Merge tag 'iio-for-v3.7d' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-next

IIO new drivers, features and rework for the 3.7 cycle, 4th set.

Here we have

1) a set cleaning up and moving the ad7476 driver out of staging.
Support for a number of additional parts is also added to that driver.

2) cleanups from various people for the in kernel interface code as that
is getting more an more real use and hence people are picking up on
minor issues that made it through review.  Also a related useful set
of utility functions to avoid duplicate code for converting IIO
representations to other forms.

3) a new fractional type for our read_raw / write_raw functions.
  This allows avoiding loss of accuracy via the in kernel interfaces in some
  cases as well as being rather convenient for a lot of range -> scale
  conversions.

4) New AD5755 DAC driver.

5) Some Blackfin timer trigger improvements including hardware pulse control
for device triggering.

6) Support for the ad7091r in the ad7476 driver.

8 files changed, 1136 insertions, 11 deletions

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index d0ae71ec2aa0..03791a6de349 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -30,6 +30,21 @@ config AD7791
 	  To compile this driver as a module, choose M here: the module will be
 	  called ad7791.
 
+config AD7476
+	tristate "Analog Devices AD7476 and similar 1-channel ADCs driver"
+	depends on SPI
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
+	help
+	  Say yes here to build support for Analog Devices AD7273, AD7274, AD7276,
+	  AD7277, AD7278, AD7475, AD7476, AD7477, AD7478, AD7466, AD7467, AD7468,
+	  AD7495, AD7910, AD7920, AD7920 SPI analog to digital converters (ADC).
+
+	  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 ad7476.
+
 config AT91_ADC
 	tristate "Atmel AT91 ADC"
 	depends on ARCH_AT91
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index f187ff6c2a16..9824a70f4fd8 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -4,5 +4,6 @@
 
