Johannes Stratmann / mbed-dev

added prescaler for 16 bit pwm in LPC1347 target

Fork of mbed-dev by mbed official

common/I2C.cpp@147:ba84b7dc41a7, 2016-09-10 (annotated)

Committer:
JojoS
Date:
Sat Sep 10 15:32:04 2016 +0000
Revision:
147:ba84b7dc41a7
Parent:
144:ef7eb2e8f9f7 
added prescaler for 16 bit timers (solution as in LPC11xx), default prescaler 31 for max 28 ms period time

Who changed what in which revision?

UserRevisionLine numberNew contents of line
<> 144:ef7eb2e8f9f7 1 /* mbed Microcontroller Library
<> 144:ef7eb2e8f9f7 2 * Copyright (c) 2006-2015 ARM Limited
<> 144:ef7eb2e8f9f7 3 *
<> 144:ef7eb2e8f9f7 4 * Licensed under the Apache License, Version 2.0 (the "License");
<> 144:ef7eb2e8f9f7 5 * you may not use this file except in compliance with the License.
<> 144:ef7eb2e8f9f7 6 * You may obtain a copy of the License at
<> 144:ef7eb2e8f9f7 7 *
<> 144:ef7eb2e8f9f7 8 * http://www.apache.org/licenses/LICENSE-2.0
<> 144:ef7eb2e8f9f7 9 *
<> 144:ef7eb2e8f9f7 10 * Unless required by applicable law or agreed to in writing, software
<> 144:ef7eb2e8f9f7 11 * distributed under the License is distributed on an "AS IS" BASIS,
<> 144:ef7eb2e8f9f7 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
<> 144:ef7eb2e8f9f7 13 * See the License for the specific language governing permissions and
<> 144:ef7eb2e8f9f7 14 * limitations under the License.
<> 144:ef7eb2e8f9f7 15 */
<> 144:ef7eb2e8f9f7 16 #include "I2C.h"
<> 144:ef7eb2e8f9f7 17
<> 144:ef7eb2e8f9f7 18 #if DEVICE_I2C
<> 144:ef7eb2e8f9f7 19
<> 144:ef7eb2e8f9f7 20 namespace mbed {
<> 144:ef7eb2e8f9f7 21
<> 144:ef7eb2e8f9f7 22 I2C *I2C::_owner = NULL;
<> 144:ef7eb2e8f9f7 23 SingletonPtr<PlatformMutex> I2C::_mutex;
<> 144:ef7eb2e8f9f7 24
<> 144:ef7eb2e8f9f7 25 I2C::I2C(PinName sda, PinName scl) :
<> 144:ef7eb2e8f9f7 26 #if DEVICE_I2C_ASYNCH
<> 144:ef7eb2e8f9f7 27 _irq(this), _usage(DMA_USAGE_NEVER),
<> 144:ef7eb2e8f9f7 28 #endif
<> 144:ef7eb2e8f9f7 29 _i2c(), _hz(100000) {
<> 144:ef7eb2e8f9f7 30 // No lock needed in the constructor
<> 144:ef7eb2e8f9f7 31
<> 144:ef7eb2e8f9f7 32 // The init function also set the frequency to 100000
<> 144:ef7eb2e8f9f7 33 i2c_init(&_i2c, sda, scl);
<> 144:ef7eb2e8f9f7 34
<> 144:ef7eb2e8f9f7 35 // Used to avoid unnecessary frequency updates
<> 144:ef7eb2e8f9f7 36 _owner = this;
<> 144:ef7eb2e8f9f7 37 }
<> 144:ef7eb2e8f9f7 38
<> 144:ef7eb2e8f9f7 39 void I2C::frequency(int hz) {
