Merge tag 'iio-for-4.11b' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into work-next

Jonathan writes:

Second round of IIO new device support, cleanups and features for the 4.11 cycle

New device support:
* lsm6dsx imu
- new driver and bindings.
* max11100 adc
- new driver and bindings.
* tlc4541
- new driver
* tmp007 thermopile
- new driver.

Core
* in kernel interfaces
- pass through raw values if no scaling provided and a processed value is
requested.
* trigger
- close a race condition in acquiring trigger reference.
- constify device_type structures.
- rework the viio_trigger_alloc function to be much neater and easier to
read.
- free trigger resources correctly on some error paths. Avoids putting a
module we don't have.

Documentation
* ABI
- specify a unit for proximity measurements.

Cleanups and features
* ads1015
- constify iio_info structure.
* ads7950 cleanups following merge in previous pull
- Add device tree bindings
- Drop the ti prefix from the module name in common with other drivers.
- Change regulator name to vref to match datasheet and other drivers.
* ak8974
- remove a redundant zero timeout check.
* bmi160
- use variable names for sizeof instead of types.
* cm3605
- mark PM functions as __maybe_unused to avoid a build warning.
* isl29028 (on it's way towards moving out of staging).
- alignment fixes and newline improvements.
- combine proxim_get and read_proxim for simpler code.
- drop unused ISL29028_DEV_ATTR macro
- move some error logging into functions to cut out repitition.
- make error messages more consistent.
- tidy up some brackets.
- drop the enable flag that nothing uses.
- only set proximity rate and ALS scale when relevant channel type is enabled.
- runtime pm support.
* lsm6dsx
- fix wrong values for gyro sensitivitiy.
* mag3110
- claim direct mode during sysfs reads to avoid a race condition.
* max1363
- export OF device table IDs as module aliases.
* max30100
- use msleep for long uncritical delays.
* mcp4531
- export OF device table as module aliases.
* ms5611
- claim direct mode during sysfs reads to avoid a race condition.
* opt3001
- export OF device table as module aliases.
* sx9500
- claim direct mode during oversampling changes to avoid a race condition.

Documentation/ABI/testing/sysfs-bus-iio

···
 		reflectivity of infrared or ultrasound emitted.
 		Often these sensors are unit less and as such conversion
 		to SI units is not possible. Higher proximity measurements
-		indicate closer objects, and vice versa.
+		indicate closer objects, and vice versa. Units after
+		application of scale and offset are meters.
 
 What:		/sys/.../iio:deviceX/in_illuminance_input
 What:		/sys/.../iio:deviceX/in_illuminance_raw

Documentation/devicetree/bindings/iio/adc/max11100.txt

···
+* Maxim max11100 Analog to Digital Converter (ADC)
+
+Required properties:
+  - compatible: Should be "maxim,max11100"
+  - reg: the adc unit address
+  - vref-supply: phandle to the regulator that provides reference voltage
+
+Optional properties:
+  - spi-max-frequency: SPI maximum frequency
+
+Example:
+
+max11100: adc@0 {
+        compatible = "maxim,max11100";
+        reg = <0>;
+        vref-supply = <&adc0_vref>;
+        spi-max-frequency = <240000>;
+};

Documentation/devicetree/bindings/iio/adc/ti-ads7950.txt

···
+* Texas Instruments ADS7950 family of A/DC chips
+
+Required properties:
+ - compatible: Must be one of "ti,ads7950", "ti,ads7951", "ti,ads7952",
+   "ti,ads7953", "ti,ads7954", "ti,ads7955", "ti,ads7956", "ti,ads7957",
+   "ti,ads7958", "ti,ads7959", "ti,ads7960", or "ti,ads7961"
+ - reg: SPI chip select number for the device
+ - #io-channel-cells: Must be 1 as per ../iio-bindings.txt
+ - vref-supply: phandle to a regulator node that supplies the 2.5V or 5V
+   reference voltage
+
+Recommended properties:
+ - spi-max-frequency: Definition as per
+		Documentation/devicetree/bindings/spi/spi-bus.txt
+
+Example:
+adc@0 {
+	compatible = "ti,ads7957";
+	reg = <0>;
+	#io-channel-cells = <1>;
+	vref-supply = <&refin_supply>;
+	spi-max-frequency = <10000000>;
+};

Documentation/devicetree/bindings/iio/imu/st_lsm6dsx.txt

···
+* ST_LSM6DSx driver for STM 6-axis (acc + gyro) imu Mems sensors
+
+Required properties:
+- compatible: must be one of:
+  "st,lsm6ds3"
+  "st,lsm6dsm"
+- reg: i2c address of the sensor / spi cs line
+
+Optional properties:
+- interrupt-parent: should be the phandle for the interrupt controller
+- interrupts: interrupt mapping for IRQ. It should be configured with
+  flags IRQ_TYPE_LEVEL_HIGH or IRQ_TYPE_EDGE_RISING.
+
+  Refer to interrupt-controller/interrupts.txt for generic interrupt
+  client node bindings.
+
+Example:
+
+lsm6dsm@6b {
+	compatible = "st,lsm6dsm";
+	reg = <0x6b>;
+	interrupt-parent = <&gpio0>;
+	interrupts = <0 IRQ_TYPE_EDGE_RISING>;
+};

Documentation/devicetree/bindings/iio/temperature/tmp007.txt

···
+* TI TMP007 - IR thermopile sensor with integrated math engine
+
+Link to datasheet: http://www.ti.com/lit/ds/symlink/tmp007.pdf
+
+Required properties:
+
+  - compatible: should be "ti,tmp007"
+  - reg: the I2C address of the sensor (changeable via ADR pins)
+		------------------------------
+		|ADR1 | ADR0 | Device Address|
+		------------------------------
+		   0      0        0x40
+		   0	  1	   0x41
+		   0	 SDA       0x42
+		   0     SCL       0x43
+		   1      0        0x44
+		   1      1        0x45
+		   1	 SDA	   0x46
+		   1     SCL       0x47
+
+Example:
+
+tmp007@40 {
+        compatible = "ti,tmp007";
+        reg = <0x40>;
+};
+

drivers/iio/adc/Kconfig

···
 	  To compile this driver as a module, choose M here: the module will be
 	  called max1027.
 
+config MAX11100
+	tristate "Maxim max11100 ADC driver"
+	depends on SPI_MASTER
+	help
+	  Say yes here to build support for Maxim max11100 SPI ADC
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called max11100.
+
 config MAX1363
 	tristate "Maxim max1363 ADC driver"
 	depends on I2C
···
 
 	  To compile this driver as a module, choose M here: the module will be
 	  called ti_am335x_adc.
+
+config TI_TLC4541
+	tristate "Texas Instruments TLC4541 ADC driver"
+	depends on SPI
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
+	help
+	  Say yes here to build support for Texas Instruments TLC4541 / TLC3541
+	  ADC chips.
+
+	  This driver can also be built as a module. If so, the module will be
+	  called ti-tlc4541.
 
 config TWL4030_MADC
 	tristate "TWL4030 MADC (Monitoring A/D Converter)"

drivers/iio/adc/Makefile

···
 obj-$(CONFIG_LPC18XX_ADC) += lpc18xx_adc.o
 obj-$(CONFIG_LTC2485) += ltc2485.o
 obj-$(CONFIG_MAX1027) += max1027.o
+obj-$(CONFIG_MAX11100) += max11100.o
 obj-$(CONFIG_MAX1363) += max1363.o
 obj-$(CONFIG_MCP320X) += mcp320x.o
 obj-$(CONFIG_MCP3422) += mcp3422.o
···
 obj-$(CONFIG_TI_ADS7950) += ti-ads7950.o
 obj-$(CONFIG_TI_ADS8688) += ti-ads8688.o
 obj-$(CONFIG_TI_AM335X_ADC) += ti_am335x_adc.o
+obj-$(CONFIG_TI_TLC4541) += ti-tlc4541.o
 obj-$(CONFIG_TWL4030_MADC) += twl4030-madc.o
 obj-$(CONFIG_TWL6030_GPADC) += twl6030-gpadc.o
 obj-$(CONFIG_VF610_ADC) += vf610_adc.o

drivers/iio/adc/max11100.c

···
+/*
+ * iio/adc/max11100.c
+ * Maxim max11100 ADC Driver with IIO interface
+ *
+ * Copyright (C) 2016-17 Renesas Electronics Corporation
+ * Copyright (C) 2016-17 Jacopo Mondi
+ *
+ * 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/kernel.h>
+#include <linux/module.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/driver.h>
+
+/*
+ * LSB is the ADC single digital step
+ * 1 LSB = (vref_mv / 2 ^ 16)
+ *
+ * LSB is used to calculate analog voltage value
+ * from the number of ADC steps count
+ *
+ * Ain = (count * LSB)
+ */
+#define MAX11100_LSB_DIV		(1 << 16)
+
+struct max11100_state {
+	struct regulator *vref_reg;
+	struct spi_device *spi;
+
+	/*
+	 * DMA (thus cache coherency maintenance) requires the
+	 * transfer buffers to live in their own cache lines.
+	 */
+	u8 buffer[3] ____cacheline_aligned;
+};
+
+static struct iio_chan_spec max11100_channels[] = {
+	{ /* [0] */
+		.type = IIO_VOLTAGE,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+				      BIT(IIO_CHAN_INFO_SCALE),
+	},
+};
+
+static int max11100_read_single(struct iio_dev *indio_dev, int *val)
+{
+	int ret;
+	struct max11100_state *state = iio_priv(indio_dev);
+
+	ret = spi_read(state->spi, state->buffer, sizeof(state->buffer));
+	if (ret) {
+		dev_err(&indio_dev->dev, "SPI transfer failed\n");
+		return ret;
+	}
+
+	/* the first 8 bits sent out from ADC must be 0s */
+	if (state->buffer[0]) {
+		dev_err(&indio_dev->dev, "Invalid value: buffer[0] != 0\n");
+		return -EINVAL;
+	}
+
+	*val = (state->buffer[1] << 8) | state->buffer[2];
+
+	return 0;
+}
+
+static int max11100_read_raw(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan,
+			     int *val, int *val2, long info)
+{
+	int ret, vref_uv;
+	struct max11100_state *state = iio_priv(indio_dev);
+
+	switch (info) {
+	case IIO_CHAN_INFO_RAW:
+		ret = max11100_read_single(indio_dev, val);
+		if (ret)
+			return ret;
+
+		return IIO_VAL_INT;
+
+	case IIO_CHAN_INFO_SCALE:
+		vref_uv = regulator_get_voltage(state->vref_reg);
+		if (vref_uv < 0)
+			/* dummy regulator "get_voltage" returns -EINVAL */
+			return -EINVAL;
+
+		*val =  vref_uv / 1000;
+		*val2 = MAX11100_LSB_DIV;
+		return IIO_VAL_FRACTIONAL;
+	}
+
+	return -EINVAL;
+}
+
+static const struct iio_info max11100_info = {
+	.driver_module = THIS_MODULE,
+	.read_raw = max11100_read_raw,
+};
+
+static int max11100_probe(struct spi_device *spi)
+{
+	int ret;
+	struct iio_dev *indio_dev;
+	struct max11100_state *state;
+
+	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*state));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	spi_set_drvdata(spi, indio_dev);
+
+	state = iio_priv(indio_dev);
+	state->spi = spi;
+
+	indio_dev->dev.parent = &spi->dev;
+	indio_dev->dev.of_node = spi->dev.of_node;
+	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),
+
+	state->vref_reg = devm_regulator_get(&spi->dev, "vref");
+	if (IS_ERR(state->vref_reg))
+		return PTR_ERR(state->vref_reg);
+
+	ret = regulator_enable(state->vref_reg);
+	if (ret)
+		return ret;
+
+	ret = iio_device_register(indio_dev);
+	if (ret)
+		goto disable_regulator;
+
+	return 0;
+
+disable_regulator:
+	regulator_disable(state->vref_reg);
+
+	return ret;
+}
+
+static int max11100_remove(struct spi_device *spi)
+{
+	struct iio_dev *indio_dev = spi_get_drvdata(spi);
+	struct max11100_state *state = iio_priv(indio_dev);
+
+	iio_device_unregister(indio_dev);
+	regulator_disable(state->vref_reg);
+
+	return 0;
+}
+
+static const struct of_device_id max11100_ids[] = {
+	{.compatible = "maxim,max11100"},
+	{ },
+};
+MODULE_DEVICE_TABLE(of, max11100_ids);
+
+static struct spi_driver max11100_driver = {
+	.driver = {
+		.name	= "max11100",
+		.owner	= THIS_MODULE,
+		.of_match_table = of_match_ptr(max11100_ids),
+	},
+	.probe		= max11100_probe,
+	.remove		= max11100_remove,
+};
+
+module_spi_driver(max11100_driver);
+
+MODULE_AUTHOR("Jacopo Mondi <[e-mail]>");
+MODULE_DESCRIPTION("Maxim max11100 ADC Driver");
+MODULE_LICENSE("GPL v2");

drivers/iio/adc/max1363.c

···
 	MAX1363_COMPATIBLE("maxim,max11647", max11647),
 	{ /* sentinel */ }
 };
+MODULE_DEVICE_TABLE(of, max1363_of_match);
 #endif
 
 static int max1363_probe(struct i2c_client *client,

drivers/iio/adc/ti-ads1015.c

···
 	.attrs = ads1115_attributes,
 };
 
-static struct iio_info ads1015_info = {
+static const struct iio_info ads1015_info = {
 	.driver_module	= THIS_MODULE,
 	.read_raw	= ads1015_read_raw,
 	.write_raw	= ads1015_write_raw,
 	.attrs          = &ads1015_attribute_group,
 };
 
-static struct iio_info ads1115_info = {
+static const struct iio_info ads1115_info = {
 	.driver_module	= THIS_MODULE,
 	.read_raw	= ads1015_read_raw,
 	.write_raw	= ads1015_write_raw,

drivers/iio/adc/ti-ads7950.c

···
 	spi_message_init_with_transfers(&st->scan_single_msg,
 					st->scan_single_xfer, 3);
 
-	st->reg = devm_regulator_get(&spi->dev, "refin");
+	st->reg = devm_regulator_get(&spi->dev, "vref");
 	if (IS_ERR(st->reg)) {
-		dev_err(&spi->dev, "Failed get get regulator \"refin\"\n");
+		dev_err(&spi->dev, "Failed get get regulator \"vref\"\n");
 		return PTR_ERR(st->reg);
 	}
 
 	ret = regulator_enable(st->reg);
 	if (ret) {
-		dev_err(&spi->dev, "Failed to enable regulator \"refin\"\n");
+		dev_err(&spi->dev, "Failed to enable regulator \"vref\"\n");
 		return ret;
 	}
 
