siva surendar / mbed-dev

mbed library sources. Supersedes mbed-src.

Fork of mbed-dev by mbed official

targets/TARGET_Maxim/TARGET_MAX32600/spi_api.c@150:da61ba4e9755, 2016-11-25 (annotated)

Committer:
sivasuren
Date:
Fri Nov 25 07:57:40 2016 +0000
Revision:
150:da61ba4e9755
Parent:
149:156823d33999 
surendar changes

Who changed what in which revision?

UserRevisionLine numberNew contents of line
<> 144:ef7eb2e8f9f7 1 /*******************************************************************************
<> 144:ef7eb2e8f9f7 2 * Copyright (C) 2015 Maxim Integrated Products, Inc., All Rights Reserved.
<> 144:ef7eb2e8f9f7 3 *
<> 144:ef7eb2e8f9f7 4 * Permission is hereby granted, free of charge, to any person obtaining a
<> 144:ef7eb2e8f9f7 5 * copy of this software and associated documentation files (the "Software"),
<> 144:ef7eb2e8f9f7 6 * to deal in the Software without restriction, including without limitation
<> 144:ef7eb2e8f9f7 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
<> 144:ef7eb2e8f9f7 8 * and/or sell copies of the Software, and to permit persons to whom the
<> 144:ef7eb2e8f9f7 9 * Software is furnished to do so, subject to the following conditions:
<> 144:ef7eb2e8f9f7 10 *
<> 144:ef7eb2e8f9f7 11 * The above copyright notice and this permission notice shall be included
<> 144:ef7eb2e8f9f7 12 * in all copies or substantial portions of the Software.
<> 144:ef7eb2e8f9f7 13 *
<> 144:ef7eb2e8f9f7 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
<> 144:ef7eb2e8f9f7 15 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
<> 144:ef7eb2e8f9f7 16 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
<> 144:ef7eb2e8f9f7 17 * IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES
<> 144:ef7eb2e8f9f7 18 * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
<> 144:ef7eb2e8f9f7 19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
<> 144:ef7eb2e8f9f7 20 * OTHER DEALINGS IN THE SOFTWARE.
<> 144:ef7eb2e8f9f7 21 *
<> 144:ef7eb2e8f9f7 22 * Except as contained in this notice, the name of Maxim Integrated
<> 144:ef7eb2e8f9f7 23 * Products, Inc. shall not be used except as stated in the Maxim Integrated
<> 144:ef7eb2e8f9f7 24 * Products, Inc. Branding Policy.
<> 144:ef7eb2e8f9f7 25 *
<> 144:ef7eb2e8f9f7 26 * The mere transfer of this software does not imply any licenses
<> 144:ef7eb2e8f9f7 27 * of trade secrets, proprietary technology, copyrights, patents,
<> 144:ef7eb2e8f9f7 28 * trademarks, maskwork rights, or any other form of intellectual
<> 144:ef7eb2e8f9f7 29 * property whatsoever. Maxim Integrated Products, Inc. retains all
<> 144:ef7eb2e8f9f7 30 * ownership rights.
