Gan likun / mbed1-dev

001

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

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

Who changed what in which revision?

UserRevisionLine numberNew contents of line
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 #include "drivers/I2C.h"
ganlikun 0:13413ea9a877 17
ganlikun 0:13413ea9a877 18 #if DEVICE_I2C
ganlikun 0:13413ea9a877 19
ganlikun 0:13413ea9a877 20 #if DEVICE_I2C_ASYNCH
ganlikun 0:13413ea9a877 21 #include "platform/mbed_sleep.h"
ganlikun 0:13413ea9a877 22 #endif
ganlikun 0:13413ea9a877 23
ganlikun 0:13413ea9a877 24 namespace mbed {
ganlikun 0:13413ea9a877 25
ganlikun 0:13413ea9a877 26 I2C *I2C::_owner = NULL;
ganlikun 0:13413ea9a877 27 SingletonPtr<PlatformMutex> I2C::_mutex;
ganlikun 0:13413ea9a877 28
ganlikun 0:13413ea9a877 29 I2C::I2C(PinName sda, PinName scl) :
ganlikun 0:13413ea9a877 30 #if DEVICE_I2C_ASYNCH
ganlikun 0:13413ea9a877 31 _irq(this), _usage(DMA_USAGE_NEVER),
ganlikun 0:13413ea9a877 32 #endif
ganlikun 0:13413ea9a877 33 _i2c(), _hz(100000) {
ganlikun 0:13413ea9a877 34 // No lock needed in the constructor
ganlikun 0:13413ea9a877 35
ganlikun 0:13413ea9a877 36 // The init function also set the frequency to 100000
ganlikun 0:13413ea9a877 37 i2c_init(&_i2c, sda, scl);
ganlikun 0:13413ea9a877 38
ganlikun 0:13413ea9a877 39 // Used to avoid unnecessary frequency updates
ganlikun 0:13413ea9a877 40 _owner = this;
ganlikun 0:13413ea9a877 41 }
ganlikun 0:13413ea9a877 42
ganlikun 0:13413ea9a877 43 void I2C::frequency(int hz) {
ganlikun 0:13413ea9a877 44 lock();
ganlikun 0:13413ea9a877 45 _hz = hz;
ganlikun 0:13413ea9a877 46
ganlikun 0:13413ea9a877 47 // We want to update the frequency even if we are already the bus owners
ganlikun 0:13413ea9a877 48 i2c_frequency(&_i2c, _hz);
ganlikun 0:13413ea9a877 49
ganlikun 0:13413ea9a877 50 // Updating the frequency of the bus we become the owners of it
ganlikun 0:13413ea9a877 51 _owner = this;
ganlikun 0:13413ea9a877 52 unlock();
ganlikun 0:13413ea9a877 53 }
ganlikun 0:13413ea9a877 54
ganlikun 0:13413ea9a877 55 void I2C::aquire() {
ganlikun 0:13413ea9a877 56 lock();
ganlikun 0:13413ea9a877 57 if (_owner != this) {
ganlikun 0:13413ea9a877 58 i2c_frequency(&_i2c, _hz);
ganlikun 0:13413ea9a877 59 _owner = this;
ganlikun 0:13413ea9a877 60 }
ganlikun 0:13413ea9a877 61 unlock();
ganlikun 0:13413ea9a877 62 }
ganlikun 0:13413ea9a877 63
ganlikun 0:13413ea9a877 64 // write - Master Transmitter Mode
ganlikun 0:13413ea9a877 65 int I2C::write(int address, const char* data, int length, bool repeated) {
ganlikun 0:13413ea9a877 66 lock();
ganlikun 0:13413ea9a877 67 aquire();
ganlikun 0:13413ea9a877 68
ganlikun 0:13413ea9a877 69 int stop = (repeated) ? 0 : 1;
ganlikun 0:13413ea9a877 70 int written = i2c_write(&_i2c, address, data, length, stop);
ganlikun 0:13413ea9a877 71
ganlikun 0:13413ea9a877 72 unlock();
ganlikun 0:13413ea9a877 73 return length != written;
ganlikun 0:13413ea9a877 74 }
ganlikun 0:13413ea9a877 75
ganlikun 0:13413ea9a877 76 int I2C::write(int data) {
ganlikun 0:13413ea9a877 77 lock();
ganlikun 0:13413ea9a877 78 int ret = i2c_byte_write(&_i2c, data);
ganlikun 0:13413ea9a877 79 unlock();
ganlikun 0:13413ea9a877 80 return ret;
ganlikun 0:13413ea9a877 81 }
ganlikun 0:13413ea9a877 82
ganlikun 0:13413ea9a877 83 // read - Master Reciever Mode
ganlikun 0:13413ea9a877 84 int I2C::read(int address, char* data, int length, bool repeated) {
ganlikun 0:13413ea9a877 85 lock();
ganlikun 0:13413ea9a877 86 aquire();
ganlikun 0:13413ea9a877 87
ganlikun 0:13413ea9a877 88 int stop = (repeated) ? 0 : 1;
