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Last commit 20 Feb 2019 by mbed official

targets/hal/TARGET_NXP/TARGET_LPC15XX/spi_api.c@261:ee1cf08b7bc7, 2014-07-21 (annotated)

Committer:
mbed_official
Date:
Mon Jul 21 07:45:07 2014 +0100
Revision:
261:ee1cf08b7bc7
Parent:
251:de9a1e4ffd79
Child:
266:69e8a32876bd
Synchronized with git revision d712c8f2f24ccef06c8c41cd5373c28370fc4497



Full URL: https://github.com/mbedmicro/mbed/commit/d712c8f2f24ccef06c8c41cd5373c28370fc4497/



[LPC1549] Fixed SPI frequency issue

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbed_official 103:9b881da47c92 1 /* mbed Microcontroller Library
mbed_official 103:9b881da47c92 2 * Copyright (c) 2006-2013 ARM Limited
mbed_official 103:9b881da47c92 3 *
mbed_official 103:9b881da47c92 4 * Licensed under the Apache License, Version 2.0 (the "License");
mbed_official 103:9b881da47c92 5 * you may not use this file except in compliance with the License.
mbed_official 103:9b881da47c92 6 * You may obtain a copy of the License at
mbed_official 103:9b881da47c92 7 *
mbed_official 103:9b881da47c92 8 * http://www.apache.org/licenses/LICENSE-2.0
mbed_official 103:9b881da47c92 9 *
mbed_official 103:9b881da47c92 10 * Unless required by applicable law or agreed to in writing, software
mbed_official 103:9b881da47c92 11 * distributed under the License is distributed on an "AS IS" BASIS,
mbed_official 103:9b881da47c92 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
mbed_official 103:9b881da47c92 13 * See the License for the specific language governing permissions and
mbed_official 103:9b881da47c92 14 * limitations under the License.
mbed_official 103:9b881da47c92 15 */
mbed_official 227:7bd0639b8911 16 #include "mbed_assert.h"
mbed_official 103:9b881da47c92 17 #include <math.h>
mbed_official 103:9b881da47c92 18
mbed_official 103:9b881da47c92 19 #include "spi_api.h"
mbed_official 103:9b881da47c92 20 #include "cmsis.h"
mbed_official 103:9b881da47c92 21 #include "pinmap.h"
mbed_official 251:de9a1e4ffd79 22 #include "error.h"
mbed_official 103:9b881da47c92 23
mbed_official 103:9b881da47c92 24 static const SWM_Map SWM_SPI_SSEL[] = {
mbed_official 103:9b881da47c92 25 {4, 0},
mbed_official 103:9b881da47c92 26 {5, 24},
mbed_official 103:9b881da47c92 27 };
mbed_official 103:9b881da47c92 28
mbed_official 103:9b881da47c92 29 static const SWM_Map SWM_SPI_SCLK[] = {
mbed_official 103:9b881da47c92 30 {3, 8},
mbed_official 103:9b881da47c92 31 {5, 0},
mbed_official 103:9b881da47c92 32 };
mbed_official 103:9b881da47c92 33
mbed_official 103:9b881da47c92 34 static const SWM_Map SWM_SPI_MOSI[] = {
mbed_official 103:9b881da47c92 35 {3, 16},
mbed_official 103:9b881da47c92 36 {5, 8},
mbed_official 103:9b881da47c92 37 };
mbed_official 103:9b881da47c92 38
mbed_official 103:9b881da47c92 39 static const SWM_Map SWM_SPI_MISO[] = {
mbed_official 103:9b881da47c92 40 {3, 24},
mbed_official 103:9b881da47c92 41 {5, 16},
mbed_official 103:9b881da47c92 42 };
mbed_official 103:9b881da47c92 43
mbed_official 103:9b881da47c92 44 // bit flags for used SPIs
mbed_official 103:9b881da47c92 45 static unsigned char spi_used = 0;
mbed_official 261:ee1cf08b7bc7 46 static int get_available_spi(void)
mbed_official 261:ee1cf08b7bc7 47 {
