Merge tag 'for-linus-5.16-1' of https://github.com/cminyard/linux-ipmi

- compatible : should be one of

	"aspeed,ast2400-ibt-bmc"

	"aspeed,ast2500-ibt-bmc"

	"aspeed,ast2600-ibt-bmc"

- reg: physical address and size of the registers

Optional properties:

# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)

%YAML 1.2

---

$id: http://devicetree.org/schemas/ipmi/ipmi-ipmb.yaml#

$schema: http://devicetree.org/meta-schemas/core.yaml#

title: IPMI IPMB device bindings

description: IPMI IPMB device bindings

maintainers:

  - Corey Minyard <cminyard@mvista.com>

properties:

  compatible:

    enum:

      - ipmi-ipmb

  device_type:

    items:

      - const: "ipmi"

  reg:

    maxItems: 1

  bmcaddr:

    $ref: /schemas/types.yaml#/definitions/uint8

    description: The address of the BMC on the IPMB bus.  Defaults to 0x20.

  retry-time:

    $ref: /schemas/types.yaml#/definitions/uint32

    description: |

      Time between retries of sends, in milliseconds.  Defaults to 250.

  max-retries:

    $ref: /schemas/types.yaml#/definitions/uint32

    description: Number of retries before a failure is declared.  Defaults to 1.

required:

  - compatible

  - reg

additionalProperties: false

examples:

  - |

    i2c {

            #address-cells = <1>;

            #size-cells = <0>;

            ipmi-ipmb@40 {

                    compatible = "ipmi-ipmb";

                    device_type = "ipmi";

                    reg = <0x40>;

                    bmcaddr = /bits/ 8 <0x20>;

                    retry-time = <250>;

                    max-retries = <1>;

            };

    };

straight to the BMC on the current card.  The channel must be

IPMI_BMC_CHANNEL.

Messages that are destined to go out on the IPMB bus use the

IPMI_IPMB_ADDR_TYPE address type.  The format is::

Messages that are destined to go out on the IPMB bus going through the

BMC use the IPMI_IPMB_ADDR_TYPE address type.  The format is::

  struct ipmi_ipmb_addr

  {

than one channel, it corresponds to the channel as defined in the IPMI

spec.

There is also an IPMB direct address for a situation where the sender

is directly on an IPMB bus and doesn't have to go through the BMC.

You can send messages to a specific management controller (MC) on the

IPMB using the IPMI_IPMB_DIRECT_ADDR_TYPE with the following format::

  struct ipmi_ipmb_direct_addr

  {

	int           addr_type;

	short         channel;

	unsigned char slave_addr;

	unsigned char rq_lun;

	unsigned char rs_lun;

  };

The channel is always zero.  You can also receive commands from other

MCs that you have registered to handle and respond to them, so you can

use this to implement a management controller on a bus..

Messages

--------

may register for different commands, or the same command if the

channel bitmasks do not overlap.

To respond to a received command, set the response bit in the returned

netfn, use the address from the received message, and use the same

msgid that you got in the receive message.

From userland, equivalent IOCTLs are provided to do these functions.

The driver supports a hot add and remove of interfaces through the I2C

sysfs interface.

The IPMI IPMB Driver

--------------------

This driver is for supporting a system that sits on an IPMB bus; it

allows the interface to look like a normal IPMI interface.  Sending

system interface addressed messages to it will cause the message to go

to the registered BMC on the system (default at IPMI address 0x20).

It also allows you to directly address other MCs on the bus using the

ipmb direct addressing.  You can receive commands from other MCs on

the bus and they will be handled through the normal received command

mechanism described above.

Parameters are::

  ipmi_ipmb.bmcaddr=<address to use for system interface addresses messages>

	ipmi_ipmb.retry_time_ms=<Time between retries on IPMB>

	ipmi_ipmb.max_retries=<Number of times to retry a message>

Loading the module will not result in the driver automatcially

starting unless there is device tree information setting it up.  If

you want to instantiate one of these by hand, do::

  echo ipmi-ipmb <addr> > /sys/class/i2c-dev/i2c-<n>/device/new_device

Note that the address you give here is the I2C address, not the IPMI

address.  So if you want your MC address to be 0x60, you put 0x30

here.  See the I2C driver info for more details.

Command bridging to other IPMB busses through this interface does not

work.  The receive message queue is not implemented, by design.  There

is only one receive message queue on a BMC, and that is meant for the

host drivers, not something on the IPMB bus.

A BMC may have multiple IPMB busses, which bus your device sits on

depends on how the system is wired.  You can fetch the channels with

"ipmitool channel info <n>" where <n> is the channel, with the

channels being 0-7 and try the IPMB channels.

Other Pieces

------------

config IPMI_SSIF

	tristate 'IPMI SMBus handler (SSIF)'

	select I2C

	depends on I2C

	help

	  Provides a driver for a SMBus interface to a BMC, meaning that you

	  have a driver that must be accessed over an I2C bus instead of a

	  standard interface.  This module requires I2C support.

config IPMI_IPMB

	tristate 'IPMI IPMB interface'

	depends on I2C && I2C_SLAVE

	help

	  Provides a driver for a system running right on the IPMB bus.

	  It supports normal system interface messages to a BMC on the IPMB

	  bus, and it also supports direct messaging on the bus using

	  IPMB direct messages.  This module requires I2C support.

config IPMI_POWERNV

	depends on PPC_POWERNV

	tristate 'POWERNV (OPAL firmware) IPMI interface'

obj-$(CONFIG_IPMI_DMI_DECODE) += ipmi_dmi.o

obj-$(CONFIG_IPMI_PLAT_DATA) += ipmi_plat_data.o

obj-$(CONFIG_IPMI_SSIF) += ipmi_ssif.o

obj-$(CONFIG_IPMI_IPMB) += ipmi_ipmb.o

obj-$(CONFIG_IPMI_POWERNV) += ipmi_powernv.o

obj-$(CONFIG_IPMI_WATCHDOG) += ipmi_watchdog.o

obj-$(CONFIG_IPMI_POWEROFF) += ipmi_poweroff.o