Merge tag 'staging-3.6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging

Pull staging tree update from Greg Kroah-Hartman:
 "Here is the big staging tree update for the 3.7-rc1 merge window.

  There are a few patches in here that are outside of the staging area,
  namely HID and IIO patches, but all of them have been acked by the
  relevant subsystem maintainers.  The IIO stuff is still coming in
  through this tree as it hasn't entirely moved out of the staging tree,
  but is almost there.

  Other than that, there wa a ton of work on the comedi drivers to make
  them more readable and the correct style.  Doing that removed a lot of
  code, but we added a new driver to the staging tree, so we didn't end
  up with a net reduction this time around:

   662 files changed, 51649 insertions(+), 26582 deletions(-)

  All of these patches have been in the linux-next tree already.

  Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>"

* tag 'staging-3.6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (1094 commits)
  staging: comedi: jr3_pci: fix iomem dereference
  staging: comedi: drivers: use comedi_fc.h cmdtest helpers
  Staging: winbond: usb_free_urb(NULL) is safe
  Staging: winbond: checkpatch cleanup
  Staging: winbond: Removed undesired spaces, lines and tabs
  Staging: winbond: Typo corrections in comments
  Staging: winbond: Changed c99 comments to c89 comments
  staging: r8712u: Do not queue cloned skb
  staging: comedi: ni_mio_common: always lock in ni_ai_poll()
  staging: comedi: s626: add FIXME comment
  staging: comedi: s626: don't dereference insn->data
  staging: comedi: s526: fix if() check in s526_gpct_winsn()
  staging: comedi: s626: cleanup comments in s626_initialize()
  staging: comedi: s626: remove clear of kzalloc'ed data
  staging: comedi: s626: remove 'WDInterval' from private data
  staging: comedi: s626: remove 'ChargeEnabled' from private data
  staging: comedi: s626: remove 'IsBoardRevA' comment
  staging: comedi: s626: #if 0 out the "SAA7146 BUG WORKAROUND"
  staging: comedi: s626: remove 'allocatedBuf' from private data
  staging: comedi: s626: add final attach message
  ...

8 files changed, 1675 insertions, 60 deletions

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 8a78b4f3ef58..492758120338 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -3,6 +3,11 @@
 #
 menu "Analog to digital converters"
 
+config AD_SIGMA_DELTA
+	tristate
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
+
 config AD7266
 	tristate "Analog Devices AD7265/AD7266 ADC driver"
 	depends on SPI_MASTER
@@ -13,6 +18,33 @@ config AD7266
 	  Say yes here to build support for Analog Devices AD7265 and AD7266
 	  ADCs.
 
+config AD7791
+	tristate "Analog Devices AD7791 ADC driver"
+	depends on SPI
+	select AD_SIGMA_DELTA
+	help
+	  Say yes here to build support for Analog Devices AD7787, AD7788, AD7789,
+	  AD7790 and AD7791 SPI analog to digital converters (ADC). If unsure, say
+	  N (but it is safe to say "Y").
+
+	  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
@@ -22,4 +54,10 @@ config AT91_ADC
 	help
 	  Say yes here to build support for Atmel AT91 ADC.
 
+config LP8788_ADC
+	bool "LP8788 ADC driver"
+	depends on MFD_LP8788
+	help
+	  Say yes here to build support for TI LP8788 ADC.
+
 endmenu
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 52eec254c38c..900995d5e179 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -2,5 +2,9 @@
 # Makefile for IIO ADC drivers
 #
 
+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-$(CONFIG_AT91_ADC) += at91_adc.o
+obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o
diff --git a/drivers/iio/adc/ad7266.c b/drivers/iio/adc/ad7266.c
index 5c3f1ba5a06d..b11f214779a2 100644
--- a/drivers/iio/adc/ad7266.c
+++ b/drivers/iio/adc/ad7266.c
@@ -99,7 +99,7 @@ static irqreturn_t ad7266_trigger_handler(int irq, void *p)
 	if (ret == 0) {
 		if (indio_dev->scan_timestamp)
 			((s64 *)st->data)[1] = pf->timestamp;
-		iio_push_to_buffer(buffer, (u8 *)st->data, pf->timestamp);
+		iio_push_to_buffer(buffer, (u8 *)st->data);
 	}
 
