diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-07-14 01:07:02 +0300 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-07-14 01:07:02 +0300 |
commit | 92adeb616c9172dea9678f53ea6e5501fc4f4338 (patch) | |
tree | 7df0079de88ac11852908588b7c3551fd0c4f35f /Documentation | |
parent | 43c95d3694cc448fdf50bd53b7ff3a5bb4655883 (diff) | |
parent | ac499fba98c3c65078fd84fa0a62cd6f6d5837ed (diff) | |
download | linux-92adeb616c9172dea9678f53ea6e5501fc4f4338.tar.xz |
Merge tag 'for-linus-5.3' of git://github.com/cminyard/linux-ipmi
Pull IPMI updates from Corey Minyard:
"Some small fixes for various things, nothing huge, mostly found by
automated tools.
Plus add a driver that allows Linux to act as an IPMB slave device, so
it can be a satellite MC in an IPMI network"
* tag 'for-linus-5.3' of git://github.com/cminyard/linux-ipmi:
docs: ipmb: place it at driver-api and convert to ReST
fix platform_no_drv_owner.cocci warnings
ipmi: ipmb: don't allocate i2c_client on stack
ipmi: ipmb: Fix build error while CONFIG_I2C is set to m
Add support for IPMB driver
drivers: ipmi: Drop device reference
ipmi_ssif: fix unexpected driver unregister warning
ipmi_si: use bool type for initialized variable
ipmi_si: fix unexpected driver unregister warning
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/driver-api/index.rst | 1 | ||||
-rw-r--r-- | Documentation/driver-api/ipmb.rst | 105 |
2 files changed, 106 insertions, 0 deletions
diff --git a/Documentation/driver-api/index.rst b/Documentation/driver-api/index.rst index 0dbaa987aa11..6cd750a03ea0 100644 --- a/Documentation/driver-api/index.rst +++ b/Documentation/driver-api/index.rst @@ -34,6 +34,7 @@ available subsections can be seen below. pci/index spi i2c + ipmb i3c/index hsi edac diff --git a/Documentation/driver-api/ipmb.rst b/Documentation/driver-api/ipmb.rst new file mode 100644 index 000000000000..7e2265144157 --- /dev/null +++ b/Documentation/driver-api/ipmb.rst @@ -0,0 +1,105 @@ +============================== +IPMB Driver for a Satellite MC +============================== + +The Intelligent Platform Management Bus or IPMB, is an +I2C bus that provides a standardized interconnection between +different boards within a chassis. This interconnection is +between the baseboard management (BMC) and chassis electronics. +IPMB is also associated with the messaging protocol through the +IPMB bus. + +The devices using the IPMB are usually management +controllers that perform management functions such as servicing +the front panel interface, monitoring the baseboard, +hot-swapping disk drivers in the system chassis, etc... + +When an IPMB is implemented in the system, the BMC serves as +a controller to give system software access to the IPMB. The BMC +sends IPMI requests to a device (usually a Satellite Management +Controller or Satellite MC) via IPMB and the device +sends a response back to the BMC. + +For more information on IPMB and the format of an IPMB message, +refer to the IPMB and IPMI specifications. + +IPMB driver for Satellite MC +---------------------------- + +ipmb-dev-int - This is the driver needed on a Satellite MC to +receive IPMB messages from a BMC and send a response back. +This driver works with the I2C driver and a userspace +program such as OpenIPMI: + +1) It is an I2C slave backend driver. So, it defines a callback + function to set the Satellite MC as an I2C slave. + This callback function handles the received IPMI requests. + +2) It defines the read and write functions to enable a user + space program (such as OpenIPMI) to communicate with the kernel. + + +Load the IPMB driver +-------------------- + +The driver needs to be loaded at boot time or manually first. +First, make sure you have the following in your config file: +CONFIG_IPMB_DEVICE_INTERFACE=y + +1) If you want the driver to be loaded at boot time: + +a) Add this entry to your ACPI table, under the appropriate SMBus:: + + Device (SMB0) // Example SMBus host controller + { + Name (_HID, "<Vendor-Specific HID>") // Vendor-Specific HID + Name (_UID, 0) // Unique ID of particular host controller + : + : + Device (IPMB) + { + Name (_HID, "IPMB0001") // IPMB device interface + Name (_UID, 0) // Unique device identifier + } + } + +b) Example for device tree:: + + &i2c2 { + status = "okay"; + + ipmb@10 { + compatible = "ipmb-dev"; + reg = <0x10>; + }; + }; + +2) Manually from Linux:: + + modprobe ipmb-dev-int + + +Instantiate the device +---------------------- + +After loading the driver, you can instantiate the device as +described in 'Documentation/i2c/instantiating-devices'. +If you have multiple BMCs, each connected to your Satellite MC via +a different I2C bus, you can instantiate a device for each of +those BMCs. + +The name of the instantiated device contains the I2C bus number +associated with it as follows:: + + BMC1 ------ IPMB/I2C bus 1 ---------| /dev/ipmb-1 + Satellite MC + BMC1 ------ IPMB/I2C bus 2 ---------| /dev/ipmb-2 + +For instance, you can instantiate the ipmb-dev-int device from +user space at the 7 bit address 0x10 on bus 2:: + + # echo ipmb-dev 0x1010 > /sys/bus/i2c/devices/i2c-2/new_device + +This will create the device file /dev/ipmb-2, which can be accessed +by the user space program. The device needs to be instantiated +before running the user space program. |