test / mbed-src

mbed library sources

Dependents:   bare

Fork of mbed-src by mbed official

targets/hal/TARGET_NXP/TARGET_LPC408X/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:
15:4892fe388435 
Synchronized with git revision 2a782f50677ef823f25764c76cfed1bec98740be



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



Remove unnecessary semicolons.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
bogdanm 15:4892fe388435 1 /* mbed Microcontroller Library
bogdanm 15:4892fe388435 2 * Copyright (c) 2006-2013 ARM Limited
bogdanm 15:4892fe388435 3 *
bogdanm 15:4892fe388435 4 * Licensed under the Apache License, Version 2.0 (the "License");
bogdanm 15:4892fe388435 5 * you may not use this file except in compliance with the License.
bogdanm 15:4892fe388435 6 * You may obtain a copy of the License at
bogdanm 15:4892fe388435 7 *
bogdanm 15:4892fe388435 8 * http://www.apache.org/licenses/LICENSE-2.0
bogdanm 15:4892fe388435 9 *
bogdanm 15:4892fe388435 10 * Unless required by applicable law or agreed to in writing, software
bogdanm 15:4892fe388435 11 * distributed under the License is distributed on an "AS IS" BASIS,
bogdanm 15:4892fe388435 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
bogdanm 15:4892fe388435 13 * See the License for the specific language governing permissions and
bogdanm 15:4892fe388435 14 * limitations under the License.
bogdanm 15:4892fe388435 15 */
bogdanm 15:4892fe388435 16 #include <math.h>
bogdanm 15:4892fe388435 17
bogdanm 15:4892fe388435 18 #include "spi_api.h"
bogdanm 15:4892fe388435 19 #include "cmsis.h"
bogdanm 15:4892fe388435 20 #include "pinmap.h"
bogdanm 15:4892fe388435 21 #include "error.h"
bogdanm 15:4892fe388435 22
bogdanm 15:4892fe388435 23 static const PinMap PinMap_SPI_SCLK[] = {
bogdanm 15:4892fe388435 24 {P0_7 , SPI_1, 2},
bogdanm 15:4892fe388435 25 {P0_15, SPI_0, 2},
bogdanm 15:4892fe388435 26 {P1_0, SPI_2, 4},
bogdanm 15:4892fe388435 27 {P1_19, SPI_1, 5},
bogdanm 15:4892fe388435 28 {P1_20, SPI_0, 5},
bogdanm 15:4892fe388435 29 {P1_31, SPI_1, 2},
bogdanm 15:4892fe388435 30 {P2_22, SPI_0, 2},
bogdanm 15:4892fe388435 31 {P4_20, SPI_1, 3},
bogdanm 15:4892fe388435 32 {P5_2, SPI_2, 2},
bogdanm 15:4892fe388435 33 {NC , NC , 0}
bogdanm 15:4892fe388435 34 };
bogdanm 15:4892fe388435 35
bogdanm 15:4892fe388435 36 static const PinMap PinMap_SPI_MOSI[] = {
bogdanm 15:4892fe388435 37 {P0_9 , SPI_1, 2},
bogdanm 15:4892fe388435 38 {P0_13, SPI_1, 2},
bogdanm 15:4892fe388435 39 {P0_18, SPI_0, 2},
bogdanm 15:4892fe388435 40 {P1_1, SPI_2, 4},
bogdanm 15:4892fe388435 41 {P1_22, SPI_1, 5},
bogdanm 15:4892fe388435 42 {P1_24, SPI_0, 5},
bogdanm 15:4892fe388435 43 {P2_27, SPI_0, 2},
bogdanm 15:4892fe388435 44 {P4_23, SPI_1, 3},
bogdanm 15:4892fe388435 45 {P5_0, SPI_2, 2},
bogdanm 15:4892fe388435 46 {NC , NC , 0}
bogdanm 15:4892fe388435 47 };
bogdanm 15:4892fe388435 48
bogdanm 15:4892fe388435 49 static const PinMap PinMap_SPI_MISO[] = {
bogdanm 15:4892fe388435 50 {P0_8 , SPI_1, 2},
bogdanm 15:4892fe388435 51 {P0_12, SPI_1, 2},
