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/******************************************************************************
* The MIT License
*
* Copyright (c) 2012 LeafLabs, LLC.
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use, copy,
* modify, merge, publish, distribute, sublicense, and/or sell copies
* of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*****************************************************************************/
/**
* @file libmaple/stm32f2/usart.c
* @author Marti Bolivar <mbolivar@leaflabs.com>
* @brief STM32F2 USART.
*/
#include <libmaple/usart.h>
#include <libmaple/gpio.h>
#include "usart_private.h"
/*
* Devices
*/
static ring_buffer usart1_rb;
static usart_dev usart1 = {
.regs = USART1_BASE,
.rb = &usart1_rb,
.max_baud = 4500000UL, /* TODO: are these correct? 5250000UL for STM32F4? */
.clk_id = RCC_USART1,
.irq_num = NVIC_USART1,
};
/** USART1 device */
usart_dev *USART1 = &usart1;
static ring_buffer usart2_rb;
static usart_dev usart2 = {
.regs = USART2_BASE,
.rb = &usart2_rb,
.max_baud = 2250000UL, /* TODO: are these correct? 2620000UL for STM32F4? */
.clk_id = RCC_USART2,
.irq_num = NVIC_USART2,
};
/** USART2 device */
usart_dev *USART2 = &usart2;
static ring_buffer usart3_rb;
static usart_dev usart3 = {
.regs = USART3_BASE,
.rb = &usart3_rb,
.max_baud = 2250000UL, /* TODO: are these correct? */
.clk_id = RCC_USART3,
.irq_num = NVIC_USART3,
};
/** USART3 device */
usart_dev *USART3 = &usart3;
static ring_buffer uart4_rb;
static usart_dev uart4 = {
.regs = UART4_BASE,
.rb = &uart4_rb,
.max_baud = 2250000UL, /* TODO: are these correct? */
.clk_id = RCC_UART4,
.irq_num = NVIC_UART4,
};
/** UART4 device */
usart_dev *UART4 = &uart4;
static ring_buffer uart5_rb;
static usart_dev uart5 = {
.regs = UART5_BASE,
.rb = &uart5_rb,
.max_baud = 2250000UL, /* TODO: are these correct? */
.clk_id = RCC_UART5,
.irq_num = NVIC_UART5,
};
/** UART5 device */
usart_dev *UART5 = &uart5;
static ring_buffer usart6_rb;
static usart_dev usart6 = {
.regs = USART6_BASE,
.rb = &usart6_rb,
.max_baud = 4500000UL, /* TODO: are these correct? 5250000UL for STM32F4? */
.clk_id = RCC_USART6,
.irq_num = NVIC_USART6,
};
usart_dev *USART6 = &usart6;
/*
* Routines
*/
void usart_config_gpios_async(usart_dev *udev,
gpio_dev *rx_dev, uint8 rx,
gpio_dev *tx_dev, uint8 tx,
unsigned flags) {
gpio_af af = usart_get_af(udev);
gpio_set_modef(rx_dev, rx, GPIO_MODE_AF, 0);
gpio_set_modef(tx_dev, tx, GPIO_MODE_AF, 0);
gpio_set_af(rx_dev, rx, af);
gpio_set_af(tx_dev, tx, af);
}
void usart_set_baud_rate(usart_dev *dev, uint32 clock_speed, uint32 baud) {
uint32 integer_part;
uint32 fractional_part;
uint32 tmp;
uint32 over8 = !!(dev->regs->CR1 & USART_CR1_OVER8);
ASSERT(!over8); /* OVER8 is currently unsupported. */
/* Figure out the clock speed, if the user doesn't give one. */
if (clock_speed == 0) {
clock_speed = _usart_clock_freq(dev);
}
ASSERT(clock_speed);
/* Convert desired baud rate to baud rate register setting. */
integer_part = (25 * clock_speed) / (2 * (2 - over8) * baud);
tmp = (integer_part / 100) << 4;
fractional_part = integer_part - (100 * (tmp >> 4));
tmp |= ((fractional_part * 16 + 50) / 100) & (uint8)0x0F;
dev->regs->BRR = tmp;
}
/**
* @brief Call a function on each USART.
* @param fn Function to call.
*/
void usart_foreach(void (*fn)(usart_dev*)) {
fn(USART1);
fn(USART2);
fn(USART3);
fn(UART4);
fn(UART5);
fn(USART6);
}
/**
* @brief Get GPIO alternate function mode for a USART.
* @param dev USART whose gpio_af to get.
* @return gpio_af corresponding to dev.
*/
gpio_af usart_get_af(usart_dev *dev) {
switch (dev->clk_id) {
case RCC_USART1:
case RCC_USART2:
case RCC_USART3:
return GPIO_AF_USART_1_2_3;
case RCC_UART4:
case RCC_UART5:
case RCC_USART6:
return GPIO_AF_USART_4_5_6;
default:
ASSERT(0); /* Can't happen */
return (gpio_af)-1;
}
}
/*
* Interrupt handlers.
*/
void __irq_usart1(void) {
usart_irq(&usart1_rb, USART1_BASE);
}
void __irq_usart2(void) {
usart_irq(&usart2_rb, USART2_BASE);
}
void __irq_usart3(void) {
usart_irq(&usart3_rb, USART3_BASE);
}
void __irq_uart4(void) {
usart_irq(&uart4_rb, UART4_BASE);
}
void __irq_uart5(void) {
usart_irq(&uart5_rb, UART5_BASE);
}
void __irq_usart6(void) {
usart_irq(&usart6_rb, USART6_BASE);
}
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