R L / mbed-src

mbed library sources

Fork of mbed-src by mbed official

api/I2C.h@636:21ce76d41a4f, 2016-02-21 (annotated)

Committer:
rllamado
Date:
Sun Feb 21 07:27:08 2016 +0000
Revision:
636:21ce76d41a4f
Parent:
564:24a7119bd73a 
something

Who changed what in which revision?

UserRevisionLine numberNew contents of line
bogdanm 13:0645d8841f51 1 /* mbed Microcontroller Library
mbed_official 525:c320967f86b9 2 * Copyright (c) 2006-2015 ARM Limited
bogdanm 13:0645d8841f51 3 *
bogdanm 13:0645d8841f51 4 * Licensed under the Apache License, Version 2.0 (the "License");
bogdanm 13:0645d8841f51 5 * you may not use this file except in compliance with the License.
bogdanm 13:0645d8841f51 6 * You may obtain a copy of the License at
bogdanm 13:0645d8841f51 7 *
bogdanm 13:0645d8841f51 8 * http://www.apache.org/licenses/LICENSE-2.0
bogdanm 13:0645d8841f51 9 *
bogdanm 13:0645d8841f51 10 * Unless required by applicable law or agreed to in writing, software
bogdanm 13:0645d8841f51 11 * distributed under the License is distributed on an "AS IS" BASIS,
bogdanm 13:0645d8841f51 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
bogdanm 13:0645d8841f51 13 * See the License for the specific language governing permissions and
bogdanm 13:0645d8841f51 14 * limitations under the License.
bogdanm 13:0645d8841f51 15 */
bogdanm 13:0645d8841f51 16 #ifndef MBED_I2C_H
bogdanm 13:0645d8841f51 17 #define MBED_I2C_H
bogdanm 13:0645d8841f51 18
bogdanm 13:0645d8841f51 19 #include "platform.h"
bogdanm 13:0645d8841f51 20
bogdanm 13:0645d8841f51 21 #if DEVICE_I2C
bogdanm 13:0645d8841f51 22
bogdanm 13:0645d8841f51 23 #include "i2c_api.h"
bogdanm 13:0645d8841f51 24
mbed_official 525:c320967f86b9 25 #if DEVICE_I2C_ASYNCH
mbed_official 525:c320967f86b9 26 #include "CThunk.h"
mbed_official 525:c320967f86b9 27 #include "dma_api.h"
mbed_official 525:c320967f86b9 28 #include "FunctionPointer.h"
mbed_official 525:c320967f86b9 29 #endif
mbed_official 525:c320967f86b9 30
bogdanm 13:0645d8841f51 31 namespace mbed {
bogdanm 13:0645d8841f51 32
bogdanm 13:0645d8841f51 33 /** An I2C Master, used for communicating with I2C slave devices
bogdanm 13:0645d8841f51 34 *
bogdanm 13:0645d8841f51 35 * Example:
bogdanm 13:0645d8841f51 36 * @code
bogdanm 13:0645d8841f51 37 * // Read from I2C slave at address 0x62
bogdanm 13:0645d8841f51 38 *
bogdanm 13:0645d8841f51 39 * #include "mbed.h"
bogdanm 13:0645d8841f51 40 *
bogdanm 13:0645d8841f51 41 * I2C i2c(p28, p27);
bogdanm 13:0645d8841f51 42 *
bogdanm 13:0645d8841f51 43 * int main() {
bogdanm 13:0645d8841f51 44 * int address = 0x62;
bogdanm 13:0645d8841f51 45 * char data[2];
bogdanm 13:0645d8841f51 46 * i2c.read(address, data, 2);
bogdanm 13:0645d8841f51 47 * }
bogdanm 13:0645d8841f51 48 * @endcode
bogdanm 13:0645d8841f51 49 */
bogdanm 13:0645d8841f51 50 class I2C {
bogdanm 13:0645d8841f51 51
bogdanm 13:0645d8841f51 52 public:
bogdanm 13:0645d8841f51 53 enum RxStatus {
bogdanm 13:0645d8841f51 54 NoData,
bogdanm 13:0645d8841f51 55 MasterGeneralCall,
bogdanm 13:0645d8841f51 56 MasterWrite,
bogdanm 13:0645d8841f51 57 MasterRead
