teralytic / mbed-dev

mbed library sources. Supersedes mbed-src.

Fork of mbed by teralytic

targets/hal/TARGET_STM/TARGET_STM32F0/spi_api.c@148:4802eb17e82b, 2016-10-17 (annotated)

Committer:
rodriguise
Date:
Mon Oct 17 18:47:01 2016 +0000
Revision:
148:4802eb17e82b
Parent:
144:ef7eb2e8f9f7 
backup

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<> 144:ef7eb2e8f9f7 1 /* mbed Microcontroller Library
<> 144:ef7eb2e8f9f7 2 *******************************************************************************
<> 144:ef7eb2e8f9f7 3 * Copyright (c) 2015, STMicroelectronics
<> 144:ef7eb2e8f9f7 4 * All rights reserved.
<> 144:ef7eb2e8f9f7 5 *
<> 144:ef7eb2e8f9f7 6 * Redistribution and use in source and binary forms, with or without
<> 144:ef7eb2e8f9f7 7 * modification, are permitted provided that the following conditions are met:
<> 144:ef7eb2e8f9f7 8 *
<> 144:ef7eb2e8f9f7 9 * 1. Redistributions of source code must retain the above copyright notice,
<> 144:ef7eb2e8f9f7 10 * this list of conditions and the following disclaimer.
<> 144:ef7eb2e8f9f7 11 * 2. Redistributions in binary form must reproduce the above copyright notice,
<> 144:ef7eb2e8f9f7 12 * this list of conditions and the following disclaimer in the documentation
<> 144:ef7eb2e8f9f7 13 * and/or other materials provided with the distribution.
<> 144:ef7eb2e8f9f7 14 * 3. Neither the name of STMicroelectronics nor the names of its contributors
<> 144:ef7eb2e8f9f7 15 * may be used to endorse or promote products derived from this software
<> 144:ef7eb2e8f9f7 16 * without specific prior written permission.
<> 144:ef7eb2e8f9f7 17 *
<> 144:ef7eb2e8f9f7 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
<> 144:ef7eb2e8f9f7 19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
<> 144:ef7eb2e8f9f7 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
<> 144:ef7eb2e8f9f7 21 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
<> 144:ef7eb2e8f9f7 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
<> 144:ef7eb2e8f9f7 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
<> 144:ef7eb2e8f9f7 24 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
<> 144:ef7eb2e8f9f7 25 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
<> 144:ef7eb2e8f9f7 26 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
<> 144:ef7eb2e8f9f7 27 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
<> 144:ef7eb2e8f9f7 28 *******************************************************************************
<> 144:ef7eb2e8f9f7 29 */
<> 144:ef7eb2e8f9f7 30 #include "mbed_assert.h"
