diff options
Diffstat (limited to 'libmaple/usart.c')
| -rw-r--r-- | libmaple/usart.c | 344 |
1 files changed, 181 insertions, 163 deletions
diff --git a/libmaple/usart.c b/libmaple/usart.c index 44a5c92..fbd4d70 100644 --- a/libmaple/usart.c +++ b/libmaple/usart.c @@ -3,228 +3,246 @@ * * Copyright (c) 2010 Perry Hung. * - * 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 + * 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 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. + * 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 usart.c + * @author Marti Bolivar <mbolivar@leaflabs.com, + * Perry Hung <perry@leaflabs.com> * @brief USART control routines */ -#include "libmaple.h" -#include "rcc.h" -#include "nvic.h" #include "usart.h" -#define USART1_BASE 0x40013800 -#define USART2_BASE 0x40004400 -#define USART3_BASE 0x40004800 -#define UART4_BASE 0x40004C00 // High-density devices only (Maple Native) -#define UART5_BASE 0x40005000 // High-density devices only (Maple Native) - -#define USART_UE BIT(13) -#define USART_M BIT(12) -#define USART_TE BIT(3) -#define USART_RE BIT(2) -#define USART_RXNEIE BIT(5) // read data register not empty interrupt enable -#define USART_TC BIT(6) - -/* usart descriptor table */ -struct usart_dev usart_dev_table[] = { - [USART1] = { - .base = (usart_port*)USART1_BASE, - .rcc_dev_num = RCC_USART1, - .nvic_dev_num = NVIC_USART1 - }, - [USART2] = { - .base = (usart_port*)USART2_BASE, - .rcc_dev_num = RCC_USART2, - .nvic_dev_num = NVIC_USART2 - }, - [USART3] = { - .base = (usart_port*)USART3_BASE, - .rcc_dev_num = RCC_USART3, - .nvic_dev_num = NVIC_USART3 - }, -#if NR_USART >= 5 - /* TODO test */ - [UART4] = { - .base = (usart_port*)UART4_BASE, - .rcc_dev_num = RCC_UART4, - .nvic_dev_num = NVIC_UART4 - }, - [UART5] = { - .base = (usart_port*)UART5_BASE, - .rcc_dev_num = RCC_UART5, - .nvic_dev_num = NVIC_UART5 - }, -#endif -}; - /* - * Usart interrupt handlers. + * Devices */ -static inline void usart_irq(int usart_num) { -#ifdef USART_SAFE_INSERT - /* Ignore old bytes if the user defines USART_SAFE_INSERT. */ - rb_safe_insert(&(usart_dev_table[usart_num].rb), - (uint8)((usart_dev_table[usart_num].base)->DR)); -#else - /* By default, push bytes around in the ring buffer. */ - rb_push_insert(&(usart_dev_table[usart_num].rb), - (uint8)((usart_dev_table[usart_num].base)->DR)); +static ring_buffer usart1_rb; +static usart_dev usart1 = { + .regs = USART1_BASE, + .rb = &usart1_rb, + .max_baud = 4500000UL, + .clk_id = RCC_USART1, + .irq_num = NVIC_USART1 +}; +usart_dev *USART1 = &usart1; + +static ring_buffer usart2_rb; +static usart_dev usart2 = { + .regs = USART2_BASE, + .rb = &usart2_rb, + .max_baud = 2250000UL, + .clk_id = RCC_USART2, + .irq_num = NVIC_USART2 +}; +usart_dev *USART2 = &usart2; + +static ring_buffer usart3_rb; +static usart_dev usart3 = { + .regs = USART3_BASE, + .rb = &usart3_rb, + .max_baud = 2250000UL, + .clk_id = RCC_USART3, + .irq_num = NVIC_USART3 +}; +usart_dev *USART3 = &usart3; + +#ifdef STM32_HIGH_DENSITY +static ring_buffer uart4_rb; +static usart_dev uart4 = { + .regs = UART4_BASE, + .rb = &uart4_rb, + .max_baud = 2250000UL, + .clk_id = RCC_UART4, + .irq_num = NVIC_UART4 +}; +usart_dev *UART4 = &uart4; + +static ring_buffer uart5_rb; +static usart_dev uart5 = { + .regs = UART5_BASE, + .rb = &uart5_rb, + .max_baud = 2250000UL, + .clk_id = RCC_UART5, + .irq_num = NVIC_UART5 +}; +usart_dev *UART5 = &uart5; #endif -} - -/* TODO: Check the disassembly for the following functions to make - sure GCC inlined properly. */ - -void USART1_IRQHandler(void) { - usart_irq(USART1); -} - -void USART2_IRQHandler(void) { - usart_irq(USART2); -} -void USART3_IRQHandler(void) { - usart_irq(USART3); -} - -#if NR_USART >= 5 -void UART4_IRQHandler(void) { - usart_irq(UART4); -} - -void UART5_IRQHandler(void) { - usart_irq(UART5); +/** + * @brief Initialize a serial port. + * @param dev Serial port to be initialized + */ +void usart_init(usart_dev *dev) { + rb_init(dev->rb, USART_RX_BUF_SIZE, dev->rx_buf); + rcc_clk_enable(dev->clk_id); + nvic_irq_enable(dev->irq_num); } -#endif /** - * @brief Enable a USART in single buffer transmission mode, multibuffer - * receiver mode. - * @param usart_num USART to be initialized - * @param baud Baud rate to be set at + * @brief Configure a serial port's baud rate. + * + * @param dev Serial port to be configured + * @param clock_speed Clock speed, in megahertz. + * @param baud Baud rate for transmit/receive. */ -void usart_init(uint8 usart_num, uint32 baud) { - ASSERT(usart_num <= NR_USART); - usart_port *port; - ring_buffer *ring_buf; - - uint32 clk_speed; +void usart_set_baud_rate(usart_dev *dev, uint32 clock_speed, uint32 baud) { uint32 integer_part; uint32 fractional_part; uint32 tmp; - port = usart_dev_table[usart_num].base; - rcc_clk_enable(usart_dev_table[usart_num].rcc_dev_num); - nvic_irq_enable(usart_dev_table[usart_num].nvic_dev_num); - - /* usart1 is mad fast */ - clk_speed = (usart_num == USART1) ? 72000000UL : 36000000UL; - - /* Initialize rx ring buffer */ - rb_init(&usart_dev_table[usart_num].rb, - sizeof (usart_dev_table[usart_num].rx_buf), - usart_dev_table[usart_num].rx_buf); - - /* Set baud rate */ - integer_part = ((25 * clk_speed) / (4 * baud)); + /* See ST RM0008 for the details on configuring the baud rate register */ + integer_part = (25 * clock_speed) / (4 * baud); tmp = (integer_part / 100) << 4; - fractional_part = integer_part - (100 * (tmp >> 4)); tmp |= (((fractional_part * 16) + 50) / 100) & ((uint8)0x0F); - port->BRR = (uint16)tmp; - - port->CR1 = USART_TE | // transmitter enable - USART_RE | // receiver enable - USART_RXNEIE; // receive interrupt enable - - - /* Enable the USART and set mode to 8n1 */ - port->CR1 |= USART_UE; + dev->regs->BRR = (uint16)tmp; } /** - * @brief Turn off all USARTs. + * @brief Enable a serial port. + * + * USART is enabled in single buffer transmission mode, multibuffer + * receiver mode, 8n1. + * + * Serial port must have a baud rate configured to work properly. + * + * @param dev Serial port to enable. + * @see usart_set_baud_rate() */ -void usart_disable_all() { - usart_disable(USART1); - usart_disable(USART2); - usart_disable(USART3); -#if NR_USART >= 5 - usart_disable(UART4); - usart_disable(UART5); -#endif +void usart_enable(usart_dev *dev) { + usart_reg_map *regs = dev->regs; + regs->CR1 = USART_CR1_TE | USART_CR1_RE | USART_CR1_RXNEIE; + regs->CR1 |= USART_CR1_UE; } /** - * @brief Turn off a USART. - * @param USART to be disabled + * @brief Turn off a serial port. + * @param dev Serial port to be disabled */ -void usart_disable(uint8 usart_num) { - usart_port *port = usart_dev_table[usart_num].base; +void usart_disable(usart_dev *dev) { + /* FIXME this misbehaves if you try to use PWM on TX afterwards */ + usart_reg_map *regs = dev->regs; - /* TC bit must be high before disabling the usart */ - while((port->CR1 & USART_UE) && !(port->SR & USART_TC)) + /* TC bit must be high before disabling the USART */ + while((regs->CR1 & USART_CR1_UE) && !(regs->SR & USART_SR_TC)) ; /* Disable UE */ - port->CR1 = 0; + regs->CR1 &= ~USART_CR1_UE; /* Clean up buffer */ - usart_reset_rx(usart_num); + usart_reset_rx(dev); } - /** - * @brief Print a null terminated string to the specified USART - * - * @param usart_num usart to send on - * @param str string to send + * @brief Call a function on each USART. + * @param fn Function to call. */ -void usart_putstr(uint8 usart_num, const char* str) { - char ch; +void usart_foreach(void (*fn)(usart_dev*)) { + fn(USART1); + fn(USART2); + fn(USART3); +#ifdef STM32_HIGH_DENSITY + fn(UART4); + fn(UART5); +#endif +} - while((ch = *(str++)) != '\0') { - usart_putc(usart_num, ch); +/** + * @brief Nonblocking USART transmit + * @param dev Serial port to transmit over + * @param buf Buffer to transmit + * @param len Maximum number of bytes to transmit + * @return Number of bytes transmitted + */ +uint32 usart_tx(usart_dev *dev, const uint8 *buf, uint32 len) { + usart_reg_map *regs = dev->regs; + uint32 txed = 0; + while ((regs->SR & USART_SR_TXE) && (txed < len)) { + regs->DR = buf[txed++]; } + return txed; } /** - * @brief Print an unsigned integer to the specified usart + * @brief Transmit an unsigned integer to the specified serial port in + * decimal format. * - * @param usart_num usart to send on - * @param val number to print + * This function blocks until the integer's digits have been + * completely transmitted. + * + * @param dev Serial port to send on + * @param val Number to print */ -void usart_putudec(uint8 usart_num, uint32 val) { +void usart_putudec(usart_dev *dev, uint32 val) { char digits[12]; - int i; + int i = 0; - i = 0; do { digits[i++] = val % 10 + '0'; val /= 10; } while (val > 0); + while (--i >= 0) { - usart_putc(usart_num, digits[i]); + usart_putc(dev, digits[i]); } } + +/* + * Interrupt handlers. + */ + +static inline void usart_irq(usart_dev *dev) { +#ifdef USART_SAFE_INSERT + /* If the buffer is full and the user defines USART_SAFE_INSERT, + * ignore new bytes. */ + rb_safe_insert(dev->rb, (uint8)dev->regs->DR); +#else + /* By default, push bytes around in the ring buffer. */ + rb_push_insert(dev->rb, (uint8)dev->regs->DR); +#endif +} + +void __irq_usart1(void) { + usart_irq(USART1); +} + +void __irq_usart2(void) { + usart_irq(USART2); +} + +void __irq_usart3(void) { + usart_irq(USART3); +} + +#ifdef STM32_HIGH_DENSITY +void __irq_uart4(void) { + usart_irq(UART4); +} + +void __irq_uart5(void) { + usart_irq(UART5); +} +#endif |