Lancaster University / mbed-src

Lancaster University's (short term!) clone of mbed-src for micro:bit. This is a copy of the github branch https://github.com/lancaster-university/mbed-classic

Fork of mbed-src by mbed official

common/SPI.cpp@552:a1b9575155a3, 2015-05-27 (annotated)

Committer:
mbed_official
Date:
Wed May 27 13:30:08 2015 +0100
Revision:
552:a1b9575155a3
Parent:
525:c320967f86b9
Child:
563:536c9fb088a0
Synchronized with git revision a74a8f14fd8c4bf3dc09980c4bf9498ebcf4c207



Full URL: https://github.com/mbedmicro/mbed/commit/a74a8f14fd8c4bf3dc09980c4bf9498ebcf4c207/

Who changed what in which revision?

UserRevisionLine numberNew contents of line
bogdanm 13:0645d8841f51 1 /* mbed Microcontroller Library
bogdanm 13:0645d8841f51 2 * Copyright (c) 2006-2013 ARM Limited
bogdanm 13:0645d8841f51 3 *
bogdanm 13:0645d8841f51 4 * Licensed under the Apache License, Version 2.0 (the "License");
bogdanm 13:0645d8841f51 5 * you may not use this file except in compliance with the License.
bogdanm 13:0645d8841f51 6 * You may obtain a copy of the License at
bogdanm 13:0645d8841f51 7 *
bogdanm 13:0645d8841f51 8 * http://www.apache.org/licenses/LICENSE-2.0
bogdanm 13:0645d8841f51 9 *
bogdanm 13:0645d8841f51 10 * Unless required by applicable law or agreed to in writing, software
bogdanm 13:0645d8841f51 11 * distributed under the License is distributed on an "AS IS" BASIS,
bogdanm 13:0645d8841f51 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
bogdanm 13:0645d8841f51 13 * See the License for the specific language governing permissions and
bogdanm 13:0645d8841f51 14 * limitations under the License.
bogdanm 13:0645d8841f51 15 */
bogdanm 13:0645d8841f51 16 #include "SPI.h"
bogdanm 13:0645d8841f51 17
bogdanm 13:0645d8841f51 18 #if DEVICE_SPI
bogdanm 13:0645d8841f51 19
bogdanm 13:0645d8841f51 20 namespace mbed {
bogdanm 13:0645d8841f51 21
mbed_official 525:c320967f86b9 22 #if DEVICE_SPI_ASYNCH && TRANSACTION_QUEUE_SIZE_SPI
mbed_official 525:c320967f86b9 23 CircularBuffer<Transaction<SPI>, TRANSACTION_QUEUE_SIZE_SPI> SPI::_transaction_buffer;
mbed_official 525:c320967f86b9 24 #endif
mbed_official 525:c320967f86b9 25
mbed_official 552:a1b9575155a3 26 SPI::SPI(PinName mosi, PinName miso, PinName sclk, PinName ssel) :
mbed_official 212:34d62c0b2af6 27 _spi(),
mbed_official 525:c320967f86b9 28 #if DEVICE_SPI_ASYNCH
mbed_official 525:c320967f86b9 29 _irq(this),
mbed_official 525:c320967f86b9 30 _usage(DMA_USAGE_NEVER),
mbed_official 525:c320967f86b9 31 #endif
mbed_official 212:34d62c0b2af6 32 _bits(8),
mbed_official 212:34d62c0b2af6 33 _mode(0),
mbed_official 212:34d62c0b2af6 34 _hz(1000000) {
mbed_official 552:a1b9575155a3 35 spi_init(&_spi, mosi, miso, sclk, ssel);
bogdanm 13:0645d8841f51 36 spi_format(&_spi, _bits, _mode, 0);
bogdanm 13:0645d8841f51 37 spi_frequency(&_spi, _hz);
bogdanm 13:0645d8841f51 38 }
bogdanm 13:0645d8841f51 39
bogdanm 13:0645d8841f51 40 void SPI::format(int bits, int mode) {
bogdanm 13:0645d8841f51 41 _bits = bits;
bogdanm 13:0645d8841f51 42 _mode = mode;
bogdanm 13:0645d8841f51 43 SPI::_owner = NULL; // Not that elegant, but works. rmeyer
bogdanm 13:0645d8841f51 44 aquire();
bogdanm 13:0645d8841f51 45 }
bogdanm 13:0645d8841f51 46
bogdanm 13:0645d8841f51 47 void SPI::frequency(int hz) {
bogdanm 13:0645d8841f51 48 _hz = hz;
bogdanm 13:0645d8841f51 49 SPI::_owner = NULL; // Not that elegant, but works. rmeyer
bogdanm 13:0645d8841f51 50 aquire();
bogdanm 13:0645d8841f51 51 }
bogdanm 13:0645d8841f51 52
bogdanm 13:0645d8841f51 53 SPI* SPI::_owner = NULL;
