Merge tag 'iio-for-4.16a' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-next

Jonathan writes:

First set of new device support, cleanups and features for IIO in the 4.16 cycle

New device support
* IDT Z0PT2201 ambient light and UVB sensor
  - new driver and DT bindings.
* MAX30102 (pulse oximetery sensor)
  - support for MAX30105 sensor (smoke detector)  Just goes to show
    how two supposedly totally different applications can use very similar
    devices.
* UVIS25 UV sensor
  - new driver and DT bindings.

Major new features
* at91-sama5d2-adc
  - DMA support including bindings + a fix for an issue with acking the
    interrupt to prevent false overrun reports.
* ina2xx
  - allow control of shunt voltage PGA and bus voltage range to give better
    accuracy in some cases.
* stm32-adc
  - support differential channels (precursor patch reworked how channel names
    were created to enable this).

Cleanups / minor fixes / features
* core
  - mark a deliberate switch fallthrough.
  - macro to populate struct iio_map array elements.
* docs
  - typo fix.
* MAINTAINERS
  - add some missing entries for IIO ABI files.

* ad7152
  - tidy up unlocking paths.
* ad7746
  - tidy up unlocking paths.
* ak8975
  - add an ACPI id found on a prototype board.
* aspeed-adc
  - deassert reset in probe to ensure device is usable.
* bfin-trigger
  - platform_get_irq return value fixing.
* bmc150
  - OF device ID table for i2c (spi to be done).
* cros_ec
  - unused variable cleanup.
* da208
  - ACPI binding seen on Linx 820 tablet.
* ina2xx
  - shift down raw value to drop status flags from value (likely to have
    been hidden in the noise).
  - tidy up a special case that wasn't needed.
* inv_mpu6050
  - i2c_unregister_device knows about null values so don't check it twice.
* kxsd9
  - fix missing MODULE_LICENSE and MODULE_DESCRIPTION.
* max30102
  - missing new lines in dev_err.
  - inconsistent punctuation in error messages.
  - fix LED mode mask number of bits.
  - check return value of power mode functions to handle errors.
  - introduce an intensity channel macro to reduce duplication.
  - fix minor issue where device wasn't necessarily enabled during
    a get temperature.
  - use indicies for LED channels.
  - move the mode seetting to buffer_postenable - precursor to new device
    support.
  - prepare to allow copying of varying numbers of measurement.
* meson-saradc
  - drop irrelevant clock and update bindings.
* mma8452
  - a couple of renames for readability reasons.
* qcom_vadc
  - fix missing MODULE_LICENSE and MODULE_DESCRIPTION.
* st_accel
  - drop an unused variable.
* sx9500
  - add an ACPI id found on a prototype board.

Documentation/ABI/testing/sysfs-bus-iio

@@ -1290,7 +1290,7 @@ KernelVersion:	3.4
 Contact:	linux-iio@vger.kernel.org
 Description:
 		Unit-less light intensity. Modifiers both and ir indicate
-		that measurements contains visible and infrared light
+		that measurements contain visible and infrared light
 		components or just infrared light, respectively. Modifier uv indicates
 		that measurements contain ultraviolet light components.
 

Documentation/devicetree/bindings/iio/adc/amlogic,meson-saradc.txt

@@ -15,7 +15,6 @@ Required properties:
 			- "clkin" for the reference clock (typically XTAL)
 			- "core" for the SAR ADC core clock
 		optional clocks:
-			- "sana" for the analog clock
 			- "adc_clk" for the ADC (sampling) clock
 			- "adc_sel" for the ADC (sampling) clock mux
 - vref-supply:	the regulator supply for the ADC reference voltage

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

@@ -8,6 +8,7 @@ Required properties:
 - reg: memory window mapping address and length
 - clocks: Input clock used to derive the sample clock. Expected to be the
           SoC's APB clock.
+- resets: Reset controller phandle
 - #io-channel-cells: Must be set to <1> to indicate channels are selected
                      by index.
 
@@ -15,6 +16,7 @@ Example:
 	adc@1e6e9000 {
 		compatible = "aspeed,ast2400-adc";
 		reg = <0x1e6e9000 0xb0>;
-		clocks = <&clk_apb>;
+		clocks = <&syscon ASPEED_CLK_APB>;
+		resets = <&syscon ASPEED_RESET_ADC>;
 		#io-channel-cells = <1>;
 	};

Documentation/devicetree/bindings/iio/adc/at91-sama5d2_adc.txt

@@ -17,6 +17,11 @@ Required properties:
   This property uses the IRQ edge types values: IRQ_TYPE_EDGE_RISING ,
   IRQ_TYPE_EDGE_FALLING or IRQ_TYPE_EDGE_BOTH
 
+Optional properties:
+  - dmas: Phandle to dma channel for the ADC.
+  - dma-names: Must be "rx" when dmas property is being used.
+  See ../../dma/dma.txt for details.
+
 Example:
 
 adc: adc@fc030000 {
@@ -31,4 +36,6 @@ adc: adc@fc030000 {
 	vddana-supply = <&vdd_3v3_lp_reg>;
 	vref-supply = <&vdd_3v3_lp_reg>;
 	atmel,trigger-edge-type = <IRQ_TYPE_EDGE_BOTH>;
+	dmas = <&dma0 (AT91_XDMAC_DT_MEM_IF(0) | AT91_XDMAC_DT_PER_IF(1) | AT91_XDMAC_DT_PERID(25))>;
+	dma-names = "rx";
 }

Documentation/devicetree/bindings/iio/adc/st,stm32-adc.txt

@@ -62,6 +62,15 @@ Required properties:
 - st,adc-channels: List of single-ended channels muxed for this ADC.
   It can have up to 16 channels on stm32f4 or 20 channels on stm32h7, numbered
   from 0 to 15 or 19 (resp. for in0..in15 or in0..in19).
+- st,adc-diff-channels: List of differential channels muxed for this ADC.
+  Depending on part used, some channels can be configured as differential
+  instead of single-ended (e.g. stm32h7). List here positive and negative
+  inputs pairs as <vinp vinn>, <vinp vinn>,... vinp and vinn are numbered
+  from 0 to 19 on stm32h7)
+  Note: At least one of "st,adc-channels" or "st,adc-diff-channels" is required.
+  Both properties can be used together. Some channels can be used as
+  single-ended and some other ones as differential (mixed). But channels
+  can't be configured both as single-ended and differential (invalid).
 - #io-channel-cells = <1>: See the IIO bindings section "IIO consumers" in
   Documentation/devicetree/bindings/iio/iio-bindings.txt
 
@@ -111,3 +120,18 @@ Example:
 		...
 		other adc child nodes follow...
 	};
+
+Example to setup:
+- channel 1 as single-ended
+- channels 2 & 3 as differential (with resp. 6 & 7 negative inputs)
+
+	adc: adc@40022000 {
+		compatible = "st,stm32h7-adc-core";
+		...
+		adc1: adc@0 {
+			compatible = "st,stm32h7-adc";
+			...
+			st,adc-channels = <1>;
+			st,adc-diff-channels = <2 6>, <3 7>;
+		};
+	};

Documentation/devicetree/bindings/iio/health/max30102.txt

@@ -1,9 +1,11 @@
 Maxim MAX30102 heart rate and pulse oximeter sensor
+Maxim MAX30105 optical particle-sensing module
 
 * https://datasheets.maximintegrated.com/en/ds/MAX30102.pdf
+* https://datasheets.maximintegrated.com/en/ds/MAX30105.pdf
 
 Required properties:
-  - compatible: must be "maxim,max30102"
+  - compatible: must be "maxim,max30102" or "maxim,max30105"
   - reg: the I2C address of the sensor
   - interrupt-parent: should be the phandle for the interrupt controller
   - interrupts: the sole interrupt generated by the device
@@ -12,8 +14,10 @@ Required properties:
   interrupt client node bindings.
 
 Optional properties:
-  - maxim,red-led-current-microamp: configuration for RED LED current
+  - maxim,red-led-current-microamp: configuration for red LED current
   - maxim,ir-led-current-microamp: configuration for IR LED current
+  - maxim,green-led-current-microamp: configuration for green LED current
+    (max30105 only)
 
     Note that each step is approximately 200 microamps, ranging from 0 uA to
     50800 uA.

Documentation/devicetree/bindings/iio/light/uvis25.txt

@@ -0,0 +1,23 @@
+* ST UVIS25 uv sensor
+
+Required properties:
+- compatible: should be "st,uvis25"
+- 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, IRQ_TYPE_EDGE_RISING, IRQ_TYPE_LEVEL_LOW or
+  IRQ_TYPE_EDGE_FALLING.
+
+  Refer to interrupt-controller/interrupts.txt for generic interrupt
+  client node bindings.
+
+Example:
+
+uvis25@47 {
+	compatible = "st,uvis25";
+	reg = <0x47>;
+	interrupt-parent = <&gpio0>;
+	interrupts = <0 IRQ_TYPE_EDGE_RISING>;
+};

MAINTAINERS

@@ -262,6 +262,7 @@ ACCES 104-QUAD-8 IIO DRIVER
 M:	William Breathitt Gray <vilhelm.gray@gmail.com>
 L:	linux-iio@vger.kernel.org
 S:	Maintained
+F:	Documentation/ABI/testing/sysfs-bus-iio-counter-104-quad-8
 F:	drivers/iio/counter/104-quad-8.c
 
 ACCES PCI-IDIO-16 GPIO DRIVER
@@ -845,6 +846,8 @@ M:	Michael Hennerich <Michael.Hennerich@analog.com>
 W:	http://wiki.analog.com/
 W:	http://ez.analog.com/community/linux-device-drivers
 S:	Supported
+F:	Documentation/ABI/testing/sysfs-bus-iio-frequency-ad9523
+F:	Documentation/ABI/testing/sysfs-bus-iio-frequency-adf4350
 F:	drivers/iio/*/ad*
 F:	drivers/iio/adc/ltc2497*
 X:	drivers/iio/*/adjd*
@@ -4126,6 +4129,7 @@ DEVANTECH SRF ULTRASONIC RANGER IIO DRIVER
 M:	Andreas Klinger <ak@it-klinger.de>
 L:	linux-iio@vger.kernel.org
 S:	Maintained
+F:	Documentation/ABI/testing/sysfs-bus-iio-distance-srf08
 F:	drivers/iio/proximity/srf*.c
 
 DEVICE COREDUMP (DEV_COREDUMP)
@@ -6829,6 +6833,8 @@ R:	Peter Meerwald-Stadler <pmeerw@pmeerw.net>
 L:	linux-iio@vger.kernel.org
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio.git
 S:	Maintained
+F:	Documentation/ABI/testing/configfs-iio*
+F:	Documentation/ABI/testing/sysfs-bus-iio*
 F:	Documentation/devicetree/bindings/iio/
 F:	drivers/iio/
 F:	drivers/staging/iio/

drivers/iio/accel/bmc150-accel-i2c.c

@@ -81,9 +81,21 @@ static const struct i2c_device_id bmc150_accel_id[] = {
 
 MODULE_DEVICE_TABLE(i2c, bmc150_accel_id);
 
+static const struct of_device_id bmc150_accel_of_match[] = {
+	{ .compatible = "bosch,bmc150_accel" },
+	{ .compatible = "bosch,bmi055_accel" },
+	{ .compatible = "bosch,bma255" },
+	{ .compatible = "bosch,bma250e" },
+	{ .compatible = "bosch,bma222e" },
+	{ .compatible = "bosch,bma280" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, bmc150_accel_of_match);
+
 static struct i2c_driver bmc150_accel_driver = {
 	.driver = {
 		.name	= "bmc150_accel_i2c",
+		.of_match_table = bmc150_accel_of_match,
 		.acpi_match_table = ACPI_PTR(bmc150_accel_acpi_match),
 		.pm	= &bmc150_accel_pm_ops,
 	},

drivers/iio/accel/da280.c

@@ -11,6 +11,7 @@
 
 #include <linux/module.h>
 #include <linux/i2c.h>
+#include <linux/acpi.h>
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
 #include <linux/byteorder/generic.h>
@@ -25,7 +26,7 @@
 #define DA280_MODE_ENABLE		0x1e
 #define DA280_MODE_DISABLE		0x9e
 
-enum { da226, da280 };
+enum da280_chipset { da226, da280 };
 
 /*
  * a value of + or -4096 corresponds to + or - 1G
@@ -91,12 +92,24 @@ static const struct iio_info da280_info = {
 	.read_raw	= da280_read_raw,
 };
 
+static enum da280_chipset da280_match_acpi_device(struct device *dev)
+{
+	const struct acpi_device_id *id;
+
+	id = acpi_match_device(dev->driver->acpi_match_table, dev);
+	if (!id)
+		return -EINVAL;
+
+	return (enum da280_chipset) id->driver_data;
+}
+
 static int da280_probe(struct i2c_client *client,
 			const struct i2c_device_id *id)
 {
 	int ret;
 	struct iio_dev *indio_dev;
 	struct da280_data *data;
+	enum da280_chipset chip;
 
 	ret = i2c_smbus_read_byte_data(client, DA280_REG_CHIP_ID);
 	if (ret != DA280_CHIP_ID)
@@ -114,7 +127,14 @@ static int da280_probe(struct i2c_client *client,
 	indio_dev->info = &da280_info;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->channels = da280_channels;
-	if (id->driver_data == da226) {
+
+	if (ACPI_HANDLE(&client->dev)) {
+		chip = da280_match_acpi_device(&client->dev);
+	} else {
+		chip = id->driver_data;
+	}
+
+	if (chip == da226) {
 		indio_dev->name = "da226";
 		indio_dev->num_channels = 2;
 	} else {
@@ -158,6 +178,12 @@ static int da280_resume(struct device *dev)
 
 static SIMPLE_DEV_PM_OPS(da280_pm_ops, da280_suspend, da280_resume);
 
+static const struct acpi_device_id da280_acpi_match[] = {
+	{"MIRAACC", da280},
+	{},
+};
+MODULE_DEVICE_TABLE(acpi, da280_acpi_match);
+
 static const struct i2c_device_id da280_i2c_id[] = {
 	{ "da226", da226 },
 	{ "da280", da280 },
@@ -168,6 +194,7 @@ MODULE_DEVICE_TABLE(i2c, da280_i2c_id);
 static struct i2c_driver da280_driver = {
 	.driver = {
 		.name = "da280",
+		.acpi_match_table = ACPI_PTR(da280_acpi_match),
 		.pm = &da280_pm_ops,
 	},
 	.probe		= da280_probe,

drivers/iio/accel/kxsd9-i2c.c

@@ -63,3 +63,6 @@ static struct i2c_driver kxsd9_i2c_driver = {
 	.id_table	= kxsd9_i2c_id,
 };
 module_i2c_driver(kxsd9_i2c_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("KXSD9 accelerometer I2C interface");

drivers/iio/accel/mma8452.c

@@ -135,7 +135,7 @@ struct mma8452_event_regs {
 		u8 ev_count;
 };
 
-static const struct mma8452_event_regs ev_regs_accel_falling = {
+static const struct mma8452_event_regs ff_mt_ev_regs = {
 		.ev_cfg = MMA8452_FF_MT_CFG,
 		.ev_cfg_ele = MMA8452_FF_MT_CFG_ELE,
 		.ev_cfg_chan_shift = MMA8452_FF_MT_CHAN_SHIFT,
@@ -145,7 +145,7 @@ static const struct mma8452_event_regs ev_regs_accel_falling = {
 		.ev_count = MMA8452_FF_MT_COUNT
 };
 
-static const struct mma8452_event_regs ev_regs_accel_rising = {
+static const struct mma8452_event_regs trans_ev_regs = {
 		.ev_cfg = MMA8452_TRANSIENT_CFG,
 		.ev_cfg_ele = MMA8452_TRANSIENT_CFG_ELE,
 		.ev_cfg_chan_shift = MMA8452_TRANSIENT_CHAN_SHIFT,
@@ -284,7 +284,7 @@ static const int mma8452_samp_freq[8][2] = {
 };
 
 /* Datasheet table: step time "Relationship with the ODR" (sample frequency) */
-static const unsigned int mma8452_transient_time_step_us[4][8] = {
+static const unsigned int mma8452_time_step_us[4][8] = {
 	{ 1250, 2500, 5000, 10000, 20000, 20000, 20000, 20000 },  /* normal */
 	{ 1250, 2500, 5000, 10000, 20000, 80000, 80000, 80000 },  /* l p l n */
 	{ 1250, 2500, 2500, 2500, 2500, 2500, 2500, 2500 },	  /* high res*/
@@ -777,12 +777,12 @@ static int mma8452_get_event_regs(struct mma8452_data *data,
 					& MMA8452_INT_TRANS) &&
 				(data->chip_info->enabled_events
 					& MMA8452_INT_TRANS))
-				*ev_reg = &ev_regs_accel_rising;
+				*ev_reg = &trans_ev_regs;
 			else
-				*ev_reg = &ev_regs_accel_falling;
+				*ev_reg = &ff_mt_ev_regs;
 			return 0;
 		case IIO_EV_DIR_FALLING:
-			*ev_reg = &ev_regs_accel_falling;
+			*ev_reg = &ff_mt_ev_regs;
 			return 0;
 		default:
 			return -EINVAL;
@@ -826,7 +826,7 @@ static int mma8452_read_event_value(struct iio_dev *indio_dev,
 		if (power_mode < 0)
 			return power_mode;
 
-		us = ret * mma8452_transient_time_step_us[power_mode][
+		us = ret * mma8452_time_step_us[power_mode][
 				mma8452_get_odr_index(data)];
 		*val = us / USEC_PER_SEC;
 		*val2 = us % USEC_PER_SEC;
@@ -883,7 +883,7 @@ static int mma8452_write_event_value(struct iio_dev *indio_dev,
 			return ret;
 
 		steps = (val * USEC_PER_SEC + val2) /
-				mma8452_transient_time_step_us[ret][
+				mma8452_time_step_us[ret][
 					mma8452_get_odr_index(data)];
 
 		if (steps < 0 || steps > 0xff)

drivers/iio/accel/st_accel_core.c

@@ -920,8 +920,6 @@ static const struct iio_trigger_ops st_accel_trigger_ops = {
 int st_accel_common_probe(struct iio_dev *indio_dev)
 {
 	struct st_sensor_data *adata = iio_priv(indio_dev);
-	struct st_sensors_platform_data *pdata =
-		(struct st_sensors_platform_data *)adata->dev->platform_data;
 	int irq = adata->get_irq_data_ready(indio_dev);
 	int err;
 
