EL4121 Embedded System / mbed-os

mbed-os

Dependents:   cobaLCDJoyMotor_Thread odometry_omni_3roda_v3 odometry_omni_3roda_v1 odometry_omni_3roda_v2 ... more

targets/TARGET_NXP/TARGET_LPC15XX/spi_api.c@0:b74591d5ab33, 2017-12-11 (annotated)

Committer:
be_bryan
Date:
Mon Dec 11 17:54:04 2017 +0000
Revision:
0:b74591d5ab33
motor ++

Who changed what in which revision?

UserRevisionLine numberNew contents of line
be_bryan 0:b74591d5ab33 1 /* mbed Microcontroller Library
be_bryan 0:b74591d5ab33 2 * Copyright (c) 2006-2013 ARM Limited
be_bryan 0:b74591d5ab33 3 *
be_bryan 0:b74591d5ab33 4 * Licensed under the Apache License, Version 2.0 (the "License");
be_bryan 0:b74591d5ab33 5 * you may not use this file except in compliance with the License.
be_bryan 0:b74591d5ab33 6 * You may obtain a copy of the License at
be_bryan 0:b74591d5ab33 7 *
be_bryan 0:b74591d5ab33 8 * http://www.apache.org/licenses/LICENSE-2.0
be_bryan 0:b74591d5ab33 9 *
be_bryan 0:b74591d5ab33 10 * Unless required by applicable law or agreed to in writing, software
be_bryan 0:b74591d5ab33 11 * distributed under the License is distributed on an "AS IS" BASIS,
be_bryan 0:b74591d5ab33 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
be_bryan 0:b74591d5ab33 13 * See the License for the specific language governing permissions and
be_bryan 0:b74591d5ab33 14 * limitations under the License.
be_bryan 0:b74591d5ab33 15 */
be_bryan 0:b74591d5ab33 16 #include "mbed_assert.h"
be_bryan 0:b74591d5ab33 17 #include <math.h>
be_bryan 0:b74591d5ab33 18
be_bryan 0:b74591d5ab33 19 #include "spi_api.h"
be_bryan 0:b74591d5ab33 20 #include "cmsis.h"
be_bryan 0:b74591d5ab33 21 #include "pinmap.h"
be_bryan 0:b74591d5ab33 22 #include "mbed_error.h"
be_bryan 0:b74591d5ab33 23
be_bryan 0:b74591d5ab33 24 static const SWM_Map SWM_SPI_SSEL[] = {
be_bryan 0:b74591d5ab33 25 {4, 0},
be_bryan 0:b74591d5ab33 26 {5, 24},
be_bryan 0:b74591d5ab33 27 };
be_bryan 0:b74591d5ab33 28
be_bryan 0:b74591d5ab33 29 static const SWM_Map SWM_SPI_SCLK[] = {
be_bryan 0:b74591d5ab33 30 {3, 8},
be_bryan 0:b74591d5ab33 31 {5, 0},
be_bryan 0:b74591d5ab33 32 };
be_bryan 0:b74591d5ab33 33
be_bryan 0:b74591d5ab33 34 static const SWM_Map SWM_SPI_MOSI[] = {
be_bryan 0:b74591d5ab33 35 {3, 16},
be_bryan 0:b74591d5ab33 36 {5, 8},
be_bryan 0:b74591d5ab33 37 };
be_bryan 0:b74591d5ab33 38
be_bryan 0:b74591d5ab33 39 static const SWM_Map SWM_SPI_MISO[] = {
be_bryan 0:b74591d5ab33 40 {3, 24},
be_bryan 0:b74591d5ab33 41 {5, 16},
be_bryan 0:b74591d5ab33 42 };
be_bryan 0:b74591d5ab33 43
be_bryan 0:b74591d5ab33 44 // bit flags for used SPIs
be_bryan 0:b74591d5ab33 45 static unsigned char spi_used = 0;
be_bryan 0:b74591d5ab33 46 static int get_available_spi(PinName mosi, PinName miso, PinName sclk, PinName ssel)
be_bryan 0:b74591d5ab33 47 {
be_bryan 0:b74591d5ab33 48 if (spi_used == 0) {
be_bryan 0:b74591d5ab33 49 return 0; // The first user
