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ASoC: fix ABE_TWL6040 dependency
[mirror_ubuntu-eoan-kernel.git] / drivers / acpi / acpica / hwregs.c
1 /*******************************************************************************
2 *
3 * Module Name: hwregs - Read/write access functions for the various ACPI
4 * control and status registers.
5 *
6 ******************************************************************************/
7
8 /*
9 * Copyright (C) 2000 - 2016, Intel Corp.
10 * All rights reserved.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions, and the following disclaimer,
17 * without modification.
18 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
19 * substantially similar to the "NO WARRANTY" disclaimer below
20 * ("Disclaimer") and any redistribution must be conditioned upon
21 * including a substantially similar Disclaimer requirement for further
22 * binary redistribution.
23 * 3. Neither the names of the above-listed copyright holders nor the names
24 * of any contributors may be used to endorse or promote products derived
25 * from this software without specific prior written permission.
26 *
27 * Alternatively, this software may be distributed under the terms of the
28 * GNU General Public License ("GPL") version 2 as published by the Free
29 * Software Foundation.
30 *
31 * NO WARRANTY
32 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
33 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
34 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
35 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
36 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
37 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
38 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
39 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
40 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
41 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
42 * POSSIBILITY OF SUCH DAMAGES.
43 */
44
45 #include <acpi/acpi.h>
46 #include "accommon.h"
47 #include "acevents.h"
48
49 #define _COMPONENT ACPI_HARDWARE
50 ACPI_MODULE_NAME("hwregs")
51
52 #if (!ACPI_REDUCED_HARDWARE)
53 /* Local Prototypes */
54 static u8
55 acpi_hw_get_access_bit_width(struct acpi_generic_address *reg,
56 u8 max_bit_width);
57
58 static acpi_status
59 acpi_hw_read_multiple(u32 *value,
60 struct acpi_generic_address *register_a,
61 struct acpi_generic_address *register_b);
62
63 static acpi_status
64 acpi_hw_write_multiple(u32 value,
65 struct acpi_generic_address *register_a,
66 struct acpi_generic_address *register_b);
67
68 #endif /* !ACPI_REDUCED_HARDWARE */
69
70 /******************************************************************************
71 *
72 * FUNCTION: acpi_hw_get_access_bit_width
73 *
74 * PARAMETERS: reg - GAS register structure
75 * max_bit_width - Max bit_width supported (32 or 64)
76 *
77 * RETURN: Status
78 *
79 * DESCRIPTION: Obtain optimal access bit width
80 *
81 ******************************************************************************/
82
83 static u8
84 acpi_hw_get_access_bit_width(struct acpi_generic_address *reg, u8 max_bit_width)
85 {
86 u64 address;
87
88 if (!reg->access_width) {
89 /*
90 * Detect old register descriptors where only the bit_width field
91 * makes senses. The target address is copied to handle possible
92 * alignment issues.
93 */
94 ACPI_MOVE_64_TO_64(&address, &reg->address);
95 if (!reg->bit_offset && reg->bit_width &&
96 ACPI_IS_POWER_OF_TWO(reg->bit_width) &&
97 ACPI_IS_ALIGNED(reg->bit_width, 8) &&
98 ACPI_IS_ALIGNED(address, reg->bit_width)) {
99 return (reg->bit_width);
100 } else {
101 if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_IO) {
102 return (32);
103 } else {
104 return (max_bit_width);
105 }
106 }
107 } else {
108 return (1 << (reg->access_width + 2));
109 }
110 }
111
112 /******************************************************************************
113 *
114 * FUNCTION: acpi_hw_validate_register
115 *
116 * PARAMETERS: reg - GAS register structure
117 * max_bit_width - Max bit_width supported (32 or 64)
118 * address - Pointer to where the gas->address
119 * is returned
120 *
121 * RETURN: Status
122 *
123 * DESCRIPTION: Validate the contents of a GAS register. Checks the GAS
124 * pointer, Address, space_id, bit_width, and bit_offset.
