Merge tag 'iio-for-4.12c' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-next

Third set of new device support, cleanups and features for IIO in the 4.12 cycle

Somewhat dominated in patch numbers of last of the outreachy application
window related patches (they are still coming, despite window being closed
which is good to see!)

Good set of new drivers as well.

New device support
* ASPEED ADC
  - new driver
* cpcap PMIC ADC
  - new driver
* hid-humidity
  - driver for HID compatible humidity sensors.
* ltc2497 ADC
  - new driver
* mpu6050
  - bring bindings up to date and add trivial support for 9250
* rockchip-saradc
  - update bindings to cover rk3328
* vl6180 light, proximity and time of flight sensor.
  - new driver

Features
* meson-saradc
  - add calibration

Cleanup and minor fixes
* ad5504
  - constify attribute_group structure
  - drop casting of void *
* ad7150
  - replace some shifts of 1 by BIT macro usage
* ad7152
  - blank lines between function definitions
* ad7280a
  - octal permissions.
* ad7606
  - replace use of core mlock mutex with a local lock
* ad7746
  - replace some shifts of 1 by BIT macro usage
  - function parameter alignment
  - drop some excessive brackets (introduced in last pull request)
* ad7753
  - white space cleanup
* ad7754
  - includes in alphabetical order and groupped appropriately.
  - change from missuse of internal mlock mutex to using the buffer lock to
  also protect values during frequency update.
* ad779x
  - constify attribute_group structures
* ad9832
  - octal permissions
* adis16060
  - remove use of core mlock mutex in favour of adding a local
  _spi_write_then_read which can use the local buffer protection lock.
  - fix naming of above function.
* adis16203
  - remove locking during reads of calibbias that doesn't protect anything
  not protected elsewhere.
* adis16209
  - remove unnecessary braces in single statement if
* adis16240
  - remove unnecessary braces in single statement if
* adt7136
  - drop excess blank lines and put some in between functions.
* ams-iaq
  - replace comma with semi colon. Not actual bug, just unusual syntax.
* apds9960
  - constify attribute group structure
* as3935
  - constify attribute group structure
* bm1750
  - constify attribute group structure
* cros_ec
  - devm version of triggered buffer setup to simplify code.
* exynos
  - drop casting of void *
* hdc100x
  - constify attribute_group structure
* hid-accel
  - fix wrong scale for newly introduced gravity sensor.
* hts221
  - drop casting of void *
* hx711
  - constify attribute_group structure
* imx7d_adc
  - drop casting of void *
* lm35333
  - constify attribute_group structure
* lsm6dsx
  - drop casting of void *
  - hold ODR configuration until enabling to avoid a race condition.
* max1027
  - drop casting of void *
* max11100
  - fix a comma where semicolon was intended (no actual bug, just odd)
* max1363
  - constify attribute_group structure
* ms sensors
  - drop casting of void *
* rockchip_saradc
  - drop casting of void *
* sun4i-gpadc
  - fix missing dependency on THERMAL or presence of stubs (issue only
  introduced in pervious set)
  - drop casting of void *
* tsl2x7x
  - fix wrong standard deviation calc.  Note these aren't actually used for
  anything at the moment so bug didn't really matter.
  - constify attribute group structure.
* vf610adc
  - drop casting of void *
* vz89x
  - replace comma with semicolon. Not actual bug, just odd syntax.
* zpa2326
  - drop casting of void *

16 files changed, 1703 insertions, 13 deletions

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 2268a6fb9865..b7b3a9a80043 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -130,6 +130,17 @@ config AD799X
 	  To compile this driver as a module, choose M here: the module will be
 	  called ad799x.
 
+config ASPEED_ADC
+	tristate "Aspeed ADC"
+	depends on ARCH_ASPEED || COMPILE_TEST
+	depends on COMMON_CLK
+	help
+	  If you say yes here you get support for the ADC included in Aspeed
+	  BMC SoCs.
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called aspeed_adc.
+
 config AT91_ADC
 	tristate "Atmel AT91 ADC"
 	depends on ARCH_AT91
@@ -195,6 +206,17 @@ config CC10001_ADC
 	  This driver can also be built as a module. If so, the module will be
 	  called cc10001_adc.
 
+config CPCAP_ADC
+	tristate "Motorola CPCAP PMIC ADC driver"
+	depends on MFD_CPCAP
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
+	help
+	  Say yes here to build support for Motorola CPCAP PMIC ADC.
+
+	  This driver can also be built as a module. If so, the module will be
+	  called cpcap-adc.
+
 config DA9150_GPADC
 	tristate "Dialog DA9150 GPADC driver support"
 	depends on MFD_DA9150
@@ -326,6 +348,16 @@ config LTC2485
 	  To compile this driver as a module, choose M here: the module will be
 	  called ltc2485.
 
+config LTC2497
+	tristate "Linear Technology LTC2497 ADC driver"
+	depends on I2C
+	help
+	  Say yes here to build support for Linear Technology LTC2497
+	  16-Bit 8-/16-Channel Delta Sigma ADC.
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called ltc2497.
+
 config MAX1027
 	tristate "Maxim max1027 ADC driver"
 	depends on SPI
@@ -563,6 +595,7 @@ config SUN4I_GPADC
 	tristate "Support for the Allwinner SoCs GPADC"
 	depends on IIO
 	depends on MFD_SUN4I_GPADC
+	depends on THERMAL || !THERMAL_OF
 	help
 	  Say yes here to build support for Allwinner (A10, A13 and A31) SoCs
 	  GPADC. This ADC provides 4 channels which can be used as an ADC or as
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 73dbe399f894..3d9174ab26c8 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -14,12 +14,14 @@ obj-$(CONFIG_AD7791) += ad7791.o
 obj-$(CONFIG_AD7793) += ad7793.o
 obj-$(CONFIG_AD7887) += ad7887.o
 obj-$(CONFIG_AD799X) += ad799x.o
+obj-$(CONFIG_ASPEED_ADC) += aspeed_adc.o
 obj-$(CONFIG_AT91_ADC) += at91_adc.o
 obj-$(CONFIG_AT91_SAMA5D2_ADC) += at91-sama5d2_adc.o
 obj-$(CONFIG_AXP288_ADC) += axp288_adc.o
 obj-$(CONFIG_BCM_IPROC_ADC) += bcm_iproc_adc.o
 obj-$(CONFIG_BERLIN2_ADC) += berlin2-adc.o
 obj-$(CONFIG_CC10001_ADC) += cc10001_adc.o
+obj-$(CONFIG_CPCAP_ADC) += cpcap-adc.o
 obj-$(CONFIG_DA9150_GPADC) += da9150-gpadc.o
 obj-$(CONFIG_ENVELOPE_DETECTOR) += envelope-detector.o
 obj-$(CONFIG_EXYNOS_ADC) += exynos_adc.o
@@ -32,6 +34,7 @@ obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o
 obj-$(CONFIG_LPC18XX_ADC) += lpc18xx_adc.o
 obj-$(CONFIG_LPC32XX_ADC) += lpc32xx_adc.o
 obj-$(CONFIG_LTC2485) += ltc2485.o
+obj-$(CONFIG_LTC2497) += ltc2497.o
 obj-$(CONFIG_MAX1027) += max1027.o
 obj-$(CONFIG_MAX11100) += max11100.o
 obj-$(CONFIG_MAX1363) += max1363.o
diff --git a/drivers/iio/adc/ad799x.c b/drivers/iio/adc/ad799x.c
index 9704090b7908..22426ae4af97 100644
--- a/drivers/iio/adc/ad799x.c
+++ b/drivers/iio/adc/ad799x.c
@@ -520,7 +520,7 @@ static struct attribute *ad799x_event_attributes[] = {
 	NULL,
 };
 
-static struct attribute_group ad799x_event_attrs_group = {
+static const struct attribute_group ad799x_event_attrs_group = {
 	.attrs = ad799x_event_attributes,
 };
 
