mbed official / mbed-dev

mbed library sources. Supersedes mbed-src.

Dependents:   Nucleo_Hello_Encoder BLE_iBeaconScan AM1805_DEMO DISCO-F429ZI_ExportTemplate1 ... more

cmsis/BUILD/mbed/drivers/I2C.h@189:f392fc9709a3, 2019-02-20 (annotated)

Committer:
AnnaBridge
Date:
Wed Feb 20 22:31:08 2019 +0000
Revision:
189:f392fc9709a3
mbed library release version 165

Who changed what in which revision?

UserRevisionLine numberNew contents of line
AnnaBridge 189:f392fc9709a3 1 /* mbed Microcontroller Library
AnnaBridge 189:f392fc9709a3 2 * Copyright (c) 2006-2015 ARM Limited
AnnaBridge 189:f392fc9709a3 3 * SPDX-License-Identifier: Apache-2.0
AnnaBridge 189:f392fc9709a3 4 *
AnnaBridge 189:f392fc9709a3 5 * Licensed under the Apache License, Version 2.0 (the "License");
AnnaBridge 189:f392fc9709a3 6 * you may not use this file except in compliance with the License.
AnnaBridge 189:f392fc9709a3 7 * You may obtain a copy of the License at
AnnaBridge 189:f392fc9709a3 8 *
AnnaBridge 189:f392fc9709a3 9 * http://www.apache.org/licenses/LICENSE-2.0
AnnaBridge 189:f392fc9709a3 10 *
AnnaBridge 189:f392fc9709a3 11 * Unless required by applicable law or agreed to in writing, software
AnnaBridge 189:f392fc9709a3 12 * distributed under the License is distributed on an "AS IS" BASIS,
AnnaBridge 189:f392fc9709a3 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
AnnaBridge 189:f392fc9709a3 14 * See the License for the specific language governing permissions and
AnnaBridge 189:f392fc9709a3 15 * limitations under the License.
AnnaBridge 189:f392fc9709a3 16 */
AnnaBridge 189:f392fc9709a3 17 #ifndef MBED_I2C_H
AnnaBridge 189:f392fc9709a3 18 #define MBED_I2C_H
AnnaBridge 189:f392fc9709a3 19
AnnaBridge 189:f392fc9709a3 20 #include "platform/platform.h"
AnnaBridge 189:f392fc9709a3 21 #include "hal/gpio_api.h"
AnnaBridge 189:f392fc9709a3 22
AnnaBridge 189:f392fc9709a3 23 #if DEVICE_I2C || defined(DOXYGEN_ONLY)
AnnaBridge 189:f392fc9709a3 24
AnnaBridge 189:f392fc9709a3 25 #include "hal/i2c_api.h"
AnnaBridge 189:f392fc9709a3 26 #include "platform/SingletonPtr.h"
AnnaBridge 189:f392fc9709a3 27 #include "platform/PlatformMutex.h"
AnnaBridge 189:f392fc9709a3 28 #include "platform/NonCopyable.h"
AnnaBridge 189:f392fc9709a3 29
AnnaBridge 189:f392fc9709a3 30 #if DEVICE_I2C_ASYNCH
AnnaBridge 189:f392fc9709a3 31 #include "platform/CThunk.h"
AnnaBridge 189:f392fc9709a3 32 #include "hal/dma_api.h"
AnnaBridge 189:f392fc9709a3 33 #include "platform/FunctionPointer.h"
AnnaBridge 189:f392fc9709a3 34 #endif
AnnaBridge 189:f392fc9709a3 35
AnnaBridge 189:f392fc9709a3 36 namespace mbed {
AnnaBridge 189:f392fc9709a3 37 /** \addtogroup drivers */
AnnaBridge 189:f392fc9709a3 38
AnnaBridge 189:f392fc9709a3 39 /** An I2C Master, used for communicating with I2C slave devices
AnnaBridge 189:f392fc9709a3 40 *
AnnaBridge 189:f392fc9709a3 41 * @note Synchronization level: Thread safe
AnnaBridge 189:f392fc9709a3 42 *
AnnaBridge 189:f392fc9709a3 43 * Example:
AnnaBridge 189:f392fc9709a3 44 * @code
AnnaBridge 189:f392fc9709a3 45 * Read temperature from LM75BD