 	iio_trigger_notify_done(indio_dev->trig);
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/adc/ad7791.c b/drivers/iio/adc/ad7791.c
new file mode 100644
index 000000000000..e93740843b2b
--- /dev/null
+++ b/drivers/iio/adc/ad7791.c
@@ -0,0 +1,460 @@
+/*
+ * AD7787/AD7788/AD7789/AD7790/AD7791 SPI ADC driver
+ *
+ * Copyright 2012 Analog Devices Inc.
+ *  Author: Lars-Peter Clausen <lars@metafoo.de>
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/interrupt.h>
+#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/sched.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/adc/ad_sigma_delta.h>
+
+#include <linux/platform_data/ad7791.h>
+
+#define AD7791_REG_COMM			0x0 /* For writes */
+#define AD7791_REG_STATUS		0x0 /* For reads */
+#define AD7791_REG_MODE			0x1
+#define AD7791_REG_FILTER		0x2
+#define AD7791_REG_DATA			0x3
+
+#define AD7791_MODE_CONTINUOUS		0x00
+#define AD7791_MODE_SINGLE		0x02
+#define AD7791_MODE_POWERDOWN		0x03
+
+#define AD7791_CH_AIN1P_AIN1N		0x00
+#define AD7791_CH_AIN2			0x01
+#define AD7791_CH_AIN1N_AIN1N		0x02
+#define AD7791_CH_AVDD_MONITOR		0x03
+
+#define AD7791_FILTER_CLK_DIV_1		(0x0 << 4)
+#define AD7791_FILTER_CLK_DIV_2		(0x1 << 4)
+#define AD7791_FILTER_CLK_DIV_4		(0x2 << 4)
+#define AD7791_FILTER_CLK_DIV_8		(0x3 << 4)
+#define AD7791_FILTER_CLK_MASK		(0x3 << 4)
+#define AD7791_FILTER_RATE_120		0x0
+#define AD7791_FILTER_RATE_100		0x1
+#define AD7791_FILTER_RATE_33_3		0x2
+#define AD7791_FILTER_RATE_20		0x3
+#define AD7791_FILTER_RATE_16_6		0x4
+#define AD7791_FILTER_RATE_16_7		0x5
+#define AD7791_FILTER_RATE_13_3		0x6
+#define AD7791_FILTER_RATE_9_5		0x7
+#define AD7791_FILTER_RATE_MASK		0x7
+
+#define AD7791_MODE_BUFFER		BIT(1)
+#define AD7791_MODE_UNIPOLAR		BIT(2)
+#define AD7791_MODE_BURNOUT		BIT(3)
+#define AD7791_MODE_SEL_MASK		(0x3 << 6)
+#define AD7791_MODE_SEL(x)		((x) << 6)
+
+#define DECLARE_AD7787_CHANNELS(name, bits, storagebits) \
+const struct iio_chan_spec name[] = { \
+	AD_SD_DIFF_CHANNEL(0, 0, 0, AD7791_CH_AIN1P_AIN1N, \
+		(bits), (storagebits), 0), \
+	AD_SD_CHANNEL(1, 1, AD7791_CH_AIN2, (bits), (storagebits), 0), \
+	AD_SD_SHORTED_CHANNEL(2, 0, AD7791_CH_AIN1N_AIN1N, \
+		(bits), (storagebits), 0), \
+	AD_SD_SUPPLY_CHANNEL(3, 2, AD7791_CH_AVDD_MONITOR,  \
+		(bits), (storagebits), 0), \
+	IIO_CHAN_SOFT_TIMESTAMP(4), \
+}
+
+#define DECLARE_AD7791_CHANNELS(name, bits, storagebits) \
+const struct iio_chan_spec name[] = { \
+	AD_SD_DIFF_CHANNEL(0, 0, 0, AD7791_CH_AIN1P_AIN1N, \
+		(bits), (storagebits), 0), \
+	AD_SD_SHORTED_CHANNEL(1, 0, AD7791_CH_AIN1N_AIN1N, \
+		(bits), (storagebits), 0), \
+	AD_SD_SUPPLY_CHANNEL(2, 1, AD7791_CH_AVDD_MONITOR, \
+		(bits), (storagebits), 0), \
+	IIO_CHAN_SOFT_TIMESTAMP(3), \
+}
+
+static DECLARE_AD7787_CHANNELS(ad7787_channels, 24, 32);
+static DECLARE_AD7791_CHANNELS(ad7790_channels, 16, 16);
+static DECLARE_AD7791_CHANNELS(ad7791_channels, 24, 32);
+
+enum {
+	AD7787,
+	AD7788,
+	AD7789,
+	AD7790,
+	AD7791,
+};
+
+enum ad7791_chip_info_flags {
+	AD7791_FLAG_HAS_FILTER		= (1 << 0),
+	AD7791_FLAG_HAS_BUFFER		= (1 << 1),
+	AD7791_FLAG_HAS_UNIPOLAR	= (1 << 2),
+	AD7791_FLAG_HAS_BURNOUT		= (1 << 3),
+};
+
+struct ad7791_chip_info {
+	const struct iio_chan_spec *channels;
+	unsigned int num_channels;
+	enum ad7791_chip_info_flags flags;
+};
+
+static const struct ad7791_chip_info ad7791_chip_infos[] = {
+	[AD7787] = {
+		.channels = ad7787_channels,
+		.num_channels = ARRAY_SIZE(ad7787_channels),
+		.flags = AD7791_FLAG_HAS_FILTER | AD7791_FLAG_HAS_BUFFER |
+			AD7791_FLAG_HAS_UNIPOLAR | AD7791_FLAG_HAS_BURNOUT,
+	},
+	[AD7788] = {
+		.channels = ad7790_channels,
+		.num_channels = ARRAY_SIZE(ad7790_channels),
+		.flags = AD7791_FLAG_HAS_UNIPOLAR,
+	},
+	[AD7789] = {
+		.channels = ad7791_channels,
+		.num_channels = ARRAY_SIZE(ad7791_channels),
+		.flags = AD7791_FLAG_HAS_UNIPOLAR,
+	},
+	[AD7790] = {
+		.channels = ad7790_channels,
+		.num_channels = ARRAY_SIZE(ad7790_channels),
+		.flags = AD7791_FLAG_HAS_FILTER | AD7791_FLAG_HAS_BUFFER |
+			AD7791_FLAG_HAS_BURNOUT,
+	},
+	[AD7791] = {
+		.channels = ad7791_channels,
+		.num_channels = ARRAY_SIZE(ad7791_channels),
+		.flags = AD7791_FLAG_HAS_FILTER | AD7791_FLAG_HAS_BUFFER |
+			AD7791_FLAG_HAS_UNIPOLAR | AD7791_FLAG_HAS_BURNOUT,
+	},
+};
+
+struct ad7791_state {
+	struct ad_sigma_delta sd;
+	uint8_t mode;
+	uint8_t filter;
+
+	struct regulator *reg;
+	const struct ad7791_chip_info *info;
+};
+
+static struct ad7791_state *ad_sigma_delta_to_ad7791(struct ad_sigma_delta *sd)
+{
+	return container_of(sd, struct ad7791_state, sd);
+}
+
+static int ad7791_set_channel(struct ad_sigma_delta *sd, unsigned int channel)
+{
+	ad_sd_set_comm(sd, channel);
+
+	return 0;
+}
+
+static int ad7791_set_mode(struct ad_sigma_delta *sd,
+	enum ad_sigma_delta_mode mode)
+{
+	struct ad7791_state *st = ad_sigma_delta_to_ad7791(sd);
+
+	switch (mode) {
+	case AD_SD_MODE_CONTINUOUS:
+		mode = AD7791_MODE_CONTINUOUS;
+		break;
+	case AD_SD_MODE_SINGLE:
+		mode = AD7791_MODE_SINGLE;
+		break;
+	case AD_SD_MODE_IDLE:
+	case AD_SD_MODE_POWERDOWN:
+		mode = AD7791_MODE_POWERDOWN;
+		break;
+	}
+
+	st->mode &= ~AD7791_MODE_SEL_MASK;
+	st->mode |= AD7791_MODE_SEL(mode);
+
+	return ad_sd_write_reg(sd, AD7791_REG_MODE, sizeof(st->mode), st->mode);
+}
+
+static const struct ad_sigma_delta_info ad7791_sigma_delta_info = {
+	.set_channel = ad7791_set_channel,
+	.set_mode = ad7791_set_mode,
+	.has_registers = true,
+	.addr_shift = 4,
+	.read_mask = BIT(3),
+};
+
+static int ad7791_read_raw(struct iio_dev *indio_dev,
+	const struct iio_chan_spec *chan, int *val, int *val2, long info)
+{
+	struct ad7791_state *st = iio_priv(indio_dev);
+	bool unipolar = !!(st->mode & AD7791_MODE_UNIPOLAR);
+	unsigned long long scale_pv;
+
+	switch (info) {
+	case IIO_CHAN_INFO_RAW:
+		return ad_sigma_delta_single_conversion(indio_dev, chan, val);
+	case IIO_CHAN_INFO_OFFSET:
+		/**
+		 * Unipolar: 0 to VREF
+		 * Bipolar -VREF to VREF
+		 **/
+		if (unipolar)
+			*val = 0;
+		else
+			*val = -(1 << (chan->scan_type.realbits - 1));
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		/* The monitor channel uses an internal reference. */
+		if (chan->address == AD7791_CH_AVDD_MONITOR) {
+			scale_pv = 5850000000000ULL;
+		} else {
+			int voltage_uv;
+
+			voltage_uv = regulator_get_voltage(st->reg);
+			if (voltage_uv < 0)
+				return voltage_uv;
+			scale_pv = (unsigned long long)voltage_uv * 1000000;
+		}
+		if (unipolar)
+			scale_pv >>= chan->scan_type.realbits;
+		else
+			scale_pv >>= chan->scan_type.realbits - 1;
+		*val2 = do_div(scale_pv, 1000000000);
