18 files changed, 620 insertions, 27 deletions

diff --git a/drivers/iio/adc/ad7793.c b/drivers/iio/adc/ad7793.c
index e6706a09e100..47c3d7f32900 100644
--- a/drivers/iio/adc/ad7793.c
+++ b/drivers/iio/adc/ad7793.c
@@ -257,7 +257,7 @@ static int ad7793_setup(struct iio_dev *indio_dev,
 	unsigned int vref_mv)
 {
 	struct ad7793_state *st = iio_priv(indio_dev);
-	int i, ret = -1;
+	int i, ret;
 	unsigned long long scale_uv;
 	u32 id;
 
@@ -266,7 +266,7 @@ static int ad7793_setup(struct iio_dev *indio_dev,
 		return ret;
 
 	/* reset the serial interface */
-	ret = spi_write(st->sd.spi, (u8 *)&ret, sizeof(ret));
+	ret = ad_sd_reset(&st->sd, 32);
 	if (ret < 0)
 		goto out;
 	usleep_range(500, 2000); /* Wait for at least 500us */
diff --git a/drivers/iio/adc/ad_sigma_delta.c b/drivers/iio/adc/ad_sigma_delta.c
index d10bd0c97233..22c4c17cd996 100644
--- a/drivers/iio/adc/ad_sigma_delta.c
+++ b/drivers/iio/adc/ad_sigma_delta.c
@@ -177,6 +177,34 @@ out:
 }
 EXPORT_SYMBOL_GPL(ad_sd_read_reg);
 
+/**
+ * ad_sd_reset() - Reset the serial interface
+ *
+ * @sigma_delta: The sigma delta device
+ * @reset_length: Number of SCLKs with DIN = 1
+ *
+ * Returns 0 on success, an error code otherwise.
+ **/
+int ad_sd_reset(struct ad_sigma_delta *sigma_delta,
+	unsigned int reset_length)
+{
+	uint8_t *buf;
+	unsigned int size;
+	int ret;
+
+	size = DIV_ROUND_UP(reset_length, 8);
+	buf = kcalloc(size, sizeof(*buf), GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	memset(buf, 0xff, size);
+	ret = spi_write(sigma_delta->spi, buf, size);
+	kfree(buf);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(ad_sd_reset);
+
 static int ad_sd_calibrate(struct ad_sigma_delta *sigma_delta,
 	unsigned int mode, unsigned int channel)
 {
diff --git a/drivers/iio/adc/mcp320x.c b/drivers/iio/adc/mcp320x.c
index 634717ae12f3..071dd23a33d9 100644
--- a/drivers/iio/adc/mcp320x.c
+++ b/drivers/iio/adc/mcp320x.c
@@ -17,6 +17,8 @@
  * MCP3204
  * MCP3208
  * ------------
+ * 13 bit converter
+ * MCP3301
  *
  * Datasheet can be found here:
  * http://ww1.microchip.com/downloads/en/DeviceDoc/21293C.pdf  mcp3001
@@ -96,7 +98,7 @@ static int mcp320x_channel_to_tx_data(int device_index,
 }
 
 static int mcp320x_adc_conversion(struct mcp320x *adc, u8 channel,
-				  bool differential, int device_index)
+				  bool differential, int device_index, int *val)
 {
 	int ret;
 
@@ -117,19 +119,25 @@ static int mcp320x_adc_conversion(struct mcp320x *adc, u8 channel,
 
 	switch (device_index) {
 	case mcp3001:
-		return (adc->rx_buf[0] << 5 | adc->rx_buf[1] >> 3);
+		*val = (adc->rx_buf[0] << 5 | adc->rx_buf[1] >> 3);
+		return 0;
 	case mcp3002:
 	case mcp3004:
 	case mcp3008:
-		return (adc->rx_buf[0] << 2 | adc->rx_buf[1] >> 6);
+		*val = (adc->rx_buf[0] << 2 | adc->rx_buf[1] >> 6);
+		return 0;
 	case mcp3201:
-		return (adc->rx_buf[0] << 7 | adc->rx_buf[1] >> 1);
+		*val = (adc->rx_buf[0] << 7 | adc->rx_buf[1] >> 1);
+		return 0;
 	case mcp3202:
 	case mcp3204:
 	case mcp3208:
-		return (adc->rx_buf[0] << 4 | adc->rx_buf[1] >> 4);
+		*val = (adc->rx_buf[0] << 4 | adc->rx_buf[1] >> 4);
+		return 0;
 	case mcp3301:
-		return sign_extend32((adc->rx_buf[0] & 0x1f) << 8 | adc->rx_buf[1], 12);
+		*val = sign_extend32((adc->rx_buf[0] & 0x1f) << 8
+				    | adc->rx_buf[1], 12);
+		return 0;
 	default:
 		return -EINVAL;
 	}
@@ -150,12 +158,10 @@ static int mcp320x_read_raw(struct iio_dev *indio_dev,
 	switch (mask) {
 	case IIO_CHAN_INFO_RAW:
 		ret = mcp320x_adc_conversion(adc, channel->address,
-			channel->differential, device_index);
-
+			channel->differential, device_index, val);
 		if (ret < 0)
 			goto out;
 
