Jonathan Piat / mbed-src

mbed library sources

Fork of mbed-src by mbed official

targets/hal/TARGET_NXP/TARGET_LPC81X/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:
285:31249416b6f9 
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 46:bebbbd80dd87 1 /* mbed Microcontroller Library
mbed_official 46:bebbbd80dd87 2 * Copyright (c) 2006-2013 ARM Limited
mbed_official 46:bebbbd80dd87 3 *
mbed_official 46:bebbbd80dd87 4 * Licensed under the Apache License, Version 2.0 (the "License");
mbed_official 46:bebbbd80dd87 5 * you may not use this file except in compliance with the License.
mbed_official 46:bebbbd80dd87 6 * You may obtain a copy of the License at
mbed_official 46:bebbbd80dd87 7 *
mbed_official 46:bebbbd80dd87 8 * http://www.apache.org/licenses/LICENSE-2.0
mbed_official 46:bebbbd80dd87 9 *
mbed_official 46:bebbbd80dd87 10 * Unless required by applicable law or agreed to in writing, software
mbed_official 46:bebbbd80dd87 11 * distributed under the License is distributed on an "AS IS" BASIS,
mbed_official 46:bebbbd80dd87 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
mbed_official 46:bebbbd80dd87 13 * See the License for the specific language governing permissions and
mbed_official 46:bebbbd80dd87 14 * limitations under the License.
mbed_official 46:bebbbd80dd87 15 */
mbed_official 227:7bd0639b8911 16 #include "mbed_assert.h"
mbed_official 46:bebbbd80dd87 17 #include <math.h>
mbed_official 46:bebbbd80dd87 18
mbed_official 46:bebbbd80dd87 19 #include "spi_api.h"
mbed_official 46:bebbbd80dd87 20 #include "cmsis.h"
mbed_official 46:bebbbd80dd87 21 #include "pinmap.h"
mbed_official 285:31249416b6f9 22 #include "mbed_error.h"
mbed_official 46:bebbbd80dd87 23
mbed_official 46:bebbbd80dd87 24 static const SWM_Map SWM_SPI_SSEL[] = {
mbed_official 46:bebbbd80dd87 25 {4, 16},
mbed_official 46:bebbbd80dd87 26 {5, 16},
mbed_official 46:bebbbd80dd87 27 };
mbed_official 46:bebbbd80dd87 28
mbed_official 46:bebbbd80dd87 29 static const SWM_Map SWM_SPI_SCLK[] = {
mbed_official 46:bebbbd80dd87 30 {3, 24},
mbed_official 46:bebbbd80dd87 31 {4, 24},
mbed_official 46:bebbbd80dd87 32 };
mbed_official 46:bebbbd80dd87 33
mbed_official 46:bebbbd80dd87 34 static const SWM_Map SWM_SPI_MOSI[] = {
mbed_official 46:bebbbd80dd87 35 {4, 0},
mbed_official 46:bebbbd80dd87 36 {5, 0},
mbed_official 46:bebbbd80dd87 37 };
mbed_official 46:bebbbd80dd87 38
mbed_official 46:bebbbd80dd87 39 static const SWM_Map SWM_SPI_MISO[] = {
mbed_official 46:bebbbd80dd87 40 {4, 8},
mbed_official 46:bebbbd80dd87 41 {5, 16},
mbed_official 46:bebbbd80dd87 42 };
mbed_official 46:bebbbd80dd87 43
mbed_official 46:bebbbd80dd87 44 // bit flags for used SPIs
mbed_official 46:bebbbd80dd87 45 static unsigned char spi_used = 0;
mbed_official 46:bebbbd80dd87 46 static int get_available_spi(void) {
mbed_official 46:bebbbd80dd87 47 int i;