+		*val = scale_pv;
+
+		return IIO_VAL_INT_PLUS_NANO;
+	}
+
+	return -EINVAL;
+}
+
+static const char * const ad7791_sample_freq_avail[] = {
+	[AD7791_FILTER_RATE_120] = "120",
+	[AD7791_FILTER_RATE_100] = "100",
+	[AD7791_FILTER_RATE_33_3] = "33.3",
+	[AD7791_FILTER_RATE_20] = "20",
+	[AD7791_FILTER_RATE_16_6] = "16.6",
+	[AD7791_FILTER_RATE_16_7] = "16.7",
+	[AD7791_FILTER_RATE_13_3] = "13.3",
+	[AD7791_FILTER_RATE_9_5] = "9.5",
+};
+
+static ssize_t ad7791_read_frequency(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct ad7791_state *st = iio_priv(indio_dev);
+	unsigned int rate = st->filter & AD7791_FILTER_RATE_MASK;
+
+	return sprintf(buf, "%s\n", ad7791_sample_freq_avail[rate]);
+}
+
+static ssize_t ad7791_write_frequency(struct device *dev,
+	struct device_attribute *attr, const char *buf, size_t len)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct ad7791_state *st = iio_priv(indio_dev);
+	int i, ret;
+
+	mutex_lock(&indio_dev->mlock);
+	if (iio_buffer_enabled(indio_dev)) {
+		mutex_unlock(&indio_dev->mlock);
+		return -EBUSY;
+	}
+	mutex_unlock(&indio_dev->mlock);
+
+	ret = -EINVAL;
+
+	for (i = 0; i < ARRAY_SIZE(ad7791_sample_freq_avail); i++) {
+		if (sysfs_streq(ad7791_sample_freq_avail[i], buf)) {
+
+			mutex_lock(&indio_dev->mlock);
+			st->filter &= ~AD7791_FILTER_RATE_MASK;
+			st->filter |= i;
+			ad_sd_write_reg(&st->sd, AD7791_REG_FILTER,
+					 sizeof(st->filter), st->filter);
+			mutex_unlock(&indio_dev->mlock);
+			ret = 0;
+			break;
+		}
+	}
+
+	return ret ? ret : len;
+}
+
+static IIO_DEV_ATTR_SAMP_FREQ(S_IWUSR | S_IRUGO,
+		ad7791_read_frequency,
+		ad7791_write_frequency);
+
+static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("120 100 33.3 20 16.7 16.6 13.3 9.5");
+
+static struct attribute *ad7791_attributes[] = {
+	&iio_dev_attr_sampling_frequency.dev_attr.attr,
+	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
+	NULL
+};
+
+static const struct attribute_group ad7791_attribute_group = {
+	.attrs = ad7791_attributes,
+};
+
+static const struct iio_info ad7791_info = {
+	.read_raw = &ad7791_read_raw,
+	.attrs = &ad7791_attribute_group,
+	.validate_trigger = ad_sd_validate_trigger,
+	.driver_module = THIS_MODULE,
+};
+
+static const struct iio_info ad7791_no_filter_info = {
+	.read_raw = &ad7791_read_raw,
+	.validate_trigger = ad_sd_validate_trigger,
+	.driver_module = THIS_MODULE,
+};
+
+static int __devinit ad7791_setup(struct ad7791_state *st,
+	struct ad7791_platform_data *pdata)
+{
+	/* Set to poweron-reset default values */
+	st->mode = AD7791_MODE_BUFFER;
+	st->filter = AD7791_FILTER_RATE_16_6;
+
+	if (!pdata)
+		return 0;
+
+	if ((st->info->flags & AD7791_FLAG_HAS_BUFFER) && !pdata->buffered)
+		st->mode &= ~AD7791_MODE_BUFFER;
+
+	if ((st->info->flags & AD7791_FLAG_HAS_BURNOUT) &&
+		pdata->burnout_current)
+		st->mode |= AD7791_MODE_BURNOUT;
+
+	if ((st->info->flags & AD7791_FLAG_HAS_UNIPOLAR) && pdata->unipolar)
+		st->mode |= AD7791_MODE_UNIPOLAR;
+
+	return ad_sd_write_reg(&st->sd, AD7791_REG_MODE, sizeof(st->mode),
+		st->mode);
+}
+
+static int __devinit ad7791_probe(struct spi_device *spi)
+{
+	struct ad7791_platform_data *pdata = spi->dev.platform_data;
+	struct iio_dev *indio_dev;
+	struct ad7791_state *st;
+	int ret;
+
+	if (!spi->irq) {
+		dev_err(&spi->dev, "Missing IRQ.\n");
+		return -ENXIO;
+	}
+
+	indio_dev = iio_device_alloc(sizeof(*st));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	st = iio_priv(indio_dev);
+
+	st->reg = regulator_get(&spi->dev, "refin");
+	if (IS_ERR(st->reg)) {
+		ret = PTR_ERR(st->reg);
+		goto err_iio_free;
+	}
+
+	ret = regulator_enable(st->reg);
+	if (ret)
+		goto error_put_reg;
+
+	st->info = &ad7791_chip_infos[spi_get_device_id(spi)->driver_data];
+	ad_sd_init(&st->sd, indio_dev, spi, &ad7791_sigma_delta_info);
+
+	spi_set_drvdata(spi, indio_dev);
+
+	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->info->channels;
+	indio_dev->num_channels = st->info->num_channels;
+	if (st->info->flags & AD7791_FLAG_HAS_FILTER)
+		indio_dev->info = &ad7791_info;
+	else
+		indio_dev->info = &ad7791_no_filter_info;
+
+	ret = ad_sd_setup_buffer_and_trigger(indio_dev);
+	if (ret)
+		goto error_disable_reg;
+
+	ret = ad7791_setup(st, pdata);
+	if (ret)
+		goto error_remove_trigger;
+
+	ret = iio_device_register(indio_dev);
+	if (ret)
+		goto error_remove_trigger;
+
+	return 0;
+
+error_remove_trigger:
+	ad_sd_cleanup_buffer_and_trigger(indio_dev);
+error_disable_reg:
+	regulator_disable(st->reg);
+error_put_reg:
+	regulator_put(st->reg);
+err_iio_free:
+	iio_device_free(indio_dev);
+
+	return ret;
+}
+
+static int __devexit ad7791_remove(struct spi_device *spi)
+{
+	struct iio_dev *indio_dev = spi_get_drvdata(spi);
+	struct ad7791_state *st = iio_priv(indio_dev);
+
+	iio_device_unregister(indio_dev);
+	ad_sd_cleanup_buffer_and_trigger(indio_dev);
+
+	regulator_disable(st->reg);
+	regulator_put(st->reg);
+
+	iio_device_free(indio_dev);
+
+	return 0;
+}
+
+static const struct spi_device_id ad7791_spi_ids[] = {
+	{ "ad7787", AD7787 },
+	{ "ad7788", AD7788 },
+	{ "ad7789", AD7789 },
+	{ "ad7790", AD7790 },
+	{ "ad7791", AD7791 },
+	{}
+};
+MODULE_DEVICE_TABLE(spi, ad7791_spi_ids);
+
+static struct spi_driver ad7791_driver = {
+	.driver = {
+		.name	= "ad7791",
+		.owner	= THIS_MODULE,
+	},
+	.probe		= ad7791_probe,
+	.remove		= __devexit_p(ad7791_remove),
+	.id_table	= ad7791_spi_ids,
+};
+module_spi_driver(ad7791_driver);
+
+MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
+MODULE_DESCRIPTION("Analog Device AD7787/AD7788/AD7789/AD7790/AD7791 ADC driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/adc/ad_sigma_delta.c b/drivers/iio/adc/ad_sigma_delta.c
new file mode 100644
index 000000000000..67baa1363d7a
--- /dev/null
+++ b/drivers/iio/adc/ad_sigma_delta.c
@@ -0,0 +1,558 @@
+/*
+ * Support code for Analog Devices Sigma-Delta ADCs
+ *
+ * Copyright 2012 Analog Devices Inc.
+ *  Author: Lars-Peter Clausen <lars@metafoo.de>
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/spi/spi.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.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/adc/ad_sigma_delta.h>
+
+#include <asm/unaligned.h>
+
+
+#define AD_SD_COMM_CHAN_MASK	0x3
+
+#define AD_SD_REG_COMM		0x00
+#define AD_SD_REG_DATA		0x03
+
+/**
+ * ad_sd_set_comm() - Set communications register
+ *
+ * @sigma_delta: The sigma delta device
+ * @comm: New value for the communications register
+ */
+void ad_sd_set_comm(struct ad_sigma_delta *sigma_delta, uint8_t comm)
+{
+	/* Some variants use the lower two bits of the communications register
