added util to repo

5 files changed, 518 insertions, 0 deletions

diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..4359c25
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "brnkl-util"]
+	path = brnkl-util
+	url = https://github.com/brnkl/brnkl-util.git
diff --git a/brnkl-util b/brnkl-util
new file mode 160000
+Subproject 40b51b270579af9772190ed9681438416a62ce7
diff --git a/util/README.md b/util/README.md
new file mode 100644
index 0000000..bda72c8
--- /dev/null
+++ b/util/README.md
@@ -0,0 +1,72 @@
+# brnkl-util
+
+Small collection of helper functions required by some of our open source code
+
+## File I/O
+
+Functions to handle boilerplate when reading and writing from files.
+
+```c
+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);
+
+le_result_t ioutil_appendToFile(const char* path,
+                                void* value,
+                                size_t size,
+                                size_t count);
+
+```
+
+## General
+
+Collection of unsorted helper functions
+
+```c
+uint64_t GetCurrentTimestamp(void);
+time_t util_getMTime(char* path);
+int util_getUnixDatetime();
+le_result_t util_flattenRes(le_result_t* res, int nRes);
+bool util_fileExists(const char* path);
+bool util_alreadyMounted(const char* devPath);
+void* util_find(Functional* f);
+void util_listDir(const char* dir, char* dest, size_t size);
+```
+
+## GPIO (Linux SysFS)
+
+Provides API calls for all functionality supported by the Linux SysFS GPIO interface
+
+```c
+le_result_t gpio_exportPin(char* pin);
+le_result_t gpio_unexportPin(char* pin);
+void getGpioPath(char* outputStr, char* pin, char* subDir);
+le_result_t gpio_setDirection(char* pin, char* direction);
+le_result_t gpio_setInput(char* pin);
+le_result_t gpio_setOutput(char* pin);
+le_result_t gpio_setActiveState(char* pin, bool isActiveLow);
+le_result_t gpio_isActive(char* pin, bool* isActive);
+le_result_t gpio_setValue(char* pin, bool state);
+le_result_t gpio_setLow(char* pin);
+le_result_t gpio_setHigh(char* pin);
+le_result_t gpio_setPull(char* pin, char* pull);
+le_result_t gpio_pullDown(char* pin);
+le_result_t gpio_pullUp(char* pin);
+```
+
+## Serial
+
+Handler boilerplate for reading and writing to a serial port
+
+```c
+int fd_openSerial(const char* device, int baud);
+speed_t fd_convertBaud(int baud);
+int fd_puts(const int fd, const char* s);
+int fd_getChar(const int fd);
+void fd_flush(const int fd);
+int fd_dataAvail(int fd, int* data);
+void fd_flushInput(const int fd);
+```
diff --git a/util/util.c b/util/util.c
new file mode 100644
index 0000000..3042c22
--- /dev/null
+++ b/util/util.c
@@ -0,0 +1,366 @@
+#include "util.h"
+#include "legato.h"
+#include <termios.h>
+
+le_result_t readFromFile(const char* path,
+                         void* value,
+                         int (*scanCallback)(FILE* f, 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, value);
+  if (numScanned != 1)
+    return LE_FORMAT_ERROR;
+  fclose(f);
+  return LE_OK;
+}
+
+int scanIntCallback(FILE* f, void* value) {
+  int* val = value;
+  return fscanf(f, "%d", val);
+}
+
+int scanDoubleCallback(FILE* f, void* value) {
+  double* val = value;
+  return fscanf(f, "%lf", val);
+}
+
+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 writeToFile(const char* path,
