Lee Kai Xuan / mbed-os

mbed-os

Fork of mbed-os by erkin yucel

drivers/SPI.h@0:f269e3021894, 2016-10-23 (annotated)

Committer:
elessair
Date:
Sun Oct 23 15:10:02 2016 +0000
Revision:
0:f269e3021894
Initial commit

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elessair 0:f269e3021894 1 /* mbed Microcontroller Library
elessair 0:f269e3021894 2 * Copyright (c) 2006-2015 ARM Limited
elessair 0:f269e3021894 3 *
elessair 0:f269e3021894 4 * Licensed under the Apache License, Version 2.0 (the "License");
elessair 0:f269e3021894 5 * you may not use this file except in compliance with the License.
elessair 0:f269e3021894 6 * You may obtain a copy of the License at
elessair 0:f269e3021894 7 *
elessair 0:f269e3021894 8 * http://www.apache.org/licenses/LICENSE-2.0
elessair 0:f269e3021894 9 *
elessair 0:f269e3021894 10 * Unless required by applicable law or agreed to in writing, software
elessair 0:f269e3021894 11 * distributed under the License is distributed on an "AS IS" BASIS,
elessair 0:f269e3021894 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
elessair 0:f269e3021894 13 * See the License for the specific language governing permissions and
elessair 0:f269e3021894 14 * limitations under the License.
elessair 0:f269e3021894 15 */
elessair 0:f269e3021894 16 #ifndef MBED_SPI_H
elessair 0:f269e3021894 17 #define MBED_SPI_H
elessair 0:f269e3021894 18
elessair 0:f269e3021894 19 #include "platform/platform.h"
elessair 0:f269e3021894 20
elessair 0:f269e3021894 21 #if DEVICE_SPI
elessair 0:f269e3021894 22
elessair 0:f269e3021894 23 #include "platform/PlatformMutex.h"
elessair 0:f269e3021894 24 #include "hal/spi_api.h"
elessair 0:f269e3021894 25 #include "platform/SingletonPtr.h"
elessair 0:f269e3021894 26
elessair 0:f269e3021894 27 #if DEVICE_SPI_ASYNCH
elessair 0:f269e3021894 28 #include "platform/CThunk.h"
elessair 0:f269e3021894 29 #include "hal/dma_api.h"
elessair 0:f269e3021894 30 #include "platform/CircularBuffer.h"
elessair 0:f269e3021894 31 #include "platform/FunctionPointer.h"
elessair 0:f269e3021894 32 #include "platform/Transaction.h"
elessair 0:f269e3021894 33 #endif
elessair 0:f269e3021894 34
elessair 0:f269e3021894 35 namespace mbed {
elessair 0:f269e3021894 36 /** \addtogroup drivers */
elessair 0:f269e3021894 37 /** @{*/
elessair 0:f269e3021894 38
elessair 0:f269e3021894 39 /** A SPI Master, used for communicating with SPI slave devices
elessair 0:f269e3021894 40 *
elessair 0:f269e3021894 41 * The default format is set to 8-bits, mode 0, and a clock frequency of 1MHz
elessair 0:f269e3021894 42 *
elessair 0:f269e3021894 43 * Most SPI devices will also require Chip Select and Reset signals. These
elessair 0:f269e3021894 44 * can be controlled using <DigitalOut> pins
elessair 0:f269e3021894 45 *
elessair 0:f269e3021894 46 * @Note Synchronization level: Thread safe
elessair 0:f269e3021894 47 *
elessair 0:f269e3021894 48 * Example:
elessair 0:f269e3021894 49 * @code
elessair 0:f269e3021894 50 * // Send a byte to a SPI slave, and record the response
elessair 0:f269e3021894 51 *
elessair 0:f269e3021894 52 * #include "mbed.h"
elessair 0:f269e3021894 53 *
elessair 0:f269e3021894 54 * // hardware ssel (where applicable)
elessair 0:f269e3021894 55 * //SPI device(p5, p6, p7, p8); // mosi, miso, sclk, ssel
elessair 0:f269e3021894 56 *
elessair 0:f269e3021894 57 * // software ssel
elessair 0:f269e3021894 58 * SPI device(p5, p6, p7); // mosi, miso, sclk