ganlikun 0:13413ea9a877 89 int read = i2c_read(&_i2c, address, data, length, stop);
ganlikun 0:13413ea9a877 90
ganlikun 0:13413ea9a877 91 unlock();
ganlikun 0:13413ea9a877 92 return length != read;
ganlikun 0:13413ea9a877 93 }
ganlikun 0:13413ea9a877 94
ganlikun 0:13413ea9a877 95 int I2C::read(int ack) {
ganlikun 0:13413ea9a877 96 lock();
ganlikun 0:13413ea9a877 97 int ret;
ganlikun 0:13413ea9a877 98 if (ack) {
ganlikun 0:13413ea9a877 99 ret = i2c_byte_read(&_i2c, 0);
ganlikun 0:13413ea9a877 100 } else {
ganlikun 0:13413ea9a877 101 ret = i2c_byte_read(&_i2c, 1);
ganlikun 0:13413ea9a877 102 }
ganlikun 0:13413ea9a877 103 unlock();
ganlikun 0:13413ea9a877 104 return ret;
ganlikun 0:13413ea9a877 105 }
ganlikun 0:13413ea9a877 106
ganlikun 0:13413ea9a877 107 void I2C::start(void) {
ganlikun 0:13413ea9a877 108 lock();
ganlikun 0:13413ea9a877 109 i2c_start(&_i2c);
ganlikun 0:13413ea9a877 110 unlock();
ganlikun 0:13413ea9a877 111 }
ganlikun 0:13413ea9a877 112
ganlikun 0:13413ea9a877 113 void I2C::stop(void) {
ganlikun 0:13413ea9a877 114 lock();
ganlikun 0:13413ea9a877 115 i2c_stop(&_i2c);
ganlikun 0:13413ea9a877 116 unlock();
ganlikun 0:13413ea9a877 117 }
ganlikun 0:13413ea9a877 118
ganlikun 0:13413ea9a877 119 void I2C::lock() {
ganlikun 0:13413ea9a877 120 _mutex->lock();
ganlikun 0:13413ea9a877 121 }
ganlikun 0:13413ea9a877 122
ganlikun 0:13413ea9a877 123 void I2C::unlock() {
ganlikun 0:13413ea9a877 124 _mutex->unlock();
ganlikun 0:13413ea9a877 125 }
ganlikun 0:13413ea9a877 126
ganlikun 0:13413ea9a877 127 #if DEVICE_I2C_ASYNCH
ganlikun 0:13413ea9a877 128
ganlikun 0:13413ea9a877 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)
ganlikun 0:13413ea9a877 130 {
ganlikun 0:13413ea9a877 131 lock();
ganlikun 0:13413ea9a877 132 if (i2c_active(&_i2c)) {
ganlikun 0:13413ea9a877 133 unlock();
ganlikun 0:13413ea9a877 134 return -1; // transaction ongoing
ganlikun 0:13413ea9a877 135 }
ganlikun 0:13413ea9a877 136 sleep_manager_lock_deep_sleep();
ganlikun 0:13413ea9a877 137 aquire();
ganlikun 0:13413ea9a877 138
ganlikun 0:13413ea9a877 139 _callback = callback;
ganlikun 0:13413ea9a877 140 int stop = (repeated) ? 0 : 1;
ganlikun 0:13413ea9a877 141 _irq.callback(&I2C::irq_handler_asynch);
ganlikun 0:13413ea9a877 142 i2c_transfer_asynch(&_i2c, (void *)tx_buffer, tx_length, (void *)rx_buffer, rx_length, address, stop, _irq.entry(), event, _usage);
ganlikun 0:13413ea9a877 143 unlock();
ganlikun 0:13413ea9a877 144 return 0;
ganlikun 0:13413ea9a877 145 }
ganlikun 0:13413ea9a877 146
ganlikun 0:13413ea9a877 147 void I2C::abort_transfer(void)
ganlikun 0:13413ea9a877 148 {
ganlikun 0:13413ea9a877 149 lock();
ganlikun 0:13413ea9a877 150 i2c_abort_asynch(&_i2c);
ganlikun 0:13413ea9a877 151 sleep_manager_unlock_deep_sleep();
ganlikun 0:13413ea9a877 152 unlock();
ganlikun 0:13413ea9a877 153 }
ganlikun 0:13413ea9a877 154
ganlikun 0:13413ea9a877 155 void I2C::irq_handler_asynch(void)
ganlikun 0:13413ea9a877 156 {
ganlikun 0:13413ea9a877 157 int event = i2c_irq_handler_asynch(&_i2c);
ganlikun 0:13413ea9a877 158 if (_callback && event) {
ganlikun 0:13413ea9a877 159 _callback.call(event);
ganlikun 0:13413ea9a877 160 }
ganlikun 0:13413ea9a877 161 if (event) {
ganlikun 0:13413ea9a877 162 sleep_manager_unlock_deep_sleep();
ganlikun 0:13413ea9a877 163 }
ganlikun 0:13413ea9a877 164
ganlikun 0:13413ea9a877 165 }
ganlikun 0:13413ea9a877 166
ganlikun 0:13413ea9a877 167
ganlikun 0:13413ea9a877 168 #endif
ganlikun 0:13413ea9a877 169
ganlikun 0:13413ea9a877 170 } // namespace mbed
ganlikun 0:13413ea9a877 171
ganlikun 0:13413ea9a877 172 #endif
ganlikun 0:13413ea9a877 173