AMD's Advanced Platform Management Link (APML) interface provides system
management functionality accessed by the baseboard management controller (BMC).
sbrmi driver under hwmon subsystem, which is probed as an i2c driver and
reports power using APML specified protocol.
However, APML interface defines few other protocols to support
full system management functionality out-of-band.
Out-of-band management is term used for BMC talking to system management unit
(IP in the processor). AMD's documentation called this link as side band interface.
This patchset is an attempt to add all APML core functionality in one place
and provide hwmon and user space interface
1. [Patch 1] Move the i2c client probe, hwmon sensors and sbrmi core functionality
from drivers/hwmon to drivers/misc/
2. [Patch 2] Convert i2c to regmap which provides multiple benefits
over direct smbus APIs.
a. i2c/i3c support and
b. 1 byte/2 byte RMI register size addressing
3. [Patch 3] Optimize wait condition with regmap API regmap_read_poll_timeout as per
suggestion from Arnd
4. [Patch 4, 5] Register a misc device which provides
a. An ioctl interface through node /dev/sbrmiX
b. Register sets is common across APML protocols. IOCTL is providing
synchronization among protocols as transactions may create
race condition.
5. [Subsequent patches 6, 7 and 8] add support for AMD custom protocols
a. CPUID
b. MCAMSR
c. Register xfer
6. [Patch 9] AMD side band description document
Open-sourced and widely used https://github.com/amd/esmi_oob_library
will continue to provide user-space programmable API.
Akshay Gupta (9):
hwmon/misc: amd-sbi: Move core sbrmi from hwmon to misc
misc: amd-sbi: Use regmap subsystem
misc: amd-sbi: Optimize the wait condition for mailbox command
completion
misc: amd-sbi: Add support for AMD_SBI IOCTL
misc: amd-sbi: Add support for mailbox error codes
misc: amd-sbi: Add support for CPUID protocol
misc: amd-sbi: Add support for MCA register protocol
misc: amd-sbi: Add supoort for register xfer
misc: amd-sbi: Add document for AMD SB IOCTL description
Documentation/misc-devices/amd-sbi.rst | 84 ++++
Documentation/misc-devices/index.rst | 1 +
.../userspace-api/ioctl/ioctl-number.rst | 2 +
drivers/hwmon/Kconfig | 10 -
drivers/hwmon/sbrmi.c | 357 --------------
drivers/misc/Kconfig | 1 +
drivers/misc/Makefile | 1 +
drivers/misc/amd-sbi/Kconfig | 9 +
drivers/misc/amd-sbi/Makefile | 3 +
drivers/misc/amd-sbi/rmi-core.c | 452 ++++++++++++++++++
drivers/misc/amd-sbi/rmi-core.h | 67 +++
drivers/misc/amd-sbi/rmi-hwmon.c | 122 +++++
drivers/misc/amd-sbi/rmi-i2c.c | 135 ++++++
include/uapi/misc/amd-apml.h | 97 ++++
14 files changed, 974 insertions(+), 367 deletions(-)
create mode 100644 Documentation/misc-devices/amd-sbi.rst
delete mode 100644 drivers/hwmon/sbrmi.c
create mode 100644 drivers/misc/amd-sbi/Kconfig
create mode 100644 drivers/misc/amd-sbi/Makefile
create mode 100644 drivers/misc/amd-sbi/rmi-core.c
create mode 100644 drivers/misc/amd-sbi/rmi-core.h
create mode 100644 drivers/misc/amd-sbi/rmi-hwmon.c
create mode 100644 drivers/misc/amd-sbi/rmi-i2c.c
create mode 100644 include/uapi/misc/amd-apml.h
--
2.25.1