@@ -948,9 +946,6 @@ int st_accel_common_probe(struct iio_dev *indio_dev)
 					&adata->sensor_settings->fs.fs_avl[0];
 	adata->odr = adata->sensor_settings->odr.odr_avl[0].hz;
 
-	if (!pdata)
-		pdata = (struct st_sensors_platform_data *)&default_accel_pdata;
-
 	err = st_sensors_init_sensor(indio_dev, adata->dev->platform_data);
 	if (err < 0)
 		goto st_accel_power_off;

drivers/iio/adc/Kconfig

@@ -158,6 +158,7 @@ config AT91_SAMA5D2_ADC
 	tristate "Atmel AT91 SAMA5D2 ADC"
 	depends on ARCH_AT91 || COMPILE_TEST
 	depends on HAS_IOMEM
+	depends on HAS_DMA
 	select IIO_TRIGGERED_BUFFER
 	help
 	  Say yes here to build support for Atmel SAMA5D2 ADC which is

drivers/iio/adc/aspeed_adc.c

@@ -17,6 +17,7 @@
 #include <linux/module.h>
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>
+#include <linux/reset.h>
 #include <linux/spinlock.h>
 #include <linux/types.h>
 
@@ -53,11 +54,12 @@ struct aspeed_adc_model_data {
 };
 
 struct aspeed_adc_data {
-	struct device	*dev;
-	void __iomem	*base;
-	spinlock_t	clk_lock;
-	struct clk_hw	*clk_prescaler;
-	struct clk_hw	*clk_scaler;
+	struct device		*dev;
+	void __iomem		*base;
+	spinlock_t		clk_lock;
+	struct clk_hw		*clk_prescaler;
+	struct clk_hw		*clk_scaler;
+	struct reset_control	*rst;
 };
 
 #define ASPEED_CHAN(_idx, _data_reg_addr) {			\
@@ -217,6 +219,15 @@ static int aspeed_adc_probe(struct platform_device *pdev)
 		goto scaler_error;
 	}
 
+	data->rst = devm_reset_control_get_exclusive(&pdev->dev, NULL);
+	if (IS_ERR(data->rst)) {
+		dev_err(&pdev->dev,
+			"invalid or missing reset controller device tree entry");
+		ret = PTR_ERR(data->rst);
+		goto reset_error;
+	}
+	reset_control_deassert(data->rst);
+
 	model_data = of_device_get_match_data(&pdev->dev);
 
 	if (model_data->wait_init_sequence) {
@@ -263,9 +274,10 @@ iio_register_error:
 	writel(ASPEED_OPERATION_MODE_POWER_DOWN,
 		data->base + ASPEED_REG_ENGINE_CONTROL);
 	clk_disable_unprepare(data->clk_scaler->clk);
+reset_error:
+	reset_control_assert(data->rst);
 clk_enable_error:
 	clk_hw_unregister_divider(data->clk_scaler);
-
 scaler_error:
 	clk_hw_unregister_divider(data->clk_prescaler);
 	return ret;
@@ -280,6 +292,7 @@ static int aspeed_adc_remove(struct platform_device *pdev)
 	writel(ASPEED_OPERATION_MODE_POWER_DOWN,
 		data->base + ASPEED_REG_ENGINE_CONTROL);
 	clk_disable_unprepare(data->clk_scaler->clk);
+	reset_control_assert(data->rst);
 	clk_hw_unregister_divider(data->clk_scaler);
 	clk_hw_unregister_divider(data->clk_prescaler);
 

drivers/iio/adc/at91-sama5d2_adc.c

@@ -16,6 +16,8 @@
 
 #include <linux/bitops.h>
 #include <linux/clk.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/module.h>
@@ -100,6 +102,8 @@
 #define AT91_SAMA5D2_LCDR	0x20
 /* Interrupt Enable Register */
 #define AT91_SAMA5D2_IER	0x24
+/* Interrupt Enable Register - general overrun error */
+#define AT91_SAMA5D2_IER_GOVRE BIT(25)
 /* Interrupt Disable Register */
 #define AT91_SAMA5D2_IDR	0x28
 /* Interrupt Mask Register */
@@ -167,13 +171,19 @@
 
 /*
  * Maximum number of bytes to hold conversion from all channels
- * plus the timestamp
+ * without the timestamp.
  */
-#define AT91_BUFFER_MAX_BYTES ((AT91_SAMA5D2_SINGLE_CHAN_CNT +		\
-				AT91_SAMA5D2_DIFF_CHAN_CNT) * 2 + 8)
+#define AT91_BUFFER_MAX_CONVERSION_BYTES ((AT91_SAMA5D2_SINGLE_CHAN_CNT + \
+					 AT91_SAMA5D2_DIFF_CHAN_CNT) * 2)
+
+/* This total must also include the timestamp */
+#define AT91_BUFFER_MAX_BYTES (AT91_BUFFER_MAX_CONVERSION_BYTES + 8)
 
 #define AT91_BUFFER_MAX_HWORDS (AT91_BUFFER_MAX_BYTES / 2)
 
+#define AT91_HWFIFO_MAX_SIZE_STR	"128"
+#define AT91_HWFIFO_MAX_SIZE		128
+
 #define AT91_SAMA5D2_CHAN_SINGLE(num, addr)				\
 	{								\
 		.type = IIO_VOLTAGE,					\
@@ -228,6 +238,28 @@ struct at91_adc_trigger {
 	bool				hw_trig;
 };
 
+/**
+ * at91_adc_dma - at91-sama5d2 dma information struct
+ * @dma_chan:		the dma channel acquired
+ * @rx_buf:		dma coherent allocated area
+ * @rx_dma_buf:		dma handler for the buffer
+ * @phys_addr:		physical address of the ADC base register
+ * @buf_idx:		index inside the dma buffer where reading was last done
+ * @rx_buf_sz:		size of buffer used by DMA operation
+ * @watermark:		number of conversions to copy before DMA triggers irq
+ * @dma_ts:		hold the start timestamp of dma operation
+ */
+struct at91_adc_dma {
+	struct dma_chan			*dma_chan;
+	u8				*rx_buf;
+	dma_addr_t			rx_dma_buf;
+	phys_addr_t			phys_addr;
+	int				buf_idx;
+	int				rx_buf_sz;
+	int				watermark;
+	s64				dma_ts;
+};
+
 struct at91_adc_state {
 	void __iomem			*base;
 	int				irq;
@@ -242,6 +274,7 @@ struct at91_adc_state {
 	u32				conversion_value;
 	struct at91_adc_soc_info	soc_info;
 	wait_queue_head_t		wq_data_available;
+	struct at91_adc_dma		dma_st;
 	u16				buffer[AT91_BUFFER_MAX_HWORDS];
 	/*
 	 * lock to prevent concurrent 'single conversion' requests through
@@ -322,11 +355,17 @@ static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state)
 		if (state) {
 			at91_adc_writel(st, AT91_SAMA5D2_CHER,
 					BIT(chan->channel));
-			at91_adc_writel(st, AT91_SAMA5D2_IER,
-					BIT(chan->channel));
+			/* enable irq only if not using DMA */
+			if (!st->dma_st.dma_chan) {
+				at91_adc_writel(st, AT91_SAMA5D2_IER,
+						BIT(chan->channel));
+			}
 		} else {
-			at91_adc_writel(st, AT91_SAMA5D2_IDR,
-					BIT(chan->channel));
+			/* disable irq only if not using DMA */
+			if (!st->dma_st.dma_chan) {
+				at91_adc_writel(st, AT91_SAMA5D2_IDR,
+						BIT(chan->channel));
+			}
 			at91_adc_writel(st, AT91_SAMA5D2_CHDR,
 					BIT(chan->channel));
 		}
@@ -340,6 +379,10 @@ static int at91_adc_reenable_trigger(struct iio_trigger *trig)
 	struct iio_dev *indio = iio_trigger_get_drvdata(trig);
 	struct at91_adc_state *st = iio_priv(indio);
 
+	/* if we are using DMA, we must not reenable irq after each trigger */
+	if (st->dma_st.dma_chan)
+		return 0;
+
 	enable_irq(st->irq);
 
 	/* Needed to ACK the DRDY interruption */
@@ -350,6 +393,153 @@ static int at91_adc_reenable_trigger(struct iio_trigger *trig)
 static const struct iio_trigger_ops at91_adc_trigger_ops = {
 	.set_trigger_state = &at91_adc_configure_trigger,
 	.try_reenable = &at91_adc_reenable_trigger,
+	.validate_device = iio_trigger_validate_own_device,
+};
+
+static int at91_adc_dma_size_done(struct at91_adc_state *st)
+{
+	struct dma_tx_state state;
+	enum dma_status status;
+	int i, size;
+
+	status = dmaengine_tx_status(st->dma_st.dma_chan,
+				     st->dma_st.dma_chan->cookie,
+				     &state);
+	if (status != DMA_IN_PROGRESS)
+		return 0;
+
+	/* Transferred length is size in bytes from end of buffer */
+	i = st->dma_st.rx_buf_sz - state.residue;
+
+	/* Return available bytes */
+	if (i >= st->dma_st.buf_idx)
+		size = i - st->dma_st.buf_idx;
+	else
+		size = st->dma_st.rx_buf_sz + i - st->dma_st.buf_idx;
+	return size;
+}
+
+static void at91_dma_buffer_done(void *data)
+{
+	struct iio_dev *indio_dev = data;
+
+	iio_trigger_poll_chained(indio_dev->trig);
+}
+
+static int at91_adc_dma_start(struct iio_dev *indio_dev)
+{
+	struct at91_adc_state *st = iio_priv(indio_dev);
+	struct dma_async_tx_descriptor *desc;
+	dma_cookie_t cookie;
+	int ret;
+	u8 bit;
+
+	if (!st->dma_st.dma_chan)
+		return 0;
+
+	/* we start a new DMA, so set buffer index to start */
+	st->dma_st.buf_idx = 0;
+
+	/*
+	 * compute buffer size w.r.t. watermark and enabled channels.
+	 * scan_bytes is aligned so we need an exact size for DMA
+	 */
+	st->dma_st.rx_buf_sz = 0;
+
+	for_each_set_bit(bit, indio_dev->active_scan_mask,
+			 indio_dev->num_channels) {
+		struct iio_chan_spec const *chan = indio_dev->channels + bit;
+
+		st->dma_st.rx_buf_sz += chan->scan_type.storagebits / 8;
+	}
+	st->dma_st.rx_buf_sz *= st->dma_st.watermark;
+
+	/* Prepare a DMA cyclic transaction */
+	desc = dmaengine_prep_dma_cyclic(st->dma_st.dma_chan,
+					 st->dma_st.rx_dma_buf,
+					 st->dma_st.rx_buf_sz,
+					 st->dma_st.rx_buf_sz / 2,
+					 DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT);
+
+	if (!desc) {
+		dev_err(&indio_dev->dev, "cannot prepare DMA cyclic\n");
+		return -EBUSY;
+	}
+
+	desc->callback = at91_dma_buffer_done;
+	desc->callback_param = indio_dev;
+
+	cookie = dmaengine_submit(desc);
+	ret = dma_submit_error(cookie);
+	if (ret) {
+		dev_err(&indio_dev->dev, "cannot submit DMA cyclic\n");
+		dmaengine_terminate_async(st->dma_st.dma_chan);
+		return ret;
+	}
+
+	/* enable general overrun error signaling */
+	at91_adc_writel(st, AT91_SAMA5D2_IER, AT91_SAMA5D2_IER_GOVRE);
+	/* Issue pending DMA requests */
+	dma_async_issue_pending(st->dma_st.dma_chan);
+
+	/* consider current time as DMA start time for timestamps */
+	st->dma_st.dma_ts = iio_get_time_ns(indio_dev);
+
+	dev_dbg(&indio_dev->dev, "DMA cyclic started\n");
+
+	return 0;
+}
+
+static int at91_adc_buffer_postenable(struct iio_dev *indio_dev)
+{
+	int ret;
+
+	ret = at91_adc_dma_start(indio_dev);
+	if (ret) {
+		dev_err(&indio_dev->dev, "buffer postenable failed\n");
+		return ret;
+	}
+
+	return iio_triggered_buffer_postenable(indio_dev);
+}
+
+static int at91_adc_buffer_predisable(struct iio_dev *indio_dev)
+{
+	struct at91_adc_state *st = iio_priv(indio_dev);
+	int ret;
+	u8 bit;
+
+	ret = iio_triggered_buffer_predisable(indio_dev);
+	if (ret < 0)
+		dev_err(&indio_dev->dev, "buffer predisable failed\n");
+
+	if (!st->dma_st.dma_chan)
+		return ret;
+
+	/* if we are using DMA we must clear registers and end DMA */
+	dmaengine_terminate_sync(st->dma_st.dma_chan);
+
+	/*
+	 * For each enabled channel we must read the last converted value
+	 * to clear EOC status and not get a possible interrupt later.
+	 * This value is being read by DMA from LCDR anyway
+	 */
+	for_each_set_bit(bit, indio_dev->active_scan_mask,
+			 indio_dev->num_channels) {
+		struct iio_chan_spec const *chan = indio_dev->channels + bit;
+
+		if (st->dma_st.dma_chan)
+			at91_adc_readl(st, chan->address);
+	}
+
+	/* read overflow register to clear possible overflow status */
+	at91_adc_readl(st, AT91_SAMA5D2_OVER);
+	return ret;
+}
+
+static const struct iio_buffer_setup_ops at91_buffer_setup_ops = {
+	.postenable = &at91_adc_buffer_postenable,
+	.predisable = &at91_adc_buffer_predisable,
 };
 
 static struct iio_trigger *at91_adc_allocate_trigger(struct iio_dev *indio,
@@ -388,24 +578,77 @@ static int at91_adc_trigger_init(struct iio_dev *indio)
 	return 0;
 }
 
-static irqreturn_t at91_adc_trigger_handler(int irq, void *p)
+static void at91_adc_trigger_handler_nodma(struct iio_dev *indio_dev,
+					   struct iio_poll_func *pf)
 {
-	struct iio_poll_func *pf = p;
-	struct iio_dev *indio = pf->indio_dev;
-	struct at91_adc_state *st = iio_priv(indio);
+	struct at91_adc_state *st = iio_priv(indio_dev);
 	int i = 0;
 	u8 bit;
 
-	for_each_set_bit(bit, indio->active_scan_mask, indio->num_channels) {
-		struct iio_chan_spec const *chan = indio->channels + bit;
+	for_each_set_bit(bit, indio_dev->active_scan_mask,
+			 indio_dev->num_channels) {
+		struct iio_chan_spec const *chan = indio_dev->channels + bit;
 
 		st->buffer[i] = at91_adc_readl(st, chan->address);
 		i++;
 	}
+	iio_push_to_buffers_with_timestamp(indio_dev, st->buffer,
+					   pf->timestamp);
+}
 
-	iio_push_to_buffers_with_timestamp(indio, st->buffer, pf->timestamp);
+static void at91_adc_trigger_handler_dma(struct iio_dev *indio_dev)
+{
+	struct at91_adc_state *st = iio_priv(indio_dev);
+	int transferred_len = at91_adc_dma_size_done(st);
+	s64 ns = iio_get_time_ns(indio_dev);
+	s64 interval;
+	int sample_index = 0, sample_count, sample_size;
+
+	u32 status = at91_adc_readl(st, AT91_SAMA5D2_ISR);
+	/* if we reached this point, we cannot sample faster */
+	if (status & AT91_SAMA5D2_IER_GOVRE)
+		pr_info_ratelimited("%s: conversion overrun detected\n",
+				    indio_dev->name);
 
-	iio_trigger_notify_done(indio->trig);
+	sample_size = div_s64(st->dma_st.rx_buf_sz, st->dma_st.watermark);
+
+	sample_count = div_s64(transferred_len, sample_size);
+
+	/*
+	 * interval between samples is total time since last transfer handling
+	 * divided by the number of samples (total size divided by sample size)
+	 */
+	interval = div_s64((ns - st->dma_st.dma_ts), sample_count);
+
+	while (transferred_len >= sample_size) {
+		iio_push_to_buffers_with_timestamp(indio_dev,
+				(st->dma_st.rx_buf + st->dma_st.buf_idx),
+				(st->dma_st.dma_ts + interval * sample_index));
+		/* adjust remaining length */
+		transferred_len -= sample_size;
+		/* adjust buffer index */
+		st->dma_st.buf_idx += sample_size;
+		/* in case of reaching end of buffer, reset index */
+		if (st->dma_st.buf_idx >= st->dma_st.rx_buf_sz)
+			st->dma_st.buf_idx = 0;
+		sample_index++;
+	}
+	/* adjust saved time for next transfer handling */
+	st->dma_st.dma_ts = iio_get_time_ns(indio_dev);
+}
+
+static irqreturn_t at91_adc_trigger_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct at91_adc_state *st = iio_priv(indio_dev);
+
+	if (st->dma_st.dma_chan)
+		at91_adc_trigger_handler_dma(indio_dev);
+	else
+		at91_adc_trigger_handler_nodma(indio_dev, pf);
+
+	iio_trigger_notify_done(indio_dev->trig);
 
 	return IRQ_HANDLED;
 }
@@ -414,7 +657,7 @@ static int at91_adc_buffer_init(struct iio_dev *indio)
 {
 	return devm_iio_triggered_buffer_setup(&indio->dev, indio,
 			&iio_pollfunc_store_time,
-			&at91_adc_trigger_handler, NULL);
+			&at91_adc_trigger_handler, &at91_buffer_setup_ops);
 }
 
 static unsigned at91_adc_startup_time(unsigned startup_time_min,
@@ -485,10 +728,13 @@ static irqreturn_t at91_adc_interrupt(int irq, void *private)
 	if (!(status & imr))
 		return IRQ_NONE;
 
