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)
58 int pinm = mraa_setup_gpio(pin);
62 mraa_gpio_context r = mraa_gpio_init_raw(pinm);
65 if (advance_func->gpio_init_post != NULL) {
66 mraa_result_t ret = advance_func->gpio_init_post(r);
67 if (ret != MRAA_SUCCESS) {
76 mraa_gpio_init_raw(int pin)
78 if (advance_func->gpio_init_pre != NULL) {
79 if (advance_func->gpio_init_pre(pin) != MRAA_SUCCESS)
89 mraa_gpio_context dev = (mraa_gpio_context) malloc(sizeof(struct _gpio));
91 syslog(LOG_CRIT, "gpio: Failed to allocate memory for context");
95 memset(dev, 0, sizeof(struct _gpio));
97 dev->isr_value_fp = -1;
101 char directory[MAX_SIZE];
102 snprintf(directory, MAX_SIZE, SYSFS_CLASS_GPIO "/gpio%d/", dev->pin);
104 if (stat(directory, &dir) == 0 && S_ISDIR(dir.st_mode)) {
105 dev->owner = 0; // Not Owner
107 int export = open(SYSFS_CLASS_GPIO "/export", O_WRONLY);
109 syslog(LOG_ERR, "gpio: Failed to open export for writing");
113 length = snprintf(bu, sizeof(bu), "%d", dev->pin);
114 if (write(export, bu, length*sizeof(char)) == -1) {
115 syslog(LOG_ERR, "gpio: Failed to write to export");
127 mraa_gpio_write_register(mraa_gpio_context dev,int value)
129 if (advance_func->gpio_mmaped_write_replace != NULL)
130 return advance_func->gpio_mmaped_write_replace(dev,value);
131 if (advance_func->gpio_mmaped_write_pre != NULL) {
132 mraa_result_t pre_ret = (advance_func->gpio_mmaped_write_pre(dev,value));
133 if(pre_ret != MRAA_SUCCESS)
137 *((unsigned *)dev->reg) |= (1<<dev->reg_bit_pos);
140 *((unsigned *)dev->reg) &= ~(1<<dev->reg_bit_pos);
142 if (advance_func->gpio_mmaped_write_post != NULL)
143 return advance_func->gpio_mmaped_write_post(dev,value);
148 mraa_gpio_wait_interrupt(int fd)
153 // setup poll on POLLPRI
155 pfd.events = POLLPRI;
157 // do an initial read to clear interupt
161 return MRAA_ERROR_INVALID_RESOURCE;
164 // Wait for it forever or until pthread_cancel
165 // poll is a cancelable point like sleep()
166 int x = poll (&pfd, 1, -1);
168 // do a final read to clear interupt
175 mraa_gpio_interrupt_handler(void* arg)
177 mraa_gpio_context dev = (mraa_gpio_context) arg;
180 // open gpio value with open(3)
182 sprintf(bu, SYSFS_CLASS_GPIO "/gpio%d/value", dev->pin);
183 dev->isr_value_fp = open(bu, O_RDONLY);
186 ret = mraa_gpio_wait_interrupt(dev->isr_value_fp);
187 if (ret == MRAA_SUCCESS) {
188 pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
190 // In order to call a python object (all python functions are objects) we
191 // need to aquire the GIL (Global Interpreter Lock). This may not always be
192 // nessecary but especially if doing IO (like print()) python will segfault
193 // if we do not hold a lock on the GIL
194 PyGILState_STATE gilstate = PyGILState_Ensure();
197 arglist = Py_BuildValue("(i)", dev->isr_args);
198 if (arglist == NULL) {
199 syslog(LOG_ERR, "gpio: Py_BuildValue NULL");
201 ret = PyEval_CallObject((PyObject*)dev->isr, arglist);
203 syslog(LOG_ERR, "gpio: PyEval_CallObject failed");
210 PyGILState_Release (gilstate);
212 dev->isr(dev->isr_args);
214 pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
216 // we must have got an error code so die nicely
217 pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
218 close(dev->isr_value_fp);
219 dev->isr_value_fp = -1;
226 mraa_gpio_edge_mode(mraa_gpio_context dev, gpio_edge_t mode)
228 if (dev->value_fp != -1) {
229 close(dev->value_fp);
233 char filepath[MAX_SIZE];
