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Last commit 20 Feb 2019 by mbed official

targets/hal/TARGET_STM/TARGET_STM32F4XX/spi_api.c@621:9c82b0f79f3d, 2015-09-11 (annotated)

Committer:
mbed_official
Date:
Fri Sep 11 09:30:09 2015 +0100
Revision:
621:9c82b0f79f3d
Parent:
552:a1b9575155a3 
Synchronized with git revision 6c1d63e069ab9bd86de92e8296ca783681257538



Full URL: https://github.com/mbedmicro/mbed/commit/6c1d63e069ab9bd86de92e8296ca783681257538/



ignore target files not supported by the yotta module

Who changed what in which revision?

UserRevisionLine numberNew contents of line
bogdanm 20:4263a77256ae 1 /* mbed Microcontroller Library
bogdanm 20:4263a77256ae 2 * Copyright (c) 2006-2013 ARM Limited
bogdanm 20:4263a77256ae 3 *
bogdanm 20:4263a77256ae 4 * Licensed under the Apache License, Version 2.0 (the "License");
bogdanm 20:4263a77256ae 5 * you may not use this file except in compliance with the License.
bogdanm 20:4263a77256ae 6 * You may obtain a copy of the License at
bogdanm 20:4263a77256ae 7 *
bogdanm 20:4263a77256ae 8 * http://www.apache.org/licenses/LICENSE-2.0
bogdanm 20:4263a77256ae 9 *
bogdanm 20:4263a77256ae 10 * Unless required by applicable law or agreed to in writing, software
bogdanm 20:4263a77256ae 11 * distributed under the License is distributed on an "AS IS" BASIS,
bogdanm 20:4263a77256ae 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
bogdanm 20:4263a77256ae 13 * See the License for the specific language governing permissions and
bogdanm 20:4263a77256ae 14 * limitations under the License.
bogdanm 20:4263a77256ae 15 */
mbed_official 227:7bd0639b8911 16 #include "mbed_assert.h"
bogdanm 20:4263a77256ae 17 #include "spi_api.h"
bogdanm 20:4263a77256ae 18
bogdanm 20:4263a77256ae 19 #if DEVICE_SPI
bogdanm 20:4263a77256ae 20 #include <math.h>
bogdanm 20:4263a77256ae 21
bogdanm 20:4263a77256ae 22 #include "cmsis.h"
bogdanm 20:4263a77256ae 23 #include "pinmap.h"
bogdanm 20:4263a77256ae 24
bogdanm 20:4263a77256ae 25 static const PinMap PinMap_SPI_SCLK[] = {
bogdanm 20:4263a77256ae 26 {PA_5, SPI_1, STM_PIN_DATA(2, 5)},
bogdanm 20:4263a77256ae 27 {PB_3, SPI_1, STM_PIN_DATA(2, 5)},
bogdanm 20:4263a77256ae 28 {PB_3, SPI_3, STM_PIN_DATA(2, 6)},
bogdanm 20:4263a77256ae 29 {PB_10, SPI_2, STM_PIN_DATA(2, 5)},
bogdanm 20:4263a77256ae 30 {PB_13, SPI_2, STM_PIN_DATA(2, 5)},
bogdanm 20:4263a77256ae 31 {PC_10, SPI_3, STM_PIN_DATA(2, 6)},
bogdanm 20:4263a77256ae 32 {NC, NC, 0}
bogdanm 20:4263a77256ae 33 };
