Merge tag 'iio-for-v4.2b' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-next

Jonathan writes:

Second set of new driver, functionality and cleanups for IIO in the 4.2 cycle.

Core functionality
* i and q modifiers from quadrature channels.
* IIO_CHAN_INFO_OVERSAMPLING_RATIO added.
* High pass filter attributes added to mirror the existing low pass filter
  ones.

Core cleanups
* Make IIO tools building more cross compiler friendly.
* Substantial rework of the function __iio_update_buffers to greatly simplify
  a hideously evolved function.

New drivers and support
* ACPI0008 ambient light sensor driver. This one has been around a long time to
  will be good to finally get it into mainline.
* Berlin SOC ADC support.
* BMC150 magnetometer.  The accelerometer in the same package has been supported
  for quite some time, so good to have this half as well.
* m62332 DAC driver
* MEMSIC MMC35420 magnetometer.
* ROHM BH1710 and similar ambient light sensors.
* Sensortek STK3310 light sensor.
* Sensortek STK8312 accelerometer.
* Sensortek STK8BA50 accelerometer.
* ti-adc128s052 gains support form the adc122s021 2 channel ADC.

Driver cleanups and functionality.
* Allow various drivers to compile with !GPIOLIB if COMPILE_TEST enabled.
* bmc150 - decouple trigger from buffer to allow other triggers to be used.
* bmg160 - decouple trigger from buffer to allow other triggers to be used.
  Fix a trivial unused field.
* Constify a load of platform_device_id structures.
* inv_mpu6050 - device tree bindings.
* hid-sensors - fix a memory leak during probe if certain errors occur.
* ltr501 - illuminance channel derived (in an non obvious fashion) from the
  intensity channels.
* ltr501 - fix a boundary check on the proximity threshold.
* mlx90614 - drop a pointless return.
* mma8452 - Debugfs register access and fix a bug that had no effect (by
  coincidence)
* ti_am335x_adc - add device tree bindings for sample-delay, open-delay and
  averaging.  The ideal settings for these tend to be board design specific.

7 files changed, 816 insertions, 32 deletions

diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
index 7c9a9a94a8ce..00e7bcbdbe24 100644
--- a/drivers/iio/accel/Kconfig
+++ b/drivers/iio/accel/Kconfig
@@ -136,4 +136,25 @@ config MMA9553
 
 	  To compile this driver as a module, choose M here: the module
 	  will be called mma9553.
+
+config STK8312
+	tristate "Sensortek STK8312 3-Axis Accelerometer Driver"
+	depends on I2C
+	help
+	  Say yes here to get support for the Sensortek STK8312 3-axis
+	  accelerometer.
+
+	  Choosing M will build the driver as a module. If so, the module
+	  will be called stk8312.
+
+config STK8BA50
+	tristate "Sensortek STK8BA50 3-Axis Accelerometer Driver"
+	depends on I2C
+	help
+	  Say yes here to get support for the Sensortek STK8BA50 3-axis
+	  accelerometer.
+
+	  Choosing M will build the driver as a module. If so, the module
+	  will be called stk8ba50.
+
 endmenu
diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile
index 99d89e46cad1..ebd2675b2a02 100644
--- a/drivers/iio/accel/Makefile
+++ b/drivers/iio/accel/Makefile
@@ -14,6 +14,9 @@ obj-$(CONFIG_MMA9551_CORE)	+= mma9551_core.o
 obj-$(CONFIG_MMA9551)		+= mma9551.o
 obj-$(CONFIG_MMA9553)		+= mma9553.o
 
