Elijah Stanger-Jones / mbed-dev-f303

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drivers/I2C.h@2:4364577b5ad8, 2020-11-09 (annotated)

Committer:
elijahsj
Date:
Mon Nov 09 00:33:19 2020 -0500
Revision:
2:4364577b5ad8
Parent:
1:8a094db1347f 
copied mbed library

Who changed what in which revision?

UserRevisionLine numberNew contents of line
elijahsj 1:8a094db1347f 1 /* mbed Microcontroller Library
elijahsj 1:8a094db1347f 2 * Copyright (c) 2006-2015 ARM Limited
elijahsj 1:8a094db1347f 3 *
elijahsj 1:8a094db1347f 4 * Licensed under the Apache License, Version 2.0 (the "License");
elijahsj 1:8a094db1347f 5 * you may not use this file except in compliance with the License.
elijahsj 1:8a094db1347f 6 * You may obtain a copy of the License at
elijahsj 1:8a094db1347f 7 *
elijahsj 1:8a094db1347f 8 * http://www.apache.org/licenses/LICENSE-2.0
elijahsj 1:8a094db1347f 9 *
elijahsj 1:8a094db1347f 10 * Unless required by applicable law or agreed to in writing, software
elijahsj 1:8a094db1347f 11 * distributed under the License is distributed on an "AS IS" BASIS,
elijahsj 1:8a094db1347f 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
elijahsj 1:8a094db1347f 13 * See the License for the specific language governing permissions and
elijahsj 1:8a094db1347f 14 * limitations under the License.
elijahsj 1:8a094db1347f 15 */
elijahsj 1:8a094db1347f 16 #ifndef MBED_I2C_H
elijahsj 1:8a094db1347f 17 #define MBED_I2C_H
elijahsj 1:8a094db1347f 18
elijahsj 1:8a094db1347f 19 #include "platform/platform.h"
elijahsj 1:8a094db1347f 20
elijahsj 1:8a094db1347f 21 #if defined (DEVICE_I2C) || defined(DOXYGEN_ONLY)
elijahsj 1:8a094db1347f 22
elijahsj 1:8a094db1347f 23 #include "hal/i2c_api.h"
elijahsj 1:8a094db1347f 24 #include "platform/SingletonPtr.h"
elijahsj 1:8a094db1347f 25 #include "platform/PlatformMutex.h"
elijahsj 1:8a094db1347f 26 #include "platform/NonCopyable.h"
elijahsj 1:8a094db1347f 27
elijahsj 1:8a094db1347f 28 #if DEVICE_I2C_ASYNCH
elijahsj 1:8a094db1347f 29 #include "platform/CThunk.h"
elijahsj 1:8a094db1347f 30 #include "hal/dma_api.h"
elijahsj 1:8a094db1347f 31 #include "platform/FunctionPointer.h"
elijahsj 1:8a094db1347f 32 #endif
elijahsj 1:8a094db1347f 33
elijahsj 1:8a094db1347f 34 namespace mbed {
elijahsj 1:8a094db1347f 35 /** \addtogroup drivers */
elijahsj 1:8a094db1347f 36
elijahsj 1:8a094db1347f 37 /** An I2C Master, used for communicating with I2C slave devices
elijahsj 1:8a094db1347f 38 *
elijahsj 1:8a094db1347f 39 * @note Synchronization level: Thread safe
elijahsj 1:8a094db1347f 40 *
elijahsj 1:8a094db1347f 41 * Example:
elijahsj 1:8a094db1347f 42 * @code
elijahsj 1:8a094db1347f 43 * // Read from I2C slave at address 0x62
elijahsj 1:8a094db1347f 44 *
elijahsj 1:8a094db1347f 45 * #include "mbed.h"
elijahsj 1:8a094db1347f 46 *
elijahsj 1:8a094db1347f 47 * I2C i2c(p28, p27);
elijahsj 1:8a094db1347f 48 *
elijahsj 1:8a094db1347f 49 * int main() {
elijahsj 1:8a094db1347f 50 * int address = 0x62;
elijahsj 1:8a094db1347f 51 * char data[2];
