50448497f8
Sigh; Emacs's elide-head feature makes it easy to forget to update these. Signed-off-by: Marti Bolivar <mbolivar@leaflabs.com>
139 lines
4 KiB
C
139 lines
4 KiB
C
/******************************************************************************
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* The MIT License
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*
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* Copyright (c) 2010 Perry Hung.
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* Copyright (c) 2011 LeafLabs, LLC.
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*
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* Permission is hereby granted, free of charge, to any person
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* obtaining a copy of this software and associated documentation
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* files (the "Software"), to deal in the Software without
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* restriction, including without limitation the rights to use, copy,
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* modify, merge, publish, distribute, sublicense, and/or sell copies
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* of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be
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* included in all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
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* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
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* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*****************************************************************************/
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/**
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* @file libmaple/usart.c
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* @author Marti Bolivar <mbolivar@leaflabs.com>,
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* Perry Hung <perry@leaflabs.com>
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* @brief Portable USART routines
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*/
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#include <libmaple/usart.h>
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/**
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* @brief Initialize a serial port.
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* @param dev Serial port to be initialized
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*/
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void usart_init(usart_dev *dev) {
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rb_init(dev->rb, USART_RX_BUF_SIZE, dev->rx_buf);
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rcc_clk_enable(dev->clk_id);
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nvic_irq_enable(dev->irq_num);
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}
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/**
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* @brief Enable a serial port.
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*
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* USART is enabled in single buffer transmission mode, multibuffer
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* receiver mode, 8n1.
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*
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* Serial port must have a baud rate configured to work properly.
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*
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* @param dev Serial port to enable.
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* @see usart_set_baud_rate()
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*/
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void usart_enable(usart_dev *dev) {
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usart_reg_map *regs = dev->regs;
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regs->CR1 = (USART_CR1_TE | USART_CR1_RE | USART_CR1_RXNEIE |
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USART_CR1_M_8N1);
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regs->CR1 |= USART_CR1_UE;
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}
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/**
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* @brief Turn off a serial port.
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* @param dev Serial port to be disabled
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*/
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void usart_disable(usart_dev *dev) {
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/* FIXME this misbehaves (on F1) if you try to use PWM on TX afterwards */
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usart_reg_map *regs = dev->regs;
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/* TC bit must be high before disabling the USART */
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while((regs->CR1 & USART_CR1_UE) && !(regs->SR & USART_SR_TC))
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;
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/* Disable UE */
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regs->CR1 &= ~USART_CR1_UE;
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/* Clean up buffer */
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usart_reset_rx(dev);
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}
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/**
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* @brief Nonblocking USART transmit
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* @param dev Serial port to transmit over
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* @param buf Buffer to transmit
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* @param len Maximum number of bytes to transmit
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* @return Number of bytes transmitted
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*/
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uint32 usart_tx(usart_dev *dev, const uint8 *buf, uint32 len) {
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usart_reg_map *regs = dev->regs;
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uint32 txed = 0;
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while ((regs->SR & USART_SR_TXE) && (txed < len)) {
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regs->DR = buf[txed++];
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}
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return txed;
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}
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/**
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* @brief Nonblocking USART receive.
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* @param dev Serial port to receive bytes from
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* @param buf Buffer to store received bytes into
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* @param len Maximum number of bytes to store
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* @return Number of bytes received
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*/
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uint32 usart_rx(usart_dev *dev, uint8 *buf, uint32 len) {
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uint32 rxed = 0;
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while (usart_data_available(dev) && rxed < len) {
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*buf++ = usart_getc(dev);
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rxed++;
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}
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return rxed;
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}
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/**
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* @brief Transmit an unsigned integer to the specified serial port in
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* decimal format.
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*
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* This function blocks until the integer's digits have been
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* completely transmitted.
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*
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* @param dev Serial port to send on
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* @param val Number to print
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*/
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void usart_putudec(usart_dev *dev, uint32 val) {
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char digits[12];
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int i = 0;
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do {
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digits[i++] = val % 10 + '0';
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val /= 10;
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} while (val > 0);
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while (--i >= 0) {
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usart_putc(dev, digits[i]);
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}
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}
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