-		*val = ret;
 		ret = IIO_VAL_INT;
 		break;
 
@@ -312,6 +318,7 @@ static int mcp320x_probe(struct spi_device *spi)
 	indio_dev->name = spi_get_device_id(spi)->name;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->info = &mcp320x_info;
+	spi_set_drvdata(spi, indio_dev);
 
 	chip_info = &mcp320x_chip_infos[spi_get_device_id(spi)->driver_data];
 	indio_dev->channels = chip_info->channels;
diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c
index 6bc602891f2f..4df32cf1650e 100644
--- a/drivers/iio/adc/stm32-adc.c
+++ b/drivers/iio/adc/stm32-adc.c
@@ -25,6 +25,7 @@
 #include <linux/dmaengine.h>
 #include <linux/iio/iio.h>
 #include <linux/iio/buffer.h>
+#include <linux/iio/timer/stm32-lptim-trigger.h>
 #include <linux/iio/timer/stm32-timer-trigger.h>
 #include <linux/iio/trigger.h>
 #include <linux/iio/trigger_consumer.h>
@@ -185,6 +186,11 @@ enum stm32_adc_extsel {
 	STM32_EXT13,
 	STM32_EXT14,
 	STM32_EXT15,
+	STM32_EXT16,
+	STM32_EXT17,
+	STM32_EXT18,
+	STM32_EXT19,
+	STM32_EXT20,
 };
 
 /**
@@ -526,6 +532,9 @@ static struct stm32_adc_trig_info stm32h7_adc_trigs[] = {
 	{ TIM4_TRGO, STM32_EXT12 },
 	{ TIM6_TRGO, STM32_EXT13 },
 	{ TIM3_CH4, STM32_EXT15 },
+	{ LPTIM1_OUT, STM32_EXT18 },
+	{ LPTIM2_OUT, STM32_EXT19 },
+	{ LPTIM3_OUT, STM32_EXT20 },
 	{},
 };
 
@@ -1082,7 +1091,8 @@ static int stm32_adc_get_trig_extsel(struct iio_dev *indio_dev,
 		 * Checking both stm32 timer trigger type and trig name
 		 * should be safe against arbitrary trigger names.
 		 */
-		if (is_stm32_timer_trigger(trig) &&
+		if ((is_stm32_timer_trigger(trig) ||
+		     is_stm32_lptim_trigger(trig)) &&
 		    !strcmp(adc->cfg->trigs[i].name, trig->name)) {
 			return adc->cfg->trigs[i].extsel;
 		}
@@ -1656,7 +1666,7 @@ static int stm32_adc_chan_of_init(struct iio_dev *indio_dev)
 
 	num_channels = of_property_count_u32_elems(node, "st,adc-channels");
 	if (num_channels < 0 ||
-	    num_channels >= adc_info->max_channels) {
+	    num_channels > adc_info->max_channels) {
 		dev_err(&indio_dev->dev, "Bad st,adc-channels?\n");
 		return num_channels < 0 ? num_channels : -EINVAL;
 	}
@@ -1764,7 +1774,7 @@ static int stm32_adc_probe(struct platform_device *pdev)
 	indio_dev->dev.parent = &pdev->dev;
 	indio_dev->dev.of_node = pdev->dev.of_node;
 	indio_dev->info = &stm32_adc_iio_info;
-	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->modes = INDIO_DIRECT_MODE | INDIO_HARDWARE_TRIGGERED;
 
 	platform_set_drvdata(pdev, adc);
 
diff --git a/drivers/iio/adc/ti-ads1015.c b/drivers/iio/adc/ti-ads1015.c
index d1210024f6bc..e0dc20488335 100644
--- a/drivers/iio/adc/ti-ads1015.c
+++ b/drivers/iio/adc/ti-ads1015.c
@@ -52,7 +52,7 @@
 
