MacroRat / MouseCode

Mouse code for the MacroRat

Dependencies:   ITG3200 QEI

mbed-dev/targets/TARGET_NXP/TARGET_LPC11UXX/spi_api.c@46:b156ef445742, 2017-06-03 (annotated)

Committer:
sahilmgandhi
Date:
Sat Jun 03 00:22:44 2017 +0000
Revision:
46:b156ef445742
Parent:
18:6a4db94011d3 
Final code for internal battlebot competition.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
sahilmgandhi 18:6a4db94011d3 1 /* mbed Microcontroller Library
sahilmgandhi 18:6a4db94011d3 2 * Copyright (c) 2006-2013 ARM Limited
sahilmgandhi 18:6a4db94011d3 3 *
sahilmgandhi 18:6a4db94011d3 4 * Licensed under the Apache License, Version 2.0 (the "License");
sahilmgandhi 18:6a4db94011d3 5 * you may not use this file except in compliance with the License.
sahilmgandhi 18:6a4db94011d3 6 * You may obtain a copy of the License at
sahilmgandhi 18:6a4db94011d3 7 *
sahilmgandhi 18:6a4db94011d3 8 * http://www.apache.org/licenses/LICENSE-2.0
sahilmgandhi 18:6a4db94011d3 9 *
sahilmgandhi 18:6a4db94011d3 10 * Unless required by applicable law or agreed to in writing, software
sahilmgandhi 18:6a4db94011d3 11 * distributed under the License is distributed on an "AS IS" BASIS,
sahilmgandhi 18:6a4db94011d3 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
sahilmgandhi 18:6a4db94011d3 13 * See the License for the specific language governing permissions and
sahilmgandhi 18:6a4db94011d3 14 * limitations under the License.
sahilmgandhi 18:6a4db94011d3 15 */
sahilmgandhi 18:6a4db94011d3 16 #include "mbed_assert.h"
sahilmgandhi 18:6a4db94011d3 17 #include <math.h>
sahilmgandhi 18:6a4db94011d3 18 #include "spi_api.h"
sahilmgandhi 18:6a4db94011d3 19 #include "cmsis.h"
sahilmgandhi 18:6a4db94011d3 20 #include "pinmap.h"
sahilmgandhi 18:6a4db94011d3 21 #include "mbed_error.h"
sahilmgandhi 18:6a4db94011d3 22 #include "PeripheralPins.h" // For the Peripheral to Pin Definitions found in the individual Target's Platform
sahilmgandhi 18:6a4db94011d3 23
sahilmgandhi 18:6a4db94011d3 24 static inline int ssp_disable(spi_t *obj);
sahilmgandhi 18:6a4db94011d3 25 static inline int ssp_enable(spi_t *obj);
sahilmgandhi 18:6a4db94011d3 26
sahilmgandhi 18:6a4db94011d3 27 void spi_init(spi_t *obj, PinName mosi, PinName miso, PinName sclk, PinName ssel) {
sahilmgandhi 18:6a4db94011d3 28 // determine the SPI to use
sahilmgandhi 18:6a4db94011d3 29 SPIName spi_mosi = (SPIName)pinmap_peripheral(mosi, PinMap_SPI_MOSI);
sahilmgandhi 18:6a4db94011d3 30 SPIName spi_miso = (SPIName)pinmap_peripheral(miso, PinMap_SPI_MISO);
sahilmgandhi 18:6a4db94011d3 31 SPIName spi_sclk = (SPIName)pinmap_peripheral(sclk, PinMap_SPI_SCLK);
