/** * \file * * \brief SPI Master Mode management * * Copyright (c) 2010-2015 Atmel Corporation. All rights reserved. * * \asf_license_start * * \page License * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * * 3. The name of Atmel may not be used to endorse or promote products derived * from this software without specific prior written permission. * * 4. This software may only be redistributed and used in connection with an * Atmel microcontroller product. * * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * * \asf_license_stop * */ /* * Support and FAQ: visit Atmel Support */ #ifndef SPI_MASTER_H_INCLUDED #define SPI_MASTER_H_INCLUDED #include #if XMEGA # include "xmega_spi/spi_master.h" #elif MEGA_RF # include "megarf_spi/spi_master.h" #elif UC3 # include "uc3_spi/spi_master.h" #elif SAM # include "sam_spi/spi_master.h" #else # error Unsupported chip type #endif /** * * \defgroup spi_group Serial Peripheral Interface (SPI) * * This is the common API for SPI interface. Additional features are available * in the documentation of the specific modules. * * \section spi_group_platform Platform Dependencies * * The SPI API is partially chip- or platform-specific. While all * platforms provide mostly the same functionality, there are some * variations around how different bus types and clock tree structures * are handled. * * The following functions are available on all platforms, but there may * be variations in the function signature (i.e. parameters) and * behavior. These functions are typically called by platform-specific * parts of drivers, and applications that aren't intended to be * portable: * - spi_master_init() * - spi_master_setup_device() * - spi_select_device() * - spi_deselect_device() * - spi_write_single() * - spi_write_packet() * - spi_read_single() * - spi_read_packet() * - spi_is_tx_empty() * - spi_is_tx_ready() * - spi_is_rx_full() * - spi_is_rx_ready() * - spi_enable() * - spi_disable() * - spi_is_enabled() * * \section spi_master_quickstart_section Quick Start Guide * See \ref common_spi_master_quickstart * @{ */ //! @} /** * \page common_spi_master_quickstart Quick Start Guide for the SPI Master Driver * * This is the quick start guide for the \ref spi_group "SPI Driver", with * step-by-step instructions on how to configure and use the driver for a * specific use case. * * The use case contain several code fragments. The code fragments in the * steps for setup can be copied into a custom initialization function, while * the steps for usage can be copied into, e.g., the main application function. * * The steps for setting up the SPI master for XMEGA and UC3 use exactly the * same approach, but note that there are different names on the peripherals. So * to use this Quick Start for UC3 please make sure that all the peripheral * names are updated according to the UC3 datasheet. * - \subpage spi_master_xmega * */ /** * \page spi_master_xmega Basic setup for SPI master on XMEGA devices * * \section spi_master_xmega_basic Basic setup for XMEGA devices * The SPI module will be set up as master: * - SPI on PORTD * - 1MHz SPI clock speed * - Slave Chip Select connected on PORTD pin 1 * - SPI mode 0 (data on rising clock edge) * * \section spi_master_xmega_basic_setup Setup steps * \subsection spi_master_xmega_basic_setup_code Example code * Add to application C-file (e.g. main.c): * \code void spi_init_pins(void) { ioport_configure_port_pin(&PORTD, PIN1_bm, IOPORT_INIT_HIGH | IOPORT_DIR_OUTPUT); ioport_configure_port_pin(&PORTD, PIN4_bm, IOPORT_PULL_UP | IOPORT_DIR_INPUT); ioport_configure_port_pin(&PORTD, PIN5_bm, IOPORT_INIT_HIGH | IOPORT_DIR_OUTPUT); ioport_configure_port_pin(&PORTD, PIN6_bm, IOPORT_DIR_INPUT); ioport_configure_port_pin(&PORTD, PIN7_bm, IOPORT_INIT_HIGH | IOPORT_DIR_OUTPUT); } void spi_init_module(void) { struct spi_device spi_device_conf = { .id = IOPORT_CREATE_PIN(PORTD, 1) }; spi_master_init(&SPID); spi_master_setup_device(&SPID, &spi_device_conf, SPI_MODE_0, 1000000, 0); spi_enable(&SPID); } \endcode * * \subsection spi_master_xmega_basic_setup Workflow * -# Ensure that \ref conf_spi_master.h