test / mbed-src

mbed library sources

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Fork of mbed-src by mbed official

targets/hal/TARGET_NXP/TARGET_LPC43XX/spi_api.c@81:a9456fdf72fa, 2014-01-31 (annotated)

Committer:
mbed_official
Date:
Fri Jan 31 09:00:05 2014 +0000
Revision:
81:a9456fdf72fa
Parent:
20:4263a77256ae 
Synchronized with git revision 2a782f50677ef823f25764c76cfed1bec98740be



Full URL: https://github.com/mbedmicro/mbed/commit/2a782f50677ef823f25764c76cfed1bec98740be/



Remove unnecessary semicolons.

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bogdanm 20:4263a77256ae 1 /* mbed Microcontroller Library
bogdanm 20:4263a77256ae 2 * Copyright (c) 2006-2013 ARM Limited
bogdanm 20:4263a77256ae 3 *
bogdanm 20:4263a77256ae 4 * Licensed under the Apache License, Version 2.0 (the "License");
bogdanm 20:4263a77256ae 5 * you may not use this file except in compliance with the License.
bogdanm 20:4263a77256ae 6 * You may obtain a copy of the License at
bogdanm 20:4263a77256ae 7 *
bogdanm 20:4263a77256ae 8 * http://www.apache.org/licenses/LICENSE-2.0
bogdanm 20:4263a77256ae 9 *
bogdanm 20:4263a77256ae 10 * Unless required by applicable law or agreed to in writing, software
bogdanm 20:4263a77256ae 11 * distributed under the License is distributed on an "AS IS" BASIS,
bogdanm 20:4263a77256ae 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
bogdanm 20:4263a77256ae 13 * See the License for the specific language governing permissions and
bogdanm 20:4263a77256ae 14 * limitations under the License.
bogdanm 20:4263a77256ae 15 *
bogdanm 20:4263a77256ae 16 * Ported to NXP LPC43XX by Micromint USA <support@micromint.com>
bogdanm 20:4263a77256ae 17 */
bogdanm 20:4263a77256ae 18 #include <math.h>
bogdanm 20:4263a77256ae 19
bogdanm 20:4263a77256ae 20 #include "spi_api.h"
bogdanm 20:4263a77256ae 21 #include "cmsis.h"
bogdanm 20:4263a77256ae 22 #include "pinmap.h"
bogdanm 20:4263a77256ae 23 #include "error.h"
bogdanm 20:4263a77256ae 24
bogdanm 20:4263a77256ae 25 static const PinMap PinMap_SPI_SCLK[] = {
bogdanm 20:4263a77256ae 26 {P3_0 , SPI_0, (SCU_PINIO_FAST | 2)},
bogdanm 20:4263a77256ae 27 {PF_4 , SPI_1, (SCU_PINIO_FAST | 2)},
bogdanm 20:4263a77256ae 28 {NC , NC , 0}
bogdanm 20:4263a77256ae 29 };
bogdanm 20:4263a77256ae 30
bogdanm 20:4263a77256ae 31 static const PinMap PinMap_SPI_MOSI[] = {
bogdanm 20:4263a77256ae 32 {P1_2 , SPI_0, (SCU_PINIO_FAST | 2)},
bogdanm 20:4263a77256ae 33 {P1_4 , SPI_1, (SCU_PINIO_FAST | 2)},
bogdanm 20:4263a77256ae 34 {NC , NC , 0}
bogdanm 20:4263a77256ae 35 };
bogdanm 20:4263a77256ae 36
bogdanm 20:4263a77256ae 37 static const PinMap PinMap_SPI_MISO[] = {
bogdanm 20:4263a77256ae 38 {P1_1 , SPI_0, (SCU_PINIO_FAST | 2)},
