7 files changed, 773 insertions, 0 deletions

diff --git a/drivers/staging/iio/dac/Kconfig b/drivers/staging/iio/dac/Kconfig
new file mode 100644
index 000000000000..9191bd23cc08
--- /dev/null
+++ b/drivers/staging/iio/dac/Kconfig
@@ -0,0 +1,21 @@
+#
+# DAC drivers
+#
+comment "Digital to analog convertors"
+
+config AD5624R_SPI
+	tristate "Analog Devices AD5624/44/64R DAC spi driver"
+	depends on SPI
+	help
+	  Say yes here to build support for Analog Devices AD5624R, AD5644R and
+	  AD5664R convertors (DAC). This driver uses the common SPI interface.
+
+config AD5446
+	tristate "Analog Devices AD5444/6, AD5620/40/60 and AD5541A/12A DAC SPI driver"
+	depends on SPI
+	help
+	  Say yes here to build support for Analog Devices AD5444, AD5446,
+	  AD5620, AD5640, AD5660 and AD5541A, AD5512A DACs.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ad5446.
diff --git a/drivers/staging/iio/dac/Makefile b/drivers/staging/iio/dac/Makefile
new file mode 100644
index 000000000000..7cf331b4e001
--- /dev/null
+++ b/drivers/staging/iio/dac/Makefile
@@ -0,0 +1,6 @@
+#
+# Makefile for industrial I/O DAC drivers
+#
+
+obj-$(CONFIG_AD5624R_SPI) += ad5624r_spi.o
+obj-$(CONFIG_AD5446) += ad5446.o
diff --git a/drivers/staging/iio/dac/ad5446.c b/drivers/staging/iio/dac/ad5446.c
new file mode 100644
index 000000000000..e3387cd31145
--- /dev/null
+++ b/drivers/staging/iio/dac/ad5446.c
@@ -0,0 +1,323 @@
+/*
+ * AD5446 SPI DAC driver
+ *
+ * Copyright 2010 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/workqueue.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <linux/list.h>
+#include <linux/spi/spi.h>
+#include <linux/regulator/consumer.h>
+#include <linux/err.h>
+
+#include "../iio.h"
+#include "../sysfs.h"
+#include "dac.h"
+
+#include "ad5446.h"
+
+static void ad5446_store_sample(struct ad5446_state *st, unsigned val)
+{
+	st->data.d16 = cpu_to_be16(AD5446_LOAD |
+					(val << st->chip_info->left_shift));
+}
+
+static void ad5542_store_sample(struct ad5446_state *st, unsigned val)
+{
+	st->data.d16 = cpu_to_be16(val << st->chip_info->left_shift);
+}
+
+static void ad5620_store_sample(struct ad5446_state *st, unsigned val)
+{
+	st->data.d16 = cpu_to_be16(AD5620_LOAD |
+					(val << st->chip_info->left_shift));
+}
+
+static void ad5660_store_sample(struct ad5446_state *st, unsigned val)
+{
+	val |= AD5660_LOAD;
+	st->data.d24[0] = (val >> 16) & 0xFF;
+	st->data.d24[1] = (val >> 8) & 0xFF;
+	st->data.d24[2] = val & 0xFF;
+}
+
+static ssize_t ad5446_write(struct device *dev,
+		struct device_attribute *attr,
+		const char *buf,
+		size_t len)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct ad5446_state *st = dev_info->dev_data;
+	int ret;
+	long val;
+
+	ret = strict_strtol(buf, 10, &val);
+	if (ret)
+		goto error_ret;
+
+	if (val > RES_MASK(st->chip_info->bits)) {
+		ret = -EINVAL;
+		goto error_ret;
+	}
+
+	mutex_lock(&dev_info->mlock);
+	st->chip_info->store_sample(st, val);