···
 }
 
 static const struct spi_device_id ti_ads7950_id[] = {
-	{"ti-ads7950", TI_ADS7950},
-	{"ti-ads7951", TI_ADS7951},
-	{"ti-ads7952", TI_ADS7952},
-	{"ti-ads7953", TI_ADS7953},
-	{"ti-ads7954", TI_ADS7954},
-	{"ti-ads7955", TI_ADS7955},
-	{"ti-ads7956", TI_ADS7956},
-	{"ti-ads7957", TI_ADS7957},
-	{"ti-ads7958", TI_ADS7958},
-	{"ti-ads7959", TI_ADS7959},
-	{"ti-ads7960", TI_ADS7960},
-	{"ti-ads7961", TI_ADS7961},
+	{ "ads7950", TI_ADS7950 },
+	{ "ads7951", TI_ADS7951 },
+	{ "ads7952", TI_ADS7952 },
+	{ "ads7953", TI_ADS7953 },
+	{ "ads7954", TI_ADS7954 },
+	{ "ads7955", TI_ADS7955 },
+	{ "ads7956", TI_ADS7956 },
+	{ "ads7957", TI_ADS7957 },
+	{ "ads7958", TI_ADS7958 },
+	{ "ads7959", TI_ADS7959 },
+	{ "ads7960", TI_ADS7960 },
+	{ "ads7961", TI_ADS7961 },
 	{ }
 };
 MODULE_DEVICE_TABLE(spi, ti_ads7950_id);
 
 static struct spi_driver ti_ads7950_driver = {
 	.driver = {
-		.name	= "ti-ads7950",
+		.name	= "ads7950",
 	},
 	.probe		= ti_ads7950_probe,
 	.remove		= ti_ads7950_remove,

drivers/iio/adc/ti-tlc4541.c

···
+/*
+ * TI tlc4541 ADC Driver
+ *
+ * Copyright (C) 2017 Phil Reid
+ *
+ * Datasheets can be found here:
+ * http://www.ti.com/lit/gpn/tlc3541
+ * http://www.ti.com/lit/gpn/tlc4541
+ *
+ * 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.
+ *
+ * The tlc4541 requires 24 clock cycles to start a transfer.
+ * Conversion then takes 2.94us to complete before data is ready
+ * Data is returned MSB first.
+ */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/interrupt.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>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+#include <linux/spi/spi.h>
+#include <linux/sysfs.h>
+
+struct tlc4541_state {
+	struct spi_device               *spi;
+	struct regulator                *reg;
+	struct spi_transfer             scan_single_xfer[3];
+	struct spi_message              scan_single_msg;
+
+	/*
+	 * DMA (thus cache coherency maintenance) requires the
+	 * transfer buffers to live in their own cache lines.
+	 * 2 bytes data + 6 bytes padding + 8 bytes timestamp when
+	 * call iio_push_to_buffers_with_timestamp.
+	 */
+	__be16                          rx_buf[8] ____cacheline_aligned;
+};
+
+struct tlc4541_chip_info {
+	const struct iio_chan_spec *channels;
+	unsigned int num_channels;
+};
+
+enum tlc4541_id {
+	TLC3541,
+	TLC4541,
+};
+
+#define TLC4541_V_CHAN(bits, bitshift) {                              \
+		.type = IIO_VOLTAGE,                                  \
+		.info_mask_separate       = BIT(IIO_CHAN_INFO_RAW),   \
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
+		.scan_type = {                                        \
+			.sign = 'u',                                  \
+			.realbits = (bits),                           \
+			.storagebits = 16,                            \
+			.shift = (bitshift),                          \
+			.endianness = IIO_BE,                         \
+		},                                                    \
+	}
+
+#define DECLARE_TLC4541_CHANNELS(name, bits, bitshift) \
+const struct iio_chan_spec name ## _channels[] = { \
+	TLC4541_V_CHAN(bits, bitshift), \
+	IIO_CHAN_SOFT_TIMESTAMP(1), \
+}
+
+static DECLARE_TLC4541_CHANNELS(tlc3541, 14, 2);
+static DECLARE_TLC4541_CHANNELS(tlc4541, 16, 0);
+
+static const struct tlc4541_chip_info tlc4541_chip_info[] = {
+	[TLC3541] = {
+		.channels = tlc3541_channels,
+		.num_channels = ARRAY_SIZE(tlc3541_channels),
+	},
+	[TLC4541] = {
+		.channels = tlc4541_channels,
+		.num_channels = ARRAY_SIZE(tlc4541_channels),
+	},
+};
+
+static irqreturn_t tlc4541_trigger_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct tlc4541_state *st = iio_priv(indio_dev);
+	int ret;
+
+	ret = spi_sync(st->spi, &st->scan_single_msg);
+	if (ret < 0)
+		goto done;
+
+	iio_push_to_buffers_with_timestamp(indio_dev, st->rx_buf,
+					   iio_get_time_ns(indio_dev));
+
+done:
+	iio_trigger_notify_done(indio_dev->trig);
+	return IRQ_HANDLED;
+}
+
+static int tlc4541_get_range(struct tlc4541_state *st)
+{
+	int vref;
+
+	vref = regulator_get_voltage(st->reg);
+	if (vref < 0)
+		return vref;
+
+	vref /= 1000;
+
+	return vref;
+}
+
+static int tlc4541_read_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan,
+			    int *val,
+			    int *val2,
+			    long m)
+{
+	int ret = 0;
+	struct tlc4541_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 = spi_sync(st->spi, &st->scan_single_msg);
+		iio_device_release_direct_mode(indio_dev);
+		if (ret < 0)
+			return ret;
+		*val = be16_to_cpu(st->rx_buf[0]);
+		*val = *val >> chan->scan_type.shift;
+		*val &= GENMASK(chan->scan_type.realbits - 1, 0);
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		ret = tlc4541_get_range(st);
+		if (ret < 0)
+			return ret;
+		*val = ret;
+		*val2 = chan->scan_type.realbits;
+		return IIO_VAL_FRACTIONAL_LOG2;
+	}
+	return -EINVAL;
+}
+
+static const struct iio_info tlc4541_info = {
+	.read_raw = &tlc4541_read_raw,
+	.driver_module = THIS_MODULE,
+};
+
+static int tlc4541_probe(struct spi_device *spi)
+{
+	struct tlc4541_state *st;
+	struct iio_dev *indio_dev;
+	const struct tlc4541_chip_info *info;
+	int ret;
+	int8_t device_init = 0;
+
+	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+	if (indio_dev == NULL)
+		return -ENOMEM;
+
+	st = iio_priv(indio_dev);
+
+	spi_set_drvdata(spi, indio_dev);
+
+	st->spi = spi;
+
+	info = &tlc4541_chip_info[spi_get_device_id(spi)->driver_data];
+
+	indio_dev->name = spi_get_device_id(spi)->name;
+	indio_dev->dev.parent = &spi->dev;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = info->channels;
+	indio_dev->num_channels = info->num_channels;
+	indio_dev->info = &tlc4541_info;
+
+	/* perform reset */
+	spi_write(spi, &device_init, 1);
+
+	/* Setup default message */
+	st->scan_single_xfer[0].rx_buf = &st->rx_buf[0];
+	st->scan_single_xfer[0].len = 3;
+	st->scan_single_xfer[1].delay_usecs = 3;
+	st->scan_single_xfer[2].rx_buf = &st->rx_buf[0];
+	st->scan_single_xfer[2].len = 2;
+
+	spi_message_init_with_transfers(&st->scan_single_msg,
+					st->scan_single_xfer, 3);
+
+	st->reg = devm_regulator_get(&spi->dev, "vref");
+	if (IS_ERR(st->reg))
+		return PTR_ERR(st->reg);
+
+	ret = regulator_enable(st->reg);
+	if (ret)
+		return ret;
+
+	ret = iio_triggered_buffer_setup(indio_dev, NULL,
+			&tlc4541_trigger_handler, NULL);
+	if (ret)
+		goto error_disable_reg;
+
+	ret = iio_device_register(indio_dev);
+	if (ret)
+		goto error_cleanup_buffer;
+
+	return 0;
+
+error_cleanup_buffer:
+	iio_triggered_buffer_cleanup(indio_dev);
+error_disable_reg:
+	regulator_disable(st->reg);
+
+	return ret;
+}
+
+static int tlc4541_remove(struct spi_device *spi)
+{
+	struct iio_dev *indio_dev = spi_get_drvdata(spi);
+	struct tlc4541_state *st = iio_priv(indio_dev);
+
+	iio_device_unregister(indio_dev);
+	iio_triggered_buffer_cleanup(indio_dev);
+	regulator_disable(st->reg);
+
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id tlc4541_dt_ids[] = {
+	{ .compatible = "ti,tlc3541", },
+	{ .compatible = "ti,tlc4541", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, tlc4541_dt_ids);
+#endif
+
+static const struct spi_device_id tlc4541_id[] = {
+	{"tlc3541", TLC3541},
+	{"tlc4541", TLC4541},
+	{}
+};
+MODULE_DEVICE_TABLE(spi, tlc4541_id);
+
+static struct spi_driver tlc4541_driver = {
+	.driver = {
+		.name   = "tlc4541",
+		.of_match_table = of_match_ptr(tlc4541_dt_ids),
+	},
+	.probe          = tlc4541_probe,
+	.remove         = tlc4541_remove,
+	.id_table       = tlc4541_id,
+};
+module_spi_driver(tlc4541_driver);
+
+MODULE_AUTHOR("Phil Reid <[e-mail]>");
+MODULE_DESCRIPTION("Texas Instruments TLC4541 ADC");
+MODULE_LICENSE("GPL v2");

drivers/iio/health/max30100.c

···
 	if (ret)
 		return ret;
 
-	usleep_range(35000, 50000);
+	msleep(35);
 
 	return max30100_read_temp(data, val);
 }

drivers/iio/imu/Kconfig

···
 	  be called kmx61.
 
 source "drivers/iio/imu/inv_mpu6050/Kconfig"
+source "drivers/iio/imu/st_lsm6dsx/Kconfig"
 
 endmenu
 

drivers/iio/imu/Makefile

···
 obj-y += inv_mpu6050/
 
 obj-$(CONFIG_KMX61) += kmx61.o
+
+obj-y += st_lsm6dsx/

drivers/iio/imu/bmi160/bmi160_core.c

···
 	__le16 sample;
 	enum bmi160_sensor_type t = bmi160_to_sensor(chan_type);
 
-	reg = bmi160_regs[t].data + (axis - IIO_MOD_X) * sizeof(__le16);
+	reg = bmi160_regs[t].data + (axis - IIO_MOD_X) * sizeof(sample);
 
-	ret = regmap_bulk_read(data->regmap, reg, &sample, sizeof(__le16));
+	ret = regmap_bulk_read(data->regmap, reg, &sample, sizeof(sample));
 	if (ret < 0)
 		return ret;
 
···
 
 	for_each_set_bit(i, indio_dev->active_scan_mask,
 			 indio_dev->masklength) {
-		ret = regmap_bulk_read(data->regmap, base + i * sizeof(__le16),
-				       &sample, sizeof(__le16));
+		ret = regmap_bulk_read(data->regmap, base + i * sizeof(sample),
+				       &sample, sizeof(sample));
 		if (ret < 0)
 			goto done;
 		buf[j++] = sample;

drivers/iio/imu/st_lsm6dsx/Kconfig

···
+
+config IIO_ST_LSM6DSX
+	tristate "ST_LSM6DSx driver for STM 6-axis IMU MEMS sensors"
+	depends on (I2C || SPI)
+	select IIO_BUFFER
+	select IIO_KFIFO_BUF
+	select IIO_ST_LSM6DSX_I2C if (I2C)
+	select IIO_ST_LSM6DSX_SPI if (SPI_MASTER)
+	help
+	  Say yes here to build support for STMicroelectronics LSM6DSx imu
+	  sensor. Supported devices: lsm6ds3, lsm6dsm
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called st_lsm6dsx.
+
+config IIO_ST_LSM6DSX_I2C
+	tristate
+	depends on IIO_ST_LSM6DSX
+
+config IIO_ST_LSM6DSX_SPI
+	tristate
+	depends on IIO_ST_LSM6DSX

drivers/iio/imu/st_lsm6dsx/Makefile

···
+st_lsm6dsx-y := st_lsm6dsx_core.o st_lsm6dsx_buffer.o
+
+obj-$(CONFIG_IIO_ST_LSM6DSX) += st_lsm6dsx.o
+obj-$(CONFIG_IIO_ST_LSM6DSX_I2C) += st_lsm6dsx_i2c.o
+obj-$(CONFIG_IIO_ST_LSM6DSX_SPI) += st_lsm6dsx_spi.o

drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h

···
+/*
+ * STMicroelectronics st_lsm6dsx sensor driver
+ *
+ * Copyright 2016 STMicroelectronics Inc.
+ *
+ * Lorenzo Bianconi <[e-mail]>
+ * Denis Ciocca <[e-mail]>
+ *
+ * Licensed under the GPL-2.
+ */
+
+#ifndef ST_LSM6DSX_H
+#define ST_LSM6DSX_H
+
+#include <linux/device.h>
+
+#define ST_LSM6DS3_DEV_NAME	"lsm6ds3"
+#define ST_LSM6DSM_DEV_NAME	"lsm6dsm"
+
+enum st_lsm6dsx_hw_id {
+	ST_LSM6DS3_ID,
+	ST_LSM6DSM_ID,
+};
+
+#define ST_LSM6DSX_CHAN_SIZE		2
+#define ST_LSM6DSX_SAMPLE_SIZE		6
+#define ST_LSM6DSX_SAMPLE_DEPTH		(ST_LSM6DSX_SAMPLE_SIZE / \
+					 ST_LSM6DSX_CHAN_SIZE)
+
+#if defined(CONFIG_SPI_MASTER)
+#define ST_LSM6DSX_RX_MAX_LENGTH	256
+#define ST_LSM6DSX_TX_MAX_LENGTH	8
+
+struct st_lsm6dsx_transfer_buffer {
+	u8 rx_buf[ST_LSM6DSX_RX_MAX_LENGTH];
+	u8 tx_buf[ST_LSM6DSX_TX_MAX_LENGTH] ____cacheline_aligned;
+};
+#endif /* CONFIG_SPI_MASTER */
+
+struct st_lsm6dsx_transfer_function {
+	int (*read)(struct device *dev, u8 addr, int len, u8 *data);
+	int (*write)(struct device *dev, u8 addr, int len, u8 *data);
+};
+
+struct st_lsm6dsx_reg {
+	u8 addr;
+	u8 mask;
+};
+
+struct st_lsm6dsx_settings {
+	u8 wai;
+	u16 max_fifo_size;
+	enum st_lsm6dsx_hw_id id;
+};
+
+enum st_lsm6dsx_sensor_id {
+	ST_LSM6DSX_ID_ACC,
+	ST_LSM6DSX_ID_GYRO,
+	ST_LSM6DSX_ID_MAX,
+};
+
+enum st_lsm6dsx_fifo_mode {
+	ST_LSM6DSX_FIFO_BYPASS = 0x0,
+	ST_LSM6DSX_FIFO_CONT = 0x6,
+};
+
+/**
+ * struct st_lsm6dsx_sensor - ST IMU sensor instance
+ * @id: Sensor identifier.
+ * @hw: Pointer to instance of struct st_lsm6dsx_hw.
+ * @gain: Configured sensor sensitivity.
+ * @odr: Output data rate of the sensor [Hz].
+ * @watermark: Sensor watermark level.
+ * @sip: Number of samples in a given pattern.
+ * @decimator: FIFO decimation factor.
+ * @decimator_mask: Sensor mask for decimation register.
+ * @delta_ts: Delta time between two consecutive interrupts.
+ * @ts: Latest timestamp from the interrupt handler.
+ */
+struct st_lsm6dsx_sensor {
+	enum st_lsm6dsx_sensor_id id;
+	struct st_lsm6dsx_hw *hw;
+
+	u32 gain;
+	u16 odr;
+
+	u16 watermark;
+	u8 sip;
+	u8 decimator;
+	u8 decimator_mask;
+
+	s64 delta_ts;
+	s64 ts;
+};
+
+/**
+ * struct st_lsm6dsx_hw - ST IMU MEMS hw instance
+ * @dev: Pointer to instance of struct device (I2C or SPI).
+ * @irq: Device interrupt line (I2C or SPI).
+ * @lock: Mutex to protect read and write operations.
+ * @fifo_lock: Mutex to prevent concurrent access to the hw FIFO.
+ * @fifo_mode: FIFO operating mode supported by the device.
+ * @enable_mask: Enabled sensor bitmask.
+ * @sip: Total number of samples (acc/gyro) in a given pattern.
+ * @iio_devs: Pointers to acc/gyro iio_dev instances.
+ * @settings: Pointer to the specific sensor settings in use.
+ * @tf: Transfer function structure used by I/O operations.
+ * @tb: Transfer buffers used by SPI I/O operations.
+ */
+struct st_lsm6dsx_hw {
+	struct device *dev;
+	int irq;
+
+	struct mutex lock;
+	struct mutex fifo_lock;
+
+	enum st_lsm6dsx_fifo_mode fifo_mode;
+	u8 enable_mask;
+	u8 sip;
+
+	struct iio_dev *iio_devs[ST_LSM6DSX_ID_MAX];
+
+	const struct st_lsm6dsx_settings *settings;
+
+	const struct st_lsm6dsx_transfer_function *tf;
+#if defined(CONFIG_SPI_MASTER)
+	struct st_lsm6dsx_transfer_buffer tb;
+#endif /* CONFIG_SPI_MASTER */
+};
+
+int st_lsm6dsx_probe(struct device *dev, int irq, int hw_id,
+		     const struct st_lsm6dsx_transfer_function *tf_ops);
+int st_lsm6dsx_sensor_enable(struct st_lsm6dsx_sensor *sensor);
+int st_lsm6dsx_sensor_disable(struct st_lsm6dsx_sensor *sensor);
+int st_lsm6dsx_fifo_setup(struct st_lsm6dsx_hw *hw);
+int st_lsm6dsx_write_with_mask(struct st_lsm6dsx_hw *hw, u8 addr, u8 mask,
+			       u8 val);
+int st_lsm6dsx_update_watermark(struct st_lsm6dsx_sensor *sensor,
+				u16 watermark);
+
+#endif /* ST_LSM6DSX_H */

drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c

···
+/*
+ * STMicroelectronics st_lsm6dsx FIFO buffer library driver
+ *
+ * LSM6DS3/LSM6DSM: The FIFO buffer can be configured to store data
+ * from gyroscope and accelerometer. Samples are queued without any tag
+ * according to a specific pattern based on 'FIFO data sets' (6 bytes each):
+ *  - 1st data set is reserved for gyroscope data
+ *  - 2nd data set is reserved for accelerometer data
+ * The FIFO pattern changes depending on the ODRs and decimation factors
+ * assigned to the FIFO data sets. The first sequence of data stored in FIFO
+ * buffer contains the data of all the enabled FIFO data sets
+ * (e.g. Gx, Gy, Gz, Ax, Ay, Az), then data are repeated depending on the
+ * value of the decimation factor and ODR set for each FIFO data set.
+ * FIFO supported modes:
+ *  - BYPASS: FIFO disabled
+ *  - CONTINUOUS: FIFO enabled. When the buffer is full, the FIFO index
+ *    restarts from the beginning and the oldest sample is overwritten
+ *
+ * Copyright 2016 STMicroelectronics Inc.
+ *
+ * Lorenzo Bianconi <[e-mail]>
+ * Denis Ciocca <[e-mail]>
+ *
+ * Licensed under the GPL-2.
+ */
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/iio/kfifo_buf.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+
+#include "st_lsm6dsx.h"
+
+#define ST_LSM6DSX_REG_FIFO_THL_ADDR		0x06
+#define ST_LSM6DSX_REG_FIFO_THH_ADDR		0x07
+#define ST_LSM6DSX_FIFO_TH_MASK			GENMASK(11, 0)
+#define ST_LSM6DSX_REG_FIFO_DEC_GXL_ADDR	0x08
+#define ST_LSM6DSX_REG_FIFO_MODE_ADDR		0x0a
+#define ST_LSM6DSX_FIFO_MODE_MASK		GENMASK(2, 0)
+#define ST_LSM6DSX_FIFO_ODR_MASK		GENMASK(6, 3)
+#define ST_LSM6DSX_REG_FIFO_DIFFL_ADDR		0x3a
+#define ST_LSM6DSX_FIFO_DIFF_MASK		GENMASK(11, 0)
+#define ST_LSM6DSX_FIFO_EMPTY_MASK		BIT(12)
+#define ST_LSM6DSX_REG_FIFO_OUTL_ADDR		0x3e
+
+#define ST_LSM6DSX_MAX_FIFO_ODR_VAL		0x08
+
+struct st_lsm6dsx_decimator_entry {
+	u8 decimator;
+	u8 val;
+};
+
+static const
+struct st_lsm6dsx_decimator_entry st_lsm6dsx_decimator_table[] = {
+	{  0, 0x0 },
+	{  1, 0x1 },
+	{  2, 0x2 },
+	{  3, 0x3 },
+	{  4, 0x4 },
+	{  8, 0x5 },
+	{ 16, 0x6 },
+	{ 32, 0x7 },
+};
+
+static int st_lsm6dsx_get_decimator_val(u8 val)
+{
+	const int max_size = ARRAY_SIZE(st_lsm6dsx_decimator_table);
+	int i;
+
+	for (i = 0; i < max_size; i++)
+		if (st_lsm6dsx_decimator_table[i].decimator == val)
+			break;
+
+	return i == max_size ? 0 : st_lsm6dsx_decimator_table[i].val;
+}
+
+static void st_lsm6dsx_get_max_min_odr(struct st_lsm6dsx_hw *hw,
+				       u16 *max_odr, u16 *min_odr)
+{
+	struct st_lsm6dsx_sensor *sensor;
+	int i;
+
+	*max_odr = 0, *min_odr = ~0;
+	for (i = 0; i < ST_LSM6DSX_ID_MAX; i++) {
+		sensor = iio_priv(hw->iio_devs[i]);
+
+		if (!(hw->enable_mask & BIT(sensor->id)))
+			continue;
+
+		*max_odr = max_t(u16, *max_odr, sensor->odr);
+		*min_odr = min_t(u16, *min_odr, sensor->odr);
+	}
+}
+
+static int st_lsm6dsx_update_decimators(struct st_lsm6dsx_hw *hw)
+{
+	struct st_lsm6dsx_sensor *sensor;
+	u16 max_odr, min_odr, sip = 0;
+	int err, i;
+	u8 data;
+
+	st_lsm6dsx_get_max_min_odr(hw, &max_odr, &min_odr);
+
+	for (i = 0; i < ST_LSM6DSX_ID_MAX; i++) {
+		sensor = iio_priv(hw->iio_devs[i]);
+
+		/* update fifo decimators and sample in pattern */
+		if (hw->enable_mask & BIT(sensor->id)) {
+			sensor->sip = sensor->odr / min_odr;
+			sensor->decimator = max_odr / sensor->odr;
+			data = st_lsm6dsx_get_decimator_val(sensor->decimator);
+		} else {
+			sensor->sip = 0;
+			sensor->decimator = 0;
+			data = 0;
+		}
+
+		err = st_lsm6dsx_write_with_mask(hw,
+					ST_LSM6DSX_REG_FIFO_DEC_GXL_ADDR,
+					sensor->decimator_mask, data);
+		if (err < 0)
+			return err;
+
+		sip += sensor->sip;
+	}
+	hw->sip = sip;
+
+	return 0;
+}
+
+static int st_lsm6dsx_set_fifo_mode(struct st_lsm6dsx_hw *hw,
+				    enum st_lsm6dsx_fifo_mode fifo_mode)
+{
+	u8 data;
+	int err;
+
+	switch (fifo_mode) {
+	case ST_LSM6DSX_FIFO_BYPASS:
+		data = fifo_mode;
+		break;
+	case ST_LSM6DSX_FIFO_CONT:
+		data = (ST_LSM6DSX_MAX_FIFO_ODR_VAL <<
+			__ffs(ST_LSM6DSX_FIFO_ODR_MASK)) | fifo_mode;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	err = hw->tf->write(hw->dev, ST_LSM6DSX_REG_FIFO_MODE_ADDR,
+			    sizeof(data), &data);
+	if (err < 0)
+		return err;
+
+	hw->fifo_mode = fifo_mode;
+
+	return 0;
+}
+
+int st_lsm6dsx_update_watermark(struct st_lsm6dsx_sensor *sensor, u16 watermark)
+{
+	u16 fifo_watermark = ~0, cur_watermark, sip = 0;
+	struct st_lsm6dsx_hw *hw = sensor->hw;
+	struct st_lsm6dsx_sensor *cur_sensor;
+	__le16 wdata;
+	int i, err;
+	u8 data;
+
+	for (i = 0; i < ST_LSM6DSX_ID_MAX; i++) {
+		cur_sensor = iio_priv(hw->iio_devs[i]);
+
+		if (!(hw->enable_mask & BIT(cur_sensor->id)))
+			continue;
+
+		cur_watermark = (cur_sensor == sensor) ? watermark
+						       : cur_sensor->watermark;
+
+		fifo_watermark = min_t(u16, fifo_watermark, cur_watermark);
+		sip += cur_sensor->sip;
+	}
+
+	if (!sip)
+		return 0;
+
+	fifo_watermark = max_t(u16, fifo_watermark, sip);
+	fifo_watermark = (fifo_watermark / sip) * sip;
+	fifo_watermark = fifo_watermark * ST_LSM6DSX_SAMPLE_DEPTH;
+
+	mutex_lock(&hw->lock);
+
+	err = hw->tf->read(hw->dev, ST_LSM6DSX_REG_FIFO_THH_ADDR,
+			   sizeof(data), &data);
+	if (err < 0)
+		goto out;
+
+	fifo_watermark = ((data & ~ST_LSM6DSX_FIFO_TH_MASK) << 8) |
+			  (fifo_watermark & ST_LSM6DSX_FIFO_TH_MASK);
+
+	wdata = cpu_to_le16(fifo_watermark);
+	err = hw->tf->write(hw->dev, ST_LSM6DSX_REG_FIFO_THL_ADDR,
+			    sizeof(wdata), (u8 *)&wdata);
+out:
+	mutex_unlock(&hw->lock);
+
+	return err < 0 ? err : 0;
+}
+
+/**
+ * st_lsm6dsx_read_fifo() - LSM6DS3-LSM6DSM read FIFO routine
+ * @hw: Pointer to instance of struct st_lsm6dsx_hw.
+ *
+ * Read samples from the hw FIFO and push them to IIO buffers.
+ *
+ * Return: Number of bytes read from the FIFO
+ */
+static int st_lsm6dsx_read_fifo(struct st_lsm6dsx_hw *hw)
+{
+	u16 fifo_len, pattern_len = hw->sip * ST_LSM6DSX_SAMPLE_SIZE;
+	int err, acc_sip, gyro_sip, read_len, samples, offset;
+	struct st_lsm6dsx_sensor *acc_sensor, *gyro_sensor;
+	s64 acc_ts, acc_delta_ts, gyro_ts, gyro_delta_ts;
+	u8 iio_buff[ALIGN(ST_LSM6DSX_SAMPLE_SIZE, sizeof(s64)) + sizeof(s64)];
+	u8 buff[pattern_len];
+	__le16 fifo_status;
+
+	err = hw->tf->read(hw->dev, ST_LSM6DSX_REG_FIFO_DIFFL_ADDR,
+			   sizeof(fifo_status), (u8 *)&fifo_status);
+	if (err < 0)
+		return err;
+
+	if (fifo_status & cpu_to_le16(ST_LSM6DSX_FIFO_EMPTY_MASK))
+		return 0;
+
+	fifo_len = (le16_to_cpu(fifo_status) & ST_LSM6DSX_FIFO_DIFF_MASK) *
+		   ST_LSM6DSX_CHAN_SIZE;
+	samples = fifo_len / ST_LSM6DSX_SAMPLE_SIZE;
+	fifo_len = (fifo_len / pattern_len) * pattern_len;
+
+	/*
+	 * compute delta timestamp between two consecutive samples
+	 * in order to estimate queueing time of data generated
+	 * by the sensor
+	 */
+	acc_sensor = iio_priv(hw->iio_devs[ST_LSM6DSX_ID_ACC]);
+	acc_ts = acc_sensor->ts - acc_sensor->delta_ts;
+	acc_delta_ts = div_s64(acc_sensor->delta_ts * acc_sensor->decimator,
+			       samples);
+
+	gyro_sensor = iio_priv(hw->iio_devs[ST_LSM6DSX_ID_GYRO]);
+	gyro_ts = gyro_sensor->ts - gyro_sensor->delta_ts;
+	gyro_delta_ts = div_s64(gyro_sensor->delta_ts * gyro_sensor->decimator,
+				samples);
+
+	for (read_len = 0; read_len < fifo_len; read_len += pattern_len) {
+		err = hw->tf->read(hw->dev, ST_LSM6DSX_REG_FIFO_OUTL_ADDR,
+				   sizeof(buff), buff);
+		if (err < 0)
+			return err;
+
+		/*
+		 * Data are written to the FIFO with a specific pattern
+		 * depending on the configured ODRs. The first sequence of data
+		 * stored in FIFO contains the data of all enabled sensors
+		 * (e.g. Gx, Gy, Gz, Ax, Ay, Az), then data are repeated
+		 * depending on the value of the decimation factor set for each
+		 * sensor.
+		 *
+		 * Supposing the FIFO is storing data from gyroscope and
+		 * accelerometer at different ODRs:
+		 *   - gyroscope ODR = 208Hz, accelerometer ODR = 104Hz
+		 * Since the gyroscope ODR is twice the accelerometer one, the
+		 * following pattern is repeated every 9 samples:
+		 *   - Gx, Gy, Gz, Ax, Ay, Az, Gx, Gy, Gz
+		 */
+		gyro_sip = gyro_sensor->sip;
+		acc_sip = acc_sensor->sip;
+		offset = 0;
+
+		while (acc_sip > 0 || gyro_sip > 0) {
+			if (gyro_sip-- > 0) {
+				memcpy(iio_buff, &buff[offset],
+				       ST_LSM6DSX_SAMPLE_SIZE);
+				iio_push_to_buffers_with_timestamp(
+					hw->iio_devs[ST_LSM6DSX_ID_GYRO],
+					iio_buff, gyro_ts);
+				offset += ST_LSM6DSX_SAMPLE_SIZE;
+				gyro_ts += gyro_delta_ts;
+			}
+
+			if (acc_sip-- > 0) {
+				memcpy(iio_buff, &buff[offset],
+				       ST_LSM6DSX_SAMPLE_SIZE);
+				iio_push_to_buffers_with_timestamp(
+					hw->iio_devs[ST_LSM6DSX_ID_ACC],
+					iio_buff, acc_ts);
+				offset += ST_LSM6DSX_SAMPLE_SIZE;
+				acc_ts += acc_delta_ts;
+			}
+		}
+	}
+
+	return read_len;
+}
+
+static int st_lsm6dsx_flush_fifo(struct st_lsm6dsx_hw *hw)
+{
+	int err;
+
+	mutex_lock(&hw->fifo_lock);
+
+	st_lsm6dsx_read_fifo(hw);
+	err = st_lsm6dsx_set_fifo_mode(hw, ST_LSM6DSX_FIFO_BYPASS);
+
+	mutex_unlock(&hw->fifo_lock);
+
+	return err;
+}
+
+static int st_lsm6dsx_update_fifo(struct iio_dev *iio_dev, bool enable)
+{
+	struct st_lsm6dsx_sensor *sensor = iio_priv(iio_dev);
+	struct st_lsm6dsx_hw *hw = sensor->hw;
+	int err;
+
+	if (hw->fifo_mode != ST_LSM6DSX_FIFO_BYPASS) {
+		err = st_lsm6dsx_flush_fifo(hw);
+		if (err < 0)
+			return err;
+	}
+
+	if (enable) {
+		err = st_lsm6dsx_sensor_enable(sensor);
+		if (err < 0)
+			return err;
+	} else {
+		err = st_lsm6dsx_sensor_disable(sensor);
+		if (err < 0)
+			return err;
+	}
+
+	err = st_lsm6dsx_update_decimators(hw);
+	if (err < 0)
+		return err;
+
+	err = st_lsm6dsx_update_watermark(sensor, sensor->watermark);
+	if (err < 0)
+		return err;
+
+	if (hw->enable_mask) {
+		err = st_lsm6dsx_set_fifo_mode(hw, ST_LSM6DSX_FIFO_CONT);
+		if (err < 0)
+			return err;
+
+		/*
+		 * store enable buffer timestamp as reference to compute
+		 * first delta timestamp
+		 */
+		sensor->ts = iio_get_time_ns(iio_dev);
+	}
+
+	return 0;
+}
+
+static irqreturn_t st_lsm6dsx_handler_irq(int irq, void *private)
+{
+	struct st_lsm6dsx_hw *hw = (struct st_lsm6dsx_hw *)private;
+	struct st_lsm6dsx_sensor *sensor;
+	int i;
+
+	if (!hw->sip)
+		return IRQ_NONE;
+
+	for (i = 0; i < ST_LSM6DSX_ID_MAX; i++) {
+		sensor = iio_priv(hw->iio_devs[i]);
+
+		if (sensor->sip > 0) {
+			s64 timestamp;
+
+			timestamp = iio_get_time_ns(hw->iio_devs[i]);
+			sensor->delta_ts = timestamp - sensor->ts;
+			sensor->ts = timestamp;
+		}
+	}
+
+	return IRQ_WAKE_THREAD;
+}
+
+static irqreturn_t st_lsm6dsx_handler_thread(int irq, void *private)
+{
+	struct st_lsm6dsx_hw *hw = (struct st_lsm6dsx_hw *)private;
+	int count;
+
+	mutex_lock(&hw->fifo_lock);
+	count = st_lsm6dsx_read_fifo(hw);
+	mutex_unlock(&hw->fifo_lock);
+
+	return !count ? IRQ_NONE : IRQ_HANDLED;
+}
+
+static int st_lsm6dsx_buffer_preenable(struct iio_dev *iio_dev)
+{
+	return st_lsm6dsx_update_fifo(iio_dev, true);
+}
+
+static int st_lsm6dsx_buffer_postdisable(struct iio_dev *iio_dev)
+{
+	return st_lsm6dsx_update_fifo(iio_dev, false);
+}
+
+static const struct iio_buffer_setup_ops st_lsm6dsx_buffer_ops = {
+	.preenable = st_lsm6dsx_buffer_preenable,
+	.postdisable = st_lsm6dsx_buffer_postdisable,
+};
+
+int st_lsm6dsx_fifo_setup(struct st_lsm6dsx_hw *hw)
+{
+	struct iio_buffer *buffer;
+	unsigned long irq_type;
+	int i, err;
+
+	irq_type = irqd_get_trigger_type(irq_get_irq_data(hw->irq));
+
+	switch (irq_type) {
+	case IRQF_TRIGGER_HIGH:
+	case IRQF_TRIGGER_RISING:
+		break;
+	default:
+		dev_info(hw->dev, "mode %lx unsupported\n", irq_type);
+		return -EINVAL;
+	}
+
+	err = devm_request_threaded_irq(hw->dev, hw->irq,
+					st_lsm6dsx_handler_irq,
+					st_lsm6dsx_handler_thread,
+					irq_type | IRQF_ONESHOT,
+					"lsm6dsx", hw);
+	if (err) {
+		dev_err(hw->dev, "failed to request trigger irq %d\n",
+			hw->irq);
+		return err;
+	}
+
+	for (i = 0; i < ST_LSM6DSX_ID_MAX; i++) {
+		buffer = devm_iio_kfifo_allocate(hw->dev);
+		if (!buffer)
+			return -ENOMEM;
+
+		iio_device_attach_buffer(hw->iio_devs[i], buffer);
+		hw->iio_devs[i]->modes |= INDIO_BUFFER_SOFTWARE;
+		hw->iio_devs[i]->setup_ops = &st_lsm6dsx_buffer_ops;
+	}
+
+	return 0;
+}

drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c

···
+/*
+ * STMicroelectronics st_lsm6dsx sensor driver
+ *
+ * The ST LSM6DSx IMU MEMS series consists of 3D digital accelerometer
+ * and 3D digital gyroscope system-in-package with a digital I2C/SPI serial
+ * interface standard output.
+ * LSM6DSx IMU MEMS series has a dynamic user-selectable full-scale
+ * acceleration range of +-2/+-4/+-8/+-16 g and an angular rate range of
+ * +-125/+-245/+-500/+-1000/+-2000 dps
+ * LSM6DSx series has an integrated First-In-First-Out (FIFO) buffer
+ * allowing dynamic batching of sensor data.
+ *
+ * Supported sensors:
+ * - LSM6DS3:
+ *   - Accelerometer/Gyroscope supported ODR [Hz]: 13, 26, 52, 104, 208, 416
+ *   - Accelerometer supported full-scale [g]: +-2/+-4/+-8/+-16
+ *   - Gyroscope supported full-scale [dps]: +-125/+-245/+-500/+-1000/+-2000
+ *   - FIFO size: 8KB
+ *
+ * - LSM6DSM:
+ *   - Accelerometer/Gyroscope supported ODR [Hz]: 13, 26, 52, 104, 208, 416
+ *   - Accelerometer supported full-scale [g]: +-2/+-4/+-8/+-16
+ *   - Gyroscope supported full-scale [dps]: +-125/+-245/+-500/+-1000/+-2000
+ *   - FIFO size: 4KB
+ *
+ * Copyright 2016 STMicroelectronics Inc.
+ *
+ * Lorenzo Bianconi <[e-mail]>
+ * Denis Ciocca <[e-mail]>
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#include "st_lsm6dsx.h"
+
+#define ST_LSM6DSX_REG_ACC_DEC_MASK		GENMASK(2, 0)
+#define ST_LSM6DSX_REG_GYRO_DEC_MASK		GENMASK(5, 3)
+#define ST_LSM6DSX_REG_INT1_ADDR		0x0d
+#define ST_LSM6DSX_REG_FIFO_FTH_IRQ_MASK	BIT(3)
+#define ST_LSM6DSX_REG_WHOAMI_ADDR		0x0f
+#define ST_LSM6DSX_REG_RESET_ADDR		0x12
+#define ST_LSM6DSX_REG_RESET_MASK		BIT(0)
+#define ST_LSM6DSX_REG_BDU_ADDR			0x12
+#define ST_LSM6DSX_REG_BDU_MASK			BIT(6)
+#define ST_LSM6DSX_REG_INT2_ON_INT1_ADDR	0x13
+#define ST_LSM6DSX_REG_INT2_ON_INT1_MASK	BIT(5)
+#define ST_LSM6DSX_REG_ROUNDING_ADDR		0x16
+#define ST_LSM6DSX_REG_ROUNDING_MASK		BIT(2)
+#define ST_LSM6DSX_REG_LIR_ADDR			0x58
+#define ST_LSM6DSX_REG_LIR_MASK			BIT(0)
+
+#define ST_LSM6DSX_REG_ACC_ODR_ADDR		0x10
+#define ST_LSM6DSX_REG_ACC_ODR_MASK		GENMASK(7, 4)
+#define ST_LSM6DSX_REG_ACC_FS_ADDR		0x10
+#define ST_LSM6DSX_REG_ACC_FS_MASK		GENMASK(3, 2)
+#define ST_LSM6DSX_REG_ACC_OUT_X_L_ADDR		0x28
+#define ST_LSM6DSX_REG_ACC_OUT_Y_L_ADDR		0x2a
+#define ST_LSM6DSX_REG_ACC_OUT_Z_L_ADDR		0x2c
+
+#define ST_LSM6DSX_REG_GYRO_ODR_ADDR		0x11
+#define ST_LSM6DSX_REG_GYRO_ODR_MASK		GENMASK(7, 4)
+#define ST_LSM6DSX_REG_GYRO_FS_ADDR		0x11
+#define ST_LSM6DSX_REG_GYRO_FS_MASK		GENMASK(3, 2)
+#define ST_LSM6DSX_REG_GYRO_OUT_X_L_ADDR	0x22
+#define ST_LSM6DSX_REG_GYRO_OUT_Y_L_ADDR	0x24
+#define ST_LSM6DSX_REG_GYRO_OUT_Z_L_ADDR	0x26
+
+#define ST_LSM6DS3_WHOAMI			0x69
+#define ST_LSM6DSM_WHOAMI			0x6a
+
+#define ST_LSM6DS3_MAX_FIFO_SIZE		8192
+#define ST_LSM6DSM_MAX_FIFO_SIZE		4096
+
+#define ST_LSM6DSX_ACC_FS_2G_GAIN		IIO_G_TO_M_S_2(61)
+#define ST_LSM6DSX_ACC_FS_4G_GAIN		IIO_G_TO_M_S_2(122)
+#define ST_LSM6DSX_ACC_FS_8G_GAIN		IIO_G_TO_M_S_2(244)
+#define ST_LSM6DSX_ACC_FS_16G_GAIN		IIO_G_TO_M_S_2(488)
+
+#define ST_LSM6DSX_GYRO_FS_245_GAIN		IIO_DEGREE_TO_RAD(8750)
+#define ST_LSM6DSX_GYRO_FS_500_GAIN		IIO_DEGREE_TO_RAD(17500)
+#define ST_LSM6DSX_GYRO_FS_1000_GAIN		IIO_DEGREE_TO_RAD(35000)
+#define ST_LSM6DSX_GYRO_FS_2000_GAIN		IIO_DEGREE_TO_RAD(70000)
+
+struct st_lsm6dsx_odr {
+	u16 hz;
+	u8 val;
+};
+
+#define ST_LSM6DSX_ODR_LIST_SIZE	6
+struct st_lsm6dsx_odr_table_entry {
+	struct st_lsm6dsx_reg reg;
+	struct st_lsm6dsx_odr odr_avl[ST_LSM6DSX_ODR_LIST_SIZE];
+};
+
+static const struct st_lsm6dsx_odr_table_entry st_lsm6dsx_odr_table[] = {
+	[ST_LSM6DSX_ID_ACC] = {
+		.reg = {
+			.addr = ST_LSM6DSX_REG_ACC_ODR_ADDR,
+			.mask = ST_LSM6DSX_REG_ACC_ODR_MASK,
+		},
+		.odr_avl[0] = {  13, 0x01 },
+		.odr_avl[1] = {  26, 0x02 },
+		.odr_avl[2] = {  52, 0x03 },
+		.odr_avl[3] = { 104, 0x04 },
+		.odr_avl[4] = { 208, 0x05 },
+		.odr_avl[5] = { 416, 0x06 },
+	},
+	[ST_LSM6DSX_ID_GYRO] = {
+		.reg = {
+			.addr = ST_LSM6DSX_REG_GYRO_ODR_ADDR,
+			.mask = ST_LSM6DSX_REG_GYRO_ODR_MASK,
+		},
+		.odr_avl[0] = {  13, 0x01 },
+		.odr_avl[1] = {  26, 0x02 },
+		.odr_avl[2] = {  52, 0x03 },
+		.odr_avl[3] = { 104, 0x04 },
+		.odr_avl[4] = { 208, 0x05 },
+		.odr_avl[5] = { 416, 0x06 },
+	}
+};
+
+struct st_lsm6dsx_fs {
+	u32 gain;
+	u8 val;
+};
+
+#define ST_LSM6DSX_FS_LIST_SIZE		4
+struct st_lsm6dsx_fs_table_entry {
+	struct st_lsm6dsx_reg reg;
+	struct st_lsm6dsx_fs fs_avl[ST_LSM6DSX_FS_LIST_SIZE];
+};
+
+static const struct st_lsm6dsx_fs_table_entry st_lsm6dsx_fs_table[] = {
+	[ST_LSM6DSX_ID_ACC] = {
+		.reg = {
+			.addr = ST_LSM6DSX_REG_ACC_FS_ADDR,
+			.mask = ST_LSM6DSX_REG_ACC_FS_MASK,
+		},
+		.fs_avl[0] = {  ST_LSM6DSX_ACC_FS_2G_GAIN, 0x0 },
+		.fs_avl[1] = {  ST_LSM6DSX_ACC_FS_4G_GAIN, 0x2 },
+		.fs_avl[2] = {  ST_LSM6DSX_ACC_FS_8G_GAIN, 0x3 },
+		.fs_avl[3] = { ST_LSM6DSX_ACC_FS_16G_GAIN, 0x1 },
+	},
+	[ST_LSM6DSX_ID_GYRO] = {
+		.reg = {
+			.addr = ST_LSM6DSX_REG_GYRO_FS_ADDR,
+			.mask = ST_LSM6DSX_REG_GYRO_FS_MASK,
+		},
+		.fs_avl[0] = {  ST_LSM6DSX_GYRO_FS_245_GAIN, 0x0 },
+		.fs_avl[1] = {  ST_LSM6DSX_GYRO_FS_500_GAIN, 0x1 },
+		.fs_avl[2] = { ST_LSM6DSX_GYRO_FS_1000_GAIN, 0x2 },
+		.fs_avl[3] = { ST_LSM6DSX_GYRO_FS_2000_GAIN, 0x3 },
+	}
+};
+
+static const struct st_lsm6dsx_settings st_lsm6dsx_sensor_settings[] = {
+	{
+		.wai = ST_LSM6DS3_WHOAMI,
+		.max_fifo_size = ST_LSM6DS3_MAX_FIFO_SIZE,
+		.id = ST_LSM6DS3_ID,
+	},
+	{
+		.wai = ST_LSM6DSM_WHOAMI,
+		.max_fifo_size = ST_LSM6DSM_MAX_FIFO_SIZE,
+		.id = ST_LSM6DSM_ID,
+	},
+};
+
+#define ST_LSM6DSX_CHANNEL(chan_type, addr, mod, scan_idx)		\
+{									\
+	.type = chan_type,						\
+	.address = addr,						\
+	.modified = 1,							\
+	.channel2 = mod,						\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |			\
+			      BIT(IIO_CHAN_INFO_SCALE),			\
+	.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),	\
+	.scan_index = scan_idx,						\
+	.scan_type = {							\
+		.sign = 's',						\
+		.realbits = 16,						\
+		.storagebits = 16,					\
+		.endianness = IIO_LE,					\
+	},								\
+}
+
+static const struct iio_chan_spec st_lsm6dsx_acc_channels[] = {
+	ST_LSM6DSX_CHANNEL(IIO_ACCEL, ST_LSM6DSX_REG_ACC_OUT_X_L_ADDR,
+			   IIO_MOD_X, 0),
+	ST_LSM6DSX_CHANNEL(IIO_ACCEL, ST_LSM6DSX_REG_ACC_OUT_Y_L_ADDR,
+			   IIO_MOD_Y, 1),
+	ST_LSM6DSX_CHANNEL(IIO_ACCEL, ST_LSM6DSX_REG_ACC_OUT_Z_L_ADDR,
+			   IIO_MOD_Z, 2),
+	IIO_CHAN_SOFT_TIMESTAMP(3),
+};
+
+static const struct iio_chan_spec st_lsm6dsx_gyro_channels[] = {
+	ST_LSM6DSX_CHANNEL(IIO_ANGL_VEL, ST_LSM6DSX_REG_GYRO_OUT_X_L_ADDR,
+			   IIO_MOD_X, 0),
+	ST_LSM6DSX_CHANNEL(IIO_ANGL_VEL, ST_LSM6DSX_REG_GYRO_OUT_Y_L_ADDR,
+			   IIO_MOD_Y, 1),
+	ST_LSM6DSX_CHANNEL(IIO_ANGL_VEL, ST_LSM6DSX_REG_GYRO_OUT_Z_L_ADDR,
+			   IIO_MOD_Z, 2),
+	IIO_CHAN_SOFT_TIMESTAMP(3),
+};
+
+int st_lsm6dsx_write_with_mask(struct st_lsm6dsx_hw *hw, u8 addr, u8 mask,
+			       u8 val)
+{
+	u8 data;
+	int err;
+
+	mutex_lock(&hw->lock);
+
+	err = hw->tf->read(hw->dev, addr, sizeof(data), &data);
+	if (err < 0) {
+		dev_err(hw->dev, "failed to read %02x register\n", addr);
+		goto out;
+	}
+
+	data = (data & ~mask) | ((val << __ffs(mask)) & mask);
+
+	err = hw->tf->write(hw->dev, addr, sizeof(data), &data);
+	if (err < 0)
+		dev_err(hw->dev, "failed to write %02x register\n", addr);
+
+out:
+	mutex_unlock(&hw->lock);
+
+	return err;
+}
+
+static int st_lsm6dsx_check_whoami(struct st_lsm6dsx_hw *hw, int id)
+{
+	int err, i;
+	u8 data;
+
+	for (i = 0; i < ARRAY_SIZE(st_lsm6dsx_sensor_settings); i++) {
+		if (id == st_lsm6dsx_sensor_settings[i].id)
+			break;
+	}
+
+	if (i == ARRAY_SIZE(st_lsm6dsx_sensor_settings)) {
+		dev_err(hw->dev, "unsupported hw id [%02x]\n", id);
+		return -ENODEV;
+	}
+
+	err = hw->tf->read(hw->dev, ST_LSM6DSX_REG_WHOAMI_ADDR, sizeof(data),
+			   &data);
+	if (err < 0) {
+		dev_err(hw->dev, "failed to read whoami register\n");
+		return err;
+	}
+
+	if (data != st_lsm6dsx_sensor_settings[i].wai) {
+		dev_err(hw->dev, "unsupported whoami [%02x]\n", data);
+		return -ENODEV;
+	}
+
+	hw->settings = &st_lsm6dsx_sensor_settings[i];
+
+	return 0;
+}
+
+static int st_lsm6dsx_set_full_scale(struct st_lsm6dsx_sensor *sensor,
+				     u32 gain)
+{
+	enum st_lsm6dsx_sensor_id id = sensor->id;
+	int i, err;
+	u8 val;
+
+	for (i = 0; i < ST_LSM6DSX_FS_LIST_SIZE; i++)
+		if (st_lsm6dsx_fs_table[id].fs_avl[i].gain == gain)
+			break;
+
+	if (i == ST_LSM6DSX_FS_LIST_SIZE)
+		return -EINVAL;
+
+	val = st_lsm6dsx_fs_table[id].fs_avl[i].val;
+	err = st_lsm6dsx_write_with_mask(sensor->hw,
+					 st_lsm6dsx_fs_table[id].reg.addr,
+					 st_lsm6dsx_fs_table[id].reg.mask,
+					 val);
+	if (err < 0)
+		return err;
+
+	sensor->gain = gain;
+
+	return 0;
+}
+
+static int st_lsm6dsx_set_odr(struct st_lsm6dsx_sensor *sensor, u16 odr)
+{
+	enum st_lsm6dsx_sensor_id id = sensor->id;
+	int i, err;
+	u8 val;
+
+	for (i = 0; i < ST_LSM6DSX_ODR_LIST_SIZE; i++)
+		if (st_lsm6dsx_odr_table[id].odr_avl[i].hz == odr)
+			break;
+
+	if (i == ST_LSM6DSX_ODR_LIST_SIZE)
+		return -EINVAL;
+
+	val = st_lsm6dsx_odr_table[id].odr_avl[i].val;
+	err = st_lsm6dsx_write_with_mask(sensor->hw,
+					 st_lsm6dsx_odr_table[id].reg.addr,
+					 st_lsm6dsx_odr_table[id].reg.mask,
+					 val);
+	if (err < 0)
+		return err;
+
+	sensor->odr = odr;
+
+	return 0;
+}
+
+int st_lsm6dsx_sensor_enable(struct st_lsm6dsx_sensor *sensor)
+{
+	int err;
+
+	err = st_lsm6dsx_set_odr(sensor, sensor->odr);
+	if (err < 0)
+		return err;
+
+	sensor->hw->enable_mask |= BIT(sensor->id);
+
+	return 0;
+}
+
+int st_lsm6dsx_sensor_disable(struct st_lsm6dsx_sensor *sensor)
+{
+	enum st_lsm6dsx_sensor_id id = sensor->id;
+	int err;
+
+	err = st_lsm6dsx_write_with_mask(sensor->hw,
+					 st_lsm6dsx_odr_table[id].reg.addr,
+					 st_lsm6dsx_odr_table[id].reg.mask, 0);
+	if (err < 0)
+		return err;
+
+	sensor->hw->enable_mask &= ~BIT(id);
+
+	return 0;
+}
+
+static int st_lsm6dsx_read_oneshot(struct st_lsm6dsx_sensor *sensor,
+				   u8 addr, int *val)
+{
+	int err, delay;
+	__le16 data;
+
+	err = st_lsm6dsx_sensor_enable(sensor);
+	if (err < 0)
+		return err;
+
+	delay = 1000000 / sensor->odr;
+	usleep_range(delay, 2 * delay);
+
+	err = sensor->hw->tf->read(sensor->hw->dev, addr, sizeof(data),
+				   (u8 *)&data);
+	if (err < 0)
+		return err;
+
+	st_lsm6dsx_sensor_disable(sensor);
+
+	*val = (s16)data;
+
+	return IIO_VAL_INT;
+}
+
+static int st_lsm6dsx_read_raw(struct iio_dev *iio_dev,
+			       struct iio_chan_spec const *ch,
+			       int *val, int *val2, long mask)
+{
+	struct st_lsm6dsx_sensor *sensor = iio_priv(iio_dev);
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		ret = iio_device_claim_direct_mode(iio_dev);
+		if (ret)
+			break;
+
+		ret = st_lsm6dsx_read_oneshot(sensor, ch->address, val);
+		iio_device_release_direct_mode(iio_dev);
+		break;
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		*val = sensor->odr;
+		ret = IIO_VAL_INT;
+		break;
+	case IIO_CHAN_INFO_SCALE:
+		*val = 0;
+		*val2 = sensor->gain;
+		ret = IIO_VAL_INT_PLUS_MICRO;
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	return ret;
+}
+
+static int st_lsm6dsx_write_raw(struct iio_dev *iio_dev,
+				struct iio_chan_spec const *chan,
+				int val, int val2, long mask)
+{
+	struct st_lsm6dsx_sensor *sensor = iio_priv(iio_dev);
+	int err;
+
+	err = iio_device_claim_direct_mode(iio_dev);
+	if (err)
+		return err;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_SCALE:
+		err = st_lsm6dsx_set_full_scale(sensor, val2);
+		break;
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		err = st_lsm6dsx_set_odr(sensor, val);
+		break;
+	default:
+		err = -EINVAL;
+		break;
+	}
+
+	iio_device_release_direct_mode(iio_dev);
+
+	return err;
+}
+
+static int st_lsm6dsx_set_watermark(struct iio_dev *iio_dev, unsigned int val)
+{
+	struct st_lsm6dsx_sensor *sensor = iio_priv(iio_dev);
+	struct st_lsm6dsx_hw *hw = sensor->hw;
+	int err, max_fifo_len;
+
+	max_fifo_len = hw->settings->max_fifo_size / ST_LSM6DSX_SAMPLE_SIZE;
+	if (val < 1 || val > max_fifo_len)
+		return -EINVAL;
+
+	err = st_lsm6dsx_update_watermark(sensor, val);
+	if (err < 0)
+		return err;
+
+	sensor->watermark = val;
+
+	return 0;
+}
+
+static ssize_t
+st_lsm6dsx_sysfs_sampling_frequency_avail(struct device *dev,
+					  struct device_attribute *attr,
+					  char *buf)
+{
+	struct st_lsm6dsx_sensor *sensor = iio_priv(dev_get_drvdata(dev));
+	enum st_lsm6dsx_sensor_id id = sensor->id;
+	int i, len = 0;
+
+	for (i = 0; i < ST_LSM6DSX_ODR_LIST_SIZE; i++)
+		len += scnprintf(buf + len, PAGE_SIZE - len, "%d ",
+				 st_lsm6dsx_odr_table[id].odr_avl[i].hz);
+	buf[len - 1] = '\n';
+
+	return len;
+}
+
+static ssize_t st_lsm6dsx_sysfs_scale_avail(struct device *dev,
+					    struct device_attribute *attr,
+					    char *buf)
+{
+	struct st_lsm6dsx_sensor *sensor = iio_priv(dev_get_drvdata(dev));
+	enum st_lsm6dsx_sensor_id id = sensor->id;
+	int i, len = 0;
+
+	for (i = 0; i < ST_LSM6DSX_FS_LIST_SIZE; i++)
+		len += scnprintf(buf + len, PAGE_SIZE - len, "0.%06u ",
+				 st_lsm6dsx_fs_table[id].fs_avl[i].gain);
+	buf[len - 1] = '\n';
+
+	return len;
+}
+
+static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(st_lsm6dsx_sysfs_sampling_frequency_avail);
+static IIO_DEVICE_ATTR(in_accel_scale_available, 0444,
+		       st_lsm6dsx_sysfs_scale_avail, NULL, 0);
+static IIO_DEVICE_ATTR(in_anglvel_scale_available, 0444,
+		       st_lsm6dsx_sysfs_scale_avail, NULL, 0);
+
+static struct attribute *st_lsm6dsx_acc_attributes[] = {
+	&iio_dev_attr_sampling_frequency_available.dev_attr.attr,
+	&iio_dev_attr_in_accel_scale_available.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group st_lsm6dsx_acc_attribute_group = {
+	.attrs = st_lsm6dsx_acc_attributes,
+};
+
+static const struct iio_info st_lsm6dsx_acc_info = {
+	.driver_module = THIS_MODULE,
+	.attrs = &st_lsm6dsx_acc_attribute_group,
+	.read_raw = st_lsm6dsx_read_raw,
+	.write_raw = st_lsm6dsx_write_raw,
+	.hwfifo_set_watermark = st_lsm6dsx_set_watermark,
+};
+
+static struct attribute *st_lsm6dsx_gyro_attributes[] = {
+	&iio_dev_attr_sampling_frequency_available.dev_attr.attr,
+	&iio_dev_attr_in_anglvel_scale_available.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group st_lsm6dsx_gyro_attribute_group = {
+	.attrs = st_lsm6dsx_gyro_attributes,
+};
+
+static const struct iio_info st_lsm6dsx_gyro_info = {
+	.driver_module = THIS_MODULE,
+	.attrs = &st_lsm6dsx_gyro_attribute_group,
+	.read_raw = st_lsm6dsx_read_raw,
+	.write_raw = st_lsm6dsx_write_raw,
+	.hwfifo_set_watermark = st_lsm6dsx_set_watermark,
+};
+
+static const unsigned long st_lsm6dsx_available_scan_masks[] = {0x7, 0x0};
+
+static int st_lsm6dsx_init_device(struct st_lsm6dsx_hw *hw)
+{
+	int err;
+	u8 data;
+
+	data = ST_LSM6DSX_REG_RESET_MASK;
+	err = hw->tf->write(hw->dev, ST_LSM6DSX_REG_RESET_ADDR, sizeof(data),
+			    &data);
+	if (err < 0)
+		return err;
+
+	msleep(200);
+
+	/* latch interrupts */
+	err = st_lsm6dsx_write_with_mask(hw, ST_LSM6DSX_REG_LIR_ADDR,
+					 ST_LSM6DSX_REG_LIR_MASK, 1);
+	if (err < 0)
+		return err;
+
+	/* enable Block Data Update */
+	err = st_lsm6dsx_write_with_mask(hw, ST_LSM6DSX_REG_BDU_ADDR,
+					 ST_LSM6DSX_REG_BDU_MASK, 1);
+	if (err < 0)
+		return err;
+
+	err = st_lsm6dsx_write_with_mask(hw, ST_LSM6DSX_REG_ROUNDING_ADDR,
+					 ST_LSM6DSX_REG_ROUNDING_MASK, 1);
+	if (err < 0)
+		return err;
+
+	/* enable FIFO watermak interrupt */
+	err = st_lsm6dsx_write_with_mask(hw, ST_LSM6DSX_REG_INT1_ADDR,
+					 ST_LSM6DSX_REG_FIFO_FTH_IRQ_MASK, 1);
+	if (err < 0)
+		return err;
+
+	/* redirect INT2 on INT1 */
+	return st_lsm6dsx_write_with_mask(hw, ST_LSM6DSX_REG_INT2_ON_INT1_ADDR,
+					  ST_LSM6DSX_REG_INT2_ON_INT1_MASK, 1);
+}
+
+static struct iio_dev *st_lsm6dsx_alloc_iiodev(struct st_lsm6dsx_hw *hw,
+					       enum st_lsm6dsx_sensor_id id)
+{
+	struct st_lsm6dsx_sensor *sensor;
+	struct iio_dev *iio_dev;
+
+	iio_dev = devm_iio_device_alloc(hw->dev, sizeof(*sensor));
+	if (!iio_dev)
+		return NULL;
+
+	iio_dev->modes = INDIO_DIRECT_MODE;
+	iio_dev->dev.parent = hw->dev;
+	iio_dev->available_scan_masks = st_lsm6dsx_available_scan_masks;
+
+	sensor = iio_priv(iio_dev);
+	sensor->id = id;
+	sensor->hw = hw;
+	sensor->odr = st_lsm6dsx_odr_table[id].odr_avl[0].hz;
+	sensor->gain = st_lsm6dsx_fs_table[id].fs_avl[0].gain;
+	sensor->watermark = 1;
+
+	switch (id) {
+	case ST_LSM6DSX_ID_ACC:
+		iio_dev->channels = st_lsm6dsx_acc_channels;
+		iio_dev->num_channels = ARRAY_SIZE(st_lsm6dsx_acc_channels);
+		iio_dev->name = "lsm6dsx_accel";
+		iio_dev->info = &st_lsm6dsx_acc_info;
+
+		sensor->decimator_mask = ST_LSM6DSX_REG_ACC_DEC_MASK;
+		break;
+	case ST_LSM6DSX_ID_GYRO:
+		iio_dev->channels = st_lsm6dsx_gyro_channels;
+		iio_dev->num_channels = ARRAY_SIZE(st_lsm6dsx_gyro_channels);
+		iio_dev->name = "lsm6dsx_gyro";
+		iio_dev->info = &st_lsm6dsx_gyro_info;
+
+		sensor->decimator_mask = ST_LSM6DSX_REG_GYRO_DEC_MASK;
+		break;
+	default:
+		return NULL;
+	}
+
+	return iio_dev;
+}
+
+int st_lsm6dsx_probe(struct device *dev, int irq, int hw_id,
+		     const struct st_lsm6dsx_transfer_function *tf_ops)
+{
+	struct st_lsm6dsx_hw *hw;
+	int i, err;
+
+	hw = devm_kzalloc(dev, sizeof(*hw), GFP_KERNEL);
+	if (!hw)
+		return -ENOMEM;
+
+	dev_set_drvdata(dev, (void *)hw);
+
+	mutex_init(&hw->lock);
+	mutex_init(&hw->fifo_lock);
+
+	hw->dev = dev;
+	hw->irq = irq;
+	hw->tf = tf_ops;
+
+	err = st_lsm6dsx_check_whoami(hw, hw_id);
+	if (err < 0)
+		return err;
+
+	for (i = 0; i < ST_LSM6DSX_ID_MAX; i++) {
+		hw->iio_devs[i] = st_lsm6dsx_alloc_iiodev(hw, i);
+		if (!hw->iio_devs[i])
+			return -ENOMEM;
+	}
+
+	err = st_lsm6dsx_init_device(hw);
+	if (err < 0)
+		return err;
+
+	if (hw->irq > 0) {
+		err = st_lsm6dsx_fifo_setup(hw);
+		if (err < 0)
+			return err;
+	}
+
+	for (i = 0; i < ST_LSM6DSX_ID_MAX; i++) {
+		err = devm_iio_device_register(hw->dev, hw->iio_devs[i]);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(st_lsm6dsx_probe);
+
+MODULE_AUTHOR("Lorenzo Bianconi <[e-mail]>");
+MODULE_AUTHOR("Denis Ciocca <[e-mail]>");
+MODULE_DESCRIPTION("STMicroelectronics st_lsm6dsx driver");
+MODULE_LICENSE("GPL v2");

drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_i2c.c

···
+/*
+ * STMicroelectronics st_lsm6dsx i2c driver
+ *
+ * Copyright 2016 STMicroelectronics Inc.
+ *
+ * Lorenzo Bianconi <[e-mail]>
+ * Denis Ciocca <[e-mail]>
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+
+#include "st_lsm6dsx.h"
+
+static int st_lsm6dsx_i2c_read(struct device *dev, u8 addr, int len, u8 *data)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct i2c_msg msg[2];
+
+	msg[0].addr = client->addr;
+	msg[0].flags = client->flags;
+	msg[0].len = 1;
+	msg[0].buf = &addr;
+
+	msg[1].addr = client->addr;
+	msg[1].flags = client->flags | I2C_M_RD;
+	msg[1].len = len;
+	msg[1].buf = data;
+
+	return i2c_transfer(client->adapter, msg, 2);
+}
+
+static int st_lsm6dsx_i2c_write(struct device *dev, u8 addr, int len, u8 *data)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct i2c_msg msg;
+	u8 send[len + 1];
+
+	send[0] = addr;
+	memcpy(&send[1], data, len * sizeof(u8));
+
+	msg.addr = client->addr;
+	msg.flags = client->flags;
+	msg.len = len + 1;
+	msg.buf = send;
+
+	return i2c_transfer(client->adapter, &msg, 1);
+}
+
+static const struct st_lsm6dsx_transfer_function st_lsm6dsx_transfer_fn = {
+	.read = st_lsm6dsx_i2c_read,
+	.write = st_lsm6dsx_i2c_write,
+};
+
+static int st_lsm6dsx_i2c_probe(struct i2c_client *client,
+				const struct i2c_device_id *id)
+{
+	return st_lsm6dsx_probe(&client->dev, client->irq,
+				(int)id->driver_data,
+				&st_lsm6dsx_transfer_fn);
+}
+
+static const struct of_device_id st_lsm6dsx_i2c_of_match[] = {
+	{
+		.compatible = "st,lsm6ds3",
+		.data = (void *)ST_LSM6DS3_ID,
+	},
+	{
+		.compatible = "st,lsm6dsm",
+		.data = (void *)ST_LSM6DSM_ID,
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, st_lsm6dsx_i2c_of_match);
+
+static const struct i2c_device_id st_lsm6dsx_i2c_id_table[] = {
+	{ ST_LSM6DS3_DEV_NAME, ST_LSM6DS3_ID },
+	{ ST_LSM6DSM_DEV_NAME, ST_LSM6DSM_ID },
+	{},
+};
+MODULE_DEVICE_TABLE(i2c, st_lsm6dsx_i2c_id_table);
+
+static struct i2c_driver st_lsm6dsx_driver = {
+	.driver = {
+		.name = "st_lsm6dsx_i2c",
+		.of_match_table = of_match_ptr(st_lsm6dsx_i2c_of_match),
+	},
+	.probe = st_lsm6dsx_i2c_probe,
+	.id_table = st_lsm6dsx_i2c_id_table,
+};
+module_i2c_driver(st_lsm6dsx_driver);
+
+MODULE_AUTHOR("Lorenzo Bianconi <[e-mail]>");
+MODULE_AUTHOR("Denis Ciocca <[e-mail]>");
+MODULE_DESCRIPTION("STMicroelectronics st_lsm6dsx i2c driver");
+MODULE_LICENSE("GPL v2");

drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_spi.c

···
+/*
+ * STMicroelectronics st_lsm6dsx spi driver
+ *
+ * Copyright 2016 STMicroelectronics Inc.
+ *
+ * Lorenzo Bianconi <[e-mail]>
+ * Denis Ciocca <[e-mail]>
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/spi/spi.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+
+#include "st_lsm6dsx.h"
+
+#define SENSORS_SPI_READ	BIT(7)
+
+static int st_lsm6dsx_spi_read(struct device *dev, u8 addr, int len,
+			       u8 *data)
+{
+	struct spi_device *spi = to_spi_device(dev);
+	struct st_lsm6dsx_hw *hw = spi_get_drvdata(spi);
+	int err;
+
+	struct spi_transfer xfers[] = {
+		{
+			.tx_buf = hw->tb.tx_buf,
+			.bits_per_word = 8,
+			.len = 1,
+		},
+		{
+			.rx_buf = hw->tb.rx_buf,
+			.bits_per_word = 8,
+			.len = len,
+		}
+	};
+
+	hw->tb.tx_buf[0] = addr | SENSORS_SPI_READ;
+
+	err = spi_sync_transfer(spi, xfers,  ARRAY_SIZE(xfers));
+	if (err < 0)
+		return err;
+
+	memcpy(data, hw->tb.rx_buf, len * sizeof(u8));
+
+	return len;
+}
+
+static int st_lsm6dsx_spi_write(struct device *dev, u8 addr, int len,
+				u8 *data)
+{
+	struct st_lsm6dsx_hw *hw;
+	struct spi_device *spi;
+
+	if (len >= ST_LSM6DSX_TX_MAX_LENGTH)
+		return -ENOMEM;
+
+	spi = to_spi_device(dev);
+	hw = spi_get_drvdata(spi);
+
+	hw->tb.tx_buf[0] = addr;
+	memcpy(&hw->tb.tx_buf[1], data, len);
+
+	return spi_write(spi, hw->tb.tx_buf, len + 1);
+}
+
+static const struct st_lsm6dsx_transfer_function st_lsm6dsx_transfer_fn = {
+	.read = st_lsm6dsx_spi_read,
+	.write = st_lsm6dsx_spi_write,
+};
+
+static int st_lsm6dsx_spi_probe(struct spi_device *spi)
+{
+	const struct spi_device_id *id = spi_get_device_id(spi);
+
+	return st_lsm6dsx_probe(&spi->dev, spi->irq,
+				(int)id->driver_data,
+				&st_lsm6dsx_transfer_fn);
+}
+
+static const struct of_device_id st_lsm6dsx_spi_of_match[] = {
+	{
+		.compatible = "st,lsm6ds3",
+		.data = (void *)ST_LSM6DS3_ID,
+	},
+	{
+		.compatible = "st,lsm6dsm",
+		.data = (void *)ST_LSM6DSM_ID,
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, st_lsm6dsx_spi_of_match);
+
+static const struct spi_device_id st_lsm6dsx_spi_id_table[] = {
+	{ ST_LSM6DS3_DEV_NAME, ST_LSM6DS3_ID },
+	{ ST_LSM6DSM_DEV_NAME, ST_LSM6DSM_ID },
+	{},
+};
+MODULE_DEVICE_TABLE(spi, st_lsm6dsx_spi_id_table);
+
+static struct spi_driver st_lsm6dsx_driver = {
+	.driver = {
+		.name = "st_lsm6dsx_spi",
+		.of_match_table = of_match_ptr(st_lsm6dsx_spi_of_match),
+	},
+	.probe = st_lsm6dsx_spi_probe,
+	.id_table = st_lsm6dsx_spi_id_table,
+};
+module_spi_driver(st_lsm6dsx_driver);
+
+MODULE_AUTHOR("Lorenzo Bianconi <[e-mail]>");
+MODULE_AUTHOR("Denis Ciocca <[e-mail]>");
+MODULE_DESCRIPTION("STMicroelectronics st_lsm6dsx spi driver");
+MODULE_LICENSE("GPL v2");

drivers/iio/industrialio-trigger.c

···
 	return NULL;
 }
 
-static struct iio_trigger *iio_trigger_find_by_name(const char *name,
-						    size_t len)
+static struct iio_trigger *iio_trigger_acquire_by_name(const char *name)
 {
 	struct iio_trigger *trig = NULL, *iter;
 
···
 	list_for_each_entry(iter, &iio_trigger_list, list)
 		if (sysfs_streq(iter->name, name)) {
 			trig = iter;
+			iio_trigger_get(trig);
 			break;
 		}
 	mutex_unlock(&iio_trigger_list_lock);
···
 	}
 	mutex_unlock(&indio_dev->mlock);
 
-	trig = iio_trigger_find_by_name(buf, len);
-	if (oldtrig == trig)
-		return len;
+	trig = iio_trigger_acquire_by_name(buf);
+	if (oldtrig == trig) {
+		ret = len;
+		goto out_trigger_put;
+	}
 
 	if (trig && indio_dev->info->validate_trigger) {
 		ret = indio_dev->info->validate_trigger(indio_dev, trig);
 		if (ret)
-			return ret;
+			goto out_trigger_put;
 	}
 
 	if (trig && trig->ops->validate_device) {
 		ret = trig->ops->validate_device(trig, indio_dev);
 		if (ret)
-			return ret;
+			goto out_trigger_put;
 	}
 
 	indio_dev->trig = trig;
···
 		iio_trigger_put(oldtrig);
 	}
 	if (indio_dev->trig) {
-		iio_trigger_get(indio_dev->trig);
 		if (indio_dev->modes & INDIO_EVENT_TRIGGERED)
 			iio_trigger_attach_poll_func(indio_dev->trig,
 						     indio_dev->pollfunc_event);
 	}
 
 	return len;
+
+out_trigger_put:
+	iio_trigger_put(trig);
+	return ret;
 }
 
 static DEVICE_ATTR(current_trigger, S_IRUGO | S_IWUSR,
···
 	kfree(trig);
 }
 
-static struct device_type iio_trig_type = {
+static const struct device_type iio_trig_type = {
 	.release = iio_trig_release,
 	.groups = iio_trig_dev_groups,
 };
···
 static struct iio_trigger *viio_trigger_alloc(const char *fmt, va_list vargs)
 {
 	struct iio_trigger *trig;
+	int i;
+
 	trig = kzalloc(sizeof *trig, GFP_KERNEL);
-	if (trig) {
-		int i;
-		trig->dev.type = &iio_trig_type;
-		trig->dev.bus = &iio_bus_type;
-		device_initialize(&trig->dev);
+	if (!trig)
+		return NULL;
 
-		mutex_init(&trig->pool_lock);
-		trig->subirq_base
-			= irq_alloc_descs(-1, 0,
-					  CONFIG_IIO_CONSUMERS_PER_TRIGGER,
-					  0);
-		if (trig->subirq_base < 0) {
-			kfree(trig);
-			return NULL;
-		}
+	trig->dev.type = &iio_trig_type;
+	trig->dev.bus = &iio_bus_type;
+	device_initialize(&trig->dev);
 
-		trig->name = kvasprintf(GFP_KERNEL, fmt, vargs);
-		if (trig->name == NULL) {
-			irq_free_descs(trig->subirq_base,
-				       CONFIG_IIO_CONSUMERS_PER_TRIGGER);
-			kfree(trig);
-			return NULL;
-		}
-		trig->subirq_chip.name = trig->name;
-		trig->subirq_chip.irq_mask = &iio_trig_subirqmask;
-		trig->subirq_chip.irq_unmask = &iio_trig_subirqunmask;
-		for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
-			irq_set_chip(trig->subirq_base + i,
-				     &trig->subirq_chip);
-			irq_set_handler(trig->subirq_base + i,
-					&handle_simple_irq);
-			irq_modify_status(trig->subirq_base + i,
-					  IRQ_NOREQUEST | IRQ_NOAUTOEN,
-					  IRQ_NOPROBE);
-		}
-		get_device(&trig->dev);
+	mutex_init(&trig->pool_lock);
+	trig->subirq_base = irq_alloc_descs(-1, 0,
+					    CONFIG_IIO_CONSUMERS_PER_TRIGGER,
+					    0);
+	if (trig->subirq_base < 0)
+		goto free_trig;
+
+	trig->name = kvasprintf(GFP_KERNEL, fmt, vargs);
+	if (trig->name == NULL)
+		goto free_descs;
+
+	trig->subirq_chip.name = trig->name;
+	trig->subirq_chip.irq_mask = &iio_trig_subirqmask;
+	trig->subirq_chip.irq_unmask = &iio_trig_subirqunmask;
+	for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
+		irq_set_chip(trig->subirq_base + i, &trig->subirq_chip);
+		irq_set_handler(trig->subirq_base + i, &handle_simple_irq);
+		irq_modify_status(trig->subirq_base + i,
+				  IRQ_NOREQUEST | IRQ_NOAUTOEN, IRQ_NOPROBE);
 	}
+	get_device(&trig->dev);
 
 	return trig;
+
+free_descs:
+	irq_free_descs(trig->subirq_base, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
+free_trig:
+	kfree(trig);
+	return NULL;
 }
 
 struct iio_trigger *iio_trigger_alloc(const char *fmt, ...)

drivers/iio/inkern.c

···
 
 	scale_type = iio_channel_read(chan, &scale_val, &scale_val2,
 					IIO_CHAN_INFO_SCALE);
-	if (scale_type < 0)
-		return scale_type;
+	if (scale_type < 0) {
+		/*
+		 * Just pass raw values as processed if no scaling is
+		 * available.
+		 */
+		*processed = raw;
+		return 0;
+	}
 
 	switch (scale_type) {
 	case IIO_VAL_INT:

drivers/iio/light/cm3605.c

···
 	return 0;
 }
 
-static int cm3605_pm_suspend(struct device *dev)
+static int __maybe_unused cm3605_pm_suspend(struct device *dev)
 {
 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
 	struct cm3605 *cm3605 = iio_priv(indio_dev);
···
 	return 0;
 }
 
-static int cm3605_pm_resume(struct device *dev)
+static int __maybe_unused cm3605_pm_resume(struct device *dev)
 {
 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
 	struct cm3605 *cm3605 = iio_priv(indio_dev);

drivers/iio/light/opt3001.c

···
 	{ .compatible = "ti,opt3001" },
 	{ }
 };
+MODULE_DEVICE_TABLE(of, opt3001_of_match);
 
 static struct i2c_driver opt3001_driver = {
 	.probe = opt3001_probe,

drivers/iio/magnetometer/ak8974.c

···
 		if (val & AK8974_STATUS_DRDY)
 			return 0;
 	} while (--timeout);
-	if (!timeout) {
-		dev_err(&ak8974->i2c->dev,
-			"timeout waiting for DRDY\n");
-		return -ETIMEDOUT;
-	}
 
-	return 0;
+	dev_err(&ak8974->i2c->dev, "timeout waiting for DRDY\n");
+	return -ETIMEDOUT;
 }
 
 static int ak8974_getresult(struct ak8974 *ak8974, __le16 *result)

drivers/iio/magnetometer/mag3110.c

···
 			     int val, int val2, long mask)
 {
 	struct mag3110_data *data = iio_priv(indio_dev);
-	int rate;
+	int rate, ret;
 
-	if (iio_buffer_enabled(indio_dev))
-		return -EBUSY;
+	ret = iio_device_claim_direct_mode(indio_dev);
+	if (ret)
+		return ret;
 
 	switch (mask) {
 	case IIO_CHAN_INFO_SAMP_FREQ:
 		rate = mag3110_get_samp_freq_index(data, val, val2);
-		if (rate < 0)
-			return -EINVAL;
+		if (rate < 0) {
+			ret = -EINVAL;
+			break;
+		}
 
 		data->ctrl_reg1 &= ~MAG3110_CTRL_DR_MASK;
 		data->ctrl_reg1 |= rate << MAG3110_CTRL_DR_SHIFT;
-		return i2c_smbus_write_byte_data(data->client,
+		ret = i2c_smbus_write_byte_data(data->client,
 			MAG3110_CTRL_REG1, data->ctrl_reg1);
+		break;
 	case IIO_CHAN_INFO_CALIBBIAS:
-		if (val < -10000 || val > 10000)
-			return -EINVAL;
-		return i2c_smbus_write_word_swapped(data->client,
+		if (val < -10000 || val > 10000) {
+			ret = -EINVAL;
+			break;
+		}
+		ret = i2c_smbus_write_word_swapped(data->client,
 			MAG3110_OFF_X + 2 * chan->scan_index, val << 1);
+		break;
 	default:
-		return -EINVAL;
+		ret = -EINVAL;
+		break;
 	}
+	iio_device_release_direct_mode(indio_dev);
+	return ret;
 }
 
 static irqreturn_t mag3110_trigger_handler(int irq, void *p)

drivers/iio/potentiometer/mcp4531.c

···
 	MCP4531_COMPATIBLE("microchip,mcp4662-104", MCP466x_104),
 	{ /* sentinel */ }
 };
+MODULE_DEVICE_TABLE(of, mcp4531_of_match);
 #endif
 
 static int mcp4531_probe(struct i2c_client *client,

drivers/iio/pressure/ms5611_core.c

···
 {
 	struct ms5611_state *st = iio_priv(indio_dev);
 	const struct ms5611_osr *osr = NULL;
+	int ret;
 
 	if (mask != IIO_CHAN_INFO_OVERSAMPLING_RATIO)
 		return -EINVAL;
···
 	if (!osr)
 		return -EINVAL;
 
-	mutex_lock(&st->lock);
+	ret = iio_device_claim_direct_mode(indio_dev);
+	if (ret)
+		return ret;
 
-	if (iio_buffer_enabled(indio_dev)) {
-		mutex_unlock(&st->lock);
-		return -EBUSY;
-	}
+	mutex_lock(&st->lock);
 
 	if (chan->type == IIO_TEMP)
 		st->temp_osr = osr;
···
 		st->pressure_osr = osr;
 
 	mutex_unlock(&st->lock);
+	iio_device_release_direct_mode(indio_dev);
+
 	return 0;
 }
 

drivers/iio/proximity/sx9500.c

···
 			   int *val, int *val2, long mask)
 {
 	struct sx9500_data *data = iio_priv(indio_dev);
+	int ret;
 
 	switch (chan->type) {
 	case IIO_PROXIMITY:
 		switch (mask) {
 		case IIO_CHAN_INFO_RAW:
-			if (iio_buffer_enabled(indio_dev))
-				return -EBUSY;
-			return sx9500_read_proximity(data, chan, val);
+			ret = iio_device_claim_direct_mode(indio_dev);
+			if (ret)
+				return ret;
+			ret = sx9500_read_proximity(data, chan, val);
+			iio_device_release_direct_mode(indio_dev);
+			return ret;
 		case IIO_CHAN_INFO_SAMP_FREQ:
 			return sx9500_read_samp_freq(data, val, val2);
 		default:

drivers/iio/temperature/Kconfig

···
 	  This driver can also be built as a module. If so, the module will
 	  be called tmp006.
 
