[deliverable/linux.git] / drivers / acpi / acpica / exfield.c

/******************************************************************************
 *
 * Module Name: exfield - ACPI AML (p-code) execution - field manipulation
 *
 *****************************************************************************/

/*
 * Copyright (C) 2000 - 2008, 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 "accommon.h"
#include "acdispat.h"
#include "acinterp.h"

#define _COMPONENT          ACPI_EXECUTER
ACPI_MODULE_NAME("exfield")

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_read_data_from_field
 *
 * PARAMETERS:  walk_state          - Current execution state
 *              obj_desc            - The named field
 *              ret_buffer_desc     - Where the return data object is stored
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Read from a named field.  Returns either an Integer or a
 *              Buffer, depending on the size of the field.
 *
 ******************************************************************************/
acpi_status
acpi_ex_read_data_from_field(struct acpi_walk_state *walk_state,
			     union acpi_operand_object *obj_desc,
			     union acpi_operand_object **ret_buffer_desc)
{
	acpi_status status;
	union acpi_operand_object *buffer_desc;
	acpi_size length;
	void *buffer;

	ACPI_FUNCTION_TRACE_PTR(ex_read_data_from_field, obj_desc);

	/* Parameter validation */

	if (!obj_desc) {
		return_ACPI_STATUS(AE_AML_NO_OPERAND);
	}
	if (!ret_buffer_desc) {
		return_ACPI_STATUS(AE_BAD_PARAMETER);
	}

	if (ACPI_GET_OBJECT_TYPE(obj_desc) == ACPI_TYPE_BUFFER_FIELD) {
		/*
		 * If the buffer_field arguments have not been previously evaluated,
		 * evaluate them now and save the results.
		 */
		if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
			status = acpi_ds_get_buffer_field_arguments(obj_desc);
			if (ACPI_FAILURE(status)) {
				return_ACPI_STATUS(status);
			}
		}
	} else
	    if ((ACPI_GET_OBJECT_TYPE(obj_desc) == ACPI_TYPE_LOCAL_REGION_FIELD)
		&& (obj_desc->field.region_obj->region.space_id ==
		    ACPI_ADR_SPACE_SMBUS)) {
		/*
		 * This is an SMBus read.  We must create a buffer to hold the data
		 * and directly access the region handler.
		 */
		buffer_desc =
		    acpi_ut_create_buffer_object(ACPI_SMBUS_BUFFER_SIZE);
		if (!buffer_desc) {
			return_ACPI_STATUS(AE_NO_MEMORY);
		}

		/* Lock entire transaction if requested */

		acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);

		/*
		 * Perform the read.
		 * Note: Smbus protocol value is passed in upper 16-bits of Function
		 */
		status = acpi_ex_access_region(obj_desc, 0,
					       ACPI_CAST_PTR(acpi_integer,
							     buffer_desc->
							     buffer.pointer),
					       ACPI_READ | (obj_desc->field.
							    attribute << 16));
		acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
		goto exit;
	}

	/*
	 * Allocate a buffer for the contents of the field.
	 *
	 * If the field is larger than the size of an acpi_integer, create
	 * a BUFFER to hold it.  Otherwise, use an INTEGER.  This allows
	 * the use of arithmetic operators on the returned value if the
	 * field size is equal or smaller than an Integer.
	 *
	 * Note: Field.length is in bits.
	 */
	length =
	    (acpi_size) ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->field.bit_length);
	if (length > acpi_gbl_integer_byte_width) {

		/* Field is too large for an Integer, create a Buffer instead */

		buffer_desc = acpi_ut_create_buffer_object(length);
		if (!buffer_desc) {
			return_ACPI_STATUS(AE_NO_MEMORY);
		}
		buffer = buffer_desc->buffer.pointer;
	} else {
		/* Field will fit within an Integer (normal case) */

		buffer_desc = acpi_ut_create_internal_object(ACPI_TYPE_INTEGER);
		if (!buffer_desc) {
			return_ACPI_STATUS(AE_NO_MEMORY);
		}

		length = acpi_gbl_integer_byte_width;
		buffer_desc->integer.value = 0;
		buffer = &buffer_desc->integer.value;
	}