mbed_official 103:9b881da47c92 48 int i;
mbed_official 103:9b881da47c92 49 for (i=0; i<2; i++) {
mbed_official 103:9b881da47c92 50 if ((spi_used & (1 << i)) == 0)
mbed_official 103:9b881da47c92 51 return i;
mbed_official 103:9b881da47c92 52 }
mbed_official 103:9b881da47c92 53 return -1;
mbed_official 103:9b881da47c92 54 }
mbed_official 103:9b881da47c92 55
mbed_official 103:9b881da47c92 56 static inline void spi_disable(spi_t *obj);
mbed_official 103:9b881da47c92 57 static inline void spi_enable(spi_t *obj);
mbed_official 103:9b881da47c92 58
mbed_official 261:ee1cf08b7bc7 59 void spi_init(spi_t *obj, PinName mosi, PinName miso, PinName sclk, PinName ssel)
mbed_official 261:ee1cf08b7bc7 60 {
mbed_official 103:9b881da47c92 61 int spi_n = get_available_spi();
mbed_official 103:9b881da47c92 62 if (spi_n == -1) {
mbed_official 103:9b881da47c92 63 error("No available SPI");
mbed_official 103:9b881da47c92 64 }
mbed_official 103:9b881da47c92 65
mbed_official 103:9b881da47c92 66 obj->spi_n = spi_n;
mbed_official 103:9b881da47c92 67 spi_used |= (1 << spi_n);
mbed_official 261:ee1cf08b7bc7 68
mbed_official 103:9b881da47c92 69 obj->spi = (spi_n) ? (LPC_SPI0_Type *)(LPC_SPI1_BASE) : (LPC_SPI0_Type *)(LPC_SPI0_BASE);
mbed_official 261:ee1cf08b7bc7 70
mbed_official 103:9b881da47c92 71 const SWM_Map *swm;
mbed_official 103:9b881da47c92 72 uint32_t regVal;
mbed_official 261:ee1cf08b7bc7 73
mbed_official 103:9b881da47c92 74 if (sclk != NC) {
mbed_official 103:9b881da47c92 75 swm = &SWM_SPI_SCLK[obj->spi_n];
mbed_official 103:9b881da47c92 76 regVal = LPC_SWM->PINASSIGN[swm->n] & ~(0xFF << swm->offset);
mbed_official 103:9b881da47c92 77 LPC_SWM->PINASSIGN[swm->n] = regVal | (sclk << swm->offset);
mbed_official 103:9b881da47c92 78 }
mbed_official 261:ee1cf08b7bc7 79
mbed_official 103:9b881da47c92 80 if (mosi != NC) {
mbed_official 103:9b881da47c92 81 swm = &SWM_SPI_MOSI[obj->spi_n];
mbed_official 103:9b881da47c92 82 regVal = LPC_SWM->PINASSIGN[swm->n] & ~(0xFF << swm->offset);
mbed_official 103:9b881da47c92 83 LPC_SWM->PINASSIGN[swm->n] = regVal | (mosi << swm->offset);
mbed_official 103:9b881da47c92 84 }
mbed_official 261:ee1cf08b7bc7 85
mbed_official 103:9b881da47c92 86 if (miso != NC) {
mbed_official 103:9b881da47c92 87 swm = &SWM_SPI_MISO[obj->spi_n];
mbed_official 103:9b881da47c92 88 regVal = LPC_SWM->PINASSIGN[swm->n] & ~(0xFF << swm->offset);
mbed_official 103:9b881da47c92 89 LPC_SWM->PINASSIGN[swm->n] = regVal | (miso << swm->offset);
mbed_official 103:9b881da47c92 90 }
mbed_official 103:9b881da47c92 91
mbed_official 103:9b881da47c92 92 if (ssel != NC) {
mbed_official 103:9b881da47c92 93 swm = &SWM_SPI_SSEL[obj->spi_n];
mbed_official 103:9b881da47c92 94 regVal = LPC_SWM->PINASSIGN[swm->n] & ~(0xFF << swm->offset);
mbed_official 103:9b881da47c92 95 LPC_SWM->PINASSIGN[swm->n] = regVal | (ssel << swm->offset);
mbed_official 103:9b881da47c92 96 }
mbed_official 103:9b881da47c92 97
mbed_official 103:9b881da47c92 98 // clear interrupts
mbed_official 103:9b881da47c92 99 obj->spi->INTENCLR = 0x3f;
mbed_official 103:9b881da47c92 100
mbed_official 261:ee1cf08b7bc7 101 // enable power and clocking
mbed_official 261:ee1cf08b7bc7 102 LPC_SYSCON->SYSAHBCLKCTRL1 |= (0x1 << (obj->spi_n + 9));
