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targets/hal/TARGET_NXP/TARGET_LPC11U6X/spi_api.c@603:f00c7e78e8b4, 2015-08-09 (annotated)

Committer:
HiAlgoBoost
Date:
Sun Aug 09 05:18:54 2015 +0000
Revision:
603:f00c7e78e8b4
Parent:
552:a1b9575155a3 
Evening of August 8th version

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbed_official 174:8bb9f3a33240 1 /* mbed Microcontroller Library
mbed_official 174:8bb9f3a33240 2 * Copyright (c) 2006-2013 ARM Limited
mbed_official 174:8bb9f3a33240 3 *
mbed_official 174:8bb9f3a33240 4 * Licensed under the Apache License, Version 2.0 (the "License");
mbed_official 174:8bb9f3a33240 5 * you may not use this file except in compliance with the License.
mbed_official 174:8bb9f3a33240 6 * You may obtain a copy of the License at
mbed_official 174:8bb9f3a33240 7 *
mbed_official 174:8bb9f3a33240 8 * http://www.apache.org/licenses/LICENSE-2.0
mbed_official 174:8bb9f3a33240 9 *
mbed_official 174:8bb9f3a33240 10 * Unless required by applicable law or agreed to in writing, software
mbed_official 174:8bb9f3a33240 11 * distributed under the License is distributed on an "AS IS" BASIS,
mbed_official 174:8bb9f3a33240 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
mbed_official 174:8bb9f3a33240 13 * See the License for the specific language governing permissions and
mbed_official 174:8bb9f3a33240 14 * limitations under the License.
mbed_official 174:8bb9f3a33240 15 */
mbed_official 227:7bd0639b8911 16 #include "mbed_assert.h"
mbed_official 174:8bb9f3a33240 17 #include <math.h>
mbed_official 174:8bb9f3a33240 18
mbed_official 174:8bb9f3a33240 19 #include "spi_api.h"
mbed_official 174:8bb9f3a33240 20 #include "cmsis.h"
mbed_official 174:8bb9f3a33240 21 #include "pinmap.h"
mbed_official 285:31249416b6f9 22 #include "mbed_error.h"
mbed_official 174:8bb9f3a33240 23
mbed_official 174:8bb9f3a33240 24 #if DEVICE_SPI
mbed_official 174:8bb9f3a33240 25
mbed_official 174:8bb9f3a33240 26 static const PinMap PinMap_SPI_SCLK[] = {
mbed_official 174:8bb9f3a33240 27 {P0_6 , SPI_0, 0x02},
mbed_official 174:8bb9f3a33240 28 {P1_29, SPI_0, 0x01},
mbed_official 174:8bb9f3a33240 29 {P2_7 , SPI_0, 0x01},
mbed_official 174:8bb9f3a33240 30 {P1_20, SPI_1, 0x02},
mbed_official 174:8bb9f3a33240 31 {P1_27, SPI_1, 0x04},
mbed_official 174:8bb9f3a33240 32 {NC , NC , 0}
mbed_official 174:8bb9f3a33240 33 };
mbed_official 174:8bb9f3a33240 34
mbed_official 174:8bb9f3a33240 35 static const PinMap PinMap_SPI_MOSI[] = {
mbed_official 174:8bb9f3a33240 36 {P0_9 , SPI_0, 0x01},
mbed_official 174:8bb9f3a33240 37 {P1_12, SPI_0, 0x01},
mbed_official 174:8bb9f3a33240 38 {P0_21, SPI_1, 0x02},
mbed_official 174:8bb9f3a33240 39 {P1_22, SPI_1, 0x01},
mbed_official 174:8bb9f3a33240 40 {NC , NC , 0}
mbed_official 174:8bb9f3a33240 41 };
mbed_official 174:8bb9f3a33240 42
mbed_official 174:8bb9f3a33240 43 static const PinMap PinMap_SPI_MISO[] = {
mbed_official 174:8bb9f3a33240 44 {P0_8 , SPI_0, 0x01},
mbed_official 174:8bb9f3a33240 45 {P1_16, SPI_0, 0x01},
mbed_official 174:8bb9f3a33240 46 {P0_22, SPI_1, 0x03},
mbed_official 174:8bb9f3a33240 47 {P1_21, SPI_1, 0x02},
