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Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux...
[linux/fpc-iii.git] / drivers / acpi / acpica / hwregs.c
blob5ba0498412fd5773d07feadd44ca442d88211b91
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 acpi_status
55 acpi_hw_read_multiple(u32 *value,
56 struct acpi_generic_address *register_a,
57 struct acpi_generic_address *register_b);
58
59 static acpi_status
60 acpi_hw_write_multiple(u32 value,
61 struct acpi_generic_address *register_a,
62 struct acpi_generic_address *register_b);
63
64 #endif /* !ACPI_REDUCED_HARDWARE */
65
66 /******************************************************************************
67 *
68 * FUNCTION: acpi_hw_validate_register
69 *
70 * PARAMETERS: reg - GAS register structure
71 * max_bit_width - Max bit_width supported (32 or 64)
72 * address - Pointer to where the gas->address
73 * is returned
74 *
75 * RETURN: Status
76 *
77 * DESCRIPTION: Validate the contents of a GAS register. Checks the GAS
78 * pointer, Address, space_id, bit_width, and bit_offset.
79 *
80 ******************************************************************************/
81
82 acpi_status
83 acpi_hw_validate_register(struct acpi_generic_address *reg,
84 u8 max_bit_width, u64 *address)
85 {
86
87 /* Must have a valid pointer to a GAS structure */
88
89 if (!reg) {
90 return (AE_BAD_PARAMETER);
91 }
92
93 /*
94 * Copy the target address. This handles possible alignment issues.
95 * Address must not be null. A null address also indicates an optional
96 * ACPI register that is not supported, so no error message.
97 */
98 ACPI_MOVE_64_TO_64(address, &reg->address);
99 if (!(*address)) {
100 return (AE_BAD_ADDRESS);
101 }
102
103 /* Validate the space_ID */
104
105 if ((reg->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY) &&
106 (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO)) {
107 ACPI_ERROR((AE_INFO,
108 "Unsupported address space: 0x%X", reg->space_id));
109 return (AE_SUPPORT);
110 }
111
112 /* Validate the bit_width */
113
114 if ((reg->bit_width != 8) &&
115 (reg->bit_width != 16) &&
116 (reg->bit_width != 32) && (reg->bit_width != max_bit_width)) {
117 ACPI_ERROR((AE_INFO,
118 "Unsupported register bit width: 0x%X",
119 reg->bit_width));
120 return (AE_SUPPORT);
121 }
122
123 /* Validate the bit_offset. Just a warning for now. */
124
125 if (reg->bit_offset != 0) {
126 ACPI_WARNING((AE_INFO,
127 "Unsupported register bit offset: 0x%X",
128 reg->bit_offset));
129 }
130
131 return (AE_OK);
132 }
133
134 /******************************************************************************
135 *
136 * FUNCTION: acpi_hw_read
137 *
138 * PARAMETERS: value - Where the value is returned
139 * reg - GAS register structure
140 *
141 * RETURN: Status
142 *
143 * DESCRIPTION: Read from either memory or IO space. This is a 32-bit max
144 * version of acpi_read, used internally since the overhead of
145 * 64-bit values is not needed.
146 *
147 * LIMITATIONS: <These limitations also apply to acpi_hw_write>
148 * bit_width must be exactly 8, 16, or 32.
149 * space_ID must be system_memory or system_IO.
150 * bit_offset and access_width are currently ignored, as there has
151 * not been a need to implement these.
