Merge tag 'staging-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging

Pull staging/IIO updates from Greg KH:
 "Here is the big staging/iio driver pull request for 5.1-rc1.

  Lots of good IIO driver updates and cleanups in here as always.
  Combined with the removal of the xgifb driver, we have a net "loss" of
  over 9000 lines in the pull request, always a nice thing.

  As the outreachy application process is currently happening, there are
  loads of tiny checkpatch cleanup fixes all over the staging tree,
  which accounts for the majority of the fixups"

* tag 'staging-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (341 commits)
  staging: mt7621-dma: remove license boilerplate text
  staging: mt7621-dma: add SPDX GPL-2.0+ license identifier
  Staging: ks7010: Replace typecast to int
  Staging: vt6655: Align a static function declaration
  staging: speakup: fix line over 80 characters.
  staging: mt7621-eth: Remove license boilerplate text
  staging: mt7621-eth: Add SPDX license identifier
  staging: ks7010: removed custom Michael MIC implementation.
  staging: rtl8192e: Fix space and suspect issue
  Staging: vt6655: Modify comment style of SPDX License Identifier
  Staging: vt6655: Modify comment style for SPDX-License-Identifier
  Staging: vt6655: Align a function declaration
  Staging: vt6655: Alignment of function declaration
  staging: rtl8712: Fix indentation issue
  staging: wilc1000: fix incorrent type in initializer
  staging: rtl8188eu: remove unused P2P_PRIVATE_IOCTL_SET_LEN
  staging: rtl8188eu: remove unused enum P2P_PROTO_WK_ID
  staging: rtl8723bs: Remove duplicated include from drv_types.h
  Staging: vt6655: Alignment should match open parenthesis
  staging: erofs: fix mis-acted TAIL merging behavior
  ...

15 files changed, 2757 insertions, 20 deletions

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 7a3ca4ec0cb7..5debc67df70a 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -57,18 +57,48 @@ config AD7298
 	  module will be called ad7298.
 
 config AD7476
-	tristate "Analog Devices AD7476 and similar 1-channel ADCs driver"
+	tristate "Analog Devices AD7476 1-channel ADCs driver and other similar devices from AD an TI"
 	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).
+	  Say yes here to build support for the following SPI analog to
+	  digital converters (ADCs):
+	  Analog Devices: AD7273, AD7274, AD7276, AD7277, AD7278, AD7475,
+	  AD7476, AD7477, AD7478, AD7466, AD7467, AD7468, AD7495, AD7910,
+	  AD7920.
+	  Texas Instruments: ADS7866, ADS7867, ADS7868.
 
 	  To compile this driver as a module, choose M here: the
 	  module will be called ad7476.
 
+config AD7606
+	tristate
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
+
+config AD7606_IFACE_PARALLEL
+	tristate "Analog Devices AD7606 ADC driver with parallel interface support"
+	depends on HAS_IOMEM
+	select AD7606
+	help
+	  Say yes here to build parallel interface support for Analog Devices:
+	  ad7605-4, ad7606, ad7606-6, ad7606-4 analog to digital converters (ADC).
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ad7606_parallel.
+
+config AD7606_IFACE_SPI
+	tristate "Analog Devices AD7606 ADC driver with spi interface support"
+	depends on SPI
+	select AD7606
+	help
+	  Say yes here to build spi interface support for Analog Devices:
+	  ad7605-4, ad7606, ad7606-6, ad7606-4 analog to digital converters (ADC).
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ad7606_spi.
+
 config AD7766
 	tristate "Analog Devices AD7766/AD7767 ADC driver"
 	depends on SPI_MASTER
@@ -81,6 +111,19 @@ config AD7766
 	  To compile this driver as a module, choose M here: the module will be
 	  called ad7766.
 
+config AD7768_1
+	tristate "Analog Devices AD7768-1 ADC driver"
+	depends on SPI
+	select IIO_BUFFER
+	select IIO_TRIGGER
+	select IIO_TRIGGERED_BUFFER
+	help
+	  Say yes here to build support for Analog Devices AD7768-1 SPI
+	  simultaneously sampling sigma-delta analog to digital converter (ADC).
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called ad7768-1.
+
 config AD7791
 	tristate "Analog Devices AD7791 ADC driver"
 	depends on SPI
@@ -367,6 +410,15 @@ config INA2XX_ADC
 	  Say yes here to build support for TI INA2xx family of Power Monitors.
 	  This driver is mutually exclusive with the HWMON version.
 