 obj-$(CONFIG_AD_SIGMA_DELTA) += ad_sigma_delta.o
 obj-$(CONFIG_AD7266) += ad7266.o
+obj-$(CONFIG_AD7476) += ad7476.o
 obj-$(CONFIG_AD7791) += ad7791.o
 obj-$(CONFIG_AT91_ADC) += at91_adc.o
diff --git a/drivers/iio/adc/ad7476.c b/drivers/iio/adc/ad7476.c
new file mode 100644
index 000000000000..7f2f45a0a48d
--- /dev/null
+++ b/drivers/iio/adc/ad7476.c
@@ -0,0 +1,332 @@
+/*
+ * AD7466/7/8 AD7476/5/7/8 (A) SPI ADC driver
+ *
+ * Copyright 2010 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <linux/spi/spi.h>
+#include <linux/regulator/consumer.h>
+#include <linux/err.h>
+#include <linux/module.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+
+#define RES_MASK(bits)	((1 << (bits)) - 1)
+
+struct ad7476_state;
+
+struct ad7476_chip_info {
+	unsigned int			int_vref_uv;
+	struct iio_chan_spec		channel[2];
+	void (*reset)(struct ad7476_state *);
+};
+
+struct ad7476_state {
+	struct spi_device		*spi;
+	const struct ad7476_chip_info	*chip_info;
+	struct regulator		*reg;
+	struct spi_transfer		xfer;
+	struct spi_message		msg;
+	/*
+	 * DMA (thus cache coherency maintenance) requires the
+	 * transfer buffers to live in their own cache lines.
+	 * Make the buffer large enough for one 16 bit sample and one 64 bit
+	 * aligned 64 bit timestamp.
+	 */
+	unsigned char data[ALIGN(2, sizeof(s64)) + sizeof(s64)]
+			____cacheline_aligned;
+};
+
+enum ad7476_supported_device_ids {
+	ID_AD7091R,
+	ID_AD7276,
+	ID_AD7277,
+	ID_AD7278,
+	ID_AD7466,
+	ID_AD7467,
+	ID_AD7468,
+	ID_AD7495,
+	ID_AD7940,
+};
+
+static irqreturn_t ad7476_trigger_handler(int irq, void  *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct ad7476_state *st = iio_priv(indio_dev);
+	s64 time_ns;
+	int b_sent;
+
+	b_sent = spi_sync(st->spi, &st->msg);
+	if (b_sent < 0)
+		goto done;
+
+	time_ns = iio_get_time_ns();
+
+	if (indio_dev->scan_timestamp)
+		((s64 *)st->data)[1] = time_ns;
+
+	iio_push_to_buffer(indio_dev->buffer, st->data);
+done:
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
+static void ad7091_reset(struct ad7476_state *st)
+{
+	/* Any transfers with 8 scl cycles will reset the device */
+	spi_read(st->spi, st->data, 1);
+}
+
+static int ad7476_scan_direct(struct ad7476_state *st)
+{
+	int ret;
+
+	ret = spi_sync(st->spi, &st->msg);
+	if (ret)
+		return ret;
+
+	return be16_to_cpup((__be16 *)st->data);
+}
+
+static int ad7476_read_raw(struct iio_dev *indio_dev,
+			   struct iio_chan_spec const *chan,
+			   int *val,
+			   int *val2,
+			   long m)
+{
+	int ret;
+	struct ad7476_state *st = iio_priv(indio_dev);
+	int scale_uv;
+
+	switch (m) {
+	case IIO_CHAN_INFO_RAW:
+		mutex_lock(&indio_dev->mlock);
+		if (iio_buffer_enabled(indio_dev))
+			ret = -EBUSY;
+		else
+			ret = ad7476_scan_direct(st);
+		mutex_unlock(&indio_dev->mlock);
+
+		if (ret < 0)
+			return ret;
+		*val = (ret >> st->chip_info->channel[0].scan_type.shift) &
+			RES_MASK(st->chip_info->channel[0].scan_type.realbits);
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		if (!st->chip_info->int_vref_uv) {
+			scale_uv = regulator_get_voltage(st->reg);
+			if (scale_uv < 0)
+				return scale_uv;
+		} else {
+			scale_uv = st->chip_info->int_vref_uv;
+		}
+		scale_uv >>= chan->scan_type.realbits;
+		*val =  scale_uv / 1000;
+		*val2 = (scale_uv % 1000) * 1000;
+		return IIO_VAL_INT_PLUS_MICRO;
+	}
+	return -EINVAL;
+}
+
+#define _AD7476_CHAN(bits, _shift, _info_mask)			\
+	{							\
+	.type = IIO_VOLTAGE,					\
+	.indexed = 1,						\
+	.info_mask = _info_mask |				\
+	IIO_CHAN_INFO_SCALE_SHARED_BIT,				\
+	.scan_type = {						\
+		.sign = 'u',					\
+		.realbits = (bits),				\
+		.storagebits = 16,				\
+		.shift = (_shift),				\
+		.endianness = IIO_BE,				\
+	},							\
+}
+
+#define AD7476_CHAN(bits) _AD7476_CHAN((bits), 13 - (bits), \
+		IIO_CHAN_INFO_RAW_SEPARATE_BIT)
+#define AD7940_CHAN(bits) _AD7476_CHAN((bits), 15 - (bits), \
+		IIO_CHAN_INFO_RAW_SEPARATE_BIT)
+#define AD7091R_CHAN(bits) _AD7476_CHAN((bits), 16 - (bits), 0)
+
+static const struct ad7476_chip_info ad7476_chip_info_tbl[] = {
+	[ID_AD7091R] = {
+		.channel[0] = AD7091R_CHAN(12),
+		.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
+		.reset = ad7091_reset,
+	},
+	[ID_AD7276] = {
+		.channel[0] = AD7940_CHAN(12),
