Jonathan Piat / mbed-src

mbed library sources

Fork of mbed-src by mbed official

targets/hal/TARGET_NXP/TARGET_LPC15XX/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 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 285:31249416b6f9 22 #include "mbed_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 266:69e8a32876bd 46 static int get_available_spi(PinName mosi, PinName miso, PinName sclk, PinName ssel)
mbed_official 261:ee1cf08b7bc7 47 {
mbed_official 266:69e8a32876bd 48 if (spi_used == 0) {
mbed_official 266:69e8a32876bd 49 return 0; // The first user
mbed_official 103:9b881da47c92 50 }
mbed_official 266:69e8a32876bd 51
mbed_official 266:69e8a32876bd 52 const SWM_Map *swm;
mbed_official 266:69e8a32876bd 53 uint32_t regVal;
mbed_official 266:69e8a32876bd 54
mbed_official 266:69e8a32876bd 55 // Investigate if same pins as the used SPI0/1 - to be able to reuse it
mbed_official 266:69e8a32876bd 56 for (int spi_n = 0; spi_n < 2; spi_n++) {
mbed_official 266:69e8a32876bd 57 if (spi_used & (1<<spi_n)) {
mbed_official 266:69e8a32876bd 58 if (sclk != NC) {
mbed_official 266:69e8a32876bd 59 swm = &SWM_SPI_SCLK[spi_n];
mbed_official 266:69e8a32876bd 60 regVal = LPC_SWM->PINASSIGN[swm->n] & (0xFF << swm->offset);
mbed_official 266:69e8a32876bd 61 if (regVal != (sclk << swm->offset)) {
mbed_official 266:69e8a32876bd 62 // Existing pin is not the same as the one we want
mbed_official 266:69e8a32876bd 63 continue;
mbed_official 266:69e8a32876bd 64 }
mbed_official 266:69e8a32876bd 65 }
mbed_official 266:69e8a32876bd 66
mbed_official 266:69e8a32876bd 67 if (mosi != NC) {
mbed_official 266:69e8a32876bd 68 swm = &SWM_SPI_MOSI[spi_n];
mbed_official 266:69e8a32876bd 69 regVal = LPC_SWM->PINASSIGN[swm->n] & (0xFF << swm->offset);
mbed_official 266:69e8a32876bd 70 if (regVal != (mosi << swm->offset)) {
mbed_official 266:69e8a32876bd 71 // Existing pin is not the same as the one we want
mbed_official 266:69e8a32876bd 72 continue;
mbed_official 266:69e8a32876bd 73 }
mbed_official 266:69e8a32876bd 74 }
mbed_official 266:69e8a32876bd 75
mbed_official 266:69e8a32876bd 76 if (miso != NC) {
mbed_official 266:69e8a32876bd 77 swm = &SWM_SPI_MISO[spi_n];
mbed_official 266:69e8a32876bd 78 regVal = LPC_SWM->PINASSIGN[swm->n] & (0xFF << swm->offset);
mbed_official 266:69e8a32876bd 79 if (regVal != (miso << swm->offset)) {
mbed_official 266:69e8a32876bd 80 // Existing pin is not the same as the one we want
mbed_official 266:69e8a32876bd 81 continue;
mbed_official 266:69e8a32876bd 82 }
mbed_official 266:69e8a32876bd 83 }
mbed_official 266:69e8a32876bd 84
mbed_official 266:69e8a32876bd 85 if (ssel != NC) {
mbed_official 266:69e8a32876bd 86 swm = &SWM_SPI_SSEL[spi_n];
mbed_official 266:69e8a32876bd 87 regVal = LPC_SWM->PINASSIGN[swm->n] & (0xFF << swm->offset);
mbed_official 266:69e8a32876bd 88 if (regVal != (ssel << swm->offset)) {
mbed_official 266:69e8a32876bd 89 // Existing pin is not the same as the one we want
mbed_official 266:69e8a32876bd 90 continue;
mbed_official 266:69e8a32876bd 91 }
mbed_official 266:69e8a32876bd 92 }
mbed_official 266:69e8a32876bd 93
mbed_official 266:69e8a32876bd 94 // The pins for the currently used SPIx are the same as the