+config INGENIC_ADC
+	tristate "Ingenic JZ47xx SoCs ADC driver"
+	depends on MIPS || COMPILE_TEST
+	help
+	  Say yes here to build support for the Ingenic JZ47xx SoCs ADC unit.
+
+	  This driver can also be built as a module. If so, the module will be
+	  called ingenic_adc.
+
 config IMX7D_ADC
 	tristate "Freescale IMX7D ADC driver"
 	depends on ARCH_MXC || COMPILE_TEST
@@ -576,6 +628,16 @@ config NAU7802
 	  To compile this driver as a module, choose M here: the
 	  module will be called nau7802.
 
+config NPCM_ADC
+	tristate "Nuvoton NPCM ADC driver"
+	depends on ARCH_NPCM || COMPILE_TEST
+	depends on HAS_IOMEM
+	help
+	  Say yes here to build support for Nuvoton NPCM ADC.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called npcm_adc.
+
 config PALMAS_GPADC
 	tristate "TI Palmas General Purpose ADC"
 	depends on MFD_PALMAS
@@ -908,6 +970,16 @@ config TI_ADS8688
 	  This driver can also be built as a module. If so, the module will be
 	  called ti-ads8688.
 
+config TI_ADS124S08
+	tristate "Texas Instruments ADS124S08"
+	depends on SPI && OF
+	help
+	  If you say yes here you get support for Texas Instruments ADS124S08
+	  and ADS124S06 ADC chips
+
+	  This driver can also be built as a module. If so, the module will be
+	  called ti-ads124s08.
+
 config TI_AM335X_ADC
 	tristate "TI's AM335X ADC driver"
 	depends on MFD_TI_AM335X_TSCADC && HAS_DMA
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 07df37f621bd..d50eb47da484 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -11,7 +11,11 @@ obj-$(CONFIG_AD7291) += ad7291.o
 obj-$(CONFIG_AD7298) += ad7298.o
 obj-$(CONFIG_AD7923) += ad7923.o
 obj-$(CONFIG_AD7476) += ad7476.o
+obj-$(CONFIG_AD7606_IFACE_PARALLEL) += ad7606_par.o
+obj-$(CONFIG_AD7606_IFACE_SPI) += ad7606_spi.o
+obj-$(CONFIG_AD7606) += ad7606.o
 obj-$(CONFIG_AD7766) += ad7766.o
+obj-$(CONFIG_AD7768_1) += ad7768-1.o
 obj-$(CONFIG_AD7791) += ad7791.o
 obj-$(CONFIG_AD7793) += ad7793.o
 obj-$(CONFIG_AD7887) += ad7887.o
@@ -36,6 +40,7 @@ obj-$(CONFIG_HI8435) += hi8435.o
 obj-$(CONFIG_HX711) += hx711.o
 obj-$(CONFIG_IMX7D_ADC) += imx7d_adc.o
 obj-$(CONFIG_INA2XX_ADC) += ina2xx-adc.o
+obj-$(CONFIG_INGENIC_ADC) += ingenic-adc.o
 obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o
 obj-$(CONFIG_LPC18XX_ADC) += lpc18xx_adc.o
 obj-$(CONFIG_LPC32XX_ADC) += lpc32xx_adc.o
@@ -55,6 +60,7 @@ obj-$(CONFIG_MEN_Z188_ADC) += men_z188_adc.o
 obj-$(CONFIG_MESON_SARADC) += meson_saradc.o
 obj-$(CONFIG_MXS_LRADC_ADC) += mxs-lradc-adc.o
 obj-$(CONFIG_NAU7802) += nau7802.o
+obj-$(CONFIG_NPCM_ADC) += npcm_adc.o
 obj-$(CONFIG_PALMAS_GPADC) += palmas_gpadc.o
 obj-$(CONFIG_QCOM_SPMI_ADC5) += qcom-spmi-adc5.o
 obj-$(CONFIG_QCOM_SPMI_IADC) += qcom-spmi-iadc.o
@@ -81,6 +87,7 @@ obj-$(CONFIG_TI_ADC161S626) += ti-adc161s626.o
 obj-$(CONFIG_TI_ADS1015) += ti-ads1015.o
 obj-$(CONFIG_TI_ADS7950) += ti-ads7950.o
 obj-$(CONFIG_TI_ADS8688) += ti-ads8688.o
+obj-$(CONFIG_TI_ADS124S08) += ti-ads124s08.o
 obj-$(CONFIG_TI_AM335X_ADC) += ti_am335x_adc.o
 obj-$(CONFIG_TI_TLC4541) += ti-tlc4541.o
 obj-$(CONFIG_TWL4030_MADC) += twl4030-madc.o
diff --git a/drivers/iio/adc/ad7476.c b/drivers/iio/adc/ad7476.c
index 0549686b9ef8..76747488044b 100644
--- a/drivers/iio/adc/ad7476.c
+++ b/drivers/iio/adc/ad7476.c
@@ -59,6 +59,9 @@ enum ad7476_supported_device_ids {
 	ID_ADC081S,
 	ID_ADC101S,
 	ID_ADC121S,
+	ID_ADS7866,
+	ID_ADS7867,
+	ID_ADS7868,
 };
 
