/*
   *  acpi_utils.c - ACPI Utility Functions ($Revision: 10 $)
   *
   *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   *
   * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   *
   *  This program is free software; you can redistribute it and/or modify
   *  it under the terms of the GNU General Public License as published by
   *  the Free Software Foundation; either version 2 of the License, or (at
   *  your option) any later version.
   *
   *  This program is distributed in the hope that it will be useful, but
   *  WITHOUT ANY WARRANTY; without even the implied warranty of
   *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   *  General Public License for more details.
   *
   * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   */
  
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/slab.h>
  #include <linux/init.h>
  #include <linux/types.h>
  #include <linux/hardirq.h>
  #include <linux/acpi.h>
  #include <linux/dynamic_debug.h>
  
  #include "internal.h"
  
  #define _COMPONENT		ACPI_BUS_COMPONENT
  ACPI_MODULE_NAME("utils");
  
  /* --------------------------------------------------------------------------
                              Object Evaluation Helpers
     -------------------------------------------------------------------------- */
  static void
  acpi_util_eval_error(acpi_handle h, acpi_string p, acpi_status s)
  {
  #ifdef ACPI_DEBUG_OUTPUT
  	char prefix[80] = {'\0'};
  	struct acpi_buffer buffer = {sizeof(prefix), prefix};
  	acpi_get_name(h, ACPI_FULL_PATHNAME, &buffer);
  	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Evaluate [%s.%s]: %s
  ",
  		(char *) prefix, p, acpi_format_exception(s)));
  #else
  	return;
  #endif
  }
  
  acpi_status
  acpi_extract_package(union acpi_object *package,
  		     struct acpi_buffer *format, struct acpi_buffer *buffer)
  {
  	u32 size_required = 0;
  	u32 tail_offset = 0;
  	char *format_string = NULL;
  	u32 format_count = 0;
  	u32 i = 0;
  	u8 *head = NULL;
  	u8 *tail = NULL;
  
  
  	if (!package || (package->type != ACPI_TYPE_PACKAGE)
  	    || (package->package.count < 1)) {
  		printk(KERN_WARNING PREFIX "Invalid package argument
  ");
  		return AE_BAD_PARAMETER;
  	}
  
  	if (!format || !format->pointer || (format->length < 1)) {
  		printk(KERN_WARNING PREFIX "Invalid format argument
  ");
  		return AE_BAD_PARAMETER;
  	}
  
  	if (!buffer) {
  		printk(KERN_WARNING PREFIX "Invalid buffer argument
  ");
  		return AE_BAD_PARAMETER;
  	}
  
  	format_count = (format->length / sizeof(char)) - 1;
  	if (format_count > package->package.count) {
  		printk(KERN_WARNING PREFIX "Format specifies more objects [%d]"
  			      " than exist in package [%d].
  ",
  			      format_count, package->package.count);
  		return AE_BAD_DATA;
  	}
  
  	format_string = format->pointer;
  
  	/*
  	 * Calculate size_required.
  	 */
  	for (i = 0; i < format_count; i++) {
  
  		union acpi_object *element = &(package->package.elements[i]);
  
  		switch (element->type) {
  
  		case ACPI_TYPE_INTEGER:
  			switch (format_string[i]) {
  			case 'N':
  				size_required += sizeof(u64);
  				tail_offset += sizeof(u64);
  				break;
  			case 'S':
  				size_required +=
  				    sizeof(char *) + sizeof(u64) +
  				    sizeof(char);
  				tail_offset += sizeof(char *);
  				break;
  			default:
  				printk(KERN_WARNING PREFIX "Invalid package element"
  					      " [%d]: got number, expecting"
  					      " [%c]
  ",
  					      i, format_string[i]);
  				return AE_BAD_DATA;
  				break;
  			}
  			break;
  
  		case ACPI_TYPE_STRING:
  		case ACPI_TYPE_BUFFER:
  			switch (format_string[i]) {
  			case 'S':
  				size_required +=
  				    sizeof(char *) +
  				    (element->string.length * sizeof(char)) +
  				    sizeof(char);
  				tail_offset += sizeof(char *);
  				break;
  			case 'B':
  				size_required +=
  				    sizeof(u8 *) + element->buffer.length;
  				tail_offset += sizeof(u8 *);
  				break;
  			default:
  				printk(KERN_WARNING PREFIX "Invalid package element"
  					      " [%d] got string/buffer,"
  					      " expecting [%c]
  ",
  					      i, format_string[i]);
  				return AE_BAD_DATA;
  				break;
  			}
  			break;
  		case ACPI_TYPE_LOCAL_REFERENCE:
  			switch (format_string[i]) {
  			case 'R':
  				size_required += sizeof(void *);
  				tail_offset += sizeof(void *);
  				break;
  			default:
  				printk(KERN_WARNING PREFIX "Invalid package element"
  					      " [%d] got reference,"
  					      " expecting [%c]
  ",
  					      i, format_string[i]);
  				return AE_BAD_DATA;
  				break;
  			}
  			break;
  
