ipmi:ipmb: Add initial support for IPMI over IPMB

This provides access to the management controllers on an IPMB bus to a
device sitting on the IPMB bus.  It also provides slave capability to
respond to received messages on the bus.

Signed-off-by: Corey Minyard <minyard@acm.org>
Tested-by: Andrew Manley <andrew.manley@sealingtech.com>
Reviewed-by: Andrew Manley <andrew.manley@sealingtech.com>

drivers/char/ipmi/Kconfig

@@ -75,6 +75,15 @@ config IPMI_SSIF
 	  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_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'

drivers/char/ipmi/Makefile

@@ -19,6 +19,7 @@ obj-$(CONFIG_IPMI_SI) += ipmi_si.o
 obj-$(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