+                        void* value,
+                        size_t size,
+                        size_t count,
+                        const char* openMode) {
+  FILE* f = fopen(path, openMode);
+  if (f == NULL) {
+    LE_WARN("Failed to open %s for writing", path);
+    return LE_IO_ERROR;
+  }
+  fwrite(value, size, count, f);
+  fflush(f);
+  fclose(f);
+  return LE_OK;
+}
+
+le_result_t ioutil_writeToFile(const char* path,
+                               void* value,
+                               size_t size,
+                               size_t count) {
+  return writeToFile(path, value, size, count, "w");
+}
+
+le_result_t ioutil_appendToFile(const char* path,
+                                void* value,
+                                size_t size,
+                                size_t count) {
+  return writeToFile(path, value, size, count, "a");
+}
+
+le_result_t util_flattenRes(le_result_t* res, int nRes) {
+  for (int i = 0; i < nRes; i++) {
+    if (res[i] != LE_OK)
+      return res[i];
+  }
+  return LE_OK;
+}
+
+int util_getUnixDatetime() {
+  struct timeval tv;
+  gettimeofday(&tv, NULL);
+  return tv.tv_sec;
+}
+
+/**
+ * Get the last modified datetime
+ * of the file at path
+ */
+time_t util_getMTime(char* path) {
+  struct stat st;
+  if (stat(path, &st) != 0)
+    return -1;
+  else
+    return st.st_mtime;
+}
+
+bool util_fileExists(const char* path) {
+  struct stat st;
+  return stat(path, &st) == 0;
+}
+
+bool util_alreadyMounted(const char* devPath) {
+  char content[2048];
+  FILE* f = fopen("/proc/mounts", "r");
+  if (f == NULL) {
+    return false;
+  }
+  fread(content, sizeof(char), sizeof(content), f);
+  // if this ref is non-null, we found a match
+  return strstr(content, devPath) != NULL;
+}
+
+uint64_t GetCurrentTimestamp(void) {
+  struct timeval tv;
+  gettimeofday(&tv, NULL);
+  uint64_t utcMilliSec =
+      (uint64_t)(tv.tv_sec) * 1000 + (uint64_t)(tv.tv_usec) / 1000;
+  return utcMilliSec;
+}
+
+// TODO verify this is working
+le_result_t gpio_exportPin(char* pin) {
+  int len = strlen(pin);
+  return ioutil_writeToFile("/sys/class/gpio/export", &pin, sizeof(char), len);
+}
+
+le_result_t gpio_unexportPin(char* pin) {
+  int len = strlen(pin);
+  return ioutil_writeToFile("/sys/class/gpio/unexport", &pin, sizeof(char),
+                            len);
+}
+
+void getGpioPath(char* outputStr, char* pin, char* subDir) {
+  sprintf(outputStr, "/sys/class/gpio/gpio%s/%s", pin, subDir);
+}
+
+le_result_t gpio_setDirection(char* pin, char* direction) {
+  char path[100];
+  getGpioPath(path, pin, "direction");
+  return ioutil_writeToFile(path, direction, sizeof(char), strlen(direction));
+}
+
+le_result_t gpio_setPull(char* pin, char* pull) {
+  char path[100];
+  getGpioPath(path, pin, "pull");
+  return ioutil_writeToFile(path, pull, sizeof(char), strlen(pull));
+}
+
+le_result_t gpio_pullDown(char* pin) {
+  return gpio_setPull(pin, "down");
+}
+
+le_result_t gpio_pullUp(char* pin) {
+  return gpio_setPull(pin, "up");
+}
+
+le_result_t gpio_setInput(char* pin) {
+  return gpio_setDirection(pin, "in");
+}
+
+le_result_t gpio_setOutput(char* pin) {
+  return gpio_setDirection(pin, "out");
+}
+
+le_result_t gpio_setActiveState(char* pin, bool isActiveLow) {
