1 /******************************************************************************
3 * Module Name: exfield - ACPI AML (p-code) execution - field manipulation
5 *****************************************************************************/
8 * Copyright (C) 2000 - 2005, R. Byron Moore
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
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.
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.
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
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41 * POSSIBILITY OF SUCH DAMAGES.
45 #include <acpi/acpi.h>
46 #include <acpi/acdispat.h>
47 #include <acpi/acinterp.h>
50 #define _COMPONENT ACPI_EXECUTER
51 ACPI_MODULE_NAME ("exfield")
54 /*******************************************************************************
56 * FUNCTION: acpi_ex_read_data_from_field
58 * PARAMETERS: walk_state - Current execution state
59 * obj_desc - The named field
60 * ret_buffer_desc - Where the return data object is stored
64 * DESCRIPTION: Read from a named field. Returns either an Integer or a
65 * Buffer, depending on the size of the field.
67 ******************************************************************************/
70 acpi_ex_read_data_from_field (
71 struct acpi_walk_state *walk_state,
72 union acpi_operand_object *obj_desc,
73 union acpi_operand_object **ret_buffer_desc)
76 union acpi_operand_object *buffer_desc;
82 ACPI_FUNCTION_TRACE_PTR ("ex_read_data_from_field", obj_desc);
85 /* Parameter validation */
88 return_ACPI_STATUS (AE_AML_NO_OPERAND);
91 if (ACPI_GET_OBJECT_TYPE (obj_desc) == ACPI_TYPE_BUFFER_FIELD) {
93 * If the buffer_field arguments have not been previously evaluated,
94 * evaluate them now and save the results.
96 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
97 status = acpi_ds_get_buffer_field_arguments (obj_desc);
98 if (ACPI_FAILURE (status)) {
99 return_ACPI_STATUS (status);
103 else if ((ACPI_GET_OBJECT_TYPE (obj_desc) == ACPI_TYPE_LOCAL_REGION_FIELD) &&
104 (obj_desc->field.region_obj->region.space_id == ACPI_ADR_SPACE_SMBUS)) {
106 * This is an SMBus read. We must create a buffer to hold the data
107 * and directly access the region handler.
109 buffer_desc = acpi_ut_create_buffer_object (ACPI_SMBUS_BUFFER_SIZE);
111 return_ACPI_STATUS (AE_NO_MEMORY);
114 /* Lock entire transaction if requested */
116 locked = acpi_ex_acquire_global_lock (obj_desc->common_field.field_flags);
120 * Note: Smbus protocol value is passed in upper 16-bits of Function
122 status = acpi_ex_access_region (obj_desc, 0,
123 ACPI_CAST_PTR (acpi_integer, buffer_desc->buffer.pointer),
124 ACPI_READ | (obj_desc->field.attribute << 16));
125 acpi_ex_release_global_lock (locked);
130 * Allocate a buffer for the contents of the field.
132 * If the field is larger than the size of an acpi_integer, create
133 * a BUFFER to hold it. Otherwise, use an INTEGER. This allows
134 * the use of arithmetic operators on the returned value if the
135 * field size is equal or smaller than an Integer.
137 * Note: Field.length is in bits.
139 length = (acpi_size) ACPI_ROUND_BITS_UP_TO_BYTES (obj_desc->field.bit_length);
140 if (length > acpi_gbl_integer_byte_width) {
141 /* Field is too large for an Integer, create a Buffer instead */
143 buffer_desc = acpi_ut_create_buffer_object (length);
145 return_ACPI_STATUS (AE_NO_MEMORY);
147 buffer = buffer_desc->buffer.pointer;
150 /* Field will fit within an Integer (normal case) */
152 buffer_desc = acpi_ut_create_internal_object (ACPI_TYPE_INTEGER);
154 return_ACPI_STATUS (AE_NO_MEMORY);
157 length = acpi_gbl_integer_byte_width;
158 buffer_desc->integer.value = 0;
159 buffer = &buffer_desc->integer.value;
162 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
163 "field_read [TO]: Obj %p, Type %X, Buf %p, byte_len %X\n",
164 obj_desc, ACPI_GET_OBJECT_TYPE (obj_desc), buffer, (u32) length));
165 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
166 "field_read [FROM]: bit_len %X, bit_off %X, byte_off %X\n",
167 obj_desc->common_field.bit_length,
168 obj_desc->common_field.start_field_bit_offset,
169 obj_desc->common_field.base_byte_offset));
171 /* Lock entire transaction if requested */
173 locked = acpi_ex_acquire_global_lock (obj_desc->common_field.field_flags);
175 /* Read from the field */
177 status = acpi_ex_extract_from_field (obj_desc, buffer, (u32) length);
178 acpi_ex_release_global_lock (locked);
182 if (ACPI_FAILURE (status)) {
183 acpi_ut_remove_reference (buffer_desc);
185 else if (ret_buffer_desc) {
186 *ret_buffer_desc = buffer_desc;
189 return_ACPI_STATUS (status);
193 /*******************************************************************************
195 * FUNCTION: acpi_ex_write_data_to_field
197 * PARAMETERS: source_desc - Contains data to write
198 * obj_desc - The named field
199 * result_desc - Where the return value is returned, if any
203 * DESCRIPTION: Write to a named field
205 ******************************************************************************/
208 acpi_ex_write_data_to_field (
209 union acpi_operand_object *source_desc,
210 union acpi_operand_object *obj_desc,
211 union acpi_operand_object **result_desc)
219 union acpi_operand_object *buffer_desc;
222 ACPI_FUNCTION_TRACE_PTR ("ex_write_data_to_field", obj_desc);
225 /* Parameter validation */
227 if (!source_desc || !obj_desc) {
228 return_ACPI_STATUS (AE_AML_NO_OPERAND);
231 if (ACPI_GET_OBJECT_TYPE (obj_desc) == ACPI_TYPE_BUFFER_FIELD) {
233 * If the buffer_field arguments have not been previously evaluated,
234 * evaluate them now and save the results.
