spmi: Add MSM PMIC Arbiter SPMI controller

Qualcomm's PMIC Arbiter SPMI controller functions as a bus master and
is used to communication with one or more PMIC (slave) devices on the
SPMI bus.  The PMIC Arbiter is actually a hardware wrapper around the
SPMI controller that provides concurrent and autonomous PMIC access
to various entities that need to communicate with the PMIC.

The SPMI controller hardware handles all of the SPMI bus activity (bus
arbitration, sequence start condition, transmission of frames, etc).
This software driver uses the PMIC Arbiter register interface to
initiate command sequences on the SPMI bus.  The status register is
read to determine when the command sequence has completed and whether
or not it completed successfully.

Signed-off-by: Kenneth Heitke <kheitke@codeaurora.org>
Signed-off-by: Josh Cartwright <joshc@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/spmi/Kconfig

@@ -7,3 +7,20 @@ menuconfig SPMI
 	  SPMI (System Power Management Interface) is a two-wire
 	  serial interface between baseband and application processors
 	  and Power Management Integrated Circuits (PMIC).
+
+if SPMI
+
+config SPMI_MSM_PMIC_ARB
+	tristate "Qualcomm MSM SPMI Controller (PMIC Arbiter)"
+	depends on ARM
+	depends on ARCH_MSM || COMPILE_TEST
+	default ARCH_MSM
+	help
+	  If you say yes to this option, support will be included for the
+	  built-in SPMI PMIC Arbiter interface on Qualcomm MSM family
+	  processors.
+
+	  This is required for communicating with Qualcomm PMICs and
+	  other devices that have the SPMI interface.
+
+endif

drivers/spmi/Makefile

@@ -2,3 +2,5 @@
 # Makefile for kernel SPMI framework.
 #
 obj-$(CONFIG_SPMI)	+= spmi.o
+
+obj-$(CONFIG_SPMI_MSM_PMIC_ARB)	+= spmi-pmic-arb.o