diff --git a/drivers/iio/adc/aspeed_adc.c b/drivers/iio/adc/aspeed_adc.c
new file mode 100644
index 000000000000..62670cbfa2bb
--- /dev/null
+++ b/drivers/iio/adc/aspeed_adc.c
@@ -0,0 +1,295 @@
+/*
+ * Aspeed AST2400/2500 ADC
+ *
+ * Copyright (C) 2017 Google, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/driver.h>
+
+#define ASPEED_RESOLUTION_BITS		10
+#define ASPEED_CLOCKS_PER_SAMPLE	12
+
+#define ASPEED_REG_ENGINE_CONTROL	0x00
+#define ASPEED_REG_INTERRUPT_CONTROL	0x04
+#define ASPEED_REG_VGA_DETECT_CONTROL	0x08
+#define ASPEED_REG_CLOCK_CONTROL	0x0C
+#define ASPEED_REG_MAX			0xC0
+
+#define ASPEED_OPERATION_MODE_POWER_DOWN	(0x0 << 1)
+#define ASPEED_OPERATION_MODE_STANDBY		(0x1 << 1)
+#define ASPEED_OPERATION_MODE_NORMAL		(0x7 << 1)
+
+#define ASPEED_ENGINE_ENABLE		BIT(0)
+
+struct aspeed_adc_model_data {
+	const char *model_name;
+	unsigned int min_sampling_rate;	// Hz
+	unsigned int max_sampling_rate;	// Hz
+	unsigned int vref_voltage;	// mV
+};
+
+struct aspeed_adc_data {
+	struct device	*dev;
+	void __iomem	*base;
+	spinlock_t	clk_lock;
+	struct clk_hw	*clk_prescaler;
+	struct clk_hw	*clk_scaler;
+};
+
+#define ASPEED_CHAN(_idx, _data_reg_addr) {			\
+	.type = IIO_VOLTAGE,					\
+	.indexed = 1,						\
+	.channel = (_idx),					\
+	.address = (_data_reg_addr),				\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |	\
+				BIT(IIO_CHAN_INFO_SAMP_FREQ),	\
+}
+
+static const struct iio_chan_spec aspeed_adc_iio_channels[] = {
+	ASPEED_CHAN(0, 0x10),
+	ASPEED_CHAN(1, 0x12),
+	ASPEED_CHAN(2, 0x14),
+	ASPEED_CHAN(3, 0x16),
+	ASPEED_CHAN(4, 0x18),
+	ASPEED_CHAN(5, 0x1A),
+	ASPEED_CHAN(6, 0x1C),
+	ASPEED_CHAN(7, 0x1E),
+	ASPEED_CHAN(8, 0x20),
+	ASPEED_CHAN(9, 0x22),
+	ASPEED_CHAN(10, 0x24),
+	ASPEED_CHAN(11, 0x26),
+	ASPEED_CHAN(12, 0x28),
+	ASPEED_CHAN(13, 0x2A),
+	ASPEED_CHAN(14, 0x2C),
+	ASPEED_CHAN(15, 0x2E),
+};
+
+static int aspeed_adc_read_raw(struct iio_dev *indio_dev,
+			       struct iio_chan_spec const *chan,
+			       int *val, int *val2, long mask)
+{
+	struct aspeed_adc_data *data = iio_priv(indio_dev);
+	const struct aspeed_adc_model_data *model_data =
+			of_device_get_match_data(data->dev);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		*val = readw(data->base + chan->address);
+		return IIO_VAL_INT;
+
+	case IIO_CHAN_INFO_SCALE:
+		*val = model_data->vref_voltage;
+		*val2 = ASPEED_RESOLUTION_BITS;
+		return IIO_VAL_FRACTIONAL_LOG2;
+
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		*val = clk_get_rate(data->clk_scaler->clk) /
+				ASPEED_CLOCKS_PER_SAMPLE;
+		return IIO_VAL_INT;
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static int aspeed_adc_write_raw(struct iio_dev *indio_dev,
+				struct iio_chan_spec const *chan,
+				int val, int val2, long mask)
+{
+	struct aspeed_adc_data *data = iio_priv(indio_dev);
+	const struct aspeed_adc_model_data *model_data =
+			of_device_get_match_data(data->dev);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		if (val < model_data->min_sampling_rate ||
+			val > model_data->max_sampling_rate)
+			return -EINVAL;
+
+		clk_set_rate(data->clk_scaler->clk,
+				val * ASPEED_CLOCKS_PER_SAMPLE);
+		return 0;
+
+	case IIO_CHAN_INFO_SCALE:
+	case IIO_CHAN_INFO_RAW:
+		/*
+		 * Technically, these could be written but the only reasons
+		 * for doing so seem better handled in userspace.  EPERM is
+		 * returned to signal this is a policy choice rather than a
+		 * hardware limitation.
+		 */
+		return -EPERM;
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static int aspeed_adc_reg_access(struct iio_dev *indio_dev,
+				 unsigned int reg, unsigned int writeval,
+				 unsigned int *readval)
+{
+	struct aspeed_adc_data *data = iio_priv(indio_dev);
+
+	if (!readval || reg % 4 || reg > ASPEED_REG_MAX)
+		return -EINVAL;
+
+	*readval = readl(data->base + reg);
+
+	return 0;
+}
+
+static const struct iio_info aspeed_adc_iio_info = {
+	.driver_module = THIS_MODULE,
+	.read_raw = aspeed_adc_read_raw,
+	.write_raw = aspeed_adc_write_raw,
+	.debugfs_reg_access = aspeed_adc_reg_access,
+};
+
+static int aspeed_adc_probe(struct platform_device *pdev)
+{
+	struct iio_dev *indio_dev;
+	struct aspeed_adc_data *data;
+	const struct aspeed_adc_model_data *model_data;
+	struct resource *res;
+	const char *clk_parent_name;
+	int ret;
+	u32 adc_engine_control_reg_val;
+
+	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	data = iio_priv(indio_dev);
+	data->dev = &pdev->dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	data->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(data->base))
+		return PTR_ERR(data->base);
+
+	/* Register ADC clock prescaler with source specified by device tree. */
+	spin_lock_init(&data->clk_lock);
+	clk_parent_name = of_clk_get_parent_name(pdev->dev.of_node, 0);
+
+	data->clk_prescaler = clk_hw_register_divider(
+				&pdev->dev, "prescaler", clk_parent_name, 0,
+				data->base + ASPEED_REG_CLOCK_CONTROL,
+				17, 15, 0, &data->clk_lock);
+	if (IS_ERR(data->clk_prescaler))
+		return PTR_ERR(data->clk_prescaler);
+
+	/*
+	 * Register ADC clock scaler downstream from the prescaler. Allow rate
+	 * setting to adjust the prescaler as well.
+	 */
+	data->clk_scaler = clk_hw_register_divider(
+				&pdev->dev, "scaler", "prescaler",
+				CLK_SET_RATE_PARENT,
+				data->base + ASPEED_REG_CLOCK_CONTROL,
+				0, 10, 0, &data->clk_lock);
+	if (IS_ERR(data->clk_scaler)) {
+		ret = PTR_ERR(data->clk_scaler);
+		goto scaler_error;
+	}
+
+	/* Start all channels in normal mode. */
+	clk_prepare_enable(data->clk_scaler->clk);
+	adc_engine_control_reg_val = GENMASK(31, 16) |
+		ASPEED_OPERATION_MODE_NORMAL | ASPEED_ENGINE_ENABLE;
+	writel(adc_engine_control_reg_val,
+		data->base + ASPEED_REG_ENGINE_CONTROL);
+
+	model_data = of_device_get_match_data(&pdev->dev);
+	indio_dev->name = model_data->model_name;
+	indio_dev->dev.parent = &pdev->dev;
+	indio_dev->info = &aspeed_adc_iio_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = aspeed_adc_iio_channels;
+	indio_dev->num_channels = ARRAY_SIZE(aspeed_adc_iio_channels);
+
+	ret = iio_device_register(indio_dev);
+	if (ret)
+		goto iio_register_error;
+
+	return 0;
+
+iio_register_error:
+	writel(ASPEED_OPERATION_MODE_POWER_DOWN,
+		data->base + ASPEED_REG_ENGINE_CONTROL);
+	clk_disable_unprepare(data->clk_scaler->clk);
+	clk_hw_unregister_divider(data->clk_scaler);
+
+scaler_error:
+	clk_hw_unregister_divider(data->clk_prescaler);
+	return ret;
+}
+
+static int aspeed_adc_remove(struct platform_device *pdev)
+{
+	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+	struct aspeed_adc_data *data = iio_priv(indio_dev);
+
+	iio_device_unregister(indio_dev);
+	writel(ASPEED_OPERATION_MODE_POWER_DOWN,
+		data->base + ASPEED_REG_ENGINE_CONTROL);
+	clk_disable_unprepare(data->clk_scaler->clk);
+	clk_hw_unregister_divider(data->clk_scaler);
+	clk_hw_unregister_divider(data->clk_prescaler);
+
+	return 0;
+}
+
+static const struct aspeed_adc_model_data ast2400_model_data = {
+	.model_name = "ast2400-adc",
+	.vref_voltage = 2500, // mV
+	.min_sampling_rate = 10000,
+	.max_sampling_rate = 500000,
+};
+
+static const struct aspeed_adc_model_data ast2500_model_data = {
+	.model_name = "ast2500-adc",
+	.vref_voltage = 1800, // mV
+	.min_sampling_rate = 1,
+	.max_sampling_rate = 1000000,
+};
+
+static const struct of_device_id aspeed_adc_matches[] = {
+	{ .compatible = "aspeed,ast2400-adc", .data = &ast2400_model_data },
+	{ .compatible = "aspeed,ast2500-adc", .data = &ast2500_model_data },
+	{},
+};
+MODULE_DEVICE_TABLE(of, aspeed_adc_matches);
+
+static struct platform_driver aspeed_adc_driver = {
+	.probe = aspeed_adc_probe,
+	.remove = aspeed_adc_remove,
+	.driver = {
+		.name = KBUILD_MODNAME,
+		.of_match_table = aspeed_adc_matches,
+	}
+};
+
+module_platform_driver(aspeed_adc_driver);
+
+MODULE_AUTHOR("Rick Altherr <raltherr@google.com>");
+MODULE_DESCRIPTION("Aspeed AST2400/2500 ADC Driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/iio/adc/cpcap-adc.c b/drivers/iio/adc/cpcap-adc.c
new file mode 100644
index 000000000000..62d37f8725b8
--- /dev/null
+++ b/drivers/iio/adc/cpcap-adc.c
@@ -0,0 +1,1007 @@
+/*
+ * Copyright (C) 2017 Tony Lindgren <tony@atomide.com>
+ *
+ * Rewritten for Linux IIO framework with some code based on
+ * earlier driver found in the Motorola Linux kernel:
+ *
+ * Copyright (C) 2009-2010 Motorola, Inc.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include <linux/iio/buffer.h>
+#include <linux/iio/driver.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/kfifo_buf.h>
+#include <linux/mfd/motorola-cpcap.h>
+
+/* Register CPCAP_REG_ADCC1 bits */
+#define CPCAP_BIT_ADEN_AUTO_CLR		BIT(15)	/* Currently unused */
+#define CPCAP_BIT_CAL_MODE		BIT(14) /* Set with BIT_RAND0 */
+#define CPCAP_BIT_ADC_CLK_SEL1		BIT(13)	/* Currently unused */
+#define CPCAP_BIT_ADC_CLK_SEL0		BIT(12)	/* Currently unused */
+#define CPCAP_BIT_ATOX			BIT(11)
+#define CPCAP_BIT_ATO3			BIT(10)
+#define CPCAP_BIT_ATO2			BIT(9)
+#define CPCAP_BIT_ATO1			BIT(8)
+#define CPCAP_BIT_ATO0			BIT(7)
+#define CPCAP_BIT_ADA2			BIT(6)