bogdanm 15:4892fe388435 52 {P0_17, SPI_0, 2},
bogdanm 15:4892fe388435 53 {P1_4, SPI_2, 4},
bogdanm 15:4892fe388435 54 {P1_18, SPI_1, 5},
bogdanm 15:4892fe388435 55 {P1_23, SPI_0, 5},
bogdanm 15:4892fe388435 56 {P2_26, SPI_0, 2},
bogdanm 15:4892fe388435 57 {P4_22, SPI_1, 3},
bogdanm 15:4892fe388435 58 {P5_1, SPI_2, 2},
bogdanm 15:4892fe388435 59 {NC , NC , 0}
bogdanm 15:4892fe388435 60 };
bogdanm 15:4892fe388435 61
bogdanm 15:4892fe388435 62 static const PinMap PinMap_SPI_SSEL[] = {
bogdanm 15:4892fe388435 63 {P0_6 , SPI_1, 2},
bogdanm 15:4892fe388435 64 {P0_14, SPI_1, 2},
bogdanm 15:4892fe388435 65 {P0_16, SPI_0, 2},
bogdanm 15:4892fe388435 66 {P1_8, SPI_2, 4},
bogdanm 15:4892fe388435 67 {P1_21, SPI_0, 3},
bogdanm 15:4892fe388435 68 {P1_26, SPI_1, 5},
bogdanm 15:4892fe388435 69 {P1_28, SPI_0, 5},
bogdanm 15:4892fe388435 70 {P2_23, SPI_0, 2},
bogdanm 15:4892fe388435 71 {P4_21, SPI_1, 3},
bogdanm 15:4892fe388435 72 {NC , NC , 0}
bogdanm 15:4892fe388435 73 };
bogdanm 15:4892fe388435 74
bogdanm 15:4892fe388435 75 static inline int ssp_disable(spi_t *obj);
bogdanm 15:4892fe388435 76 static inline int ssp_enable(spi_t *obj);
bogdanm 15:4892fe388435 77
bogdanm 15:4892fe388435 78 void spi_init(spi_t *obj, PinName mosi, PinName miso, PinName sclk, PinName ssel) {
bogdanm 15:4892fe388435 79 // determine the SPI to use
bogdanm 15:4892fe388435 80 SPIName spi_mosi = (SPIName)pinmap_peripheral(mosi, PinMap_SPI_MOSI);
bogdanm 15:4892fe388435 81 SPIName spi_miso = (SPIName)pinmap_peripheral(miso, PinMap_SPI_MISO);
bogdanm 15:4892fe388435 82 SPIName spi_sclk = (SPIName)pinmap_peripheral(sclk, PinMap_SPI_SCLK);
bogdanm 15:4892fe388435 83 SPIName spi_ssel = (SPIName)pinmap_peripheral(ssel, PinMap_SPI_SSEL);
bogdanm 15:4892fe388435 84 SPIName spi_data = (SPIName)pinmap_merge(spi_mosi, spi_miso);
bogdanm 15:4892fe388435 85 SPIName spi_cntl = (SPIName)pinmap_merge(spi_sclk, spi_ssel);
bogdanm 15:4892fe388435 86 obj->spi = (LPC_SSP_TypeDef*)pinmap_merge(spi_data, spi_cntl);
bogdanm 15:4892fe388435 87 if ((int)obj->spi == NC) {
bogdanm 15:4892fe388435 88 error("SPI pinout mapping failed");
bogdanm 15:4892fe388435 89 }
bogdanm 15:4892fe388435 90
bogdanm 15:4892fe388435 91 // enable power and clocking
bogdanm 15:4892fe388435 92 switch ((int)obj->spi) {
bogdanm 15:4892fe388435 93 case SPI_0: LPC_SC->PCONP |= 1 << 21; break;
bogdanm 15:4892fe388435 94 case SPI_1: LPC_SC->PCONP |= 1 << 10; break;
bogdanm 15:4892fe388435 95 case SPI_2: LPC_SC->PCONP |= 1 << 20; break;
bogdanm 15:4892fe388435 96 }
bogdanm 15:4892fe388435 97
bogdanm 15:4892fe388435 98 // set default format and frequency
bogdanm 15:4892fe388435 99 if (ssel == NC) {
bogdanm 15:4892fe388435 100 spi_format(obj, 8, 0, 0); // 8 bits, mode 0, master
bogdanm 15:4892fe388435 101 } else {
bogdanm 15:4892fe388435 102 spi_format(obj, 8, 0, 1); // 8 bits, mode 0, slave
bogdanm 15:4892fe388435 103 }
bogdanm 15:4892fe388435 104 spi_frequency(obj, 1000000);
bogdanm 15:4892fe388435 105
bogdanm 15:4892fe388435 106 // enable the ssp channel
bogdanm 15:4892fe388435 107 ssp_enable(obj);