  		case ACPI_TYPE_PACKAGE:
  		default:
  			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
  					  "Found unsupported element at index=%d
  ",
  					  i));
  			/* TBD: handle nested packages... */
  			return AE_SUPPORT;
  			break;
  		}
  	}
  
  	/*
  	 * Validate output buffer.
  	 */
  	if (buffer->length == ACPI_ALLOCATE_BUFFER) {
  		buffer->pointer = ACPI_ALLOCATE_ZEROED(size_required);
  		if (!buffer->pointer)
  			return AE_NO_MEMORY;
  		buffer->length = size_required;
  	} else {
  		if (buffer->length < size_required) {
  			buffer->length = size_required;
  			return AE_BUFFER_OVERFLOW;
  		} else if (buffer->length != size_required ||
  			   !buffer->pointer) {
  			return AE_BAD_PARAMETER;
  		}
  	}
  
  	head = buffer->pointer;
  	tail = buffer->pointer + tail_offset;
  
  	/*
  	 * Extract package data.
  	 */
  	for (i = 0; i < format_count; i++) {
  
  		u8 **pointer = NULL;
  		union acpi_object *element = &(package->package.elements[i]);
  
  		if (!element) {
  			return AE_BAD_DATA;
  		}
  
  		switch (element->type) {
  
  		case ACPI_TYPE_INTEGER:
  			switch (format_string[i]) {
  			case 'N':
  				*((u64 *) head) =
  				    element->integer.value;
  				head += sizeof(u64);
  				break;
  			case 'S':
  				pointer = (u8 **) head;
  				*pointer = tail;
  				*((u64 *) tail) =
  				    element->integer.value;
  				head += sizeof(u64 *);
  				tail += sizeof(u64);
  				/* NULL terminate string */
  				*tail = (char)0;
  				tail += sizeof(char);
  				break;
  			default:
  				/* Should never get here */
  				break;
  			}
  			break;
  
  		case ACPI_TYPE_STRING:
  		case ACPI_TYPE_BUFFER:
  			switch (format_string[i]) {
  			case 'S':
  				pointer = (u8 **) head;
  				*pointer = tail;
  				memcpy(tail, element->string.pointer,
  				       element->string.length);
  				head += sizeof(char *);
  				tail += element->string.length * sizeof(char);
  				/* NULL terminate string */
  				*tail = (char)0;
  				tail += sizeof(char);
  				break;
  			case 'B':
  				pointer = (u8 **) head;
  				*pointer = tail;
  				memcpy(tail, element->buffer.pointer,
  				       element->buffer.length);
  				head += sizeof(u8 *);
  				tail += element->buffer.length;
  				break;
  			default:
  				/* Should never get here */
  				break;
  			}
  			break;
  		case ACPI_TYPE_LOCAL_REFERENCE:
  			switch (format_string[i]) {
  			case 'R':
  				*(void **)head =
  				    (void *)element->reference.handle;
  				head += sizeof(void *);
  				break;
  			default:
  				/* Should never get here */
  				break;
  			}
  			break;
  		case ACPI_TYPE_PACKAGE:
  			/* TBD: handle nested packages... */
  		default:
  			/* Should never get here */
  			break;
  		}
  	}
  
  	return AE_OK;
  }
  
  EXPORT_SYMBOL(acpi_extract_package);
  
  acpi_status
  acpi_evaluate_integer(acpi_handle handle,
  		      acpi_string pathname,
  		      struct acpi_object_list *arguments, unsigned long long *data)
  {
  	acpi_status status = AE_OK;
  	union acpi_object element;
  	struct acpi_buffer buffer = { 0, NULL };
  
  	if (!data)
  		return AE_BAD_PARAMETER;
  
  	buffer.length = sizeof(union acpi_object);
  	buffer.pointer = &element;
  	status = acpi_evaluate_object(handle, pathname, arguments, &buffer);
  	if (ACPI_FAILURE(status)) {
  		acpi_util_eval_error(handle, pathname, status);
  		return status;
  	}
  
  	if (element.type != ACPI_TYPE_INTEGER) {
  		acpi_util_eval_error(handle, pathname, AE_BAD_DATA);
  		return AE_BAD_DATA;
  	}
  