+  // Any non zero value toggles the existing value
+  // so we must read the existing value first
+  char path[100];
+  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(char* pin, bool* isActive) {
+  char path[50];
+  getGpioPath(path, pin, "value");
+  int val;
+  le_result_t readRes = ioutil_readIntFromFile(path, &val);
+  *isActive = val;
+  return readRes;
+}
+
+le_result_t gpio_setValue(char* pin, bool state) {
+  char path[50];
+  getGpioPath(path, pin, "value");
+  char* strState = state ? "1" : "0";
+  return ioutil_writeToFile(path, &strState, sizeof(char), strlen(strState));
+}
+
+le_result_t gpio_setLow(char* pin) {
+  return gpio_setValue(pin, LOW);
+}
+
+le_result_t gpio_setHigh(char* pin) {
+  return gpio_setValue(pin, HIGH);
+}
+
+void* util_find(Functional* f) {
+  f->args.i = 0;
+  while (f->args.i < f->n) {
+    if (f->callback(&f->args)) {
+      return f->derefCallback(f->args.i, f->args.arr);
+    }
+    f->args.i++;
+  }
+  return NULL;
+}
+
+void util_listDir(const char* dir, char* dest, size_t size) {
+  struct dirent* de;
+  char toConcat[1024];
+  DIR* dr = opendir(dir);
+  if (dr == NULL)
+    return;
+  while ((de = readdir(dr)) != NULL) {
+    if (de->d_name[0] != '.') {
+      snprintf(toConcat, size, "%s,", de->d_name);
+      strncat(dest, toConcat, size);
+    }
+  }
+  closedir(dr);
+}
+
+/**
+ * Convert an integer baud rate to a speed_t
+ */
+speed_t fd_convertBaud(int baud) {
+  speed_t b;
+  switch (baud) {
+    case 50:
+      b = B50;
+      break;
+    case 75:
+      b = B75;
+      break;
+    case 110:
+      b = B110;
+      break;
+    case 134:
+      b = B134;
+      break;
+    case 150:
+      b = B150;
+      break;
+    case 200:
+      b = B200;
+      break;
+    case 300:
+      b = B300;
+      break;
+    case 600:
+      b = B600;
+      break;
+    case 1200:
+      b = B1200;
+      break;
+    case 1800:
+      b = B1800;
+      break;
+    case 2400:
+      b = B2400;
+      break;
+    case 9600:
+      b = B9600;
+      break;
+    case 19200:
+      b = B19200;
+      break;
+    case 38400:
+      b = B38400;
+      break;
+    case 57600:
+      b = B57600;
+      break;
+    case 115200:
+      b = B115200;
+      break;
+    case 230400:
+      b = B230400;
+      break;
+    case 921600:
+      b = B921600;
+      break;
+    default:
+      b = -2;
+  }
+  return b;
+}
+
+/**
+ * Open a serial connection on device
+ *
+ * Lifted from here
+ * https://github.com/WiringPi/WiringPi/blob/master/wiringPi/wiringSerial.c
+ */
+int fd_openSerial(const char* device, int baud) {
+  struct termios options;
+  speed_t binaryBaud = fd_convertBaud(baud);
+  int status, fd;
+  if ((fd = open(device, O_RDWR | O_NOCTTY | O_NDELAY | O_NONBLOCK)) == -1)
+    return -1;
+  fcntl(fd, F_SETFL, O_RDWR);
+  tcgetattr(fd, &options);
+  cfmakeraw(&options);
+  cfsetispeed(&options, binaryBaud);
+  cfsetospeed(&options, binaryBaud);
+
+  options.c_cflag |= (CLOCAL | CREAD);
+  options.c_cflag &= ~PARENB;
+  options.c_cflag &= ~CSTOPB;
+  options.c_cflag &= ~CSIZE;
+  options.c_cflag |= CS8;
+  options.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG);
+  options.c_oflag &= ~OPOST;
+
+  options.c_cc[VMIN] = 0;
+  options.c_cc[VTIME] = 10;  // Ten seconds (100 deciseconds)
+
