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Diffstat (limited to 'libmaple/stm32f2/usart.c')
| -rw-r--r-- | libmaple/stm32f2/usart.c | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/libmaple/stm32f2/usart.c b/libmaple/stm32f2/usart.c new file mode 100644 index 0000000..1472d13 --- /dev/null +++ b/libmaple/stm32f2/usart.c @@ -0,0 +1,204 @@ +/****************************************************************************** + * 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); +} |