tool/mbed/mbed-sdk/libraries/mbed/targets/hal/TARGET_STM/TARGET_STM32L0/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
  87     // Configure the SPI pins
  88     pinmap_pinout(mosi, PinMap_SPI_MOSI);
  89     pinmap_pinout(miso, PinMap_SPI_MISO);
  90     pinmap_pinout(sclk, PinMap_SPI_SCLK);
  91
  92     // Save new values
  93     obj->bits = SPI_DATASIZE_8BIT;
  94     obj->cpol = SPI_POLARITY_LOW;
  95     obj->cpha = SPI_PHASE_1EDGE;
  96     obj->br_presc = SPI_BAUDRATEPRESCALER_256;
  97
  98     obj->pin_miso = miso;
  99     obj->pin_mosi = mosi;
 100     obj->pin_sclk = sclk;
 101     obj->pin_ssel = ssel;
 102
 103     if (ssel == NC) { // SW NSS Master mode
 104         obj->mode = SPI_MODE_MASTER;
 105         obj->nss = SPI_NSS_SOFT;
 106     } else { // Slave
 107         pinmap_pinout(ssel, PinMap_SPI_SSEL);
 108         obj->mode = SPI_MODE_SLAVE;
 109         obj->nss = SPI_NSS_HARD_INPUT;
 110     }
 111
 112     init_spi(obj);
 113 }
 114
 115 void spi_free(spi_t *obj)
 116 {
 117     // Reset SPI and disable clock
 118     if (obj->spi == SPI_1) {
 119         __SPI1_FORCE_RESET();
 120         __SPI1_RELEASE_RESET();
 121         __SPI1_CLK_DISABLE();
 122     }
 123
 124     if (obj->spi == SPI_2) {
 125         __SPI2_FORCE_RESET();
 126         __SPI2_RELEASE_RESET();
 127         __SPI2_CLK_DISABLE();
 128     }
 129
 130     // Configure GPIO
 131     pin_function(obj->pin_miso, STM_PIN_DATA(STM_MODE_INPUT, GPIO_NOPULL, 0));
 132     pin_function(obj->pin_mosi, STM_PIN_DATA(STM_MODE_INPUT, GPIO_NOPULL, 0));
 133     pin_function(obj->pin_sclk, STM_PIN_DATA(STM_MODE_INPUT, GPIO_NOPULL, 0));
 134     pin_function(obj->pin_ssel, STM_PIN_DATA(STM_MODE_INPUT, GPIO_NOPULL, 0));
 135 }
 136
 137 void spi_format(spi_t *obj, int bits, int mode, int slave)
 138 {
 139     // Save new values
 140     if (bits == 16) {
 141         obj->bits = SPI_DATASIZE_16BIT;
 142     } else {
 143         obj->bits = SPI_DATASIZE_8BIT;
 144     }
 145
 146     switch (mode) {
 147         case 0:
 148             obj->cpol = SPI_POLARITY_LOW;
 149             obj->cpha = SPI_PHASE_1EDGE;
 150             break;
 151         case 1:
 152             obj->cpol = SPI_POLARITY_LOW;
 153             obj->cpha = SPI_PHASE_2EDGE;
 154             break;
 155         case 2:
 156             obj->cpol = SPI_POLARITY_HIGH;
 157             obj->cpha = SPI_PHASE_1EDGE;
 158             break;
 159         default:
 160             obj->cpol = SPI_POLARITY_HIGH;
 161             obj->cpha = SPI_PHASE_2EDGE;
 162             break;
 163     }
 164
 165     if (slave == 0) {
 166         obj->mode = SPI_MODE_MASTER;
 167         obj->nss = SPI_NSS_SOFT;
 168     } else {
 169         obj->mode = SPI_MODE_SLAVE;
 170         obj->nss = SPI_NSS_HARD_INPUT;
 171     }
 172
 173     init_spi(obj);
 174 }
 175
 176 void spi_frequency(spi_t *obj, int hz)
 177 {