+	 * to select the channel */
+	sigma_delta->comm = comm & AD_SD_COMM_CHAN_MASK;
+}
+EXPORT_SYMBOL_GPL(ad_sd_set_comm);
+
+/**
+ * ad_sd_write_reg() - Write a register
+ *
+ * @sigma_delta: The sigma delta device
+ * @reg: Address of the register
+ * @size: Size of the register (0-3)
+ * @val: Value to write to the register
+ *
+ * Returns 0 on success, an error code otherwise.
+ **/
+int ad_sd_write_reg(struct ad_sigma_delta *sigma_delta, unsigned int reg,
+	unsigned int size, unsigned int val)
+{
+	uint8_t *data = sigma_delta->data;
+	struct spi_transfer t = {
+		.tx_buf		= data,
+		.len		= size + 1,
+		.cs_change	= sigma_delta->bus_locked,
+	};
+	struct spi_message m;
+	int ret;
+
+	data[0] = (reg << sigma_delta->info->addr_shift) | sigma_delta->comm;
+
+	switch (size) {
+	case 3:
+		data[1] = val >> 16;
+		data[2] = val >> 8;
+		data[3] = val;
+		break;
+	case 2:
+		put_unaligned_be16(val, &data[1]);
+		break;
+	case 1:
+		data[1] = val;
+		break;
+	case 0:
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	spi_message_init(&m);
+	spi_message_add_tail(&t, &m);
+
+	if (sigma_delta->bus_locked)
+		ret = spi_sync_locked(sigma_delta->spi, &m);
+	else
+		ret = spi_sync(sigma_delta->spi, &m);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(ad_sd_write_reg);
+
+static int ad_sd_read_reg_raw(struct ad_sigma_delta *sigma_delta,
+	unsigned int reg, unsigned int size, uint8_t *val)
+{
+	uint8_t *data = sigma_delta->data;
+	int ret;
+	struct spi_transfer t[] = {
+		{
+			.tx_buf = data,
+			.len = 1,
+		}, {
+			.rx_buf = val,
+			.len = size,
+			.cs_change = sigma_delta->bus_locked,
+		},
+	};
+	struct spi_message m;
+
+	spi_message_init(&m);
+
+	if (sigma_delta->info->has_registers) {
+		data[0] = reg << sigma_delta->info->addr_shift;
+		data[0] |= sigma_delta->info->read_mask;
+		spi_message_add_tail(&t[0], &m);
+	}
+	spi_message_add_tail(&t[1], &m);
+
+	if (sigma_delta->bus_locked)
+		ret = spi_sync_locked(sigma_delta->spi, &m);
+	else
+		ret = spi_sync(sigma_delta->spi, &m);
+
+	return ret;
+}
+
+/**
+ * ad_sd_read_reg() - Read a register
+ *
+ * @sigma_delta: The sigma delta device
+ * @reg: Address of the register
+ * @size: Size of the register (1-4)
+ * @val: Read value
+ *
+ * Returns 0 on success, an error code otherwise.
+ **/
+int ad_sd_read_reg(struct ad_sigma_delta *sigma_delta,
+	unsigned int reg, unsigned int size, unsigned int *val)
+{
+	int ret;
+
+	ret = ad_sd_read_reg_raw(sigma_delta, reg, size, sigma_delta->data);
+	if (ret < 0)
+		goto out;
+
+	switch (size) {
+	case 4:
+		*val = get_unaligned_be32(sigma_delta->data);
+		break;
+	case 3:
+		*val = (sigma_delta->data[0] << 16) |
+			(sigma_delta->data[1] << 8) |
+			sigma_delta->data[2];
+		break;
+	case 2:
+		*val = get_unaligned_be16(sigma_delta->data);
+		break;
+	case 1:
+		*val = sigma_delta->data[0];
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+out:
+	return ret;
+}
+EXPORT_SYMBOL_GPL(ad_sd_read_reg);
+
+static int ad_sd_calibrate(struct ad_sigma_delta *sigma_delta,
+	unsigned int mode, unsigned int channel)
+{
+	int ret;
+
+	ret = ad_sigma_delta_set_channel(sigma_delta, channel);
+	if (ret)
+		return ret;
+
+	spi_bus_lock(sigma_delta->spi->master);
+	sigma_delta->bus_locked = true;
+	INIT_COMPLETION(sigma_delta->completion);
+
+	ret = ad_sigma_delta_set_mode(sigma_delta, mode);
+	if (ret < 0)
+		goto out;
+
+	sigma_delta->irq_dis = false;
+	enable_irq(sigma_delta->spi->irq);
+	ret = wait_for_completion_timeout(&sigma_delta->completion, 2*HZ);
+	if (ret == 0) {
+		sigma_delta->irq_dis = true;
+		disable_irq_nosync(sigma_delta->spi->irq);
+		ret = -EIO;
+	} else {
+		ret = 0;
+	}
+out:
+	sigma_delta->bus_locked = false;
+	spi_bus_unlock(sigma_delta->spi->master);
+	ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_IDLE);
+
+	return ret;
+}
+
+/**
+ * ad_sd_calibrate_all() - Performs channel calibration
+ * @sigma_delta: The sigma delta device
+ * @cb: Array of channels and calibration type to perform
+ * @n: Number of items in cb
+ *
+ * Returns 0 on success, an error code otherwise.
+ **/
+int ad_sd_calibrate_all(struct ad_sigma_delta *sigma_delta,
+	const struct ad_sd_calib_data *cb, unsigned int n)
+{
+	unsigned int i;
+	int ret;
+
+	for (i = 0; i < n; i++) {
+		ret = ad_sd_calibrate(sigma_delta, cb[i].mode, cb[i].channel);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ad_sd_calibrate_all);
+
+/**
+ * ad_sigma_delta_single_conversion() - Performs a single data conversion
+ * @indio_dev: The IIO device
+ * @chan: The conversion is done for this channel
+ * @val: Pointer to the location where to store the read value
+ *
+ * Returns: 0 on success, an error value otherwise.
+ */
+int ad_sigma_delta_single_conversion(struct iio_dev *indio_dev,
+	const struct iio_chan_spec *chan, int *val)
+{
+	struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev);
+	unsigned int sample, raw_sample;
+	int ret = 0;
+
+	if (iio_buffer_enabled(indio_dev))
+		return -EBUSY;
+
+	mutex_lock(&indio_dev->mlock);
+	ad_sigma_delta_set_channel(sigma_delta, chan->address);
+
+	spi_bus_lock(sigma_delta->spi->master);
+	sigma_delta->bus_locked = true;
+	INIT_COMPLETION(sigma_delta->completion);
+
+	ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_SINGLE);
+
+	sigma_delta->irq_dis = false;
+	enable_irq(sigma_delta->spi->irq);
+	ret = wait_for_completion_interruptible_timeout(
+			&sigma_delta->completion, HZ);
+
+	sigma_delta->bus_locked = false;
+	spi_bus_unlock(sigma_delta->spi->master);
+
+	if (ret == 0)
+		ret = -EIO;
+	if (ret < 0)
+		goto out;
+
+	ret = ad_sd_read_reg(sigma_delta, AD_SD_REG_DATA,
+		DIV_ROUND_UP(chan->scan_type.realbits + chan->scan_type.shift, 8),
+		&raw_sample);
+
+out:
+	if (!sigma_delta->irq_dis) {
+		disable_irq_nosync(sigma_delta->spi->irq);
+		sigma_delta->irq_dis = true;
+	}
+
+	ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_IDLE);
+	mutex_unlock(&indio_dev->mlock);
+
+	if (ret)
+		return ret;
+
+	sample = raw_sample >> chan->scan_type.shift;
+	sample &= (1 << chan->scan_type.realbits) - 1;
+	*val = sample;
+
+	ret = ad_sigma_delta_postprocess_sample(sigma_delta, raw_sample);
+	if (ret)
+		return ret;
+
+	return IIO_VAL_INT;
+}
+EXPORT_SYMBOL_GPL(ad_sigma_delta_single_conversion);
+
+static int ad_sd_buffer_postenable(struct iio_dev *indio_dev)
+{
+	struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev);
+	unsigned int channel;
+	int ret;
+
+	ret = iio_triggered_buffer_postenable(indio_dev);
+	if (ret < 0)
+		return ret;
+
+	channel = find_first_bit(indio_dev->active_scan_mask,