	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
			  "FieldRead [TO]:   Obj %p, Type %X, Buf %p, ByteLen %X\n",
			  obj_desc, ACPI_GET_OBJECT_TYPE(obj_desc), buffer,
			  (u32) length));
	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
			  "FieldRead [FROM]: BitLen %X, BitOff %X, ByteOff %X\n",
			  obj_desc->common_field.bit_length,
			  obj_desc->common_field.start_field_bit_offset,
			  obj_desc->common_field.base_byte_offset));

	/* Lock entire transaction if requested */

	acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);

	/* Read from the field */

	status = acpi_ex_extract_from_field(obj_desc, buffer, (u32) length);
	acpi_ex_release_global_lock(obj_desc->common_field.field_flags);

      exit:
	if (ACPI_FAILURE(status)) {
		acpi_ut_remove_reference(buffer_desc);
	} else {
		*ret_buffer_desc = buffer_desc;
	}

	return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_write_data_to_field
 *
 * PARAMETERS:  source_desc         - Contains data to write
 *              obj_desc            - The named field
 *              result_desc         - Where the return value is returned, if any
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Write to a named field
 *
 ******************************************************************************/

acpi_status
acpi_ex_write_data_to_field(union acpi_operand_object *source_desc,
			    union acpi_operand_object *obj_desc,
			    union acpi_operand_object **result_desc)
{
	acpi_status status;
	u32 length;
	void *buffer;
	union acpi_operand_object *buffer_desc;

	ACPI_FUNCTION_TRACE_PTR(ex_write_data_to_field, obj_desc);

	/* Parameter validation */

	if (!source_desc || !obj_desc) {
		return_ACPI_STATUS(AE_AML_NO_OPERAND);
	}

	if (ACPI_GET_OBJECT_TYPE(obj_desc) == ACPI_TYPE_BUFFER_FIELD) {
		/*
		 * If the buffer_field arguments have not been previously evaluated,
		 * evaluate them now and save the results.
		 */
		if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
			status = acpi_ds_get_buffer_field_arguments(obj_desc);
			if (ACPI_FAILURE(status)) {
				return_ACPI_STATUS(status);
			}
		}
	} else
	    if ((ACPI_GET_OBJECT_TYPE(obj_desc) == ACPI_TYPE_LOCAL_REGION_FIELD)
		&& (obj_desc->field.region_obj->region.space_id ==
		    ACPI_ADR_SPACE_SMBUS)) {
		/*
		 * This is an SMBus write.  We will bypass the entire field mechanism
		 * and handoff the buffer directly to the handler.
		 *
		 * Source must be a buffer of sufficient size (ACPI_SMBUS_BUFFER_SIZE).
		 */
		if (ACPI_GET_OBJECT_TYPE(source_desc) != ACPI_TYPE_BUFFER) {
			ACPI_ERROR((AE_INFO,
				    "SMBus write requires Buffer, found type %s",
				    acpi_ut_get_object_type_name(source_desc)));

			return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
		}

		if (source_desc->buffer.length < ACPI_SMBUS_BUFFER_SIZE) {
			ACPI_ERROR((AE_INFO,
				    "SMBus write requires Buffer of length %X, found length %X",
				    ACPI_SMBUS_BUFFER_SIZE,
				    source_desc->buffer.length));

			return_ACPI_STATUS(AE_AML_BUFFER_LIMIT);
		}

		buffer_desc =
		    acpi_ut_create_buffer_object(ACPI_SMBUS_BUFFER_SIZE);
		if (!buffer_desc) {
			return_ACPI_STATUS(AE_NO_MEMORY);
		}

		buffer = buffer_desc->buffer.pointer;
		ACPI_MEMCPY(buffer, source_desc->buffer.pointer,
			    ACPI_SMBUS_BUFFER_SIZE);

		/* Lock entire transaction if requested */

		acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);

		/*
		 * Perform the write (returns status and perhaps data in the
		 * same buffer)
		 * Note: SMBus protocol type is passed in upper 16-bits of Function.
		 */
		status = acpi_ex_access_region(obj_desc, 0,
					       (acpi_integer *) buffer,
					       ACPI_WRITE | (obj_desc->field.
							     attribute << 16));
		acpi_ex_release_global_lock(obj_desc->common_field.field_flags);

