Revert "ARM: tegra: tegratab: dummy change"
[linux-2.6.git] / drivers / acpi / acpica / hwregs.c
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 - 2012, 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 #if (!ACPI_REDUCED_HARDWARE)
55 /* Local Prototypes */
56 static acpi_status
57 acpi_hw_read_multiple(u32 *value,
58                       struct acpi_generic_address *register_a,
59                       struct acpi_generic_address *register_b);
60
61 static acpi_status
62 acpi_hw_write_multiple(u32 value,
63                        struct acpi_generic_address *register_a,
64                        struct acpi_generic_address *register_b);
65
66 #endif                          /* !ACPI_REDUCED_HARDWARE */
67
68 /******************************************************************************
69  *
70  * FUNCTION:    acpi_hw_validate_register
71  *
72  * PARAMETERS:  Reg                 - GAS register structure
73  *              max_bit_width       - Max bit_width supported (32 or 64)
74  *              Address             - Pointer to where the gas->address
75  *                                    is returned
76  *
77  * RETURN:      Status
78  *
79  * DESCRIPTION: Validate the contents of a GAS register. Checks the GAS
80  *              pointer, Address, space_id, bit_width, and bit_offset.
81  *
82  ******************************************************************************/
83
84 acpi_status
85 acpi_hw_validate_register(struct acpi_generic_address *reg,
86                           u8 max_bit_width, u64 *address)
87 {
88
89         /* Must have a valid pointer to a GAS structure */
90
91         if (!reg) {
92                 return (AE_BAD_PARAMETER);
93         }
94
95         /*
96          * Copy the target address. This handles possible alignment issues.
97          * Address must not be null. A null address also indicates an optional
98          * ACPI register that is not supported, so no error message.
99          */
100         ACPI_MOVE_64_TO_64(address, &reg->address);
101         if (!(*address)) {
102                 return (AE_BAD_ADDRESS);
103         }
104
105         /* Validate the space_iD */
106
107         if ((reg->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY) &&
108             (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO)) {
109                 ACPI_ERROR((AE_INFO,
110                             "Unsupported address space: 0x%X", reg->space_id));
111                 return (AE_SUPPORT);
112         }
113
114         /* Validate the bit_width */
115
116         if ((reg->bit_width != 8) &&
117             (reg->bit_width != 16) &&
118             (reg->bit_width != 32) && (reg->bit_width != max_bit_width)) {
119                 ACPI_ERROR((AE_INFO,
120                             "Unsupported register bit width: 0x%X",
121                             reg->bit_width));
122                 return (AE_SUPPORT);
123         }
124
125         /* Validate the bit_offset. Just a warning for now. */
126
127         if (reg->bit_offset != 0) {
128                 ACPI_WARNING((AE_INFO,
129                               "Unsupported register bit offset: 0x%X",
130                               reg->bit_offset));
131         }
132
133         return (AE_OK);
134 }
135
136 /******************************************************************************
137  *
138  * FUNCTION:    acpi_hw_read
139  *
140  * PARAMETERS:  Value               - Where the value is returned
141  *              Reg                 - GAS register structure
142  *
143  * RETURN:      Status
144  *
145  * DESCRIPTION: Read from either memory or IO space. This is a 32-bit max
146  *              version of acpi_read, used internally since the overhead of
147  *              64-bit values is not needed.
148  *
149  * LIMITATIONS: <These limitations also apply to acpi_hw_write>
150  *      bit_width must be exactly 8, 16, or 32.
151  *      space_iD must be system_memory or system_iO.
152  *      bit_offset and access_width are currently ignored, as there has
153  *          not been a need to implement these.