 #define ADS1015_CFG_COMP_QUE_MASK	GENMASK(1, 0)
 #define ADS1015_CFG_COMP_LAT_MASK	BIT(2)
-#define ADS1015_CFG_COMP_POL_MASK	BIT(2)
+#define ADS1015_CFG_COMP_POL_MASK	BIT(3)
 #define ADS1015_CFG_COMP_MODE_MASK	BIT(4)
 #define ADS1015_CFG_DR_MASK	GENMASK(7, 5)
 #define ADS1015_CFG_MOD_MASK	BIT(8)
@@ -1017,10 +1017,12 @@ static int ads1015_probe(struct i2c_client *client,
 
 		switch (irq_trig) {
 		case IRQF_TRIGGER_LOW:
-			cfg_comp |= ADS1015_CFG_COMP_POL_LOW;
+			cfg_comp |= ADS1015_CFG_COMP_POL_LOW <<
+					ADS1015_CFG_COMP_POL_SHIFT;
 			break;
 		case IRQF_TRIGGER_HIGH:
-			cfg_comp |= ADS1015_CFG_COMP_POL_HIGH;
+			cfg_comp |= ADS1015_CFG_COMP_POL_HIGH <<
+					ADS1015_CFG_COMP_POL_SHIFT;
 			break;
 		default:
 			return -EINVAL;
diff --git a/drivers/iio/adc/twl4030-madc.c b/drivers/iio/adc/twl4030-madc.c
index bd3d37fc2144..e3cfb91bffc6 100644
--- a/drivers/iio/adc/twl4030-madc.c
+++ b/drivers/iio/adc/twl4030-madc.c
@@ -35,7 +35,7 @@
 #include <linux/delay.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
-#include <linux/i2c/twl.h>
+#include <linux/mfd/twl.h>
 #include <linux/module.h>
 #include <linux/stddef.h>
 #include <linux/mutex.h>
@@ -887,21 +887,27 @@ static int twl4030_madc_probe(struct platform_device *pdev)
 
 	/* Enable 3v1 bias regulator for MADC[3:6] */
 	madc->usb3v1 = devm_regulator_get(madc->dev, "vusb3v1");
-	if (IS_ERR(madc->usb3v1))
-		return -ENODEV;
+	if (IS_ERR(madc->usb3v1)) {
+		ret = -ENODEV;
+		goto err_i2c;
+	}
 
 	ret = regulator_enable(madc->usb3v1);
-	if (ret)
+	if (ret) {
 		dev_err(madc->dev, "could not enable 3v1 bias regulator\n");
+		goto err_i2c;
+	}
 
 	ret = iio_device_register(iio_dev);
 	if (ret) {
 		dev_err(&pdev->dev, "could not register iio device\n");
-		goto err_i2c;
+		goto err_usb3v1;
 	}
 
 	return 0;
 
+err_usb3v1:
+	regulator_disable(madc->usb3v1);
 err_i2c:
 	twl4030_madc_set_current_generator(madc, 0, 0);
 err_current_generator:
diff --git a/drivers/iio/adc/twl6030-gpadc.c b/drivers/iio/adc/twl6030-gpadc.c
index becbb0aef232..bc0e60b9da45 100644
--- a/drivers/iio/adc/twl6030-gpadc.c
+++ b/drivers/iio/adc/twl6030-gpadc.c
@@ -33,7 +33,7 @@
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/of_platform.h>
-#include <linux/i2c/twl.h>
+#include <linux/mfd/twl.h>
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
 
diff --git a/drivers/iio/common/st_sensors/st_sensors_core.c b/drivers/iio/common/st_sensors/st_sensors_core.c
index d99bb1460fe2..02e833b14db0 100644
--- a/drivers/iio/common/st_sensors/st_sensors_core.c
+++ b/drivers/iio/common/st_sensors/st_sensors_core.c
@@ -463,8 +463,17 @@ int st_sensors_set_dataready_irq(struct iio_dev *indio_dev, bool enable)
 	u8 drdy_mask;
 	struct st_sensor_data *sdata = iio_priv(indio_dev);
 
-	if (!sdata->sensor_settings->drdy_irq.addr)
+	if (!sdata->sensor_settings->drdy_irq.addr) {
+		/*
+		 * there are some devices (e.g. LIS3MDL) where drdy line is
+		 * routed to a given pin and it is not possible to select a
+		 * different one. Take into account irq status register
+		 * to understand if irq trigger can be properly supported
+		 */
+		if (sdata->sensor_settings->drdy_irq.addr_stat_drdy)
+			sdata->hw_irq_trigger = enable;
 		return 0;
+	}
 
 	/* Enable/Disable the interrupt generator 1. */
 	if (sdata->sensor_settings->drdy_irq.ig1.en_addr > 0) {
diff --git a/drivers/iio/counter/Kconfig b/drivers/iio/counter/Kconfig
index b37e5fc03149..474e1ac4e7c0 100644
--- a/drivers/iio/counter/Kconfig
+++ b/drivers/iio/counter/Kconfig
@@ -21,4 +21,13 @@ config 104_QUAD_8
 	  The base port addresses for the devices may be configured via the base
 	  array module parameter.
 
