1// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2/******************************************************************************
3 *
4 * Module Name: exserial - field_unit support for serial address spaces
5 *
6 * Copyright (C) 2000 - 2025, Intel Corp.
7 *
8 *****************************************************************************/
9
10#include <acpi/acpi.h>
11#include "accommon.h"
12#include "acdispat.h"
13#include "acinterp.h"
14#include "amlcode.h"
15
16#define _COMPONENT ACPI_EXECUTER
17ACPI_MODULE_NAME("exserial")
18
19/*******************************************************************************
20 *
21 * FUNCTION: acpi_ex_read_gpio
22 *
23 * PARAMETERS: obj_desc - The named field to read
24 * buffer - Where the return data is returned
25 *
26 * RETURN: Status
27 *
28 * DESCRIPTION: Read from a named field that references a Generic Serial Bus
29 * field
30 *
31 ******************************************************************************/
32acpi_status acpi_ex_read_gpio(union acpi_operand_object *obj_desc, void *buffer)
33{
34 acpi_status status;
35
36 ACPI_FUNCTION_TRACE_PTR(ex_read_gpio, obj_desc);
37
38 /*
39 * For GPIO (general_purpose_io), the Address will be the bit offset
40 * from the previous Connection() operator, making it effectively a
41 * pin number index. The bit_length is the length of the field, which
42 * is thus the number of pins.
43 */
44 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
45 "GPIO FieldRead [FROM]: Pin %u Bits %u\n",
46 obj_desc->field.pin_number_index,
47 obj_desc->field.bit_length));
48
49 /* Lock entire transaction if requested */
50
51 acpi_ex_acquire_global_lock(rule: obj_desc->common_field.field_flags);
52
53 /* Perform the read */
54
55 status = acpi_ex_access_region(obj_desc, field_datum_byte_offset: 0, value: (u64 *)buffer, ACPI_READ);
56
57 acpi_ex_release_global_lock(rule: obj_desc->common_field.field_flags);
58 return_ACPI_STATUS(status);
59}
60
61/*******************************************************************************
62 *
63 * FUNCTION: acpi_ex_write_gpio
64 *
65 * PARAMETERS: source_desc - Contains data to write. Expect to be
66 * an Integer object.
67 * obj_desc - The named field
68 * result_desc - Where the return value is returned, if any
69 *
70 * RETURN: Status
71 *
72 * DESCRIPTION: Write to a named field that references a General Purpose I/O
73 * field.
74 *
75 ******************************************************************************/
76
77acpi_status
78acpi_ex_write_gpio(union acpi_operand_object *source_desc,
79 union acpi_operand_object *obj_desc,
80 union acpi_operand_object **return_buffer)
81{
82 acpi_status status;
83 void *buffer;
84
85 ACPI_FUNCTION_TRACE_PTR(ex_write_gpio, obj_desc);
86
87 /*
88 * For GPIO (general_purpose_io), we will bypass the entire field
89 * mechanism and handoff the bit address and bit width directly to
90 * the handler. The Address will be the bit offset
91 * from the previous Connection() operator, making it effectively a
92 * pin number index. The bit_length is the length of the field, which
93 * is thus the number of pins.
94 */
95 if (source_desc->common.type != ACPI_TYPE_INTEGER) {
96 return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
97 }
98
99 ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
100 "GPIO FieldWrite [FROM]: (%s:%X), Value %.8X [TO]: Pin %u Bits %u\n",
101 acpi_ut_get_type_name(source_desc->common.type),
102 source_desc->common.type,
103 (u32)source_desc->integer.value,
104 obj_desc->field.pin_number_index,
105 obj_desc->field.bit_length));
106
107 buffer = &source_desc->integer.value;
108
109 /* Lock entire transaction if requested */
110
111 acpi_ex_acquire_global_lock(rule: obj_desc->common_field.field_flags);
112
113 /* Perform the write */
114
115 status = acpi_ex_access_region(obj_desc, field_datum_byte_offset: 0, value: (u64 *)buffer, ACPI_WRITE);
116 acpi_ex_release_global_lock(rule: obj_desc->common_field.field_flags);
117 return_ACPI_STATUS(status);
118}
119
120/*******************************************************************************
121 *
122 * FUNCTION: acpi_ex_read_serial_bus
123 *
124 * PARAMETERS: obj_desc - The named field to read
125 * return_buffer - Where the return value is returned, if any
126 *
127 * RETURN: Status
128 *
129 * DESCRIPTION: Read from a named field that references a serial bus
130 * (SMBus, IPMI, or GSBus).