<> 144:ef7eb2e8f9f7 31 *******************************************************************************
<> 144:ef7eb2e8f9f7 32 */
<> 144:ef7eb2e8f9f7 33
<> 144:ef7eb2e8f9f7 34 #include <string.h>
<> 144:ef7eb2e8f9f7 35 #include "mbed_assert.h"
<> 144:ef7eb2e8f9f7 36 #include "cmsis.h"
<> 144:ef7eb2e8f9f7 37 #include "spi_api.h"
<> 144:ef7eb2e8f9f7 38 #include "pinmap.h"
<> 144:ef7eb2e8f9f7 39 #include "ioman_regs.h"
<> 144:ef7eb2e8f9f7 40 #include "clkman_regs.h"
<> 144:ef7eb2e8f9f7 41 #include "PeripheralPins.h"
<> 144:ef7eb2e8f9f7 42
<> 144:ef7eb2e8f9f7 43 #define DEFAULT_CHAR 8
<> 144:ef7eb2e8f9f7 44 #define DEFAULT_MODE 0
<> 144:ef7eb2e8f9f7 45 #define DEFAULT_FREQ 1000000
<> 144:ef7eb2e8f9f7 46
<> 144:ef7eb2e8f9f7 47 // Formatting settings
<> 144:ef7eb2e8f9f7 48 static int spi_bits;
<> 144:ef7eb2e8f9f7 49
<> 144:ef7eb2e8f9f7 50 //******************************************************************************
<> 144:ef7eb2e8f9f7 51 void spi_init(spi_t *obj, PinName mosi, PinName miso, PinName sclk, PinName ssel)
<> 144:ef7eb2e8f9f7 52 {
<> 144:ef7eb2e8f9f7 53 // Make sure pins are pointing to the same SPI instance
<> 144:ef7eb2e8f9f7 54 SPIName spi_mosi = (SPIName)pinmap_peripheral(mosi, PinMap_SPI_MOSI);
<> 144:ef7eb2e8f9f7 55 SPIName spi_miso = (SPIName)pinmap_peripheral(miso, PinMap_SPI_MISO);
<> 144:ef7eb2e8f9f7 56 SPIName spi_sclk = (SPIName)pinmap_peripheral(sclk, PinMap_SPI_SCLK);
<> 144:ef7eb2e8f9f7 57 SPIName spi_ssel = (SPIName)pinmap_peripheral(ssel, PinMap_SPI_SSEL);
<> 144:ef7eb2e8f9f7 58
<> 144:ef7eb2e8f9f7 59 SPIName spi_data = (SPIName)pinmap_merge(spi_mosi, spi_miso);
<> 144:ef7eb2e8f9f7 60 SPIName spi_cntl;
<> 144:ef7eb2e8f9f7 61
<> 144:ef7eb2e8f9f7 62 // Give the application the option to manually control Slave Select
<> 144:ef7eb2e8f9f7 63 if((SPIName)spi_ssel != (SPIName)NC) {
<> 144:ef7eb2e8f9f7 64 spi_cntl = (SPIName)pinmap_merge(spi_sclk, spi_ssel);
<> 144:ef7eb2e8f9f7 65 } else {
<> 144:ef7eb2e8f9f7 66 spi_cntl = spi_sclk;
<> 144:ef7eb2e8f9f7 67 }
<> 144:ef7eb2e8f9f7 68
<> 144:ef7eb2e8f9f7 69 SPIName spi = (SPIName)pinmap_merge(spi_data, spi_cntl);
<> 144:ef7eb2e8f9f7 70
<> 144:ef7eb2e8f9f7 71 MBED_ASSERT((SPIName)spi != (SPIName)NC);
<> 144:ef7eb2e8f9f7 72
<> 144:ef7eb2e8f9f7 73 // Set the obj pointer to the proper SPI Instance
<> 144:ef7eb2e8f9f7 74 obj->spi = (mxc_spi_regs_t*)spi;
<> 144:ef7eb2e8f9f7 75
<> 144:ef7eb2e8f9f7 76 // Set the SPI index and FIFOs
<> 144:ef7eb2e8f9f7 77 obj->index = MXC_SPI_BASE_TO_INSTANCE(obj->spi);
<> 144:ef7eb2e8f9f7 78 obj->rxfifo = MXC_SPI_GET_RXFIFO(obj->index);
<> 144:ef7eb2e8f9f7 79 obj->txfifo = MXC_SPI_GET_TXFIFO(obj->index);
<> 144:ef7eb2e8f9f7 80
