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/* Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
/* uart.h - UART module for Chrome EC */
#ifndef __CROS_EC_UART_H
#define __CROS_EC_UART_H
#include <stdarg.h> /* For va_list */
#include "common.h"
/**
* Initialize the UART module.
*/
void uart_init(void);
/**
* Return non-zero if UART init has completed.
*/
int uart_init_done(void);
/*
* Output functions
*
* Output is buffered. If the buffer overflows, subsequent output is
* discarded.
*
* Modules should use the output functions in console.h in preference to these
* routines, so that output can be filtered on a module-by-module basis.
*/
/**
* Put a null-terminated string to the UART, like fputs().
*
* @return EC_SUCCESS, or non-zero if output was truncated.
*/
int uart_puts(const char *outstr);
/**
* Print formatted output to the UART, like printf().
*
* See printf.h for valid formatting codes.
*
* @return EC_SUCCESS, or non-zero if output was truncated.
*/
int uart_printf(const char *format, ...);
/**
* Print formatted output to the UART, like vprintf().
*
* See printf.h for valid formatting codes.
*
* @return EC_SUCCESS, or non-zero if output was truncated.
*/
int uart_vprintf(const char *format, va_list args);
/**
* Flush output. Blocks until UART has transmitted all output.
*/
void uart_flush_output(void);
/*
* Input functions
*
* Input is buffered. If the buffer overflows, the oldest input in
* the buffer is discarded to make room for the new input.
*
* Input lines may be terminated by CR ('\r'), LF ('\n'), or CRLF; all
* are translated to newline.
*/
/**
* Flush input buffer, discarding all input.
*/
void uart_flush_input(void);
/**
* Non-destructively check for a character in the input buffer.
*
* @param c Character to search for
*
* @return the offset into the input buffer of the first match, or -1 if no
* match found in the input buffer.
*/
int uart_peek(int c);
/**
* Read a single character of input, similar to fgetc().
*
* @return the character, or -1 if no input waiting.
*/
int uart_getc(void);
/**
* Read characters from the UART, similar to fgets().
*
* Reads input until one of the following conditions is met:
* (1) <size-1> characters have been read.
* (2) A newline ('\n') has been read.
* (3) The input buffer is empty.
*
* Condition (3) means this call never blocks. This is important
* because it prevents a race condition where the caller calls
* uart_peek() to see if input is waiting, or is notified by the
* callack that input is waiting, but then the input buffer overflows
* or someone else grabs the input before uart_gets() is called.
*
* Characters are stored in <dest> and are null-terminated.
* Characters include the newline if present, so that the caller can
* distinguish between a complete line and a truncated one. If the
* input buffer is empty, a null-terminated empty string ("") is
* returned.
*
* @param dest Destination for input
* @param size Size of buffer pointed to by dest
*
* @return the number of characters read, not counting the terminating null.
*/
int uart_gets(char *dest, int size);
/*
* Hardware UART driver functions
*/
/**
* Flush the transmit FIFO.
*/
void uart_tx_flush(void);
/**
* Return non-zero if there is room to transmit a character immediately.
*/
int uart_tx_ready(void);
/**
* Return non-zero if the UART has a character available to read.
*/
int uart_rx_available(void);
/**
* Send a character to the UART data register.
*
* If the transmit FIFO is full, blocks until there is space.
*
* @param c Character to send.
*/
void uart_write_char(char c);
/**
* Read one char from the UART data register.
*
* @return The character read.
*/
int uart_read_char(void);
/**
* Disable all UART related IRQs.
*
* Used to avoid concurrent accesses on UART management variables.
*/
void uart_disable_interrupt(void);
/**
* Re-enable UART IRQs.
*/
void uart_enable_interrupt(void);
/**
* Re-enable the UART transmit interrupt.
*
* This also forces triggering an interrupt if the hardware doesn't
* automatically trigger it when the transmit buffer was filled beforehand.
*/
void uart_tx_start(void);
/**
* Disable the UART transmit interrupt.
*/
void uart_tx_stop(void);
/**
* Return non-zero if the UART transmit interrupt is disabled.
*/
int uart_tx_stopped(void);
/**
* Helper for UART processing.
*
* Reads the input FIFO until empty, then fills the output FIFO until the
* transmit buffer is empty or the FIFO full.
*
* Designed to be called from the driver interrupt handler.
*/
void uart_process(void);
/*
* COMx functions
*/
/**
* Enable COMx interrupts
*/
void uart_comx_enable(void);
/**
* Return non-zero if ok to put a character via uart_comx_putc().
*/
int uart_comx_putc_ok(void);
/**
* Write a character to the COMx UART interface.
*/
void uart_comx_putc(int c);
#endif /* __CROS_EC_UART_H */
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