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RIOT/cpu/stm32f2/periph/spi.c
DipSwitch 4064858e8d stm32f2: add initial support for stm32f2
2015-12-13 11:00:06 +01:00

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/*
* Copyright (C) 2014 Hamburg University of Applied Sciences
*
* This file is subject to the terms and conditions of the GNU Lesser General
* Public License v2.1. See the file LICENSE in the top level directory for more
* details.
*/
/**
* @ingroup cpu_stm32f2
* @{
*
* @file
* @brief Low-level SPI driver implementation
*
* @author Peter Kietzmann <peter.kietzmann@haw-hamburg.de>
* @author Fabian Nack <nack@inf.fu-berlin.de>
* @author Hauke Petersen <hauke.petersen@fu-berlin.de>
*
* @}
*/
#include <stdio.h>
#include "board.h"
#include "cpu.h"
#include "mutex.h"
#include "periph/spi.h"
#include "periph_conf.h"
#include "thread.h"
#include "sched.h"
#define ENABLE_DEBUG (0)
#include "debug.h"
/* guard this file in case no SPI device is defined */
#if SPI_NUMOF
/**
* @brief Data-structure holding the state for a SPI device
*/
typedef struct {
char(*cb)(char data);
} spi_state_t;
static inline void irq_handler_transfer(SPI_TypeDef *spi, spi_t dev);
/**
* @brief Reserve memory for saving the SPI device's state
*/
static spi_state_t spi_config[SPI_NUMOF];
/* static bus div mapping */
static const uint8_t spi_bus_div_map[SPI_NUMOF] = {
#if SPI_0_EN
[SPI_0] = SPI_0_BUS_DIV,
#endif
#if SPI_1_EN
[SPI_1] = SPI_1_BUS_DIV,
#endif
#if SPI_2_EN
[SPI_2] = SPI_2_BUS_DIV,
#endif
};
/**
* @brief Array holding one pre-initialized mutex for each SPI device
*/
static mutex_t locks[] = {
#if SPI_0_EN
[SPI_0] = MUTEX_INIT,
#endif
#if SPI_1_EN
[SPI_1] = MUTEX_INIT,
#endif
#if SPI_2_EN
[SPI_2] = MUTEX_INIT
#endif
};
int spi_init_master(spi_t dev, spi_conf_t conf, spi_speed_t speed)
{
uint8_t speed_devider;
SPI_TypeDef *spi_port;
switch (speed) {
case SPI_SPEED_100KHZ:
return -2; /* not possible for stm32f2, APB2 minimum is 328 kHz */
break;
case SPI_SPEED_400KHZ:
speed_devider = 0x05 + spi_bus_div_map[dev]; /* makes 656 kHz */
break;
case SPI_SPEED_1MHZ:
speed_devider = 0x04 + spi_bus_div_map[dev]; /* makes 1.3 MHz */
break;
case SPI_SPEED_5MHZ:
speed_devider = 0x02 + spi_bus_div_map[dev]; /* makes 5.3 MHz */
break;
case SPI_SPEED_10MHZ:
speed_devider = 0x01 + spi_bus_div_map[dev]; /* makes 10.5 MHz */
break;
default:
return -1;
}
switch (dev) {
#if SPI_0_EN
case SPI_0:
spi_port = SPI_0_DEV;
/* enable clocks */
SPI_0_CLKEN();
SPI_0_SCK_PORT_CLKEN();
SPI_0_MISO_PORT_CLKEN();
SPI_0_MOSI_PORT_CLKEN();
break;
#endif /* SPI_0_EN */
#if SPI_1_EN
case SPI_1:
spi_port = SPI_1_DEV;
/* enable clocks */
SPI_1_CLKEN();
SPI_1_SCK_PORT_CLKEN();
SPI_1_MISO_PORT_CLKEN();
SPI_1_MOSI_PORT_CLKEN();
break;
#endif /* SPI_1_EN */
#if SPI_2_EN
case SPI_2:
spi_port = SPI_2_DEV;
/* enable clocks */
SPI_2_CLKEN();
SPI_2_SCK_PORT_CLKEN();
SPI_2_MISO_PORT_CLKEN();
SPI_2_MOSI_PORT_CLKEN();
break;
#endif /* SPI_2_EN */
default:
return -2;
}