sahilmgandhi 18:6a4db94011d3 32 SPIName spi_ssel = (SPIName)pinmap_peripheral(ssel, PinMap_SPI_SSEL);
sahilmgandhi 18:6a4db94011d3 33 SPIName spi_data = (SPIName)pinmap_merge(spi_mosi, spi_miso);
sahilmgandhi 18:6a4db94011d3 34 SPIName spi_cntl = (SPIName)pinmap_merge(spi_sclk, spi_ssel);
sahilmgandhi 18:6a4db94011d3 35
sahilmgandhi 18:6a4db94011d3 36 obj->spi = (LPC_SSPx_Type*)pinmap_merge(spi_data, spi_cntl);
sahilmgandhi 18:6a4db94011d3 37 MBED_ASSERT((int)obj->spi != NC);
sahilmgandhi 18:6a4db94011d3 38
sahilmgandhi 18:6a4db94011d3 39 // enable power and clocking
sahilmgandhi 18:6a4db94011d3 40 switch ((int)obj->spi) {
sahilmgandhi 18:6a4db94011d3 41 case SPI_0:
sahilmgandhi 18:6a4db94011d3 42 LPC_SYSCON->SYSAHBCLKCTRL |= 1 << 11;
sahilmgandhi 18:6a4db94011d3 43 LPC_SYSCON->SSP0CLKDIV = 0x01;
sahilmgandhi 18:6a4db94011d3 44 LPC_SYSCON->PRESETCTRL |= 1 << 0;
sahilmgandhi 18:6a4db94011d3 45 break;
sahilmgandhi 18:6a4db94011d3 46 case SPI_1:
sahilmgandhi 18:6a4db94011d3 47 LPC_SYSCON->SYSAHBCLKCTRL |= 1 << 18;
sahilmgandhi 18:6a4db94011d3 48 LPC_SYSCON->SSP1CLKDIV = 0x01;
sahilmgandhi 18:6a4db94011d3 49 LPC_SYSCON->PRESETCTRL |= 1 << 2;
sahilmgandhi 18:6a4db94011d3 50 break;
sahilmgandhi 18:6a4db94011d3 51 }
sahilmgandhi 18:6a4db94011d3 52
sahilmgandhi 18:6a4db94011d3 53 // pin out the spi pins
sahilmgandhi 18:6a4db94011d3 54 pinmap_pinout(mosi, PinMap_SPI_MOSI);
sahilmgandhi 18:6a4db94011d3 55 pinmap_pinout(miso, PinMap_SPI_MISO);
sahilmgandhi 18:6a4db94011d3 56 pinmap_pinout(sclk, PinMap_SPI_SCLK);
sahilmgandhi 18:6a4db94011d3 57 if (ssel != NC) {
sahilmgandhi 18:6a4db94011d3 58 pinmap_pinout(ssel, PinMap_SPI_SSEL);
sahilmgandhi 18:6a4db94011d3 59 }
sahilmgandhi 18:6a4db94011d3 60 }
sahilmgandhi 18:6a4db94011d3 61
sahilmgandhi 18:6a4db94011d3 62 void spi_free(spi_t *obj) {}
sahilmgandhi 18:6a4db94011d3 63
sahilmgandhi 18:6a4db94011d3 64 void spi_format(spi_t *obj, int bits, int mode, int slave) {
sahilmgandhi 18:6a4db94011d3 65 MBED_ASSERT((bits >= 4 && bits <= 16) || (mode >= 0 && mode <= 3));
sahilmgandhi 18:6a4db94011d3 66
sahilmgandhi 18:6a4db94011d3 67 ssp_disable(obj);
sahilmgandhi 18:6a4db94011d3 68
sahilmgandhi 18:6a4db94011d3 69 int polarity = (mode & 0x2) ? 1 : 0;
sahilmgandhi 18:6a4db94011d3 70 int phase = (mode & 0x1) ? 1 : 0;
sahilmgandhi 18:6a4db94011d3 71
sahilmgandhi 18:6a4db94011d3 72 // set it up
sahilmgandhi 18:6a4db94011d3 73 int DSS = bits - 1; // DSS (data select size)
sahilmgandhi 18:6a4db94011d3 74 int SPO = (polarity) ? 1 : 0; // SPO - clock out polarity
sahilmgandhi 18:6a4db94011d3 75 int SPH = (phase) ? 1 : 0; // SPH - clock out phase