+#define CPCAP_BIT_ADA1			BIT(5)
+#define CPCAP_BIT_ADA0			BIT(4)
+#define CPCAP_BIT_AD_SEL1		BIT(3)	/* Set for bank1 */
+#define CPCAP_BIT_RAND1			BIT(2)	/* Set for channel 16 & 17 */
+#define CPCAP_BIT_RAND0			BIT(1)	/* Set with CAL_MODE */
+#define CPCAP_BIT_ADEN			BIT(0)	/* Currently unused */
+
+/* Register CPCAP_REG_ADCC2 bits */
+#define CPCAP_BIT_CAL_FACTOR_ENABLE	BIT(15)	/* Currently unused */
+#define CPCAP_BIT_BATDETB_EN		BIT(14)	/* Currently unused */
+#define CPCAP_BIT_ADTRIG_ONESHOT	BIT(13)	/* Set for !TIMING_IMM */
+#define CPCAP_BIT_ASC			BIT(12)	/* Set for TIMING_IMM */
+#define CPCAP_BIT_ATOX_PS_FACTOR	BIT(11)
+#define CPCAP_BIT_ADC_PS_FACTOR1	BIT(10)
+#define CPCAP_BIT_ADC_PS_FACTOR0	BIT(9)
+#define CPCAP_BIT_AD4_SELECT		BIT(8)	/* Currently unused */
+#define CPCAP_BIT_ADC_BUSY		BIT(7)	/* Currently unused */
+#define CPCAP_BIT_THERMBIAS_EN		BIT(6)	/* Currently unused */
+#define CPCAP_BIT_ADTRIG_DIS		BIT(5)	/* Disable interrupt */
+#define CPCAP_BIT_LIADC			BIT(4)	/* Currently unused */
+#define CPCAP_BIT_TS_REFEN		BIT(3)	/* Currently unused */
+#define CPCAP_BIT_TS_M2			BIT(2)	/* Currently unused */
+#define CPCAP_BIT_TS_M1			BIT(1)	/* Currently unused */
+#define CPCAP_BIT_TS_M0			BIT(0)	/* Currently unused */
+
+#define CPCAP_MAX_TEMP_LVL		27
+#define CPCAP_FOUR_POINT_TWO_ADC	801
+#define ST_ADC_CAL_CHRGI_HIGH_THRESHOLD	530
+#define ST_ADC_CAL_CHRGI_LOW_THRESHOLD	494
+#define ST_ADC_CAL_BATTI_HIGH_THRESHOLD	530
+#define ST_ADC_CAL_BATTI_LOW_THRESHOLD	494
+#define ST_ADC_CALIBRATE_DIFF_THRESHOLD	3
+
+#define CPCAP_ADC_MAX_RETRIES		5	/* Calibration and quirk */
+
+/**
+ * struct cpcap_adc_ato - timing settings for cpcap adc
+ *
+ * Unfortunately no cpcap documentation available, please document when
+ * using these.
+ */
+struct cpcap_adc_ato {
+	unsigned short ato_in;
+	unsigned short atox_in;
+	unsigned short adc_ps_factor_in;
+	unsigned short atox_ps_factor_in;
+	unsigned short ato_out;
+	unsigned short atox_out;
+	unsigned short adc_ps_factor_out;
+	unsigned short atox_ps_factor_out;
+};
+
+/**
+ * struct cpcap-adc - cpcap adc device driver data
+ * @reg: cpcap regmap
+ * @dev: struct device
+ * @vendor: cpcap vendor
+ * @irq: interrupt
+ * @lock: mutex
+ * @ato: request timings
+ * @wq_data_avail: work queue
+ * @done: work done
+ */
+struct cpcap_adc {
+	struct regmap *reg;
+	struct device *dev;
+	u16 vendor;
+	int irq;
+	struct mutex lock;	/* ADC register access lock */
+	const struct cpcap_adc_ato *ato;
+	wait_queue_head_t wq_data_avail;
+	bool done;
+};
+
+/**
+ * enum cpcap_adc_channel - cpcap adc channels
+ */
+enum cpcap_adc_channel {
+	/* Bank0 channels */
+	CPCAP_ADC_AD0_BATTDETB,	/* Battery detection */
+	CPCAP_ADC_BATTP,	/* Battery voltage */
+	CPCAP_ADC_VBUS,		/* USB VBUS voltage */
+	CPCAP_ADC_AD3,		/* Battery temperature when charging */
+	CPCAP_ADC_BPLUS_AD4,	/* Another battery or system voltage */
+	CPCAP_ADC_CHG_ISENSE,	/* Calibrated charge current */
+	CPCAP_ADC_BATTI,	/* Calibrated system current */
+	CPCAP_ADC_USB_ID,	/* USB OTG ID, unused on droid 4? */
+
+	/* Bank1 channels */
+	CPCAP_ADC_AD8,		/* Seems unused */
+	CPCAP_ADC_AD9,		/* Seems unused */
+	CPCAP_ADC_LICELL,	/* Maybe system voltage? Always 3V */
+	CPCAP_ADC_HV_BATTP,	/* Another battery detection? */
+	CPCAP_ADC_TSX1_AD12,	/* Seems unused, for touchscreen? */
+	CPCAP_ADC_TSX2_AD13,	/* Seems unused, for touchscreen? */
+	CPCAP_ADC_TSY1_AD14,	/* Seems unused, for touchscreen? */
+	CPCAP_ADC_TSY2_AD15,	/* Seems unused, for touchscreen? */
+
+	/* Remuxed channels using bank0 entries */
+	CPCAP_ADC_BATTP_PI16,	/* Alternative mux mode for BATTP */
+	CPCAP_ADC_BATTI_PI17,	/* Alternative mux mode for BATTI */
+
+	CPCAP_ADC_CHANNEL_NUM,
+};
+
+/**
+ * enum cpcap_adc_timing - cpcap adc timing options
+ *
+ * CPCAP_ADC_TIMING_IMM seems to be immediate with no timings.
+ * Please document when using.
+ */
+enum cpcap_adc_timing {
+	CPCAP_ADC_TIMING_IMM,
+	CPCAP_ADC_TIMING_IN,
+	CPCAP_ADC_TIMING_OUT,
+};
+
+/**
+ * struct cpcap_adc_phasing_tbl - cpcap phasing table
+ * @offset: offset in the phasing table
+ * @multiplier: multiplier in the phasing table
+ * @divider: divider in the phasing table
+ * @min: minimum value
+ * @max: maximum value
+ */
+struct cpcap_adc_phasing_tbl {
+	short offset;
+	unsigned short multiplier;
+	unsigned short divider;
+	short min;
+	short max;
+};
+
+/**
+ * struct cpcap_adc_conversion_tbl - cpcap conversion table
+ * @conv_type: conversion type
+ * @align_offset: align offset
+ * @conv_offset: conversion offset
+ * @cal_offset: calibration offset
+ * @multiplier: conversion multiplier
+ * @divider: conversion divider
+ */
+struct cpcap_adc_conversion_tbl {
+	enum iio_chan_info_enum conv_type;
+	int align_offset;
+	int conv_offset;
+	int cal_offset;
+	int multiplier;
+	int divider;
+};
+
+/**
+ * struct cpcap_adc_request - cpcap adc request
+ * @channel: request channel
+ * @phase_tbl: channel phasing table
+ * @conv_tbl: channel conversion table
+ * @bank_index: channel index within the bank
+ * @timing: timing settings
+ * @result: result
+ */
+struct cpcap_adc_request {
+	int channel;
+	const struct cpcap_adc_phasing_tbl *phase_tbl;
+	const struct cpcap_adc_conversion_tbl *conv_tbl;
+	int bank_index;
+	enum cpcap_adc_timing timing;
+	int result;
+};
+
+/* Phasing table for channels. Note that channels 16 & 17 use BATTP and BATTI */
+static const struct cpcap_adc_phasing_tbl bank_phasing[] = {
+	/* Bank0 */
+	[CPCAP_ADC_AD0_BATTDETB] = {0, 0x80, 0x80,    0, 1023},
+	[CPCAP_ADC_BATTP] =        {0, 0x80, 0x80,    0, 1023},
+	[CPCAP_ADC_VBUS] =         {0, 0x80, 0x80,    0, 1023},
+	[CPCAP_ADC_AD3] =          {0, 0x80, 0x80,    0, 1023},
+	[CPCAP_ADC_BPLUS_AD4] =    {0, 0x80, 0x80,    0, 1023},
+	[CPCAP_ADC_CHG_ISENSE] =   {0, 0x80, 0x80, -512,  511},
+	[CPCAP_ADC_BATTI] =        {0, 0x80, 0x80, -512,  511},
+	[CPCAP_ADC_USB_ID] =       {0, 0x80, 0x80,    0, 1023},
+
+	/* Bank1 */
+	[CPCAP_ADC_AD8] =          {0, 0x80, 0x80,    0, 1023},
+	[CPCAP_ADC_AD9] =          {0, 0x80, 0x80,    0, 1023},
+	[CPCAP_ADC_LICELL] =       {0, 0x80, 0x80,    0, 1023},
+	[CPCAP_ADC_HV_BATTP] =     {0, 0x80, 0x80,    0, 1023},
+	[CPCAP_ADC_TSX1_AD12] =    {0, 0x80, 0x80,    0, 1023},
+	[CPCAP_ADC_TSX2_AD13] =    {0, 0x80, 0x80,    0, 1023},
+	[CPCAP_ADC_TSY1_AD14] =    {0, 0x80, 0x80,    0, 1023},
+	[CPCAP_ADC_TSY2_AD15] =    {0, 0x80, 0x80,    0, 1023},
+};
+
+/*
+ * Conversion table for channels. Updated during init based on calibration.
+ * Here too channels 16 & 17 use BATTP and BATTI.
+ */
+static struct cpcap_adc_conversion_tbl bank_conversion[] = {
+	/* Bank0 */
+	[CPCAP_ADC_AD0_BATTDETB] = {
+		IIO_CHAN_INFO_PROCESSED,    0,    0, 0,     1,    1,
+	},
+	[CPCAP_ADC_BATTP] = {
+		IIO_CHAN_INFO_PROCESSED,    0, 2400, 0,  2300, 1023,
+	},
+	[CPCAP_ADC_VBUS] = {
+		IIO_CHAN_INFO_PROCESSED,    0,    0, 0, 10000, 1023,
+	},
+	[CPCAP_ADC_AD3] = {
+		IIO_CHAN_INFO_PROCESSED,    0,    0, 0,     1,    1,
+		},
+	[CPCAP_ADC_BPLUS_AD4] = {
+		IIO_CHAN_INFO_PROCESSED,    0, 2400, 0,  2300, 1023,
+	},
+	[CPCAP_ADC_CHG_ISENSE] = {
+		IIO_CHAN_INFO_PROCESSED, -512,    2, 0,  5000, 1023,
+	},
+	[CPCAP_ADC_BATTI] = {
+		IIO_CHAN_INFO_PROCESSED, -512,    2, 0,  5000, 1023,
+	},
+	[CPCAP_ADC_USB_ID] = {
+		IIO_CHAN_INFO_RAW,          0,    0, 0,     1,    1,
+	},
+
+	/* Bank1 */
+	[CPCAP_ADC_AD8] = {
+		IIO_CHAN_INFO_RAW,          0,    0, 0,     1,    1,
+	},
+	[CPCAP_ADC_AD9] = {
+		IIO_CHAN_INFO_RAW,          0,    0, 0,     1,    1,
+	},
+	[CPCAP_ADC_LICELL] = {
+		IIO_CHAN_INFO_PROCESSED,    0,    0, 0,  3400, 1023,
+	},
+	[CPCAP_ADC_HV_BATTP] = {
+		IIO_CHAN_INFO_RAW,          0,    0, 0,     1,    1,
+	},
+	[CPCAP_ADC_TSX1_AD12] = {
+		IIO_CHAN_INFO_RAW,          0,    0, 0,     1,    1,
+	},
+	[CPCAP_ADC_TSX2_AD13] = {
+		IIO_CHAN_INFO_RAW,          0,    0, 0,     1,    1,
+	},
+	[CPCAP_ADC_TSY1_AD14] = {
+		IIO_CHAN_INFO_RAW,          0,    0, 0,     1,    1,
+	},
+	[CPCAP_ADC_TSY2_AD15] = {
+		IIO_CHAN_INFO_RAW,          0,    0, 0,     1,    1,
+	},
+};
+
+/*
+ * Temperature lookup table of register values to milliCelcius.
+ * REVISIT: Check the duplicate 0x3ff entry in a freezer
+ */
+static const int temp_map[CPCAP_MAX_TEMP_LVL][2] = {
+	{ 0x03ff, -40000 },
+	{ 0x03ff, -35000 },
+	{ 0x03ef, -30000 },
+	{ 0x03b2, -25000 },
+	{ 0x036c, -20000 },
+	{ 0x0320, -15000 },
+	{ 0x02d0, -10000 },
+	{ 0x027f, -5000 },
+	{ 0x022f, 0 },
+	{ 0x01e4, 5000 },
+	{ 0x019f, 10000 },
+	{ 0x0161, 15000 },
+	{ 0x012b, 20000 },
+	{ 0x00fc, 25000 },
+	{ 0x00d4, 30000 },
+	{ 0x00b2, 35000 },
+	{ 0x0095, 40000 },
+	{ 0x007d, 45000 },
+	{ 0x0069, 50000 },
+	{ 0x0059, 55000 },
+	{ 0x004b, 60000 },
+	{ 0x003f, 65000 },
+	{ 0x0036, 70000 },
+	{ 0x002e, 75000 },
+	{ 0x0027, 80000 },
+	{ 0x0022, 85000 },
+	{ 0x001d, 90000 },
+};
+
+#define CPCAP_CHAN(_type, _index, _address, _datasheet_name) {	\
+	.type = (_type), \
+	.address = (_address), \
+	.indexed = 1, \
+	.channel = (_index), \
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
+			      BIT(IIO_CHAN_INFO_PROCESSED), \
