joey shelton / LED_Demo2

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Dependencies:   MAX44000 PWM_Tone_Library nexpaq_mdk

Fork of LED_Demo by joey shelton

mbd_os/hal/api/I2C.h@1:55a6170b404f, 2016-09-17 (annotated)

Committer:
nexpaq
Date:
Sat Sep 17 16:32:05 2016 +0000
Revision:
1:55a6170b404f
checking in for sharing

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nexpaq 1:55a6170b404f 1 /* mbed Microcontroller Library
nexpaq 1:55a6170b404f 2 * Copyright (c) 2006-2015 ARM Limited
nexpaq 1:55a6170b404f 3 *
nexpaq 1:55a6170b404f 4 * Licensed under the Apache License, Version 2.0 (the "License");
nexpaq 1:55a6170b404f 5 * you may not use this file except in compliance with the License.
nexpaq 1:55a6170b404f 6 * You may obtain a copy of the License at
nexpaq 1:55a6170b404f 7 *
nexpaq 1:55a6170b404f 8 * http://www.apache.org/licenses/LICENSE-2.0
nexpaq 1:55a6170b404f 9 *
nexpaq 1:55a6170b404f 10 * Unless required by applicable law or agreed to in writing, software
nexpaq 1:55a6170b404f 11 * distributed under the License is distributed on an "AS IS" BASIS,
nexpaq 1:55a6170b404f 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
nexpaq 1:55a6170b404f 13 * See the License for the specific language governing permissions and
nexpaq 1:55a6170b404f 14 * limitations under the License.
nexpaq 1:55a6170b404f 15 */
nexpaq 1:55a6170b404f 16 #ifndef MBED_I2C_H
nexpaq 1:55a6170b404f 17 #define MBED_I2C_H
nexpaq 1:55a6170b404f 18
nexpaq 1:55a6170b404f 19 #include "platform.h"
nexpaq 1:55a6170b404f 20
nexpaq 1:55a6170b404f 21 #if DEVICE_I2C
nexpaq 1:55a6170b404f 22
nexpaq 1:55a6170b404f 23 #include "i2c_api.h"
nexpaq 1:55a6170b404f 24 #include "SingletonPtr.h"
nexpaq 1:55a6170b404f 25 #include "PlatformMutex.h"
nexpaq 1:55a6170b404f 26
nexpaq 1:55a6170b404f 27 #if DEVICE_I2C_ASYNCH
nexpaq 1:55a6170b404f 28 #include "CThunk.h"
nexpaq 1:55a6170b404f 29 #include "dma_api.h"
nexpaq 1:55a6170b404f 30 #include "FunctionPointer.h"
nexpaq 1:55a6170b404f 31 #endif
nexpaq 1:55a6170b404f 32
nexpaq 1:55a6170b404f 33 namespace mbed {
nexpaq 1:55a6170b404f 34
nexpaq 1:55a6170b404f 35 /** An I2C Master, used for communicating with I2C slave devices
nexpaq 1:55a6170b404f 36 *
nexpaq 1:55a6170b404f 37 * @Note Synchronization level: Thread safe
nexpaq 1:55a6170b404f 38 *
nexpaq 1:55a6170b404f 39 * Example:
nexpaq 1:55a6170b404f 40 * @code
nexpaq 1:55a6170b404f 41 * // Read from I2C slave at address 0x62
nexpaq 1:55a6170b404f 42 *
nexpaq 1:55a6170b404f 43 * #include "mbed.h"
nexpaq 1:55a6170b404f 44 *
nexpaq 1:55a6170b404f 45 * I2C i2c(p28, p27);
nexpaq 1:55a6170b404f 46 *
nexpaq 1:55a6170b404f 47 * int main() {
nexpaq 1:55a6170b404f 48 * int address = 0x62;
nexpaq 1:55a6170b404f 49 * char data[2];
nexpaq 1:55a6170b404f 50 * i2c.read(address, data, 2);
nexpaq 1:55a6170b404f 51 * }
nexpaq 1:55a6170b404f 52 * @endcode
nexpaq 1:55a6170b404f 53 */
nexpaq 1:55a6170b404f 54 class I2C {
nexpaq 1:55a6170b404f 55
nexpaq 1:55a6170b404f 56 public:
nexpaq 1:55a6170b404f 57 enum RxStatus {
nexpaq 1:55a6170b404f 58 NoData,
nexpaq 1:55a6170b404f 59 MasterGeneralCall,
nexpaq 1:55a6170b404f 60 MasterWrite,
nexpaq 1:55a6170b404f 61 MasterRead