AnnaBridge 189:f392fc9709a3 46 * #include "mbed.h"
AnnaBridge 189:f392fc9709a3 47 * I2C i2c(I2C_SDA , I2C_SCL);
AnnaBridge 189:f392fc9709a3 48 * const int addr7bit = 0x48; // 7-bit I2C address
AnnaBridge 189:f392fc9709a3 49 * const int addr8bit = 0x48 << 1; // 8-bit I2C address, 0x90
AnnaBridge 189:f392fc9709a3 50 *
AnnaBridge 189:f392fc9709a3 51 * int main() {
AnnaBridge 189:f392fc9709a3 52 * char cmd[2];
AnnaBridge 189:f392fc9709a3 53 * while (1) {
AnnaBridge 189:f392fc9709a3 54 * cmd[0] = 0x01;
AnnaBridge 189:f392fc9709a3 55 * cmd[1] = 0x00;
AnnaBridge 189:f392fc9709a3 56 *
AnnaBridge 189:f392fc9709a3 57 * // read and write takes the 8-bit version of the address.
AnnaBridge 189:f392fc9709a3 58 * // set up configuration register (at 0x01)
AnnaBridge 189:f392fc9709a3 59 * i2c.write(addr8bit, cmd, 2);
AnnaBridge 189:f392fc9709a3 60 *
AnnaBridge 189:f392fc9709a3 61 * wait(0.5);
AnnaBridge 189:f392fc9709a3 62 *
AnnaBridge 189:f392fc9709a3 63 * // read temperature register
AnnaBridge 189:f392fc9709a3 64 * cmd[0] = 0x00;
AnnaBridge 189:f392fc9709a3 65 * i2c.write(addr8bit, cmd, 1);
AnnaBridge 189:f392fc9709a3 66 * i2c.read( addr8bit, cmd, 2);
AnnaBridge 189:f392fc9709a3 67 *
AnnaBridge 189:f392fc9709a3 68 * float tmp = (float((cmd[0]<<8)|cmd[1]) / 256.0);
AnnaBridge 189:f392fc9709a3 69 * printf("Temp = %.2f\n", tmp);
AnnaBridge 189:f392fc9709a3 70 * }
AnnaBridge 189:f392fc9709a3 71 * }
AnnaBridge 189:f392fc9709a3 72 * @endcode
AnnaBridge 189:f392fc9709a3 73 * @ingroup drivers
AnnaBridge 189:f392fc9709a3 74 */
AnnaBridge 189:f392fc9709a3 75 class I2C : private NonCopyable<I2C> {
AnnaBridge 189:f392fc9709a3 76
AnnaBridge 189:f392fc9709a3 77 public:
AnnaBridge 189:f392fc9709a3 78 enum RxStatus {
AnnaBridge 189:f392fc9709a3 79 NoData,
AnnaBridge 189:f392fc9709a3 80 MasterGeneralCall,
AnnaBridge 189:f392fc9709a3 81 MasterWrite,
AnnaBridge 189:f392fc9709a3 82 MasterRead
AnnaBridge 189:f392fc9709a3 83 };
AnnaBridge 189:f392fc9709a3 84
AnnaBridge 189:f392fc9709a3 85 enum Acknowledge {
AnnaBridge 189:f392fc9709a3 86 NoACK = 0,
AnnaBridge 189:f392fc9709a3 87 ACK = 1
AnnaBridge 189:f392fc9709a3 88 };
AnnaBridge 189:f392fc9709a3 89
AnnaBridge 189:f392fc9709a3 90 /** Create an I2C Master interface, connected to the specified pins
AnnaBridge 189:f392fc9709a3 91 *
AnnaBridge 189:f392fc9709a3 92 * @param sda I2C data line pin
AnnaBridge 189:f392fc9709a3 93 * @param scl I2C clock line pin
AnnaBridge 189:f392fc9709a3 94 */
AnnaBridge 189:f392fc9709a3 95 I2C(PinName sda, PinName scl);
AnnaBridge 189:f392fc9709a3 96
AnnaBridge 189:f392fc9709a3 97 /** Set the frequency of the I2C interface
AnnaBridge 189:f392fc9709a3 98 *
AnnaBridge 189:f392fc9709a3 99 * @param hz The bus frequency in hertz
AnnaBridge 189:f392fc9709a3 100 */
AnnaBridge 189:f392fc9709a3 101 void frequency(int hz);
AnnaBridge 189:f392fc9709a3 102
AnnaBridge 189:f392fc9709a3 103 /** Read from an I2C slave
AnnaBridge 189:f392fc9709a3 104 *
AnnaBridge 189:f392fc9709a3 105 * Performs a complete read transaction. The bottom bit of
AnnaBridge 189:f392fc9709a3 106 * the address is forced to 1 to indicate a read.