+config STM32_LPTIMER_CNT
+	tristate "STM32 LP Timer encoder counter driver"
+	depends on MFD_STM32_LPTIMER || COMPILE_TEST
+	help
+	  Select this option to enable STM32 Low-Power Timer quadrature encoder
+	  and counter driver.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called stm32-lptimer-cnt.
 endmenu
diff --git a/drivers/iio/counter/Makefile b/drivers/iio/counter/Makefile
index 007e88411648..1b9a896eb488 100644
--- a/drivers/iio/counter/Makefile
+++ b/drivers/iio/counter/Makefile
@@ -5,3 +5,4 @@
 # When adding new entries keep the list in alphabetical order
 
 obj-$(CONFIG_104_QUAD_8)	+= 104-quad-8.o
+obj-$(CONFIG_STM32_LPTIMER_CNT)	+= stm32-lptimer-cnt.o
diff --git a/drivers/iio/counter/stm32-lptimer-cnt.c b/drivers/iio/counter/stm32-lptimer-cnt.c
new file mode 100644
index 000000000000..1c5909bb1605
--- /dev/null
+++ b/drivers/iio/counter/stm32-lptimer-cnt.c
@@ -0,0 +1,383 @@
+/*
+ * STM32 Low-Power Timer Encoder and Counter driver
+ *
+ * Copyright (C) STMicroelectronics 2017
+ *
+ * Author: Fabrice Gasnier <fabrice.gasnier@st.com>
+ *
+ * Inspired by 104-quad-8 and stm32-timer-trigger drivers.
+ *
+ * License terms:  GNU General Public License (GPL), version 2
+ */
+
+#include <linux/bitfield.h>
+#include <linux/iio/iio.h>
+#include <linux/mfd/stm32-lptimer.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+struct stm32_lptim_cnt {
+	struct device *dev;
+	struct regmap *regmap;
+	struct clk *clk;
+	u32 preset;
+	u32 polarity;
+	u32 quadrature_mode;
+};
+
+static int stm32_lptim_is_enabled(struct stm32_lptim_cnt *priv)
+{
+	u32 val;
+	int ret;
+
+	ret = regmap_read(priv->regmap, STM32_LPTIM_CR, &val);
+	if (ret)
+		return ret;
+
+	return FIELD_GET(STM32_LPTIM_ENABLE, val);
+}
+
+static int stm32_lptim_set_enable_state(struct stm32_lptim_cnt *priv,
+					int enable)
+{
+	int ret;
+	u32 val;
+
+	val = FIELD_PREP(STM32_LPTIM_ENABLE, enable);
+	ret = regmap_write(priv->regmap, STM32_LPTIM_CR, val);
+	if (ret)
+		return ret;
+
+	if (!enable) {
+		clk_disable(priv->clk);
+		return 0;
+	}
+
+	/* LP timer must be enabled before writing CMP & ARR */
+	ret = regmap_write(priv->regmap, STM32_LPTIM_ARR, priv->preset);
+	if (ret)
+		return ret;
+
+	ret = regmap_write(priv->regmap, STM32_LPTIM_CMP, 0);
+	if (ret)
+		return ret;
+
+	/* ensure CMP & ARR registers are properly written */
+	ret = regmap_read_poll_timeout(priv->regmap, STM32_LPTIM_ISR, val,
+				       (val & STM32_LPTIM_CMPOK_ARROK),
+				       100, 1000);
+	if (ret)
+		return ret;
+
+	ret = regmap_write(priv->regmap, STM32_LPTIM_ICR,
+			   STM32_LPTIM_CMPOKCF_ARROKCF);
+	if (ret)
+		return ret;
+
+	ret = clk_enable(priv->clk);
+	if (ret) {
+		regmap_write(priv->regmap, STM32_LPTIM_CR, 0);
+		return ret;
+	}
+
+	/* Start LP timer in continuous mode */
+	return regmap_update_bits(priv->regmap, STM32_LPTIM_CR,
+				  STM32_LPTIM_CNTSTRT, STM32_LPTIM_CNTSTRT);
+}
+
+static int stm32_lptim_setup(struct stm32_lptim_cnt *priv, int enable)
+{
+	u32 mask = STM32_LPTIM_ENC | STM32_LPTIM_COUNTMODE |
+		   STM32_LPTIM_CKPOL | STM32_LPTIM_PRESC;
+	u32 val;
+
+	/* Setup LP timer encoder/counter and polarity, without prescaler */
+	if (priv->quadrature_mode)
+		val = enable ? STM32_LPTIM_ENC : 0;
+	else
+		val = enable ? STM32_LPTIM_COUNTMODE : 0;
+	val |= FIELD_PREP(STM32_LPTIM_CKPOL, enable ? priv->polarity : 0);
+
+	return regmap_update_bits(priv->regmap, STM32_LPTIM_CFGR, mask, val);
+}
+
+static int stm32_lptim_write_raw(struct iio_dev *indio_dev,
+				 struct iio_chan_spec const *chan,
+				 int val, int val2, long mask)
+{
+	struct stm32_lptim_cnt *priv = iio_priv(indio_dev);
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_ENABLE:
+		if (val < 0 || val > 1)
+			return -EINVAL;
+