154  *
155  ******************************************************************************/
156
157 acpi_status acpi_hw_read(u32 *value, struct acpi_generic_address *reg)
158 {
159         u64 address;
160         u64 value64;
161         acpi_status status;
162
163         ACPI_FUNCTION_NAME(hw_read);
164
165         /* Validate contents of the GAS register */
166
167         status = acpi_hw_validate_register(reg, 32, &address);
168         if (ACPI_FAILURE(status)) {
169                 return (status);
170         }
171
172         /* Initialize entire 32-bit return value to zero */
173
174         *value = 0;
175
176         /*
177          * Two address spaces supported: Memory or IO. PCI_Config is
178          * not supported here because the GAS structure is insufficient
179          */
180         if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
181                 status = acpi_os_read_memory((acpi_physical_address)
182                                              address, &value64, reg->bit_width);
183
184                 *value = (u32)value64;
185         } else {                /* ACPI_ADR_SPACE_SYSTEM_IO, validated earlier */
186
187                 status = acpi_hw_read_port((acpi_io_address)
188                                            address, value, reg->bit_width);
189         }
190
191         ACPI_DEBUG_PRINT((ACPI_DB_IO,
192                           "Read:  %8.8X width %2d from %8.8X%8.8X (%s)\n",
193                           *value, reg->bit_width, ACPI_FORMAT_UINT64(address),
194                           acpi_ut_get_region_name(reg->space_id)));
195
196         return (status);
197 }
198
199 /******************************************************************************
200  *
201  * FUNCTION:    acpi_hw_write
202  *
203  * PARAMETERS:  Value               - Value to be written
204  *              Reg                 - GAS register structure
205  *
206  * RETURN:      Status
207  *
208  * DESCRIPTION: Write to either memory or IO space. This is a 32-bit max
209  *              version of acpi_write, used internally since the overhead of
210  *              64-bit values is not needed.
211  *
212  ******************************************************************************/
213
214 acpi_status acpi_hw_write(u32 value, struct acpi_generic_address *reg)
215 {
216         u64 address;
217         acpi_status status;
218
219         ACPI_FUNCTION_NAME(hw_write);
220
221         /* Validate contents of the GAS register */
222
223         status = acpi_hw_validate_register(reg, 32, &address);
224         if (ACPI_FAILURE(status)) {
225                 return (status);
226         }
227
228         /*
229          * Two address spaces supported: Memory or IO. PCI_Config is
230          * not supported here because the GAS structure is insufficient
231          */
232         if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
233                 status = acpi_os_write_memory((acpi_physical_address)
234                                               address, (u64)value,
235                                               reg->bit_width);
236         } else {                /* ACPI_ADR_SPACE_SYSTEM_IO, validated earlier */
237
238                 status = acpi_hw_write_port((acpi_io_address)
239                                             address, value, reg->bit_width);
240         }
241
242         ACPI_DEBUG_PRINT((ACPI_DB_IO,
243                           "Wrote: %8.8X width %2d   to %8.8X%8.8X (%s)\n",
244                           value, reg->bit_width, ACPI_FORMAT_UINT64(address),
245                           acpi_ut_get_region_name(reg->space_id)));
246
247         return (status);
248 }
249
250 #if (!ACPI_REDUCED_HARDWARE)
251 /*******************************************************************************
252  *
253  * FUNCTION:    acpi_hw_clear_acpi_status
254  *
255  * PARAMETERS:  None
256  *
257  * RETURN:      Status
258  *
259  * DESCRIPTION: Clears all fixed and general purpose status bits
260  *
261  ******************************************************************************/
262
263 acpi_status acpi_hw_clear_acpi_status(void)
264 {
265         acpi_status status;
266         acpi_cpu_flags lock_flags = 0;
267
268         ACPI_FUNCTION_TRACE(hw_clear_acpi_status);
269
270         ACPI_DEBUG_PRINT((ACPI_DB_IO, "About to write %04X to %8.8X%8.8X\n",
271                           ACPI_BITMASK_ALL_FIXED_STATUS,
272                           ACPI_FORMAT_UINT64(acpi_gbl_xpm1a_status.address)));
273
274         lock_flags = acpi_os_acquire_lock(acpi_gbl_hardware_lock);
275
276         /* Clear the fixed events in PM1 A/B */
277
278         status = acpi_hw_register_write(ACPI_REGISTER_PM1_STATUS,
279                                         ACPI_BITMASK_ALL_FIXED_STATUS);
280
281         acpi_os_release_lock(acpi_gbl_hardware_lock, lock_flags);
282
283         if (ACPI_FAILURE(status))
284                 goto exit;
285
286         /* Clear the GPE Bits in all GPE registers in all GPE blocks */
287
288         status = acpi_ev_walk_gpe_list(acpi_hw_clear_gpe_block, NULL);
289
290 exit:
291         return_ACPI_STATUS(status);
292 }
293
294 /*******************************************************************************
295  *
296  * FUNCTION:    acpi_hw_get_bit_register_info
297  *
298  * PARAMETERS:  register_id         - Index of ACPI Register to access
299  *
300  * RETURN:      The bitmask to be used when accessing the register
301  *
302  * DESCRIPTION: Map register_id into a register bitmask.
