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/******************************************************************************
* The MIT License
*
* 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
* 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 usart.h
* @brief USART definitions and prototypes
*/
#ifndef _USART_H_
#define _USART_H_
#include "ring_buffer.h"
#ifdef __cplusplus
extern "C"{
#endif
#define USART_TXE BIT(7)
/* usart device numbers */
enum {
USART1,
USART2,
USART3,
UART4,
UART5,
};
/* peripheral register struct */
typedef struct usart_port {
volatile uint32 SR; // Status register
volatile uint32 DR; // Data register
volatile uint32 BRR; // Baud rate register
volatile uint32 CR1; // Control register 1
volatile uint32 CR2; // Control register 2
volatile uint32 CR3; // Control register 3
volatile uint32 GTPR; // Guard time and prescaler register
} usart_port;
/* usart descriptor */
struct usart_dev {
usart_port *base;
ring_buffer rb;
uint8 rx_buf[64];
const uint8 rcc_dev_num;
const uint8 nvic_dev_num;
};
extern struct usart_dev usart_dev_table[];
/**
* @brief send one character on a usart
* @param usart_num usart to send on
* @param byte byte to send
*/
static inline void usart_putc(uint8 usart_num, uint8 byte) {
usart_port *port = usart_dev_table[usart_num].base;
port->DR = byte;
/* Wait for transmission to complete */
while ((port->SR & USART_TXE) == 0)
;
}
/**
* @brief read one character from a usart
* @param usart_num usart to read from
* @return byte read
*/
static inline uint8 usart_getc(uint8 usart_num) {
return rb_remove(&usart_dev_table[usart_num].rb);
}
/**
* @brief return the amount of data available in the rx buffer
* @param usart_num which usart to check
* @return number of bytes in the rx buffer
*/
static inline uint32 usart_data_available(uint8 usart_num) {
return rb_full_count(&usart_dev_table[usart_num].rb);
}
/**
* @brief removes the contents of the rx fifo
* @param usart_num which usart to reset
*/
static inline void usart_reset_rx(uint8 usart_num) {
rb_reset(&usart_dev_table[usart_num].rb);
}
void usart_init(uint8 usart_num, uint32 baud);
void usart_disable(uint8 usart_num);
void usart_disable_all();
void usart_putstr(uint8 usart_num, const char*);
void usart_putudec(uint8 usart_num, uint32 val);
#ifdef __cplusplus
} // extern "C"
#endif
#endif // _USART_H_
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