+	.scan_index = (_index), \
+	.scan_type = { \
+		.sign = 'u', \
+		.realbits = 10, \
+		.storagebits = 16, \
+		.endianness = IIO_CPU, \
+	}, \
+	.datasheet_name = (_datasheet_name), \
+}
+
+/*
+ * The datasheet names are from Motorola mapphone Linux kernel except
+ * for the last two which might be uncalibrated charge voltage and
+ * current.
+ */
+static const struct iio_chan_spec cpcap_adc_channels[] = {
+	/* Bank0 */
+	CPCAP_CHAN(IIO_TEMP,    0, CPCAP_REG_ADCD0,  "battdetb"),
+	CPCAP_CHAN(IIO_VOLTAGE, 1, CPCAP_REG_ADCD1,  "battp"),
+	CPCAP_CHAN(IIO_VOLTAGE, 2, CPCAP_REG_ADCD2,  "vbus"),
+	CPCAP_CHAN(IIO_TEMP,    3, CPCAP_REG_ADCD3,  "ad3"),
+	CPCAP_CHAN(IIO_VOLTAGE, 4, CPCAP_REG_ADCD4,  "ad4"),
+	CPCAP_CHAN(IIO_CURRENT, 5, CPCAP_REG_ADCD5,  "chg_isense"),
+	CPCAP_CHAN(IIO_CURRENT, 6, CPCAP_REG_ADCD6,  "batti"),
+	CPCAP_CHAN(IIO_VOLTAGE, 7, CPCAP_REG_ADCD7,  "usb_id"),
+
+	/* Bank1 */
+	CPCAP_CHAN(IIO_CURRENT, 8, CPCAP_REG_ADCD0,  "ad8"),
+	CPCAP_CHAN(IIO_VOLTAGE, 9, CPCAP_REG_ADCD1,  "ad9"),
+	CPCAP_CHAN(IIO_VOLTAGE, 10, CPCAP_REG_ADCD2, "licell"),
+	CPCAP_CHAN(IIO_VOLTAGE, 11, CPCAP_REG_ADCD3, "hv_battp"),
+	CPCAP_CHAN(IIO_VOLTAGE, 12, CPCAP_REG_ADCD4, "tsx1_ad12"),
+	CPCAP_CHAN(IIO_VOLTAGE, 13, CPCAP_REG_ADCD5, "tsx2_ad13"),
+	CPCAP_CHAN(IIO_VOLTAGE, 14, CPCAP_REG_ADCD6, "tsy1_ad14"),
+	CPCAP_CHAN(IIO_VOLTAGE, 15, CPCAP_REG_ADCD7, "tsy2_ad15"),
+
+	/* There are two registers with multiplexed functionality */
+	CPCAP_CHAN(IIO_VOLTAGE, 16, CPCAP_REG_ADCD0, "chg_vsense"),
+	CPCAP_CHAN(IIO_CURRENT, 17, CPCAP_REG_ADCD1, "batti2"),
+};
+
+static irqreturn_t cpcap_adc_irq_thread(int irq, void *data)
+{
+	struct iio_dev *indio_dev = data;
+	struct cpcap_adc *ddata = iio_priv(indio_dev);
+	int error;
+
+	error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
+				   CPCAP_BIT_ADTRIG_DIS,
+				   CPCAP_BIT_ADTRIG_DIS);
+	if (error)
+		return IRQ_NONE;
+
+	ddata->done = true;
+	wake_up_interruptible(&ddata->wq_data_avail);
+
+	return IRQ_HANDLED;
+}
+
+/* ADC calibration functions */
+static void cpcap_adc_setup_calibrate(struct cpcap_adc *ddata,
+				      enum cpcap_adc_channel chan)
+{
+	unsigned int value = 0;
+	unsigned long timeout = jiffies + msecs_to_jiffies(3000);
+	int error;
+
+	if ((chan != CPCAP_ADC_CHG_ISENSE) &&
+	    (chan != CPCAP_ADC_BATTI))
+		return;
+
+	value |= CPCAP_BIT_CAL_MODE | CPCAP_BIT_RAND0;
+	value |= ((chan << 4) &
+		  (CPCAP_BIT_ADA2 | CPCAP_BIT_ADA1 | CPCAP_BIT_ADA0));
+
+	error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC1,
+				   CPCAP_BIT_CAL_MODE | CPCAP_BIT_ATOX |
+				   CPCAP_BIT_ATO3 | CPCAP_BIT_ATO2 |
+				   CPCAP_BIT_ATO1 | CPCAP_BIT_ATO0 |
+				   CPCAP_BIT_ADA2 | CPCAP_BIT_ADA1 |
+				   CPCAP_BIT_ADA0 | CPCAP_BIT_AD_SEL1 |
+				   CPCAP_BIT_RAND1 | CPCAP_BIT_RAND0,
+				   value);
+	if (error)
+		return;
+
+	error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
+				   CPCAP_BIT_ATOX_PS_FACTOR |
+				   CPCAP_BIT_ADC_PS_FACTOR1 |
+				   CPCAP_BIT_ADC_PS_FACTOR0,
+				   0);
+	if (error)
+		return;
+
+	error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
+				   CPCAP_BIT_ADTRIG_DIS,
+				   CPCAP_BIT_ADTRIG_DIS);
+	if (error)
+		return;
+
+	error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
+				   CPCAP_BIT_ASC,
+				   CPCAP_BIT_ASC);
+	if (error)
+		return;
+
+	do {
+		schedule_timeout_uninterruptible(1);
+		error = regmap_read(ddata->reg, CPCAP_REG_ADCC2, &value);
+		if (error)
+			return;
+	} while ((value & CPCAP_BIT_ASC) && time_before(jiffies, timeout));
+
+	if (value & CPCAP_BIT_ASC)
+		dev_err(ddata->dev,
+			"Timeout waiting for calibration to complete\n");
+
+	error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC1,
+				   CPCAP_BIT_CAL_MODE, 0);
+	if (error)
+		return;
+}
+
+static int cpcap_adc_calibrate_one(struct cpcap_adc *ddata,
+				   int channel,
+				   u16 calibration_register,
+				   int lower_threshold,
+				   int upper_threshold)
+{
+	unsigned int calibration_data[2];
+	unsigned short cal_data_diff;
+	int i, error;
+
+	for (i = 0; i < CPCAP_ADC_MAX_RETRIES; i++) {
+		calibration_data[0]  = 0;
+		calibration_data[1]  = 0;
+		cal_data_diff = 0;
+		cpcap_adc_setup_calibrate(ddata, channel);
+		error = regmap_read(ddata->reg, calibration_register,
+				    &calibration_data[0]);
+		if (error)
+			return error;
+		cpcap_adc_setup_calibrate(ddata, channel);
+		error = regmap_read(ddata->reg, calibration_register,
+				    &calibration_data[1]);
+		if (error)
+			return error;
+
+		if (calibration_data[0] > calibration_data[1])
+			cal_data_diff =
+				calibration_data[0] - calibration_data[1];
+		else
+			cal_data_diff =
+				calibration_data[1] - calibration_data[0];
+
+		if (((calibration_data[1] >= lower_threshold) &&
+		     (calibration_data[1] <= upper_threshold) &&
+		     (cal_data_diff <= ST_ADC_CALIBRATE_DIFF_THRESHOLD)) ||
+		    (ddata->vendor == CPCAP_VENDOR_TI)) {
+			bank_conversion[channel].cal_offset =
+				((short)calibration_data[1] * -1) + 512;
+			dev_dbg(ddata->dev, "ch%i calibration complete: %i\n",
+				channel, bank_conversion[channel].cal_offset);
+			break;
+		}
+		usleep_range(5000, 10000);
+	}
+
+	return 0;
+}
+
+static int cpcap_adc_calibrate(struct cpcap_adc *ddata)
+{
+	int error;
+
+	error = cpcap_adc_calibrate_one(ddata, CPCAP_ADC_CHG_ISENSE,
+					CPCAP_REG_ADCAL1,
+					ST_ADC_CAL_CHRGI_LOW_THRESHOLD,
+					ST_ADC_CAL_CHRGI_HIGH_THRESHOLD);
+	if (error)
+		return error;
+
+	error = cpcap_adc_calibrate_one(ddata, CPCAP_ADC_BATTI,
+					CPCAP_REG_ADCAL2,
+					ST_ADC_CAL_BATTI_LOW_THRESHOLD,
+					ST_ADC_CAL_BATTI_HIGH_THRESHOLD);
+	if (error)
+		return error;
+
+	return 0;
+}
+
+/* ADC setup, read and scale functions */
+static void cpcap_adc_setup_bank(struct cpcap_adc *ddata,
+				 struct cpcap_adc_request *req)
+{
+	const struct cpcap_adc_ato *ato = ddata->ato;
+	unsigned short value1 = 0;
+	unsigned short value2 = 0;
+	int error;
+
+	if (!ato)
+		return;
+
+	switch (req->channel) {
+	case CPCAP_ADC_AD8 ... CPCAP_ADC_TSY2_AD15:
+		value1 |= CPCAP_BIT_AD_SEL1;
+		break;
+	case CPCAP_ADC_BATTP_PI16 ... CPCAP_ADC_BATTI_PI17:
+		value1 |= CPCAP_BIT_RAND1;
+	default:
+		break;
+	}
+
+	switch (req->timing) {
+	case CPCAP_ADC_TIMING_IN:
+		value1 |= ato->ato_in;
+		value1 |= ato->atox_in;
+		value2 |= ato->adc_ps_factor_in;
+		value2 |= ato->atox_ps_factor_in;
+		break;
+	case CPCAP_ADC_TIMING_OUT:
+		value1 |= ato->ato_out;
+		value1 |= ato->atox_out;
+		value2 |= ato->adc_ps_factor_out;
+		value2 |= ato->atox_ps_factor_out;
+		break;
+
+	case CPCAP_ADC_TIMING_IMM:
+	default:
+		break;
+	}
+
+	error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC1,
+				   CPCAP_BIT_CAL_MODE | CPCAP_BIT_ATOX |
+				   CPCAP_BIT_ATO3 | CPCAP_BIT_ATO2 |
+				   CPCAP_BIT_ATO1 | CPCAP_BIT_ATO0 |
+				   CPCAP_BIT_ADA2 | CPCAP_BIT_ADA1 |
+				   CPCAP_BIT_ADA0 | CPCAP_BIT_AD_SEL1 |
+				   CPCAP_BIT_RAND1 | CPCAP_BIT_RAND0,
+				   value1);
+	if (error)
+		return;
+
+	error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
+				   CPCAP_BIT_ATOX_PS_FACTOR |
+				   CPCAP_BIT_ADC_PS_FACTOR1 |
+				   CPCAP_BIT_ADC_PS_FACTOR0,
+				   value2);
+	if (error)
+		return;
+
+	if (req->timing == CPCAP_ADC_TIMING_IMM) {
+		error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
+					   CPCAP_BIT_ADTRIG_DIS,
+					   CPCAP_BIT_ADTRIG_DIS);
+		if (error)
+			return;
+
+		error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
+					   CPCAP_BIT_ASC,
+					   CPCAP_BIT_ASC);
+		if (error)
+			return;
+	} else {
+		error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
+					   CPCAP_BIT_ADTRIG_ONESHOT,
+					   CPCAP_BIT_ADTRIG_ONESHOT);
+		if (error)
+			return;
+
+		error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
+					   CPCAP_BIT_ADTRIG_DIS, 0);
+		if (error)
+			return;
+	}
+}
+
+/*
+ * Occasionally the ADC does not seem to start and there will be no
+ * interrupt. Let's re-init interrupt to prevent the ADC from hanging
+ * for the next request. It is unclear why this happens, but the next
+ * request will usually work after doing this.
+ */
+static void cpcap_adc_quirk_reset_lost_irq(struct cpcap_adc *ddata)
+{
+	int error;
+
+	dev_info(ddata->dev, "lost ADC irq, attempting to reinit\n");
+	disable_irq(ddata->irq);
+	error = regmap_update_bits(ddata->reg, CPCAP_REG_ADCC2,
+				   CPCAP_BIT_ADTRIG_DIS,
+				   CPCAP_BIT_ADTRIG_DIS);
+	if (error)
+		dev_warn(ddata->dev, "%s reset failed: %i\n",
+			 __func__, error);
+	enable_irq(ddata->irq);
+}
+
+static int cpcap_adc_start_bank(struct cpcap_adc *ddata,
+				struct cpcap_adc_request *req)
+{
+	int i, error;
+
+	req->timing = CPCAP_ADC_TIMING_IMM;
+	ddata->done = false;
+
+	for (i = 0; i < CPCAP_ADC_MAX_RETRIES; i++) {
+		cpcap_adc_setup_bank(ddata, req);
+		error = wait_event_interruptible_timeout(ddata->wq_data_avail,
+							 ddata->done,
+							 msecs_to_jiffies(50));
+		if (error > 0)
+			return 0;
+
+		if (error == 0) {
+			cpcap_adc_quirk_reset_lost_irq(ddata);
+			error = -ETIMEDOUT;
+			continue;
+		}
+
+		if (error < 0)
+			return error;