mbed_official 46:bebbbd80dd87 48 for (i=0; i<2; i++) {
mbed_official 46:bebbbd80dd87 49 if ((spi_used & (1 << i)) == 0)
mbed_official 46:bebbbd80dd87 50 return i;
mbed_official 46:bebbbd80dd87 51 }
mbed_official 46:bebbbd80dd87 52 return -1;
mbed_official 46:bebbbd80dd87 53 }
mbed_official 46:bebbbd80dd87 54
mbed_official 46:bebbbd80dd87 55 static inline int ssp_disable(spi_t *obj);
mbed_official 46:bebbbd80dd87 56 static inline int ssp_enable(spi_t *obj);
mbed_official 46:bebbbd80dd87 57
mbed_official 46:bebbbd80dd87 58 void spi_init(spi_t *obj, PinName mosi, PinName miso, PinName sclk, PinName ssel) {
mbed_official 46:bebbbd80dd87 59 int spi_n = get_available_spi();
mbed_official 46:bebbbd80dd87 60 if (spi_n == -1) {
mbed_official 46:bebbbd80dd87 61 error("No available SPI");
mbed_official 46:bebbbd80dd87 62 }
mbed_official 46:bebbbd80dd87 63 obj->spi_n = spi_n;
mbed_official 46:bebbbd80dd87 64 spi_used |= (1 << spi_n);
mbed_official 46:bebbbd80dd87 65
mbed_official 46:bebbbd80dd87 66 obj->spi = (spi_n) ? (LPC_SPI_TypeDef *)(LPC_SPI1_BASE) : (LPC_SPI_TypeDef *)(LPC_SPI0_BASE);
mbed_official 46:bebbbd80dd87 67
mbed_official 46:bebbbd80dd87 68 const SWM_Map *swm;
mbed_official 46:bebbbd80dd87 69 uint32_t regVal;
mbed_official 46:bebbbd80dd87 70
mbed_official 46:bebbbd80dd87 71 swm = &SWM_SPI_SCLK[obj->spi_n];
mbed_official 46:bebbbd80dd87 72 regVal = LPC_SWM->PINASSIGN[swm->n] & ~(0xFF << swm->offset);
mbed_official 46:bebbbd80dd87 73 LPC_SWM->PINASSIGN[swm->n] = regVal | (sclk << swm->offset);
mbed_official 46:bebbbd80dd87 74
mbed_official 46:bebbbd80dd87 75 swm = &SWM_SPI_MOSI[obj->spi_n];
mbed_official 46:bebbbd80dd87 76 regVal = LPC_SWM->PINASSIGN[swm->n] & ~(0xFF << swm->offset);
mbed_official 46:bebbbd80dd87 77 LPC_SWM->PINASSIGN[swm->n] = regVal | (mosi << swm->offset);
mbed_official 46:bebbbd80dd87 78
mbed_official 46:bebbbd80dd87 79 swm = &SWM_SPI_MISO[obj->spi_n];
mbed_official 46:bebbbd80dd87 80 regVal = LPC_SWM->PINASSIGN[swm->n] & ~(0xFF << swm->offset);
mbed_official 46:bebbbd80dd87 81 LPC_SWM->PINASSIGN[swm->n] = regVal | (miso << swm->offset);
mbed_official 46:bebbbd80dd87 82
mbed_official 46:bebbbd80dd87 83 swm = &SWM_SPI_SSEL[obj->spi_n];
mbed_official 46:bebbbd80dd87 84 regVal = LPC_SWM->PINASSIGN[swm->n] & ~(0xFF << swm->offset);
mbed_official 46:bebbbd80dd87 85 LPC_SWM->PINASSIGN[swm->n] = regVal | (ssel << swm->offset);
mbed_official 46:bebbbd80dd87 86
mbed_official 46:bebbbd80dd87 87 // clear interrupts
mbed_official 46:bebbbd80dd87 88 obj->spi->INTENCLR = 0x3f;
mbed_official 46:bebbbd80dd87 89
mbed_official 46:bebbbd80dd87 90 // enable power and clocking
mbed_official 46:bebbbd80dd87 91 switch (obj->spi_n) {
mbed_official 46:bebbbd80dd87 92 case 0:
mbed_official 46:bebbbd80dd87 93 LPC_SYSCON->SYSAHBCLKCTRL |= (1<<11);
