Jonathan Piat / mbed-src

mbed library sources

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targets/hal/TARGET_NXP/TARGET_LPC408X/TARGET_LPC4088_DM/spi_api.c@552:a1b9575155a3, 2015-05-27 (annotated)

Committer:
mbed_official
Date:
Wed May 27 13:30:08 2015 +0100
Revision:
552:a1b9575155a3
Parent:
462:e03396e14338 
Synchronized with git revision a74a8f14fd8c4bf3dc09980c4bf9498ebcf4c207



Full URL: https://github.com/mbedmicro/mbed/commit/a74a8f14fd8c4bf3dc09980c4bf9498ebcf4c207/

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbed_official 462:e03396e14338 1 /* mbed Microcontroller Library
mbed_official 462:e03396e14338 2 * Copyright (c) 2006-2013 ARM Limited
mbed_official 462:e03396e14338 3 *
mbed_official 462:e03396e14338 4 * Licensed under the Apache License, Version 2.0 (the "License");
mbed_official 462:e03396e14338 5 * you may not use this file except in compliance with the License.
mbed_official 462:e03396e14338 6 * You may obtain a copy of the License at
mbed_official 462:e03396e14338 7 *
mbed_official 462:e03396e14338 8 * http://www.apache.org/licenses/LICENSE-2.0
mbed_official 462:e03396e14338 9 *
mbed_official 462:e03396e14338 10 * Unless required by applicable law or agreed to in writing, software
mbed_official 462:e03396e14338 11 * distributed under the License is distributed on an "AS IS" BASIS,
mbed_official 462:e03396e14338 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
mbed_official 462:e03396e14338 13 * See the License for the specific language governing permissions and
mbed_official 462:e03396e14338 14 * limitations under the License.
mbed_official 462:e03396e14338 15 */
mbed_official 462:e03396e14338 16 #include <math.h>
mbed_official 462:e03396e14338 17
mbed_official 462:e03396e14338 18 #include "spi_api.h"
mbed_official 462:e03396e14338 19 #include "cmsis.h"
mbed_official 462:e03396e14338 20 #include "pinmap.h"
mbed_official 462:e03396e14338 21 #include "mbed_error.h"
mbed_official 462:e03396e14338 22
mbed_official 462:e03396e14338 23 static const PinMap PinMap_SPI_SCLK[] = {
mbed_official 462:e03396e14338 24 {P0_7 , SPI_1, 2},
mbed_official 462:e03396e14338 25 {P1_19, SPI_1, 5},
mbed_official 462:e03396e14338 26 {P1_20, SPI_0, 5},
mbed_official 462:e03396e14338 27 {P2_22, SPI_0, 2},
mbed_official 462:e03396e14338 28 {P5_2, SPI_2, 2},
mbed_official 462:e03396e14338 29 {NC , NC , 0}
mbed_official 462:e03396e14338 30 };
mbed_official 462:e03396e14338 31
mbed_official 462:e03396e14338 32 static const PinMap PinMap_SPI_MOSI[] = {
mbed_official 462:e03396e14338 33 {P0_9 , SPI_1, 2},
mbed_official 462:e03396e14338 34 {P1_24, SPI_0, 5},
mbed_official 462:e03396e14338 35 {P2_27, SPI_0, 2},
mbed_official 462:e03396e14338 36 {P5_0, SPI_2, 2},
mbed_official 462:e03396e14338 37 {NC , NC , 0}
mbed_official 462:e03396e14338 38 };
mbed_official 462:e03396e14338 39
mbed_official 462:e03396e14338 40 static const PinMap PinMap_SPI_MISO[] = {
mbed_official 462:e03396e14338 41 {P0_8 , SPI_1, 2},