<> 144:ef7eb2e8f9f7 31 #include "mbed_error.h"
<> 144:ef7eb2e8f9f7 32 #include "spi_api.h"
<> 144:ef7eb2e8f9f7 33
<> 144:ef7eb2e8f9f7 34 #if DEVICE_SPI
<> 144:ef7eb2e8f9f7 35
<> 144:ef7eb2e8f9f7 36 #include <math.h>
<> 144:ef7eb2e8f9f7 37 #include "cmsis.h"
<> 144:ef7eb2e8f9f7 38 #include "pinmap.h"
<> 144:ef7eb2e8f9f7 39 #include "PeripheralPins.h"
<> 144:ef7eb2e8f9f7 40
<> 144:ef7eb2e8f9f7 41 static SPI_HandleTypeDef SpiHandle;
<> 144:ef7eb2e8f9f7 42
<> 144:ef7eb2e8f9f7 43 static void init_spi(spi_t *obj) {
<> 144:ef7eb2e8f9f7 44 SpiHandle.Instance = (SPI_TypeDef *)(obj->spi);
<> 144:ef7eb2e8f9f7 45
<> 144:ef7eb2e8f9f7 46 __HAL_SPI_DISABLE(&SpiHandle);
<> 144:ef7eb2e8f9f7 47
<> 144:ef7eb2e8f9f7 48 SpiHandle.Init.Mode = obj->mode;
<> 144:ef7eb2e8f9f7 49 SpiHandle.Init.BaudRatePrescaler = obj->br_presc;
<> 144:ef7eb2e8f9f7 50 SpiHandle.Init.Direction = SPI_DIRECTION_2LINES;
<> 144:ef7eb2e8f9f7 51 SpiHandle.Init.CLKPhase = obj->cpha;
<> 144:ef7eb2e8f9f7 52 SpiHandle.Init.CLKPolarity = obj->cpol;
<> 144:ef7eb2e8f9f7 53 SpiHandle.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLED;
<> 144:ef7eb2e8f9f7 54 SpiHandle.Init.CRCPolynomial = 7;
<> 144:ef7eb2e8f9f7 55 SpiHandle.Init.DataSize = obj->bits;
<> 144:ef7eb2e8f9f7 56 SpiHandle.Init.FirstBit = SPI_FIRSTBIT_MSB;
<> 144:ef7eb2e8f9f7 57 SpiHandle.Init.NSS = obj->nss;
<> 144:ef7eb2e8f9f7 58 SpiHandle.Init.TIMode = SPI_TIMODE_DISABLED;
<> 144:ef7eb2e8f9f7 59
<> 144:ef7eb2e8f9f7 60 HAL_SPI_Init(&SpiHandle);
<> 144:ef7eb2e8f9f7 61
<> 144:ef7eb2e8f9f7 62 __HAL_SPI_ENABLE(&SpiHandle);
<> 144:ef7eb2e8f9f7 63 }
<> 144:ef7eb2e8f9f7 64
<> 144:ef7eb2e8f9f7 65 void spi_init(spi_t *obj, PinName mosi, PinName miso, PinName sclk, PinName ssel) {
<> 144:ef7eb2e8f9f7 66 // Determine the SPI to use
<> 144:ef7eb2e8f9f7 67 SPIName spi_mosi = (SPIName)pinmap_peripheral(mosi, PinMap_SPI_MOSI);
<> 144:ef7eb2e8f9f7 68 SPIName spi_miso = (SPIName)pinmap_peripheral(miso, PinMap_SPI_MISO);
<> 144:ef7eb2e8f9f7 69 SPIName spi_sclk = (SPIName)pinmap_peripheral(sclk, PinMap_SPI_SCLK);
<> 144:ef7eb2e8f9f7 70 SPIName spi_ssel = (SPIName)pinmap_peripheral(ssel, PinMap_SPI_SSEL);
<> 144:ef7eb2e8f9f7 71
<> 144:ef7eb2e8f9f7 72 SPIName spi_data = (SPIName)pinmap_merge(spi_mosi, spi_miso);
<> 144:ef7eb2e8f9f7 73 SPIName spi_cntl = (SPIName)pinmap_merge(spi_sclk, spi_ssel);
<> 144:ef7eb2e8f9f7 74
<> 144:ef7eb2e8f9f7 75 obj->spi = (SPIName)pinmap_merge(spi_data, spi_cntl);
<> 144:ef7eb2e8f9f7 76 MBED_ASSERT(obj->spi != (SPIName)NC);
<> 144:ef7eb2e8f9f7 77