elessair 0:f269e3021894 59 * DigitalOut cs(p8); // ssel
elessair 0:f269e3021894 60 *
elessair 0:f269e3021894 61 * int main() {
elessair 0:f269e3021894 62 * // hardware ssel (where applicable)
elessair 0:f269e3021894 63 * //int response = device.write(0xFF);
elessair 0:f269e3021894 64 *
elessair 0:f269e3021894 65 * device.lock();
elessair 0:f269e3021894 66 * // software ssel
elessair 0:f269e3021894 67 * cs = 0;
elessair 0:f269e3021894 68 * int response = device.write(0xFF);
elessair 0:f269e3021894 69 * cs = 1;
elessair 0:f269e3021894 70 * device.unlock();
elessair 0:f269e3021894 71 *
elessair 0:f269e3021894 72 * }
elessair 0:f269e3021894 73 * @endcode
elessair 0:f269e3021894 74 */
elessair 0:f269e3021894 75 class SPI {
elessair 0:f269e3021894 76
elessair 0:f269e3021894 77 public:
elessair 0:f269e3021894 78
elessair 0:f269e3021894 79 /** Create a SPI master connected to the specified pins
elessair 0:f269e3021894 80 *
elessair 0:f269e3021894 81 * mosi or miso can be specfied as NC if not used
elessair 0:f269e3021894 82 *
elessair 0:f269e3021894 83 * @param mosi SPI Master Out, Slave In pin
elessair 0:f269e3021894 84 * @param miso SPI Master In, Slave Out pin
elessair 0:f269e3021894 85 * @param sclk SPI Clock pin
elessair 0:f269e3021894 86 * @param ssel SPI chip select pin
elessair 0:f269e3021894 87 */
elessair 0:f269e3021894 88 SPI(PinName mosi, PinName miso, PinName sclk, PinName ssel=NC);
elessair 0:f269e3021894 89
elessair 0:f269e3021894 90 /** Configure the data transmission format
elessair 0:f269e3021894 91 *
elessair 0:f269e3021894 92 * @param bits Number of bits per SPI frame (4 - 16)
elessair 0:f269e3021894 93 * @param mode Clock polarity and phase mode (0 - 3)
elessair 0:f269e3021894 94 *
elessair 0:f269e3021894 95 * @code
elessair 0:f269e3021894 96 * mode | POL PHA
elessair 0:f269e3021894 97 * -----+--------
elessair 0:f269e3021894 98 * 0 | 0 0
elessair 0:f269e3021894 99 * 1 | 0 1
elessair 0:f269e3021894 100 * 2 | 1 0
elessair 0:f269e3021894 101 * 3 | 1 1
elessair 0:f269e3021894 102 * @endcode
elessair 0:f269e3021894 103 */
elessair 0:f269e3021894 104 void format(int bits, int mode = 0);
elessair 0:f269e3021894 105
elessair 0:f269e3021894 106 /** Set the spi bus clock frequency
elessair 0:f269e3021894 107 *
elessair 0:f269e3021894 108 * @param hz SCLK frequency in hz (default = 1MHz)
elessair 0:f269e3021894 109 */
elessair 0:f269e3021894 110 void frequency(int hz = 1000000);
elessair 0:f269e3021894 111
elessair 0:f269e3021894 112 /** Write to the SPI Slave and return the response
elessair 0:f269e3021894 113 *
elessair 0:f269e3021894 114 * @param value Data to be sent to the SPI slave
elessair 0:f269e3021894 115 *
elessair 0:f269e3021894 116 * @returns
elessair 0:f269e3021894 117 * Response from the SPI slave
elessair 0:f269e3021894 118 */
elessair 0:f269e3021894 119 virtual int write(int value);
elessair 0:f269e3021894 120
elessair 0:f269e3021894 121 /** Acquire exclusive access to this SPI bus
elessair 0:f269e3021894 122 */
elessair 0:f269e3021894 123 virtual void lock(void);
elessair 0:f269e3021894 124
elessair 0:f269e3021894 125 /** Release exclusive access to this SPI bus
elessair 0:f269e3021894 126 */
elessair 0:f269e3021894 127 virtual void unlock(void);
elessair 0:f269e3021894 128
elessair 0:f269e3021894 129 #if DEVICE_SPI_ASYNCH
elessair 0:f269e3021894 130
elessair 0:f269e3021894 131 /** Start non-blocking SPI transfer using 8bit buffers.