+				 indio_dev->masklength);
+	ret = ad_sigma_delta_set_channel(sigma_delta,
+		indio_dev->channels[channel].address);
+	if (ret)
+		goto err_predisable;
+
+	spi_bus_lock(sigma_delta->spi->master);
+	sigma_delta->bus_locked = true;
+	ret = ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_CONTINUOUS);
+	if (ret)
+		goto err_unlock;
+
+	sigma_delta->irq_dis = false;
+	enable_irq(sigma_delta->spi->irq);
+
+	return 0;
+
+err_unlock:
+	spi_bus_unlock(sigma_delta->spi->master);
+err_predisable:
+
+	return ret;
+}
+
+static int ad_sd_buffer_postdisable(struct iio_dev *indio_dev)
+{
+	struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev);
+
+	INIT_COMPLETION(sigma_delta->completion);
+	wait_for_completion_timeout(&sigma_delta->completion, HZ);
+
+	if (!sigma_delta->irq_dis) {
+		disable_irq_nosync(sigma_delta->spi->irq);
+		sigma_delta->irq_dis = true;
+	}
+
+	ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_IDLE);
+
+	sigma_delta->bus_locked = false;
+	return spi_bus_unlock(sigma_delta->spi->master);
+}
+
+static irqreturn_t ad_sd_trigger_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev);
+	unsigned int reg_size;
+	uint8_t data[16];
+	int ret;
+
+	memset(data, 0x00, 16);
+
+	/* Guaranteed to be aligned with 8 byte boundary */
+	if (indio_dev->scan_timestamp)
+		((s64 *)data)[1] = pf->timestamp;
+
+	reg_size = indio_dev->channels[0].scan_type.realbits +
+			indio_dev->channels[0].scan_type.shift;
+	reg_size = DIV_ROUND_UP(reg_size, 8);
+
+	switch (reg_size) {
+	case 4:
+	case 2:
+	case 1:
+		ret = ad_sd_read_reg_raw(sigma_delta, AD_SD_REG_DATA,
+			reg_size, &data[0]);
+		break;
+	case 3:
+		/* We store 24 bit samples in a 32 bit word. Keep the upper
+		 * byte set to zero. */
+		ret = ad_sd_read_reg_raw(sigma_delta, AD_SD_REG_DATA,
+			reg_size, &data[1]);
+		break;
+	}
+
+	iio_push_to_buffer(indio_dev->buffer, (uint8_t *)data);
+
+	iio_trigger_notify_done(indio_dev->trig);
+	sigma_delta->irq_dis = false;
+	enable_irq(sigma_delta->spi->irq);
+
+	return IRQ_HANDLED;
+}
+
+static const struct iio_buffer_setup_ops ad_sd_buffer_setup_ops = {
+	.preenable = &iio_sw_buffer_preenable,
+	.postenable = &ad_sd_buffer_postenable,
+	.predisable = &iio_triggered_buffer_predisable,
+	.postdisable = &ad_sd_buffer_postdisable,
+	.validate_scan_mask = &iio_validate_scan_mask_onehot,
+};
+
+static irqreturn_t ad_sd_data_rdy_trig_poll(int irq, void *private)
+{
+	struct ad_sigma_delta *sigma_delta = private;
+
+	complete(&sigma_delta->completion);
+	disable_irq_nosync(irq);
+	sigma_delta->irq_dis = true;
+	iio_trigger_poll(sigma_delta->trig, iio_get_time_ns());
+
+	return IRQ_HANDLED;
+}
+
+/**
+ * ad_sd_validate_trigger() - validate_trigger callback for ad_sigma_delta devices
+ * @indio_dev: The IIO device
+ * @trig: The new trigger
+ *
+ * Returns: 0 if the 'trig' matches the trigger registered by the ad_sigma_delta
+ * device, -EINVAL otherwise.
+ */
+int ad_sd_validate_trigger(struct iio_dev *indio_dev, struct iio_trigger *trig)
+{
+	struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev);
+
+	if (sigma_delta->trig != trig)
+		return -EINVAL;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ad_sd_validate_trigger);
+
+static const struct iio_trigger_ops ad_sd_trigger_ops = {
+	.owner = THIS_MODULE,
+};
+
+static int ad_sd_probe_trigger(struct iio_dev *indio_dev)
+{
+	struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev);
+	int ret;
+
+	sigma_delta->trig = iio_trigger_alloc("%s-dev%d", indio_dev->name,
+						indio_dev->id);
+	if (sigma_delta->trig == NULL) {
+		ret = -ENOMEM;
+		goto error_ret;
+	}
+	sigma_delta->trig->ops = &ad_sd_trigger_ops;
+	init_completion(&sigma_delta->completion);
+
+	ret = request_irq(sigma_delta->spi->irq,
+			  ad_sd_data_rdy_trig_poll,
+			  IRQF_TRIGGER_LOW,
+			  indio_dev->name,
+			  sigma_delta);
+	if (ret)
+		goto error_free_trig;
+
+	if (!sigma_delta->irq_dis) {
+		sigma_delta->irq_dis = true;
+		disable_irq_nosync(sigma_delta->spi->irq);
+	}
+	sigma_delta->trig->dev.parent = &sigma_delta->spi->dev;
+	sigma_delta->trig->private_data = sigma_delta;
+
+	ret = iio_trigger_register(sigma_delta->trig);
+	if (ret)
+		goto error_free_irq;
+
+	/* select default trigger */
+	indio_dev->trig = sigma_delta->trig;
+
+	return 0;
+
+error_free_irq:
+	free_irq(sigma_delta->spi->irq, sigma_delta);
+error_free_trig:
+	iio_trigger_free(sigma_delta->trig);
+error_ret:
+	return ret;
+}
+
+static void ad_sd_remove_trigger(struct iio_dev *indio_dev)
+{
+	struct ad_sigma_delta *sigma_delta = iio_device_get_drvdata(indio_dev);
+
+	iio_trigger_unregister(sigma_delta->trig);
+	free_irq(sigma_delta->spi->irq, sigma_delta);
+	iio_trigger_free(sigma_delta->trig);
+}
+
+/**
+ * ad_sd_setup_buffer_and_trigger() -
+ * @indio_dev: The IIO device
+ */
+int ad_sd_setup_buffer_and_trigger(struct iio_dev *indio_dev)
+{
+	int ret;
+
+	ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
+			&ad_sd_trigger_handler, &ad_sd_buffer_setup_ops);
+	if (ret)
+		return ret;
+
+	ret = ad_sd_probe_trigger(indio_dev);
+	if (ret) {
+		iio_triggered_buffer_cleanup(indio_dev);
+		return ret;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ad_sd_setup_buffer_and_trigger);
+
+/**
+ * ad_sd_cleanup_buffer_and_trigger() -
+ * @indio_dev: The IIO device
+ */
+void ad_sd_cleanup_buffer_and_trigger(struct iio_dev *indio_dev)
+{
+	ad_sd_remove_trigger(indio_dev);
+	iio_triggered_buffer_cleanup(indio_dev);
+}
+EXPORT_SYMBOL_GPL(ad_sd_cleanup_buffer_and_trigger);
+
+/**
+ * ad_sd_init() - Initializes a ad_sigma_delta struct
+ * @sigma_delta: The ad_sigma_delta device
+ * @indio_dev: The IIO device which the Sigma Delta device is used for
+ * @spi: The SPI device for the ad_sigma_delta device
+ * @info: Device specific callbacks and options
+ *
+ * This function needs to be called before any other operations are performed on
+ * the ad_sigma_delta struct.
+ */
+int ad_sd_init(struct ad_sigma_delta *sigma_delta, struct iio_dev *indio_dev,
+	struct spi_device *spi, const struct ad_sigma_delta_info *info)
+{
+	sigma_delta->spi = spi;
+	sigma_delta->info = info;
+	iio_device_set_drvdata(indio_dev, sigma_delta);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ad_sd_init);
+
+MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
+MODULE_DESCRIPTION("Analog Devices Sigma-Delta ADCs");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c
index 3bd5540238a7..3ed94bf80596 100644
--- a/drivers/iio/adc/at91_adc.c
+++ b/drivers/iio/adc/at91_adc.c
@@ -82,7 +82,7 @@ static irqreturn_t at91_adc_trigger_handler(int irq, void *p)
 		*timestamp = pf->timestamp;
 	}
 