234 snprintf(filepath, MAX_SIZE, SYSFS_CLASS_GPIO "/gpio%d/edge", dev->pin);
236 int edge = open(filepath, O_RDWR);
238 syslog(LOG_ERR, "gpio: Failed to open edge for writing");
239 return MRAA_ERROR_INVALID_RESOURCE;
245 case MRAA_GPIO_EDGE_NONE:
246 length = snprintf(bu, sizeof(bu), "none");
248 case MRAA_GPIO_EDGE_BOTH:
249 length = snprintf(bu, sizeof(bu), "both");
251 case MRAA_GPIO_EDGE_RISING:
252 length = snprintf(bu, sizeof(bu), "rising");
254 case MRAA_GPIO_EDGE_FALLING:
255 length = snprintf(bu, sizeof(bu), "falling");
259 return MRAA_ERROR_FEATURE_NOT_IMPLEMENTED;
261 if (write(edge, bu, length*sizeof(char)) == -1) {
262 syslog(LOG_ERR, "gpio: Failed to write to edge");
264 return MRAA_ERROR_INVALID_RESOURCE;
272 mraa_gpio_isr(mraa_gpio_context dev, gpio_edge_t mode, void (*fptr)(void *), void * args)
274 // we only allow one isr per mraa_gpio_context
275 if (dev->thread_id != 0) {
276 return MRAA_ERROR_NO_RESOURCES;
279 if (MRAA_SUCCESS != mraa_gpio_edge_mode(dev, mode)) {
280 return MRAA_ERROR_UNSPECIFIED;
284 dev->isr_args = args;
285 pthread_create (&dev->thread_id, NULL, mraa_gpio_interrupt_handler, (void *) dev);
291 mraa_gpio_isr_exit(mraa_gpio_context dev)
293 mraa_result_t ret = MRAA_SUCCESS;
295 // wasting our time, there is no isr to exit from
296 if (dev->thread_id == 0 && dev->isr_value_fp == -1) {
300 // stop isr being useful
301 ret = mraa_gpio_edge_mode(dev, MRAA_GPIO_EDGE_NONE);
303 if ((dev->thread_id != 0)) {
304 if ((pthread_cancel(dev->thread_id) != 0) || (pthread_join(dev->thread_id, NULL) != 0)) {
305 ret = MRAA_ERROR_INVALID_HANDLE;
309 // close the filehandle in case it's still open
310 if (dev->isr_value_fp != -1) {
311 if (close(dev->isr_value_fp) != 0) {
312 ret = MRAA_ERROR_INVALID_PARAMETER;
317 // Dereference our Python call back function
321 // assume our thread will exit either way we just lost it's handle
323 dev->isr_value_fp = -1;
328 mraa_gpio_mode(mraa_gpio_context dev, gpio_mode_t mode)
330 if (advance_func->gpio_mode_replace != NULL)
331 return advance_func->gpio_mode_replace(dev,mode);
333 if (advance_func->gpio_mode_pre != NULL) {
334 mraa_result_t pre_ret = (advance_func->gpio_mode_pre(dev,mode));
335 if(pre_ret != MRAA_SUCCESS)
339 if (dev->value_fp != -1) {
340 close(dev->value_fp);
344 char filepath[MAX_SIZE];
345 snprintf(filepath, MAX_SIZE, SYSFS_CLASS_GPIO "/gpio%d/drive", dev->pin);
347 int drive = open(filepath, O_WRONLY);
349 syslog(LOG_ERR, "gpio: Failed to open drive for writing");
350 return MRAA_ERROR_INVALID_RESOURCE;
356 case MRAA_GPIO_STRONG:
357 length = snprintf(bu, sizeof(bu), "strong");
359 case MRAA_GPIO_PULLUP:
360 length = snprintf(bu, sizeof(bu), "pullup");
362 case MRAA_GPIO_PULLDOWN:
363 length = snprintf(bu, sizeof(bu), "pulldown");
366 length = snprintf(bu, sizeof(bu), "hiz");
370 return MRAA_ERROR_FEATURE_NOT_IMPLEMENTED;
372 if (write(drive, bu, length*sizeof(char)) == -1) {
373 syslog(LOG_ERR, "gpio: Failed to write to drive mode");
375 return MRAA_ERROR_INVALID_RESOURCE;
380 if (advance_func->gpio_mode_post != NULL)
381 return advance_func->gpio_mode_post(dev,mode);
386 mraa_gpio_dir(mraa_gpio_context dev, gpio_dir_t dir)
388 if (advance_func->gpio_dir_replace != NULL)
389 return advance_func->gpio_dir_replace(dev,dir);
390 if (advance_func->gpio_dir_pre != NULL) {
391 mraa_result_t pre_ret = (advance_func->gpio_dir_pre(dev,dir));
392 if(pre_ret != MRAA_SUCCESS)
397 return MRAA_ERROR_INVALID_HANDLE;