303  *
304  ******************************************************************************/
305
306 struct acpi_bit_register_info *acpi_hw_get_bit_register_info(u32 register_id)
307 {
308         ACPI_FUNCTION_ENTRY();
309
310         if (register_id > ACPI_BITREG_MAX) {
311                 ACPI_ERROR((AE_INFO, "Invalid BitRegister ID: 0x%X",
312                             register_id));
313                 return (NULL);
314         }
315
316         return (&acpi_gbl_bit_register_info[register_id]);
317 }
318
319 /******************************************************************************
320  *
321  * FUNCTION:    acpi_hw_write_pm1_control
322  *
323  * PARAMETERS:  pm1a_control        - Value to be written to PM1A control
324  *              pm1b_control        - Value to be written to PM1B control
325  *
326  * RETURN:      Status
327  *
328  * DESCRIPTION: Write the PM1 A/B control registers. These registers are
329  *              different than than the PM1 A/B status and enable registers
330  *              in that different values can be written to the A/B registers.
331  *              Most notably, the SLP_TYP bits can be different, as per the
332  *              values returned from the _Sx predefined methods.
333  *
334  ******************************************************************************/
335
336 acpi_status acpi_hw_write_pm1_control(u32 pm1a_control, u32 pm1b_control)
337 {
338         acpi_status status;
339
340         ACPI_FUNCTION_TRACE(hw_write_pm1_control);
341
342         status =
343             acpi_hw_write(pm1a_control, &acpi_gbl_FADT.xpm1a_control_block);
344         if (ACPI_FAILURE(status)) {
345                 return_ACPI_STATUS(status);
346         }
347
348         if (acpi_gbl_FADT.xpm1b_control_block.address) {
349                 status =
350                     acpi_hw_write(pm1b_control,
351                                   &acpi_gbl_FADT.xpm1b_control_block);
352         }
353         return_ACPI_STATUS(status);
354 }
355
356 /******************************************************************************
357  *
358  * FUNCTION:    acpi_hw_register_read
359  *
360  * PARAMETERS:  register_id         - ACPI Register ID
361  *              return_value        - Where the register value is returned
362  *
363  * RETURN:      Status and the value read.
364  *
365  * DESCRIPTION: Read from the specified ACPI register
366  *
367  ******************************************************************************/
368 acpi_status
369 acpi_hw_register_read(u32 register_id, u32 * return_value)
370 {
371         u32 value = 0;
372         acpi_status status;
373
374         ACPI_FUNCTION_TRACE(hw_register_read);
375
376         switch (register_id) {
377         case ACPI_REGISTER_PM1_STATUS:  /* PM1 A/B: 16-bit access each */
378
379                 status = acpi_hw_read_multiple(&value,
380                                                &acpi_gbl_xpm1a_status,
381                                                &acpi_gbl_xpm1b_status);
382                 break;
383
384         case ACPI_REGISTER_PM1_ENABLE:  /* PM1 A/B: 16-bit access each */
385
386                 status = acpi_hw_read_multiple(&value,
387                                                &acpi_gbl_xpm1a_enable,
388                                                &acpi_gbl_xpm1b_enable);
389                 break;
390
391         case ACPI_REGISTER_PM1_CONTROL: /* PM1 A/B: 16-bit access each */
392
393                 status = acpi_hw_read_multiple(&value,
394                                                &acpi_gbl_FADT.
395                                                xpm1a_control_block,
396                                                &acpi_gbl_FADT.
397                                                xpm1b_control_block);
398
399                 /*
400                  * Zero the write-only bits. From the ACPI specification, "Hardware
401                  * Write-Only Bits": "Upon reads to registers with write-only bits,
402                  * software masks out all write-only bits."
