Commit c55d6282 authored by Srinivas Pandruvada's avatar Srinivas Pandruvada Committed by Zhang Rui
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ACPI / LPAT: Common table processing functions 



Since LPAT table processing is also required for other thermal drivers,
moved LPAT table related functions from intel PMIC driver (intel_pmic.c)
to a stand alonge module with exported interfaces.
In this way there will be no code duplication.

Signed-off-by: default avatarSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: default avatarZhang Rui <rui.zhang@intel.com>
parent acebf7ee

drivers/acpi/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -55,6 +55,7 @@ acpi-$(CONFIG_ACPI_PROCFS_POWER) += cm_sbs.o 
ifdef CONFIG_ACPI_VIDEO

acpi-y				+= video_detect.o

endif

acpi-y				+= acpi_lpat.o



# These are (potentially) separate modules

drivers/acpi/acpi_lpat.c

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Original line number Diff line number Diff line 
/*

 * acpi_lpat.c - LPAT table processing functions

 *

 * Copyright (C) 2015 Intel Corporation. All rights reserved.

 *

 * 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.

 */



#include <linux/module.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 temerature from the

 *       above mapping table

 *

 * A positive converted temperarure 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: the temperature_raw mapping table

 * @temp: the temperature, used as a key to get the raw value 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_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);



MODULE_LICENSE("GPL");

include/acpi/acpi_lpat.h

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Original line number Diff line number Diff line 
/*

 * acpi_lpat.h - LPAT table processing functions

 *

 * Copyright (C) 2015 Intel Corporation. All rights reserved.

 *

 * 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.

 */



#ifndef ACPI_LPAT_H

#define ACPI_LPAT_H



struct acpi_lpat {

	int temp;

	int raw;

};



struct acpi_lpat_conversion_table {

	struct acpi_lpat *lpat;

	int lpat_count;

};



#ifdef CONFIG_ACPI



int acpi_lpat_raw_to_temp(struct acpi_lpat_conversion_table *lpat_table,

			  int raw);

int acpi_lpat_temp_to_raw(struct acpi_lpat_conversion_table *lpat_table,

			  int temp);

struct acpi_lpat_conversion_table *acpi_lpat_get_conversion_table(acpi_handle

								  handle);

void acpi_lpat_free_conversion_table(struct acpi_lpat_conversion_table

				     *lpat_table);



#else

static int acpi_lpat_raw_to_temp(struct acpi_lpat_conversion_table *lpat_table,

				 int raw)

{

	return 0;

}



static int acpi_lpat_temp_to_raw(struct acpi_lpat_conversion_table *lpat_table,

				 int temp)

{

	return 0;

}



static struct acpi_lpat_conversion_table *acpi_lpat_get_conversion_table(

							acpi_handle handle)

{

	return NULL;

}



static void acpi_lpat_free_conversion_table(struct acpi_lpat_conversion_table

					    *lpat_table)

{

}



#endif

#endif

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