elessair 0:f269e3021894 132 *
elessair 0:f269e3021894 133 * @param tx_buffer The TX buffer with data to be transfered. If NULL is passed,
elessair 0:f269e3021894 134 * the default SPI value is sent
elessair 0:f269e3021894 135 * @param tx_length The length of TX buffer in bytes
elessair 0:f269e3021894 136 * @param rx_buffer The RX buffer which is used for received data. If NULL is passed,
elessair 0:f269e3021894 137 * received data are ignored
elessair 0:f269e3021894 138 * @param rx_length The length of RX buffer in bytes
elessair 0:f269e3021894 139 * @param callback The event callback function
elessair 0:f269e3021894 140 * @param event The logical OR of events to modify. Look at spi hal header file for SPI events.
elessair 0:f269e3021894 141 * @return Zero if the transfer has started, or -1 if SPI peripheral is busy
elessair 0:f269e3021894 142 */
elessair 0:f269e3021894 143 template<typename Type>
elessair 0:f269e3021894 144 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) {
elessair 0:f269e3021894 145 if (spi_active(&_spi)) {
elessair 0:f269e3021894 146 return queue_transfer(tx_buffer, tx_length, rx_buffer, rx_length, sizeof(Type)*8, callback, event);
elessair 0:f269e3021894 147 }
elessair 0:f269e3021894 148 start_transfer(tx_buffer, tx_length, rx_buffer, rx_length, sizeof(Type)*8, callback, event);
elessair 0:f269e3021894 149 return 0;
elessair 0:f269e3021894 150 }
elessair 0:f269e3021894 151
elessair 0:f269e3021894 152 /** Abort the on-going SPI transfer, and continue with transfer's in the queue if any.
elessair 0:f269e3021894 153 */
elessair 0:f269e3021894 154 void abort_transfer();
elessair 0:f269e3021894 155
elessair 0:f269e3021894 156 /** Clear the transaction buffer
elessair 0:f269e3021894 157 */
elessair 0:f269e3021894 158 void clear_transfer_buffer();
elessair 0:f269e3021894 159
elessair 0:f269e3021894 160 /** Clear the transaction buffer and abort on-going transfer.
elessair 0:f269e3021894 161 */
elessair 0:f269e3021894 162 void abort_all_transfers();
elessair 0:f269e3021894 163
elessair 0:f269e3021894 164 /** Configure DMA usage suggestion for non-blocking transfers
elessair 0:f269e3021894 165 *
elessair 0:f269e3021894 166 * @param usage The usage DMA hint for peripheral
elessair 0:f269e3021894 167 * @return Zero if the usage was set, -1 if a transaction is on-going
elessair 0:f269e3021894 168 */
elessair 0:f269e3021894 169 int set_dma_usage(DMAUsage usage);
elessair 0:f269e3021894 170
elessair 0:f269e3021894 171 protected:
elessair 0:f269e3021894 172 /** SPI IRQ handler
elessair 0:f269e3021894 173 *
elessair 0:f269e3021894 174 */
elessair 0:f269e3021894 175 void irq_handler_asynch(void);
elessair 0:f269e3021894 176
elessair 0:f269e3021894 177 /** Common transfer method
elessair 0:f269e3021894 178 *
elessair 0:f269e3021894 179 * @param tx_buffer The TX buffer with data to be transfered. If NULL is passed,
elessair 0:f269e3021894 180 * the default SPI value is sent
elessair 0:f269e3021894 181 * @param tx_length The length of TX buffer in bytes
elessair 0:f269e3021894 182 * @param rx_buffer The RX buffer which is used for received data. If NULL is passed,
elessair 0:f269e3021894 183 * received data are ignored
elessair 0:f269e3021894 184 * @param rx_length The length of RX buffer in bytes
elessair 0:f269e3021894 185 * @param bit_width The buffers element width
elessair 0:f269e3021894 186 * @param callback The event callback function
elessair 0:f269e3021894 187 * @param event The logical OR of events to modify
elessair 0:f269e3021894 188 * @return Zero if the transfer has started or was added to the queue, or -1 if SPI peripheral is busy/buffer is full
elessair 0:f269e3021894 189 */
elessair 0:f269e3021894 190 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);
elessair 0:f269e3021894 191
elessair 0:f269e3021894 192 /**
elessair 0:f269e3021894 193 *
