Documentation/ABI/testing/debugfs-wilco-ec

Source file repositories/reference/linux-study-clean/Documentation/ABI/testing/debugfs-wilco-ec

File Facts

System
Linux kernel
Corpus path
Documentation/ABI/testing/debugfs-wilco-ec
Extension
[no extension]
Size
1702 bytes
Lines
46
Domain
Support Tooling And Documentation
Bucket
Documentation
Inferred role
Support Tooling And Documentation: Documentation
Status
atlas-only

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

What:		/sys/kernel/debug/wilco_ec/h1_gpio
Date:		April 2019
KernelVersion:	5.2
Description:
		As part of Chrome OS's FAFT (Fully Automated Firmware Testing)
		tests, we need to ensure that the H1 chip is properly setting
		some GPIO lines. The h1_gpio attribute exposes the state
		of the lines:
		- ENTRY_TO_FACT_MODE in BIT(0)
		- SPI_CHROME_SEL in BIT(1)

		Output will formatted with "0x%02x\n".

What:		/sys/kernel/debug/wilco_ec/raw
Date:		January 2019
KernelVersion:	5.1
Description:
		Write and read raw mailbox commands to the EC.

		You can write a hexadecimal sentence to raw, and that series of
		bytes will be sent to the EC. Then, you can read the bytes of
		response by reading from raw.

		For writing, bytes 0-1 indicate the message type, one of enum
		wilco_ec_msg_type. Byte 2+ consist of the data passed in the
		request, starting at MBOX[0]. At least three bytes are required
		for writing, two for the type and at least a single byte of
		data.

		Example::

		    // Request EC info type 3 (EC firmware build date)
		    // Corresponds with sending type 0x00f0 with
		    // MBOX = [38, 00, 03, 00]
		    $ echo 00 f0 38 00 03 00 > /sys/kernel/debug/wilco_ec/raw
		    // View the result. The decoded ASCII result "12/21/18" is
		    // included after the raw hex.
		    // Corresponds with MBOX = [00, 00, 31, 32, 2f, 32, 31, 38, ...]
		    $ cat /sys/kernel/debug/wilco_ec/raw
		    00 00 31 32 2f 32 31 2f 31 38 00 38 00 01 00 2f 00  ..12/21/18.8...

		Note that the first 16 bytes of the received MBOX[] will be
		printed, even if some of the data is junk, and skipping bytes
		17 to 32. It is up to you to know how many of the first bytes of
		data are the actual response.

Annotation

Implementation Notes