mbed_official 174:8bb9f3a33240 48 {NC , NC , 0}
mbed_official 174:8bb9f3a33240 49 };
mbed_official 174:8bb9f3a33240 50
mbed_official 174:8bb9f3a33240 51 static const PinMap PinMap_SPI_SSEL[] = {
mbed_official 174:8bb9f3a33240 52 {P0_2 , SPI_0, 0x01},
mbed_official 174:8bb9f3a33240 53 {P1_15, SPI_0, 0x01},
mbed_official 174:8bb9f3a33240 54 {P0_23, SPI_1, 0x04},
mbed_official 174:8bb9f3a33240 55 {P1_23, SPI_1, 0x02},
mbed_official 174:8bb9f3a33240 56 {NC , NC , 0}
mbed_official 174:8bb9f3a33240 57 };
mbed_official 174:8bb9f3a33240 58
mbed_official 174:8bb9f3a33240 59 static inline int ssp_disable(spi_t *obj);
mbed_official 174:8bb9f3a33240 60 static inline int ssp_enable(spi_t *obj);
mbed_official 174:8bb9f3a33240 61
mbed_official 174:8bb9f3a33240 62 void spi_init(spi_t *obj, PinName mosi, PinName miso, PinName sclk, PinName ssel) {
mbed_official 174:8bb9f3a33240 63 // determine the SPI to use
mbed_official 174:8bb9f3a33240 64 SPIName spi_mosi = (SPIName)pinmap_peripheral(mosi, PinMap_SPI_MOSI);
mbed_official 174:8bb9f3a33240 65 SPIName spi_miso = (SPIName)pinmap_peripheral(miso, PinMap_SPI_MISO);
mbed_official 174:8bb9f3a33240 66 SPIName spi_sclk = (SPIName)pinmap_peripheral(sclk, PinMap_SPI_SCLK);
mbed_official 174:8bb9f3a33240 67 SPIName spi_ssel = (SPIName)pinmap_peripheral(ssel, PinMap_SPI_SSEL);
mbed_official 174:8bb9f3a33240 68 SPIName spi_data = (SPIName)pinmap_merge(spi_mosi, spi_miso);
mbed_official 174:8bb9f3a33240 69 SPIName spi_cntl = (SPIName)pinmap_merge(spi_sclk, spi_ssel);
mbed_official 174:8bb9f3a33240 70
mbed_official 174:8bb9f3a33240 71 obj->spi = (LPC_SSP0_Type*)pinmap_merge(spi_data, spi_cntl);
mbed_official 227:7bd0639b8911 72 MBED_ASSERT((int)obj->spi != NC);
mbed_official 174:8bb9f3a33240 73
mbed_official 174:8bb9f3a33240 74 // enable power and clocking
mbed_official 174:8bb9f3a33240 75 switch ((int)obj->spi) {
mbed_official 174:8bb9f3a33240 76 case SPI_0:
mbed_official 174:8bb9f3a33240 77 LPC_SYSCON->SYSAHBCLKCTRL |= 1 << 11;
mbed_official 174:8bb9f3a33240 78 LPC_SYSCON->SSP0CLKDIV = 0x01;
mbed_official 174:8bb9f3a33240 79 LPC_SYSCON->PRESETCTRL |= 1 << 0;
mbed_official 174:8bb9f3a33240 80 break;
mbed_official 174:8bb9f3a33240 81 case SPI_1:
mbed_official 174:8bb9f3a33240 82 LPC_SYSCON->SYSAHBCLKCTRL |= 1 << 18;
mbed_official 174:8bb9f3a33240 83 LPC_SYSCON->SSP1CLKDIV = 0x01;
mbed_official 174:8bb9f3a33240 84 LPC_SYSCON->PRESETCTRL |= 1 << 2;
mbed_official 174:8bb9f3a33240 85 break;
mbed_official 174:8bb9f3a33240 86 }
mbed_official 174:8bb9f3a33240 87
mbed_official 174:8bb9f3a33240 88 // pin out the spi pins
mbed_official 174:8bb9f3a33240 89 pinmap_pinout(mosi, PinMap_SPI_MOSI);
mbed_official 174:8bb9f3a33240 90 pinmap_pinout(miso, PinMap_SPI_MISO);
mbed_official 174:8bb9f3a33240 91 pinmap_pinout(sclk, PinMap_SPI_SCLK);
mbed_official 174:8bb9f3a33240 92 if (ssel != NC) {
mbed_official 174:8bb9f3a33240 93 pinmap_pinout(ssel, PinMap_SPI_SSEL);
mbed_official 174:8bb9f3a33240 94 }
mbed_official 174:8bb9f3a33240 95 }
mbed_official 174:8bb9f3a33240 96
mbed_official 174:8bb9f3a33240 97 void spi_free(spi_t *obj) {}
mbed_official 174:8bb9f3a33240 98
