Egor Rumjantsev / mbed

The official mbed C/C SDK provides the software platform and libraries to build your applications.

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I2C.h@99:7f6c6de930c0, 2015-05-03 (annotated)

Committer:
Mikchel
Date:
Sun May 03 16:04:42 2015 +0000
Revision:
99:7f6c6de930c0
Parent:
98:8ab26030e058 
12

Who changed what in which revision?

UserRevisionLine numberNew contents of line
bogdanm 65:5798e58a58b1 1 /* mbed Microcontroller Library
Kojto 98:8ab26030e058 2 * Copyright (c) 2006-2015 ARM Limited
bogdanm 65:5798e58a58b1 3 *
bogdanm 65:5798e58a58b1 4 * Licensed under the Apache License, Version 2.0 (the "License");
bogdanm 65:5798e58a58b1 5 * you may not use this file except in compliance with the License.
bogdanm 65:5798e58a58b1 6 * You may obtain a copy of the License at
bogdanm 65:5798e58a58b1 7 *
bogdanm 65:5798e58a58b1 8 * http://www.apache.org/licenses/LICENSE-2.0
bogdanm 65:5798e58a58b1 9 *
bogdanm 65:5798e58a58b1 10 * Unless required by applicable law or agreed to in writing, software
bogdanm 65:5798e58a58b1 11 * distributed under the License is distributed on an "AS IS" BASIS,
bogdanm 65:5798e58a58b1 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
bogdanm 65:5798e58a58b1 13 * See the License for the specific language governing permissions and
bogdanm 65:5798e58a58b1 14 * limitations under the License.
bogdanm 65:5798e58a58b1 15 */
bogdanm 65:5798e58a58b1 16 #ifndef MBED_I2C_H
bogdanm 65:5798e58a58b1 17 #define MBED_I2C_H
bogdanm 65:5798e58a58b1 18
bogdanm 65:5798e58a58b1 19 #include "platform.h"
bogdanm 65:5798e58a58b1 20
bogdanm 65:5798e58a58b1 21 #if DEVICE_I2C
bogdanm 65:5798e58a58b1 22
bogdanm 65:5798e58a58b1 23 #include "i2c_api.h"
bogdanm 65:5798e58a58b1 24
Kojto 98:8ab26030e058 25 #if DEVICE_I2C_ASYNCH
Kojto 98:8ab26030e058 26 #include "CThunk.h"
Kojto 98:8ab26030e058 27 #include "dma_api.h"
Kojto 98:8ab26030e058 28 #include "FunctionPointer.h"
Kojto 98:8ab26030e058 29 #endif
Kojto 98:8ab26030e058 30
bogdanm 65:5798e58a58b1 31 namespace mbed {
bogdanm 65:5798e58a58b1 32
bogdanm 65:5798e58a58b1 33 /** An I2C Master, used for communicating with I2C slave devices
bogdanm 65:5798e58a58b1 34 *
bogdanm 65:5798e58a58b1 35 * Example:
bogdanm 65:5798e58a58b1 36 * @code
bogdanm 65:5798e58a58b1 37 * // Read from I2C slave at address 0x62
bogdanm 65:5798e58a58b1 38 *
bogdanm 65:5798e58a58b1 39 * #include "mbed.h"
bogdanm 65:5798e58a58b1 40 *
bogdanm 65:5798e58a58b1 41 * I2C i2c(p28, p27);
bogdanm 65:5798e58a58b1 42 *
bogdanm 65:5798e58a58b1 43 * int main() {
bogdanm 65:5798e58a58b1 44 * int address = 0x62;
bogdanm 65:5798e58a58b1 45 * char data[2];
bogdanm 65:5798e58a58b1 46 * i2c.read(address, data, 2);
bogdanm 65:5798e58a58b1 47 * }
bogdanm 65:5798e58a58b1 48 * @endcode
bogdanm 65:5798e58a58b1 49 */
bogdanm 65:5798e58a58b1 50 class I2C {
bogdanm 65:5798e58a58b1 51
bogdanm 65:5798e58a58b1 52 public:
bogdanm 65:5798e58a58b1 53 enum RxStatus {
bogdanm 65:5798e58a58b1 54 NoData,
bogdanm 65:5798e58a58b1 55 MasterGeneralCall,
