[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / acpi / executer / exfield.c

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

/*
 * Copyright (C) 2000 - 2006, R. Byron Moore
 * 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 <acpi/acdispat.h>
#include <acpi/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;
	u8 locked;

	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 */

		locked =
		    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(locked);
		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,
			  "field_read [TO]:  Obj %p, Type %X, Buf %p, byte_len %X\n",
			  obj_desc, ACPI_GET_OBJECT_TYPE(obj_desc), buffer,
			  (u32) length));
	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
			  "field_read [FROM]: bit_len %X, bit_off %X, byte_off %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 */

	locked =
	    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(locked);

      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;
	u32 required_length;
	void *buffer;
	void *new_buffer;
	u8 locked;
	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_REPORT_ERROR(("SMBus write requires Buffer, found type %s\n", 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_REPORT_ERROR(("SMBus write requires Buffer of length %X, found length %X\n", 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 */

		locked =
		    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(locked);

		*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);
	}

	/*
	 * We must have a buffer that is at least as long as the field
	 * we are writing to.  This is because individual fields are
	 * indivisible and partial writes are not supported -- as per
	 * the ACPI specification.
	 */
	new_buffer = NULL;
	required_length =
	    ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length);

	if (length < required_length) {
		/* We need to create a new buffer */

		new_buffer = ACPI_MEM_CALLOCATE(required_length);
		if (!new_buffer) {
			return_ACPI_STATUS(AE_NO_MEMORY);
		}

		/*
		 * Copy the original data to the new buffer, starting
		 * at Byte zero.  All unused (upper) bytes of the
		 * buffer will be 0.
		 */
		ACPI_MEMCPY((char *)new_buffer, (char *)buffer, length);
		buffer = new_buffer;
		length = required_length;
	}

	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
			  "field_write [FROM]: Obj %p (%s:%X), Buf %p, byte_len %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,
			  "field_write [TO]:  Obj %p (%s:%X), bit_len %X, bit_off %X, byte_off %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 */

	locked =
	    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(locked);

