text: /************************************************************************
   *
   *   Copyright (c) 2012-2014 PX4 Development Team. All rights reserved.
   *   Copyright (c) 2010 libopencm3 project
   *
   * This program is free software: you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation, either version 3 of the License, or
   * (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
   *
   * LICENSE NOTE FOR EXTERNAL LIBOPENCM3 LIBRARY:
   *
   *   The PX4 development team considers libopencm3 to be
   *   still GPL, not LGPL licensed, as it is unclear if
   *   each and every author agreed to the LGPS -> GPL change.
   *
   ***********************************************************************/
  
  /*
   * USART interface for the bootloader.
   */
  
  #include "hw_config.h"
  
  # include <libopencm3/stm32/rcc.h>
  # include <libopencm3/stm32/gpio.h>
  
  #include <libopencm3/stm32/usart.h>
  
  #if !defined(USART_SR)
  #define USART_SR USART_ISR
  #endif
  #include "bl.h"
  #include "uart.h"
  
  uint32_t usart;
  
  void
  uart_cinit(void *config)
  {
  	usart = (uint32_t)config;
  
  	/* board is expected to do pin and clock setup */
  
  	/* do usart setup */
  	//USART_CR1(usart) |= (1 << 15);	/* because libopencm3 doesn't know the OVER8 bit */
  	usart_set_baudrate(usart, USART_BAUDRATE);
  	usart_set_databits(usart, 8);
  	usart_set_stopbits(usart, USART_STOPBITS_1);
  	usart_set_mode(usart, USART_MODE_TX_RX);
  	usart_set_parity(usart, USART_PARITY_NONE);
  	usart_set_flow_control(usart, USART_FLOWCONTROL_NONE);
  
  	/* and enable */
  	usart_enable(usart);
  
  
  #if 0
  	usart_send_blocking(usart, 'B');
  	usart_send_blocking(usart, 'B');
  	usart_send_blocking(usart, 'B');
  	usart_send_blocking(usart, 'B');
  
  	while (true) {
  		int c;
  		c = usart_recv_blocking(usart);
  		usart_send_blocking(usart, c);
  	}
  
  #endif
  }
  
  void
  uart_cfini(void)
  {
  	usart_disable(usart);
  }
  
  int
  uart_cin(void)
  {
  	int c = -1;
  
  	if (USART_SR(usart) & USART_FLAG_RXNE) {
  		c = usart_recv(usart);
  	}
  
  	return c;
  }
  
  void
  uart_cout(uint8_t *buf, unsigned len)
  {
  	while (len--) {
  		usart_send_blocking(usart, *buf++);
  	}
  }
  