+obj-$(CONFIG_STK8312)		+= stk8312.o
+obj-$(CONFIG_STK8BA50)		+= stk8ba50.o
+
 obj-$(CONFIG_IIO_SSP_SENSORS_COMMONS) += ssp_accel_sensor.o
 
 obj-$(CONFIG_IIO_ST_ACCEL_3AXIS) += st_accel.o
diff --git a/drivers/iio/accel/bmc150-accel.c b/drivers/iio/accel/bmc150-accel.c
index 73e87739d219..4e70f51c2370 100644
--- a/drivers/iio/accel/bmc150-accel.c
+++ b/drivers/iio/accel/bmc150-accel.c
@@ -196,7 +196,7 @@ struct bmc150_accel_data {
 	u32 slope_thres;
 	u32 range;
 	int ev_enable_state;
-	int64_t timestamp, old_timestamp;
+	int64_t timestamp, old_timestamp; /* Only used in hw fifo mode. */
 	const struct bmc150_accel_chip_info *chip_info;
 };
 
@@ -1183,7 +1183,6 @@ static const struct iio_info bmc150_accel_info = {
 	.write_event_value	= bmc150_accel_write_event,
 	.write_event_config	= bmc150_accel_write_event_config,
 	.read_event_config	= bmc150_accel_read_event_config,
-	.validate_trigger	= bmc150_accel_validate_trigger,
 	.driver_module		= THIS_MODULE,
 };
 
@@ -1222,7 +1221,7 @@ static irqreturn_t bmc150_accel_trigger_handler(int irq, void *p)
 	mutex_unlock(&data->mutex);
 
 	iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
-					   data->timestamp);
+					   pf->timestamp);
 err_read:
 	iio_trigger_notify_done(indio_dev->trig);
 
@@ -1535,6 +1534,13 @@ static int bmc150_accel_fifo_set_mode(struct bmc150_accel_data *data)
 	return ret;
 }
 
+static int bmc150_accel_buffer_preenable(struct iio_dev *indio_dev)
+{
+	struct bmc150_accel_data *data = iio_priv(indio_dev);
+
+	return bmc150_accel_set_power_state(data, true);
+}
+
 static int bmc150_accel_buffer_postenable(struct iio_dev *indio_dev)
 {
 	struct bmc150_accel_data *data = iio_priv(indio_dev);
@@ -1591,9 +1597,18 @@ out:
 	return 0;
 }
 
+static int bmc150_accel_buffer_postdisable(struct iio_dev *indio_dev)
+{
+	struct bmc150_accel_data *data = iio_priv(indio_dev);
+
+	return bmc150_accel_set_power_state(data, false);
+}
+
 static const struct iio_buffer_setup_ops bmc150_accel_buffer_ops = {
+	.preenable = bmc150_accel_buffer_preenable,
 	.postenable = bmc150_accel_buffer_postenable,
 	.predisable = bmc150_accel_buffer_predisable,
+	.postdisable = bmc150_accel_buffer_postdisable,
 };
 
 static int bmc150_accel_probe(struct i2c_client *client,
@@ -1636,6 +1651,15 @@ static int bmc150_accel_probe(struct i2c_client *client,
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->info = &bmc150_accel_info;
 
+	ret = iio_triggered_buffer_setup(indio_dev,
+					 &iio_pollfunc_store_time,
+					 bmc150_accel_trigger_handler,
+					 &bmc150_accel_buffer_ops);
+	if (ret < 0) {
+		dev_err(&client->dev, "Failed: iio triggered buffer setup\n");
+		return ret;
+	}
+
 	if (client->irq < 0)
 		client->irq = bmc150_accel_gpio_probe(client, data);
 
@@ -1648,7 +1672,7 @@ static int bmc150_accel_probe(struct i2c_client *client,
 						BMC150_ACCEL_IRQ_NAME,
 						indio_dev);
 		if (ret)
-			return ret;
+			goto err_buffer_cleanup;
 
