Gan likun / mbed1-dev

001

drivers/I2C.h@0:13413ea9a877, 2022-06-12 (annotated)

Committer:
ganlikun
Date:
Sun Jun 12 14:02:44 2022 +0000
Revision:
0:13413ea9a877
00

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ganlikun 0:13413ea9a877 1 /* mbed Microcontroller Library
ganlikun 0:13413ea9a877 2 * Copyright (c) 2006-2015 ARM Limited
ganlikun 0:13413ea9a877 3 *
ganlikun 0:13413ea9a877 4 * Licensed under the Apache License, Version 2.0 (the "License");
ganlikun 0:13413ea9a877 5 * you may not use this file except in compliance with the License.
ganlikun 0:13413ea9a877 6 * You may obtain a copy of the License at
ganlikun 0:13413ea9a877 7 *
ganlikun 0:13413ea9a877 8 * http://www.apache.org/licenses/LICENSE-2.0
ganlikun 0:13413ea9a877 9 *
ganlikun 0:13413ea9a877 10 * Unless required by applicable law or agreed to in writing, software
ganlikun 0:13413ea9a877 11 * distributed under the License is distributed on an "AS IS" BASIS,
ganlikun 0:13413ea9a877 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
ganlikun 0:13413ea9a877 13 * See the License for the specific language governing permissions and
ganlikun 0:13413ea9a877 14 * limitations under the License.
ganlikun 0:13413ea9a877 15 */
ganlikun 0:13413ea9a877 16 #ifndef MBED_I2C_H
ganlikun 0:13413ea9a877 17 #define MBED_I2C_H
ganlikun 0:13413ea9a877 18
ganlikun 0:13413ea9a877 19 #include "platform/platform.h"
ganlikun 0:13413ea9a877 20
ganlikun 0:13413ea9a877 21 #if defined (DEVICE_I2C) || defined(DOXYGEN_ONLY)
ganlikun 0:13413ea9a877 22
ganlikun 0:13413ea9a877 23 #include "hal/i2c_api.h"
ganlikun 0:13413ea9a877 24 #include "platform/SingletonPtr.h"
ganlikun 0:13413ea9a877 25 #include "platform/PlatformMutex.h"
ganlikun 0:13413ea9a877 26 #include "platform/NonCopyable.h"
ganlikun 0:13413ea9a877 27
ganlikun 0:13413ea9a877 28 #if DEVICE_I2C_ASYNCH
ganlikun 0:13413ea9a877 29 #include "platform/CThunk.h"
ganlikun 0:13413ea9a877 30 #include "hal/dma_api.h"
ganlikun 0:13413ea9a877 31 #include "platform/FunctionPointer.h"
ganlikun 0:13413ea9a877 32 #endif
ganlikun 0:13413ea9a877 33
ganlikun 0:13413ea9a877 34 namespace mbed {
ganlikun 0:13413ea9a877 35 /** \addtogroup drivers */
ganlikun 0:13413ea9a877 36
ganlikun 0:13413ea9a877 37 /** An I2C Master, used for communicating with I2C slave devices
ganlikun 0:13413ea9a877 38 *
ganlikun 0:13413ea9a877 39 * @note Synchronization level: Thread safe
ganlikun 0:13413ea9a877 40 *
ganlikun 0:13413ea9a877 41 * Example:
ganlikun 0:13413ea9a877 42 * @code
ganlikun 0:13413ea9a877 43 * // Read from I2C slave at address 0x62
ganlikun 0:13413ea9a877 44 *
ganlikun 0:13413ea9a877 45 * #include "mbed.h"
ganlikun 0:13413ea9a877 46 *
ganlikun 0:13413ea9a877 47 * I2C i2c(p28, p27);
ganlikun 0:13413ea9a877 48 *
ganlikun 0:13413ea9a877 49 * int main() {
ganlikun 0:13413ea9a877 50 * int address = 0x62;
ganlikun 0:13413ea9a877 51 * char data[2];
ganlikun 0:13413ea9a877 52 * i2c.read(address, data, 2);
