Jonathan Piat / mbed-src

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targets/hal/TARGET_NXP/TARGET_LPC2460/spi_api.c@554:edd95c0879f8, 2015-06-01 (annotated)

Committer:
mbed_official
Date:
Mon Jun 01 11:00:11 2015 +0100
Revision:
554:edd95c0879f8
Synchronized with git revision 7a1d25e3dfbe5bc1457774d4af3c73383a0ff81d



Full URL: https://github.com/mbedmicro/mbed/commit/7a1d25e3dfbe5bc1457774d4af3c73383a0ff81d/



Silicon Labs - Initial test framework pin definitions for EFM32 platforms

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbed_official 554:edd95c0879f8 1 /* mbed Microcontroller Library
mbed_official 554:edd95c0879f8 2 * Copyright (c) 2006-2015 ARM Limited
mbed_official 554:edd95c0879f8 3 *
mbed_official 554:edd95c0879f8 4 * Licensed under the Apache License, Version 2.0 (the "License");
mbed_official 554:edd95c0879f8 5 * you may not use this file except in compliance with the License.
mbed_official 554:edd95c0879f8 6 * You may obtain a copy of the License at
mbed_official 554:edd95c0879f8 7 *
mbed_official 554:edd95c0879f8 8 * http://www.apache.org/licenses/LICENSE-2.0
mbed_official 554:edd95c0879f8 9 *
mbed_official 554:edd95c0879f8 10 * Unless required by applicable law or agreed to in writing, software
mbed_official 554:edd95c0879f8 11 * distributed under the License is distributed on an "AS IS" BASIS,
mbed_official 554:edd95c0879f8 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
mbed_official 554:edd95c0879f8 13 * See the License for the specific language governing permissions and
mbed_official 554:edd95c0879f8 14 * limitations under the License.
mbed_official 554:edd95c0879f8 15 */
mbed_official 554:edd95c0879f8 16 #include "mbed_assert.h"
mbed_official 554:edd95c0879f8 17 #include <math.h>
mbed_official 554:edd95c0879f8 18
mbed_official 554:edd95c0879f8 19 #include "spi_api.h"
mbed_official 554:edd95c0879f8 20 #include "cmsis.h"
mbed_official 554:edd95c0879f8 21 #include "pinmap.h"
mbed_official 554:edd95c0879f8 22 #include "mbed_error.h"
mbed_official 554:edd95c0879f8 23
mbed_official 554:edd95c0879f8 24 static const PinMap PinMap_SPI_SCLK[] = {
mbed_official 554:edd95c0879f8 25 {P0_7 , SPI_1, 2},
mbed_official 554:edd95c0879f8 26 {P0_15, SPI_0, 2},
mbed_official 554:edd95c0879f8 27 {P1_20, SPI_0, 3},
mbed_official 554:edd95c0879f8 28 {P1_31, SPI_1, 2},
mbed_official 554:edd95c0879f8 29 {NC , NC , 0}
mbed_official 554:edd95c0879f8 30 };
mbed_official 554:edd95c0879f8 31
mbed_official 554:edd95c0879f8 32 static const PinMap PinMap_SPI_MOSI[] = {
mbed_official 554:edd95c0879f8 33 {P0_9 , SPI_1, 2},
mbed_official 554:edd95c0879f8 34 {P0_13, SPI_1, 2},
mbed_official 554:edd95c0879f8 35 {P0_18, SPI_0, 2},
mbed_official 554:edd95c0879f8 36 {P1_24, SPI_0, 3},
mbed_official 554:edd95c0879f8 37 {NC , NC , 0}
mbed_official 554:edd95c0879f8 38 };
mbed_official 554:edd95c0879f8 39
mbed_official 554:edd95c0879f8 40 static const PinMap PinMap_SPI_MISO[] = {
mbed_official 554:edd95c0879f8 41 {P0_8 , SPI_1, 2},
mbed_official 554:edd95c0879f8 42 {P0_12, SPI_1, 2},
mbed_official 554:edd95c0879f8 43 {P0_17, SPI_0, 2},
mbed_official 554:edd95c0879f8 44 {P1_23, SPI_0, 3},
mbed_official 554:edd95c0879f8 45 {NC , NC , 0}
mbed_official 554:edd95c0879f8 46 };
mbed_official 554:edd95c0879f8 47
mbed_official 554:edd95c0879f8 48 static const PinMap PinMap_SPI_SSEL[] = {
