teralytic / mbed-dev

mbed library sources. Supersedes mbed-src.

Fork of mbed by teralytic

api/I2C.h@148:4802eb17e82b, 2016-10-17 (annotated)

Committer:
rodriguise
Date:
Mon Oct 17 18:47:01 2016 +0000
Revision:
148:4802eb17e82b
Parent:
144:ef7eb2e8f9f7 
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<> 144:ef7eb2e8f9f7 1 /* mbed Microcontroller Library
<> 144:ef7eb2e8f9f7 2 * Copyright (c) 2006-2015 ARM Limited
<> 144:ef7eb2e8f9f7 3 *
<> 144:ef7eb2e8f9f7 4 * Licensed under the Apache License, Version 2.0 (the "License");
<> 144:ef7eb2e8f9f7 5 * you may not use this file except in compliance with the License.
<> 144:ef7eb2e8f9f7 6 * You may obtain a copy of the License at
<> 144:ef7eb2e8f9f7 7 *
<> 144:ef7eb2e8f9f7 8 * http://www.apache.org/licenses/LICENSE-2.0
<> 144:ef7eb2e8f9f7 9 *
<> 144:ef7eb2e8f9f7 10 * Unless required by applicable law or agreed to in writing, software
<> 144:ef7eb2e8f9f7 11 * distributed under the License is distributed on an "AS IS" BASIS,
<> 144:ef7eb2e8f9f7 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
<> 144:ef7eb2e8f9f7 13 * See the License for the specific language governing permissions and
<> 144:ef7eb2e8f9f7 14 * limitations under the License.
<> 144:ef7eb2e8f9f7 15 */
<> 144:ef7eb2e8f9f7 16 #ifndef MBED_I2C_H
<> 144:ef7eb2e8f9f7 17 #define MBED_I2C_H
<> 144:ef7eb2e8f9f7 18
<> 144:ef7eb2e8f9f7 19 #include "platform.h"
<> 144:ef7eb2e8f9f7 20
<> 144:ef7eb2e8f9f7 21 #if DEVICE_I2C
<> 144:ef7eb2e8f9f7 22
<> 144:ef7eb2e8f9f7 23 #include "i2c_api.h"
<> 144:ef7eb2e8f9f7 24 #include "SingletonPtr.h"
<> 144:ef7eb2e8f9f7 25 #include "PlatformMutex.h"
<> 144:ef7eb2e8f9f7 26
<> 144:ef7eb2e8f9f7 27 #if DEVICE_I2C_ASYNCH
<> 144:ef7eb2e8f9f7 28 #include "CThunk.h"
<> 144:ef7eb2e8f9f7 29 #include "dma_api.h"
<> 144:ef7eb2e8f9f7 30 #include "FunctionPointer.h"
<> 144:ef7eb2e8f9f7 31 #endif
<> 144:ef7eb2e8f9f7 32
<> 144:ef7eb2e8f9f7 33 namespace mbed {
<> 144:ef7eb2e8f9f7 34
<> 144:ef7eb2e8f9f7 35 /** An I2C Master, used for communicating with I2C slave devices
<> 144:ef7eb2e8f9f7 36 *
<> 144:ef7eb2e8f9f7 37 * @Note Synchronization level: Thread safe
<> 144:ef7eb2e8f9f7 38 *
<> 144:ef7eb2e8f9f7 39 * Example:
<> 144:ef7eb2e8f9f7 40 * @code
<> 144:ef7eb2e8f9f7 41 * // Read from I2C slave at address 0x62
<> 144:ef7eb2e8f9f7 42 *
<> 144:ef7eb2e8f9f7 43 * #include "mbed.h"
<> 144:ef7eb2e8f9f7 44 *
<> 144:ef7eb2e8f9f7 45 * I2C i2c(p28, p27);
<> 144:ef7eb2e8f9f7 46 *
<> 144:ef7eb2e8f9f7 47 * int main() {
<> 144:ef7eb2e8f9f7 48 * int address = 0x62;
<> 144:ef7eb2e8f9f7 49 * char data[2];
<> 144:ef7eb2e8f9f7 50 * i2c.read(address, data, 2);