-	if (iio_buffer_enabled(indio)) {
+	if (iio_buffer_enabled(indio) && !st->dma_st.dma_chan) {
 		disable_irq_nosync(irq);
 		iio_trigger_poll(indio->trig);
-	} else {
+	} else if (iio_buffer_enabled(indio) && st->dma_st.dma_chan) {
+		disable_irq_nosync(irq);
+		WARN(true, "Unexpected irq occurred\n");
+	} else if (!iio_buffer_enabled(indio)) {
 		st->conversion_value = at91_adc_readl(st, st->chan->address);
 		st->conversion_done = true;
 		wake_up_interruptible(&st->wq_data_available);
@@ -510,7 +756,6 @@ static int at91_adc_read_raw(struct iio_dev *indio_dev,
 		ret = iio_device_claim_direct_mode(indio_dev);
 		if (ret)
 			return ret;
-
 		mutex_lock(&st->lock);
 
 		st->chan = chan;
@@ -541,6 +786,9 @@ static int at91_adc_read_raw(struct iio_dev *indio_dev,
 		at91_adc_writel(st, AT91_SAMA5D2_IDR, BIT(chan->channel));
 		at91_adc_writel(st, AT91_SAMA5D2_CHDR, BIT(chan->channel));
 
+		/* Needed to ACK the DRDY interruption */
+		at91_adc_readl(st, AT91_SAMA5D2_LCDR);
+
 		mutex_unlock(&st->lock);
 
 		iio_device_release_direct_mode(indio_dev);
@@ -580,9 +828,123 @@ static int at91_adc_write_raw(struct iio_dev *indio_dev,
 	return 0;
 }
 
+static void at91_adc_dma_init(struct platform_device *pdev)
+{
+	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+	struct at91_adc_state *st = iio_priv(indio_dev);
+	struct dma_slave_config config = {0};
+	/*
+	 * We make the buffer double the size of the fifo,
+	 * such that DMA uses one half of the buffer (full fifo size)
+	 * and the software uses the other half to read/write.
+	 */
+	unsigned int pages = DIV_ROUND_UP(AT91_HWFIFO_MAX_SIZE *
+					  AT91_BUFFER_MAX_CONVERSION_BYTES * 2,
+					  PAGE_SIZE);
+
+	if (st->dma_st.dma_chan)
+		return;
+
+	st->dma_st.dma_chan = dma_request_slave_channel(&pdev->dev, "rx");
+
+	if (!st->dma_st.dma_chan)  {
+		dev_info(&pdev->dev, "can't get DMA channel\n");
+		goto dma_exit;
+	}
+
+	st->dma_st.rx_buf = dma_alloc_coherent(st->dma_st.dma_chan->device->dev,
+					       pages * PAGE_SIZE,
+					       &st->dma_st.rx_dma_buf,
+					       GFP_KERNEL);
+	if (!st->dma_st.rx_buf) {
+		dev_info(&pdev->dev, "can't allocate coherent DMA area\n");
+		goto dma_chan_disable;
+	}
+
+	/* Configure DMA channel to read data register */
+	config.direction = DMA_DEV_TO_MEM;
+	config.src_addr = (phys_addr_t)(st->dma_st.phys_addr
+			  + AT91_SAMA5D2_LCDR);
+	config.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
+	config.src_maxburst = 1;
+	config.dst_maxburst = 1;
+
+	if (dmaengine_slave_config(st->dma_st.dma_chan, &config)) {
+		dev_info(&pdev->dev, "can't configure DMA slave\n");
+		goto dma_free_area;
+	}
+
+	dev_info(&pdev->dev, "using %s for rx DMA transfers\n",
+		 dma_chan_name(st->dma_st.dma_chan));
+
+	return;
+
+dma_free_area:
+	dma_free_coherent(st->dma_st.dma_chan->device->dev, pages * PAGE_SIZE,
+			  st->dma_st.rx_buf, st->dma_st.rx_dma_buf);
+dma_chan_disable:
+	dma_release_channel(st->dma_st.dma_chan);
+	st->dma_st.dma_chan = 0;
+dma_exit:
+	dev_info(&pdev->dev, "continuing without DMA support\n");
+}
+
+static void at91_adc_dma_disable(struct platform_device *pdev)
+{
+	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+	struct at91_adc_state *st = iio_priv(indio_dev);
+	unsigned int pages = DIV_ROUND_UP(AT91_HWFIFO_MAX_SIZE *
+					  AT91_BUFFER_MAX_CONVERSION_BYTES * 2,
+					  PAGE_SIZE);
+
+	/* if we are not using DMA, just return */
+	if (!st->dma_st.dma_chan)
+		return;
+
+	/* wait for all transactions to be terminated first*/
+	dmaengine_terminate_sync(st->dma_st.dma_chan);
+
+	dma_free_coherent(st->dma_st.dma_chan->device->dev, pages * PAGE_SIZE,
+			  st->dma_st.rx_buf, st->dma_st.rx_dma_buf);
+	dma_release_channel(st->dma_st.dma_chan);
+	st->dma_st.dma_chan = 0;
+
+	dev_info(&pdev->dev, "continuing without DMA support\n");
+}
+
+static int at91_adc_set_watermark(struct iio_dev *indio_dev, unsigned int val)
+{
+	struct at91_adc_state *st = iio_priv(indio_dev);
+
+	if (val > AT91_HWFIFO_MAX_SIZE)
+		return -EINVAL;
+
+	if (!st->selected_trig->hw_trig) {
+		dev_dbg(&indio_dev->dev, "we need hw trigger for DMA\n");
+		return 0;
+	}
+
+	dev_dbg(&indio_dev->dev, "new watermark is %u\n", val);
+	st->dma_st.watermark = val;
+
+	/*
+	 * The logic here is: if we have watermark 1, it means we do
+	 * each conversion with it's own IRQ, thus we don't need DMA.
+	 * If the watermark is higher, we do DMA to do all the transfers in bulk
+	 */
+
+	if (val == 1)
+		at91_adc_dma_disable(to_platform_device(&indio_dev->dev));
+	else if (val > 1)
+		at91_adc_dma_init(to_platform_device(&indio_dev->dev));
+
+	return 0;
+}
+
 static const struct iio_info at91_adc_info = {
 	.read_raw = &at91_adc_read_raw,
 	.write_raw = &at91_adc_write_raw,
+	.hwfifo_set_watermark = &at91_adc_set_watermark,
 };
 
 static void at91_adc_hw_init(struct at91_adc_state *st)
@@ -599,6 +961,42 @@ static void at91_adc_hw_init(struct at91_adc_state *st)
 	at91_adc_setup_samp_freq(st, st->soc_info.min_sample_rate);
 }
 
+static ssize_t at91_adc_get_fifo_state(struct device *dev,
+				       struct device_attribute *attr, char *buf)
+{
+	struct iio_dev *indio_dev =
+			platform_get_drvdata(to_platform_device(dev));
+	struct at91_adc_state *st = iio_priv(indio_dev);
+
+	return scnprintf(buf, PAGE_SIZE, "%d\n", !!st->dma_st.dma_chan);
+}
+
+static ssize_t at91_adc_get_watermark(struct device *dev,
+				      struct device_attribute *attr, char *buf)
+{
+	struct iio_dev *indio_dev =
+			platform_get_drvdata(to_platform_device(dev));
+	struct at91_adc_state *st = iio_priv(indio_dev);
+
+	return scnprintf(buf, PAGE_SIZE, "%d\n", st->dma_st.watermark);
+}
+
+static IIO_DEVICE_ATTR(hwfifo_enabled, 0444,
+		       at91_adc_get_fifo_state, NULL, 0);
+static IIO_DEVICE_ATTR(hwfifo_watermark, 0444,
+		       at91_adc_get_watermark, NULL, 0);
+
+static IIO_CONST_ATTR(hwfifo_watermark_min, "2");
+static IIO_CONST_ATTR(hwfifo_watermark_max, AT91_HWFIFO_MAX_SIZE_STR);
+
+static const struct attribute *at91_adc_fifo_attributes[] = {
+	&iio_const_attr_hwfifo_watermark_min.dev_attr.attr,
+	&iio_const_attr_hwfifo_watermark_max.dev_attr.attr,
+	&iio_dev_attr_hwfifo_watermark.dev_attr.attr,
+	&iio_dev_attr_hwfifo_enabled.dev_attr.attr,
+	NULL,
+};
+
 static int at91_adc_probe(struct platform_device *pdev)
 {
 	struct iio_dev *indio_dev;
@@ -674,6 +1072,9 @@ static int at91_adc_probe(struct platform_device *pdev)
 	if (!res)
 		return -EINVAL;
 
+	/* if we plan to use DMA, we need the physical address of the regs */
+	st->dma_st.phys_addr = res->start;
+
 	st->base = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(st->base))
 		return PTR_ERR(st->base);
@@ -737,11 +1138,22 @@ static int at91_adc_probe(struct platform_device *pdev)
 			dev_err(&pdev->dev, "couldn't setup the triggers.\n");
 			goto per_clk_disable_unprepare;
 		}
+		/*
+		 * Initially the iio buffer has a length of 2 and
+		 * a watermark of 1
+		 */
+		st->dma_st.watermark = 1;
+
+		iio_buffer_set_attrs(indio_dev->buffer,
+				     at91_adc_fifo_attributes);
 	}
 
+	if (dma_coerce_mask_and_coherent(&indio_dev->dev, DMA_BIT_MASK(32)))
+		dev_info(&pdev->dev, "cannot set DMA mask to 32-bit\n");
+
 	ret = iio_device_register(indio_dev);
 	if (ret < 0)
-		goto per_clk_disable_unprepare;
+		goto dma_disable;
 
 	if (st->selected_trig->hw_trig)
 		dev_info(&pdev->dev, "setting up trigger as %s\n",
@@ -752,6 +1164,8 @@ static int at91_adc_probe(struct platform_device *pdev)
 
 	return 0;
 
+dma_disable:
+	at91_adc_dma_disable(pdev);
 per_clk_disable_unprepare:
 	clk_disable_unprepare(st->per_clk);
 vref_disable:
@@ -768,6 +1182,8 @@ static int at91_adc_remove(struct platform_device *pdev)
 
 	iio_device_unregister(indio_dev);
 
+	at91_adc_dma_disable(pdev);
+
 	clk_disable_unprepare(st->per_clk);
 
 	regulator_disable(st->vref);

drivers/iio/adc/axp288_adc.c

@@ -92,22 +92,14 @@ static const struct iio_chan_spec axp288_adc_channels[] = {
 	},
 };
 
-#define AXP288_ADC_MAP(_adc_channel_label, _consumer_dev_name,	\
-		_consumer_channel)				\
-	{							\
-		.adc_channel_label = _adc_channel_label,	\
-		.consumer_dev_name = _consumer_dev_name,	\
-		.consumer_channel = _consumer_channel,		\
-	}
-
 /* for consumer drivers */
 static struct iio_map axp288_adc_default_maps[] = {
-	AXP288_ADC_MAP("TS_PIN", "axp288-batt", "axp288-batt-temp"),
-	AXP288_ADC_MAP("PMIC_TEMP", "axp288-pmic", "axp288-pmic-temp"),
-	AXP288_ADC_MAP("GPADC", "axp288-gpadc", "axp288-system-temp"),
-	AXP288_ADC_MAP("BATT_CHG_I", "axp288-chrg", "axp288-chrg-curr"),
-	AXP288_ADC_MAP("BATT_DISCHRG_I", "axp288-chrg", "axp288-chrg-d-curr"),
-	AXP288_ADC_MAP("BATT_V", "axp288-batt", "axp288-batt-volt"),
+	IIO_MAP("TS_PIN", "axp288-batt", "axp288-batt-temp"),
+	IIO_MAP("PMIC_TEMP", "axp288-pmic", "axp288-pmic-temp"),
+	IIO_MAP("GPADC", "axp288-gpadc", "axp288-system-temp"),
+	IIO_MAP("BATT_CHG_I", "axp288-chrg", "axp288-chrg-curr"),
+	IIO_MAP("BATT_DISCHRG_I", "axp288-chrg", "axp288-chrg-d-curr"),
+	IIO_MAP("BATT_V", "axp288-batt", "axp288-batt-volt"),
 	{},
 };
 

drivers/iio/adc/ina2xx-adc.c

@@ -44,13 +44,14 @@
 
 #define INA226_MASK_ENABLE		0x06
 #define INA226_CVRF			BIT(3)
-#define INA219_CNVR			BIT(1)
 
 #define INA2XX_MAX_REGISTERS            8
 
 /* settings - depend on use case */
-#define INA219_CONFIG_DEFAULT           0x399F	/* PGA=8 */
+#define INA219_CONFIG_DEFAULT           0x399F	/* PGA=1/8, BRNG=32V */
 #define INA219_DEFAULT_IT		532
+#define INA219_DEFAULT_BRNG             1   /* 32V */
+#define INA219_DEFAULT_PGA              125 /* 1000/8 */
 #define INA226_CONFIG_DEFAULT           0x4327
 #define INA226_DEFAULT_AVG              4
 #define INA226_DEFAULT_IT		1110
@@ -63,6 +64,14 @@
  */
 #define INA2XX_MODE_MASK	GENMASK(3, 0)
 
+/* Gain for VShunt: 1/8 (default), 1/4, 1/2, 1 */
+#define INA219_PGA_MASK		GENMASK(12, 11)
+#define INA219_SHIFT_PGA(val)	((val) << 11)
+
+/* VBus range: 32V (default), 16V */
+#define INA219_BRNG_MASK	BIT(13)
+#define INA219_SHIFT_BRNG(val)	((val) << 13)
+
 /* Averaging for VBus/VShunt/Power */
 #define INA226_AVG_MASK		GENMASK(11, 9)
 #define INA226_SHIFT_AVG(val)	((val) << 9)
@@ -79,6 +88,11 @@
 #define INA226_ITS_MASK		GENMASK(5, 3)
 #define INA226_SHIFT_ITS(val)	((val) << 3)
 
+/* INA219 Bus voltage register, low bits are flags */
+#define INA219_OVF		BIT(0)
+#define INA219_CNVR		BIT(1)
+#define INA219_BUS_VOLTAGE_SHIFT	3
+
 /* Cosmetic macro giving the sampling period for a full P=UxI cycle */
 #define SAMPLING_PERIOD(c)	((c->int_time_vbus + c->int_time_vshunt) \
 				 * c->avg)
@@ -111,8 +125,8 @@ enum ina2xx_ids { ina219, ina226 };
 struct ina2xx_config {
 	u16 config_default;
 	int calibration_factor;
-	int shunt_div;
-	int bus_voltage_shift;
+	int shunt_voltage_lsb;	/* nV */
+	int bus_voltage_shift;	/* position of lsb */
 	int bus_voltage_lsb;	/* uV */
 	int power_lsb;		/* uW */
 	enum ina2xx_ids chip_id;
@@ -127,6 +141,8 @@ struct ina2xx_chip_info {
 	int avg;
 	int int_time_vbus; /* Bus voltage integration time uS */
 	int int_time_vshunt; /* Shunt voltage integration time uS */
+	int range_vbus; /* Bus voltage maximum in V */
+	int pga_gain_vshunt; /* Shunt voltage PGA gain */
 	bool allow_async_readout;
 };
 
@@ -134,8 +150,8 @@ static const struct ina2xx_config ina2xx_config[] = {
 	[ina219] = {
 		.config_default = INA219_CONFIG_DEFAULT,
 		.calibration_factor = 40960000,
-		.shunt_div = 100,
-		.bus_voltage_shift = 3,
+		.shunt_voltage_lsb = 10000,
+		.bus_voltage_shift = INA219_BUS_VOLTAGE_SHIFT,
 		.bus_voltage_lsb = 4000,
 		.power_lsb = 20000,
 		.chip_id = ina219,
@@ -143,7 +159,7 @@ static const struct ina2xx_config ina2xx_config[] = {
 	[ina226] = {
 		.config_default = INA226_CONFIG_DEFAULT,
 		.calibration_factor = 5120000,
-		.shunt_div = 400,
+		.shunt_voltage_lsb = 2500,
 		.bus_voltage_shift = 0,
 		.bus_voltage_lsb = 1250,
 		.power_lsb = 25000,
@@ -170,6 +186,9 @@ static int ina2xx_read_raw(struct iio_dev *indio_dev,
 		else
 			*val  = regval;
 
+		if (chan->address == INA2XX_BUS_VOLTAGE)
+			*val >>= chip->config->bus_voltage_shift;
+
 		return IIO_VAL_INT;
 
 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
@@ -197,15 +216,15 @@ static int ina2xx_read_raw(struct iio_dev *indio_dev,
 	case IIO_CHAN_INFO_SCALE:
 		switch (chan->address) {
 		case INA2XX_SHUNT_VOLTAGE:
-			/* processed (mV) = raw/shunt_div */
-			*val2 = chip->config->shunt_div;
-			*val = 1;
+			/* processed (mV) = raw * lsb(nV) / 1000000 */
+			*val = chip->config->shunt_voltage_lsb;
+			*val2 = 1000000;
 			return IIO_VAL_FRACTIONAL;
 
 		case INA2XX_BUS_VOLTAGE:
-			/* processed (mV) = raw*lsb (uV) / (1000 << shift) */
+			/* processed (mV) = raw * lsb (uV) / 1000 */
 			*val = chip->config->bus_voltage_lsb;
-			*val2 = 1000 << chip->config->bus_voltage_shift;
+			*val2 = 1000;
 			return IIO_VAL_FRACTIONAL;
 
 		case INA2XX_POWER:
@@ -219,6 +238,18 @@ static int ina2xx_read_raw(struct iio_dev *indio_dev,
 			*val = 1;
 			return IIO_VAL_INT;
 		}
+
+	case IIO_CHAN_INFO_HARDWAREGAIN:
+		switch (chan->address) {
+		case INA2XX_SHUNT_VOLTAGE:
+			*val = chip->pga_gain_vshunt;
+			*val2 = 1000;
+			return IIO_VAL_FRACTIONAL;
+
+		case INA2XX_BUS_VOLTAGE:
+			*val = chip->range_vbus == 32 ? 1 : 2;
+			return IIO_VAL_INT;
+		}
 	}
 
 	return -EINVAL;
@@ -353,6 +384,74 @@ static int ina219_set_int_time_vshunt(struct ina2xx_chip_info *chip,
 	return 0;
 }
 