mbed_official 554:edd95c0879f8 49 {P0_6 , SPI_1, 2},
mbed_official 554:edd95c0879f8 50 {P0_14, SPI_1, 3},
mbed_official 554:edd95c0879f8 51 {P0_16, SPI_0, 2},
mbed_official 554:edd95c0879f8 52 {P1_21, SPI_0, 3},
mbed_official 554:edd95c0879f8 53 {NC , NC , 0}
mbed_official 554:edd95c0879f8 54 };
mbed_official 554:edd95c0879f8 55
mbed_official 554:edd95c0879f8 56 static inline int ssp_disable(spi_t *obj);
mbed_official 554:edd95c0879f8 57 static inline int ssp_enable(spi_t *obj);
mbed_official 554:edd95c0879f8 58
mbed_official 554:edd95c0879f8 59 void spi_init(spi_t *obj, PinName mosi, PinName miso, PinName sclk, PinName ssel) {
mbed_official 554:edd95c0879f8 60 // determine the SPI to use
mbed_official 554:edd95c0879f8 61 SPIName spi_mosi = (SPIName)pinmap_peripheral(mosi, PinMap_SPI_MOSI);
mbed_official 554:edd95c0879f8 62 SPIName spi_miso = (SPIName)pinmap_peripheral(miso, PinMap_SPI_MISO);
mbed_official 554:edd95c0879f8 63 SPIName spi_sclk = (SPIName)pinmap_peripheral(sclk, PinMap_SPI_SCLK);
mbed_official 554:edd95c0879f8 64 SPIName spi_ssel = (SPIName)pinmap_peripheral(ssel, PinMap_SPI_SSEL);
mbed_official 554:edd95c0879f8 65 SPIName spi_data = (SPIName)pinmap_merge(spi_mosi, spi_miso);
mbed_official 554:edd95c0879f8 66 SPIName spi_cntl = (SPIName)pinmap_merge(spi_sclk, spi_ssel);
mbed_official 554:edd95c0879f8 67 obj->spi = (LPC_SSP_TypeDef*)pinmap_merge(spi_data, spi_cntl);
mbed_official 554:edd95c0879f8 68 MBED_ASSERT((int)obj->spi != NC);
mbed_official 554:edd95c0879f8 69
mbed_official 554:edd95c0879f8 70 // enable power and clocking
mbed_official 554:edd95c0879f8 71 switch ((int)obj->spi) {
mbed_official 554:edd95c0879f8 72 case SPI_0: LPC_SC->PCONP |= 1 << PCSSP0; break;
mbed_official 554:edd95c0879f8 73 case SPI_1: LPC_SC->PCONP |= 1 << PCSSP1; break;
mbed_official 554:edd95c0879f8 74 }
mbed_official 554:edd95c0879f8 75
mbed_official 554:edd95c0879f8 76 // set default format and frequency
mbed_official 554:edd95c0879f8 77 if (ssel == NC) {
mbed_official 554:edd95c0879f8 78 spi_format(obj, 8, 0, 0); // 8 bits, mode 0, master
mbed_official 554:edd95c0879f8 79 } else {
mbed_official 554:edd95c0879f8 80 spi_format(obj, 8, 0, 1); // 8 bits, mode 0, slave
mbed_official 554:edd95c0879f8 81 }
mbed_official 554:edd95c0879f8 82 spi_frequency(obj, 1000000);
mbed_official 554:edd95c0879f8 83
mbed_official 554:edd95c0879f8 84 // enable the ssp channel
mbed_official 554:edd95c0879f8 85 ssp_enable(obj);
mbed_official 554:edd95c0879f8 86
mbed_official 554:edd95c0879f8 87 // pin out the spi pins
mbed_official 554:edd95c0879f8 88 pinmap_pinout(mosi, PinMap_SPI_MOSI);
mbed_official 554:edd95c0879f8 89 pinmap_pinout(miso, PinMap_SPI_MISO);
mbed_official 554:edd95c0879f8 90 pinmap_pinout(sclk, PinMap_SPI_SCLK);
mbed_official 554:edd95c0879f8 91 if (ssel != NC) {
mbed_official 554:edd95c0879f8 92 pinmap_pinout(ssel, PinMap_SPI_SSEL);
mbed_official 554:edd95c0879f8 93 }
mbed_official 554:edd95c0879f8 94 }
mbed_official 554:edd95c0879f8 95
mbed_official 554:edd95c0879f8 96 void spi_free(spi_t *obj) {}
mbed_official 554:edd95c0879f8 97
mbed_official 554:edd95c0879f8 98 void spi_format(spi_t *obj, int bits, int mode, int slave) {
mbed_official 554:edd95c0879f8 99 MBED_ASSERT(((bits >= 4) && (bits <= 16)) && ((mode >= 0) && (mode <= 3)));