bogdanm 20:4263a77256ae 39 {P1_3 , SPI_1, (SCU_PINIO_FAST | 2)},
bogdanm 20:4263a77256ae 40 {NC , NC , 0}
bogdanm 20:4263a77256ae 41 };
bogdanm 20:4263a77256ae 42
bogdanm 20:4263a77256ae 43 static const PinMap PinMap_SPI_SSEL[] = {
bogdanm 20:4263a77256ae 44 {P1_0 , SPI_0, (SCU_PINIO_FAST | 2)},
bogdanm 20:4263a77256ae 45 {P1_5 , SPI_1, (SCU_PINIO_FAST | 2)},
bogdanm 20:4263a77256ae 46 {NC , NC , 0}
bogdanm 20:4263a77256ae 47 };
bogdanm 20:4263a77256ae 48
bogdanm 20:4263a77256ae 49 static inline int ssp_disable(spi_t *obj);
bogdanm 20:4263a77256ae 50 static inline int ssp_enable(spi_t *obj);
bogdanm 20:4263a77256ae 51
bogdanm 20:4263a77256ae 52 void spi_init(spi_t *obj, PinName mosi, PinName miso, PinName sclk, PinName ssel) {
bogdanm 20:4263a77256ae 53 // determine the SPI to use
bogdanm 20:4263a77256ae 54 SPIName spi_mosi = (SPIName)pinmap_peripheral(mosi, PinMap_SPI_MOSI);
bogdanm 20:4263a77256ae 55 SPIName spi_miso = (SPIName)pinmap_peripheral(miso, PinMap_SPI_MISO);
bogdanm 20:4263a77256ae 56 SPIName spi_sclk = (SPIName)pinmap_peripheral(sclk, PinMap_SPI_SCLK);
bogdanm 20:4263a77256ae 57 SPIName spi_ssel = (SPIName)pinmap_peripheral(ssel, PinMap_SPI_SSEL);
bogdanm 20:4263a77256ae 58 SPIName spi_data = (SPIName)pinmap_merge(spi_mosi, spi_miso);
bogdanm 20:4263a77256ae 59 SPIName spi_cntl = (SPIName)pinmap_merge(spi_sclk, spi_ssel);
bogdanm 20:4263a77256ae 60
bogdanm 20:4263a77256ae 61 obj->spi = (LPC_SSP_T*)pinmap_merge(spi_data, spi_cntl);
bogdanm 20:4263a77256ae 62 if ((int)obj->spi == NC) {
bogdanm 20:4263a77256ae 63 error("SPI pinout mapping failed");
bogdanm 20:4263a77256ae 64 }
bogdanm 20:4263a77256ae 65
bogdanm 20:4263a77256ae 66 // set default format and frequency
bogdanm 20:4263a77256ae 67 if (ssel == NC) {
bogdanm 20:4263a77256ae 68 spi_format(obj, 8, 0, 0); // 8 bits, mode 0, master
bogdanm 20:4263a77256ae 69 } else {
bogdanm 20:4263a77256ae 70 spi_format(obj, 8, 0, 1); // 8 bits, mode 0, slave
bogdanm 20:4263a77256ae 71 }
bogdanm 20:4263a77256ae 72 spi_frequency(obj, 1000000);
bogdanm 20:4263a77256ae 73
bogdanm 20:4263a77256ae 74 // enable the ssp channel
bogdanm 20:4263a77256ae 75 ssp_enable(obj);
bogdanm 20:4263a77256ae 76
bogdanm 20:4263a77256ae 77 // pin out the spi pins
bogdanm 20:4263a77256ae 78 pinmap_pinout(mosi, PinMap_SPI_MOSI);
bogdanm 20:4263a77256ae 79 pinmap_pinout(miso, PinMap_SPI_MISO);
bogdanm 20:4263a77256ae 80 pinmap_pinout(sclk, PinMap_SPI_SCLK);
bogdanm 20:4263a77256ae 81 if (ssel != NC) {
bogdanm 20:4263a77256ae 82 pinmap_pinout(ssel, PinMap_SPI_SSEL);
bogdanm 20:4263a77256ae 83 }
bogdanm 20:4263a77256ae 84 }
bogdanm 20:4263a77256ae 85
bogdanm 20:4263a77256ae 86 void spi_free(spi_t *obj) {}
bogdanm 20:4263a77256ae 87