<> 144:ef7eb2e8f9f7 51 * }
<> 144:ef7eb2e8f9f7 52 * @endcode
<> 144:ef7eb2e8f9f7 53 */
<> 144:ef7eb2e8f9f7 54 class I2C {
<> 144:ef7eb2e8f9f7 55
<> 144:ef7eb2e8f9f7 56 public:
<> 144:ef7eb2e8f9f7 57 enum RxStatus {
<> 144:ef7eb2e8f9f7 58 NoData,
<> 144:ef7eb2e8f9f7 59 MasterGeneralCall,
<> 144:ef7eb2e8f9f7 60 MasterWrite,
<> 144:ef7eb2e8f9f7 61 MasterRead
<> 144:ef7eb2e8f9f7 62 };
<> 144:ef7eb2e8f9f7 63
<> 144:ef7eb2e8f9f7 64 enum Acknowledge {
<> 144:ef7eb2e8f9f7 65 NoACK = 0,
<> 144:ef7eb2e8f9f7 66 ACK = 1
<> 144:ef7eb2e8f9f7 67 };
<> 144:ef7eb2e8f9f7 68
<> 144:ef7eb2e8f9f7 69 /** Create an I2C Master interface, connected to the specified pins
<> 144:ef7eb2e8f9f7 70 *
<> 144:ef7eb2e8f9f7 71 * @param sda I2C data line pin
<> 144:ef7eb2e8f9f7 72 * @param scl I2C clock line pin
<> 144:ef7eb2e8f9f7 73 */
<> 144:ef7eb2e8f9f7 74 I2C(PinName sda, PinName scl);
<> 144:ef7eb2e8f9f7 75
<> 144:ef7eb2e8f9f7 76 /** Set the frequency of the I2C interface
<> 144:ef7eb2e8f9f7 77 *
<> 144:ef7eb2e8f9f7 78 * @param hz The bus frequency in hertz
<> 144:ef7eb2e8f9f7 79 */
<> 144:ef7eb2e8f9f7 80 void frequency(int hz);
<> 144:ef7eb2e8f9f7 81
<> 144:ef7eb2e8f9f7 82 /** Read from an I2C slave
<> 144:ef7eb2e8f9f7 83 *
<> 144:ef7eb2e8f9f7 84 * Performs a complete read transaction. The bottom bit of
<> 144:ef7eb2e8f9f7 85 * the address is forced to 1 to indicate a read.
<> 144:ef7eb2e8f9f7 86 *
<> 144:ef7eb2e8f9f7 87 * @param address 8-bit I2C slave address [ addr | 1 ]
<> 144:ef7eb2e8f9f7 88 * @param data Pointer to the byte-array to read data in to
<> 144:ef7eb2e8f9f7 89 * @param length Number of bytes to read
<> 144:ef7eb2e8f9f7 90 * @param repeated Repeated start, true - don't send stop at end
<> 144:ef7eb2e8f9f7 91 *
<> 144:ef7eb2e8f9f7 92 * @returns
<> 144:ef7eb2e8f9f7 93 * 0 on success (ack),
<> 144:ef7eb2e8f9f7 94 * non-0 on failure (nack)
<> 144:ef7eb2e8f9f7 95 */
<> 144:ef7eb2e8f9f7 96 int read(int address, char *data, int length, bool repeated = false);
<> 144:ef7eb2e8f9f7 97
<> 144:ef7eb2e8f9f7 98 /** Read a single byte from the I2C bus
<> 144:ef7eb2e8f9f7 99 *
<> 144:ef7eb2e8f9f7 100 * @param ack indicates if the byte is to be acknowledged (1 = acknowledge)
<> 144:ef7eb2e8f9f7 101 *
<> 144:ef7eb2e8f9f7 102 * @returns
<> 144:ef7eb2e8f9f7 103 * the byte read
<> 144:ef7eb2e8f9f7 104 */
<> 144:ef7eb2e8f9f7 105 int read(int ack);
<> 144:ef7eb2e8f9f7 106
<> 144:ef7eb2e8f9f7 107 /** Write to an I2C slave
<> 144:ef7eb2e8f9f7 108 *
<> 144:ef7eb2e8f9f7 109 * Performs a complete write transaction. The bottom bit of
<> 144:ef7eb2e8f9f7 110 * the address is forced to 0 to indicate a write.