mbed_official 462:e03396e14338 42 {P1_23, SPI_0, 5},
mbed_official 462:e03396e14338 43 {P2_26, SPI_0, 2},
mbed_official 462:e03396e14338 44 {P5_1, SPI_2, 2},
mbed_official 462:e03396e14338 45 {NC , NC , 0}
mbed_official 462:e03396e14338 46 };
mbed_official 462:e03396e14338 47
mbed_official 462:e03396e14338 48 static const PinMap PinMap_SPI_SSEL[] = {
mbed_official 462:e03396e14338 49 {P0_6 , SPI_1, 2},
mbed_official 462:e03396e14338 50 {P2_23, SPI_0, 2},
mbed_official 462:e03396e14338 51 {P5_3, SPI_2, 2},
mbed_official 462:e03396e14338 52 {NC , NC , 0}
mbed_official 462:e03396e14338 53 };
mbed_official 462:e03396e14338 54
mbed_official 462:e03396e14338 55 static inline int ssp_disable(spi_t *obj);
mbed_official 462:e03396e14338 56 static inline int ssp_enable(spi_t *obj);
mbed_official 462:e03396e14338 57
mbed_official 462:e03396e14338 58 void spi_init(spi_t *obj, PinName mosi, PinName miso, PinName sclk, PinName ssel) {
mbed_official 462:e03396e14338 59 // determine the SPI to use
mbed_official 462:e03396e14338 60 SPIName spi_mosi = (SPIName)pinmap_peripheral(mosi, PinMap_SPI_MOSI);
mbed_official 462:e03396e14338 61 SPIName spi_miso = (SPIName)pinmap_peripheral(miso, PinMap_SPI_MISO);
mbed_official 462:e03396e14338 62 SPIName spi_sclk = (SPIName)pinmap_peripheral(sclk, PinMap_SPI_SCLK);
mbed_official 462:e03396e14338 63 SPIName spi_ssel = (SPIName)pinmap_peripheral(ssel, PinMap_SPI_SSEL);
mbed_official 462:e03396e14338 64 SPIName spi_data = (SPIName)pinmap_merge(spi_mosi, spi_miso);
mbed_official 462:e03396e14338 65 SPIName spi_cntl = (SPIName)pinmap_merge(spi_sclk, spi_ssel);
mbed_official 462:e03396e14338 66 obj->spi = (LPC_SSP_TypeDef*)pinmap_merge(spi_data, spi_cntl);
mbed_official 462:e03396e14338 67 MBED_ASSERT((int)obj->spi != NC);
mbed_official 462:e03396e14338 68
mbed_official 462:e03396e14338 69 // enable power and clocking
mbed_official 462:e03396e14338 70 switch ((int)obj->spi) {
mbed_official 462:e03396e14338 71 case SPI_0: LPC_SC->PCONP |= 1 << 21; break;
mbed_official 462:e03396e14338 72 case SPI_1: LPC_SC->PCONP |= 1 << 10; break;
mbed_official 462:e03396e14338 73 case SPI_2: LPC_SC->PCONP |= 1 << 20; break;
mbed_official 462:e03396e14338 74 }
mbed_official 462:e03396e14338 75
mbed_official 462:e03396e14338 76 // pin out the spi pins
mbed_official 462:e03396e14338 77 pinmap_pinout(mosi, PinMap_SPI_MOSI);
mbed_official 462:e03396e14338 78 pinmap_pinout(miso, PinMap_SPI_MISO);
mbed_official 462:e03396e14338 79 pinmap_pinout(sclk, PinMap_SPI_SCLK);
mbed_official 462:e03396e14338 80 if (ssel != NC) {
mbed_official 462:e03396e14338 81 pinmap_pinout(ssel, PinMap_SPI_SSEL);
mbed_official 462:e03396e14338 82 }
mbed_official 462:e03396e14338 83 }
mbed_official 462:e03396e14338 84
mbed_official 462:e03396e14338 85 void spi_free(spi_t *obj) {}
mbed_official 462:e03396e14338 86
mbed_official 462:e03396e14338 87 void spi_format(spi_t *obj, int bits, int mode, int slave) {
mbed_official 462:e03396e14338 88 MBED_ASSERT(((bits >= 4) && (bits <= 16)) && ((mode >= 0) && (mode <= 3)));
