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staging: iio: max517: Fix iio_info changes
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / acpi / acpica / hwregs.c
blob55accb7018bb24776f32541fddfe7cf7498383f8
1
2 /*******************************************************************************
3 *
4 * Module Name: hwregs - Read/write access functions for the various ACPI
5 * control and status registers.
6 *
7 ******************************************************************************/
8
9 /*
10 * Copyright (C) 2000 - 2011, Intel Corp.
11 * All rights reserved.
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
15 * are met:
16 * 1. Redistributions of source code must retain the above copyright
17 * notice, this list of conditions, and the following disclaimer,
18 * without modification.
19 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
20 * substantially similar to the "NO WARRANTY" disclaimer below
21 * ("Disclaimer") and any redistribution must be conditioned upon
22 * including a substantially similar Disclaimer requirement for further
23 * binary redistribution.
24 * 3. Neither the names of the above-listed copyright holders nor the names
25 * of any contributors may be used to endorse or promote products derived
26 * from this software without specific prior written permission.
27 *
28 * Alternatively, this software may be distributed under the terms of the
29 * GNU General Public License ("GPL") version 2 as published by the Free
30 * Software Foundation.
31 *
32 * NO WARRANTY
33 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
34 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
35 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
36 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
37 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
38 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
39 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
40 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
41 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
42 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
43 * POSSIBILITY OF SUCH DAMAGES.
44 */
45
46 #include <acpi/acpi.h>
47 #include "accommon.h"
48 #include "acnamesp.h"
49 #include "acevents.h"
50
51 #define _COMPONENT ACPI_HARDWARE
52 ACPI_MODULE_NAME("hwregs")
53
54 /* Local Prototypes */
55 static acpi_status
56 acpi_hw_read_multiple(u32 *value,
57 struct acpi_generic_address *register_a,
58 struct acpi_generic_address *register_b);
59
60 static acpi_status
61 acpi_hw_write_multiple(u32 value,
62 struct acpi_generic_address *register_a,
63 struct acpi_generic_address *register_b);
64
65 /******************************************************************************
66 *
67 * FUNCTION: acpi_hw_validate_register
68 *
69 * PARAMETERS: Reg - GAS register structure
70 * max_bit_width - Max bit_width supported (32 or 64)
71 * Address - Pointer to where the gas->address
72 * is returned
73 *
74 * RETURN: Status
75 *
76 * DESCRIPTION: Validate the contents of a GAS register. Checks the GAS
77 * pointer, Address, space_id, bit_width, and bit_offset.
78 *
79 ******************************************************************************/
80
81 acpi_status
82 acpi_hw_validate_register(struct acpi_generic_address *reg,
83 u8 max_bit_width, u64 *address)
84 {
85
86 /* Must have a valid pointer to a GAS structure */
87
88 if (!reg) {
89 return (AE_BAD_PARAMETER);
90 }
91
92 /*
93 * Copy the target address. This handles possible alignment issues.
94 * Address must not be null. A null address also indicates an optional
95 * ACPI register that is not supported, so no error message.
96 */
97 ACPI_MOVE_64_TO_64(address, &reg->address);
98 if (!(*address)) {
99 return (AE_BAD_ADDRESS);
100 }
101
102 /* Validate the space_iD */
103
104 if ((reg->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY) &&
105 (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO)) {
106 ACPI_ERROR((AE_INFO,
107 "Unsupported address space: 0x%X", reg->space_id));
108 return (AE_SUPPORT);
109 }
110
111 /* Validate the bit_width */
112
113 if ((reg->bit_width != 8) &&
114 (reg->bit_width != 16) &&
115 (reg->bit_width != 32) && (reg->bit_width != max_bit_width)) {
116 ACPI_ERROR((AE_INFO,
117 "Unsupported register bit width: 0x%X",
118 reg->bit_width));
119 return (AE_SUPPORT);
120 }
121
122 /* Validate the bit_offset. Just a warning for now. */
123
124 if (reg->bit_offset != 0) {
125 ACPI_WARNING((AE_INFO,
126 "Unsupported register bit offset: 0x%X",
127 reg->bit_offset));
128 }
129
130 return (AE_OK);
131 }
132
133 /******************************************************************************
134 *
135 * FUNCTION: acpi_hw_read
136 *
137 * PARAMETERS: Value - Where the value is returned
138 * Reg - GAS register structure
139 *
140 * RETURN: Status
141 *
142 * DESCRIPTION: Read from either memory or IO space. This is a 32-bit max
143 * version of acpi_read, used internally since the overhead of
144 * 64-bit values is not needed.