AnnaBridge 189:f392fc9709a3 107 *
AnnaBridge 189:f392fc9709a3 108 * @param address 8-bit I2C slave address [ addr | 1 ]
AnnaBridge 189:f392fc9709a3 109 * @param data Pointer to the byte-array to read data in to
AnnaBridge 189:f392fc9709a3 110 * @param length Number of bytes to read
AnnaBridge 189:f392fc9709a3 111 * @param repeated Repeated start, true - don't send stop at end
AnnaBridge 189:f392fc9709a3 112 * default value is false.
AnnaBridge 189:f392fc9709a3 113 *
AnnaBridge 189:f392fc9709a3 114 * @returns
AnnaBridge 189:f392fc9709a3 115 * 0 on success (ack),
AnnaBridge 189:f392fc9709a3 116 * nonzero on failure (nack)
AnnaBridge 189:f392fc9709a3 117 */
AnnaBridge 189:f392fc9709a3 118 int read(int address, char *data, int length, bool repeated = false);
AnnaBridge 189:f392fc9709a3 119
AnnaBridge 189:f392fc9709a3 120 /** Read a single byte from the I2C bus
AnnaBridge 189:f392fc9709a3 121 *
AnnaBridge 189:f392fc9709a3 122 * @param ack indicates if the byte is to be acknowledged (1 = acknowledge)
AnnaBridge 189:f392fc9709a3 123 *
AnnaBridge 189:f392fc9709a3 124 * @returns
AnnaBridge 189:f392fc9709a3 125 * the byte read
AnnaBridge 189:f392fc9709a3 126 */
AnnaBridge 189:f392fc9709a3 127 int read(int ack);
AnnaBridge 189:f392fc9709a3 128
AnnaBridge 189:f392fc9709a3 129 /** Write to an I2C slave
AnnaBridge 189:f392fc9709a3 130 *
AnnaBridge 189:f392fc9709a3 131 * Performs a complete write transaction. The bottom bit of
AnnaBridge 189:f392fc9709a3 132 * the address is forced to 0 to indicate a write.
AnnaBridge 189:f392fc9709a3 133 *
AnnaBridge 189:f392fc9709a3 134 * @param address 8-bit I2C slave address [ addr | 0 ]
AnnaBridge 189:f392fc9709a3 135 * @param data Pointer to the byte-array data to send
AnnaBridge 189:f392fc9709a3 136 * @param length Number of bytes to send
AnnaBridge 189:f392fc9709a3 137 * @param repeated Repeated start, true - do not send stop at end
AnnaBridge 189:f392fc9709a3 138 * default value is false.