mbed_official 261:ee1cf08b7bc7 103 LPC_SYSCON->PRESETCTRL1 |= (0x1 << (obj->spi_n + 9));
mbed_official 261:ee1cf08b7bc7 104 LPC_SYSCON->PRESETCTRL1 &= ~(0x1 << (obj->spi_n + 9));
mbed_official 261:ee1cf08b7bc7 105
mbed_official 103:9b881da47c92 106 // set default format and frequency
mbed_official 103:9b881da47c92 107 if (ssel == NC) {
mbed_official 103:9b881da47c92 108 spi_format(obj, 8, 0, 0); // 8 bits, mode 0, master
mbed_official 103:9b881da47c92 109 } else {
mbed_official 103:9b881da47c92 110 spi_format(obj, 8, 0, 1); // 8 bits, mode 0, slave
mbed_official 103:9b881da47c92 111 }
mbed_official 103:9b881da47c92 112 spi_frequency(obj, 1000000);
mbed_official 261:ee1cf08b7bc7 113
mbed_official 103:9b881da47c92 114 // enable the spi channel
mbed_official 103:9b881da47c92 115 spi_enable(obj);
mbed_official 103:9b881da47c92 116 }
mbed_official 103:9b881da47c92 117
mbed_official 261:ee1cf08b7bc7 118 void spi_free(spi_t *obj)
mbed_official 261:ee1cf08b7bc7 119 {
mbed_official 261:ee1cf08b7bc7 120 }
mbed_official 103:9b881da47c92 121
mbed_official 261:ee1cf08b7bc7 122 void spi_format(spi_t *obj, int bits, int mode, int slave)
mbed_official 261:ee1cf08b7bc7 123 {
mbed_official 103:9b881da47c92 124 spi_disable(obj);
mbed_official 227:7bd0639b8911 125 MBED_ASSERT((bits >= 1 && bits <= 16) && (mode >= 0 && mode <= 3));
mbed_official 261:ee1cf08b7bc7 126
mbed_official 103:9b881da47c92 127 int polarity = (mode & 0x2) ? 1 : 0;
mbed_official 103:9b881da47c92 128 int phase = (mode & 0x1) ? 1 : 0;
mbed_official 261:ee1cf08b7bc7 129
mbed_official 103:9b881da47c92 130 // set it up
mbed_official 103:9b881da47c92 131 int LEN = bits - 1; // LEN - Data Length
mbed_official 103:9b881da47c92 132 int CPOL = (polarity) ? 1 : 0; // CPOL - Clock Polarity select
mbed_official 103:9b881da47c92 133 int CPHA = (phase) ? 1 : 0; // CPHA - Clock Phase select
mbed_official 261:ee1cf08b7bc7 134
mbed_official 103:9b881da47c92 135 uint32_t tmp = obj->spi->CFG;
mbed_official 103:9b881da47c92 136 tmp &= ~((1 << 5) | (1 << 4) | (1 << 2));
mbed_official 103:9b881da47c92 137 tmp |= (CPOL << 5) | (CPHA << 4) | ((slave ? 0 : 1) << 2);
mbed_official 103:9b881da47c92 138 obj->spi->CFG = tmp;
mbed_official 261:ee1cf08b7bc7 139
mbed_official 103:9b881da47c92 140 // select frame length
mbed_official 103:9b881da47c92 141 tmp = obj->spi->TXDATCTL;
mbed_official 103:9b881da47c92 142 tmp &= ~(0xf << 24);
mbed_official 103:9b881da47c92 143 tmp |= (LEN << 24);
mbed_official 103:9b881da47c92 144 obj->spi->TXDATCTL = tmp;
mbed_official 261:ee1cf08b7bc7 145
mbed_official 103:9b881da47c92 146 spi_enable(obj);
mbed_official 103:9b881da47c92 147 }
mbed_official 103:9b881da47c92 148
mbed_official 261:ee1cf08b7bc7 149 void spi_frequency(spi_t *obj, int hz)
mbed_official 261:ee1cf08b7bc7 150 {
mbed_official 103:9b881da47c92 151 spi_disable(obj);
mbed_official 261:ee1cf08b7bc7 152
mbed_official 261:ee1cf08b7bc7 153 // rise DIV value if it cannot be divided
mbed_official 261:ee1cf08b7bc7 154 obj->spi->DIV = (SystemCoreClock + (hz - 1))/hz - 1;
mbed_official 103:9b881da47c92 155 obj->spi->DLY = 0;
mbed_official 261:ee1cf08b7bc7 156
mbed_official 103:9b881da47c92 157 spi_enable(obj);
mbed_official 103:9b881da47c92 158 }
