mirror of https://github.com/ARMmbed/mbed-os.git
308 lines
9.9 KiB
C++
308 lines
9.9 KiB
C++
/* mbed Microcontroller Library
|
|
* Copyright (c) 2006-2015 ARM Limited
|
|
*
|
|
* 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 defined (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:
|
|
* @code
|
|
* // Send a byte to a SPI slave, and record the response
|
|
*
|
|
* #include "mbed.h"
|
|
*
|
|
* // hardware ssel (where applicable)
|
|
* //SPI device(p5, p6, p7, p8); // mosi, miso, sclk, ssel
|
|
*
|
|
* // software ssel
|
|
* SPI device(p5, p6, p7); // mosi, miso, sclk
|
|
* DigitalOut cs(p8); // ssel
|
|
*
|
|
* int main() {
|
|
* // hardware ssel (where applicable)
|
|
* //int response = device.write(0xFF);
|
|
*
|
|
* device.lock();
|
|
* // software ssel
|
|
* cs = 0;
|
|
* int response = device.write(0xFF);
|
|
* cs = 1;
|
|
* device.unlock();
|
|
*
|
|
* }
|
|
* @endcode
|
|
* @ingroup drivers
|
|
*/
|
|
class SPI : private NonCopyable<SPI> {
|
|
|
|
public:
|
|
|
|
/** Create a SPI master connected to the specified pins
|
|
*
|
|
* mosi or miso can be specified 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);
|
|
|
|
/** 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 SCLK 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
|
|
*
|
|
* @returns
|
|
* 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
|
|
* @returns
|
|
* 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 while 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 transfered. 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 logical OR of events to modify. Look at spi hal header file for SPI events.
|
|
* @return Zero if the transfer has started, or -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 transfer's in the queue if any.
|
|
*/
|
|
void abort_transfer();
|
|
|
|
/** Clear the transaction buffer
|
|
*/
|
|
void clear_transfer_buffer();
|
|
|
|
/** Clear the transaction buffer and abort on-going transfer.
|
|
*/
|
|
void abort_all_transfers();
|
|
|
|
/** Configure DMA usage suggestion for non-blocking transfers
|
|
*
|
|
* @param usage The usage DMA hint for peripheral
|
|
* @return Zero if the usage was set, -1 if a transaction is on-going
|
|
*/
|
|
int set_dma_usage(DMAUsage usage);
|
|
|
|
protected:
|
|
/** SPI IRQ handler
|
|
*
|
|
*/
|
|
void irq_handler_asynch(void);
|
|
|
|
/** Common transfer method
|
|
*
|
|
* @param tx_buffer The TX buffer with data to be transfered. 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 logical OR of events to modify
|
|
* @return Zero if the transfer has started or was added to the queue, or -1 if SPI peripheral is busy/buffer 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);
|
|
|
|
/**
|
|
*
|
|
* @param tx_buffer The TX buffer with data to be transfered. 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 logical OR of events to modify
|
|
* @return Zero if a transfer was added to the queue, or -1 if the 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);
|
|
|
|
/** Configures a callback, spi peripheral and initiate a new transfer
|
|
*
|
|
* @param tx_buffer The TX buffer with data to be transfered. 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 logical OR 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
|
|
*
|
|
*/
|
|
void dequeue_transaction();
|
|
static CircularBuffer<Transaction<SPI>, TRANSACTION_QUEUE_SIZE_SPI> _transaction_buffer;
|
|
#endif
|
|
|
|
#endif
|
|
|
|
public:
|
|
virtual ~SPI() {
|
|
}
|
|
|
|
protected:
|
|
spi_t _spi;
|
|
|
|
#if DEVICE_SPI_ASYNCH
|
|
CThunk<SPI> _irq;
|
|
event_callback_t _callback;
|
|
DMAUsage _usage;
|
|
bool _deep_sleep_locked;
|
|
#endif
|
|
|
|
void aquire(void);
|
|
static SPI *_owner;
|
|
static SingletonPtr<PlatformMutex> _mutex;
|
|
int _bits;
|
|
int _mode;
|
|
int _hz;
|
|
char _write_fill;
|
|
|
|
private:
|
|
/* Private acquire function without locking/unlocking
|
|
* Implemented in order to avoid duplicate locking and boost performance
|
|
*/
|
|
void _acquire(void);
|
|
};
|
|
|
|
} // namespace mbed
|
|
|
|
#endif
|
|
|
|
#endif
|