Gan likun / mbed-dev11

1232

drivers/I2C.cpp@0:06036f8bee2d, 2022-10-24 (annotated)

Committer:
ganlikun
Date:
Mon Oct 24 15:19:39 2022 +0000
Revision:
0:06036f8bee2d
11

Who changed what in which revision?

UserRevisionLine numberNew contents of line
ganlikun 0:06036f8bee2d 1 /* mbed Microcontroller Library
ganlikun 0:06036f8bee2d 2 * Copyright (c) 2006-2015 ARM Limited
ganlikun 0:06036f8bee2d 3 *
ganlikun 0:06036f8bee2d 4 * Licensed under the Apache License, Version 2.0 (the "License");
ganlikun 0:06036f8bee2d 5 * you may not use this file except in compliance with the License.
ganlikun 0:06036f8bee2d 6 * You may obtain a copy of the License at
ganlikun 0:06036f8bee2d 7 *
ganlikun 0:06036f8bee2d 8 * http://www.apache.org/licenses/LICENSE-2.0
ganlikun 0:06036f8bee2d 9 *
ganlikun 0:06036f8bee2d 10 * Unless required by applicable law or agreed to in writing, software
ganlikun 0:06036f8bee2d 11 * distributed under the License is distributed on an "AS IS" BASIS,
ganlikun 0:06036f8bee2d 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
ganlikun 0:06036f8bee2d 13 * See the License for the specific language governing permissions and
ganlikun 0:06036f8bee2d 14 * limitations under the License.
ganlikun 0:06036f8bee2d 15 */
ganlikun 0:06036f8bee2d 16 #include "drivers/I2C.h"
ganlikun 0:06036f8bee2d 17
ganlikun 0:06036f8bee2d 18 #if DEVICE_I2C
ganlikun 0:06036f8bee2d 19
ganlikun 0:06036f8bee2d 20 #if DEVICE_I2C_ASYNCH
ganlikun 0:06036f8bee2d 21 #include "platform/mbed_sleep.h"
ganlikun 0:06036f8bee2d 22 #endif
ganlikun 0:06036f8bee2d 23
ganlikun 0:06036f8bee2d 24 namespace mbed {
ganlikun 0:06036f8bee2d 25
ganlikun 0:06036f8bee2d 26 I2C *I2C::_owner = NULL;
ganlikun 0:06036f8bee2d 27 SingletonPtr<PlatformMutex> I2C::_mutex;
ganlikun 0:06036f8bee2d 28
ganlikun 0:06036f8bee2d 29 I2C::I2C(PinName sda, PinName scl) :
ganlikun 0:06036f8bee2d 30 #if DEVICE_I2C_ASYNCH
ganlikun 0:06036f8bee2d 31 _irq(this), _usage(DMA_USAGE_NEVER),
ganlikun 0:06036f8bee2d 32 #endif
ganlikun 0:06036f8bee2d 33 _i2c(), _hz(100000) {
ganlikun 0:06036f8bee2d 34 // No lock needed in the constructor
ganlikun 0:06036f8bee2d 35
ganlikun 0:06036f8bee2d 36 // The init function also set the frequency to 100000
ganlikun 0:06036f8bee2d 37 i2c_init(&_i2c, sda, scl);
ganlikun 0:06036f8bee2d 38
ganlikun 0:06036f8bee2d 39 // Used to avoid unnecessary frequency updates
ganlikun 0:06036f8bee2d 40 _owner = this;
ganlikun 0:06036f8bee2d 41 }
ganlikun 0:06036f8bee2d 42
ganlikun 0:06036f8bee2d 43 void I2C::frequency(int hz) {
ganlikun 0:06036f8bee2d 44 lock();
ganlikun 0:06036f8bee2d 45 _hz = hz;
ganlikun 0:06036f8bee2d 46
ganlikun 0:06036f8bee2d 47 // We want to update the frequency even if we are already the bus owners