bogdanm 20:4263a77256ae 34
bogdanm 20:4263a77256ae 35 static const PinMap PinMap_SPI_MOSI[] = {
bogdanm 20:4263a77256ae 36 {PA_7, SPI_1, STM_PIN_DATA(2, 5)},
bogdanm 20:4263a77256ae 37 {PB_5, SPI_1, STM_PIN_DATA(2, 5)},
bogdanm 20:4263a77256ae 38 {PB_5, SPI_3, STM_PIN_DATA(2, 6)},
bogdanm 20:4263a77256ae 39 {PB_15, SPI_2, STM_PIN_DATA(2, 5)},
bogdanm 20:4263a77256ae 40 {PC_3, SPI_2, STM_PIN_DATA(2, 5)},
bogdanm 20:4263a77256ae 41 {PC_12, SPI_3, STM_PIN_DATA(2, 6)},
bogdanm 20:4263a77256ae 42 {NC, NC, 0}
bogdanm 20:4263a77256ae 43 };
bogdanm 20:4263a77256ae 44
bogdanm 20:4263a77256ae 45 static const PinMap PinMap_SPI_MISO[] = {
bogdanm 20:4263a77256ae 46 {PA_6, SPI_1, STM_PIN_DATA(2, 5)},
bogdanm 20:4263a77256ae 47 {PB_4, SPI_1, STM_PIN_DATA(2, 5)},
bogdanm 20:4263a77256ae 48 {PB_4, SPI_3, STM_PIN_DATA(2, 6)},
bogdanm 20:4263a77256ae 49 {PB_14, SPI_2, STM_PIN_DATA(2, 5)},
bogdanm 20:4263a77256ae 50 {PC_2, SPI_2, STM_PIN_DATA(2, 5)},
bogdanm 20:4263a77256ae 51 {PC_11, SPI_3, STM_PIN_DATA(2, 6)},
bogdanm 20:4263a77256ae 52 {NC, NC, 0}
bogdanm 20:4263a77256ae 53 };
bogdanm 20:4263a77256ae 54
bogdanm 20:4263a77256ae 55 static const PinMap PinMap_SPI_SSEL[] = {
bogdanm 20:4263a77256ae 56 {PA_4, SPI_1, STM_PIN_DATA(2, 5)},
bogdanm 20:4263a77256ae 57 {PA_4, SPI_3, STM_PIN_DATA(2, 6)},
bogdanm 20:4263a77256ae 58 {PA_15, SPI_1, STM_PIN_DATA(2, 5)},
bogdanm 20:4263a77256ae 59 {PA_15, SPI_3, STM_PIN_DATA(2, 6)},
mbed_official 227:7bd0639b8911 60 {PB_9, SPI_2, STM_PIN_DATA(2, 5)},
bogdanm 20:4263a77256ae 61 {PB_12, SPI_2, STM_PIN_DATA(2, 5)},
bogdanm 20:4263a77256ae 62 {NC, NC, 0}
bogdanm 20:4263a77256ae 63 };
bogdanm 20:4263a77256ae 64
bogdanm 20:4263a77256ae 65
bogdanm 20:4263a77256ae 66 static inline int ssp_disable(spi_t *obj);
bogdanm 20:4263a77256ae 67 static inline int ssp_enable(spi_t *obj);
bogdanm 20:4263a77256ae 68
bogdanm 20:4263a77256ae 69 void spi_init(spi_t *obj, PinName mosi, PinName miso, PinName sclk, PinName ssel) {
bogdanm 20:4263a77256ae 70 // determine the SPI to use
bogdanm 20:4263a77256ae 71 SPIName spi_mosi = (SPIName)pinmap_peripheral(mosi, PinMap_SPI_MOSI);
bogdanm 20:4263a77256ae 72 SPIName spi_miso = (SPIName)pinmap_peripheral(miso, PinMap_SPI_MISO);
bogdanm 20:4263a77256ae 73 SPIName spi_sclk = (SPIName)pinmap_peripheral(sclk, PinMap_SPI_SCLK);
bogdanm 20:4263a77256ae 74 SPIName spi_ssel = (SPIName)pinmap_peripheral(ssel, PinMap_SPI_SSEL);
bogdanm 20:4263a77256ae 75 SPIName spi_data = (SPIName)pinmap_merge(spi_mosi, spi_miso);
