Diff: I2CDriver.h

Revision:

0:13c962fecb13

Child:

1:90455d5bdd8c

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/I2CDriver.h	Sat Apr 13 13:37:29 2013 +0000
@@ -0,0 +1,152 @@
+#ifndef I2CDRIVER_H
+#define I2CDRIVER_H
+
+#include "stdint.h"
+
+#include "I2C.h"
+
+#include "Thread.h"
+#include "Semaphore.h"
+#include "Mutex.h"
+
+namespace mbed
+{
+
+class I2CDriver : protected I2C
+{
+public:
+    using I2C::RxStatus;
+    using I2C::Acknowledge;
+    using I2C::frequency;
+
+    /** 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);
+
+    /** Set the frequency of the I2C interface
+     *
+     *  @param hz The bus frequency in hertz
+     */
+    void frequency(int hz);
+
+    /** Read from an I2C slave
+     *
+     * Performs a complete read 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 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 read(int address, char *data, int length, bool repeated = false);
+
+    /** Read a single byte from the I2C bus
+     *
+     *  @param ack indicates if the byte is to be acknowledged (1 = acknowledge)
+     *
+     *  @returns
+     *    the byte read
+     */
+    int read(int ack);
+
+    /** Write to an I2C slave
+     *
+     * Performs a complete write transaction. The bottom bit of
+     * the address is forced to 0 to indicate a write.
+     *
+     *  @param address 8-bit I2C slave address [ addr | 0 ]
+     *  @param data Pointer to the byte-array data to send
+     *  @param length Number of bytes to send
+     *  @param repeated Repeated start, true - do not send stop at end
+     *
+     *  @returns
+     *       0 on success (ack),
+     *   non-0 on failure (nack)
+     */
+    int write(int address, const char *data, int length, bool repeated = false);
+
+    /** Write single byte out on the I2C bus
+     *
+     *  @param data data to write out on bus
+     *
+     *  @returns
+     *    '1' if an ACK was received,
+     *    '0' otherwise
+     */
+    int write(int data);
+
+    /// Creates a start condition on the I2C bus
+    void start(void);
+
+    ///Creates a stop condition on the I2C bus
+    void stop(void);
+
+    /// Wait until the i2c driver becomes available.
+    void lock() {
+        // if 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
+    void osStatus unlock() {
+        m_channel.mutex.unlock(osWaitForever);
+    }
+
+
+protected:
+
+    enum Command {
+        START,
+        STOP,
+        WRITE_BYTE,
+        WRITE,
+        READ_BYTE,
+        READ,
+        READ_FROM_REGISTER
+    }
+
+    struct Transfer {
+        Command cmd;
+        int freq;
+        int adr;
+        int reg;
+        char* dta;
+        int len;
+        bool rep;
+        int res;
+    }
+
+    struct Channel {
+        osThreadId caller;
+        osThreadId driver;
+        Mutex  mutex;
+        Transfer transfer;
+        int freq;
+    }
+
+    static const PinName c_sda[]= {p9,p28};
+    static const PinName c_scl[]= {p10,p27};
+
+    static Channel* s_channels[2];
+
+    Channel& m_channel;
+
+    static void channel_0_ISR();
+    static void channel_1_ISR();
+
+    static void threadFun(void* const args);
+
+    void sendNwait();
+
+}
+}
+#endif