404 lines
12 KiB
C
404 lines
12 KiB
C
/****************************************************************************
|
|
* libc/msic/lib_slcddecode.c
|
|
* Decoding 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 <stdbool.h>
|
|
#include <assert.h>
|
|
#include <debug.h>
|
|
|
|
#include <nuttx/streams.h>
|
|
#include <nuttx/ascii.h>
|
|
#include <nuttx/lcd/slcd_codec.h>
|
|
|
|
/****************************************************************************
|
|
* Pre-processor Definitions
|
|
****************************************************************************/
|
|
/* Configuration ************************************************************/
|
|
/* Define CONFIG_DEBUG_LCD to enable detailed LCD debug output. Verbose
|
|
* debug must also be enabled.
|
|
*/
|
|
|
|
#ifndef CONFIG_DEBUG
|
|
# undef CONFIG_DEBUG_VERBOSE
|
|
# undef CONFIG_DEBUG_LCD
|
|
#endif
|
|
|
|
#ifndef CONFIG_DEBUG_VERBOSE
|
|
# undef CONFIG_DEBUG_LCD
|
|
#endif
|
|
|
|
/* Indices, counts, helper macros ******************************************/
|
|
|
|
#define NDX_ESC 0
|
|
#define NDX_BRACKET 1
|
|
#define NDX_CODE3 2
|
|
#define NDX_COUNTH 2
|
|
#define NDX_COUNTL 3
|
|
#define NDX_CODE5 4
|
|
|
|
#define NCH_ESC 1
|
|
#define NCH_BRACKET 2
|
|
#define NCH_CODE3 3
|
|
#define NCH_COUNTH 3
|
|
#define NCH_COUNTL 4
|
|
#define NCH_CODE5 5
|
|
|
|
#define IS_HEX(a) ((((a) >= '0') && ((a) <= '9')) || \
|
|
(((a) >= 'a') && ((a) <= 'f')))
|
|
#define CODE_MIN ('A' + FIRST_SLCDCODE)
|
|
#define CODE_MAX ('A' + LAST_SLCDCODE)
|
|
#define IS_CODE(a) (((a) >= CODE_MIN) && ((a) <= CODE_MAX))
|
|
#define CODE_RETURN(a) (enum slcdcode_e)((a) - 'A')
|
|
|
|
/* Debug ********************************************************************/
|
|
|
|
#ifdef CONFIG_DEBUG_LCD
|
|
# define lcddbg dbg
|
|
# define lcdvdbg vdbg
|
|
#else
|
|
# define lcddbg(x...)
|
|
# define lcdvdbg(x...)
|
|
#endif
|
|
|
|
/****************************************************************************
|
|
* Private Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: slcd_nibble
|
|
*
|
|
* Description:
|
|
* Convert a ASCII hexadecimal character (using only lower case alphabetics
|
|
* into a binary nibble
|
|
*
|
|
* Input Parameters:
|
|
* ascii - The nibble characgter.
|
|
*
|
|
* Returned Value:
|
|
* The binary value of the nibble.
|
|
*
|
|
****************************************************************************/
|
|
|
|
static uint8_t slcd_nibble(uint8_t ascii)
|
|
{
|
|
if (ascii >= '0' && ascii <= '9')
|
|
{
|
|
return ascii - '0';
|
|
}
|
|
else
|
|
{
|
|
return ascii - 'a';
|
|
}
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: slcd_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
|
|
* slcd_keycode_e
|
|
*
|
|
* Returned Value:
|
|
* Always SLCDRET_CHAR
|
|
*
|
|
****************************************************************************/
|
|
|
|
static enum slcdret_e slcd_reget(FAR struct slcdstate_s *state,
|
|
FAR uint8_t *pch, FAR uint8_t *parg)
|
|
{
|
|
/* Return the next character */
|
|
|
|
*pch = state->buf[state->ndx];
|
|
*parg = 0;
|
|
|
|
/* Bump up the indices and return false (meaning a normal character) */
|
|
|
|
state->ndx++;
|
|
state->nch--;
|
|
return SLCDRET_CHAR;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: slcd_decode
|
|
*
|
|
* Description:
|
|
* Get one byte of data or special command from the application provided
|
|
* input buffer.