bogdanm 20:4263a77256ae 88 void spi_format(spi_t *obj, int bits, int mode, int slave) {
bogdanm 20:4263a77256ae 89 ssp_disable(obj);
bogdanm 20:4263a77256ae 90
bogdanm 20:4263a77256ae 91 if (!(bits >= 4 && bits <= 16) || !(mode >= 0 && mode <= 3)) {
bogdanm 20:4263a77256ae 92 error("SPI format error");
bogdanm 20:4263a77256ae 93 }
bogdanm 20:4263a77256ae 94
bogdanm 20:4263a77256ae 95 int polarity = (mode & 0x2) ? 1 : 0;
bogdanm 20:4263a77256ae 96 int phase = (mode & 0x1) ? 1 : 0;
bogdanm 20:4263a77256ae 97
bogdanm 20:4263a77256ae 98 // set it up
bogdanm 20:4263a77256ae 99 int DSS = bits - 1; // DSS (data select size)
bogdanm 20:4263a77256ae 100 int SPO = (polarity) ? 1 : 0; // SPO - clock out polarity
bogdanm 20:4263a77256ae 101 int SPH = (phase) ? 1 : 0; // SPH - clock out phase
bogdanm 20:4263a77256ae 102
bogdanm 20:4263a77256ae 103 int FRF = 0; // FRF (frame format) = SPI
bogdanm 20:4263a77256ae 104 uint32_t tmp = obj->spi->CR0;
bogdanm 20:4263a77256ae 105 tmp &= ~(0xFFFF);
bogdanm 20:4263a77256ae 106 tmp |= DSS << 0
bogdanm 20:4263a77256ae 107 | FRF << 4
bogdanm 20:4263a77256ae 108 | SPO << 6
bogdanm 20:4263a77256ae 109 | SPH << 7;
bogdanm 20:4263a77256ae 110 obj->spi->CR0 = tmp;
bogdanm 20:4263a77256ae 111
bogdanm 20:4263a77256ae 112 tmp = obj->spi->CR1;
bogdanm 20:4263a77256ae 113 tmp &= ~(0xD);
bogdanm 20:4263a77256ae 114 tmp |= 0 << 0 // LBM - loop back mode - off
bogdanm 20:4263a77256ae 115 | ((slave) ? 1 : 0) << 2 // MS - master slave mode, 1 = slave
bogdanm 20:4263a77256ae 116 | 0 << 3; // SOD - slave output disable - na
bogdanm 20:4263a77256ae 117 obj->spi->CR1 = tmp;
bogdanm 20:4263a77256ae 118 ssp_enable(obj);
bogdanm 20:4263a77256ae 119 }
bogdanm 20:4263a77256ae 120
bogdanm 20:4263a77256ae 121 void spi_frequency(spi_t *obj, int hz) {
bogdanm 20:4263a77256ae 122 ssp_disable(obj);
bogdanm 20:4263a77256ae 123
bogdanm 20:4263a77256ae 124 uint32_t PCLK = SystemCoreClock;
bogdanm 20:4263a77256ae 125
bogdanm 20:4263a77256ae 126 int prescaler;
bogdanm 20:4263a77256ae 127
bogdanm 20:4263a77256ae 128 for (prescaler = 2; prescaler <= 254; prescaler += 2) {
bogdanm 20:4263a77256ae 129 int prescale_hz = PCLK / prescaler;
bogdanm 20:4263a77256ae 130
bogdanm 20:4263a77256ae 131 // calculate the divider
bogdanm 20:4263a77256ae 132 int divider = floor(((float)prescale_hz / (float)hz) + 0.5f);
bogdanm 20:4263a77256ae 133
bogdanm 20:4263a77256ae 134 // check we can support the divider
bogdanm 20:4263a77256ae 135 if (divider < 256) {
bogdanm 20:4263a77256ae 136 // prescaler
bogdanm 20:4263a77256ae 137 obj->spi->CPSR = prescaler;
bogdanm 20:4263a77256ae 138
bogdanm 20:4263a77256ae 139 // divider
bogdanm 20:4263a77256ae 140 obj->spi->CR0 &= ~(0xFFFF << 8);
bogdanm 20:4263a77256ae 141 obj->spi->CR0 |= (divider - 1) << 8;
