ec/acpi: Add ACPI methods for generic EC access
Port most of the functions found in ec/acpi/ec.c to ACPI Source Language
(ASL). These functions are used to control embedded controllers with the
standard ACPI interface (mostly through i/o ports 0x62 / 0x66).
The following methods are implemented and tested against the power
managements channels of a ITE IT8516E embedded controller:
* WAIT_EC_SC Wait for a bit in the EC_SC register
* SEND_EC_COMMAND Send one command byte to the EC_SC register
* SEND_EC_DATA Send one data byte to the EC_DATA register
* RECV_EC_DATA Read one byte of data from the EC_DATA register
* EC_READ Read one byte from ec memory (through cmd 0x80)
* EC_WRITE Write one byte to ec memory (through cmd 0x81)
To use the provided methods, one should include `ec/acpi/ec.asl` in the
EC device code. Prior doing so, two macros should be defined to identify
the used i/o ports:
* EC_SC_IO I/o address of the EC_SC register
* EC_DATA_IO I/o address of the EC_DATA register
Change-Id: I8c6706075fb4980329c228e5b830d5f4e9b188dd
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: http://review.coreboot.org/3285
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Tested-by: build bot (Jenkins)
1 file changed