bogdanm 65:5798e58a58b1 56 MasterWrite,
bogdanm 65:5798e58a58b1 57 MasterRead
bogdanm 65:5798e58a58b1 58 };
bogdanm 65:5798e58a58b1 59
bogdanm 65:5798e58a58b1 60 enum Acknowledge {
bogdanm 65:5798e58a58b1 61 NoACK = 0,
bogdanm 65:5798e58a58b1 62 ACK = 1
bogdanm 65:5798e58a58b1 63 };
bogdanm 65:5798e58a58b1 64
bogdanm 65:5798e58a58b1 65 /** Create an I2C Master interface, connected to the specified pins
bogdanm 65:5798e58a58b1 66 *
bogdanm 65:5798e58a58b1 67 * @param sda I2C data line pin
bogdanm 65:5798e58a58b1 68 * @param scl I2C clock line pin
bogdanm 65:5798e58a58b1 69 */
bogdanm 65:5798e58a58b1 70 I2C(PinName sda, PinName scl);
bogdanm 65:5798e58a58b1 71
bogdanm 65:5798e58a58b1 72 /** Set the frequency of the I2C interface
bogdanm 65:5798e58a58b1 73 *
bogdanm 65:5798e58a58b1 74 * @param hz The bus frequency in hertz
bogdanm 65:5798e58a58b1 75 */
bogdanm 65:5798e58a58b1 76 void frequency(int hz);
bogdanm 65:5798e58a58b1 77
bogdanm 65:5798e58a58b1 78 /** Read from an I2C slave
bogdanm 65:5798e58a58b1 79 *
bogdanm 65:5798e58a58b1 80 * Performs a complete read transaction. The bottom bit of
bogdanm 65:5798e58a58b1 81 * the address is forced to 1 to indicate a read.
bogdanm 65:5798e58a58b1 82 *
bogdanm 65:5798e58a58b1 83 * @param address 8-bit I2C slave address [ addr | 1 ]
bogdanm 65:5798e58a58b1 84 * @param data Pointer to the byte-array to read data in to
bogdanm 65:5798e58a58b1 85 * @param length Number of bytes to read
bogdanm 65:5798e58a58b1 86 * @param repeated Repeated start, true - don't send stop at end
bogdanm 65:5798e58a58b1 87 *
bogdanm 65:5798e58a58b1 88 * @returns
bogdanm 65:5798e58a58b1 89 * 0 on success (ack),
bogdanm 65:5798e58a58b1 90 * non-0 on failure (nack)
bogdanm 65:5798e58a58b1 91 */
bogdanm 65:5798e58a58b1 92 int read(int address, char *data, int length, bool repeated = false);
bogdanm 65:5798e58a58b1 93
bogdanm 65:5798e58a58b1 94 /** Read a single byte from the I2C bus
bogdanm 65:5798e58a58b1 95 *
bogdanm 65:5798e58a58b1 96 * @param ack indicates if the byte is to be acknowledged (1 = acknowledge)
bogdanm 65:5798e58a58b1 97 *
bogdanm 65:5798e58a58b1 98 * @returns
bogdanm 65:5798e58a58b1 99 * the byte read
bogdanm 65:5798e58a58b1 100 */
bogdanm 65:5798e58a58b1 101 int read(int ack);
bogdanm 65:5798e58a58b1 102
bogdanm 65:5798e58a58b1 103 /** Write to an I2C slave
bogdanm 65:5798e58a58b1 104 *
bogdanm 65:5798e58a58b1 105 * Performs a complete write transaction. The bottom bit of
bogdanm 65:5798e58a58b1 106 * the address is forced to 0 to indicate a write.
bogdanm 65:5798e58a58b1 107 *
bogdanm 65:5798e58a58b1 108 * @param address 8-bit I2C slave address [ addr | 0 ]
bogdanm 65:5798e58a58b1 109 * @param data Pointer to the byte-array data to send
bogdanm 65:5798e58a58b1 110 * @param length Number of bytes to send
bogdanm 65:5798e58a58b1 111 * @param repeated Repeated start, true - do not send stop at end
bogdanm 65:5798e58a58b1 112 *
bogdanm 65:5798e58a58b1 113 * @returns
bogdanm 65:5798e58a58b1 114 * 0 on success (ack),