be_bryan 0:b74591d5ab33 50 }
be_bryan 0:b74591d5ab33 51
be_bryan 0:b74591d5ab33 52 const SWM_Map *swm;
be_bryan 0:b74591d5ab33 53 uint32_t regVal;
be_bryan 0:b74591d5ab33 54
be_bryan 0:b74591d5ab33 55 // Investigate if same pins as the used SPI0/1 - to be able to reuse it
be_bryan 0:b74591d5ab33 56 for (int spi_n = 0; spi_n < 2; spi_n++) {
be_bryan 0:b74591d5ab33 57 if (spi_used & (1<<spi_n)) {
be_bryan 0:b74591d5ab33 58 if (sclk != NC) {
be_bryan 0:b74591d5ab33 59 swm = &SWM_SPI_SCLK[spi_n];
be_bryan 0:b74591d5ab33 60 regVal = LPC_SWM->PINASSIGN[swm->n] & (0xFF << swm->offset);
be_bryan 0:b74591d5ab33 61 if (regVal != (sclk << swm->offset)) {
be_bryan 0:b74591d5ab33 62 // Existing pin is not the same as the one we want
be_bryan 0:b74591d5ab33 63 continue;
be_bryan 0:b74591d5ab33 64 }
be_bryan 0:b74591d5ab33 65 }
be_bryan 0:b74591d5ab33 66
be_bryan 0:b74591d5ab33 67 if (mosi != NC) {
be_bryan 0:b74591d5ab33 68 swm = &SWM_SPI_MOSI[spi_n];
be_bryan 0:b74591d5ab33 69 regVal = LPC_SWM->PINASSIGN[swm->n] & (0xFF << swm->offset);
be_bryan 0:b74591d5ab33 70 if (regVal != (mosi << swm->offset)) {
be_bryan 0:b74591d5ab33 71 // Existing pin is not the same as the one we want
be_bryan 0:b74591d5ab33 72 continue;
be_bryan 0:b74591d5ab33 73 }
be_bryan 0:b74591d5ab33 74 }
be_bryan 0:b74591d5ab33 75
be_bryan 0:b74591d5ab33 76 if (miso != NC) {
be_bryan 0:b74591d5ab33 77 swm = &SWM_SPI_MISO[spi_n];
be_bryan 0:b74591d5ab33 78 regVal = LPC_SWM->PINASSIGN[swm->n] & (0xFF << swm->offset);
be_bryan 0:b74591d5ab33 79 if (regVal != (miso << swm->offset)) {
be_bryan 0:b74591d5ab33 80 // Existing pin is not the same as the one we want
be_bryan 0:b74591d5ab33 81 continue;
be_bryan 0:b74591d5ab33 82 }
be_bryan 0:b74591d5ab33 83 }
be_bryan 0:b74591d5ab33 84
be_bryan 0:b74591d5ab33 85 if (ssel != NC) {
be_bryan 0:b74591d5ab33 86 swm = &SWM_SPI_SSEL[spi_n];
be_bryan 0:b74591d5ab33 87 regVal = LPC_SWM->PINASSIGN[swm->n] & (0xFF << swm->offset);
be_bryan 0:b74591d5ab33 88 if (regVal != (ssel << swm->offset)) {
be_bryan 0:b74591d5ab33 89 // Existing pin is not the same as the one we want
be_bryan 0:b74591d5ab33 90 continue;
be_bryan 0:b74591d5ab33 91 }
be_bryan 0:b74591d5ab33 92 }
be_bryan 0:b74591d5ab33 93
be_bryan 0:b74591d5ab33 94 // The pins for the currently used SPIx are the same as the
be_bryan 0:b74591d5ab33 95 // ones we want so we will reuse it
be_bryan 0:b74591d5ab33 96 return spi_n;
be_bryan 0:b74591d5ab33 97 }
be_bryan 0:b74591d5ab33 98 }
be_bryan 0:b74591d5ab33 99
be_bryan 0:b74591d5ab33 100 // None of the existing SPIx pin setups match the pins we want
be_bryan 0:b74591d5ab33 101 // so the last hope is to select one unused SPIx
be_bryan 0:b74591d5ab33 102 if ((spi_used & 1) == 0) {
be_bryan 0:b74591d5ab33 103 return 0;
be_bryan 0:b74591d5ab33 104 } else if ((spi_used & 2) == 0) {
be_bryan 0:b74591d5ab33 105 return 1;
be_bryan 0:b74591d5ab33 106 }
be_bryan 0:b74591d5ab33 107
