hwsleep.c

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/******************************************************************************
 *
 * Name: hwsleep.c - ACPI Hardware Sleep/Wake Support functions for the
 *                   original/legacy sleep/PM registers.
 *
 *****************************************************************************/

/*
 * Copyright (C) 2000 - 2012, Intel Corp.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    substantially similar to the "NO WARRANTY" disclaimer below
 *    ("Disclaimer") and any redistribution must be conditioned upon
 *    including a substantially similar Disclaimer requirement for further
 *    binary redistribution.
 * 3. Neither the names of the above-listed copyright holders nor the names
 *    of any contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * NO WARRANTY
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 */

#include <acpi/acpi.h>
#include <linux/acpi.h>
#include "accommon.h"
#include <linux/module.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);
    }

    /* Clear all fixed and general purpose status bits */

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

    /*
     * 1) Disable/Clear all GPEs
     * 2) Enable all wakeup GPEs
     */
    status = acpi_hw_disable_all_gpes();
    if (ACPI_FAILURE(status)) {
        return_ACPI_STATUS(status);
    }
    acpi_gbl_system_awake_and_running = FALSE;

    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 */

    ACPI_FLUSH_CPU_CACHE();

    status = acpi_os_prepare_sleep(sleep_state, pm1a_control,
                       pm1b_control);
    if (ACPI_SKIP(status))
        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(10000000);

        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;
    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.
     */
    status = acpi_get_sleep_type_data(ACPI_STATE_S0,
                      &acpi_gbl_sleep_type_a,
                      &acpi_gbl_sleep_type_b);
    if (ACPI_SUCCESS(status)) {
        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 <<
                     sleep_type_reg_info->bit_position);
            pm1b_control |= (acpi_gbl_sleep_type_b <<
                     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/Clear 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.
     */
    acpi_write_bit_register(ACPI_BITREG_WAKE_STATUS, 1);
    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);

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

#endif              /* !ACPI_REDUCED_HARDWARE */