145 *
146 * LIMITATIONS: <These limitations also apply to acpi_hw_write>
147 * bit_width must be exactly 8, 16, or 32.
148 * space_iD must be system_memory or system_iO.
149 * bit_offset and access_width are currently ignored, as there has
150 * not been a need to implement these.
151 *
152 ******************************************************************************/
153
154 acpi_status acpi_hw_read(u32 *value, struct acpi_generic_address *reg)
155 {
156 u64 address;
157 acpi_status status;
158
159 ACPI_FUNCTION_NAME(hw_read);
160
161 /* Validate contents of the GAS register */
162
163 status = acpi_hw_validate_register(reg, 32, &address);
164 if (ACPI_FAILURE(status)) {
165 return (status);
166 }
167
168 /* Initialize entire 32-bit return value to zero */
169
170 *value = 0;
171
172 /*
173 * Two address spaces supported: Memory or IO. PCI_Config is
174 * not supported here because the GAS structure is insufficient
175 */
176 if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
177 status = acpi_os_read_memory((acpi_physical_address)
178 address, value, reg->bit_width);
179 } else { /* ACPI_ADR_SPACE_SYSTEM_IO, validated earlier */
180
181 status = acpi_hw_read_port((acpi_io_address)
182 address, value, reg->bit_width);
183 }
184
185 ACPI_DEBUG_PRINT((ACPI_DB_IO,
186 "Read: %8.8X width %2d from %8.8X%8.8X (%s)\n",
187 *value, reg->bit_width, ACPI_FORMAT_UINT64(address),
188 acpi_ut_get_region_name(reg->space_id)));
189
190 return (status);
191 }
192
193 /******************************************************************************
194 *
195 * FUNCTION: acpi_hw_write
196 *
197 * PARAMETERS: Value - Value to be written
198 * Reg - GAS register structure
199 *
200 * RETURN: Status
201 *
202 * DESCRIPTION: Write to either memory or IO space. This is a 32-bit max
203 * version of acpi_write, used internally since the overhead of
204 * 64-bit values is not needed.
205 *
206 ******************************************************************************/
207
208 acpi_status acpi_hw_write(u32 value, struct acpi_generic_address *reg)
209 {
210 u64 address;
211 acpi_status status;
212
213 ACPI_FUNCTION_NAME(hw_write);
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 * Two address spaces supported: Memory or IO. PCI_Config is
224 * not supported here because the GAS structure is insufficient
225 */
226 if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
227 status = acpi_os_write_memory((acpi_physical_address)
228 address, value, reg->bit_width);
229 } else { /* ACPI_ADR_SPACE_SYSTEM_IO, validated earlier */
230
231 status = acpi_hw_write_port((acpi_io_address)
232 address, value, reg->bit_width);
233 }
234
235 ACPI_DEBUG_PRINT((ACPI_DB_IO,
236 "Wrote: %8.8X width %2d to %8.8X%8.8X (%s)\n",
237 value, reg->bit_width, ACPI_FORMAT_UINT64(address),
238 acpi_ut_get_region_name(reg->space_id)));
239
240 return (status);
241 }
242
243 /*******************************************************************************
244 *
245 * FUNCTION: acpi_hw_clear_acpi_status
246 *
247 * PARAMETERS: None
248 *
249 * RETURN: Status
250 *
251 * DESCRIPTION: Clears all fixed and general purpose status bits
252 *
253 ******************************************************************************/
254
255 acpi_status acpi_hw_clear_acpi_status(void)
256 {
257 acpi_status status;
258 acpi_cpu_flags lock_flags = 0;
259
260 ACPI_FUNCTION_TRACE(hw_clear_acpi_status);
261
262 ACPI_DEBUG_PRINT((ACPI_DB_IO, "About to write %04X to %8.8X%8.8X\n",
263 ACPI_BITMASK_ALL_FIXED_STATUS,
264 ACPI_FORMAT_UINT64(acpi_gbl_xpm1a_status.address)));
265
266 lock_flags = acpi_os_acquire_lock(acpi_gbl_hardware_lock);
267
268 /* Clear the fixed events in PM1 A/B */
269
270 status = acpi_hw_register_write(ACPI_REGISTER_PM1_STATUS,
271 ACPI_BITMASK_ALL_FIXED_STATUS);
272 if (ACPI_FAILURE(status)) {
273 goto unlock_and_exit;
274 }
275
276 /* Clear the GPE Bits in all GPE registers in all GPE blocks */
277
278 status = acpi_ev_walk_gpe_list(acpi_hw_clear_gpe_block, NULL);
279
280 unlock_and_exit:
281 acpi_os_release_lock(acpi_gbl_hardware_lock, lock_flags);
282 return_ACPI_STATUS(status);
283 }
284
285 /*******************************************************************************
286 *
287 * FUNCTION: acpi_hw_get_register_bit_mask
288 *
289 * PARAMETERS: register_id - Index of ACPI Register to access
290 *
291 * RETURN: The bitmask to be used when accessing the register
292 *
293 * DESCRIPTION: Map register_id into a register bitmask.