<> 144:ef7eb2e8f9f7 81 // Configure the pins
<> 144:ef7eb2e8f9f7 82 pinmap_pinout(mosi, PinMap_SPI_MOSI);
<> 144:ef7eb2e8f9f7 83 pinmap_pinout(miso, PinMap_SPI_MISO);
<> 144:ef7eb2e8f9f7 84 pinmap_pinout(sclk, PinMap_SPI_SCLK);
<> 144:ef7eb2e8f9f7 85 pinmap_pinout(ssel, PinMap_SPI_SSEL);
<> 144:ef7eb2e8f9f7 86
<> 144:ef7eb2e8f9f7 87 // Enable SPI and FIFOs
<> 144:ef7eb2e8f9f7 88 obj->spi->gen_ctrl = (MXC_F_SPI_GEN_CTRL_SPI_MSTR_EN |
<> 144:ef7eb2e8f9f7 89 MXC_F_SPI_GEN_CTRL_TX_FIFO_EN |
<> 144:ef7eb2e8f9f7 90 MXC_F_SPI_GEN_CTRL_RX_FIFO_EN );
<> 144:ef7eb2e8f9f7 91 }
<> 144:ef7eb2e8f9f7 92
<> 144:ef7eb2e8f9f7 93 //******************************************************************************
<> 144:ef7eb2e8f9f7 94 void spi_format(spi_t *obj, int bits, int mode, int slave)
<> 144:ef7eb2e8f9f7 95 {
<> 144:ef7eb2e8f9f7 96 // Check the validity of the inputs
<> 144:ef7eb2e8f9f7 97 MBED_ASSERT(((bits >= 1) && (bits <= 32)) && ((mode >= 0) && (mode <= 3)));
<> 144:ef7eb2e8f9f7 98
<> 144:ef7eb2e8f9f7 99 // Only supports master mode
<> 144:ef7eb2e8f9f7 100 MBED_ASSERT(!slave);
<> 144:ef7eb2e8f9f7 101
<> 144:ef7eb2e8f9f7 102 // Save formatting data
<> 144:ef7eb2e8f9f7 103 spi_bits = bits;
<> 144:ef7eb2e8f9f7 104
<> 144:ef7eb2e8f9f7 105 // Set the mode
<> 144:ef7eb2e8f9f7 106 obj->spi->mstr_cfg &= ~(MXC_F_SPI_MSTR_CFG_SPI_MODE);
<> 144:ef7eb2e8f9f7 107 obj->spi->mstr_cfg |= (mode << MXC_F_SPI_MSTR_CFG_SPI_MODE_POS);
<> 144:ef7eb2e8f9f7 108 }
<> 144:ef7eb2e8f9f7 109
<> 144:ef7eb2e8f9f7 110 //******************************************************************************
<> 144:ef7eb2e8f9f7 111 void spi_frequency(spi_t *obj, int hz)
<> 144:ef7eb2e8f9f7 112 {
<> 144:ef7eb2e8f9f7 113 // Maximum frequency is half the system frequency
<> 144:ef7eb2e8f9f7 114 MBED_ASSERT((unsigned int)hz <= (SystemCoreClock / 2));
<> 144:ef7eb2e8f9f7 115 unsigned clocks = ((SystemCoreClock/2)/(hz));
<> 144:ef7eb2e8f9f7 116
<> 144:ef7eb2e8f9f7 117 // Figure out the divider ratio
<> 144:ef7eb2e8f9f7 118 int clk_div = 1;
<> 144:ef7eb2e8f9f7 119 while(clk_div < 10) {
<> 144:ef7eb2e8f9f7 120 if(clocks < 0x10) {
<> 144:ef7eb2e8f9f7 121 break;
<> 144:ef7eb2e8f9f7 122 }
<> 144:ef7eb2e8f9f7 123 clk_div++;
<> 144:ef7eb2e8f9f7 124 clocks = clocks >> 1;
<> 144:ef7eb2e8f9f7 125 }
<> 144:ef7eb2e8f9f7 126
<> 144:ef7eb2e8f9f7 127 // Turn on the SPI clock
<> 144:ef7eb2e8f9f7 128 if(obj->index == 0) {
<> 144:ef7eb2e8f9f7 129 MXC_CLKMAN->clk_ctrl_3_spi0 = clk_div;
<> 144:ef7eb2e8f9f7 130 } else if(obj->index == 1) {
<> 144:ef7eb2e8f9f7 131 MXC_CLKMAN->clk_ctrl_4_spi1 = clk_div;
<> 144:ef7eb2e8f9f7 132 } else if(obj->index == 2) {
