diff options
Diffstat (limited to 'recipes-demo/de10-nano-gpio-apps/files/toggle_fpga_leds.c')
| -rw-r--r-- | recipes-demo/de10-nano-gpio-apps/files/toggle_fpga_leds.c | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/recipes-demo/de10-nano-gpio-apps/files/toggle_fpga_leds.c b/recipes-demo/de10-nano-gpio-apps/files/toggle_fpga_leds.c new file mode 100644 index 0000000..87493b7 --- /dev/null +++ b/recipes-demo/de10-nano-gpio-apps/files/toggle_fpga_leds.c @@ -0,0 +1,133 @@ +#include <stdio.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <fcntl.h> +#include <error.h> +#include <errno.h> +#include <limits.h> +#include <unistd.h> + +int main(void) { + + int i; + const char *leds_array[] = { + "fpga_led0", + "fpga_led1", + "fpga_led2", + "fpga_led3", + "fpga_led4", + "fpga_led5", + "fpga_led6", + "fpga_led7" + }; + int leds_array_count = (sizeof leds_array) / (sizeof *leds_array); + int led_fd; + char path[PATH_MAX]; + int path_length; + int result; + char brightness; + + // turn off all leds + for (i = 0 ; i < leds_array_count ; i++ ) { + // set trigger to none + path_length = snprintf(path, PATH_MAX, + "/sys/class/leds/%s/trigger", + leds_array[i]); + if(path_length < 0) + error(1, 0, "path output error"); + if(path_length >= PATH_MAX) + error(1, 0, "path length overflow"); + + led_fd = open(path, O_WRONLY | O_SYNC); + if(led_fd < 0) + error(1, errno, "could not open file '%s'", path); + + result = write(led_fd, "none", 4); + if(result < 0) + error(1, errno, "writing 'none' to '%s'", path); + if(result != 4) + error(1, 0, "did not write 4 bytes to '%s'", path); + + result = close(led_fd); + if(result < 0) + error(1, errno, "could not close file '%s'", path); + + // set brightness to 0 + path_length = snprintf(path, PATH_MAX, + "/sys/class/leds/%s/brightness", + leds_array[i]); + if(path_length < 0) + error(1, 0, "path output error"); + if(path_length >= PATH_MAX) + error(1, 0, "path length overflow"); + + led_fd = open(path, O_WRONLY | O_SYNC); + if(led_fd < 0) + error(1, errno, "could not open file '%s'", path); + + result = write(led_fd, "0", 1); + if(result < 0) + error(1, errno, "writing 'none' to '%s'", path); + if(result != 1) + + led_fd = open(path, O_WRONLY | O_SYNC); + if(led_fd < 0) + error(1, errno, "could not open file '%s'", path); + + result = write(led_fd, "0", 1); + if(result < 0) + error(1, errno, "writing '0' to '%s'", path); + if(result != 1) + error(1, 0, "did not write 1 byte to '%s'", path); + + result = close(led_fd); + if(result < 0) + error(1, errno, "could not close file '%s'", path); + } + + // toggle the leds individually + for (i = 0 ; i < (leds_array_count * 2) ; i++ ) { + // toggle the brightness + path_length = snprintf(path, PATH_MAX, + "/sys/class/leds/%s/brightness", + leds_array[i % leds_array_count]); + if(path_length < 0) + error(1, 0, "path output error"); + if(path_length >= PATH_MAX) + error(1, 0, "path length overflow"); + + led_fd = open(path, O_RDWR | O_SYNC); + if(led_fd < 0) + error(1, errno, "could not open file '%s'", path); + + result = read(led_fd, &brightness, 1); + if(result < 0) + error(1, errno, "reading 1 byte from '%s'", path); + if(result != 1) + error(1, 0, "did not read 1 byte from '%s'", path); + + if(brightness == '0') + brightness = '1'; + else if(brightness == '1') + brightness = '0'; + else + error(1, 0, "unexpected value for brightness"); + + result = write(led_fd, &brightness, 1); + if(result < 0) + error(1, errno, "writing brightness to '%s'", path); + if(result != 1) + error(1, 0, "did not write 1 byte to '%s'", path); + + result = close(led_fd); + if(result < 0) + error(1, errno, "could not close file '%s'", path); + + result = usleep(125000); + if(result < 0) + error(1, errno, "usleep error"); + } + + return 0; +} + |