Diff: targets/hal/TARGET_STM/TARGET_DISCO_F051R8/spi_api.c

Revision:

130:1dec54e4aec3

Child:

227:7bd0639b8911

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/hal/TARGET_STM/TARGET_DISCO_F051R8/spi_api.c	Fri Mar 21 11:45:09 2014 +0000
@@ -0,0 +1,270 @@
+/* mbed Microcontroller Library
+ *******************************************************************************
+ * Copyright (c) 2014, STMicroelectronics
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. Neither the name of STMicroelectronics nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *******************************************************************************
+ */
+#include "spi_api.h"
+
+#if DEVICE_SPI
+
+#include <math.h>
+#include "cmsis.h"
+#include "pinmap.h"
+#include "error.h"
+
+static const PinMap PinMap_SPI_MOSI[] = {
+    {PA_7,  SPI_1, STM_PIN_DATA(GPIO_Mode_AF, GPIO_OType_PP, GPIO_PuPd_NOPULL, GPIO_AF_0)},
+    {NC,    NC,    0}
+};
+
+static const PinMap PinMap_SPI_MISO[] = {
+    {PA_6,  SPI_1, STM_PIN_DATA(GPIO_Mode_AF, GPIO_OType_PP, GPIO_PuPd_NOPULL, GPIO_AF_0)},
+    {NC,    NC,    0}
+};
+
+static const PinMap PinMap_SPI_SCLK[] = {
+    {PA_5,  SPI_1, STM_PIN_DATA(GPIO_Mode_AF, GPIO_OType_PP, GPIO_PuPd_NOPULL, GPIO_AF_0)},
+    {NC,    NC,    0}
+};
+
+// Only used in Slave mode
+static const PinMap PinMap_SPI_SSEL[] = {
+    {PB_6,  SPI_1, STM_PIN_DATA(GPIO_Mode_IN, GPIO_OType_PP, GPIO_PuPd_NOPULL, 0)}, // Generic IO, not real H/W NSS pin
+    {NC,    NC,    0}
+};
+
+static void init_spi(spi_t *obj) {
+    SPI_TypeDef *spi = (SPI_TypeDef *)(obj->spi);
+    SPI_InitTypeDef SPI_InitStructure;
+
+    SPI_Cmd(spi, DISABLE);
+
+    SPI_InitStructure.SPI_Mode = obj->mode;
+    SPI_InitStructure.SPI_NSS = obj->nss;    
+    SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;    
+    SPI_InitStructure.SPI_DataSize = obj->bits;
+    SPI_InitStructure.SPI_CPOL = obj->cpol;
+    SPI_InitStructure.SPI_CPHA = obj->cpha;    
+    SPI_InitStructure.SPI_BaudRatePrescaler = obj->br_presc;
+    SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
+    SPI_InitStructure.SPI_CRCPolynomial = 7;
+    SPI_Init(spi, &SPI_InitStructure);
+
+    SPI_RxFIFOThresholdConfig(spi, SPI_RxFIFOThreshold_QF);
+
+    SPI_Cmd(spi, ENABLE);
+}
+
+void spi_init(spi_t *obj, PinName mosi, PinName miso, PinName sclk, PinName ssel) {
+    // Determine the SPI to use
+    SPIName spi_mosi = (SPIName)pinmap_peripheral(mosi, PinMap_SPI_MOSI);
+    SPIName spi_miso = (SPIName)pinmap_peripheral(miso, PinMap_SPI_MISO);
+    SPIName spi_sclk = (SPIName)pinmap_peripheral(sclk, PinMap_SPI_SCLK);
+    SPIName spi_ssel = (SPIName)pinmap_peripheral(ssel, PinMap_SPI_SSEL);
+  
+    SPIName spi_data = (SPIName)pinmap_merge(spi_mosi, spi_miso);
+    SPIName spi_cntl = (SPIName)pinmap_merge(spi_sclk, spi_ssel);
+  
+    obj->spi = (SPIName)pinmap_merge(spi_data, spi_cntl);
+  
+    if (obj->spi == (SPIName)NC) {
+        error("SPI pinout mapping failed");
+    }
+    
+    // Enable SPI clock
+    if (obj->spi == SPI_1) {
+        RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1, ENABLE); 
+    }
+    if (obj->spi == SPI_2) {
+        RCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI2, ENABLE); 
+    }
+    
+    // Configure the SPI pins
+    pinmap_pinout(mosi, PinMap_SPI_MOSI);
+    pinmap_pinout(miso, PinMap_SPI_MISO);
+    pinmap_pinout(sclk, PinMap_SPI_SCLK);
+    
+    // Save new values
+    obj->bits = SPI_DataSize_8b;
+    obj->cpol = SPI_CPOL_Low;
+    obj->cpha = SPI_CPHA_1Edge;
+    obj->br_presc = SPI_BaudRatePrescaler_8; // 1 MHz
+    
+    if (ssel == NC) { // Master
+        obj->mode = SPI_Mode_Master;
+        obj->nss = SPI_NSS_Soft;
+    }
+    else { // Slave
+        pinmap_pinout(ssel, PinMap_SPI_SSEL);
+        obj->mode = SPI_Mode_Slave;
+        obj->nss = SPI_NSS_Soft;
+    }
+
+    init_spi(obj);