+		.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
+	},
+	[ID_AD7277] = {
+		.channel[0] = AD7940_CHAN(10),
+		.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
+	},
+	[ID_AD7278] = {
+		.channel[0] = AD7940_CHAN(8),
+		.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
+	},
+	[ID_AD7466] = {
+		.channel[0] = AD7476_CHAN(12),
+		.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
+	},
+	[ID_AD7467] = {
+		.channel[0] = AD7476_CHAN(10),
+		.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
+	},
+	[ID_AD7468] = {
+		.channel[0] = AD7476_CHAN(8),
+		.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
+	},
+	[ID_AD7495] = {
+		.channel[0] = AD7476_CHAN(12),
+		.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
+		.int_vref_uv = 2500000,
+	},
+	[ID_AD7940] = {
+		.channel[0] = AD7940_CHAN(14),
+		.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
+	},
+};
+
+static const struct iio_info ad7476_info = {
+	.driver_module = THIS_MODULE,
+	.read_raw = &ad7476_read_raw,
+};
+
+static int __devinit ad7476_probe(struct spi_device *spi)
+{
+	struct ad7476_state *st;
+	struct iio_dev *indio_dev;
+	int ret;
+
+	indio_dev = iio_device_alloc(sizeof(*st));
+	if (indio_dev == NULL) {
+		ret = -ENOMEM;
+		goto error_ret;
+	}
+	st = iio_priv(indio_dev);
+	st->chip_info =
+		&ad7476_chip_info_tbl[spi_get_device_id(spi)->driver_data];
+
+	st->reg = regulator_get(&spi->dev, "vcc");
+	if (IS_ERR(st->reg)) {
+		ret = PTR_ERR(st->reg);
+		goto error_free_dev;
+	}
+
+	ret = regulator_enable(st->reg);
+	if (ret)
+		goto error_put_reg;
+
+	spi_set_drvdata(spi, indio_dev);
+
+	st->spi = spi;
+
+	/* Establish that the iio_dev is a child of the spi device */
+	indio_dev->dev.parent = &spi->dev;
+	indio_dev->name = spi_get_device_id(spi)->name;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = st->chip_info->channel;
+	indio_dev->num_channels = 2;
+	indio_dev->info = &ad7476_info;
+	/* Setup default message */
+
+	st->xfer.rx_buf = &st->data;
+	st->xfer.len = st->chip_info->channel[0].scan_type.storagebits / 8;
+
+	spi_message_init(&st->msg);
+	spi_message_add_tail(&st->xfer, &st->msg);
+
+	ret = iio_triggered_buffer_setup(indio_dev, NULL,
+			&ad7476_trigger_handler, NULL);
+	if (ret)
+		goto error_disable_reg;
+
+	if (st->chip_info->reset)
+		st->chip_info->reset(st);
+
+	ret = iio_device_register(indio_dev);
+	if (ret)
+		goto error_ring_unregister;
+	return 0;
+
+error_ring_unregister:
+	iio_triggered_buffer_cleanup(indio_dev);
+error_disable_reg:
+	regulator_disable(st->reg);
+error_put_reg:
+	regulator_put(st->reg);
+error_free_dev:
+	iio_device_free(indio_dev);
+
+error_ret:
+	return ret;
+}
+
+static int __devexit ad7476_remove(struct spi_device *spi)
+{
+	struct iio_dev *indio_dev = spi_get_drvdata(spi);
+	struct ad7476_state *st = iio_priv(indio_dev);
+
+	iio_device_unregister(indio_dev);
+	iio_triggered_buffer_cleanup(indio_dev);
+	regulator_disable(st->reg);
+	regulator_put(st->reg);
+	iio_device_free(indio_dev);
+
+	return 0;
+}
+
+static const struct spi_device_id ad7476_id[] = {
+	{"ad7091r", ID_AD7091R},
+	{"ad7273", ID_AD7277},
+	{"ad7274", ID_AD7276},
+	{"ad7276", ID_AD7276},
+	{"ad7277", ID_AD7277},
+	{"ad7278", ID_AD7278},
+	{"ad7466", ID_AD7466},
+	{"ad7467", ID_AD7467},
+	{"ad7468", ID_AD7468},
+	{"ad7475", ID_AD7466},
+	{"ad7476", ID_AD7466},
+	{"ad7476a", ID_AD7466},
+	{"ad7477", ID_AD7467},
+	{"ad7477a", ID_AD7467},
+	{"ad7478", ID_AD7468},
+	{"ad7478a", ID_AD7468},
+	{"ad7495", ID_AD7495},
+	{"ad7910", ID_AD7467},
+	{"ad7920", ID_AD7466},
+	{"ad7940", ID_AD7940},
+	{}
+};
+MODULE_DEVICE_TABLE(spi, ad7476_id);
+
+static struct spi_driver ad7476_driver = {
+	.driver = {
+		.name	= "ad7476",
+		.owner	= THIS_MODULE,
+	},
+	.probe		= ad7476_probe,
+	.remove		= __devexit_p(ad7476_remove),
+	.id_table	= ad7476_id,
+};
+module_spi_driver(ad7476_driver);
+
+MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
+MODULE_DESCRIPTION("Analog Devices AD7476 and similar 1-channel ADCs");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
index 78452630f85d..b1c0ee5294ca 100644
--- a/drivers/iio/dac/Kconfig
+++ b/drivers/iio/dac/Kconfig
@@ -77,6 +77,17 @@ config AD5504
 	  To compile this driver as a module, choose M here: the
 	  module will be called ad5504.
 