sahilmgandhi 18:6a4db94011d3 76
sahilmgandhi 18:6a4db94011d3 77 int FRF = 0; // FRF (frame format) = SPI
sahilmgandhi 18:6a4db94011d3 78 uint32_t tmp = obj->spi->CR0;
sahilmgandhi 18:6a4db94011d3 79 tmp &= ~(0xFFFF);
sahilmgandhi 18:6a4db94011d3 80 tmp |= DSS << 0
sahilmgandhi 18:6a4db94011d3 81 | FRF << 4
sahilmgandhi 18:6a4db94011d3 82 | SPO << 6
sahilmgandhi 18:6a4db94011d3 83 | SPH << 7;
sahilmgandhi 18:6a4db94011d3 84 obj->spi->CR0 = tmp;
sahilmgandhi 18:6a4db94011d3 85
sahilmgandhi 18:6a4db94011d3 86 tmp = obj->spi->CR1;
sahilmgandhi 18:6a4db94011d3 87 tmp &= ~(0xD);
sahilmgandhi 18:6a4db94011d3 88 tmp |= 0 << 0 // LBM - loop back mode - off
sahilmgandhi 18:6a4db94011d3 89 | ((slave) ? 1 : 0) << 2 // MS - master slave mode, 1 = slave
sahilmgandhi 18:6a4db94011d3 90 | 0 << 3; // SOD - slave output disable - na
sahilmgandhi 18:6a4db94011d3 91 obj->spi->CR1 = tmp;
sahilmgandhi 18:6a4db94011d3 92
sahilmgandhi 18:6a4db94011d3 93 ssp_enable(obj);
sahilmgandhi 18:6a4db94011d3 94 }
sahilmgandhi 18:6a4db94011d3 95
sahilmgandhi 18:6a4db94011d3 96 void spi_frequency(spi_t *obj, int hz) {
sahilmgandhi 18:6a4db94011d3 97 ssp_disable(obj);
sahilmgandhi 18:6a4db94011d3 98
sahilmgandhi 18:6a4db94011d3 99 uint32_t PCLK = SystemCoreClock;
sahilmgandhi 18:6a4db94011d3 100
sahilmgandhi 18:6a4db94011d3 101 int prescaler;
sahilmgandhi 18:6a4db94011d3 102
sahilmgandhi 18:6a4db94011d3 103 for (prescaler = 2; prescaler <= 254; prescaler += 2) {
sahilmgandhi 18:6a4db94011d3 104 int prescale_hz = PCLK / prescaler;
sahilmgandhi 18:6a4db94011d3 105
sahilmgandhi 18:6a4db94011d3 106 // calculate the divider
sahilmgandhi 18:6a4db94011d3 107 int divider = floor(((float)prescale_hz / (float)hz) + 0.5f);
sahilmgandhi 18:6a4db94011d3 108
sahilmgandhi 18:6a4db94011d3 109 // check we can support the divider
sahilmgandhi 18:6a4db94011d3 110 if (divider < 256) {
sahilmgandhi 18:6a4db94011d3 111 // prescaler
sahilmgandhi 18:6a4db94011d3 112 obj->spi->CPSR = prescaler;
sahilmgandhi 18:6a4db94011d3 113
sahilmgandhi 18:6a4db94011d3 114 // divider
sahilmgandhi 18:6a4db94011d3 115 obj->spi->CR0 &= ~(0xFFFF << 8);
sahilmgandhi 18:6a4db94011d3 116 obj->spi->CR0 |= (divider - 1) << 8;
sahilmgandhi 18:6a4db94011d3 117 ssp_enable(obj);
sahilmgandhi 18:6a4db94011d3 118 return;
sahilmgandhi 18:6a4db94011d3 119 }
sahilmgandhi 18:6a4db94011d3 120 }
sahilmgandhi 18:6a4db94011d3 121 error("Couldn't setup requested SPI frequency");
sahilmgandhi 18:6a4db94011d3 122 }
sahilmgandhi 18:6a4db94011d3 123
sahilmgandhi 18:6a4db94011d3 124 static inline int ssp_disable(spi_t *obj) {