+config TMP007
+        tristate "TMP007 infrared thermopile sensor with Integrated Math Engine"
+        depends on I2C
+        help
+          If you say yes here you get support for the Texas Instruments
+          TMP007 infrared thermopile sensor with Integrated Math Engine.
+
+          This driver can also be built as a module. If so, the module will
+          be called tmp007.
+
 config TSYS01
 	tristate "Measurement Specialties TSYS01 temperature sensor using I2C bus connection"
 	depends on I2C

drivers/iio/temperature/Makefile

···
 obj-$(CONFIG_MAXIM_THERMOCOUPLE) += maxim_thermocouple.o
 obj-$(CONFIG_MLX90614) += mlx90614.o
 obj-$(CONFIG_TMP006) += tmp006.o
+obj-$(CONFIG_TMP007) += tmp007.o
 obj-$(CONFIG_TSYS01) += tsys01.o
 obj-$(CONFIG_TSYS02D) += tsys02d.o

drivers/iio/temperature/tmp007.c

···
+/*
+ * tmp007.c - Support for TI TMP007 IR thermopile sensor with integrated math engine
+ *
+ * Copyright (c) 2017 Manivannan Sadhasivam <[e-mail]>
+ *
+ * This file is subject to the terms and conditions of version 2 of
+ * the GNU General Public License.  See the file COPYING in the main
+ * directory of this archive for more details.
+ *
+ * Driver for the Texas Instruments I2C 16-bit IR thermopile sensor
+ *
+ * (7-bit I2C slave address (0x40 - 0x47), changeable via ADR pins)
+ *
+ * Note: This driver assumes that the sensor has been calibrated beforehand
+ *
+ * TODO: ALERT irq, limit threshold events
+ *
+ */
+
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/pm.h>
+#include <linux/bitops.h>
+#include <linux/of.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#define TMP007_TDIE 0x01
+#define TMP007_CONFIG 0x02
+#define TMP007_TOBJECT 0x03
+#define TMP007_STATUS 0x04
+#define TMP007_STATUS_MASK 0x05
+#define TMP007_MANUFACTURER_ID 0x1e
+#define TMP007_DEVICE_ID 0x1f
+
+#define TMP007_CONFIG_CONV_EN BIT(12)
+#define TMP007_CONFIG_COMP_EN BIT(5)
+#define TMP007_CONFIG_TC_EN BIT(6)
+#define TMP007_CONFIG_CR_MASK GENMASK(11, 9)
+#define TMP007_CONFIG_CR_SHIFT 9
+
+#define TMP007_STATUS_CONV_READY BIT(14)
+#define TMP007_STATUS_DATA_VALID BIT(9)
+
+#define TMP007_MANUFACTURER_MAGIC 0x5449
+#define TMP007_DEVICE_MAGIC 0x0078
+
+#define TMP007_TEMP_SHIFT 2
+
+struct tmp007_data {
+	struct i2c_client *client;
+	u16 config;
+};
+
+static const int tmp007_avgs[5][2] = { {4, 0}, {2, 0}, {1, 0},
+					{0, 500000}, {0, 250000} };
+
+static int tmp007_read_temperature(struct tmp007_data *data, u8 reg)
+{
+	s32 ret;
+	int tries = 50;
+
+	while (tries-- > 0) {
+		ret = i2c_smbus_read_word_swapped(data->client,
+			TMP007_STATUS);
+		if (ret < 0)
+			return ret;
+		if ((ret & TMP007_STATUS_CONV_READY) &&
+			!(ret & TMP007_STATUS_DATA_VALID))
+				break;
+		msleep(100);
+	}
+
+	if (tries < 0)
+		return -EIO;
+
+	return i2c_smbus_read_word_swapped(data->client, reg);
+}
+
+static int tmp007_powerdown(struct tmp007_data *data)
+{
+	return i2c_smbus_write_word_swapped(data->client, TMP007_CONFIG,
+			data->config & ~TMP007_CONFIG_CONV_EN);
+}
+
+static int tmp007_read_raw(struct iio_dev *indio_dev,
+		struct iio_chan_spec const *channel, int *val,
+		int *val2, long mask)
+{
+	struct tmp007_data *data = iio_priv(indio_dev);
+	s32 ret;
+	int conv_rate;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		switch (channel->channel2) {
+		case IIO_MOD_TEMP_AMBIENT: /* LSB: 0.03125 degree Celsius */
+			ret = i2c_smbus_read_word_swapped(data->client, TMP007_TDIE);
+			if (ret < 0)
+				return ret;
+			break;
+		case IIO_MOD_TEMP_OBJECT:
+			ret = tmp007_read_temperature(data, TMP007_TOBJECT);
+			if (ret < 0)
+				return ret;
+			break;
+		default:
+			return -EINVAL;
+		}
+
+		*val = sign_extend32(ret, 15) >> TMP007_TEMP_SHIFT;
+
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		*val = 31;
+		*val2 = 250000;
+
+		return IIO_VAL_INT_PLUS_MICRO;
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		conv_rate = (data->config & TMP007_CONFIG_CR_MASK)
+				>> TMP007_CONFIG_CR_SHIFT;
+		*val = tmp007_avgs[conv_rate][0];
+		*val2 = tmp007_avgs[conv_rate][1];
+
+		return IIO_VAL_INT_PLUS_MICRO;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int tmp007_write_raw(struct iio_dev *indio_dev,
+		struct iio_chan_spec const *channel, int val,
+		int val2, long mask)
+{
+	struct tmp007_data *data = iio_priv(indio_dev);
+	int i;
+	u16 tmp;
+
+	if (mask == IIO_CHAN_INFO_SAMP_FREQ) {
+		for (i = 0; i < ARRAY_SIZE(tmp007_avgs); i++) {
+			if ((val == tmp007_avgs[i][0]) &&
+			(val2 == tmp007_avgs[i][1])) {
+				tmp = data->config & ~TMP007_CONFIG_CR_MASK;
+				tmp |= (i << TMP007_CONFIG_CR_SHIFT);
+
+				return i2c_smbus_write_word_swapped(data->client,
+								TMP007_CONFIG,
+								data->config = tmp);
+			}
+		}
+	}
+
+	return -EINVAL;
+}
+
+static IIO_CONST_ATTR(sampling_frequency_available, "4 2 1 0.5 0.25");
+
+static struct attribute *tmp007_attributes[] = {
+	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
+	NULL
+};
+
+static const struct attribute_group tmp007_attribute_group = {
+	.attrs = tmp007_attributes,
+};
+
+static const struct iio_chan_spec tmp007_channels[] = {
+	{
+		.type = IIO_TEMP,
+		.modified = 1,
+		.channel2 = IIO_MOD_TEMP_AMBIENT,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+				BIT(IIO_CHAN_INFO_SCALE),
+		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
+	},
+	{
+		.type = IIO_TEMP,
+		.modified = 1,
+		.channel2 = IIO_MOD_TEMP_OBJECT,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+				BIT(IIO_CHAN_INFO_SCALE),
+		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
+	}
+};
+
+static const struct iio_info tmp007_info = {
+	.read_raw = tmp007_read_raw,
+	.write_raw = tmp007_write_raw,
+	.attrs = &tmp007_attribute_group,
+	.driver_module = THIS_MODULE,
+};
+
+static bool tmp007_identify(struct i2c_client *client)
+{
+	int manf_id, dev_id;
+
+	manf_id = i2c_smbus_read_word_swapped(client, TMP007_MANUFACTURER_ID);
+	if (manf_id < 0)
+		return false;
+
+	dev_id = i2c_smbus_read_word_swapped(client, TMP007_DEVICE_ID);
+	if (dev_id < 0)
+		return false;
+
+	return (manf_id == TMP007_MANUFACTURER_MAGIC && dev_id == TMP007_DEVICE_MAGIC);
+}
+
+static int tmp007_probe(struct i2c_client *client,
+			const struct i2c_device_id *tmp007_id)
+{
+	struct tmp007_data *data;
+	struct iio_dev *indio_dev;
+	int ret;
+	u16  status;
+
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
+		return -EOPNOTSUPP;
+
+	if (!tmp007_identify(client)) {
+		dev_err(&client->dev, "TMP007 not found\n");
+		return -ENODEV;
+	}
+
+	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	data = iio_priv(indio_dev);
+	i2c_set_clientdata(client, indio_dev);
+	data->client = client;
+
+	indio_dev->dev.parent = &client->dev;
+	indio_dev->name = dev_name(&client->dev);
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->info = &tmp007_info;
+
+	indio_dev->channels = tmp007_channels;
+	indio_dev->num_channels = ARRAY_SIZE(tmp007_channels);
+
+	/*
+	 * Set Configuration register:
+	 * 1. Conversion ON
+	 * 2. Comparator mode
+	 * 3. Transient correction enable
+	 */
+
+	ret = i2c_smbus_read_word_swapped(data->client, TMP007_CONFIG);
+	if (ret < 0)
+		return ret;
+
+	data->config = ret;
+	data->config |= (TMP007_CONFIG_CONV_EN | TMP007_CONFIG_COMP_EN | TMP007_CONFIG_TC_EN);
+
+	ret = i2c_smbus_write_word_swapped(data->client, TMP007_CONFIG,
+					data->config);
+	if (ret < 0)
+		return ret;
+
+	/*
+	 * Set Status Mask register:
+	 * 1. Conversion ready enable
+	 * 2. Data valid enable
+	 */
+
+	ret = i2c_smbus_read_word_swapped(data->client, TMP007_STATUS_MASK);
+	if (ret < 0)
+		goto error_powerdown;
+
+	status = ret;
+	status |= (TMP007_STATUS_CONV_READY | TMP007_STATUS_DATA_VALID);
+
+	ret = i2c_smbus_write_word_swapped(data->client, TMP007_STATUS_MASK, status);
+	if (ret < 0)
+		goto error_powerdown;
+
+	return iio_device_register(indio_dev);
+
+error_powerdown:
+	tmp007_powerdown(data);
+
+	return ret;
+}
+
+static int tmp007_remove(struct i2c_client *client)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(client);
+	struct tmp007_data *data = iio_priv(indio_dev);
+
+	iio_device_unregister(indio_dev);
+	tmp007_powerdown(data);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int tmp007_suspend(struct device *dev)
+{
+	struct tmp007_data *data = iio_priv(i2c_get_clientdata(
+			to_i2c_client(dev)));
+
+	return tmp007_powerdown(data);
+}
+
+static int tmp007_resume(struct device *dev)
+{
+	struct tmp007_data *data = iio_priv(i2c_get_clientdata(
+			to_i2c_client(dev)));
+
+	return i2c_smbus_write_word_swapped(data->client, TMP007_CONFIG,
+			data->config | TMP007_CONFIG_CONV_EN);
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(tmp007_pm_ops, tmp007_suspend, tmp007_resume);
+
+static const struct of_device_id tmp007_of_match[] = {
+	{ .compatible = "ti,tmp007", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, tmp007_of_match);
+
+static const struct i2c_device_id tmp007_id[] = {
+	{ "tmp007", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, tmp007_id);
+
+static struct i2c_driver tmp007_driver = {
+	.driver = {
+		.name	= "tmp007",
+		.of_match_table = of_match_ptr(tmp007_of_match),
+		.pm	= &tmp007_pm_ops,
+	},
+	.probe		= tmp007_probe,
+	.remove		= tmp007_remove,
+	.id_table	= tmp007_id,
+};
+module_i2c_driver(tmp007_driver);
+
+MODULE_AUTHOR("Manivannan Sadhasivam <[e-mail]>");
+MODULE_DESCRIPTION("TI TMP007 IR thermopile sensor driver");
+MODULE_LICENSE("GPL");

drivers/iio/trigger/iio-trig-interrupt.c

···
 	trig_info = kzalloc(sizeof(*trig_info), GFP_KERNEL);
 	if (!trig_info) {
 		ret = -ENOMEM;
-		goto error_put_trigger;
+		goto error_free_trigger;
 	}
 	iio_trigger_set_drvdata(trig, trig_info);
 	trig_info->irq = irq;
···
 	free_irq(irq, trig);
 error_free_trig_info:
 	kfree(trig_info);
-error_put_trigger:
-	iio_trigger_put(trig);
+error_free_trigger:
+	iio_trigger_free(trig);
 error_ret:
 	return ret;
 }
···
 	iio_trigger_unregister(trig);
 	free_irq(trig_info->irq, trig);
 	kfree(trig_info);
-	iio_trigger_put(trig);
+	iio_trigger_free(trig);
 
 	return 0;
 }

drivers/iio/trigger/iio-trig-sysfs.c

···
 	return 0;
 
 out2:
-	iio_trigger_put(t->trig);
+	iio_trigger_free(t->trig);
 free_t:
 	kfree(t);
 out1:

drivers/staging/iio/light/isl29028.c

···
 #include <linux/regmap.h>
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
+#include <linux/pm_runtime.h>
 
 #define ISL29028_CONV_TIME_MS			100
 
···
 
 #define ISL29028_NUM_REGS			(ISL29028_REG_TEST2_MODE + 1)
 
+#define ISL29028_POWER_OFF_DELAY_MS		2000
+
 enum isl29028_als_ir_mode {
 	ISL29028_MODE_NONE = 0,
 	ISL29028_MODE_ALS,
···
 };
 
 struct isl29028_chip {
-	struct mutex		lock;
-	struct regmap		*regmap;
-
-	unsigned int		prox_sampling;
-	bool			enable_prox;
-
-	int			lux_scale;
+	struct mutex			lock;
+	struct regmap			*regmap;
+	unsigned int			prox_sampling;
+	bool				enable_prox;
+	int				lux_scale;
 	enum isl29028_als_ir_mode	als_ir_mode;
 };
 
 static int isl29028_set_proxim_sampling(struct isl29028_chip *chip,
 					unsigned int sampling)
 {
+	struct device *dev = regmap_get_device(chip->regmap);
 	static unsigned int prox_period[] = {800, 400, 200, 100, 75, 50, 12, 0};
-	int sel;
 	unsigned int period = DIV_ROUND_UP(1000, sampling);
+	int sel, ret;
 
 	for (sel = 0; sel < ARRAY_SIZE(prox_period); ++sel) {
 		if (period >= prox_period[sel])
 			break;
 	}
-	return regmap_update_bits(chip->regmap, ISL29028_REG_CONFIGURE,
-				  ISL29028_CONF_PROX_SLP_MASK,
-				  sel << ISL29028_CONF_PROX_SLP_SH);
+
+	ret = regmap_update_bits(chip->regmap, ISL29028_REG_CONFIGURE,
+				 ISL29028_CONF_PROX_SLP_MASK,
+				 sel << ISL29028_CONF_PROX_SLP_SH);
+
+	if (ret < 0) {
+		dev_err(dev, "%s(): Error %d setting the proximity sampling\n",
+			__func__, ret);
+		return ret;
+	}
+
+	chip->prox_sampling = sampling;
+
+	return ret;
 }
 
-static int isl29028_enable_proximity(struct isl29028_chip *chip, bool enable)
+static int isl29028_enable_proximity(struct isl29028_chip *chip)
 {
 	int ret;
-	int val = 0;
 
-	if (enable)
-		val = ISL29028_CONF_PROX_EN;
+	ret = isl29028_set_proxim_sampling(chip, chip->prox_sampling);
+	if (ret < 0)
+		return ret;
+
 	ret = regmap_update_bits(chip->regmap, ISL29028_REG_CONFIGURE,
-				 ISL29028_CONF_PROX_EN_MASK, val);
+				 ISL29028_CONF_PROX_EN_MASK,
+				 ISL29028_CONF_PROX_EN);
 	if (ret < 0)
 		return ret;
 
 	/* Wait for conversion to be complete for first sample */
 	mdelay(DIV_ROUND_UP(1000, chip->prox_sampling));
+
 	return 0;
 }
 
 static int isl29028_set_als_scale(struct isl29028_chip *chip, int lux_scale)
 {
+	struct device *dev = regmap_get_device(chip->regmap);
 	int val = (lux_scale == 2000) ? ISL29028_CONF_ALS_RANGE_HIGH_LUX :
 					ISL29028_CONF_ALS_RANGE_LOW_LUX;
+	int ret;
 
