Staging: IIO: DAC: AD5624R: Update to IIO ABI

This driver did not conform with the IIO ABI for such devices.
Also the sysfs files that this driver adds were not complete and
partially un-documented.

Update and document ABI
Change License notice, stick to GPL-v2.
Fix indention style
Add option to specify external reference voltage via the regulator framework.
Add mandatory name attribute
Add mandatory out_scale attribute

Changes since V1:
Refine outY_powerdown_mode description
Remove bonus white line
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/iio/Documentation/sysfs-bus-iio

@@ -271,6 +271,38 @@ Description:
 		where a single output sets the value for multiple channels
 		simultaneously.
 
+What:		/sys/bus/iio/devices/deviceX/outY_powerdown_mode
+What:		/sys/bus/iio/devices/deviceX/out_powerdown_mode
+KernelVersion:	2.6.38
+Contact:	linux-iio@vger.kernel.org
+Description:
+		Specifies the output powerdown mode.
+		DAC output stage is disconnected from the amplifier and
+		1kohm_to_gnd: connected to ground via an 1kOhm resistor
+		100kohm_to_gnd: connected to ground via an 100kOhm resistor
+		three_state: left floating
+		For a list of available output power down options read
+		outX_powerdown_mode_available. If Y is not present the
+		mode is shared across all outputs.
+
+What:		/sys/bus/iio/devices/deviceX/outY_powerdown_mode_available
+What:		/sys/bus/iio/devices/deviceX/out_powerdown_mode_available
+KernelVersion:	2.6.38
+Contact:	linux-iio@vger.kernel.org
+Description:
+		Lists all available output power down modes.
+		If Y is not present the mode is shared across all outputs.
+
+What:		/sys/bus/iio/devices/deviceX/outY_powerdown
+What:		/sys/bus/iio/devices/deviceX/out_powerdown
+KernelVersion:	2.6.38
+Contact:	linux-iio@vger.kernel.org
+Description:
+		Writing 1 causes output Y to enter the power down mode specified
+		by the corresponding outY_powerdown_mode. Clearing returns to
+		normal operation. Y may be suppressed if all outputs are
+		controlled together.
+
 What:		/sys/bus/iio/devices/deviceX/deviceX:eventY
 KernelVersion:	2.6.35
 Contact:	linux-iio@vger.kernel.org

drivers/staging/iio/dac/ad5624r.h

+/*
+ * AD5624R SPI DAC driver
+ *
+ * Copyright 2010-2011 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2.
+ */
 #ifndef SPI_AD5624R_H_
 #define SPI_AD5624R_H_
 
-#define AD5624R_DAC_CHANNELS	4
+#define AD5624R_DAC_CHANNELS			4
 
-#define AD5624R_ADDR_DAC0	0x0
-#define AD5624R_ADDR_DAC1	0x1
-#define AD5624R_ADDR_DAC2	0x2
-#define AD5624R_ADDR_DAC3	0x3
-#define AD5624R_ADDR_ALL_DAC	0x7
+#define AD5624R_ADDR_DAC0			0x0
+#define AD5624R_ADDR_DAC1			0x1
+#define AD5624R_ADDR_DAC2			0x2
+#define AD5624R_ADDR_DAC3			0x3
+#define AD5624R_ADDR_ALL_DAC			0x7
 
-#define AD5624R_CMD_WRITE_INPUT_N             0x0
-#define AD5624R_CMD_UPDATE_DAC_N              0x1
-#define AD5624R_CMD_WRITE_INPUT_N_UPDATE_ALL  0x2
-#define AD5624R_CMD_WRITE_INPUT_N_UPDATE_N    0x3
-#define AD5624R_CMD_POWERDOWN_DAC             0x4
-#define AD5624R_CMD_RESET                     0x5
-#define AD5624R_CMD_LDAC_SETUP                0x6
-#define AD5624R_CMD_INTERNAL_REFER_SETUP      0x7
+#define AD5624R_CMD_WRITE_INPUT_N		0x0
+#define AD5624R_CMD_UPDATE_DAC_N		0x1
+#define AD5624R_CMD_WRITE_INPUT_N_UPDATE_ALL	0x2
+#define AD5624R_CMD_WRITE_INPUT_N_UPDATE_N	0x3
+#define AD5624R_CMD_POWERDOWN_DAC		0x4
+#define AD5624R_CMD_RESET			0x5
+#define AD5624R_CMD_LDAC_SETUP			0x6
+#define AD5624R_CMD_INTERNAL_REFER_SETUP	0x7
 
-#endif
+#define AD5624R_LDAC_PWRDN_NONE			0x0
+#define AD5624R_LDAC_PWRDN_1K			0x1
+#define AD5624R_LDAC_PWRDN_100K			0x2
+#define AD5624R_LDAC_PWRDN_3STATE		0x3
+
+/**
+ * struct ad5624r_chip_info - chip specific information
+ * @bits:		accuracy of the DAC in bits
+ * @int_vref_mv:	AD5620/40/60: the internal reference voltage
+ */
+
+struct ad5624r_chip_info {
+	u8				bits;
+	u16				int_vref_mv;
+};
+
+/**
+ * struct ad5446_state - driver instance specific data
+ * @indio_dev:		the industrial I/O device
+ * @us:			spi_device
+ * @chip_info:		chip model specific constants, available modes etc
+ * @reg:		supply regulator
+ * @vref_mv:		actual reference voltage used
+ * @pwr_down_mask	power down mask
+ * @pwr_down_mode	current power down mode
+ */
+
+struct ad5624r_state {
+	struct iio_dev			*indio_dev;
+	struct spi_device		*us;
+	const struct ad5624r_chip_info	*chip_info;
+	struct regulator		*reg;
+	unsigned short			vref_mv;
+	unsigned			pwr_down_mask;
+	unsigned			pwr_down_mode;
+};
+
+/**
+ * ad5624r_supported_device_ids:
+ * The AD5624/44/64 parts are available in different
+ * fixed internal reference voltage options.
+ */
+
+enum ad5624r_supported_device_ids {
+	ID_AD5624R3,
+	ID_AD5644R3,
+	ID_AD5664R3,
+	ID_AD5624R5,
+	ID_AD5644R5,
+	ID_AD5664R5,
+};
+
+#endif /* SPI_AD5624R_H_ */