tools/power/acpi/os_specific/service_layers/oslibcfs.c

/******************************************************************************
 *
 * Module Name: oslibcfs - C library OSL for file I/O
 *
 *****************************************************************************/

/*
 * Copyright (C) 2000 - 2015, Intel Corp.
 * All rights reserved.
 *
 * 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,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    substantially similar to the "NO WARRANTY" disclaimer below
 *    ("Disclaimer") and any redistribution must be conditioned upon
 *    including a substantially similar Disclaimer requirement for further
 *    binary redistribution.
 * 3. Neither the names of the above-listed copyright holders nor the names
 *    of any contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * NO WARRANTY
 * 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 MERCHANTIBILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR 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 DAMAGES.
 */

#include <acpi/acpi.h>
#include <stdio.h>
#include <stdarg.h>

#define _COMPONENT          ACPI_OS_SERVICES
ACPI_MODULE_NAME("oslibcfs")

/*******************************************************************************
 *
 * FUNCTION:    acpi_os_open_file
 *
 * PARAMETERS:  path                - File path
 *              modes               - File operation type
 *
 * RETURN:      File descriptor.
 *
 * DESCRIPTION: Open a file for reading (ACPI_FILE_READING) or/and writing
 *              (ACPI_FILE_WRITING).
 *
 ******************************************************************************/
ACPI_FILE acpi_os_open_file(const char *path, u8 modes)
{
	ACPI_FILE file;
	u32 i = 0;
	char modes_str[4];

	if (modes & ACPI_FILE_READING) {
		modes_str[i++] = 'r';
	}
	if (modes & ACPI_FILE_WRITING) {
		modes_str[i++] = 'w';
	}
	if (modes & ACPI_FILE_BINARY) {
		modes_str[i++] = 'b';
	}

	modes_str[i++] = '\0';

	file = fopen(path, modes_str);
	if (!file) {
		perror("Could not open file");
	}

	return (file);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_os_close_file
 *
 * PARAMETERS:  file                - An open file descriptor
 *
 * RETURN:      None.
 *
 * DESCRIPTION: Close a file opened via acpi_os_open_file.
 *
 ******************************************************************************/

void acpi_os_close_file(ACPI_FILE file)
{
	fclose(file);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_os_read_file
 *
 * PARAMETERS:  file                - An open file descriptor
 *              buffer              - Data buffer
 *              size                - Data block size
 *              count               - Number of data blocks
 *
 * RETURN:      Number of bytes actually read.
 *
 * DESCRIPTION: Read from a file.
 *
 ******************************************************************************/

int
acpi_os_read_file(ACPI_FILE file, void *buffer, acpi_size size, acpi_size count)
{
	int length;

	length = fread(buffer, size, count, file);
	if (length < 0) {
		perror("Error reading file");
	}

	return (length);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_os_write_file
 *
 * PARAMETERS:  file                - An open file descriptor
 *              buffer              - Data buffer
 *              size                - Data block size
 *              count               - Number of data blocks
 *
 * RETURN:      Number of bytes actually written.
 *
 * DESCRIPTION: Write to a file.
 *
 ******************************************************************************/

int
acpi_os_write_file(ACPI_FILE file,
		   void *buffer, acpi_size size, acpi_size count)
{
	int length;

	length = fwrite(buffer, size, count, file);
	if (length < 0) {
		perror("Error writing file");
	}

	return (length);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_os_get_file_offset
 *
 * PARAMETERS:  file                - An open file descriptor
 *
 * RETURN:      Current file pointer position.
 *
 * DESCRIPTION: Get current file offset.
 *
 ******************************************************************************/

long acpi_os_get_file_offset(ACPI_FILE file)
{
	long offset;

	offset = ftell(file);
	return (offset);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_os_set_file_offset
 *
 * PARAMETERS:  file                - An open file descriptor
 *              offset              - New file offset
 *              from                - From begin/end of file
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Set current file offset.
 *
 ******************************************************************************/

acpi_status acpi_os_set_file_offset(ACPI_FILE file, long offset, u8 from)
{
	int ret = 0;

	if (from == ACPI_FILE_BEGIN) {
		ret = fseek(file, offset, SEEK_SET);
	}
	if (from == ACPI_FILE_END) {
		ret = fseek(file, offset, SEEK_END);
	}

	if (ret < 0) {
		return (AE_ERROR);
	} else {
		return (AE_OK);
	}
}