linux_dsm_epyc7002/Documentation/ABI/testing/debugfs-wilco-ec
Nick Crews 2ad1f7a914 platform/chrome: wilco_ec: Remove 256 byte transfers
The 0xF6 command, intended to send and receive 256 byte payloads to
and from the EC, is not needed. The 0xF5 command for 32 byte
payloads is sufficient. This patch removes support for the 0xF6
command and 256 byte payloads.

Signed-off-by: Nick Crews <ncrews@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
2019-05-20 10:18:10 +02:00

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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.