[PATCH 0/8] hw/i2c: PMBus updates and adm1266 fixes

Titus Rwantare <[email protected]> Wed, 29 Jul 2026 23:13:15 +0000
Newsgroups org.nongnu.qemu-arm,org.nongnu.qemu-devel
Message-ID <[email protected]>
This series adds various fixes to PMBus and SMBus support.

Since v1:
- Added the adm1266 patches that fix accessing the MFR_* registers
- Fixed vout_mode handling to avoid values overflowing/being truncated
  by the adm1266 implementation.
- Added fix for PMBus vout_mode bug where guests accesses would break
  due to the bitfields being packed in the wrong order.
- Updated VMState to work around breaking migration while still storing
  the increased SMBus data.

The maximum SMBus data length is increased to 257 bytes, (payload is 255 bytes) to support SMBus 3.0 block transfers. SMBus devices don’t have to report their specification version, and this change allows us to enable newer PMBus devices that are based on top of SMBus 3.0.

Additionally, this series:
  - Adds the `DIV_ROUND_CLOSEST` helper macro, lifted from the linux implementation, to match the rounding in linux drivers.
  - Adds PMBus helper functions to convert sensor values in milliunits to/from linear mode format (Linear16).

Jason Fan (1):
  hw/i2c: fix VOUT_MODE representation on little-endian machines

Titus Rwantare (7):
  osdep: add DIV_ROUND_CLOSEST
  hw/i2c: pmbus: add milliunits linear mode functions
  hw/i2c: smbus: increase MAX_DATA_LEN
  hw/sensor: update adm1266 block transfers
  hw/sensor: switch adm1266 to millivolts vout
  hw/sensor: adm1266: expose vout_mode over QMP
  hw/sensor: adm1266: set default VOUT mode

 hw/i2c/pmbus_device.c         |  39 +++++++
 hw/i2c/smbus_slave.c          |  27 ++++-
 hw/sensor/adm1266.c           | 176 +++++++++++++++++++++++-----
 include/hw/i2c/pmbus_device.h |  25 ++++
 include/hw/i2c/smbus_slave.h  |   2 +-
 include/qemu/osdep.h          |  13 +++
 tests/qtest/adm1266-test.c    | 210 ++++++++++++++++++++++++++++++++--
 7 files changed, 452 insertions(+), 40 deletions(-)

-- 
2.55.0.508.g3f0d502094-goog