elessair 0:f269e3021894 194 * @param tx_buffer The TX buffer with data to be transfered. If NULL is passed,
elessair 0:f269e3021894 195 * the default SPI value is sent
elessair 0:f269e3021894 196 * @param tx_length The length of TX buffer in bytes
elessair 0:f269e3021894 197 * @param rx_buffer The RX buffer which is used for received data. If NULL is passed,
elessair 0:f269e3021894 198 * received data are ignored
elessair 0:f269e3021894 199 * @param rx_length The length of RX buffer in bytes
elessair 0:f269e3021894 200 * @param bit_width The buffers element width
elessair 0:f269e3021894 201 * @param callback The event callback function
elessair 0:f269e3021894 202 * @param event The logical OR of events to modify
elessair 0:f269e3021894 203 * @return Zero if a transfer was added to the queue, or -1 if the queue is full
elessair 0:f269e3021894 204 */
elessair 0:f269e3021894 205 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);
elessair 0:f269e3021894 206
elessair 0:f269e3021894 207 /** Configures a callback, spi peripheral and initiate a new transfer
elessair 0:f269e3021894 208 *
elessair 0:f269e3021894 209 * @param tx_buffer The TX buffer with data to be transfered. If NULL is passed,
elessair 0:f269e3021894 210 * the default SPI value is sent
elessair 0:f269e3021894 211 * @param tx_length The length of TX buffer in bytes
elessair 0:f269e3021894 212 * @param rx_buffer The RX buffer which is used for received data. If NULL is passed,
elessair 0:f269e3021894 213 * received data are ignored
elessair 0:f269e3021894 214 * @param rx_length The length of RX buffer in bytes
elessair 0:f269e3021894 215 * @param bit_width The buffers element width
elessair 0:f269e3021894 216 * @param callback The event callback function
elessair 0:f269e3021894 217 * @param event The logical OR of events to modify
elessair 0:f269e3021894 218 */
elessair 0:f269e3021894 219 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);
elessair 0:f269e3021894 220
elessair 0:f269e3021894 221 #if TRANSACTION_QUEUE_SIZE_SPI
elessair 0:f269e3021894 222
elessair 0:f269e3021894 223 /** Start a new transaction
elessair 0:f269e3021894 224 *
elessair 0:f269e3021894 225 * @param data Transaction data
elessair 0:f269e3021894 226 */
elessair 0:f269e3021894 227 void start_transaction(transaction_t *data);
elessair 0:f269e3021894 228
elessair 0:f269e3021894 229 /** Dequeue a transaction
elessair 0:f269e3021894 230 *
elessair 0:f269e3021894 231 */
elessair 0:f269e3021894 232 void dequeue_transaction();
elessair 0:f269e3021894 233 static CircularBuffer<Transaction<SPI>, TRANSACTION_QUEUE_SIZE_SPI> _transaction_buffer;
elessair 0:f269e3021894 234 #endif
elessair 0:f269e3021894 235
elessair 0:f269e3021894 236 #endif
elessair 0:f269e3021894 237
elessair 0:f269e3021894 238 public:
elessair 0:f269e3021894 239 virtual ~SPI() {
elessair 0:f269e3021894 240 }
elessair 0:f269e3021894 241
elessair 0:f269e3021894 242 protected:
elessair 0:f269e3021894 243 spi_t _spi;
elessair 0:f269e3021894 244
elessair 0:f269e3021894 245 #if DEVICE_SPI_ASYNCH
elessair 0:f269e3021894 246 CThunk<SPI> _irq;
elessair 0:f269e3021894 247 event_callback_t _callback;
elessair 0:f269e3021894 248 DMAUsage _usage;
elessair 0:f269e3021894 249 #endif
elessair 0:f269e3021894 250
elessair 0:f269e3021894 251 void aquire(void);
elessair 0:f269e3021894 252 static SPI *_owner;
elessair 0:f269e3021894 253 static SingletonPtr<PlatformMutex> _mutex;
elessair 0:f269e3021894 254 int _bits;
elessair 0:f269e3021894 255 int _mode;
elessair 0:f269e3021894 256 int _hz;
elessair 0:f269e3021894 257 };
elessair 0:f269e3021894 258
elessair 0:f269e3021894 259 } // namespace mbed
elessair 0:f269e3021894 260
elessair 0:f269e3021894 261 #endif
elessair 0:f269e3021894 262
elessair 0:f269e3021894 263 #endif
elessair 0:f269e3021894 264
elessair 0:f269e3021894 265 /** @}*/