+	ret = spi_sync(st->spi, &st->msg);
+	mutex_unlock(&dev_info->mlock);
+
+error_ret:
+	return ret ? ret : len;
+}
+
+static IIO_DEV_ATTR_OUT_RAW(0, ad5446_write, 0);
+
+static ssize_t ad5446_show_scale(struct device *dev,
+				struct device_attribute *attr,
+				char *buf)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct ad5446_state *st = iio_dev_get_devdata(dev_info);
+	/* Corresponds to Vref / 2^(bits) */
+	unsigned int scale_uv = (st->vref_mv * 1000) >> st->chip_info->bits;
+
+	return sprintf(buf, "%d.%d\n", scale_uv / 1000, scale_uv % 1000);
+}
+static IIO_DEVICE_ATTR(out_scale, S_IRUGO, ad5446_show_scale, NULL, 0);
+
+static ssize_t ad5446_show_name(struct device *dev,
+				 struct device_attribute *attr,
+				 char *buf)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct ad5446_state *st = iio_dev_get_devdata(dev_info);
+
+	return sprintf(buf, "%s\n", spi_get_device_id(st->spi)->name);
+}
+static IIO_DEVICE_ATTR(name, S_IRUGO, ad5446_show_name, NULL, 0);
+
+static struct attribute *ad5446_attributes[] = {
+	&iio_dev_attr_out0_raw.dev_attr.attr,
+	&iio_dev_attr_out_scale.dev_attr.attr,
+	&iio_dev_attr_name.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group ad5446_attribute_group = {
+	.attrs = ad5446_attributes,
+};
+
+static const struct ad5446_chip_info ad5446_chip_info_tbl[] = {
+	[ID_AD5444] = {
+		.bits = 12,
+		.storagebits = 16,
+		.left_shift = 2,
+		.store_sample = ad5446_store_sample,
+	},
+	[ID_AD5446] = {
+		.bits = 14,
+		.storagebits = 16,
+		.left_shift = 0,
+		.store_sample = ad5446_store_sample,
+	},
+	[ID_AD5542A] = {
+		.bits = 16,
+		.storagebits = 16,
+		.left_shift = 0,
+		.store_sample = ad5542_store_sample,
+	},
+	[ID_AD5512A] = {
+		.bits = 12,
+		.storagebits = 16,
+		.left_shift = 4,
+		.store_sample = ad5542_store_sample,
+	},
+	[ID_AD5620_2500] = {
+		.bits = 12,
+		.storagebits = 16,
+		.left_shift = 2,
+		.int_vref_mv = 2500,
+		.store_sample = ad5620_store_sample,
+	},
+	[ID_AD5620_1250] = {
+		.bits = 12,
+		.storagebits = 16,
+		.left_shift = 2,
+		.int_vref_mv = 1250,
+		.store_sample = ad5620_store_sample,
+	},
+	[ID_AD5640_2500] = {
+		.bits = 14,
+		.storagebits = 16,
+		.left_shift = 0,
+		.int_vref_mv = 2500,
+		.store_sample = ad5620_store_sample,
+	},
+	[ID_AD5640_1250] = {
+		.bits = 14,
+		.storagebits = 16,
+		.left_shift = 0,
+		.int_vref_mv = 1250,
+		.store_sample = ad5620_store_sample,
+	},
+	[ID_AD5660_2500] = {
+		.bits = 16,
+		.storagebits = 24,
+		.left_shift = 0,
+		.int_vref_mv = 2500,
+		.store_sample = ad5660_store_sample,
+	},
+	[ID_AD5660_1250] = {
+		.bits = 16,
+		.storagebits = 24,
+		.left_shift = 0,
+		.int_vref_mv = 1250,
+		.store_sample = ad5660_store_sample,
+	},
+};
+
+static int __devinit ad5446_probe(struct spi_device *spi)
+{
+	struct ad5446_state *st;
+	int ret, voltage_uv = 0;
+
+	st = kzalloc(sizeof(*st), GFP_KERNEL);
+	if (st == NULL) {
+		ret = -ENOMEM;
+		goto error_ret;
+	}
+