125 *
126 ******************************************************************************/
127
128 acpi_status
129 acpi_hw_validate_register(struct acpi_generic_address *reg,
130 u8 max_bit_width, u64 *address)
131 {
132 u8 bit_width;
133 u8 access_width;
134
135 /* Must have a valid pointer to a GAS structure */
136
137 if (!reg) {
138 return (AE_BAD_PARAMETER);
139 }
140
141 /*
142 * Copy the target address. This handles possible alignment issues.
143 * Address must not be null. A null address also indicates an optional
144 * ACPI register that is not supported, so no error message.
145 */
146 ACPI_MOVE_64_TO_64(address, &reg->address);
147 if (!(*address)) {
148 return (AE_BAD_ADDRESS);
149 }
150
151 /* Validate the space_ID */
152
153 if ((reg->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY) &&
154 (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO)) {
155 ACPI_ERROR((AE_INFO,
156 "Unsupported address space: 0x%X", reg->space_id));
157 return (AE_SUPPORT);
158 }
159
160 /* Validate the access_width */
161
162 if (reg->access_width > 4) {
163 ACPI_ERROR((AE_INFO,
164 "Unsupported register access width: 0x%X",
165 reg->access_width));
166 return (AE_SUPPORT);
167 }
168
169 /* Validate the bit_width, convert access_width into number of bits */
170
171 access_width = acpi_hw_get_access_bit_width(reg, max_bit_width);
172 bit_width =
173 ACPI_ROUND_UP(reg->bit_offset + reg->bit_width, access_width);
174 if (max_bit_width < bit_width) {
175 ACPI_WARNING((AE_INFO,
176 "Requested bit width 0x%X is smaller than register bit width 0x%X",
177 max_bit_width, bit_width));
178 return (AE_SUPPORT);
179 }
180
181 return (AE_OK);
182 }
183
184 /******************************************************************************
185 *
186 * FUNCTION: acpi_hw_read
187 *
188 * PARAMETERS: value - Where the value is returned
189 * reg - GAS register structure
190 *
191 * RETURN: Status
192 *
193 * DESCRIPTION: Read from either memory or IO space. This is a 32-bit max
194 * version of acpi_read, used internally since the overhead of
195 * 64-bit values is not needed.
196 *
197 * LIMITATIONS: <These limitations also apply to acpi_hw_write>
198 * space_ID must be system_memory or system_IO.
199 *
200 ******************************************************************************/
201
202 acpi_status acpi_hw_read(u32 *value, struct acpi_generic_address *reg)
203 {
204 u64 address;
205 u8 access_width;
206 u32 bit_width;
207 u8 bit_offset;
208 u64 value64;
209 u32 value32;
210 u8 index;
211 acpi_status status;
212
213 ACPI_FUNCTION_NAME(hw_read);
214
215 /* Validate contents of the GAS register */
216
217 status = acpi_hw_validate_register(reg, 32, &address);
218 if (ACPI_FAILURE(status)) {
219 return (status);
220 }
221
222 /*
223 * Initialize entire 32-bit return value to zero, convert access_width
224 * into number of bits based
225 */
226 *value = 0;
227 access_width = acpi_hw_get_access_bit_width(reg, 32);
228 bit_width = reg->bit_offset + reg->bit_width;
229 bit_offset = reg->bit_offset;
230
231 /*
232 * Two address spaces supported: Memory or IO. PCI_Config is
233 * not supported here because the GAS structure is insufficient
234 */
235 index = 0;
236 while (bit_width) {
237 if (bit_offset >= access_width) {
238 value32 = 0;
239 bit_offset -= access_width;
240 } else {
241 if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
242 status =
243 acpi_os_read_memory((acpi_physical_address)
244 address +
245 index *
246 ACPI_DIV_8
247 (access_width),
248 &value64, access_width);
249 value32 = (u32)value64;
250 } else { /* ACPI_ADR_SPACE_SYSTEM_IO, validated earlier */
251
252 status = acpi_hw_read_port((acpi_io_address)
253 address +
254 index *
255 ACPI_DIV_8
256 (access_width),
257 &value32,
258 access_width);
259 }
260
261 /*
262 * Use offset style bit masks because:
263 * bit_offset < access_width/bit_width < access_width, and
264 * access_width is ensured to be less than 32-bits by
265 * acpi_hw_validate_register().