be_bryan 0:b74591d5ab33 108 // No matching setup and no free SPIx
be_bryan 0:b74591d5ab33 109 return -1;
be_bryan 0:b74591d5ab33 110 }
be_bryan 0:b74591d5ab33 111
be_bryan 0:b74591d5ab33 112 static inline void spi_disable(spi_t *obj);
be_bryan 0:b74591d5ab33 113 static inline void spi_enable(spi_t *obj);
be_bryan 0:b74591d5ab33 114
be_bryan 0:b74591d5ab33 115 void spi_init(spi_t *obj, PinName mosi, PinName miso, PinName sclk, PinName ssel)
be_bryan 0:b74591d5ab33 116 {
be_bryan 0:b74591d5ab33 117 int spi_n = get_available_spi(mosi, miso, sclk, ssel);
be_bryan 0:b74591d5ab33 118 if (spi_n == -1) {
be_bryan 0:b74591d5ab33 119 error("No available SPI");
be_bryan 0:b74591d5ab33 120 }
be_bryan 0:b74591d5ab33 121
be_bryan 0:b74591d5ab33 122 obj->spi_n = spi_n;
be_bryan 0:b74591d5ab33 123 spi_used |= (1 << spi_n);
be_bryan 0:b74591d5ab33 124
be_bryan 0:b74591d5ab33 125 obj->spi = (spi_n) ? (LPC_SPI0_Type *)(LPC_SPI1_BASE) : (LPC_SPI0_Type *)(LPC_SPI0_BASE);
be_bryan 0:b74591d5ab33 126
be_bryan 0:b74591d5ab33 127 const SWM_Map *swm;
be_bryan 0:b74591d5ab33 128 uint32_t regVal;
be_bryan 0:b74591d5ab33 129
be_bryan 0:b74591d5ab33 130 if (sclk != NC) {
be_bryan 0:b74591d5ab33 131 swm = &SWM_SPI_SCLK[obj->spi_n];
be_bryan 0:b74591d5ab33 132 regVal = LPC_SWM->PINASSIGN[swm->n] & ~(0xFF << swm->offset);
be_bryan 0:b74591d5ab33 133 LPC_SWM->PINASSIGN[swm->n] = regVal | (sclk << swm->offset);
be_bryan 0:b74591d5ab33 134 }
be_bryan 0:b74591d5ab33 135
be_bryan 0:b74591d5ab33 136 if (mosi != NC) {
be_bryan 0:b74591d5ab33 137 swm = &SWM_SPI_MOSI[obj->spi_n];
be_bryan 0:b74591d5ab33 138 regVal = LPC_SWM->PINASSIGN[swm->n] & ~(0xFF << swm->offset);
be_bryan 0:b74591d5ab33 139 LPC_SWM->PINASSIGN[swm->n] = regVal | (mosi << swm->offset);
be_bryan 0:b74591d5ab33 140 }
be_bryan 0:b74591d5ab33 141
be_bryan 0:b74591d5ab33 142 if (miso != NC) {
be_bryan 0:b74591d5ab33 143 swm = &SWM_SPI_MISO[obj->spi_n];
be_bryan 0:b74591d5ab33 144 regVal = LPC_SWM->PINASSIGN[swm->n] & ~(0xFF << swm->offset);
be_bryan 0:b74591d5ab33 145 LPC_SWM->PINASSIGN[swm->n] = regVal | (miso << swm->offset);
be_bryan 0:b74591d5ab33 146 }
be_bryan 0:b74591d5ab33 147
be_bryan 0:b74591d5ab33 148 if (ssel != NC) {
be_bryan 0:b74591d5ab33 149 swm = &SWM_SPI_SSEL[obj->spi_n];
be_bryan 0:b74591d5ab33 150 regVal = LPC_SWM->PINASSIGN[swm->n] & ~(0xFF << swm->offset);
be_bryan 0:b74591d5ab33 151 LPC_SWM->PINASSIGN[swm->n] = regVal | (ssel << swm->offset);
be_bryan 0:b74591d5ab33 152 }
be_bryan 0:b74591d5ab33 153
be_bryan 0:b74591d5ab33 154 // clear interrupts
be_bryan 0:b74591d5ab33 155 obj->spi->INTENCLR = 0x3f;
be_bryan 0:b74591d5ab33 156
be_bryan 0:b74591d5ab33 157 // enable power and clocking
be_bryan 0:b74591d5ab33 158 LPC_SYSCON->SYSAHBCLKCTRL1 |= (0x1 << (obj->spi_n + 9));
be_bryan 0:b74591d5ab33 159 LPC_SYSCON->PRESETCTRL1 |= (0x1 << (obj->spi_n + 9));
be_bryan 0:b74591d5ab33 160 LPC_SYSCON->PRESETCTRL1 &= ~(0x1 << (obj->spi_n + 9));
