/******************************************************************************* * Copyright (C) 2015 Maxim Integrated Products, Inc., All Rights Reserved. * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included * in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. * IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR * OTHER DEALINGS IN THE SOFTWARE. * * Except as contained in this notice, the name of Maxim Integrated * Products, Inc. shall not be used except as stated in the Maxim Integrated * Products, Inc. Branding Policy. * * The mere transfer of this software does not imply any licenses * of trade secrets, proprietary technology, copyrights, patents, * trademarks, maskwork rights, or any other form of intellectual * property whatsoever. Maxim Integrated Products, Inc. retains all * ownership rights. ******************************************************************************* */ #include #include "mbed_assert.h" #include "cmsis.h" #include "spi_api.h" #include "pinmap.h" #include "ioman_regs.h" #include "clkman_regs.h" #include "PeripheralPins.h" #define DEFAULT_CHAR 8 #define DEFAULT_MODE 0 #define DEFAULT_FREQ 1000000 // Formatting settings static int spi_bits; //****************************************************************************** void spi_init(spi_t *obj, PinName mosi, PinName miso, PinName sclk, PinName ssel) { // Make sure pins are pointing to the same SPI instance SPIName spi_mosi = (SPIName)pinmap_peripheral(mosi, PinMap_SPI_MOSI); SPIName spi_miso = (SPIName)pinmap_peripheral(miso, PinMap_SPI_MISO); SPIName spi_sclk = (SPIName)pinmap_peripheral(sclk, PinMap_SPI_SCLK); SPIName spi_ssel = (SPIName)pinmap_peripheral(ssel, PinMap_SPI_SSEL); SPIName spi_data = (SPIName)pinmap_merge(spi_mosi, spi_miso); SPIName spi_cntl; // Give the application the option to manually control Slave Select if((SPIName)spi_ssel != (SPIName)NC) { spi_cntl = (SPIName)pinmap_merge(spi_sclk, spi_ssel); } else { spi_cntl = spi_sclk; } SPIName spi = (SPIName)pinmap_merge(spi_data, spi_cntl); MBED_ASSERT((SPIName)spi != (SPIName)NC); // Set the obj pointer to the proper SPI Instance obj->spi = (mxc_spi_regs_t*)spi; // Set the SPI index and FIFOs obj->index = MXC_SPI_BASE_TO_INSTANCE(obj->spi); obj->rxfifo = MXC_SPI_GET_RXFIFO(obj->index); obj->txfifo = MXC_SPI_GET_TXFIFO(obj->index); // Configure the pins pinmap_pinout(mosi, PinMap_SPI_MOSI); pinmap_pinout(miso, PinMap_SPI_MISO); pinmap_pinout(sclk, PinMap_SPI_SCLK); pinmap_pinout(ssel, PinMap_SPI_SSEL); // Enable SPI and FIFOs obj->spi->gen_ctrl = (MXC_F_SPI_GEN_CTRL_SPI_MSTR_EN | MXC_F_SPI_GEN_CTRL_TX_FIFO_EN | MXC_F_SPI_GEN_CTRL_RX_FIFO_EN ); // Give instance the default settings spi_format(obj, DEFAULT_CHAR, DEFAULT_MODE, 0); spi_frequency(obj, DEFAULT_FREQ); } //****************************************************************************** void spi_format(spi_t *obj, int bits, int mode, int slave) { // Check the validity of the inputs MBED_ASSERT(((bits >= 1) && (bits <= 32)) && ((mode >= 0) && (mode <= 3))); // Only supports master mode MBED_ASSERT(!slave); // Save formatting data spi_bits = bits; // Set the mode obj->spi->mstr_cfg &= ~(MXC_F_SPI_MSTR_CFG_SPI_MODE); obj->spi->mstr_cfg |= (mode << MXC_F_SPI_MSTR_CFG_SPI_MODE_POS); } //****************************************************************************** void spi_frequency(spi_t *obj, int hz) { // Maximum frequency is half the system frequency MBED_ASSERT((unsigned int)hz < (SystemCoreClock / 2)); unsigned clocks = ((SystemCoreClock/2)/(hz)); // Figure out the divider ratio int clk_div = 1; while(clk_div < 10) { if(clocks < 0x10) { break; } clk_div++; clocks = clocks >> 1; } // Turn on the SPI clock if(obj->index == 0) { MXC_CLKMAN->clk_ctrl_3_spi0 = clk_div; } else if(obj->index == 1) { MXC_CLKMAN->clk_ctrl_4_spi1 = clk_div; } else if(obj->index == 2) { MXC_CLKMAN->clk_ctrl_5_spi2 = clk_div; } else { MBED_ASSERT(0); } // Set the number of clocks to hold sclk high and low MXC_SET_FIELD(&obj->spi->mstr_cfg, (MXC_F_SPI_MSTR_CFG_SCK_HI_CLK | MXC_F_SPI_MSTR_CFG_SCK_LO_CLK), ((clocks << MXC_F_SPI_MSTR_CFG_SCK_HI_CLK_POS) | (clocks << MXC_F_SPI_MSTR_CFG_SCK_LO_CLK_POS))); } //****************************************************************************** int spi_master_write(spi_t *obj, int value) { int bits = spi_bits; if(spi_bits == 32) { bits = 0; } // Create the header uint16_t header = ((0x3 << MXC_F_SPI_FIFO_DIR_POS ) | // TX and RX (0x0 << MXC_F_SPI_FIFO_UNIT_POS) | // Send bits (bits << MXC_F_SPI_FIFO_SIZE_POS) | // Number of units (0x1 << MXC_F_SPI_FIFO_DASS_POS)); // Deassert SS // Send the message header obj->txfifo->txfifo_16 = header; // Send the data if(spi_bits < 17) { obj->txfifo->txfifo_16 = (uint16_t)value; } else { obj->txfifo->txfifo_32 = (uint32_t)value; } // Get the data bits = spi_bits; int result = 0; int i = 0; while(bits > 0) { // Wait for data while(((obj->spi->fifo_ctrl & MXC_F_SPI_FIFO_CTRL_RX_FIFO_USED) >> MXC_F_SPI_FIFO_CTRL_RX_FIFO_USED_POS) < 1) {} result |= (obj->rxfifo->rxfifo_8 << (i++*8)); bits-=8; } return result; } //****************************************************************************** int spi_busy(spi_t *obj) { return !(obj->spi->intfl & MXC_F_SPI_INTFL_TX_READY); }