mbed_official 103:9b881da47c92 159
mbed_official 261:ee1cf08b7bc7 160 static inline void spi_disable(spi_t *obj)
mbed_official 261:ee1cf08b7bc7 161 {
mbed_official 103:9b881da47c92 162 obj->spi->CFG &= ~(1 << 0);
mbed_official 103:9b881da47c92 163 }
mbed_official 103:9b881da47c92 164
mbed_official 261:ee1cf08b7bc7 165 static inline void spi_enable(spi_t *obj)
mbed_official 261:ee1cf08b7bc7 166 {
mbed_official 103:9b881da47c92 167 obj->spi->CFG |= (1 << 0);
mbed_official 103:9b881da47c92 168 }
mbed_official 103:9b881da47c92 169
mbed_official 261:ee1cf08b7bc7 170 static inline int spi_readable(spi_t *obj)
mbed_official 261:ee1cf08b7bc7 171 {
mbed_official 103:9b881da47c92 172 return obj->spi->STAT & (1 << 0);
mbed_official 103:9b881da47c92 173 }
mbed_official 103:9b881da47c92 174
mbed_official 261:ee1cf08b7bc7 175 static inline int spi_writeable(spi_t *obj)
mbed_official 261:ee1cf08b7bc7 176 {
mbed_official 103:9b881da47c92 177 return obj->spi->STAT & (1 << 1);
mbed_official 103:9b881da47c92 178 }
mbed_official 103:9b881da47c92 179
mbed_official 261:ee1cf08b7bc7 180 static inline void spi_write(spi_t *obj, int value)
mbed_official 261:ee1cf08b7bc7 181 {
mbed_official 103:9b881da47c92 182 while (!spi_writeable(obj));
mbed_official 103:9b881da47c92 183 // end of transfer
mbed_official 103:9b881da47c92 184 obj->spi->TXDATCTL |= (1 << 20);
mbed_official 103:9b881da47c92 185 obj->spi->TXDAT = value;
mbed_official 103:9b881da47c92 186 }
mbed_official 103:9b881da47c92 187
mbed_official 261:ee1cf08b7bc7 188 static inline int spi_read(spi_t *obj)
mbed_official 261:ee1cf08b7bc7 189 {
mbed_official 103:9b881da47c92 190 while (!spi_readable(obj));
mbed_official 103:9b881da47c92 191 return obj->spi->RXDAT;
mbed_official 103:9b881da47c92 192 }
mbed_official 103:9b881da47c92 193
mbed_official 261:ee1cf08b7bc7 194 int spi_busy(spi_t *obj)
mbed_official 261:ee1cf08b7bc7 195 {
mbed_official 103:9b881da47c92 196 // checking RXOV(Receiver Overrun interrupt flag)
mbed_official 103:9b881da47c92 197 return obj->spi->STAT & (1 << 2);
mbed_official 261:ee1cf08b7bc7 198 }
mbed_official 103:9b881da47c92 199
mbed_official 261:ee1cf08b7bc7 200 int spi_master_write(spi_t *obj, int value)
mbed_official 261:ee1cf08b7bc7 201 {
mbed_official 103:9b881da47c92 202 spi_write(obj, value);
mbed_official 103:9b881da47c92 203 return spi_read(obj);
mbed_official 103:9b881da47c92 204 }
mbed_official 103:9b881da47c92 205
mbed_official 261:ee1cf08b7bc7 206 int spi_slave_receive(spi_t *obj)
mbed_official 261:ee1cf08b7bc7 207 {
mbed_official 103:9b881da47c92 208 return (spi_readable(obj) && !spi_busy(obj)) ? (1) : (0);
mbed_official 103:9b881da47c92 209 }
mbed_official 103:9b881da47c92 210
mbed_official 261:ee1cf08b7bc7 211 int spi_slave_read(spi_t *obj)
mbed_official 261:ee1cf08b7bc7 212 {
mbed_official 103:9b881da47c92 213 return obj->spi->RXDAT;
mbed_official 103:9b881da47c92 214 }
mbed_official 103:9b881da47c92 215
mbed_official 261:ee1cf08b7bc7 216 void spi_slave_write(spi_t *obj, int value)
mbed_official 261:ee1cf08b7bc7 217 {
mbed_official 103:9b881da47c92 218 while (spi_writeable(obj) == 0) ;
mbed_official 103:9b881da47c92 219 obj->spi->TXDAT = value;
mbed_official 103:9b881da47c92 220 }