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/* Copyright (c) 2011 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.
*/
/* ec_uart.h - UART module for Chrome EC */
#ifndef __CROS_EC_UART_H
#define __CROS_EC_UART_H
#include "ec_common.h"
/* Initializes the UART module. */
EcError EcUartInit(void);
/*****************************************************************************/
/* Output functions
*
* Output is buffered. If the buffer overflows, subsequent output is
* discarded. */
/* Print formatted output to the UART, like printf().
*
* Returns error if output was truncated.
*
* Must support format strings for:
* char (%c)
* string (%s)
* native int (signed/unsigned) (%d / %u / %x)
* int32_t / uint32_t (%d / %x)
* int64_t / uint64_t (%ld / %lu / %lx)
* pointer (%p)
* including padding (%-5s, %8d, %08x)
*
* Note: Floating point output (%f / %g) is not required.
*/
EcError EcUartPrintf(const char* format, ...);
/* Put a null-terminated string to the UART, like puts().
*
* Returns error if output was truncated. */
EcError EcUartPuts(const char* outstr);
/* Flushes output. Blocks until UART has transmitted all output. */
void EcUartFlushOutput(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. */
/* Flushes input buffer, discarding all input. */
void EcUartFlushInput(void);
/* Non-destructively checks for a character in the input buffer.
*
* Returns the offset into the input buffer of character <c>, or -1 if
* it is not in the input buffer. */
int EcUartPeek(int c);
/* Reads 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
* UartPeek() 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 UartGets() 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.
*
* Returns the number of characters read (not counting the terminating
* null). */
int EcUartGets(char* dest, int size);
/* Callback handler prototype, called when the UART has input. */
typedef void (*UartHasInputCallback)(void);
/* Registers an input callback handler, replacing any existing
* callback handler. If callback==NULL, disables callbacks.
*
* Callback will be called whenever the UART receives character <c>.
* If c<0, callback will be called when the UART receives any
* character. */
void EcUartRegisterHasInputCallback(UartHasInputCallback callback, int c);
/* TODO: getc(), putc() equivalents? */
#endif /* __CROS_EC_UART_H */
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