ganlikun 0:06036f8bee2d 48 i2c_frequency(&_i2c, _hz);
ganlikun 0:06036f8bee2d 49
ganlikun 0:06036f8bee2d 50 // Updating the frequency of the bus we become the owners of it
ganlikun 0:06036f8bee2d 51 _owner = this;
ganlikun 0:06036f8bee2d 52 unlock();
ganlikun 0:06036f8bee2d 53 }
ganlikun 0:06036f8bee2d 54
ganlikun 0:06036f8bee2d 55 void I2C::aquire() {
ganlikun 0:06036f8bee2d 56 lock();
ganlikun 0:06036f8bee2d 57 if (_owner != this) {
ganlikun 0:06036f8bee2d 58 i2c_frequency(&_i2c, _hz);
ganlikun 0:06036f8bee2d 59 _owner = this;
ganlikun 0:06036f8bee2d 60 }
ganlikun 0:06036f8bee2d 61 unlock();
ganlikun 0:06036f8bee2d 62 }
ganlikun 0:06036f8bee2d 63
ganlikun 0:06036f8bee2d 64 // write - Master Transmitter Mode
ganlikun 0:06036f8bee2d 65 int I2C::write(int address, const char* data, int length, bool repeated) {
ganlikun 0:06036f8bee2d 66 lock();
ganlikun 0:06036f8bee2d 67 aquire();
ganlikun 0:06036f8bee2d 68
ganlikun 0:06036f8bee2d 69 int stop = (repeated) ? 0 : 1;
ganlikun 0:06036f8bee2d 70 int written = i2c_write(&_i2c, address, data, length, stop);
ganlikun 0:06036f8bee2d 71
ganlikun 0:06036f8bee2d 72 unlock();
ganlikun 0:06036f8bee2d 73 return length != written;
ganlikun 0:06036f8bee2d 74 }
ganlikun 0:06036f8bee2d 75
ganlikun 0:06036f8bee2d 76 int I2C::write(int data) {
ganlikun 0:06036f8bee2d 77 lock();
ganlikun 0:06036f8bee2d 78 int ret = i2c_byte_write(&_i2c, data);
ganlikun 0:06036f8bee2d 79 unlock();
ganlikun 0:06036f8bee2d 80 return ret;
ganlikun 0:06036f8bee2d 81 }
ganlikun 0:06036f8bee2d 82
ganlikun 0:06036f8bee2d 83 // read - Master Reciever Mode
ganlikun 0:06036f8bee2d 84 int I2C::read(int address, char* data, int length, bool repeated) {
ganlikun 0:06036f8bee2d 85 lock();
ganlikun 0:06036f8bee2d 86 aquire();
ganlikun 0:06036f8bee2d 87
ganlikun 0:06036f8bee2d 88 int stop = (repeated) ? 0 : 1;
ganlikun 0:06036f8bee2d 89 int read = i2c_read(&_i2c, address, data, length, stop);
ganlikun 0:06036f8bee2d 90
ganlikun 0:06036f8bee2d 91 unlock();
ganlikun 0:06036f8bee2d 92 return length != read;
ganlikun 0:06036f8bee2d 93 }
ganlikun 0:06036f8bee2d 94
ganlikun 0:06036f8bee2d 95 int I2C::read(int ack) {
ganlikun 0:06036f8bee2d 96 lock();
ganlikun 0:06036f8bee2d 97 int ret;
ganlikun 0:06036f8bee2d 98 if (ack) {
ganlikun 0:06036f8bee2d 99 ret = i2c_byte_read(&_i2c, 0);
ganlikun 0:06036f8bee2d 100 } else {
ganlikun 0:06036f8bee2d 101 ret = i2c_byte_read(&_i2c, 1);
ganlikun 0:06036f8bee2d 102 }
ganlikun 0:06036f8bee2d 103 unlock();
ganlikun 0:06036f8bee2d 104 return ret;
ganlikun 0:06036f8bee2d 105 }
ganlikun 0:06036f8bee2d 106
ganlikun 0:06036f8bee2d 107 void I2C::start(void) {
ganlikun 0:06036f8bee2d 108 lock();
ganlikun 0:06036f8bee2d 109 i2c_start(&_i2c);
