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2 * Copyright (C) 2015 Maxim Integrated Products, Inc., All Rights Reserved.
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31 *******************************************************************************
35 #include "mbed_assert.h"
39 #include "ioman_regs.h"
40 #include "clkman_regs.h"
41 #include "PeripheralPins.h"
43 #define DEFAULT_CHAR 8
44 #define DEFAULT_MODE 0
45 #define DEFAULT_FREQ 1000000
47 // Formatting settings
50 //******************************************************************************
51 void spi_init(spi_t *obj, PinName mosi, PinName miso, PinName sclk, PinName ssel)
53 // Make sure pins are pointing to the same SPI instance
54 SPIName spi_mosi = (SPIName)pinmap_peripheral(mosi, PinMap_SPI_MOSI);
55 SPIName spi_miso = (SPIName)pinmap_peripheral(miso, PinMap_SPI_MISO);
56 SPIName spi_sclk = (SPIName)pinmap_peripheral(sclk, PinMap_SPI_SCLK);
57 SPIName spi_ssel = (SPIName)pinmap_peripheral(ssel, PinMap_SPI_SSEL);
59 SPIName spi_data = (SPIName)pinmap_merge(spi_mosi, spi_miso);
62 // Give the application the option to manually control Slave Select
63 if((SPIName)spi_ssel != (SPIName)NC) {
64 spi_cntl = (SPIName)pinmap_merge(spi_sclk, spi_ssel);
69 SPIName spi = (SPIName)pinmap_merge(spi_data, spi_cntl);
71 MBED_ASSERT((SPIName)spi != (SPIName)NC);
73 // Set the obj pointer to the proper SPI Instance
74 obj->spi = (mxc_spi_regs_t*)spi;
76 // Set the SPI index and FIFOs
77 obj->index = MXC_SPI_BASE_TO_INSTANCE(obj->spi);
78 obj->rxfifo = MXC_SPI_GET_RXFIFO(obj->index);
79 obj->txfifo = MXC_SPI_GET_TXFIFO(obj->index);
82 pinmap_pinout(mosi, PinMap_SPI_MOSI);
83 pinmap_pinout(miso, PinMap_SPI_MISO);
84 pinmap_pinout(sclk, PinMap_SPI_SCLK);
85 pinmap_pinout(ssel, PinMap_SPI_SSEL);
87 // Enable SPI and FIFOs
88 obj->spi->gen_ctrl = (MXC_F_SPI_GEN_CTRL_SPI_MSTR_EN |
89 MXC_F_SPI_GEN_CTRL_TX_FIFO_EN |
90 MXC_F_SPI_GEN_CTRL_RX_FIFO_EN );
92 // Give instance the default settings
93 spi_format(obj, DEFAULT_CHAR, DEFAULT_MODE, 0);
94 spi_frequency(obj, DEFAULT_FREQ);
97 //******************************************************************************
98 void spi_format(spi_t *obj, int bits, int mode, int slave)
100 // Check the validity of the inputs
101 MBED_ASSERT(((bits >= 1) && (bits <= 32)) && ((mode >= 0) && (mode <= 3)));
103 // Only supports master mode
106 // Save formatting data
110 obj->spi->mstr_cfg &= ~(MXC_F_SPI_MSTR_CFG_SPI_MODE);
111 obj->spi->mstr_cfg |= (mode << MXC_F_SPI_MSTR_CFG_SPI_MODE_POS);
114 //******************************************************************************
115 void spi_frequency(spi_t *obj, int hz)
117 // Maximum frequency is half the system frequency
118 MBED_ASSERT((unsigned int)hz < (SystemCoreClock / 2));
119 unsigned clocks = ((SystemCoreClock/2)/(hz));
121 // Figure out the divider ratio
123 while(clk_div < 10) {
128 clocks = clocks >> 1;
131 // Turn on the SPI clock
132 if(obj->index == 0) {
133 MXC_CLKMAN->clk_ctrl_3_spi0 = clk_div;
134 } else if(obj->index == 1) {
135 MXC_CLKMAN->clk_ctrl_4_spi1 = clk_div;
136 } else if(obj->index == 2) {
137 MXC_CLKMAN->clk_ctrl_5_spi2 = clk_div;
142 // Set the number of clocks to hold sclk high and low
143 MXC_SET_FIELD(&obj->spi->mstr_cfg, (MXC_F_SPI_MSTR_CFG_SCK_HI_CLK | MXC_F_SPI_MSTR_CFG_SCK_LO_CLK),
144 ((clocks << MXC_F_SPI_MSTR_CFG_SCK_HI_CLK_POS) | (clocks << MXC_F_SPI_MSTR_CFG_SCK_LO_CLK_POS)));
147 //******************************************************************************
148 int spi_master_write(spi_t *obj, int value)
155 uint16_t header = ((0x3 << MXC_F_SPI_FIFO_DIR_POS ) | // TX and RX
156 (0x0 << MXC_F_SPI_FIFO_UNIT_POS) | // Send bits
157 (bits << MXC_F_SPI_FIFO_SIZE_POS) | // Number of units
158 (0x1 << MXC_F_SPI_FIFO_DASS_POS)); // Deassert SS
160 // Send the message header
161 obj->txfifo->txfifo_16 = header;
165 obj->txfifo->txfifo_16 = (uint16_t)value;
167 obj->txfifo->txfifo_32 = (uint32_t)value;
176 while(((obj->spi->fifo_ctrl & MXC_F_SPI_FIFO_CTRL_RX_FIFO_USED)
177 >> MXC_F_SPI_FIFO_CTRL_RX_FIFO_USED_POS) < 1) {}
179 result |= (obj->rxfifo->rxfifo_8 << (i++*8));
186 //******************************************************************************
187 int spi_busy(spi_t *obj)
189 return !(obj->spi->intfl & MXC_F_SPI_INTFL_TX_READY);