drivers/acpi/acpica/hwsleep.c

Source file repositories/reference/linux-study-clean/drivers/acpi/acpica/hwsleep.c

File Facts

System
Linux kernel
Corpus path
drivers/acpi/acpica/hwsleep.c
Extension
.c
Size
8782 bytes
Lines
319
Domain
Driver Families
Bucket
drivers/acpi
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

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
 *

Annotation

Implementation Notes