Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /******************************************************************************* |
| 2 | * |
| 3 | * Module Name: hwregs - Read/write access functions for the various ACPI |
| 4 | * control and status registers. |
| 5 | * |
| 6 | ******************************************************************************/ |
| 7 | |
| 8 | /* |
Bob Moore | 25f044e | 2013-01-25 05:38:56 +0000 | [diff] [blame] | 9 | * Copyright (C) 2000 - 2013, Intel Corp. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 45 | #include <acpi/acpi.h> |
Len Brown | e2f7a77 | 2009-01-09 00:30:03 -0500 | [diff] [blame] | 46 | #include "accommon.h" |
Len Brown | e2f7a77 | 2009-01-09 00:30:03 -0500 | [diff] [blame] | 47 | #include "acevents.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | |
| 49 | #define _COMPONENT ACPI_HARDWARE |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 50 | ACPI_MODULE_NAME("hwregs") |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 51 | |
Bob Moore | 33620c5 | 2012-02-14 18:14:27 +0800 | [diff] [blame] | 52 | #if (!ACPI_REDUCED_HARDWARE) |
Bob Moore | c520aba | 2009-02-18 14:20:12 +0800 | [diff] [blame] | 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 | |
Bob Moore | 33620c5 | 2012-02-14 18:14:27 +0800 | [diff] [blame] | 64 | #endif /* !ACPI_REDUCED_HARDWARE */ |
| 65 | |
Bob Moore | c6b5774 | 2009-06-24 09:44:06 +0800 | [diff] [blame] | 66 | /****************************************************************************** |
| 67 | * |
| 68 | * FUNCTION: acpi_hw_validate_register |
| 69 | * |
Bob Moore | ba494be | 2012-07-12 09:40:10 +0800 | [diff] [blame] | 70 | * PARAMETERS: reg - GAS register structure |
Bob Moore | c6b5774 | 2009-06-24 09:44:06 +0800 | [diff] [blame] | 71 | * max_bit_width - Max bit_width supported (32 or 64) |
Bob Moore | ba494be | 2012-07-12 09:40:10 +0800 | [diff] [blame] | 72 | * address - Pointer to where the gas->address |
Bob Moore | c6b5774 | 2009-06-24 09:44:06 +0800 | [diff] [blame] | 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, ®->address); |
| 99 | if (!(*address)) { |
| 100 | return (AE_BAD_ADDRESS); |
| 101 | } |
| 102 | |
Bob Moore | ba494be | 2012-07-12 09:40:10 +0800 | [diff] [blame] | 103 | /* Validate the space_ID */ |
Bob Moore | c6b5774 | 2009-06-24 09:44:06 +0800 | [diff] [blame] | 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 | * |
Bob Moore | ba494be | 2012-07-12 09:40:10 +0800 | [diff] [blame] | 138 | * PARAMETERS: value - Where the value is returned |
| 139 | * reg - GAS register structure |
Bob Moore | c6b5774 | 2009-06-24 09:44:06 +0800 | [diff] [blame] | 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. |
Bob Moore | ba494be | 2012-07-12 09:40:10 +0800 | [diff] [blame] | 149 | * space_ID must be system_memory or system_IO. |
Bob Moore | c6b5774 | 2009-06-24 09:44:06 +0800 | [diff] [blame] | 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; |
Bob Moore | 653f4b5 | 2012-02-14 18:29:55 +0800 | [diff] [blame] | 158 | u64 value64; |
Bob Moore | c6b5774 | 2009-06-24 09:44:06 +0800 | [diff] [blame] | 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) |
Bob Moore | 653f4b5 | 2012-02-14 18:29:55 +0800 | [diff] [blame] | 180 | address, &value64, reg->bit_width); |
| 181 | |
| 182 | *value = (u32)value64; |
Bob Moore | c6b5774 | 2009-06-24 09:44:06 +0800 | [diff] [blame] | 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 | * |
Bob Moore | ba494be | 2012-07-12 09:40:10 +0800 | [diff] [blame] | 201 | * PARAMETERS: value - Value to be written |
| 202 | * reg - GAS register structure |