 178     // Note: The frequencies are obtained with SPI1 clock = 32 MHz (APB2 clock)
 179     if (hz < 250000) {
 180         obj->br_presc = SPI_BAUDRATEPRESCALER_256; // 125 kHz
 181     } else if ((hz >= 250000) && (hz < 500000)) {
 182         obj->br_presc = SPI_BAUDRATEPRESCALER_128; // 250 kHz
 183     } else if ((hz >= 500000) && (hz < 1000000)) {
 184         obj->br_presc = SPI_BAUDRATEPRESCALER_64; // 500 kHz
 185     } else if ((hz >= 1000000) && (hz < 2000000)) {
 186         obj->br_presc = SPI_BAUDRATEPRESCALER_32; // 1 MHz
 187     } else if ((hz >= 2000000) && (hz < 4000000)) {
 188         obj->br_presc = SPI_BAUDRATEPRESCALER_16; // 2 MHz
 189     } else if ((hz >= 4000000) && (hz < 8000000)) {
 190         obj->br_presc = SPI_BAUDRATEPRESCALER_8; // 4 MHz
 191     } else if ((hz >= 8000000) && (hz < 16000000)) {
 192         obj->br_presc = SPI_BAUDRATEPRESCALER_4; // 8 MHz
 193     } else { // >= 16000000
 194         obj->br_presc = SPI_BAUDRATEPRESCALER_2; // 16 MHz
 195     }
 196     init_spi(obj);
 197 }
 198
 199 static inline int ssp_readable(spi_t *obj)
 200 {
 201     int status;
 202     SpiHandle.Instance = (SPI_TypeDef *)(obj->spi);
 203     // Check if data is received
 204     status = ((__HAL_SPI_GET_FLAG(&SpiHandle, SPI_FLAG_RXNE) != RESET) ? 1 : 0);
 205     return status;
 206 }
 207
 208 static inline int ssp_writeable(spi_t *obj)
 209 {
 210     int status;
 211     SpiHandle.Instance = (SPI_TypeDef *)(obj->spi);
 212     // Check if data is transmitted
 213     status = ((__HAL_SPI_GET_FLAG(&SpiHandle, SPI_FLAG_TXE) != RESET) ? 1 : 0);
 214     return status;
 215 }
 216
 217 static inline void ssp_write(spi_t *obj, int value)
 218 {
 219     SPI_TypeDef *spi = (SPI_TypeDef *)(obj->spi);
 220     while (!ssp_writeable(obj));
 221     spi->DR = (uint16_t)value;
 222 }
 223
 224 static inline int ssp_read(spi_t *obj)
 225 {
 226     SPI_TypeDef *spi = (SPI_TypeDef *)(obj->spi);
 227     while (!ssp_readable(obj));
 228     return (int)spi->DR;
 229 }
 230
 231 static inline int ssp_busy(spi_t *obj)
 232 {
 233     int status;
 234     SpiHandle.Instance = (SPI_TypeDef *)(obj->spi);
 235     status = ((__HAL_SPI_GET_FLAG(&SpiHandle, SPI_FLAG_BSY) != RESET) ? 1 : 0);
 236     return status;
 237 }
 238
 239 int spi_master_write(spi_t *obj, int value)
 240 {
 241     ssp_write(obj, value);
 242     return ssp_read(obj);
 243 }
 244
 245 int spi_slave_receive(spi_t *obj)
 246 {
 247     return (ssp_readable(obj) ? 1 : 0);
 248 };
 249
 250 int spi_slave_read(spi_t *obj)
 251 {
 252     SPI_TypeDef *spi = (SPI_TypeDef *)(obj->spi);
 253     while (!ssp_readable(obj));
 254     return (int)spi->DR;
 255 }
 256
 257 void spi_slave_write(spi_t *obj, int value)
 258 {
 259     SPI_TypeDef *spi = (SPI_TypeDef *)(obj->spi);
 260     while (!ssp_writeable(obj));
 261     spi->DR = (uint16_t)value;
 262 }
 263
 264 int spi_busy(spi_t *obj)
 265 {
 266     return ssp_busy(obj);
 267 }
 268
 269 #endif