mbed_official 266:69e8a32876bd 95 // ones we want so we will reuse it
mbed_official 266:69e8a32876bd 96 return spi_n;
mbed_official 266:69e8a32876bd 97 }
mbed_official 266:69e8a32876bd 98 }
mbed_official 266:69e8a32876bd 99
mbed_official 266:69e8a32876bd 100 // None of the existing SPIx pin setups match the pins we want
mbed_official 266:69e8a32876bd 101 // so the last hope is to select one unused SPIx
mbed_official 266:69e8a32876bd 102 if ((spi_used & 1) == 0) {
mbed_official 266:69e8a32876bd 103 return 0;
mbed_official 266:69e8a32876bd 104 } else if ((spi_used & 2) == 0) {
mbed_official 266:69e8a32876bd 105 return 1;
mbed_official 266:69e8a32876bd 106 }
mbed_official 266:69e8a32876bd 107
mbed_official 266:69e8a32876bd 108 // No matching setup and no free SPIx
mbed_official 103:9b881da47c92 109 return -1;
mbed_official 103:9b881da47c92 110 }
mbed_official 103:9b881da47c92 111
mbed_official 103:9b881da47c92 112 static inline void spi_disable(spi_t *obj);
mbed_official 103:9b881da47c92 113 static inline void spi_enable(spi_t *obj);
mbed_official 103:9b881da47c92 114
mbed_official 261:ee1cf08b7bc7 115 void spi_init(spi_t *obj, PinName mosi, PinName miso, PinName sclk, PinName ssel)
mbed_official 261:ee1cf08b7bc7 116 {
mbed_official 266:69e8a32876bd 117 int spi_n = get_available_spi(mosi, miso, sclk, ssel);
mbed_official 103:9b881da47c92 118 if (spi_n == -1) {
mbed_official 103:9b881da47c92 119 error("No available SPI");
mbed_official 103:9b881da47c92 120 }
mbed_official 103:9b881da47c92 121
mbed_official 103:9b881da47c92 122 obj->spi_n = spi_n;
mbed_official 103:9b881da47c92 123 spi_used |= (1 << spi_n);
mbed_official 261:ee1cf08b7bc7 124
mbed_official 103:9b881da47c92 125 obj->spi = (spi_n) ? (LPC_SPI0_Type *)(LPC_SPI1_BASE) : (LPC_SPI0_Type *)(LPC_SPI0_BASE);
mbed_official 261:ee1cf08b7bc7 126
mbed_official 103:9b881da47c92 127 const SWM_Map *swm;
mbed_official 103:9b881da47c92 128 uint32_t regVal;
mbed_official 261:ee1cf08b7bc7 129
mbed_official 103:9b881da47c92 130 if (sclk != NC) {
mbed_official 103:9b881da47c92 131 swm = &SWM_SPI_SCLK[obj->spi_n];
mbed_official 103:9b881da47c92 132 regVal = LPC_SWM->PINASSIGN[swm->n] & ~(0xFF << swm->offset);
mbed_official 103:9b881da47c92 133 LPC_SWM->PINASSIGN[swm->n] = regVal | (sclk << swm->offset);
mbed_official 103:9b881da47c92 134 }
mbed_official 261:ee1cf08b7bc7 135
mbed_official 103:9b881da47c92 136 if (mosi != NC) {
mbed_official 103:9b881da47c92 137 swm = &SWM_SPI_MOSI[obj->spi_n];
mbed_official 103:9b881da47c92 138 regVal = LPC_SWM->PINASSIGN[swm->n] & ~(0xFF << swm->offset);
mbed_official 103:9b881da47c92 139 LPC_SWM->PINASSIGN[swm->n] = regVal | (mosi << swm->offset);
mbed_official 103:9b881da47c92 140 }
mbed_official 261:ee1cf08b7bc7 141
mbed_official 103:9b881da47c92 142 if (miso != NC) {
mbed_official 103:9b881da47c92 143 swm = &SWM_SPI_MISO[obj->spi_n];
mbed_official 103:9b881da47c92 144 regVal = LPC_SWM->PINASSIGN[swm->n] & ~(0xFF << swm->offset);
mbed_official 103:9b881da47c92 145 LPC_SWM->PINASSIGN[swm->n] = regVal | (miso << swm->offset);
mbed_official 103:9b881da47c92 146 }
mbed_official 103:9b881da47c92 147
mbed_official 103:9b881da47c92 148 if (ssel != NC) {
mbed_official 103:9b881da47c92 149 swm = &SWM_SPI_SSEL[obj->spi_n];
