mangOH green i2c tutorial

samples/tutorials/hardwareInterfaces/i2c/BatteryChargerReading/batteryReading.adef

+sandboxed: true
+version: 1.0.0
+maxFileSystemBytes: 512K
+start: manual
+
+executables:
+{
+    batteryReading = ( batteryReadingComponent )
+}
+
+processes:
+{
+    envVars:
+    {
+        LE_LOG_LEVEL = DEBUG
+    }
+    run:
+    {
+        (batteryReading)
+    }
+    faultAction: restart
+}
+
+requires:
+{
+   device:
+   {
+       [rw] /dev/i2c-0 /dev/i2c-0
+   }
+}

samples/tutorials/hardwareInterfaces/i2c/BatteryChargerReading/batteryReadingComponent/Component.cdef

+
+sources:
+{
+   batteryReading.c
+}

samples/tutorials/hardwareInterfaces/i2c/BatteryChargerReading/batteryReadingComponent/batteryReading.c

+//--------------------------------------------------------------------------------------------------
+/** 
+ * This app reads all the Register on BQ24196 or BQ24296 Battery Chargers
+ * It also writes output voltage for battery charger to 3.7V
+ */
+//--------------------------------------------------------------------------------------------------
+#include "legato.h"
+#include "interfaces.h"
+#include <linux/i2c-dev-user.h>
+
+//-------------------------------------------------------------------------------------------------
+//* Static functions
+//--------------------------------------------------------------------------------------------------
+/**
+ * Get the file handle for the given I2C bus and configure it for access to the given I2C address.
+ *
+ * @return
+ *      - LE_FAULT on failure
+ *      - A filehandle to the I2C bus
+ */
+//--------------------------------------------------------------------------------------------------
+static int I2cAccessBusAddr
+(
+    uint8_t i2cBus,
+    uint8_t i2cAddr
+)
+{
+    const size_t filenameSize = 32;
+    char filename[filenameSize];
+
+    snprintf(filename, filenameSize, "/dev/i2c/%d", i2cBus);
+
+    LE_DEBUG("Opening I2C bus: '%s'", filename);
+    int fd = open(filename, O_RDWR);
+    if (fd < 0 && (errno == ENOENT || errno == ENOTDIR))
+    {
+        snprintf(filename, filenameSize, "/dev/i2c-%d", i2cBus);
+        LE_DEBUG("Opening I2C bus: '%s'", filename);
+        fd = open(filename, O_RDWR);
+    }
+
+    if (fd < 0)
+    {
+        if (errno == ENOENT)
+        {
+            LE_ERROR(
+                "Could not open file /dev/i2c-%d or /dev/i2c/%d: %s\n",
+                i2cBus,
+                i2cBus,
+                strerror(ENOENT));
+        }
+        else
+        {
+            LE_ERROR("Could not open file %s': %s\n", filename, strerror(errno));
+        }
+
+        return LE_FAULT;
+    }
+
+    if (ioctl(fd, I2C_SLAVE_FORCE, i2cAddr) < 0)
+    {
+        LE_ERROR("Could not set address to 0x%02x: %s\n", i2cAddr, strerror(errno));
+        return LE_FAULT;
+    }
+
+    return fd;
+}
+
+//--------------------------------------------------------------------------------------------------
+/**
+ * Performs an SMBUS read of a 1 byte register
+ *
+ * @return
+ *      - LE_OK
+ *      - LE_FAULT
+ */
+//--------------------------------------------------------------------------------------------------
+static le_result_t SmbusReadReg
+(
+    uint8_t i2cBus,  ///< [IN] I2C bus to perform the read on
+    uint8_t i2cAddr, ///< [IN] I2C address to read from
+    uint8_t  reg,     ///< [IN] Register within the I2C device to read
+    uint8_t *data    ///< [OUT] Value stored within the register.  This value is only valid if the
+                     ///  function returned LE_OK.
+)
+{
+    int i2cFd = I2cAccessBusAddr(i2cBus, i2cAddr);
+    if (i2cFd < 0)
+    {
+        LE_ERROR("failed to open i2c bus %d for access to address %d\n", i2cBus, i2cAddr);
+        return  LE_FAULT;
+    }
+
+    le_result_t result;
+
+    const int readResult = i2c_smbus_read_byte_data(i2cFd, reg);
+
+    if (readResult < 0)
+    {
+        LE_ERROR("smbus read failed with error %d", readResult);
+        result = LE_FAULT;
+    }
+    else
+    {
+        *data = readResult;
+        LE_DEBUG("SMBUS READ addr=0x%x, reg=0x%x, data=0x%x", i2cAddr, reg, *data);
+        result = LE_OK;
+    }
+
+    close(i2cFd);
+
+    return result;
+}
+
+//--------------------------------------------------------------------------------------------------
+/**
+ * Performs an SMBUS write of a 1 byte register
+ *
+ * @return
+ *      - LE_OK
+ *      - LE_FAULT
+ */
+//--------------------------------------------------------------------------------------------------
+static le_result_t SmbusWriteReg