  	*data = element.integer.value;
  
  	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Return value [%llu]
  ", *data));
  
  	return AE_OK;
  }
  
  EXPORT_SYMBOL(acpi_evaluate_integer);
  
  acpi_status
  acpi_evaluate_reference(acpi_handle handle,
  			acpi_string pathname,
  			struct acpi_object_list *arguments,
  			struct acpi_handle_list *list)
  {
  	acpi_status status = AE_OK;
  	union acpi_object *package = NULL;
  	union acpi_object *element = NULL;
  	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
  	u32 i = 0;
  
  
  	if (!list) {
  		return AE_BAD_PARAMETER;
  	}
  
  	/* Evaluate object. */
  
  	status = acpi_evaluate_object(handle, pathname, arguments, &buffer);
  	if (ACPI_FAILURE(status))
  		goto end;
  
  	package = buffer.pointer;
  
  	if ((buffer.length == 0) || !package) {
  		status = AE_BAD_DATA;
  		acpi_util_eval_error(handle, pathname, status);
  		goto end;
  	}
  	if (package->type != ACPI_TYPE_PACKAGE) {
  		status = AE_BAD_DATA;
  		acpi_util_eval_error(handle, pathname, status);
  		goto end;
  	}
  	if (!package->package.count) {
  		status = AE_BAD_DATA;
  		acpi_util_eval_error(handle, pathname, status);
  		goto end;
  	}
  
  	if (package->package.count > ACPI_MAX_HANDLES) {
  		return AE_NO_MEMORY;
  	}
  	list->count = package->package.count;
  
  	/* Extract package data. */
  
  	for (i = 0; i < list->count; i++) {
  
  		element = &(package->package.elements[i]);
  
  		if (element->type != ACPI_TYPE_LOCAL_REFERENCE) {
  			status = AE_BAD_DATA;
  			acpi_util_eval_error(handle, pathname, status);
  			break;
  		}
  
  		if (!element->reference.handle) {
  			status = AE_NULL_ENTRY;
  			acpi_util_eval_error(handle, pathname, status);
  			break;
  		}
  		/* Get the  acpi_handle. */
  
  		list->handles[i] = element->reference.handle;
  		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found reference [%p]
  ",
  				  list->handles[i]));
  	}
  
        end:
  	if (ACPI_FAILURE(status)) {
  		list->count = 0;
  		//kfree(list->handles);
  	}
  
  	kfree(buffer.pointer);
  
  	return status;
  }
  
  EXPORT_SYMBOL(acpi_evaluate_reference);
  
  acpi_status
  acpi_get_physical_device_location(acpi_handle handle, struct acpi_pld_info **pld)
  {
  	acpi_status status;
  	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
  	union acpi_object *output;
  
  	status = acpi_evaluate_object(handle, "_PLD", NULL, &buffer);
  
  	if (ACPI_FAILURE(status))
  		return status;
  
  	output = buffer.pointer;
  
  	if (!output || output->type != ACPI_TYPE_PACKAGE
  	    || !output->package.count
  	    || output->package.elements[0].type != ACPI_TYPE_BUFFER
  	    || output->package.elements[0].buffer.length < ACPI_PLD_REV1_BUFFER_SIZE) {
  		status = AE_TYPE;
  		goto out;
  	}
  
  	status = acpi_decode_pld_buffer(
  			output->package.elements[0].buffer.pointer,
  			output->package.elements[0].buffer.length,
  			pld);
  
  out:
  	kfree(buffer.pointer);
  	return status;
  }
  EXPORT_SYMBOL(acpi_get_physical_device_location);
  
  /**
   * acpi_evaluate_ost: Evaluate _OST for hotplug operations
   * @handle: ACPI device handle
   * @source_event: source event code
   * @status_code: status code
   * @status_buf: optional detailed information (NULL if none)
   *
   * Evaluate _OST for hotplug operations. All ACPI hotplug handlers
   * must call this function when evaluating _OST for hotplug operations.
   * When the platform does not support _OST, this function has no effect.
   */
  acpi_status
  acpi_evaluate_ost(acpi_handle handle, u32 source_event, u32 status_code,
  		  struct acpi_buffer *status_buf)
  {
  	union acpi_object params[3] = {
  		{.type = ACPI_TYPE_INTEGER,},
  		{.type = ACPI_TYPE_INTEGER,},
  		{.type = ACPI_TYPE_BUFFER,}
  	};
  	struct acpi_object_list arg_list = {3, params};
  
  	params[0].integer.value = source_event;
  	params[1].integer.value = status_code;
  	if (status_buf != NULL) {
  		params[2].buffer.pointer = status_buf->pointer;
  		params[2].buffer.length = status_buf->length;
  	} else {
  		params[2].buffer.pointer = NULL;
  		params[2].buffer.length = 0;
  	}
  
  	return acpi_evaluate_object(handle, "_OST", &arg_list, NULL);
  }
  EXPORT_SYMBOL(acpi_evaluate_ost);
  