|
|
*
|
|
* Input Parameters:
|
|
* stream - An instance of lib_instream_s to do the low-level get
|
|
* operation.
|
|
* state - A user provided buffer to support parsing. This structure
|
|
* should be cleared the first time that slcd_decode is called.
|
|
* pch - The location to save the returned value. This may be
|
|
* either a normal, character code or a special command from enum
|
|
* slcdcode_e, depending on the return value from slcd_decode()
|
|
* parg - The location to save the count argument that accompanies some
|
|
* special actions
|
|
*
|
|
* Returned Value:
|
|
*
|
|
* false: Normal character
|
|
* true: Special SLCD action code with possible argument
|
|
*
|
|
****************************************************************************/
|
|
|
|
enum slcdret_e slcd_decode(FAR struct lib_instream_s *stream,
|
|
FAR struct slcdstate_s *state, FAR uint8_t *pch,
|
|
FAR uint8_t *parg)
|
|
|
|
{
|
|
enum slcdcode_e code;
|
|
uint8_t count;
|
|
int ch;
|
|
|
|
DEBUGASSERT(stream && state && pch && parg);
|
|
|
|
/* Are their ungotten characters from the last, failed parse? */
|
|
|
|
if (state->nch > 0)
|
|
{
|
|
/* Yes, return the next ungotten character */
|
|
|
|
return slcd_reget(state, pch, parg);
|
|
}
|
|
|
|
state->ndx = 0;
|
|
|
|
/* No, ungotten characters. Get the next character from the buffer. */
|
|
|
|
ch = stream->get(stream);
|
|
if (ch == EOF)
|
|
{
|
|
/* End of file/stream (or perhaps an I/O error) */
|
|
|
|
return SLCDRET_EOF;
|
|
}
|
|
|
|
/* Save the character (whatever it is) in case we fail parsing later */
|
|
|
|
state->buf[NDX_ESC] = (uint8_t)ch;
|
|
state->nch = NCH_ESC;
|
|
|
|
/* Check for the beginning of an escape sequence */
|
|
|
|
if (ch != ASCII_ESC)
|
|
{
|
|
/* Not the beginning of an escape sequence. Return the character. */
|
|
|
|
return slcd_reget(state, pch, parg);
|
|
}
|
|
|
|
/* Get the next character from the buffer */
|
|
|
|
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 slcd_reget(state, pch, parg);
|
|
}
|
|
|
|
/* Save the character (whatever it is) in case we fail parsing later */
|
|
|
|
state->buf[NDX_BRACKET] = ch;
|
|
state->nch = NCH_BRACKET;
|
|
|
|
/* Check for ESC-[ */
|
|
|
|
if (ch != '[')
|
|
{
|
|
/* Not the beginning of an escape sequence. Return the ESC now,
|
|
* return the following characters later.
|
|
*/
|
|
|
|
lcddbg("Parsing failed: ESC followed by %02x\n", ch);
|
|
return slcd_reget(state, pch, parg);
|
|
}
|
|
|
|
/* Get the next character from the buffer */
|
|
|
|
ch = stream->get(stream);
|
|
if (ch == EOF)
|
|
{
|
|
/* End of file/stream. Return the ESC now; return the following
|
|
* characters later.
|
|
*/
|
|
|
|
return slcd_reget(state, pch, parg);
|
|
}
|
|
|
|
/* If the next character is a hexidecimal value (with lower case
|
|
* alphabetic characters), then we are parsing a 5-byte sequence.