Bob Moore | c6b5774 | 2009-06-24 09:44:06 +0800 | [diff] [blame] | 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) |
Bob Moore | 653f4b5 | 2012-02-14 18:29:55 +0800 | [diff] [blame] | 232 | address, (u64)value, |
| 233 | reg->bit_width); |
Bob Moore | c6b5774 | 2009-06-24 09:44:06 +0800 | [diff] [blame] | 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 | |
Bob Moore | 33620c5 | 2012-02-14 18:14:27 +0800 | [diff] [blame] | 248 | #if (!ACPI_REDUCED_HARDWARE) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 249 | /******************************************************************************* |
| 250 | * |
| 251 | * FUNCTION: acpi_hw_clear_acpi_status |
| 252 | * |
Bob Moore | d8c71b6 | 2007-02-02 19:48:21 +0300 | [diff] [blame] | 253 | * PARAMETERS: None |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 254 | * |
Bob Moore | 7db5d82 | 2008-12-30 11:04:48 +0800 | [diff] [blame] | 255 | * RETURN: Status |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 256 | * |
| 257 | * DESCRIPTION: Clears all fixed and general purpose status bits |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 258 | * |
| 259 | ******************************************************************************/ |
Bob Moore | c520aba | 2009-02-18 14:20:12 +0800 | [diff] [blame] | 260 | |
Bob Moore | d8c71b6 | 2007-02-02 19:48:21 +0300 | [diff] [blame] | 261 | acpi_status acpi_hw_clear_acpi_status(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 262 | { |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 263 | acpi_status status; |
Bob Moore | 4c90ece | 2006-06-08 16:29:00 -0400 | [diff] [blame] | 264 | acpi_cpu_flags lock_flags = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 265 | |
Bob Moore | b229cf9 | 2006-04-21 17:15:00 -0400 | [diff] [blame] | 266 | ACPI_FUNCTION_TRACE(hw_clear_acpi_status); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 267 | |
Bob Moore | 8eb7b24 | 2009-04-22 10:28:22 +0800 | [diff] [blame] | 268 | ACPI_DEBUG_PRINT((ACPI_DB_IO, "About to write %04X to %8.8X%8.8X\n", |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 269 | ACPI_BITMASK_ALL_FIXED_STATUS, |
Bob Moore | 8eb7b24 | 2009-04-22 10:28:22 +0800 | [diff] [blame] | 270 | ACPI_FORMAT_UINT64(acpi_gbl_xpm1a_status.address))); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 271 | |
Bob Moore | 4c90ece | 2006-06-08 16:29:00 -0400 | [diff] [blame] | 272 | lock_flags = acpi_os_acquire_lock(acpi_gbl_hardware_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 273 | |
Bob Moore | 227243a | 2009-02-18 14:24:50 +0800 | [diff] [blame] | 274 | /* Clear the fixed events in PM1 A/B */ |
Bob Moore | 531c633 | 2009-02-18 14:06:12 +0800 | [diff] [blame] | 275 | |
Alexey Starikovskiy | d30dc9ab | 2007-09-30 22:39:36 +0400 | [diff] [blame] | 276 | status = acpi_hw_register_write(ACPI_REGISTER_PM1_STATUS, |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 277 | ACPI_BITMASK_ALL_FIXED_STATUS); |
Rakib Mullick | f7f71cf | 2011-11-06 21:18:17 +0600 | [diff] [blame] | 278 | |
| 279 | acpi_os_release_lock(acpi_gbl_hardware_lock, lock_flags); |
| 280 | |
| 281 | if (ACPI_FAILURE(status)) |
| 282 | goto exit; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 283 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 284 | /* Clear the GPE Bits in all GPE registers in all GPE blocks */ |
| 285 | |
Bob Moore | e97d6bf | 2008-12-30 09:45:17 +0800 | [diff] [blame] | 286 | status = acpi_ev_walk_gpe_list(acpi_hw_clear_gpe_block, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 287 | |
Rakib Mullick | f7f71cf | 2011-11-06 21:18:17 +0600 | [diff] [blame] | 288 | exit: |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 289 | return_ACPI_STATUS(status); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 290 | } |