403                  */
404                 value &= ~ACPI_PM1_CONTROL_WRITEONLY_BITS;
405                 break;
406
407         case ACPI_REGISTER_PM2_CONTROL: /* 8-bit access */
408
409                 status =
410                     acpi_hw_read(&value, &acpi_gbl_FADT.xpm2_control_block);
411                 break;
412
413         case ACPI_REGISTER_PM_TIMER:    /* 32-bit access */
414
415                 status = acpi_hw_read(&value, &acpi_gbl_FADT.xpm_timer_block);
416                 break;
417
418         case ACPI_REGISTER_SMI_COMMAND_BLOCK:   /* 8-bit access */
419
420                 status =
421                     acpi_hw_read_port(acpi_gbl_FADT.smi_command, &value, 8);
422                 break;
423
424         default:
425                 ACPI_ERROR((AE_INFO, "Unknown Register ID: 0x%X", register_id));
426                 status = AE_BAD_PARAMETER;
427                 break;
428         }
429
430         if (ACPI_SUCCESS(status)) {
431                 *return_value = value;
432         }
433
434         return_ACPI_STATUS(status);
435 }
436
437 /******************************************************************************
438  *
439  * FUNCTION:    acpi_hw_register_write
440  *
441  * PARAMETERS:  register_id         - ACPI Register ID
442  *              Value               - The value to write
443  *
444  * RETURN:      Status
445  *
446  * DESCRIPTION: Write to the specified ACPI register
447  *
448  * NOTE: In accordance with the ACPI specification, this function automatically
449  * preserves the value of the following bits, meaning that these bits cannot be
450  * changed via this interface:
451  *
452  * PM1_CONTROL[0] = SCI_EN
453  * PM1_CONTROL[9]
454  * PM1_STATUS[11]
455  *
456  * ACPI References:
457  * 1) Hardware Ignored Bits: When software writes to a register with ignored
458  *      bit fields, it preserves the ignored bit fields
459  * 2) SCI_EN: OSPM always preserves this bit position
460  *
461  ******************************************************************************/
462
463 acpi_status acpi_hw_register_write(u32 register_id, u32 value)
464 {
465         acpi_status status;
466         u32 read_value;
467
468         ACPI_FUNCTION_TRACE(hw_register_write);
469
470         switch (register_id) {
471         case ACPI_REGISTER_PM1_STATUS:  /* PM1 A/B: 16-bit access each */
472                 /*
473                  * Handle the "ignored" bit in PM1 Status. According to the ACPI
474                  * specification, ignored bits are to be preserved when writing.
475                  * Normally, this would mean a read/modify/write sequence. However,
476                  * preserving a bit in the status register is different. Writing a
477                  * one clears the status, and writing a zero preserves the status.
478                  * Therefore, we must always write zero to the ignored bit.
479                  *
480                  * This behavior is clarified in the ACPI 4.0 specification.
481                  */
482                 value &= ~ACPI_PM1_STATUS_PRESERVED_BITS;
483
484                 status = acpi_hw_write_multiple(value,
485                                                 &acpi_gbl_xpm1a_status,
486                                                 &acpi_gbl_xpm1b_status);
487                 break;
488
489         case ACPI_REGISTER_PM1_ENABLE:  /* PM1 A/B: 16-bit access */
490
491                 status = acpi_hw_write_multiple(value,
492                                                 &acpi_gbl_xpm1a_enable,
493                                                 &acpi_gbl_xpm1b_enable);
494                 break;
495
496         case ACPI_REGISTER_PM1_CONTROL: /* PM1 A/B: 16-bit access each */
497
498                 /*
499                  * Perform a read first to preserve certain bits (per ACPI spec)
500                  * Note: This includes SCI_EN, we never want to change this bit
501                  */
502                 status = acpi_hw_read_multiple(&read_value,
503                                                &acpi_gbl_FADT.
504                                                xpm1a_control_block,
505                                                &acpi_gbl_FADT.
506                                                xpm1b_control_block);
507                 if (ACPI_FAILURE(status)) {
508                         goto exit;
509                 }
510
511                 /* Insert the bits to be preserved */
512
513                 ACPI_INSERT_BITS(value, ACPI_PM1_CONTROL_PRESERVED_BITS,
514                                  read_value);
515
516                 /* Now we can write the data */
517
518                 status = acpi_hw_write_multiple(value,
519                                                 &acpi_gbl_FADT.
520                                                 xpm1a_control_block,
521                                                 &acpi_gbl_FADT.
522                                                 xpm1b_control_block);
523                 break;
524
525         case ACPI_REGISTER_PM2_CONTROL: /* 8-bit access */
526
527                 /*
528                  * For control registers, all reserved bits must be preserved,
529                  * as per the ACPI spec.