266 */
267 if (bit_offset) {
268 value32 &= ACPI_MASK_BITS_BELOW(bit_offset);
269 bit_offset = 0;
270 }
271 if (bit_width < access_width) {
272 value32 &= ACPI_MASK_BITS_ABOVE(bit_width);
273 }
274 }
275
276 /*
277 * Use offset style bit writes because "Index * AccessWidth" is
278 * ensured to be less than 32-bits by acpi_hw_validate_register().
279 */
280 ACPI_SET_BITS(value, index * access_width,
281 ACPI_MASK_BITS_ABOVE_32(access_width), value32);
282
283 bit_width -=
284 bit_width > access_width ? access_width : bit_width;
285 index++;
286 }
287
288 ACPI_DEBUG_PRINT((ACPI_DB_IO,
289 "Read: %8.8X width %2d from %8.8X%8.8X (%s)\n",
290 *value, access_width, ACPI_FORMAT_UINT64(address),
291 acpi_ut_get_region_name(reg->space_id)));
292
293 return (status);
294 }
295
296 /******************************************************************************
297 *
298 * FUNCTION: acpi_hw_write
299 *
300 * PARAMETERS: value - Value to be written
301 * reg - GAS register structure
302 *
303 * RETURN: Status
304 *
305 * DESCRIPTION: Write to either memory or IO space. This is a 32-bit max
306 * version of acpi_write, used internally since the overhead of
307 * 64-bit values is not needed.
308 *
309 ******************************************************************************/
310
311 acpi_status acpi_hw_write(u32 value, struct acpi_generic_address *reg)
312 {
313 u64 address;
314 u8 access_width;
315 u32 bit_width;
316 u8 bit_offset;
317 u64 value64;
318 u32 new_value32, old_value32;
319 u8 index;
320 acpi_status status;
321
322 ACPI_FUNCTION_NAME(hw_write);
323
324 /* Validate contents of the GAS register */
325
326 status = acpi_hw_validate_register(reg, 32, &address);
327 if (ACPI_FAILURE(status)) {
328 return (status);
329 }
330
331 /* Convert access_width into number of bits based */
332
333 access_width = acpi_hw_get_access_bit_width(reg, 32);
334 bit_width = reg->bit_offset + reg->bit_width;
335 bit_offset = reg->bit_offset;
336
337 /*
338 * Two address spaces supported: Memory or IO. PCI_Config is
339 * not supported here because the GAS structure is insufficient
340 */
341 index = 0;
342 while (bit_width) {
343 /*
344 * Use offset style bit reads because "Index * AccessWidth" is
345 * ensured to be less than 32-bits by acpi_hw_validate_register().
346 */
347 new_value32 = ACPI_GET_BITS(&value, index * access_width,
348 ACPI_MASK_BITS_ABOVE_32
349 (access_width));
350
351 if (bit_offset >= access_width) {
352 bit_offset -= access_width;
353 } else {
354 /*
355 * Use offset style bit masks because access_width is ensured
356 * to be less than 32-bits by acpi_hw_validate_register() and
357 * bit_offset/bit_width is less than access_width here.
358 */
359 if (bit_offset) {
360 new_value32 &= ACPI_MASK_BITS_BELOW(bit_offset);
361 }
362 if (bit_width < access_width) {
363 new_value32 &= ACPI_MASK_BITS_ABOVE(bit_width);
364 }
365
366 if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
367 if (bit_offset || bit_width < access_width) {
368 /*
369 * Read old values in order not to modify the bits that
370 * are beyond the register bit_width/bit_offset setting.
371 */
372 status =
373 acpi_os_read_memory((acpi_physical_address)
374 address +
375 index *
376 ACPI_DIV_8
377 (access_width),
378 &value64,
379 access_width);
380 old_value32 = (u32)value64;
381
382 /*
383 * Use offset style bit masks because access_width is
384 * ensured to be less than 32-bits by
385 * acpi_hw_validate_register() and bit_offset/bit_width is
386 * less than access_width here.