152 *
153 ******************************************************************************/
154
155 acpi_status acpi_hw_read(u32 *value, struct acpi_generic_address *reg)
156 {
157 u64 address;
158 u64 value64;
159 acpi_status status;
160
161 ACPI_FUNCTION_NAME(hw_read);
162
163 /* Validate contents of the GAS register */
164
165 status = acpi_hw_validate_register(reg, 32, &address);
166 if (ACPI_FAILURE(status)) {
167 return (status);
168 }
169
170 /* Initialize entire 32-bit return value to zero */
171
172 *value = 0;
173
174 /*
175 * Two address spaces supported: Memory or IO. PCI_Config is
176 * not supported here because the GAS structure is insufficient
177 */
178 if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
179 status = acpi_os_read_memory((acpi_physical_address)
180 address, &value64, reg->bit_width);
181
182 *value = (u32)value64;
183 } else { /* ACPI_ADR_SPACE_SYSTEM_IO, validated earlier */
184
185 status = acpi_hw_read_port((acpi_io_address)
186 address, value, reg->bit_width);
187 }
188
189 ACPI_DEBUG_PRINT((ACPI_DB_IO,
190 "Read: %8.8X width %2d from %8.8X%8.8X (%s)\n",
191 *value, reg->bit_width, ACPI_FORMAT_UINT64(address),
192 acpi_ut_get_region_name(reg->space_id)));
193
194 return (status);
195 }
196
197 /******************************************************************************
198 *
199 * FUNCTION: acpi_hw_write
200 *
201 * PARAMETERS: value - Value to be written
202 * reg - GAS register structure
203 *
204 * RETURN: Status
205 *
206 * DESCRIPTION: Write to either memory or IO space. This is a 32-bit max
207 * version of acpi_write, used internally since the overhead of
208 * 64-bit values is not needed.
209 *
210 ******************************************************************************/
211
212 acpi_status acpi_hw_write(u32 value, struct acpi_generic_address *reg)
213 {
214 u64 address;
215 acpi_status status;
216
217 ACPI_FUNCTION_NAME(hw_write);
218
219 /* Validate contents of the GAS register */
220
221 status = acpi_hw_validate_register(reg, 32, &address);
222 if (ACPI_FAILURE(status)) {
223 return (status);
224 }
225
226 /*
227 * Two address spaces supported: Memory or IO. PCI_Config is
228 * not supported here because the GAS structure is insufficient
229 */
230 if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
231 status = acpi_os_write_memory((acpi_physical_address)
232 address, (u64)value,
233 reg->bit_width);
234 } else { /* ACPI_ADR_SPACE_SYSTEM_IO, validated earlier */
235
236 status = acpi_hw_write_port((acpi_io_address)
237 address, value, reg->bit_width);
238 }
239
240 ACPI_DEBUG_PRINT((ACPI_DB_IO,
241 "Wrote: %8.8X width %2d to %8.8X%8.8X (%s)\n",
242 value, reg->bit_width, ACPI_FORMAT_UINT64(address),
243 acpi_ut_get_region_name(reg->space_id)));
244
245 return (status);
246 }
247
248 #if (!ACPI_REDUCED_HARDWARE)
249 /*******************************************************************************
250 *
251 * FUNCTION: acpi_hw_clear_acpi_status
252 *
253 * PARAMETERS: None
254 *
255 * RETURN: Status
256 *
257 * DESCRIPTION: Clears all fixed and general purpose status bits
258 *
259 ******************************************************************************/
260
261 acpi_status acpi_hw_clear_acpi_status(void)
262 {
263 acpi_status status;
264 acpi_cpu_flags lock_flags = 0;
265
266 ACPI_FUNCTION_TRACE(hw_clear_acpi_status);
267
268 ACPI_DEBUG_PRINT((ACPI_DB_IO, "About to write %04X to %8.8X%8.8X\n",
269 ACPI_BITMASK_ALL_FIXED_STATUS,
270 ACPI_FORMAT_UINT64(acpi_gbl_xpm1a_status.address)));
271
272 lock_flags = acpi_os_acquire_lock(acpi_gbl_hardware_lock);
273
274 /* Clear the fixed events in PM1 A/B */
275
276 status = acpi_hw_register_write(ACPI_REGISTER_PM1_STATUS,
277 ACPI_BITMASK_ALL_FIXED_STATUS);
278
279 acpi_os_release_lock(acpi_gbl_hardware_lock, lock_flags);
280
281 if (ACPI_FAILURE(status)) {
282 goto exit;
283 }
284
285 /* Clear the GPE Bits in all GPE registers in all GPE blocks */
286
287 status = acpi_ev_walk_gpe_list(acpi_hw_clear_gpe_block, NULL);
288
289 exit:
290 return_ACPI_STATUS(status);
291 }
292
293 /*******************************************************************************
294 *
295 * FUNCTION: acpi_hw_get_bit_register_info
296 *
297 * PARAMETERS: register_id - Index of ACPI Register to access
298 *
299 * RETURN: The bitmask to be used when accessing the register
300 *
301 * DESCRIPTION: Map register_id into a register bitmask.