+	st->reg = regulator_get(&spi->dev, "vcc");
+	if (!IS_ERR(st->reg)) {
+		ret = regulator_enable(st->reg);
+		if (ret)
+			goto error_put_reg;
+
+		voltage_uv = regulator_get_voltage(st->reg);
+	}
+
+	st->chip_info =
+		&ad5446_chip_info_tbl[spi_get_device_id(spi)->driver_data];
+
+	spi_set_drvdata(spi, st);
+
+	st->spi = spi;
+
+	st->indio_dev = iio_allocate_device();
+	if (st->indio_dev == NULL) {
+		ret = -ENOMEM;
+		goto error_disable_reg;
+	}
+
+	/* Estabilish that the iio_dev is a child of the spi device */
+	st->indio_dev->dev.parent = &spi->dev;
+	st->indio_dev->attrs = &ad5446_attribute_group;
+	st->indio_dev->dev_data = (void *)(st);
+	st->indio_dev->driver_module = THIS_MODULE;
+	st->indio_dev->modes = INDIO_DIRECT_MODE;
+
+	/* Setup default message */
+
+	st->xfer.tx_buf = &st->data;
+	st->xfer.len = st->chip_info->storagebits / 8;
+
+	spi_message_init(&st->msg);
+	spi_message_add_tail(&st->xfer, &st->msg);
+
+	switch (spi_get_device_id(spi)->driver_data) {
+		case ID_AD5620_2500:
+		case ID_AD5620_1250:
+		case ID_AD5640_2500:
+		case ID_AD5640_1250:
+		case ID_AD5660_2500:
+		case ID_AD5660_1250:
+			st->vref_mv = st->chip_info->int_vref_mv;
+			break;
+		default:
+			if (voltage_uv)
+				st->vref_mv = voltage_uv / 1000;
+			else
+				dev_warn(&spi->dev,
+					 "reference voltage unspecified\n");
+	}
+
+	ret = iio_device_register(st->indio_dev);
+	if (ret)
+		goto error_free_device;
+
+	return 0;
+
+error_free_device:
+	iio_free_device(st->indio_dev);
+error_disable_reg:
+	if (!IS_ERR(st->reg))
+		regulator_disable(st->reg);
+error_put_reg:
+	if (!IS_ERR(st->reg))
+		regulator_put(st->reg);
+	kfree(st);
+error_ret:
+	return ret;
+}
+
+static int ad5446_remove(struct spi_device *spi)
+{
+	struct ad5446_state *st = spi_get_drvdata(spi);
+	struct iio_dev *indio_dev = st->indio_dev;
+
+	iio_device_unregister(indio_dev);
+	if (!IS_ERR(st->reg)) {
+		regulator_disable(st->reg);
+		regulator_put(st->reg);
+	}
+	kfree(st);
+	return 0;
+}
+
+static const struct spi_device_id ad5446_id[] = {
+	{"ad5444", ID_AD5444},
+	{"ad5446", ID_AD5446},
+	{"ad5542a", ID_AD5542A},
+	{"ad5512a", ID_AD5512A},
+	{"ad5620-2500", ID_AD5620_2500}, /* AD5620/40/60: */
+	{"ad5620-1250", ID_AD5620_1250}, /* part numbers may look differently */
+	{"ad5640-2500", ID_AD5640_2500},
+	{"ad5640-1250", ID_AD5640_1250},
+	{"ad5660-2500", ID_AD5660_2500},
+	{"ad5660-1250", ID_AD5660_1250},
+	{}
+};
+
+static struct spi_driver ad5446_driver = {
+	.driver = {
+		.name	= "ad5446",
+		.bus	= &spi_bus_type,
+		.owner	= THIS_MODULE,
+	},
+	.probe		= ad5446_probe,
+	.remove		= __devexit_p(ad5446_remove),
+	.id_table	= ad5446_id,
+};
+
+static int __init ad5446_init(void)
+{
+	return spi_register_driver(&ad5446_driver);
+}
+module_init(ad5446_init);
+
+static void __exit ad5446_exit(void)
+{
+	spi_unregister_driver(&ad5446_driver);
+}
+module_exit(ad5446_exit);
+
+MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