530                  */
531                 status =
532                     acpi_hw_read(&read_value,
533                                  &acpi_gbl_FADT.xpm2_control_block);
534                 if (ACPI_FAILURE(status)) {
535                         goto exit;
536                 }
537
538                 /* Insert the bits to be preserved */
539
540                 ACPI_INSERT_BITS(value, ACPI_PM2_CONTROL_PRESERVED_BITS,
541                                  read_value);
542
543                 status =
544                     acpi_hw_write(value, &acpi_gbl_FADT.xpm2_control_block);
545                 break;
546
547         case ACPI_REGISTER_PM_TIMER:    /* 32-bit access */
548
549                 status = acpi_hw_write(value, &acpi_gbl_FADT.xpm_timer_block);
550                 break;
551
552         case ACPI_REGISTER_SMI_COMMAND_BLOCK:   /* 8-bit access */
553
554                 /* SMI_CMD is currently always in IO space */
555
556                 status =
557                     acpi_hw_write_port(acpi_gbl_FADT.smi_command, value, 8);
558                 break;
559
560         default:
561                 ACPI_ERROR((AE_INFO, "Unknown Register ID: 0x%X", register_id));
562                 status = AE_BAD_PARAMETER;
563                 break;
564         }
565
566       exit:
567         return_ACPI_STATUS(status);
568 }
569
570 /******************************************************************************
571  *
572  * FUNCTION:    acpi_hw_read_multiple
573  *
574  * PARAMETERS:  Value               - Where the register value is returned
575  *              register_a           - First ACPI register (required)
576  *              register_b           - Second ACPI register (optional)
577  *
578  * RETURN:      Status
579  *
580  * DESCRIPTION: Read from the specified two-part ACPI register (such as PM1 A/B)
581  *
582  ******************************************************************************/
583
584 static acpi_status
585 acpi_hw_read_multiple(u32 *value,
586                       struct acpi_generic_address *register_a,
587                       struct acpi_generic_address *register_b)
588 {
589         u32 value_a = 0;
590         u32 value_b = 0;
591         acpi_status status;
592
593         /* The first register is always required */
594
595         status = acpi_hw_read(&value_a, register_a);
596         if (ACPI_FAILURE(status)) {
597                 return (status);
598         }
599
600         /* Second register is optional */
601
602         if (register_b->address) {
603                 status = acpi_hw_read(&value_b, register_b);
604                 if (ACPI_FAILURE(status)) {
605                         return (status);
606                 }
607         }
608
609         /*
610          * OR the two return values together. No shifting or masking is necessary,
611          * because of how the PM1 registers are defined in the ACPI specification:
612          *
613          * "Although the bits can be split between the two register blocks (each
614          * register block has a unique pointer within the FADT), the bit positions
615          * are maintained. The register block with unimplemented bits (that is,
616          * those implemented in the other register block) always returns zeros,
617          * and writes have no side effects"
618          */
619         *value = (value_a | value_b);
620         return (AE_OK);
621 }
622
623 /******************************************************************************
624  *
625  * FUNCTION:    acpi_hw_write_multiple
626  *
627  * PARAMETERS:  Value               - The value to write
628  *              register_a           - First ACPI register (required)
629  *              register_b           - Second ACPI register (optional)
630  *
631  * RETURN:      Status
632  *
633  * DESCRIPTION: Write to the specified two-part ACPI register (such as PM1 A/B)
634  *
635  ******************************************************************************/
636
637 static acpi_status
638 acpi_hw_write_multiple(u32 value,
639                        struct acpi_generic_address *register_a,
640                        struct acpi_generic_address *register_b)
641 {
642         acpi_status status;
643
644         /* The first register is always required */
645
646         status = acpi_hw_write(value, register_a);
647         if (ACPI_FAILURE(status)) {
648                 return (status);
649         }
650
651         /*
652          * Second register is optional
653          *
654          * No bit shifting or clearing is necessary, because of how the PM1
655          * registers are defined in the ACPI specification:
656          *
657          * "Although the bits can be split between the two register blocks (each
658          * register block has a unique pointer within the FADT), the bit positions
659          * are maintained. The register block with unimplemented bits (that is,
660          * those implemented in the other register block) always returns zeros,
661          * and writes have no side effects"
662          */
663         if (register_b->address) {
664                 status = acpi_hw_write(value, register_b);
665         }
666
667         return (status);
668 }
669
670 #endif                          /* !ACPI_REDUCED_HARDWARE */