ganlikun 0:06036f8bee2d 110 unlock();
ganlikun 0:06036f8bee2d 111 }
ganlikun 0:06036f8bee2d 112
ganlikun 0:06036f8bee2d 113 void I2C::stop(void) {
ganlikun 0:06036f8bee2d 114 lock();
ganlikun 0:06036f8bee2d 115 i2c_stop(&_i2c);
ganlikun 0:06036f8bee2d 116 unlock();
ganlikun 0:06036f8bee2d 117 }
ganlikun 0:06036f8bee2d 118
ganlikun 0:06036f8bee2d 119 void I2C::lock() {
ganlikun 0:06036f8bee2d 120 _mutex->lock();
ganlikun 0:06036f8bee2d 121 }
ganlikun 0:06036f8bee2d 122
ganlikun 0:06036f8bee2d 123 void I2C::unlock() {
ganlikun 0:06036f8bee2d 124 _mutex->unlock();
ganlikun 0:06036f8bee2d 125 }
ganlikun 0:06036f8bee2d 126
ganlikun 0:06036f8bee2d 127 #if DEVICE_I2C_ASYNCH
ganlikun 0:06036f8bee2d 128
ganlikun 0:06036f8bee2d 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 0:06036f8bee2d 130 {
ganlikun 0:06036f8bee2d 131 lock();
ganlikun 0:06036f8bee2d 132 if (i2c_active(&_i2c)) {
ganlikun 0:06036f8bee2d 133 unlock();
ganlikun 0:06036f8bee2d 134 return -1; // transaction ongoing
ganlikun 0:06036f8bee2d 135 }
ganlikun 0:06036f8bee2d 136 sleep_manager_lock_deep_sleep();
ganlikun 0:06036f8bee2d 137 aquire();
ganlikun 0:06036f8bee2d 138
ganlikun 0:06036f8bee2d 139 _callback = callback;
ganlikun 0:06036f8bee2d 140 int stop = (repeated) ? 0 : 1;
ganlikun 0:06036f8bee2d 141 _irq.callback(&I2C::irq_handler_asynch);
ganlikun 0:06036f8bee2d 142 i2c_transfer_asynch(&_i2c, (void *)tx_buffer, tx_length, (void *)rx_buffer, rx_length, address, stop, _irq.entry(), event, _usage);
ganlikun 0:06036f8bee2d 143 unlock();
ganlikun 0:06036f8bee2d 144 return 0;
ganlikun 0:06036f8bee2d 145 }
ganlikun 0:06036f8bee2d 146
ganlikun 0:06036f8bee2d 147 void I2C::abort_transfer(void)
ganlikun 0:06036f8bee2d 148 {
ganlikun 0:06036f8bee2d 149 lock();
ganlikun 0:06036f8bee2d 150 i2c_abort_asynch(&_i2c);
ganlikun 0:06036f8bee2d 151 sleep_manager_unlock_deep_sleep();
ganlikun 0:06036f8bee2d 152 unlock();
ganlikun 0:06036f8bee2d 153 }
ganlikun 0:06036f8bee2d 154
ganlikun 0:06036f8bee2d 155 void I2C::irq_handler_asynch(void)
ganlikun 0:06036f8bee2d 156 {
ganlikun 0:06036f8bee2d 157 int event = i2c_irq_handler_asynch(&_i2c);
ganlikun 0:06036f8bee2d 158 if (_callback && event) {
ganlikun 0:06036f8bee2d 159 _callback.call(event);
ganlikun 0:06036f8bee2d 160 }
ganlikun 0:06036f8bee2d 161 if (event) {
ganlikun 0:06036f8bee2d 162 sleep_manager_unlock_deep_sleep();
ganlikun 0:06036f8bee2d 163 }
ganlikun 0:06036f8bee2d 164
ganlikun 0:06036f8bee2d 165 }
ganlikun 0:06036f8bee2d 166
ganlikun 0:06036f8bee2d 167
ganlikun 0:06036f8bee2d 168 #endif
ganlikun 0:06036f8bee2d 169
ganlikun 0:06036f8bee2d 170 } // namespace mbed
ganlikun 0:06036f8bee2d 171
ganlikun 0:06036f8bee2d 172 #endif
ganlikun 0:06036f8bee2d 173