be_bryan 0:b74591d5ab33 161 }
be_bryan 0:b74591d5ab33 162
be_bryan 0:b74591d5ab33 163 void spi_free(spi_t *obj)
be_bryan 0:b74591d5ab33 164 {
be_bryan 0:b74591d5ab33 165 }
be_bryan 0:b74591d5ab33 166
be_bryan 0:b74591d5ab33 167 void spi_format(spi_t *obj, int bits, int mode, int slave)
be_bryan 0:b74591d5ab33 168 {
be_bryan 0:b74591d5ab33 169 spi_disable(obj);
be_bryan 0:b74591d5ab33 170 MBED_ASSERT((bits >= 1 && bits <= 16) && (mode >= 0 && mode <= 3));
be_bryan 0:b74591d5ab33 171
be_bryan 0:b74591d5ab33 172 int polarity = (mode & 0x2) ? 1 : 0;
be_bryan 0:b74591d5ab33 173 int phase = (mode & 0x1) ? 1 : 0;
be_bryan 0:b74591d5ab33 174
be_bryan 0:b74591d5ab33 175 // set it up
be_bryan 0:b74591d5ab33 176 int LEN = bits - 1; // LEN - Data Length
be_bryan 0:b74591d5ab33 177 int CPOL = (polarity) ? 1 : 0; // CPOL - Clock Polarity select
be_bryan 0:b74591d5ab33 178 int CPHA = (phase) ? 1 : 0; // CPHA - Clock Phase select
be_bryan 0:b74591d5ab33 179
be_bryan 0:b74591d5ab33 180 uint32_t tmp = obj->spi->CFG;
be_bryan 0:b74591d5ab33 181 tmp &= ~((1 << 5) | (1 << 4) | (1 << 2));
be_bryan 0:b74591d5ab33 182 tmp |= (CPOL << 5) | (CPHA << 4) | ((slave ? 0 : 1) << 2);
be_bryan 0:b74591d5ab33 183 obj->spi->CFG = tmp;
be_bryan 0:b74591d5ab33 184
be_bryan 0:b74591d5ab33 185 // select frame length
be_bryan 0:b74591d5ab33 186 tmp = obj->spi->TXCTL;
be_bryan 0:b74591d5ab33 187 tmp &= ~(0xf << 24);
be_bryan 0:b74591d5ab33 188 tmp |= (LEN << 24);
be_bryan 0:b74591d5ab33 189 obj->spi->TXCTL = tmp;
be_bryan 0:b74591d5ab33 190
be_bryan 0:b74591d5ab33 191 spi_enable(obj);
be_bryan 0:b74591d5ab33 192 }
be_bryan 0:b74591d5ab33 193
be_bryan 0:b74591d5ab33 194 void spi_frequency(spi_t *obj, int hz)
be_bryan 0:b74591d5ab33 195 {
be_bryan 0:b74591d5ab33 196 spi_disable(obj);
be_bryan 0:b74591d5ab33 197
be_bryan 0:b74591d5ab33 198 // rise DIV value if it cannot be divided
be_bryan 0:b74591d5ab33 199 obj->spi->DIV = (SystemCoreClock + (hz - 1))/hz - 1;
be_bryan 0:b74591d5ab33 200 obj->spi->DLY = 0;
be_bryan 0:b74591d5ab33 201
be_bryan 0:b74591d5ab33 202 spi_enable(obj);
be_bryan 0:b74591d5ab33 203 }
be_bryan 0:b74591d5ab33 204
be_bryan 0:b74591d5ab33 205 static inline void spi_disable(spi_t *obj)
be_bryan 0:b74591d5ab33 206 {
be_bryan 0:b74591d5ab33 207 obj->spi->CFG &= ~(1 << 0);
be_bryan 0:b74591d5ab33 208 }
be_bryan 0:b74591d5ab33 209
be_bryan 0:b74591d5ab33 210 static inline void spi_enable(spi_t *obj)
be_bryan 0:b74591d5ab33 211 {
be_bryan 0:b74591d5ab33 212 obj->spi->CFG |= (1 << 0);
be_bryan 0:b74591d5ab33 213 }
be_bryan 0:b74591d5ab33 214
be_bryan 0:b74591d5ab33 215 static inline int spi_readable(spi_t *obj)
be_bryan 0:b74591d5ab33 216 {
be_bryan 0:b74591d5ab33 217 return obj->spi->STAT & (1 << 0);
be_bryan 0:b74591d5ab33 218 }
be_bryan 0:b74591d5ab33 219
be_bryan 0:b74591d5ab33 220 static inline int spi_writeable(spi_t *obj)
be_bryan 0:b74591d5ab33 221 {
