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
17 ACPI_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  ******************************************************************************/
32 acpi_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(obj_desc->common_field.field_flags);
52 
53 	/* Perform the read */
54 
55 	status = acpi_ex_access_region(obj_desc, 0, (u64 *)buffer, ACPI_READ);
56 
57 	acpi_ex_release_global_lock(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 
77 acpi_status
78 acpi_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(obj_desc->common_field.field_flags);
112 
113 	/* Perform the write */
114 
115 	status = acpi_ex_access_region(obj_desc, 0, (u64 *)buffer, ACPI_WRITE);
116 	acpi_ex_release_global_lock(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 
134 acpi_status
135 acpi_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(accessor_type,
183 						       &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_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(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, 0,
228 				       ACPI_CAST_PTR(u64,
229 						     buffer_desc->buffer.
230 						     pointer), function);
231 	acpi_ex_release_global_lock(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 
252 acpi_status
253 acpi_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(accessor_type,
311 						       &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_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(buffer, source_desc->buffer.pointer, data_length);
354 
355 	/* Lock entire transaction if requested */
356 
357 	acpi_ex_acquire_global_lock(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, 0, (u64 *)buffer, function);
364 	acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
365 
366 	*return_buffer = buffer_desc;
367 	return_ACPI_STATUS(status);
368 }
369