+config AD5755
+	tristate "Analog Devices AD5755/AD5755-1/AD5757/AD5735/AD5737 DAC driver"
+	depends on SPI_MASTER
+	help
+	  Say yes here to build support for Analog Devices AD5755, AD5755-1,
+	  AD5757, AD5735, AD5737 quad channel Digital to
+	  Analog Converter.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ad5755.
+
 config AD5764
 	tristate "Analog Devices AD5764/64R/44/44R DAC driver"
 	depends on SPI_MASTER
diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile
index 9ea3ceeefc07..c0d333b23ba3 100644
--- a/drivers/iio/dac/Makefile
+++ b/drivers/iio/dac/Makefile
@@ -9,6 +9,7 @@ obj-$(CONFIG_AD5624R_SPI) += ad5624r_spi.o
 obj-$(CONFIG_AD5064) += ad5064.o
 obj-$(CONFIG_AD5504) += ad5504.o
 obj-$(CONFIG_AD5446) += ad5446.o
+obj-$(CONFIG_AD5755) += ad5755.o
 obj-$(CONFIG_AD5764) += ad5764.o
 obj-$(CONFIG_AD5791) += ad5791.o
 obj-$(CONFIG_AD5686) += ad5686.o
diff --git a/drivers/iio/dac/ad5755.c b/drivers/iio/dac/ad5755.c
new file mode 100644
index 000000000000..e6dbe5ff7e5a
--- /dev/null
+++ b/drivers/iio/dac/ad5755.c
@@ -0,0 +1,650 @@
+/*
+ * AD5755, AD5755-1, AD5757, AD5735, AD5737 Digital to analog converters driver
+ *
+ * Copyright 2012 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/spi/spi.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <linux/delay.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/platform_data/ad5755.h>
+
+#define AD5755_NUM_CHANNELS 4
+
+#define AD5755_ADDR(x)			((x) << 16)
+
+#define AD5755_WRITE_REG_DATA(chan)	(chan)
+#define AD5755_WRITE_REG_GAIN(chan)	(0x08 | (chan))
+#define AD5755_WRITE_REG_OFFSET(chan)	(0x10 | (chan))
+#define AD5755_WRITE_REG_CTRL(chan)	(0x1c | (chan))
+
+#define AD5755_READ_REG_DATA(chan)	(chan)
+#define AD5755_READ_REG_CTRL(chan)	(0x4 | (chan))
+#define AD5755_READ_REG_GAIN(chan)	(0x8 | (chan))
+#define AD5755_READ_REG_OFFSET(chan)	(0xc | (chan))
+#define AD5755_READ_REG_CLEAR(chan)	(0x10 | (chan))
+#define AD5755_READ_REG_SLEW(chan)	(0x14 | (chan))
+#define AD5755_READ_REG_STATUS		0x18
+#define AD5755_READ_REG_MAIN		0x19
+#define AD5755_READ_REG_DC_DC		0x1a
+
+#define AD5755_CTRL_REG_SLEW	0x0
+#define AD5755_CTRL_REG_MAIN	0x1
+#define AD5755_CTRL_REG_DAC	0x2
+#define AD5755_CTRL_REG_DC_DC	0x3
+#define AD5755_CTRL_REG_SW	0x4
+
+#define AD5755_READ_FLAG 0x800000
+
+#define AD5755_NOOP 0x1CE000
+
+#define AD5755_DAC_INT_EN			BIT(8)
+#define AD5755_DAC_CLR_EN			BIT(7)
+#define AD5755_DAC_OUT_EN			BIT(6)
+#define AD5755_DAC_INT_CURRENT_SENSE_RESISTOR	BIT(5)
+#define AD5755_DAC_DC_DC_EN			BIT(4)
+#define AD5755_DAC_VOLTAGE_OVERRANGE_EN		BIT(3)
+
+#define AD5755_DC_DC_MAXV			0
+#define AD5755_DC_DC_FREQ_SHIFT			2
+#define AD5755_DC_DC_PHASE_SHIFT		4
+#define AD5755_EXT_DC_DC_COMP_RES		BIT(6)
+
+#define AD5755_SLEW_STEP_SIZE_SHIFT		0
+#define AD5755_SLEW_RATE_SHIFT			3
+#define AD5755_SLEW_ENABLE			BIT(12)
+
+/**
+ * struct ad5755_chip_info - chip specific information
+ * @channel_template:	channel specification
+ * @calib_shift:	shift for the calibration data registers
+ * @has_voltage_out:	whether the chip has voltage outputs
+ */
+struct ad5755_chip_info {
+	const struct iio_chan_spec channel_template;
+	unsigned int calib_shift;
+	bool has_voltage_out;
+};
+
+/**
+ * struct ad5755_state - driver instance specific data
+ * @spi:	spi device the driver is attached to
+ * @chip_info:	chip model specific constants, available modes etc
+ * @pwr_down:	bitmask which contains  hether a channel is powered down or not
+ * @ctrl:	software shadow of the channel ctrl registers
+ * @channels:	iio channel spec for the device
+ * @data:	spi transfer buffers
+ */
+struct ad5755_state {
+	struct spi_device		*spi;
+	const struct ad5755_chip_info	*chip_info;
+	unsigned int			pwr_down;
+	unsigned int			ctrl[AD5755_NUM_CHANNELS];
+	struct iio_chan_spec		channels[AD5755_NUM_CHANNELS];
+
+	/*
+	 * DMA (thus cache coherency maintenance) requires the
+	 * transfer buffers to live in their own cache lines.
+	 */
+
+	union {
+		u32 d32;
+		u8 d8[4];
+	} data[2] ____cacheline_aligned;
+};
+
+enum ad5755_type {
+	ID_AD5755,
+	ID_AD5757,
+	ID_AD5735,
+	ID_AD5737,
+};
+
+static int ad5755_write_unlocked(struct iio_dev *indio_dev,
+	unsigned int reg, unsigned int val)
+{
+	struct ad5755_state *st = iio_priv(indio_dev);
+
+	st->data[0].d32 = cpu_to_be32((reg << 16) | val);
+
+	return spi_write(st->spi, &st->data[0].d8[1], 3);
+}
+
+static int ad5755_write_ctrl_unlocked(struct iio_dev *indio_dev,
+	unsigned int channel, unsigned int reg, unsigned int val)
+{
+	return ad5755_write_unlocked(indio_dev,
+		AD5755_WRITE_REG_CTRL(channel), (reg << 13) | val);
+}
+
+static int ad5755_write(struct iio_dev *indio_dev, unsigned int reg,
+	unsigned int val)
+{
+	int ret;
+
+	mutex_lock(&indio_dev->mlock);