294 *
295 ******************************************************************************/
296
297 struct acpi_bit_register_info *acpi_hw_get_bit_register_info(u32 register_id)
298 {
299 ACPI_FUNCTION_ENTRY();
300
301 if (register_id > ACPI_BITREG_MAX) {
302 ACPI_ERROR((AE_INFO, "Invalid BitRegister ID: 0x%X",
303 register_id));
304 return (NULL);
305 }
306
307 return (&acpi_gbl_bit_register_info[register_id]);
308 }
309
310 /******************************************************************************
311 *
312 * FUNCTION: acpi_hw_write_pm1_control
313 *
314 * PARAMETERS: pm1a_control - Value to be written to PM1A control
315 * pm1b_control - Value to be written to PM1B control
316 *
317 * RETURN: Status
318 *
319 * DESCRIPTION: Write the PM1 A/B control registers. These registers are
320 * different than than the PM1 A/B status and enable registers
321 * in that different values can be written to the A/B registers.
322 * Most notably, the SLP_TYP bits can be different, as per the
323 * values returned from the _Sx predefined methods.
324 *
325 ******************************************************************************/
326
327 acpi_status acpi_hw_write_pm1_control(u32 pm1a_control, u32 pm1b_control)
328 {
329 acpi_status status;
330
331 ACPI_FUNCTION_TRACE(hw_write_pm1_control);
332
333 status =
334 acpi_hw_write(pm1a_control, &acpi_gbl_FADT.xpm1a_control_block);
335 if (ACPI_FAILURE(status)) {
336 return_ACPI_STATUS(status);
337 }
338
339 if (acpi_gbl_FADT.xpm1b_control_block.address) {
340 status =
341 acpi_hw_write(pm1b_control,
342 &acpi_gbl_FADT.xpm1b_control_block);
343 }
344 return_ACPI_STATUS(status);
345 }
346
347 /******************************************************************************
348 *
349 * FUNCTION: acpi_hw_register_read
350 *
351 * PARAMETERS: register_id - ACPI Register ID
352 * return_value - Where the register value is returned
353 *
354 * RETURN: Status and the value read.
355 *
356 * DESCRIPTION: Read from the specified ACPI register
357 *
358 ******************************************************************************/
359 acpi_status
360 acpi_hw_register_read(u32 register_id, u32 * return_value)
361 {
362 u32 value = 0;
363 acpi_status status;
364
365 ACPI_FUNCTION_TRACE(hw_register_read);
366
367 switch (register_id) {
368 case ACPI_REGISTER_PM1_STATUS: /* PM1 A/B: 16-bit access each */
369
370 status = acpi_hw_read_multiple(&value,
371 &acpi_gbl_xpm1a_status,
372 &acpi_gbl_xpm1b_status);
373 break;
374
375 case ACPI_REGISTER_PM1_ENABLE: /* PM1 A/B: 16-bit access each */
376
377 status = acpi_hw_read_multiple(&value,
378 &acpi_gbl_xpm1a_enable,
379 &acpi_gbl_xpm1b_enable);
380 break;
381
382 case ACPI_REGISTER_PM1_CONTROL: /* PM1 A/B: 16-bit access each */
383
384 status = acpi_hw_read_multiple(&value,
385 &acpi_gbl_FADT.
386 xpm1a_control_block,
387 &acpi_gbl_FADT.
388 xpm1b_control_block);
389
390 /*
391 * Zero the write-only bits. From the ACPI specification, "Hardware
392 * Write-Only Bits": "Upon reads to registers with write-only bits,
393 * software masks out all write-only bits."
