openmv/src/spi.c
2014-03-07 20:38:03 +02:00

115 lines
3.5 KiB
C

#include <stdint.h>
#include <stm32f4xx.h>
#include <stm32f4xx_rcc.h>
#include <stm32f4xx_spi.h>
#include <stm32f4xx_gpio.h>
#include "spi.h"
#define GPIO_SPI_AF GPIO_AF_SPI3
#define GPIO_PIN_CS GPIO_Pin_15
#define GPIO_PIN_SCLK GPIO_Pin_10
#define GPIO_PIN_MISO GPIO_Pin_11
#define GPIO_PIN_MOSI GPIO_Pin_12
#define GPIO_SOURCE_SCLK GPIO_PinSource10
#define GPIO_SOURCE_MISO GPIO_PinSource11
#define GPIO_SOURCE_MOSI GPIO_PinSource12
#define GPIO_PORT_CS GPIOA
#define GPIO_PORT_SCLK GPIOC
#define GPIO_PORT_MISO GPIOC
#define GPIO_PORT_MOSI GPIOC
#define GPIO_CLK_CS RCC_AHB1Periph_GPIOA
#define GPIO_CLK_SCLK RCC_AHB1Periph_GPIOC
#define GPIO_CLK_MISO RCC_AHB1Periph_GPIOC
#define GPIO_CLK_MOSI RCC_AHB1Periph_GPIOC
#define SPIx SPI3
#define SPIx_CLK RCC_APB1Periph_SPI3
#define SPIx_CLK_CMD RCC_APB1PeriphClockCmd
#define GPIO_CLK_CMD RCC_AHB1PeriphClockCmd
void spi_init()
{
SPI_InitTypeDef SPI_InitStructure;
GPIO_InitTypeDef GPIO_InitStructure;
/* Enable SPI clock */
SPIx_CLK_CMD(SPIx_CLK, ENABLE);
/* Enable GPIO clocks */
GPIO_CLK_CMD(GPIO_CLK_CS | GPIO_CLK_SCLK | GPIO_CLK_MISO | GPIO_CLK_MOSI, ENABLE);
/* Connect SPI pins to AF */
GPIO_PinAFConfig(GPIO_PORT_SCLK, GPIO_SOURCE_SCLK, GPIO_SPI_AF);
GPIO_PinAFConfig(GPIO_PORT_MISO, GPIO_SOURCE_MISO, GPIO_SPI_AF);
GPIO_PinAFConfig(GPIO_PORT_MOSI, GPIO_SOURCE_MOSI, GPIO_SPI_AF);
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
/* SPI MISO pin configuration */
GPIO_InitStructure.GPIO_Pin = GPIO_PIN_MISO;
GPIO_Init(GPIO_PORT_MISO, &GPIO_InitStructure);
/* SPI MOSI pin configuration */
GPIO_InitStructure.GPIO_Pin = GPIO_PIN_MOSI;
GPIO_Init(GPIO_PORT_MOSI, &GPIO_InitStructure);
/* SPI SCK pin configuration */
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_DOWN;
GPIO_InitStructure.GPIO_Pin = GPIO_PIN_SCLK;
GPIO_Init(GPIO_PORT_SCLK, &GPIO_InitStructure);
/* SPI configuration */
SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
SPI_InitStructure.SPI_Mode = SPI_Mode_Master;
SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b;
SPI_InitStructure.SPI_CPOL = SPI_CPOL_Low;
SPI_InitStructure.SPI_CPHA = SPI_CPHA_1Edge;
SPI_InitStructure.SPI_NSS = SPI_NSS_Soft;
SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_4;
SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
SPI_InitStructure.SPI_CRCPolynomial = 7;
SPI_Init(SPIx, &SPI_InitStructure);
SPI_CalculateCRC(SPIx, DISABLE);
SPI_Cmd(SPIx, ENABLE);
/* drain SPI */
while (SPI_I2S_GetFlagStatus(SPIx, SPI_I2S_FLAG_TXE) == RESET);
/* dummy read */
SPI_I2S_ReceiveData(SPIx);
}
uint8_t spi_read()
{
/* Send byte through the SPI */
SPI_I2S_SendData(SPIx, 0xFF);
/* Wait to receive a byte */
while (SPI_I2S_GetFlagStatus(SPIx, SPI_I2S_FLAG_RXNE) == RESET);
/* Read byte from the SPI */
return SPI_I2S_ReceiveData(SPIx);
}
uint8_t spi_write(uint8_t b)
{
while (SPI_I2S_GetFlagStatus(SPIx, SPI_I2S_FLAG_TXE) == RESET);
/* Send byte through the SPI */
SPI_I2S_SendData(SPIx, b);
/* Wait to receive a byte */
while (SPI_I2S_GetFlagStatus(SPIx, SPI_I2S_FLAG_RXNE) == RESET);
/* Read byte from the SPI */
return SPI_I2S_ReceiveData(SPIx);
}