| 291 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 292 | /******************************************************************************* |
| 293 | * |
Bob Moore | 33620c5 | 2012-02-14 18:14:27 +0800 | [diff] [blame] | 294 | * FUNCTION: acpi_hw_get_bit_register_info |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 295 | * |
| 296 | * PARAMETERS: register_id - Index of ACPI Register to access |
| 297 | * |
Robert Moore | 44f6c01 | 2005-04-18 22:49:35 -0400 | [diff] [blame] | 298 | * RETURN: The bitmask to be used when accessing the register |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 299 | * |
Robert Moore | 44f6c01 | 2005-04-18 22:49:35 -0400 | [diff] [blame] | 300 | * DESCRIPTION: Map register_id into a register bitmask. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 301 | * |
| 302 | ******************************************************************************/ |
Bob Moore | 7db5d82 | 2008-12-30 11:04:48 +0800 | [diff] [blame] | 303 | |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 304 | struct acpi_bit_register_info *acpi_hw_get_bit_register_info(u32 register_id) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 305 | { |
Bob Moore | 4a90c7e | 2006-01-13 16:22:00 -0500 | [diff] [blame] | 306 | ACPI_FUNCTION_ENTRY(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 307 | |
| 308 | if (register_id > ACPI_BITREG_MAX) { |
Bob Moore | f6a22b0 | 2010-03-05 17:56:40 +0800 | [diff] [blame] | 309 | ACPI_ERROR((AE_INFO, "Invalid BitRegister ID: 0x%X", |
Bob Moore | b8e4d89 | 2006-01-27 16:43:00 -0500 | [diff] [blame] | 310 | register_id)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 311 | return (NULL); |
| 312 | } |
| 313 | |
| 314 | return (&acpi_gbl_bit_register_info[register_id]); |
| 315 | } |
| 316 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 317 | /****************************************************************************** |
| 318 | * |
Bob Moore | 32c9ef9 | 2009-02-18 14:36:05 +0800 | [diff] [blame] | 319 | * FUNCTION: acpi_hw_write_pm1_control |
| 320 | * |
| 321 | * PARAMETERS: pm1a_control - Value to be written to PM1A control |
| 322 | * pm1b_control - Value to be written to PM1B control |
| 323 | * |
| 324 | * RETURN: Status |
| 325 | * |
| 326 | * DESCRIPTION: Write the PM1 A/B control registers. These registers are |
| 327 | * different than than the PM1 A/B status and enable registers |
| 328 | * in that different values can be written to the A/B registers. |
| 329 | * Most notably, the SLP_TYP bits can be different, as per the |
| 330 | * values returned from the _Sx predefined methods. |
| 331 | * |
| 332 | ******************************************************************************/ |
| 333 | |
| 334 | acpi_status acpi_hw_write_pm1_control(u32 pm1a_control, u32 pm1b_control) |
| 335 | { |
| 336 | acpi_status status; |
| 337 | |
| 338 | ACPI_FUNCTION_TRACE(hw_write_pm1_control); |
| 339 | |
Bob Moore | c6b5774 | 2009-06-24 09:44:06 +0800 | [diff] [blame] | 340 | status = |
| 341 | acpi_hw_write(pm1a_control, &acpi_gbl_FADT.xpm1a_control_block); |
Bob Moore | 32c9ef9 | 2009-02-18 14:36:05 +0800 | [diff] [blame] | 342 | if (ACPI_FAILURE(status)) { |
| 343 | return_ACPI_STATUS(status); |
| 344 | } |
| 345 | |
| 346 | if (acpi_gbl_FADT.xpm1b_control_block.address) { |
| 347 | status = |
Bob Moore | c6b5774 | 2009-06-24 09:44:06 +0800 | [diff] [blame] | 348 | acpi_hw_write(pm1b_control, |
| 349 | &acpi_gbl_FADT.xpm1b_control_block); |
