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author | patacongo <patacongo@42af7a65-404d-4744-a932-0658087f49c3> | 2012-12-25 17:22:58 +0000 |
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committer | patacongo <patacongo@42af7a65-404d-4744-a932-0658087f49c3> | 2012-12-25 17:22:58 +0000 |
commit | 81167b4592a18d9d80d1ed7795953addb71844c8 (patch) | |
tree | 2e052235e4dcf59a648996f8a77a98e9ad5e904b /nuttx/libc/misc/lib_kbddecode.c | |
parent | 62b8fb69badccc3f10fb5184b9d375fea23ca59f (diff) | |
download | px4-nuttx-81167b4592a18d9d80d1ed7795953addb71844c8.tar.gz px4-nuttx-81167b4592a18d9d80d1ed7795953addb71844c8.tar.bz2 px4-nuttx-81167b4592a18d9d80d1ed7795953addb71844c8.zip |
Add logic to serialize and marshal out-of-band keyboard commands
git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5460 42af7a65-404d-4744-a932-0658087f49c3
Diffstat (limited to 'nuttx/libc/misc/lib_kbddecode.c')
-rw-r--r-- | nuttx/libc/misc/lib_kbddecode.c | 258 |
1 files changed, 258 insertions, 0 deletions
diff --git a/nuttx/libc/misc/lib_kbddecode.c b/nuttx/libc/misc/lib_kbddecode.c new file mode 100644 index 000000000..046d570f9 --- /dev/null +++ b/nuttx/libc/misc/lib_kbddecode.c @@ -0,0 +1,258 @@ +/******************************************************************************************** + * 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 <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 NCX_SEMICOLON 3 + +#define NCH_ESC 1 +#define NCH_BRACKET 2 +#define NCH_CODE 3 +#define NCH_SEMICOLON 4 + +/******************************************************************************************** + * Private Functions + ********************************************************************************************/ + +/**************************************************************************** + * Name: kbd_reget + * + * Description: + * We have unused characters from the last, unsuccessful. Return one of + * these instead of the . + * + * 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, "in-band" ASCII characer or a special, "out-of-band" + * command. + * state - A user provided buffer to support parsing. This structure + * should be cleared the first time that kbd_get is called. + * + * Returned Value: + * 2 - Indicates the successful receipt of a special, "out-of-band" command + * 1 - Indicates the successful receipt of normal, "in-band" ASCII data. + * 0 - Indicates end-of-file or that the stream has been closed + * EOF - An error has getting the next character (reported by the stream). + * + ****************************************************************************/ + +static int kbd_reget(FAR struct kget_getstate_s *state, FAR uint8_t *pch) +{ + /* Return the next character */ + + *pch = state->buf[state->ndx]; + state->ndx++; + state->nch--; + return KBD_NORMAL; +} + +/******************************************************************************************** + * Public Functions + ********************************************************************************************/ + +/**************************************************************************** + * Name: kbd_get + * + * Description: + * Put 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 character to save the returned value. This may be + * either a normal, "in-band" ASCII characer or a special, "out-of-band" + * command. + * state - A user provided buffer to support parsing. This structure + * should be cleared the first time that kbd_get is called. + * + * Returned Value: + * 1 - Indicates the successful receipt of a special, "out-of-band" command + * 0 - Indicates the successful receipt of normal, "in-band" ASCII data. + * EOF - An error has getting the next character (reported by the stream). + * Normally indicates the end of file. + * + ****************************************************************************/ + +int kbd_get(FAR struct lib_instream_s *stream, + FAR struct kget_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, "out-of-band" command code */ + + 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[NCX_SEMICOLON] = (uint8_t)ch; + state->nch = NCH_SEMICOLON; + + /* Check for a valid special command code */ + + if (ch != ';') + { + /* 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 the entire escape sequence. Return the + * special code in pch and the value 2. + */ + + *pch = state->buf[NDX_CODE]; + state->nch = 0; + return KBD_SPECIAL; +} + |