+static const int ina219_vbus_range_tab[] = { 1, 2 };
+static int ina219_set_vbus_range_denom(struct ina2xx_chip_info *chip,
+				       unsigned int range,
+				       unsigned int *config)
+{
+	if (range == 1)
+		chip->range_vbus = 32;
+	else if (range == 2)
+		chip->range_vbus = 16;
+	else
+		return -EINVAL;
+
+	*config &= ~INA219_BRNG_MASK;
+	*config |= INA219_SHIFT_BRNG(range == 1 ? 1 : 0) & INA219_BRNG_MASK;
+
+	return 0;
+}
+
+static const int ina219_vshunt_gain_tab[] = { 125, 250, 500, 1000 };
+static const int ina219_vshunt_gain_frac[] = {
+	125, 1000, 250, 1000, 500, 1000, 1000, 1000 };
+
+static int ina219_set_vshunt_pga_gain(struct ina2xx_chip_info *chip,
+				      unsigned int gain,
+				      unsigned int *config)
+{
+	int bits;
+
+	if (gain < 125 || gain > 1000)
+		return -EINVAL;
+
+	bits = find_closest(gain, ina219_vshunt_gain_tab,
+			    ARRAY_SIZE(ina219_vshunt_gain_tab));
+
+	chip->pga_gain_vshunt = ina219_vshunt_gain_tab[bits];
+	bits = 3 - bits;
+
+	*config &= ~INA219_PGA_MASK;
+	*config |= INA219_SHIFT_PGA(bits) & INA219_PGA_MASK;
+
+	return 0;
+}
+
+static int ina2xx_read_avail(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan,
+			     const int **vals, int *type, int *length,
+			     long mask)
+{
+	switch (mask) {
+	case IIO_CHAN_INFO_HARDWAREGAIN:
+		switch (chan->address) {
+		case INA2XX_SHUNT_VOLTAGE:
+			*type = IIO_VAL_FRACTIONAL;
+			*length = sizeof(ina219_vshunt_gain_frac) / sizeof(int);
+			*vals = ina219_vshunt_gain_frac;
+			return IIO_AVAIL_LIST;
+
+		case INA2XX_BUS_VOLTAGE:
+			*type = IIO_VAL_INT;
+			*length = sizeof(ina219_vbus_range_tab) / sizeof(int);
+			*vals = ina219_vbus_range_tab;
+			return IIO_AVAIL_LIST;
+		}
+	}
+
+	return -EINVAL;
+}
+
 static int ina2xx_write_raw(struct iio_dev *indio_dev,
 			    struct iio_chan_spec const *chan,
 			    int val, int val2, long mask)
@@ -395,6 +494,14 @@ static int ina2xx_write_raw(struct iio_dev *indio_dev,
 		}
 		break;
 
+	case IIO_CHAN_INFO_HARDWAREGAIN:
+		if (chan->address == INA2XX_SHUNT_VOLTAGE)
+			ret = ina219_set_vshunt_pga_gain(chip, val * 1000 +
+							 val2 / 1000, &tmp);
+		else
+			ret = ina219_set_vbus_range_denom(chip, val, &tmp);
+		break;
+
 	default:
 		ret = -EINVAL;
 	}
@@ -532,19 +639,23 @@ static ssize_t ina2xx_shunt_resistor_store(struct device *dev,
  * Sampling Freq is a consequence of the integration times of
  * the Voltage channels.
  */
-#define INA219_CHAN_VOLTAGE(_index, _address) { \
+#define INA219_CHAN_VOLTAGE(_index, _address, _shift) { \
 	.type = IIO_VOLTAGE, \
 	.address = (_address), \
 	.indexed = 1, \
 	.channel = (_index), \
 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
 			      BIT(IIO_CHAN_INFO_SCALE) | \
-			      BIT(IIO_CHAN_INFO_INT_TIME), \
+			      BIT(IIO_CHAN_INFO_INT_TIME) | \
+			      BIT(IIO_CHAN_INFO_HARDWAREGAIN), \
+	.info_mask_separate_available = \
+			      BIT(IIO_CHAN_INFO_HARDWAREGAIN), \
 	.info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
 	.scan_index = (_index), \
 	.scan_type = { \
 		.sign = 'u', \
-		.realbits = 16, \
+		.shift = _shift, \
+		.realbits = 16 - _shift, \
 		.storagebits = 16, \
 		.endianness = IIO_LE, \
 	} \
@@ -579,8 +690,8 @@ static const struct iio_chan_spec ina226_channels[] = {
 };
 
 static const struct iio_chan_spec ina219_channels[] = {
-	INA219_CHAN_VOLTAGE(0, INA2XX_SHUNT_VOLTAGE),
-	INA219_CHAN_VOLTAGE(1, INA2XX_BUS_VOLTAGE),
+	INA219_CHAN_VOLTAGE(0, INA2XX_SHUNT_VOLTAGE, 0),
+	INA219_CHAN_VOLTAGE(1, INA2XX_BUS_VOLTAGE, INA219_BUS_VOLTAGE_SHIFT),
 	INA219_CHAN(IIO_POWER, 2, INA2XX_POWER),
 	INA219_CHAN(IIO_CURRENT, 3, INA2XX_CURRENT),
 	IIO_CHAN_SOFT_TIMESTAMP(4),
@@ -746,7 +857,6 @@ static IIO_CONST_ATTR_NAMED(ina226_integration_time_available,
 			    integration_time_available,
 			    "0.000140 0.000204 0.000332 0.000588 0.001100 0.002116 0.004156 0.008244");
 
-
 static IIO_DEVICE_ATTR(in_allow_async_readout, S_IRUGO | S_IWUSR,
 		       ina2xx_allow_async_readout_show,
 		       ina2xx_allow_async_readout_store, 0);
@@ -780,6 +890,7 @@ static const struct attribute_group ina226_attribute_group = {
 static const struct iio_info ina219_info = {
 	.attrs = &ina219_attribute_group,
 	.read_raw = ina2xx_read_raw,
+	.read_avail = ina2xx_read_avail,
 	.write_raw = ina2xx_write_raw,
 	.debugfs_reg_access = ina2xx_debug_reg,
 };
@@ -860,6 +971,8 @@ static int ina2xx_probe(struct i2c_client *client,
 		chip->avg = 1;
 		ina219_set_int_time_vbus(chip, INA219_DEFAULT_IT, &val);
 		ina219_set_int_time_vshunt(chip, INA219_DEFAULT_IT, &val);
+		ina219_set_vbus_range_denom(chip, INA219_DEFAULT_BRNG, &val);
+		ina219_set_vshunt_pga_gain(chip, INA219_DEFAULT_PGA, &val);
 	}
 
 	ret = ina2xx_init(chip, val);

drivers/iio/adc/meson_saradc.c

@@ -231,7 +231,6 @@ struct meson_sar_adc_priv {
 	const struct meson_sar_adc_data		*data;
 	struct clk				*clkin;
 	struct clk				*core_clk;
-	struct clk				*sana_clk;
 	struct clk				*adc_sel_clk;
 	struct clk				*adc_clk;
 	struct clk_gate				clk_gate;
@@ -708,12 +707,6 @@ static int meson_sar_adc_hw_enable(struct iio_dev *indio_dev)
 		goto err_core_clk;
 	}
 
-	ret = clk_prepare_enable(priv->sana_clk);
-	if (ret) {
-		dev_err(indio_dev->dev.parent, "failed to enable sana clk\n");
-		goto err_sana_clk;
-	}
-
 	regval = FIELD_PREP(MESON_SAR_ADC_REG0_FIFO_CNT_IRQ_MASK, 1);
 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG0,
 			   MESON_SAR_ADC_REG0_FIFO_CNT_IRQ_MASK, regval);
@@ -741,8 +734,6 @@ err_adc_clk:
 			   MESON_SAR_ADC_REG3_ADC_EN, 0);
 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG11,
 			   MESON_SAR_ADC_REG11_BANDGAP_EN, 0);
-	clk_disable_unprepare(priv->sana_clk);
-err_sana_clk:
 	clk_disable_unprepare(priv->core_clk);
 err_core_clk:
 	regulator_disable(priv->vref);
@@ -768,7 +759,6 @@ static int meson_sar_adc_hw_disable(struct iio_dev *indio_dev)
 	regmap_update_bits(priv->regmap, MESON_SAR_ADC_REG11,
 			   MESON_SAR_ADC_REG11_BANDGAP_EN, 0);
 
-	clk_disable_unprepare(priv->sana_clk);
 	clk_disable_unprepare(priv->core_clk);
 
 	regulator_disable(priv->vref);
@@ -961,16 +951,6 @@ static int meson_sar_adc_probe(struct platform_device *pdev)
 		return PTR_ERR(priv->core_clk);
 	}
 
-	priv->sana_clk = devm_clk_get(&pdev->dev, "sana");
-	if (IS_ERR(priv->sana_clk)) {
-		if (PTR_ERR(priv->sana_clk) == -ENOENT) {
-			priv->sana_clk = NULL;
-		} else {
-			dev_err(&pdev->dev, "failed to get sana clk\n");
-			return PTR_ERR(priv->sana_clk);
-		}
-	}
-
 	priv->adc_clk = devm_clk_get(&pdev->dev, "adc_clk");
 	if (IS_ERR(priv->adc_clk)) {
 		if (PTR_ERR(priv->adc_clk) == -ENOENT) {

drivers/iio/adc/qcom-vadc-common.c

@@ -5,6 +5,7 @@
 #include <linux/math64.h>
 #include <linux/log2.h>
 #include <linux/err.h>
+#include <linux/module.h>
 
 #include "qcom-vadc-common.h"
 
@@ -229,3 +230,6 @@ int qcom_vadc_decimation_from_dt(u32 value)
 	return __ffs64(value / VADC_DECIMATION_MIN);
 }
 EXPORT_SYMBOL(qcom_vadc_decimation_from_dt);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Qualcomm ADC common functionality");

drivers/iio/adc/stm32-adc.c

@@ -92,6 +92,7 @@
 #define STM32H7_ADC_SQR3		0x38
 #define STM32H7_ADC_SQR4		0x3C
 #define STM32H7_ADC_DR			0x40
+#define STM32H7_ADC_DIFSEL		0xC0
 #define STM32H7_ADC_CALFACT		0xC4
 #define STM32H7_ADC_CALFACT2		0xC8
 
@@ -153,6 +154,8 @@ enum stm32h7_adc_dmngt {
 /* BOOST bit must be set on STM32H7 when ADC clock is above 20MHz */
 #define STM32H7_BOOST_CLKRATE		20000000UL
 
+#define STM32_ADC_CH_MAX		20	/* max number of channels */
+#define STM32_ADC_CH_SZ			10	/* max channel name size */
 #define STM32_ADC_MAX_SQ		16	/* SQ1..SQ16 */
 #define STM32_ADC_MAX_SMP		7	/* SMPx range is [0..7] */
 #define STM32_ADC_TIMEOUT_US		100000
@@ -297,9 +300,11 @@ struct stm32_adc_cfg {
  * @rx_buf:		dma rx buffer cpu address
  * @rx_dma_buf:		dma rx buffer bus address
  * @rx_buf_sz:		dma rx buffer size
+ * @difsel		bitmask to set single-ended/differential channel
  * @pcsel		bitmask to preselect channels on some devices
  * @smpr_val:		sampling time settings (e.g. smpr1 / smpr2)
  * @cal:		optional calibration data on some devices
+ * @chan_name:		channel name array
  */
 struct stm32_adc {
 	struct stm32_adc_common	*common;
@@ -318,72 +323,37 @@ struct stm32_adc {
 	u8			*rx_buf;
 	dma_addr_t		rx_dma_buf;
 	unsigned int		rx_buf_sz;
+	u32			difsel;
 	u32			pcsel;
 	u32			smpr_val[2];
 	struct stm32_adc_calib	cal;
+	char			chan_name[STM32_ADC_CH_MAX][STM32_ADC_CH_SZ];
 };
 
-/**
- * struct stm32_adc_chan_spec - specification of stm32 adc channel
- * @type:	IIO channel type
- * @channel:	channel number (single ended)
- * @name:	channel name (single ended)
- */
-struct stm32_adc_chan_spec {
-	enum iio_chan_type	type;
-	int			channel;
-	const char		*name;
+struct stm32_adc_diff_channel {
+	u32 vinp;
+	u32 vinn;
 };
 
 /**
  * struct stm32_adc_info - stm32 ADC, per instance config data
- * @channels:		Reference to stm32 channels spec
  * @max_channels:	Number of channels
  * @resolutions:	available resolutions
  * @num_res:		number of available resolutions
  */
 struct stm32_adc_info {
-	const struct stm32_adc_chan_spec *channels;
 	int max_channels;
 	const unsigned int *resolutions;
 	const unsigned int num_res;
 };
 
-/*
- * Input definitions common for all instances:
- * stm32f4 can have up to 16 channels
- * stm32h7 can have up to 20 channels
- */
-static const struct stm32_adc_chan_spec stm32_adc_channels[] = {
-	{ IIO_VOLTAGE, 0, "in0" },
-	{ IIO_VOLTAGE, 1, "in1" },
-	{ IIO_VOLTAGE, 2, "in2" },
-	{ IIO_VOLTAGE, 3, "in3" },
-	{ IIO_VOLTAGE, 4, "in4" },
-	{ IIO_VOLTAGE, 5, "in5" },
-	{ IIO_VOLTAGE, 6, "in6" },
-	{ IIO_VOLTAGE, 7, "in7" },
-	{ IIO_VOLTAGE, 8, "in8" },
-	{ IIO_VOLTAGE, 9, "in9" },
-	{ IIO_VOLTAGE, 10, "in10" },
-	{ IIO_VOLTAGE, 11, "in11" },
-	{ IIO_VOLTAGE, 12, "in12" },
-	{ IIO_VOLTAGE, 13, "in13" },
-	{ IIO_VOLTAGE, 14, "in14" },
-	{ IIO_VOLTAGE, 15, "in15" },
-	{ IIO_VOLTAGE, 16, "in16" },
-	{ IIO_VOLTAGE, 17, "in17" },
-	{ IIO_VOLTAGE, 18, "in18" },
-	{ IIO_VOLTAGE, 19, "in19" },
-};
-
 static const unsigned int stm32f4_adc_resolutions[] = {
 	/* sorted values so the index matches RES[1:0] in STM32F4_ADC_CR1 */
 	12, 10, 8, 6,
 };
 
+/* stm32f4 can have up to 16 channels */
 static const struct stm32_adc_info stm32f4_adc_info = {
-	.channels = stm32_adc_channels,
 	.max_channels = 16,
 	.resolutions = stm32f4_adc_resolutions,
 	.num_res = ARRAY_SIZE(stm32f4_adc_resolutions),
@@ -394,9 +364,9 @@ static const unsigned int stm32h7_adc_resolutions[] = {
 	16, 14, 12, 10, 8,
 };
 
+/* stm32h7 can have up to 20 channels */
 static const struct stm32_adc_info stm32h7_adc_info = {
-	.channels = stm32_adc_channels,
-	.max_channels = 20,
+	.max_channels = STM32_ADC_CH_MAX,
 	.resolutions = stm32h7_adc_resolutions,
 	.num_res = ARRAY_SIZE(stm32h7_adc_resolutions),
 };
@@ -983,15 +953,19 @@ pwr_dwn:
  * stm32h7_adc_prepare() - Leave power down mode to enable ADC.
  * @adc: stm32 adc instance
  * Leave power down mode.
+ * Configure channels as single ended or differential before enabling ADC.
  * Enable ADC.
  * Restore calibration data.
- * Pre-select channels that may be used in PCSEL (required by input MUX / IO).
+ * Pre-select channels that may be used in PCSEL (required by input MUX / IO):
+ * - Only one input is selected for single ended (e.g. 'vinp')
+ * - Two inputs are selected for differential channels (e.g. 'vinp' & 'vinn')
  */
 static int stm32h7_adc_prepare(struct stm32_adc *adc)
 {
 	int ret;
 
 	stm32h7_adc_exit_pwr_down(adc);
+	stm32_adc_writel(adc, STM32H7_ADC_DIFSEL, adc->difsel);
 
 	ret = stm32h7_adc_enable(adc);
 	if (ret)
@@ -1263,10 +1237,23 @@ static int stm32_adc_read_raw(struct iio_dev *indio_dev,
 		return ret;
 
 	case IIO_CHAN_INFO_SCALE:
-		*val = adc->common->vref_mv;
-		*val2 = chan->scan_type.realbits;
+		if (chan->differential) {
+			*val = adc->common->vref_mv * 2;
+			*val2 = chan->scan_type.realbits;
+		} else {
+			*val = adc->common->vref_mv;
+			*val2 = chan->scan_type.realbits;
+		}
 		return IIO_VAL_FRACTIONAL_LOG2;
 