<> 144:ef7eb2e8f9f7 40 lock();
<> 144:ef7eb2e8f9f7 41 _hz = hz;
<> 144:ef7eb2e8f9f7 42
<> 144:ef7eb2e8f9f7 43 // We want to update the frequency even if we are already the bus owners
<> 144:ef7eb2e8f9f7 44 i2c_frequency(&_i2c, _hz);
<> 144:ef7eb2e8f9f7 45
<> 144:ef7eb2e8f9f7 46 // Updating the frequency of the bus we become the owners of it
<> 144:ef7eb2e8f9f7 47 _owner = this;
<> 144:ef7eb2e8f9f7 48 unlock();
<> 144:ef7eb2e8f9f7 49 }
<> 144:ef7eb2e8f9f7 50
<> 144:ef7eb2e8f9f7 51 void I2C::aquire() {
<> 144:ef7eb2e8f9f7 52 lock();
<> 144:ef7eb2e8f9f7 53 if (_owner != this) {
<> 144:ef7eb2e8f9f7 54 i2c_frequency(&_i2c, _hz);
<> 144:ef7eb2e8f9f7 55 _owner = this;
<> 144:ef7eb2e8f9f7 56 }
<> 144:ef7eb2e8f9f7 57 unlock();
<> 144:ef7eb2e8f9f7 58 }
<> 144:ef7eb2e8f9f7 59
<> 144:ef7eb2e8f9f7 60 // write - Master Transmitter Mode
<> 144:ef7eb2e8f9f7 61 int I2C::write(int address, const char* data, int length, bool repeated) {
<> 144:ef7eb2e8f9f7 62 lock();
<> 144:ef7eb2e8f9f7 63 aquire();
<> 144:ef7eb2e8f9f7 64
<> 144:ef7eb2e8f9f7 65 int stop = (repeated) ? 0 : 1;
<> 144:ef7eb2e8f9f7 66 int written = i2c_write(&_i2c, address, data, length, stop);
<> 144:ef7eb2e8f9f7 67
<> 144:ef7eb2e8f9f7 68 unlock();
<> 144:ef7eb2e8f9f7 69 return length != written;
<> 144:ef7eb2e8f9f7 70 }
<> 144:ef7eb2e8f9f7 71
<> 144:ef7eb2e8f9f7 72 int I2C::write(int data) {
<> 144:ef7eb2e8f9f7 73 lock();
<> 144:ef7eb2e8f9f7 74 int ret = i2c_byte_write(&_i2c, data);
<> 144:ef7eb2e8f9f7 75 unlock();
<> 144:ef7eb2e8f9f7 76 return ret;
<> 144:ef7eb2e8f9f7 77 }
<> 144:ef7eb2e8f9f7 78
<> 144:ef7eb2e8f9f7 79 // read - Master Reciever Mode
<> 144:ef7eb2e8f9f7 80 int I2C::read(int address, char* data, int length, bool repeated) {
<> 144:ef7eb2e8f9f7 81 lock();
<> 144:ef7eb2e8f9f7 82 aquire();
<> 144:ef7eb2e8f9f7 83
<> 144:ef7eb2e8f9f7 84 int stop = (repeated) ? 0 : 1;
<> 144:ef7eb2e8f9f7 85 int read = i2c_read(&_i2c, address, data, length, stop);
<> 144:ef7eb2e8f9f7 86
<> 144:ef7eb2e8f9f7 87 unlock();
<> 144:ef7eb2e8f9f7 88 return length != read;
<> 144:ef7eb2e8f9f7 89 }
<> 144:ef7eb2e8f9f7 90
<> 144:ef7eb2e8f9f7 91 int I2C::read(int ack) {
<> 144:ef7eb2e8f9f7 92 lock();
<> 144:ef7eb2e8f9f7 93 int ret;
<> 144:ef7eb2e8f9f7 94 if (ack) {
<> 144:ef7eb2e8f9f7 95 ret = i2c_byte_read(&_i2c, 0);
<> 144:ef7eb2e8f9f7 96 } else {
<> 144:ef7eb2e8f9f7 97 ret = i2c_byte_read(&_i2c, 1);
<> 144:ef7eb2e8f9f7 98 }
<> 144:ef7eb2e8f9f7 99 unlock();