+	}
+
+	return error;
+}
+
+static void cpcap_adc_phase(struct cpcap_adc_request *req)
+{
+	const struct cpcap_adc_conversion_tbl *conv_tbl = req->conv_tbl;
+	const struct cpcap_adc_phasing_tbl *phase_tbl = req->phase_tbl;
+	int index = req->channel;
+
+	/* Remuxed channels 16 and 17 use BATTP and BATTI entries */
+	switch (req->channel) {
+	case CPCAP_ADC_BATTP:
+	case CPCAP_ADC_BATTP_PI16:
+		index = req->bank_index;
+		req->result -= phase_tbl[index].offset;
+		req->result -= CPCAP_FOUR_POINT_TWO_ADC;
+		req->result *= phase_tbl[index].multiplier;
+		if (phase_tbl[index].divider == 0)
+			return;
+		req->result /= phase_tbl[index].divider;
+		req->result += CPCAP_FOUR_POINT_TWO_ADC;
+		break;
+	case CPCAP_ADC_BATTI_PI17:
+		index = req->bank_index;
+		/* fallthrough */
+	default:
+		req->result += conv_tbl[index].cal_offset;
+		req->result += conv_tbl[index].align_offset;
+		req->result *= phase_tbl[index].multiplier;
+		if (phase_tbl[index].divider == 0)
+			return;
+		req->result /= phase_tbl[index].divider;
+		req->result += phase_tbl[index].offset;
+		break;
+	}
+
+	if (req->result < phase_tbl[index].min)
+		req->result = phase_tbl[index].min;
+	else if (req->result > phase_tbl[index].max)
+		req->result = phase_tbl[index].max;
+}
+
+/* Looks up temperatures in a table and calculates averages if needed */
+static int cpcap_adc_table_to_millicelcius(unsigned short value)
+{
+	int i, result = 0, alpha;
+
+	if (value <= temp_map[CPCAP_MAX_TEMP_LVL - 1][0])
+		return temp_map[CPCAP_MAX_TEMP_LVL - 1][1];
+
+	if (value >= temp_map[0][0])
+		return temp_map[0][1];
+
+	for (i = 0; i < CPCAP_MAX_TEMP_LVL - 1; i++) {
+		if ((value <= temp_map[i][0]) &&
+		    (value >= temp_map[i + 1][0])) {
+			if (value == temp_map[i][0]) {
+				result = temp_map[i][1];
+			} else if (value == temp_map[i + 1][0]) {
+				result = temp_map[i + 1][1];
+			} else {
+				alpha = ((value - temp_map[i][0]) * 1000) /
+					(temp_map[i + 1][0] - temp_map[i][0]);
+
+				result = temp_map[i][1] +
+					((alpha * (temp_map[i + 1][1] -
+						 temp_map[i][1])) / 1000);
+			}
+			break;
+		}
+	}
+
+	return result;
+}
+
+static void cpcap_adc_convert(struct cpcap_adc_request *req)
+{
+	const struct cpcap_adc_conversion_tbl *conv_tbl = req->conv_tbl;
+	int index = req->channel;
+
+	/* Remuxed channels 16 and 17 use BATTP and BATTI entries */
+	switch (req->channel) {
+	case CPCAP_ADC_BATTP_PI16:
+		index = CPCAP_ADC_BATTP;
+		break;
+	case CPCAP_ADC_BATTI_PI17:
+		index = CPCAP_ADC_BATTI;
+		break;
+	default:
+		break;
+	}
+
+	/* No conversion for raw channels */
+	if (conv_tbl[index].conv_type == IIO_CHAN_INFO_RAW)
+		return;
+
+	/* Temperatures use a lookup table instead of conversion table */
+	if ((req->channel == CPCAP_ADC_AD0_BATTDETB) ||
+	    (req->channel == CPCAP_ADC_AD3)) {
+		req->result =
+			cpcap_adc_table_to_millicelcius(req->result);
+
+		return;
+	}
+
+	/* All processed channels use a conversion table */
+	req->result *= conv_tbl[index].multiplier;
+	if (conv_tbl[index].divider == 0)
+		return;
+	req->result /= conv_tbl[index].divider;
+	req->result += conv_tbl[index].conv_offset;
+}
+
+/*
+ * REVISIT: Check if timed sampling can use multiple channels at the
+ * same time. If not, replace channel_mask with just channel.
+ */
+static int cpcap_adc_read_bank_scaled(struct cpcap_adc *ddata,
+				      struct cpcap_adc_request *req)
+{
+	int calibration_data, error, addr;
+
+	if (ddata->vendor == CPCAP_VENDOR_TI) {
+		error = regmap_read(ddata->reg, CPCAP_REG_ADCAL1,
+				    &calibration_data);
+		if (error)
+			return error;
+		bank_conversion[CPCAP_ADC_CHG_ISENSE].cal_offset =
+			((short)calibration_data * -1) + 512;
+
+		error = regmap_read(ddata->reg, CPCAP_REG_ADCAL2,
+				    &calibration_data);
+		if (error)
+			return error;
+		bank_conversion[CPCAP_ADC_BATTI].cal_offset =
+			((short)calibration_data * -1) + 512;
+	}
+
+	addr = CPCAP_REG_ADCD0 + req->bank_index * 4;
+
+	error = regmap_read(ddata->reg, addr, &req->result);
+	if (error)
+		return error;
+
+	req->result &= 0x3ff;
+	cpcap_adc_phase(req);
+	cpcap_adc_convert(req);
+
+	return 0;
+}
+
+static int cpcap_adc_init_request(struct cpcap_adc_request *req,
+				  int channel)
+{
+	req->channel = channel;
+	req->phase_tbl = bank_phasing;
+	req->conv_tbl = bank_conversion;
+
+	switch (channel) {
+	case CPCAP_ADC_AD0_BATTDETB ... CPCAP_ADC_USB_ID:
+		req->bank_index = channel;
+		break;
+	case CPCAP_ADC_AD8 ... CPCAP_ADC_TSY2_AD15:
+		req->bank_index = channel - 8;
+		break;
+	case CPCAP_ADC_BATTP_PI16:
+		req->bank_index = CPCAP_ADC_BATTP;
+		break;
+	case CPCAP_ADC_BATTI_PI17:
+		req->bank_index = CPCAP_ADC_BATTI;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int cpcap_adc_read(struct iio_dev *indio_dev,
+			  struct iio_chan_spec const *chan,
+			  int *val, int *val2, long mask)
+{
+	struct cpcap_adc *ddata = iio_priv(indio_dev);
+	struct cpcap_adc_request req;
+	int error;
+
+	error = cpcap_adc_init_request(&req, chan->channel);
+	if (error)
+		return error;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		mutex_lock(&ddata->lock);
+		error = cpcap_adc_start_bank(ddata, &req);
+		if (error)
+			goto err_unlock;
+		error = regmap_read(ddata->reg, chan->address, val);
+		if (error)
+			goto err_unlock;
+		mutex_unlock(&ddata->lock);
+		break;
+	case IIO_CHAN_INFO_PROCESSED:
+		mutex_lock(&ddata->lock);
+		error = cpcap_adc_start_bank(ddata, &req);
+		if (error)
+			goto err_unlock;
+		error = cpcap_adc_read_bank_scaled(ddata, &req);
+		if (error)
+			goto err_unlock;
+		mutex_unlock(&ddata->lock);
+		*val = req.result;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return IIO_VAL_INT;
+
+err_unlock:
+	mutex_unlock(&ddata->lock);
+	dev_err(ddata->dev, "error reading ADC: %i\n", error);
+
+	return error;
+}
+
+static const struct iio_info cpcap_adc_info = {
+	.read_raw = &cpcap_adc_read,
+	.driver_module = THIS_MODULE,
+};
+
+/*
+ * Configuration for Motorola mapphone series such as droid 4.
+ * Copied from the Motorola mapphone kernel tree.
+ */
+static const struct cpcap_adc_ato mapphone_adc = {
+	.ato_in = 0x0480,
+	.atox_in = 0,
+	.adc_ps_factor_in = 0x0200,
+	.atox_ps_factor_in = 0,
+	.ato_out = 0,
+	.atox_out = 0,
+	.adc_ps_factor_out = 0,
+	.atox_ps_factor_out = 0,
+};
+
+static const struct of_device_id cpcap_adc_id_table[] = {
+	{
+		.compatible = "motorola,cpcap-adc",
+	},
+	{
+		.compatible = "motorola,mapphone-cpcap-adc",
+		.data = &mapphone_adc,
+	},
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, cpcap_adc_id_table);
+
+static int cpcap_adc_probe(struct platform_device *pdev)
+{
+	const struct of_device_id *match;
+	struct cpcap_adc *ddata;
+	struct iio_dev *indio_dev;
+	int error;
+
+	match = of_match_device(of_match_ptr(cpcap_adc_id_table),
+				&pdev->dev);
+	if (!match)
+		return -EINVAL;
+
+	if (!match->data) {
+		dev_err(&pdev->dev, "no configuration data found\n");
+
+		return -ENODEV;
+	}
+
+	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*ddata));
+	if (!indio_dev) {
+		dev_err(&pdev->dev, "failed to allocate iio device\n");
+
+		return -ENOMEM;
+	}
+	ddata = iio_priv(indio_dev);
+	ddata->ato = match->data;
+	ddata->dev = &pdev->dev;
+
+	mutex_init(&ddata->lock);
+	init_waitqueue_head(&ddata->wq_data_avail);
+
+	indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE;
+	indio_dev->dev.parent = &pdev->dev;
+	indio_dev->dev.of_node = pdev->dev.of_node;
+	indio_dev->channels = cpcap_adc_channels;
+	indio_dev->num_channels = ARRAY_SIZE(cpcap_adc_channels);
+	indio_dev->name = dev_name(&pdev->dev);
+	indio_dev->info = &cpcap_adc_info;
+
+	ddata->reg = dev_get_regmap(pdev->dev.parent, NULL);
+	if (!ddata->reg)
+		return -ENODEV;
+
+	error = cpcap_get_vendor(ddata->dev, ddata->reg, &ddata->vendor);
+	if (error)
+		return error;
+
+	platform_set_drvdata(pdev, indio_dev);
+
+	ddata->irq = platform_get_irq_byname(pdev, "adcdone");
+	if (!ddata->irq)
+		return -ENODEV;
+
+	error = devm_request_threaded_irq(&pdev->dev, ddata->irq, NULL,
+					  cpcap_adc_irq_thread,
+					  IRQF_TRIGGER_NONE,
+					  "cpcap-adc", indio_dev);
+	if (error) {
+		dev_err(&pdev->dev, "could not get irq: %i\n",
+			error);
+
+		return error;
+	}
+
+	error = cpcap_adc_calibrate(ddata);
+	if (error)
+		return error;
+
+	dev_info(&pdev->dev, "CPCAP ADC device probed\n");
+
+	return devm_iio_device_register(&pdev->dev, indio_dev);
+}
+
+static struct platform_driver cpcap_adc_driver = {
+	.driver = {
+		.name = "cpcap_adc",
+		.of_match_table = of_match_ptr(cpcap_adc_id_table),
+	},
+	.probe = cpcap_adc_probe,
+};
+
+module_platform_driver(cpcap_adc_driver);
+
+MODULE_ALIAS("platform:cpcap_adc");
+MODULE_DESCRIPTION("CPCAP ADC driver");
+MODULE_AUTHOR("Tony Lindgren <tony@atomide.com");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/adc/exynos_adc.c b/drivers/iio/adc/exynos_adc.c
index ad1775b5f83c..6c5a7be9f8c1 100644
--- a/drivers/iio/adc/exynos_adc.c
+++ b/drivers/iio/adc/exynos_adc.c
@@ -579,7 +579,7 @@ static int exynos_read_s3c64xx_ts(struct iio_dev *indio_dev, int *x, int *y)
 