		*result_desc = buffer_desc;
		return_ACPI_STATUS(status);
	}

	/* Get a pointer to the data to be written */

	switch (ACPI_GET_OBJECT_TYPE(source_desc)) {
	case ACPI_TYPE_INTEGER:
		buffer = &source_desc->integer.value;
		length = sizeof(source_desc->integer.value);
		break;

	case ACPI_TYPE_BUFFER:
		buffer = source_desc->buffer.pointer;
		length = source_desc->buffer.length;
		break;

	case ACPI_TYPE_STRING:
		buffer = source_desc->string.pointer;
		length = source_desc->string.length;
		break;

	default:
		return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
	}

	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
			  "FieldWrite [FROM]: Obj %p (%s:%X), Buf %p, ByteLen %X\n",
			  source_desc,
			  acpi_ut_get_type_name(ACPI_GET_OBJECT_TYPE
						(source_desc)),
			  ACPI_GET_OBJECT_TYPE(source_desc), buffer, length));

	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
			  "FieldWrite [TO]:   Obj %p (%s:%X), BitLen %X, BitOff %X, ByteOff %X\n",
			  obj_desc,
			  acpi_ut_get_type_name(ACPI_GET_OBJECT_TYPE(obj_desc)),
			  ACPI_GET_OBJECT_TYPE(obj_desc),
			  obj_desc->common_field.bit_length,
			  obj_desc->common_field.start_field_bit_offset,
			  obj_desc->common_field.base_byte_offset));

	/* Lock entire transaction if requested */

	acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);

	/* Write to the field */

	status = acpi_ex_insert_into_field(obj_desc, buffer, length);
	acpi_ex_release_global_lock(obj_desc->common_field.field_flags);

