tool/mbed/mbed-sdk/libraries/mbed/targets/hal/TARGET_STM/TARGET_STM32L1/spi_api.c

   1 /* mbed Microcontroller Library
   2  *******************************************************************************
   3  * Copyright (c) 2014, STMicroelectronics
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions are met:
   8  *
   9  * 1. Redistributions of source code must retain the above copyright notice,
  10  *    this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright notice,
  12  *    this list of conditions and the following disclaimer in the documentation
  13  *    and/or other materials provided with the distribution.
  14  * 3. Neither the name of STMicroelectronics nor the names of its contributors
  15  *    may be used to endorse or promote products derived from this software
  16  *    without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  19  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  21  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
  22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  24  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  25  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  26  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  27  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28  *******************************************************************************
  29  */
  30 #include "mbed_assert.h"
  31 #include "spi_api.h"
  32
  33 #if DEVICE_SPI
  34
  35 #include <math.h>
  36 #include "cmsis.h"
  37 #include "pinmap.h"
  38 #include "PeripheralPins.h"
  39
  40 static SPI_HandleTypeDef SpiHandle;
  41
  42 static void init_spi(spi_t *obj)
  43 {
  44     SpiHandle.Instance = (SPI_TypeDef *)(obj->spi);
  45
  46     __HAL_SPI_DISABLE(&SpiHandle);
  47
  48     SpiHandle.Init.Mode              = obj->mode;
  49     SpiHandle.Init.BaudRatePrescaler = obj->br_presc;
  50     SpiHandle.Init.Direction         = SPI_DIRECTION_2LINES;
  51     SpiHandle.Init.CLKPhase          = obj->cpha;
  52     SpiHandle.Init.CLKPolarity       = obj->cpol;
  53     SpiHandle.Init.CRCCalculation    = SPI_CRCCALCULATION_DISABLED;
  54     SpiHandle.Init.CRCPolynomial     = 7;
  55     SpiHandle.Init.DataSize          = obj->bits;
  56     SpiHandle.Init.FirstBit          = SPI_FIRSTBIT_MSB;
  57     SpiHandle.Init.NSS               = obj->nss;
  58     SpiHandle.Init.TIMode            = SPI_TIMODE_DISABLED;
  59
  60     HAL_SPI_Init(&SpiHandle);
  61
  62     __HAL_SPI_ENABLE(&SpiHandle);
  63 }
  64
  65 void spi_init(spi_t *obj, PinName mosi, PinName miso, PinName sclk, PinName ssel)
  66 {
  67     // Determine the SPI to use
  68     SPIName spi_mosi = (SPIName)pinmap_peripheral(mosi, PinMap_SPI_MOSI);
  69     SPIName spi_miso = (SPIName)pinmap_peripheral(miso, PinMap_SPI_MISO);
  70     SPIName spi_sclk = (SPIName)pinmap_peripheral(sclk, PinMap_SPI_SCLK);
  71     SPIName spi_ssel = (SPIName)pinmap_peripheral(ssel, PinMap_SPI_SSEL);
  72
  73     SPIName spi_data = (SPIName)pinmap_merge(spi_mosi, spi_miso);
  74     SPIName spi_cntl = (SPIName)pinmap_merge(spi_sclk, spi_ssel);
  75
  76     obj->spi = (SPIName)pinmap_merge(spi_data, spi_cntl);
  77     MBED_ASSERT(obj->spi != (SPIName)NC);
  78
  79     // Enable SPI clock
  80     if (obj->spi == SPI_1) {
  81         __SPI1_CLK_ENABLE();
  82     }
  83     if (obj->spi == SPI_2) {
  84         __SPI2_CLK_ENABLE();
  85     }
  86     if (obj->spi == SPI_3) {
  87         __SPI3_CLK_ENABLE();
  88     }
  89
  90     // Configure the SPI pins