 static irqreturn_t ad7476_trigger_handler(int irq, void  *p)
@@ -157,6 +160,8 @@ static int ad7476_read_raw(struct iio_dev *indio_dev,
 #define AD7940_CHAN(bits) _AD7476_CHAN((bits), 15 - (bits), \
 		BIT(IIO_CHAN_INFO_RAW))
 #define AD7091R_CHAN(bits) _AD7476_CHAN((bits), 16 - (bits), 0)
+#define ADS786X_CHAN(bits) _AD7476_CHAN((bits), 12 - (bits), \
+		BIT(IIO_CHAN_INFO_RAW))
 
 static const struct ad7476_chip_info ad7476_chip_info_tbl[] = {
 	[ID_AD7091R] = {
@@ -209,6 +214,18 @@ static const struct ad7476_chip_info ad7476_chip_info_tbl[] = {
 		.channel[0] = ADC081S_CHAN(12),
 		.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
 	},
+	[ID_ADS7866] = {
+		.channel[0] = ADS786X_CHAN(12),
+		.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
+	},
+	[ID_ADS7867] = {
+		.channel[0] = ADS786X_CHAN(10),
+		.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
+	},
+	[ID_ADS7868] = {
+		.channel[0] = ADS786X_CHAN(8),
+		.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
+	},
 };
 