bogdanm 20:4263a77256ae 76 SPIName spi_cntl = (SPIName)pinmap_merge(spi_sclk, spi_ssel);
bogdanm 20:4263a77256ae 77 obj->spi = (SPI_TypeDef*)pinmap_merge(spi_data, spi_cntl);
mbed_official 271:ccdf646660f2 78 MBED_ASSERT((int)obj->spi != NC);
bogdanm 20:4263a77256ae 79
bogdanm 20:4263a77256ae 80 // enable power and clocking
bogdanm 20:4263a77256ae 81 switch ((int)obj->spi) {
bogdanm 20:4263a77256ae 82 case SPI_1:
bogdanm 20:4263a77256ae 83 RCC->AHB1ENR |= RCC_AHB1ENR_GPIOAEN | RCC_AHB1ENR_GPIOBEN;
bogdanm 20:4263a77256ae 84 RCC->APB2ENR |= RCC_APB2ENR_SPI1EN;
bogdanm 20:4263a77256ae 85 break;
bogdanm 20:4263a77256ae 86 case SPI_2:
bogdanm 20:4263a77256ae 87 RCC->AHB1ENR |= RCC_AHB1ENR_GPIOBEN | RCC_AHB1ENR_GPIOCEN;
bogdanm 20:4263a77256ae 88 RCC->APB1ENR |= RCC_APB1ENR_SPI2EN;
bogdanm 20:4263a77256ae 89 break;
bogdanm 20:4263a77256ae 90 case SPI_3:
bogdanm 20:4263a77256ae 91 RCC->AHB1ENR |= RCC_AHB1ENR_GPIOBEN | RCC_AHB1ENR_GPIOCEN;
bogdanm 20:4263a77256ae 92 RCC->APB1ENR |= RCC_APB1ENR_SPI3EN;
bogdanm 20:4263a77256ae 93 break;
bogdanm 20:4263a77256ae 94 }
bogdanm 20:4263a77256ae 95
bogdanm 20:4263a77256ae 96 // pin out the spi pins
bogdanm 20:4263a77256ae 97 pinmap_pinout(mosi, PinMap_SPI_MOSI);
bogdanm 20:4263a77256ae 98 pinmap_pinout(miso, PinMap_SPI_MISO);
bogdanm 20:4263a77256ae 99 pinmap_pinout(sclk, PinMap_SPI_SCLK);
bogdanm 20:4263a77256ae 100 if (ssel != NC) {
bogdanm 20:4263a77256ae 101 pinmap_pinout(ssel, PinMap_SPI_SSEL);
mbed_official 552:a1b9575155a3 102 } else {
bogdanm 20:4263a77256ae 103 // Use software slave management
bogdanm 20:4263a77256ae 104 obj->spi->CR1 |= SPI_CR1_SSM | SPI_CR1_SSI;
bogdanm 20:4263a77256ae 105 }
bogdanm 20:4263a77256ae 106 }
bogdanm 20:4263a77256ae 107
bogdanm 20:4263a77256ae 108 void spi_free(spi_t *obj) {}
bogdanm 20:4263a77256ae 109
bogdanm 20:4263a77256ae 110 void spi_format(spi_t *obj, int bits, int mode, int slave) {
mbed_official 227:7bd0639b8911 111 MBED_ASSERT(((bits == 8) || (bits == 16)) && ((mode >= 0) && (mode <= 3)));
bogdanm 20:4263a77256ae 112 ssp_disable(obj);
bogdanm 20:4263a77256ae 113
bogdanm 20:4263a77256ae 114 int polarity = (mode & 0x2) ? 1 : 0;
bogdanm 20:4263a77256ae 115 int phase = (mode & 0x1) ? 1 : 0;
bogdanm 20:4263a77256ae 116
bogdanm 20:4263a77256ae 117 obj->spi->CR1 &= ~0x807;
bogdanm 20:4263a77256ae 118 obj->spi->CR1 |= ((phase) ? 1 : 0) << 0 |
bogdanm 20:4263a77256ae 119 ((polarity) ? 1 : 0) << 1 |
bogdanm 20:4263a77256ae 120 ((slave) ? 0: 1) << 2 |