mbed_official 103:9b881da47c92 150 regVal = LPC_SWM->PINASSIGN[swm->n] & ~(0xFF << swm->offset);
mbed_official 103:9b881da47c92 151 LPC_SWM->PINASSIGN[swm->n] = regVal | (ssel << swm->offset);
mbed_official 103:9b881da47c92 152 }
mbed_official 103:9b881da47c92 153
mbed_official 103:9b881da47c92 154 // clear interrupts
mbed_official 103:9b881da47c92 155 obj->spi->INTENCLR = 0x3f;
mbed_official 103:9b881da47c92 156
mbed_official 261:ee1cf08b7bc7 157 // enable power and clocking
mbed_official 261:ee1cf08b7bc7 158 LPC_SYSCON->SYSAHBCLKCTRL1 |= (0x1 << (obj->spi_n + 9));
mbed_official 261:ee1cf08b7bc7 159 LPC_SYSCON->PRESETCTRL1 |= (0x1 << (obj->spi_n + 9));
mbed_official 261:ee1cf08b7bc7 160 LPC_SYSCON->PRESETCTRL1 &= ~(0x1 << (obj->spi_n + 9));
mbed_official 103:9b881da47c92 161 }
mbed_official 103:9b881da47c92 162
mbed_official 261:ee1cf08b7bc7 163 void spi_free(spi_t *obj)
mbed_official 261:ee1cf08b7bc7 164 {
mbed_official 261:ee1cf08b7bc7 165 }
mbed_official 103:9b881da47c92 166
mbed_official 261:ee1cf08b7bc7 167 void spi_format(spi_t *obj, int bits, int mode, int slave)
mbed_official 261:ee1cf08b7bc7 168 {
mbed_official 103:9b881da47c92 169 spi_disable(obj);
mbed_official 227:7bd0639b8911 170 MBED_ASSERT((bits >= 1 && bits <= 16) && (mode >= 0 && mode <= 3));
mbed_official 261:ee1cf08b7bc7 171
mbed_official 103:9b881da47c92 172 int polarity = (mode & 0x2) ? 1 : 0;
mbed_official 103:9b881da47c92 173 int phase = (mode & 0x1) ? 1 : 0;
mbed_official 261:ee1cf08b7bc7 174
mbed_official 103:9b881da47c92 175 // set it up
mbed_official 103:9b881da47c92 176 int LEN = bits - 1; // LEN - Data Length
mbed_official 103:9b881da47c92 177 int CPOL = (polarity) ? 1 : 0; // CPOL - Clock Polarity select
mbed_official 103:9b881da47c92 178 int CPHA = (phase) ? 1 : 0; // CPHA - Clock Phase select
mbed_official 261:ee1cf08b7bc7 179
mbed_official 103:9b881da47c92 180 uint32_t tmp = obj->spi->CFG;
mbed_official 103:9b881da47c92 181 tmp &= ~((1 << 5) | (1 << 4) | (1 << 2));
mbed_official 103:9b881da47c92 182 tmp |= (CPOL << 5) | (CPHA << 4) | ((slave ? 0 : 1) << 2);
mbed_official 103:9b881da47c92 183 obj->spi->CFG = tmp;
mbed_official 261:ee1cf08b7bc7 184
mbed_official 103:9b881da47c92 185 // select frame length
mbed_official 266:69e8a32876bd 186 tmp = obj->spi->TXCTL;
mbed_official 103:9b881da47c92 187 tmp &= ~(0xf << 24);
mbed_official 103:9b881da47c92 188 tmp |= (LEN << 24);
mbed_official 266:69e8a32876bd 189 obj->spi->TXCTL = tmp;
mbed_official 261:ee1cf08b7bc7 190
mbed_official 103:9b881da47c92 191 spi_enable(obj);
mbed_official 103:9b881da47c92 192 }
mbed_official 103:9b881da47c92 193
mbed_official 261:ee1cf08b7bc7 194 void spi_frequency(spi_t *obj, int hz)
mbed_official 261:ee1cf08b7bc7 195 {
mbed_official 103:9b881da47c92 196 spi_disable(obj);
mbed_official 261:ee1cf08b7bc7 197
mbed_official 261:ee1cf08b7bc7 198 // rise DIV value if it cannot be divided
mbed_official 261:ee1cf08b7bc7 199 obj->spi->DIV = (SystemCoreClock + (hz - 1))/hz - 1;
mbed_official 103:9b881da47c92 200 obj->spi->DLY = 0;
mbed_official 261:ee1cf08b7bc7 201
mbed_official 103:9b881da47c92 202 spi_enable(obj);
mbed_official 103:9b881da47c92 203 }
mbed_official 103:9b881da47c92 204
mbed_official 261:ee1cf08b7bc7 205 static inline void spi_disable(spi_t *obj)