bogdanm 65:5798e58a58b1 115 * non-0 on failure (nack)
bogdanm 65:5798e58a58b1 116 */
bogdanm 65:5798e58a58b1 117 int write(int address, const char *data, int length, bool repeated = false);
bogdanm 65:5798e58a58b1 118
bogdanm 65:5798e58a58b1 119 /** Write single byte out on the I2C bus
bogdanm 65:5798e58a58b1 120 *
bogdanm 65:5798e58a58b1 121 * @param data data to write out on bus
bogdanm 65:5798e58a58b1 122 *
bogdanm 65:5798e58a58b1 123 * @returns
bogdanm 65:5798e58a58b1 124 * '1' if an ACK was received,
bogdanm 65:5798e58a58b1 125 * '0' otherwise
bogdanm 65:5798e58a58b1 126 */
bogdanm 65:5798e58a58b1 127 int write(int data);
bogdanm 65:5798e58a58b1 128
bogdanm 65:5798e58a58b1 129 /** Creates a start condition on the I2C bus
bogdanm 65:5798e58a58b1 130 */
bogdanm 65:5798e58a58b1 131
bogdanm 65:5798e58a58b1 132 void start(void);
bogdanm 65:5798e58a58b1 133
bogdanm 65:5798e58a58b1 134 /** Creates a stop condition on the I2C bus
bogdanm 65:5798e58a58b1 135 */
bogdanm 65:5798e58a58b1 136 void stop(void);
bogdanm 65:5798e58a58b1 137
Kojto 98:8ab26030e058 138 #if DEVICE_I2C_ASYNCH
Kojto 98:8ab26030e058 139
Kojto 98:8ab26030e058 140 /** Start non-blocking I2C transfer.
Kojto 98:8ab26030e058 141 *
Kojto 98:8ab26030e058 142 * @param address 8/10 bit I2c slave address
Kojto 98:8ab26030e058 143 * @param tx_buffer The TX buffer with data to be transfered
Kojto 98:8ab26030e058 144 * @param tx_length The length of TX buffer
Kojto 98:8ab26030e058 145 * @param rx_buffer The RX buffer which is used for received data
Kojto 98:8ab26030e058 146 * @param rx_length The length of RX buffer
Kojto 98:8ab26030e058 147 * @param event The logical OR of events to modify
Kojto 98:8ab26030e058 148 * @param callback The event callback function
Kojto 98:8ab26030e058 149 * @param repeated Repeated start, true - do not send stop at end
Kojto 98:8ab26030e058 150 * @return Zero if the transfer has started, or -1 if I2C peripheral is busy
Kojto 98:8ab26030e058 151 */
Kojto 98:8ab26030e058 152 int transfer(int address, 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);
Kojto 98:8ab26030e058 153
Kojto 98:8ab26030e058 154 /** Abort the on-going I2C transfer
Kojto 98:8ab26030e058 155 */
Kojto 98:8ab26030e058 156 void abort_transfer();
Kojto 98:8ab26030e058 157 protected:
Kojto 98:8ab26030e058 158 void irq_handler_asynch(void);
Kojto 98:8ab26030e058 159 event_callback_t _callback;
Kojto 98:8ab26030e058 160 CThunk<I2C> _irq;
Kojto 98:8ab26030e058 161 DMAUsage _usage;
Kojto 98:8ab26030e058 162 #endif
Kojto 98:8ab26030e058 163
bogdanm 65:5798e58a58b1 164 protected:
bogdanm 65:5798e58a58b1 165 void aquire();
bogdanm 65:5798e58a58b1 166
bogdanm 65:5798e58a58b1 167 i2c_t _i2c;
bogdanm 65:5798e58a58b1 168 static I2C *_owner;
bogdanm 65:5798e58a58b1 169 int _hz;
bogdanm 65:5798e58a58b1 170 };
bogdanm 65:5798e58a58b1 171
bogdanm 65:5798e58a58b1 172 } // namespace mbed
bogdanm 65:5798e58a58b1 173
bogdanm 65:5798e58a58b1 174 #endif
bogdanm 65:5798e58a58b1 175
bogdanm 65:5798e58a58b1 176 #endif