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diff -r c53985209d09 source/event_gpio.c
--- a/source/event_gpio.c Sun Oct 30 22:41:09 2016 +0000
+++ b/source/event_gpio.c Thu Feb 23 18:22:28 2017 +0100
@@ -24,6 +24,7 @@
#include <sys/epoll.h>
#include <stdio.h>
#include <stdlib.h>
+#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
@@ -62,17 +63,64 @@
int thread_running = 0;
int epfd_thread = -1;
int epfd_blocking = -1;
+int pin_base = -1;
/************* /sys/class/gpio functions ************/
+void gpio_find_chip_base()
+{
+ DIR *gpio_dir;
+ struct dirent *child;
+ char label_path[128];
+ char label[128];
+ int fd;
+
+ /* No need to search for it twice */
+ if (pin_base >= 0)
+ return;
+
+ if ((gpio_dir = opendir("/sys/class/gpio")) == NULL) {
+ pin_base = 0;
+ return;
+ }
+
+ while ((child = readdir(gpio_dir)) != NULL) {
+ if (!strstr(child->d_name, "gpiochip"))
+ continue;
+
+ if (snprintf(label_path, sizeof(label_path),
+ "/sys/class/gpio/%s/label", child->d_name) < 0) {
+ pin_base = 0;
+ return;
+ }
+
+ if ((fd = open(label_path, O_RDONLY)) < 0) {
+ pin_base = 0;
+ return;
+ }
+
+ if (read(fd, label, sizeof(label)) > 0 &&
+ strstr(label, "pinctrl-bcm2835")) {
+ pin_base = atoi(child->d_name + 8);
+ break;
+ }
+ close(fd);
+ }
+
+ if (pin_base < 0)
+ pin_base = 0;
+}
+
int gpio_export(unsigned int gpio)
{
int fd, len;
- char str_gpio[3];
+ char str_gpio[64];
if ((fd = open("/sys/class/gpio/export", O_WRONLY)) < 0)
return -1;
- len = snprintf(str_gpio, sizeof(str_gpio), "%d", gpio);
+ gpio_find_chip_base();
+
+ len = snprintf(str_gpio, sizeof(str_gpio), "%d", pin_base + gpio);
write(fd, str_gpio, len);
close(fd);
@@ -82,12 +130,14 @@
int gpio_unexport(unsigned int gpio)
{
int fd, len;
- char str_gpio[3];
+ char str_gpio[64];
if ((fd = open("/sys/class/gpio/unexport", O_WRONLY)) < 0)
return -1;
- len = snprintf(str_gpio, sizeof(str_gpio), "%d", gpio);
+ gpio_find_chip_base();
+
+ len = snprintf(str_gpio, sizeof(str_gpio), "%d", pin_base + gpio);
write(fd, str_gpio, len);
close(fd);
@@ -99,9 +149,11 @@
int retry;
struct timespec delay;
int fd;
- char filename[33];
+ char filename[64];
- snprintf(filename, sizeof(filename), "/sys/class/gpio/gpio%d/direction", gpio);
+ gpio_find_chip_base();
+
+ snprintf(filename, sizeof(filename), "/sys/class/gpio/gpio%d/direction", pin_base + gpio);
// retry waiting for udev to set correct file permissions
delay.tv_sec = 0;
@@ -126,9 +178,11 @@
int gpio_set_edge(unsigned int gpio, unsigned int edge)
{
int fd;
- char filename[28];
+ char filename[64];
- snprintf(filename, sizeof(filename), "/sys/class/gpio/gpio%d/edge", gpio);
+ gpio_find_chip_base();
+
+ snprintf(filename, sizeof(filename), "/sys/class/gpio/gpio%d/edge", pin_base + gpio);
if ((fd = open(filename, O_WRONLY)) < 0)
return -1;
@@ -141,10 +195,12 @@
int open_value_file(unsigned int gpio)
{
int fd;
- char filename[29];
+ char filename[64];
+
+ gpio_find_chip_base();
// create file descriptor of value file
- snprintf(filename, sizeof(filename), "/sys/class/gpio/gpio%d/value", gpio);
+ snprintf(filename, sizeof(filename), "/sys/class/gpio/gpio%d/value", pin_base + gpio);
if ((fd = open(filename, O_RDONLY | O_NONBLOCK)) < 0)
return -1;
return fd;
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