+	case IIO_CHAN_INFO_OFFSET:
+		if (chan->differential)
+			/* ADC_full_scale / 2 */
+			*val = -((1 << chan->scan_type.realbits) / 2);
+		else
+			*val = 0;
+		return IIO_VAL_INT;
+
 	default:
 		return -EINVAL;
 	}
@@ -1628,29 +1615,40 @@ static void stm32_adc_smpr_init(struct stm32_adc *adc, int channel, u32 smp_ns)
 }
 
 static void stm32_adc_chan_init_one(struct iio_dev *indio_dev,
-				    struct iio_chan_spec *chan,
-				    const struct stm32_adc_chan_spec *channel,
-				    int scan_index, u32 smp)
+				    struct iio_chan_spec *chan, u32 vinp,
+				    u32 vinn, int scan_index, bool differential)
 {
 	struct stm32_adc *adc = iio_priv(indio_dev);
-
-	chan->type = channel->type;
-	chan->channel = channel->channel;
-	chan->datasheet_name = channel->name;
+	char *name = adc->chan_name[vinp];
+
+	chan->type = IIO_VOLTAGE;
+	chan->channel = vinp;
+	if (differential) {
+		chan->differential = 1;
+		chan->channel2 = vinn;
+		snprintf(name, STM32_ADC_CH_SZ, "in%d-in%d", vinp, vinn);
+	} else {
+		snprintf(name, STM32_ADC_CH_SZ, "in%d", vinp);
+	}
+	chan->datasheet_name = name;
 	chan->scan_index = scan_index;
 	chan->indexed = 1;
 	chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
-	chan->info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE);
+	chan->info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |
+					 BIT(IIO_CHAN_INFO_OFFSET);
 	chan->scan_type.sign = 'u';
 	chan->scan_type.realbits = adc->cfg->adc_info->resolutions[adc->res];
 	chan->scan_type.storagebits = 16;
 	chan->ext_info = stm32_adc_ext_info;
 
-	/* Prepare sampling time settings */
-	stm32_adc_smpr_init(adc, chan->channel, smp);
-
 	/* pre-build selected channels mask */
 	adc->pcsel |= BIT(chan->channel);
+	if (differential) {
+		/* pre-build diff channels mask */
+		adc->difsel |= BIT(chan->channel);
+		/* Also add negative input to pre-selected channels */
+		adc->pcsel |= BIT(chan->channel2);
+	}
 }
 
 static int stm32_adc_chan_of_init(struct iio_dev *indio_dev)
@@ -1658,17 +1656,40 @@ static int stm32_adc_chan_of_init(struct iio_dev *indio_dev)
 	struct device_node *node = indio_dev->dev.of_node;
 	struct stm32_adc *adc = iio_priv(indio_dev);
 	const struct stm32_adc_info *adc_info = adc->cfg->adc_info;
+	struct stm32_adc_diff_channel diff[STM32_ADC_CH_MAX];
 	struct property *prop;
 	const __be32 *cur;
 	struct iio_chan_spec *channels;
-	int scan_index = 0, num_channels, ret;
+	int scan_index = 0, num_channels = 0, num_diff = 0, ret, i;
 	u32 val, smp = 0;
 
-	num_channels = of_property_count_u32_elems(node, "st,adc-channels");
-	if (num_channels < 0 ||
-	    num_channels > adc_info->max_channels) {
+	ret = of_property_count_u32_elems(node, "st,adc-channels");
+	if (ret > adc_info->max_channels) {
 		dev_err(&indio_dev->dev, "Bad st,adc-channels?\n");
-		return num_channels < 0 ? num_channels : -EINVAL;
+		return -EINVAL;
+	} else if (ret > 0) {
+		num_channels += ret;
+	}
+
+	ret = of_property_count_elems_of_size(node, "st,adc-diff-channels",
+					      sizeof(*diff));
+	if (ret > adc_info->max_channels) {
+		dev_err(&indio_dev->dev, "Bad st,adc-diff-channels?\n");
+		return -EINVAL;
+	} else if (ret > 0) {
+		int size = ret * sizeof(*diff) / sizeof(u32);
+
+		num_diff = ret;
+		num_channels += ret;
+		ret = of_property_read_u32_array(node, "st,adc-diff-channels",
+						 (u32 *)diff, size);
+		if (ret)
+			return ret;
+	}
+
+	if (!num_channels) {
+		dev_err(&indio_dev->dev, "No channels configured\n");
+		return -ENODATA;
 	}
 
 	/* Optional sample time is provided either for each, or all channels */
@@ -1689,6 +1710,33 @@ static int stm32_adc_chan_of_init(struct iio_dev *indio_dev)
 			return -EINVAL;
 		}
 
+		/* Channel can't be configured both as single-ended & diff */
+		for (i = 0; i < num_diff; i++) {
+			if (val == diff[i].vinp) {
+				dev_err(&indio_dev->dev,
+					"channel %d miss-configured\n",	val);
+				return -EINVAL;
+			}
+		}
+		stm32_adc_chan_init_one(indio_dev, &channels[scan_index], val,
+					0, scan_index, false);
+		scan_index++;
+	}
+
+	for (i = 0; i < num_diff; i++) {
+		if (diff[i].vinp >= adc_info->max_channels ||
+		    diff[i].vinn >= adc_info->max_channels) {
+			dev_err(&indio_dev->dev, "Invalid channel in%d-in%d\n",
+				diff[i].vinp, diff[i].vinn);
+			return -EINVAL;
+		}
+		stm32_adc_chan_init_one(indio_dev, &channels[scan_index],
+					diff[i].vinp, diff[i].vinn, scan_index,
+					true);
+		scan_index++;
+	}
+
+	for (i = 0; i < scan_index; i++) {
 		/*
 		 * Using of_property_read_u32_index(), smp value will only be
 		 * modified if valid u32 value can be decoded. This allows to
@@ -1696,12 +1744,9 @@ static int stm32_adc_chan_of_init(struct iio_dev *indio_dev)
 		 * value per channel.
 		 */
 		of_property_read_u32_index(node, "st,min-sample-time-nsecs",
-					   scan_index, &smp);
-
-		stm32_adc_chan_init_one(indio_dev, &channels[scan_index],
-					&adc_info->channels[val],
-					scan_index, smp);
-		scan_index++;
+					   i, &smp);
+		/* Prepare sampling time settings */
+		stm32_adc_smpr_init(adc, channels[i].channel, smp);
 	}
 
 	indio_dev->num_channels = scan_index;

drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c

@@ -191,7 +191,6 @@ static int cros_ec_sensors_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent);
-	struct cros_ec_device *ec_device;
 	struct iio_dev *indio_dev;
 	struct cros_ec_sensors_state *state;
 	struct iio_chan_spec *channel;
@@ -201,7 +200,6 @@ static int cros_ec_sensors_probe(struct platform_device *pdev)
 		dev_warn(&pdev->dev, "No CROS EC device found.\n");
 		return -EINVAL;
 	}
-	ec_device = ec_dev->ec_dev;
 
 	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*state));
 	if (!indio_dev)

drivers/iio/health/max30102.c

@@ -3,6 +3,9 @@
  *
  * Copyright (C) 2017 Matt Ranostay <matt@ranostay.consulting>
  *
+ * Support for MAX30105 optical particle sensor
+ * Copyright (C) 2017 Peter Meerwald-Stadler <pmeerw@pmeerw.net>
+ *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
@@ -13,6 +16,7 @@
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU General Public License for more details.
  *
+ * 7-bit I2C chip address: 0x57
  * TODO: proximity power saving feature
  */
 
@@ -32,6 +36,18 @@
 
 #define MAX30102_REGMAP_NAME	"max30102_regmap"
 #define MAX30102_DRV_NAME	"max30102"
+#define MAX30102_PART_NUMBER	0x15
+
+enum max30102_chip_id {
+	max30102,
+	max30105,
+};
+
+enum max3012_led_idx {
+	MAX30102_LED_RED,
+	MAX30102_LED_IR,
+	MAX30105_LED_GREEN,
+};
 
 #define MAX30102_REG_INT_STATUS			0x00
 #define MAX30102_REG_INT_STATUS_PWR_RDY		BIT(0)
@@ -52,7 +68,7 @@
 #define MAX30102_REG_FIFO_OVR_CTR		0x05
 #define MAX30102_REG_FIFO_RD_PTR		0x06
 #define MAX30102_REG_FIFO_DATA			0x07
-#define MAX30102_REG_FIFO_DATA_ENTRY_LEN	6
+#define MAX30102_REG_FIFO_DATA_BYTES		3
 
 #define MAX30102_REG_FIFO_CONFIG		0x08
 #define MAX30102_REG_FIFO_CONFIG_AVG_4SAMPLES	BIT(1)
@@ -60,11 +76,18 @@
 #define MAX30102_REG_FIFO_CONFIG_AFULL		BIT(0)
 
 #define MAX30102_REG_MODE_CONFIG		0x09
-#define MAX30102_REG_MODE_CONFIG_MODE_SPO2_EN	BIT(0)
-#define MAX30102_REG_MODE_CONFIG_MODE_HR_EN	BIT(1)
-#define MAX30102_REG_MODE_CONFIG_MODE_MASK	0x03
+#define MAX30102_REG_MODE_CONFIG_MODE_NONE	0x00
+#define MAX30102_REG_MODE_CONFIG_MODE_HR	0x02 /* red LED */
+#define MAX30102_REG_MODE_CONFIG_MODE_HR_SPO2	0x03 /* red + IR LED */
+#define MAX30102_REG_MODE_CONFIG_MODE_MULTI	0x07 /* multi-LED mode */
+#define MAX30102_REG_MODE_CONFIG_MODE_MASK	GENMASK(2, 0)
 #define MAX30102_REG_MODE_CONFIG_PWR		BIT(7)
 
+#define MAX30102_REG_MODE_CONTROL_SLOT21	0x11 /* multi-LED control */
+#define MAX30102_REG_MODE_CONTROL_SLOT43	0x12
+#define MAX30102_REG_MODE_CONTROL_SLOT_MASK	(GENMASK(6, 4) | GENMASK(2, 0))
+#define MAX30102_REG_MODE_CONTROL_SLOT_SHIFT	4
+
 #define MAX30102_REG_SPO2_CONFIG		0x0a
 #define MAX30102_REG_SPO2_CONFIG_PULSE_411_US	0x03
 #define MAX30102_REG_SPO2_CONFIG_SR_400HZ	0x03
@@ -75,6 +98,7 @@
 
 #define MAX30102_REG_RED_LED_CONFIG		0x0c
 #define MAX30102_REG_IR_LED_CONFIG		0x0d
+#define MAX30105_REG_GREEN_LED_CONFIG		0x0e
 
 #define MAX30102_REG_TEMP_CONFIG		0x21
 #define MAX30102_REG_TEMP_CONFIG_TEMP_EN	BIT(0)
@@ -82,14 +106,18 @@
 #define MAX30102_REG_TEMP_INTEGER		0x1f
 #define MAX30102_REG_TEMP_FRACTION		0x20
 
+#define MAX30102_REG_REV_ID			0xfe
+#define MAX30102_REG_PART_ID			0xff
+
 struct max30102_data {
 	struct i2c_client *client;
 	struct iio_dev *indio_dev;
 	struct mutex lock;
 	struct regmap *regmap;
+	enum max30102_chip_id chip_id;
 
-	u8 buffer[8];
-	__be32 processed_buffer[2]; /* 2 x 18-bit (padded to 32-bits) */
+	u8 buffer[12];
+	__be32 processed_buffer[3]; /* 3 x 18-bit (padded to 32-bits) */
 };
 
 static const struct regmap_config max30102_regmap_config = {
@@ -99,37 +127,47 @@ static const struct regmap_config max30102_regmap_config = {
 	.val_bits = 8,
 };
 
-static const unsigned long max30102_scan_masks[] = {0x3, 0};
+static const unsigned long max30102_scan_masks[] = {
+	BIT(MAX30102_LED_RED) | BIT(MAX30102_LED_IR),
+	0
+};
+
+static const unsigned long max30105_scan_masks[] = {
+	BIT(MAX30102_LED_RED) | BIT(MAX30102_LED_IR),
+	BIT(MAX30102_LED_RED) | BIT(MAX30102_LED_IR) |
+		BIT(MAX30105_LED_GREEN),
+	0
+};
+
+#define MAX30102_INTENSITY_CHANNEL(_si, _mod) { \
+		.type = IIO_INTENSITY, \
+		.channel2 = _mod, \
+		.modified = 1, \
+		.scan_index = _si, \
+		.scan_type = { \
+			.sign = 'u', \
+			.shift = 8, \
+			.realbits = 18, \
+			.storagebits = 32, \
+			.endianness = IIO_BE, \
+		}, \
+	}
 
 static const struct iio_chan_spec max30102_channels[] = {
+	MAX30102_INTENSITY_CHANNEL(MAX30102_LED_RED, IIO_MOD_LIGHT_RED),
+	MAX30102_INTENSITY_CHANNEL(MAX30102_LED_IR, IIO_MOD_LIGHT_IR),
 	{
-		.type = IIO_INTENSITY,
-		.channel2 = IIO_MOD_LIGHT_RED,
-		.modified = 1,
-
-		.scan_index = 0,
-		.scan_type = {
-			.sign = 'u',
-			.shift = 8,
-			.realbits = 18,
-			.storagebits = 32,
-			.endianness = IIO_BE,
-		},
-	},
-	{
-		.type = IIO_INTENSITY,
-		.channel2 = IIO_MOD_LIGHT_IR,
-		.modified = 1,
-
-		.scan_index = 1,
-		.scan_type = {
-			.sign = 'u',
-			.shift = 8,
-			.realbits = 18,
-			.storagebits = 32,
-			.endianness = IIO_BE,
-		},
+		.type = IIO_TEMP,
+		.info_mask_separate =
+			BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
+		.scan_index = -1,
 	},
+};
+
+static const struct iio_chan_spec max30105_channels[] = {
+	MAX30102_INTENSITY_CHANNEL(MAX30102_LED_RED, IIO_MOD_LIGHT_RED),
+	MAX30102_INTENSITY_CHANNEL(MAX30102_LED_IR, IIO_MOD_LIGHT_IR),
+	MAX30102_INTENSITY_CHANNEL(MAX30105_LED_GREEN, IIO_MOD_LIGHT_GREEN),
 	{
 		.type = IIO_TEMP,
 		.info_mask_separate =
@@ -138,25 +176,69 @@ static const struct iio_chan_spec max30102_channels[] = {
 	},
 };
 
-static int max30102_set_powermode(struct max30102_data *data, bool state)
+static int max30102_set_power(struct max30102_data *data, bool en)
 {
 	return regmap_update_bits(data->regmap, MAX30102_REG_MODE_CONFIG,
 				  MAX30102_REG_MODE_CONFIG_PWR,
-				  state ? 0 : MAX30102_REG_MODE_CONFIG_PWR);
+				  en ? 0 : MAX30102_REG_MODE_CONFIG_PWR);
 }
 
+static int max30102_set_powermode(struct max30102_data *data, u8 mode, bool en)
+{
+	u8 reg = mode;
+
+	if (!en)
+		reg |= MAX30102_REG_MODE_CONFIG_PWR;
+
+	return regmap_update_bits(data->regmap, MAX30102_REG_MODE_CONFIG,
+				  MAX30102_REG_MODE_CONFIG_PWR |
+				  MAX30102_REG_MODE_CONFIG_MODE_MASK, reg);
+}
+
+#define MAX30102_MODE_CONTROL_LED_SLOTS(slot2, slot1) \
+	((slot2 << MAX30102_REG_MODE_CONTROL_SLOT_SHIFT) | slot1)
+
 static int max30102_buffer_postenable(struct iio_dev *indio_dev)
 {
 	struct max30102_data *data = iio_priv(indio_dev);
+	int ret;
+	u8 reg;
 
-	return max30102_set_powermode(data, true);
+	switch (*indio_dev->active_scan_mask) {
+	case BIT(MAX30102_LED_RED) | BIT(MAX30102_LED_IR):
+		reg = MAX30102_REG_MODE_CONFIG_MODE_HR_SPO2;
+		break;
+	case BIT(MAX30102_LED_RED) | BIT(MAX30102_LED_IR) |
+	     BIT(MAX30105_LED_GREEN):
+		ret = regmap_update_bits(data->regmap,
+					 MAX30102_REG_MODE_CONTROL_SLOT21,
+					 MAX30102_REG_MODE_CONTROL_SLOT_MASK,
+					 MAX30102_MODE_CONTROL_LED_SLOTS(2, 1));
+		if (ret)
+			return ret;
+
+		ret = regmap_update_bits(data->regmap,
+					 MAX30102_REG_MODE_CONTROL_SLOT43,
+					 MAX30102_REG_MODE_CONTROL_SLOT_MASK,
+					 MAX30102_MODE_CONTROL_LED_SLOTS(0, 3));
+		if (ret)
+			return ret;
+
+		reg = MAX30102_REG_MODE_CONFIG_MODE_MULTI;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return max30102_set_powermode(data, reg, true);
 }
 
 static int max30102_buffer_predisable(struct iio_dev *indio_dev)
 {
 	struct max30102_data *data = iio_priv(indio_dev);
 
-	return max30102_set_powermode(data, false);
+	return max30102_set_powermode(data, MAX30102_REG_MODE_CONFIG_MODE_NONE,
+				      false);
 }
 
 static const struct iio_buffer_setup_ops max30102_buffer_setup_ops = {
@@ -180,32 +262,51 @@ static inline int max30102_fifo_count(struct max30102_data *data)
 	return 0;
 }
 
-static int max30102_read_measurement(struct max30102_data *data)
+#define MAX30102_COPY_DATA(i) \
+	memcpy(&data->processed_buffer[(i)], \
+	       &buffer[(i) * MAX30102_REG_FIFO_DATA_BYTES], \
+	       MAX30102_REG_FIFO_DATA_BYTES)
+
+static int max30102_read_measurement(struct max30102_data *data,
+				     unsigned int measurements)
 {
 	int ret;
 	u8 *buffer = (u8 *) &data->buffer;
 
 	ret = i2c_smbus_read_i2c_block_data(data->client,
 					    MAX30102_REG_FIFO_DATA,
-					    MAX30102_REG_FIFO_DATA_ENTRY_LEN,
+					    measurements *
+					    MAX30102_REG_FIFO_DATA_BYTES,
 					    buffer);
 
-	memcpy(&data->processed_buffer[0], &buffer[0], 3);
-	memcpy(&data->processed_buffer[1], &buffer[3], 3);
+	switch (measurements) {
+	case 3:
+		MAX30102_COPY_DATA(2);
+	case 2: /* fall-through */
+		MAX30102_COPY_DATA(1);
+	case 1: /* fall-through */
+		MAX30102_COPY_DATA(0);
+		break;
+	default:
+		return -EINVAL;
+	}
 
