(bu, O_RDONLY);
187 syslog(LOG_ERR, "gpio: failed to open gpio%d/value", dev->pin);
190 dev->isr_value_fp = fp;
193 ret = mraa_gpio_wait_interrupt(dev->isr_value_fp);
194 if (ret == MRAA_SUCCESS) {
195 pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
197 // In order to call a python object (all python functions are objects) we
198 // need to aquire the GIL (Global Interpreter Lock). This may not always be
199 // nessecary but especially if doing IO (like print()) python will segfault
200 // if we do not hold a lock on the GIL
201 PyGILState_STATE gilstate = PyGILState_Ensure();
204 arglist = Py_BuildValue("(i)", dev->isr_args);
205 if (arglist == NULL) {
206 syslog(LOG_ERR, "gpio: Py_BuildValue NULL");
208 ret = PyEval_CallObject((PyObject*) dev->isr, arglist);
210 syslog(LOG_ERR, "gpio: PyEval_CallObject failed");
217 PyGILState_Release(gilstate);
219 dev->isr(dev->isr_args);
221 pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
223 // we must have got an error code so die nicely
224 pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
225 close(dev->isr_value_fp);
226 dev->isr_value_fp = -1;
233 mraa_gpio_edge_mode(mraa_gpio_context dev, mraa_gpio_edge_t mode)
235 if (dev->value_fp != -1) {
236 close(dev->value_fp);
240 char filepath[MAX_SIZE];
241 snprintf(filepath, MAX_SIZE, SYSFS_CLASS_GPIO "/gpio%d/edge", dev->pin);
243 int edge = open(filepath, O_RDWR);
245 syslog(LOG_ERR, "gpio: Failed to open edge for writing");
246 return MRAA_ERROR_INVALID_RESOURCE;
252 case MRAA_GPIO_EDGE_NONE:
253 length = snprintf(bu, sizeof(bu), "none");
255 case MRAA_GPIO_EDGE_BOTH:
256 length = snprintf(bu, sizeof(bu), "both");
258 case MRAA_GPIO_EDGE_RISING:
259 length = snprintf(bu, sizeof(bu), "rising");
261 case MRAA_GPIO_EDGE_FALLING:
262 length = snprintf(bu, sizeof(bu), "falling");
266 return MRAA_ERROR_FEATURE_NOT_IMPLEMENTED;
268 if (write(edge, bu, length * sizeof(char)) == -1) {
269 syslog(LOG_ERR, "gpio: Failed to write to edge");
271 return MRAA_ERROR_INVALID_RESOURCE;
279 mraa_gpio_isr(mraa_gpio_context dev, mraa_gpio_edge_t mode, void (*fptr)(void*), void* args)
281 // we only allow one isr per mraa_gpio_context
282 if (dev->thread_id != 0) {
283 return MRAA_ERROR_NO_RESOURCES;
286 if (MRAA_SUCCESS != mraa_gpio_edge_mode(dev, mode)) {
287 return MRAA_ERROR_UNSPECIFIED;
291 dev->isr_args = args;
292 pthread_create(&dev->thread_id, NULL, mraa_gpio_interrupt_handler, (void*) dev);
298 mraa_gpio_isr_exit(mraa_gpio_context dev)
300 mraa_result_t ret = MRAA_SUCCESS;