	return_ACPI_STATUS(status);
}
Commit	Line	Data
1da177e4 LT	1	/******************************************************************************
	2	*
	3	* Module Name: exfield - ACPI AML (p-code) execution - field manipulation
	4	*
	5	*****************************************************************************/
	6
	7	/*
75a44ce0	8	* Copyright (C) 2000 - 2008, Intel Corp.
1da177e4 LT	9	* All rights reserved.
	10	*
	11	* Redistribution and use in source and binary forms, with or without
	12	* modification, are permitted provided that the following conditions
	13	* are met:
	14	* 1. Redistributions of source code must retain the above copyright
	15	* notice, this list of conditions, and the following disclaimer,
	16	* without modification.
	17	* 2. Redistributions in binary form must reproduce at minimum a disclaimer
	18	* substantially similar to the "NO WARRANTY" disclaimer below
	19	* ("Disclaimer") and any redistribution must be conditioned upon
	20	* including a substantially similar Disclaimer requirement for further
	21	* binary redistribution.
	22	* 3. Neither the names of the above-listed copyright holders nor the names
	23	* of any contributors may be used to endorse or promote products derived
	24	* from this software without specific prior written permission.
	25	*
	26	* Alternatively, this software may be distributed under the terms of the
	27	* GNU General Public License ("GPL") version 2 as published by the Free
	28	* Software Foundation.
	29	*
	30	* NO WARRANTY
	31	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	32	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	33	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
	34	* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	35	* HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	36	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	37	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	38	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
	39	* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
	40	* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
	41	* POSSIBILITY OF SUCH DAMAGES.
	42	*/
	43
1da177e4	44	#include <acpi/acpi.h>
e2f7a777 LB	45	#include "accommon.h"
	46	#include "acdispat.h"
	47	#include "acinterp.h"
1da177e4	48
1da177e4	49	#define _COMPONENT ACPI_EXECUTER
4be44fcd	50	ACPI_MODULE_NAME("exfield")
1da177e4 LT	51
	52	/*******************************************************************************
	53	*
	54	* FUNCTION: acpi_ex_read_data_from_field
	55	*
	56	* PARAMETERS: walk_state - Current execution state
	57	* obj_desc - The named field
	58	* ret_buffer_desc - Where the return data object is stored
	59	*
	60	* RETURN: Status
	61	*
	62	* DESCRIPTION: Read from a named field. Returns either an Integer or a
	63	* Buffer, depending on the size of the field.
	64	*
	65	******************************************************************************/
1da177e4	66	acpi_status
4be44fcd LB	67	acpi_ex_read_data_from_field(struct acpi_walk_state *walk_state,
	68	union acpi_operand_object *obj_desc,
	69	union acpi_operand_object **ret_buffer_desc)
1da177e4	70	{
4be44fcd LB	71	acpi_status status;
	72	union acpi_operand_object *buffer_desc;
	73	acpi_size length;
	74	void *buffer;
1da177e4	75
b229cf92	76	ACPI_FUNCTION_TRACE_PTR(ex_read_data_from_field, obj_desc);
1da177e4 LT	77
	78	/* Parameter validation */
	79
	80	if (!obj_desc) {
4be44fcd	81	return_ACPI_STATUS(AE_AML_NO_OPERAND);
1da177e4	82	}
88ac00f5	83	if (!ret_buffer_desc) {
4be44fcd	84	return_ACPI_STATUS(AE_BAD_PARAMETER);
88ac00f5	85	}
1da177e4	86
4be44fcd	87	if (ACPI_GET_OBJECT_TYPE(obj_desc) == ACPI_TYPE_BUFFER_FIELD) {
1da177e4 LT	88	/*
	89	* If the buffer_field arguments have not been previously evaluated,
	90	* evaluate them now and save the results.
	91	*/
	92	if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
4be44fcd LB	93	status = acpi_ds_get_buffer_field_arguments(obj_desc);
	94	if (ACPI_FAILURE(status)) {
	95	return_ACPI_STATUS(status);
1da177e4 LT	96	}
1da177e4 LT	97	}
4be44fcd LB	98	} else
	99	if ((ACPI_GET_OBJECT_TYPE(obj_desc) == ACPI_TYPE_LOCAL_REGION_FIELD)
	100	&& (obj_desc->field.region_obj->region.space_id ==
	101	ACPI_ADR_SPACE_SMBUS)) {
1da177e4 LT	102	/*
	103	* This is an SMBus read. We must create a buffer to hold the data
	104	* and directly access the region handler.
	105	*/
4be44fcd LB	106	buffer_desc =