 static irqreturn_t exynos_adc_isr(int irq, void *dev_id)
 {
-	struct exynos_adc *info = (struct exynos_adc *)dev_id;
+	struct exynos_adc *info = dev_id;
 	u32 mask = info->data->mask;
 
 	/* Read value */
diff --git a/drivers/iio/adc/hx711.c b/drivers/iio/adc/hx711.c
index 139639f73769..27005d84ed73 100644
--- a/drivers/iio/adc/hx711.c
+++ b/drivers/iio/adc/hx711.c
@@ -369,7 +369,7 @@ static struct attribute *hx711_attributes[] = {
 	NULL,
 };
 
-static struct attribute_group hx711_attribute_group = {
+static const struct attribute_group hx711_attribute_group = {
 	.attrs = hx711_attributes,
 };
 
diff --git a/drivers/iio/adc/imx7d_adc.c b/drivers/iio/adc/imx7d_adc.c
index e2241ee94783..254b29a68b9d 100644
--- a/drivers/iio/adc/imx7d_adc.c
+++ b/drivers/iio/adc/imx7d_adc.c
@@ -365,7 +365,7 @@ static int imx7d_adc_read_data(struct imx7d_adc *info)
 
 static irqreturn_t imx7d_adc_isr(int irq, void *dev_id)
 {
-	struct imx7d_adc *info = (struct imx7d_adc *)dev_id;
+	struct imx7d_adc *info = dev_id;
 	int status;
 