bogdanm 13:0645d8841f51 54
bogdanm 13:0645d8841f51 55 // ignore the fact there are multiple physical spis, and always update if it wasnt us last
bogdanm 13:0645d8841f51 56 void SPI::aquire() {
bogdanm 13:0645d8841f51 57 if (_owner != this) {
bogdanm 13:0645d8841f51 58 spi_format(&_spi, _bits, _mode, 0);
bogdanm 13:0645d8841f51 59 spi_frequency(&_spi, _hz);
bogdanm 13:0645d8841f51 60 _owner = this;
bogdanm 13:0645d8841f51 61 }
bogdanm 13:0645d8841f51 62 }
bogdanm 13:0645d8841f51 63
bogdanm 13:0645d8841f51 64 int SPI::write(int value) {
bogdanm 13:0645d8841f51 65 aquire();
bogdanm 13:0645d8841f51 66 return spi_master_write(&_spi, value);
bogdanm 13:0645d8841f51 67 }
bogdanm 13:0645d8841f51 68
mbed_official 525:c320967f86b9 69 #if DEVICE_SPI_ASYNCH
mbed_official 525:c320967f86b9 70
mbed_official 525:c320967f86b9 71 int SPI::transfer(void *tx_buffer, int tx_length, void *rx_buffer, int rx_length, unsigned char bit_width, const event_callback_t& callback, int event)
mbed_official 525:c320967f86b9 72 {
mbed_official 525:c320967f86b9 73 if (spi_active(&_spi)) {
mbed_official 525:c320967f86b9 74 return queue_transfer(tx_buffer, tx_length, rx_buffer, rx_length, bit_width, callback, event);
mbed_official 525:c320967f86b9 75 }
mbed_official 525:c320967f86b9 76 start_transfer(tx_buffer, tx_length, rx_buffer, rx_length, bit_width, callback, event);
mbed_official 525:c320967f86b9 77 return 0;
mbed_official 525:c320967f86b9 78 }
mbed_official 525:c320967f86b9 79
mbed_official 525:c320967f86b9 80 void SPI::abort_transfer()
mbed_official 525:c320967f86b9 81 {
mbed_official 525:c320967f86b9 82 spi_abort_asynch(&_spi);
mbed_official 525:c320967f86b9 83 #if TRANSACTION_QUEUE_SIZE_SPI
mbed_official 525:c320967f86b9 84 dequeue_transaction();
mbed_official 525:c320967f86b9 85 #endif
mbed_official 525:c320967f86b9 86 }
mbed_official 525:c320967f86b9 87
mbed_official 525:c320967f86b9 88
mbed_official 525:c320967f86b9 89 void SPI::clear_transfer_buffer()
mbed_official 525:c320967f86b9 90 {
mbed_official 525:c320967f86b9 91 #if TRANSACTION_QUEUE_SIZE_SPI
mbed_official 525:c320967f86b9 92 _transaction_buffer.reset();
mbed_official 525:c320967f86b9 93 #endif
mbed_official 525:c320967f86b9 94 }
mbed_official 525:c320967f86b9 95
mbed_official 525:c320967f86b9 96 void SPI::abort_all_transfers()
mbed_official 525:c320967f86b9 97 {
mbed_official 525:c320967f86b9 98 clear_transfer_buffer();
mbed_official 525:c320967f86b9 99 abort_transfer();
mbed_official 525:c320967f86b9 100 }
mbed_official 525:c320967f86b9 101
mbed_official 525:c320967f86b9 102 int SPI::set_dma_usage(DMAUsage usage)
mbed_official 525:c320967f86b9 103 {
mbed_official 525:c320967f86b9 104 if (spi_active(&_spi)) {
mbed_official 525:c320967f86b9 105 return -1;
mbed_official 525:c320967f86b9 106 }
mbed_official 525:c320967f86b9 107 _usage = usage;
mbed_official 525:c320967f86b9 108 return 0;
mbed_official 525:c320967f86b9 109 }
mbed_official 525:c320967f86b9 110
mbed_official 525:c320967f86b9 111 int SPI::queue_transfer(void *tx_buffer, int tx_length, void *rx_buffer, int rx_length, unsigned char bit_width, const event_callback_t& callback, int event)
mbed_official 525:c320967f86b9 112 {
mbed_official 525:c320967f86b9 113 #if TRANSACTION_QUEUE_SIZE_SPI
mbed_official 525:c320967f86b9 114 transaction_t t;
mbed_official 525:c320967f86b9 115
mbed_official 525:c320967f86b9 116 t.tx_buffer = tx_buffer;
mbed_official 525:c320967f86b9 117 t.tx_length = tx_length;
mbed_official 525:c320967f86b9 118 t.rx_buffer = rx_buffer;
mbed_official 525:c320967f86b9 119 t.rx_length = rx_length;