Bob Moore | 32c9ef9 | 2009-02-18 14:36:05 +0800 | [diff] [blame] | 350 | } |
| 351 | return_ACPI_STATUS(status); |
| 352 | } |
| 353 | |
| 354 | /****************************************************************************** |
| 355 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 356 | * FUNCTION: acpi_hw_register_read |
| 357 | * |
Alexey Starikovskiy | d30dc9ab | 2007-09-30 22:39:36 +0400 | [diff] [blame] | 358 | * PARAMETERS: register_id - ACPI Register ID |
Robert Moore | 44f6c01 | 2005-04-18 22:49:35 -0400 | [diff] [blame] | 359 | * return_value - Where the register value is returned |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 360 | * |
| 361 | * RETURN: Status and the value read. |
| 362 | * |
Bob Moore | 967440e3 | 2006-06-23 17:04:00 -0400 | [diff] [blame] | 363 | * DESCRIPTION: Read from the specified ACPI register |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 364 | * |
| 365 | ******************************************************************************/ |
Lv Zheng | 3e8214e | 2012-12-19 05:37:15 +0000 | [diff] [blame] | 366 | acpi_status acpi_hw_register_read(u32 register_id, u32 *return_value) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 367 | { |
Bob Moore | c520aba | 2009-02-18 14:20:12 +0800 | [diff] [blame] | 368 | u32 value = 0; |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 369 | acpi_status status; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 370 | |
Bob Moore | b229cf9 | 2006-04-21 17:15:00 -0400 | [diff] [blame] | 371 | ACPI_FUNCTION_TRACE(hw_register_read); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 372 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 373 | switch (register_id) { |
Bob Moore | c520aba | 2009-02-18 14:20:12 +0800 | [diff] [blame] | 374 | case ACPI_REGISTER_PM1_STATUS: /* PM1 A/B: 16-bit access each */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 375 | |
Bob Moore | c520aba | 2009-02-18 14:20:12 +0800 | [diff] [blame] | 376 | status = acpi_hw_read_multiple(&value, |
| 377 | &acpi_gbl_xpm1a_status, |
| 378 | &acpi_gbl_xpm1b_status); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 379 | break; |
| 380 | |
Bob Moore | c520aba | 2009-02-18 14:20:12 +0800 | [diff] [blame] | 381 | case ACPI_REGISTER_PM1_ENABLE: /* PM1 A/B: 16-bit access each */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 382 | |
Bob Moore | c520aba | 2009-02-18 14:20:12 +0800 | [diff] [blame] | 383 | status = acpi_hw_read_multiple(&value, |
| 384 | &acpi_gbl_xpm1a_enable, |
| 385 | &acpi_gbl_xpm1b_enable); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 386 | break; |
| 387 | |
Bob Moore | c520aba | 2009-02-18 14:20:12 +0800 | [diff] [blame] | 388 | case ACPI_REGISTER_PM1_CONTROL: /* PM1 A/B: 16-bit access each */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 389 | |
Bob Moore | c520aba | 2009-02-18 14:20:12 +0800 | [diff] [blame] | 390 | status = acpi_hw_read_multiple(&value, |
| 391 | &acpi_gbl_FADT. |
| 392 | xpm1a_control_block, |
| 393 | &acpi_gbl_FADT. |
| 394 | xpm1b_control_block); |
Lin Ming | c3dd25f | 2009-03-19 09:51:01 +0800 | [diff] [blame] | 395 | |
| 396 | /* |
| 397 | * Zero the write-only bits. From the ACPI specification, "Hardware |
| 398 | * Write-Only Bits": "Upon reads to registers with write-only bits, |
| 399 | * software masks out all write-only bits." |
| 400 | */ |
| 401 | value &= ~ACPI_PM1_CONTROL_WRITEONLY_BITS; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 402 | break; |
| 403 | |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 404 | case ACPI_REGISTER_PM2_CONTROL: /* 8-bit access */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 405 | |
