Diff: I2CDriver.h

Revision:

3:967dde37e712

Parent:

2:514105beb343

Child:

5:8a418c89e515

--- a/I2CDriver.h	Sun Apr 14 21:42:22 2013 +0000
+++ b/I2CDriver.h	Fri Apr 19 21:33:29 2013 +0000
@@ -6,25 +6,36 @@
 #include "I2C.h"
 
 #include "Thread.h"
-#include "Semaphore.h"
 #include "Mutex.h"
 
 namespace mbed
 {
-
-class I2CDriver : protected I2C
+/// class i2c driver
+class I2CDriver
 {
 public:
-    using I2C::RxStatus;
-    using I2C::Acknowledge;
-    using I2C::frequency;
+
+    enum SlaveRxStatus {
+        NoData         = 0,
+        ReadAddressed  = 1,
+        WriteGeneral   = 2,
+        WriteAddressed = 3
+    };
 
     /** Create an I2C Master interface, connected to the specified pins
      *
      *  @param sda I2C data line pin
      *  @param scl I2C clock line pin
      */
-    I2CDriver(PinName sda, PinName scl);
+    I2CDriver(PinName sda, PinName scl, int hz=100000, int slaveAdr=0);
+
+    /** Set the frequency of the I2C interface
+    *
+    *  @param hz The bus frequency in hertz
+    */
+    void frequency(int hz) {
+        m_freq = hz;
+    }
 
     /** Read from an I2C slave
      *
@@ -40,9 +51,24 @@
      *       0 on success (ack),
      *   non-0 on failure (nack)
      */
-    int read(int address, char *data, int length, bool repeated = false);
+    int readMaster(int address, char *data, int length, bool repeated = false);
 
-    int read(int address, uint8_t regist, char *data, int length, bool repeated = false);
+    /** Read from a given I2C slave register
+     *
+     * Performs a complete write-register-read-data-transaction. The bottom bit of
+     * the address is forced to 1 to indicate a read.
+     *
+     *  @param address 8-bit I2C slave address [ addr | 1 ]
+     *  @param _register 8-bit regster address
+     *  @param data Pointer to the byte-array to read data in to
+     *  @param length Number of bytes to read
+     *  @param repeated Repeated start, true - don't send stop at end
+     *
+     *  @returns
+     *       0 on success (ack),
+     *   non-0 on failure (nack)
+     */
+    int readMaster(int address, uint8_t _register, char *data, int length, bool repeated = false);
 
     /** Read a single byte from the I2C bus
      *
@@ -51,7 +77,7 @@
      *  @returns
      *    the byte read
      */
-    int read(int ack);
+    int readMaster(int ack=1);
 
     /** Write to an I2C slave
      *
@@ -67,7 +93,7 @@
      *       0 on success (ack),
      *   non-0 on failure (nack)
      */
-    int write(int address, const char *data, int length, bool repeated = false);
+    int writeMaster(int address, const char *data, int length, bool repeated = false);
 
     /** Write single byte out on the I2C bus
      *
@@ -77,60 +103,136 @@
      *    '1' if an ACK was received,
      *    '0' otherwise
      */
-    int write(int data);
+    int writeMaster(int data);
+
+    /** Sets the I2C slave address.
+     *
+     *  @param address The address to set for the slave (ignoring the least
+     *  signifcant bit). If set to 0, the slave will only respond to the
+     *  general call address.
+     */
+    void addressSlave(int address) {
+        m_slaveAdr=address;
+    }
+
+    /** Checks to see if this I2C Slave has been addressed.
+     *
+     *  @returns
+     *  A status indicating if the device has been addressed, and how
+     *  - NoData            - the slave has not been addressed
+     *  - ReadAddressed     - the master has requested a read from this slave
+     *  - WriteAddressed    - the master is writing to this slave
+     *  - WriteGeneral      - the master is writing to all slave
+     */
+    int receiveSlave(uint32_t timeout_ms=osWaitForever);
+
+    /** Read from an I2C master.
+     *
+     *  @param data pointer to the byte array to read data in to
+     *  @param length maximum number of bytes to read
+     *
+     *  @returns
+     *       0 on success,
+     *   non-0 otherwise
+     */
+    int readSlave(char *data, int length);
+
+    /** Read a single byte from an I2C master.
+    *
+    *  @returns
+    *    the byte read
+    */
+    int readSlave(void);
+
+    /** Write to an I2C master.
+     *
+     *  @param data pointer to the byte array to be transmitted
+     *  @param length the number of bytes to transmite
+     *
+     *  @returns
+     *       0 on success,
+     *   non-0 otherwise
+     */
+    int writeSlave(const char *data, int length);
+
+    /** Write a single byte to an I2C master.
+    *
+    *  @data the byte to write
+    *
+    *  @returns
+    *    '1' if an ACK was received,
+    *    '0' otherwise
+    */
+    int writeSlave(int data);
+
 
     /// Creates a start condition on the I2C bus
-    void start(void);
+    void startMaster(void);
 
     ///Creates a stop condition on the I2C bus
-    void stop(void);
+    void stopSlave(void);
+
+    ///Creates a stop condition on the I2C bus
+    void stopMaster(void);
+
+
 
     /// Wait until the i2c driver becomes available.
+    ///
+    /// Useful if you want to run a sequence of command without interrution by another thread.
+    /// There's no need to call this function for running single request, because all driver functions
+    /// will lock the device for exclusive access automatically.
     void lock()  {
-        // if one and the same thread can lock twice, but then it needs also to unlock twice.
+        // One and the same thread can lock twice, but then it needs also to unlock twice.
         // exactly what we need here
         m_channel->mutex.lock(osWaitForever);
     }
 
-    /// Unlock the driver that has previously been locked by the same thread
+    /// Unlock the driver that has previously been locked by the same thread.
     void unlock() {
         m_channel->mutex.unlock();
     }
 
-
 protected:
 
     enum Command {
         START,
         STOP,
-        WRITE_BYTE,
-        WRITE,
+        READ_MST,
+        READ_MST_REG,
+        READ_SLV,
         READ_BYTE,
-        READ,
-        READ_FROM_REGISTER
+        WRITE_MST,
+        WRITE_SLV,
+        WRITE_BYTE,
+        RECEIVE
     };
 
     struct Transfer {
-        osThreadId caller;
         Command cmd;
+        int ret;
         int freq;
         int adr;
-        uint8_t reg;
         char* dta;
         const char* wdta;
         int len;
         int ack;
         bool rep;
-        int ret;
+        uint8_t reg;
+        bool slv;
+        uint32_t tmout;
+        osThreadId caller;
     };
 
     struct Channel {
-        volatile osThreadId driver;
+        volatile osThreadId driver; // evillive: do we really need that volatile
         rtos::Mutex  mutex;
         volatile Transfer transfer;
-        volatile int freq;
     };
 
+    int m_freq;
+    int m_slaveAdr;
+
     static const PinName c_sdas[2];
     static const PinName c_scls[2];
 
@@ -143,8 +245,7 @@
 
     static void threadFun(void const *args);
 
-    void sendNwait();
-
+    int sendNwait();
 };
 }
 #endif