mbed_official 261:ee1cf08b7bc7 206 {
mbed_official 103:9b881da47c92 207 obj->spi->CFG &= ~(1 << 0);
mbed_official 103:9b881da47c92 208 }
mbed_official 103:9b881da47c92 209
mbed_official 261:ee1cf08b7bc7 210 static inline void spi_enable(spi_t *obj)
mbed_official 261:ee1cf08b7bc7 211 {
mbed_official 103:9b881da47c92 212 obj->spi->CFG |= (1 << 0);
mbed_official 103:9b881da47c92 213 }
mbed_official 103:9b881da47c92 214
mbed_official 261:ee1cf08b7bc7 215 static inline int spi_readable(spi_t *obj)
mbed_official 261:ee1cf08b7bc7 216 {
mbed_official 103:9b881da47c92 217 return obj->spi->STAT & (1 << 0);
mbed_official 103:9b881da47c92 218 }
mbed_official 103:9b881da47c92 219
mbed_official 261:ee1cf08b7bc7 220 static inline int spi_writeable(spi_t *obj)
mbed_official 261:ee1cf08b7bc7 221 {
mbed_official 103:9b881da47c92 222 return obj->spi->STAT & (1 << 1);
mbed_official 103:9b881da47c92 223 }
mbed_official 103:9b881da47c92 224
mbed_official 261:ee1cf08b7bc7 225 static inline void spi_write(spi_t *obj, int value)
mbed_official 261:ee1cf08b7bc7 226 {
mbed_official 103:9b881da47c92 227 while (!spi_writeable(obj));
mbed_official 103:9b881da47c92 228 // end of transfer
mbed_official 266:69e8a32876bd 229 obj->spi->TXCTL |= (1 << 20);
mbed_official 266:69e8a32876bd 230 obj->spi->TXDAT = (value & 0xffff);
mbed_official 103:9b881da47c92 231 }
mbed_official 103:9b881da47c92 232
mbed_official 261:ee1cf08b7bc7 233 static inline int spi_read(spi_t *obj)
mbed_official 261:ee1cf08b7bc7 234 {
mbed_official 103:9b881da47c92 235 while (!spi_readable(obj));
mbed_official 266:69e8a32876bd 236 return obj->spi->RXDAT & 0xffff; // Only the lower 16 bits contain data
mbed_official 103:9b881da47c92 237 }
mbed_official 103:9b881da47c92 238
mbed_official 261:ee1cf08b7bc7 239 int spi_busy(spi_t *obj)
mbed_official 261:ee1cf08b7bc7 240 {
mbed_official 103:9b881da47c92 241 // checking RXOV(Receiver Overrun interrupt flag)
mbed_official 103:9b881da47c92 242 return obj->spi->STAT & (1 << 2);
mbed_official 261:ee1cf08b7bc7 243 }
mbed_official 103:9b881da47c92 244
mbed_official 261:ee1cf08b7bc7 245 int spi_master_write(spi_t *obj, int value)
mbed_official 261:ee1cf08b7bc7 246 {
mbed_official 103:9b881da47c92 247 spi_write(obj, value);
mbed_official 103:9b881da47c92 248 return spi_read(obj);
mbed_official 103:9b881da47c92 249 }
mbed_official 103:9b881da47c92 250
mbed_official 261:ee1cf08b7bc7 251 int spi_slave_receive(spi_t *obj)
mbed_official 261:ee1cf08b7bc7 252 {
mbed_official 103:9b881da47c92 253 return (spi_readable(obj) && !spi_busy(obj)) ? (1) : (0);
mbed_official 103:9b881da47c92 254 }
mbed_official 103:9b881da47c92 255
mbed_official 261:ee1cf08b7bc7 256 int spi_slave_read(spi_t *obj)
mbed_official 261:ee1cf08b7bc7 257 {
mbed_official 266:69e8a32876bd 258 return obj->spi->RXDAT & 0xffff; // Only the lower 16 bits contain data
mbed_official 103:9b881da47c92 259 }
mbed_official 103:9b881da47c92 260
mbed_official 261:ee1cf08b7bc7 261 void spi_slave_write(spi_t *obj, int value)
mbed_official 261:ee1cf08b7bc7 262 {
mbed_official 103:9b881da47c92 263 while (spi_writeable(obj) == 0) ;
mbed_official 103:9b881da47c92 264 obj->spi->TXDAT = value;
mbed_official 103:9b881da47c92 265 }