394 */
395 value &= ~ACPI_PM1_CONTROL_WRITEONLY_BITS;
396 break;
397
398 case ACPI_REGISTER_PM2_CONTROL: /* 8-bit access */
399
400 status =
401 acpi_hw_read(&value, &acpi_gbl_FADT.xpm2_control_block);
402 break;
403
404 case ACPI_REGISTER_PM_TIMER: /* 32-bit access */
405
406 status = acpi_hw_read(&value, &acpi_gbl_FADT.xpm_timer_block);
407 break;
408
409 case ACPI_REGISTER_SMI_COMMAND_BLOCK: /* 8-bit access */
410
411 status =
412 acpi_hw_read_port(acpi_gbl_FADT.smi_command, &value, 8);
413 break;
414
415 default:
416 ACPI_ERROR((AE_INFO, "Unknown Register ID: 0x%X", register_id));
417 status = AE_BAD_PARAMETER;
418 break;
419 }
420
421 if (ACPI_SUCCESS(status)) {
422 *return_value = value;
423 }
424
425 return_ACPI_STATUS(status);
426 }
427
428 /******************************************************************************
429 *
430 * FUNCTION: acpi_hw_register_write
431 *
432 * PARAMETERS: register_id - ACPI Register ID
433 * Value - The value to write
434 *
435 * RETURN: Status
436 *
437 * DESCRIPTION: Write to the specified ACPI register
438 *
439 * NOTE: In accordance with the ACPI specification, this function automatically
440 * preserves the value of the following bits, meaning that these bits cannot be
441 * changed via this interface:
442 *
443 * PM1_CONTROL[0] = SCI_EN
444 * PM1_CONTROL[9]
445 * PM1_STATUS[11]
446 *
447 * ACPI References:
448 * 1) Hardware Ignored Bits: When software writes to a register with ignored
449 * bit fields, it preserves the ignored bit fields
450 * 2) SCI_EN: OSPM always preserves this bit position
451 *
452 ******************************************************************************/
453
454 acpi_status acpi_hw_register_write(u32 register_id, u32 value)
455 {
456 acpi_status status;
457 u32 read_value;
458
459 ACPI_FUNCTION_TRACE(hw_register_write);
460
461 switch (register_id) {
462 case ACPI_REGISTER_PM1_STATUS: /* PM1 A/B: 16-bit access each */
463 /*
464 * Handle the "ignored" bit in PM1 Status. According to the ACPI
465 * specification, ignored bits are to be preserved when writing.
466 * Normally, this would mean a read/modify/write sequence. However,
467 * preserving a bit in the status register is different. Writing a
468 * one clears the status, and writing a zero preserves the status.
469 * Therefore, we must always write zero to the ignored bit.
470 *
471 * This behavior is clarified in the ACPI 4.0 specification.
472 */
473 value &= ~ACPI_PM1_STATUS_PRESERVED_BITS;
474
475 status = acpi_hw_write_multiple(value,
476 &acpi_gbl_xpm1a_status,
477 &acpi_gbl_xpm1b_status);
478 break;
479
480 case ACPI_REGISTER_PM1_ENABLE: /* PM1 A/B: 16-bit access */
481
482 status = acpi_hw_write_multiple(value,
483 &acpi_gbl_xpm1a_enable,
484 &acpi_gbl_xpm1b_enable);
485 break;
486
487 case ACPI_REGISTER_PM1_CONTROL: /* PM1 A/B: 16-bit access each */
488
489 /*
490 * Perform a read first to preserve certain bits (per ACPI spec)
491 * Note: This includes SCI_EN, we never want to change this bit
492 */
493 status = acpi_hw_read_multiple(&read_value,
494 &acpi_gbl_FADT.
495 xpm1a_control_block,
496 &acpi_gbl_FADT.
497 xpm1b_control_block);
498 if (ACPI_FAILURE(status)) {
499 goto exit;
500 }
501
502 /* Insert the bits to be preserved */
503
504 ACPI_INSERT_BITS(value, ACPI_PM1_CONTROL_PRESERVED_BITS,
505 read_value);
506
507 /* Now we can write the data */
508
509 status = acpi_hw_write_multiple(value,
510 &acpi_gbl_FADT.
511 xpm1a_control_block,
512 &acpi_gbl_FADT.