<> 144:ef7eb2e8f9f7 78 // Enable SPI clock
<> 144:ef7eb2e8f9f7 79 if (obj->spi == SPI_1) {
<> 144:ef7eb2e8f9f7 80 __SPI1_CLK_ENABLE();
<> 144:ef7eb2e8f9f7 81 }
<> 144:ef7eb2e8f9f7 82 #if defined(SPI2_BASE)
<> 144:ef7eb2e8f9f7 83 if (obj->spi == SPI_2) {
<> 144:ef7eb2e8f9f7 84 __SPI2_CLK_ENABLE();
<> 144:ef7eb2e8f9f7 85 }
<> 144:ef7eb2e8f9f7 86 #endif
<> 144:ef7eb2e8f9f7 87
<> 144:ef7eb2e8f9f7 88 // Configure the SPI pins
<> 144:ef7eb2e8f9f7 89 pinmap_pinout(mosi, PinMap_SPI_MOSI);
<> 144:ef7eb2e8f9f7 90 pinmap_pinout(miso, PinMap_SPI_MISO);
<> 144:ef7eb2e8f9f7 91 pinmap_pinout(sclk, PinMap_SPI_SCLK);
<> 144:ef7eb2e8f9f7 92
<> 144:ef7eb2e8f9f7 93 // Save new values
<> 144:ef7eb2e8f9f7 94 obj->bits = SPI_DATASIZE_8BIT;
<> 144:ef7eb2e8f9f7 95 obj->cpol = SPI_POLARITY_LOW;
<> 144:ef7eb2e8f9f7 96 obj->cpha = SPI_PHASE_1EDGE;
<> 144:ef7eb2e8f9f7 97 obj->br_presc = SPI_BAUDRATEPRESCALER_256;
<> 144:ef7eb2e8f9f7 98
<> 144:ef7eb2e8f9f7 99 obj->pin_miso = miso;
<> 144:ef7eb2e8f9f7 100 obj->pin_mosi = mosi;
<> 144:ef7eb2e8f9f7 101 obj->pin_sclk = sclk;
<> 144:ef7eb2e8f9f7 102 obj->pin_ssel = ssel;
<> 144:ef7eb2e8f9f7 103
<> 144:ef7eb2e8f9f7 104 if (ssel != NC) {
<> 144:ef7eb2e8f9f7 105 pinmap_pinout(ssel, PinMap_SPI_SSEL);
<> 144:ef7eb2e8f9f7 106 } else {
<> 144:ef7eb2e8f9f7 107 obj->nss = SPI_NSS_SOFT;
<> 144:ef7eb2e8f9f7 108 }
<> 144:ef7eb2e8f9f7 109
<> 144:ef7eb2e8f9f7 110 init_spi(obj);
<> 144:ef7eb2e8f9f7 111 }
<> 144:ef7eb2e8f9f7 112
<> 144:ef7eb2e8f9f7 113 void spi_free(spi_t *obj) {
<> 144:ef7eb2e8f9f7 114 // Reset SPI and disable clock
<> 144:ef7eb2e8f9f7 115 if (obj->spi == SPI_1) {
<> 144:ef7eb2e8f9f7 116 __SPI1_FORCE_RESET();
<> 144:ef7eb2e8f9f7 117 __SPI1_RELEASE_RESET();
<> 144:ef7eb2e8f9f7 118 __SPI1_CLK_DISABLE();
<> 144:ef7eb2e8f9f7 119 }
<> 144:ef7eb2e8f9f7 120
<> 144:ef7eb2e8f9f7 121 #if defined(SPI2_BASE)
<> 144:ef7eb2e8f9f7 122 if (obj->spi == SPI_2) {
<> 144:ef7eb2e8f9f7 123 __SPI2_FORCE_RESET();
<> 144:ef7eb2e8f9f7 124 __SPI2_RELEASE_RESET();
<> 144:ef7eb2e8f9f7 125 __SPI2_CLK_DISABLE();
<> 144:ef7eb2e8f9f7 126 }
<> 144:ef7eb2e8f9f7 127 #endif
<> 144:ef7eb2e8f9f7 128
<> 144:ef7eb2e8f9f7 129 // Configure GPIOs
<> 144:ef7eb2e8f9f7 130 pin_function(obj->pin_miso, STM_PIN_DATA(STM_MODE_INPUT, GPIO_NOPULL, 0));
<> 144:ef7eb2e8f9f7 131 pin_function(obj->pin_mosi, STM_PIN_DATA(STM_MODE_INPUT, GPIO_NOPULL, 0));
<> 144:ef7eb2e8f9f7 132 pin_function(obj->pin_sclk, STM_PIN_DATA(STM_MODE_INPUT, GPIO_NOPULL, 0));
<> 144:ef7eb2e8f9f7 133 pin_function(obj->pin_ssel, STM_PIN_DATA(STM_MODE_INPUT, GPIO_NOPULL, 0));