+	ret = ad5755_write_unlocked(indio_dev, reg, val);
+	mutex_unlock(&indio_dev->mlock);
+
+	return ret;
+}
+
+static int ad5755_write_ctrl(struct iio_dev *indio_dev, unsigned int channel,
+	unsigned int reg, unsigned int val)
+{
+	int ret;
+
+	mutex_lock(&indio_dev->mlock);
+	ret = ad5755_write_ctrl_unlocked(indio_dev, channel, reg, val);
+	mutex_unlock(&indio_dev->mlock);
+
+	return ret;
+}
+
+static int ad5755_read(struct iio_dev *indio_dev, unsigned int addr)
+{
+	struct ad5755_state *st = iio_priv(indio_dev);
+	struct spi_message m;
+	int ret;
+	struct spi_transfer t[] = {
+		{
+			.tx_buf = &st->data[0].d8[1],
+			.len = 3,
+			.cs_change = 1,
+		}, {
+			.tx_buf = &st->data[1].d8[1],
+			.rx_buf = &st->data[1].d8[1],
+			.len = 3,
+		},
+	};
+
+	spi_message_init(&m);
+	spi_message_add_tail(&t[0], &m);
+	spi_message_add_tail(&t[1], &m);
+
+	mutex_lock(&indio_dev->mlock);
+
+	st->data[0].d32 = cpu_to_be32(AD5755_READ_FLAG | (addr << 16));
+	st->data[1].d32 = cpu_to_be32(AD5755_NOOP);
+
+	ret = spi_sync(st->spi, &m);
+	if (ret >= 0)
+		ret = be32_to_cpu(st->data[1].d32) & 0xffff;
+
+	mutex_unlock(&indio_dev->mlock);
+
+	return ret;
+}
+
+static int ad5755_update_dac_ctrl(struct iio_dev *indio_dev,
+	unsigned int channel, unsigned int set, unsigned int clr)
+{
+	struct ad5755_state *st = iio_priv(indio_dev);
+	int ret;
+
+	st->ctrl[channel] |= set;
+	st->ctrl[channel] &= ~clr;
+
+	ret = ad5755_write_ctrl_unlocked(indio_dev, channel,
+		AD5755_CTRL_REG_DAC, st->ctrl[channel]);
+
+	return ret;
+}
+
+static int ad5755_set_channel_pwr_down(struct iio_dev *indio_dev,
+	unsigned int channel, bool pwr_down)
+{
+	struct ad5755_state *st = iio_priv(indio_dev);
+	unsigned int mask = BIT(channel);
+
+	mutex_lock(&indio_dev->mlock);
+
+	if ((bool)(st->pwr_down & mask) == pwr_down)
+		goto out_unlock;
+
+	if (!pwr_down) {
+		st->pwr_down &= ~mask;
+		ad5755_update_dac_ctrl(indio_dev, channel,
+			AD5755_DAC_INT_EN | AD5755_DAC_DC_DC_EN, 0);
+		udelay(200);
+		ad5755_update_dac_ctrl(indio_dev, channel,
+			AD5755_DAC_OUT_EN, 0);
+	} else {
+		st->pwr_down |= mask;
+		ad5755_update_dac_ctrl(indio_dev, channel,
+			0, AD5755_DAC_INT_EN | AD5755_DAC_OUT_EN |
+				AD5755_DAC_DC_DC_EN);
+	}
+
+out_unlock:
+	mutex_unlock(&indio_dev->mlock);
+
+	return 0;
+}
+
+static const int ad5755_min_max_table[][2] = {
+	[AD5755_MODE_VOLTAGE_0V_5V] = { 0, 5000 },
+	[AD5755_MODE_VOLTAGE_0V_10V] = { 0, 10000 },
+	[AD5755_MODE_VOLTAGE_PLUSMINUS_5V] = { -5000, 5000 },
+	[AD5755_MODE_VOLTAGE_PLUSMINUS_10V] = { -10000, 10000 },
+	[AD5755_MODE_CURRENT_4mA_20mA] = { 4, 20 },
+	[AD5755_MODE_CURRENT_0mA_20mA] = { 0, 20 },
+	[AD5755_MODE_CURRENT_0mA_24mA] = { 0, 24 },
+};
+
+static void ad5755_get_min_max(struct ad5755_state *st,
+	struct iio_chan_spec const *chan, int *min, int *max)
+{
+	enum ad5755_mode mode = st->ctrl[chan->channel] & 7;
+	*min = ad5755_min_max_table[mode][0];
+	*max = ad5755_min_max_table[mode][1];
+}
+
+static inline int ad5755_get_offset(struct ad5755_state *st,
+	struct iio_chan_spec const *chan)
+{
+	int min, max;
+
+	ad5755_get_min_max(st, chan, &min, &max);
+	return (min * (1 << chan->scan_type.realbits)) / (max - min);
+}
+
+static inline int ad5755_get_scale(struct ad5755_state *st,
+	struct iio_chan_spec const *chan)
+{
+	int min, max;
+
+	ad5755_get_min_max(st, chan, &min, &max);
+	return ((max - min) * 1000000000ULL) >> chan->scan_type.realbits;
+}
+
+static int ad5755_chan_reg_info(struct ad5755_state *st,
+	struct iio_chan_spec const *chan, long info, bool write,
+	unsigned int *reg, unsigned int *shift, unsigned int *offset)
+{
+	switch (info) {
+	case IIO_CHAN_INFO_RAW:
+		if (write)
+			*reg = AD5755_WRITE_REG_DATA(chan->address);
+		else
+			*reg = AD5755_READ_REG_DATA(chan->address);
+		*shift = chan->scan_type.shift;
+		*offset = 0;
+		break;
+	case IIO_CHAN_INFO_CALIBBIAS:
+		if (write)
+			*reg = AD5755_WRITE_REG_OFFSET(chan->address);
+		else
+			*reg = AD5755_READ_REG_OFFSET(chan->address);
+		*shift = st->chip_info->calib_shift;
+		*offset = 32768;
+		break;
+	case IIO_CHAN_INFO_CALIBSCALE:
+		if (write)
+			*reg =  AD5755_WRITE_REG_GAIN(chan->address);
+		else
+			*reg =  AD5755_READ_REG_GAIN(chan->address);
+		*shift = st->chip_info->calib_shift;
+		*offset = 0;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int ad5755_read_raw(struct iio_dev *indio_dev,
+	const struct iio_chan_spec *chan, int *val, int *val2, long info)
+{
+	struct ad5755_state *st = iio_priv(indio_dev);
+	unsigned int reg, shift, offset;
+	int ret;
+
+	switch (info) {
+	case IIO_CHAN_INFO_SCALE:
+		*val = 0;
+		*val2 = ad5755_get_scale(st, chan);
+		return IIO_VAL_INT_PLUS_NANO;
+	case IIO_CHAN_INFO_OFFSET:
+		*val = ad5755_get_offset(st, chan);