mbed_official 462:e03396e14338 89 ssp_disable(obj);
mbed_official 462:e03396e14338 90
mbed_official 462:e03396e14338 91 int polarity = (mode & 0x2) ? 1 : 0;
mbed_official 462:e03396e14338 92 int phase = (mode & 0x1) ? 1 : 0;
mbed_official 462:e03396e14338 93
mbed_official 462:e03396e14338 94 // set it up
mbed_official 462:e03396e14338 95 int DSS = bits - 1; // DSS (data select size)
mbed_official 462:e03396e14338 96 int SPO = (polarity) ? 1 : 0; // SPO - clock out polarity
mbed_official 462:e03396e14338 97 int SPH = (phase) ? 1 : 0; // SPH - clock out phase
mbed_official 462:e03396e14338 98
mbed_official 462:e03396e14338 99 int FRF = 0; // FRF (frame format) = SPI
mbed_official 462:e03396e14338 100 uint32_t tmp = obj->spi->CR0;
mbed_official 462:e03396e14338 101 tmp &= ~(0xFFFF);
mbed_official 462:e03396e14338 102 tmp |= DSS << 0
mbed_official 462:e03396e14338 103 | FRF << 4
mbed_official 462:e03396e14338 104 | SPO << 6
mbed_official 462:e03396e14338 105 | SPH << 7;
mbed_official 462:e03396e14338 106 obj->spi->CR0 = tmp;
mbed_official 462:e03396e14338 107
mbed_official 462:e03396e14338 108 tmp = obj->spi->CR1;
mbed_official 462:e03396e14338 109 tmp &= ~(0xD);
mbed_official 462:e03396e14338 110 tmp |= 0 << 0 // LBM - loop back mode - off
mbed_official 462:e03396e14338 111 | ((slave) ? 1 : 0) << 2 // MS - master slave mode, 1 = slave
mbed_official 462:e03396e14338 112 | 0 << 3; // SOD - slave output disable - na
mbed_official 462:e03396e14338 113 obj->spi->CR1 = tmp;
mbed_official 462:e03396e14338 114 ssp_enable(obj);
mbed_official 462:e03396e14338 115 }
mbed_official 462:e03396e14338 116
mbed_official 462:e03396e14338 117 void spi_frequency(spi_t *obj, int hz) {
mbed_official 462:e03396e14338 118 ssp_disable(obj);
mbed_official 462:e03396e14338 119
mbed_official 462:e03396e14338 120 uint32_t PCLK = PeripheralClock;
mbed_official 462:e03396e14338 121
mbed_official 462:e03396e14338 122 int prescaler;
mbed_official 462:e03396e14338 123
mbed_official 462:e03396e14338 124 for (prescaler = 2; prescaler <= 254; prescaler += 2) {
mbed_official 462:e03396e14338 125 int prescale_hz = PCLK / prescaler;
mbed_official 462:e03396e14338 126
mbed_official 462:e03396e14338 127 // calculate the divider
mbed_official 462:e03396e14338 128 int divider = floor(((float)prescale_hz / (float)hz) + 0.5f);
mbed_official 462:e03396e14338 129
mbed_official 462:e03396e14338 130 // check we can support the divider
mbed_official 462:e03396e14338 131 if (divider < 256) {
mbed_official 462:e03396e14338 132 // prescaler
mbed_official 462:e03396e14338 133 obj->spi->CPSR = prescaler;
mbed_official 462:e03396e14338 134
mbed_official 462:e03396e14338 135 // divider
mbed_official 462:e03396e14338 136 obj->spi->CR0 &= ~(0xFFFF << 8);
mbed_official 462:e03396e14338 137 obj->spi->CR0 |= (divider - 1) << 8;
mbed_official 462:e03396e14338 138 ssp_enable(obj);
mbed_official 462:e03396e14338 139 return;
mbed_official 462:e03396e14338 140 }