 	status = readl(info->regs + IMX7D_REG_ADC_INT_STATUS);
diff --git a/drivers/iio/adc/ltc2497.c b/drivers/iio/adc/ltc2497.c
new file mode 100644
index 000000000000..2691b10023f5
--- /dev/null
+++ b/drivers/iio/adc/ltc2497.c
@@ -0,0 +1,279 @@
+/*
+ * ltc2497.c - Driver for Analog Devices/Linear Technology LTC2497 ADC
+ *
+ * Copyright (C) 2017 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2.
+ *
+ * Datasheet: http://cds.linear.com/docs/en/datasheet/2497fd.pdf
+ */
+
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/regulator/consumer.h>
+
+#define LTC2497_ENABLE			0xA0
+#define LTC2497_SGL			BIT(4)
+#define LTC2497_DIFF			0
+#define LTC2497_SIGN			BIT(3)
+#define LTC2497_CONFIG_DEFAULT		LTC2497_ENABLE
+#define LTC2497_CONVERSION_TIME_MS	150ULL
+
+struct ltc2497_st {
+	struct i2c_client *client;
+	struct regulator *ref;
+	ktime_t	time_prev;
+	u8 addr_prev;
+	/*
+	 * DMA (thus cache coherency maintenance) requires the
+	 * transfer buffers to live in their own cache lines.
+	 */
+	__be32 buf ____cacheline_aligned;
+};
+
+static int ltc2497_wait_conv(struct ltc2497_st *st)
+{
+	s64 time_elapsed;
+
+	time_elapsed = ktime_ms_delta(ktime_get(), st->time_prev);
+
+	if (time_elapsed < LTC2497_CONVERSION_TIME_MS) {
+		/* delay if conversion time not passed
+		 * since last read or write
+		 */
+		if (msleep_interruptible(
+		    LTC2497_CONVERSION_TIME_MS - time_elapsed))
+			return -ERESTARTSYS;
+
+		return 0;
+	}
+
+	if (time_elapsed - LTC2497_CONVERSION_TIME_MS <= 0) {
+		/* We're in automatic mode -
+		 * so the last reading is stil not outdated
+		 */
+		return 0;
+	}
+
+	return 1;
+}
+
+static int ltc2497_read(struct ltc2497_st *st, u8 address, int *val)
+{
+	struct i2c_client *client = st->client;
+	int ret;
+
+	ret = ltc2497_wait_conv(st);
+	if (ret < 0)
+		return ret;
+
+	if (ret || st->addr_prev != address) {
+		ret = i2c_smbus_write_byte(st->client,
+					   LTC2497_ENABLE | address);
+		if (ret < 0)
+			return ret;
+		st->addr_prev = address;
+		if (msleep_interruptible(LTC2497_CONVERSION_TIME_MS))
+			return -ERESTARTSYS;
+	}
+	ret = i2c_master_recv(client, (char *)&st->buf, 3);
+	if (ret < 0)  {
+		dev_err(&client->dev, "i2c_master_recv failed\n");
+		return ret;
+	}
+	st->time_prev = ktime_get();
+
+	/* convert and shift the result,
+	 * and finally convert from offset binary to signed integer
+	 */
+	*val = (be32_to_cpu(st->buf) >> 14) - (1 << 17);
+
+	return ret;
+}
+
+static int ltc2497_read_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan,
+			    int *val, int *val2, long mask)
+{
+	struct ltc2497_st *st = iio_priv(indio_dev);
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		mutex_lock(&indio_dev->mlock);
+		ret = ltc2497_read(st, chan->address, val);
+		mutex_unlock(&indio_dev->mlock);
+		if (ret < 0)
+			return ret;
+
+		return IIO_VAL_INT;
+
+	case IIO_CHAN_INFO_SCALE:
+		ret = regulator_get_voltage(st->ref);
+		if (ret < 0)
+			return ret;
+
+		*val = ret / 1000;
+		*val2 = 17;
+
+		return IIO_VAL_FRACTIONAL_LOG2;
+
+	default:
+		return -EINVAL;
+	}
+}
+
+#define LTC2497_CHAN(_chan, _addr) { \
+	.type = IIO_VOLTAGE, \
+	.indexed = 1, \
+	.channel = (_chan), \
+	.address = (_addr | (_chan / 2) | ((_chan & 1) ? LTC2497_SIGN : 0)), \
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
+}
+
+#define LTC2497_CHAN_DIFF(_chan, _addr) { \
+	.type = IIO_VOLTAGE, \
+	.indexed = 1, \
+	.channel = (_chan) * 2 + ((_addr) & LTC2497_SIGN ? 1 : 0), \
+	.channel2 = (_chan) * 2 + ((_addr) & LTC2497_SIGN ? 0 : 1),\
+	.address = (_addr | _chan), \
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
+	.differential = 1, \
+}
+
+static const struct iio_chan_spec ltc2497_channel[] = {
+	LTC2497_CHAN(0, LTC2497_SGL),
+	LTC2497_CHAN(1, LTC2497_SGL),
+	LTC2497_CHAN(2, LTC2497_SGL),
+	LTC2497_CHAN(3, LTC2497_SGL),
+	LTC2497_CHAN(4, LTC2497_SGL),
+	LTC2497_CHAN(5, LTC2497_SGL),
+	LTC2497_CHAN(6, LTC2497_SGL),
+	LTC2497_CHAN(7, LTC2497_SGL),
+	LTC2497_CHAN(8, LTC2497_SGL),
+	LTC2497_CHAN(9, LTC2497_SGL),
+	LTC2497_CHAN(10, LTC2497_SGL),
+	LTC2497_CHAN(11, LTC2497_SGL),
+	LTC2497_CHAN(12, LTC2497_SGL),
+	LTC2497_CHAN(13, LTC2497_SGL),
+	LTC2497_CHAN(14, LTC2497_SGL),
+	LTC2497_CHAN(15, LTC2497_SGL),
+	LTC2497_CHAN_DIFF(0, LTC2497_DIFF),
+	LTC2497_CHAN_DIFF(1, LTC2497_DIFF),
+	LTC2497_CHAN_DIFF(2, LTC2497_DIFF),
+	LTC2497_CHAN_DIFF(3, LTC2497_DIFF),
+	LTC2497_CHAN_DIFF(4, LTC2497_DIFF),
+	LTC2497_CHAN_DIFF(5, LTC2497_DIFF),
+	LTC2497_CHAN_DIFF(6, LTC2497_DIFF),
+	LTC2497_CHAN_DIFF(7, LTC2497_DIFF),
+	LTC2497_CHAN_DIFF(0, LTC2497_DIFF | LTC2497_SIGN),
+	LTC2497_CHAN_DIFF(1, LTC2497_DIFF | LTC2497_SIGN),
+	LTC2497_CHAN_DIFF(2, LTC2497_DIFF | LTC2497_SIGN),
+	LTC2497_CHAN_DIFF(3, LTC2497_DIFF | LTC2497_SIGN),
+	LTC2497_CHAN_DIFF(4, LTC2497_DIFF | LTC2497_SIGN),
+	LTC2497_CHAN_DIFF(5, LTC2497_DIFF | LTC2497_SIGN),
+	LTC2497_CHAN_DIFF(6, LTC2497_DIFF | LTC2497_SIGN),
+	LTC2497_CHAN_DIFF(7, LTC2497_DIFF | LTC2497_SIGN),
+};
+
+static const struct iio_info ltc2497_info = {
+	.read_raw = ltc2497_read_raw,
+	.driver_module = THIS_MODULE,
+};
+
+static int ltc2497_probe(struct i2c_client *client,
+			 const struct i2c_device_id *id)
+{
+	struct iio_dev *indio_dev;
+	struct ltc2497_st *st;
+	int ret;
+
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
+				     I2C_FUNC_SMBUS_WRITE_BYTE))
+		return -EOPNOTSUPP;
+
+	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	st = iio_priv(indio_dev);
+	i2c_set_clientdata(client, indio_dev);
+	st->client = client;
+
+	indio_dev->dev.parent = &client->dev;
+	indio_dev->name = id->name;
+	indio_dev->info = &ltc2497_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = ltc2497_channel;
+	indio_dev->num_channels = ARRAY_SIZE(ltc2497_channel);
+
+	st->ref = devm_regulator_get(&client->dev, "vref");
+	if (IS_ERR(st->ref))
+		return PTR_ERR(st->ref);
+
+	ret = regulator_enable(st->ref);
+	if (ret < 0)
+		return ret;
+
+	ret = i2c_smbus_write_byte(st->client, LTC2497_CONFIG_DEFAULT);
+	if (ret < 0)
+		goto err_regulator_disable;
+
+	st->addr_prev = LTC2497_CONFIG_DEFAULT;
+	st->time_prev = ktime_get();
+
+	ret = iio_device_register(indio_dev);
+	if (ret < 0)
+		goto err_regulator_disable;
+
+	return 0;
+
+err_regulator_disable:
+	regulator_disable(st->ref);
+
+	return ret;
+}
+
+static int ltc2497_remove(struct i2c_client *client)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(client);
+	struct ltc2497_st *st = iio_priv(indio_dev);
+
+	iio_device_unregister(indio_dev);
+	regulator_disable(st->ref);
+
+	return 0;
+}
+
+static const struct i2c_device_id ltc2497_id[] = {
+	{ "ltc2497", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, ltc2497_id);
+
+static const struct of_device_id ltc2497_of_match[] = {
+	{ .compatible = "lltc,ltc2497", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, ltc2497_of_match);
+
+static struct i2c_driver ltc2497_driver = {
+	.driver = {
+		.name = "ltc2497",
+		.of_match_table = of_match_ptr(ltc2497_of_match),
+	},
+	.probe = ltc2497_probe,
+	.remove = ltc2497_remove,
+	.id_table = ltc2497_id,
+};
+module_i2c_driver(ltc2497_driver);
+
+MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
+MODULE_DESCRIPTION("Linear Technology LTC2497 ADC driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/adc/max1027.c b/drivers/iio/adc/max1027.c
index 3b7c4f78f37a..ebc715927e63 100644
--- a/drivers/iio/adc/max1027.c
+++ b/drivers/iio/adc/max1027.c
@@ -364,7 +364,7 @@ static int max1027_set_trigger_state(struct iio_trigger *trig, bool state)
 
