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
Diff: common/SPI.cpp
- Revision:
- 525:c320967f86b9
- Parent:
- 212:34d62c0b2af6
- Child:
- 552:a1b9575155a3
diff -r c0134becc221 -r c320967f86b9 common/SPI.cpp --- a/common/SPI.cpp Mon Apr 27 09:45:08 2015 +0100 +++ b/common/SPI.cpp Tue Apr 28 11:45:12 2015 +0100 @@ -19,8 +19,16 @@ namespace mbed { +#if DEVICE_SPI_ASYNCH && TRANSACTION_QUEUE_SIZE_SPI +CircularBuffer<Transaction<SPI>, TRANSACTION_QUEUE_SIZE_SPI> SPI::_transaction_buffer; +#endif + SPI::SPI(PinName mosi, PinName miso, PinName sclk, PinName _unused) : _spi(), +#if DEVICE_SPI_ASYNCH + _irq(this), + _usage(DMA_USAGE_NEVER), +#endif _bits(8), _mode(0), _hz(1000000) { @@ -58,6 +66,115 @@ return spi_master_write(&_spi, value); } +#if DEVICE_SPI_ASYNCH + +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) +{ + if (spi_active(&_spi)) { + return queue_transfer(tx_buffer, tx_length, rx_buffer, rx_length, bit_width, callback, event); + } + start_transfer(tx_buffer, tx_length, rx_buffer, rx_length, bit_width, callback, event); + return 0; +} + +void SPI::abort_transfer() +{ + spi_abort_asynch(&_spi); +#if TRANSACTION_QUEUE_SIZE_SPI + dequeue_transaction(); +#endif +} + + +void SPI::clear_transfer_buffer() +{ +#if TRANSACTION_QUEUE_SIZE_SPI + _transaction_buffer.reset(); +#endif +} + +void SPI::abort_all_transfers() +{ + clear_transfer_buffer(); + abort_transfer(); +} + +int SPI::set_dma_usage(DMAUsage usage) +{ + if (spi_active(&_spi)) { + return -1; + } + _usage = usage; + return 0; +} + +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) +{ +#if TRANSACTION_QUEUE_SIZE_SPI + transaction_t t; + + t.tx_buffer = tx_buffer; + t.tx_length = tx_length; + t.rx_buffer = rx_buffer; + t.rx_length = rx_length; + t.event = event; + t.callback = callback; + t.width = bit_width; + Transaction<SPI> transaction(this, t); + if (_transaction_buffer.full()) { + return -1; // the buffer is full + } else { + _transaction_buffer.push(transaction); + return 0; + } +#else + return -1; +#endif +} + +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) +{ + aquire(); + _callback = callback; + _irq.callback(&SPI::irq_handler_asynch); + spi_master_transfer(&_spi, tx_buffer, tx_length, rx_buffer, rx_length, bit_width, _irq.entry(), event , _usage); +} + +#if TRANSACTION_QUEUE_SIZE_SPI + +void SPI::start_transaction(transaction_t *data) +{ + start_transfer(data->tx_buffer, data->tx_length, data->rx_buffer, data->rx_length, data->width, data->callback, data->event); +} + +void SPI::dequeue_transaction() +{ + Transaction<SPI> t; + if (_transaction_buffer.pop(t)) { + SPI* obj = t.get_object(); + transaction_t* data = t.get_transaction(); + obj->start_transaction(data); + } +} + +#endif + +void SPI::irq_handler_asynch(void) +{ + int event = spi_irq_handler_asynch(&_spi); + if (_callback && (event & SPI_EVENT_ALL)) { + _callback.call(event & SPI_EVENT_ALL); + } +#if TRANSACTION_QUEUE_SIZE_SPI + if (event & (SPI_EVENT_ALL | SPI_EVENT_INTERNAL_TRANSFER_COMPLETE)) { + // SPI peripheral is free (event happend), dequeue transaction + dequeue_transaction(); + } +#endif +} + +#endif + } // namespace mbed #endif