 		/*
 		 * Set latched mode interrupt. While certain interrupts are
@@ -1661,24 +1685,14 @@ static int bmc150_accel_probe(struct i2c_client *client,
 					     BMC150_ACCEL_INT_MODE_LATCH_RESET);
 		if (ret < 0) {
 			dev_err(&data->client->dev, "Error writing reg_int_rst_latch\n");
-			return ret;
+			goto err_buffer_cleanup;
 		}
 
 		bmc150_accel_interrupts_setup(indio_dev, data);
 
 		ret = bmc150_accel_triggers_setup(indio_dev, data);
 		if (ret)
-			return ret;
-
-		ret = iio_triggered_buffer_setup(indio_dev,
-						 &iio_pollfunc_store_time,
-						 bmc150_accel_trigger_handler,
-						 &bmc150_accel_buffer_ops);
-		if (ret < 0) {
-			dev_err(&client->dev,
-				"Failed: iio triggered buffer setup\n");
-			goto err_trigger_unregister;
-		}
+			goto err_buffer_cleanup;
 
 		if (i2c_check_functionality(client->adapter, I2C_FUNC_I2C) ||
 		    i2c_check_functionality(client->adapter,
@@ -1692,7 +1706,7 @@ static int bmc150_accel_probe(struct i2c_client *client,
 	ret = iio_device_register(indio_dev);
 	if (ret < 0) {
 		dev_err(&client->dev, "Unable to register iio device\n");
-		goto err_buffer_cleanup;
+		goto err_trigger_unregister;
 	}
 
 	ret = pm_runtime_set_active(&client->dev);
@@ -1708,11 +1722,10 @@ static int bmc150_accel_probe(struct i2c_client *client,
 
 err_iio_unregister:
 	iio_device_unregister(indio_dev);
-err_buffer_cleanup:
-	if (indio_dev->pollfunc)
-		iio_triggered_buffer_cleanup(indio_dev);
 err_trigger_unregister:
 	bmc150_accel_unregister_triggers(data, BMC150_ACCEL_TRIGGERS - 1);
+err_buffer_cleanup:
+	iio_triggered_buffer_cleanup(indio_dev);
 
 	return ret;
 }
@@ -1730,6 +1743,8 @@ static int bmc150_accel_remove(struct i2c_client *client)
 
 	bmc150_accel_unregister_triggers(data, BMC150_ACCEL_TRIGGERS - 1);
 
+	iio_triggered_buffer_cleanup(indio_dev);
+
 	mutex_lock(&data->mutex);
 	bmc150_accel_set_mode(data, BMC150_ACCEL_SLEEP_MODE_DEEP_SUSPEND, 0);
 	mutex_unlock(&data->mutex);
diff --git a/drivers/iio/accel/hid-sensor-accel-3d.c b/drivers/iio/accel/hid-sensor-accel-3d.c
index 2b4fad6998c1..ab1e238d5c75 100644
--- a/drivers/iio/accel/hid-sensor-accel-3d.c
+++ b/drivers/iio/accel/hid-sensor-accel-3d.c
@@ -299,7 +299,6 @@ static int hid_accel_3d_probe(struct platform_device *pdev)
 	struct iio_dev *indio_dev;
 	struct accel_3d_state *accel_state;
 	struct hid_sensor_hub_device *hsdev = pdev->dev.platform_data;
-	struct iio_chan_spec *channels;
 
 	indio_dev = devm_iio_device_alloc(&pdev->dev,
 					  sizeof(struct accel_3d_state));
@@ -320,21 +319,21 @@ static int hid_accel_3d_probe(struct platform_device *pdev)
 		return ret;
 	}
 
-	channels = kmemdup(accel_3d_channels, sizeof(accel_3d_channels),
-			   GFP_KERNEL);
-	if (!channels) {
+	indio_dev->channels = kmemdup(accel_3d_channels,
+				      sizeof(accel_3d_channels), GFP_KERNEL);
+	if (!indio_dev->channels) {
 		dev_err(&pdev->dev, "failed to duplicate channels\n");
 		return -ENOMEM;
 	}
 
-	ret = accel_3d_parse_report(pdev, hsdev, channels,
-					HID_USAGE_SENSOR_ACCEL_3D, accel_state);
+	ret = accel_3d_parse_report(pdev, hsdev,
+				    (struct iio_chan_spec *)indio_dev->channels,
+				    HID_USAGE_SENSOR_ACCEL_3D, accel_state);
 	if (ret) {
 		dev_err(&pdev->dev, "failed to setup attributes\n");
 		goto error_free_dev_mem;
 	}
 
