mbed library sources. Supersedes mbed-src.
Dependents: Nucleo_Hello_Encoder BLE_iBeaconScan AM1805_DEMO DISCO-F429ZI_ExportTemplate1 ... more
Diff: cmsis/BUILD/mbed/drivers/SPI.h
- Revision:
- 189:f392fc9709a3
diff -r bcfe06ba3d64 -r f392fc9709a3 cmsis/BUILD/mbed/drivers/SPI.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/cmsis/BUILD/mbed/drivers/SPI.h Wed Feb 20 22:31:08 2019 +0000 @@ -0,0 +1,340 @@ +/* mbed Microcontroller Library + * Copyright (c) 2006-2015 ARM Limited + * SPDX-License-Identifier: Apache-2.0 + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +#ifndef MBED_SPI_H +#define MBED_SPI_H + +#include "platform/platform.h" + +#if DEVICE_SPI || defined(DOXYGEN_ONLY) + +#include "platform/PlatformMutex.h" +#include "hal/spi_api.h" +#include "platform/SingletonPtr.h" +#include "platform/NonCopyable.h" + +#if DEVICE_SPI_ASYNCH +#include "platform/CThunk.h" +#include "hal/dma_api.h" +#include "platform/CircularBuffer.h" +#include "platform/FunctionPointer.h" +#include "platform/Transaction.h" +#endif + +namespace mbed { +/** \addtogroup drivers */ + +/** A SPI Master, used for communicating with SPI slave devices. + * + * The default format is set to 8-bits, mode 0, and a clock frequency of 1MHz. + * + * Most SPI devices will also require Chip Select and Reset signals. These + * can be controlled using DigitalOut pins. + * + * @note Synchronization level: Thread safe + * + * Example of how to send a byte to a SPI slave and record the response: + * @code + * #include "mbed.h" + * + * SPI device(SPI_MOSI, SPI_MISO, SPI_SCLK) + * + * DigitalOut chip_select(SPI_CS); + * + * int main() { + * device.lock(); + * chip_select = 0; + * + * int response = device.write(0xFF); + * + * chip_select = 1; + * device.unlock(); + * } + * @endcode + * + * Example using hardware Chip Select line: + * @code + * #include "mbed.h" + * + * SPI device(SPI_MOSI, SPI_MISO, SPI_SCLK, SPI_CS) + * + * int main() { + * device.lock(); + * int response = device.write(0xFF); + * device.unlock(); + * } + * @endcode + * @ingroup drivers + */ +class SPI : private NonCopyable<SPI> { + +public: + + /** Create a SPI master connected to the specified pins. + * + * @note You can specify mosi or miso as NC if not used. + * + * @param mosi SPI Master Out, Slave In pin. + * @param miso SPI Master In, Slave Out pin. + * @param sclk SPI Clock pin. + * @param ssel SPI Chip Select pin. + */ + SPI(PinName mosi, PinName miso, PinName sclk, PinName ssel = NC); + virtual ~SPI(); + + /** Configure the data transmission format. + * + * @param bits Number of bits per SPI frame (4 - 16). + * @param mode Clock polarity and phase mode (0 - 3). + * + * @code + * mode | POL PHA + * -----+-------- + * 0 | 0 0 + * 1 | 0 1 + * 2 | 1 0 + * 3 | 1 1 + * @endcode + */ + void format(int bits, int mode = 0); + + /** Set the SPI bus clock frequency. + * + * @param hz Clock frequency in Hz (default = 1MHz). + */ + void frequency(int hz = 1000000); + + /** Write to the SPI Slave and return the response. + * + * @param value Data to be sent to the SPI slave. + * + * @return Response from the SPI slave. + */ + virtual int write(int value); + + /** Write to the SPI Slave and obtain the response. + * + * The total number of bytes sent and received will be the maximum of + * tx_length and rx_length. The bytes written will be padded with the + * value 0xff. + * + * @param tx_buffer Pointer to the byte-array of data to write to the device. + * @param tx_length Number of bytes to write, may be zero. + * @param rx_buffer Pointer to the byte-array of data to read from the device. + * @param rx_length Number of bytes to read, may be zero. + * @return + * The number of bytes written and read from the device. This is + * maximum of tx_length and rx_length. + */ + virtual int write(const char *tx_buffer, int tx_length, char *rx_buffer, int rx_length); + + /** Acquire exclusive access to this SPI bus. + */ + virtual void lock(void); + + /** Release exclusive access to this SPI bus. + */ + virtual void unlock(void); + + /** Set default write data. + * SPI requires the master to send some data during a read operation. + * Different devices may require different default byte values. + * For example: A SD Card requires default bytes to be 0xFF. + * + * @param data Default character to be transmitted during a read operation. + */ + void set_default_write_value(char data); + +#if DEVICE_SPI_ASYNCH + + /** Start non-blocking SPI transfer using 8bit buffers. + * + * This function locks the deep sleep until any event has occurred. + * + * @param tx_buffer The TX buffer with data to be transferred. If NULL is passed, + * the default SPI value is sent. + * @param tx_length The length of TX buffer in bytes. + * @param rx_buffer The RX buffer which is used for received data. If NULL is passed, + * received data are ignored. + * @param rx_length The length of RX buffer in bytes. + * @param callback The event callback function. + * @param event The event mask of events to modify. @see spi_api.h for SPI events. + * + * @return Operation result. + * @retval 0 If the transfer has started. + * @retval -1 If SPI peripheral is busy. + */ + template<typename Type> + int transfer(const Type *tx_buffer, int tx_length, Type *rx_buffer, int