mbed_official 46:bebbbd80dd87 94 LPC_SYSCON->PRESETCTRL &= ~(0x1<<0);
mbed_official 46:bebbbd80dd87 95 LPC_SYSCON->PRESETCTRL |= (0x1<<0);
mbed_official 46:bebbbd80dd87 96 break;
mbed_official 46:bebbbd80dd87 97 case 1:
mbed_official 46:bebbbd80dd87 98 LPC_SYSCON->SYSAHBCLKCTRL |= (1<<12);
mbed_official 46:bebbbd80dd87 99 LPC_SYSCON->PRESETCTRL &= ~(0x1<<1);
mbed_official 46:bebbbd80dd87 100 LPC_SYSCON->PRESETCTRL |= (0x1<<1);
mbed_official 46:bebbbd80dd87 101 break;
mbed_official 46:bebbbd80dd87 102 }
mbed_official 46:bebbbd80dd87 103 }
mbed_official 46:bebbbd80dd87 104
mbed_official 46:bebbbd80dd87 105 void spi_free(spi_t *obj) {}
mbed_official 46:bebbbd80dd87 106
mbed_official 46:bebbbd80dd87 107 void spi_format(spi_t *obj, int bits, int mode, int slave) {
mbed_official 227:7bd0639b8911 108 MBED_ASSERT(((bits >= 1) && (bits <= 16)) && ((mode >= 0) && (mode <= 3)));
mbed_official 46:bebbbd80dd87 109 ssp_disable(obj);
mbed_official 46:bebbbd80dd87 110
mbed_official 46:bebbbd80dd87 111 int polarity = (mode & 0x2) ? 1 : 0;
mbed_official 46:bebbbd80dd87 112 int phase = (mode & 0x1) ? 1 : 0;
mbed_official 46:bebbbd80dd87 113
mbed_official 46:bebbbd80dd87 114 // set it up
mbed_official 46:bebbbd80dd87 115 int DSS = bits - 1; // DSS (data select size)
mbed_official 46:bebbbd80dd87 116 int SPO = (polarity) ? 1 : 0; // SPO - clock out polarity
mbed_official 46:bebbbd80dd87 117 int SPH = (phase) ? 1 : 0; // SPH - clock out phase
mbed_official 46:bebbbd80dd87 118
mbed_official 46:bebbbd80dd87 119 uint32_t tmp = obj->spi->CFG;
mbed_official 46:bebbbd80dd87 120 tmp &= ~((1 << 2) | (1 << 4) | (1 << 5));
mbed_official 46:bebbbd80dd87 121 tmp |= (SPH << 4) | (SPO << 5) | ((slave ? 0 : 1) << 2);
mbed_official 46:bebbbd80dd87 122 obj->spi->CFG = tmp;
mbed_official 46:bebbbd80dd87 123
mbed_official 46:bebbbd80dd87 124 // select frame length
mbed_official 46:bebbbd80dd87 125 tmp = obj->spi->TXDATCTL;
mbed_official 46:bebbbd80dd87 126 tmp &= ~(0xf << 24);
mbed_official 46:bebbbd80dd87 127 tmp |= (DSS << 24);
mbed_official 46:bebbbd80dd87 128 obj->spi->TXDATCTL = tmp;
mbed_official 46:bebbbd80dd87 129
mbed_official 46:bebbbd80dd87 130 ssp_enable(obj);
mbed_official 46:bebbbd80dd87 131 }
mbed_official 46:bebbbd80dd87 132
mbed_official 46:bebbbd80dd87 133 void spi_frequency(spi_t *obj, int hz) {
mbed_official 46:bebbbd80dd87 134 ssp_disable(obj);
mbed_official 46:bebbbd80dd87 135
mbed_official 46:bebbbd80dd87 136 uint32_t PCLK = SystemCoreClock;
mbed_official 46:bebbbd80dd87 137
mbed_official 46:bebbbd80dd87 138 obj->spi->DIV = PCLK/hz - 1;
mbed_official 46:bebbbd80dd87 139 obj->spi->DLY = 0;
mbed_official 46:bebbbd80dd87 140 ssp_enable(obj);
mbed_official 46:bebbbd80dd87 141 }
mbed_official 46:bebbbd80dd87 142
mbed_official 46:bebbbd80dd87 143 static inline int ssp_disable(spi_t *obj) {
mbed_official 46:bebbbd80dd87 144 return obj->spi->CFG &= ~(1 << 0);