mbed_official 174:8bb9f3a33240 99 void spi_format(spi_t *obj, int bits, int mode, int slave) {
mbed_official 174:8bb9f3a33240 100 ssp_disable(obj);
mbed_official 227:7bd0639b8911 101 MBED_ASSERT(((bits >= 4) && (bits <= 16)) || ((mode >= 0) && (mode <= 3)));
mbed_official 174:8bb9f3a33240 102
mbed_official 174:8bb9f3a33240 103 int polarity = (mode & 0x2) ? 1 : 0;
mbed_official 174:8bb9f3a33240 104 int phase = (mode & 0x1) ? 1 : 0;
mbed_official 174:8bb9f3a33240 105
mbed_official 174:8bb9f3a33240 106 // set it up
mbed_official 174:8bb9f3a33240 107 int DSS = bits - 1; // DSS (data select size)
mbed_official 174:8bb9f3a33240 108 int SPO = (polarity) ? 1 : 0; // SPO - clock out polarity
mbed_official 174:8bb9f3a33240 109 int SPH = (phase) ? 1 : 0; // SPH - clock out phase
mbed_official 174:8bb9f3a33240 110
mbed_official 174:8bb9f3a33240 111 int FRF = 0; // FRF (frame format) = SPI
mbed_official 174:8bb9f3a33240 112 uint32_t tmp = obj->spi->CR0;
mbed_official 174:8bb9f3a33240 113 tmp &= ~(0xFFFF);
mbed_official 174:8bb9f3a33240 114 tmp |= DSS << 0
mbed_official 174:8bb9f3a33240 115 | FRF << 4
mbed_official 174:8bb9f3a33240 116 | SPO << 6
mbed_official 174:8bb9f3a33240 117 | SPH << 7;
mbed_official 174:8bb9f3a33240 118 obj->spi->CR0 = tmp;
mbed_official 174:8bb9f3a33240 119
mbed_official 174:8bb9f3a33240 120 tmp = obj->spi->CR1;
mbed_official 174:8bb9f3a33240 121 tmp &= ~(0xD);
mbed_official 174:8bb9f3a33240 122 tmp |= 0 << 0 // LBM - loop back mode - off
mbed_official 174:8bb9f3a33240 123 | ((slave) ? 1 : 0) << 2 // MS - master slave mode, 1 = slave
mbed_official 174:8bb9f3a33240 124 | 0 << 3; // SOD - slave output disable - na
mbed_official 174:8bb9f3a33240 125 obj->spi->CR1 = tmp;
mbed_official 174:8bb9f3a33240 126
mbed_official 174:8bb9f3a33240 127 ssp_enable(obj);
mbed_official 174:8bb9f3a33240 128 }
mbed_official 174:8bb9f3a33240 129
mbed_official 174:8bb9f3a33240 130 void spi_frequency(spi_t *obj, int hz) {
mbed_official 174:8bb9f3a33240 131 ssp_disable(obj);
mbed_official 174:8bb9f3a33240 132
mbed_official 174:8bb9f3a33240 133 uint32_t PCLK = SystemCoreClock;
mbed_official 174:8bb9f3a33240 134
mbed_official 174:8bb9f3a33240 135 int prescaler;
mbed_official 174:8bb9f3a33240 136
mbed_official 174:8bb9f3a33240 137 for (prescaler = 2; prescaler <= 254; prescaler += 2) {
mbed_official 174:8bb9f3a33240 138 int prescale_hz = PCLK / prescaler;
mbed_official 174:8bb9f3a33240 139
mbed_official 174:8bb9f3a33240 140 // calculate the divider
mbed_official 174:8bb9f3a33240 141 int divider = floor(((float)prescale_hz / (float)hz) + 0.5f);
mbed_official 174:8bb9f3a33240 142
mbed_official 174:8bb9f3a33240 143 // check we can support the divider
mbed_official 174:8bb9f3a33240 144 if (divider < 256) {
mbed_official 174:8bb9f3a33240 145 // prescaler
mbed_official 174:8bb9f3a33240 146 obj->spi->CPSR = prescaler;
mbed_official 174:8bb9f3a33240 147
mbed_official 174:8bb9f3a33240 148 // divider
mbed_official 174:8bb9f3a33240 149 obj->spi->CR0 &= ~(0xFFFF << 8);
mbed_official 174:8bb9f3a33240 150 obj->spi->CR0 |= (divider - 1) << 8;
mbed_official 174:8bb9f3a33240 151 ssp_enable(obj);