387 */
388 if (bit_offset) {
389 old_value32 &=
390 ACPI_MASK_BITS_ABOVE
391 (bit_offset);
392 bit_offset = 0;
393 }
394 if (bit_width < access_width) {
395 old_value32 &=
396 ACPI_MASK_BITS_BELOW
397 (bit_width);
398 }
399
400 new_value32 |= old_value32;
401 }
402
403 value64 = (u64)new_value32;
404 status =
405 acpi_os_write_memory((acpi_physical_address)
406 address +
407 index *
408 ACPI_DIV_8
409 (access_width),
410 value64, access_width);
411 } else { /* ACPI_ADR_SPACE_SYSTEM_IO, validated earlier */
412
413 if (bit_offset || bit_width < access_width) {
414 /*
415 * Read old values in order not to modify the bits that
416 * are beyond the register bit_width/bit_offset setting.
417 */
418 status =
419 acpi_hw_read_port((acpi_io_address)
420 address +
421 index *
422 ACPI_DIV_8
423 (access_width),
424 &old_value32,
425 access_width);
426
427 /*
428 * Use offset style bit masks because access_width is
429 * ensured to be less than 32-bits by
430 * acpi_hw_validate_register() and bit_offset/bit_width is
431 * less than access_width here.
432 */
433 if (bit_offset) {
434 old_value32 &=
435 ACPI_MASK_BITS_ABOVE
436 (bit_offset);
437 bit_offset = 0;
438 }
439 if (bit_width < access_width) {
440 old_value32 &=
441 ACPI_MASK_BITS_BELOW
442 (bit_width);
443 }
444
445 new_value32 |= old_value32;
446 }
447
448 status = acpi_hw_write_port((acpi_io_address)
449 address +
450 index *
451 ACPI_DIV_8
452 (access_width),
453 new_value32,
454 access_width);
455 }
456 }
457
458 /*
459 * Index * access_width is ensured to be less than 32-bits by
460 * acpi_hw_validate_register().
461 */
462 bit_width -=
463 bit_width > access_width ? access_width : bit_width;
464 index++;
465 }
466
467 ACPI_DEBUG_PRINT((ACPI_DB_IO,
468 "Wrote: %8.8X width %2d to %8.8X%8.8X (%s)\n",
469 value, access_width, ACPI_FORMAT_UINT64(address),
470 acpi_ut_get_region_name(reg->space_id)));
471
472 return (status);
473 }
474
475 #if (!ACPI_REDUCED_HARDWARE)
476 /*******************************************************************************
477 *
478 * FUNCTION: acpi_hw_clear_acpi_status
479 *
480 * PARAMETERS: None
481 *
482 * RETURN: Status
483 *
484 * DESCRIPTION: Clears all fixed and general purpose status bits
485 *
486 ******************************************************************************/
487
488 acpi_status acpi_hw_clear_acpi_status(void)
489 {
490 acpi_status status;
491 acpi_cpu_flags lock_flags = 0;
492
493 ACPI_FUNCTION_TRACE(hw_clear_acpi_status);
494
495 ACPI_DEBUG_PRINT((ACPI_DB_IO, "About to write %04X to %8.8X%8.8X\n",
496 ACPI_BITMASK_ALL_FIXED_STATUS,
497 ACPI_FORMAT_UINT64(acpi_gbl_xpm1a_status.address)));
498
499 lock_flags = acpi_os_acquire_lock(acpi_gbl_hardware_lock);
500
501 /* Clear the fixed events in PM1 A/B */
502
503 status = acpi_hw_register_write(ACPI_REGISTER_PM1_STATUS,
504 ACPI_BITMASK_ALL_FIXED_STATUS);
505
506 acpi_os_release_lock(acpi_gbl_hardware_lock, lock_flags);
507
508 if (ACPI_FAILURE(status)) {
509 goto exit;
510 }
511
512 /* Clear the GPE Bits in all GPE registers in all GPE blocks */
513
514 status = acpi_ev_walk_gpe_list(acpi_hw_clear_gpe_block, NULL);
515
516 exit:
517 return_ACPI_STATUS(status);
518 }
519
520 /*******************************************************************************
521 *
522 * FUNCTION: acpi_hw_get_bit_register_info
523 *
524 * PARAMETERS: register_id - Index of ACPI Register to access
525 *
526 * RETURN: The bitmask to be used when accessing the register
527 *
528 * DESCRIPTION: Map register_id into a register bitmask.