 static irqreturn_t max1027_trigger_handler(int irq, void *private)
 {
-	struct iio_poll_func *pf = (struct iio_poll_func *)private;
+	struct iio_poll_func *pf = private;
 	struct iio_dev *indio_dev = pf->indio_dev;
 	struct max1027_state *st = iio_priv(indio_dev);
 
diff --git a/drivers/iio/adc/max11100.c b/drivers/iio/adc/max11100.c
index 23c060e1b663..1180bcc22ff1 100644
--- a/drivers/iio/adc/max11100.c
+++ b/drivers/iio/adc/max11100.c
@@ -124,8 +124,8 @@ static int max11100_probe(struct spi_device *spi)
 	indio_dev->name = "max11100";
 	indio_dev->info = &max11100_info;
 	indio_dev->modes = INDIO_DIRECT_MODE;
-	indio_dev->channels = max11100_channels,
-	indio_dev->num_channels = ARRAY_SIZE(max11100_channels),
+	indio_dev->channels = max11100_channels;
+	indio_dev->num_channels = ARRAY_SIZE(max11100_channels);
 
 	state->vref_reg = devm_regulator_get(&spi->dev, "vref");
 	if (IS_ERR(state->vref_reg))
diff --git a/drivers/iio/adc/max1363.c b/drivers/iio/adc/max1363.c
index c6c12feb4a08..80eada4886b3 100644
--- a/drivers/iio/adc/max1363.c
+++ b/drivers/iio/adc/max1363.c
@@ -1007,7 +1007,7 @@ static struct attribute *max1363_event_attributes[] = {
 	NULL,
 };
 
-static struct attribute_group max1363_event_attribute_group = {
+static const struct attribute_group max1363_event_attribute_group = {
 	.attrs = max1363_event_attributes,
 };
 
diff --git a/drivers/iio/adc/meson_saradc.c b/drivers/iio/adc/meson_saradc.c
index cde9ca7a01b8..dd4190b50df6 100644
--- a/drivers/iio/adc/meson_saradc.c
+++ b/drivers/iio/adc/meson_saradc.c
@@ -166,6 +166,8 @@
 
 #define MESON_SAR_ADC_MAX_FIFO_SIZE				32
 #define MESON_SAR_ADC_TIMEOUT					100 /* ms */
+/* for use with IIO_VAL_INT_PLUS_MICRO */
+#define MILLION							1000000
 
 #define MESON_SAR_ADC_CHAN(_chan) {					\
 	.type = IIO_VOLTAGE,						\
@@ -173,7 +175,9 @@
 	.channel = _chan,						\
 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |			\
 				BIT(IIO_CHAN_INFO_AVERAGE_RAW),		\
-	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),		\
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |		\
+				BIT(IIO_CHAN_INFO_CALIBBIAS) |		\
+				BIT(IIO_CHAN_INFO_CALIBSCALE),		\
 	.datasheet_name = "SAR_ADC_CH"#_chan,				\
 }
 
@@ -233,6 +237,8 @@ struct meson_sar_adc_priv {
 	struct clk				*adc_div_clk;
 	struct clk_divider			clk_div;
 	struct completion			done;
+	int					calibbias;
+	int					calibscale;
 };
 
 static const struct regmap_config meson_sar_adc_regmap_config = {
@@ -252,6 +258,17 @@ static unsigned int meson_sar_adc_get_fifo_count(struct iio_dev *indio_dev)
 	return FIELD_GET(MESON_SAR_ADC_REG0_FIFO_COUNT_MASK, regval);
 }
 
+static int meson_sar_adc_calib_val(struct iio_dev *indio_dev, int val)
+{
+	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
+	int tmp;
+
+	/* use val_calib = scale * val_raw + offset calibration function */
+	tmp = div_s64((s64)val * priv->calibscale, MILLION) + priv->calibbias;
+
+	return clamp(tmp, 0, (1 << priv->data->resolution) - 1);
+}
+
 static int meson_sar_adc_wait_busy_clear(struct iio_dev *indio_dev)
 {
 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
@@ -302,7 +319,7 @@ static int meson_sar_adc_read_raw_sample(struct iio_dev *indio_dev,
 
 	fifo_val = FIELD_GET(MESON_SAR_ADC_FIFO_RD_SAMPLE_VALUE_MASK, regval);
 	fifo_val &= GENMASK(priv->data->resolution - 1, 0);
-	*val = fifo_val;
+	*val = meson_sar_adc_calib_val(indio_dev, fifo_val);
 
 	return 0;
 }
@@ -527,6 +544,15 @@ static int meson_sar_adc_iio_info_read_raw(struct iio_dev *indio_dev,
 		*val2 = priv->data->resolution;
 		return IIO_VAL_FRACTIONAL_LOG2;
 
+	case IIO_CHAN_INFO_CALIBBIAS:
+		*val = priv->calibbias;
+		return IIO_VAL_INT;
+
+	case IIO_CHAN_INFO_CALIBSCALE:
+		*val = priv->calibscale / MILLION;
+		*val2 = priv->calibscale % MILLION;
+		return IIO_VAL_INT_PLUS_MICRO;
+
 	default:
 		return -EINVAL;
 	}
@@ -762,6 +788,47 @@ static irqreturn_t meson_sar_adc_irq(int irq, void *data)
 	return IRQ_HANDLED;
 }
 
+static int meson_sar_adc_calib(struct iio_dev *indio_dev)
+{
+	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
+	int ret, nominal0, nominal1, value0, value1;
+
+	/* use points 25% and 75% for calibration */
+	nominal0 = (1 << priv->data->resolution) / 4;
+	nominal1 = (1 << priv->data->resolution) * 3 / 4;
+
+	meson_sar_adc_set_chan7_mux(indio_dev, CHAN7_MUX_VDD_DIV4);
+	usleep_range(10, 20);
+	ret = meson_sar_adc_get_sample(indio_dev,
+				       &meson_sar_adc_iio_channels[7],
+				       MEAN_AVERAGING, EIGHT_SAMPLES, &value0);
+	if (ret < 0)
+		goto out;
+
+	meson_sar_adc_set_chan7_mux(indio_dev, CHAN7_MUX_VDD_MUL3_DIV4);
+	usleep_range(10, 20);
+	ret = meson_sar_adc_get_sample(indio_dev,
+				       &meson_sar_adc_iio_channels[7],
+				       MEAN_AVERAGING, EIGHT_SAMPLES, &value1);
+	if (ret < 0)
+		goto out;
+
+	if (value1 <= value0) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	priv->calibscale = div_s64((nominal1 - nominal0) * (s64)MILLION,
+				   value1 - value0);
+	priv->calibbias = nominal0 - div_s64((s64)value0 * priv->calibscale,
+					     MILLION);
+	ret = 0;
+out:
+	meson_sar_adc_set_chan7_mux(indio_dev, CHAN7_MUX_CH7_INPUT);
+
+	return ret;
+}
+
 static const struct iio_info meson_sar_adc_iio_info = {
 	.read_raw = meson_sar_adc_iio_info_read_raw,
 	.driver_module = THIS_MODULE,
@@ -901,6 +968,8 @@ static int meson_sar_adc_probe(struct platform_device *pdev)
 		return PTR_ERR(priv->vref);
 	}
 
+	priv->calibscale = MILLION;
+
 	ret = meson_sar_adc_init(indio_dev);
 	if (ret)
 		goto err;
@@ -909,6 +978,10 @@ static int meson_sar_adc_probe(struct platform_device *pdev)
 	if (ret)
 		goto err;
 
+	ret = meson_sar_adc_calib(indio_dev);
+	if (ret)
+		dev_warn(&pdev->dev, "calibration failed\n");
+
 	platform_set_drvdata(pdev, indio_dev);
 
 	ret = iio_device_register(indio_dev);
diff --git a/drivers/iio/adc/rockchip_saradc.c b/drivers/iio/adc/rockchip_saradc.c
index 85d701291654..ae6d3324f518 100644
--- a/drivers/iio/adc/rockchip_saradc.c
+++ b/drivers/iio/adc/rockchip_saradc.c
@@ -109,7 +109,7 @@ static int rockchip_saradc_read_raw(struct iio_dev *indio_dev,
 
 static irqreturn_t rockchip_saradc_isr(int irq, void *dev_id)
 {
-	struct rockchip_saradc *info = (struct rockchip_saradc *)dev_id;
+	struct rockchip_saradc *info = dev_id;
 
 	/* Read value */
 	info->last_val = readl_relaxed(info->regs + SARADC_DATA);
diff --git a/drivers/iio/adc/sun4i-gpadc-iio.c b/drivers/iio/adc/sun4i-gpadc-iio.c
index a8e134fa190d..e53182510150 100644
--- a/drivers/iio/adc/sun4i-gpadc-iio.c
+++ b/drivers/iio/adc/sun4i-gpadc-iio.c
@@ -382,7 +382,7 @@ static int sun4i_gpadc_runtime_resume(struct device *dev)
 
 static int sun4i_gpadc_get_temp(void *data, int *temp)
 {
-	struct sun4i_gpadc_iio *info = (struct sun4i_gpadc_iio *)data;
+	struct sun4i_gpadc_iio *info = data;
 	int val, scale, offset;
 
 	if (sun4i_gpadc_temp_read(info->indio_dev, &val))
diff --git a/drivers/iio/adc/vf610_adc.c b/drivers/iio/adc/vf610_adc.c
index 228a003adeed..01fc76f7d660 100644
--- a/drivers/iio/adc/vf610_adc.c
+++ b/drivers/iio/adc/vf610_adc.c
@@ -584,7 +584,7 @@ static int vf610_adc_read_data(struct vf610_adc *info)
 
 static irqreturn_t vf610_adc_isr(int irq, void *dev_id)
 {
-	struct iio_dev *indio_dev = (struct iio_dev *)dev_id;
+	struct iio_dev *indio_dev = dev_id;
 	struct vf610_adc *info = iio_priv(indio_dev);
 	int coco;