 static const struct iio_info ad7476_info = {
@@ -314,6 +331,9 @@ static const struct spi_device_id ad7476_id[] = {
 	{"adc081s", ID_ADC081S},
 	{"adc101s", ID_ADC101S},
 	{"adc121s", ID_ADC121S},
+	{"ads7866", ID_ADS7866},
+	{"ads7867", ID_ADS7867},
+	{"ads7868", ID_ADS7868},
 	{}
 };
 MODULE_DEVICE_TABLE(spi, ad7476_id);
diff --git a/drivers/iio/adc/ad7606.c b/drivers/iio/adc/ad7606.c
new file mode 100644
index 000000000000..ebb8de03bbce
--- /dev/null
+++ b/drivers/iio/adc/ad7606.c
@@ -0,0 +1,583 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * AD7606 SPI ADC driver
+ *
+ * Copyright 2011 Analog Devices Inc.
+ */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/gpio/consumer.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/regulator/consumer.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <linux/util_macros.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/trigger_consumer.h>
+
+#include "ad7606.h"
+
+/*
+ * Scales are computed as 5000/32768 and 10000/32768 respectively,
+ * so that when applied to the raw values they provide mV values
+ */
+static const unsigned int scale_avail[2] = {
+	152588, 305176
+};
+
+static const unsigned int ad7606_oversampling_avail[7] = {
+	1, 2, 4, 8, 16, 32, 64,
+};
+
+static int ad7606_reset(struct ad7606_state *st)
+{
+	if (st->gpio_reset) {
+		gpiod_set_value(st->gpio_reset, 1);
+		ndelay(100); /* t_reset >= 100ns */
+		gpiod_set_value(st->gpio_reset, 0);
+		return 0;
+	}
+
+	return -ENODEV;
+}
+
+static int ad7606_read_samples(struct ad7606_state *st)
+{
+	unsigned int num = st->chip_info->num_channels;
+	u16 *data = st->data;
+	int ret;
+
+	/*
+	 * The frstdata signal is set to high while and after reading the sample
+	 * of the first channel and low for all other channels. This can be used
+	 * to check that the incoming data is correctly aligned. During normal
+	 * operation the data should never become unaligned, but some glitch or
+	 * electrostatic discharge might cause an extra read or clock cycle.
+	 * Monitoring the frstdata signal allows to recover from such failure
+	 * situations.
+	 */
+
+	if (st->gpio_frstdata) {
+		ret = st->bops->read_block(st->dev, 1, data);
+		if (ret)
+			return ret;
+
+		if (!gpiod_get_value(st->gpio_frstdata)) {
+			ad7606_reset(st);
+			return -EIO;
+		}
+
+		data++;
+		num--;
+	}
+
+	return st->bops->read_block(st->dev, num, data);
+}
+
+static irqreturn_t ad7606_trigger_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct ad7606_state *st = iio_priv(indio_dev);
+	int ret;
+
+	mutex_lock(&st->lock);
+
+	ret = ad7606_read_samples(st);
+	if (ret == 0)
+		iio_push_to_buffers_with_timestamp(indio_dev, st->data,
+						   iio_get_time_ns(indio_dev));
+
+	iio_trigger_notify_done(indio_dev->trig);
+	/* The rising edge of the CONVST signal starts a new conversion. */
+	gpiod_set_value(st->gpio_convst, 1);
+
+	mutex_unlock(&st->lock);
+
+	return IRQ_HANDLED;
+}
+
+static int ad7606_scan_direct(struct iio_dev *indio_dev, unsigned int ch)
+{
+	struct ad7606_state *st = iio_priv(indio_dev);
+	int ret;
+
+	gpiod_set_value(st->gpio_convst, 1);
+	ret = wait_for_completion_timeout(&st->completion,
+					  msecs_to_jiffies(1000));
+	if (!ret) {
+		ret = -ETIMEDOUT;
+		goto error_ret;
+	}
+
+	ret = ad7606_read_samples(st);
+	if (ret == 0)
+		ret = st->data[ch];
+
+error_ret:
+	gpiod_set_value(st->gpio_convst, 0);
+
+	return ret;
+}
+
+static int ad7606_read_raw(struct iio_dev *indio_dev,
+			   struct iio_chan_spec const *chan,
+			   int *val,
+			   int *val2,
+			   long m)
+{
+	int ret;
+	struct ad7606_state *st = iio_priv(indio_dev);
+
+	switch (m) {
+	case IIO_CHAN_INFO_RAW:
+		ret = iio_device_claim_direct_mode(indio_dev);
+		if (ret)
+			return ret;
+
+		ret = ad7606_scan_direct(indio_dev, chan->address);
+		iio_device_release_direct_mode(indio_dev);
+
+		if (ret < 0)
+			return ret;
+		*val = (short)ret;
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		*val = 0;
+		*val2 = scale_avail[st->range];
+		return IIO_VAL_INT_PLUS_MICRO;