mbed_official 554:edd95c0879f8 100 ssp_disable(obj);
mbed_official 554:edd95c0879f8 101
mbed_official 554:edd95c0879f8 102 int polarity = (mode & 0x2) ? 1 : 0;
mbed_official 554:edd95c0879f8 103 int phase = (mode & 0x1) ? 1 : 0;
mbed_official 554:edd95c0879f8 104
mbed_official 554:edd95c0879f8 105 // set it up
mbed_official 554:edd95c0879f8 106 int DSS = bits - 1; // DSS (data select size)
mbed_official 554:edd95c0879f8 107 int SPO = (polarity) ? 1 : 0; // SPO - clock out polarity
mbed_official 554:edd95c0879f8 108 int SPH = (phase) ? 1 : 0; // SPH - clock out phase
mbed_official 554:edd95c0879f8 109
mbed_official 554:edd95c0879f8 110 int FRF = 0; // FRF (frame format) = SPI
mbed_official 554:edd95c0879f8 111 uint32_t tmp = obj->spi->CR0;
mbed_official 554:edd95c0879f8 112 tmp &= ~(0xFFFF);
mbed_official 554:edd95c0879f8 113 tmp |= DSS << 0
mbed_official 554:edd95c0879f8 114 | FRF << 4
mbed_official 554:edd95c0879f8 115 | SPO << 6
mbed_official 554:edd95c0879f8 116 | SPH << 7;
mbed_official 554:edd95c0879f8 117 obj->spi->CR0 = tmp;
mbed_official 554:edd95c0879f8 118
mbed_official 554:edd95c0879f8 119 tmp = obj->spi->CR1;
mbed_official 554:edd95c0879f8 120 tmp &= ~(0xD);
mbed_official 554:edd95c0879f8 121 tmp |= 0 << 0 // LBM - loop back mode - off
mbed_official 554:edd95c0879f8 122 | ((slave) ? 1 : 0) << 2 // MS - master slave mode, 1 = slave
mbed_official 554:edd95c0879f8 123 | 0 << 3; // SOD - slave output disable - na
mbed_official 554:edd95c0879f8 124 obj->spi->CR1 = tmp;
mbed_official 554:edd95c0879f8 125
mbed_official 554:edd95c0879f8 126 ssp_enable(obj);
mbed_official 554:edd95c0879f8 127 }
mbed_official 554:edd95c0879f8 128
mbed_official 554:edd95c0879f8 129 void spi_frequency(spi_t *obj, int hz) {
mbed_official 554:edd95c0879f8 130 ssp_disable(obj);
mbed_official 554:edd95c0879f8 131
mbed_official 554:edd95c0879f8 132 // setup the spi clock diveder to /1
mbed_official 554:edd95c0879f8 133 switch ((int)obj->spi) {
mbed_official 554:edd95c0879f8 134 case SPI_0:
mbed_official 554:edd95c0879f8 135 LPC_SC->PCLKSEL1 &= ~(3 << 10);
mbed_official 554:edd95c0879f8 136 LPC_SC->PCLKSEL1 |= (1 << 10);
mbed_official 554:edd95c0879f8 137 break;
mbed_official 554:edd95c0879f8 138 case SPI_1:
mbed_official 554:edd95c0879f8 139 LPC_SC->PCLKSEL0 &= ~(3 << 20);
mbed_official 554:edd95c0879f8 140 LPC_SC->PCLKSEL0 |= (1 << 20);
mbed_official 554:edd95c0879f8 141 break;
mbed_official 554:edd95c0879f8 142 }
mbed_official 554:edd95c0879f8 143
mbed_official 554:edd95c0879f8 144 uint32_t PCLK = SystemCoreClock;
mbed_official 554:edd95c0879f8 145
mbed_official 554:edd95c0879f8 146 int prescaler;
mbed_official 554:edd95c0879f8 147
mbed_official 554:edd95c0879f8 148 for (prescaler = 2; prescaler <= 254; prescaler += 2) {
mbed_official 554:edd95c0879f8 149 int prescale_hz = PCLK / prescaler;
mbed_official 554:edd95c0879f8 150
mbed_official 554:edd95c0879f8 151 // calculate the divider
mbed_official 554:edd95c0879f8 152 int divider = floor(((float)prescale_hz / (float)hz) + 0.5f);
mbed_official 554:edd95c0879f8 153
mbed_official 554:edd95c0879f8 154 // check we can support the divider
mbed_official 554:edd95c0879f8 155 if (divider < 256) {
mbed_official 554:edd95c0879f8 156 // prescaler
mbed_official 554:edd95c0879f8 157 obj->spi->CPSR = prescaler;
mbed_official 554:edd95c0879f8 158