mbed_official 462:e03396e14338 141 }
mbed_official 462:e03396e14338 142 error("Couldn't setup requested SPI frequency");
mbed_official 462:e03396e14338 143 }
mbed_official 462:e03396e14338 144
mbed_official 462:e03396e14338 145 static inline int ssp_disable(spi_t *obj) {
mbed_official 462:e03396e14338 146 return obj->spi->CR1 &= ~(1 << 1);
mbed_official 462:e03396e14338 147 }
mbed_official 462:e03396e14338 148
mbed_official 462:e03396e14338 149 static inline int ssp_enable(spi_t *obj) {
mbed_official 462:e03396e14338 150 return obj->spi->CR1 |= (1 << 1);
mbed_official 462:e03396e14338 151 }
mbed_official 462:e03396e14338 152
mbed_official 462:e03396e14338 153 static inline int ssp_readable(spi_t *obj) {
mbed_official 462:e03396e14338 154 return obj->spi->SR & (1 << 2);
mbed_official 462:e03396e14338 155 }
mbed_official 462:e03396e14338 156
mbed_official 462:e03396e14338 157 static inline int ssp_writeable(spi_t *obj) {
mbed_official 462:e03396e14338 158 return obj->spi->SR & (1 << 1);
mbed_official 462:e03396e14338 159 }
mbed_official 462:e03396e14338 160
mbed_official 462:e03396e14338 161 static inline void ssp_write(spi_t *obj, int value) {
mbed_official 462:e03396e14338 162 while (!ssp_writeable(obj));
mbed_official 462:e03396e14338 163 obj->spi->DR = value;
mbed_official 462:e03396e14338 164 }
mbed_official 462:e03396e14338 165
mbed_official 462:e03396e14338 166 static inline int ssp_read(spi_t *obj) {
mbed_official 462:e03396e14338 167 while (!ssp_readable(obj));
mbed_official 462:e03396e14338 168 return obj->spi->DR;
mbed_official 462:e03396e14338 169 }
mbed_official 462:e03396e14338 170
mbed_official 462:e03396e14338 171 static inline int ssp_busy(spi_t *obj) {
mbed_official 462:e03396e14338 172 return (obj->spi->SR & (1 << 4)) ? (1) : (0);
mbed_official 462:e03396e14338 173 }
mbed_official 462:e03396e14338 174
mbed_official 462:e03396e14338 175 int spi_master_write(spi_t *obj, int value) {
mbed_official 462:e03396e14338 176 ssp_write(obj, value);
mbed_official 462:e03396e14338 177 return ssp_read(obj);
mbed_official 462:e03396e14338 178 }
mbed_official 462:e03396e14338 179
mbed_official 462:e03396e14338 180 int spi_slave_receive(spi_t *obj) {
mbed_official 462:e03396e14338 181 return (ssp_readable(obj) && !ssp_busy(obj)) ? (1) : (0);
mbed_official 462:e03396e14338 182 }
mbed_official 462:e03396e14338 183
mbed_official 462:e03396e14338 184 int spi_slave_read(spi_t *obj) {
mbed_official 462:e03396e14338 185 return obj->spi->DR;
mbed_official 462:e03396e14338 186 }
mbed_official 462:e03396e14338 187
mbed_official 462:e03396e14338 188 void spi_slave_write(spi_t *obj, int value) {
mbed_official 462:e03396e14338 189 while (ssp_writeable(obj) == 0) ;
mbed_official 462:e03396e14338 190 obj->spi->DR = value;
mbed_official 462:e03396e14338 191 }
mbed_official 462:e03396e14338 192
mbed_official 462:e03396e14338 193 int spi_busy(spi_t *obj) {
mbed_official 462:e03396e14338 194 return ssp_busy(obj);
mbed_official 462:e03396e14338 195 }