bogdanm 20:4263a77256ae 121 ((bits == 16) ? 1 : 0) << 11;
bogdanm 20:4263a77256ae 122
mbed_official 552:a1b9575155a3 123 if (slave) {
mbed_official 552:a1b9575155a3 124 // Use software slave management
mbed_official 552:a1b9575155a3 125 obj->spi->CR1 |= SPI_CR1_SSM | SPI_CR1_SSI;
mbed_official 552:a1b9575155a3 126 }
mbed_official 552:a1b9575155a3 127
bogdanm 20:4263a77256ae 128 if (obj->spi->SR & SPI_SR_MODF) {
bogdanm 20:4263a77256ae 129 obj->spi->CR1 = obj->spi->CR1;
bogdanm 20:4263a77256ae 130 }
bogdanm 20:4263a77256ae 131
bogdanm 20:4263a77256ae 132 ssp_enable(obj);
bogdanm 20:4263a77256ae 133 }
bogdanm 20:4263a77256ae 134
bogdanm 20:4263a77256ae 135 void spi_frequency(spi_t *obj, int hz) {
bogdanm 20:4263a77256ae 136 ssp_disable(obj);
bogdanm 20:4263a77256ae 137
bogdanm 20:4263a77256ae 138 // SPI1 runs from PCLK2, which runs at SystemCoreClock / 2. SPI2 and SPI3
bogdanm 20:4263a77256ae 139 // run from PCLK1, which runs at SystemCoreClock / 4.
bogdanm 20:4263a77256ae 140 uint32_t PCLK = SystemCoreClock;
bogdanm 20:4263a77256ae 141 switch ((int)obj->spi) {
bogdanm 20:4263a77256ae 142 case SPI_1: PCLK = PCLK >> 1; break;
bogdanm 20:4263a77256ae 143 case SPI_2: PCLK = PCLK >> 2; break;
bogdanm 20:4263a77256ae 144 case SPI_3: PCLK = PCLK >> 2; break;
bogdanm 20:4263a77256ae 145 }
bogdanm 20:4263a77256ae 146
bogdanm 20:4263a77256ae 147 // Choose the baud rate divisor (between 2 and 256)
bogdanm 20:4263a77256ae 148 uint32_t divisor = PCLK / hz;
bogdanm 20:4263a77256ae 149
bogdanm 20:4263a77256ae 150 // Find the nearest power-of-2
bogdanm 20:4263a77256ae 151 divisor = divisor > 0 ? divisor-1 : 0;
bogdanm 20:4263a77256ae 152 divisor |= divisor >> 1;
bogdanm 20:4263a77256ae 153 divisor |= divisor >> 2;
bogdanm 20:4263a77256ae 154 divisor |= divisor >> 4;
bogdanm 20:4263a77256ae 155 divisor |= divisor >> 8;
bogdanm 20:4263a77256ae 156 divisor |= divisor >> 16;
bogdanm 20:4263a77256ae 157 divisor++;
bogdanm 20:4263a77256ae 158
bogdanm 20:4263a77256ae 159 uint32_t baud_rate = __builtin_ffs(divisor) - 1;
bogdanm 20:4263a77256ae 160 baud_rate = baud_rate > 0x7 ? 0x7 : baud_rate;
bogdanm 20:4263a77256ae 161
bogdanm 20:4263a77256ae 162 obj->spi->CR1 &= ~(0x7 << 3);
bogdanm 20:4263a77256ae 163 obj->spi->CR1 |= baud_rate << 3;
bogdanm 20:4263a77256ae 164
bogdanm 20:4263a77256ae 165 ssp_enable(obj);
bogdanm 20:4263a77256ae 166 }
bogdanm 20:4263a77256ae 167
bogdanm 20:4263a77256ae 168 static inline int ssp_disable(spi_t *obj) {
bogdanm 20:4263a77256ae 169 // TODO: Follow the instructions in 25.3.8 for safely disabling the SPI