bogdanm 13:0645d8841f51 58 };
bogdanm 13:0645d8841f51 59
bogdanm 13:0645d8841f51 60 enum Acknowledge {
bogdanm 13:0645d8841f51 61 NoACK = 0,
bogdanm 13:0645d8841f51 62 ACK = 1
bogdanm 13:0645d8841f51 63 };
bogdanm 13:0645d8841f51 64
bogdanm 13:0645d8841f51 65 /** Create an I2C Master interface, connected to the specified pins
bogdanm 13:0645d8841f51 66 *
bogdanm 13:0645d8841f51 67 * @param sda I2C data line pin
bogdanm 13:0645d8841f51 68 * @param scl I2C clock line pin
bogdanm 13:0645d8841f51 69 */
bogdanm 13:0645d8841f51 70 I2C(PinName sda, PinName scl);
bogdanm 13:0645d8841f51 71
bogdanm 13:0645d8841f51 72 /** Set the frequency of the I2C interface
bogdanm 13:0645d8841f51 73 *
bogdanm 13:0645d8841f51 74 * @param hz The bus frequency in hertz
bogdanm 13:0645d8841f51 75 */
bogdanm 13:0645d8841f51 76 void frequency(int hz);
bogdanm 13:0645d8841f51 77
bogdanm 13:0645d8841f51 78 /** Read from an I2C slave
bogdanm 13:0645d8841f51 79 *
bogdanm 13:0645d8841f51 80 * Performs a complete read transaction. The bottom bit of
bogdanm 13:0645d8841f51 81 * the address is forced to 1 to indicate a read.
bogdanm 13:0645d8841f51 82 *
bogdanm 13:0645d8841f51 83 * @param address 8-bit I2C slave address [ addr | 1 ]
bogdanm 13:0645d8841f51 84 * @param data Pointer to the byte-array to read data in to
bogdanm 13:0645d8841f51 85 * @param length Number of bytes to read
bogdanm 13:0645d8841f51 86 * @param repeated Repeated start, true - don't send stop at end
bogdanm 13:0645d8841f51 87 *
bogdanm 13:0645d8841f51 88 * @returns
bogdanm 13:0645d8841f51 89 * 0 on success (ack),
bogdanm 13:0645d8841f51 90 * non-0 on failure (nack)
bogdanm 13:0645d8841f51 91 */
bogdanm 13:0645d8841f51 92 int read(int address, char *data, int length, bool repeated = false);
bogdanm 13:0645d8841f51 93
bogdanm 13:0645d8841f51 94 /** Read a single byte from the I2C bus
bogdanm 13:0645d8841f51 95 *
bogdanm 13:0645d8841f51 96 * @param ack indicates if the byte is to be acknowledged (1 = acknowledge)
bogdanm 13:0645d8841f51 97 *
bogdanm 13:0645d8841f51 98 * @returns
bogdanm 13:0645d8841f51 99 * the byte read
bogdanm 13:0645d8841f51 100 */
bogdanm 13:0645d8841f51 101 int read(int ack);
bogdanm 13:0645d8841f51 102
bogdanm 13:0645d8841f51 103 /** Write to an I2C slave
bogdanm 13:0645d8841f51 104 *
bogdanm 13:0645d8841f51 105 * Performs a complete write transaction. The bottom bit of
bogdanm 13:0645d8841f51 106 * the address is forced to 0 to indicate a write.
bogdanm 13:0645d8841f51 107 *
bogdanm 13:0645d8841f51 108 * @param address 8-bit I2C slave address [ addr | 0 ]
bogdanm 13:0645d8841f51 109 * @param data Pointer to the byte-array data to send
bogdanm 13:0645d8841f51 110 * @param length Number of bytes to send
bogdanm 13:0645d8841f51 111 * @param repeated Repeated start, true - do not send stop at end
bogdanm 13:0645d8841f51 112 *
bogdanm 13:0645d8841f51 113 * @returns
bogdanm 13:0645d8841f51 114 * 0 on success (ack),
bogdanm 13:0645d8841f51 115 * non-0 on failure (nack)
bogdanm 13:0645d8841f51 116 */
bogdanm 13:0645d8841f51 117 int write(int address, const char *data, int length, bool repeated = false);
