268 lines
8.2 KiB
C
268 lines
8.2 KiB
C
/****************************************************************************
|
|
* libs/libc/msic/lib_kbddecode.c
|
|
* Decoding side of the Keyboard CODEC
|
|
*
|
|
* Copyright (C) 2012 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 <debug.h>
|
|
|
|
#include <nuttx/streams.h>
|
|
#include <nuttx/ascii.h>
|
|
#include <nuttx/input/kbd_codec.h>
|
|
|
|
/****************************************************************************
|
|
* Pre-processor Definitions
|
|
****************************************************************************/
|
|
|
|
#define NDX_ESC 0
|
|
#define NDX_BRACKET 1
|
|
#define NDX_CODE 2
|
|
#define NDX_TERMINATOR 3
|
|
|
|
#define NCH_ESC 1
|
|
#define NCH_BRACKET 2
|
|
#define NCH_CODE 3
|
|
#define NCH_TERMINATOR 4
|
|
|
|
#define TERM_MIN ('a' + KBD_RELEASE)
|
|
#define TERM_MAX ('a' + KBD_SPECREL)
|
|
#define TERM_RETURN(a) ((a) - 'a')
|
|
|
|
/****************************************************************************
|
|
* Private Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: kbd_reget
|
|
*
|
|
* Description:
|
|
* We have unused characters from the last, unsuccessful decode attempt.
|
|
* Return one of these instead of the new character from the stream.
|
|
*
|
|
* Input Parameters:
|
|
* stream - An instance of lib_instream_s to do the low-level get
|
|
* operation.
|
|
* pch - The location character to save the returned value. This may be
|
|
* either a normal, character code or a special command from enum
|
|
* kbd_keycode_e
|
|
*
|
|
* Returned Value:
|
|
* KBD_PRESS - Indicates the successful receipt of norma keyboard data.
|
|
*
|
|
****************************************************************************/
|
|
|
|
static int kbd_reget(FAR struct kbd_getstate_s *state, FAR uint8_t *pch)
|
|
{
|
|
/* Return the next character */
|
|
|
|
*pch = state->buf[state->ndx];
|
|
state->ndx++;
|
|
state->nch--;
|
|
return KBD_PRESS;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: kbd_decode
|
|
*
|
|
* Description:
|
|
* Get one byte of data or special command from the driver provided input
|
|
* buffer.
|
|
*
|
|
* Input Parameters:
|
|
* stream - An instance of lib_instream_s to do the low-level get
|
|
* operation.
|
|
* pch - The location to save the returned value. This may be
|
|
* either a normal, character code or a special command from enum
|
|
* kbd_keycode_e
|
|
* state - A user provided buffer to support parsing. This structure
|
|
* should be cleared the first time that kbd_decode is called.
|
|
*
|
|
* Returned Value:
|
|
*
|
|
* KBD_PRESS - Indicates the successful receipt of normal, keyboard data.
|
|
* This corresponds to a keypress event. The returned value in pch is a
|
|
* simple byte of text or control data corresponding to the pressed key.
|
|
* KBD_RELEASE - Indicates a key release event. The returned value in pch
|
|
* is the byte of text or control data corresponding to the released key.
|
|
* KBD_SPECPRESS - Indicates the successful receipt of a special keyboard
|
|
* command. The returned value in pch is a value from enum kbd_getstate_s.
|
|
* KBD_SPECREL - Indicates a special key release event. The returned value
|
|
* in pch is a value from enum kbd_getstate_s.
|
|
* EOF - An error has getting the next character (reported by the stream).
|
|
* Normally indicates the end of file.
|
|
*
|
|
****************************************************************************/
|
|
|
|
int kbd_decode(FAR struct lib_instream_s *stream,
|
|
FAR struct kbd_getstate_s *state, FAR uint8_t *pch)
|
|
{
|
|
int ch;
|
|
|
|
DEBUGASSERT(stream && state && pch);
|
|
|
|
/* Are their ungotten characters from the last, failed parse? */
|
|
|
|
if (state->nch > 0)
|
|
{
|
|
/* Yes, return the next ungotten character */
|
|
|
|
return kbd_reget(state, pch);
|
|
}
|
|
|
|
state->ndx = 0;
|
|
|
|
/* No, ungotten characters. Check for the beginning of an ESC sequence. */
|
|
|
|
ch = stream->get(stream);
|
|
if (ch == EOF)
|
|
{
|
|
/* End of file/stream */
|
|
|
|
return KBD_ERROR;
|
|
}
|
|
else
|
|
{
|
|
state->buf[NDX_ESC] = (uint8_t)ch;
|
|
state->nch = NCH_ESC;
|
|
|
|
if (ch != ASCII_ESC)
|
|
{
|
|
/* Not the beginning of an escape sequence. Return the character. */
|
|
|
|
return kbd_reget(state, pch);
|
|
}
|
|
}
|
|
|
|
/* Check for ESC-[ */
|
|
|
|
ch = stream->get(stream);
|
|
if (ch == EOF)
|
|
{
|
|
/* End of file/stream. Return the escape character now. We will
|
|
* return the EOF indication next time.
|
|
*/
|
|
|
|
return kbd_reget(state, pch);
|
|
}
|
|
else
|
|
{
|
|
state->buf[NDX_BRACKET] = ch;
|
|
state->nch = NCH_BRACKET;
|
|
|
|
if (ch != '[')
|
|
{
|
|
/* Not the beginning of an escape sequence. Return the ESC now,
|
|
* return the following character later.
|
|
*/
|
|
|
|
return kbd_reget(state, pch);
|
|
}
|
|
}
|
|
|
|
/* Get and verify the special keyboard data to decode */
|
|
|
|
ch = stream->get(stream);
|
|
if (ch == EOF)
|
|
{
|
|
/* End of file/stream. Unget everything and return the ESC character.
|
|
*/
|
|
|
|
return kbd_reget(state, pch);
|
|
}
|
|
else
|
|
{
|
|
state->buf[NDX_CODE] = (uint8_t)ch;
|
|
state->nch = NCH_CODE;
|
|
|
|
/* Check for a valid special command code */
|
|
|
|
if (ch < FIRST_KEYCODE || ch > LAST_KEYCODE)
|
|
{
|
|
/* Not a special command code, return the ESC now and the next two
|
|
* characters later.
|
|
*/
|
|
|
|
return kbd_reget(state, pch);
|
|
}
|
|
}
|
|
|
|
/* Check for the final semicolon */
|
|
|
|
ch = stream->get(stream);
|
|
if (ch == EOF)
|
|
{
|
|
/* End of file/stream. Unget everything and return the ESC character.
|
|
*/
|
|
|
|
return kbd_reget(state, pch);
|
|
}
|
|
else
|
|
{
|
|
state->buf[NDX_TERMINATOR] = (uint8_t)ch;
|
|
state->nch = NCH_TERMINATOR;
|
|
|
|
/* Check for a valid special command code */
|
|
|
|
if (ch < TERM_MIN || ch > TERM_MAX)
|
|
{
|
|
/* Not a special command code, return the ESC now and the next two
|
|
* characters later.
|
|
*/
|
|
|
|
return kbd_reget(state, pch);
|
|
}
|
|
}
|
|
|
|
/* We have successfully parsed the entire escape sequence. Return the
|
|
* keyboard value in pch and the value an indication determined by the
|
|
* terminating character.
|
|
*/
|
|
|
|
*pch = state->buf[NDX_CODE];
|
|
state->nch = 0;
|
|
return TERM_RETURN(state->buf[NDX_TERMINATOR]);
|
|
}
|
|
|