bogdanm 20:4263a77256ae 170 return obj->spi->CR1 &= ~SPI_CR1_SPE;
bogdanm 20:4263a77256ae 171 }
bogdanm 20:4263a77256ae 172
bogdanm 20:4263a77256ae 173 static inline int ssp_enable(spi_t *obj) {
bogdanm 20:4263a77256ae 174 return obj->spi->CR1 |= SPI_CR1_SPE;
bogdanm 20:4263a77256ae 175 }
bogdanm 20:4263a77256ae 176
bogdanm 20:4263a77256ae 177 static inline int ssp_readable(spi_t *obj) {
bogdanm 20:4263a77256ae 178 return obj->spi->SR & SPI_SR_RXNE;
bogdanm 20:4263a77256ae 179 }
bogdanm 20:4263a77256ae 180
bogdanm 20:4263a77256ae 181 static inline int ssp_writeable(spi_t *obj) {
bogdanm 20:4263a77256ae 182 return obj->spi->SR & SPI_SR_TXE;
bogdanm 20:4263a77256ae 183 }
bogdanm 20:4263a77256ae 184
bogdanm 20:4263a77256ae 185 static inline void ssp_write(spi_t *obj, int value) {
bogdanm 20:4263a77256ae 186 while (!ssp_writeable(obj));
bogdanm 20:4263a77256ae 187 obj->spi->DR = value;
bogdanm 20:4263a77256ae 188 }
bogdanm 20:4263a77256ae 189
bogdanm 20:4263a77256ae 190 static inline int ssp_read(spi_t *obj) {
bogdanm 20:4263a77256ae 191 while (!ssp_readable(obj));
bogdanm 20:4263a77256ae 192 return obj->spi->DR;
bogdanm 20:4263a77256ae 193 }
bogdanm 20:4263a77256ae 194
bogdanm 20:4263a77256ae 195 static inline int ssp_busy(spi_t *obj) {
bogdanm 20:4263a77256ae 196 return (obj->spi->SR & SPI_SR_BSY) ? (1) : (0);
bogdanm 20:4263a77256ae 197 }
bogdanm 20:4263a77256ae 198
bogdanm 20:4263a77256ae 199 int spi_master_write(spi_t *obj, int value) {
bogdanm 20:4263a77256ae 200 ssp_write(obj, value);
bogdanm 20:4263a77256ae 201 return ssp_read(obj);
bogdanm 20:4263a77256ae 202 }
bogdanm 20:4263a77256ae 203
bogdanm 20:4263a77256ae 204 int spi_slave_receive(spi_t *obj) {
bogdanm 20:4263a77256ae 205 return (ssp_readable(obj) && !ssp_busy(obj)) ? (1) : (0);
bogdanm 20:4263a77256ae 206 };
bogdanm 20:4263a77256ae 207
bogdanm 20:4263a77256ae 208 int spi_slave_read(spi_t *obj) {
bogdanm 20:4263a77256ae 209 return obj->spi->DR;
bogdanm 20:4263a77256ae 210 }
bogdanm 20:4263a77256ae 211
bogdanm 20:4263a77256ae 212 void spi_slave_write(spi_t *obj, int value) {
bogdanm 20:4263a77256ae 213 while (ssp_writeable(obj) == 0) ;
bogdanm 20:4263a77256ae 214 obj->spi->DR = value;
bogdanm 20:4263a77256ae 215 }
bogdanm 20:4263a77256ae 216
bogdanm 20:4263a77256ae 217 int spi_busy(spi_t *obj) {
bogdanm 20:4263a77256ae 218 return ssp_busy(obj);
bogdanm 20:4263a77256ae 219 }
bogdanm 20:4263a77256ae 220
bogdanm 20:4263a77256ae 221 #endif