mbed library sources. Supersedes mbed-src.
Dependents: LPCXpresso1769_blinky
Fork of mbed-dev by
SPI.h
00001 /* mbed Microcontroller Library 00002 * Copyright (c) 2006-2015 ARM Limited 00003 * 00004 * Licensed under the Apache License, Version 2.0 (the "License"); 00005 * you may not use this file except in compliance with the License. 00006 * You may obtain a copy of the License at 00007 * 00008 * http://www.apache.org/licenses/LICENSE-2.0 00009 * 00010 * Unless required by applicable law or agreed to in writing, software 00011 * distributed under the License is distributed on an "AS IS" BASIS, 00012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 00013 * See the License for the specific language governing permissions and 00014 * limitations under the License. 00015 */ 00016 #ifndef MBED_SPI_H 00017 #define MBED_SPI_H 00018 00019 #include "platform.h" 00020 00021 #if DEVICE_SPI 00022 00023 #include "PlatformMutex.h" 00024 #include "spi_api.h" 00025 #include "SingletonPtr.h" 00026 00027 #if DEVICE_SPI_ASYNCH 00028 #include "CThunk.h" 00029 #include "dma_api.h" 00030 #include "CircularBuffer.h" 00031 #include "FunctionPointer.h" 00032 #include "Transaction.h" 00033 #endif 00034 00035 namespace mbed { 00036 00037 /** A SPI Master, used for communicating with SPI slave devices 00038 * 00039 * The default format is set to 8-bits, mode 0, and a clock frequency of 1MHz 00040 * 00041 * Most SPI devices will also require Chip Select and Reset signals. These 00042 * can be controlled using <DigitalOut> pins 00043 * 00044 * @Note Synchronization level: Thread safe 00045 * 00046 * Example: 00047 * @code 00048 * // Send a byte to a SPI slave, and record the response 00049 * 00050 * #include "mbed.h" 00051 * 00052 * // hardware ssel (where applicable) 00053 * //SPI device(p5, p6, p7, p8); // mosi, miso, sclk, ssel 00054 * 00055 * // software ssel 00056 * SPI device(p5, p6, p7); // mosi, miso, sclk 00057 * DigitalOut cs(p8); // ssel 00058 * 00059 * int main() { 00060 * // hardware ssel (where applicable) 00061 * //int response = device.write(0xFF); 00062 * 00063 * device.lock(); 00064 * // software ssel 00065 * cs = 0; 00066 * int response = device.write(0xFF); 00067 * cs = 1; 00068 * device.unlock(); 00069 * 00070 * } 00071 * @endcode 00072 */ 00073 class SPI { 00074 00075 public: 00076 00077 /** Create a SPI master connected to the specified pins 00078 * 00079 * mosi or miso can be specfied as NC if not used 00080 * 00081 * @param mosi SPI Master Out, Slave In pin 00082 * @param miso SPI Master In, Slave Out pin 00083 * @param sclk SPI Clock pin 00084 * @param ssel SPI chip select pin 00085 */ 00086 SPI(PinName mosi, PinName miso, PinName sclk, PinName ssel=NC); 00087 00088 /** Configure the data transmission format 00089 * 00090 * @param bits Number of bits per SPI frame (4 - 16) 00091 * @param mode Clock polarity and phase mode (0 - 3) 00092 * 00093 * @code 00094 * mode | POL PHA 00095 * -----+-------- 00096 * 0 | 0 0 00097 * 1 | 0 1 00098 * 2 | 1 0 00099 * 3 | 1 1 00100 * @endcode 00101 */ 00102 void format(int bits, int mode = 0); 00103 00104 /** Set the spi bus clock frequency 00105 * 00106 * @param hz SCLK frequency in hz (default = 1MHz) 00107 */ 00108 void frequency(int hz = 1000000); 00109 00110 /** Write to the SPI Slave and return the response 00111 * 00112 * @param value Data to be sent to the SPI slave 00113 * 00114 * @returns 00115 * Response from the SPI slave 00116 */ 00117 virtual int write(int value); 00118 00119 /** Acquire exclusive access to this SPI bus 00120 */ 00121 virtual void lock(void); 00122 00123 /** Release exclusive access to this SPI bus 00124 */ 00125 virtual void unlock(void); 00126 00127 #if DEVICE_SPI_ASYNCH 00128 00129 /** Start non-blocking SPI transfer using 8bit buffers. 00130 * 00131 * @param tx_buffer The TX buffer with data to be transfered. If NULL is passed, 00132 * the default SPI value is sent 00133 * @param tx_length The length of TX buffer in bytes 00134 * @param rx_buffer The RX buffer which is used for received data. If NULL is passed, 00135 * received data are ignored 00136 * @param rx_length The length of RX buffer in bytes 00137 * @param callback The event callback function 00138 * @param event The logical OR of events to modify. Look at spi hal header file for SPI events. 