ganlikun 0:13413ea9a877 53 * }
ganlikun 0:13413ea9a877 54 * @endcode
ganlikun 0:13413ea9a877 55 * @ingroup drivers
ganlikun 0:13413ea9a877 56 */
ganlikun 0:13413ea9a877 57 class I2C : private NonCopyable<I2C> {
ganlikun 0:13413ea9a877 58
ganlikun 0:13413ea9a877 59 public:
ganlikun 0:13413ea9a877 60 enum RxStatus {
ganlikun 0:13413ea9a877 61 NoData,
ganlikun 0:13413ea9a877 62 MasterGeneralCall,
ganlikun 0:13413ea9a877 63 MasterWrite,
ganlikun 0:13413ea9a877 64 MasterRead
ganlikun 0:13413ea9a877 65 };
ganlikun 0:13413ea9a877 66
ganlikun 0:13413ea9a877 67 enum Acknowledge {
ganlikun 0:13413ea9a877 68 NoACK = 0,
ganlikun 0:13413ea9a877 69 ACK = 1
ganlikun 0:13413ea9a877 70 };
ganlikun 0:13413ea9a877 71
ganlikun 0:13413ea9a877 72 /** Create an I2C Master interface, connected to the specified pins
ganlikun 0:13413ea9a877 73 *
ganlikun 0:13413ea9a877 74 * @param sda I2C data line pin
ganlikun 0:13413ea9a877 75 * @param scl I2C clock line pin
ganlikun 0:13413ea9a877 76 */
ganlikun 0:13413ea9a877 77 I2C(PinName sda, PinName scl);
ganlikun 0:13413ea9a877 78
ganlikun 0:13413ea9a877 79 /** Set the frequency of the I2C interface
ganlikun 0:13413ea9a877 80 *
ganlikun 0:13413ea9a877 81 * @param hz The bus frequency in hertz
ganlikun 0:13413ea9a877 82 */
ganlikun 0:13413ea9a877 83 void frequency(int hz);
ganlikun 0:13413ea9a877 84
ganlikun 0:13413ea9a877 85 /** Read from an I2C slave
ganlikun 0:13413ea9a877 86 *
ganlikun 0:13413ea9a877 87 * Performs a complete read transaction. The bottom bit of
ganlikun 0:13413ea9a877 88 * the address is forced to 1 to indicate a read.
ganlikun 0:13413ea9a877 89 *
ganlikun 0:13413ea9a877 90 * @param address 8-bit I2C slave address [ addr | 1 ]
ganlikun 0:13413ea9a877 91 * @param data Pointer to the byte-array to read data in to
ganlikun 0:13413ea9a877 92 * @param length Number of bytes to read
ganlikun 0:13413ea9a877 93 * @param repeated Repeated start, true - don't send stop at end
ganlikun 0:13413ea9a877 94 *
ganlikun 0:13413ea9a877 95 * @returns
ganlikun 0:13413ea9a877 96 * 0 on success (ack),
ganlikun 0:13413ea9a877 97 * non-0 on failure (nack)
ganlikun 0:13413ea9a877 98 */
ganlikun 0:13413ea9a877 99 int read(int address, char *data, int length, bool repeated = false);
ganlikun 0:13413ea9a877 100
ganlikun 0:13413ea9a877 101 /** Read a single byte from the I2C bus
ganlikun 0:13413ea9a877 102 *
ganlikun 0:13413ea9a877 103 * @param ack indicates if the byte is to be acknowledged (1 = acknowledge)
ganlikun 0:13413ea9a877 104 *
ganlikun 0:13413ea9a877 105 * @returns
ganlikun 0:13413ea9a877 106 * the byte read
ganlikun 0:13413ea9a877 107 */
ganlikun 0:13413ea9a877 108 int read(int ack);
ganlikun 0:13413ea9a877 109
ganlikun 0:13413ea9a877 110 /** Write to an I2C slave
ganlikun 0:13413ea9a877 111 *
ganlikun 0:13413ea9a877 112 * Performs a complete write transaction. The bottom bit of
ganlikun 0:13413ea9a877 113 * the address is forced to 0 to indicate a write.