mbed_official 525:c320967f86b9 120 t.event = event;
mbed_official 525:c320967f86b9 121 t.callback = callback;
mbed_official 525:c320967f86b9 122 t.width = bit_width;
mbed_official 525:c320967f86b9 123 Transaction<SPI> transaction(this, t);
mbed_official 525:c320967f86b9 124 if (_transaction_buffer.full()) {
mbed_official 525:c320967f86b9 125 return -1; // the buffer is full
mbed_official 525:c320967f86b9 126 } else {
mbed_official 525:c320967f86b9 127 _transaction_buffer.push(transaction);
mbed_official 525:c320967f86b9 128 return 0;
mbed_official 525:c320967f86b9 129 }
mbed_official 525:c320967f86b9 130 #else
mbed_official 525:c320967f86b9 131 return -1;
mbed_official 525:c320967f86b9 132 #endif
mbed_official 525:c320967f86b9 133 }
mbed_official 525:c320967f86b9 134
mbed_official 525:c320967f86b9 135 void SPI::start_transfer(void *tx_buffer, int tx_length, void *rx_buffer, int rx_length, unsigned char bit_width, const event_callback_t& callback, int event)
mbed_official 525:c320967f86b9 136 {
mbed_official 525:c320967f86b9 137 aquire();
mbed_official 525:c320967f86b9 138 _callback = callback;
mbed_official 525:c320967f86b9 139 _irq.callback(&SPI::irq_handler_asynch);
mbed_official 525:c320967f86b9 140 spi_master_transfer(&_spi, tx_buffer, tx_length, rx_buffer, rx_length, bit_width, _irq.entry(), event , _usage);
mbed_official 525:c320967f86b9 141 }
mbed_official 525:c320967f86b9 142
mbed_official 525:c320967f86b9 143 #if TRANSACTION_QUEUE_SIZE_SPI
mbed_official 525:c320967f86b9 144
mbed_official 525:c320967f86b9 145 void SPI::start_transaction(transaction_t *data)
mbed_official 525:c320967f86b9 146 {
mbed_official 525:c320967f86b9 147 start_transfer(data->tx_buffer, data->tx_length, data->rx_buffer, data->rx_length, data->width, data->callback, data->event);
mbed_official 525:c320967f86b9 148 }
mbed_official 525:c320967f86b9 149
mbed_official 525:c320967f86b9 150 void SPI::dequeue_transaction()
mbed_official 525:c320967f86b9 151 {
mbed_official 525:c320967f86b9 152 Transaction<SPI> t;
mbed_official 525:c320967f86b9 153 if (_transaction_buffer.pop(t)) {
mbed_official 525:c320967f86b9 154 SPI* obj = t.get_object();
mbed_official 525:c320967f86b9 155 transaction_t* data = t.get_transaction();
mbed_official 525:c320967f86b9 156 obj->start_transaction(data);
mbed_official 525:c320967f86b9 157 }
mbed_official 525:c320967f86b9 158 }
mbed_official 525:c320967f86b9 159
mbed_official 525:c320967f86b9 160 #endif
mbed_official 525:c320967f86b9 161
mbed_official 525:c320967f86b9 162 void SPI::irq_handler_asynch(void)
mbed_official 525:c320967f86b9 163 {
mbed_official 525:c320967f86b9 164 int event = spi_irq_handler_asynch(&_spi);
mbed_official 525:c320967f86b9 165 if (_callback && (event & SPI_EVENT_ALL)) {
mbed_official 525:c320967f86b9 166 _callback.call(event & SPI_EVENT_ALL);
mbed_official 525:c320967f86b9 167 }
mbed_official 525:c320967f86b9 168 #if TRANSACTION_QUEUE_SIZE_SPI
mbed_official 525:c320967f86b9 169 if (event & (SPI_EVENT_ALL | SPI_EVENT_INTERNAL_TRANSFER_COMPLETE)) {
mbed_official 525:c320967f86b9 170 // SPI peripheral is free (event happend), dequeue transaction
mbed_official 525:c320967f86b9 171 dequeue_transaction();
mbed_official 525:c320967f86b9 172 }
mbed_official 525:c320967f86b9 173 #endif
mbed_official 525:c320967f86b9 174 }
mbed_official 525:c320967f86b9 175
mbed_official 525:c320967f86b9 176 #endif
mbed_official 525:c320967f86b9 177
bogdanm 13:0645d8841f51 178 } // namespace mbed
bogdanm 13:0645d8841f51 179
bogdanm 13:0645d8841f51 180 #endif