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-rw-r--r--Documentation/ABI/testing/debugfs-wilco-ec32
1 files changed, 21 insertions, 11 deletions
diff --git a/Documentation/ABI/testing/debugfs-wilco-ec b/Documentation/ABI/testing/debugfs-wilco-ec
index f814f112e213..7ff6b45be703 100644
--- a/Documentation/ABI/testing/debugfs-wilco-ec
+++ b/Documentation/ABI/testing/debugfs-wilco-ec
@@ -4,20 +4,30 @@ KernelVersion: 5.1
Description:
Write and read raw mailbox commands to the EC.
- For writing:
- Bytes 0-1 indicate the message type:
- 00 F0 = Execute Legacy Command
- 00 F2 = Read/Write NVRAM Property
- Byte 2 provides the command code
- Bytes 3+ consist of the data passed in the request
+ 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.
- At least three bytes are required, for the msg type and command,
- with additional bytes optional for additional data.
+ 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. Only the first
+ EC_MAILBOX_DATA_SIZE bytes of MBOX will be used.
Example:
// Request EC info type 3 (EC firmware build date)
- $ echo 00 f0 38 00 03 00 > raw
+ // 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.
- $ cat raw
- 00 31 32 2f 32 31 2f 31 38 00 38 00 01 00 2f 00 .12/21/18.8...
+ // 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 32 bytes of the received MBOX[] will be
+ printed, even if some of the data is junk. It is up to you to
+ know how many of the first bytes of data are the actual
+ response.