<> 144:ef7eb2e8f9f7 134 }
<> 144:ef7eb2e8f9f7 135
<> 144:ef7eb2e8f9f7 136 void spi_format(spi_t *obj, int bits, int mode, int slave) {
<> 144:ef7eb2e8f9f7 137 // Save new values
<> 144:ef7eb2e8f9f7 138 if (bits == 16) {
<> 144:ef7eb2e8f9f7 139 obj->bits = SPI_DATASIZE_16BIT;
<> 144:ef7eb2e8f9f7 140 } else {
<> 144:ef7eb2e8f9f7 141 obj->bits = SPI_DATASIZE_8BIT;
<> 144:ef7eb2e8f9f7 142 }
<> 144:ef7eb2e8f9f7 143
<> 144:ef7eb2e8f9f7 144 switch (mode) {
<> 144:ef7eb2e8f9f7 145 case 0:
<> 144:ef7eb2e8f9f7 146 obj->cpol = SPI_POLARITY_LOW;
<> 144:ef7eb2e8f9f7 147 obj->cpha = SPI_PHASE_1EDGE;
<> 144:ef7eb2e8f9f7 148 break;
<> 144:ef7eb2e8f9f7 149 case 1:
<> 144:ef7eb2e8f9f7 150 obj->cpol = SPI_POLARITY_LOW;
<> 144:ef7eb2e8f9f7 151 obj->cpha = SPI_PHASE_2EDGE;
<> 144:ef7eb2e8f9f7 152 break;
<> 144:ef7eb2e8f9f7 153 case 2:
<> 144:ef7eb2e8f9f7 154 obj->cpol = SPI_POLARITY_HIGH;
<> 144:ef7eb2e8f9f7 155 obj->cpha = SPI_PHASE_1EDGE;
<> 144:ef7eb2e8f9f7 156 break;
<> 144:ef7eb2e8f9f7 157 default:
<> 144:ef7eb2e8f9f7 158 obj->cpol = SPI_POLARITY_HIGH;
<> 144:ef7eb2e8f9f7 159 obj->cpha = SPI_PHASE_2EDGE;
<> 144:ef7eb2e8f9f7 160 break;
<> 144:ef7eb2e8f9f7 161 }
<> 144:ef7eb2e8f9f7 162
<> 144:ef7eb2e8f9f7 163 if (obj->nss != SPI_NSS_SOFT) {
<> 144:ef7eb2e8f9f7 164 obj->nss = (slave) ? SPI_NSS_HARD_INPUT : SPI_NSS_HARD_OUTPUT;
<> 144:ef7eb2e8f9f7 165 }
<> 144:ef7eb2e8f9f7 166
<> 144:ef7eb2e8f9f7 167 obj->mode = (slave) ? SPI_MODE_SLAVE : SPI_MODE_MASTER;
<> 144:ef7eb2e8f9f7 168
<> 144:ef7eb2e8f9f7 169 init_spi(obj);
<> 144:ef7eb2e8f9f7 170 }
<> 144:ef7eb2e8f9f7 171
<> 144:ef7eb2e8f9f7 172 static const uint16_t baudrate_prescaler_table[] = {SPI_BAUDRATEPRESCALER_2,
<> 144:ef7eb2e8f9f7 173 SPI_BAUDRATEPRESCALER_4,
<> 144:ef7eb2e8f9f7 174 SPI_BAUDRATEPRESCALER_8,
<> 144:ef7eb2e8f9f7 175 SPI_BAUDRATEPRESCALER_16,
<> 144:ef7eb2e8f9f7 176 SPI_BAUDRATEPRESCALER_32,
<> 144:ef7eb2e8f9f7 177 SPI_BAUDRATEPRESCALER_64,
<> 144:ef7eb2e8f9f7 178 SPI_BAUDRATEPRESCALER_128,
<> 144:ef7eb2e8f9f7 179 SPI_BAUDRATEPRESCALER_256};
<> 144:ef7eb2e8f9f7 180
<> 144:ef7eb2e8f9f7 181 void spi_frequency(spi_t *obj, int hz) {
<> 144:ef7eb2e8f9f7 182 int spi_hz = 0;
<> 144:ef7eb2e8f9f7 183 uint8_t prescaler_rank = 0;
<> 144:ef7eb2e8f9f7 184
<> 144:ef7eb2e8f9f7 185 /* SPI_1, SPI_2. Source CLK is PCKL1 */
<> 144:ef7eb2e8f9f7 186 spi_hz = HAL_RCC_GetPCLK1Freq();
<> 144:ef7eb2e8f9f7 187
<> 144:ef7eb2e8f9f7 188 /* Define pre-scaler in order to get highest available frequency below requested frequency */
