linux/drivers/acpi/acpi_lpat.c
Thomas Gleixner 1802d0beec treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation 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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 655 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070034.575739538@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:41 -07:00

152 lines
4.0 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* acpi_lpat.c - LPAT table processing functions
*
* Copyright (C) 2015 Intel Corporation. All rights reserved.
*/
#include <linux/export.h>
#include <linux/acpi.h>
#include <acpi/acpi_lpat.h>
/**
* acpi_lpat_raw_to_temp(): Return temperature from raw value through
* LPAT conversion table
*
* @lpat_table: the temperature_raw mapping table structure
* @raw: the raw value, used as a key to get the temperature from the
* above mapping table
*
* A positive converted temperature value will be returned on success,
* a negative errno will be returned in error cases.
*/
int acpi_lpat_raw_to_temp(struct acpi_lpat_conversion_table *lpat_table,
int raw)
{
int i, delta_temp, delta_raw, temp;
struct acpi_lpat *lpat = lpat_table->lpat;
for (i = 0; i < lpat_table->lpat_count - 1; i++) {
if ((raw >= lpat[i].raw && raw <= lpat[i+1].raw) ||
(raw <= lpat[i].raw && raw >= lpat[i+1].raw))
break;
}
if (i == lpat_table->lpat_count - 1)
return -ENOENT;
delta_temp = lpat[i+1].temp - lpat[i].temp;
delta_raw = lpat[i+1].raw - lpat[i].raw;
temp = lpat[i].temp + (raw - lpat[i].raw) * delta_temp / delta_raw;
return temp;
}
EXPORT_SYMBOL_GPL(acpi_lpat_raw_to_temp);
/**
* acpi_lpat_temp_to_raw(): Return raw value from temperature through
* LPAT conversion table
*
* @lpat_table: the temperature_raw mapping table
* @temp: the temperature, used as a key to get the raw value from the
* above mapping table
*
* The raw value will be returned on success,
* a negative errno will be returned in error cases.
*/
int acpi_lpat_temp_to_raw(struct acpi_lpat_conversion_table *lpat_table,
int temp)
{
int i, delta_temp, delta_raw, raw;
struct acpi_lpat *lpat = lpat_table->lpat;
for (i = 0; i < lpat_table->lpat_count - 1; i++) {
if (temp >= lpat[i].temp && temp <= lpat[i+1].temp)
break;
}
if (i == lpat_table->lpat_count - 1)
return -ENOENT;
delta_temp = lpat[i+1].temp - lpat[i].temp;
delta_raw = lpat[i+1].raw - lpat[i].raw;
raw = lpat[i].raw + (temp - lpat[i].temp) * delta_raw / delta_temp;
return raw;
}
EXPORT_SYMBOL_GPL(acpi_lpat_temp_to_raw);
/**
* acpi_lpat_get_conversion_table(): Parse ACPI LPAT table if present.
*
* @handle: Handle to acpi device
*
* Parse LPAT table to a struct of type acpi_lpat_table. On success
* it returns a pointer to newly allocated table. This table must
* be freed by the caller when finished processing, using a call to
* acpi_lpat_free_conversion_table.
*/
struct acpi_lpat_conversion_table *acpi_lpat_get_conversion_table(acpi_handle
handle)
{
struct acpi_lpat_conversion_table *lpat_table = NULL;
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
union acpi_object *obj_p, *obj_e;
int *lpat, i;
acpi_status status;
status = acpi_evaluate_object(handle, "LPAT", NULL, &buffer);
if (ACPI_FAILURE(status))
return NULL;
obj_p = (union acpi_object *)buffer.pointer;
if (!obj_p || (obj_p->type != ACPI_TYPE_PACKAGE) ||
(obj_p->package.count % 2) || (obj_p->package.count < 4))
goto out;
lpat = kcalloc(obj_p->package.count, sizeof(int), GFP_KERNEL);
if (!lpat)
goto out;
for (i = 0; i < obj_p->package.count; i++) {
obj_e = &obj_p->package.elements[i];
if (obj_e->type != ACPI_TYPE_INTEGER) {
kfree(lpat);
goto out;
}
lpat[i] = (s64)obj_e->integer.value;
}
lpat_table = kzalloc(sizeof(*lpat_table), GFP_KERNEL);
if (!lpat_table) {
kfree(lpat);
goto out;
}
lpat_table->lpat = (struct acpi_lpat *)lpat;
lpat_table->lpat_count = obj_p->package.count / 2;
out:
kfree(buffer.pointer);
return lpat_table;
}
EXPORT_SYMBOL_GPL(acpi_lpat_get_conversion_table);
/**
* acpi_lpat_free_conversion_table(): Free LPAT table.
*
* @lpat_table: the temperature_raw mapping table structure
*
* Frees the LPAT table previously allocated by a call to
* acpi_lpat_get_conversion_table.
*/
void acpi_lpat_free_conversion_table(struct acpi_lpat_conversion_table
*lpat_table)
{
if (lpat_table) {
kfree(lpat_table->lpat);
kfree(lpat_table);
}
}
EXPORT_SYMBOL_GPL(acpi_lpat_free_conversion_table);