mbed_official 174:8bb9f3a33240 152 return;
mbed_official 174:8bb9f3a33240 153 }
mbed_official 174:8bb9f3a33240 154 }
mbed_official 174:8bb9f3a33240 155 error("Couldn't setup requested SPI frequency");
mbed_official 174:8bb9f3a33240 156 }
mbed_official 174:8bb9f3a33240 157
mbed_official 174:8bb9f3a33240 158 static inline int ssp_disable(spi_t *obj) {
mbed_official 174:8bb9f3a33240 159 return obj->spi->CR1 &= ~(1 << 1);
mbed_official 174:8bb9f3a33240 160 }
mbed_official 174:8bb9f3a33240 161
mbed_official 174:8bb9f3a33240 162 static inline int ssp_enable(spi_t *obj) {
mbed_official 174:8bb9f3a33240 163 return obj->spi->CR1 |= (1 << 1);
mbed_official 174:8bb9f3a33240 164 }
mbed_official 174:8bb9f3a33240 165
mbed_official 174:8bb9f3a33240 166 static inline int ssp_readable(spi_t *obj) {
mbed_official 174:8bb9f3a33240 167 return obj->spi->SR & (1 << 2);
mbed_official 174:8bb9f3a33240 168 }
mbed_official 174:8bb9f3a33240 169
mbed_official 174:8bb9f3a33240 170 static inline int ssp_writeable(spi_t *obj) {
mbed_official 174:8bb9f3a33240 171 return obj->spi->SR & (1 << 1);
mbed_official 174:8bb9f3a33240 172 }
mbed_official 174:8bb9f3a33240 173
mbed_official 174:8bb9f3a33240 174 static inline void ssp_write(spi_t *obj, int value) {
mbed_official 174:8bb9f3a33240 175 while (!ssp_writeable(obj));
mbed_official 174:8bb9f3a33240 176 obj->spi->DR = value;
mbed_official 174:8bb9f3a33240 177 }
mbed_official 174:8bb9f3a33240 178
mbed_official 174:8bb9f3a33240 179 static inline int ssp_read(spi_t *obj) {
mbed_official 174:8bb9f3a33240 180 while (!ssp_readable(obj));
mbed_official 174:8bb9f3a33240 181 return obj->spi->DR;
mbed_official 174:8bb9f3a33240 182 }
mbed_official 174:8bb9f3a33240 183
mbed_official 174:8bb9f3a33240 184 static inline int ssp_busy(spi_t *obj) {
mbed_official 174:8bb9f3a33240 185 return (obj->spi->SR & (1 << 4)) ? (1) : (0);
mbed_official 174:8bb9f3a33240 186 }
mbed_official 174:8bb9f3a33240 187
mbed_official 174:8bb9f3a33240 188 int spi_master_write(spi_t *obj, int value) {
mbed_official 174:8bb9f3a33240 189 ssp_write(obj, value);
mbed_official 174:8bb9f3a33240 190 return ssp_read(obj);
mbed_official 174:8bb9f3a33240 191 }
mbed_official 174:8bb9f3a33240 192
mbed_official 174:8bb9f3a33240 193 int spi_slave_receive(spi_t *obj) {
mbed_official 174:8bb9f3a33240 194 return (ssp_readable(obj) && !ssp_busy(obj)) ? (1) : (0);
mbed_official 174:8bb9f3a33240 195 }
mbed_official 174:8bb9f3a33240 196
mbed_official 174:8bb9f3a33240 197 int spi_slave_read(spi_t *obj) {
mbed_official 174:8bb9f3a33240 198 return obj->spi->DR;
mbed_official 174:8bb9f3a33240 199 }
mbed_official 174:8bb9f3a33240 200
mbed_official 174:8bb9f3a33240 201 void spi_slave_write(spi_t *obj, int value) {
mbed_official 174:8bb9f3a33240 202 while (ssp_writeable(obj) == 0) ;
mbed_official 174:8bb9f3a33240 203 obj->spi->DR = value;
mbed_official 174:8bb9f3a33240 204 }
mbed_official 174:8bb9f3a33240 205
mbed_official 174:8bb9f3a33240 206 int spi_busy(spi_t *obj) {
mbed_official 174:8bb9f3a33240 207 return ssp_busy(obj);
mbed_official 174:8bb9f3a33240 208 }
mbed_official 174:8bb9f3a33240 209
mbed_official 174:8bb9f3a33240 210 #endif