+		/* Check nobody uses the timer, or already disabled/enabled */
+		ret = stm32_lptim_is_enabled(priv);
+		if ((ret < 0) || (!ret && !val))
+			return ret;
+		if (val && ret)
+			return -EBUSY;
+
+		ret = stm32_lptim_setup(priv, val);
+		if (ret)
+			return ret;
+		return stm32_lptim_set_enable_state(priv, val);
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static int stm32_lptim_read_raw(struct iio_dev *indio_dev,
+				struct iio_chan_spec const *chan,
+				int *val, int *val2, long mask)
+{
+	struct stm32_lptim_cnt *priv = iio_priv(indio_dev);
+	u32 dat;
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		ret = regmap_read(priv->regmap, STM32_LPTIM_CNT, &dat);
+		if (ret)
+			return ret;
+		*val = dat;
+		return IIO_VAL_INT;
+
+	case IIO_CHAN_INFO_ENABLE:
+		ret = stm32_lptim_is_enabled(priv);
+		if (ret < 0)
+			return ret;
+		*val = ret;
+		return IIO_VAL_INT;
+
+	case IIO_CHAN_INFO_SCALE:
+		/* Non-quadrature mode: scale = 1 */
+		*val = 1;
+		*val2 = 0;
+		if (priv->quadrature_mode) {
+			/*
+			 * Quadrature encoder mode:
+			 * - both edges, quarter cycle, scale is 0.25
+			 * - either rising/falling edge scale is 0.5
+			 */
+			if (priv->polarity > 1)
+				*val2 = 2;
+			else
+				*val2 = 1;
+		}
+		return IIO_VAL_FRACTIONAL_LOG2;
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct iio_info stm32_lptim_cnt_iio_info = {
+	.read_raw = stm32_lptim_read_raw,
+	.write_raw = stm32_lptim_write_raw,
+	.driver_module = THIS_MODULE,
+};
+
+static const char *const stm32_lptim_quadrature_modes[] = {
+	"non-quadrature",
+	"quadrature",
+};
+
+static int stm32_lptim_get_quadrature_mode(struct iio_dev *indio_dev,
+					   const struct iio_chan_spec *chan)
+{
+	struct stm32_lptim_cnt *priv = iio_priv(indio_dev);
+
+	return priv->quadrature_mode;
+}
+
+static int stm32_lptim_set_quadrature_mode(struct iio_dev *indio_dev,
+					   const struct iio_chan_spec *chan,
+					   unsigned int type)
+{
+	struct stm32_lptim_cnt *priv = iio_priv(indio_dev);
+
+	if (stm32_lptim_is_enabled(priv))
+		return -EBUSY;
+
+	priv->quadrature_mode = type;
+
+	return 0;
+}
+
+static const struct iio_enum stm32_lptim_quadrature_mode_en = {
+	.items = stm32_lptim_quadrature_modes,
+	.num_items = ARRAY_SIZE(stm32_lptim_quadrature_modes),
+	.get = stm32_lptim_get_quadrature_mode,
+	.set = stm32_lptim_set_quadrature_mode,
+};
+
+static const char * const stm32_lptim_cnt_polarity[] = {
+	"rising-edge", "falling-edge", "both-edges",
+};
+
+static int stm32_lptim_cnt_get_polarity(struct iio_dev *indio_dev,
+					const struct iio_chan_spec *chan)
+{
+	struct stm32_lptim_cnt *priv = iio_priv(indio_dev);
+
+	return priv->polarity;
+}
+
+static int stm32_lptim_cnt_set_polarity(struct iio_dev *indio_dev,
+					const struct iio_chan_spec *chan,
+					unsigned int type)
+{
+	struct stm32_lptim_cnt *priv = iio_priv(indio_dev);
+
+	if (stm32_lptim_is_enabled(priv))
+		return -EBUSY;
+
+	priv->polarity = type;
+
+	return 0;
+}
+
+static const struct iio_enum stm32_lptim_cnt_polarity_en = {
+	.items = stm32_lptim_cnt_polarity,
+	.num_items = ARRAY_SIZE(stm32_lptim_cnt_polarity),
+	.get = stm32_lptim_cnt_get_polarity,
+	.set = stm32_lptim_cnt_set_polarity,
+};
+
+static ssize_t stm32_lptim_cnt_get_preset(struct iio_dev *indio_dev,
+					  uintptr_t private,
+					  const struct iio_chan_spec *chan,
+					  char *buf)
+{
+	struct stm32_lptim_cnt *priv = iio_priv(indio_dev);
+
+	return snprintf(buf, PAGE_SIZE, "%u\n", priv->preset);
+}
+
+static ssize_t stm32_lptim_cnt_set_preset(struct iio_dev *indio_dev,
+					  uintptr_t private,
+					  const struct iio_chan_spec *chan,
+					  const char *buf, size_t len)
+{
+	struct stm32_lptim_cnt *priv = iio_priv(indio_dev);
+	int ret;
+
+	if (stm32_lptim_is_enabled(priv))