-	buffer->access->store_to(buffer, (u8 *)st->buffer, pf->timestamp);
+	buffer->access->store_to(buffer, (u8 *)st->buffer);
 
 	iio_trigger_notify_done(idev->trig);
 	st->irq_enabled = true;
@@ -545,13 +545,6 @@ static int __devinit at91_adc_probe(struct platform_device *pdev)
 		goto error_free_device;
 	}
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (!res) {
-		dev_err(&pdev->dev, "No resource defined\n");
-		ret = -ENXIO;
-		goto error_ret;
-	}
-
 	platform_set_drvdata(pdev, idev);
 
 	idev->dev.parent = &pdev->dev;
@@ -566,18 +559,12 @@ static int __devinit at91_adc_probe(struct platform_device *pdev)
 		goto error_free_device;
 	}
 
-	if (!request_mem_region(res->start, resource_size(res),
-				"AT91 adc registers")) {
-		dev_err(&pdev->dev, "Resources are unavailable.\n");
-		ret = -EBUSY;
-		goto error_free_device;
-	}
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 
-	st->reg_base = ioremap(res->start, resource_size(res));
+	st->reg_base = devm_request_and_ioremap(&pdev->dev, res);
 	if (!st->reg_base) {
-		dev_err(&pdev->dev, "Failed to map registers.\n");
 		ret = -ENOMEM;
-		goto error_release_mem;
+		goto error_free_device;
 	}
 