Bob Moore | c6b5774 | 2009-06-24 09:44:06 +0800 | [diff] [blame] | 406 | status = |
| 407 | acpi_hw_read(&value, &acpi_gbl_FADT.xpm2_control_block); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 408 | break; |
| 409 | |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 410 | case ACPI_REGISTER_PM_TIMER: /* 32-bit access */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 411 | |
Bob Moore | c6b5774 | 2009-06-24 09:44:06 +0800 | [diff] [blame] | 412 | status = acpi_hw_read(&value, &acpi_gbl_FADT.xpm_timer_block); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 413 | break; |
| 414 | |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 415 | case ACPI_REGISTER_SMI_COMMAND_BLOCK: /* 8-bit access */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 416 | |
Bob Moore | f3d2e78 | 2007-02-02 19:48:18 +0300 | [diff] [blame] | 417 | status = |
Bob Moore | 7f07190 | 2009-03-19 09:37:47 +0800 | [diff] [blame] | 418 | acpi_hw_read_port(acpi_gbl_FADT.smi_command, &value, 8); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 419 | break; |
| 420 | |
| 421 | default: |
Bob Moore | f6a22b0 | 2010-03-05 17:56:40 +0800 | [diff] [blame] | 422 | ACPI_ERROR((AE_INFO, "Unknown Register ID: 0x%X", register_id)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 423 | status = AE_BAD_PARAMETER; |
| 424 | break; |
| 425 | } |
| 426 | |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 427 | if (ACPI_SUCCESS(status)) { |
Bob Moore | c520aba | 2009-02-18 14:20:12 +0800 | [diff] [blame] | 428 | *return_value = value; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 429 | } |
| 430 | |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 431 | return_ACPI_STATUS(status); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 432 | } |
| 433 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 434 | /****************************************************************************** |
| 435 | * |
| 436 | * FUNCTION: acpi_hw_register_write |
| 437 | * |
Alexey Starikovskiy | d30dc9ab | 2007-09-30 22:39:36 +0400 | [diff] [blame] | 438 | * PARAMETERS: register_id - ACPI Register ID |
Bob Moore | ba494be | 2012-07-12 09:40:10 +0800 | [diff] [blame] | 439 | * value - The value to write |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 440 | * |
| 441 | * RETURN: Status |
| 442 | * |
Bob Moore | 967440e3 | 2006-06-23 17:04:00 -0400 | [diff] [blame] | 443 | * DESCRIPTION: Write to the specified ACPI register |
| 444 | * |
| 445 | * NOTE: In accordance with the ACPI specification, this function automatically |
| 446 | * preserves the value of the following bits, meaning that these bits cannot be |
| 447 | * changed via this interface: |
| 448 | * |
| 449 | * PM1_CONTROL[0] = SCI_EN |
| 450 | * PM1_CONTROL[9] |
| 451 | * PM1_STATUS[11] |
| 452 | * |
| 453 | * ACPI References: |
| 454 | * 1) Hardware Ignored Bits: When software writes to a register with ignored |
| 455 | * bit fields, it preserves the ignored bit fields |
| 456 | * 2) SCI_EN: OSPM always preserves this bit position |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 457 | * |
| 458 | ******************************************************************************/ |
| 459 | |
Alexey Starikovskiy | d30dc9ab | 2007-09-30 22:39:36 +0400 | [diff] [blame] | 460 | acpi_status acpi_hw_register_write(u32 register_id, u32 value) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 461 | { |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 462 | acpi_status status; |
Bob Moore | 967440e3 | 2006-06-23 17:04:00 -0400 | [diff] [blame] | 463 | u32 read_value; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 464 | |