+		return IIO_VAL_INT;
+	default:
+		ret = ad5755_chan_reg_info(st, chan, info, false,
+						&reg, &shift, &offset);
+		if (ret)
+			return ret;
+
+		ret = ad5755_read(indio_dev, reg);
+		if (ret < 0)
+			return ret;
+
+		*val = (ret - offset) >> shift;
+
+		return IIO_VAL_INT;
+	}
+
+	return -EINVAL;
+}
+
+static int ad5755_write_raw(struct iio_dev *indio_dev,
+	const struct iio_chan_spec *chan, int val, int val2, long info)
+{
+	struct ad5755_state *st = iio_priv(indio_dev);
+	unsigned int shift, reg, offset;
+	int ret;
+
+	ret = ad5755_chan_reg_info(st, chan, info, true,
+					&reg, &shift, &offset);
+	if (ret)
+		return ret;
+
+	val <<= shift;
+	val += offset;
+
+	if (val < 0 || val > 0xffff)
+		return -EINVAL;
+
+	return ad5755_write(indio_dev, reg, val);
+}
+
+static ssize_t ad5755_read_powerdown(struct iio_dev *indio_dev, uintptr_t priv,
+	const struct iio_chan_spec *chan, char *buf)
+{
+	struct ad5755_state *st = iio_priv(indio_dev);
+
+	return sprintf(buf, "%d\n",
+		       (bool)(st->pwr_down & (1 << chan->channel)));
+}
+
+static ssize_t ad5755_write_powerdown(struct iio_dev *indio_dev, uintptr_t priv,
+	struct iio_chan_spec const *chan, const char *buf, size_t len)
+{
+	bool pwr_down;
+	int ret;
+
+	ret = strtobool(buf, &pwr_down);
+	if (ret)
+		return ret;
+
+	ret = ad5755_set_channel_pwr_down(indio_dev, chan->channel, pwr_down);
+	return ret ? ret : len;
+}
+
+static const struct iio_info ad5755_info = {
+	.read_raw = ad5755_read_raw,
+	.write_raw = ad5755_write_raw,
+	.driver_module = THIS_MODULE,
+};
+
+static const struct iio_chan_spec_ext_info ad5755_ext_info[] = {
+	{
+		.name = "powerdown",
+		.read = ad5755_read_powerdown,
+		.write = ad5755_write_powerdown,
+	},
+	{ },
+};
+
+#define AD5755_CHANNEL(_bits) {					\
+	.indexed = 1,						\
+	.output = 1,						\
+	.info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT |		\
+		IIO_CHAN_INFO_SCALE_SEPARATE_BIT |		\
+		IIO_CHAN_INFO_OFFSET_SEPARATE_BIT |		\
+		IIO_CHAN_INFO_CALIBSCALE_SEPARATE_BIT |		\
+		IIO_CHAN_INFO_CALIBBIAS_SEPARATE_BIT,		\
+	.scan_type = IIO_ST('u', (_bits), 16, 16 - (_bits)),	\
+	.ext_info = ad5755_ext_info,				\
+}
+
+static const struct ad5755_chip_info ad5755_chip_info_tbl[] = {
+	[ID_AD5735] = {
+		.channel_template = AD5755_CHANNEL(14),
+		.has_voltage_out = true,
+		.calib_shift = 4,
+	},
+	[ID_AD5737] = {
+		.channel_template = AD5755_CHANNEL(14),
+		.has_voltage_out = false,
+		.calib_shift = 4,
+	},
+	[ID_AD5755] = {
+		.channel_template = AD5755_CHANNEL(16),
+		.has_voltage_out = true,
+		.calib_shift = 0,
+	},
+	[ID_AD5757] = {
+		.channel_template = AD5755_CHANNEL(16),
+		.has_voltage_out = false,
+		.calib_shift = 0,
+	},
+};
+
+static bool ad5755_is_valid_mode(struct ad5755_state *st, enum ad5755_mode mode)
+{
+	switch (mode) {
+	case AD5755_MODE_VOLTAGE_0V_5V:
+	case AD5755_MODE_VOLTAGE_0V_10V:
+	case AD5755_MODE_VOLTAGE_PLUSMINUS_5V:
+	case AD5755_MODE_VOLTAGE_PLUSMINUS_10V:
+		return st->chip_info->has_voltage_out;
+	case AD5755_MODE_CURRENT_4mA_20mA:
+	case AD5755_MODE_CURRENT_0mA_20mA:
+	case AD5755_MODE_CURRENT_0mA_24mA:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static int __devinit ad5755_setup_pdata(struct iio_dev *indio_dev,
+	const struct ad5755_platform_data *pdata)
+{
+	struct ad5755_state *st = iio_priv(indio_dev);
+	unsigned int ret;
+	unsigned int val;
+	unsigned int i;
+
+	if (pdata->dc_dc_phase > AD5755_DC_DC_PHASE_90_DEGREE ||
+		pdata->dc_dc_freq > AD5755_DC_DC_FREQ_650kHZ ||
+		pdata->dc_dc_maxv > AD5755_DC_DC_MAXV_29V5)
+		return -EINVAL;
+
+	val = pdata->dc_dc_maxv << AD5755_DC_DC_MAXV;
+	val |= pdata->dc_dc_freq << AD5755_DC_DC_FREQ_SHIFT;
+	val |= pdata->dc_dc_phase << AD5755_DC_DC_PHASE_SHIFT;
+	if (pdata->ext_dc_dc_compenstation_resistor)
+		val |= AD5755_EXT_DC_DC_COMP_RES;
+
+	ret = ad5755_write_ctrl(indio_dev, 0, AD5755_CTRL_REG_DC_DC, val);
+	if (ret < 0)
+		return ret;
+
+	for (i = 0; i < ARRAY_SIZE(pdata->dac); ++i) {
+		val = pdata->dac[i].slew.step_size <<
+			AD5755_SLEW_STEP_SIZE_SHIFT;
+		val |= pdata->dac[i].slew.rate <<
+			AD5755_SLEW_RATE_SHIFT;
+		if (pdata->dac[i].slew.enable)
+			val |= AD5755_SLEW_ENABLE;
+
+		ret = ad5755_write_ctrl(indio_dev, i,
+					AD5755_CTRL_REG_SLEW, val);
+		if (ret < 0)
+			return ret;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(pdata->dac); ++i) {
+		if (!ad5755_is_valid_mode(st, pdata->dac[i].mode))
+			return -EINVAL;
+
+		val = 0;
+		if (!pdata->dac[i].ext_current_sense_resistor)
+			val |= AD5755_DAC_INT_CURRENT_SENSE_RESISTOR;
+		if (pdata->dac[i].enable_voltage_overrange)
+			val |= AD5755_DAC_VOLTAGE_OVERRANGE_EN;
+		val |= pdata->dac[i].mode;
+
+		ret = ad5755_update_dac_ctrl(indio_dev, i, val, 0);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