<> 144:ef7eb2e8f9f7 133 MXC_CLKMAN->clk_ctrl_5_spi2 = clk_div;
<> 144:ef7eb2e8f9f7 134 } else {
<> 144:ef7eb2e8f9f7 135 MBED_ASSERT(0);
<> 144:ef7eb2e8f9f7 136 }
<> 144:ef7eb2e8f9f7 137
<> 144:ef7eb2e8f9f7 138 // Set the number of clocks to hold sclk high and low
<> 144:ef7eb2e8f9f7 139 MXC_SET_FIELD(&obj->spi->mstr_cfg, (MXC_F_SPI_MSTR_CFG_SCK_HI_CLK | MXC_F_SPI_MSTR_CFG_SCK_LO_CLK),
<> 144:ef7eb2e8f9f7 140 ((clocks << MXC_F_SPI_MSTR_CFG_SCK_HI_CLK_POS) | (clocks << MXC_F_SPI_MSTR_CFG_SCK_LO_CLK_POS)));
<> 144:ef7eb2e8f9f7 141 }
<> 144:ef7eb2e8f9f7 142
<> 144:ef7eb2e8f9f7 143 //******************************************************************************
<> 144:ef7eb2e8f9f7 144 int spi_master_write(spi_t *obj, int value)
<> 144:ef7eb2e8f9f7 145 {
<> 144:ef7eb2e8f9f7 146 int bits = spi_bits;
<> 144:ef7eb2e8f9f7 147 if(spi_bits == 32) {
<> 144:ef7eb2e8f9f7 148 bits = 0;
<> 144:ef7eb2e8f9f7 149 }
<> 144:ef7eb2e8f9f7 150 // Create the header
<> 144:ef7eb2e8f9f7 151 uint16_t header = ((0x3 << MXC_F_SPI_FIFO_DIR_POS ) | // TX and RX
<> 144:ef7eb2e8f9f7 152 (0x0 << MXC_F_SPI_FIFO_UNIT_POS) | // Send bits
<> 144:ef7eb2e8f9f7 153 (bits << MXC_F_SPI_FIFO_SIZE_POS) | // Number of units
<> 144:ef7eb2e8f9f7 154 (0x1 << MXC_F_SPI_FIFO_DASS_POS)); // Deassert SS
<> 144:ef7eb2e8f9f7 155
<> 144:ef7eb2e8f9f7 156 // Send the message header
<> 144:ef7eb2e8f9f7 157 obj->txfifo->txfifo_16 = header;
<> 144:ef7eb2e8f9f7 158
<> 144:ef7eb2e8f9f7 159 // Send the data
<> 144:ef7eb2e8f9f7 160 if(spi_bits < 17) {
<> 144:ef7eb2e8f9f7 161 obj->txfifo->txfifo_16 = (uint16_t)value;
<> 144:ef7eb2e8f9f7 162 } else {
<> 144:ef7eb2e8f9f7 163 obj->txfifo->txfifo_32 = (uint32_t)value;
<> 144:ef7eb2e8f9f7 164 }
<> 144:ef7eb2e8f9f7 165
<> 144:ef7eb2e8f9f7 166 // Get the data
<> 144:ef7eb2e8f9f7 167 bits = spi_bits;
<> 144:ef7eb2e8f9f7 168 int result = 0;
<> 144:ef7eb2e8f9f7 169 int i = 0;
<> 144:ef7eb2e8f9f7 170 while(bits > 0) {
<> 144:ef7eb2e8f9f7 171 // Wait for data
<> 144:ef7eb2e8f9f7 172 while(((obj->spi->fifo_ctrl & MXC_F_SPI_FIFO_CTRL_RX_FIFO_USED)
<> 144:ef7eb2e8f9f7 173 >> MXC_F_SPI_FIFO_CTRL_RX_FIFO_USED_POS) < 1) {}
<> 144:ef7eb2e8f9f7 174
<> 144:ef7eb2e8f9f7 175 result |= (obj->rxfifo->rxfifo_8 << (i++*8));
<> 144:ef7eb2e8f9f7 176 bits-=8;
<> 144:ef7eb2e8f9f7 177 }
<> 144:ef7eb2e8f9f7 178
<> 144:ef7eb2e8f9f7 179 return result;
<> 144:ef7eb2e8f9f7 180 }
<> 144:ef7eb2e8f9f7 181
<> 144:ef7eb2e8f9f7 182 //******************************************************************************
<> 144:ef7eb2e8f9f7 183 int spi_busy(spi_t *obj)
<> 144:ef7eb2e8f9f7 184 {
<> 144:ef7eb2e8f9f7 185 return !(obj->spi->intfl & MXC_F_SPI_INTFL_TX_READY);
<> 144:ef7eb2e8f9f7 186 }