bogdanm 15:4892fe388435 108
bogdanm 15:4892fe388435 109 // pin out the spi pins
bogdanm 15:4892fe388435 110 pinmap_pinout(mosi, PinMap_SPI_MOSI);
bogdanm 15:4892fe388435 111 pinmap_pinout(miso, PinMap_SPI_MISO);
bogdanm 15:4892fe388435 112 pinmap_pinout(sclk, PinMap_SPI_SCLK);
bogdanm 15:4892fe388435 113 if (ssel != NC) {
bogdanm 15:4892fe388435 114 pinmap_pinout(ssel, PinMap_SPI_SSEL);
bogdanm 15:4892fe388435 115 }
bogdanm 15:4892fe388435 116 }
bogdanm 15:4892fe388435 117
bogdanm 15:4892fe388435 118 void spi_free(spi_t *obj) {}
bogdanm 15:4892fe388435 119
bogdanm 15:4892fe388435 120 void spi_format(spi_t *obj, int bits, int mode, int slave) {
bogdanm 15:4892fe388435 121 ssp_disable(obj);
bogdanm 15:4892fe388435 122
bogdanm 15:4892fe388435 123 if (!(bits >= 4 && bits <= 16) || !(mode >= 0 && mode <= 3)) {
bogdanm 15:4892fe388435 124 error("SPI format error");
bogdanm 15:4892fe388435 125 }
bogdanm 15:4892fe388435 126
bogdanm 15:4892fe388435 127 int polarity = (mode & 0x2) ? 1 : 0;
bogdanm 15:4892fe388435 128 int phase = (mode & 0x1) ? 1 : 0;
bogdanm 15:4892fe388435 129
bogdanm 15:4892fe388435 130 // set it up
bogdanm 15:4892fe388435 131 int DSS = bits - 1; // DSS (data select size)
bogdanm 15:4892fe388435 132 int SPO = (polarity) ? 1 : 0; // SPO - clock out polarity
bogdanm 15:4892fe388435 133 int SPH = (phase) ? 1 : 0; // SPH - clock out phase
bogdanm 15:4892fe388435 134
bogdanm 15:4892fe388435 135 int FRF = 0; // FRF (frame format) = SPI
bogdanm 15:4892fe388435 136 uint32_t tmp = obj->spi->CR0;
bogdanm 15:4892fe388435 137 tmp &= ~(0xFFFF);
bogdanm 15:4892fe388435 138 tmp |= DSS << 0
bogdanm 15:4892fe388435 139 | FRF << 4
bogdanm 15:4892fe388435 140 | SPO << 6
bogdanm 15:4892fe388435 141 | SPH << 7;
bogdanm 15:4892fe388435 142 obj->spi->CR0 = tmp;
bogdanm 15:4892fe388435 143
bogdanm 15:4892fe388435 144 tmp = obj->spi->CR1;
bogdanm 15:4892fe388435 145 tmp &= ~(0xD);
bogdanm 15:4892fe388435 146 tmp |= 0 << 0 // LBM - loop back mode - off
bogdanm 15:4892fe388435 147 | ((slave) ? 1 : 0) << 2 // MS - master slave mode, 1 = slave
bogdanm 15:4892fe388435 148 | 0 << 3; // SOD - slave output disable - na
bogdanm 15:4892fe388435 149 obj->spi->CR1 = tmp;
bogdanm 15:4892fe388435 150 ssp_enable(obj);
bogdanm 15:4892fe388435 151 }
bogdanm 15:4892fe388435 152
bogdanm 15:4892fe388435 153 void spi_frequency(spi_t *obj, int hz) {
bogdanm 15:4892fe388435 154 ssp_disable(obj);
bogdanm 15:4892fe388435 155
bogdanm 15:4892fe388435 156 uint32_t PCLK = PeripheralClock;
bogdanm 15:4892fe388435 157
bogdanm 15:4892fe388435 158 int prescaler;
bogdanm 15:4892fe388435 159
bogdanm 15:4892fe388435 160 for (prescaler = 2; prescaler <= 254; prescaler += 2) {
bogdanm 15:4892fe388435 161 int prescale_hz = PCLK / prescaler;
bogdanm 15:4892fe388435 162
bogdanm 15:4892fe388435 163 // calculate the divider
bogdanm 15:4892fe388435 164 int divider = floor(((float)prescale_hz / (float)hz) + 0.5f);
bogdanm 15:4892fe388435 165
bogdanm 15:4892fe388435 166 // check we can support the divider