+static bool __devinit ad5755_is_voltage_mode(enum ad5755_mode mode)
+{
+	switch (mode) {
+	case AD5755_MODE_VOLTAGE_0V_5V:
+	case AD5755_MODE_VOLTAGE_0V_10V:
+	case AD5755_MODE_VOLTAGE_PLUSMINUS_5V:
+	case AD5755_MODE_VOLTAGE_PLUSMINUS_10V:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static int __devinit ad5755_init_channels(struct iio_dev *indio_dev,
+	const struct ad5755_platform_data *pdata)
+{
+	struct ad5755_state *st = iio_priv(indio_dev);
+	struct iio_chan_spec *channels = st->channels;
+	unsigned int i;
+
+	for (i = 0; i < AD5755_NUM_CHANNELS; ++i) {
+		channels[i] = st->chip_info->channel_template;
+		channels[i].channel = i;
+		channels[i].address = i;
+		if (pdata && ad5755_is_voltage_mode(pdata->dac[i].mode))
+			channels[i].type = IIO_VOLTAGE;
+		else
+			channels[i].type = IIO_CURRENT;
+	}
+
+	indio_dev->channels = channels;
+
+	return 0;
+}
+
+#define AD5755_DEFAULT_DAC_PDATA { \
+		.mode = AD5755_MODE_CURRENT_4mA_20mA, \
+		.ext_current_sense_resistor = true, \
+		.enable_voltage_overrange = false, \
+		.slew = { \
+			.enable = false, \
+			.rate = AD5755_SLEW_RATE_64k, \
+			.step_size = AD5755_SLEW_STEP_SIZE_1, \
+		}, \
+	}
+
+static const struct ad5755_platform_data ad5755_default_pdata = {
+	.ext_dc_dc_compenstation_resistor = false,
+	.dc_dc_phase = AD5755_DC_DC_PHASE_ALL_SAME_EDGE,
+	.dc_dc_freq = AD5755_DC_DC_FREQ_410kHZ,
+	.dc_dc_maxv = AD5755_DC_DC_MAXV_23V,
+	.dac = {
+		[0] = AD5755_DEFAULT_DAC_PDATA,
+		[1] = AD5755_DEFAULT_DAC_PDATA,
+		[2] = AD5755_DEFAULT_DAC_PDATA,
+		[3] = AD5755_DEFAULT_DAC_PDATA,
+	},
+};
+
+static int __devinit ad5755_probe(struct spi_device *spi)
+{
+	enum ad5755_type type = spi_get_device_id(spi)->driver_data;
+	const struct ad5755_platform_data *pdata = dev_get_platdata(&spi->dev);
+	struct iio_dev *indio_dev;
+	struct ad5755_state *st;
+	int ret;
+
+	indio_dev = iio_device_alloc(sizeof(*st));
+	if (indio_dev == NULL) {
+		dev_err(&spi->dev, "Failed to allocate iio device\n");
+		return  -ENOMEM;
+	}
+
+	st = iio_priv(indio_dev);
+	spi_set_drvdata(spi, indio_dev);
+
+	st->chip_info = &ad5755_chip_info_tbl[type];
+	st->spi = spi;
+	st->pwr_down = 0xf;
+
+	indio_dev->dev.parent = &spi->dev;
+	indio_dev->name = spi_get_device_id(spi)->name;
+	indio_dev->info = &ad5755_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->num_channels = AD5755_NUM_CHANNELS;
+
+	if (!pdata)
+		pdata = &ad5755_default_pdata;
+
+	ret = ad5755_init_channels(indio_dev, pdata);
+	if (ret)
+		goto error_free;
+
+	ret = ad5755_setup_pdata(indio_dev, pdata);
+	if (ret)
+		goto error_free;
+
+	ret = iio_device_register(indio_dev);
+	if (ret) {
+		dev_err(&spi->dev, "Failed to register iio device: %d\n", ret);
+		goto error_free;
+	}
+
+	return 0;
+
+error_free:
+	iio_device_free(indio_dev);
+
+	return ret;
+}
+
+static int __devexit ad5755_remove(struct spi_device *spi)
+{
+	struct iio_dev *indio_dev = spi_get_drvdata(spi);
+
+	iio_device_unregister(indio_dev);
+	iio_device_free(indio_dev);
+
+	return 0;
+}
+
+static const struct spi_device_id ad5755_id[] = {
+	{ "ad5755", ID_AD5755 },
+	{ "ad5755-1", ID_AD5755 },
+	{ "ad5757", ID_AD5757 },
+	{ "ad5735", ID_AD5735 },
+	{ "ad5737", ID_AD5737 },
+	{}
+};
+MODULE_DEVICE_TABLE(spi, ad5755_id);
+
+static struct spi_driver ad5755_driver = {
+	.driver = {
+		.name = "ad5755",
+		.owner = THIS_MODULE,
+	},
+	.probe = ad5755_probe,
+	.remove = __devexit_p(ad5755_remove),
+	.id_table = ad5755_id,
+};
+module_spi_driver(ad5755_driver);
+
+MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
+MODULE_DESCRIPTION("Analog Devices AD5755/55-1/57/35/37 DAC");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index 0499330d6e98..6eb24dbc081e 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -366,6 +366,7 @@ static ssize_t iio_read_channel_info(struct device *dev,
 {
 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+	unsigned long long tmp;
 	int val, val2;
 	bool scale_db = false;
 	int ret = indio_dev->info->read_raw(indio_dev, this_attr->c,
@@ -391,6 +392,11 @@ static ssize_t iio_read_channel_info(struct device *dev,
 			return sprintf(buf, "-%d.%09u\n", val, -val2);
 		else
 			return sprintf(buf, "%d.%09u\n", val, val2);
+	case IIO_VAL_FRACTIONAL:
+		tmp = div_s64((s64)val * 1000000000LL, val2);
+		val2 = do_div(tmp, 1000000000LL);
+		val = tmp;
+		return sprintf(buf, "%d.%09u\n", val, val2);
 	default:
 		return 0;
 	}
diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c
index a14e55dd8ddc..25b00761005a 100644
--- a/drivers/iio/inkern.c
+++ b/drivers/iio/inkern.c
@@ -130,18 +130,27 @@ struct iio_channel *iio_channel_get(const char *name, const char *channel_name)
 	if (c == NULL)
 		return ERR_PTR(-ENODEV);
 