-	return (ret == MAX30102_REG_FIFO_DATA_ENTRY_LEN) ? 0 : -EINVAL;
+	return (ret == measurements * MAX30102_REG_FIFO_DATA_BYTES) ?
+	       0 : -EINVAL;
 }
 
 static irqreturn_t max30102_interrupt_handler(int irq, void *private)
 {
 	struct iio_dev *indio_dev = private;
 	struct max30102_data *data = iio_priv(indio_dev);
+	unsigned int measurements = bitmap_weight(indio_dev->active_scan_mask,
+						  indio_dev->masklength);
 	int ret, cnt = 0;
 
 	mutex_lock(&data->lock);
 
 	while (cnt || (cnt = max30102_fifo_count(data)) > 0) {
-		ret = max30102_read_measurement(data);
+		ret = max30102_read_measurement(data, measurements);
 		if (ret)
 			break;
 
@@ -251,6 +352,29 @@ static int max30102_led_init(struct max30102_data *data)
 	if (ret)
 		return ret;
 
+	if (data->chip_id == max30105) {
+		ret = of_property_read_u32(np,
+			"maxim,green-led-current-microamp", &val);
+		if (ret) {
+			dev_info(dev, "no green-led-current-microamp set\n");
+
+			/* Default to 7 mA green LED */
+			val = 7000;
+		}
+
+		ret = max30102_get_current_idx(val, &reg);
+		if (ret) {
+			dev_err(dev, "invalid green LED current setting %d\n",
+				val);
+			return ret;
+		}
+
+		ret = regmap_write(data->regmap, MAX30105_REG_GREEN_LED_CONFIG,
+				   reg);
+		if (ret)
+			return ret;
+	}
+
 	ret = of_property_read_u32(np, "maxim,ir-led-current-microamp", &val);
 	if (ret) {
 		dev_info(dev, "no ir-led-current-microamp set\n");
@@ -261,7 +385,7 @@ static int max30102_led_init(struct max30102_data *data)
 
 	ret = max30102_get_current_idx(val, &reg);
 	if (ret) {
-		dev_err(dev, "invalid IR LED current setting %d", val);
+		dev_err(dev, "invalid IR LED current setting %d\n", val);
 		return ret;
 	}
 
@@ -277,7 +401,7 @@ static int max30102_chip_init(struct max30102_data *data)
 	if (ret)
 		return ret;
 
-	/* enable 18-bit HR + SPO2 readings at 400Hz */
+	/* configure 18-bit HR + SpO2 readings at 400Hz */
 	ret = regmap_write(data->regmap, MAX30102_REG_SPO2_CONFIG,
 				(MAX30102_REG_SPO2_CONFIG_ADC_4096_STEPS
 				 << MAX30102_REG_SPO2_CONFIG_ADC_MASK_SHIFT) |
@@ -287,14 +411,6 @@ static int max30102_chip_init(struct max30102_data *data)
 	if (ret)
 		return ret;
 
-	/* enable SPO2 mode */
-	ret = regmap_update_bits(data->regmap, MAX30102_REG_MODE_CONFIG,
-				 MAX30102_REG_MODE_CONFIG_MODE_MASK,
-				 MAX30102_REG_MODE_CONFIG_MODE_HR_EN |
-				 MAX30102_REG_MODE_CONFIG_MODE_SPO2_EN);
-	if (ret)
-		return ret;
-
 	/* average 4 samples + generate FIFO interrupt */
 	ret = regmap_write(data->regmap, MAX30102_REG_FIFO_CONFIG,
 				(MAX30102_REG_FIFO_CONFIG_AVG_4SAMPLES
@@ -329,20 +445,31 @@ static int max30102_read_temp(struct max30102_data *data, int *val)
 	return 0;
 }
 
-static int max30102_get_temp(struct max30102_data *data, int *val)
+static int max30102_get_temp(struct max30102_data *data, int *val, bool en)
 {
 	int ret;
 
+	if (en) {
+		ret = max30102_set_power(data, true);
+		if (ret)
+			return ret;
+	}
+
 	/* start acquisition */
 	ret = regmap_update_bits(data->regmap, MAX30102_REG_TEMP_CONFIG,
 				 MAX30102_REG_TEMP_CONFIG_TEMP_EN,
 				 MAX30102_REG_TEMP_CONFIG_TEMP_EN);
 	if (ret)
-		return ret;
+		goto out;
 
 	msleep(35);
+	ret = max30102_read_temp(data, val);
 
-	return max30102_read_temp(data, val);
+out:
+	if (en)
+		max30102_set_power(data, false);
+
+	return ret;
 }
 
 static int max30102_read_raw(struct iio_dev *indio_dev,
@@ -355,20 +482,19 @@ static int max30102_read_raw(struct iio_dev *indio_dev,
 	switch (mask) {
 	case IIO_CHAN_INFO_RAW:
 		/*
-		 * Temperature reading can only be acquired while engine
-		 * is running
+		 * Temperature reading can only be acquired when not in
+		 * shutdown; leave shutdown briefly when buffer not running
 		 */
 		mutex_lock(&indio_dev->mlock);
-
 		if (!iio_buffer_enabled(indio_dev))
-			ret = -EBUSY;
-		else {
-			ret = max30102_get_temp(data, val);
-			if (!ret)
-				ret = IIO_VAL_INT;
-		}
-
+			ret = max30102_get_temp(data, val, true);
+		else
+			ret = max30102_get_temp(data, val, false);
 		mutex_unlock(&indio_dev->mlock);
+		if (ret)
+			return ret;
+
+		ret = IIO_VAL_INT;
 		break;
 	case IIO_CHAN_INFO_SCALE:
 		*val = 1;  /* 0.0625 */
@@ -391,6 +517,7 @@ static int max30102_probe(struct i2c_client *client,
 	struct iio_buffer *buffer;
 	struct iio_dev *indio_dev;
 	int ret;
+	unsigned int reg;
 
 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 	if (!indio_dev)
@@ -403,10 +530,7 @@ static int max30102_probe(struct i2c_client *client,
 	iio_device_attach_buffer(indio_dev, buffer);
 
 	indio_dev->name = MAX30102_DRV_NAME;
-	indio_dev->channels = max30102_channels;
 	indio_dev->info = &max30102_info;
-	indio_dev->num_channels = ARRAY_SIZE(max30102_channels);
-	indio_dev->available_scan_masks = max30102_scan_masks;
 	indio_dev->modes = (INDIO_BUFFER_SOFTWARE | INDIO_DIRECT_MODE);
 	indio_dev->setup_ops = &max30102_buffer_setup_ops;
 	indio_dev->dev.parent = &client->dev;
@@ -414,16 +538,50 @@ static int max30102_probe(struct i2c_client *client,
 	data = iio_priv(indio_dev);
 	data->indio_dev = indio_dev;
 	data->client = client;
+	data->chip_id = id->driver_data;
 
 	mutex_init(&data->lock);
 	i2c_set_clientdata(client, indio_dev);
 
+	switch (data->chip_id) {
+	case max30105:
+		indio_dev->channels = max30105_channels;
+		indio_dev->num_channels = ARRAY_SIZE(max30105_channels);
+		indio_dev->available_scan_masks = max30105_scan_masks;
+		break;
+	case max30102:
+		indio_dev->channels = max30102_channels;
+		indio_dev->num_channels = ARRAY_SIZE(max30102_channels);
+		indio_dev->available_scan_masks = max30102_scan_masks;
+		break;
+	default:
+		return -ENODEV;
+	}
+
 	data->regmap = devm_regmap_init_i2c(client, &max30102_regmap_config);
 	if (IS_ERR(data->regmap)) {
-		dev_err(&client->dev, "regmap initialization failed.\n");
+		dev_err(&client->dev, "regmap initialization failed\n");
 		return PTR_ERR(data->regmap);
 	}
-	max30102_set_powermode(data, false);
+
+	/* check part ID */
+	ret = regmap_read(data->regmap, MAX30102_REG_PART_ID, &reg);
+	if (ret)
+		return ret;
+	if (reg != MAX30102_PART_NUMBER)
+		return -ENODEV;
+
+	/* show revision ID */
+	ret = regmap_read(data->regmap, MAX30102_REG_REV_ID, &reg);
+	if (ret)
+		return ret;
+	dev_dbg(&client->dev, "max3010x revision %02x\n", reg);
+
+	/* clear mode setting, chip shutdown */
+	ret = max30102_set_powermode(data, MAX30102_REG_MODE_CONFIG_MODE_NONE,
+				     false);
+	if (ret)
+		return ret;
 
 	ret = max30102_chip_init(data);
 	if (ret)
@@ -452,19 +610,21 @@ static int max30102_remove(struct i2c_client *client)
 	struct max30102_data *data = iio_priv(indio_dev);
 
 	iio_device_unregister(indio_dev);
-	max30102_set_powermode(data, false);
+	max30102_set_power(data, false);
 
 	return 0;
 }
 
 static const struct i2c_device_id max30102_id[] = {
-	{ "max30102", 0 },
+	{ "max30102", max30102 },
+	{ "max30105", max30105 },
 	{}
 };
 MODULE_DEVICE_TABLE(i2c, max30102_id);
 
 static const struct of_device_id max30102_dt_ids[] = {
 	{ .compatible = "maxim,max30102" },
+	{ .compatible = "maxim,max30105" },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, max30102_dt_ids);
@@ -481,5 +641,5 @@ static struct i2c_driver max30102_driver = {
 module_i2c_driver(max30102_driver);
 
 MODULE_AUTHOR("Matt Ranostay <matt@ranostay.consulting>");
-MODULE_DESCRIPTION("MAX30102 heart rate and pulse oximeter sensor");
+MODULE_DESCRIPTION("MAX30102 heart rate/pulse oximeter and MAX30105 particle sensor driver");
 MODULE_LICENSE("GPL");

drivers/iio/imu/inv_mpu6050/inv_mpu_acpi.c

@@ -196,8 +196,7 @@ void inv_mpu_acpi_delete_mux_client(struct i2c_client *client)
 {
 	struct inv_mpu6050_state *st = iio_priv(dev_get_drvdata(&client->dev));
 
-	if (st->mux_client)
-		i2c_unregister_device(st->mux_client);
+	i2c_unregister_device(st->mux_client);
 }
 #else
 

drivers/iio/industrialio-core.c

@@ -588,6 +588,7 @@ static ssize_t __iio_format_value(char *buf, size_t len, unsigned int type,
 		return snprintf(buf, len, "%d", vals[0]);
 	case IIO_VAL_INT_PLUS_MICRO_DB:
 		scale_db = true;
+		/* fall through */
 	case IIO_VAL_INT_PLUS_MICRO:
 		if (vals[1] < 0)
 			return snprintf(buf, len, "-%d.%06u%s", abs(vals[0]),

drivers/iio/light/Kconfig

@@ -334,6 +334,30 @@ config STK3310
 	 Choosing M will build the driver as a module. If so, the module
 	 will be called stk3310.
 
+config ST_UVIS25
+	tristate "STMicroelectronics UVIS25 sensor driver"
+	depends on (I2C || SPI)
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
+	select ST_UVIS25_I2C if (I2C)
+	select ST_UVIS25_SPI if (SPI_MASTER)
+	help
+	  Say yes here to build support for STMicroelectronics UVIS25
+	  uv sensor
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called st_uvis25.
+
+config ST_UVIS25_I2C
+	tristate
+	depends on ST_UVIS25
+	select REGMAP_I2C
+
+config ST_UVIS25_SPI
+	tristate
+	depends on ST_UVIS25
+	select REGMAP_SPI
+
 config TCS3414
 	tristate "TAOS TCS3414 digital color sensor"
 	depends on I2C
@@ -425,4 +449,14 @@ config VL6180
 	 To compile this driver as a module, choose M here: the
 	 module will be called vl6180.
 
+config ZOPT2201
+	tristate "ZOPT2201 ALS and UV B sensor"
+	depends on I2C
+	help
+	 Say Y here if you want to build a driver for the IDT
+	 ZOPT2201 ambient light and UV B sensor.
+
+	 To compile this driver as a module, choose M here: the
+	 module will be called zopt2201.
+
 endmenu

drivers/iio/light/Makefile

@@ -33,6 +33,9 @@ obj-$(CONFIG_RPR0521)		+= rpr0521.o
 obj-$(CONFIG_SENSORS_TSL2563)	+= tsl2563.o
 obj-$(CONFIG_SI1145)		+= si1145.o
 obj-$(CONFIG_STK3310)          += stk3310.o
+obj-$(CONFIG_ST_UVIS25)		+= st_uvis25_core.o
+obj-$(CONFIG_ST_UVIS25_I2C)	+= st_uvis25_i2c.o
+obj-$(CONFIG_ST_UVIS25_SPI)	+= st_uvis25_spi.o
 obj-$(CONFIG_TCS3414)		+= tcs3414.o
 obj-$(CONFIG_TCS3472)		+= tcs3472.o
 obj-$(CONFIG_TSL2583)		+= tsl2583.o
@@ -41,3 +44,4 @@ obj-$(CONFIG_US5182D)		+= us5182d.o
 obj-$(CONFIG_VCNL4000)		+= vcnl4000.o
 obj-$(CONFIG_VEML6070)		+= veml6070.o
 obj-$(CONFIG_VL6180)		+= vl6180.o
+obj-$(CONFIG_ZOPT2201)		+= zopt2201.o

drivers/iio/light/cros_ec_light_prox.c

@@ -181,7 +181,6 @@ static int cros_ec_light_prox_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent);
-	struct cros_ec_device *ec_device;
 	struct iio_dev *indio_dev;
 	struct cros_ec_light_prox_state *state;
 	struct iio_chan_spec *channel;
@@ -191,7 +190,6 @@ static int cros_ec_light_prox_probe(struct platform_device *pdev)
 		dev_warn(dev, "No CROS EC device found.\n");
 		return -EINVAL;
 	}
-	ec_device = ec_dev->ec_dev;
 
 	indio_dev = devm_iio_device_alloc(dev, sizeof(*state));
 	if (!indio_dev)

drivers/iio/light/st_uvis25.h

@@ -0,0 +1,37 @@
+/*
+ * STMicroelectronics uvis25 sensor driver
+ *
+ * Copyright 2017 STMicroelectronics Inc.
+ *
+ * Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
+ *
+ * Licensed under the GPL-2.
+ */
+
+#ifndef ST_UVIS25_H
+#define ST_UVIS25_H
+
+#define ST_UVIS25_DEV_NAME		"uvis25"
+
+#include <linux/iio/iio.h>
+
+/**
+ * struct st_uvis25_hw - ST UVIS25 sensor instance
+ * @regmap: Register map of the device.
+ * @trig: The trigger in use by the driver.
+ * @enabled: Status of the sensor (false->off, true->on).
+ * @irq: Device interrupt line (I2C or SPI).
+ */
+struct st_uvis25_hw {
+	struct regmap *regmap;
+
+	struct iio_trigger *trig;
+	bool enabled;
+	int irq;
+};
+
+extern const struct dev_pm_ops st_uvis25_pm_ops;
+
+int st_uvis25_probe(struct device *dev, int irq, struct regmap *regmap);
+
+#endif /* ST_UVIS25_H */