AnnaBridge 189:f392fc9709a3 139 *
AnnaBridge 189:f392fc9709a3 140 * @returns
AnnaBridge 189:f392fc9709a3 141 * 0 on success (ack),
AnnaBridge 189:f392fc9709a3 142 * nonzero on failure (nack)
AnnaBridge 189:f392fc9709a3 143 */
AnnaBridge 189:f392fc9709a3 144 int write(int address, const char *data, int length, bool repeated = false);
AnnaBridge 189:f392fc9709a3 145
AnnaBridge 189:f392fc9709a3 146 /** Write single byte out on the I2C bus
AnnaBridge 189:f392fc9709a3 147 *
AnnaBridge 189:f392fc9709a3 148 * @param data data to write out on bus
AnnaBridge 189:f392fc9709a3 149 *
AnnaBridge 189:f392fc9709a3 150 * @returns
AnnaBridge 189:f392fc9709a3 151 * '0' - NAK was received
AnnaBridge 189:f392fc9709a3 152 * '1' - ACK was received,
AnnaBridge 189:f392fc9709a3 153 * '2' - timeout
AnnaBridge 189:f392fc9709a3 154 */
AnnaBridge 189:f392fc9709a3 155 int write(int data);
AnnaBridge 189:f392fc9709a3 156
AnnaBridge 189:f392fc9709a3 157 /** Creates a start condition on the I2C bus
AnnaBridge 189:f392fc9709a3 158 */
AnnaBridge 189:f392fc9709a3 159 void start(void);
AnnaBridge 189:f392fc9709a3 160
AnnaBridge 189:f392fc9709a3 161 /** Creates a stop condition on the I2C bus
AnnaBridge 189:f392fc9709a3 162 */
AnnaBridge 189:f392fc9709a3 163 void stop(void);
AnnaBridge 189:f392fc9709a3 164
AnnaBridge 189:f392fc9709a3 165 /** Acquire exclusive access to this I2C bus
AnnaBridge 189:f392fc9709a3 166 */
AnnaBridge 189:f392fc9709a3 167 virtual void lock(void);
AnnaBridge 189:f392fc9709a3 168
AnnaBridge 189:f392fc9709a3 169 /** Release exclusive access to this I2C bus
AnnaBridge 189:f392fc9709a3 170 */
AnnaBridge 189:f392fc9709a3 171 virtual void unlock(void);
AnnaBridge 189:f392fc9709a3 172
AnnaBridge 189:f392fc9709a3 173 virtual ~I2C()
AnnaBridge 189:f392fc9709a3 174 {
AnnaBridge 189:f392fc9709a3 175 // Do nothing
AnnaBridge 189:f392fc9709a3 176 }
AnnaBridge 189:f392fc9709a3 177
AnnaBridge 189:f392fc9709a3 178 #if DEVICE_I2C_ASYNCH
AnnaBridge 189:f392fc9709a3 179
AnnaBridge 189:f392fc9709a3 180 /** Start nonblocking I2C transfer.
AnnaBridge 189:f392fc9709a3 181 *
AnnaBridge 189:f392fc9709a3 182 * This function locks the deep sleep until any event has occurred
AnnaBridge 189:f392fc9709a3 183 *
AnnaBridge 189:f392fc9709a3 184 * @param address 8/10 bit I2C slave address
AnnaBridge 189:f392fc9709a3 185 * @param tx_buffer The TX buffer with data to be transferred
AnnaBridge 189:f392fc9709a3 186 * @param tx_length The length of TX buffer in bytes
AnnaBridge 189:f392fc9709a3 187 * @param rx_buffer The RX buffer, which is used for received data
AnnaBridge 189:f392fc9709a3 188 * @param rx_length The length of RX buffer in bytes
AnnaBridge 189:f392fc9709a3 189 * @param event The logical OR of events to modify
AnnaBridge 189:f392fc9709a3 190 * @param callback The event callback function
AnnaBridge 189:f392fc9709a3 191 * @param repeated Repeated start, true - do not send stop at end
AnnaBridge 189:f392fc9709a3 192 * default value is false.