Bob Moore | b229cf9 | 2006-04-21 17:15:00 -0400 | [diff] [blame] | 465 | ACPI_FUNCTION_TRACE(hw_register_write); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 466 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 467 | switch (register_id) { |
Bob Moore | c520aba | 2009-02-18 14:20:12 +0800 | [diff] [blame] | 468 | case ACPI_REGISTER_PM1_STATUS: /* PM1 A/B: 16-bit access each */ |
Bob Moore | 8636f8d | 2009-03-09 16:32:20 +0800 | [diff] [blame] | 469 | /* |
| 470 | * Handle the "ignored" bit in PM1 Status. According to the ACPI |
| 471 | * specification, ignored bits are to be preserved when writing. |
| 472 | * Normally, this would mean a read/modify/write sequence. However, |
| 473 | * preserving a bit in the status register is different. Writing a |
| 474 | * one clears the status, and writing a zero preserves the status. |
| 475 | * Therefore, we must always write zero to the ignored bit. |
| 476 | * |
| 477 | * This behavior is clarified in the ACPI 4.0 specification. |
| 478 | */ |
| 479 | value &= ~ACPI_PM1_STATUS_PRESERVED_BITS; |
Bob Moore | 967440e3 | 2006-06-23 17:04:00 -0400 | [diff] [blame] | 480 | |
Bob Moore | c520aba | 2009-02-18 14:20:12 +0800 | [diff] [blame] | 481 | status = acpi_hw_write_multiple(value, |
| 482 | &acpi_gbl_xpm1a_status, |
| 483 | &acpi_gbl_xpm1b_status); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 484 | break; |
| 485 | |
Lv Zheng | 75c8044 | 2012-12-19 05:36:49 +0000 | [diff] [blame] | 486 | case ACPI_REGISTER_PM1_ENABLE: /* PM1 A/B: 16-bit access each */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 487 | |
Bob Moore | c520aba | 2009-02-18 14:20:12 +0800 | [diff] [blame] | 488 | status = acpi_hw_write_multiple(value, |
| 489 | &acpi_gbl_xpm1a_enable, |
| 490 | &acpi_gbl_xpm1b_enable); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 491 | break; |
| 492 | |
Bob Moore | c520aba | 2009-02-18 14:20:12 +0800 | [diff] [blame] | 493 | case ACPI_REGISTER_PM1_CONTROL: /* PM1 A/B: 16-bit access each */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 494 | |
Bob Moore | 967440e3 | 2006-06-23 17:04:00 -0400 | [diff] [blame] | 495 | /* |
| 496 | * Perform a read first to preserve certain bits (per ACPI spec) |
Bob Moore | c520aba | 2009-02-18 14:20:12 +0800 | [diff] [blame] | 497 | * Note: This includes SCI_EN, we never want to change this bit |
Bob Moore | 967440e3 | 2006-06-23 17:04:00 -0400 | [diff] [blame] | 498 | */ |
Bob Moore | c520aba | 2009-02-18 14:20:12 +0800 | [diff] [blame] | 499 | status = acpi_hw_read_multiple(&read_value, |
| 500 | &acpi_gbl_FADT. |
| 501 | xpm1a_control_block, |
| 502 | &acpi_gbl_FADT. |
| 503 | xpm1b_control_block); |
Bob Moore | 967440e3 | 2006-06-23 17:04:00 -0400 | [diff] [blame] | 504 | if (ACPI_FAILURE(status)) { |
Alexey Starikovskiy | d30dc9ab | 2007-09-30 22:39:36 +0400 | [diff] [blame] | 505 | goto exit; |
Bob Moore | 967440e3 | 2006-06-23 17:04:00 -0400 | [diff] [blame] | 506 | } |
| 507 | |
| 508 | /* Insert the bits to be preserved */ |
| 509 | |
| 510 | ACPI_INSERT_BITS(value, ACPI_PM1_CONTROL_PRESERVED_BITS, |
| 511 | read_value); |
| 512 | |
| 513 | /* Now we can write the data */ |
| 514 | |
Bob Moore | c520aba | 2009-02-18 14:20:12 +0800 | [diff] [blame] | 515 | status = acpi_hw_write_multiple(value, |
| 516 | &acpi_gbl_FADT. |
| 517 | xpm1a_control_block, |
| 518 | &acpi_gbl_FADT. |
| 519 | xpm1b_control_block); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 520 | break; |
| 521 | |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 522 | case ACPI_REGISTER_PM2_CONTROL: /* 8-bit access */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 523 | |