mbed_official 554:edd95c0879f8 159 // divider
mbed_official 554:edd95c0879f8 160 obj->spi->CR0 &= ~(0xFFFF << 8);
mbed_official 554:edd95c0879f8 161 obj->spi->CR0 |= (divider - 1) << 8;
mbed_official 554:edd95c0879f8 162 ssp_enable(obj);
mbed_official 554:edd95c0879f8 163 return;
mbed_official 554:edd95c0879f8 164 }
mbed_official 554:edd95c0879f8 165 }
mbed_official 554:edd95c0879f8 166 error("Couldn't setup requested SPI frequency");
mbed_official 554:edd95c0879f8 167 }
mbed_official 554:edd95c0879f8 168
mbed_official 554:edd95c0879f8 169 static inline int ssp_disable(spi_t *obj) {
mbed_official 554:edd95c0879f8 170 return obj->spi->CR1 &= ~(1 << 1);
mbed_official 554:edd95c0879f8 171 }
mbed_official 554:edd95c0879f8 172
mbed_official 554:edd95c0879f8 173 static inline int ssp_enable(spi_t *obj) {
mbed_official 554:edd95c0879f8 174 return obj->spi->CR1 |= (1 << 1);
mbed_official 554:edd95c0879f8 175 }
mbed_official 554:edd95c0879f8 176
mbed_official 554:edd95c0879f8 177 static inline int ssp_readable(spi_t *obj) {
mbed_official 554:edd95c0879f8 178 return obj->spi->SR & (1 << 2);
mbed_official 554:edd95c0879f8 179 }
mbed_official 554:edd95c0879f8 180
mbed_official 554:edd95c0879f8 181 static inline int ssp_writeable(spi_t *obj) {
mbed_official 554:edd95c0879f8 182 return obj->spi->SR & (1 << 1);
mbed_official 554:edd95c0879f8 183 }
mbed_official 554:edd95c0879f8 184
mbed_official 554:edd95c0879f8 185 static inline void ssp_write(spi_t *obj, int value) {
mbed_official 554:edd95c0879f8 186 while (!ssp_writeable(obj));
mbed_official 554:edd95c0879f8 187 obj->spi->DR = value;
mbed_official 554:edd95c0879f8 188 }
mbed_official 554:edd95c0879f8 189
mbed_official 554:edd95c0879f8 190 static inline int ssp_read(spi_t *obj) {
mbed_official 554:edd95c0879f8 191 while (!ssp_readable(obj));
mbed_official 554:edd95c0879f8 192 return obj->spi->DR;
mbed_official 554:edd95c0879f8 193 }
mbed_official 554:edd95c0879f8 194
mbed_official 554:edd95c0879f8 195 static inline int ssp_busy(spi_t *obj) {
mbed_official 554:edd95c0879f8 196 return (obj->spi->SR & (1 << 4)) ? (1) : (0);
mbed_official 554:edd95c0879f8 197 }
mbed_official 554:edd95c0879f8 198
mbed_official 554:edd95c0879f8 199 int spi_master_write(spi_t *obj, int value) {
mbed_official 554:edd95c0879f8 200 ssp_write(obj, value);
mbed_official 554:edd95c0879f8 201 return ssp_read(obj);
mbed_official 554:edd95c0879f8 202 }
mbed_official 554:edd95c0879f8 203
mbed_official 554:edd95c0879f8 204 int spi_slave_receive(spi_t *obj) {
mbed_official 554:edd95c0879f8 205 return (ssp_readable(obj) && !ssp_busy(obj)) ? (1) : (0);
mbed_official 554:edd95c0879f8 206 }
mbed_official 554:edd95c0879f8 207
mbed_official 554:edd95c0879f8 208 int spi_slave_read(spi_t *obj) {
mbed_official 554:edd95c0879f8 209 return obj->spi->DR;
mbed_official 554:edd95c0879f8 210 }
mbed_official 554:edd95c0879f8 211
mbed_official 554:edd95c0879f8 212 void spi_slave_write(spi_t *obj, int value) {
mbed_official 554:edd95c0879f8 213 while (ssp_writeable(obj) == 0) ;
mbed_official 554:edd95c0879f8 214 obj->spi->DR = value;
mbed_official 554:edd95c0879f8 215 }
mbed_official 554:edd95c0879f8 216
mbed_official 554:edd95c0879f8 217 int spi_busy(spi_t *obj) {
mbed_official 554:edd95c0879f8 218 return ssp_busy(obj);
mbed_official 554:edd95c0879f8 219 }