+	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+		*val = st->oversampling;
+		return IIO_VAL_INT;
+	}
+	return -EINVAL;
+}
+
+static ssize_t in_voltage_scale_available_show(struct device *dev,
+					       struct device_attribute *attr,
+					       char *buf)
+{
+	int i, len = 0;
+
+	for (i = 0; i < ARRAY_SIZE(scale_avail); i++)
+		len += scnprintf(buf + len, PAGE_SIZE - len, "0.%06u ",
+				 scale_avail[i]);
+
+	buf[len - 1] = '\n';
+
+	return len;
+}
+
+static IIO_DEVICE_ATTR_RO(in_voltage_scale_available, 0);
+
+static int ad7606_write_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan,
+			    int val,
+			    int val2,
+			    long mask)
+{
+	struct ad7606_state *st = iio_priv(indio_dev);
+	DECLARE_BITMAP(values, 3);
+	int i;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_SCALE:
+		mutex_lock(&st->lock);
+		i = find_closest(val2, scale_avail, ARRAY_SIZE(scale_avail));
+		gpiod_set_value(st->gpio_range, i);
+		st->range = i;
+		mutex_unlock(&st->lock);
+
+		return 0;
+	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+		if (val2)
+			return -EINVAL;
+		i = find_closest(val, ad7606_oversampling_avail,
+				 ARRAY_SIZE(ad7606_oversampling_avail));
+
+		values[0] = i;
+
+		mutex_lock(&st->lock);
+		gpiod_set_array_value(ARRAY_SIZE(values), st->gpio_os->desc,
+				      st->gpio_os->info, values);
+		st->oversampling = ad7606_oversampling_avail[i];
+		mutex_unlock(&st->lock);
+
+		return 0;
+	default:
+		return -EINVAL;
+	}
+}
+
+static IIO_CONST_ATTR(oversampling_ratio_available, "1 2 4 8 16 32 64");
+
+static struct attribute *ad7606_attributes_os_and_range[] = {
+	&iio_dev_attr_in_voltage_scale_available.dev_attr.attr,
+	&iio_const_attr_oversampling_ratio_available.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group ad7606_attribute_group_os_and_range = {
+	.attrs = ad7606_attributes_os_and_range,
+};
+
+static struct attribute *ad7606_attributes_os[] = {
+	&iio_const_attr_oversampling_ratio_available.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group ad7606_attribute_group_os = {
+	.attrs = ad7606_attributes_os,
+};
+
+static struct attribute *ad7606_attributes_range[] = {
+	&iio_dev_attr_in_voltage_scale_available.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group ad7606_attribute_group_range = {
+	.attrs = ad7606_attributes_range,
+};
+
+#define AD760X_CHANNEL(num, mask) {				\
+		.type = IIO_VOLTAGE,				\
+		.indexed = 1,					\
+		.channel = num,					\
+		.address = num,					\
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),\
+		.info_mask_shared_by_all = mask,		\
+		.scan_index = num,				\
+		.scan_type = {					\
+			.sign = 's',				\
+			.realbits = 16,				\
+			.storagebits = 16,			\
+			.endianness = IIO_CPU,			\
+		},						\
+}
+
+#define AD7605_CHANNEL(num)	\
+	AD760X_CHANNEL(num, 0)
+
+#define AD7606_CHANNEL(num)	\
+	AD760X_CHANNEL(num, BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO))
+
+static const struct iio_chan_spec ad7605_channels[] = {
+	IIO_CHAN_SOFT_TIMESTAMP(4),
+	AD7605_CHANNEL(0),
+	AD7605_CHANNEL(1),
+	AD7605_CHANNEL(2),
+	AD7605_CHANNEL(3),
+};
+
+static const struct iio_chan_spec ad7606_channels[] = {
+	IIO_CHAN_SOFT_TIMESTAMP(8),
+	AD7606_CHANNEL(0),
+	AD7606_CHANNEL(1),
+	AD7606_CHANNEL(2),
+	AD7606_CHANNEL(3),
+	AD7606_CHANNEL(4),
+	AD7606_CHANNEL(5),
+	AD7606_CHANNEL(6),
+	AD7606_CHANNEL(7),
+};
+
+static const struct ad7606_chip_info ad7606_chip_info_tbl[] = {
+	/* More devices added in future */
+	[ID_AD7605_4] = {
+		.channels = ad7605_channels,
+		.num_channels = 5,
+	},
+	[ID_AD7606_8] = {
+		.channels = ad7606_channels,
+		.num_channels = 9,
+		.has_oversampling = true,
+	},
+	[ID_AD7606_6] = {
+		.channels = ad7606_channels,
+		.num_channels = 7,
+		.has_oversampling = true,
+	},
+	[ID_AD7606_4] = {
+		.channels = ad7606_channels,
+		.num_channels = 5,
+		.has_oversampling = true,
+	},
+};
+
+static int ad7606_request_gpios(struct ad7606_state *st)
+{
+	struct device *dev = st->dev;
+
+	st->gpio_convst = devm_gpiod_get(dev, "adi,conversion-start",
+					 GPIOD_OUT_LOW);
+	if (IS_ERR(st->gpio_convst))