elijahsj 1:8a094db1347f 52 * i2c.read(address, data, 2);
elijahsj 1:8a094db1347f 53 * }
elijahsj 1:8a094db1347f 54 * @endcode
elijahsj 1:8a094db1347f 55 * @ingroup drivers
elijahsj 1:8a094db1347f 56 */
elijahsj 1:8a094db1347f 57 class I2C : private NonCopyable<I2C> {
elijahsj 1:8a094db1347f 58
elijahsj 1:8a094db1347f 59 public:
elijahsj 1:8a094db1347f 60 enum RxStatus {
elijahsj 1:8a094db1347f 61 NoData,
elijahsj 1:8a094db1347f 62 MasterGeneralCall,
elijahsj 1:8a094db1347f 63 MasterWrite,
elijahsj 1:8a094db1347f 64 MasterRead
elijahsj 1:8a094db1347f 65 };
elijahsj 1:8a094db1347f 66
elijahsj 1:8a094db1347f 67 enum Acknowledge {
elijahsj 1:8a094db1347f 68 NoACK = 0,
elijahsj 1:8a094db1347f 69 ACK = 1
elijahsj 1:8a094db1347f 70 };
elijahsj 1:8a094db1347f 71
elijahsj 1:8a094db1347f 72 /** Create an I2C Master interface, connected to the specified pins
elijahsj 1:8a094db1347f 73 *
elijahsj 1:8a094db1347f 74 * @param sda I2C data line pin
elijahsj 1:8a094db1347f 75 * @param scl I2C clock line pin
elijahsj 1:8a094db1347f 76 */
elijahsj 1:8a094db1347f 77 I2C(PinName sda, PinName scl);
elijahsj 1:8a094db1347f 78
elijahsj 1:8a094db1347f 79 /** Set the frequency of the I2C interface
elijahsj 1:8a094db1347f 80 *
elijahsj 1:8a094db1347f 81 * @param hz The bus frequency in hertz
elijahsj 1:8a094db1347f 82 */
elijahsj 1:8a094db1347f 83 void frequency(int hz);
elijahsj 1:8a094db1347f 84
elijahsj 1:8a094db1347f 85 /** Read from an I2C slave
elijahsj 1:8a094db1347f 86 *
elijahsj 1:8a094db1347f 87 * Performs a complete read transaction. The bottom bit of
elijahsj 1:8a094db1347f 88 * the address is forced to 1 to indicate a read.
elijahsj 1:8a094db1347f 89 *
elijahsj 1:8a094db1347f 90 * @param address 8-bit I2C slave address [ addr | 1 ]
elijahsj 1:8a094db1347f 91 * @param data Pointer to the byte-array to read data in to
elijahsj 1:8a094db1347f 92 * @param length Number of bytes to read
elijahsj 1:8a094db1347f 93 * @param repeated Repeated start, true - don't send stop at end
elijahsj 1:8a094db1347f 94 *
elijahsj 1:8a094db1347f 95 * @returns
elijahsj 1:8a094db1347f 96 * 0 on success (ack),
elijahsj 1:8a094db1347f 97 * non-0 on failure (nack)
elijahsj 1:8a094db1347f 98 */
elijahsj 1:8a094db1347f 99 int read(int address, char *data, int length, bool repeated = false);
elijahsj 1:8a094db1347f 100
elijahsj 1:8a094db1347f 101 /** Read a single byte from the I2C bus
elijahsj 1:8a094db1347f 102 *
elijahsj 1:8a094db1347f 103 * @param ack indicates if the byte is to be acknowledged (1 = acknowledge)
elijahsj 1:8a094db1347f 104 *
elijahsj 1:8a094db1347f 105 * @returns
elijahsj 1:8a094db1347f 106 * the byte read
elijahsj 1:8a094db1347f 107 */
elijahsj 1:8a094db1347f 108 int read(int ack);
elijahsj 1:8a094db1347f 109
elijahsj 1:8a094db1347f 110 /** Write to an I2C slave
elijahsj 1:8a094db1347f 111 *
elijahsj 1:8a094db1347f 112 * Performs a complete write transaction. The bottom bit of
elijahsj 1:8a094db1347f 113 * the address is forced to 0 to indicate a write.