drivers/iio/light/st_uvis25_core.c

@@ -0,0 +1,359 @@
+/*
+ * STMicroelectronics uvis25 sensor driver
+ *
+ * Copyright 2017 STMicroelectronics Inc.
+ *
+ * Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/iio/sysfs.h>
+#include <linux/delay.h>
+#include <linux/pm.h>
+#include <linux/interrupt.h>
+#include <linux/irqreturn.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/buffer.h>
+#include <linux/regmap.h>
+
+#include "st_uvis25.h"
+
+#define ST_UVIS25_REG_WHOAMI_ADDR	0x0f
+#define ST_UVIS25_REG_WHOAMI_VAL	0xca
+#define ST_UVIS25_REG_CTRL1_ADDR	0x20
+#define ST_UVIS25_REG_ODR_MASK		BIT(0)
+#define ST_UVIS25_REG_BDU_MASK		BIT(1)
+#define ST_UVIS25_REG_CTRL2_ADDR	0x21
+#define ST_UVIS25_REG_BOOT_MASK		BIT(7)
+#define ST_UVIS25_REG_CTRL3_ADDR	0x22
+#define ST_UVIS25_REG_HL_MASK		BIT(7)
+#define ST_UVIS25_REG_STATUS_ADDR	0x27
+#define ST_UVIS25_REG_UV_DA_MASK	BIT(0)
+#define ST_UVIS25_REG_OUT_ADDR		0x28
+
+static const struct iio_chan_spec st_uvis25_channels[] = {
+	{
+		.type = IIO_UVINDEX,
+		.address = ST_UVIS25_REG_OUT_ADDR,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+		.scan_index = 0,
+		.scan_type = {
+			.sign = 'u',
+			.realbits = 8,
+			.storagebits = 8,
+		},
+	},
+	IIO_CHAN_SOFT_TIMESTAMP(1),
+};
+
+static int st_uvis25_check_whoami(struct st_uvis25_hw *hw)
+{
+	int err, data;
+
+	err = regmap_read(hw->regmap, ST_UVIS25_REG_WHOAMI_ADDR, &data);
+	if (err < 0) {
+		dev_err(regmap_get_device(hw->regmap),
+			"failed to read whoami register\n");
+		return err;
+	}
+
+	if (data != ST_UVIS25_REG_WHOAMI_VAL) {
+		dev_err(regmap_get_device(hw->regmap),
+			"wrong whoami {%02x vs %02x}\n",
+			data, ST_UVIS25_REG_WHOAMI_VAL);
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static int st_uvis25_set_enable(struct st_uvis25_hw *hw, bool enable)
+{
+	int err;
+
+	err = regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL1_ADDR,
+				 ST_UVIS25_REG_ODR_MASK, enable);
+	if (err < 0)
+		return err;
+
+	hw->enabled = enable;
+
+	return 0;
+}
+
+static int st_uvis25_read_oneshot(struct st_uvis25_hw *hw, u8 addr, int *val)
+{
+	int err;
+
+	err = st_uvis25_set_enable(hw, true);
+	if (err < 0)
+		return err;
+
+	msleep(1500);
+
+	/*
+	 * in order to avoid possible race conditions with interrupt
+	 * generation, disable the sensor first and then poll output
+	 * register. That sequence guarantees the interrupt will be reset
+	 * when irq line is unmasked
+	 */
+	err = st_uvis25_set_enable(hw, false);
+	if (err < 0)
+		return err;
+
+	err = regmap_read(hw->regmap, addr, val);
+
+	return err < 0 ? err : IIO_VAL_INT;
+}
+
+static int st_uvis25_read_raw(struct iio_dev *iio_dev,
+			      struct iio_chan_spec const *ch,
+			      int *val, int *val2, long mask)
+{
+	int ret;
+
+	ret = iio_device_claim_direct_mode(iio_dev);
+	if (ret)
+		return ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_PROCESSED: {
+		struct st_uvis25_hw *hw = iio_priv(iio_dev);
+
+		/*
+		 * mask irq line during oneshot read since the sensor
+		 * does not export the capability to disable data-ready line
+		 * in the register map and it is enabled by default.
+		 * If the line is unmasked during read_raw() it will be set
+		 * active and never reset since the trigger is disabled
+		 */
+		if (hw->irq > 0)
+			disable_irq(hw->irq);
+		ret = st_uvis25_read_oneshot(hw, ch->address, val);
+		if (hw->irq > 0)
+			enable_irq(hw->irq);
+		break;
+	}
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	iio_device_release_direct_mode(iio_dev);
+
+	return ret;
+}
+
+static irqreturn_t st_uvis25_trigger_handler_thread(int irq, void *private)
+{
+	struct st_uvis25_hw *hw = private;
+	int err, status;
+
+	err = regmap_read(hw->regmap, ST_UVIS25_REG_STATUS_ADDR, &status);
+	if (err < 0)
+		return IRQ_HANDLED;
+
+	if (!(status & ST_UVIS25_REG_UV_DA_MASK))
+		return IRQ_NONE;
+
+	iio_trigger_poll_chained(hw->trig);
+
+	return IRQ_HANDLED;
+}
+
+static int st_uvis25_allocate_trigger(struct iio_dev *iio_dev)
+{
+	struct st_uvis25_hw *hw = iio_priv(iio_dev);
+	struct device *dev = regmap_get_device(hw->regmap);
+	bool irq_active_low = false;
+	unsigned long irq_type;
+	int 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;
+	case IRQF_TRIGGER_LOW:
+	case IRQF_TRIGGER_FALLING:
+		irq_active_low = true;
+		break;
+	default:
+		dev_info(dev, "mode %lx unsupported\n", irq_type);
+		return -EINVAL;
+	}
+
+	err = regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL3_ADDR,
+				 ST_UVIS25_REG_HL_MASK, irq_active_low);
+	if (err < 0)
+		return err;
+
+	err = devm_request_threaded_irq(dev, hw->irq, NULL,
+					st_uvis25_trigger_handler_thread,
+					irq_type | IRQF_ONESHOT,
+					iio_dev->name, hw);
+	if (err) {
+		dev_err(dev, "failed to request trigger irq %d\n",
+			hw->irq);
+		return err;
+	}
+
+	hw->trig = devm_iio_trigger_alloc(dev, "%s-trigger",
+					  iio_dev->name);
+	if (!hw->trig)
+		return -ENOMEM;
+
+	iio_trigger_set_drvdata(hw->trig, iio_dev);
+	hw->trig->dev.parent = dev;
+
+	return devm_iio_trigger_register(dev, hw->trig);
+}
+
+static int st_uvis25_buffer_preenable(struct iio_dev *iio_dev)
+{
+	return st_uvis25_set_enable(iio_priv(iio_dev), true);
+}
+
+static int st_uvis25_buffer_postdisable(struct iio_dev *iio_dev)
+{
+	return st_uvis25_set_enable(iio_priv(iio_dev), false);
+}
+
+static const struct iio_buffer_setup_ops st_uvis25_buffer_ops = {
+	.preenable = st_uvis25_buffer_preenable,
+	.postenable = iio_triggered_buffer_postenable,
+	.predisable = iio_triggered_buffer_predisable,
+	.postdisable = st_uvis25_buffer_postdisable,
+};
+
+static irqreturn_t st_uvis25_buffer_handler_thread(int irq, void *p)
+{
+	u8 buffer[ALIGN(sizeof(u8), sizeof(s64)) + sizeof(s64)];
+	struct iio_poll_func *pf = p;
+	struct iio_dev *iio_dev = pf->indio_dev;
+	struct st_uvis25_hw *hw = iio_priv(iio_dev);
+	int err;
+
+	err = regmap_read(hw->regmap, ST_UVIS25_REG_OUT_ADDR, (int *)buffer);
+	if (err < 0)
+		goto out;
+
+	iio_push_to_buffers_with_timestamp(iio_dev, buffer,
+					   iio_get_time_ns(iio_dev));
+
+out:
+	iio_trigger_notify_done(hw->trig);
+
+	return IRQ_HANDLED;
+}
+
+static int st_uvis25_allocate_buffer(struct iio_dev *iio_dev)
+{
+	struct st_uvis25_hw *hw = iio_priv(iio_dev);
+
+	return devm_iio_triggered_buffer_setup(regmap_get_device(hw->regmap),
+					       iio_dev, NULL,
+					       st_uvis25_buffer_handler_thread,
+					       &st_uvis25_buffer_ops);
+}
+
+static const struct iio_info st_uvis25_info = {
+	.read_raw = st_uvis25_read_raw,
+};
+
+static int st_uvis25_init_sensor(struct st_uvis25_hw *hw)
+{
+	int err;
+
+	err = regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL2_ADDR,
+				 ST_UVIS25_REG_BOOT_MASK, 1);
+	if (err < 0)
+		return err;
+
+	msleep(2000);
+
+	return regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL1_ADDR,
+				  ST_UVIS25_REG_BDU_MASK, 1);
+}
+
+int st_uvis25_probe(struct device *dev, int irq, struct regmap *regmap)
+{
+	struct st_uvis25_hw *hw;
+	struct iio_dev *iio_dev;
+	int err;
+
+	iio_dev = devm_iio_device_alloc(dev, sizeof(*hw));
+	if (!iio_dev)
+		return -ENOMEM;
+
+	dev_set_drvdata(dev, (void *)iio_dev);
+
+	hw = iio_priv(iio_dev);
+	hw->irq = irq;
+	hw->regmap = regmap;
+
+	err = st_uvis25_check_whoami(hw);
+	if (err < 0)
+		return err;
+
+	iio_dev->modes = INDIO_DIRECT_MODE;
+	iio_dev->dev.parent = dev;
+	iio_dev->channels = st_uvis25_channels;
+	iio_dev->num_channels = ARRAY_SIZE(st_uvis25_channels);
+	iio_dev->name = ST_UVIS25_DEV_NAME;
+	iio_dev->info = &st_uvis25_info;
+
+	err = st_uvis25_init_sensor(hw);
+	if (err < 0)
+		return err;
+
+	if (hw->irq > 0) {
+		err = st_uvis25_allocate_buffer(iio_dev);
+		if (err < 0)
+			return err;
+
+		err = st_uvis25_allocate_trigger(iio_dev);
+		if (err)
+			return err;
+	}
+
+	return devm_iio_device_register(dev, iio_dev);
+}
+EXPORT_SYMBOL(st_uvis25_probe);
+
+static int __maybe_unused st_uvis25_suspend(struct device *dev)
+{
+	struct iio_dev *iio_dev = dev_get_drvdata(dev);
+	struct st_uvis25_hw *hw = iio_priv(iio_dev);
+
+	return regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL1_ADDR,
+				  ST_UVIS25_REG_ODR_MASK, 0);
+}
+
+static int __maybe_unused st_uvis25_resume(struct device *dev)
+{
+	struct iio_dev *iio_dev = dev_get_drvdata(dev);
+	struct st_uvis25_hw *hw = iio_priv(iio_dev);
+
+	if (hw->enabled)
+		return regmap_update_bits(hw->regmap, ST_UVIS25_REG_CTRL1_ADDR,
+					  ST_UVIS25_REG_ODR_MASK, 1);
+
+	return 0;
+}
+
+const struct dev_pm_ops st_uvis25_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(st_uvis25_suspend, st_uvis25_resume)
+};
+EXPORT_SYMBOL(st_uvis25_pm_ops);
+
+MODULE_AUTHOR("Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>");
+MODULE_DESCRIPTION("STMicroelectronics uvis25 sensor driver");
+MODULE_LICENSE("GPL v2");

drivers/iio/light/st_uvis25_i2c.c

@@ -0,0 +1,69 @@
+/*
+ * STMicroelectronics uvis25 i2c driver
+ *
+ * Copyright 2017 STMicroelectronics Inc.
+ *
+ * Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/acpi.h>
+#include <linux/i2c.h>
+#include <linux/slab.h>
+#include <linux/regmap.h>
+
+#include "st_uvis25.h"
+
+#define UVIS25_I2C_AUTO_INCREMENT	BIT(7)
+
+const struct regmap_config st_uvis25_i2c_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.write_flag_mask = UVIS25_I2C_AUTO_INCREMENT,
+	.read_flag_mask = UVIS25_I2C_AUTO_INCREMENT,
+};
+
+static int st_uvis25_i2c_probe(struct i2c_client *client,
+			       const struct i2c_device_id *id)
+{
+	struct regmap *regmap;
+
+	regmap = devm_regmap_init_i2c(client, &st_uvis25_i2c_regmap_config);
+	if (IS_ERR(regmap)) {
+		dev_err(&client->dev, "Failed to register i2c regmap %d\n",
+			(int)PTR_ERR(regmap));
+		return PTR_ERR(regmap);
+	}
+
+	return st_uvis25_probe(&client->dev, client->irq, regmap);
+}
+
+static const struct of_device_id st_uvis25_i2c_of_match[] = {
+	{ .compatible = "st,uvis25", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, st_uvis25_i2c_of_match);
+
+static const struct i2c_device_id st_uvis25_i2c_id_table[] = {
+	{ ST_UVIS25_DEV_NAME },
+	{},
+};
+MODULE_DEVICE_TABLE(i2c, st_uvis25_i2c_id_table);
+
+static struct i2c_driver st_uvis25_driver = {
+	.driver = {
+		.name = "st_uvis25_i2c",
+		.pm = &st_uvis25_pm_ops,
+		.of_match_table = of_match_ptr(st_uvis25_i2c_of_match),
+	},
+	.probe = st_uvis25_i2c_probe,
+	.id_table = st_uvis25_i2c_id_table,
+};
+module_i2c_driver(st_uvis25_driver);
+
+MODULE_AUTHOR("Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>");
+MODULE_DESCRIPTION("STMicroelectronics uvis25 i2c driver");
+MODULE_LICENSE("GPL v2");

drivers/iio/light/st_uvis25_spi.c

@@ -0,0 +1,68 @@
+/*
+ * STMicroelectronics uvis25 spi driver
+ *
+ * Copyright 2017 STMicroelectronics Inc.
+ *
+ * Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/spi/spi.h>
+#include <linux/slab.h>
+#include <linux/regmap.h>
+
+#include "st_uvis25.h"
+
+#define UVIS25_SENSORS_SPI_READ		BIT(7)
+#define UVIS25_SPI_AUTO_INCREMENT	BIT(6)
+
+const struct regmap_config st_uvis25_spi_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.read_flag_mask = UVIS25_SENSORS_SPI_READ | UVIS25_SPI_AUTO_INCREMENT,
+	.write_flag_mask = UVIS25_SPI_AUTO_INCREMENT,
+};
+
+static int st_uvis25_spi_probe(struct spi_device *spi)
+{
+	struct regmap *regmap;
+
+	regmap = devm_regmap_init_spi(spi, &st_uvis25_spi_regmap_config);
+	if (IS_ERR(regmap)) {
+		dev_err(&spi->dev, "Failed to register spi regmap %d\n",
+			(int)PTR_ERR(regmap));
+		return PTR_ERR(regmap);
+	}
+
+	return st_uvis25_probe(&spi->dev, spi->irq, regmap);
+}
+
+static const struct of_device_id st_uvis25_spi_of_match[] = {
+	{ .compatible = "st,uvis25", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, st_uvis25_spi_of_match);
+
+static const struct spi_device_id st_uvis25_spi_id_table[] = {
+	{ ST_UVIS25_DEV_NAME },
+	{},
+};
+MODULE_DEVICE_TABLE(spi, st_uvis25_spi_id_table);
+
+static struct spi_driver st_uvis25_driver = {
+	.driver = {
+		.name = "st_uvis25_spi",
+		.pm = &st_uvis25_pm_ops,
+		.of_match_table = of_match_ptr(st_uvis25_spi_of_match),
+	},
+	.probe = st_uvis25_spi_probe,
+	.id_table = st_uvis25_spi_id_table,
+};
+module_spi_driver(st_uvis25_driver);
+
+MODULE_AUTHOR("Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>");
+MODULE_DESCRIPTION("STMicroelectronics uvis25 spi driver");
+MODULE_LICENSE("GPL v2");