is present for the driver. * - \note This file is only for the driver and should not be included by the * user. In this example the file can be left empty. * -# Initialize the pins used by the SPI interface (this initialization is for * the ATxmega32A4U device). * -# Set the pin used for slave select as output high: * \code ioport_configure_port_pin(&PORTD, PIN1_bm, IOPORT_INIT_HIGH | IOPORT_DIR_OUTPUT); \endcode * -# Enable pull-up on own chip select (SS): * \code ioport_configure_port_pin(&PORTD, PIN4_bm, IOPORT_PULL_UP | IOPORT_DIR_INPUT); \endcode * \attention If this pin is pulled low the SPI module will go into slave mode. * -# Set MOSI and SCL as output high, and set MISO as input: * \code ioport_configure_port_pin(&PORTD, PIN5_bm, IOPORT_INIT_HIGH | IOPORT_DIR_OUTPUT); ioport_configure_port_pin(&PORTD, PIN6_bm, IOPORT_DIR_INPUT); ioport_configure_port_pin(&PORTD, PIN7_bm, IOPORT_INIT_HIGH | IOPORT_DIR_OUTPUT); \endcode * -# Define the SPI device configuration struct to describe which pin the * slave select (slave chip select) is connected to, in this case the slave * select pin has been connected to PORTD pin 1 (PD1): * - \code struct spi_device spi_device_conf = { .id = IOPORT_CREATE_PIN(PORTD, 1) }; \endcode * -# Initialize the SPI module, in this case SPI on PORTD has been chosen: * - \code spi_master_init(&SPID); \endcode * -# Setup the SPI master module for a specific device: * - \code spi_master_setup_device(&SPID, &spi_device_conf, SPI_MODE_0, 1000000, 0); \endcode * - \note The last argument, which is zero in this case, can be ignored and is * only included for compatibility purposes. * -# Then enable the SPI: * - \code spi_enable(&SPID); \endcode * * \section spi_master_xmega_basic_usage Usage steps * \subsection spi_master_xmega_basic_usage_code Example code * Add to, e.g., the main loop in the application C-file: * \code uint8_t data_buffer[1] = {0xAA}; struct spi_device spi_device_conf = { .id = IOPORT_CREATE_PIN(PORTD, 1) }; spi_select_device(&SPID, &spi_device_conf); spi_write_packet(&SPID, data_buffer, 1); spi_read_packet(&SPID, data_buffer, 1); spi_deselect_device(&SPID, &spi_device_conf); \endcode * * \subsection spi_master_xmega_basic_usage_flow Workflow * -# Create a buffer for data to be sent/received on the SPI bus, in this case * a single byte buffer is used. The buffer can be of arbitrary size as long as * there is space left in SRAM: * - \code uint8_t data_buffer[1] = {0xAA}; \endcode * -# Define the SPI device configuration struct to describe which pin the * slave select (slave chip select) is connected to, in this case the slave * select pin has been connected to PORTD pin 1 (PD1): * - \code struct spi_device spi_device_conf = { .id = IOPORT_CREATE_PIN(PORTD, 1) }; \endcode * - \note As this struct is the same for both the initializing part and the usage * part it could be a good idea to make the struct global, and hence accessible * for both the initializing part and usage part. Another solution could be to * create the struct in the main function and pass the address of the struct to * the spi_init_module() function, e.g.: * \code void spi_init_module(struct spi_device *spi_device_conf) { ... spi_master_setup_device(&SPID, spi_device_conf, SPI_MODE_0, 1000000, 0); ... } \endcode * -# Write data to the SPI slave device, in this case write one byte from the * data_buffer: * - \code spi_write_packet(&SPID, data_buffer, 1); \endcode * -# Read data from the SPI slave device, in this case read one byte and put it * into the data_buffer: * - \code spi_read_packet(&SPID, data_buffer, 1); \endcode * - \attention As the SPI works as a shift register so that data is shifted in at * the same time as data is shifted out a read operation will mean that a dummy * byte \ref CONFIG_SPI_MASTER_DUMMY is written to the SPI bus. \ref CONFIG_SPI_MASTER_DUMMY * defaults to 0xFF, but can be changed by defining it inside the \ref conf_spi_master.h * file. * -# When read and write operations is done de-select the slave: * - \code spi_deselect_device(&SPID, &spi_device_conf); \endcode * */ #endif /* SPI_MASTER_H_INCLUDED */