  91     pinmap_pinout(mosi, PinMap_SPI_MOSI);
  92     pinmap_pinout(miso, PinMap_SPI_MISO);
  93     pinmap_pinout(sclk, PinMap_SPI_SCLK);
  94
  95     // Save new values
  96     obj->bits = SPI_DATASIZE_8BIT;
  97     obj->cpol = SPI_POLARITY_LOW;
  98     obj->cpha = SPI_PHASE_1EDGE;
  99     obj->br_presc = SPI_BAUDRATEPRESCALER_256;
 100
 101     obj->pin_miso = miso;
 102     obj->pin_mosi = mosi;
 103     obj->pin_sclk = sclk;
 104     obj->pin_ssel = ssel;
 105
 106     if (ssel == NC) { // SW NSS Master mode
 107         obj->mode = SPI_MODE_MASTER;
 108         obj->nss = SPI_NSS_SOFT;
 109     } else { // Slave
 110         pinmap_pinout(ssel, PinMap_SPI_SSEL);
 111         obj->mode = SPI_MODE_SLAVE;
 112         obj->nss = SPI_NSS_HARD_INPUT;
 113     }
 114
 115     init_spi(obj);
 116 }
 117
 118 void spi_free(spi_t *obj)
 119 {
 120     // Reset SPI and disable clock
 121     if (obj->spi == SPI_1) {
 122         __SPI1_FORCE_RESET();
 123         __SPI1_RELEASE_RESET();
 124         __SPI1_CLK_DISABLE();
 125     }
 126
 127     if (obj->spi == SPI_2) {
 128         __SPI2_FORCE_RESET();
 129         __SPI2_RELEASE_RESET();
 130         __SPI2_CLK_DISABLE();
 131     }
 132
 133     if (obj->spi == SPI_3) {
 134         __SPI3_FORCE_RESET();
 135         __SPI3_RELEASE_RESET();
 136         __SPI3_CLK_DISABLE();
 137     }
 138
 139     // Configure GPIO
 140     pin_function(obj->pin_miso, STM_PIN_DATA(STM_MODE_INPUT, GPIO_NOPULL, 0));
 141     pin_function(obj->pin_mosi, STM_PIN_DATA(STM_MODE_INPUT, GPIO_NOPULL, 0));
 142     pin_function(obj->pin_sclk, STM_PIN_DATA(STM_MODE_INPUT, GPIO_NOPULL, 0));
 143     pin_function(obj->pin_ssel, STM_PIN_DATA(STM_MODE_INPUT, GPIO_NOPULL, 0));
 144 }
 145
 146 void spi_format(spi_t *obj, int bits, int mode, int slave)
 147 {
 148     // Save new values
 149     if (bits == 16) {
 150         obj->bits = SPI_DATASIZE_16BIT;
 151     } else {
 152         obj->bits = SPI_DATASIZE_8BIT;
 153     }
 154
 155     switch (mode) {
 156         case 0:
 157             obj->cpol = SPI_POLARITY_LOW;
 158             obj->cpha = SPI_PHASE_1EDGE;
 159             break;
 160         case 1:
 161             obj->cpol = SPI_POLARITY_LOW;
 162             obj->cpha = SPI_PHASE_2EDGE;
 163             break;
 164         case 2:
 165             obj->cpol = SPI_POLARITY_HIGH;
 166             obj->cpha = SPI_PHASE_1EDGE;
 167             break;
 168         default:
 169             obj->cpol = SPI_POLARITY_HIGH;
 170             obj->cpha = SPI_PHASE_2EDGE;
 171             break;
 172     }
 173
 174     if (slave == 0) {
 175         obj->mode = SPI_MODE_MASTER;
 176         obj->nss = SPI_NSS_SOFT;
 177     } else {
 178         obj->mode = SPI_MODE_SLAVE;
 179         obj->nss = SPI_NSS_HARD_INPUT;
 180     }
 181
 182     init_spi(obj);
 183 }
 184
 185 void spi_frequency(spi_t *obj, int hz)
 186 {
 187     // Values depend of PCLK1 and PCLK2: 32 MHz if HSI is used, 24 MHz if HSE is used
 188     if (SystemCoreClock == 32000000) { // HSI
 189         if (hz < 250000) {
 190             obj->br_presc = SPI_BAUDRATEPRESCALER_256; // 125 kHz
 191         } else if ((hz >= 250000) && (hz < 500000)) {
 192             obj->br_presc = SPI_BAUDRATEPRESCALER_128; // 250 kHz
 193         } else if ((hz >= 500000) && (hz < 1000000)) {
 194             obj->br_presc = SPI_BAUDRATEPRESCALER_64; // 500 kHz
 195         } else if ((hz >= 1000000) && (hz < 2000000)) {
 196             obj->br_presc = SPI_BAUDRATEPRESCALER_32; // 1 MHz
