/****************************************************************************** * 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? */ .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? */ .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? */ .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); }