	/* Free temporary buffer if we used one */

	if (new_buffer) {
		ACPI_MEM_FREE(new_buffer);
	}

	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	/*
4a90c7e8	8	* Copyright (C) 2000 - 2006, R. Byron Moore
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 LT	44	#include <acpi/acpi.h>
	45	#include <acpi/acdispat.h>
	46	#include <acpi/acinterp.h>
	47
1da177e4	48	#define _COMPONENT ACPI_EXECUTER
4be44fcd	49	ACPI_MODULE_NAME("exfield")
1da177e4 LT	50
	51	/*******************************************************************************
	52	*
	53	* FUNCTION: acpi_ex_read_data_from_field
	54	*
	55	* PARAMETERS: walk_state - Current execution state
	56	* obj_desc - The named field
	57	* ret_buffer_desc - Where the return data object is stored
	58	*
	59	* RETURN: Status
	60	*
	61	* DESCRIPTION: Read from a named field. Returns either an Integer or a
	62	* Buffer, depending on the size of the field.
	63	*
	64	******************************************************************************/
1da177e4	65	acpi_status
4be44fcd LB	66	acpi_ex_read_data_from_field(struct acpi_walk_state *walk_state,
	67	union acpi_operand_object *obj_desc,
	68	union acpi_operand_object **ret_buffer_desc)
1da177e4	69	{
4be44fcd LB	70	acpi_status status;
	71	union acpi_operand_object *buffer_desc;
	72	acpi_size length;
	73	void *buffer;
	74	u8 locked;
1da177e4	75
4be44fcd	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
4be44fcd LB	114	locked =
	115	acpi_ex_acquire_global_lock(obj_desc->common_field.
	116	field_flags);
1da177e4 LT	117
	118	/*
	119	* Perform the read.
	120	* Note: Smbus protocol value is passed in upper 16-bits of Function
	121	*/
4be44fcd LB	122	status = acpi_ex_access_region(obj_desc, 0,
	123	ACPI_CAST_PTR(acpi_integer,
	124	buffer_desc->
	125	buffer.pointer),
	126	ACPI_READ \| (obj_desc->field.
	127	attribute << 16));
	128	acpi_ex_release_global_lock(locked);
1da177e4 LT	129	goto exit;
	130	}
	131
	132	/*
	133	* Allocate a buffer for the contents of the field.
	134	*
	135	* If the field is larger than the size of an acpi_integer, create
	136	* a BUFFER to hold it. Otherwise, use an INTEGER. This allows
	137	* the use of arithmetic operators on the returned value if the
	138	* field size is equal or smaller than an Integer.
	139	*
	140	* Note: Field.length is in bits.
	141	*/
4be44fcd LB	142	length =
4be44fcd LB	143	(acpi_size) ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->field.bit_length);
1da177e4 LT	144	if (length > acpi_gbl_integer_byte_width) {
	145	/* Field is too large for an Integer, create a Buffer instead */
	146
4be44fcd	147	buffer_desc = acpi_ut_create_buffer_object(length);
1da177e4	148	if (!buffer_desc) {
4be44fcd	149	return_ACPI_STATUS(AE_NO_MEMORY);
1da177e4 LT	150	}
1da177e4 LT	151	buffer = buffer_desc->buffer.pointer;
4be44fcd	152	} else {
1da177e4 LT	153	/* Field will fit within an Integer (normal case) */
1da177e4 LT	154
4be44fcd	155	buffer_desc = acpi_ut_create_internal_object(ACPI_TYPE_INTEGER);
1da177e4	156	if (!buffer_desc) {
4be44fcd	157	return_ACPI_STATUS(AE_NO_MEMORY);
1da177e4 LT	158	}
	159
	160	length = acpi_gbl_integer_byte_width;
	161	buffer_desc->integer.value = 0;
	162	buffer = &buffer_desc->integer.value;
	163	}
	164
4be44fcd LB	165	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
	166	"field_read [TO]: Obj %p, Type %X, Buf %p, byte_len %X\n",
	167	obj_desc, ACPI_GET_OBJECT_TYPE(obj_desc), buffer,
	168	(u32) length));
	169	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
	170	"field_read [FROM]: bit_len %X, bit_off %X, byte_off %X\n",
	171	obj_desc->common_field.bit_length,
	172	obj_desc->common_field.start_field_bit_offset,
	173	obj_desc->common_field.base_byte_offset));
1da177e4 LT	174
	175	/* Lock entire transaction if requested */
	176
4be44fcd LB	177	locked =
4be44fcd LB	178	acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
1da177e4 LT	179
	180	/* Read from the field */
	181
4be44fcd LB	182	status = acpi_ex_extract_from_field(obj_desc, buffer, (u32) length);
4be44fcd LB	183	acpi_ex_release_global_lock(locked);
1da177e4	184
4be44fcd LB	185	exit:
	186	if (ACPI_FAILURE(status)) {
	187	acpi_ut_remove_reference(buffer_desc);
	188	} else {
1da177e4 LT	189	*ret_buffer_desc = buffer_desc;
	190	}
	191
4be44fcd	192	return_ACPI_STATUS(status);
1da177e4 LT	193	}
1da177e4 LT	194
1da177e4 LT	195	/*******************************************************************************
	196	*
	197	* FUNCTION: acpi_ex_write_data_to_field
	198	*
	199	* PARAMETERS: source_desc - Contains data to write
	200	* obj_desc - The named field
44f6c012	201	* result_desc - Where the return value is returned, if any
1da177e4 LT	202	*
	203	* RETURN: Status
	204	*
	205	* DESCRIPTION: Write to a named field
	206	*
	207	******************************************************************************/
	208
	209	acpi_status
4be44fcd LB	210	acpi_ex_write_data_to_field(union acpi_operand_object *source_desc,
	211	union acpi_operand_object *obj_desc,
	212	union acpi_operand_object **result_desc)
1da177e4	213	{
4be44fcd LB	214	acpi_status status;
	215	u32 length;
	216	u32 required_length;
	217	void *buffer;
	218	void *new_buffer;
	219	u8 locked;
	220	union acpi_operand_object *buffer_desc;
1da177e4	221
