serial.c
Author: cmaier@cmassoc.net

    /*====================================================================*
     *
     *   Copyright (c) 2013 Qualcomm Atheros, Inc.
     *
     *   All rights reserved.
     *
     *   Redistribution and use in source and binary forms, with or
     *   without modification, are permitted (subject to the limitations
     *   in the disclaimer below) provided that the following conditions
     *   are met:
     *
     *   * Redistributions of source code must retain the above copyright
     *     notice, this list of conditions and the following disclaimer.
     *
     *   * 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.
     *
     *   * Neither the name of Qualcomm Atheros nor the names of
     *     its contributors may be used to endorse or promote products
     *     derived from this software without specific prior written
     *     permission.
     *
     *   NO EXPRESS OR IMPLIED LICENSES TO ANY PARTY'S PATENT RIGHTS ARE
     *   GRANTED BY THIS LICENSE. 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.
     *
     *--------------------------------------------------------------------*/

    /*====================================================================*
     *
     *   serial.c - Atheros Serial Line Command Buffer Management;
     *
     *   serial.h
     *
     *   this module contains a serial line command buffer and functions
     *   to encode and decode it in different formats and send or receive
     *   it over the serial line;
     *
     *   Contributor(s):
     *	Charles Maier <cmaier@qca.qualcomm.com>
     *
     *--------------------------------------------------------------------*/

    #ifndef SERIAL_SOURCE
    #define SERIAL_SOURCE

    /*====================================================================*
     *   system header files;
     *--------------------------------------------------------------------*/

    #include <unistd.h>
    #include <stdlib.h>
    #include <stdint.h>
    #include <memory.h>
    #include <errno.h>

    #if defined (WIN32)
    #include <Windows.h>
    #endif

    /*====================================================================*
     *   custom header files;
     *--------------------------------------------------------------------*/

    #include "../serial/serial.h"
    #include "../tools/number.h"
    #include "../tools/types.h"
    #include "../tools/flags.h"
    #include "../tools/error.h"

    /*====================================================================*
     *   private variables;
     *--------------------------------------------------------------------*/

    struct command command;

    /*====================================================================*
     *
     *   void clearcommand ();
     *
     *   serial.h
     *
     *   erase the current command by writing 0s;
     *
     *--------------------------------------------------------------------*/

    void clearcommand ()

    {
    	extern struct command command;
    	memset (&command, 0, sizeof (command));
    	return;
    }

    /*====================================================================*
     *
     *   void sendcommand (struct _file_ * port, flag_t flags);
     *
     *   serial.h
     *
     *   echo then send the command;
     *
     *--------------------------------------------------------------------*/

    void sendcommand (struct _file_ * port, flag_t flags)

    {
    	extern struct command command;
    	if (_anyset (flags, UART_VERBOSE))
    	{
    		write (STDERR_FILENO, command.buffer, command.length);
    		write (STDERR_FILENO, "\n", sizeof (char));
    	}
    	if (write (port->file, command.buffer, command.length) != (signed)(command.length))
    	{
    		error (1, errno, "Can't write to %s", port->name);
    	}
    	clearcommand ();
    	return;
    }

    /*====================================================================*
     *
     *   void readcommand (struct _file_ * port, flag_t flags);
     *
     *   serial.h
     *
     *   read response serial line and log the response;
     *
     *--------------------------------------------------------------------*/

    void readcommand (struct _file_ * port, flag_t flags)

    {
    	extern struct command command;

    #if defined (WIN32)

    	PAUSE (250);
    	memset (&command, 0, sizeof (command));
    	command.length = read (port->file, command.buffer, sizeof (command.buffer));
    	if (command.length < 0)
    	{
    		error (1, errno, "Bad response from %s", port->name);
    	}
    	if (command.length == 0)
    	{
    		error (1, errno, "No response from %s", port->name);
    	}

