Initial commit

2 files changed, 162 insertions, 0 deletions

diff --git a/util.c b/util.c
new file mode 100644
index 0000000..8bb9ba1
--- /dev/null
+++ b/util.c
@@ -0,0 +1,126 @@
+#include "legato.h"
+#include "util.h"
+
+le_result_t readFromFile (const char *path, void *value,
+  int (*scanCallback) (FILE *f, const char *formatter, void *val)) {
+  FILE *f = fopen(path, "r");
+  if (f == NULL) {
+    LE_WARN("Couldn't open '%s' - %m", path);
+    return LE_IO_ERROR;
+  }
+  int numScanned = scanCallback(f, "%lf", value);
+  if (numScanned != 1) return LE_FORMAT_ERROR;
+  fclose(f);
+  return LE_OK;
+}
+
+int scanIntCallback (FILE *f, const char *formatter, void *value) {
+  int *val = value;
+  return fscanf(f, "%d", val);
+}
+
+int scanDoubleCallback (FILE *f, const char *formatter, void *value) {
+  double *val = value;
+  return fscanf(f, "%lf", val);
+}
+
+// TODO camel case these methods
+le_result_t ioutil_readIntFromFile (const char *path, int *value) {
+  return readFromFile(path, value, scanIntCallback);
+}
+
+le_result_t ioutil_readDoubleFromFile (const char *path, double *value) {
+  return readFromFile(path, value, scanDoubleCallback);
+}
+
+le_result_t ioutil_writeToFile (const char *path, void *value, size_t size, size_t count) {
+  LE_INFO("Attempting to write to %s", path);
+  FILE *f = fopen(path, "w");
+  if (f == NULL) {
+    LE_WARN("Failed to open %s for writing", path);
+    return LE_IO_ERROR;
+  }
+  size_t nWritten = fwrite(value, size, count, f);
+  LE_INFO("Wrote %d bytes", nWritten);
+  fclose(f);
+  return LE_OK;
+}
+
+le_result_t gpio_exportPin (int pin) {
+  return ioutil_writeToFile ("/sys/class/gpio/export", &pin, sizeof(int), 1);
+}
+
+le_result_t gpio_unexportPin (int pin) {
+  return ioutil_writeToFile ("/sys/class/gpio/unexport", &pin, sizeof(int), 1);
+}
+
+void getGpioPath (char *outputStr, int pin, char *subDir) {
+  sprintf(outputStr, "/sys/class/gpio/gpio%d/%s", pin, subDir);
+}
+
+le_result_t gpio_setDirection (int pin, char *direction) {
+  char path[50];
+  getGpioPath(path, pin, "direction");
+  return ioutil_writeToFile(path, direction, sizeof(char), strlen(direction));
+}
+
+le_result_t gpio_setInput (int pin) {
+  return gpio_setDirection(pin, "in");
+}
+
+le_result_t gpio_setOutput (int pin) {
+  return gpio_setDirection(pin, "out");
+}
+
+le_result_t gpio_setActiveState (int pin, bool isActiveLow) {
+  // Any non zero value toggles the existing value
+  // so we must read the existing value first
+  char path[50];
+  int isActiveLowSet;
+  getGpioPath(path, pin, "active_low");
+  le_result_t readRes = ioutil_readIntFromFile(path, &isActiveLowSet);
+  le_result_t writeRes = LE_OK;
+  if (isActiveLow != isActiveLowSet) {
+    writeRes = ioutil_writeToFile(path, "1", sizeof(char), 1);
+  }
+  return readRes == LE_OK && writeRes == LE_OK ?
+    LE_OK : LE_FAULT;
+}
+
+le_result_t gpio_isActive (int pin, bool *isActive) {
+  char path[50];
+  getGpioPath(path, pin, "value");
+  int val;
+  return ioutil_readIntFromFile(path, &val);
+  LE_FATAL_IF(val != 0 || val != 1, "value is not boolean");
+  *isActive = (bool)val;
+}
+
+le_result_t gpio_setValue (int pin, bool state) {
+  char path[50];
+  getGpioPath(path, pin, "value");
+  return ioutil_writeToFile(path, &state, sizeof(bool), 1);
+}
+
+le_result_t gpio_setLow (int pin) {
+  return gpio_setValue(pin, LOW);
+}
+
+le_result_t gpio_setHigh (int pin) {
+  return gpio_setValue(pin, HIGH);
+}
+
+void delayMicro (unsigned long microsecs) {
+  unsigned long retTime = getTimeMicrosecs() + microsecs;
+  while (getTimeMicrosecs() < retTime);
+}
+
+void delayMilli (unsigned long millisecs) {
+  delayMicro(millisecs * 1000);
+}
+
+long getTimeMicrosecs () {
+  struct timeval currentTime;
+  gettimeofday(&currentTime, NULL);
+  return currentTime.tv_sec * (int)1e6 + currentTime.tv_usec;
+}
\ No newline at end of file
diff --git a/util.h b/util.h
new file mode 100644
index 0000000..6881eda
--- /dev/null
+++ b/util.h
@@ -0,0 +1,36 @@
+#ifndef UTIL_H
+#define UTIL_H
+
+#include "legato.h"
+
+#define HIGH 1
+#define LOW 0
+
+// ioutil
+le_result_t readFromFile (const char *path, void *value,
+  int (*scanCallback) (FILE *f, const char *formatter, void *val));
+int scanIntCallback (FILE *f, const char *formatter, void *value);
+int scanDoubleCallback (FILE *f, const char *formatter, void *value);
+le_result_t ioutil_readIntFromFile (const char *path, int *value);
+le_result_t ioutil_readDoubleFromFile (const char *filePath, double *value);
+le_result_t ioutil_writeToFile (const char *path, void *value, size_t size, size_t count);
+
+// gpio
+void getGpioPath (char *outputStr, int pin, char *subDir);
+le_result_t gpio_exportPin (int pin);
+le_result_t gpio_unexportPin (int pin);
+le_result_t gpio_setDirection (int pin, char *direction);
+le_result_t gpio_setInput (int pin);
+le_result_t gpio_setOutput (int pin);
+le_result_t gpio_setActiveState (int pin, bool isActiveLow);
+le_result_t gpio_isActive (int pin, bool *isActive);
+le_result_t gpio_setValue (int pin, bool state);
+le_result_t gpio_setLow (int pin);
+le_result_t gpio_setHigh (int pin);
+
+// time util
+void delayMicro (unsigned long microsecs);
+void delayMilli (unsigned long millisecs);
+long getTimeMicrosecs ();
+
+#endif