[PATCH net-next v3 0/6] eth: fbnic: expand hwmon sensor support

[Zinc Lim <limzhineng2@gmail.com>]

fbnic currently exposes only the raw temperature and voltage readings
(temp1_input, in0_input) via hwmon. This series builds that out into a
complete sensor interface and hardens the read path.

The firmware capability response already carries per-board sensor
thresholds, and the firmware can asynchronously report when a sensor
crosses one of them. This series surfaces both to userspace and cleans
up the supporting plumbing:

 - Move the sensor read logic out of fbnic_mac, closer to its only
   caller in the hwmon code, and drop the now-unused get_sensor op.
 - Expose all hwmon attributes unconditionally as read-only (0444).
 - Cache the temperature and voltage readings for the current jiffy so
   a burst of attribute reads issues a single firmware round-trip.
 - Parse and expose the temperature (min/max/crit) and voltage
   (min/max) thresholds. Thresholds the firmware did not populate read
   back as -ENODATA.
 - Add the corresponding alarm attributes, computed by comparing a live
   reading against the stored thresholds.
 - Translate the firmware's sensor-threshold-exceeded message into an
   hwmon event so userspace is notified on the relevant attribute.

Changes from v2:
 - Addressed Jakub's patch 3 feedback on jiffy comparison when
   checking cache validity.

Changes from v1:
 - Addressed Jakub's patch 6 feedback on including a
   if (!IS_REACHABLE(CONFIG_HWMON)) return; guard.

Zinc Lim (6):
  eth: fbnic: move sensor read logic out of fbnic_mac
  eth: fbnic: expose all hwmon attributes unconditionally as read-only
  eth: fbnic: cache hwmon sensor readings
  eth: fbnic: report temperature and voltage thresholds via hwmon
  eth: fbnic: report temperature and voltage alarms via hwmon
  eth: fbnic: firmware notifies hwmon on sensor threshold events

 drivers/net/ethernet/meta/fbnic/fbnic.h       |   8 +
 drivers/net/ethernet/meta/fbnic/fbnic_fw.c    |  75 +++++
 drivers/net/ethernet/meta/fbnic/fbnic_fw.h    |  30 ++
 drivers/net/ethernet/meta/fbnic/fbnic_hwmon.c | 262 ++++++++++++++++--
 drivers/net/ethernet/meta/fbnic/fbnic_mac.c   |  55 ----
 drivers/net/ethernet/meta/fbnic/fbnic_mac.h   |   2 -
 6 files changed, 348 insertions(+), 84 deletions(-)

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2.53.0-Meta