ganlikun 0:13413ea9a877 114 *
ganlikun 0:13413ea9a877 115 * @param address 8-bit I2C slave address [ addr | 0 ]
ganlikun 0:13413ea9a877 116 * @param data Pointer to the byte-array data to send
ganlikun 0:13413ea9a877 117 * @param length Number of bytes to send
ganlikun 0:13413ea9a877 118 * @param repeated Repeated start, true - do not send stop at end
ganlikun 0:13413ea9a877 119 *
ganlikun 0:13413ea9a877 120 * @returns
ganlikun 0:13413ea9a877 121 * 0 on success (ack),
ganlikun 0:13413ea9a877 122 * non-0 on failure (nack)
ganlikun 0:13413ea9a877 123 */
ganlikun 0:13413ea9a877 124 int write(int address, const char *data, int length, bool repeated = false);
ganlikun 0:13413ea9a877 125
ganlikun 0:13413ea9a877 126 /** Write single byte out on the I2C bus
ganlikun 0:13413ea9a877 127 *
ganlikun 0:13413ea9a877 128 * @param data data to write out on bus
ganlikun 0:13413ea9a877 129 *
ganlikun 0:13413ea9a877 130 * @returns
ganlikun 0:13413ea9a877 131 * '0' - NAK was received
ganlikun 0:13413ea9a877 132 * '1' - ACK was received,
ganlikun 0:13413ea9a877 133 * '2' - timeout
ganlikun 0:13413ea9a877 134 */
ganlikun 0:13413ea9a877 135 int write(int data);
ganlikun 0:13413ea9a877 136
ganlikun 0:13413ea9a877 137 /** Creates a start condition on the I2C bus
ganlikun 0:13413ea9a877 138 */
ganlikun 0:13413ea9a877 139
ganlikun 0:13413ea9a877 140 void start(void);
ganlikun 0:13413ea9a877 141
ganlikun 0:13413ea9a877 142 /** Creates a stop condition on the I2C bus
ganlikun 0:13413ea9a877 143 */
ganlikun 0:13413ea9a877 144 void stop(void);
ganlikun 0:13413ea9a877 145
ganlikun 0:13413ea9a877 146 /** Acquire exclusive access to this I2C bus
ganlikun 0:13413ea9a877 147 */
ganlikun 0:13413ea9a877 148 virtual void lock(void);
ganlikun 0:13413ea9a877 149
ganlikun 0:13413ea9a877 150 /** Release exclusive access to this I2C bus
ganlikun 0:13413ea9a877 151 */
ganlikun 0:13413ea9a877 152 virtual void unlock(void);
ganlikun 0:13413ea9a877 153
ganlikun 0:13413ea9a877 154 virtual ~I2C() {
ganlikun 0:13413ea9a877 155 // Do nothing
ganlikun 0:13413ea9a877 156 }
ganlikun 0:13413ea9a877 157
ganlikun 0:13413ea9a877 158 #if DEVICE_I2C_ASYNCH
ganlikun 0:13413ea9a877 159
ganlikun 0:13413ea9a877 160 /** Start non-blocking I2C transfer.
ganlikun 0:13413ea9a877 161 *
ganlikun 0:13413ea9a877 162 * This function locks the deep sleep until any event has occured
ganlikun 0:13413ea9a877 163 *
ganlikun 0:13413ea9a877 164 * @param address 8/10 bit I2c slave address
ganlikun 0:13413ea9a877 165 * @param tx_buffer The TX buffer with data to be transfered
ganlikun 0:13413ea9a877 166 * @param tx_length The length of TX buffer in bytes
ganlikun 0:13413ea9a877 167 * @param rx_buffer The RX buffer which is used for received data
ganlikun 0:13413ea9a877 168 * @param rx_length The length of RX buffer in bytes
ganlikun 0:13413ea9a877 169 * @param event The logical OR of events to modify
ganlikun 0:13413ea9a877 170 * @param callback The event callback function
ganlikun 0:13413ea9a877 171 * @param repeated Repeated start, true - do not send stop at end
ganlikun 0:13413ea9a877 172 * @return Zero if the transfer has started, or -1 if I2C peripheral is busy
ganlikun 0:13413ea9a877 173 */
ganlikun 0:13413ea9a877 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);
ganlikun 0:13413ea9a877 175
ganlikun 0:13413ea9a877 176 /** Abort the on-going I2C transfer
ganlikun 0:13413ea9a877 177 */
ganlikun 0:13413ea9a877 178 void abort_transfer();
ganlikun 0:13413ea9a877 179 protected:
ganlikun 0:13413ea9a877 180 void irq_handler_asynch(void);
ganlikun 0:13413ea9a877 181 event_callback_t _callback;
ganlikun 0:13413ea9a877 182 CThunk<I2C> _irq;
ganlikun 0:13413ea9a877 183 DMAUsage _usage;
ganlikun 0:13413ea9a877 184 #endif
ganlikun 0:13413ea9a877 185
ganlikun 0:13413ea9a877 186 protected:
ganlikun 0:13413ea9a877 187 void aquire();
ganlikun 0:13413ea9a877 188
ganlikun 0:13413ea9a877 189 i2c_t _i2c;
ganlikun 0:13413ea9a877 190 static I2C *_owner;
ganlikun 0:13413ea9a877 191 int _hz;
ganlikun 0:13413ea9a877 192 static SingletonPtr<PlatformMutex> _mutex;
ganlikun 0:13413ea9a877 193 };
ganlikun 0:13413ea9a877 194
ganlikun 0:13413ea9a877 195 } // namespace mbed
ganlikun 0:13413ea9a877 196
ganlikun 0:13413ea9a877 197 #endif
ganlikun 0:13413ea9a877 198
ganlikun 0:13413ea9a877 199 #endif
ganlikun 0:13413ea9a877 200