+		return PTR_ERR(st->gpio_convst);
+
+	st->gpio_reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(st->gpio_reset))
+		return PTR_ERR(st->gpio_reset);
+
+	st->gpio_range = devm_gpiod_get_optional(dev, "adi,range",
+						 GPIOD_OUT_LOW);
+	if (IS_ERR(st->gpio_range))
+		return PTR_ERR(st->gpio_range);
+
+	st->gpio_standby = devm_gpiod_get_optional(dev, "standby",
+						   GPIOD_OUT_HIGH);
+	if (IS_ERR(st->gpio_standby))
+		return PTR_ERR(st->gpio_standby);
+
+	st->gpio_frstdata = devm_gpiod_get_optional(dev, "adi,first-data",
+						    GPIOD_IN);
+	if (IS_ERR(st->gpio_frstdata))
+		return PTR_ERR(st->gpio_frstdata);
+
+	if (!st->chip_info->has_oversampling)
+		return 0;
+
+	st->gpio_os = devm_gpiod_get_array_optional(dev,
+						    "adi,oversampling-ratio",
+						    GPIOD_OUT_LOW);
+	return PTR_ERR_OR_ZERO(st->gpio_os);
+}
+
+/*
+ * The BUSY signal indicates when conversions are in progress, so when a rising
+ * edge of CONVST is applied, BUSY goes logic high and transitions low at the
+ * end of the entire conversion process. The falling edge of the BUSY signal
+ * triggers this interrupt.
+ */
+static irqreturn_t ad7606_interrupt(int irq, void *dev_id)
+{
+	struct iio_dev *indio_dev = dev_id;
+	struct ad7606_state *st = iio_priv(indio_dev);
+
+	if (iio_buffer_enabled(indio_dev)) {
+		gpiod_set_value(st->gpio_convst, 0);
+		iio_trigger_poll_chained(st->trig);
+	} else {
+		complete(&st->completion);
+	}
+
+	return IRQ_HANDLED;
+};
+
+static int ad7606_validate_trigger(struct iio_dev *indio_dev,
+				   struct iio_trigger *trig)
+{
+	struct ad7606_state *st = iio_priv(indio_dev);
+
+	if (st->trig != trig)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int ad7606_buffer_postenable(struct iio_dev *indio_dev)
+{
+	struct ad7606_state *st = iio_priv(indio_dev);
+
+	iio_triggered_buffer_postenable(indio_dev);
+	gpiod_set_value(st->gpio_convst, 1);
+
+	return 0;
+}
+
+static int ad7606_buffer_predisable(struct iio_dev *indio_dev)
+{
+	struct ad7606_state *st = iio_priv(indio_dev);
+
+	gpiod_set_value(st->gpio_convst, 0);
+
+	return iio_triggered_buffer_predisable(indio_dev);
+}
+
+static const struct iio_buffer_setup_ops ad7606_buffer_ops = {
+	.postenable = &ad7606_buffer_postenable,
+	.predisable = &ad7606_buffer_predisable,
+};
+
+static const struct iio_info ad7606_info_no_os_or_range = {
+	.read_raw = &ad7606_read_raw,
+	.validate_trigger = &ad7606_validate_trigger,
+};
+
+static const struct iio_info ad7606_info_os_and_range = {
+	.read_raw = &ad7606_read_raw,
+	.write_raw = &ad7606_write_raw,
+	.attrs = &ad7606_attribute_group_os_and_range,
+	.validate_trigger = &ad7606_validate_trigger,
+};
+
+static const struct iio_info ad7606_info_os = {
+	.read_raw = &ad7606_read_raw,
+	.write_raw = &ad7606_write_raw,
+	.attrs = &ad7606_attribute_group_os,
+	.validate_trigger = &ad7606_validate_trigger,
+};
+
+static const struct iio_info ad7606_info_range = {
+	.read_raw = &ad7606_read_raw,
+	.write_raw = &ad7606_write_raw,
+	.attrs = &ad7606_attribute_group_range,
+	.validate_trigger = &ad7606_validate_trigger,
+};
+
+static const struct iio_trigger_ops ad7606_trigger_ops = {
+	.validate_device = iio_trigger_validate_own_device,
+};
+
+static void ad7606_regulator_disable(void *data)
+{
+	struct ad7606_state *st = data;
+
+	regulator_disable(st->reg);
+}
+
+int ad7606_probe(struct device *dev, int irq, void __iomem *base_address,
+		 const char *name, unsigned int id,
+		 const struct ad7606_bus_ops *bops)
+{
+	struct ad7606_state *st;
+	int ret;
+	struct iio_dev *indio_dev;
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	st = iio_priv(indio_dev);
+	dev_set_drvdata(dev, indio_dev);
+
+	st->dev = dev;
+	mutex_init(&st->lock);
+	st->bops = bops;
+	st->base_address = base_address;
+	/* tied to logic low, analog input range is +/- 5V */
+	st->range = 0;
+	st->oversampling = 1;
+
+	st->reg = devm_regulator_get(dev, "avcc");
+	if (IS_ERR(st->reg))
+		return PTR_ERR(st->reg);
+
+	ret = regulator_enable(st->reg);
+	if (ret) {
+		dev_err(dev, "Failed to enable specified AVcc supply\n");