302 *
303 ******************************************************************************/
304
305 struct acpi_bit_register_info *acpi_hw_get_bit_register_info(u32 register_id)
306 {
307 ACPI_FUNCTION_ENTRY();
308
309 if (register_id > ACPI_BITREG_MAX) {
310 ACPI_ERROR((AE_INFO, "Invalid BitRegister ID: 0x%X",
311 register_id));
312 return (NULL);
313 }
314
315 return (&acpi_gbl_bit_register_info[register_id]);
316 }
317
318 /******************************************************************************
319 *
320 * FUNCTION: acpi_hw_write_pm1_control
321 *
322 * PARAMETERS: pm1a_control - Value to be written to PM1A control
323 * pm1b_control - Value to be written to PM1B control
324 *
325 * RETURN: Status
326 *
327 * DESCRIPTION: Write the PM1 A/B control registers. These registers are
328 * different than than the PM1 A/B status and enable registers
329 * in that different values can be written to the A/B registers.
330 * Most notably, the SLP_TYP bits can be different, as per the
331 * values returned from the _Sx predefined methods.
332 *
333 ******************************************************************************/
334
335 acpi_status acpi_hw_write_pm1_control(u32 pm1a_control, u32 pm1b_control)
336 {
337 acpi_status status;
338
339 ACPI_FUNCTION_TRACE(hw_write_pm1_control);
340
341 status =
342 acpi_hw_write(pm1a_control, &acpi_gbl_FADT.xpm1a_control_block);
343 if (ACPI_FAILURE(status)) {
344 return_ACPI_STATUS(status);
345 }
346
347 if (acpi_gbl_FADT.xpm1b_control_block.address) {
348 status =
349 acpi_hw_write(pm1b_control,
350 &acpi_gbl_FADT.xpm1b_control_block);
351 }
352 return_ACPI_STATUS(status);
353 }
354
355 /******************************************************************************
356 *
357 * FUNCTION: acpi_hw_register_read
358 *
359 * PARAMETERS: register_id - ACPI Register ID
360 * return_value - Where the register value is returned
361 *
362 * RETURN: Status and the value read.
363 *
364 * DESCRIPTION: Read from the specified ACPI register
365 *
366 ******************************************************************************/
367 acpi_status acpi_hw_register_read(u32 register_id, u32 *return_value)
368 {
369 u32 value = 0;
370 acpi_status status;
371
372 ACPI_FUNCTION_TRACE(hw_register_read);
373
374 switch (register_id) {
375 case ACPI_REGISTER_PM1_STATUS: /* PM1 A/B: 16-bit access each */
376
377 status = acpi_hw_read_multiple(&value,
378 &acpi_gbl_xpm1a_status,
379 &acpi_gbl_xpm1b_status);
380 break;
381
382 case ACPI_REGISTER_PM1_ENABLE: /* PM1 A/B: 16-bit access each */
383
384 status = acpi_hw_read_multiple(&value,
385 &acpi_gbl_xpm1a_enable,
386 &acpi_gbl_xpm1b_enable);
387 break;
388
389 case ACPI_REGISTER_PM1_CONTROL: /* PM1 A/B: 16-bit access each */
390
391 status = acpi_hw_read_multiple(&value,
392 &acpi_gbl_FADT.
393 xpm1a_control_block,
394 &acpi_gbl_FADT.
395 xpm1b_control_block);
396
397 /*
398 * Zero the write-only bits. From the ACPI specification, "Hardware
399 * Write-Only Bits": "Upon reads to registers with write-only bits,
400 * software masks out all write-only bits."
