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firmware: arm_scmi: Add new sensor unit types

PATCH In review Artem Shimko 3 participants 6 messages Oct 21, 2025 – Feb 3 System control & power/management interface (SCPI/SCMI) Message Protocol drivers

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PATCH 1/1 firmware: arm_scmi: Add new sensor unit types

Add support for two new sensor unit types introduced in Arm SCMI
- STATE_BINARY (0x5E): Binary state (1: enabled/on, 0: disabled/off)
- BYTES_SEC (0x5F): Bytes per second

These unit types are used for sensors that report binary state information and data transfer rate measurements respectively.

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Hello,

This patch adds definitions for two new sensor unit types that were introduced in the Arm System Control and Management Interface (SCMI) Specification version 4.0:

STATE_BINARY (0x5E) - Used for sensors that represent binary states where:
1 indicates enabled/on state
0 indicates disabled/off state

BYTES_SEC (0x5F) - Used for sensors that measure data transfer rates in bytes per second

These additions ensure compatibility with SCMIv4.0 and allow proper handling of binary state sensors and bandwidth measurement sensors in the Linux SCMI driver.

The patch follows the existing pattern for sensor unit type definitions and maintains backward compatibility with previous SCMI versions.

Thank you for your consideration.

Best regards,
Artem Shimko

 include/linux/scmi_protocol.h | 2 ++
 1 file changed, 2 insertions(+)
include/linux/scmi_protocol.h +2 -0
index aafaac1496b0..629acb7831eb 100644
@@ -488,6 +488,8 @@ enum scmi_sensor_class {
 	CUBIC_METERS_SEC = 0x5B,
 	MM_MERCURY = 0x5C,
 	RADIANS_SEC_SQUARED = 0x5D,
+	STATE_BINARY = 0x5E,
+	BYTES_SEC = 0x5F,
 	OEM_UNIT = 0xFF
 };
 
Signature · 1 line
2.43.0
#1 lore raw
Quoted 7 lines · Artem Shimko

Add support for two new sensor unit types introduced in Arm SCMI
- STATE_BINARY (0x5E): Binary state (1: enabled/on, 0: disabled/off)
- BYTES_SEC (0x5F): Bytes per second

These unit types are used for sensors that report binary state information and data transfer rate measurements respectively.

Quoted 8 lines

---
Hello,

This patch adds definitions for two new sensor unit types that were introduced in the Arm System Control and Management Interface (SCMI) Specification version 4.0:

It is still alpha, we don't add anything into the kernel unless it is of beta quality. Do you have a use or you are just adding to match the spec ?

Signature · 2 lines
Regards,
Sudeep
#2 lore raw
Quoted 3 lines · Sudeep Holla

It is still alpha, we don't add anything into the kernel unless it is of beta quality. Do you have a use or you are just adding to match the spec ?

Hi Sudeep,

I'm adding it to meet the specifications.

Trying to be useful

Thank you.

Best regards,
Artem

#3 lore raw
In reply to Sudeep Holla
Quoted 2 lines · Sudeep Holla

It is still alpha, we don't add anything into the kernel unless it is of beta quality.

Hi Sudeep,

Just a polite ping.

Is it still too early for 4.0 bet0?

Thank you!

Regards,
Artem

maintainer
#4 lore raw
Quoted 10 lines · Artem Shimko
Quoted 2 lines · Sudeep Holla

It is still alpha, we don't add anything into the kernel unless it is of beta quality.

Hi Sudeep,

Just a polite ping.

Is it still too early for 4.0 bet0?

v4.0 beta is out but I would take this with telemetry support that may start using this. Let me know if there are any users before that.

Signature · 2 lines
Regards,
Sudeep
#5 lore raw
Quoted 1 line · Sudeep Holla

Let me know if there are any users before that.

Hi Sudeep,

There are no users before that.

Thank you!

Regards,
Artem