529 *
530 ******************************************************************************/
531
532 struct acpi_bit_register_info *acpi_hw_get_bit_register_info(u32 register_id)
533 {
534 ACPI_FUNCTION_ENTRY();
535
536 if (register_id > ACPI_BITREG_MAX) {
537 ACPI_ERROR((AE_INFO, "Invalid BitRegister ID: 0x%X",
538 register_id));
539 return (NULL);
540 }
541
542 return (&acpi_gbl_bit_register_info[register_id]);
543 }
544
545 /******************************************************************************
546 *
547 * FUNCTION: acpi_hw_write_pm1_control
548 *
549 * PARAMETERS: pm1a_control - Value to be written to PM1A control
550 * pm1b_control - Value to be written to PM1B control
551 *
552 * RETURN: Status
553 *
554 * DESCRIPTION: Write the PM1 A/B control registers. These registers are
555 * different than than the PM1 A/B status and enable registers
556 * in that different values can be written to the A/B registers.
557 * Most notably, the SLP_TYP bits can be different, as per the
558 * values returned from the _Sx predefined methods.
559 *
560 ******************************************************************************/
561
562 acpi_status acpi_hw_write_pm1_control(u32 pm1a_control, u32 pm1b_control)
563 {
564 acpi_status status;
565
566 ACPI_FUNCTION_TRACE(hw_write_pm1_control);
567
568 status =
569 acpi_hw_write(pm1a_control, &acpi_gbl_FADT.xpm1a_control_block);
570 if (ACPI_FAILURE(status)) {
571 return_ACPI_STATUS(status);
572 }
573
574 if (acpi_gbl_FADT.xpm1b_control_block.address) {
575 status =
576 acpi_hw_write(pm1b_control,
577 &acpi_gbl_FADT.xpm1b_control_block);
578 }
579 return_ACPI_STATUS(status);
580 }
581
582 /******************************************************************************
583 *
584 * FUNCTION: acpi_hw_register_read
585 *
586 * PARAMETERS: register_id - ACPI Register ID
587 * return_value - Where the register value is returned
588 *
589 * RETURN: Status and the value read.
590 *
591 * DESCRIPTION: Read from the specified ACPI register
592 *
593 ******************************************************************************/
594 acpi_status acpi_hw_register_read(u32 register_id, u32 *return_value)
595 {
596 u32 value = 0;
597 acpi_status status;
598
599 ACPI_FUNCTION_TRACE(hw_register_read);
600
601 switch (register_id) {
602 case ACPI_REGISTER_PM1_STATUS: /* PM1 A/B: 16-bit access each */
603
604 status = acpi_hw_read_multiple(&value,
605 &acpi_gbl_xpm1a_status,
606 &acpi_gbl_xpm1b_status);
607 break;
608
609 case ACPI_REGISTER_PM1_ENABLE: /* PM1 A/B: 16-bit access each */
610
611 status = acpi_hw_read_multiple(&value,
612 &acpi_gbl_xpm1a_enable,
613 &acpi_gbl_xpm1b_enable);
614 break;
615
616 case ACPI_REGISTER_PM1_CONTROL: /* PM1 A/B: 16-bit access each */
617
618 status = acpi_hw_read_multiple(&value,
619 &acpi_gbl_FADT.
620 xpm1a_control_block,
621 &acpi_gbl_FADT.
622 xpm1b_control_block);
623
624 /*
625 * Zero the write-only bits. From the ACPI specification, "Hardware
626 * Write-Only Bits": "Upon reads to registers with write-only bits,
627 * software masks out all write-only bits."