+		return -EBUSY;
+
+	ret = kstrtouint(buf, 0, &priv->preset);
+	if (ret)
+		return ret;
+
+	if (priv->preset > STM32_LPTIM_MAX_ARR)
+		return -EINVAL;
+
+	return len;
+}
+
+/* LP timer with encoder */
+static const struct iio_chan_spec_ext_info stm32_lptim_enc_ext_info[] = {
+	{
+		.name = "preset",
+		.shared = IIO_SEPARATE,
+		.read = stm32_lptim_cnt_get_preset,
+		.write = stm32_lptim_cnt_set_preset,
+	},
+	IIO_ENUM("polarity", IIO_SEPARATE, &stm32_lptim_cnt_polarity_en),
+	IIO_ENUM_AVAILABLE("polarity", &stm32_lptim_cnt_polarity_en),
+	IIO_ENUM("quadrature_mode", IIO_SEPARATE,
+		 &stm32_lptim_quadrature_mode_en),
+	IIO_ENUM_AVAILABLE("quadrature_mode", &stm32_lptim_quadrature_mode_en),
+	{}
+};
+
+static const struct iio_chan_spec stm32_lptim_enc_channels = {
+	.type = IIO_COUNT,
+	.channel = 0,
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+			      BIT(IIO_CHAN_INFO_ENABLE) |
+			      BIT(IIO_CHAN_INFO_SCALE),
+	.ext_info = stm32_lptim_enc_ext_info,
+	.indexed = 1,
+};
+
+/* LP timer without encoder (counter only) */
+static const struct iio_chan_spec_ext_info stm32_lptim_cnt_ext_info[] = {
+	{
+		.name = "preset",
+		.shared = IIO_SEPARATE,
+		.read = stm32_lptim_cnt_get_preset,
+		.write = stm32_lptim_cnt_set_preset,
+	},
+	IIO_ENUM("polarity", IIO_SEPARATE, &stm32_lptim_cnt_polarity_en),
+	IIO_ENUM_AVAILABLE("polarity", &stm32_lptim_cnt_polarity_en),
+	{}
+};
+
+static const struct iio_chan_spec stm32_lptim_cnt_channels = {
+	.type = IIO_COUNT,
+	.channel = 0,
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+			      BIT(IIO_CHAN_INFO_ENABLE) |
+			      BIT(IIO_CHAN_INFO_SCALE),
+	.ext_info = stm32_lptim_cnt_ext_info,
+	.indexed = 1,
+};
+
+static int stm32_lptim_cnt_probe(struct platform_device *pdev)
+{
+	struct stm32_lptimer *ddata = dev_get_drvdata(pdev->dev.parent);
+	struct stm32_lptim_cnt *priv;
+	struct iio_dev *indio_dev;
+
+	if (IS_ERR_OR_NULL(ddata))
+		return -EINVAL;
+
+	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*priv));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	priv = iio_priv(indio_dev);
+	priv->dev = &pdev->dev;
+	priv->regmap = ddata->regmap;
+	priv->clk = ddata->clk;
+	priv->preset = STM32_LPTIM_MAX_ARR;
+
+	indio_dev->name = dev_name(&pdev->dev);
+	indio_dev->dev.parent = &pdev->dev;
+	indio_dev->dev.of_node = pdev->dev.of_node;
+	indio_dev->info = &stm32_lptim_cnt_iio_info;
+	if (ddata->has_encoder)
+		indio_dev->channels = &stm32_lptim_enc_channels;
+	else
+		indio_dev->channels = &stm32_lptim_cnt_channels;
+	indio_dev->num_channels = 1;
+
+	platform_set_drvdata(pdev, priv);
+
+	return devm_iio_device_register(&pdev->dev, indio_dev);
+}
+
+static const struct of_device_id stm32_lptim_cnt_of_match[] = {
+	{ .compatible = "st,stm32-lptimer-counter", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, stm32_lptim_cnt_of_match);
+
+static struct platform_driver stm32_lptim_cnt_driver = {
+	.probe = stm32_lptim_cnt_probe,
+	.driver = {
+		.name = "stm32-lptimer-counter",
+		.of_match_table = stm32_lptim_cnt_of_match,
+	},
+};
+module_platform_driver(stm32_lptim_cnt_driver);
+
+MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>");
+MODULE_ALIAS("platform:stm32-lptimer-counter");
+MODULE_DESCRIPTION("STMicroelectronics STM32 LPTIM counter driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index 17ec4cee51dc..a47428b4d31b 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -310,8 +310,10 @@ static ssize_t iio_debugfs_read_reg(struct file *file, char __user *userbuf,
 	ret = indio_dev->info->debugfs_reg_access(indio_dev,
 						  indio_dev->cached_reg_addr,
 						  0, &val);
-	if (ret)
+	if (ret) {
 		dev_err(indio_dev->dev.parent, "%s: read failed\n", __func__);
+		return ret;
+	}
 
