zhang boie / mbed-dev-f30333

drivers/I2C.cpp@0:bdf663c61a82, 2022-06-14 (annotated)

Committer:
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4
Date:
Tue Jun 14 09:21:18 2022 +0000
Revision:
0:bdf663c61a82
lib

Who changed what in which revision?

UserRevisionLine numberNew contents of line
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 1 /* mbed Microcontroller Library
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 2 * Copyright (c) 2006-2015 ARM Limited
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 3 *
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 4 * Licensed under the Apache License, Version 2.0 (the "License");
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 5 * you may not use this file except in compliance with the License.
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 6 * You may obtain a copy of the License at
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 7 *
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 8 * http://www.apache.org/licenses/LICENSE-2.0
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 9 *
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 10 * Unless required by applicable law or agreed to in writing, software
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 11 * distributed under the License is distributed on an "AS IS" BASIS,
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 13 * See the License for the specific language governing permissions and
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 14 * limitations under the License.
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 15 */
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 16 #include "drivers/I2C.h"
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 17
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 18 #if DEVICE_I2C
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 19
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 20 #if DEVICE_I2C_ASYNCH
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 21 #include "platform/mbed_sleep.h"
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 22 #endif
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 23
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 24 namespace mbed {
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 25
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 26 I2C *I2C::_owner = NULL;
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 27 SingletonPtr<PlatformMutex> I2C::_mutex;
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 28
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 29 I2C::I2C(PinName sda, PinName scl) :
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 30 #if DEVICE_I2C_ASYNCH
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 31 _irq(this), _usage(DMA_USAGE_NEVER),
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 32 #endif
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 33 _i2c(), _hz(100000) {
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 34 // No lock needed in the constructor
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 35
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 36 // The init function also set the frequency to 100000
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 37 i2c_init(&_i2c, sda, scl);
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 38
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 39 // Used to avoid unnecessary frequency updates
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 40 _owner = this;
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 41 }
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 42
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 43 void I2C::frequency(int hz) {
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 44 lock();
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 45 _hz = hz;
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 46
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 47 // We want to update the frequency even if we are already the bus owners
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 48 i2c_frequency(&_i2c, _hz);
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 49
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 50 // Updating the frequency of the bus we become the owners of it
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 51 _owner = this;
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 52 unlock();
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 53 }
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 54
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 55 void I2C::aquire() {
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 56 lock();
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 57 if (_owner != this) {
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 58 i2c_frequency(&_i2c, _hz);
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 59 _owner = this;
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 60 }
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 61 unlock();
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 62 }
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 63
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 64 // write - Master Transmitter Mode
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 65 int I2C::write(int address, const char* data, int length, bool repeated) {
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 66 lock();
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 67 aquire();
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 68
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 69 int stop = (repeated) ? 0 : 1;
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 70 int written = i2c_write(&_i2c, address, data, length, stop);
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 71
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 72 unlock();
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 73 return length != written;
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 74 }
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 75
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 76 int I2C::write(int data) {
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 77 lock();
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 78 int ret = i2c_byte_write(&_i2c, data);
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 79 unlock();
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 80 return ret;
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 81 }
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 82
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 83 // read - Master Reciever Mode
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 84 int I2C::read(int address, char* data, int length, bool repeated) {
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 85 lock();
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 86 aquire();
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 87
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 88 int stop = (repeated) ? 0 : 1;
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 89 int read = i2c_read(&_i2c, address, data, length, stop);
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 90
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 91 unlock();
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 92 return length != read;
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 93 }
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 94
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 95 int I2C::read(int ack) {
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 96 lock();
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 97 int ret;
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 98 if (ack) {
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 99 ret = i2c_byte_read(&_i2c, 0);
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 100 } else {
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 101 ret = i2c_byte_read(&_i2c, 1);
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 102 }
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 103 unlock();
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 104 return ret;
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 105 }
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 106
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 107 void I2C::start(void) {
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 108 lock();
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 109 i2c_start(&_i2c);
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 110 unlock();
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 111 }
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 112
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 113 void I2C::stop(void) {
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 114 lock();
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 115 i2c_stop(&_i2c);
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 116 unlock();
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 117 }
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 118
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 119 void I2C::lock() {
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 120 _mutex->lock();
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 121 }
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 122
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 123 void I2C::unlock() {
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 124 _mutex->unlock();
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 125 }
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 126
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 127 #if DEVICE_I2C_ASYNCH
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 128
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 129 int I2C::transfer(int address, const char *tx_buffer, int tx_length, char *rx_buffer, int rx_length, const event_callback_t& callback, int event, bool repeated)
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 130 {
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 131 lock();
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 132 if (i2c_active(&_i2c)) {
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 133 unlock();
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 134 return -1; // transaction ongoing
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 135 }
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 136 sleep_manager_lock_deep_sleep();
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 137 aquire();
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 138
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 139 _callback = callback;
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 140 int stop = (repeated) ? 0 : 1;
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 141 _irq.callback(&I2C::irq_handler_asynch);
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 142 i2c_transfer_asynch(&_i2c, (void *)tx_buffer, tx_length, (void *)rx_buffer, rx_length, address, stop, _irq.entry(), event, _usage);
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 143 unlock();
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 144 return 0;
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 145 }
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 146
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 147 void I2C::abort_transfer(void)
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 148 {
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 149 lock();
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 150 i2c_abort_asynch(&_i2c);
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 151 sleep_manager_unlock_deep_sleep();
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 152 unlock();
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 153 }
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 154
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 155 void I2C::irq_handler_asynch(void)
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 156 {
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 157 int event = i2c_irq_handler_asynch(&_i2c);
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 158 if (_callback && event) {
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 159 _callback.call(event);
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 160 }
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 161 if (event) {
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 162 sleep_manager_unlock_deep_sleep();
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 163 }
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 164
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 165 }
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 166
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 167
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 168 #endif
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 169
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 170 } // namespace mbed
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 171
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 172 #endif
abe5b02d-a2d4-4fe9-818e-c4e57c809ea4 0:bdf663c61a82 173