ipmi: Add SMBus interface driver (SSIF) (25930707) · Commits · e / devices / android_kernel_oneplus_sm7250

Documentation/IPMI.txt

+71 −3

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		@@ -42,7 +42,13 @@ The driver interface depends on your hardware. If your system
		properly provides the SMBIOS info for IPMI, the driver will detect it
		and just work. If you have a board with a standard interface (These
		will generally be either "KCS", "SMIC", or "BT", consult your hardware
		manual), choose the 'IPMI SI handler' option.
		manual), choose the 'IPMI SI handler' option. A driver also exists
		for direct I2C access to the IPMI management controller. Some boards
		support this, but it is unknown if it will work on every board. For
		this, choose 'IPMI SMBus handler', but be ready to try to do some
		figuring to see if it will work on your system if the SMBIOS/APCI
		information is wrong or not present. It is fairly safe to have both
		these enabled and let the drivers auto-detect what is present.

		You should generally enable ACPI on your system, as systems with IPMI
		can have ACPI tables describing them.
		@@ -52,7 +58,8 @@ their job correctly, the IPMI controller should be automatically
		detected (via ACPI or SMBIOS tables) and should just work. Sadly,
		many boards do not have this information. The driver attempts
		standard defaults, but they may not work. If you fall into this
		situation, you need to read the section below named 'The SI Driver'.
		situation, you need to read the section below named 'The SI Driver' or
		"The SMBus Driver" on how to hand-configure your system.

		IPMI defines a standard watchdog timer. You can enable this with the
		'IPMI Watchdog Timer' config option. If you compile the driver into
		@@ -97,7 +104,12 @@ driver, each open file for this device ties in to the message handler
		as an IPMI user.

		ipmi_si - A driver for various system interfaces. This supports KCS,
		SMIC, and BT interfaces.
		SMIC, and BT interfaces. Unless you have an SMBus interface or your
		own custom interface, you probably need to use this.

		ipmi_ssif - A driver for accessing BMCs on the SMBus. It uses the
		I2C kernel driver's SMBus interfaces to send and receive IPMI messages
		over the SMBus.

		ipmi_watchdog - IPMI requires systems to have a very capable watchdog
		timer. This driver implements the standard Linux watchdog timer
		@@ -476,6 +488,62 @@ for specifying an interface. Note that when removing an interface,
		only the first three parameters (si type, address type, and address)
		are used for the comparison. Any options are ignored for removing.

		The SMBus Driver (SSIF)
		-----------------------

		The SMBus driver allows up to 4 SMBus devices to be configured in the
		system. By default, the driver will only register with something it
		finds in DMI or ACPI tables. You can change this
		at module load time (for a module) with:

		modprobe ipmi_ssif.o
		addr=<i2caddr1>[,<i2caddr2>[,...]]
		adapter=<adapter1>[,<adapter2>[...]]
		dbg=<flags1>,<flags2>...
		slave_addrs=<addr1>,<addr2>,...
		[dbg_probe=1]

		The addresses are normal I2C addresses. The adapter is the string
		name of the adapter, as shown in /sys/class/i2c-adapter/i2c-<n>/name.
		It is NOT i2c-<n> itself.

		The debug flags are bit flags for each BMC found, they are:
		IPMI messages: 1, driver state: 2, timing: 4, I2C probe: 8

		Setting dbg_probe to 1 will enable debugging of the probing and
		detection process for BMCs on the SMBusses.

		The slave_addrs specifies the IPMI address of the local BMC. This is
		usually 0x20 and the driver defaults to that, but in case it's not, it
		can be specified when the driver starts up.

		Discovering the IPMI compliant BMC on the SMBus can cause devices on
		the I2C bus to fail. The SMBus driver writes a "Get Device ID" IPMI
		message as a block write to the I2C bus and waits for a response.
		This action can be detrimental to some I2C devices. It is highly
		recommended that the known I2C address be given to the SMBus driver in
		the smb_addr parameter unless you have DMI or ACPI data to tell the
		driver what to use.

		When compiled into the kernel, the addresses can be specified on the
		kernel command line as:

		ipmb_ssif.addr=<i2caddr1>[,<i2caddr2>[...]]
		ipmi_ssif.adapter=<adapter1>[,<adapter2>[...]]
		ipmi_ssif.dbg=<flags1>[,<flags2>[...]]
		ipmi_ssif.dbg_probe=1
		ipmi_ssif.slave_addrs=<addr1>[,<addr2>[...]]

		These are the same options as on the module command line.

		The I2C driver does not support non-blocking access or polling, so
		this driver cannod to IPMI panic events, extend the watchdog at panic
		time, or other panic-related IPMI functions without special kernel
		patches and driver modifications. You can get those at the openipmi
		web page.

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

		Other Pieces
		------------

drivers/char/ipmi/Kconfig

+8 −0

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		@@ -62,6 +62,14 @@ config IPMI_SI_PROBE_DEFAULTS
		only be available on older systems if the "ipmi_si_intf.trydefaults=1"
		boot argument is passed.

		config IPMI_SSIF
		tristate 'IPMI SMBus handler (SSIF)'
		select 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_WATCHDOG
		tristate 'IPMI Watchdog Timer'
		help

drivers/char/ipmi/Makefile

+1 −0

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		@@ -7,5 +7,6 @@ ipmi_si-y := ipmi_si_intf.o ipmi_kcs_sm.o ipmi_smic_sm.o ipmi_bt_sm.o
		obj-$(CONFIG_IPMI_HANDLER) += ipmi_msghandler.o
		obj-$(CONFIG_IPMI_DEVICE_INTERFACE) += ipmi_devintf.o
		obj-$(CONFIG_IPMI_SI) += ipmi_si.o
		obj-$(CONFIG_IPMI_SSIF) += ipmi_ssif.o
		obj-$(CONFIG_IPMI_WATCHDOG) += ipmi_watchdog.o
		obj-$(CONFIG_IPMI_POWEROFF) += ipmi_poweroff.o