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author | Nico Huber <nico.huber@secunet.com> | 2013-05-23 16:35:05 +0200 |
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committer | Stefan Reinauer <stefan.reinauer@coreboot.org> | 2013-06-06 21:19:28 +0200 |
commit | 7bb02512d9e3f1c2c95f83ef02a2209c5366ae58 (patch) | |
tree | b9e21d976513941f1c99b7431582ee3fcbb553a2 /src/ec | |
parent | ccc7d1f229ab4b0dc9b10f63966640bbac750722 (diff) | |
download | coreboot-7bb02512d9e3f1c2c95f83ef02a2209c5366ae58.tar.xz |
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)
Diffstat (limited to 'src/ec')
-rw-r--r-- | src/ec/acpi/ec.asl | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/src/ec/acpi/ec.asl b/src/ec/acpi/ec.asl new file mode 100644 index 0000000000..4bc72f712e --- /dev/null +++ b/src/ec/acpi/ec.asl @@ -0,0 +1,171 @@ +/* + * This file is part of the coreboot project. + * + * Copyright (C) 2013 secunet Security Networks AG + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; version 2 of + * the License. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, + * MA 02110-1301 USA + */ + +/* + * ACPI style embedded controller commands + * + * Controlled by the following preprocessor defines: + * EC_SC_IO I/o address of the EC_SC register + * EC_DATA_IO I/o address of the EC_DATA register + */ + +#define EC_MUTEX ECMX +#define WAIT_EC_SC WECC +#define SEND_EC_COMMAND SECC +#define SEND_EC_DATA SECD +#define RECV_EC_DATA RECD +#define EC_READ ECRD +#define EC_WRITE ECWR +#define EC_SC ECSC +#define EC_DATA ECDT + +#define EC_OBF 0x01 /* Output buffer full (EC_DATA) */ +#define EC_IBF 0x02 /* Input buffer full (EC_DATA or EC_SC) */ + +#define EC_ERROR_MASK 0xff00 +#define EC_TIMEOUT 0x8000 + +#define EC_READ_CMD 0x80 +#define EC_WRITE_CMD 0x81 + +Mutex(EC_MUTEX, 1) + +OperationRegion(ERSC, SystemIO, EC_SC_IO, 1) +Field(ERSC, ByteAcc, NoLock, Preserve) { EC_SC, 8 } +OperationRegion(ERDT, SystemIO, EC_DATA_IO, 1) +Field(ERDT, ByteAcc, NoLock, Preserve) { EC_DATA, 8 } + +/* + * Wait for a bit in the status and command (EC_SC) register + * + * The caller is responsible of acquiring the EC_MUTEX before + * calling this method. + * + * Arg0: Mask, Arg1: State waiting for + * Returns EC_TIMEOUT if timed out, 0 else + */ +Method (WAIT_EC_SC, 2) +{ + Store (0x7ff, Local0) /* Timeout */ + While (LAnd (LNotEqual (And (EC_SC, Arg0), Arg1), Decrement (Local0))) { + Stall (10) + } + If (Local0) { + Return (0) + } Else { + Return (EC_TIMEOUT) + } +} + +/* + * Send command byte in Arg0 to status and command (EC_SC) register + * + * The caller is responsible of acquiring the EC_MUTEX before + * calling this method. + * + * Returns EC_TIMEOUT if timed out, 0 else + */ +Method (SEND_EC_COMMAND, 1) +{ + Store (WAIT_EC_SC (EC_IBF, 0), Local0) + If (LNot (Local0)) { + Store (Arg0, EC_SC) + } + Return (Local0) +} + +/* + * Send data byte in Arg0 to data (EC_DATA) register + * + * The caller is responsible of acquiring the EC_MUTEX before + * calling this method. + * + * Returns EC_TIMEOUT if timed out, 0 else + */ +Method (SEND_EC_DATA, 1) +{ + Store (WAIT_EC_SC (EC_IBF, 0), Local0) + If (LNot (Local0)) { + Store (Arg0, EC_DATA) + } + Return (Local0) +} + +/* + * Read one byte of data from data (EC_DATA) register + * + * The caller is responsible of acquiring the EC_MUTEX before + * calling this method. + * + * Returns EC_TIMEOUT if timed out, the read data byte else + */ +Method (RECV_EC_DATA) +{ + Store (WAIT_EC_SC (EC_OBF, EC_OBF), Local0) + If (LNot (Local0)) { + Return (EC_DATA) + } Else { + Return (Local0) + } +} + +/* + * Read one byte from ec memory (cmd 0x80) + * + * Arg0: Address (1 byte) to read from + * Returns EC_TIMEOUT if timed out, the read data byte else + */ +Method (EC_READ, 1) +{ + Acquire (EC_MUTEX, 0xffff) + Store (SEND_EC_COMMAND (EC_READ_CMD), Local0) + If (LNot (Local0)) { + Store (SEND_EC_DATA (Arg0), Local0) + } + If (LNot (Local0)) { + Store (RECV_EC_DATA (), Local0) + } + Release (EC_MUTEX) + + Return (Local0) +} + +/* + * Write one byte to ec memory (cmd 0x81) + * + * Arg0: Address (1 byte) to write to + * Arg1: Byte to write + * Returns EC_TIMEOUT if timed out, 0 else + */ +Method (EC_WRITE, 2) +{ + Acquire (EC_MUTEX, 0xffff) + Store (SEND_EC_COMMAND (EC_WRITE_CMD), Local0) + If (LNot (Local0)) { + Store (SEND_EC_DATA (Arg0), Local0) + } + If (LNot (Local0)) { + Store (SEND_EC_DATA (Arg1), Local0) + } + Release (EC_MUTEX) + + Return (Local0) +} |