-	indio_dev->channels = channels;
 	indio_dev->num_channels = ARRAY_SIZE(accel_3d_channels);
 	indio_dev->dev.parent = &pdev->dev;
 	indio_dev->info = &accel_3d_info;
@@ -400,7 +399,7 @@ static int hid_accel_3d_remove(struct platform_device *pdev)
 	return 0;
 }
 
-static struct platform_device_id hid_accel_3d_ids[] = {
+static const struct platform_device_id hid_accel_3d_ids[] = {
 	{
 		/* Format: HID-SENSOR-usage_id_in_hex_lowercase */
 		.name = "HID-SENSOR-200073",
diff --git a/drivers/iio/accel/mma8452.c b/drivers/iio/accel/mma8452.c
index 5b80657883bb..877ce2954196 100644
--- a/drivers/iio/accel/mma8452.c
+++ b/drivers/iio/accel/mma8452.c
@@ -32,6 +32,9 @@
 #define MMA8452_OFF_Z 0x31
 #define MMA8452_CTRL_REG1 0x2a
 #define MMA8452_CTRL_REG2 0x2b
+#define MMA8452_CTRL_REG2_RST		BIT(6)
+
+#define MMA8452_MAX_REG 0x31
 
 #define MMA8452_STATUS_DRDY (BIT(2) | BIT(1) | BIT(0))
 
@@ -291,6 +294,28 @@ done:
 	return IRQ_HANDLED;
 }
 
+static int mma8452_reg_access_dbg(struct iio_dev *indio_dev,
+				  unsigned reg, unsigned writeval,
+				  unsigned *readval)
+{
+	int ret;
+	struct mma8452_data *data = iio_priv(indio_dev);
+
+	if (reg > MMA8452_MAX_REG)
+		return -EINVAL;
+
+	if (!readval)
+		return mma8452_change_config(data, reg, writeval);
+
+	ret = i2c_smbus_read_byte_data(data->client, reg);
+	if (ret < 0)
+		return ret;
+
+	*readval = ret;
+
+	return 0;
+}
+
 #define MMA8452_CHANNEL(axis, idx) { \
 	.type = IIO_ACCEL, \
 	.modified = 1, \
@@ -330,11 +355,36 @@ static const struct iio_info mma8452_info = {
 	.attrs = &mma8452_group,
 	.read_raw = &mma8452_read_raw,
 	.write_raw = &mma8452_write_raw,
+	.debugfs_reg_access = &mma8452_reg_access_dbg,
 	.driver_module = THIS_MODULE,
 };
 
 static const unsigned long mma8452_scan_masks[] = {0x7, 0};
 
+static int mma8452_reset(struct i2c_client *client)
+{
+	int i;
+	int ret;
+
+	ret = i2c_smbus_write_byte_data(client,	MMA8452_CTRL_REG2,
+					MMA8452_CTRL_REG2_RST);
+	if (ret < 0)
+		return ret;
+
+	for (i = 0; i < 10; i++) {
+		usleep_range(100, 200);
+		ret = i2c_smbus_read_byte_data(client, MMA8452_CTRL_REG2);
+		if (ret == -EIO)
+			continue; /* I2C comm reset */
+		if (ret < 0)
+			return ret;
+		if (!(ret & MMA8452_CTRL_REG2_RST))
+			return 0;
+	}
+
+	return -ETIMEDOUT;
+}
+
 static int mma8452_probe(struct i2c_client *client,
 			 const struct i2c_device_id *id)
 {
@@ -365,10 +415,7 @@ static int mma8452_probe(struct i2c_client *client,
 	indio_dev->num_channels = ARRAY_SIZE(mma8452_channels);
 	indio_dev->available_scan_masks = mma8452_scan_masks;
 
-	data->ctrl_reg1 = MMA8452_CTRL_ACTIVE |
-		(MMA8452_CTRL_DR_DEFAULT << MMA8452_CTRL_DR_SHIFT);
-	ret = i2c_smbus_write_byte_data(client, MMA8452_CTRL_REG1,
-		data->ctrl_reg1);
+	ret = mma8452_reset(client);
 	if (ret < 0)
 		return ret;
 