    #else

    	struct timeval tv;
    	fd_set rfd;
    	ssize_t tmp;
    	memset (&command, 0, sizeof (command));
    	while (!strchr (command.buffer, '\r'))
    	{
    		tv.tv_sec = 1;
    		tv.tv_usec = 0;
    		FD_ZERO (&rfd);
    		FD_SET (port->file, &rfd);
    		if (select (port->file + 1, &rfd, NULL, NULL, &tv) != 1)
    		{
    			error (1, errno, "Read timeout");
    		}
    		tmp = read (port->file, command.buffer + command.length, sizeof (command.buffer) - command.length - 1);
    		if (tmp < 0)
    		{
    			error (1, errno, "Could not read %s", port->name);
    		}
    		command.length += tmp;
    		command.buffer [command.length] = '\0';
    	}

    #endif

    	if (_anyset (flags, UART_VERBOSE))
    	{
    		write (STDERR_FILENO, command.buffer, command.length);
    		write (STDERR_FILENO, "\n", sizeof (char));
    	}
    	if (!memcmp (command.buffer, "ERROR", 5))
    	{
    		error (1, ECANCELED, "Device refused request");
    	}
    	return;
    }

    /*====================================================================*
     *
     *   void insert (char c);
     *
     *   serial.h
     *
     *   insert a character into the command buffer at the current buffer
     *   position then increment the buffer position pointer;
     *
     *--------------------------------------------------------------------*/

    void insert (char c)

    {
    	extern struct command command;
    	if (command.length < sizeof (command.buffer))
    	{
    		command.buffer [command.length++] = c;
    	}
    	return;
    }

    /*====================================================================*
     *
     *   unsigned readframe (signed fd, void * memory, size_t extent);
     *
     *   serial.h
     *
     *   read a file and convert hexadecimal octets to binary bytes then
     *   store them in consecutive memory locations up to a given length;
     *   return the actual number of bytes stored;
     *
     *   digits may be consecutive or separated by white space consisting
     *   of spaces, tabs, linefeeds, carriage returns, formfeeds or other
     *   characters such as punctuation; script-style comments are treated
     *   as white space;
     *
     *--------------------------------------------------------------------*/

    static signed fdgetc (signed fd)

    {
    	char c;
    	return ((read (fd, &c, sizeof (c)) == sizeof (c))? c: EOF);
    }

    size_t readframe (signed fd, void * memory, size_t extent)

    {
    	unsigned digits = 0;
    	uint8_t * origin = (uint8_t *)(memory);
    	uint8_t * offset = (uint8_t *)(memory);
    	signed c = EOF;
    	while ((extent) && ((c = fdgetc (fd)) != EOF) && (c != ';'))
    	{
    		if (isspace (c))
    		{
    			continue;
    		}
    		if (c == '#')
    		{
    			do
    			{
    				c = fdgetc (fd);
    			}
    			while ((c != '\n') && (c != EOF));
    			continue;
    		}
    		if (c == '/')
    		{
    			c = fdgetc (fd);
    			if (c == '/')
    			{
    				do
    				{
    					c = fdgetc (fd);
    				}
    				while ((c != '\n') && (c != EOF));
    				continue;
    			}
    			if (c == '*')
    			{
    				while ((c != '/') && (c != EOF))
    				{
    					while ((c != '*') && (c != EOF))
    					{
    						c = fdgetc (fd);
    					}
    					c = fdgetc (fd);
    				}
    				continue;
    			}
    			continue;
    		}
    		if (isxdigit (c))
    		{
    			*offset = c;
    			offset++;
    			digits++;
    			extent--;
    			continue;
    		}
    		error (1, ENOTSUP, "Illegal hex digit '%c' (0x%02X) in source", c, c);
    	}
    	if (digits & 1)
    	{
    		error (1, ENOTSUP, "Odd number of hex digits (%d) in source", digits);
    	}
    	return (offset - origin);
    }

    /*====================================================================*
     *
     *   void decode (void const * memory, size_t extent);
     *
     *   serial.h
     *
     *   copy a memory region into command buffer at the current position
     *   and increment the buffer position pointer; convert bytes to hex
     *   octets;
     *
     *--------------------------------------------------------------------*/

    void decode (void const * memory, size_t extent)