  /**
   * acpi_handle_path: Return the object path of handle
   *
   * Caller must free the returned buffer
   */
  static char *acpi_handle_path(acpi_handle handle)
  {
  	struct acpi_buffer buffer = {
  		.length = ACPI_ALLOCATE_BUFFER,
  		.pointer = NULL
  	};
  
  	if (in_interrupt() ||
  	    acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer) != AE_OK)
  		return NULL;
  	return buffer.pointer;
  }
  
  /**
   * acpi_handle_printk: Print message with ACPI prefix and object path
   *
   * This function is called through acpi_handle_<level> macros and prints
   * a message with ACPI prefix and object path.  This function acquires
   * the global namespace mutex to obtain an object path.  In interrupt
   * context, it shows the object path as <n/a>.
   */
  void
  acpi_handle_printk(const char *level, acpi_handle handle, const char *fmt, ...)
  {
  	struct va_format vaf;
  	va_list args;
  	const char *path;
  
  	va_start(args, fmt);
  	vaf.fmt = fmt;
  	vaf.va = &args;
  
  	path = acpi_handle_path(handle);
  	printk("%sACPI: %s: %pV", level, path ? path : "<n/a>" , &vaf);
  
  	va_end(args);
  	kfree(path);
  }
  EXPORT_SYMBOL(acpi_handle_printk);
  
  #if defined(CONFIG_DYNAMIC_DEBUG)
  /**
   * __acpi_handle_debug: pr_debug with ACPI prefix and object path
   *
   * This function is called through acpi_handle_debug macro and debug
   * prints a message with ACPI prefix and object path. This function
   * acquires the global namespace mutex to obtain an object path.  In
   * interrupt context, it shows the object path as <n/a>.
   */
  void
  __acpi_handle_debug(struct _ddebug *descriptor, acpi_handle handle,
  		    const char *fmt, ...)
  {
  	struct va_format vaf;
  	va_list args;
  	const char *path;
  
  	va_start(args, fmt);
  	vaf.fmt = fmt;
  	vaf.va = &args;
  
  	path = acpi_handle_path(handle);
  	__dynamic_pr_debug(descriptor, "ACPI: %s: %pV", path ? path : "<n/a>", &vaf);
  
  	va_end(args);
  	kfree(path);
  }
  EXPORT_SYMBOL(__acpi_handle_debug);
  #endif
  
  /**
   * acpi_has_method: Check whether @handle has a method named @name
   * @handle: ACPI device handle
   * @name: name of object or method
   *
   * Check whether @handle has a method named @name.
   */
  bool acpi_has_method(acpi_handle handle, char *name)
  {
  	acpi_handle tmp;
  
  	return ACPI_SUCCESS(acpi_get_handle(handle, name, &tmp));
  }
  EXPORT_SYMBOL(acpi_has_method);
  
  acpi_status acpi_execute_simple_method(acpi_handle handle, char *method,
  				       u64 arg)
  {
  	union acpi_object obj = { .type = ACPI_TYPE_INTEGER };
  	struct acpi_object_list arg_list = { .count = 1, .pointer = &obj, };
  
  	obj.integer.value = arg;
  
  	return acpi_evaluate_object(handle, method, &arg_list, NULL);
  }
  EXPORT_SYMBOL(acpi_execute_simple_method);
  
  /**
   * acpi_evaluate_ej0: Evaluate _EJ0 method for hotplug operations
   * @handle: ACPI device handle
   *
   * Evaluate device's _EJ0 method for hotplug operations.
   */
  acpi_status acpi_evaluate_ej0(acpi_handle handle)
  {
  	acpi_status status;
  
  	status = acpi_execute_simple_method(handle, "_EJ0", 1);
  	if (status == AE_NOT_FOUND)
  		acpi_handle_warn(handle, "No _EJ0 support for device
  ");
  	else if (ACPI_FAILURE(status))
  		acpi_handle_warn(handle, "Eject failed (0x%x)
  ", status);
  