<> 144:ef7eb2e8f9f7 189 while ((spi_hz > hz) && (prescaler_rank < sizeof(baudrate_prescaler_table)/sizeof(baudrate_prescaler_table[0]))){
<> 144:ef7eb2e8f9f7 190 spi_hz = spi_hz / 2;
<> 144:ef7eb2e8f9f7 191 prescaler_rank++;
<> 144:ef7eb2e8f9f7 192 }
<> 144:ef7eb2e8f9f7 193
<> 144:ef7eb2e8f9f7 194 if (prescaler_rank <= sizeof(baudrate_prescaler_table)/sizeof(baudrate_prescaler_table[0])) {
<> 144:ef7eb2e8f9f7 195 obj->br_presc = baudrate_prescaler_table[prescaler_rank-1];
<> 144:ef7eb2e8f9f7 196 } else {
<> 144:ef7eb2e8f9f7 197 error("Couldn't setup requested SPI frequency");
<> 144:ef7eb2e8f9f7 198 }
<> 144:ef7eb2e8f9f7 199
<> 144:ef7eb2e8f9f7 200 init_spi(obj);
<> 144:ef7eb2e8f9f7 201 }
<> 144:ef7eb2e8f9f7 202
<> 144:ef7eb2e8f9f7 203 static inline int ssp_readable(spi_t *obj) {
<> 144:ef7eb2e8f9f7 204 int status;
<> 144:ef7eb2e8f9f7 205 SpiHandle.Instance = (SPI_TypeDef *)(obj->spi);
<> 144:ef7eb2e8f9f7 206 // Check if data is received
<> 144:ef7eb2e8f9f7 207 status = ((__HAL_SPI_GET_FLAG(&SpiHandle, SPI_FLAG_RXNE) != RESET) ? 1 : 0);
<> 144:ef7eb2e8f9f7 208 return status;
<> 144:ef7eb2e8f9f7 209 }
<> 144:ef7eb2e8f9f7 210
<> 144:ef7eb2e8f9f7 211 static inline int ssp_writeable(spi_t *obj) {
<> 144:ef7eb2e8f9f7 212 int status;
<> 144:ef7eb2e8f9f7 213 SpiHandle.Instance = (SPI_TypeDef *)(obj->spi);
<> 144:ef7eb2e8f9f7 214 // Check if data is transmitted
<> 144:ef7eb2e8f9f7 215 status = ((__HAL_SPI_GET_FLAG(&SpiHandle, SPI_FLAG_TXE) != RESET) ? 1 : 0);
<> 144:ef7eb2e8f9f7 216 return status;
<> 144:ef7eb2e8f9f7 217 }
<> 144:ef7eb2e8f9f7 218
<> 144:ef7eb2e8f9f7 219 static inline void ssp_write(spi_t *obj, int value) {
<> 144:ef7eb2e8f9f7 220 SPI_TypeDef *spi = (SPI_TypeDef *)(obj->spi);
<> 144:ef7eb2e8f9f7 221 while (!ssp_writeable(obj));
<> 144:ef7eb2e8f9f7 222 if (obj->bits == SPI_DATASIZE_8BIT) {
<> 144:ef7eb2e8f9f7 223 // Force 8-bit access to the data register
<> 144:ef7eb2e8f9f7 224 uint8_t *p_spi_dr = 0;
<> 144:ef7eb2e8f9f7 225 p_spi_dr = (uint8_t *) & (spi->DR);
<> 144:ef7eb2e8f9f7 226 *p_spi_dr = (uint8_t)value;
<> 144:ef7eb2e8f9f7 227 } else { // SPI_DATASIZE_16BIT
<> 144:ef7eb2e8f9f7 228 spi->DR = (uint16_t)value;
<> 144:ef7eb2e8f9f7 229 }
<> 144:ef7eb2e8f9f7 230 }
<> 144:ef7eb2e8f9f7 231
<> 144:ef7eb2e8f9f7 232 static inline int ssp_read(spi_t *obj) {
<> 144:ef7eb2e8f9f7 233 SPI_TypeDef *spi = (SPI_TypeDef *)(obj->spi);
<> 144:ef7eb2e8f9f7 234 while (!ssp_readable(obj));
<> 144:ef7eb2e8f9f7 235 if (obj->bits == SPI_DATASIZE_8BIT) {
<> 144:ef7eb2e8f9f7 236 // Force 8-bit access to the data register