bogdanm 15:4892fe388435 167 if (divider < 256) {
bogdanm 15:4892fe388435 168 // prescaler
bogdanm 15:4892fe388435 169 obj->spi->CPSR = prescaler;
bogdanm 15:4892fe388435 170
bogdanm 15:4892fe388435 171 // divider
bogdanm 15:4892fe388435 172 obj->spi->CR0 &= ~(0xFFFF << 8);
bogdanm 15:4892fe388435 173 obj->spi->CR0 |= (divider - 1) << 8;
bogdanm 15:4892fe388435 174 ssp_enable(obj);
bogdanm 15:4892fe388435 175 return;
bogdanm 15:4892fe388435 176 }
bogdanm 15:4892fe388435 177 }
bogdanm 15:4892fe388435 178 error("Couldn't setup requested SPI frequency");
bogdanm 15:4892fe388435 179 }
bogdanm 15:4892fe388435 180
bogdanm 15:4892fe388435 181 static inline int ssp_disable(spi_t *obj) {
bogdanm 15:4892fe388435 182 return obj->spi->CR1 &= ~(1 << 1);
bogdanm 15:4892fe388435 183 }
bogdanm 15:4892fe388435 184
bogdanm 15:4892fe388435 185 static inline int ssp_enable(spi_t *obj) {
bogdanm 15:4892fe388435 186 return obj->spi->CR1 |= (1 << 1);
bogdanm 15:4892fe388435 187 }
bogdanm 15:4892fe388435 188
bogdanm 15:4892fe388435 189 static inline int ssp_readable(spi_t *obj) {
bogdanm 15:4892fe388435 190 return obj->spi->SR & (1 << 2);
bogdanm 15:4892fe388435 191 }
bogdanm 15:4892fe388435 192
bogdanm 15:4892fe388435 193 static inline int ssp_writeable(spi_t *obj) {
bogdanm 15:4892fe388435 194 return obj->spi->SR & (1 << 1);
bogdanm 15:4892fe388435 195 }
bogdanm 15:4892fe388435 196
bogdanm 15:4892fe388435 197 static inline void ssp_write(spi_t *obj, int value) {
bogdanm 15:4892fe388435 198 while (!ssp_writeable(obj));
bogdanm 15:4892fe388435 199 obj->spi->DR = value;
bogdanm 15:4892fe388435 200 }
bogdanm 15:4892fe388435 201
bogdanm 15:4892fe388435 202 static inline int ssp_read(spi_t *obj) {
bogdanm 15:4892fe388435 203 while (!ssp_readable(obj));
bogdanm 15:4892fe388435 204 return obj->spi->DR;
bogdanm 15:4892fe388435 205 }
bogdanm 15:4892fe388435 206
bogdanm 15:4892fe388435 207 static inline int ssp_busy(spi_t *obj) {
bogdanm 15:4892fe388435 208 return (obj->spi->SR & (1 << 4)) ? (1) : (0);
bogdanm 15:4892fe388435 209 }
bogdanm 15:4892fe388435 210
bogdanm 15:4892fe388435 211 int spi_master_write(spi_t *obj, int value) {
bogdanm 15:4892fe388435 212 ssp_write(obj, value);
bogdanm 15:4892fe388435 213 return ssp_read(obj);
bogdanm 15:4892fe388435 214 }
bogdanm 15:4892fe388435 215
bogdanm 15:4892fe388435 216 int spi_slave_receive(spi_t *obj) {
bogdanm 15:4892fe388435 217 return (ssp_readable(obj) && !ssp_busy(obj)) ? (1) : (0);
mbed_official 81:a9456fdf72fa 218 }
bogdanm 15:4892fe388435 219
bogdanm 15:4892fe388435 220 int spi_slave_read(spi_t *obj) {
bogdanm 15:4892fe388435 221 return obj->spi->DR;
bogdanm 15:4892fe388435 222 }
bogdanm 15:4892fe388435 223
bogdanm 15:4892fe388435 224 void spi_slave_write(spi_t *obj, int value) {
bogdanm 15:4892fe388435 225 while (ssp_writeable(obj) == 0) ;
bogdanm 15:4892fe388435 226 obj->spi->DR = value;
bogdanm 15:4892fe388435 227 }
bogdanm 15:4892fe388435 228
bogdanm 15:4892fe388435 229 int spi_busy(spi_t *obj) {
bogdanm 15:4892fe388435 230 return ssp_busy(obj);
bogdanm 15:4892fe388435 231 }