|
|
*/
|
|
|
|
if (!IS_HEX(ch))
|
|
{
|
|
/* Decode the value following the bracket */
|
|
|
|
code = CODE_RETURN(ch);
|
|
count = 0;
|
|
|
|
/* Verify the special CLCD action code */
|
|
|
|
if (code < (int)FIRST_SLCDCODE || code > (int)LAST_SLCDCODE)
|
|
{
|
|
lcddbg("Parsing failed: ESC-L followed by %02x\n", ch);
|
|
|
|
/* Not a special command code.. put the character in the reget
|
|
* buffer.
|
|
*/
|
|
|
|
state->buf[NDX_CODE3] = (uint8_t)ch;
|
|
state->nch = NCH_CODE3;
|
|
|
|
/* Return the ESC now and the next two characters later. */
|
|
|
|
return slcd_reget(state, pch, parg);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* Save the first character of the two byte hexidecimal number */
|
|
|
|
state->buf[NDX_COUNTH] = (uint8_t)ch;
|
|
state->nch = NCH_COUNTH;
|
|
|
|
/* Get the next character from the buffer */
|
|
|
|
ch = stream->get(stream);
|
|
if (ch == EOF)
|
|
{
|
|
/* End of file/stream. Return the ESC now; return the following
|
|
* characters later.
|
|
*/
|
|
|
|
return slcd_reget(state, pch, parg);
|
|
}
|
|
|
|
/* We expect the next character to be the second byte of hexidecimal
|
|
* count value.
|
|
*/
|
|
|
|
if (!IS_HEX(ch))
|
|
{
|
|
/* Not a 5-byte escape sequence. Return the ESC now; return the
|
|
* following characters later.
|
|
*/
|
|
|
|
lcddbg("Parsing failed: ESC-L-%c followed by %02x\n",
|
|
state->buf[NDX_COUNTH], ch);
|
|
|
|
return slcd_reget(state, pch, parg);
|
|
}
|
|
|
|
/* Save the second character of the two byte hexidecimal number */
|
|
|
|
state->buf[NDX_COUNTL] = (uint8_t)ch;
|
|
state->nch = NCH_COUNTL;
|
|
|
|
/* Get the next character from the buffer */
|
|
|
|
ch = stream->get(stream);
|
|
if (ch == EOF)
|
|
{
|
|
/* End of file/stream. Return the ESC now; return the following
|
|
* characters later.
|
|
*/
|
|
|
|
return slcd_reget(state, pch, parg);
|
|
}
|
|
|
|
/* Put the character in the reget buffer because there is on more way
|
|
* that we can fail.
|
|
*/
|
|
|
|
state->buf[NDX_CODE5] = (uint8_t)ch;
|
|
state->nch = NCH_CODE5;
|
|
|
|
/* Get the code and the count values. All count values must be greater
|
|
* than 0 or something is wrong.
|
|
*/
|
|
|
|
code = CODE_RETURN(ch);
|
|
count = slcd_nibble(state->buf[NDX_COUNTH]) << 4 |
|
|
slcd_nibble(state->buf[NDX_COUNTL]);
|
|
|
|
/* Verify the special CLCD action code */
|
|
|
|
if (code < (int)FIRST_SLCDCODE || code > (int)LAST_SLCDCODE)
|
|
{
|
|
/* Not a special command code. Return the ESC now and the rest
|
|
* of the characters later.
|
|
*/
|
|
|
|
lcddbg("Parsing failed: ESC-L-%c-%c followed by %02x\n",
|
|
state->buf[NDX_COUNTH], state->buf[NDX_COUNTL], ch);
|
|
|
|
return slcd_reget(state, pch, parg);
|
|
}
|
|
}
|
|
|
|
/* We have successfully parsed the entire escape sequence. Return the
|
|
* CLCD value in pch, return the count in parg, and an indication that this
|
|
* is a special action.
|
|
*/
|
|
|
|
*pch = code;
|
|
*parg = count;
|
|
state->nch = 0;
|
|
return SLCDRET_SPEC;
|
|
}
|