nexpaq 1:55a6170b404f 62 };
nexpaq 1:55a6170b404f 63
nexpaq 1:55a6170b404f 64 enum Acknowledge {
nexpaq 1:55a6170b404f 65 NoACK = 0,
nexpaq 1:55a6170b404f 66 ACK = 1
nexpaq 1:55a6170b404f 67 };
nexpaq 1:55a6170b404f 68
nexpaq 1:55a6170b404f 69 /** Create an I2C Master interface, connected to the specified pins
nexpaq 1:55a6170b404f 70 *
nexpaq 1:55a6170b404f 71 * @param sda I2C data line pin
nexpaq 1:55a6170b404f 72 * @param scl I2C clock line pin
nexpaq 1:55a6170b404f 73 */
nexpaq 1:55a6170b404f 74 I2C(PinName sda, PinName scl);
nexpaq 1:55a6170b404f 75
nexpaq 1:55a6170b404f 76 /** Set the frequency of the I2C interface
nexpaq 1:55a6170b404f 77 *
nexpaq 1:55a6170b404f 78 * @param hz The bus frequency in hertz
nexpaq 1:55a6170b404f 79 */
nexpaq 1:55a6170b404f 80 void frequency(int hz);
nexpaq 1:55a6170b404f 81
nexpaq 1:55a6170b404f 82 /** Read from an I2C slave
nexpaq 1:55a6170b404f 83 *
nexpaq 1:55a6170b404f 84 * Performs a complete read transaction. The bottom bit of
nexpaq 1:55a6170b404f 85 * the address is forced to 1 to indicate a read.
nexpaq 1:55a6170b404f 86 *
nexpaq 1:55a6170b404f 87 * @param address 8-bit I2C slave address [ addr | 1 ]
nexpaq 1:55a6170b404f 88 * @param data Pointer to the byte-array to read data in to
nexpaq 1:55a6170b404f 89 * @param length Number of bytes to read
nexpaq 1:55a6170b404f 90 * @param repeated Repeated start, true - don't send stop at end
nexpaq 1:55a6170b404f 91 *
nexpaq 1:55a6170b404f 92 * @returns
nexpaq 1:55a6170b404f 93 * 0 on success (ack),
nexpaq 1:55a6170b404f 94 * non-0 on failure (nack)
nexpaq 1:55a6170b404f 95 */
nexpaq 1:55a6170b404f 96 int read(int address, char *data, int length, bool repeated = false);
nexpaq 1:55a6170b404f 97
nexpaq 1:55a6170b404f 98 /** Read a single byte from the I2C bus
nexpaq 1:55a6170b404f 99 *
nexpaq 1:55a6170b404f 100 * @param ack indicates if the byte is to be acknowledged (1 = acknowledge)
nexpaq 1:55a6170b404f 101 *
nexpaq 1:55a6170b404f 102 * @returns
nexpaq 1:55a6170b404f 103 * the byte read
nexpaq 1:55a6170b404f 104 */
nexpaq 1:55a6170b404f 105 int read(int ack);
nexpaq 1:55a6170b404f 106
nexpaq 1:55a6170b404f 107 /** Write to an I2C slave
nexpaq 1:55a6170b404f 108 *
nexpaq 1:55a6170b404f 109 * Performs a complete write transaction. The bottom bit of
nexpaq 1:55a6170b404f 110 * the address is forced to 0 to indicate a write.
nexpaq 1:55a6170b404f 111 *
nexpaq 1:55a6170b404f 112 * @param address 8-bit I2C slave address [ addr | 0 ]
nexpaq 1:55a6170b404f 113 * @param data Pointer to the byte-array data to send
nexpaq 1:55a6170b404f 114 * @param length Number of bytes to send
nexpaq 1:55a6170b404f 115 * @param repeated Repeated start, true - do not send stop at end
nexpaq 1:55a6170b404f 116 *
nexpaq 1:55a6170b404f 117 * @returns
nexpaq 1:55a6170b404f 118 * 0 on success (ack),
nexpaq 1:55a6170b404f 119 * non-0 on failure (nack)
nexpaq 1:55a6170b404f 120 */
nexpaq 1:55a6170b404f 121 int write(int address, const char *data, int length, bool repeated = false);
nexpaq 1:55a6170b404f 122
nexpaq 1:55a6170b404f 123 /** Write single byte out on the I2C bus
nexpaq 1:55a6170b404f 124 *