302 // wasting our time, there is no isr to exit from
303 if (dev->thread_id == 0 && dev->isr_value_fp == -1) {
307 // stop isr being useful
308 ret = mraa_gpio_edge_mode(dev, MRAA_GPIO_EDGE_NONE);
310 if ((dev->thread_id != 0)) {
311 if ((pthread_cancel(dev->thread_id) != 0) || (pthread_join(dev->thread_id, NULL) != 0)) {
312 ret = MRAA_ERROR_INVALID_HANDLE;
316 // close the filehandle in case it's still open
317 if (dev->isr_value_fp != -1) {
318 if (close(dev->isr_value_fp) != 0) {
319 ret = MRAA_ERROR_INVALID_PARAMETER;
323 // assume our thread will exit either way we just lost it's handle
325 dev->isr_value_fp = -1;
330 mraa_gpio_mode(mraa_gpio_context dev, mraa_gpio_mode_t mode)
332 if (advance_func->gpio_mode_replace != NULL)
333 return advance_func->gpio_mode_replace(dev, mode);
335 if (advance_func->gpio_mode_pre != NULL) {
336 mraa_result_t pre_ret = (advance_func->gpio_mode_pre(dev, mode));
337 if (pre_ret != MRAA_SUCCESS)
341 if (dev->value_fp != -1) {
342 close(dev->value_fp);
346 char filepath[MAX_SIZE];
347 snprintf(filepath, MAX_SIZE, SYSFS_CLASS_GPIO "/gpio%d/drive", dev->pin);
349 int drive = open(filepath, O_WRONLY);
351 syslog(LOG_ERR, "gpio: Failed to open drive for writing");
352 return MRAA_ERROR_INVALID_RESOURCE;
358 case MRAA_GPIO_STRONG:
359 length = snprintf(bu, sizeof(bu), "strong");
361 case MRAA_GPIO_PULLUP:
362 length = snprintf(bu, sizeof(bu), "pullup");
364 case MRAA_GPIO_PULLDOWN:
365 length = snprintf(bu, sizeof(bu), "pulldown");
368 length = snprintf(bu, sizeof(bu), "hiz");
372 return MRAA_ERROR_FEATURE_NOT_IMPLEMENTED;
374 if (write(drive, bu, length * sizeof(char)) == -1) {
375 syslog(LOG_ERR, "gpio: Failed to write to drive mode");
377 return MRAA_ERROR_INVALID_RESOURCE;
381 if (advance_func->gpio_mode_post != NULL)
382 return advance_func->gpio_mode_post(dev, mode);
387 mraa_gpio_dir(mraa_gpio_context dev, mraa_gpio_dir_t dir)
389 if (advance_func->gpio_dir_replace != NULL) {
390 return advance_func->gpio_dir_replace(dev, dir);
392 if (advance_func->gpio_dir_pre != NULL) {
393 mraa_result_t pre_ret = (advance_func->gpio_dir_pre(dev, dir));
394 if (pre_ret != MRAA_SUCCESS) {
400 return MRAA_ERROR_INVALID_HANDLE;
402 if (dev->value_fp != -1) {
403 close(dev->value_fp);
406 char filepath[MAX_SIZE];
407 snprintf(filepath, MAX_SIZE, SYSFS_CLASS_GPIO "/gpio%d/direction", dev->pin);
409 int direction = open(filepath, O_RDWR);
411 if (direction == -1) {
412 // Direction Failed to Open. If HIGH or LOW was passed will try and set
413 // If not fail as usual.