sahilmgandhi 18:6a4db94011d3 125 return obj->spi->CR1 &= ~(1 << 1);
sahilmgandhi 18:6a4db94011d3 126 }
sahilmgandhi 18:6a4db94011d3 127
sahilmgandhi 18:6a4db94011d3 128 static inline int ssp_enable(spi_t *obj) {
sahilmgandhi 18:6a4db94011d3 129 return obj->spi->CR1 |= (1 << 1);
sahilmgandhi 18:6a4db94011d3 130 }
sahilmgandhi 18:6a4db94011d3 131
sahilmgandhi 18:6a4db94011d3 132 static inline int ssp_readable(spi_t *obj) {
sahilmgandhi 18:6a4db94011d3 133 return obj->spi->SR & (1 << 2);
sahilmgandhi 18:6a4db94011d3 134 }
sahilmgandhi 18:6a4db94011d3 135
sahilmgandhi 18:6a4db94011d3 136 static inline int ssp_writeable(spi_t *obj) {
sahilmgandhi 18:6a4db94011d3 137 return obj->spi->SR & (1 << 1);
sahilmgandhi 18:6a4db94011d3 138 }
sahilmgandhi 18:6a4db94011d3 139
sahilmgandhi 18:6a4db94011d3 140 static inline void ssp_write(spi_t *obj, int value) {
sahilmgandhi 18:6a4db94011d3 141 while (!ssp_writeable(obj));
sahilmgandhi 18:6a4db94011d3 142 obj->spi->DR = value;
sahilmgandhi 18:6a4db94011d3 143 }
sahilmgandhi 18:6a4db94011d3 144
sahilmgandhi 18:6a4db94011d3 145 static inline int ssp_read(spi_t *obj) {
sahilmgandhi 18:6a4db94011d3 146 while (!ssp_readable(obj));
sahilmgandhi 18:6a4db94011d3 147 return obj->spi->DR;
sahilmgandhi 18:6a4db94011d3 148 }
sahilmgandhi 18:6a4db94011d3 149
sahilmgandhi 18:6a4db94011d3 150 static inline int ssp_busy(spi_t *obj) {
sahilmgandhi 18:6a4db94011d3 151 return (obj->spi->SR & (1 << 4)) ? (1) : (0);
sahilmgandhi 18:6a4db94011d3 152 }
sahilmgandhi 18:6a4db94011d3 153
sahilmgandhi 18:6a4db94011d3 154 int spi_master_write(spi_t *obj, int value) {
sahilmgandhi 18:6a4db94011d3 155 ssp_write(obj, value);
sahilmgandhi 18:6a4db94011d3 156 return ssp_read(obj);
sahilmgandhi 18:6a4db94011d3 157 }
sahilmgandhi 18:6a4db94011d3 158
sahilmgandhi 18:6a4db94011d3 159 int spi_slave_receive(spi_t *obj) {
sahilmgandhi 18:6a4db94011d3 160 return (ssp_readable(obj) && !ssp_busy(obj)) ? (1) : (0);
sahilmgandhi 18:6a4db94011d3 161 }
sahilmgandhi 18:6a4db94011d3 162
sahilmgandhi 18:6a4db94011d3 163 int spi_slave_read(spi_t *obj) {
sahilmgandhi 18:6a4db94011d3 164 return obj->spi->DR;
sahilmgandhi 18:6a4db94011d3 165 }
sahilmgandhi 18:6a4db94011d3 166
sahilmgandhi 18:6a4db94011d3 167 void spi_slave_write(spi_t *obj, int value) {
sahilmgandhi 18:6a4db94011d3 168 while (ssp_writeable(obj) == 0) ;
sahilmgandhi 18:6a4db94011d3 169 obj->spi->DR = value;
sahilmgandhi 18:6a4db94011d3 170 }
sahilmgandhi 18:6a4db94011d3 171
sahilmgandhi 18:6a4db94011d3 172 int spi_busy(spi_t *obj) {
sahilmgandhi 18:6a4db94011d3 173 return ssp_busy(obj);
sahilmgandhi 18:6a4db94011d3 174 }