628 */
629 value &= ~ACPI_PM1_CONTROL_WRITEONLY_BITS;
630 break;
631
632 case ACPI_REGISTER_PM2_CONTROL: /* 8-bit access */
633
634 status =
635 acpi_hw_read(&value, &acpi_gbl_FADT.xpm2_control_block);
636 break;
637
638 case ACPI_REGISTER_PM_TIMER: /* 32-bit access */
639
640 status = acpi_hw_read(&value, &acpi_gbl_FADT.xpm_timer_block);
641 break;
642
643 case ACPI_REGISTER_SMI_COMMAND_BLOCK: /* 8-bit access */
644
645 status =
646 acpi_hw_read_port(acpi_gbl_FADT.smi_command, &value, 8);
647 break;
648
649 default:
650
651 ACPI_ERROR((AE_INFO, "Unknown Register ID: 0x%X", register_id));
652 status = AE_BAD_PARAMETER;
653 break;
654 }
655
656 if (ACPI_SUCCESS(status)) {
657 *return_value = value;
658 }
659
660 return_ACPI_STATUS(status);
661 }
662
663 /******************************************************************************
664 *
665 * FUNCTION: acpi_hw_register_write
666 *
667 * PARAMETERS: register_id - ACPI Register ID
668 * value - The value to write
669 *
670 * RETURN: Status
671 *
672 * DESCRIPTION: Write to the specified ACPI register
673 *
674 * NOTE: In accordance with the ACPI specification, this function automatically
675 * preserves the value of the following bits, meaning that these bits cannot be
676 * changed via this interface:
677 *
678 * PM1_CONTROL[0] = SCI_EN
679 * PM1_CONTROL[9]
680 * PM1_STATUS[11]
681 *
682 * ACPI References:
683 * 1) Hardware Ignored Bits: When software writes to a register with ignored
684 * bit fields, it preserves the ignored bit fields
685 * 2) SCI_EN: OSPM always preserves this bit position
686 *
687 ******************************************************************************/
688
689 acpi_status acpi_hw_register_write(u32 register_id, u32 value)
690 {
691 acpi_status status;
692 u32 read_value;
693
694 ACPI_FUNCTION_TRACE(hw_register_write);
695
696 switch (register_id) {
697 case ACPI_REGISTER_PM1_STATUS: /* PM1 A/B: 16-bit access each */
698 /*
699 * Handle the "ignored" bit in PM1 Status. According to the ACPI
700 * specification, ignored bits are to be preserved when writing.
701 * Normally, this would mean a read/modify/write sequence. However,
702 * preserving a bit in the status register is different. Writing a
703 * one clears the status, and writing a zero preserves the status.
704 * Therefore, we must always write zero to the ignored bit.
705 *
706 * This behavior is clarified in the ACPI 4.0 specification.
707 */
708 value &= ~ACPI_PM1_STATUS_PRESERVED_BITS;
709
710 status = acpi_hw_write_multiple(value,
711 &acpi_gbl_xpm1a_status,
712 &acpi_gbl_xpm1b_status);
713 break;
714
715 case ACPI_REGISTER_PM1_ENABLE: /* PM1 A/B: 16-bit access each */
716
717 status = acpi_hw_write_multiple(value,
718 &acpi_gbl_xpm1a_enable,
719 &acpi_gbl_xpm1b_enable);
720 break;
721
722 case ACPI_REGISTER_PM1_CONTROL: /* PM1 A/B: 16-bit access each */
723 /*
724 * Perform a read first to preserve certain bits (per ACPI spec)
725 * Note: This includes SCI_EN, we never want to change this bit
726 */
727 status = acpi_hw_read_multiple(&read_value,
728 &acpi_gbl_FADT.
729 xpm1a_control_block,
730 &acpi_gbl_FADT.
731 xpm1b_control_block);
732 if (ACPI_FAILURE(status)) {
733 goto exit;
734 }
735
736 /* Insert the bits to be preserved */
737
738 ACPI_INSERT_BITS(value, ACPI_PM1_CONTROL_PRESERVED_BITS,
739 read_value);
740
741 /* Now we can write the data */
742
743 status = acpi_hw_write_multiple(value,
744 &acpi_gbl_FADT.
745 xpm1a_control_block,
746 &acpi_gbl_FADT.
747 xpm1b_control_block);
748 break;
749
750 case ACPI_REGISTER_PM2_CONTROL: /* 8-bit access */
751 /*
752 * For control registers, all reserved bits must be preserved,
753 * as per the ACPI spec.
