Diff: drivers/I2CSlave.h

Revision:

0:5b88d5760320

Child:

1:9db0e321a9f4

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/drivers/I2CSlave.h	Tue Dec 17 23:23:45 2019 +0000
@@ -0,0 +1,167 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2013 ARM Limited
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * 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_SLAVE_H
+#define MBED_I2C_SLAVE_H
+
+#include "platform/platform.h"
+
+#if DEVICE_I2CSLAVE || defined(DOXYGEN_ONLY)
+
+#include "hal/i2c_api.h"
+
+namespace mbed {
+/** \addtogroup drivers */
+
+/** An I2C Slave, used for communicating with an I2C Master device.
+ *
+ * @note Synchronization level: Not protected
+ *
+ * Example Simple I2C responder:
+ * @code
+ * #include <mbed.h>
+ *
+ * const int SLAVE_ADDRESS = 0xA0;
+ * const char message[] = "Slave!";
+ *
+ * I2CSlave slave(I2C_SDA, I2C_SCL);
+ *
+ * int main() {
+ *     slave.address(SLAVE_ADDRESS);
+ *     while (1) {
+ *         int operation = slave.receive();
+ *         switch (operation) {
+ *             case I2CSlave::ReadAddressed:
+ *                 int status = slave.write(message, sizeof(message));
+ *                 if (status == 0) {
+ *                     printf("Written message: %s\n", message);
+ *                 } else {
+ *                     printf("Failed to write message.\n");
+ *                 }
+ *                 break;
+ *             case I2CSlave::WriteGeneral:
+ *                 int byte_read = slave.read();
+ *                 printf("Read General: %c (%d)\n", byte_read, byte_read);
+ *                 break;
+ *             case I2CSlave::WriteAddressed:
+ *                 int byte_read = slave.read();
+ *                 printf("Read Addressed: %c (%d)\n", byte_read, byte_read);
+ *                 break;
+ *         }
+ *     }
+ * }
+ * @endcode
+ * @ingroup drivers
+ */
+class I2CSlave {
+
+public:
+    enum RxStatus {
+        NoData         = 0,
+        ReadAddressed  = 1,
+        WriteGeneral   = 2,
+        WriteAddressed = 3
+    };
+
+    /** Create an I2C Slave interface, connected to the specified pins.
+     *
+     *  @param sda I2C data line pin.
+     *  @param scl I2C clock line pin.
+     */
+    I2CSlave(PinName sda, PinName scl);
+
+    /** Set the frequency of the I2C interface.
+     *
+     *  @param hz The bus frequency in Hertz.
+     */
+    void frequency(int hz);
+
+    /** Check if this I2C Slave has been addressed.
+     *
+     *  @return A status indicating if the device has been addressed and how.
+     *  @retval NoData          The slave has not been addressed.
+     *  @retval ReadAddressed   The master has requested a read from this slave.
+     *  @retval WriteAddressed  The master is writing to this slave.
+     *  @retval WriteGeneral    The master is writing to all slave.
+     */
+    int receive(void);
+
+    /** Read specified number of bytes from an I2C master.
+     *
+     *  @param data   Pointer to the buffer to read data into.
+     *  @param length Number of bytes to read.
+     *
+     *  @return Result of the operation.
+     *  @retval 0       If the number of bytes read is equal to length requested.
+     *  @retval nonzero On error or if the number of bytes read is less than requested.
+     */
+    int read(char *data, int length);
+
+    /** Read a single byte from an I2C master.
+     *
+     *  @return The byte read.
+     */
+    int read(void);
+
+    /** Write to an I2C master.
+     *
+     *  @param data   Pointer to the buffer containing the data to be sent.
+     *  @param length Number of bytes to send.
+     *
+     *  @return
+     *  @retval 0       If written all bytes successfully.
+     *  @retval nonzero On error or if the number of bytes written is less than requested.
+     */
+    int write(const char *data, int length);
+
+    /** Write a single byte to an I2C master.
+     *
+     *  @param data Value to write.
+     *
+     *  @return Result of the operation.
+     *  @retval 0 If a NACK is received.
+     *  @retval 1 If an ACK is received.
+     *  @retval 2 On timeout.
+     */
+    int write(int data);
+
+    /** Set the I2C slave address.
+     *
+     *  @param address The address to set for the slave (least significant bit is ignored).
+     *
+     *  @note If address is set to 0, the slave will only respond to the
+     *  general call address.
+     */
+    void address(int address);
+
+    /** Reset the I2C slave back into the known ready receiving state.
+     */
+    void stop(void);
+
+#if !defined(DOXYGEN_ONLY)
+
+protected:
+    /* Internal i2c object identifying the resources */
+    i2c_t _i2c;
+
+#endif //!defined(DOXYGEN_ONLY)
+};
+
+} // namespace mbed
+
+#endif
+
+#endif