Bob Moore | 20869dc | 2009-03-13 09:10:46 +0800 | [diff] [blame] | 524 | /* |
| 525 | * For control registers, all reserved bits must be preserved, |
| 526 | * as per the ACPI spec. |
| 527 | */ |
| 528 | status = |
Bob Moore | c6b5774 | 2009-06-24 09:44:06 +0800 | [diff] [blame] | 529 | acpi_hw_read(&read_value, |
| 530 | &acpi_gbl_FADT.xpm2_control_block); |
Bob Moore | 20869dc | 2009-03-13 09:10:46 +0800 | [diff] [blame] | 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 | |
Bob Moore | c6b5774 | 2009-06-24 09:44:06 +0800 | [diff] [blame] | 540 | status = |
| 541 | acpi_hw_write(value, &acpi_gbl_FADT.xpm2_control_block); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 542 | break; |
| 543 | |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 544 | case ACPI_REGISTER_PM_TIMER: /* 32-bit access */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 545 | |
Bob Moore | c6b5774 | 2009-06-24 09:44:06 +0800 | [diff] [blame] | 546 | status = acpi_hw_write(value, &acpi_gbl_FADT.xpm_timer_block); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 547 | break; |
| 548 | |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 549 | case ACPI_REGISTER_SMI_COMMAND_BLOCK: /* 8-bit access */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 550 | |
| 551 | /* SMI_CMD is currently always in IO space */ |
| 552 | |
Bob Moore | f3d2e78 | 2007-02-02 19:48:18 +0300 | [diff] [blame] | 553 | status = |
Bob Moore | 7f07190 | 2009-03-19 09:37:47 +0800 | [diff] [blame] | 554 | acpi_hw_write_port(acpi_gbl_FADT.smi_command, value, 8); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 555 | break; |
| 556 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 557 | default: |
Bob Moore | f6a22b0 | 2010-03-05 17:56:40 +0800 | [diff] [blame] | 558 | ACPI_ERROR((AE_INFO, "Unknown Register ID: 0x%X", register_id)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 559 | status = AE_BAD_PARAMETER; |
| 560 | break; |
| 561 | } |
| 562 | |
Alexey Starikovskiy | d30dc9ab | 2007-09-30 22:39:36 +0400 | [diff] [blame] | 563 | exit: |
Len Brown | 4be44fc | 2005-08-05 00:44:28 -0400 | [diff] [blame] | 564 | return_ACPI_STATUS(status); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 565 | } |
Bob Moore | c520aba | 2009-02-18 14:20:12 +0800 | [diff] [blame] | 566 | |
| 567 | /****************************************************************************** |
| 568 | * |
| 569 | * FUNCTION: acpi_hw_read_multiple |
| 570 | * |
Bob Moore | ba494be | 2012-07-12 09:40:10 +0800 | [diff] [blame] | 571 | * PARAMETERS: value - Where the register value is returned |
Bob Moore | c520aba | 2009-02-18 14:20:12 +0800 | [diff] [blame] | 572 | * register_a - First ACPI register (required) |
| 573 | * register_b - Second ACPI register (optional) |
| 574 | * |
| 575 | * RETURN: Status |
| 576 | * |
| 577 | * DESCRIPTION: Read from the specified two-part ACPI register (such as PM1 A/B) |
| 578 | * |
| 579 | ******************************************************************************/ |
| 580 | |
| 581 | static acpi_status |
| 582 | acpi_hw_read_multiple(u32 *value, |
| 583 | struct acpi_generic_address *register_a, |
| 584 | struct acpi_generic_address *register_b) |
| 585 | { |
| 586 | u32 value_a = 0; |
| 587 | u32 value_b = 0; |
| 588 | acpi_status status; |
| 589 | |
| 590 | /* The first register is always required */ |
| 591 | |
Bob Moore | c6b5774 | 2009-06-24 09:44:06 +0800 | [diff] [blame] | 592 | status = acpi_hw_read(&value_a, register_a); |
Bob Moore | c520aba | 2009-02-18 14:20:12 +0800 | [diff] [blame] | 593 | if (ACPI_FAILURE(status)) { |