    {
    	extern struct command command;
    	register byte * binary = (byte *)(memory);
    	while ((command.length < sizeof (command.buffer)) && (extent--))
    	{
    		insert (DIGITS_HEX [(*binary >> 4) & 0x0F]);
    		insert (DIGITS_HEX [(*binary >> 0) & 0x0F]);
    		binary++;
    	}
    	return;
    }

    /*====================================================================*
     *
     *   void encode (void * memory, size_t extent);
     *
     *   serial.h
     *
     *   encode a memory region from the current command buffer position
     *   and increment the command buffer position pointer;
     *
     *--------------------------------------------------------------------*/

    void encode (void * memory, size_t extent)

    {
    	extern struct command command;
    	register byte * binary = (byte *)(memory);
    	unsigned digit;
    	while ((command.offset < command.length) && (extent--))
    	{
    		*binary = 0;
    		if ((digit = todigit (command.buffer [command.offset++])) > 0x0F)
    		{
    			command.buffer [command.offset] = (char)(0);
    			error (1, EINVAL, "[%s]1", command.buffer);
    		}
    		*binary |= digit << 4;
    		if ((digit = todigit (command.buffer [command.offset++])) > 0x0F)
    		{
    			command.buffer [command.offset] = (char)(0);
    			error (1, EINVAL, "[%s]2", command.buffer);
    		}
    		*binary |= digit;
    		binary++;
    	}
    	return;
    }

    /*====================================================================*
     *
     *   void string (char * string);
     *
     *   serial.h
     *
     *   extract the contents of a quoted string string from the command
     *   buffer; it assumes that the current char is a quote character;
     *
     *   copy command buffer characters to an external string; start a the
     *   current buffer position and continue until the buffer exhausts or
     *   a closing quote is encountered; NUL terminate the string;
     *
     *--------------------------------------------------------------------*/

    void string (char * string)

    {
    	extern struct command command;
    	while ((command.offset < command.length) && (command.buffer [command.offset] != '\"'))
    	{
    		*string++ = command.buffer [command.offset++];
    	}
    	*string = (char)(0);
    	return;
    }

    /*====================================================================*
     *
     *   uint64_t hextoint (unsigned bytes);
     *
     *   serial.h
     *
     *   this function is used to extract a hexadecimal integer string as
     *   an integer of specified length; an error occurs of the string is
     *   to long for the specified integer size in bytes;
     *
     *--------------------------------------------------------------------*/

    uint64_t hextoint (unsigned bytes)

    {
    	extern struct command command;
    	uint64_t limit = -1;
    	uint64_t value = 0;
    	unsigned radix = 16;
    	unsigned digit = 0;
    	if (bytes < sizeof (limit))
    	{
    		limit <<= (bytes << 3);
    		limit = ~limit;
    	}
    	while ((digit = todigit (command.buffer [command.offset])) < radix)
    	{
    		value *= radix;
    		value += digit;
    		command.offset++;
    		if (value > limit)
    		{
    			command.buffer [command.offset] = (char)(0);
    			error (1, EINVAL, "[%s] exceeds %d bits", command.buffer, (bytes << 3));
    		}
    	}
    	return (value);
    }

    /*====================================================================*
     *
     *   void mustbe (char c);
     *
     *   serial.h
     *
     *   test the character at the current buffer position; advance the
     *   buffer position pointer and return true on match; terminate the
     *   program on mismatch or exhausted buffer;
     *
     *--------------------------------------------------------------------*/

    void mustbe (char c)

    {
    	extern struct command command;
    	if (command.offset >= command.length)
    	{
    		command.buffer [command.offset] = (char)(0);
    		error (1, EINVAL, "[%s]: overflow", command.buffer);
    	}
    	if (command.buffer [command.offset++] != (c))
    	{
    		command.buffer [command.offset] = (char)(0);
    		error (1, EINVAL, "[%s]: expecting 0x%02X", command.buffer, c);
    	}
    	return;
    }

    /*====================================================================*
     *
     *--------------------------------------------------------------------*/

    #endif

[PREV] [HOME] [NEXT]