+  tcsetattr(fd, TCSANOW | TCSAFLUSH, &options);
+
+  ioctl(fd, TIOCMGET, &status);
+
+  status |= TIOCM_DTR;
+  status |= TIOCM_RTS;
+
+  ioctl(fd, TIOCMSET, &status);
+  usleep(10000);  // 10mS
+  return fd;
+}
+
+int fd_puts(const int fd, const char* s) {
+  return write(fd, s, strlen(s));
+}
+
+int fd_getChar(const int fd) {
+  uint8_t x;
+
+  if (read(fd, &x, 1) != 1)
+    return -1;
+
+  return ((int)x) & 0xFF;
+}
+
+void fd_flush(const int fd) {
+  // tcflush(fd, TCIOFLUSH);
+  tcdrain(fd);
+}
+
+void fd_flushInput(const int fd) {
+  tcflush(fd, TCIFLUSH);
+}
+
+int fd_dataAvail(int fd, int* data) {
+  return ioctl(fd, FIONREAD, data);
+}
+
+double util_avgDouble(double* readings, int nReadings) {
+  double sum = 0;
+  for (int i = 0; i < nReadings; i++) {
+    sum += readings[i];
+  }
+
+  return sum / nReadings;
+}
diff --git a/util/util.h b/util/util.h
new file mode 100644
index 0000000..06ef2fb
--- /dev/null
+++ b/util/util.h
@@ -0,0 +1,77 @@
+#ifndef UTIL_H
+#define UTIL_H
+
+#include "legato.h"
+#include <termios.h>
+
+#define HIGH 1
+#define LOW 0
+
+typedef struct {
+  int i;
+  void* arr;
+  void* ctxp;
+} FunctionalArgs;
+
+typedef struct {
+  int n;                                   // number of elements in array
+  bool (*callback)(FunctionalArgs* args);  // callback applied to arr[i]
+  void* (*derefCallback)(int i, void* j);  // callback used to deference arr[i]
+  FunctionalArgs args;
+} Functional;
+
+// ioutil
+le_result_t readFromFile(const char* path,
+                         void* value,
+                         int (*scanCallback)(FILE* f, void* val));
+int scanDoubleCallback(FILE* f, 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);
+
+le_result_t ioutil_appendToFile(const char* path,
+                                void* value,
+                                size_t size,
+                                size_t count);
+
+// TODO fix this name (no PascalCase)
+uint64_t GetCurrentTimestamp(void);
+time_t util_getMTime(char* path);
+int util_getUnixDatetime();
+le_result_t util_flattenRes(le_result_t* res, int nRes);
+bool util_fileExists(const char* path);
+bool util_alreadyMounted(const char* devPath);
+double util_avgDouble(double* readings, int nReadings);
+
+// TODO verify this is working
+le_result_t gpio_exportPin(char* pin);
+le_result_t gpio_unexportPin(char* pin);
+void getGpioPath(char* outputStr, char* pin, char* subDir);
+le_result_t gpio_setDirection(char* pin, char* direction);
+le_result_t gpio_setInput(char* pin);
+le_result_t gpio_setOutput(char* pin);
+le_result_t gpio_setActiveState(char* pin, bool isActiveLow);
+le_result_t gpio_isActive(char* pin, bool* isActive);
+le_result_t gpio_setValue(char* pin, bool state);
+le_result_t gpio_setLow(char* pin);
+le_result_t gpio_setHigh(char* pin);
+le_result_t gpio_setPull(char* pin, char* pull);
+le_result_t gpio_pullDown(char* pin);
+le_result_t gpio_pullUp(char* pin);
+
+void* util_find(Functional* f);
+
+void util_listDir(const char* dir, char* dest, size_t size);
+
+int fd_openSerial(const char* device, int baud);
+speed_t fd_convertBaud(int baud);
+int fd_puts(const int fd, const char* s);
+int fd_getChar(const int fd);
+void fd_flush(const int fd);
+int fd_dataAvail(int fd, int* data);
+void fd_flushInput(const int fd);
+
+#endif