4be44fcd LB	107	acpi_ut_create_buffer_object(ACPI_SMBUS_BUFFER_SIZE);
1da177e4	108	if (!buffer_desc) {
4be44fcd	109	return_ACPI_STATUS(AE_NO_MEMORY);
1da177e4 LT	110	}
	111
	112	/* Lock entire transaction if requested */
	113
ba886cd4	114	acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
1da177e4 LT	115
	116	/*
	117	* Perform the read.
	118	* Note: Smbus protocol value is passed in upper 16-bits of Function
	119	*/
4be44fcd LB	120	status = acpi_ex_access_region(obj_desc, 0,
	121	ACPI_CAST_PTR(acpi_integer,
	122	buffer_desc->
	123	buffer.pointer),
	124	ACPI_READ \| (obj_desc->field.
	125	attribute << 16));
f02e9fa1	126	acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
1da177e4 LT	127	goto exit;
	128	}
	129
	130	/*
	131	* Allocate a buffer for the contents of the field.
	132	*
	133	* If the field is larger than the size of an acpi_integer, create
	134	* a BUFFER to hold it. Otherwise, use an INTEGER. This allows
	135	* the use of arithmetic operators on the returned value if the
	136	* field size is equal or smaller than an Integer.
	137	*
	138	* Note: Field.length is in bits.
	139	*/
4be44fcd LB	140	length =
4be44fcd LB	141	(acpi_size) ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->field.bit_length);
1da177e4	142	if (length > acpi_gbl_integer_byte_width) {
52fc0b02	143
1da177e4 LT	144	/* Field is too large for an Integer, create a Buffer instead */
1da177e4 LT	145
4be44fcd	146	buffer_desc = acpi_ut_create_buffer_object(length);
1da177e4	147	if (!buffer_desc) {
4be44fcd	148	return_ACPI_STATUS(AE_NO_MEMORY);
1da177e4 LT	149	}
1da177e4 LT	150	buffer = buffer_desc->buffer.pointer;
4be44fcd	151	} else {
1da177e4 LT	152	/* Field will fit within an Integer (normal case) */
1da177e4 LT	153
4be44fcd	154	buffer_desc = acpi_ut_create_internal_object(ACPI_TYPE_INTEGER);
1da177e4	155	if (!buffer_desc) {
4be44fcd	156	return_ACPI_STATUS(AE_NO_MEMORY);
1da177e4 LT	157	}
	158
	159	length = acpi_gbl_integer_byte_width;
	160	buffer_desc->integer.value = 0;
	161	buffer = &buffer_desc->integer.value;
	162	}
	163
4be44fcd	164	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
b229cf92	165	"FieldRead [TO]: Obj %p, Type %X, Buf %p, ByteLen %X\n",
4be44fcd LB	166	obj_desc, ACPI_GET_OBJECT_TYPE(obj_desc), buffer,
	167	(u32) length));
	168	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
b229cf92	169	"FieldRead [FROM]: BitLen %X, BitOff %X, ByteOff %X\n",
4be44fcd LB	170	obj_desc->common_field.bit_length,
	171	obj_desc->common_field.start_field_bit_offset,
	172	obj_desc->common_field.base_byte_offset));
1da177e4 LT	173
	174	/* Lock entire transaction if requested */
	175
ba886cd4	176	acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
1da177e4 LT	177
	178	/* Read from the field */
	179
4be44fcd	180	status = acpi_ex_extract_from_field(obj_desc, buffer, (u32) length);
f02e9fa1	181	acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
1da177e4	182
4be44fcd LB	183	exit:
	184	if (ACPI_FAILURE(status)) {
	185	acpi_ut_remove_reference(buffer_desc);
	186	} else {
1da177e4 LT	187	*ret_buffer_desc = buffer_desc;
	188	}
	189
4be44fcd	190	return_ACPI_STATUS(status);
1da177e4 LT	191	}
1da177e4 LT	192
1da177e4 LT	193	/*******************************************************************************
	194	*
	195	* FUNCTION: acpi_ex_write_data_to_field
	196	*
	197	* PARAMETERS: source_desc - Contains data to write
	198	* obj_desc - The named field
44f6c012	199	* result_desc - Where the return value is returned, if any
1da177e4 LT	200	*
	201	* RETURN: Status
	202	*
	203	* DESCRIPTION: Write to a named field
	204	*
	205	******************************************************************************/
	206
	207	acpi_status
4be44fcd LB	208	acpi_ex_write_data_to_field(union acpi_operand_object *source_desc,
	209	union acpi_operand_object *obj_desc,
	210	union acpi_operand_object **result_desc)
1da177e4	211	{
4be44fcd LB	212	acpi_status status;
4be44fcd LB	213	u32 length;
4be44fcd	214	void *buffer;
4be44fcd	215	union acpi_operand_object *buffer_desc;
1da177e4	216
b229cf92	217	ACPI_FUNCTION_TRACE_PTR(ex_write_data_to_field, obj_desc);
1da177e4 LT	218
	219	/* Parameter validation */
	220
	221	if (!source_desc \|\| !obj_desc) {
4be44fcd	222	return_ACPI_STATUS(AE_AML_NO_OPERAND);
1da177e4 LT	223	}
1da177e4 LT	224
4be44fcd	225	if (ACPI_GET_OBJECT_TYPE(obj_desc) == ACPI_TYPE_BUFFER_FIELD) {