@@ -378,6 +425,13 @@ static int mma8452_probe(struct i2c_client *client,
 	if (ret < 0)
 		return ret;
 
+	data->ctrl_reg1 = MMA8452_CTRL_ACTIVE |
+		(MMA8452_CTRL_DR_DEFAULT << MMA8452_CTRL_DR_SHIFT);
+	ret = i2c_smbus_write_byte_data(client, MMA8452_CTRL_REG1,
+					data->ctrl_reg1);
+	if (ret < 0)
+		return ret;
+
 	ret = iio_triggered_buffer_setup(indio_dev, NULL,
 		mma8452_trigger_handler, NULL);
 	if (ret < 0)
diff --git a/drivers/iio/accel/stk8312.c b/drivers/iio/accel/stk8312.c
new file mode 100644
index 000000000000..d211d9f3975b
--- /dev/null
+++ b/drivers/iio/accel/stk8312.c
@@ -0,0 +1,390 @@
+/**
+ * Sensortek STK8312 3-Axis Accelerometer
+ *
+ * Copyright (c) 2015, Intel Corporation.
+ *
+ * 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.
+ *
+ * IIO driver for STK8312; 7-bit I2C address: 0x3D.
+ */
+
+#include <linux/acpi.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#define STK8312_REG_XOUT		0x00
+#define STK8312_REG_YOUT		0x01
+#define STK8312_REG_ZOUT		0x02
+#define STK8312_REG_MODE		0x07
+#define STK8312_REG_STH			0x13
+#define STK8312_REG_RESET		0x20
+#define STK8312_REG_AFECTRL		0x24
+#define STK8312_REG_OTPADDR		0x3D
+#define STK8312_REG_OTPDATA		0x3E
+#define STK8312_REG_OTPCTRL		0x3F
+
+#define STK8312_MODE_ACTIVE		1
+#define STK8312_MODE_STANDBY		0
+#define STK8312_MODE_MASK		0x01
+#define STK8312_RNG_MASK		0xC0
+#define STK8312_RNG_SHIFT		6
+#define STK8312_READ_RETRIES		16
+
+#define STK8312_DRIVER_NAME		"stk8312"
+
+/*
+ * The accelerometer has two measurement ranges:
+ *
+ * -6g - +6g (8-bit, signed)
+ * -16g - +16g (8-bit, signed)
+ *
+ * scale1 = (6 + 6) * 9.81 / (2^8 - 1)     = 0.4616
+ * scale2 = (16 + 16) * 9.81 / (2^8 - 1)   = 1.2311
+ */
+#define STK8312_SCALE_AVAIL		"0.4616 1.2311"
+
+static const int stk8312_scale_table[][2] = {
+	{0, 461600}, {1, 231100}
+};
+
+#define STK8312_ACCEL_CHANNEL(reg, axis) {			\
+	.type = IIO_ACCEL,					\
+	.address = reg,						\
+	.modified = 1,						\
+	.channel2 = IIO_MOD_##axis,				\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
+}
+
+static const struct iio_chan_spec stk8312_channels[] = {
+	STK8312_ACCEL_CHANNEL(STK8312_REG_XOUT, X),
+	STK8312_ACCEL_CHANNEL(STK8312_REG_YOUT, Y),
+	STK8312_ACCEL_CHANNEL(STK8312_REG_ZOUT, Z),
+};
+
+struct stk8312_data {
+	struct i2c_client *client;
+	struct mutex lock;
+	int range;
+	u8 mode;
+};
+
+static IIO_CONST_ATTR(in_accel_scale_available, STK8312_SCALE_AVAIL);
+
+static struct attribute *stk8312_attributes[] = {
+	&iio_const_attr_in_accel_scale_available.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group stk8312_attribute_group = {
+	.attrs = stk8312_attributes
+};
+
+static int stk8312_otp_init(struct stk8312_data *data)
+{
+	int ret;
+	int count = 10;
+	struct i2c_client *client = data->client;
+
+	ret = i2c_smbus_write_byte_data(client, STK8312_REG_OTPADDR, 0x70);
+	if (ret < 0)
+		goto exit_err;
+	ret = i2c_smbus_write_byte_data(client, STK8312_REG_OTPCTRL, 0x02);
+	if (ret < 0)
+		goto exit_err;
+
+	do {
+		usleep_range(1000, 5000);