+(
+    uint8_t i2cBus,   ////< I2C bus to perform the write on
+    uint8_t i2cAddr,  ////< I2C device  address 
+    uint8_t reg,      ////< Register within the I2C device to write to
+    uint8_t data      ////< Data to write to the given register
+)
+{
+int i2cFd = I2cAccessBusAddr(i2cBus, i2cAddr);
+
+if (i2cFd == LE_FAULT)
+{
+    LE_ERROR("failed to open i2c bus %d for access to address %d\n", i2cBus, i2cAddr);
+    return LE_FAULT ;
+}
+
+le_result_t result;
+
+const int writeResult = i2c_smbus_write_byte_data(i2cFd, reg, data);
+if (writeResult < 0)
+{
+    LE_ERROR("smbus write failed with error %d", writeResult);
+    result = LE_FAULT;
+}
+else
+{
+    LE_DEBUG("SMBUS Write addr 0x%x, reg=0x%x, data=0x%x", i2cAddr, reg, data);
+    result = LE_OK;
+}
+
+close(i2cFd);
+
+return result;
+}
+
+/**-----------------------------------------------------------------------------------------------
+ * Enables I2C Switch.
+ * This switch is used on mangoh to provide buffering on the i2c lines.
+ * If this is not enabled then you cannot access the Battery charger.
+ */
+//--------------------------------------------------------------------------------------------------
+static void EnableI2cBus
+(
+    void
+)
+{
+    LE_DEBUG("Enabling TCA9546A I2C switch...");
+    const int i2cBus = 0;
+    const int i2cdev_fd = I2cAccessBusAddr(i2cBus, 0x71);
+    LE_FATAL_IF(i2cdev_fd == LE_FAULT, "failed to open i2cbus %d\n", i2cBus);
+
+    const uint8_t enableAllPorts = 0xff;
+    LE_FATAL_IF(i2c_smbus_write_byte(i2cdev_fd, enableAllPorts) == -1, "failed to write i2c data");
+}
+
+//--------------------------------------------------------------------------------------------------
+/**
+ * This functions reads and prints all the registers on  an SMBUS write of a 1 byte register
+ *
+ */
+//--------------------------------------------------------------------------------------------------
+static void ReadBatteryChargerRegister
+(
+    void
+)
+{
+// read all ten registers of Battery charger with i2c address 0x71
+    uint8_t RegisterReading;
+
+    SmbusReadReg(0, 0x6B, 0x00, &RegisterReading);
+    LE_DEBUG("Input Source Control value is %d\n",RegisterReading);
+
+    SmbusReadReg(0, 0x6B, 0x01, &RegisterReading);
+    LE_DEBUG("Power-On Configuration Register value is %d\n",RegisterReading);
+    
+    SmbusReadReg(0, 0x6B, 0x02, &RegisterReading);
+    LE_DEBUG("Charge Current Control Register value is %d\n",RegisterReading);
+
+    SmbusReadReg(0, 0x6B, 0x03, &RegisterReading);
+    LE_DEBUG(" Pre-Charge/Termination Current Control Register value is %d\n",RegisterReading);
+
+    SmbusReadReg(0, 0x6B, 0x04, &RegisterReading);
+    LE_DEBUG("Charge Voltage Control Register value is %d\n",RegisterReading);
+
+    SmbusReadReg(0, 0x6B, 0x05, &RegisterReading);
+    LE_DEBUG("Charge Termination/Timer Control Register value is %d\n",RegisterReading);
+
+    SmbusReadReg(0, 0x6B, 0x06, &RegisterReading);
+    LE_DEBUG("Thermal Regulation Control Register value is %d\n",RegisterReading);
+
+    SmbusReadReg(0, 0x6B, 0x07, &RegisterReading);
+    LE_DEBUG("Misc Operation Control Register value is %d\n",RegisterReading);
+
+    SmbusReadReg(0, 0x6B, 0x08, &RegisterReading);
+    LE_DEBUG("System Status Register value is %d\n",RegisterReading);
+
+    SmbusReadReg(0, 0x6B, 0x09, &RegisterReading);
+    LE_DEBUG("Fault Register value is %d\n",RegisterReading);
+
+    SmbusReadReg(0, 0x6B, 0x0A, &RegisterReading);
+    LE_DEBUG("Vender / Part / Revision Status Register value is %d\n",RegisterReading);
+}
+
+//--------------------------------------------------------------------------------------------------
+/**
+ * This function changes battery charger output voltage and reads back register
+ *
+ */
+//-------------------------------------------------------------------------------------------------
+static void OutputBatteryChargerVoltage
+(
+    void
+)
+{
+    uint8_t OutputVoltage;
+    SmbusWriteReg(0,0x6B,0x04,0xBA);
+
+    SmbusReadReg(0, 0x6B, 0x04,  &OutputVoltage);
+    LE_DEBUG("Output voltage is set to %d\n",OutputVoltage);
+}
+
+//--------------------------------------------------------------------------------------------------
+/**
+ * Main program starts below
+ *
+ */
+//-------------------------------------------------------------------------------------------------
+COMPONENT_INIT
+{
+      
+    LE_INFO("===============I2C Reading & Writing application has started");
+    EnableI2cBus();
+    ReadBatteryChargerRegister();
+    OutputBatteryChargerVoltage();
+}