drivers/acpi/acpica/hwxface.c

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

File Facts

System
Linux kernel
Corpus path
drivers/acpi/acpica/hwxface.c
Extension
.c
Size
13453 bytes
Lines
449
Domain
Driver Families
Bucket
drivers/acpi
Inferred role
Driver Families: exported/initcall integration point
Status
integration 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)) {
			goto unlock_and_exit;
		}

		/*
		 * Insert the input bit into the value that was just read
		 * and write the register
		 */
		ACPI_REGISTER_INSERT_VALUE(register_value,
					   bit_reg_info->bit_position,
					   bit_reg_info->access_bit_mask,
					   value);

		status = acpi_hw_register_write(bit_reg_info->parent_register,
						register_value);
	} else {
		/*
		 * 2) Case for PM1 Status
		 *
		 * The Status register is different from the rest. Clear an event
		 * by writing 1, writing 0 has no effect. So, the only relevant
		 * information is the single bit we're interested in, all others
		 * should be written as 0 so they will be left unchanged.
		 */
		register_value = ACPI_REGISTER_PREPARE_BITS(value,
							    bit_reg_info->
							    bit_position,
							    bit_reg_info->
							    access_bit_mask);

		/* No need to write the register if value is all zeros */

		if (register_value) {
			status =
			    acpi_hw_register_write(ACPI_REGISTER_PM1_STATUS,
						   register_value);
		}
	}

	ACPI_DEBUG_PRINT((ACPI_DB_IO,
			  "BitReg %X, ParentReg %X, Value %8.8X, Actual %8.8X\n",
			  register_id, bit_reg_info->parent_register, value,
			  register_value));

unlock_and_exit:

	acpi_os_release_raw_lock(acpi_gbl_hardware_lock, lock_flags);
	return_ACPI_STATUS(status);
}

ACPI_EXPORT_SYMBOL(acpi_write_bit_register)
#endif				/* !ACPI_REDUCED_HARDWARE */
/*******************************************************************************
 *
 * FUNCTION:    acpi_get_sleep_type_data
 *
 * PARAMETERS:  sleep_state         - Numeric sleep state
 *              *sleep_type_a        - Where SLP_TYPa is returned
 *              *sleep_type_b        - Where SLP_TYPb is returned
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Obtain the SLP_TYPa and SLP_TYPb values for the requested
 *              sleep state via the appropriate \_Sx object.
 *
 *  The sleep state package returned from the corresponding \_Sx_ object
 *  must contain at least one integer.
 *
 *  March 2005:
 *  Added support for a package that contains two integers. This
 *  goes against the ACPI specification which defines this object as a
 *  package with one encoded DWORD integer. However, existing practice
 *  by many BIOS vendors is to return a package with 2 or more integer
 *  elements, at least one per sleep type (A/B).
 *
 *  January 2013:
 *  Therefore, we must be prepared to accept a package with either a
 *  single integer or multiple integers.
 *
 *  The single integer DWORD format is as follows:
 *      BYTE 0 - Value for the PM1A SLP_TYP register
 *      BYTE 1 - Value for the PM1B SLP_TYP register
 *      BYTE 2-3 - Reserved
 *
 *  The dual integer format is as follows:
 *      Integer 0 - Value for the PM1A SLP_TYP register
 *      Integer 1 - Value for the PM1A SLP_TYP register
 *
 ******************************************************************************/
acpi_status

Annotation

Implementation Notes