diff options
Diffstat (limited to 'ext/I2C.h')
| -rw-r--r-- | ext/I2C.h | 176 |
1 files changed, 176 insertions, 0 deletions
diff --git a/ext/I2C.h b/ext/I2C.h new file mode 100644 index 0000000..7981cef --- /dev/null +++ b/ext/I2C.h @@ -0,0 +1,176 @@ +/* mbed Microcontroller Library
+ * Copyright (c) 2006-2015 ARM Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#ifndef MBED_I2C_H
+#define MBED_I2C_H
+
+#include "platform.h"
+
+#if DEVICE_I2C
+
+#include "i2c_api.h"
+
+#if DEVICE_I2C_ASYNCH
+#include "CThunk.h"
+#include "dma_api.h"
+#include "FunctionPointer.h"
+#endif
+
+namespace mbed {
+
+/** An I2C Master, used for communicating with I2C slave devices
+ *
+ * Example:
+ * @code
+ * // Read from I2C slave at address 0x62
+ *
+ * #include "mbed.h"
+ *
+ * I2C i2c(p28, p27);
+ *
+ * int main() {
+ * int address = 0x62;
+ * char data[2];
+ * i2c.read(address, data, 2);
+ * }
+ * @endcode
+ */
+class I2C {
+
+public:
+ enum RxStatus {
+ NoData,
+ MasterGeneralCall,
+ MasterWrite,
+ MasterRead
+ };
+
+ enum Acknowledge {
+ NoACK = 0,
+ ACK = 1
+ };
+
+ /** Create an I2C Master interface, connected to the specified pins
+ *
+ * @param sda I2C data line pin
+ * @param scl I2C clock line pin
+ */
+ I2C(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);
+
+#if DEVICE_I2C_ASYNCH
+
+ /** Start non-blocking I2C transfer.
+ *
+ * @param address 8/10 bit I2c slave address
+ * @param tx_buffer The TX buffer with data to be transfered
+ * @param tx_length The length of TX buffer in bytes
+ * @param rx_buffer The RX buffer which is used for received data
+ * @param rx_length The length of RX buffer in bytes
+ * @param event The logical OR of events to modify
+ * @param callback The event callback function
+ * @param repeated Repeated start, true - do not send stop at end
+ * @return Zero if the transfer has started, or -1 if I2C peripheral is busy
+ */
+ int transfer(int address, const char *tx_buffer, int tx_length, char *rx_buffer, int rx_length, const event_callback_t& callback, int event = I2C_EVENT_TRANSFER_COMPLETE, bool repeated = false);
+
+ /** Abort the on-going I2C transfer
+ */
+ void abort_transfer();
+protected:
+ void irq_handler_asynch(void);
+ event_callback_t _callback;
+ CThunk<I2C> _irq;
+ DMAUsage _usage;
+#endif
+
+protected:
+ void aquire();
+
+ i2c_t _i2c;
+ static I2C *_owner;
+ int _hz;
+};
+
+} // namespace mbed
+
+#endif
+
+#endif
|