1da177e4 LT	226	/*
	227	* If the buffer_field arguments have not been previously evaluated,
	228	* evaluate them now and save the results.
	229	*/
	230	if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
4be44fcd LB	231	status = acpi_ds_get_buffer_field_arguments(obj_desc);
	232	if (ACPI_FAILURE(status)) {
	233	return_ACPI_STATUS(status);
1da177e4 LT	234	}
1da177e4 LT	235	}
4be44fcd LB	236	} else
	237	if ((ACPI_GET_OBJECT_TYPE(obj_desc) == ACPI_TYPE_LOCAL_REGION_FIELD)
	238	&& (obj_desc->field.region_obj->region.space_id ==
	239	ACPI_ADR_SPACE_SMBUS)) {
1da177e4 LT	240	/*
	241	* This is an SMBus write. We will bypass the entire field mechanism
	242	* and handoff the buffer directly to the handler.
	243	*
	244	* Source must be a buffer of sufficient size (ACPI_SMBUS_BUFFER_SIZE).
	245	*/
4be44fcd	246	if (ACPI_GET_OBJECT_TYPE(source_desc) != ACPI_TYPE_BUFFER) {
b8e4d893 BM	247	ACPI_ERROR((AE_INFO,
	248	"SMBus write requires Buffer, found type %s",
	249	acpi_ut_get_object_type_name(source_desc)));
44f6c012	250
4be44fcd	251	return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
1da177e4 LT	252	}
	253
	254	if (source_desc->buffer.length < ACPI_SMBUS_BUFFER_SIZE) {
b8e4d893 BM	255	ACPI_ERROR((AE_INFO,
	256	"SMBus write requires Buffer of length %X, found length %X",
	257	ACPI_SMBUS_BUFFER_SIZE,
	258	source_desc->buffer.length));
44f6c012	259
4be44fcd	260	return_ACPI_STATUS(AE_AML_BUFFER_LIMIT);
1da177e4 LT	261	}
1da177e4 LT	262
4be44fcd LB	263	buffer_desc =
4be44fcd LB	264	acpi_ut_create_buffer_object(ACPI_SMBUS_BUFFER_SIZE);
1da177e4	265	if (!buffer_desc) {
4be44fcd	266	return_ACPI_STATUS(AE_NO_MEMORY);
1da177e4 LT	267	}
	268
	269	buffer = buffer_desc->buffer.pointer;
4be44fcd LB	270	ACPI_MEMCPY(buffer, source_desc->buffer.pointer,
4be44fcd LB	271	ACPI_SMBUS_BUFFER_SIZE);
1da177e4 LT	272
	273	/* Lock entire transaction if requested */
	274
ba886cd4	275	acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
1da177e4 LT	276
1da177e4 LT	277	/*
44f6c012 RM	278	* Perform the write (returns status and perhaps data in the
44f6c012 RM	279	* same buffer)
1da177e4 LT	280	* Note: SMBus protocol type is passed in upper 16-bits of Function.
1da177e4 LT	281	*/
4be44fcd LB	282	status = acpi_ex_access_region(obj_desc, 0,
	283	(acpi_integer *) buffer,
	284	ACPI_WRITE \| (obj_desc->field.
	285	attribute << 16));
f02e9fa1	286	acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
1da177e4 LT	287
1da177e4 LT	288	*result_desc = buffer_desc;
4be44fcd	289	return_ACPI_STATUS(status);
1da177e4 LT	290	}
1da177e4 LT	291
44f6c012 RM	292	/* Get a pointer to the data to be written */
44f6c012 RM	293
4be44fcd	294	switch (ACPI_GET_OBJECT_TYPE(source_desc)) {
1da177e4 LT	295	case ACPI_TYPE_INTEGER:
1da177e4 LT	296	buffer = &source_desc->integer.value;
4be44fcd	297	length = sizeof(source_desc->integer.value);
1da177e4 LT	298	break;
	299
	300	case ACPI_TYPE_BUFFER:
	301	buffer = source_desc->buffer.pointer;
	302	length = source_desc->buffer.length;
	303	break;
	304
	305	case ACPI_TYPE_STRING:
	306	buffer = source_desc->string.pointer;
	307	length = source_desc->string.length;
	308	break;
	309
	310	default:
4be44fcd	311	return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
1da177e4 LT	312	}
1da177e4 LT	313
4be44fcd	314	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
b229cf92	315	"FieldWrite [FROM]: Obj %p (%s:%X), Buf %p, ByteLen %X\n",
4be44fcd LB	316	source_desc,
	317	acpi_ut_get_type_name(ACPI_GET_OBJECT_TYPE
	318	(source_desc)),
	319	ACPI_GET_OBJECT_TYPE(source_desc), buffer, length));
	320
	321	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
b229cf92	322	"FieldWrite [TO]: Obj %p (%s:%X), BitLen %X, BitOff %X, ByteOff %X\n",
4be44fcd LB	323	obj_desc,
	324	acpi_ut_get_type_name(ACPI_GET_OBJECT_TYPE(obj_desc)),
	325	ACPI_GET_OBJECT_TYPE(obj_desc),
	326	obj_desc->common_field.bit_length,
	327	obj_desc->common_field.start_field_bit_offset,
	328	obj_desc->common_field.base_byte_offset));
1da177e4 LT	329
	330	/* Lock entire transaction if requested */
	331
ba886cd4	332	acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
1da177e4 LT	333
	334	/* Write to the field */
	335
4be44fcd	336	status = acpi_ex_insert_into_field(obj_desc, buffer, length);
f02e9fa1	337	acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
1da177e4	338
4be44fcd	339	return_ACPI_STATUS(status);
1da177e4	340	}