mirror of https://github.com/ARMmbed/mbed-os.git
135 lines
3.5 KiB
C++
135 lines
3.5 KiB
C++
/* mbed Microcontroller Library
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* Copyright (c) 2006-2013 ARM Limited
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* SPDX-License-Identifier: Apache-2.0
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#ifndef MBED_SPISLAVE_H
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#define MBED_SPISLAVE_H
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#include "platform/platform.h"
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#include "platform/NonCopyable.h"
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#if DEVICE_SPISLAVE || defined(DOXYGEN_ONLY)
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#include "hal/spi_api.h"
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namespace mbed {
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/** \addtogroup drivers */
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/** A SPI slave, used for communicating with a SPI master device.
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*
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* The default format is set to 8 bits, mode 0 and a clock frequency of 1MHz.
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*
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* @note Synchronization level: Not protected
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*
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* Example of how to reply to a SPI master as slave:
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* @code
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*
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* #include "mbed.h"
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*
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* SPISlave device(SPI_MOSI, SPI_MISO, SPI_SCLK, SPI_CS);
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*
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* int main() {
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* device.reply(0x00); // Prime SPI with first reply
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* while(1) {
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* if(device.receive()) {
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* int v = device.read(); // Read byte from master
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* v = (v + 1) % 0x100; // Add one to it, modulo 256
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* device.reply(v); // Make this the next reply
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* }
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* }
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* }
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* @endcode
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* @ingroup drivers
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*/
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class SPISlave : private NonCopyable<SPISlave> {
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public:
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/** Create a SPI slave connected to the specified pins.
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*
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* @note Either mosi or miso can be specified as NC if not used.
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*
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* @param mosi SPI Master Out, Slave In pin.
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* @param miso SPI Master In, Slave Out pin.
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* @param sclk SPI Clock pin.
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* @param ssel SPI Chip Select pin.
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*/
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SPISlave(PinName mosi, PinName miso, PinName sclk, PinName ssel);
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/** Configure the data transmission format.
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*
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* @param bits Number of bits per SPI frame (4 - 16).
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* @param mode Clock polarity and phase mode (0 - 3).
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*
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* @code
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* mode | POL PHA
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* -----+--------
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* 0 | 0 0
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* 1 | 0 1
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* 2 | 1 0
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* 3 | 1 1
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* @endcode
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*/
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void format(int bits, int mode = 0);
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/** Set the SPI bus clock frequency.
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*
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* @param hz Clock frequency in hz (default = 1MHz).
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*/
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void frequency(int hz = 1000000);
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/** Polls the SPI to see if data has been received.
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*
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* @return Presence of received data.
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* @retval 0 No data waiting.
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* @retval 1 Data waiting.
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*/
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int receive(void);
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/** Retrieve data from receive buffer as slave.
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*
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* @return The data in the receive buffer.
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*/
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int read(void);
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/** Fill the transmission buffer with the value to be written out
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* as slave on the next received message from the master.
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*
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* @param value The data to be transmitted next.
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*/
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void reply(int value);
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#if !defined(DOXYGEN_ONLY)
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protected:
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/* Internal SPI object identifying the resources */
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spi_t _spi;
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/* How many bits in an SPI frame */
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int _bits;
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/* Clock phase and polarity */
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int _mode;
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/* Clock frequency */
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int _hz;
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#endif //!defined(DOXYGEN_ONLY)
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};
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} // namespace mbed
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#endif
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#endif
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