elijahsj 1:8a094db1347f 114 *
elijahsj 1:8a094db1347f 115 * @param address 8-bit I2C slave address [ addr | 0 ]
elijahsj 1:8a094db1347f 116 * @param data Pointer to the byte-array data to send
elijahsj 1:8a094db1347f 117 * @param length Number of bytes to send
elijahsj 1:8a094db1347f 118 * @param repeated Repeated start, true - do not send stop at end
elijahsj 1:8a094db1347f 119 *
elijahsj 1:8a094db1347f 120 * @returns
elijahsj 1:8a094db1347f 121 * 0 on success (ack),
elijahsj 1:8a094db1347f 122 * non-0 on failure (nack)
elijahsj 1:8a094db1347f 123 */
elijahsj 1:8a094db1347f 124 int write(int address, const char *data, int length, bool repeated = false);
elijahsj 1:8a094db1347f 125
elijahsj 1:8a094db1347f 126 /** Write single byte out on the I2C bus
elijahsj 1:8a094db1347f 127 *
elijahsj 1:8a094db1347f 128 * @param data data to write out on bus
elijahsj 1:8a094db1347f 129 *
elijahsj 1:8a094db1347f 130 * @returns
elijahsj 1:8a094db1347f 131 * '0' - NAK was received
elijahsj 1:8a094db1347f 132 * '1' - ACK was received,
elijahsj 1:8a094db1347f 133 * '2' - timeout
elijahsj 1:8a094db1347f 134 */
elijahsj 1:8a094db1347f 135 int write(int data);
elijahsj 1:8a094db1347f 136
elijahsj 1:8a094db1347f 137 /** Creates a start condition on the I2C bus
elijahsj 1:8a094db1347f 138 */
elijahsj 1:8a094db1347f 139
elijahsj 1:8a094db1347f 140 void start(void);
elijahsj 1:8a094db1347f 141
elijahsj 1:8a094db1347f 142 /** Creates a stop condition on the I2C bus
elijahsj 1:8a094db1347f 143 */
elijahsj 1:8a094db1347f 144 void stop(void);
elijahsj 1:8a094db1347f 145
elijahsj 1:8a094db1347f 146 /** Acquire exclusive access to this I2C bus
elijahsj 1:8a094db1347f 147 */
elijahsj 1:8a094db1347f 148 virtual void lock(void);
elijahsj 1:8a094db1347f 149
elijahsj 1:8a094db1347f 150 /** Release exclusive access to this I2C bus
elijahsj 1:8a094db1347f 151 */
elijahsj 1:8a094db1347f 152 virtual void unlock(void);
elijahsj 1:8a094db1347f 153
elijahsj 1:8a094db1347f 154 virtual ~I2C() {
elijahsj 1:8a094db1347f 155 // Do nothing
elijahsj 1:8a094db1347f 156 }
elijahsj 1:8a094db1347f 157
elijahsj 1:8a094db1347f 158 #if DEVICE_I2C_ASYNCH
elijahsj 1:8a094db1347f 159
elijahsj 1:8a094db1347f 160 /** Start non-blocking I2C transfer.
elijahsj 1:8a094db1347f 161 *
elijahsj 1:8a094db1347f 162 * This function locks the deep sleep until any event has occured
elijahsj 1:8a094db1347f 163 *
elijahsj 1:8a094db1347f 164 * @param address 8/10 bit I2c slave address
elijahsj 1:8a094db1347f 165 * @param tx_buffer The TX buffer with data to be transfered
elijahsj 1:8a094db1347f 166 * @param tx_length The length of TX buffer in bytes
elijahsj 1:8a094db1347f 167 * @param rx_buffer The RX buffer which is used for received data
elijahsj 1:8a094db1347f 168 * @param rx_length The length of RX buffer in bytes
elijahsj 1:8a094db1347f 169 * @param event The logical OR of events to modify
elijahsj 1:8a094db1347f 170 * @param callback The event callback function
elijahsj 1:8a094db1347f 171 * @param repeated Repeated start, true - do not send stop at end
elijahsj 1:8a094db1347f 172 * @return Zero if the transfer has started, or -1 if I2C peripheral is busy
elijahsj 1:8a094db1347f 173 */
elijahsj 1:8a094db1347f 174 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);
elijahsj 1:8a094db1347f 175
elijahsj 1:8a094db1347f 176 /** Abort the on-going I2C transfer
elijahsj 1:8a094db1347f 177 */
elijahsj 1:8a094db1347f 178 void abort_transfer();
elijahsj 1:8a094db1347f 179 protected:
elijahsj 1:8a094db1347f 180 void irq_handler_asynch(void);
elijahsj 1:8a094db1347f 181 event_callback_t _callback;
elijahsj 1:8a094db1347f 182 CThunk<I2C> _irq;
elijahsj 1:8a094db1347f 183 DMAUsage _usage;
elijahsj 1:8a094db1347f 184 #endif
elijahsj 1:8a094db1347f 185
elijahsj 1:8a094db1347f 186 protected:
elijahsj 1:8a094db1347f 187 void aquire();
elijahsj 1:8a094db1347f 188
elijahsj 1:8a094db1347f 189 i2c_t _i2c;
elijahsj 1:8a094db1347f 190 static I2C *_owner;
elijahsj 1:8a094db1347f 191 int _hz;
elijahsj 1:8a094db1347f 192 static SingletonPtr<PlatformMutex> _mutex;
elijahsj 1:8a094db1347f 193 };
elijahsj 1:8a094db1347f 194
elijahsj 1:8a094db1347f 195 } // namespace mbed
elijahsj 1:8a094db1347f 196
elijahsj 1:8a094db1347f 197 #endif
elijahsj 1:8a094db1347f 198
elijahsj 1:8a094db1347f 199 #endif