401 */
402 value &= ~ACPI_PM1_CONTROL_WRITEONLY_BITS;
403 break;
404
405 case ACPI_REGISTER_PM2_CONTROL: /* 8-bit access */
406
407 status =
408 acpi_hw_read(&value, &acpi_gbl_FADT.xpm2_control_block);
409 break;
410
411 case ACPI_REGISTER_PM_TIMER: /* 32-bit access */
412
413 status = acpi_hw_read(&value, &acpi_gbl_FADT.xpm_timer_block);
414 break;
415
416 case ACPI_REGISTER_SMI_COMMAND_BLOCK: /* 8-bit access */
417
418 status =
419 acpi_hw_read_port(acpi_gbl_FADT.smi_command, &value, 8);
420 break;
421
422 default:
423
424 ACPI_ERROR((AE_INFO, "Unknown Register ID: 0x%X", register_id));
425 status = AE_BAD_PARAMETER;
426 break;
427 }
428
429 if (ACPI_SUCCESS(status)) {
430 *return_value = value;
431 }
432
433 return_ACPI_STATUS(status);
434 }
435
436 /******************************************************************************
437 *
438 * FUNCTION: acpi_hw_register_write
439 *
440 * PARAMETERS: register_id - ACPI Register ID
441 * value - The value to write
442 *
443 * RETURN: Status
444 *
445 * DESCRIPTION: Write to the specified ACPI register
446 *
447 * NOTE: In accordance with the ACPI specification, this function automatically
448 * preserves the value of the following bits, meaning that these bits cannot be
449 * changed via this interface:
450 *
451 * PM1_CONTROL[0] = SCI_EN
452 * PM1_CONTROL[9]
453 * PM1_STATUS[11]
454 *
455 * ACPI References:
456 * 1) Hardware Ignored Bits: When software writes to a register with ignored
457 * bit fields, it preserves the ignored bit fields
458 * 2) SCI_EN: OSPM always preserves this bit position
459 *
460 ******************************************************************************/
461
462 acpi_status acpi_hw_register_write(u32 register_id, u32 value)
463 {
464 acpi_status status;
465 u32 read_value;
466
467 ACPI_FUNCTION_TRACE(hw_register_write);
468
469 switch (register_id) {
470 case ACPI_REGISTER_PM1_STATUS: /* PM1 A/B: 16-bit access each */
471 /*
472 * Handle the "ignored" bit in PM1 Status. According to the ACPI
473 * specification, ignored bits are to be preserved when writing.
474 * Normally, this would mean a read/modify/write sequence. However,
475 * preserving a bit in the status register is different. Writing a
476 * one clears the status, and writing a zero preserves the status.
477 * Therefore, we must always write zero to the ignored bit.
478 *
479 * This behavior is clarified in the ACPI 4.0 specification.
480 */
481 value &= ~ACPI_PM1_STATUS_PRESERVED_BITS;
482
483 status = acpi_hw_write_multiple(value,
484 &acpi_gbl_xpm1a_status,
485 &acpi_gbl_xpm1b_status);
486 break;
487
488 case ACPI_REGISTER_PM1_ENABLE: /* PM1 A/B: 16-bit access each */
489
490 status = acpi_hw_write_multiple(value,
491 &acpi_gbl_xpm1a_enable,
492 &acpi_gbl_xpm1b_enable);
493 break;
494
495 case ACPI_REGISTER_PM1_CONTROL: /* PM1 A/B: 16-bit access each */
496 /*
497 * Perform a read first to preserve certain bits (per ACPI spec)
498 * Note: This includes SCI_EN, we never want to change this bit
499 */
500 status = acpi_hw_read_multiple(&read_value,
501 &acpi_gbl_FADT.
502 xpm1a_control_block,
503 &acpi_gbl_FADT.
504 xpm1b_control_block);
505 if (ACPI_FAILURE(status)) {
506 goto exit;
507 }
508
509 /* Insert the bits to be preserved */
510
511 ACPI_INSERT_BITS(value, ACPI_PM1_CONTROL_PRESERVED_BITS,
512 read_value);
513
514 /* Now we can write the data */
515
516 status = acpi_hw_write_multiple(value,
517 &acpi_gbl_FADT.
518 xpm1a_control_block,
519 &acpi_gbl_FADT.
520 xpm1b_control_block);
521 break;
522
523 case ACPI_REGISTER_PM2_CONTROL: /* 8-bit access */
524 /*
525 * For control registers, all reserved bits must be preserved,
526 * as per the ACPI spec.