131 *
132 ******************************************************************************/
133
134acpi_status
135acpi_ex_read_serial_bus(union acpi_operand_object *obj_desc,
136 union acpi_operand_object **return_buffer)
137{
138 acpi_status status;
139 u32 buffer_length;
140 union acpi_operand_object *buffer_desc;
141 u32 function;
142 u16 accessor_type;
143
144 ACPI_FUNCTION_TRACE_PTR(ex_read_serial_bus, obj_desc);
145
146 /*
147 * This is an SMBus, GSBus or IPMI read. We must create a buffer to
148 * hold the data and then directly access the region handler.
149 *
150 * Note: SMBus and GSBus protocol value is passed in upper 16-bits
151 * of Function
152 *
153 * Common buffer format:
154 * Status; (Byte 0 of the data buffer)
155 * Length; (Byte 1 of the data buffer)
156 * Data[x-1]: (Bytes 2-x of the arbitrary length data buffer)
157 */
158 switch (obj_desc->field.region_obj->region.space_id) {
159 case ACPI_ADR_SPACE_SMBUS:
160
161 buffer_length = ACPI_SMBUS_BUFFER_SIZE;
162 function = ACPI_READ | (obj_desc->field.attribute << 16);
163 break;
164
165 case ACPI_ADR_SPACE_IPMI:
166
167 buffer_length = ACPI_IPMI_BUFFER_SIZE;
168 function = ACPI_READ;
169 break;
170
171 case ACPI_ADR_SPACE_GSBUS:
172
173 accessor_type = obj_desc->field.attribute;
174 if (accessor_type == AML_FIELD_ATTRIB_RAW_PROCESS_BYTES) {
175 ACPI_ERROR((AE_INFO,
176 "Invalid direct read using bidirectional write-then-read protocol"));
177
178 return_ACPI_STATUS(AE_AML_PROTOCOL);
179 }
180
181 status =
182 acpi_ex_get_protocol_buffer_length(protocol_id: accessor_type,
183 return_length: &buffer_length);
184 if (ACPI_FAILURE(status)) {
185 ACPI_ERROR((AE_INFO,
186 "Invalid protocol ID for GSBus: 0x%4.4X",
187 accessor_type));
188
189 return_ACPI_STATUS(status);
190 }
191
192 /* Add header length to get the full size of the buffer */
193
194 buffer_length += ACPI_SERIAL_HEADER_SIZE;
195 function = ACPI_READ | (accessor_type << 16);
196 break;
197
198 case ACPI_ADR_SPACE_PLATFORM_RT:
199
200 buffer_length = ACPI_PRM_INPUT_BUFFER_SIZE;
201 function = ACPI_READ;
202 break;
203
204 case ACPI_ADR_SPACE_FIXED_HARDWARE:
205
206 buffer_length = ACPI_FFH_INPUT_BUFFER_SIZE;
207 function = ACPI_READ;
208 break;
209
210 default:
211 return_ACPI_STATUS(AE_AML_INVALID_SPACE_ID);
212 }
213
214 /* Create the local transfer buffer that is returned to the caller */
215
216 buffer_desc = acpi_ut_create_buffer_object(buffer_size: buffer_length);
217 if (!buffer_desc) {
218 return_ACPI_STATUS(AE_NO_MEMORY);
219 }
220
221 /* Lock entire transaction if requested */
222
223 acpi_ex_acquire_global_lock(rule: obj_desc->common_field.field_flags);
224
225 /* Call the region handler for the write-then-read */
226
227 status = acpi_ex_access_region(obj_desc, field_datum_byte_offset: 0,
228 ACPI_CAST_PTR(u64,
229 buffer_desc->buffer.
230 pointer), read_write: function);
231 acpi_ex_release_global_lock(rule: obj_desc->common_field.field_flags);
232
233 *return_buffer = buffer_desc;
234 return_ACPI_STATUS(status);
235}
236
237/*******************************************************************************
238 *
239 * FUNCTION: acpi_ex_write_serial_bus
240 *
241 * PARAMETERS: source_desc - Contains data to write
242 * obj_desc - The named field
243 * return_buffer - Where the return value is returned, if any
244 *
245 * RETURN: Status
246 *
247 * DESCRIPTION: Write to a named field that references a serial bus
248 * (SMBus, IPMI, GSBus).