 	len = snprintf(buf, sizeof(buf), "0x%X\n", val);
 
diff --git a/drivers/iio/magnetometer/st_magn_core.c b/drivers/iio/magnetometer/st_magn_core.c
index e68368b5b2a3..08aafba4481c 100644
--- a/drivers/iio/magnetometer/st_magn_core.c
+++ b/drivers/iio/magnetometer/st_magn_core.c
@@ -315,6 +315,10 @@ static const struct st_sensor_settings st_magn_sensors_settings[] = {
 				},
 			},
 		},
+		.drdy_irq = {
+			/* drdy line is routed drdy pin */
+			.addr_stat_drdy = ST_SENSORS_DEFAULT_STAT_ADDR,
+		},
 		.multi_read_bit = true,
 		.bootime = 2,
 	},
diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
index 0d2ea3ee371b..8f26428804a2 100644
--- a/drivers/iio/pressure/bmp280-core.c
+++ b/drivers/iio/pressure/bmp280-core.c
@@ -573,7 +573,7 @@ static int bmp280_chip_config(struct bmp280_data *data)
 	u8 osrs = BMP280_OSRS_TEMP_X(data->oversampling_temp + 1) |
 		  BMP280_OSRS_PRESS_X(data->oversampling_press + 1);
 
-	ret = regmap_update_bits(data->regmap, BMP280_REG_CTRL_MEAS,
+	ret = regmap_write_bits(data->regmap, BMP280_REG_CTRL_MEAS,
 				 BMP280_OSRS_TEMP_MASK |
 				 BMP280_OSRS_PRESS_MASK |
 				 BMP280_MODE_MASK,
diff --git a/drivers/iio/trigger/Kconfig b/drivers/iio/trigger/Kconfig
index e4d4e63434db..a633d2c8e805 100644
--- a/drivers/iio/trigger/Kconfig
+++ b/drivers/iio/trigger/Kconfig
@@ -24,6 +24,17 @@ config IIO_INTERRUPT_TRIGGER
 	  To compile this driver as a module, choose M here: the
 	  module will be called iio-trig-interrupt.
 
+config IIO_STM32_LPTIMER_TRIGGER
+	tristate "STM32 Low-Power Timer Trigger"
+	depends on MFD_STM32_LPTIMER || COMPILE_TEST
+	help
+	  Select this option to enable STM32 Low-Power Timer Trigger.
+	  This can be used as trigger source for STM32 internal ADC
+	  and/or DAC.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called stm32-lptimer-trigger.
+
 config IIO_STM32_TIMER_TRIGGER
 	tristate "STM32 Timer Trigger"
 	depends on (ARCH_STM32 && OF && MFD_STM32_TIMERS) || COMPILE_TEST
diff --git a/drivers/iio/trigger/Makefile b/drivers/iio/trigger/Makefile
index 5c4ecd380653..0a72a2a76cb2 100644
--- a/drivers/iio/trigger/Makefile
+++ b/drivers/iio/trigger/Makefile
@@ -6,6 +6,7 @@
 
