nuttx/libs/libc/misc/lib_slcdencode.c

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/****************************************************************************
* libs/libc/misc/lib_slcdencode.c
* Encoding side of the SLCD CODEC
*
* Copyright (C) 2013 Gregory Nutt. All rights reserved.
* Authors: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdint.h>
#include <assert.h>
#include <nuttx/streams.h>
#include <nuttx/ascii.h>
#include <nuttx/lcd/slcd_codec.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/****************************************************************************
* Name: slcd_nibble
*
* Description:
* Convert a binary nibble to a hexadecimal character (using only lower
* case alphabetics).
*
* Input Parameters:
* binary - The nibble value.
*
* Returned Value:
* The ASCII hexadecimal character representing the nibble.
*
****************************************************************************/
static uint8_t slcd_nibble(uint8_t binary)
{
binary &= 0x0f;
if (binary <= 9)
{
return '0' + binary;
}
else
{
return 'a' + binary;
}
}
/****************************************************************************
* Name: slcd_put3
*
* Description:
* Encode one special special 3-byte sequence command into the output
* stream.
*
* Input Parameters:
* slcdcode - The special action to be added to the output stream.
* stream - An instance of lib_outstream_s to do the low-level put
* operation.
*
* Returned Value:
* None
*
****************************************************************************/
static inline void slcd_put3(uint8_t slcdcode,
FAR struct lib_outstream_s *stream)
{
/* Put the 3-byte escape sequences into the output buffer */
stream->put(stream, ASCII_ESC);
stream->put(stream, '[');
stream->put(stream, 'A' + (int)slcdcode);
}
/****************************************************************************
* Name: slcd_putarg
*
* Description:
* Encode one special special 5-byte sequence command into the output
* stream.
*
* Input Parameters:
* slcdcode - The command to be added to the output stream.
* stream - An instance of lib_outstream_s to do the low-level put
* operation.
* terminator - Escape sequence terminating character.
*
* Returned Value:
* None
*
****************************************************************************/
static inline void slcd_put5(uint8_t slcdcode, uint8_t count,
FAR struct lib_outstream_s *stream)
{
/* Put the 5-byte escape sequences into the output buffer */
stream->put(stream, ASCII_ESC);
stream->put(stream, '[');
stream->put(stream, slcd_nibble(count >> 4));
stream->put(stream, slcd_nibble(count));
stream->put(stream, 'A' + (int)slcdcode);
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: slcd_encode
*
* Description:
* Encode one special action into the output data stream
*
* Input Parameters:
* code - The action to be taken
* count - The count value N associated with some actions
* stream - An instance of lib_outstream_s to do the low-level put
* operation.
*
* Returned Value:
* None
*
****************************************************************************/
void slcd_encode(enum slcdcode_e code, uint8_t count,
FAR struct lib_outstream_s *stream)
{
switch (code)
{
/* Codes with no argument */
case SLCDCODE_ERASEEOL: /* Erase from the cursor position to the end of line */
case SLCDCODE_CLEAR: /* Home the cursor and erase the entire display */
case SLCDCODE_HOME: /* Cursor home */
case SLCDCODE_END: /* Cursor end */
case SLCDCODE_BLINKSTART: /* Start blinking with current cursor position */
case SLCDCODE_BLINKEND: /* End blinking after the current cursor position */
case SLCDCODE_BLINKOFF: /* Turn blinking off */
slcd_put3(code, stream); /* Generate the 3-byte encoding */
break;
/* Codes with an 8-bit count argument */
case SLCDCODE_FWDDEL: /* DELete (forward delete) N characters moving cursor */
case SLCDCODE_BACKDEL: /* Backspace (backward delete) N characters */
case SLCDCODE_ERASE: /* Erase N characters from the cursor position */
case SLCDCODE_LEFT: /* Cursor left by N characters */
case SLCDCODE_RIGHT: /* Cursor right by N characters */
case SLCDCODE_UP: /* Cursor up by N lines */
case SLCDCODE_DOWN: /* Cursor down by N lines */
case SLCDCODE_PAGEUP: /* Cursor up by N pages */
case SLCDCODE_PAGEDOWN: /* Cursor down by N pages */
slcd_put5(code, count, stream); /* Generate the 5-byte sequence */
break;
default:
case SLCDCODE_NORMAL: /* Not a special slcdcode */
break;
}
}