drivers/iio/light/zopt2201.c

@@ -0,0 +1,568 @@
+/*
+ * zopt2201.c - Support for IDT ZOPT2201 ambient light and UV B sensor
+ *
+ * Copyright 2017 Peter Meerwald-Stadler <pmeerw@pmeerw.net>
+ *
+ * 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.
+ *
+ * Datasheet: https://www.idt.com/document/dst/zopt2201-datasheet
+ * 7-bit I2C slave addresses 0x53 (default) or 0x52 (programmed)
+ *
+ * TODO: interrupt support, ALS/UVB raw mode
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/mutex.h>
+#include <linux/err.h>
+#include <linux/delay.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#define ZOPT2201_DRV_NAME "zopt2201"
+
+/* Registers */
+#define ZOPT2201_MAIN_CTRL		0x00
+#define ZOPT2201_LS_MEAS_RATE		0x04
+#define ZOPT2201_LS_GAIN		0x05
+#define ZOPT2201_PART_ID		0x06
+#define ZOPT2201_MAIN_STATUS		0x07
+#define ZOPT2201_ALS_DATA		0x0d /* LSB first, 13 to 20 bits */
+#define ZOPT2201_UVB_DATA		0x10 /* LSB first, 13 to 20 bits */
+#define ZOPT2201_UV_COMP_DATA		0x13 /* LSB first, 13 to 20 bits */
+#define ZOPT2201_COMP_DATA		0x16 /* LSB first, 13 to 20 bits */
+#define ZOPT2201_INT_CFG		0x19
+#define ZOPT2201_INT_PST		0x1a
+
+#define ZOPT2201_MAIN_CTRL_LS_MODE	BIT(3) /* 0 .. ALS, 1 .. UV B */
+#define ZOPT2201_MAIN_CTRL_LS_EN	BIT(1)
+
+/* Values for ZOPT2201_LS_MEAS_RATE resolution / bit width */
+#define ZOPT2201_MEAS_RES_20BIT		0 /* takes 400 ms */
+#define ZOPT2201_MEAS_RES_19BIT		1 /* takes 200 ms */
+#define ZOPT2201_MEAS_RES_18BIT		2 /* takes 100 ms, default */
+#define ZOPT2201_MEAS_RES_17BIT		3 /* takes 50 ms */
+#define ZOPT2201_MEAS_RES_16BIT		4 /* takes 25 ms */
+#define ZOPT2201_MEAS_RES_13BIT		5 /* takes 3.125 ms */
+#define ZOPT2201_MEAS_RES_SHIFT		4
+
+/* Values for ZOPT2201_LS_MEAS_RATE measurement rate */
+#define ZOPT2201_MEAS_FREQ_25MS		0
+#define ZOPT2201_MEAS_FREQ_50MS		1
+#define ZOPT2201_MEAS_FREQ_100MS	2 /* default */
+#define ZOPT2201_MEAS_FREQ_200MS	3
+#define ZOPT2201_MEAS_FREQ_500MS	4
+#define ZOPT2201_MEAS_FREQ_1000MS	5
+#define ZOPT2201_MEAS_FREQ_2000MS	6
+
+/* Values for ZOPT2201_LS_GAIN */
+#define ZOPT2201_LS_GAIN_1		0
+#define ZOPT2201_LS_GAIN_3		1
+#define ZOPT2201_LS_GAIN_6		2
+#define ZOPT2201_LS_GAIN_9		3
+#define ZOPT2201_LS_GAIN_18		4
+
+/* Values for ZOPT2201_MAIN_STATUS */
+#define ZOPT2201_MAIN_STATUS_POWERON	BIT(5)
+#define ZOPT2201_MAIN_STATUS_INT	BIT(4)
+#define ZOPT2201_MAIN_STATUS_DRDY	BIT(3)
+
+#define ZOPT2201_PART_NUMBER		0xb2
+
+struct zopt2201_data {
+	struct i2c_client *client;
+	struct mutex lock;
+	u8 gain;
+	u8 res;
+	u8 rate;
+};
+
+static const struct {
+	unsigned int gain; /* gain factor */
+	unsigned int scale; /* micro lux per count */
+} zopt2201_gain_als[] = {
+	{  1, 19200000 },
+	{  3,  6400000 },
+	{  6,  3200000 },
+	{  9,  2133333 },
+	{ 18,  1066666 },
+};
+
+static const struct {
+	unsigned int gain; /* gain factor */
+	unsigned int scale; /* micro W/m2 per count */
+} zopt2201_gain_uvb[] = {
+	{  1, 460800 },
+	{  3, 153600 },
+	{  6,  76800 },
+	{  9,  51200 },
+	{ 18,  25600 },
+};
+
+static const struct {
+	unsigned int bits; /* sensor resolution in bits */
+	unsigned long us; /* measurement time in micro seconds */
+} zopt2201_resolution[] = {
+	{ 20, 400000 },
+	{ 19, 200000 },
+	{ 18, 100000 },
+	{ 17,  50000 },
+	{ 16,  25000 },
+	{ 13,   3125 },
+};
+
+static const struct {
+	unsigned int scale, uscale; /* scale factor as integer + micro */
+	u8 gain; /* gain register value */
+	u8 res; /* resolution register value */
+} zopt2201_scale_als[] = {
+	{ 19, 200000, 0, 5 },
+	{  6, 400000, 1, 5 },
+	{  3, 200000, 2, 5 },
+	{  2, 400000, 0, 4 },
+	{  2, 133333, 3, 5 },
+	{  1, 200000, 0, 3 },
+	{  1,  66666, 4, 5 },
+	{  0, 800000, 1, 4 },
+	{  0, 600000, 0, 2 },
+	{  0, 400000, 2, 4 },
+	{  0, 300000, 0, 1 },
+	{  0, 266666, 3, 4 },
+	{  0, 200000, 2, 3 },
+	{  0, 150000, 0, 0 },
+	{  0, 133333, 4, 4 },
+	{  0, 100000, 2, 2 },
+	{  0,  66666, 4, 3 },
+	{  0,  50000, 2, 1 },
+	{  0,  33333, 4, 2 },
+	{  0,  25000, 2, 0 },
+	{  0,  16666, 4, 1 },
+	{  0,   8333, 4, 0 },
+};
+
+static const struct {
+	unsigned int scale, uscale; /* scale factor as integer + micro */
+	u8 gain; /* gain register value */
+	u8 res; /* resolution register value */
+} zopt2201_scale_uvb[] = {
+	{ 0, 460800, 0, 5 },
+	{ 0, 153600, 1, 5 },
+	{ 0,  76800, 2, 5 },
+	{ 0,  57600, 0, 4 },
+	{ 0,  51200, 3, 5 },
+	{ 0,  28800, 0, 3 },
+	{ 0,  25600, 4, 5 },
+	{ 0,  19200, 1, 4 },
+	{ 0,  14400, 0, 2 },
+	{ 0,   9600, 2, 4 },
+	{ 0,   7200, 0, 1 },
+	{ 0,   6400, 3, 4 },
+	{ 0,   4800, 2, 3 },
+	{ 0,   3600, 0, 0 },
+	{ 0,   3200, 4, 4 },
+	{ 0,   2400, 2, 2 },
+	{ 0,   1600, 4, 3 },
+	{ 0,   1200, 2, 1 },
+	{ 0,    800, 4, 2 },
+	{ 0,    600, 2, 0 },
+	{ 0,    400, 4, 1 },
+	{ 0,    200, 4, 0 },
+};
+
+static int zopt2201_enable_mode(struct zopt2201_data *data, bool uvb_mode)
+{
+	u8 out = ZOPT2201_MAIN_CTRL_LS_EN;
+
+	if (uvb_mode)
+		out |= ZOPT2201_MAIN_CTRL_LS_MODE;
+
+	return i2c_smbus_write_byte_data(data->client, ZOPT2201_MAIN_CTRL, out);
+}
+
+static int zopt2201_read(struct zopt2201_data *data, u8 reg)
+{
+	struct i2c_client *client = data->client;
+	int tries = 10;
+	u8 buf[3];
+	int ret;
+
+	mutex_lock(&data->lock);
+	ret = zopt2201_enable_mode(data, reg == ZOPT2201_UVB_DATA);
+	if (ret < 0)
+		goto fail;
+
+	while (tries--) {
+		unsigned long t = zopt2201_resolution[data->res].us;
+
+		if (t <= 20000)
+			usleep_range(t, t + 1000);
+		else
+			msleep(t / 1000);
+		ret = i2c_smbus_read_byte_data(client, ZOPT2201_MAIN_STATUS);
+		if (ret < 0)
+			goto fail;
+		if (ret & ZOPT2201_MAIN_STATUS_DRDY)
+			break;
+	}
+
+	if (tries < 0) {
+		ret = -ETIMEDOUT;
+		goto fail;
+	}
+
+	ret = i2c_smbus_read_i2c_block_data(client, reg, sizeof(buf), buf);
+	if (ret < 0)
+		goto fail;
+
+	ret = i2c_smbus_write_byte_data(client, ZOPT2201_MAIN_CTRL, 0x00);
+	if (ret < 0)
+		goto fail;
+	mutex_unlock(&data->lock);
+
+	return (buf[2] << 16) | (buf[1] << 8) | buf[0];
+
+fail:
+	mutex_unlock(&data->lock);
+	return ret;
+}
+
+static const struct iio_chan_spec zopt2201_channels[] = {
+	{
+		.type = IIO_LIGHT,
+		.address = ZOPT2201_ALS_DATA,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+				      BIT(IIO_CHAN_INFO_SCALE),
+		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME),
+	},
+	{
+		.type = IIO_INTENSITY,
+		.modified = 1,
+		.channel2 = IIO_MOD_LIGHT_UV,
+		.address = ZOPT2201_UVB_DATA,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+				      BIT(IIO_CHAN_INFO_SCALE),
+		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME),
+	},
+	{
+		.type = IIO_UVINDEX,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+	},
+};
+
+static int zopt2201_read_raw(struct iio_dev *indio_dev,
+				struct iio_chan_spec const *chan,
+				int *val, int *val2, long mask)
+{
+	struct zopt2201_data *data = iio_priv(indio_dev);
+	u64 tmp;
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		ret = zopt2201_read(data, chan->address);
+		if (ret < 0)
+			return ret;
+		*val = ret;
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_PROCESSED:
+		ret = zopt2201_read(data, ZOPT2201_UVB_DATA);
+		if (ret < 0)
+			return ret;
+		*val = ret * 18 *
+			(1 << (20 - zopt2201_resolution[data->res].bits)) /
+			zopt2201_gain_uvb[data->gain].gain;
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		switch (chan->address) {
+		case ZOPT2201_ALS_DATA:
+			*val = zopt2201_gain_als[data->gain].scale;
+			break;
+		case ZOPT2201_UVB_DATA:
+			*val = zopt2201_gain_uvb[data->gain].scale;
+			break;
+		default:
+			return -EINVAL;
+		}
+
+		*val2 = 1000000;
+		*val2 *= (1 << (zopt2201_resolution[data->res].bits - 13));
+		tmp = div_s64(*val * 1000000ULL, *val2);
+		*val = div_s64_rem(tmp, 1000000, val2);
+
+		return IIO_VAL_INT_PLUS_MICRO;
+	case IIO_CHAN_INFO_INT_TIME:
+		*val = 0;
+		*val2 = zopt2201_resolution[data->res].us;
+		return IIO_VAL_INT_PLUS_MICRO;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int zopt2201_set_resolution(struct zopt2201_data *data, u8 res)
+{
+	int ret;
+
+	ret = i2c_smbus_write_byte_data(data->client, ZOPT2201_LS_MEAS_RATE,
+					(res << ZOPT2201_MEAS_RES_SHIFT) |
+					data->rate);
+	if (ret < 0)
+		return ret;
+
+	data->res = res;
+
+	return 0;
+}
+
+static int zopt2201_write_resolution(struct zopt2201_data *data,
+				     int val, int val2)
+{
+	int i, ret;
+
+	if (val != 0)
+		return -EINVAL;
+
+	for (i = 0; i < ARRAY_SIZE(zopt2201_resolution); i++)
+		if (val2 == zopt2201_resolution[i].us) {
+			mutex_lock(&data->lock);
+			ret = zopt2201_set_resolution(data, i);
+			mutex_unlock(&data->lock);
+			return ret;
+		}
+
+	return -EINVAL;
+}
+
+static int zopt2201_set_gain(struct zopt2201_data *data, u8 gain)
+{
+	int ret;
+
+	ret = i2c_smbus_write_byte_data(data->client, ZOPT2201_LS_GAIN, gain);
+	if (ret < 0)
+		return ret;
+
+	data->gain = gain;
+
+	return 0;
+}
+
+static int zopt2201_write_scale_als_by_idx(struct zopt2201_data *data, int idx)
+{
+	int ret;
+
+	mutex_lock(&data->lock);
+	ret = zopt2201_set_resolution(data, zopt2201_scale_als[idx].res);
+	if (ret < 0)
+		goto unlock;
+
+	ret = zopt2201_set_gain(data, zopt2201_scale_als[idx].gain);
+
+unlock:
+	mutex_unlock(&data->lock);
+	return ret;
+}
+
+static int zopt2201_write_scale_als(struct zopt2201_data *data,
+				     int val, int val2)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(zopt2201_scale_als); i++)
+		if (val == zopt2201_scale_als[i].scale &&
+		    val2 == zopt2201_scale_als[i].uscale) {
+			return zopt2201_write_scale_als_by_idx(data, i);
+		}
+
+	return -EINVAL;
+}
+
+static int zopt2201_write_scale_uvb_by_idx(struct zopt2201_data *data, int idx)
+{
+	int ret;
+
+	mutex_lock(&data->lock);
+	ret = zopt2201_set_resolution(data, zopt2201_scale_als[idx].res);
+	if (ret < 0)
+		goto unlock;
+
+	ret = zopt2201_set_gain(data, zopt2201_scale_als[idx].gain);
+
+unlock:
+	mutex_unlock(&data->lock);
+	return ret;
+}
+
+static int zopt2201_write_scale_uvb(struct zopt2201_data *data,
+				     int val, int val2)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(zopt2201_scale_uvb); i++)
+		if (val == zopt2201_scale_uvb[i].scale &&
+		    val2 == zopt2201_scale_uvb[i].uscale)
+			return zopt2201_write_scale_uvb_by_idx(data, i);
+
+	return -EINVAL;
+}
+
+static int zopt2201_write_raw(struct iio_dev *indio_dev,
+			      struct iio_chan_spec const *chan,
+			      int val, int val2, long mask)
+{
+	struct zopt2201_data *data = iio_priv(indio_dev);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_INT_TIME:
+		return zopt2201_write_resolution(data, val, val2);
+	case IIO_CHAN_INFO_SCALE:
+		switch (chan->address) {
+		case ZOPT2201_ALS_DATA:
+			return zopt2201_write_scale_als(data, val, val2);
+		case ZOPT2201_UVB_DATA:
+			return zopt2201_write_scale_uvb(data, val, val2);
+		default:
+			return -EINVAL;
+		}
+	}
+
+	return -EINVAL;
+}
+
+static ssize_t zopt2201_show_int_time_available(struct device *dev,
+						struct device_attribute *attr,
+						char *buf)
+{
+	size_t len = 0;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(zopt2201_resolution); i++)
+		len += scnprintf(buf + len, PAGE_SIZE - len, "0.%06lu ",
+				 zopt2201_resolution[i].us);
+	buf[len - 1] = '\n';
+
+	return len;
+}
+
+static IIO_DEV_ATTR_INT_TIME_AVAIL(zopt2201_show_int_time_available);
+
+static ssize_t zopt2201_show_als_scale_avail(struct device *dev,
+					     struct device_attribute *attr,
+					     char *buf)
+{
+	ssize_t len = 0;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(zopt2201_scale_als); i++)
+		len += scnprintf(buf + len, PAGE_SIZE - len, "%d.%06u ",
+				 zopt2201_scale_als[i].scale,
+				 zopt2201_scale_als[i].uscale);
+	buf[len - 1] = '\n';
+
+	return len;
+}
+
+static ssize_t zopt2201_show_uvb_scale_avail(struct device *dev,
+					     struct device_attribute *attr,
+					     char *buf)
+{
+	ssize_t len = 0;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(zopt2201_scale_uvb); i++)
+		len += scnprintf(buf + len, PAGE_SIZE - len, "%d.%06u ",
+				 zopt2201_scale_uvb[i].scale,
+				 zopt2201_scale_uvb[i].uscale);
+	buf[len - 1] = '\n';
+
+	return len;
+}
+
+static IIO_DEVICE_ATTR(in_illuminance_scale_available, 0444,
+		       zopt2201_show_als_scale_avail, NULL, 0);
+static IIO_DEVICE_ATTR(in_intensity_uv_scale_available, 0444,
+		       zopt2201_show_uvb_scale_avail, NULL, 0);
+
+static struct attribute *zopt2201_attributes[] = {
+	&iio_dev_attr_integration_time_available.dev_attr.attr,
+	&iio_dev_attr_in_illuminance_scale_available.dev_attr.attr,
+	&iio_dev_attr_in_intensity_uv_scale_available.dev_attr.attr,
+	NULL
+};
+
+static const struct attribute_group zopt2201_attribute_group = {
+	.attrs = zopt2201_attributes,
+};
+
+static const struct iio_info zopt2201_info = {
+	.read_raw = zopt2201_read_raw,
+	.write_raw = zopt2201_write_raw,
+	.attrs = &zopt2201_attribute_group,
+};
+
+static int zopt2201_probe(struct i2c_client *client,
+			  const struct i2c_device_id *id)
+{
+	struct zopt2201_data *data;
+	struct iio_dev *indio_dev;
+	int ret;
+
+	if (!i2c_check_functionality(client->adapter,
+				     I2C_FUNC_SMBUS_READ_I2C_BLOCK))
+		return -EOPNOTSUPP;
+
+	ret = i2c_smbus_read_byte_data(client, ZOPT2201_PART_ID);
+	if (ret < 0)
+		return ret;
+	if (ret != ZOPT2201_PART_NUMBER)
+		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;
+	mutex_init(&data->lock);
+
+	indio_dev->dev.parent = &client->dev;
+	indio_dev->info = &zopt2201_info;
+	indio_dev->channels = zopt2201_channels;
+	indio_dev->num_channels = ARRAY_SIZE(zopt2201_channels);
+	indio_dev->name = ZOPT2201_DRV_NAME;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+
+	data->rate = ZOPT2201_MEAS_FREQ_100MS;
+	ret = zopt2201_set_resolution(data, ZOPT2201_MEAS_RES_18BIT);
+	if (ret < 0)
+		return ret;
+
+	ret = zopt2201_set_gain(data, ZOPT2201_LS_GAIN_3);
+	if (ret < 0)
+		return ret;
+
+	return devm_iio_device_register(&client->dev, indio_dev);
+}
+
+static const struct i2c_device_id zopt2201_id[] = {
+	{ "zopt2201", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, zopt2201_id);
+
+static struct i2c_driver zopt2201_driver = {
+	.driver = {
+		.name   = ZOPT2201_DRV_NAME,
+	},
+	.probe  = zopt2201_probe,
+	.id_table = zopt2201_id,
+};
+
+module_i2c_driver(zopt2201_driver);
+
+MODULE_AUTHOR("Peter Meerwald-Stadler <pmeerw@pmeerw.net>");
+MODULE_DESCRIPTION("IDT ZOPT2201 ambient light and UV B sensor driver");
+MODULE_LICENSE("GPL");

drivers/iio/magnetometer/ak8975.c

@@ -788,6 +788,7 @@ static const struct acpi_device_id ak_acpi_match[] = {
 	{"AK8975", AK8975},
 	{"AK8963", AK8963},
 	{"INVN6500", AK8963},
+	{"AK009911", AK09911},
 	{"AK09911", AK09911},
 	{"AK09912", AK09912},
 	{ },

drivers/iio/proximity/sx9500.c

@@ -1022,6 +1022,7 @@ static const struct dev_pm_ops sx9500_pm_ops = {
 
 static const struct acpi_device_id sx9500_acpi_match[] = {
 	{"SSX9500", 0},
+	{"SASX9500", 0},
 	{ },
 };
 MODULE_DEVICE_TABLE(acpi, sx9500_acpi_match);

drivers/staging/iio/cdc/ad7152.c

@@ -118,22 +118,23 @@ static inline ssize_t ad7152_start_calib(struct device *dev,
 
 	mutex_lock(&chip->state_lock);
 	ret = i2c_smbus_write_byte_data(chip->client, AD7152_REG_CFG, regval);
-	if (ret < 0) {
-		mutex_unlock(&chip->state_lock);
-		return ret;
-	}
+	if (ret < 0)
+		goto unlock;
 
 	do {
 		mdelay(20);
 		ret = i2c_smbus_read_byte_data(chip->client, AD7152_REG_CFG);
-		if (ret < 0) {
-			mutex_unlock(&chip->state_lock);
-			return ret;
-		}
+		if (ret < 0)
+			goto unlock;
+
 	} while ((ret == regval) && timeout--);
 
 	mutex_unlock(&chip->state_lock);
 	return len;
+
+unlock:
+	mutex_unlock(&chip->state_lock);
+	return ret;
 }
 
 static ssize_t ad7152_start_offset_calib(struct device *dev,

drivers/staging/iio/cdc/ad7746.c

@@ -302,23 +302,24 @@ static inline ssize_t ad7746_start_calib(struct device *dev,
 	mutex_lock(&chip->lock);
 	regval |= chip->config;
 	ret = i2c_smbus_write_byte_data(chip->client, AD7746_REG_CFG, regval);
-	if (ret < 0) {
-		mutex_unlock(&chip->lock);
-		return ret;
-	}
+	if (ret < 0)
+		goto unlock;
 
 	do {
 		msleep(20);
 		ret = i2c_smbus_read_byte_data(chip->client, AD7746_REG_CFG);
-		if (ret < 0) {
-			mutex_unlock(&chip->lock);
-			return ret;
-		}
+		if (ret < 0)
+			goto unlock;
+
 	} while ((ret == regval) && timeout--);
 
 	mutex_unlock(&chip->lock);
 
 	return len;
+
+unlock:
+	mutex_unlock(&chip->lock);
+	return ret;
 }
 
 static ssize_t ad7746_start_offset_calib(struct device *dev,

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

@@ -187,9 +187,9 @@ static int iio_bfin_tmr_trigger_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	st->irq = platform_get_irq(pdev, 0);
-	if (!st->irq) {
+	if (st->irq < 0) {
 		dev_err(&pdev->dev, "No IRQs specified");
-		return -ENODEV;
+		return st->irq;
 	}
 
 	ret = iio_bfin_tmr_get_number(st->irq);

include/linux/iio/machine.h

@@ -28,4 +28,11 @@ struct iio_map {
 	void *consumer_data;
 };
 
+#define IIO_MAP(_provider_channel, _consumer_dev_name, _consumer_channel) \
+{									  \
+	.adc_channel_label = _provider_channel,				  \
+	.consumer_dev_name = _consumer_dev_name,			  \
+	.consumer_channel  = _consumer_channel,				  \
+}
+
 #endif