+}
+
+void spi_free(spi_t *obj) {
+    SPI_TypeDef *spi = (SPI_TypeDef *)(obj->spi);
+    SPI_I2S_DeInit(spi);
+}
+
+void spi_format(spi_t *obj, int bits, int mode, int slave) {  
+    // Save new values
+    if (bits == 8) {
+        obj->bits = SPI_DataSize_8b;
+    }
+    else {
+        obj->bits = SPI_DataSize_16b;
+    }
+    
+    switch (mode) {
+        case 0:
+          obj->cpol = SPI_CPOL_Low;
+          obj->cpha = SPI_CPHA_1Edge;
+        break;
+        case 1:
+          obj->cpol = SPI_CPOL_Low;
+          obj->cpha = SPI_CPHA_2Edge;
+        break;
+        case 2:
+          obj->cpol = SPI_CPOL_High;
+          obj->cpha = SPI_CPHA_1Edge;          
+        break;
+        default:
+          obj->cpol = SPI_CPOL_High;
+          obj->cpha = SPI_CPHA_2Edge;          
+        break;
+    }
+    
+    if (slave == 0) {
+        obj->mode = SPI_Mode_Master;
+        obj->nss = SPI_NSS_Soft;
+    }
+    else {
+        obj->mode = SPI_Mode_Slave;
+        obj->nss = SPI_NSS_Hard;      
+    }
+    
+    init_spi(obj);
+}
+
+void spi_frequency(spi_t *obj, int hz) {
+    // Get SPI clock frequency
+    uint32_t PCLK = SystemCoreClock;
+
+    // Choose the baud rate divisor (between 2 and 256)
+    uint32_t divisor = PCLK / hz;
+
+    // Find the nearest power-of-2
+    divisor = (divisor > 0 ? divisor-1 : 0);
+    divisor |= divisor >> 1;
+    divisor |= divisor >> 2;
+    divisor |= divisor >> 4;
+    divisor |= divisor >> 8;
+    divisor |= divisor >> 16;
+    divisor++;
+
+    uint32_t baud_rate = __builtin_ffs(divisor) - 2;
+    
+    // Save new value
+    obj->br_presc = ((baud_rate > 7) ? (7 << 3) : (baud_rate << 3));
+ 
+    init_spi(obj);
+}
+
+static inline int ssp_readable(spi_t *obj) {
+    int status;
+    SPI_TypeDef *spi = (SPI_TypeDef *)(obj->spi);
+    // Check if data is received
+    status = ((SPI_I2S_GetFlagStatus(spi, SPI_I2S_FLAG_RXNE) != RESET) ? 1 : 0);
+    return status;  
+}
+
+static inline int ssp_writeable(spi_t *obj) {
+    int status;
+    SPI_TypeDef *spi = (SPI_TypeDef *)(obj->spi);
+    // Check if data is transmitted
+    status = ((SPI_I2S_GetFlagStatus(spi, SPI_I2S_FLAG_TXE) != RESET) ? 1 : 0);
+    return status;
+}
+
+static inline void ssp_write(spi_t *obj, int value) {
+    SPI_TypeDef *spi = (SPI_TypeDef *)(obj->spi);  
+    while (!ssp_writeable(obj));
+    if(obj->bits == SPI_DataSize_8b)  // 8 bit mode
+    	SPI_SendData8(spi, (uint8_t)value);
+    else
+    	SPI_I2S_SendData16(spi, (uint16_t)value);
+}
+
+static inline int ssp_read(spi_t *obj) {
+    SPI_TypeDef *spi = (SPI_TypeDef *)(obj->spi);   
+    while (!ssp_readable(obj));
+    if(obj->bits == SPI_DataSize_8b)  // 8 bit mode
+    	return (int)SPI_ReceiveData8(spi);
+    else 								// 16 bit mode
+    	return (int)SPI_I2S_ReceiveData16(spi); 
+}
+
+static inline int ssp_busy(spi_t *obj) {
+    int status;
+    SPI_TypeDef *spi = (SPI_TypeDef *)(obj->spi);
+    status = ((SPI_I2S_GetFlagStatus(spi, SPI_I2S_FLAG_BSY) != RESET) ? 1 : 0);
+    return status;
+}
+
+int spi_master_write(spi_t *obj, int value) {
+    ssp_write(obj, value);
+    return ssp_read(obj);
+}
+
+int spi_slave_receive(spi_t *obj) {
+    return (ssp_readable(obj) && !ssp_busy(obj)) ? (1) : (0);
+};
+
+int spi_slave_read(spi_t *obj) {
+    SPI_TypeDef *spi = (SPI_TypeDef *)(obj->spi);
+    if(obj->bits == SPI_DataSize_8b)  // 8 bit mode
+    	return (int)SPI_ReceiveData8(spi);
+    else 
+    	return (int)SPI_I2S_ReceiveData16(spi); 
+}
+
+void spi_slave_write(spi_t *obj, int value) {
+    SPI_TypeDef *spi = (SPI_TypeDef *)(obj->spi);  
+    while (!ssp_writeable(obj)); 
+    if(obj->bits == SPI_DataSize_8b)  // 8 bit mode
+    	SPI_SendData8(spi, (uint8_t)value);
+    else 
+    	SPI_I2S_SendData16(spi, (uint16_t)value);
+}
+
+int spi_busy(spi_t *obj) {
+    return ssp_busy(obj);
+}
+
+#endif