| 594 | return (status); |
| 595 | } |
| 596 | |
| 597 | /* Second register is optional */ |
| 598 | |
| 599 | if (register_b->address) { |
Bob Moore | c6b5774 | 2009-06-24 09:44:06 +0800 | [diff] [blame] | 600 | status = acpi_hw_read(&value_b, register_b); |
Bob Moore | c520aba | 2009-02-18 14:20:12 +0800 | [diff] [blame] | 601 | if (ACPI_FAILURE(status)) { |
| 602 | return (status); |
| 603 | } |
| 604 | } |
| 605 | |
Bob Moore | aefc7f9 | 2009-02-18 14:26:02 +0800 | [diff] [blame] | 606 | /* |
| 607 | * OR the two return values together. No shifting or masking is necessary, |
| 608 | * because of how the PM1 registers are defined in the ACPI specification: |
| 609 | * |
| 610 | * "Although the bits can be split between the two register blocks (each |
| 611 | * register block has a unique pointer within the FADT), the bit positions |
| 612 | * are maintained. The register block with unimplemented bits (that is, |
| 613 | * those implemented in the other register block) always returns zeros, |
| 614 | * and writes have no side effects" |
| 615 | */ |
| 616 | *value = (value_a | value_b); |
Bob Moore | c520aba | 2009-02-18 14:20:12 +0800 | [diff] [blame] | 617 | return (AE_OK); |
| 618 | } |
| 619 | |
| 620 | /****************************************************************************** |
| 621 | * |
| 622 | * FUNCTION: acpi_hw_write_multiple |
| 623 | * |
Bob Moore | ba494be | 2012-07-12 09:40:10 +0800 | [diff] [blame] | 624 | * PARAMETERS: value - The value to write |
Bob Moore | c520aba | 2009-02-18 14:20:12 +0800 | [diff] [blame] | 625 | * register_a - First ACPI register (required) |
| 626 | * register_b - Second ACPI register (optional) |
| 627 | * |
| 628 | * RETURN: Status |
| 629 | * |
| 630 | * DESCRIPTION: Write to the specified two-part ACPI register (such as PM1 A/B) |
| 631 | * |
| 632 | ******************************************************************************/ |
| 633 | |
| 634 | static acpi_status |
| 635 | acpi_hw_write_multiple(u32 value, |
| 636 | struct acpi_generic_address *register_a, |
| 637 | struct acpi_generic_address *register_b) |
| 638 | { |
| 639 | acpi_status status; |
| 640 | |
| 641 | /* The first register is always required */ |
| 642 | |
Bob Moore | c6b5774 | 2009-06-24 09:44:06 +0800 | [diff] [blame] | 643 | status = acpi_hw_write(value, register_a); |
Bob Moore | c520aba | 2009-02-18 14:20:12 +0800 | [diff] [blame] | 644 | if (ACPI_FAILURE(status)) { |
| 645 | return (status); |
| 646 | } |
| 647 | |
Bob Moore | aefc7f9 | 2009-02-18 14:26:02 +0800 | [diff] [blame] | 648 | /* |
| 649 | * Second register is optional |
| 650 | * |
| 651 | * No bit shifting or clearing is necessary, because of how the PM1 |
| 652 | * registers are defined in the ACPI specification: |
| 653 | * |
| 654 | * "Although the bits can be split between the two register blocks (each |
| 655 | * register block has a unique pointer within the FADT), the bit positions |
| 656 | * are maintained. The register block with unimplemented bits (that is, |
| 657 | * those implemented in the other register block) always returns zeros, |
| 658 | * and writes have no side effects" |
| 659 | */ |
Bob Moore | c520aba | 2009-02-18 14:20:12 +0800 | [diff] [blame] | 660 | if (register_b->address) { |
Bob Moore | c6b5774 | 2009-06-24 09:44:06 +0800 | [diff] [blame] | 661 | status = acpi_hw_write(value, register_b); |
Bob Moore | c520aba | 2009-02-18 14:20:12 +0800 | [diff] [blame] | 662 | } |
| 663 | |
| 664 | return (status); |
| 665 | } |
Bob Moore | 33620c5 | 2012-02-14 18:14:27 +0800 | [diff] [blame] | 666 | |
| 667 | #endif /* !ACPI_REDUCED_HARDWARE */ |