Quelle  hwsleep.c   Sprache: C

// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/******************************************************************************
 *
 * Name: hwsleep.c - ACPI Hardware Sleep/Wake Support functions for the
 *                   original/legacy sleep/PM registers.
 *
 * Copyright (C) 2000 - 2025, Intel Corp.
 *
 *****************************************************************************/

#include <acpi/acpi.h>
#include "accommon.h"

#define _COMPONENT          ACPI_HARDWARE
ACPI_MODULE_NAME("hwsleep")

#if (!ACPI_REDUCED_HARDWARE) /* Entire module */
/*******************************************************************************
 *
 * FUNCTION:    acpi_hw_legacy_sleep
 *
 * PARAMETERS:  sleep_state         - Which sleep state to enter
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Enter a system sleep state via the legacy FADT PM registers
 *              THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED
 *
 ******************************************************************************/
acpi_status acpi_hw_legacy_sleep(u8 sleep_state)
{
 struct acpi_bit_register_info *sleep_type_reg_info;
 struct acpi_bit_register_info *sleep_enable_reg_info;
 u32 pm1a_control;
 u32 pm1b_control;
 u32 in_value;
 acpi_status status;

 ACPI_FUNCTION_TRACE(hw_legacy_sleep);

 sleep_type_reg_info =
     acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_TYPE);
 sleep_enable_reg_info =
     acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_ENABLE);

 /* Clear wake status */

 status = acpi_write_bit_register(ACPI_BITREG_WAKE_STATUS,
      ACPI_CLEAR_STATUS);
 if (ACPI_FAILURE(status)) {
  return_ACPI_STATUS(status);
 }

 /* Disable all GPEs */
 status = acpi_hw_disable_all_gpes();
 if (ACPI_FAILURE(status)) {
  return_ACPI_STATUS(status);
 }
 status = acpi_hw_clear_acpi_status();
 if (ACPI_FAILURE(status)) {
  return_ACPI_STATUS(status);
 }
 acpi_gbl_system_awake_and_running = FALSE;

  /* Enable all wakeup GPEs */
 status = acpi_hw_enable_all_wakeup_gpes();
 if (ACPI_FAILURE(status)) {
  return_ACPI_STATUS(status);
 }

 /* Get current value of PM1A control */

 status = acpi_hw_register_read(ACPI_REGISTER_PM1_CONTROL,
           &pm1a_control);
 if (ACPI_FAILURE(status)) {
  return_ACPI_STATUS(status);
 }
 ACPI_DEBUG_PRINT((ACPI_DB_INIT,
     "Entering sleep state [S%u]\n", sleep_state));

 /* Clear the SLP_EN and SLP_TYP fields */

 pm1a_control &= ~(sleep_type_reg_info->access_bit_mask |
     sleep_enable_reg_info->access_bit_mask);
 pm1b_control = pm1a_control;

 /* Insert the SLP_TYP bits */

 pm1a_control |=
     (acpi_gbl_sleep_type_a << sleep_type_reg_info->bit_position);
 pm1b_control |=
     (acpi_gbl_sleep_type_b << sleep_type_reg_info->bit_position);

 /*
 * We split the writes of SLP_TYP and SLP_EN to workaround
 * poorly implemented hardware.
 */

 /* Write #1: write the SLP_TYP data to the PM1 Control registers */

 status = acpi_hw_write_pm1_control(pm1a_control, pm1b_control);
 if (ACPI_FAILURE(status)) {
  return_ACPI_STATUS(status);
 }

 /* Insert the sleep enable (SLP_EN) bit */

 pm1a_control |= sleep_enable_reg_info->access_bit_mask;
 pm1b_control |= sleep_enable_reg_info->access_bit_mask;

 /* Flush caches, as per ACPI specification */

 if (sleep_state < ACPI_STATE_S4) {
  ACPI_FLUSH_CPU_CACHE();
 }

 status = acpi_os_enter_sleep(sleep_state, pm1a_control, pm1b_control);
 if (status == AE_CTRL_TERMINATE) {
  return_ACPI_STATUS(AE_OK);
 }
 if (ACPI_FAILURE(status)) {
  return_ACPI_STATUS(status);
 }

 /* Write #2: Write both SLP_TYP + SLP_EN */

 status = acpi_hw_write_pm1_control(pm1a_control, pm1b_control);
 if (ACPI_FAILURE(status)) {
  return_ACPI_STATUS(status);
 }

 if (sleep_state > ACPI_STATE_S3) {
  /*
 * We wanted to sleep > S3, but it didn't happen (by virtue of the
 * fact that we are still executing!)
 *
 * Wait ten seconds, then try again. This is to get S4/S5 to work on
 * all machines.
 *
 * We wait so long to allow chipsets that poll this reg very slowly
 * to still read the right value. Ideally, this block would go
 * away entirely.
 */
  acpi_os_stall(10 * ACPI_USEC_PER_SEC);

  status = acpi_hw_register_write(ACPI_REGISTER_PM1_CONTROL,
      sleep_enable_reg_info->
      access_bit_mask);
  if (ACPI_FAILURE(status)) {
   return_ACPI_STATUS(status);
  }
 }