-	channel = kmalloc(sizeof(*channel), GFP_KERNEL);
+	channel = kzalloc(sizeof(*channel), GFP_KERNEL);
 	if (channel == NULL)
 		return ERR_PTR(-ENOMEM);
 
 	channel->indio_dev = c->indio_dev;
 
-	if (c->map->adc_channel_label)
+	if (c->map->adc_channel_label) {
 		channel->channel =
 			iio_chan_spec_from_name(channel->indio_dev,
 						c->map->adc_channel_label);
 
+		if (channel->channel == NULL)
+			goto error_no_chan;
+	}
+
 	return channel;
+
+error_no_chan:
+	iio_device_put(c->indio_dev);
+	kfree(channel);
+	return ERR_PTR(-EINVAL);
 }
 EXPORT_SYMBOL_GPL(iio_channel_get);
 
@@ -229,9 +238,21 @@ void iio_channel_release_all(struct iio_channel *channels)
 }
 EXPORT_SYMBOL_GPL(iio_channel_release_all);
 
+static int iio_channel_read(struct iio_channel *chan, int *val, int *val2,
+	enum iio_chan_info_enum info)
+{
+	int unused;
+
+	if (val2 == NULL)
+		val2 = &unused;
+
+	return chan->indio_dev->info->read_raw(chan->indio_dev, chan->channel,
+						val, val2, info);
+}
+
 int iio_read_channel_raw(struct iio_channel *chan, int *val)
 {
-	int val2, ret;
+	int ret;
 
 	mutex_lock(&chan->indio_dev->info_exist_lock);
 	if (chan->indio_dev->info == NULL) {
@@ -239,10 +260,7 @@ int iio_read_channel_raw(struct iio_channel *chan, int *val)
 		goto err_unlock;
 	}
 
-	ret = chan->indio_dev->info->read_raw(chan->indio_dev,
-					      chan->channel,
-					      val, &val2,
-					      IIO_CHAN_INFO_RAW);
+	ret = iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_RAW);
 err_unlock:
 	mutex_unlock(&chan->indio_dev->info_exist_lock);
 
@@ -250,6 +268,100 @@ err_unlock:
 }
 EXPORT_SYMBOL_GPL(iio_read_channel_raw);
 
+static int iio_convert_raw_to_processed_unlocked(struct iio_channel *chan,
+	int raw, int *processed, unsigned int scale)
+{
+	int scale_type, scale_val, scale_val2, offset;
+	s64 raw64 = raw;
+	int ret;
+
+	ret = iio_channel_read(chan, &offset, NULL, IIO_CHAN_INFO_SCALE);
+	if (ret == 0)
+		raw64 += offset;
+
+	scale_type = iio_channel_read(chan, &scale_val, &scale_val2,
+					IIO_CHAN_INFO_SCALE);
+	if (scale_type < 0)
+		return scale_type;
+
+	switch (scale_type) {
+	case IIO_VAL_INT:
+		*processed = raw64 * scale_val;
+		break;
+	case IIO_VAL_INT_PLUS_MICRO:
+		if (scale_val2 < 0)
+			*processed = -raw64 * scale_val;
+		else
+			*processed = raw64 * scale_val;
+		*processed += div_s64(raw64 * (s64)scale_val2 * scale,
+				      1000000LL);
+		break;
+	case IIO_VAL_INT_PLUS_NANO:
+		if (scale_val2 < 0)
+			*processed = -raw64 * scale_val;
+		else
+			*processed = raw64 * scale_val;
+		*processed += div_s64(raw64 * (s64)scale_val2 * scale,
+				      1000000000LL);
+		break;
+	case IIO_VAL_FRACTIONAL:
+		*processed = div_s64(raw64 * (s64)scale_val * scale,
+				     scale_val2);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+int iio_convert_raw_to_processed(struct iio_channel *chan, int raw,
+	int *processed, unsigned int scale)
+{
+	int ret;
+
+	mutex_lock(&chan->indio_dev->info_exist_lock);
+	if (chan->indio_dev->info == NULL) {
+		ret = -ENODEV;
+		goto err_unlock;
+	}
+
+	ret = iio_convert_raw_to_processed_unlocked(chan, raw, processed,
+							scale);
+err_unlock:
+	mutex_unlock(&chan->indio_dev->info_exist_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(iio_convert_raw_to_processed);
+
+int iio_read_channel_processed(struct iio_channel *chan, int *val)
+{
+	int ret;
+
+	mutex_lock(&chan->indio_dev->info_exist_lock);
+	if (chan->indio_dev->info == NULL) {
+		ret = -ENODEV;
+		goto err_unlock;
+	}
+
+	if (iio_channel_has_info(chan->channel, IIO_CHAN_INFO_PROCESSED)) {
+		ret = iio_channel_read(chan, val, NULL,
+				       IIO_CHAN_INFO_PROCESSED);
+	} else {
+		ret = iio_channel_read(chan, val, NULL, IIO_CHAN_INFO_RAW);
+		if (ret < 0)
+			goto err_unlock;
+		ret = iio_convert_raw_to_processed_unlocked(chan, *val, val, 1);
+	}
+
+err_unlock:
+	mutex_unlock(&chan->indio_dev->info_exist_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(iio_read_channel_processed);
+
 int iio_read_channel_scale(struct iio_channel *chan, int *val, int *val2)
 {
 	int ret;
@@ -260,10 +372,7 @@ int iio_read_channel_scale(struct iio_channel *chan, int *val, int *val2)
 		goto err_unlock;
 	}
 
-	ret = chan->indio_dev->info->read_raw(chan->indio_dev,
-					      chan->channel,
-					      val, val2,
-					      IIO_CHAN_INFO_SCALE);
+	ret = iio_channel_read(chan, val, val2, IIO_CHAN_INFO_SCALE);
 err_unlock:
 	mutex_unlock(&chan->indio_dev->info_exist_lock);