AnnaBridge 189:f392fc9709a3 193 *
AnnaBridge 189:f392fc9709a3 194 * @returns Zero if the transfer has started, or -1 if I2C peripheral is busy
AnnaBridge 189:f392fc9709a3 195 */
AnnaBridge 189:f392fc9709a3 196 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);
AnnaBridge 189:f392fc9709a3 197
AnnaBridge 189:f392fc9709a3 198 /** Abort the ongoing I2C transfer
AnnaBridge 189:f392fc9709a3 199 */
AnnaBridge 189:f392fc9709a3 200 void abort_transfer();
AnnaBridge 189:f392fc9709a3 201
AnnaBridge 189:f392fc9709a3 202 #if !defined(DOXYGEN_ONLY)
AnnaBridge 189:f392fc9709a3 203 protected:
AnnaBridge 189:f392fc9709a3 204 /** Lock deep sleep only if it is not yet locked */
AnnaBridge 189:f392fc9709a3 205 void lock_deep_sleep();
AnnaBridge 189:f392fc9709a3 206
AnnaBridge 189:f392fc9709a3 207 /** Unlock deep sleep only if it has been locked */
AnnaBridge 189:f392fc9709a3 208 void unlock_deep_sleep();
AnnaBridge 189:f392fc9709a3 209
AnnaBridge 189:f392fc9709a3 210 void irq_handler_asynch(void);
AnnaBridge 189:f392fc9709a3 211 event_callback_t _callback;
AnnaBridge 189:f392fc9709a3 212 CThunk<I2C> _irq;
AnnaBridge 189:f392fc9709a3 213 DMAUsage _usage;
AnnaBridge 189:f392fc9709a3 214 bool _deep_sleep_locked;
AnnaBridge 189:f392fc9709a3 215 #endif
AnnaBridge 189:f392fc9709a3 216 #endif
AnnaBridge 189:f392fc9709a3 217
AnnaBridge 189:f392fc9709a3 218 #if !defined(DOXYGEN_ONLY)
AnnaBridge 189:f392fc9709a3 219 protected:
AnnaBridge 189:f392fc9709a3 220 void aquire();
AnnaBridge 189:f392fc9709a3 221
AnnaBridge 189:f392fc9709a3 222 i2c_t _i2c;
AnnaBridge 189:f392fc9709a3 223 static I2C *_owner;
AnnaBridge 189:f392fc9709a3 224 int _hz;
AnnaBridge 189:f392fc9709a3 225 static SingletonPtr<PlatformMutex> _mutex;
AnnaBridge 189:f392fc9709a3 226 PinName _sda;
AnnaBridge 189:f392fc9709a3 227 PinName _scl;
AnnaBridge 189:f392fc9709a3 228
AnnaBridge 189:f392fc9709a3 229 private:
AnnaBridge 189:f392fc9709a3 230 /** Recover I2C bus, when stuck with SDA low
AnnaBridge 189:f392fc9709a3 231 * @note : Initialization of I2C bus is required after this API.
AnnaBridge 189:f392fc9709a3 232 *
AnnaBridge 189:f392fc9709a3 233 * @param sda I2C data line pin
AnnaBridge 189:f392fc9709a3 234 * @param scl I2C clock line pin
AnnaBridge 189:f392fc9709a3 235 *
AnnaBridge 189:f392fc9709a3 236 * @returns
AnnaBridge 189:f392fc9709a3 237 * '0' - Successfully recovered
AnnaBridge 189:f392fc9709a3 238 * 'I2C_ERROR_BUS_BUSY' - In case of failure
AnnaBridge 189:f392fc9709a3 239 *
AnnaBridge 189:f392fc9709a3 240 */
AnnaBridge 189:f392fc9709a3 241 int recover(PinName sda, PinName scl);
AnnaBridge 189:f392fc9709a3 242 #endif
AnnaBridge 189:f392fc9709a3 243 };
AnnaBridge 189:f392fc9709a3 244
AnnaBridge 189:f392fc9709a3 245 } // namespace mbed
AnnaBridge 189:f392fc9709a3 246
AnnaBridge 189:f392fc9709a3 247 #endif
AnnaBridge 189:f392fc9709a3 248
AnnaBridge 189:f392fc9709a3 249 #endif