+MODULE_DESCRIPTION("Analog Devices AD5444/AD5446 DAC");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("spi:ad5446");
diff --git a/drivers/staging/iio/dac/ad5446.h b/drivers/staging/iio/dac/ad5446.h
new file mode 100644
index 000000000000..902542e22c4a
--- /dev/null
+++ b/drivers/staging/iio/dac/ad5446.h
@@ -0,0 +1,96 @@
+/*
+ * AD5446 SPI DAC driver
+ *
+ * Copyright 2010 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+#ifndef IIO_DAC_AD5446_H_
+#define IIO_DAC_AD5446_H_
+
+/* DAC Control Bits */
+
+#define AD5446_LOAD		(0x0 << 14) /* Load and update */
+#define AD5446_SDO_DIS		(0x1 << 14) /* Disable SDO */
+#define AD5446_NOP		(0x2 << 14) /* No operation */
+#define AD5446_CLK_RISING	(0x3 << 14) /* Clock data on rising edge */
+
+#define AD5620_LOAD		(0x0 << 14) /* Load and update Norm Operation*/
+#define AD5620_PWRDWN_1k	(0x1 << 14) /* Power-down: 1kOhm to GND */
+#define AD5620_PWRDWN_100k	(0x2 << 14) /* Power-down: 100kOhm to GND */
+#define AD5620_PWRDWN_TRISTATE	(0x3 << 14) /* Power-down: Three-state */
+
+#define AD5660_LOAD		(0x0 << 16) /* Load and update Norm Operation*/
+#define AD5660_PWRDWN_1k	(0x1 << 16) /* Power-down: 1kOhm to GND */
+#define AD5660_PWRDWN_100k	(0x2 << 16) /* Power-down: 100kOhm to GND */
+#define AD5660_PWRDWN_TRISTATE	(0x3 << 16) /* Power-down: Three-state */
+
+#define RES_MASK(bits)	((1 << (bits)) - 1)
+
+/**
+ * struct ad5446_state - driver instance specific data
+ * @indio_dev:		the industrial I/O device
+ * @spi:		spi_device
+ * @chip_info:		chip model specific constants, available modes etc
+ * @reg:		supply regulator
+ * @poll_work:		bottom half of polling interrupt handler
+ * @vref_mv:		actual reference voltage used
+ * @xfer:		default spi transfer
+ * @msg:		default spi message
+ * @data:		spi transmit buffer
+ */
+
+struct ad5446_state {
+	struct iio_dev			*indio_dev;
+	struct spi_device		*spi;
+	const struct ad5446_chip_info	*chip_info;
+	struct regulator		*reg;
+	struct work_struct		poll_work;
+	unsigned short			vref_mv;
+	struct spi_transfer		xfer;
+	struct spi_message		msg;
+	union {
+		unsigned short		d16;
+		unsigned char		d24[3];
+	} data;
+};
+
+/**
+ * struct ad5446_chip_info - chip specific information
+ * @bits:		accuracy of the DAC in bits
+ * @storagebits:	number of bits written to the DAC
+ * @left_shift:		number of bits the datum must be shifted
+ * @int_vref_mv:	AD5620/40/60: the internal reference voltage
+ * @store_sample:	chip specific helper function to store the datum
+ */
+
+struct ad5446_chip_info {
+	u8				bits;
+	u8				storagebits;
+	u8				left_shift;
+	u16				int_vref_mv;
+	void (*store_sample)		(struct ad5446_state *st, unsigned val);
+};
+
+/**
+ * ad5446_supported_device_ids:
+ * The AD5620/40/60 parts are available in different fixed internal reference
+ * voltage options. The actual part numbers may look differently
+ * (and a bit cryptic), however this style is used to make clear which
+ * parts are supported here.
