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-rw-r--r--util/README.md72
-rw-r--r--util/util.c366
-rw-r--r--util/util.h77
3 files changed, 515 insertions, 0 deletions
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
generated by cgit v1.2.3 (git 2.25.1) at 2025-10-31 20:43:38 +0000