415 case MRAA_GPIO_OUT_HIGH:
416 return mraa_gpio_write(dev, 1);
417 case MRAA_GPIO_OUT_LOW:
418 return mraa_gpio_write(dev, 0);
420 return MRAA_ERROR_INVALID_RESOURCE;
428 length = snprintf(bu, sizeof(bu), "out");
431 length = snprintf(bu, sizeof(bu), "in");
433 case MRAA_GPIO_OUT_HIGH:
434 length = snprintf(bu, sizeof(bu), "high");
436 case MRAA_GPIO_OUT_LOW:
437 length = snprintf(bu, sizeof(bu), "low");
441 return MRAA_ERROR_FEATURE_NOT_IMPLEMENTED;
444 if (write(direction, bu, length * sizeof(char)) == -1) {
446 return MRAA_ERROR_INVALID_RESOURCE;
450 if (advance_func->gpio_dir_post != NULL)
451 return advance_func->gpio_dir_post(dev, dir);
456 mraa_gpio_read(mraa_gpio_context dev)
461 if (dev->mmap_read != NULL)
462 return dev->mmap_read(dev);
464 if (dev->value_fp == -1) {
465 if (mraa_gpio_get_valfp(dev) != MRAA_SUCCESS) {
466 syslog(LOG_ERR, "gpio: Failed to get value file pointer");
470 // if value_fp is new this is pointless
471 lseek(dev->value_fp, 0, SEEK_SET);
474 if (read(dev->value_fp, bu, 2 * sizeof(char)) != 2) {
475 syslog(LOG_ERR, "gpio: Failed to read a sensible value from sysfs");
478 lseek(dev->value_fp, 0, SEEK_SET);
480 return (int) strtol(bu, NULL, 10);
484 mraa_gpio_write(mraa_gpio_context dev, int value)
487 return MRAA_ERROR_INVALID_HANDLE;
489 if (dev->mmap_write != NULL)
490 return dev->mmap_write(dev, value);
492 if (advance_func->gpio_write_pre != NULL) {
493 mraa_result_t pre_ret = (advance_func->gpio_write_pre(dev, value));
494 if (pre_ret != MRAA_SUCCESS)
498 if (dev->value_fp == -1) {
499 if (mraa_gpio_get_valfp(dev) != MRAA_SUCCESS) {
500 return MRAA_ERROR_INVALID_RESOURCE;
504 if (lseek(dev->value_fp, 0, SEEK_SET) == -1) {
505 return MRAA_ERROR_INVALID_RESOURCE;
509 int length = snprintf(bu, sizeof(bu), "%d", value);
510 if (write(dev->value_fp, bu, length * sizeof(char)) == -1) {
511 return MRAA_ERROR_INVALID_HANDLE;
514 if (advance_func->gpio_write_post != NULL)
515 return advance_func->gpio_write_post(dev, value);
520 mraa_gpio_unexport_force(mraa_gpio_context dev)
522 int unexport = open(SYSFS_CLASS_GPIO "/unexport", O_WRONLY);
523 if (unexport == -1) {
524 syslog(LOG_ERR, "gpio: Failed to open unexport for writing");
525 return MRAA_ERROR_INVALID_RESOURCE;
529 int length = snprintf(bu, sizeof(bu), "%d", dev->pin);
530 if (write(unexport, bu, length * sizeof(char)) == -1) {
531 syslog(LOG_ERR, "gpio: Failed to write to unexport");
533 return MRAA_ERROR_INVALID_RESOURCE;
537 mraa_gpio_isr_exit(dev);
541 mraa_gpio_unexport(mraa_gpio_context dev)
544 return mraa_gpio_unexport_force(dev);
546 return MRAA_ERROR_INVALID_RESOURCE;
550 mraa_gpio_close(mraa_gpio_context dev)
552 mraa_result_t result = MRAA_SUCCESS;
554 if (advance_func->gpio_close_pre != NULL) {
555 result = advance_func->gpio_close_pre(dev);
558 if (dev->value_fp != -1) {
559 close(dev->value_fp);
561 mraa_gpio_unexport(dev);
567 mraa_gpio_owner(mraa_gpio_context dev, mraa_boolean_t own)
570 return MRAA_ERROR_INVALID_RESOURCE;
572 syslog(LOG_DEBUG, "gpio: Set owner to %d", (int) own);
578 mraa_gpio_use_mmaped(mraa_gpio_context dev, mraa_boolean_t mmap_en)
580 if (advance_func->gpio_mmap_setup != NULL) {
581 return advance_func->gpio_mmap_setup(dev, mmap_en);
584 syslog(LOG_ERR, "gpio: mmap not implemented on this platform");
585 return MRAA_ERROR_FEATURE_NOT_IMPLEMENTED;
589 mraa_gpio_get_pin(mraa_gpio_context dev)
592 syslog(LOG_ERR, "gpio: context is invalid");
599 mraa_gpio_get_pin_raw(mraa_gpio_context dev)
602 syslog(LOG_ERR, "gpio: context is invalid");