<> 144:ef7eb2e8f9f7 100 return ret;
<> 144:ef7eb2e8f9f7 101 }
<> 144:ef7eb2e8f9f7 102
<> 144:ef7eb2e8f9f7 103 void I2C::start(void) {
<> 144:ef7eb2e8f9f7 104 lock();
<> 144:ef7eb2e8f9f7 105 i2c_start(&_i2c);
<> 144:ef7eb2e8f9f7 106 unlock();
<> 144:ef7eb2e8f9f7 107 }
<> 144:ef7eb2e8f9f7 108
<> 144:ef7eb2e8f9f7 109 void I2C::stop(void) {
<> 144:ef7eb2e8f9f7 110 lock();
<> 144:ef7eb2e8f9f7 111 i2c_stop(&_i2c);
<> 144:ef7eb2e8f9f7 112 unlock();
<> 144:ef7eb2e8f9f7 113 }
<> 144:ef7eb2e8f9f7 114
<> 144:ef7eb2e8f9f7 115 void I2C::lock() {
<> 144:ef7eb2e8f9f7 116 _mutex->lock();
<> 144:ef7eb2e8f9f7 117 }
<> 144:ef7eb2e8f9f7 118
<> 144:ef7eb2e8f9f7 119 void I2C::unlock() {
<> 144:ef7eb2e8f9f7 120 _mutex->unlock();
<> 144:ef7eb2e8f9f7 121 }
<> 144:ef7eb2e8f9f7 122
<> 144:ef7eb2e8f9f7 123 #if DEVICE_I2C_ASYNCH
<> 144:ef7eb2e8f9f7 124
<> 144:ef7eb2e8f9f7 125 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)
<> 144:ef7eb2e8f9f7 126 {
<> 144:ef7eb2e8f9f7 127 lock();
<> 144:ef7eb2e8f9f7 128 if (i2c_active(&_i2c)) {
<> 144:ef7eb2e8f9f7 129 unlock();
<> 144:ef7eb2e8f9f7 130 return -1; // transaction ongoing
<> 144:ef7eb2e8f9f7 131 }
<> 144:ef7eb2e8f9f7 132 aquire();
<> 144:ef7eb2e8f9f7 133
<> 144:ef7eb2e8f9f7 134 _callback = callback;
<> 144:ef7eb2e8f9f7 135 int stop = (repeated) ? 0 : 1;
<> 144:ef7eb2e8f9f7 136 _irq.callback(&I2C::irq_handler_asynch);
<> 144:ef7eb2e8f9f7 137 i2c_transfer_asynch(&_i2c, (void *)tx_buffer, tx_length, (void *)rx_buffer, rx_length, address, stop, _irq.entry(), event, _usage);
<> 144:ef7eb2e8f9f7 138 unlock();
<> 144:ef7eb2e8f9f7 139 return 0;
<> 144:ef7eb2e8f9f7 140 }
<> 144:ef7eb2e8f9f7 141
<> 144:ef7eb2e8f9f7 142 void I2C::abort_transfer(void)
<> 144:ef7eb2e8f9f7 143 {
<> 144:ef7eb2e8f9f7 144 lock();
<> 144:ef7eb2e8f9f7 145 i2c_abort_asynch(&_i2c);
<> 144:ef7eb2e8f9f7 146 unlock();
<> 144:ef7eb2e8f9f7 147 }
<> 144:ef7eb2e8f9f7 148
<> 144:ef7eb2e8f9f7 149 void I2C::irq_handler_asynch(void)
<> 144:ef7eb2e8f9f7 150 {
<> 144:ef7eb2e8f9f7 151 int event = i2c_irq_handler_asynch(&_i2c);
<> 144:ef7eb2e8f9f7 152 if (_callback && event) {
<> 144:ef7eb2e8f9f7 153 _callback.call(event);
<> 144:ef7eb2e8f9f7 154 }
<> 144:ef7eb2e8f9f7 155
<> 144:ef7eb2e8f9f7 156 }
<> 144:ef7eb2e8f9f7 157
<> 144:ef7eb2e8f9f7 158
<> 144:ef7eb2e8f9f7 159 #endif
<> 144:ef7eb2e8f9f7 160
<> 144:ef7eb2e8f9f7 161 } // namespace mbed
<> 144:ef7eb2e8f9f7 162
<> 144:ef7eb2e8f9f7 163 #endif