 obj-$(CONFIG_IIO_HRTIMER_TRIGGER) += iio-trig-hrtimer.o
 obj-$(CONFIG_IIO_INTERRUPT_TRIGGER) += iio-trig-interrupt.o
+obj-$(CONFIG_IIO_STM32_LPTIMER_TRIGGER) += stm32-lptimer-trigger.o
 obj-$(CONFIG_IIO_STM32_TIMER_TRIGGER) += stm32-timer-trigger.o
 obj-$(CONFIG_IIO_SYSFS_TRIGGER) += iio-trig-sysfs.o
 obj-$(CONFIG_IIO_TIGHTLOOP_TRIGGER) += iio-trig-loop.o
diff --git a/drivers/iio/trigger/stm32-lptimer-trigger.c b/drivers/iio/trigger/stm32-lptimer-trigger.c
new file mode 100644
index 000000000000..241eae6a4306
--- /dev/null
+++ b/drivers/iio/trigger/stm32-lptimer-trigger.c
@@ -0,0 +1,118 @@
+/*
+ * STM32 Low-Power Timer Trigger driver
+ *
+ * Copyright (C) STMicroelectronics 2017
+ *
+ * Author: Fabrice Gasnier <fabrice.gasnier@st.com>.
+ *
+ * License terms:  GNU General Public License (GPL), version 2
+ *
+ * Inspired by Benjamin Gaignard's stm32-timer-trigger driver
+ */
+
+#include <linux/iio/timer/stm32-lptim-trigger.h>
+#include <linux/mfd/stm32-lptimer.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+/* List Low-Power Timer triggers */
+static const char * const stm32_lptim_triggers[] = {
+	LPTIM1_OUT,
+	LPTIM2_OUT,
+	LPTIM3_OUT,
+};
+
+struct stm32_lptim_trigger {
+	struct device *dev;
+	const char *trg;
+};
+
+static int stm32_lptim_validate_device(struct iio_trigger *trig,
+				       struct iio_dev *indio_dev)
+{
+	if (indio_dev->modes & INDIO_HARDWARE_TRIGGERED)
+		return 0;
+
+	return -EINVAL;
+}
+
+static const struct iio_trigger_ops stm32_lptim_trigger_ops = {
+	.owner = THIS_MODULE,
+	.validate_device = stm32_lptim_validate_device,
+};
+
+/**
+ * is_stm32_lptim_trigger
+ * @trig: trigger to be checked
+ *
+ * return true if the trigger is a valid STM32 IIO Low-Power Timer Trigger
+ * either return false
+ */
+bool is_stm32_lptim_trigger(struct iio_trigger *trig)
+{
+	return (trig->ops == &stm32_lptim_trigger_ops);
+}
+EXPORT_SYMBOL(is_stm32_lptim_trigger);
+
+static int stm32_lptim_setup_trig(struct stm32_lptim_trigger *priv)
+{
+	struct iio_trigger *trig;
+
+	trig = devm_iio_trigger_alloc(priv->dev, "%s", priv->trg);
+	if  (!trig)
+		return -ENOMEM;
+
+	trig->dev.parent = priv->dev->parent;
+	trig->ops = &stm32_lptim_trigger_ops;
+	iio_trigger_set_drvdata(trig, priv);
+
+	return devm_iio_trigger_register(priv->dev, trig);
+}
+
+static int stm32_lptim_trigger_probe(struct platform_device *pdev)
+{
+	struct stm32_lptim_trigger *priv;
+	u32 index;
+	int ret;
+
+	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	if (of_property_read_u32(pdev->dev.of_node, "reg", &index))
+		return -EINVAL;
+
+	if (index >= ARRAY_SIZE(stm32_lptim_triggers))
+		return -EINVAL;
+
+	priv->dev = &pdev->dev;
+	priv->trg = stm32_lptim_triggers[index];
+
+	ret = stm32_lptim_setup_trig(priv);
+	if (ret)
+		return ret;
+
+	platform_set_drvdata(pdev, priv);
+
+	return 0;
+}
+
+static const struct of_device_id stm32_lptim_trig_of_match[] = {
+	{ .compatible = "st,stm32-lptimer-trigger", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, stm32_lptim_trig_of_match);
+
+static struct platform_driver stm32_lptim_trigger_driver = {
+	.probe = stm32_lptim_trigger_probe,
+	.driver = {
+		.name = "stm32-lptimer-trigger",
+		.of_match_table = stm32_lptim_trig_of_match,
+	},
+};
+module_platform_driver(stm32_lptim_trigger_driver);
+
+MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>");
+MODULE_ALIAS("platform:stm32-lptimer-trigger");
+MODULE_DESCRIPTION("STMicroelectronics STM32 LPTIM trigger driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/trigger/stm32-timer-trigger.c b/drivers/iio/trigger/stm32-timer-trigger.c
index 9b9053494daf..eb212f8c8879 100644
--- a/drivers/iio/trigger/stm32-timer-trigger.c
+++ b/drivers/iio/trigger/stm32-timer-trigger.c
@@ -174,6 +174,7 @@ static void stm32_timer_stop(struct stm32_timer_trigger *priv)
 		clk_disable(priv->clk);
 
 	/* Stop timer */
+	regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_ARPE, 0);
 	regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, 0);
 	regmap_write(priv->regmap, TIM_PSC, 0);
 	regmap_write(priv->regmap, TIM_ARR, 0);
@@ -715,8 +716,9 @@ static ssize_t stm32_count_set_preset(struct iio_dev *indio_dev,
 	if (ret)
 		return ret;
 
+	/* TIMx_ARR register shouldn't be buffered (ARPE=0) */
+	regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_ARPE, 0);
 	regmap_write(priv->regmap, TIM_ARR, preset);
-	regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_ARPE, TIM_CR1_ARPE);
 
 	return len;
 }