399 if (dev->value_fp != -1) {
400 close(dev->value_fp);
403 char filepath[MAX_SIZE];
404 snprintf(filepath, MAX_SIZE, SYSFS_CLASS_GPIO "/gpio%d/direction", dev->pin);
406 int direction = open(filepath, O_RDWR);
408 if (direction == -1) {
409 return MRAA_ERROR_INVALID_RESOURCE;
416 length = snprintf(bu, sizeof(bu), "out");
419 length = snprintf(bu, sizeof(bu), "in");
423 return MRAA_ERROR_FEATURE_NOT_IMPLEMENTED;
426 if (write(direction, bu, length*sizeof(char)) == -1) {
428 return MRAA_ERROR_INVALID_RESOURCE;
432 if (advance_func->gpio_dir_post != NULL)
433 return advance_func->gpio_dir_post(dev,dir);
438 mraa_gpio_read(mraa_gpio_context dev)
443 if (dev->value_fp == -1) {
444 if (mraa_gpio_get_valfp(dev) != MRAA_SUCCESS) {
445 syslog(LOG_ERR, "gpio: Failed to get value file pointer");
449 // if value_fp is new this is pointless
450 lseek(dev->value_fp, 0, SEEK_SET);
453 if (read(dev->value_fp, bu, 2*sizeof(char)) != 2) {
454 syslog(LOG_ERR, "gpio: Failed to read a sensible value from sysfs");
457 lseek(dev->value_fp, 0, SEEK_SET);
459 return strtol(bu, NULL, 10);
463 mraa_gpio_write(mraa_gpio_context dev, int value)
466 return MRAA_ERROR_INVALID_HANDLE;
469 return mraa_gpio_write_register(dev,value);
471 if (advance_func->gpio_write_pre != NULL) {
472 mraa_result_t pre_ret = (advance_func->gpio_write_pre(dev,value));
473 if(pre_ret != MRAA_SUCCESS)
477 if (dev->value_fp == -1) {
478 mraa_gpio_get_valfp(dev);
480 if (lseek(dev->value_fp, 0, SEEK_SET) == -1) {
481 return MRAA_ERROR_INVALID_RESOURCE;
485 int length = snprintf(bu, sizeof(bu), "%d", value);
486 if (write(dev->value_fp, bu, length*sizeof(char)) == -1) {
487 return MRAA_ERROR_INVALID_HANDLE;
490 if (advance_func->gpio_write_post != NULL)
491 return advance_func->gpio_write_post(dev,value);
496 mraa_gpio_unexport_force(mraa_gpio_context dev)
498 int unexport = open(SYSFS_CLASS_GPIO "/unexport", O_WRONLY);
499 if (unexport == -1) {
500 syslog(LOG_ERR, "gpio: Failed to open unexport for writing");
501 return MRAA_ERROR_INVALID_RESOURCE;
505 int length = snprintf(bu, sizeof(bu), "%d", dev->pin);
506 if (write(unexport, bu, length*sizeof(char)) == -1) {
507 syslog(LOG_ERR, "gpio: Failed to write to unexport");
509 return MRAA_ERROR_INVALID_RESOURCE;
513 mraa_gpio_isr_exit(dev);
517 mraa_gpio_unexport(mraa_gpio_context dev)
520 return mraa_gpio_unexport_force(dev);
522 return MRAA_ERROR_INVALID_RESOURCE;
526 mraa_gpio_close(mraa_gpio_context dev)
528 if (dev->value_fp != -1) {
529 close(dev->value_fp);
531 mraa_gpio_unexport(dev);
537 mraa_gpio_owner(mraa_gpio_context dev, mraa_boolean_t own)
540 return MRAA_ERROR_INVALID_RESOURCE;
546 mraa_gpio_use_mmaped(mraa_gpio_context dev, mraa_boolean_t mmap_en)
549 return MRAA_ERROR_INVALID_RESOURCE;
552 if (mraa_pin_mode_test(dev->phy_pin, MRAA_PIN_FAST_GPIO) == 0)
553 return MRAA_ERROR_NO_RESOURCES;
555 mraa_mmap_pin_t *mmp = mraa_setup_mmap_gpio(dev->phy_pin);
557 return MRAA_ERROR_INVALID_RESOURCE;
560 if (dev->mmap == 0) {
561 close(dev->value_fp);
563 fd = open(mmp->mem_dev, O_RDWR);
565 syslog(LOG_ERR, "gpio: Unable to open memory device");
567 return MRAA_ERROR_INVALID_RESOURCE;
569 dev->reg_sz = mmp->mem_sz;
570 dev->reg = mmap(NULL, dev->reg_sz, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
571 dev->reg_bit_pos = mmp->bit_pos;
576 return MRAA_ERROR_INVALID_PARAMETER;
580 if (dev ->mmap == 1) {
581 munmap(dev->reg, dev->reg_sz);
584 return MRAA_ERROR_INVALID_PARAMETER;