ad525x_dpot: add support for SPI parts

Split the bus logic out into separate files so that we can handle I2C and
SPI busses independently.  The new SPI bus logic brings in support for a
lot more parts:

	AD5160, AD5161, AD5162, AD5165, AD5200, AD5201, AD5203,
	AD5204, AD5206, AD5207, AD5231, AD5232, AD5233, AD5235,
	AD5260, AD5262, AD5263, AD5290, AD5291, AD5292, AD5293,
	AD7376, AD8400, AD8402, AD8403, ADN2850

[randy.dunlap@oracle.com: fix ad525X_dpot build]
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 0d0d625..69e019e 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -14,11 +14,15 @@
 if MISC_DEVICES
 
 config AD525X_DPOT
-	tristate "Analog Devices AD525x Digital Potentiometers"
-	depends on I2C && SYSFS
+	tristate "Analog Devices Digital Potentiometers"
+	depends on (I2C || SPI) && SYSFS
 	help
 	  If you say yes here, you get support for the Analog Devices
-	  AD5258, AD5259, AD5251, AD5252, AD5253, AD5254 and AD5255
+	  AD5258, AD5259, AD5251, AD5252, AD5253, AD5254, AD5255
+	  AD5160, AD5161, AD5162, AD5165, AD5200, AD5201, AD5203,
+	  AD5204, AD5206, AD5207, AD5231, AD5232, AD5233, AD5235,
+	  AD5260, AD5262, AD5263, AD5290, AD5291, AD5292, AD5293,
+	  AD7376, AD8400, AD8402, AD8403, ADN2850
 	  digital potentiometer chips.
 
 	  See Documentation/misc-devices/ad525x_dpot.txt for the
@@ -27,6 +31,26 @@
 	  This driver can also be built as a module.  If so, the module
 	  will be called ad525x_dpot.
 
+config AD525X_DPOT_I2C
+	tristate "support I2C bus connection"
+	depends on AD525X_DPOT && I2C
+	help
+	  Say Y here if you have a digital potentiometers hooked to an I2C bus.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ad525x_dpot-i2c.
+
+config AD525X_DPOT_SPI
+	tristate "support SPI bus connection"
+	depends on AD525X_DPOT && SPI_MASTER
+	help
+	  Say Y here if you have a digital potentiometers hooked to an SPI bus.
+
+	  If unsure, say N (but it's safe to say "Y").
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ad525x_dpot-spi.
+
 config ATMEL_PWM
 	tristate "Atmel AT32/AT91 PWM support"
 	depends on AVR32 || ARCH_AT91SAM9263 || ARCH_AT91SAM9RL || ARCH_AT91CAP9