+		ret = i2c_smbus_read_byte_data(client, STK8312_REG_OTPCTRL);
+		if (ret < 0)
+			goto exit_err;
+		count--;
+	} while (!(ret & 0x80) && count > 0);
+
+	if (count == 0)
+		goto exit_err;
+
+	ret = i2c_smbus_read_byte_data(client, STK8312_REG_OTPDATA);
+	if (ret < 0)
+		goto exit_err;
+
+	ret = i2c_smbus_write_byte_data(data->client,
+			STK8312_REG_AFECTRL, ret);
+	if (ret < 0)
+		goto exit_err;
+	msleep(150);
+
+	return ret;
+
+exit_err:
+	dev_err(&client->dev, "failed to initialize sensor\n");
+	return ret;
+}
+
+static int stk8312_set_mode(struct stk8312_data *data, u8 mode)
+{
+	int ret;
+	u8 masked_reg;
+	struct i2c_client *client = data->client;
+
+	if (mode > 1)
+		return -EINVAL;
+	else if (mode == data->mode)
+		return 0;
+
+	ret = i2c_smbus_read_byte_data(client, STK8312_REG_MODE);
+	if (ret < 0) {
+		dev_err(&client->dev, "failed to change sensor mode\n");
+		return ret;
+	}
+	masked_reg = ret & (~STK8312_MODE_MASK);
+	masked_reg |= mode;
+
+	ret = i2c_smbus_write_byte_data(client,
+			STK8312_REG_MODE, masked_reg);
+	if (ret < 0) {
+		dev_err(&client->dev, "failed to change sensor mode\n");
+		return ret;
+	}
+
+	data->mode = mode;
+	if (mode == STK8312_MODE_ACTIVE) {
+		/* Need to run OTP sequence before entering active mode */
+		usleep_range(1000, 5000);
+		ret = stk8312_otp_init(data);
+	}
+
+	return ret;
+}
+
+static int stk8312_set_range(struct stk8312_data *data, u8 range)
+{
+	int ret;
+	u8 masked_reg;
+	u8 mode;
+	struct i2c_client *client = data->client;
+
+	if (range != 1 && range != 2)
+		return -EINVAL;
+	else if (range == data->range)
+		return 0;
+
+	mode = data->mode;
+	/* We need to go in standby mode to modify registers */
+	ret = stk8312_set_mode(data, STK8312_MODE_STANDBY);
+	if (ret < 0)
+		return ret;
+
+	ret = i2c_smbus_read_byte_data(client, STK8312_REG_STH);
+	if (ret < 0) {
+		dev_err(&client->dev, "failed to change sensor range\n");
+		return ret;
+	}
+
+	masked_reg = ret & (~STK8312_RNG_MASK);
+	masked_reg |= range << STK8312_RNG_SHIFT;
+
+	ret = i2c_smbus_write_byte_data(client, STK8312_REG_STH, masked_reg);
+	if (ret < 0)
+		dev_err(&client->dev, "failed to change sensor range\n");
+	else
+		data->range = range;
+
+	return stk8312_set_mode(data, mode);
+}
+
+static int stk8312_read_accel(struct stk8312_data *data, u8 address)
+{
+	int ret;
+	struct i2c_client *client = data->client;
+
+	if (address > 2)
+		return -EINVAL;
+
+	ret = i2c_smbus_read_byte_data(client, address);
+	if (ret < 0) {
+		dev_err(&client->dev, "register read failed\n");
+		return ret;
+	}
+
+	return sign_extend32(ret, 7);
+}
+
+static int stk8312_read_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan,
+			    int *val, int *val2, long mask)
+{
+	struct stk8312_data *data = iio_priv(indio_dev);
+
+	if (chan->type != IIO_ACCEL)
+		return -EINVAL;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		mutex_lock(&data->lock);
+		*val = stk8312_read_accel(data, chan->address);
+		mutex_unlock(&data->lock);
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		*val = stk8312_scale_table[data->range - 1][0];