-	return regmap_update_bits(chip->regmap, ISL29028_REG_CONFIGURE,
-		ISL29028_CONF_ALS_RANGE_MASK, val);
+	ret = regmap_update_bits(chip->regmap, ISL29028_REG_CONFIGURE,
+				 ISL29028_CONF_ALS_RANGE_MASK, val);
+	if (ret < 0) {
+		dev_err(dev, "%s(): Error %d setting the ALS scale\n", __func__,
+			ret);
+		return ret;
+	}
+
+	chip->lux_scale = lux_scale;
+
+	return ret;
 }
 
 static int isl29028_set_als_ir_mode(struct isl29028_chip *chip,
 				    enum isl29028_als_ir_mode mode)
 {
-	int ret = 0;
+	int ret;
 
 	if (chip->als_ir_mode == mode)
 		return 0;
+
+	ret = isl29028_set_als_scale(chip, chip->lux_scale);
+	if (ret < 0)
+		return ret;
 
 	switch (mode) {
 	case ISL29028_MODE_ALS:
···
 					 ISL29028_CONF_ALS_RANGE_MASK,
 					 ISL29028_CONF_ALS_RANGE_HIGH_LUX);
 		break;
-
 	case ISL29028_MODE_IR:
 		ret = regmap_update_bits(chip->regmap, ISL29028_REG_CONFIGURE,
 					 ISL29028_CONF_ALS_IR_MODE_MASK,
 					 ISL29028_CONF_ALS_IR_MODE_IR);
 		break;
-
 	case ISL29028_MODE_NONE:
 		return regmap_update_bits(chip->regmap, ISL29028_REG_CONFIGURE,
-			ISL29028_CONF_ALS_EN_MASK, ISL29028_CONF_ALS_DIS);
+					  ISL29028_CONF_ALS_EN_MASK,
+					  ISL29028_CONF_ALS_DIS);
 	}
 
 	if (ret < 0)
···
 	ret = regmap_read(chip->regmap, ISL29028_REG_ALSIR_L, &lsb);
 	if (ret < 0) {
 		dev_err(dev,
-			"Error in reading register ALSIR_L err %d\n", ret);
+			"%s(): Error %d reading register ALSIR_L\n",
+			__func__, ret);
 		return ret;
 	}
 
 	ret = regmap_read(chip->regmap, ISL29028_REG_ALSIR_U, &msb);
 	if (ret < 0) {
 		dev_err(dev,
-			"Error in reading register ALSIR_U err %d\n", ret);
+			"%s(): Error %d reading register ALSIR_U\n",
+			__func__, ret);
 		return ret;
 	}
 
 	*als_ir = ((msb & 0xF) << 8) | (lsb & 0xFF);
+
 	return 0;
 }
 
···
 	unsigned int data;
 	int ret;
 
-	ret = regmap_read(chip->regmap, ISL29028_REG_PROX_DATA, &data);
-	if (ret < 0) {
-		dev_err(dev, "Error in reading register %d, error %d\n",
-			ISL29028_REG_PROX_DATA, ret);
-		return ret;
-	}
-	*prox = data;
-	return 0;
-}
-
-static int isl29028_proxim_get(struct isl29028_chip *chip, int *prox_data)
-{
-	int ret;
-
 	if (!chip->enable_prox) {
-		ret = isl29028_enable_proximity(chip, true);
+		ret = isl29028_enable_proximity(chip);
 		if (ret < 0)
 			return ret;
+
 		chip->enable_prox = true;
 	}
-	return isl29028_read_proxim(chip, prox_data);
+
+	ret = regmap_read(chip->regmap, ISL29028_REG_PROX_DATA, &data);
+	if (ret < 0) {
+		dev_err(dev, "%s(): Error %d reading register PROX_DATA\n",
+			__func__, ret);
+		return ret;
+	}
+
+	*prox = data;
+
+	return 0;
 }
 
 static int isl29028_als_get(struct isl29028_chip *chip, int *als_data)
···
 
 	ret = isl29028_set_als_ir_mode(chip, ISL29028_MODE_ALS);
 	if (ret < 0) {
-		dev_err(dev, "Error in enabling ALS mode err %d\n", ret);
+		dev_err(dev, "%s(): Error %d enabling ALS mode\n", __func__,
+			ret);
 		return ret;
 	}
 
···
 		als_ir_data = (als_ir_data * 49) / 100;
 
 	*als_data = als_ir_data;
+
 	return 0;
 }
 
···
 
 	ret = isl29028_set_als_ir_mode(chip, ISL29028_MODE_IR);
 	if (ret < 0) {
-		dev_err(dev, "Error in enabling IR mode err %d\n", ret);
+		dev_err(dev, "%s(): Error %d enabling IR mode\n", __func__,
+			ret);
 		return ret;
 	}
+
 	return isl29028_read_als_ir(chip, ir_data);
+}
+
+static int isl29028_set_pm_runtime_busy(struct isl29028_chip *chip, bool on)
+{
+	struct device *dev = regmap_get_device(chip->regmap);
+	int ret;
+
+	if (on) {
+		ret = pm_runtime_get_sync(dev);
+		if (ret < 0)
+			pm_runtime_put_noidle(dev);
+	} else {
+		pm_runtime_mark_last_busy(dev);
+		ret = pm_runtime_put_autosuspend(dev);
+	}
+
+	return ret;
 }
 
 /* Channel IO */
···
 {
 	struct isl29028_chip *chip = iio_priv(indio_dev);
 	struct device *dev = regmap_get_device(chip->regmap);
-	int ret = -EINVAL;
+	int ret;
+
+	ret = isl29028_set_pm_runtime_busy(chip, true);
+	if (ret < 0)
+		return ret;
 
 	mutex_lock(&chip->lock);
+
+	ret = -EINVAL;
 	switch (chan->type) {
 	case IIO_PROXIMITY:
 		if (mask != IIO_CHAN_INFO_SAMP_FREQ) {
 			dev_err(dev,
-				"proximity: mask value 0x%08lx not supported\n",
-				mask);
+				"%s(): proximity: Mask value 0x%08lx is not supported\n",
+				__func__, mask);
 			break;
 		}
+
 		if (val < 1 || val > 100) {
 			dev_err(dev,
-				"Samp_freq %d is not in range[1:100]\n", val);
+				"%s(): proximity: Sampling frequency %d is not in the range [1:100]\n",
+				__func__, val);
 			break;
 		}
-		ret = isl29028_set_proxim_sampling(chip, val);
-		if (ret < 0) {
-			dev_err(dev,
-				"Setting proximity samp_freq fail, err %d\n",
-				ret);
-			break;
-		}
-		chip->prox_sampling = val;
-		break;
 
+		ret = isl29028_set_proxim_sampling(chip, val);
+		break;
 	case IIO_LIGHT:
 		if (mask != IIO_CHAN_INFO_SCALE) {
 			dev_err(dev,
-				"light: mask value 0x%08lx not supported\n",
-				mask);
+				"%s(): light: Mask value 0x%08lx is not supported\n",
+				__func__, mask);
 			break;
 		}
-		if ((val != 125) && (val != 2000)) {
-			dev_err(dev,
-				"lux scale %d is invalid [125, 2000]\n", val);
-			break;
-		}
-		ret = isl29028_set_als_scale(chip, val);
-		if (ret < 0) {
-			dev_err(dev,
-				"Setting lux scale fail with error %d\n", ret);
-			break;
-		}
-		chip->lux_scale = val;
-		break;
 
+		if (val != 125 && val != 2000) {
+			dev_err(dev,
+				"%s(): light: Lux scale %d is not in the set {125, 2000}\n",
+				__func__, val);
+			break;
+		}
+
+		ret = isl29028_set_als_scale(chip, val);
+		break;
 	default:
-		dev_err(dev, "Unsupported channel type\n");
+		dev_err(dev, "%s(): Unsupported channel type %x\n",
+			__func__, chan->type);
 		break;
 	}
+
 	mutex_unlock(&chip->lock);
+
+	if (ret < 0)
+		return ret;
+
+	ret = isl29028_set_pm_runtime_busy(chip, false);
+	if (ret < 0)
+		return ret;
+
 	return ret;
 }
 
···
 {
 	struct isl29028_chip *chip = iio_priv(indio_dev);
 	struct device *dev = regmap_get_device(chip->regmap);
-	int ret = -EINVAL;
+	int ret, pm_ret;
+
+	ret = isl29028_set_pm_runtime_busy(chip, true);
+	if (ret < 0)
+		return ret;
 
 	mutex_lock(&chip->lock);
+
+	ret = -EINVAL;
 	switch (mask) {
 	case IIO_CHAN_INFO_RAW:
 	case IIO_CHAN_INFO_PROCESSED:
···
 			ret = isl29028_ir_get(chip, val);
 			break;
 		case IIO_PROXIMITY:
-			ret = isl29028_proxim_get(chip, val);
+			ret = isl29028_read_proxim(chip, val);
 			break;
 		default:
 			break;
 		}
+
 		if (ret < 0)
 			break;
+
 		ret = IIO_VAL_INT;
 		break;
-
 	case IIO_CHAN_INFO_SAMP_FREQ:
 		if (chan->type != IIO_PROXIMITY)
 			break;
+
 		*val = chip->prox_sampling;
 		ret = IIO_VAL_INT;
 		break;
-
 	case IIO_CHAN_INFO_SCALE:
 		if (chan->type != IIO_LIGHT)
 			break;
 		*val = chip->lux_scale;
 		ret = IIO_VAL_INT;
 		break;
-
 	default:
-		dev_err(dev, "mask value 0x%08lx not supported\n", mask);
+		dev_err(dev, "%s(): mask value 0x%08lx is not supported\n",
+			__func__, mask);
 		break;
 	}
+
 	mutex_unlock(&chip->lock);
+
+	if (ret < 0)
+		return ret;
+
+	/**
+	 * Preserve the ret variable if the call to
+	 * isl29028_set_pm_runtime_busy() is successful so the reading
+	 * (if applicable) is returned to user space.
+	 */
+	pm_ret = isl29028_set_pm_runtime_busy(chip, false);
+	if (pm_ret < 0)
+		return pm_ret;
+
 	return ret;
 }
 
···
 				"1 3 5 10 13 20 83 100");
 static IIO_CONST_ATTR(in_illuminance_scale_available, "125 2000");
 
-#define ISL29028_DEV_ATTR(name) (&iio_dev_attr_##name.dev_attr.attr)
 #define ISL29028_CONST_ATTR(name) (&iio_const_attr_##name.dev_attr.attr)
 static struct attribute *isl29028_attributes[] = {
 	ISL29028_CONST_ATTR(in_proximity_sampling_frequency_available),
···
 	.write_raw = isl29028_write_raw,
 };
 
-static int isl29028_chip_init_and_power_on(struct isl29028_chip *chip)
+static int isl29028_clear_configure_reg(struct isl29028_chip *chip)
 {
 	struct device *dev = regmap_get_device(chip->regmap);
 	int ret;
 
 	ret = regmap_write(chip->regmap, ISL29028_REG_CONFIGURE, 0x0);
-	if (ret < 0) {
-		dev_err(dev, "%s(): write to reg %d failed, err = %d\n",
-			__func__, ISL29028_REG_CONFIGURE, ret);
-		return ret;
-	}
-
-	ret = isl29028_set_proxim_sampling(chip, chip->prox_sampling);
-	if (ret < 0) {
-		dev_err(dev, "setting the proximity, err = %d\n", ret);
-		return ret;
-	}
-
-	ret = isl29028_set_als_scale(chip, chip->lux_scale);
 	if (ret < 0)
-		dev_err(dev, "setting als scale failed, err = %d\n", ret);
+		dev_err(dev, "%s(): Error %d clearing the CONFIGURE register\n",
+			__func__, ret);
+
+	chip->als_ir_mode = ISL29028_MODE_NONE;
+	chip->enable_prox = false;
+
 	return ret;
 }
 
···
 	int ret;
 
 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));
-	if (!indio_dev) {
-		dev_err(&client->dev, "iio allocation fails\n");
+	if (!indio_dev)
 		return -ENOMEM;
-	}
 
 	chip = iio_priv(indio_dev);
 
···
 	chip->regmap = devm_regmap_init_i2c(client, &isl29028_regmap_config);
 	if (IS_ERR(chip->regmap)) {
 		ret = PTR_ERR(chip->regmap);
-		dev_err(&client->dev, "regmap initialization failed: %d\n",
-			ret);
+		dev_err(&client->dev, "%s: Error %d initializing regmap\n",
+			__func__, ret);
 		return ret;
 	}
 
 	chip->enable_prox  = false;
 	chip->prox_sampling = 20;
 	chip->lux_scale = 2000;
-	chip->als_ir_mode = ISL29028_MODE_NONE;
 
 	ret = regmap_write(chip->regmap, ISL29028_REG_TEST1_MODE, 0x0);
 	if (ret < 0) {
 		dev_err(&client->dev,
-			"%s(): write to reg %d failed, err = %d\n", __func__,
-			ISL29028_REG_TEST1_MODE, ret);
-		return ret;
-	}
-	ret = regmap_write(chip->regmap, ISL29028_REG_TEST2_MODE, 0x0);
-	if (ret < 0) {
-		dev_err(&client->dev,
-			"%s(): write to reg %d failed, err = %d\n", __func__,
-			ISL29028_REG_TEST2_MODE, ret);
+			"%s(): Error %d writing to TEST1_MODE register\n",
+			__func__, ret);
 		return ret;
 	}
 
-	ret = isl29028_chip_init_and_power_on(chip);
+	ret = regmap_write(chip->regmap, ISL29028_REG_TEST2_MODE, 0x0);
 	if (ret < 0) {
-		dev_err(&client->dev, "chip initialization failed: %d\n", ret);
+		dev_err(&client->dev,
+			"%s(): Error %d writing to TEST2_MODE register\n",
+			__func__, ret);
 		return ret;
 	}
+
+	ret = isl29028_clear_configure_reg(chip);
+	if (ret < 0)
+		return ret;
 
 	indio_dev->info = &isl29028_info;
 	indio_dev->channels = isl29028_channels;
···
 	indio_dev->name = id->name;
 	indio_dev->dev.parent = &client->dev;
 	indio_dev->modes = INDIO_DIRECT_MODE;
+
+	pm_runtime_enable(&client->dev);
+	pm_runtime_set_autosuspend_delay(&client->dev,
+					 ISL29028_POWER_OFF_DELAY_MS);
+	pm_runtime_use_autosuspend(&client->dev);
+
 	ret = devm_iio_device_register(indio_dev->dev.parent, indio_dev);
 	if (ret < 0) {
 		dev_err(&client->dev,
-			"iio registration fails with error %d\n",
-			ret);
+			"%s(): iio registration failed with error %d\n",
+			__func__, ret);
 		return ret;
 	}
+
 	return 0;
 }
+
+static int isl29028_remove(struct i2c_client *client)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(client);
+	struct isl29028_chip *chip = iio_priv(indio_dev);
+
+	iio_device_unregister(indio_dev);
+
+	pm_runtime_disable(&client->dev);
+	pm_runtime_set_suspended(&client->dev);
+	pm_runtime_put_noidle(&client->dev);
+
+	return isl29028_clear_configure_reg(chip);
+}
+
+static int __maybe_unused isl29028_suspend(struct device *dev)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
+	struct isl29028_chip *chip = iio_priv(indio_dev);
+	int ret;
+
+	mutex_lock(&chip->lock);
+
+	ret = isl29028_clear_configure_reg(chip);
+
+	mutex_unlock(&chip->lock);
+
+	return ret;
+}
+
+static int __maybe_unused isl29028_resume(struct device *dev)
+{
+	/**
+	 * The specific component (ALS/IR or proximity) will enable itself as
+	 * needed the next time that the user requests a reading. This is done
+	 * above in isl29028_set_als_ir_mode() and isl29028_enable_proximity().
+	 */
+	return 0;
+}
+
+static const struct dev_pm_ops isl29028_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(isl29028_suspend, isl29028_resume)
+	SET_RUNTIME_PM_OPS(isl29028_suspend, isl29028_resume, NULL)
+};
 
 static const struct i2c_device_id isl29028_id[] = {
 	{"isl29028", 0},
···
 static struct i2c_driver isl29028_driver = {
 	.driver  = {
 		.name = "isl29028",
+		.pm = &isl29028_pm_ops,
 		.of_match_table = isl29028_of_match,
 	},
 	.probe	 = isl29028_probe,
+	.remove  = isl29028_remove,
 	.id_table = isl29028_id,
 };
 

drivers/staging/iio/trigger/iio-trig-bfin-timer.c

···
 out1:
 	iio_trigger_unregister(st->trig);
 out:
-	iio_trigger_put(st->trig);
+	iio_trigger_free(st->trig);
 	return ret;
 }
 
···
 		peripheral_free(st->t->pin);
 	free_irq(st->irq, st);
 	iio_trigger_unregister(st->trig);
-	iio_trigger_put(st->trig);
+	iio_trigger_free(st->trig);
 
 	return 0;
 }