Hi,

This series adds temperature monitoring for AMD Promontory 21 (PROM21)
xHCI PCI functions.

Patch 1 adds a small PROM21-specific xHCI PCI glue driver. USB host
operation is delegated to the common xhci-pci code, while the PROM21 glue
publishes an auxiliary device for optional sensor support.

Patch 2 adds an auxiliary-bus hwmon driver that binds to that auxiliary
device and exposes the PROM21 xHCI temperature value as temp1_input.

The hwmon driver reads the sensor through a vendor index/data register pair
in the xHCI PCI MMIO BAR. It does not wake the parent PCI device for hwmon
reads; if the parent is suspended, the read returns -ENODATA.

Changes in v6:
- Make USB_XHCI_PCI_PROM21 a hidden tristate that follows USB_XHCI_PCI,
  so the PROM21 PCI glue is built in with a built-in xhci-pci core and
  built as a module with a modular xhci-pci core.
- Use an IDA-allocated auxiliary device id instead of encoding the PCI
  domain/BDF into the auxiliary id.
- Use a 32-bit read for the PROM21 vendor data register and mask the low
  byte instead of using readb().

Jihong Min (2):
  usb: xhci-pci: add AMD Promontory 21 PCI glue
  hwmon: add AMD Promontory 21 xHCI temperature sensor support

 Documentation/hwmon/index.rst                 |   1 +
 Documentation/hwmon/prom21-xhci.rst           | 101 ++++++++
 drivers/hwmon/Kconfig                         |  10 +
 drivers/hwmon/Makefile                        |   1 +
 drivers/hwmon/prom21-xhci.c                   | 239 ++++++++++++++++++
 drivers/usb/host/Kconfig                      |   7 +
 drivers/usb/host/Makefile                     |   1 +
 drivers/usb/host/xhci-pci-prom21.c            | 136 ++++++++++
 drivers/usb/host/xhci-pci.c                   |  11 +
 drivers/usb/host/xhci-pci.h                   |   3 +
 include/linux/platform_data/usb-xhci-prom21.h |  22 ++
 11 files changed, 532 insertions(+)
 create mode 100644 Documentation/hwmon/prom21-xhci.rst
 create mode 100644 drivers/hwmon/prom21-xhci.c
 create mode 100644 drivers/usb/host/xhci-pci-prom21.c
 create mode 100644 include/linux/platform_data/usb-xhci-prom21.h

-- 
2.53.0