+		return ret;
+	}
+
+	ret = devm_add_action_or_reset(dev, ad7606_regulator_disable, st);
+	if (ret)
+		return ret;
+
+	st->chip_info = &ad7606_chip_info_tbl[id];
+
+	ret = ad7606_request_gpios(st);
+	if (ret)
+		return ret;
+
+	indio_dev->dev.parent = dev;
+	if (st->gpio_os) {
+		if (st->gpio_range)
+			indio_dev->info = &ad7606_info_os_and_range;
+		else
+			indio_dev->info = &ad7606_info_os;
+	} else {
+		if (st->gpio_range)
+			indio_dev->info = &ad7606_info_range;
+		else
+			indio_dev->info = &ad7606_info_no_os_or_range;
+	}
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->name = name;
+	indio_dev->channels = st->chip_info->channels;
+	indio_dev->num_channels = st->chip_info->num_channels;
+
+	init_completion(&st->completion);
+
+	ret = ad7606_reset(st);
+	if (ret)
+		dev_warn(st->dev, "failed to RESET: no RESET GPIO specified\n");
+
+	st->trig = devm_iio_trigger_alloc(dev, "%s-dev%d",
+					  indio_dev->name, indio_dev->id);
+	if (!st->trig)
+		return -ENOMEM;
+
+	st->trig->ops = &ad7606_trigger_ops;
+	st->trig->dev.parent = dev;
+	iio_trigger_set_drvdata(st->trig, indio_dev);
+	ret = devm_iio_trigger_register(dev, st->trig);
+	if (ret)
+		return ret;
+
+	indio_dev->trig = iio_trigger_get(st->trig);
+
+	ret = devm_request_threaded_irq(dev, irq,
+					NULL,
+					&ad7606_interrupt,
+					IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+					name, indio_dev);
+	if (ret)
+		return ret;
+
+	ret = devm_iio_triggered_buffer_setup(dev, indio_dev,
+					      &iio_pollfunc_store_time,
+					      &ad7606_trigger_handler,
+					      &ad7606_buffer_ops);
+	if (ret)
+		return ret;
+
+	return devm_iio_device_register(dev, indio_dev);
+}
+EXPORT_SYMBOL_GPL(ad7606_probe);
+
+#ifdef CONFIG_PM_SLEEP
+
+static int ad7606_suspend(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct ad7606_state *st = iio_priv(indio_dev);
+
+	if (st->gpio_standby) {
+		gpiod_set_value(st->gpio_range, 1);
+		gpiod_set_value(st->gpio_standby, 0);
+	}
+
+	return 0;
+}
+
+static int ad7606_resume(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct ad7606_state *st = iio_priv(indio_dev);
+
+	if (st->gpio_standby) {
+		gpiod_set_value(st->gpio_range, st->range);
+		gpiod_set_value(st->gpio_standby, 1);
+		ad7606_reset(st);
+	}
+
+	return 0;
+}
+
+SIMPLE_DEV_PM_OPS(ad7606_pm_ops, ad7606_suspend, ad7606_resume);
+EXPORT_SYMBOL_GPL(ad7606_pm_ops);
+
+#endif
+
+MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
+MODULE_DESCRIPTION("Analog Devices AD7606 ADC");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/adc/ad7606.h b/drivers/iio/adc/ad7606.h
new file mode 100644
index 000000000000..5d12410f68e1
--- /dev/null
+++ b/drivers/iio/adc/ad7606.h
@@ -0,0 +1,99 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * AD7606 ADC driver
+ *
+ * Copyright 2011 Analog Devices Inc.
+ */
+
+#ifndef IIO_ADC_AD7606_H_
+#define IIO_ADC_AD7606_H_
+
+/**
+ * struct ad7606_chip_info - chip specific information
+ * @channels:		channel specification
+ * @num_channels:	number of channels
+ * @has_oversampling:   whether the device has oversampling support
+ */
+struct ad7606_chip_info {
+	const struct iio_chan_spec	*channels;
+	unsigned int			num_channels;
+	bool				has_oversampling;
+};
+
+/**
+ * struct ad7606_state - driver instance specific data
+ * @dev		pointer to kernel device
+ * @chip_info		entry in the table of chips that describes this device
+ * @reg		regulator info for the the power supply of the device
+ * @bops		bus operations (SPI or parallel)
+ * @range		voltage range selection, selects which scale to apply
+ * @oversampling	oversampling selection
+ * @base_address	address from where to read data in parallel operation
+ * @lock		protect sensor state from concurrent accesses to GPIOs
+ * @gpio_convst	GPIO descriptor for conversion start signal (CONVST)
+ * @gpio_reset		GPIO descriptor for device hard-reset
+ * @gpio_range		GPIO descriptor for range selection
+ * @gpio_standby	GPIO descriptor for stand-by signal (STBY),
+ *			controls power-down mode of device