bogdanm 20:4263a77256ae 142 ssp_enable(obj);
bogdanm 20:4263a77256ae 143 return;
bogdanm 20:4263a77256ae 144 }
bogdanm 20:4263a77256ae 145 }
bogdanm 20:4263a77256ae 146 error("Couldn't setup requested SPI frequency");
bogdanm 20:4263a77256ae 147 }
bogdanm 20:4263a77256ae 148
bogdanm 20:4263a77256ae 149 static inline int ssp_disable(spi_t *obj) {
bogdanm 20:4263a77256ae 150 return obj->spi->CR1 &= ~(1 << 1);
bogdanm 20:4263a77256ae 151 }
bogdanm 20:4263a77256ae 152
bogdanm 20:4263a77256ae 153 static inline int ssp_enable(spi_t *obj) {
bogdanm 20:4263a77256ae 154 return obj->spi->CR1 |= (1 << 1);
bogdanm 20:4263a77256ae 155 }
bogdanm 20:4263a77256ae 156
bogdanm 20:4263a77256ae 157 static inline int ssp_readable(spi_t *obj) {
bogdanm 20:4263a77256ae 158 return obj->spi->SR & (1 << 2);
bogdanm 20:4263a77256ae 159 }
bogdanm 20:4263a77256ae 160
bogdanm 20:4263a77256ae 161 static inline int ssp_writeable(spi_t *obj) {
bogdanm 20:4263a77256ae 162 return obj->spi->SR & (1 << 1);
bogdanm 20:4263a77256ae 163 }
bogdanm 20:4263a77256ae 164
bogdanm 20:4263a77256ae 165 static inline void ssp_write(spi_t *obj, int value) {
bogdanm 20:4263a77256ae 166 while (!ssp_writeable(obj));
bogdanm 20:4263a77256ae 167 obj->spi->DR = value;
bogdanm 20:4263a77256ae 168 }
bogdanm 20:4263a77256ae 169
bogdanm 20:4263a77256ae 170 static inline int ssp_read(spi_t *obj) {
bogdanm 20:4263a77256ae 171 while (!ssp_readable(obj));
bogdanm 20:4263a77256ae 172 return obj->spi->DR;
bogdanm 20:4263a77256ae 173 }
bogdanm 20:4263a77256ae 174
bogdanm 20:4263a77256ae 175 static inline int ssp_busy(spi_t *obj) {
bogdanm 20:4263a77256ae 176 return (obj->spi->SR & (1 << 4)) ? (1) : (0);
bogdanm 20:4263a77256ae 177 }
bogdanm 20:4263a77256ae 178
bogdanm 20:4263a77256ae 179 int spi_master_write(spi_t *obj, int value) {
bogdanm 20:4263a77256ae 180 ssp_write(obj, value);
bogdanm 20:4263a77256ae 181 return ssp_read(obj);
bogdanm 20:4263a77256ae 182 }
bogdanm 20:4263a77256ae 183
bogdanm 20:4263a77256ae 184 int spi_slave_receive(spi_t *obj) {
bogdanm 20:4263a77256ae 185 return (ssp_readable(obj) && !ssp_busy(obj)) ? (1) : (0);
mbed_official 81:a9456fdf72fa 186 }
bogdanm 20:4263a77256ae 187
bogdanm 20:4263a77256ae 188 int spi_slave_read(spi_t *obj) {
bogdanm 20:4263a77256ae 189 return obj->spi->DR;
bogdanm 20:4263a77256ae 190 }
bogdanm 20:4263a77256ae 191
bogdanm 20:4263a77256ae 192 void spi_slave_write(spi_t *obj, int value) {
bogdanm 20:4263a77256ae 193 while (ssp_writeable(obj) == 0) ;
bogdanm 20:4263a77256ae 194 obj->spi->DR = value;
bogdanm 20:4263a77256ae 195 }
bogdanm 20:4263a77256ae 196
bogdanm 20:4263a77256ae 197 int spi_busy(spi_t *obj) {
bogdanm 20:4263a77256ae 198 return ssp_busy(obj);
bogdanm 20:4263a77256ae 199 }