<> 144:ef7eb2e8f9f7 237 uint8_t *p_spi_dr = 0;
<> 144:ef7eb2e8f9f7 238 p_spi_dr = (uint8_t *) & (spi->DR);
<> 144:ef7eb2e8f9f7 239 return (int)(*p_spi_dr);
<> 144:ef7eb2e8f9f7 240 } else {
<> 144:ef7eb2e8f9f7 241 return (int)spi->DR;
<> 144:ef7eb2e8f9f7 242 }
<> 144:ef7eb2e8f9f7 243 }
<> 144:ef7eb2e8f9f7 244
<> 144:ef7eb2e8f9f7 245 static inline int ssp_busy(spi_t *obj) {
<> 144:ef7eb2e8f9f7 246 int status;
<> 144:ef7eb2e8f9f7 247 SpiHandle.Instance = (SPI_TypeDef *)(obj->spi);
<> 144:ef7eb2e8f9f7 248 status = ((__HAL_SPI_GET_FLAG(&SpiHandle, SPI_FLAG_BSY) != RESET) ? 1 : 0);
<> 144:ef7eb2e8f9f7 249 return status;
<> 144:ef7eb2e8f9f7 250 }
<> 144:ef7eb2e8f9f7 251
<> 144:ef7eb2e8f9f7 252 int spi_master_write(spi_t *obj, int value) {
<> 144:ef7eb2e8f9f7 253 ssp_write(obj, value);
<> 144:ef7eb2e8f9f7 254 return ssp_read(obj);
<> 144:ef7eb2e8f9f7 255 }
<> 144:ef7eb2e8f9f7 256
<> 144:ef7eb2e8f9f7 257 int spi_slave_receive(spi_t *obj) {
<> 144:ef7eb2e8f9f7 258 return ((ssp_readable(obj) && !ssp_busy(obj)) ? 1 : 0);
<> 144:ef7eb2e8f9f7 259 };
<> 144:ef7eb2e8f9f7 260
<> 144:ef7eb2e8f9f7 261 int spi_slave_read(spi_t *obj) {
<> 144:ef7eb2e8f9f7 262 SPI_TypeDef *spi = (SPI_TypeDef *)(obj->spi);
<> 144:ef7eb2e8f9f7 263 while (!ssp_readable(obj));
<> 144:ef7eb2e8f9f7 264 if (obj->bits == SPI_DATASIZE_8BIT) {
<> 144:ef7eb2e8f9f7 265 // Force 8-bit access to the data register
<> 144:ef7eb2e8f9f7 266 uint8_t *p_spi_dr = 0;
<> 144:ef7eb2e8f9f7 267 p_spi_dr = (uint8_t *) & (spi->DR);
<> 144:ef7eb2e8f9f7 268 return (int)(*p_spi_dr);
<> 144:ef7eb2e8f9f7 269 } else {
<> 144:ef7eb2e8f9f7 270 return (int)spi->DR;
<> 144:ef7eb2e8f9f7 271 }
<> 144:ef7eb2e8f9f7 272 }
<> 144:ef7eb2e8f9f7 273
<> 144:ef7eb2e8f9f7 274 void spi_slave_write(spi_t *obj, int value) {
<> 144:ef7eb2e8f9f7 275 SPI_TypeDef *spi = (SPI_TypeDef *)(obj->spi);
<> 144:ef7eb2e8f9f7 276 while (!ssp_writeable(obj));
<> 144:ef7eb2e8f9f7 277 if (obj->bits == SPI_DATASIZE_8BIT) {
<> 144:ef7eb2e8f9f7 278 // Force 8-bit access to the data register
<> 144:ef7eb2e8f9f7 279 uint8_t *p_spi_dr = 0;
<> 144:ef7eb2e8f9f7 280 p_spi_dr = (uint8_t *) & (spi->DR);
<> 144:ef7eb2e8f9f7 281 *p_spi_dr = (uint8_t)value;
<> 144:ef7eb2e8f9f7 282 } else { // SPI_DATASIZE_16BIT
<> 144:ef7eb2e8f9f7 283 spi->DR = (uint16_t)value;
<> 144:ef7eb2e8f9f7 284 }
<> 144:ef7eb2e8f9f7 285 }
<> 144:ef7eb2e8f9f7 286
<> 144:ef7eb2e8f9f7 287 int spi_busy(spi_t *obj) {
<> 144:ef7eb2e8f9f7 288 return ssp_busy(obj);
<> 144:ef7eb2e8f9f7 289 }
<> 144:ef7eb2e8f9f7 290
<> 144:ef7eb2e8f9f7 291 #endif