4be44fcd	222	ACPI_FUNCTION_TRACE_PTR("ex_write_data_to_field", obj_desc);
1da177e4 LT	223
	224	/* Parameter validation */
	225
	226	if (!source_desc \|\| !obj_desc) {
4be44fcd	227	return_ACPI_STATUS(AE_AML_NO_OPERAND);
1da177e4 LT	228	}
1da177e4 LT	229
4be44fcd	230	if (ACPI_GET_OBJECT_TYPE(obj_desc) == ACPI_TYPE_BUFFER_FIELD) {
1da177e4 LT	231	/*
	232	* If the buffer_field arguments have not been previously evaluated,
	233	* evaluate them now and save the results.
	234	*/
	235	if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
4be44fcd LB	236	status = acpi_ds_get_buffer_field_arguments(obj_desc);
	237	if (ACPI_FAILURE(status)) {
	238	return_ACPI_STATUS(status);
1da177e4 LT	239	}
1da177e4 LT	240	}
4be44fcd LB	241	} else
	242	if ((ACPI_GET_OBJECT_TYPE(obj_desc) == ACPI_TYPE_LOCAL_REGION_FIELD)
	243	&& (obj_desc->field.region_obj->region.space_id ==
	244	ACPI_ADR_SPACE_SMBUS)) {
1da177e4 LT	245	/*
	246	* This is an SMBus write. We will bypass the entire field mechanism
	247	* and handoff the buffer directly to the handler.
	248	*
	249	* Source must be a buffer of sufficient size (ACPI_SMBUS_BUFFER_SIZE).
	250	*/
4be44fcd LB	251	if (ACPI_GET_OBJECT_TYPE(source_desc) != ACPI_TYPE_BUFFER) {
4be44fcd LB	252	ACPI_REPORT_ERROR(("SMBus write requires Buffer, found type %s\n", acpi_ut_get_object_type_name(source_desc)));
44f6c012	253
4be44fcd	254	return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
1da177e4 LT	255	}
	256
	257	if (source_desc->buffer.length < ACPI_SMBUS_BUFFER_SIZE) {
4be44fcd	258	ACPI_REPORT_ERROR(("SMBus write requires Buffer of length %X, found length %X\n", ACPI_SMBUS_BUFFER_SIZE, 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
4be44fcd LB	275	locked =
	276	acpi_ex_acquire_global_lock(obj_desc->common_field.
	277	field_flags);
1da177e4 LT	278
1da177e4 LT	279	/*
44f6c012 RM	280	* Perform the write (returns status and perhaps data in the
44f6c012 RM	281	* same buffer)
1da177e4 LT	282	* Note: SMBus protocol type is passed in upper 16-bits of Function.
1da177e4 LT	283	*/
4be44fcd LB	284	status = acpi_ex_access_region(obj_desc, 0,
	285	(acpi_integer *) buffer,
	286	ACPI_WRITE \| (obj_desc->field.
	287	attribute << 16));
	288	acpi_ex_release_global_lock(locked);
1da177e4 LT	289
1da177e4 LT	290	*result_desc = buffer_desc;
4be44fcd	291	return_ACPI_STATUS(status);
1da177e4 LT	292	}
1da177e4 LT	293
44f6c012 RM	294	/* Get a pointer to the data to be written */
44f6c012 RM	295
4be44fcd	296	switch (ACPI_GET_OBJECT_TYPE(source_desc)) {
1da177e4 LT	297	case ACPI_TYPE_INTEGER:
1da177e4 LT	298	buffer = &source_desc->integer.value;
4be44fcd	299	length = sizeof(source_desc->integer.value);
1da177e4 LT	300	break;
	301
	302	case ACPI_TYPE_BUFFER:
	303	buffer = source_desc->buffer.pointer;
	304	length = source_desc->buffer.length;
	305	break;
	306
	307	case ACPI_TYPE_STRING:
	308	buffer = source_desc->string.pointer;
	309	length = source_desc->string.length;
	310	break;
	311
	312	default:
4be44fcd	313	return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
1da177e4 LT	314	}
	315
	316	/*
	317	* We must have a buffer that is at least as long as the field
	318	* we are writing to. This is because individual fields are
	319	* indivisible and partial writes are not supported -- as per
	320	* the ACPI specification.
	321	*/
	322	new_buffer = NULL;
4be44fcd LB	323	required_length =
4be44fcd LB	324	ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->common_field.bit_length);
1da177e4 LT	325
	326	if (length < required_length) {
	327	/* We need to create a new buffer */
	328
4be44fcd	329	new_buffer = ACPI_MEM_CALLOCATE(required_length);
1da177e4	330	if (!new_buffer) {
4be44fcd	331	return_ACPI_STATUS(AE_NO_MEMORY);
1da177e4 LT	332	}
	333
	334	/*
	335	* Copy the original data to the new buffer, starting
	336	* at Byte zero. All unused (upper) bytes of the
	337	* buffer will be 0.
	338	*/
4be44fcd	339	ACPI_MEMCPY((char )new_buffer, (char )buffer, length);
1da177e4 LT	340	buffer = new_buffer;
	341	length = required_length;
	342	}
	343
4be44fcd LB	344	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
	345	"field_write [FROM]: Obj %p (%s:%X), Buf %p, byte_len %X\n",
	346	source_desc,
	347	acpi_ut_get_type_name(ACPI_GET_OBJECT_TYPE
	348	(source_desc)),
	349	ACPI_GET_OBJECT_TYPE(source_desc), buffer, length));
	350
	351	ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
	352	"field_write [TO]: Obj %p (%s:%X), bit_len %X, bit_off %X, byte_off %X\n",
	353	obj_desc,
	354	acpi_ut_get_type_name(ACPI_GET_OBJECT_TYPE(obj_desc)),
	355	ACPI_GET_OBJECT_TYPE(obj_desc),
	356	obj_desc->common_field.bit_length,
	357	obj_desc->common_field.start_field_bit_offset,
	358	obj_desc->common_field.base_byte_offset));
1da177e4 LT	359
	360	/* Lock entire transaction if requested */
	361
4be44fcd LB	362	locked =
4be44fcd LB	363	acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
1da177e4 LT	364
	365	/* Write to the field */
	366
4be44fcd LB	367	status = acpi_ex_insert_into_field(obj_desc, buffer, length);
4be44fcd LB	368	acpi_ex_release_global_lock(locked);
1da177e4 LT	369
	370	/* Free temporary buffer if we used one */
	371
	372	if (new_buffer) {
4be44fcd	373	ACPI_MEM_FREE(new_buffer);
1da177e4 LT	374	}
1da177e4 LT	375
4be44fcd	376	return_ACPI_STATUS(status);
1da177e4	377	}