mbed_official 46:bebbbd80dd87 145 }
mbed_official 46:bebbbd80dd87 146
mbed_official 46:bebbbd80dd87 147 static inline int ssp_enable(spi_t *obj) {
mbed_official 46:bebbbd80dd87 148 return obj->spi->CFG |= (1 << 0);
mbed_official 46:bebbbd80dd87 149 }
mbed_official 46:bebbbd80dd87 150
mbed_official 46:bebbbd80dd87 151 static inline int ssp_readable(spi_t *obj) {
mbed_official 46:bebbbd80dd87 152 return obj->spi->STAT & (1 << 0);
mbed_official 46:bebbbd80dd87 153 }
mbed_official 46:bebbbd80dd87 154
mbed_official 46:bebbbd80dd87 155 static inline int ssp_writeable(spi_t *obj) {
mbed_official 46:bebbbd80dd87 156 return obj->spi->STAT & (1 << 1);
mbed_official 46:bebbbd80dd87 157 }
mbed_official 46:bebbbd80dd87 158
mbed_official 46:bebbbd80dd87 159 static inline void ssp_write(spi_t *obj, int value) {
mbed_official 46:bebbbd80dd87 160 while (!ssp_writeable(obj));
mbed_official 46:bebbbd80dd87 161 // end of transfer
mbed_official 46:bebbbd80dd87 162 obj->spi->TXDATCTL |= (1 << 20);
mbed_official 46:bebbbd80dd87 163 obj->spi->TXDAT = value;
mbed_official 46:bebbbd80dd87 164 }
mbed_official 46:bebbbd80dd87 165
mbed_official 46:bebbbd80dd87 166 static inline int ssp_read(spi_t *obj) {
mbed_official 46:bebbbd80dd87 167 while (!ssp_readable(obj));
mbed_official 46:bebbbd80dd87 168 return obj->spi->RXDAT;
mbed_official 46:bebbbd80dd87 169 }
mbed_official 46:bebbbd80dd87 170
mbed_official 46:bebbbd80dd87 171 static inline int ssp_busy(spi_t *obj) {
mbed_official 69:49e45cb70de1 172 // checking RXOV(Receiver Overrun interrupt flag)
mbed_official 69:49e45cb70de1 173 return obj->spi->STAT & (1 << 2);
mbed_official 69:49e45cb70de1 174 }
mbed_official 46:bebbbd80dd87 175
mbed_official 46:bebbbd80dd87 176 int spi_master_write(spi_t *obj, int value) {
mbed_official 46:bebbbd80dd87 177 ssp_write(obj, value);
mbed_official 46:bebbbd80dd87 178 return ssp_read(obj);
mbed_official 46:bebbbd80dd87 179 }
mbed_official 46:bebbbd80dd87 180
mbed_official 46:bebbbd80dd87 181 int spi_slave_receive(spi_t *obj) {
mbed_official 46:bebbbd80dd87 182 return (ssp_readable(obj) && !ssp_busy(obj)) ? (1) : (0);
mbed_official 81:a9456fdf72fa 183 }
mbed_official 46:bebbbd80dd87 184
mbed_official 46:bebbbd80dd87 185 int spi_slave_read(spi_t *obj) {
mbed_official 46:bebbbd80dd87 186 return obj->spi->RXDAT;
mbed_official 46:bebbbd80dd87 187 }
mbed_official 46:bebbbd80dd87 188
mbed_official 46:bebbbd80dd87 189 void spi_slave_write(spi_t *obj, int value) {
mbed_official 46:bebbbd80dd87 190 while (ssp_writeable(obj) == 0) ;
mbed_official 46:bebbbd80dd87 191 obj->spi->TXDAT = value;
mbed_official 46:bebbbd80dd87 192 }
mbed_official 46:bebbbd80dd87 193
mbed_official 46:bebbbd80dd87 194 int spi_busy(spi_t *obj) {
mbed_official 46:bebbbd80dd87 195 return ssp_busy(obj);
mbed_official 46:bebbbd80dd87 196 }