  	return status;
  }
  
  /**
   * acpi_evaluate_lck: Evaluate _LCK method to lock/unlock device
   * @handle: ACPI device handle
   * @lock: lock device if non-zero, otherwise unlock device
   *
   * Evaluate device's _LCK method if present to lock/unlock device
   */
  acpi_status acpi_evaluate_lck(acpi_handle handle, int lock)
  {
  	acpi_status status;
  
  	status = acpi_execute_simple_method(handle, "_LCK", !!lock);
  	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
  		if (lock)
  			acpi_handle_warn(handle,
  				"Locking device failed (0x%x)
  ", status);
  		else
  			acpi_handle_warn(handle,
  				"Unlocking device failed (0x%x)
  ", status);
  	}
  
  	return status;
  }
  
  /**
   * acpi_evaluate_dsm - evaluate device's _DSM method
   * @handle: ACPI device handle
   * @uuid: UUID of requested functions, should be 16 bytes
   * @rev: revision number of requested function
   * @func: requested function number
   * @argv4: the function specific parameter
   *
   * Evaluate device's _DSM method with specified UUID, revision id and
   * function number. Caller needs to free the returned object.
   *
   * Though ACPI defines the fourth parameter for _DSM should be a package,
   * some old BIOSes do expect a buffer or an integer etc.
   */
  union acpi_object *
  acpi_evaluate_dsm(acpi_handle handle, const u8 *uuid, int rev, int func,
  		  union acpi_object *argv4)
  {
  	acpi_status ret;
  	struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL};
  	union acpi_object params[4];
  	struct acpi_object_list input = {
  		.count = 4,
  		.pointer = params,
  	};
  
  	params[0].type = ACPI_TYPE_BUFFER;
  	params[0].buffer.length = 16;
  	params[0].buffer.pointer = (char *)uuid;
  	params[1].type = ACPI_TYPE_INTEGER;
  	params[1].integer.value = rev;
  	params[2].type = ACPI_TYPE_INTEGER;
  	params[2].integer.value = func;
  	if (argv4) {
  		params[3] = *argv4;
  	} else {
  		params[3].type = ACPI_TYPE_PACKAGE;
  		params[3].package.count = 0;
  		params[3].package.elements = NULL;
  	}
  
  	ret = acpi_evaluate_object(handle, "_DSM", &input, &buf);
  	if (ACPI_SUCCESS(ret))
  		return (union acpi_object *)buf.pointer;
  
  	if (ret != AE_NOT_FOUND)
  		acpi_handle_warn(handle,
  				"failed to evaluate _DSM (0x%x)
  ", ret);
  
  	return NULL;
  }
  EXPORT_SYMBOL(acpi_evaluate_dsm);
  
  /**
   * acpi_check_dsm - check if _DSM method supports requested functions.
   * @handle: ACPI device handle
   * @uuid: UUID of requested functions, should be 16 bytes at least
   * @rev: revision number of requested functions
   * @funcs: bitmap of requested functions
   *
   * Evaluate device's _DSM method to check whether it supports requested
   * functions. Currently only support 64 functions at maximum, should be
   * enough for now.
   */
  bool acpi_check_dsm(acpi_handle handle, const u8 *uuid, int rev, u64 funcs)
  {
  	int i;
  	u64 mask = 0;
  	union acpi_object *obj;
  
  	if (funcs == 0)
  		return false;
  
  	obj = acpi_evaluate_dsm(handle, uuid, rev, 0, NULL);
  	if (!obj)
  		return false;
  
  	/* For compatibility, old BIOSes may return an integer */
  	if (obj->type == ACPI_TYPE_INTEGER)
  		mask = obj->integer.value;
  	else if (obj->type == ACPI_TYPE_BUFFER)
  		for (i = 0; i < obj->buffer.length && i < 8; i++)
  			mask |= (((u8)obj->buffer.pointer[i]) << (i * 8));
  	ACPI_FREE(obj);
  
  	/*
  	 * Bit 0 indicates whether there's support for any functions other than
  	 * function 0 for the specified UUID and revision.
  	 */
  	if ((mask & 0x1) && (mask & funcs) == funcs)
  		return true;
  
  	return false;
  }
  EXPORT_SYMBOL(acpi_check_dsm);
  
  /*
   * acpi_backlight= handling, this is done here rather then in video_detect.c
   * because __setup cannot be used in modules.
   */
  char acpi_video_backlight_string[16];
  EXPORT_SYMBOL(acpi_video_backlight_string);
  
  static int __init acpi_backlight(char *str)
  {
  	strlcpy(acpi_video_backlight_string, str,
  		sizeof(acpi_video_backlight_string));
  	return 1;
  }
  __setup("acpi_backlight=", acpi_backlight);