<> 144:ef7eb2e8f9f7 111 *
<> 144:ef7eb2e8f9f7 112 * @param address 8-bit I2C slave address [ addr | 0 ]
<> 144:ef7eb2e8f9f7 113 * @param data Pointer to the byte-array data to send
<> 144:ef7eb2e8f9f7 114 * @param length Number of bytes to send
<> 144:ef7eb2e8f9f7 115 * @param repeated Repeated start, true - do not send stop at end
<> 144:ef7eb2e8f9f7 116 *
<> 144:ef7eb2e8f9f7 117 * @returns
<> 144:ef7eb2e8f9f7 118 * 0 on success (ack),
<> 144:ef7eb2e8f9f7 119 * non-0 on failure (nack)
<> 144:ef7eb2e8f9f7 120 */
<> 144:ef7eb2e8f9f7 121 int write(int address, const char *data, int length, bool repeated = false);
<> 144:ef7eb2e8f9f7 122
<> 144:ef7eb2e8f9f7 123 /** Write single byte out on the I2C bus
<> 144:ef7eb2e8f9f7 124 *
<> 144:ef7eb2e8f9f7 125 * @param data data to write out on bus
<> 144:ef7eb2e8f9f7 126 *
<> 144:ef7eb2e8f9f7 127 * @returns
<> 144:ef7eb2e8f9f7 128 * '1' if an ACK was received,
<> 144:ef7eb2e8f9f7 129 * '0' otherwise
<> 144:ef7eb2e8f9f7 130 */
<> 144:ef7eb2e8f9f7 131 int write(int data);
<> 144:ef7eb2e8f9f7 132
<> 144:ef7eb2e8f9f7 133 /** Creates a start condition on the I2C bus
<> 144:ef7eb2e8f9f7 134 */
<> 144:ef7eb2e8f9f7 135
<> 144:ef7eb2e8f9f7 136 void start(void);
<> 144:ef7eb2e8f9f7 137
<> 144:ef7eb2e8f9f7 138 /** Creates a stop condition on the I2C bus
<> 144:ef7eb2e8f9f7 139 */
<> 144:ef7eb2e8f9f7 140 void stop(void);
<> 144:ef7eb2e8f9f7 141
<> 144:ef7eb2e8f9f7 142 /** Acquire exclusive access to this I2C bus
<> 144:ef7eb2e8f9f7 143 */
<> 144:ef7eb2e8f9f7 144 virtual void lock(void);
<> 144:ef7eb2e8f9f7 145
<> 144:ef7eb2e8f9f7 146 /** Release exclusive access to this I2C bus
<> 144:ef7eb2e8f9f7 147 */
<> 144:ef7eb2e8f9f7 148 virtual void unlock(void);
<> 144:ef7eb2e8f9f7 149
<> 144:ef7eb2e8f9f7 150 virtual ~I2C() {
<> 144:ef7eb2e8f9f7 151 // Do nothing
<> 144:ef7eb2e8f9f7 152 }
<> 144:ef7eb2e8f9f7 153
<> 144:ef7eb2e8f9f7 154 #if DEVICE_I2C_ASYNCH
<> 144:ef7eb2e8f9f7 155
<> 144:ef7eb2e8f9f7 156 /** Start non-blocking I2C transfer.
<> 144:ef7eb2e8f9f7 157 *
<> 144:ef7eb2e8f9f7 158 * @param address 8/10 bit I2c slave address
<> 144:ef7eb2e8f9f7 159 * @param tx_buffer The TX buffer with data to be transfered
<> 144:ef7eb2e8f9f7 160 * @param tx_length The length of TX buffer in bytes
<> 144:ef7eb2e8f9f7 161 * @param rx_buffer The RX buffer which is used for received data
<> 144:ef7eb2e8f9f7 162 * @param rx_length The length of RX buffer in bytes
<> 144:ef7eb2e8f9f7 163 * @param event The logical OR of events to modify
<> 144:ef7eb2e8f9f7 164 * @param callback The event callback function
<> 144:ef7eb2e8f9f7 165 * @param repeated Repeated start, true - do not send stop at end
<> 144:ef7eb2e8f9f7 166 * @return Zero if the transfer has started, or -1 if I2C peripheral is busy
<> 144:ef7eb2e8f9f7 167 */
<> 144:ef7eb2e8f9f7 168 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);
<> 144:ef7eb2e8f9f7 169
<> 144:ef7eb2e8f9f7 170 /** Abort the on-going I2C transfer
<> 144:ef7eb2e8f9f7 171 */
<> 144:ef7eb2e8f9f7 172 void abort_transfer();
<> 144:ef7eb2e8f9f7 173 protected:
<> 144:ef7eb2e8f9f7 174 void irq_handler_asynch(void);
<> 144:ef7eb2e8f9f7 175 event_callback_t _callback;
<> 144:ef7eb2e8f9f7 176 CThunk<I2C> _irq;
<> 144:ef7eb2e8f9f7 177 DMAUsage _usage;
<> 144:ef7eb2e8f9f7 178 #endif
<> 144:ef7eb2e8f9f7 179
<> 144:ef7eb2e8f9f7 180 protected:
<> 144:ef7eb2e8f9f7 181 void aquire();
<> 144:ef7eb2e8f9f7 182
<> 144:ef7eb2e8f9f7 183 i2c_t _i2c;
<> 144:ef7eb2e8f9f7 184 static I2C *_owner;
<> 144:ef7eb2e8f9f7 185 int _hz;
<> 144:ef7eb2e8f9f7 186 static SingletonPtr<PlatformMutex> _mutex;
<> 144:ef7eb2e8f9f7 187 };
<> 144:ef7eb2e8f9f7 188
<> 144:ef7eb2e8f9f7 189 } // namespace mbed
<> 144:ef7eb2e8f9f7 190
<> 144:ef7eb2e8f9f7 191 #endif
<> 144:ef7eb2e8f9f7 192
<> 144:ef7eb2e8f9f7 193 #endif