staging: IIO: DAC: New driver for AD5791/AD5781 High Resolution Voltage Output DACs

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/dac/Kconfig

@@ -31,6 +31,16 @@ config AD5504
 	  To compile this driver as a module, choose M here: the
 	  module will be called ad5504.
 
+config AD5791
+	tristate "Analog Devices AD5781/AD5791 DAC SPI driver"
+	depends on SPI
+	help
+	  Say yes here to build support for Analog Devices AD5781, AD5791,
+	  High Resolution Voltage Output Digital to Analog Converter.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ad5791.
+
 config MAX517
 	tristate "Maxim MAX517/518/519 DAC driver"
 	depends on I2C && EXPERIMENTAL

drivers/staging/iio/dac/Makefile

@@ -5,4 +5,5 @@
 obj-$(CONFIG_AD5624R_SPI) += ad5624r_spi.o
 obj-$(CONFIG_AD5504) += ad5504.o
 obj-$(CONFIG_AD5446) += ad5446.o
+obj-$(CONFIG_AD5791) += ad5791.o
 obj-$(CONFIG_MAX517) += max517.o

drivers/staging/iio/dac/ad5791.h

+/*
+ * AD5791 SPI DAC driver
+ *
+ * Copyright 2011 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2.
+ */
+
+#ifndef SPI_AD5791_H_
+#define SPI_AD5791_H_
+
+#define AD5791_RES_MASK(x)		((1 << (x)) - 1)
+#define AD5791_DAC_MASK			AD5791_RES_MASK(20)
+#define AD5791_DAC_MSB			(1 << 19)
+
+#define AD5791_CMD_READ			(1 << 23)
+#define AD5791_CMD_WRITE		(0 << 23)
+#define AD5791_ADDR(addr)		((addr) << 20)
+
+/* Registers */
+#define AD5791_ADDR_NOOP		0
+#define AD5791_ADDR_DAC0		1
+#define AD5791_ADDR_CTRL		2
+#define AD5791_ADDR_CLRCODE		3
+#define AD5791_ADDR_SW_CTRL		4
+
+/* Control Register */
+#define AD5791_CTRL_RBUF		(1 << 1)
+#define AD5791_CTRL_OPGND		(1 << 2)
+#define AD5791_CTRL_DACTRI		(1 << 3)
+#define AD5791_CTRL_BIN2SC		(1 << 4)
+#define AD5791_CTRL_SDODIS		(1 << 5)
+#define AD5761_CTRL_LINCOMP(x)		((x) << 6)
+
+#define AD5791_LINCOMP_0_10		0
+#define AD5791_LINCOMP_10_12		1
+#define AD5791_LINCOMP_12_16		2
+#define AD5791_LINCOMP_16_19		3
+#define AD5791_LINCOMP_19_20		12
+
+/* Software Control Register */
+#define AD5791_SWCTRL_LDAC		(1 << 0)
+#define AD5791_SWCTRL_CLR		(1 << 1)
+#define AD5791_SWCTRL_RESET		(1 << 2)
+
+#define AD5791_DAC_PWRDN_6K		0
+#define AD5791_DAC_PWRDN_3STATE		1
+
+/*
+ * TODO: struct ad5791_platform_data needs to go into include/linux/iio
+ */
+
+/**
+ * struct ad5791_platform_data - platform specific information
+ * @vref_pos_mv:	Vdd Positive Analog Supply Volatge (mV)
+ * @vref_neg_mv:	Vdd Negative Analog Supply Volatge (mV)
+ * @use_rbuf_gain2:	ext. amplifier connected in gain of two configuration
+ */
+
+struct ad5791_platform_data {
+	u16				vref_pos_mv;
+	u16				vref_neg_mv;
+	bool				use_rbuf_gain2;
+};
+
+/**
+ * struct ad5791_chip_info - chip specific information
+ * @bits:		accuracy of the DAC in bits
+ * @left_shift:		number of bits the datum must be shifted
+ */
+
+struct ad5791_chip_info {
+	u8			bits;
+	u8			left_shift;
+};
+
+/**
+ * struct ad5791_state - driver instance specific data
+ * @indio_dev:		the industrial I/O device
+ * @us:			spi_device
+ * @reg_vdd:		positive supply regulator
+ * @reg_vss:		negative supply regulator
+ * @chip_info:		chip model specific constants
+ * @vref_mv:		actual reference voltage used
+ * @pwr_down_mode	current power down mode
+ */
+
+struct ad5791_state {
+	struct iio_dev			*indio_dev;
+	struct spi_device		*spi;
+	struct regulator		*reg_vdd;
+	struct regulator		*reg_vss;
+	const struct ad5791_chip_info	*chip_info;
+	unsigned short			vref_mv;
+	unsigned			ctrl;
+	unsigned			pwr_down_mode;
+	bool				pwr_down;
+};
+
+/**
+ * ad5791_supported_device_ids:
+ */
+
+enum ad5791_supported_device_ids {
+	ID_AD5791,
+	ID_AD5781,
+};
+
+#endif /* SPI_AD5791_H_ */