nexpaq 1:55a6170b404f 125 * @param data data to write out on bus
nexpaq 1:55a6170b404f 126 *
nexpaq 1:55a6170b404f 127 * @returns
nexpaq 1:55a6170b404f 128 * '1' if an ACK was received,
nexpaq 1:55a6170b404f 129 * '0' otherwise
nexpaq 1:55a6170b404f 130 */
nexpaq 1:55a6170b404f 131 int write(int data);
nexpaq 1:55a6170b404f 132
nexpaq 1:55a6170b404f 133 /** Creates a start condition on the I2C bus
nexpaq 1:55a6170b404f 134 */
nexpaq 1:55a6170b404f 135
nexpaq 1:55a6170b404f 136 void start(void);
nexpaq 1:55a6170b404f 137
nexpaq 1:55a6170b404f 138 /** Creates a stop condition on the I2C bus
nexpaq 1:55a6170b404f 139 */
nexpaq 1:55a6170b404f 140 void stop(void);
nexpaq 1:55a6170b404f 141
nexpaq 1:55a6170b404f 142 /** Acquire exclusive access to this I2C bus
nexpaq 1:55a6170b404f 143 */
nexpaq 1:55a6170b404f 144 virtual void lock(void);
nexpaq 1:55a6170b404f 145
nexpaq 1:55a6170b404f 146 /** Release exclusive access to this I2C bus
nexpaq 1:55a6170b404f 147 */
nexpaq 1:55a6170b404f 148 virtual void unlock(void);
nexpaq 1:55a6170b404f 149
nexpaq 1:55a6170b404f 150 virtual ~I2C() {
nexpaq 1:55a6170b404f 151 // Do nothing
nexpaq 1:55a6170b404f 152 }
nexpaq 1:55a6170b404f 153
nexpaq 1:55a6170b404f 154 #if DEVICE_I2C_ASYNCH
nexpaq 1:55a6170b404f 155
nexpaq 1:55a6170b404f 156 /** Start non-blocking I2C transfer.
nexpaq 1:55a6170b404f 157 *
nexpaq 1:55a6170b404f 158 * @param address 8/10 bit I2c slave address
nexpaq 1:55a6170b404f 159 * @param tx_buffer The TX buffer with data to be transfered
nexpaq 1:55a6170b404f 160 * @param tx_length The length of TX buffer in bytes
nexpaq 1:55a6170b404f 161 * @param rx_buffer The RX buffer which is used for received data
nexpaq 1:55a6170b404f 162 * @param rx_length The length of RX buffer in bytes
nexpaq 1:55a6170b404f 163 * @param event The logical OR of events to modify
nexpaq 1:55a6170b404f 164 * @param callback The event callback function
nexpaq 1:55a6170b404f 165 * @param repeated Repeated start, true - do not send stop at end
nexpaq 1:55a6170b404f 166 * @return Zero if the transfer has started, or -1 if I2C peripheral is busy
nexpaq 1:55a6170b404f 167 */
nexpaq 1:55a6170b404f 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);
nexpaq 1:55a6170b404f 169
nexpaq 1:55a6170b404f 170 /** Abort the on-going I2C transfer
nexpaq 1:55a6170b404f 171 */
nexpaq 1:55a6170b404f 172 void abort_transfer();
nexpaq 1:55a6170b404f 173 protected:
nexpaq 1:55a6170b404f 174 void irq_handler_asynch(void);
nexpaq 1:55a6170b404f 175 event_callback_t _callback;
nexpaq 1:55a6170b404f 176 CThunk<I2C> _irq;
nexpaq 1:55a6170b404f 177 DMAUsage _usage;
nexpaq 1:55a6170b404f 178 #endif
nexpaq 1:55a6170b404f 179
nexpaq 1:55a6170b404f 180 protected:
nexpaq 1:55a6170b404f 181 void aquire();
nexpaq 1:55a6170b404f 182
nexpaq 1:55a6170b404f 183 i2c_t _i2c;
nexpaq 1:55a6170b404f 184 static I2C *_owner;
nexpaq 1:55a6170b404f 185 int _hz;
nexpaq 1:55a6170b404f 186 static SingletonPtr<PlatformMutex> _mutex;
nexpaq 1:55a6170b404f 187 };
nexpaq 1:55a6170b404f 188
nexpaq 1:55a6170b404f 189 } // namespace mbed
nexpaq 1:55a6170b404f 190
nexpaq 1:55a6170b404f 191 #endif
nexpaq 1:55a6170b404f 192
nexpaq 1:55a6170b404f 193 #endif