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| author | Ivan Vecera <ivecera@redhat.com> | 2026-04-02 20:40:55 +0200 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-04-03 16:48:01 -0700 |
| commit | 3fdea79c09d169b6ea172b8d36232c3773f39973 (patch) | |
| tree | 801bc944c21f97723cc17a0ee23c48f88d8410d6 /Documentation/driver-api | |
| parent | 353d8e7989b6babe8fe4ae06272230c7941c3f73 (diff) | |
| download | linux-next-3fdea79c09d169b6ea172b8d36232c3773f39973.tar.gz linux-next-3fdea79c09d169b6ea172b8d36232c3773f39973.zip | |
dpll: add frequency monitoring to netlink spec
Add DPLL_A_FREQUENCY_MONITOR device attribute to allow control over
the frequency monitor feature. The attribute uses the existing
dpll_feature_state enum (enable/disable) and is present in both
device-get reply and device-set request.
Add DPLL_A_PIN_MEASURED_FREQUENCY pin attribute to expose the measured
input frequency in millihertz (mHz). The attribute is present in the
pin-get reply. Add DPLL_PIN_MEASURED_FREQUENCY_DIVIDER constant to
allow userspace to extract integer and fractional parts.
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
Link: https://patch.msgid.link/20260402184057.1890514-2-ivecera@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'Documentation/driver-api')
| -rw-r--r-- | Documentation/driver-api/dpll.rst | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/Documentation/driver-api/dpll.rst b/Documentation/driver-api/dpll.rst index 83118c728ed9..93c191b2d089 100644 --- a/Documentation/driver-api/dpll.rst +++ b/Documentation/driver-api/dpll.rst @@ -250,6 +250,24 @@ in the ``DPLL_A_PIN_PHASE_OFFSET`` attribute. ``DPLL_A_PHASE_OFFSET_MONITOR`` attr state of a feature =============================== ======================== +Frequency monitor +================= + +Some DPLL devices may offer the capability to measure the actual +frequency of all available input pins. The attribute and current feature state +shall be included in the response message of the ``DPLL_CMD_DEVICE_GET`` +command for supported DPLL devices. In such cases, users can also control +the feature using the ``DPLL_CMD_DEVICE_SET`` command by setting the +``enum dpll_feature_state`` values for the attribute. +Once enabled the measured input frequency for each input pin shall be +returned in the ``DPLL_A_PIN_MEASURED_FREQUENCY`` attribute. The value +is in millihertz (mHz), using ``DPLL_PIN_MEASURED_FREQUENCY_DIVIDER`` +as the divider. + + =============================== ======================== + ``DPLL_A_FREQUENCY_MONITOR`` attr state of a feature + =============================== ======================== + Embedded SYNC ============= @@ -411,6 +429,8 @@ according to attribute purpose. ``DPLL_A_PIN_STATE`` attr state of pin on the parent pin ``DPLL_A_PIN_CAPABILITIES`` attr bitmask of pin capabilities + ``DPLL_A_PIN_MEASURED_FREQUENCY`` attr measured frequency of + an input pin in mHz ==================================== ================================== ==================================== ================================= |