+ */
+
+enum ad5446_supported_device_ids {
+	ID_AD5444,
+	ID_AD5446,
+	ID_AD5542A,
+	ID_AD5512A,
+	ID_AD5620_2500,
+	ID_AD5620_1250,
+	ID_AD5640_2500,
+	ID_AD5640_1250,
+	ID_AD5660_2500,
+	ID_AD5660_1250,
+};
+
+#endif /* IIO_DAC_AD5446_H_ */
diff --git a/drivers/staging/iio/dac/ad5624r.h b/drivers/staging/iio/dac/ad5624r.h
new file mode 100644
index 000000000000..ce518be652b7
--- /dev/null
+++ b/drivers/staging/iio/dac/ad5624r.h
@@ -0,0 +1,21 @@
+#ifndef SPI_AD5624R_H_
+#define SPI_AD5624R_H_
+
+#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_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
diff --git a/drivers/staging/iio/dac/ad5624r_spi.c b/drivers/staging/iio/dac/ad5624r_spi.c
new file mode 100644
index 000000000000..2b1c6dde4fdd
--- /dev/null
+++ b/drivers/staging/iio/dac/ad5624r_spi.c
@@ -0,0 +1,300 @@
+/*
+ * AD5624R, AD5644R, AD5664R Digital to analog convertors spi driver
+ *
+ * Copyright 2010 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/gpio.h>
+#include <linux/fs.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/spi/spi.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <linux/delay.h>
+
+#include "../iio.h"
+#include "../sysfs.h"
+#include "dac.h"
+#include "ad5624r.h"
+
+/**
+ * struct ad5624r_state - device related storage
+ * @indio_dev:	associated industrial IO device
+ * @us:		spi device
+ **/
+struct ad5624r_state {
+	struct iio_dev *indio_dev;
+	struct spi_device *us;
+	int data_len;
+	int ldac_mode;
+	int dac_power_mode[AD5624R_DAC_CHANNELS];
+	int internal_ref;
+};
+
+static int ad5624r_spi_write(struct spi_device *spi,
+			     u8 cmd, u8 addr, u16 val, u8 len)
+{
+	u32 data;
+	u8 msg[3];
+
+	/*
+	 * The input shift register is 24 bits wide. The first two bits are don't care bits.
+	 * The next three are the command bits, C2 to C0, followed by the 3-bit DAC address,
+	 * A2 to A0, and then the 16-, 14-, 12-bit data-word. The data-word comprises the 16-,
+	 * 14-, 12-bit input code followed by 0, 2, or 4 don't care bits, for the AD5664R,
+	 * AD5644R, and AD5624R, respectively.
+	 */
+	data = (0 << 22) | (cmd << 19) | (addr << 16) | (val << (16 - len));
+	msg[0] = data >> 16;
+	msg[1] = data >> 8;
+	msg[2] = data;
+
+	return spi_write(spi, msg, 3);
+}
+
+static ssize_t ad5624r_write_dac(struct device *dev,
+				 struct device_attribute *attr,
+				 const char *buf, size_t len)
+{
+	long readin;
+	int ret;
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct ad5624r_state *st = indio_dev->dev_data;
+	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+
+	ret = strict_strtol(buf, 10, &readin);
+	if (ret)
+		return ret;
+
+	ret = ad5624r_spi_write(st->us, AD5624R_CMD_WRITE_INPUT_N_UPDATE_N,
+				this_attr->address, readin, st->data_len);
+	return ret ? ret : len;
+}
+
+static ssize_t ad5624r_read_ldac_mode(struct device *dev,
+				      struct device_attribute *attr, char *buf)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct ad5624r_state *st = indio_dev->dev_data;
+
+	return sprintf(buf, "%x\n", st->ldac_mode);
+}
+
+static ssize_t ad5624r_write_ldac_mode(struct device *dev,