527 */
528 status =
529 acpi_hw_read(&read_value,
530 &acpi_gbl_FADT.xpm2_control_block);
531 if (ACPI_FAILURE(status)) {
532 goto exit;
533 }
534
535 /* Insert the bits to be preserved */
536
537 ACPI_INSERT_BITS(value, ACPI_PM2_CONTROL_PRESERVED_BITS,
538 read_value);
539
540 status =
541 acpi_hw_write(value, &acpi_gbl_FADT.xpm2_control_block);
542 break;
543
544 case ACPI_REGISTER_PM_TIMER: /* 32-bit access */
545
546 status = acpi_hw_write(value, &acpi_gbl_FADT.xpm_timer_block);
547 break;
548
549 case ACPI_REGISTER_SMI_COMMAND_BLOCK: /* 8-bit access */
550
551 /* SMI_CMD is currently always in IO space */
552
553 status =
554 acpi_hw_write_port(acpi_gbl_FADT.smi_command, value, 8);
555 break;
556
557 default:
558
559 ACPI_ERROR((AE_INFO, "Unknown Register ID: 0x%X", register_id));
560 status = AE_BAD_PARAMETER;
561 break;
562 }
563
564 exit:
565 return_ACPI_STATUS(status);
566 }
567
568 /******************************************************************************
569 *
570 * FUNCTION: acpi_hw_read_multiple
571 *
572 * PARAMETERS: value - Where the register value is returned
573 * register_a - First ACPI register (required)
574 * register_b - Second ACPI register (optional)
575 *
576 * RETURN: Status
577 *
578 * DESCRIPTION: Read from the specified two-part ACPI register (such as PM1 A/B)
579 *
580 ******************************************************************************/
581
582 static acpi_status
583 acpi_hw_read_multiple(u32 *value,
584 struct acpi_generic_address *register_a,
585 struct acpi_generic_address *register_b)
586 {
587 u32 value_a = 0;
588 u32 value_b = 0;
589 acpi_status status;
590
591 /* The first register is always required */
592
593 status = acpi_hw_read(&value_a, register_a);
594 if (ACPI_FAILURE(status)) {
595 return (status);
596 }
597
598 /* Second register is optional */
599
600 if (register_b->address) {
601 status = acpi_hw_read(&value_b, register_b);
602 if (ACPI_FAILURE(status)) {
603 return (status);
604 }
605 }
606
607 /*
608 * OR the two return values together. No shifting or masking is necessary,
609 * because of how the PM1 registers are defined in the ACPI specification:
610 *
611 * "Although the bits can be split between the two register blocks (each
612 * register block has a unique pointer within the FADT), the bit positions
613 * are maintained. The register block with unimplemented bits (that is,
614 * those implemented in the other register block) always returns zeros,
615 * and writes have no side effects"
616 */
617 *value = (value_a | value_b);
618 return (AE_OK);
619 }
620
621 /******************************************************************************
622 *
623 * FUNCTION: acpi_hw_write_multiple
624 *
625 * PARAMETERS: value - The value to write
626 * register_a - First ACPI register (required)
627 * register_b - Second ACPI register (optional)
628 *
629 * RETURN: Status
630 *
631 * DESCRIPTION: Write to the specified two-part ACPI register (such as PM1 A/B)
632 *
633 ******************************************************************************/
634
635 static acpi_status
636 acpi_hw_write_multiple(u32 value,
637 struct acpi_generic_address *register_a,
638 struct acpi_generic_address *register_b)
639 {
640 acpi_status status;
641
642 /* The first register is always required */
643
644 status = acpi_hw_write(value, register_a);
645 if (ACPI_FAILURE(status)) {
646 return (status);
647 }
648
649 /*
650 * Second register is optional
651 *
652 * No bit shifting or clearing is necessary, because of how the PM1
653 * registers are defined in the ACPI specification:
654 *
655 * "Although the bits can be split between the two register blocks (each
656 * register block has a unique pointer within the FADT), the bit positions
657 * are maintained. The register block with unimplemented bits (that is,
658 * those implemented in the other register block) always returns zeros,
659 * and writes have no side effects"
660 */
661 if (register_b->address) {
662 status = acpi_hw_write(value, register_b);
663 }
664
665 return (status);
666 }
667
668 #endif /* !ACPI_REDUCED_HARDWARE */
Linux with added FPC-III support