be_bryan 0:b74591d5ab33 222 return obj->spi->STAT & (1 << 1);
be_bryan 0:b74591d5ab33 223 }
be_bryan 0:b74591d5ab33 224
be_bryan 0:b74591d5ab33 225 static inline void spi_write(spi_t *obj, int value)
be_bryan 0:b74591d5ab33 226 {
be_bryan 0:b74591d5ab33 227 while (!spi_writeable(obj));
be_bryan 0:b74591d5ab33 228 // end of transfer
be_bryan 0:b74591d5ab33 229 obj->spi->TXCTL |= (1 << 20);
be_bryan 0:b74591d5ab33 230 obj->spi->TXDAT = (value & 0xffff);
be_bryan 0:b74591d5ab33 231 }
be_bryan 0:b74591d5ab33 232
be_bryan 0:b74591d5ab33 233 static inline int spi_read(spi_t *obj)
be_bryan 0:b74591d5ab33 234 {
be_bryan 0:b74591d5ab33 235 while (!spi_readable(obj));
be_bryan 0:b74591d5ab33 236 return obj->spi->RXDAT & 0xffff; // Only the lower 16 bits contain data
be_bryan 0:b74591d5ab33 237 }
be_bryan 0:b74591d5ab33 238
be_bryan 0:b74591d5ab33 239 int spi_busy(spi_t *obj)
be_bryan 0:b74591d5ab33 240 {
be_bryan 0:b74591d5ab33 241 // checking RXOV(Receiver Overrun interrupt flag)
be_bryan 0:b74591d5ab33 242 return obj->spi->STAT & (1 << 2);
be_bryan 0:b74591d5ab33 243 }
be_bryan 0:b74591d5ab33 244
be_bryan 0:b74591d5ab33 245 int spi_master_write(spi_t *obj, int value)
be_bryan 0:b74591d5ab33 246 {
be_bryan 0:b74591d5ab33 247 spi_write(obj, value);
be_bryan 0:b74591d5ab33 248 return spi_read(obj);
be_bryan 0:b74591d5ab33 249 }
be_bryan 0:b74591d5ab33 250
be_bryan 0:b74591d5ab33 251 int spi_master_block_write(spi_t *obj, const char *tx_buffer,
be_bryan 0:b74591d5ab33 252 int tx_length, char *rx_buffer, int rx_length, char write_fill) {
be_bryan 0:b74591d5ab33 253 int total = (tx_length > rx_length) ? tx_length : rx_length;
be_bryan 0:b74591d5ab33 254
be_bryan 0:b74591d5ab33 255 for (int i = 0; i < total; i++) {
be_bryan 0:b74591d5ab33 256 char out = (i < tx_length) ? tx_buffer[i] : write_fill;
be_bryan 0:b74591d5ab33 257 char in = spi_master_write(obj, out);
be_bryan 0:b74591d5ab33 258 if (i < rx_length) {
be_bryan 0:b74591d5ab33 259 rx_buffer[i] = in;
be_bryan 0:b74591d5ab33 260 }
be_bryan 0:b74591d5ab33 261 }
be_bryan 0:b74591d5ab33 262
be_bryan 0:b74591d5ab33 263 return total;
be_bryan 0:b74591d5ab33 264 }
be_bryan 0:b74591d5ab33 265
be_bryan 0:b74591d5ab33 266 int spi_slave_receive(spi_t *obj)
be_bryan 0:b74591d5ab33 267 {
be_bryan 0:b74591d5ab33 268 return (spi_readable(obj) && !spi_busy(obj)) ? (1) : (0);
be_bryan 0:b74591d5ab33 269 }
be_bryan 0:b74591d5ab33 270
be_bryan 0:b74591d5ab33 271 int spi_slave_read(spi_t *obj)
be_bryan 0:b74591d5ab33 272 {
be_bryan 0:b74591d5ab33 273 return obj->spi->RXDAT & 0xffff; // Only the lower 16 bits contain data
be_bryan 0:b74591d5ab33 274 }
be_bryan 0:b74591d5ab33 275
be_bryan 0:b74591d5ab33 276 void spi_slave_write(spi_t *obj, int value)
be_bryan 0:b74591d5ab33 277 {
be_bryan 0:b74591d5ab33 278 while (spi_writeable(obj) == 0) ;
be_bryan 0:b74591d5ab33 279 obj->spi->TXDAT = value;
be_bryan 0:b74591d5ab33 280 }