rx_length, const event_callback_t &callback, int event = SPI_EVENT_COMPLETE) + { + if (spi_active(&_spi)) { + return queue_transfer(tx_buffer, tx_length, rx_buffer, rx_length, sizeof(Type) * 8, callback, event); + } + start_transfer(tx_buffer, tx_length, rx_buffer, rx_length, sizeof(Type) * 8, callback, event); + return 0; + } + + /** Abort the on-going SPI transfer, and continue with transfers in the queue, if any. + */ + void abort_transfer(); + + /** Clear the queue of transfers. + */ + void clear_transfer_buffer(); + + /** Clear the queue of transfers and abort the on-going transfer. + */ + void abort_all_transfers(); + + /** Configure DMA usage suggestion for non-blocking transfers. + * + * @param usage The usage DMA hint for peripheral. + * + * @return Result of the operation. + * @retval 0 The usage was set. + * @retval -1 Usage cannot be set as there is an ongoing transaction. + */ + int set_dma_usage(DMAUsage usage); + +#if !defined(DOXYGEN_ONLY) +protected: + /** SPI interrupt handler. + */ + void irq_handler_asynch(void); + + /** Start the transfer or put it on the queue. + * + * @param tx_buffer The TX buffer with data to be transferred. If NULL is passed, + * the default SPI value is sent + * @param tx_length The length of TX buffer in bytes. + * @param rx_buffer The RX buffer which is used for received data. If NULL is passed, + * received data are ignored. + * @param rx_length The length of RX buffer in bytes. + * @param bit_width The buffers element width in bits. + * @param callback The event callback function. + * @param event The event mask of events to modify. + * + * @return Operation success. + * @retval 0 A transfer was started or added to the queue. + * @retval -1 Transfer can't be added because queue is full. + */ + int transfer(const void *tx_buffer, int tx_length, void *rx_buffer, int rx_length, unsigned char bit_width, const event_callback_t &callback, int event); + + /** Put a transfer on the transfer queue. + * + * @param tx_buffer The TX buffer with data to be transferred. If NULL is passed, + * the default SPI value is sent. + * @param tx_length The length of TX buffer in bytes. + * @param rx_buffer The RX buffer which is used for received data. If NULL is passed, + * received data are ignored. + * @param rx_length The length of RX buffer in bytes. + * @param bit_width The buffers element width in bits. + * @param callback The event callback function. + * @param event The event mask of events to modify. + * + * @return Operation success. + * @retval 0 A transfer was added to the queue. + * @retval -1 Transfer can't be added because queue is full. + */ + int queue_transfer(const void *tx_buffer, int tx_length, void *rx_buffer, int rx_length, unsigned char bit_width, const event_callback_t &callback, int event); + + /** Configure a callback, SPI peripheral, and initiate a new transfer. + * + * @param tx_buffer The TX buffer with data to be transferred. If NULL is passed, + * the default SPI value is sent. + * @param tx_length The length of TX buffer in bytes. + * @param rx_buffer The RX buffer which is used for received data. If NULL is passed, + * received data are ignored. + * @param rx_length The length of RX buffer in bytes. + * @param bit_width The buffers element width. + * @param callback The event callback function. + * @param event The event mask of events to modify. + */ + void start_transfer(const void *tx_buffer, int tx_length, void *rx_buffer, int rx_length, unsigned char bit_width, const event_callback_t &callback, int event); + +private: + /** Lock deep sleep only if it is not yet locked */ + void lock_deep_sleep(); + + /** Unlock deep sleep in case it is locked */ + void unlock_deep_sleep(); + + +#if TRANSACTION_QUEUE_SIZE_SPI + + /** Start a new transaction. + * + * @param data Transaction data. + */ + void start_transaction(transaction_t *data); + + /** Dequeue a transaction and start the transfer if there was one pending. + */ + void dequeue_transaction(); + + /* Queue of pending transfers */ + static CircularBuffer<Transaction<SPI>, TRANSACTION_QUEUE_SIZE_SPI> _transaction_buffer; +#endif + +#endif //!defined(DOXYGEN_ONLY) + +#endif //DEVICE_SPI_ASYNCH + +#if !defined(DOXYGEN_ONLY) +protected: + /* Internal SPI object identifying the resources */ + spi_t _spi; + +#if DEVICE_SPI_ASYNCH + /* Interrupt */ + CThunk<SPI> _irq; + /* Interrupt handler callback */ + event_callback_t _callback; + /* Current preferred DMA mode @see dma_api.h */ + DMAUsage _usage; + /* Current sate of the sleep manager */ + bool _deep_sleep_locked; +#endif + + /* Take over the physical SPI and apply our settings (thread safe) */ + void aquire(void); + /* Current user of the SPI */ + static SPI *_owner; + /* Used by lock and unlock for thread safety */ + static SingletonPtr<PlatformMutex> _mutex; + /* Size of the SPI frame */ + int _bits; + /* Clock polairy and phase */ + int _mode; + /* Clock frequency */ + int _hz; + /* Default character used for NULL transfers */ + char _write_fill; + +private: + /** Private acquire function without locking/unlocking. + * Implemented in order to avoid duplicate locking and boost performance. + */ + void _acquire(void); + +#endif //!defined(DOXYGEN_ONLY) +}; + +} // namespace mbed + +#endif + +#endif