513 xpm1b_control_block);
514 break;
515
516 case ACPI_REGISTER_PM2_CONTROL: /* 8-bit access */
517
518 /*
519 * For control registers, all reserved bits must be preserved,
520 * as per the ACPI spec.
521 */
522 status =
523 acpi_hw_read(&read_value,
524 &acpi_gbl_FADT.xpm2_control_block);
525 if (ACPI_FAILURE(status)) {
526 goto exit;
527 }
528
529 /* Insert the bits to be preserved */
530
531 ACPI_INSERT_BITS(value, ACPI_PM2_CONTROL_PRESERVED_BITS,
532 read_value);
533
534 status =
535 acpi_hw_write(value, &acpi_gbl_FADT.xpm2_control_block);
536 break;
537
538 case ACPI_REGISTER_PM_TIMER: /* 32-bit access */
539
540 status = acpi_hw_write(value, &acpi_gbl_FADT.xpm_timer_block);
541 break;
542
543 case ACPI_REGISTER_SMI_COMMAND_BLOCK: /* 8-bit access */
544
545 /* SMI_CMD is currently always in IO space */
546
547 status =
548 acpi_hw_write_port(acpi_gbl_FADT.smi_command, value, 8);
549 break;
550
551 default:
552 ACPI_ERROR((AE_INFO, "Unknown Register ID: 0x%X", register_id));
553 status = AE_BAD_PARAMETER;
554 break;
555 }
556
557 exit:
558 return_ACPI_STATUS(status);
559 }
560
561 /******************************************************************************
562 *
563 * FUNCTION: acpi_hw_read_multiple
564 *
565 * PARAMETERS: Value - Where the register value is returned
566 * register_a - First ACPI register (required)
567 * register_b - Second ACPI register (optional)
568 *
569 * RETURN: Status
570 *
571 * DESCRIPTION: Read from the specified two-part ACPI register (such as PM1 A/B)
572 *
573 ******************************************************************************/
574
575 static acpi_status
576 acpi_hw_read_multiple(u32 *value,
577 struct acpi_generic_address *register_a,
578 struct acpi_generic_address *register_b)
579 {
580 u32 value_a = 0;
581 u32 value_b = 0;
582 acpi_status status;
583
584 /* The first register is always required */
585
586 status = acpi_hw_read(&value_a, register_a);
587 if (ACPI_FAILURE(status)) {
588 return (status);
589 }
590
591 /* Second register is optional */
592
593 if (register_b->address) {
594 status = acpi_hw_read(&value_b, register_b);
595 if (ACPI_FAILURE(status)) {
596 return (status);
597 }
598 }
599
600 /*
601 * OR the two return values together. No shifting or masking is necessary,
602 * because of how the PM1 registers are defined in the ACPI specification:
603 *
604 * "Although the bits can be split between the two register blocks (each
605 * register block has a unique pointer within the FADT), the bit positions
606 * are maintained. The register block with unimplemented bits (that is,
607 * those implemented in the other register block) always returns zeros,
608 * and writes have no side effects"
609 */
610 *value = (value_a | value_b);
611 return (AE_OK);
612 }
613
614 /******************************************************************************
615 *
616 * FUNCTION: acpi_hw_write_multiple
617 *
618 * PARAMETERS: Value - The value to write
619 * register_a - First ACPI register (required)
620 * register_b - Second ACPI register (optional)
621 *
622 * RETURN: Status
623 *
624 * DESCRIPTION: Write to the specified two-part ACPI register (such as PM1 A/B)
625 *
626 ******************************************************************************/
627
628 static acpi_status
629 acpi_hw_write_multiple(u32 value,
630 struct acpi_generic_address *register_a,
631 struct acpi_generic_address *register_b)
632 {
633 acpi_status status;
634
635 /* The first register is always required */
636
637 status = acpi_hw_write(value, register_a);
638 if (ACPI_FAILURE(status)) {
639 return (status);
640 }
641
642 /*
643 * Second register is optional
644 *
645 * No bit shifting or clearing is necessary, because of how the PM1
646 * registers are defined in the ACPI specification:
647 *
648 * "Although the bits can be split between the two register blocks (each
649 * register block has a unique pointer within the FADT), the bit positions
650 * are maintained. The register block with unimplemented bits (that is,
651 * those implemented in the other register block) always returns zeros,
652 * and writes have no side effects"
653 */
654 if (register_b->address) {
655 status = acpi_hw_write(value, register_b);
656 }
657
658 return (status);
659 }
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