236 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
237 status = acpi_ds_get_buffer_field_arguments (obj_desc);
238 if (ACPI_FAILURE (status)) {
239 return_ACPI_STATUS (status);
243 else if ((ACPI_GET_OBJECT_TYPE (obj_desc) == ACPI_TYPE_LOCAL_REGION_FIELD) &&
244 (obj_desc->field.region_obj->region.space_id == ACPI_ADR_SPACE_SMBUS)) {
246 * This is an SMBus write. We will bypass the entire field mechanism
247 * and handoff the buffer directly to the handler.
249 * Source must be a buffer of sufficient size (ACPI_SMBUS_BUFFER_SIZE).
251 if (ACPI_GET_OBJECT_TYPE (source_desc) != ACPI_TYPE_BUFFER) {
252 ACPI_REPORT_ERROR (("SMBus write requires Buffer, found type %s\n",
253 acpi_ut_get_object_type_name (source_desc)));
255 return_ACPI_STATUS (AE_AML_OPERAND_TYPE);
258 if (source_desc->buffer.length < ACPI_SMBUS_BUFFER_SIZE) {
260 "SMBus write requires Buffer of length %X, found length %X\n",
261 ACPI_SMBUS_BUFFER_SIZE, source_desc->buffer.length));
263 return_ACPI_STATUS (AE_AML_BUFFER_LIMIT);
266 buffer_desc = acpi_ut_create_buffer_object (ACPI_SMBUS_BUFFER_SIZE);
268 return_ACPI_STATUS (AE_NO_MEMORY);
271 buffer = buffer_desc->buffer.pointer;
272 ACPI_MEMCPY (buffer, source_desc->buffer.pointer,
273 ACPI_SMBUS_BUFFER_SIZE);
275 /* Lock entire transaction if requested */
277 locked = acpi_ex_acquire_global_lock (obj_desc->common_field.field_flags);
280 * Perform the write (returns status and perhaps data in the
282 * Note: SMBus protocol type is passed in upper 16-bits of Function.
284 status = acpi_ex_access_region (obj_desc, 0,
285 (acpi_integer *) buffer,
286 ACPI_WRITE | (obj_desc->field.attribute << 16));
287 acpi_ex_release_global_lock (locked);
289 *result_desc = buffer_desc;
290 return_ACPI_STATUS (status);
293 /* Get a pointer to the data to be written */
295 switch (ACPI_GET_OBJECT_TYPE (source_desc)) {
296 case ACPI_TYPE_INTEGER:
297 buffer = &source_desc->integer.value;
298 length = sizeof (source_desc->integer.value);
301 case ACPI_TYPE_BUFFER:
302 buffer = source_desc->buffer.pointer;
303 length = source_desc->buffer.length;
306 case ACPI_TYPE_STRING:
307 buffer = source_desc->string.pointer;
308 length = source_desc->string.length;
312 return_ACPI_STATUS (AE_AML_OPERAND_TYPE);
316 * We must have a buffer that is at least as long as the field
317 * we are writing to. This is because individual fields are
318 * indivisible and partial writes are not supported -- as per
319 * the ACPI specification.
322 required_length = ACPI_ROUND_BITS_UP_TO_BYTES (
323 obj_desc->common_field.bit_length);
325 if (length < required_length) {
326 /* We need to create a new buffer */
328 new_buffer = ACPI_MEM_CALLOCATE (required_length);
330 return_ACPI_STATUS (AE_NO_MEMORY);
334 * Copy the original data to the new buffer, starting
335 * at Byte zero. All unused (upper) bytes of the
338 ACPI_MEMCPY ((char *) new_buffer, (char *) buffer, length);
340 length = required_length;
343 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
344 "field_write [FROM]: Obj %p (%s:%X), Buf %p, byte_len %X\n",
345 source_desc, acpi_ut_get_type_name (ACPI_GET_OBJECT_TYPE (source_desc)),
346 ACPI_GET_OBJECT_TYPE (source_desc), buffer, length));
348 ACPI_DEBUG_PRINT ((ACPI_DB_BFIELD,
349 "field_write [TO]: Obj %p (%s:%X), bit_len %X, bit_off %X, byte_off %X\n",
350 obj_desc, acpi_ut_get_type_name (ACPI_GET_OBJECT_TYPE (obj_desc)),
351 ACPI_GET_OBJECT_TYPE (obj_desc),
352 obj_desc->common_field.bit_length,
353 obj_desc->common_field.start_field_bit_offset,
354 obj_desc->common_field.base_byte_offset));
356 /* Lock entire transaction if requested */
358 locked = acpi_ex_acquire_global_lock (obj_desc->common_field.field_flags);
360 /* Write to the field */
362 status = acpi_ex_insert_into_field (obj_desc, buffer, length);
363 acpi_ex_release_global_lock (locked);
365 /* Free temporary buffer if we used one */
368 ACPI_MEM_FREE (new_buffer);
371 return_ACPI_STATUS (status);