+				       struct device_attribute *attr,
+				       const char *buf, size_t len)
+{
+	long readin;
+	int ret;
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct ad5624r_state *st = indio_dev->dev_data;
+
+	ret = strict_strtol(buf, 16, &readin);
+	if (ret)
+		return ret;
+
+	ret = ad5624r_spi_write(st->us, AD5624R_CMD_LDAC_SETUP, 0,
+				readin & 0xF, 16);
+	st->ldac_mode = readin & 0xF;
+
+	return ret ? ret : len;
+}
+
+static ssize_t ad5624r_read_dac_power_mode(struct device *dev,
+					   struct device_attribute *attr,
+					   char *buf)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct ad5624r_state *st = indio_dev->dev_data;
+	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+
+	return sprintf(buf, "%d\n", st->dac_power_mode[this_attr->address]);
+}
+
+static ssize_t ad5624r_write_dac_power_mode(struct device *dev,
+					    struct device_attribute *attr,
+					    const char *buf, size_t len)
+{
+	long readin;
+	int ret;
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct ad5624r_state *st = indio_dev->dev_data;
+	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+
+	ret = strict_strtol(buf, 10, &readin);
+	if (ret)
+		return ret;
+
+	ret = ad5624r_spi_write(st->us, AD5624R_CMD_POWERDOWN_DAC, 0,
+				((readin & 0x3) << 4) |
+				(1 << this_attr->address), 16);
+
+	st->dac_power_mode[this_attr->address] = readin & 0x3;
+
+	return ret ? ret : len;
+}
+
+static ssize_t ad5624r_read_internal_ref_mode(struct device *dev,
+					      struct device_attribute *attr,
+					      char *buf)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct ad5624r_state *st = indio_dev->dev_data;
+
+	return sprintf(buf, "%d\n", st->internal_ref);
+}
+
+static ssize_t ad5624r_write_internal_ref_mode(struct device *dev,
+					       struct device_attribute *attr,
+					       const char *buf, size_t len)
+{
+	long readin;
+	int ret;
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct ad5624r_state *st = indio_dev->dev_data;
+
+	ret = strict_strtol(buf, 10, &readin);
+	if (ret)
+		return ret;
+
+	ret = ad5624r_spi_write(st->us, AD5624R_CMD_INTERNAL_REFER_SETUP, 0,
+				!!readin, 16);
+
+	st->internal_ref = !!readin;
+
+	return ret ? ret : len;
+}
+
+static IIO_DEV_ATTR_OUT_RAW(0, ad5624r_write_dac, AD5624R_ADDR_DAC0);
+static IIO_DEV_ATTR_OUT_RAW(1, ad5624r_write_dac, AD5624R_ADDR_DAC1);
+static IIO_DEV_ATTR_OUT_RAW(2, ad5624r_write_dac, AD5624R_ADDR_DAC2);
+static IIO_DEV_ATTR_OUT_RAW(3, ad5624r_write_dac, AD5624R_ADDR_DAC3);
+
+static IIO_DEVICE_ATTR(ldac_mode, S_IRUGO | S_IWUSR, ad5624r_read_ldac_mode,
+		       ad5624r_write_ldac_mode, 0);
+static IIO_DEVICE_ATTR(internal_ref, S_IRUGO | S_IWUSR,
+		       ad5624r_read_internal_ref_mode,
+		       ad5624r_write_internal_ref_mode, 0);
+
+#define IIO_DEV_ATTR_DAC_POWER_MODE(_num, _show, _store, _addr)			\
+	IIO_DEVICE_ATTR(dac_power_mode_##_num, S_IRUGO | S_IWUSR, _show, _store, _addr)
+
+static IIO_DEV_ATTR_DAC_POWER_MODE(0, ad5624r_read_dac_power_mode,
+				   ad5624r_write_dac_power_mode, 0);
+static IIO_DEV_ATTR_DAC_POWER_MODE(1, ad5624r_read_dac_power_mode,
+				   ad5624r_write_dac_power_mode, 1);
