incubator-nuttx/include/nuttx/lcd/slcd_codec.h

193 lines
6.9 KiB
C

/****************************************************************************
* include/nuttx/lcd/slcd_codec.h
* Serialize and marshaling data and events for character-based, segment LCDs
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
#ifndef __INCLUDE_NUTTX_LCD_SLCD_CODEC_H
#define __INCLUDE_NUTTX_LCD_SLCD_CODEC_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <nuttx/streams.h>
#ifdef CONFIG_LIBC_SLCDCODEC
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/****************************************************************************
* Public Types
****************************************************************************/
/* These are the special SLCD commands recognized by the CODEC. NOTE: that
* some require a a count argument, N.
*/
enum slcdcode_e
{
SLCDCODE_NORMAL = 0, /* Not a special keycode */
/* Delete and Backspace keycodes (in case they may be different than the
* ASCII BKSP and DEL values.
*/
SLCDCODE_FWDDEL, /* DELete (forward delete) N characters moving text */
SLCDCODE_BACKDEL, /* Backspace (backward delete) N characters moving cursor */
SLCDCODE_ERASE, /* Erase N characters from the cursor position */
SLCDCODE_ERASEEOL, /* Erase from the cursor position to the end of line */
SLCDCODE_CLEAR, /* Home the cursor and erase the entire display */
/* Cursor movement */
SLCDCODE_HOME, /* Cursor home */
SLCDCODE_END, /* Cursor end */
SLCDCODE_LEFT, /* Cursor left by N characters */
SLCDCODE_RIGHT, /* Cursor right by N characters */
SLCDCODE_UP, /* Cursor up by N lines */
SLCDCODE_DOWN, /* Cursor down by N lines */
SLCDCODE_PAGEUP, /* Cursor up by N pages */
SLCDCODE_PAGEDOWN, /* Cursor down by N pages */
/* Blinking */
SLCDCODE_BLINKSTART, /* Start blinking with current cursor position */
SLCDCODE_BLINKEND, /* End blinking after the current cursor position */
SLCDCODE_BLINKOFF /* Turn blinking off */
};
#define FIRST_SLCDCODE SLCDCODE_FWDDEL
#define LAST_SLCDCODE SLCDCODE_BLINKOFF
/* Values returned by slcd_decode() */
enum slcdret_e
{
SLCDRET_CHAR = 0, /* A normal character was returned */
SLCDRET_SPEC, /* A special SLCD action was returned */
SLCDRET_EOF /* An EOF (or possibly an error) occurred */
};
/* Working data needed by slcd_encode that must be provided and initialized
* by the caller.
*/
struct slcdstate_s
{
uint8_t nch; /* Number of characters in the buffer */
uint8_t ndx; /* Index to next character in the buffer */
uint8_t buf[5]; /* Buffer of ungotten data */
};
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
#ifdef __cplusplus
extern "C"
{
#endif
/****************************************************************************
* The following functions are intended for use by "producer", application
* code to encode information into driver I/O buffers.
****************************************************************************/
/****************************************************************************
* Name: slcd_put
*
* Description:
* Put one byte of normal character data into the output data stream.
*
* Input Parameters:
* ch - The character to be added to the output stream.
* stream - An instance of lib_outstream_s to do the low-level put
* operation.
*
* Returned Value:
* None
*
****************************************************************************/
#define slcd_put(ch, stream) lib_stream_putc(stream, ch)
/****************************************************************************
* Name: slcd_encode
*
* Description:
* Encode one special action into the output data stream
*
* Input Parameters:
* code - The action to be taken
* count - The 8-bit unsigned 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);
/****************************************************************************
* The following functions are intended for use by "consumer" SLCD driver
* code to remove and decode information from the application provided
* buffer.
****************************************************************************/
/****************************************************************************
* 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:
*
* See enum slcdret_e
*
****************************************************************************/
enum slcdret_e slcd_decode(FAR struct lib_instream_s *stream,
FAR struct slcdstate_s *state, FAR uint8_t *pch,
FAR uint8_t *parg);
#ifdef __cplusplus
}
#endif
#endif /* CONFIG_LIBC_SLCDCODEC */
#endif /* __INCLUDE_NUTTX_LCD_SLCD_CODEC_H */