 	/*
@@ -592,45 +579,35 @@ static int __devinit at91_adc_probe(struct platform_device *pdev)
 			  idev);
 	if (ret) {
 		dev_err(&pdev->dev, "Failed to allocate IRQ.\n");
-		goto error_unmap_reg;
+		goto error_free_device;
 	}
 
-	st->clk = clk_get(&pdev->dev, "adc_clk");
+	st->clk = devm_clk_get(&pdev->dev, "adc_clk");
 	if (IS_ERR(st->clk)) {
 		dev_err(&pdev->dev, "Failed to get the clock.\n");
 		ret = PTR_ERR(st->clk);
 		goto error_free_irq;
 	}
 
-	ret = clk_prepare(st->clk);
+	ret = clk_prepare_enable(st->clk);
 	if (ret) {
-		dev_err(&pdev->dev, "Could not prepare the clock.\n");
-		goto error_free_clk;
-	}
-
-	ret = clk_enable(st->clk);
-	if (ret) {
-		dev_err(&pdev->dev, "Could not enable the clock.\n");
-		goto error_unprepare_clk;
+		dev_err(&pdev->dev,
+			"Could not prepare or enable the clock.\n");
+		goto error_free_irq;
 	}
 
-	st->adc_clk = clk_get(&pdev->dev, "adc_op_clk");
+	st->adc_clk = devm_clk_get(&pdev->dev, "adc_op_clk");
 	if (IS_ERR(st->adc_clk)) {
 		dev_err(&pdev->dev, "Failed to get the ADC clock.\n");
 		ret = PTR_ERR(st->adc_clk);
 		goto error_disable_clk;
 	}
 
-	ret = clk_prepare(st->adc_clk);
+	ret = clk_prepare_enable(st->adc_clk);
 	if (ret) {
-		dev_err(&pdev->dev, "Could not prepare the ADC clock.\n");
-		goto error_free_adc_clk;
-	}
-
-	ret = clk_enable(st->adc_clk);
-	if (ret) {
-		dev_err(&pdev->dev, "Could not enable the ADC clock.\n");
-		goto error_unprepare_adc_clk;
+		dev_err(&pdev->dev,
+			"Could not prepare or enable the ADC clock.\n");
+		goto error_disable_clk;
 	}
 
 	/*
@@ -694,23 +671,11 @@ error_remove_triggers:
 error_unregister_buffer:
 	at91_adc_buffer_remove(idev);
 error_disable_adc_clk:
-	clk_disable(st->adc_clk);
-error_unprepare_adc_clk:
-	clk_unprepare(st->adc_clk);
-error_free_adc_clk:
-	clk_put(st->adc_clk);
+	clk_disable_unprepare(st->adc_clk);
 error_disable_clk:
-	clk_disable(st->clk);
-error_unprepare_clk:
-	clk_unprepare(st->clk);
-error_free_clk:
-	clk_put(st->clk);
+	clk_disable_unprepare(st->clk);
 error_free_irq:
 	free_irq(st->irq, idev);
-error_unmap_reg:
-	iounmap(st->reg_base);
-error_release_mem:
-	release_mem_region(res->start, resource_size(res));
 error_free_device:
 	iio_device_free(idev);
 error_ret:
@@ -720,20 +685,14 @@ error_ret:
 static int __devexit at91_adc_remove(struct platform_device *pdev)
 {
 	struct iio_dev *idev = platform_get_drvdata(pdev);
-	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	struct at91_adc_state *st = iio_priv(idev);
 
 	iio_device_unregister(idev);
 	at91_adc_trigger_remove(idev);
 	at91_adc_buffer_remove(idev);
 	clk_disable_unprepare(st->adc_clk);
-	clk_put(st->adc_clk);
-	clk_disable(st->clk);
-	clk_unprepare(st->clk);
-	clk_put(st->clk);
+	clk_disable_unprepare(st->clk);
 	free_irq(st->irq, idev);
-	iounmap(st->reg_base);
-	release_mem_region(res->start, resource_size(res));
 	iio_device_free(idev);
 