 /* Wait for transition back to Working State */

 do {
  status =
      acpi_read_bit_register(ACPI_BITREG_WAKE_STATUS, &in_value);
  if (ACPI_FAILURE(status)) {
   return_ACPI_STATUS(status);
  }

 } while (!in_value);

 return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_hw_legacy_wake_prep
 *
 * PARAMETERS:  sleep_state         - Which sleep state we just exited
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Perform the first state of OS-independent ACPI cleanup after a
 *              sleep.
 *              Called with interrupts ENABLED.
 *
 ******************************************************************************/

acpi_status acpi_hw_legacy_wake_prep(u8 sleep_state)
{
 acpi_status status = AE_OK;
 struct acpi_bit_register_info *sleep_type_reg_info;
 struct acpi_bit_register_info *sleep_enable_reg_info;
 u32 pm1a_control;
 u32 pm1b_control;

 ACPI_FUNCTION_TRACE(hw_legacy_wake_prep);

 /*
 * Set SLP_TYPE and SLP_EN to state S0.
 * This is unclear from the ACPI Spec, but it is required
 * by some machines.
 */
 if (acpi_gbl_sleep_type_a_s0 != ACPI_SLEEP_TYPE_INVALID) {
  sleep_type_reg_info =
      acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_TYPE);
  sleep_enable_reg_info =
      acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_ENABLE);

  /* Get current value of PM1A control */

  status = acpi_hw_register_read(ACPI_REGISTER_PM1_CONTROL,
            &pm1a_control);
  if (ACPI_SUCCESS(status)) {

   /* Clear the SLP_EN and SLP_TYP fields */

   pm1a_control &= ~(sleep_type_reg_info->access_bit_mask |
       sleep_enable_reg_info->
       access_bit_mask);
   pm1b_control = pm1a_control;

   /* Insert the SLP_TYP bits */

   pm1a_control |= (acpi_gbl_sleep_type_a_s0 <<
      sleep_type_reg_info->bit_position);
   pm1b_control |= (acpi_gbl_sleep_type_b_s0 <<
      sleep_type_reg_info->bit_position);

   /* Write the control registers and ignore any errors */

   (void)acpi_hw_write_pm1_control(pm1a_control,
       pm1b_control);
  }
 }

 return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_hw_legacy_wake
 *
 * PARAMETERS:  sleep_state         - Which sleep state we just exited
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Perform OS-independent ACPI cleanup after a sleep
 *              Called with interrupts ENABLED.
 *
 ******************************************************************************/

acpi_status acpi_hw_legacy_wake(u8 sleep_state)
{
 acpi_status status;

 ACPI_FUNCTION_TRACE(hw_legacy_wake);

 /* Ensure enter_sleep_state_prep -> enter_sleep_state ordering */

 acpi_gbl_sleep_type_a = ACPI_SLEEP_TYPE_INVALID;
 acpi_hw_execute_sleep_method(METHOD_PATHNAME__SST, ACPI_SST_WAKING);

 /*
 * GPEs must be enabled before _WAK is called as GPEs
 * might get fired there
 *
 * Restore the GPEs:
 * 1) Disable all GPEs
 * 2) Enable all runtime GPEs
 */
 status = acpi_hw_disable_all_gpes();
 if (ACPI_FAILURE(status)) {
  return_ACPI_STATUS(status);
 }

 status = acpi_hw_enable_all_runtime_gpes();
 if (ACPI_FAILURE(status)) {
  return_ACPI_STATUS(status);
 }

 /*
 * Now we can execute _WAK, etc. Some machines require that the GPEs
 * are enabled before the wake methods are executed.
 */
 acpi_hw_execute_sleep_method(METHOD_PATHNAME__WAK, sleep_state);

 /*
 * Some BIOS code assumes that WAK_STS will be cleared on resume
 * and use it to determine whether the system is rebooting or
 * resuming. Clear WAK_STS for compatibility.
 */
 (void)acpi_write_bit_register(ACPI_BITREG_WAKE_STATUS,
          ACPI_CLEAR_STATUS);
 acpi_gbl_system_awake_and_running = TRUE;

 /* Enable power button */

 (void)
     acpi_write_bit_register(acpi_gbl_fixed_event_info
        [ACPI_EVENT_POWER_BUTTON].
        enable_register_id, ACPI_ENABLE_EVENT);

 (void)
     acpi_write_bit_register(acpi_gbl_fixed_event_info
        [ACPI_EVENT_POWER_BUTTON].
        status_register_id, ACPI_CLEAR_STATUS);

 /* Enable sleep button */

 (void)
     acpi_write_bit_register(acpi_gbl_fixed_event_info
        [ACPI_EVENT_SLEEP_BUTTON].
        enable_register_id, ACPI_ENABLE_EVENT);

 (void)
     acpi_write_bit_register(acpi_gbl_fixed_event_info
        [ACPI_EVENT_SLEEP_BUTTON].
        status_register_id, ACPI_CLEAR_STATUS);

 acpi_hw_execute_sleep_method(METHOD_PATHNAME__SST, ACPI_SST_WORKING);
 return_ACPI_STATUS(status);
}

#endif    /* !ACPI_REDUCED_HARDWARE */