/* configure SCK, MISO and MOSI pin */
spi_conf_pins(dev);
/**************** SPI-Init *****************/
spi_port->I2SCFGR &= ~(SPI_I2SCFGR_I2SMOD);/* Activate the SPI mode (Reset I2SMOD bit in I2SCFGR register) */
spi_port->CR1 = 0;
spi_port->CR2 = 0;
/* the NSS (chip select) is managed purely by software */
spi_port->CR1 |= SPI_CR1_SSM | SPI_CR1_SSI;
spi_port->CR1 |= (speed_devider << 3); /* Define serial clock baud rate. 001 leads to f_PCLK/4 */
spi_port->CR1 |= (SPI_CR1_MSTR); /* 1: master configuration */
spi_port->CR1 |= (conf);
/* enable SPI */
spi_port->CR1 |= (SPI_CR1_SPE);
return 0;
}
int spi_init_slave(spi_t dev, spi_conf_t conf, char(*cb)(char data))
{
SPI_TypeDef *spi_port;
switch (dev) {
#if SPI_0_EN
case SPI_0:
spi_port = SPI_0_DEV;
/* enable clocks */
SPI_0_CLKEN();
SPI_0_SCK_PORT_CLKEN();
SPI_0_MISO_PORT_CLKEN();
SPI_0_MOSI_PORT_CLKEN();
/* configure interrupt channel */
NVIC_SetPriority(SPI_0_IRQ, SPI_IRQ_PRIO); /* set SPI interrupt priority */
NVIC_EnableIRQ(SPI_0_IRQ); /* set SPI interrupt priority */
break;
#endif /* SPI_0_EN */
#if SPI_1_EN
case SPI_1:
spi_port = SPI_1_DEV;
/* enable clocks */
SPI_1_CLKEN();
SPI_1_SCK_PORT_CLKEN();
SPI_1_MISO_PORT_CLKEN();
SPI_1_MOSI_PORT_CLKEN();
/* configure interrupt channel */
NVIC_SetPriority(SPI_1_IRQ, SPI_IRQ_PRIO);
NVIC_EnableIRQ(SPI_1_IRQ);
break;
#endif /* SPI_1_EN */
#if SPI_2_EN
case SPI_2:
spi_port = SPI_2_DEV;
/* enable clocks */
SPI_2_CLKEN();
SPI_2_SCK_PORT_CLKEN();
SPI_2_MISO_PORT_CLKEN();
SPI_2_MOSI_PORT_CLKEN();
/* configure interrupt channel */
NVIC_SetPriority(SPI_2_IRQ, SPI_IRQ_PRIO);
NVIC_EnableIRQ(SPI_2_IRQ);
break;
#endif /* SPI_2_EN */
default:
return -1;
}
/* configure sck, miso and mosi pin */
spi_conf_pins(dev);
/***************** SPI-Init *****************/
spi_port->I2SCFGR &= ~(SPI_I2SCFGR_I2SMOD);
spi_port->CR1 = 0;
spi_port->CR2 = 0;
/* enable RXNEIE flag to enable rx buffer not empty interrupt */
spi_port->CR2 |= (SPI_CR2_RXNEIE); /*1:not masked */
spi_port->CR1 |= (conf);
/* the NSS (chip select) is managed by software and NSS is low (slave enabled) */
spi_port->CR1 |= SPI_CR1_SSM;
/* set callback */
spi_config[dev].cb = cb;
/* enable SPI device */
spi_port->CR1 |= SPI_CR1_SPE;
return 0;
}
int spi_conf_pins(spi_t dev)
{
GPIO_TypeDef *port[3];
int pin[3], af[3];
switch (dev) {
#if SPI_0_EN
case SPI_0:
port[0] = SPI_0_SCK_PORT;
pin[0] = SPI_0_SCK_PIN;
af[0] = SPI_0_SCK_AF;
port[1] = SPI_0_MOSI_PORT;
pin[1] = SPI_0_MOSI_PIN;
af[1] = SPI_0_MOSI_AF;
port[2] = SPI_0_MISO_PORT;
pin[2] = SPI_0_MISO_PIN;
af[2] = SPI_0_MISO_AF;
break;
#endif /* SPI_0_EN */
#if SPI_1_EN
case SPI_1:
port[0] = SPI_1_SCK_PORT;
pin[0] = SPI_1_SCK_PIN;
af[0] = SPI_1_SCK_AF;
port[1] = SPI_1_MOSI_PORT;
pin[1] = SPI_1_MOSI_PIN;
af[1] = SPI_1_MOSI_AF;
port[2] = SPI_1_MISO_PORT;
pin[2] = SPI_1_MISO_PIN;
af[2] = SPI_1_MISO_AF;
break;
#endif /* SPI_1_EN */
#if SPI_2_EN
case SPI_2:
port[0] = SPI_2_SCK_PORT;
pin[0] = SPI_2_SCK_PIN;
af[0] = SPI_2_SCK_AF;
port[1] = SPI_2_MOSI_PORT;
pin[1] = SPI_2_MOSI_PIN;