249 *
250 ******************************************************************************/
251
252acpi_status
253acpi_ex_write_serial_bus(union acpi_operand_object *source_desc,
254 union acpi_operand_object *obj_desc,
255 union acpi_operand_object **return_buffer)
256{
257 acpi_status status;
258 u32 buffer_length;
259 u32 data_length;
260 void *buffer;
261 union acpi_operand_object *buffer_desc;
262 u32 function;
263 u16 accessor_type;
264
265 ACPI_FUNCTION_TRACE_PTR(ex_write_serial_bus, obj_desc);
266
267 /*
268 * This is an SMBus, GSBus or IPMI write. We will bypass the entire
269 * field mechanism and handoff the buffer directly to the handler.
270 * For these address spaces, the buffer is bidirectional; on a
271 * write, return data is returned in the same buffer.
272 *
273 * Source must be a buffer of sufficient size, these are fixed size:
274 * ACPI_SMBUS_BUFFER_SIZE, or ACPI_IPMI_BUFFER_SIZE.
275 *
276 * Note: SMBus and GSBus protocol type is passed in upper 16-bits
277 * of Function
278 *
279 * Common buffer format:
280 * Status; (Byte 0 of the data buffer)
281 * Length; (Byte 1 of the data buffer)
282 * Data[x-1]: (Bytes 2-x of the arbitrary length data buffer)
283 */
284 if (source_desc->common.type != ACPI_TYPE_BUFFER) {
285 ACPI_ERROR((AE_INFO,
286 "SMBus/IPMI/GenericSerialBus write requires "
287 "Buffer, found type %s",
288 acpi_ut_get_object_type_name(source_desc)));
289
290 return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
291 }
292
293 switch (obj_desc->field.region_obj->region.space_id) {
294 case ACPI_ADR_SPACE_SMBUS:
295
296 buffer_length = ACPI_SMBUS_BUFFER_SIZE;
297 function = ACPI_WRITE | (obj_desc->field.attribute << 16);
298 break;
299
300 case ACPI_ADR_SPACE_IPMI:
301
302 buffer_length = ACPI_IPMI_BUFFER_SIZE;
303 function = ACPI_WRITE;
304 break;
305
306 case ACPI_ADR_SPACE_GSBUS:
307
308 accessor_type = obj_desc->field.attribute;
309 status =
310 acpi_ex_get_protocol_buffer_length(protocol_id: accessor_type,
311 return_length: &buffer_length);
312 if (ACPI_FAILURE(status)) {
313 ACPI_ERROR((AE_INFO,
314 "Invalid protocol ID for GSBus: 0x%4.4X",
315 accessor_type));
316
317 return_ACPI_STATUS(status);
318 }
319
320 /* Add header length to get the full size of the buffer */
321
322 buffer_length += ACPI_SERIAL_HEADER_SIZE;
323 function = ACPI_WRITE | (accessor_type << 16);
324 break;
325
326 case ACPI_ADR_SPACE_PLATFORM_RT:
327
328 buffer_length = ACPI_PRM_INPUT_BUFFER_SIZE;
329 function = ACPI_WRITE;
330 break;
331
332 case ACPI_ADR_SPACE_FIXED_HARDWARE:
333
334 buffer_length = ACPI_FFH_INPUT_BUFFER_SIZE;
335 function = ACPI_WRITE;
336 break;
337
338 default:
339 return_ACPI_STATUS(AE_AML_INVALID_SPACE_ID);
340 }
341
342 /* Create the transfer/bidirectional/return buffer */
343
344 buffer_desc = acpi_ut_create_buffer_object(buffer_size: buffer_length);
345 if (!buffer_desc) {
346 return_ACPI_STATUS(AE_NO_MEMORY);
347 }
348
349 /* Copy the input buffer data to the transfer buffer */
350
351 buffer = buffer_desc->buffer.pointer;
352 data_length = ACPI_MIN(buffer_length, source_desc->buffer.length);
353 memcpy(to: buffer, from: source_desc->buffer.pointer, len: data_length);
354
355 /* Lock entire transaction if requested */
356
357 acpi_ex_acquire_global_lock(rule: obj_desc->common_field.field_flags);
358
359 /*
360 * Perform the write (returns status and perhaps data in the
361 * same buffer)
362 */
363 status = acpi_ex_access_region(obj_desc, field_datum_byte_offset: 0, value: (u64 *)buffer, read_write: function);
364 acpi_ex_release_global_lock(rule: obj_desc->common_field.field_flags);
365
366 *return_buffer = buffer_desc;
367 return_ACPI_STATUS(status);
368}
369