bogdanm 13:0645d8841f51 118
bogdanm 13:0645d8841f51 119 /** Write single byte out on the I2C bus
bogdanm 13:0645d8841f51 120 *
bogdanm 13:0645d8841f51 121 * @param data data to write out on bus
bogdanm 13:0645d8841f51 122 *
bogdanm 13:0645d8841f51 123 * @returns
bogdanm 13:0645d8841f51 124 * '1' if an ACK was received,
bogdanm 13:0645d8841f51 125 * '0' otherwise
bogdanm 13:0645d8841f51 126 */
bogdanm 13:0645d8841f51 127 int write(int data);
bogdanm 13:0645d8841f51 128
bogdanm 13:0645d8841f51 129 /** Creates a start condition on the I2C bus
bogdanm 13:0645d8841f51 130 */
bogdanm 13:0645d8841f51 131
bogdanm 13:0645d8841f51 132 void start(void);
bogdanm 13:0645d8841f51 133
bogdanm 13:0645d8841f51 134 /** Creates a stop condition on the I2C bus
bogdanm 13:0645d8841f51 135 */
bogdanm 13:0645d8841f51 136 void stop(void);
bogdanm 13:0645d8841f51 137
mbed_official 525:c320967f86b9 138 #if DEVICE_I2C_ASYNCH
mbed_official 525:c320967f86b9 139
mbed_official 525:c320967f86b9 140 /** Start non-blocking I2C transfer.
mbed_official 525:c320967f86b9 141 *
mbed_official 525:c320967f86b9 142 * @param address 8/10 bit I2c slave address
mbed_official 525:c320967f86b9 143 * @param tx_buffer The TX buffer with data to be transfered
mbed_official 564:24a7119bd73a 144 * @param tx_length The length of TX buffer in bytes
mbed_official 525:c320967f86b9 145 * @param rx_buffer The RX buffer which is used for received data
mbed_official 564:24a7119bd73a 146 * @param rx_length The length of RX buffer in bytes
mbed_official 525:c320967f86b9 147 * @param event The logical OR of events to modify
mbed_official 525:c320967f86b9 148 * @param callback The event callback function
mbed_official 525:c320967f86b9 149 * @param repeated Repeated start, true - do not send stop at end
mbed_official 525:c320967f86b9 150 * @return Zero if the transfer has started, or -1 if I2C peripheral is busy
mbed_official 525:c320967f86b9 151 */
mbed_official 563:536c9fb088a0 152 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);
mbed_official 525:c320967f86b9 153
mbed_official 525:c320967f86b9 154 /** Abort the on-going I2C transfer
mbed_official 525:c320967f86b9 155 */
mbed_official 525:c320967f86b9 156 void abort_transfer();
mbed_official 525:c320967f86b9 157 protected:
mbed_official 525:c320967f86b9 158 void irq_handler_asynch(void);
mbed_official 525:c320967f86b9 159 event_callback_t _callback;
mbed_official 525:c320967f86b9 160 CThunk<I2C> _irq;
mbed_official 525:c320967f86b9 161 DMAUsage _usage;
mbed_official 525:c320967f86b9 162 #endif
mbed_official 525:c320967f86b9 163
bogdanm 13:0645d8841f51 164 protected:
bogdanm 13:0645d8841f51 165 void aquire();
bogdanm 13:0645d8841f51 166
bogdanm 13:0645d8841f51 167 i2c_t _i2c;
bogdanm 13:0645d8841f51 168 static I2C *_owner;
bogdanm 13:0645d8841f51 169 int _hz;
bogdanm 13:0645d8841f51 170 };
bogdanm 13:0645d8841f51 171
bogdanm 13:0645d8841f51 172 } // namespace mbed
bogdanm 13:0645d8841f51 173
bogdanm 13:0645d8841f51 174 #endif
bogdanm 13:0645d8841f51 175
bogdanm 13:0645d8841f51 176 #endif