 197         } else if ((hz >= 2000000) && (hz < 4000000)) {
 198             obj->br_presc = SPI_BAUDRATEPRESCALER_16; // 2 MHz
 199         } else if ((hz >= 4000000) && (hz < 8000000)) {
 200             obj->br_presc = SPI_BAUDRATEPRESCALER_8; // 4 MHz
 201         } else if ((hz >= 8000000) && (hz < 16000000)) {
 202             obj->br_presc = SPI_BAUDRATEPRESCALER_4; // 8 MHz
 203         } else { // >= 16000000
 204             obj->br_presc = SPI_BAUDRATEPRESCALER_2; // 16 MHz
 205         }
 206     } else { // 24 MHz - HSE
 207         if (hz < 180000) {
 208             obj->br_presc = SPI_BAUDRATEPRESCALER_256; // 94 kHz
 209         } else if ((hz >= 180000) && (hz < 350000)) {
 210             obj->br_presc = SPI_BAUDRATEPRESCALER_128; // 188 kHz
 211         } else if ((hz >= 350000) && (hz < 750000)) {
 212             obj->br_presc = SPI_BAUDRATEPRESCALER_64; // 375 kHz
 213         } else if ((hz >= 750000) && (hz < 1000000)) {
 214             obj->br_presc = SPI_BAUDRATEPRESCALER_32; // 750 kHz
 215         } else if ((hz >= 1000000) && (hz < 3000000)) {
 216             obj->br_presc = SPI_BAUDRATEPRESCALER_16; // 1.5 MHz
 217         } else if ((hz >= 3000000) && (hz < 6000000)) {
 218             obj->br_presc = SPI_BAUDRATEPRESCALER_8; // 3 MHz
 219         } else if ((hz >= 6000000) && (hz < 12000000)) {
 220             obj->br_presc = SPI_BAUDRATEPRESCALER_4; // 6 MHz
 221         } else { // >= 12000000
 222             obj->br_presc = SPI_BAUDRATEPRESCALER_2; // 12 MHz
 223         }
 224     }
 225     init_spi(obj);
 226 }
 227
 228 static inline int ssp_readable(spi_t *obj)
 229 {
 230     int status;
 231     SpiHandle.Instance = (SPI_TypeDef *)(obj->spi);
 232     // Check if data is received
 233     status = ((__HAL_SPI_GET_FLAG(&SpiHandle, SPI_FLAG_RXNE) != RESET) ? 1 : 0);
 234     return status;
 235 }
 236
 237 static inline int ssp_writeable(spi_t *obj)
 238 {
 239     int status;
 240     SpiHandle.Instance = (SPI_TypeDef *)(obj->spi);
 241     // Check if data is transmitted
 242     status = ((__HAL_SPI_GET_FLAG(&SpiHandle, SPI_FLAG_TXE) != RESET) ? 1 : 0);
 243     return status;
 244 }
 245
 246 static inline void ssp_write(spi_t *obj, int value)
 247 {
 248     SPI_TypeDef *spi = (SPI_TypeDef *)(obj->spi);
 249     while (!ssp_writeable(obj));
 250     spi->DR = (uint16_t)value;
 251 }
 252
 253 static inline int ssp_read(spi_t *obj)
 254 {
 255     SPI_TypeDef *spi = (SPI_TypeDef *)(obj->spi);
 256     while (!ssp_readable(obj));
 257     return (int)spi->DR;
 258 }
 259
 260 static inline int ssp_busy(spi_t *obj)
 261 {
 262     int status;
 263     SpiHandle.Instance = (SPI_TypeDef *)(obj->spi);
 264     status = ((__HAL_SPI_GET_FLAG(&SpiHandle, SPI_FLAG_BSY) != RESET) ? 1 : 0);
 265     return status;
 266 }
 267
 268 int spi_master_write(spi_t *obj, int value)
 269 {
 270     ssp_write(obj, value);
 271     return ssp_read(obj);
 272 }
 273
 274 int spi_slave_receive(spi_t *obj)
 275 {
 276     return (ssp_readable(obj) ? 1 : 0);
 277 };
 278
 279 int spi_slave_read(spi_t *obj)
 280 {
 281     SPI_TypeDef *spi = (SPI_TypeDef *)(obj->spi);
 282     while (!ssp_readable(obj));
 283     return (int)spi->DR;
 284 }
 285
 286 void spi_slave_write(spi_t *obj, int value)
 287 {
 288     SPI_TypeDef *spi = (SPI_TypeDef *)(obj->spi);
 289     while (!ssp_writeable(obj));
 290     spi->DR = (uint16_t)value;
 291 }
 292
 293 int spi_busy(spi_t *obj)
 294 {
 295     return ssp_busy(obj);
 296 }
 297
 298 #endif