 	return 0;
diff --git a/drivers/iio/adc/lp8788_adc.c b/drivers/iio/adc/lp8788_adc.c
new file mode 100644
index 000000000000..a93aaf0bb841
--- /dev/null
+++ b/drivers/iio/adc/lp8788_adc.c
@@ -0,0 +1,264 @@
+/*
+ * TI LP8788 MFD - ADC driver
+ *
+ * Copyright 2012 Texas Instruments
+ *
+ * Author: Milo(Woogyom) Kim <milo.kim@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/delay.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/driver.h>
+#include <linux/iio/machine.h>
+#include <linux/mfd/lp8788.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+/* register address */
+#define LP8788_ADC_CONF			0x60
+#define LP8788_ADC_RAW			0x61
+#define LP8788_ADC_DONE			0x63
+
+#define ADC_CONV_START			1
+
+struct lp8788_adc {
+	struct lp8788 *lp;
+	struct iio_map *map;
+	struct mutex lock;
+};
+
+static const int lp8788_scale[LPADC_MAX] = {
+	[LPADC_VBATT_5P5] = 1343101,
+	[LPADC_VIN_CHG]   = 3052503,
+	[LPADC_IBATT]     = 610500,
+	[LPADC_IC_TEMP]   = 61050,
+	[LPADC_VBATT_6P0] = 1465201,
+	[LPADC_VBATT_5P0] = 1221001,
+	[LPADC_ADC1]      = 610500,
+	[LPADC_ADC2]      = 610500,
+	[LPADC_VDD]       = 1025641,
+	[LPADC_VCOIN]     = 757020,
+	[LPADC_ADC3]      = 610500,
+	[LPADC_ADC4]      = 610500,
+};
+
+static int lp8788_get_adc_result(struct lp8788_adc *adc, enum lp8788_adc_id id,
+				int *val)
+{
+	unsigned int msb;
+	unsigned int lsb;
+	unsigned int result;
+	u8 data;
+	u8 rawdata[2];
+	int size = ARRAY_SIZE(rawdata);
+	int retry = 5;
+	int ret;
+
+	data = (id << 1) | ADC_CONV_START;
+	ret = lp8788_write_byte(adc->lp, LP8788_ADC_CONF, data);
+	if (ret)
+		goto err_io;
+
+	/* retry until adc conversion is done */
+	data = 0;
+	while (retry--) {
+		usleep_range(100, 200);
+
+		ret = lp8788_read_byte(adc->lp, LP8788_ADC_DONE, &data);
+		if (ret)
+			goto err_io;
+
+		/* conversion done */
+		if (data)
+			break;
+	}
+
+	ret = lp8788_read_multi_bytes(adc->lp, LP8788_ADC_RAW, rawdata, size);
+	if (ret)
+		goto err_io;
+
+	msb = (rawdata[0] << 4) & 0x00000ff0;
+	lsb = (rawdata[1] >> 4) & 0x0000000f;
+	result = msb | lsb;
+	*val = result;
+
+	return 0;
+
+err_io:
+	return ret;
+}
+
+static int lp8788_adc_read_raw(struct iio_dev *indio_dev,
+			struct iio_chan_spec const *chan,
+			int *val, int *val2, long mask)
+{
+	struct lp8788_adc *adc = iio_priv(indio_dev);
+	enum lp8788_adc_id id = chan->channel;
+	int ret;
+
+	mutex_lock(&adc->lock);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		ret = lp8788_get_adc_result(adc, id, val) ? -EIO : IIO_VAL_INT;
+		break;
+	case IIO_CHAN_INFO_SCALE:
+		*val = lp8788_scale[id] / 1000000;
+		*val2 = lp8788_scale[id] % 1000000;
+		ret = IIO_VAL_INT_PLUS_MICRO;
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	mutex_unlock(&adc->lock);
+
+	return ret;
+}
+
+static const struct iio_info lp8788_adc_info = {
+	.read_raw = &lp8788_adc_read_raw,
+	.driver_module = THIS_MODULE,
+};
+
+#define LP8788_CHAN(_id, _type) {				\
+		.type = _type,					\
+		.indexed = 1,					\
+		.channel = LPADC_##_id,				\
+		.info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT |	\
+			IIO_CHAN_INFO_SCALE_SEPARATE_BIT,	\
+		.datasheet_name = #_id,				\
+}
+
+static const struct iio_chan_spec lp8788_adc_channels[] = {
+	[LPADC_VBATT_5P5] = LP8788_CHAN(VBATT_5P5, IIO_VOLTAGE),
+	[LPADC_VIN_CHG]   = LP8788_CHAN(VIN_CHG, IIO_VOLTAGE),
+	[LPADC_IBATT]     = LP8788_CHAN(IBATT, IIO_CURRENT),
+	[LPADC_IC_TEMP]   = LP8788_CHAN(IC_TEMP, IIO_TEMP),
+	[LPADC_VBATT_6P0] = LP8788_CHAN(VBATT_6P0, IIO_VOLTAGE),
+	[LPADC_VBATT_5P0] = LP8788_CHAN(VBATT_5P0, IIO_VOLTAGE),
+	[LPADC_ADC1]      = LP8788_CHAN(ADC1, IIO_VOLTAGE),
+	[LPADC_ADC2]      = LP8788_CHAN(ADC2, IIO_VOLTAGE),
+	[LPADC_VDD]       = LP8788_CHAN(VDD, IIO_VOLTAGE),
+	[LPADC_VCOIN]     = LP8788_CHAN(VCOIN, IIO_VOLTAGE),
+	[LPADC_ADC3]      = LP8788_CHAN(ADC3, IIO_VOLTAGE),
+	[LPADC_ADC4]      = LP8788_CHAN(ADC4, IIO_VOLTAGE),
+};
+
+/* default maps used by iio consumer (lp8788-charger driver) */
+static struct iio_map lp8788_default_iio_maps[] = {
+	{
+		.consumer_dev_name = "lp8788-charger",
+		.consumer_channel = "lp8788_vbatt_5p0",
+		.adc_channel_label = "VBATT_5P0",
+	},
+	{
+		.consumer_dev_name = "lp8788-charger",
+		.consumer_channel = "lp8788_adc1",
+		.adc_channel_label = "ADC1",
+	},
+	{ }
+};
+
+static int lp8788_iio_map_register(struct iio_dev *indio_dev,
+				struct lp8788_platform_data *pdata,
+				struct lp8788_adc *adc)
+{
+	struct iio_map *map;
+	int ret;
+
+	map = (!pdata || !pdata->adc_pdata) ?
+		lp8788_default_iio_maps : pdata->adc_pdata;
+
+	ret = iio_map_array_register(indio_dev, map);
+	if (ret) {
+		dev_err(adc->lp->dev, "iio map err: %d\n", ret);
+		return ret;
+	}
+
+	adc->map = map;
+	return 0;
+}
+
+static inline void lp8788_iio_map_unregister(struct iio_dev *indio_dev,
+				struct lp8788_adc *adc)
+{
+	iio_map_array_unregister(indio_dev, adc->map);
+}
+
+static int __devinit lp8788_adc_probe(struct platform_device *pdev)
+{
+	struct lp8788 *lp = dev_get_drvdata(pdev->dev.parent);
+	struct iio_dev *indio_dev;
+	struct lp8788_adc *adc;
+	int ret;
+
+	indio_dev = iio_device_alloc(sizeof(*adc));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	adc = iio_priv(indio_dev);
+	adc->lp = lp;
+	platform_set_drvdata(pdev, indio_dev);
+
+	ret = lp8788_iio_map_register(indio_dev, lp->pdata, adc);
+	if (ret)
+		goto err_iio_map;
+
+	mutex_init(&adc->lock);
+
+	indio_dev->dev.parent = lp->dev;
+	indio_dev->name = pdev->name;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->info = &lp8788_adc_info;
+	indio_dev->channels = lp8788_adc_channels;
+	indio_dev->num_channels = ARRAY_SIZE(lp8788_adc_channels);
+
+	ret = iio_device_register(indio_dev);
+	if (ret) {
+		dev_err(lp->dev, "iio dev register err: %d\n", ret);
+		goto err_iio_device;
+	}
+
+	return 0;
+
+err_iio_device:
+	lp8788_iio_map_unregister(indio_dev, adc);
+err_iio_map:
+	iio_device_free(indio_dev);
+	return ret;
+}
+
+static int __devexit lp8788_adc_remove(struct platform_device *pdev)
+{
+	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+	struct lp8788_adc *adc = iio_priv(indio_dev);
+
+	iio_device_unregister(indio_dev);
+	lp8788_iio_map_unregister(indio_dev, adc);
+	iio_device_free(indio_dev);
+
+	return 0;
+}
+
+static struct platform_driver lp8788_adc_driver = {
+	.probe = lp8788_adc_probe,
+	.remove = __devexit_p(lp8788_adc_remove),
+	.driver = {
+		.name = LP8788_DEV_ADC,
+		.owner = THIS_MODULE,
+	},
+};
+module_platform_driver(lp8788_adc_driver);
+
+MODULE_DESCRIPTION("Texas Instruments LP8788 ADC Driver");
+MODULE_AUTHOR("Milo Kim");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:lp8788-adc");