00139 * @return Zero if the transfer has started, or -1 if SPI peripheral is busy 00140 */ 00141 template<typename Type> 00142 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) { 00143 if (spi_active(&_spi)) { 00144 return queue_transfer (tx_buffer, tx_length, rx_buffer, rx_length, sizeof(Type)*8, callback, event); 00145 } 00146 start_transfer(tx_buffer, tx_length, rx_buffer, rx_length, sizeof(Type)*8, callback, event); 00147 return 0; 00148 } 00149 00150 /** Abort the on-going SPI transfer, and continue with transfer's in the queue if any. 00151 */ 00152 void abort_transfer(); 00153 00154 /** Clear the transaction buffer 00155 */ 00156 void clear_transfer_buffer(); 00157 00158 /** Clear the transaction buffer and abort on-going transfer. 00159 */ 00160 void abort_all_transfers(); 00161 00162 /** Configure DMA usage suggestion for non-blocking transfers 00163 * 00164 * @param usage The usage DMA hint for peripheral 00165 * @return Zero if the usage was set, -1 if a transaction is on-going 00166 */ 00167 int set_dma_usage(DMAUsage usage); 00168 00169 protected: 00170 /** SPI IRQ handler 00171 * 00172 */ 00173 void irq_handler_asynch(void); 00174 00175 /** Common transfer method 00176 * 00177 * @param tx_buffer The TX buffer with data to be transfered. If NULL is passed, 00178 * the default SPI value is sent 00179 * @param tx_length The length of TX buffer in bytes 00180 * @param rx_buffer The RX buffer which is used for received data. If NULL is passed, 00181 * received data are ignored 00182 * @param rx_length The length of RX buffer in bytes 00183 * @param bit_width The buffers element width 00184 * @param callback The event callback function 00185 * @param event The logical OR of events to modify 00186 * @return Zero if the transfer has started or was added to the queue, or -1 if SPI peripheral is busy/buffer is full 00187 */ 00188 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); 00189 00190 /** 00191 * 00192 * @param tx_buffer The TX buffer with data to be transfered. If NULL is passed, 00193 * the default SPI value is sent 00194 * @param tx_length The length of TX buffer in bytes 00195 * @param rx_buffer The RX buffer which is used for received data. If NULL is passed, 00196 * received data are ignored 00197 * @param rx_length The length of RX buffer in bytes 00198 * @param bit_width The buffers element width 00199 * @param callback The event callback function 00200 * @param event The logical OR of events to modify 00201 * @return Zero if a transfer was added to the queue, or -1 if the queue is full 00202 */ 00203 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); 00204 00205 /** Configures a callback, spi peripheral and initiate a new transfer 00206 * 00207 * @param tx_buffer The TX buffer with data to be transfered. If NULL is passed, 00208 * the default SPI value is sent 00209 * @param tx_length The length of TX buffer in bytes 00210 * @param rx_buffer The RX buffer which is used for received data. If NULL is passed, 00211 * received data are ignored 00212 * @param rx_length The length of RX buffer in bytes 00213 * @param bit_width The buffers element width 00214 * @param callback The event callback function 00215 * @param event The logical OR of events to modify 00216 */ 00217 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); 00218 00219 #if TRANSACTION_QUEUE_SIZE_SPI 00220 00221 /** Start a new transaction 00222 * 00223 * @param data Transaction data 00224 */ 00225 void start_transaction(transaction_t *data); 00226 00227 /** Dequeue a transaction 00228 * 00229 */ 00230 void dequeue_transaction(); 00231 static CircularBuffer<Transaction<SPI>, TRANSACTION_QUEUE_SIZE_SPI> _transaction_buffer; 00232 #endif 00233 00234 #endif 00235 00236 public: 00237 virtual ~SPI() { 00238 } 00239 00240 protected: 00241 spi_t _spi; 00242 00243 #if DEVICE_SPI_ASYNCH 00244 CThunk<SPI> _irq; 00245 event_callback_t _callback; 00246 DMAUsage _usage; 00247 #endif 00248 00249 void aquire(void); 00250 static SPI *_owner; 00251 static SingletonPtr<PlatformMutex> _mutex; 00252 int _bits; 00253 int _mode; 00254 int _hz; 00255 }; 00256 00257 } // namespace mbed 00258 00259 #endif 00260 00261 #endif
Generated on Tue Jul 12 2022 16:04:26 by 1.7.2