+ * @gpio_frstdata	GPIO descriptor for reading from device when data
+ *			is being read on the first channel
+ * @gpio_os		GPIO descriptors to control oversampling on the device
+ * @complete		completion to indicate end of conversion
+ * @trig		The IIO trigger associated with the device.
+ * @data		buffer for reading data from the device
+ */
+struct ad7606_state {
+	struct device			*dev;
+	const struct ad7606_chip_info	*chip_info;
+	struct regulator		*reg;
+	const struct ad7606_bus_ops	*bops;
+	unsigned int			range;
+	unsigned int			oversampling;
+	void __iomem			*base_address;
+
+	struct mutex			lock; /* protect sensor state */
+	struct gpio_desc		*gpio_convst;
+	struct gpio_desc		*gpio_reset;
+	struct gpio_desc		*gpio_range;
+	struct gpio_desc		*gpio_standby;
+	struct gpio_desc		*gpio_frstdata;
+	struct gpio_descs		*gpio_os;
+	struct iio_trigger		*trig;
+	struct completion		completion;
+
+	/*
+	 * DMA (thus cache coherency maintenance) requires the
+	 * transfer buffers to live in their own cache lines.
+	 * 8 * 16-bit samples + 64-bit timestamp
+	 */
+	unsigned short			data[12] ____cacheline_aligned;
+};
+
+/**
+ * struct ad7606_bus_ops - driver bus operations
+ * @read_block		function pointer for reading blocks of data
+ */
+struct ad7606_bus_ops {
+	/* more methods added in future? */
+	int (*read_block)(struct device *dev, int num, void *data);
+};
+
+int ad7606_probe(struct device *dev, int irq, void __iomem *base_address,
+		 const char *name, unsigned int id,
+		 const struct ad7606_bus_ops *bops);
+
+enum ad7606_supported_device_ids {
+	ID_AD7605_4,
+	ID_AD7606_8,
+	ID_AD7606_6,
+	ID_AD7606_4
+};
+
+#ifdef CONFIG_PM_SLEEP
+extern const struct dev_pm_ops ad7606_pm_ops;
+#define AD7606_PM_OPS (&ad7606_pm_ops)
+#else
+#define AD7606_PM_OPS NULL
+#endif
+
+#endif /* IIO_ADC_AD7606_H_ */
diff --git a/drivers/iio/adc/ad7606_par.c b/drivers/iio/adc/ad7606_par.c
new file mode 100644
index 000000000000..1b08028facde
--- /dev/null
+++ b/drivers/iio/adc/ad7606_par.c
@@ -0,0 +1,105 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * AD7606 Parallel Interface ADC driver
+ *
+ * Copyright 2011 Analog Devices Inc.
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/types.h>
+#include <linux/err.h>
+#include <linux/io.h>
+
+#include <linux/iio/iio.h>
+#include "ad7606.h"
+
+static int ad7606_par16_read_block(struct device *dev,
+				   int count, void *buf)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct ad7606_state *st = iio_priv(indio_dev);
+
+	insw((unsigned long)st->base_address, buf, count);
+
+	return 0;
+}
+
+static const struct ad7606_bus_ops ad7606_par16_bops = {
+	.read_block = ad7606_par16_read_block,
+};
+
+static int ad7606_par8_read_block(struct device *dev,
+				  int count, void *buf)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct ad7606_state *st = iio_priv(indio_dev);
+
+	insb((unsigned long)st->base_address, buf, count * 2);
+
+	return 0;
+}
+
+static const struct ad7606_bus_ops ad7606_par8_bops = {
+	.read_block = ad7606_par8_read_block,
+};
+
+static int ad7606_par_probe(struct platform_device *pdev)
+{
+	const struct platform_device_id *id = platform_get_device_id(pdev);
+	struct resource *res;
+	void __iomem *addr;
+	resource_size_t remap_size;
+	int irq;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(&pdev->dev, "no irq: %d\n", irq);
+		return irq;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	addr = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(addr))
+		return PTR_ERR(addr);
+
+	remap_size = resource_size(res);
+
+	return ad7606_probe(&pdev->dev, irq, addr,
+			    id->name, id->driver_data,
+			    remap_size > 1 ? &ad7606_par16_bops :
+			    &ad7606_par8_bops);
+}
+
+static const struct platform_device_id ad7606_driver_ids[] = {
+	{ .name	= "ad7605-4", .driver_data = ID_AD7605_4, },
+	{ .name	= "ad7606-4", .driver_data = ID_AD7606_4, },
+	{ .name	= "ad7606-6", .driver_data = ID_AD7606_6, },
+	{ .name	= "ad7606-8", .driver_data = ID_AD7606_8, },
+	{ }
+};
+MODULE_DEVICE_TABLE(platform, ad7606_driver_ids);