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Documentation/ABI: add testing entry for AMD PMF character device interface

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Add a Documentation/ABI/testing entry describing the AMD PMF util layer
character device (/dev/amdpmf_interface) and the initial ioctl used to
query feature support and metrics data information. This interface is
available when CONFIG_AMD_PMF_UTIL_SUPPORT=y.

Also update the MAINTAINERS record with the new UAPI header.

Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
Link: https://patch.msgid.link/20260609081044.2416731-8-Shyam-sundar.S-k@amd.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
This commit is contained in:
Shyam Sundar S K
2026-06-09 13:40:44 +05:30
committed by Ilpo Järvinen
parent a5edf10e3a
commit f6ee11d77d
2 changed files with 74 additions and 0 deletions
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73
Documentation/ABI/testing/amdpmf-interface Normal file
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What: /dev/amdpmf_interface
Date: June 2026
KernelVersion: 7.2
Contact: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
Description:
The AMD Platform Management Framework (PMF) util layer exposes a
minimal user-space interface via a character device for feature
discovery and metrics monitoring.
When CONFIG_AMD_PMF_UTIL_SUPPORT is enabled, the driver creates
a character device:
======================
/dev/amdpmf_interface
======================
The interface supports a single ioctl:
============================ =======================================
IOCTL Usage
IOCTL_AMD_PMF_POPULATE_DATA User passes a struct amd_pmf_info with
the size field set to sizeof(struct
amd_pmf_info). The driver returns all
available metrics and feature status
in the structure.
============================ =======================================
struct amd_pmf_info layout:
======================= ========== ================================
Field Type Description
size __u64 Structure size for versioning
features_supported __u32 Bitmask of supported features
platform_type __u32 Platform form factor orientation
power_source __u32 AC/DC power source
laptop_placement __u32 Device placement state
lid_state __u32 Lid open/closed status
user_presence __u32 User presence detection
slider_position __u32 Current power slider position
skin_temp __s32 Skin temperature (centidegrees)
gfx_busy __u32 Graphics workload percentage
ambient_light __s32 Ambient light sensor reading
avg_c0_residency __u32 Average C0 state residency
max_c0_residency __u32 Maximum C0 state residency
socket_power __u32 Socket power consumption
bios_input[10] __u32 Custom BIOS input parameters
bios_output[10] __u32 Custom BIOS output parameters
======================= ========== ================================
Feature Support Flags (features_supported bitmask):
===================================== ==== =============================
Flag Bit Description
AMD_PMF_FEAT_AUTO_MODE 0 Auto Mode feature support
AMD_PMF_FEAT_STATIC_POWER_SLIDER 1 Static Power Slider support
AMD_PMF_FEAT_POLICY_BUILDER 2 Policy Builder (Smart PC)
AMD_PMF_FEAT_DYNAMIC_POWER_SLIDER_AC 3 Dynamic slider on AC
AMD_PMF_FEAT_DYNAMIC_POWER_SLIDER_DC 4 Dynamic slider on DC
===================================== ==== =============================
Return codes:
============= ============================================================
Return code Description
0 Success
EINVAL Invalid size or parameter
EFAULT copy_to_user/copy_from_user failures
ENODEV PMF device not available
ENOTTY Unknown ioctl command
============= ============================================================
User-space tools integrating with AMD PMF to discover capabilities and
monitor real-time metrics for thermal and power management validation.

1
MAINTAINERS
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@@ -1263,6 +1263,7 @@ L: platform-driver-x86@vger.kernel.org
S: Supported
F: Documentation/ABI/testing/sysfs-amd-pmf
F: drivers/platform/x86/amd/pmf/
F: include/uapi/linux/amd-pmf.h
AMD POWERPLAY AND SWSMU
M: Kenneth Feng <kenneth.feng@amd.com>