Diff: hal/spi_api.h

Revision:

0:098463de4c5d

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hal/spi_api.h	Wed Jan 25 20:34:15 2017 +0000
@@ -0,0 +1,219 @@
+
+/** \addtogroup hal */
+/** @{*/
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2013 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_API_H
+#define MBED_SPI_API_H
+
+#include "device.h"
+#include "hal/dma_api.h"
+#include "hal/buffer.h"
+
+#if DEVICE_SPI
+
+#define SPI_EVENT_ERROR       (1 << 1)
+#define SPI_EVENT_COMPLETE    (1 << 2)
+#define SPI_EVENT_RX_OVERFLOW (1 << 3)
+#define SPI_EVENT_ALL         (SPI_EVENT_ERROR | SPI_EVENT_COMPLETE | SPI_EVENT_RX_OVERFLOW)
+
+#define SPI_EVENT_INTERNAL_TRANSFER_COMPLETE (1 << 30) // Internal flag to report that an event occurred
+
+#define SPI_FILL_WORD         (0xFFFF)
+
+#if DEVICE_SPI_ASYNCH
+/** Asynch SPI HAL structure
+ */
+typedef struct {
+    struct spi_s spi;        /**< Target specific SPI structure */
+    struct buffer_s tx_buff; /**< Tx buffer */
+    struct buffer_s rx_buff; /**< Rx buffer */
+} spi_t;
+
+#else
+/** Non-asynch SPI HAL structure
+ */
+typedef struct spi_s spi_t;
+
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \defgroup hal_GeneralSPI SPI Configuration Functions
+ * @{
+ */
+
+/** Initialize the SPI peripheral
+ *
+ * Configures the pins used by SPI, sets a default format and frequency, and enables the peripheral
+ * @param[out] obj  The SPI object to initialize
+ * @param[in]  mosi The pin to use for MOSI
+ * @param[in]  miso The pin to use for MISO
+ * @param[in]  sclk The pin to use for SCLK
+ * @param[in]  ssel The pin to use for SSEL
+ */
+void spi_init(spi_t *obj, PinName mosi, PinName miso, PinName sclk, PinName ssel);
+
+/** Release a SPI object
+ *
+ * TODO: spi_free is currently unimplemented
+ * This will require reference counting at the C++ level to be safe
+ *
+ * Return the pins owned by the SPI object to their reset state
+ * Disable the SPI peripheral
+ * Disable the SPI clock
+ * @param[in] obj The SPI object to deinitialize
+ */
+void spi_free(spi_t *obj);
+
+/** Configure the SPI format
+ *
+ * Set the number of bits per frame, configure clock polarity and phase, shift order and master/slave mode.
+ * The default bit order is MSB.
+ * @param[in,out] obj   The SPI object to configure
+ * @param[in]     bits  The number of bits per frame
+ * @param[in]     mode  The SPI mode (clock polarity, phase, and shift direction)
+ * @param[in]     slave Zero for master mode or non-zero for slave mode
+ */
+void spi_format(spi_t *obj, int bits, int mode, int slave);
+
+/** Set the SPI baud rate
+ *
+ * Actual frequency may differ from the desired frequency due to available dividers and bus clock
+ * Configures the SPI peripheral's baud rate
+ * @param[in,out] obj The SPI object to configure
+ * @param[in]     hz  The baud rate in Hz
+ */
+void spi_frequency(spi_t *obj, int hz);
+
+/**@}*/
+/**
+ * \defgroup SynchSPI Synchronous SPI Hardware Abstraction Layer
+ * @{
+ */
+
+/** Write a byte out in master mode and receive a value
+ *
+ * @param[in] obj   The SPI peripheral to use for sending
+ * @param[in] value The value to send
+ * @return Returns the value received during send
+ */
+int  spi_master_write(spi_t *obj, int value);
+
+/** Check if a value is available to read
+ *
+ * @param[in] obj The SPI peripheral to check
+ * @return non-zero if a value is available
+ */
+int  spi_slave_receive(spi_t *obj);
+
+/** Get a received value out of the SPI receive buffer in slave mode
+ *
+ * Blocks until a value is available
+ * @param[in] obj The SPI peripheral to read
+ * @return The value received
+ */
+int  spi_slave_read(spi_t *obj);
+
+/** Write a value to the SPI peripheral in slave mode
+ *
+ * Blocks until the SPI peripheral can be written to
+ * @param[in] obj   The SPI peripheral to write
+ * @param[in] value The value to write
+ */
+void spi_slave_write(spi_t *obj, int value);
+
+/** Checks if the specified SPI peripheral is in use
+ *
+ * @param[in] obj The SPI peripheral to check
+ * @return non-zero if the peripheral is currently transmitting
+ */
+int  spi_busy(spi_t *obj);
+
+/** Get the module number
+ *
+ * @param[in] obj The SPI peripheral to check
+ * @return The module number
+ */
+uint8_t spi_get_module(spi_t *obj);
+
+/**@}*/
+
+#if DEVICE_SPI_ASYNCH
+/**
+ * \defgroup AsynchSPI Asynchronous SPI Hardware Abstraction Layer
+ * @{
+ */
+
+/** Begin the SPI transfer. Buffer pointers and lengths are specified in tx_buff and rx_buff
+ *
+ * @param[in] obj       The SPI object that holds the transfer information
+ * @param[in] tx        The transmit buffer
+ * @param[in] tx_length The number of bytes to transmit
+ * @param[in] rx        The receive buffer
+ * @param[in] rx_length The number of bytes to receive
+ * @param[in] bit_width The bit width of buffer words
+ * @param[in] event     The logical OR of events to be registered
+ * @param[in] handler   SPI interrupt handler
+ * @param[in] hint      A suggestion for how to use DMA with this transfer
+ */
+void spi_master_transfer(spi_t *obj, const void *tx, size_t tx_length, void *rx, size_t rx_length, uint8_t bit_width, uint32_t handler, uint32_t event, DMAUsage hint);
+
+/** The asynchronous IRQ handler
+ *
+ * Reads the received values out of the RX FIFO, writes values into the TX FIFO and checks for transfer termination
+ * conditions, such as buffer overflows or transfer complete.
+ * @param[in] obj     The SPI object that holds the transfer information
+ * @return Event flags if a transfer termination condition was met; otherwise 0.
+ */
+uint32_t spi_irq_handler_asynch(spi_t *obj);
+
+/** Attempts to determine if the SPI peripheral is already in use
+ *
+ * If a temporary DMA channel has been allocated, peripheral is in use.
+ * If a permanent DMA channel has been allocated, check if the DMA channel is in use.  If not, proceed as though no DMA
+ * channel were allocated.
+ * If no DMA channel is allocated, check whether tx and rx buffers have been assigned.  For each assigned buffer, check
+ * if the corresponding buffer position is less than the buffer length.  If buffers do not indicate activity, check if
+ * there are any bytes in the FIFOs.
+ * @param[in] obj The SPI object to check for activity
+ * @return Non-zero if the SPI port is active or zero if it is not.
+ */
+uint8_t spi_active(spi_t *obj);
+
+/** Abort an SPI transfer
+ *
+ * @param obj The SPI peripheral to stop
+ */
+void spi_abort_asynch(spi_t *obj);
+
+
+#endif
+
+/**@}*/
+
+#ifdef __cplusplus
+}
+#endif // __cplusplus
+
+#endif // SPI_DEVICE
+
+#endif // MBED_SPI_API_H
+
+/** @}*/