+static IIO_DEV_ATTR_DAC_POWER_MODE(2, ad5624r_read_dac_power_mode,
+				   ad5624r_write_dac_power_mode, 2);
+static IIO_DEV_ATTR_DAC_POWER_MODE(3, ad5624r_read_dac_power_mode,
+				   ad5624r_write_dac_power_mode, 3);
+
+static struct attribute *ad5624r_attributes[] = {
+	&iio_dev_attr_out0_raw.dev_attr.attr,
+	&iio_dev_attr_out1_raw.dev_attr.attr,
+	&iio_dev_attr_out2_raw.dev_attr.attr,
+	&iio_dev_attr_out3_raw.dev_attr.attr,
+	&iio_dev_attr_dac_power_mode_0.dev_attr.attr,
+	&iio_dev_attr_dac_power_mode_1.dev_attr.attr,
+	&iio_dev_attr_dac_power_mode_2.dev_attr.attr,
+	&iio_dev_attr_dac_power_mode_3.dev_attr.attr,
+	&iio_dev_attr_ldac_mode.dev_attr.attr,
+	&iio_dev_attr_internal_ref.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group ad5624r_attribute_group = {
+	.attrs = ad5624r_attributes,
+};
+
+static int __devinit ad5624r_probe(struct spi_device *spi)
+{
+	struct ad5624r_state *st;
+	int ret = 0;
+
+	st = kzalloc(sizeof(*st), GFP_KERNEL);
+	if (st == NULL) {
+		ret = -ENOMEM;
+		goto error_ret;
+	}
+	spi_set_drvdata(spi, st);
+
+	st->data_len = spi_get_device_id(spi)->driver_data;
+
+	st->us = spi;
+	st->indio_dev = iio_allocate_device();
+	if (st->indio_dev == NULL) {
+		ret = -ENOMEM;
+		goto error_free_st;
+	}
+	st->indio_dev->dev.parent = &spi->dev;
+	st->indio_dev->num_interrupt_lines = 0;
+	st->indio_dev->event_attrs = NULL;
+
+	st->indio_dev->attrs = &ad5624r_attribute_group;
+	st->indio_dev->dev_data = (void *)(st);
+	st->indio_dev->driver_module = THIS_MODULE;
+	st->indio_dev->modes = INDIO_DIRECT_MODE;
+
+	ret = iio_device_register(st->indio_dev);
+	if (ret)
+		goto error_free_dev;
+
+	spi->mode = SPI_MODE_0;
+	spi_setup(spi);
+
+	return 0;
+
+error_free_dev:
+	iio_free_device(st->indio_dev);
+error_free_st:
+	kfree(st);
+error_ret:
+	return ret;
+}
+
+static int __devexit ad5624r_remove(struct spi_device *spi)
+{
+	struct ad5624r_state *st = spi_get_drvdata(spi);
+
+	iio_device_unregister(st->indio_dev);
+	kfree(st);
+
+	return 0;
+}
+
+static const struct spi_device_id ad5624r_id[] = {
+	{"ad5624r", 12},
+	{"ad5644r", 14},
+	{"ad5664r", 16},
+	{}
+};
+
+static struct spi_driver ad5624r_driver = {
+	.driver = {
+		   .name = "ad5624r",
+		   .owner = THIS_MODULE,
+		   },
+	.probe = ad5624r_probe,
+	.remove = __devexit_p(ad5624r_remove),
+	.id_table = ad5624r_id,
+};
+
+static __init int ad5624r_spi_init(void)
+{
+	return spi_register_driver(&ad5624r_driver);
+}
+module_init(ad5624r_spi_init);
+
+static __exit void ad5624r_spi_exit(void)
+{
+	spi_unregister_driver(&ad5624r_driver);
+}
+module_exit(ad5624r_spi_exit);
+
+MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
+MODULE_DESCRIPTION("Analog Devices AD5624/44/64R DAC spi driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/staging/iio/dac/dac.h b/drivers/staging/iio/dac/dac.h
new file mode 100644
index 000000000000..1d82f353241c
--- /dev/null
+++ b/drivers/staging/iio/dac/dac.h
@@ -0,0 +1,6 @@
+/*
+ * dac.h - sysfs attributes associated with DACs
+ */
+
+#define IIO_DEV_ATTR_OUT_RAW(_num, _store, _addr)				\
+	IIO_DEVICE_ATTR(out##_num##_raw, S_IWUSR, NULL, _store, _addr)