754 */
755 status =
756 acpi_hw_read(&read_value,
757 &acpi_gbl_FADT.xpm2_control_block);
758 if (ACPI_FAILURE(status)) {
759 goto exit;
760 }
761
762 /* Insert the bits to be preserved */
763
764 ACPI_INSERT_BITS(value, ACPI_PM2_CONTROL_PRESERVED_BITS,
765 read_value);
766
767 status =
768 acpi_hw_write(value, &acpi_gbl_FADT.xpm2_control_block);
769 break;
770
771 case ACPI_REGISTER_PM_TIMER: /* 32-bit access */
772
773 status = acpi_hw_write(value, &acpi_gbl_FADT.xpm_timer_block);
774 break;
775
776 case ACPI_REGISTER_SMI_COMMAND_BLOCK: /* 8-bit access */
777
778 /* SMI_CMD is currently always in IO space */
779
780 status =
781 acpi_hw_write_port(acpi_gbl_FADT.smi_command, value, 8);
782 break;
783
784 default:
785
786 ACPI_ERROR((AE_INFO, "Unknown Register ID: 0x%X", register_id));
787 status = AE_BAD_PARAMETER;
788 break;
789 }
790
791 exit:
792 return_ACPI_STATUS(status);
793 }
794
795 /******************************************************************************
796 *
797 * FUNCTION: acpi_hw_read_multiple
798 *
799 * PARAMETERS: value - Where the register value is returned
800 * register_a - First ACPI register (required)
801 * register_b - Second ACPI register (optional)
802 *
803 * RETURN: Status
804 *
805 * DESCRIPTION: Read from the specified two-part ACPI register (such as PM1 A/B)
806 *
807 ******************************************************************************/
808
809 static acpi_status
810 acpi_hw_read_multiple(u32 *value,
811 struct acpi_generic_address *register_a,
812 struct acpi_generic_address *register_b)
813 {
814 u32 value_a = 0;
815 u32 value_b = 0;
816 acpi_status status;
817
818 /* The first register is always required */
819
820 status = acpi_hw_read(&value_a, register_a);
821 if (ACPI_FAILURE(status)) {
822 return (status);
823 }
824
825 /* Second register is optional */
826
827 if (register_b->address) {
828 status = acpi_hw_read(&value_b, register_b);
829 if (ACPI_FAILURE(status)) {
830 return (status);
831 }
832 }
833
834 /*
835 * OR the two return values together. No shifting or masking is necessary,
836 * because of how the PM1 registers are defined in the ACPI specification:
837 *
838 * "Although the bits can be split between the two register blocks (each
839 * register block has a unique pointer within the FADT), the bit positions
840 * are maintained. The register block with unimplemented bits (that is,
841 * those implemented in the other register block) always returns zeros,
842 * and writes have no side effects"
843 */
844 *value = (value_a | value_b);
845 return (AE_OK);
846 }
847
848 /******************************************************************************
849 *
850 * FUNCTION: acpi_hw_write_multiple
851 *
852 * PARAMETERS: value - The value to write
853 * register_a - First ACPI register (required)
854 * register_b - Second ACPI register (optional)
855 *
856 * RETURN: Status
857 *
858 * DESCRIPTION: Write to the specified two-part ACPI register (such as PM1 A/B)
859 *
860 ******************************************************************************/
861
862 static acpi_status
863 acpi_hw_write_multiple(u32 value,
864 struct acpi_generic_address *register_a,
865 struct acpi_generic_address *register_b)
866 {
867 acpi_status status;
868
869 /* The first register is always required */
870
871 status = acpi_hw_write(value, register_a);
872 if (ACPI_FAILURE(status)) {
873 return (status);
874 }
875
876 /*
877 * Second register is optional
878 *
879 * No bit shifting or clearing is necessary, because of how the PM1
880 * registers are defined in the ACPI specification:
881 *
882 * "Although the bits can be split between the two register blocks (each
883 * register block has a unique pointer within the FADT), the bit positions
884 * are maintained. The register block with unimplemented bits (that is,
885 * those implemented in the other register block) always returns zeros,
886 * and writes have no side effects"
887 */
888 if (register_b->address) {
889 status = acpi_hw_write(value, register_b);
890 }
891
892 return (status);
893 }
894
895 #endif /* !ACPI_REDUCED_HARDWARE */
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