af[1] = SPI_2_MOSI_AF;
port[2] = SPI_2_MISO_PORT;
pin[2] = SPI_2_MISO_PIN;
af[2] = SPI_2_MISO_AF;
break;
#endif /* SPI_2_EN */
default:
return -1;
}
/***************** GPIO-Init *****************/
for (int i = 0; i < 3; i++) {
/* Set GPIOs to AF mode */
port[i]->MODER &= ~(3 << (2 * pin[i]));
port[i]->MODER |= (2 << (2 * pin[i]));
/* Set speed */
port[i]->OSPEEDR &= ~(3 << (2 * pin[i]));
port[i]->OSPEEDR |= (3 << (2 * pin[i]));
/* Set to push-pull configuration */
port[i]->OTYPER &= ~(1 << pin[i]);
/* Configure push-pull resistors */
port[i]->PUPDR &= ~(3 << (2 * pin[i]));
port[i]->PUPDR |= (2 << (2 * pin[i]));
/* Configure GPIOs for the SPI alternate function */
int hl = (pin[i] < 8) ? 0 : 1;
port[i]->AFR[hl] &= ~(0xf << ((pin[i] - (hl * 8)) * 4));
port[i]->AFR[hl] |= (af[i] << ((pin[i] - (hl * 8)) * 4));
}
return 0;
}
int spi_acquire(spi_t dev)
{
if (dev >= SPI_NUMOF) {
return -1;
}
mutex_lock(&locks[dev]);
return 0;
}
int spi_release(spi_t dev)
{
if (dev >= SPI_NUMOF) {
return -1;
}
mutex_unlock(&locks[dev]);
return 0;
}
int spi_transfer_byte(spi_t dev, char out, char *in)
{
SPI_TypeDef *spi_port;
switch (dev) {
#if SPI_0_EN
case SPI_0:
spi_port = SPI_0_DEV;
break;
#endif
#if SPI_1_EN
case SPI_1:
spi_port = SPI_1_DEV;
break;
#endif
#if SPI_2_EN
case SPI_2:
spi_port = SPI_2_DEV;
break;
#endif
default:
return -1;
}
while (!(spi_port->SR & SPI_SR_TXE));
spi_port->DR = out;
while (!(spi_port->SR & SPI_SR_RXNE));
if (in != NULL) {
*in = spi_port->DR;
}
else {
spi_port->DR;
}
return 1;
}
void spi_transmission_begin(spi_t dev, char reset_val)
{
switch (dev) {
#if SPI_0_EN
case SPI_0:
SPI_0_DEV->DR = reset_val;
break;
#endif
#if SPI_1_EN
case SPI_1:
SPI_1_DEV->DR = reset_val;
break;
#endif
#if SPI_2_EN
case SPI_2:
SPI_2_DEV->DR = reset_val;
break;
#endif
}
}
void spi_poweron(spi_t dev)
{
switch (dev) {
#if SPI_0_EN
case SPI_0:
SPI_0_CLKEN();
break;
#endif
#if SPI_1_EN
case SPI_1:
SPI_1_CLKEN();
break;
#endif
#if SPI_2_EN
case SPI_2:
SPI_2_CLKEN();
break;
#endif
}
}
void spi_poweroff(spi_t dev)
{
switch (dev) {
#if SPI_0_EN
case SPI_0:
while (SPI_0_DEV->SR & SPI_SR_BSY);
SPI_0_CLKDIS();
break;
#endif
#if SPI_1_EN
case SPI_1:
while (SPI_1_DEV->SR & SPI_SR_BSY);
SPI_1_CLKDIS();
break;
#endif
#if SPI_2_EN
case SPI_2:
while (SPI_2_DEV->SR & SPI_SR_BSY);
SPI_2_CLKDIS();
break;
#endif
}
}
static inline void irq_handler_transfer(SPI_TypeDef *spi, spi_t dev)
{
if (spi->SR & SPI_SR_RXNE) {
char data;
data = spi->DR;
data = spi_config[dev].cb(data);
spi->DR = data;
}
/* see if a thread with higher priority wants to run now */
if (sched_context_switch_request) {
thread_yield();
}
}
#if SPI_0_EN
void SPI_0_IRQ_HANDLER(void)
{
irq_handler_transfer(SPI_0_DEV, SPI_0);
}
#endif
#if SPI_1_EN
void SPI_1_IRQ_HANDLER(void)
{
irq_handler_transfer(SPI_1_DEV, SPI_1);
}
#endif
#if SPI_2_EN
void SPI_2_IRQ_HANDLER(void)
{
irq_handler_transfer(SPI_2_DEV, SPI_2);
}
#endif
#endif /* SPI_NUMOF */
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