Based on kernel version 6.11
. Page generated on 2024-09-24 08:21 EST
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 | .. SPDX-License-Identifier: GPL-2.0-or-later Kernel driver sbrmi =================== Supported hardware: * Sideband Remote Management Interface (SB-RMI) compliant AMD SoC device connected to the BMC via the APML. Prefix: 'sbrmi' Addresses scanned: This driver doesn't support address scanning. To instantiate this driver on an AMD CPU with SB-RMI support, the i2c bus number would be the bus connected from the board management controller (BMC) to the CPU. The SMBus address is really 7 bits. Some vendors and the SMBus specification show the address as 8 bits, left justified with the R/W bit as a write (0) making bit 0. Some vendors use only the 7 bits to describe the address. As mentioned in AMD's APML specification, The SB-RMI address is normally 78h(0111 100W) or 3Ch(011 1100) for socket 0 and 70h(0111 000W) or 38h(011 1000) for socket 1, but it could vary based on hardware address select pins. Datasheet: The SB-RMI interface and protocol along with the Advanced Platform Management Link (APML) Specification is available as part of the open source SoC register reference at: https://www.amd.com/en/support/tech-docs?keyword=55898 Author: Akshay Gupta <akshay.gupta@amd.com> Description ----------- The APML provides a way to communicate with the SB Remote Management interface (SB-RMI) module from the external SMBus master that can be used to report socket power on AMD platforms using mailbox command and resembles a typical 8-pin remote power sensor's I2C interface to BMC. This driver implements current power with power cap and power cap max. sysfs-Interface --------------- Power sensors can be queried and set via the standard ``hwmon`` interface on ``sysfs``, under the directory ``/sys/class/hwmon/hwmonX`` for some value of ``X`` (search for the ``X`` such that ``/sys/class/hwmon/hwmonX/name`` has content ``sbrmi``) ================ ===== ======================================================== Name Perm Description ================ ===== ======================================================== power1_input RO Current Power consumed power1_cap RW Power limit can be set between 0 and power1_cap_max power1_cap_max RO Maximum powerlimit calculated and reported by the SMU FW ================ ===== ======================================================== The following example show how the 'Power' attribute from the i2c-addresses can be monitored using the userspace utilities like ``sensors`` binary:: # sensors sbrmi-i2c-1-38 Adapter: bcm2835 I2C adapter power1: 61.00 W (cap = 225.00 W) sbrmi-i2c-1-3c Adapter: bcm2835 I2C adapter power1: 28.39 W (cap = 224.77 W) # Also, Below shows how get and set the values from sysfs entries individually:: # cat /sys/class/hwmon/hwmon1/power1_cap_max 225000000 # echo 180000000 > /sys/class/hwmon/hwmon1/power1_cap # cat /sys/class/hwmon/hwmon1/power1_cap 180000000 |