+		*val2 = stk8312_scale_table[data->range - 1][1];
+		return IIO_VAL_INT_PLUS_MICRO;
+	}
+
+	return -EINVAL;
+}
+
+static int stk8312_write_raw(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan,
+			     int val, int val2, long mask)
+{
+	int i;
+	int index = -1;
+	int ret;
+	struct stk8312_data *data = iio_priv(indio_dev);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_SCALE:
+		for (i = 0; i < ARRAY_SIZE(stk8312_scale_table); i++)
+			if (val == stk8312_scale_table[i][0] &&
+			    val2 == stk8312_scale_table[i][1]) {
+				index = i + 1;
+				break;
+			}
+		if (index < 0)
+			return -EINVAL;
+
+		mutex_lock(&data->lock);
+		ret = stk8312_set_range(data, index);
+		mutex_unlock(&data->lock);
+
+		return ret;
+	}
+
+	return -EINVAL;
+}
+
+static const struct iio_info stk8312_info = {
+	.driver_module		= THIS_MODULE,
+	.read_raw		= stk8312_read_raw,
+	.write_raw		= stk8312_write_raw,
+	.attrs			= &stk8312_attribute_group,
+};
+
+static int stk8312_probe(struct i2c_client *client,
+			 const struct i2c_device_id *id)
+{
+	int ret;
+	struct iio_dev *indio_dev;
+	struct stk8312_data *data;
+
+	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+	if (!indio_dev) {
+		dev_err(&client->dev, "iio allocation failed!\n");
+		return -ENOMEM;
+	}
+
+	data = iio_priv(indio_dev);
+	data->client = client;
+	i2c_set_clientdata(client, indio_dev);
+	mutex_init(&data->lock);
+
+	indio_dev->dev.parent = &client->dev;
+	indio_dev->info = &stk8312_info;
+	indio_dev->name = STK8312_DRIVER_NAME;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = stk8312_channels;
+	indio_dev->num_channels = ARRAY_SIZE(stk8312_channels);
+
+	/* A software reset is recommended at power-on */
+	ret = i2c_smbus_write_byte_data(data->client, STK8312_REG_RESET, 0x00);
+	if (ret < 0) {
+		dev_err(&client->dev, "failed to reset sensor\n");
+		return ret;
+	}
+	ret = stk8312_set_range(data, 1);
+	if (ret < 0)
+		return ret;
+
+	ret = stk8312_set_mode(data, STK8312_MODE_ACTIVE);
+	if (ret < 0)
+		return ret;
+
+	ret = iio_device_register(indio_dev);
+	if (ret < 0) {
+		dev_err(&client->dev, "device_register failed\n");
+		stk8312_set_mode(data, STK8312_MODE_STANDBY);
+	}
+
+	return ret;
+}
+
+static int stk8312_remove(struct i2c_client *client)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(client);
+
+	iio_device_unregister(indio_dev);
+
+	return stk8312_set_mode(iio_priv(indio_dev), STK8312_MODE_STANDBY);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int stk8312_suspend(struct device *dev)
+{
+	struct stk8312_data *data;
+
+	data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
+
+	return stk8312_set_mode(data, STK8312_MODE_STANDBY);
+}
+
+static int stk8312_resume(struct device *dev)
+{
+	struct stk8312_data *data;
+
+	data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
+
+	return stk8312_set_mode(data, STK8312_MODE_ACTIVE);
+}
+
+static SIMPLE_DEV_PM_OPS(stk8312_pm_ops, stk8312_suspend, stk8312_resume);
+
+#define STK8312_PM_OPS (&stk8312_pm_ops)
+#else
+#define STK8312_PM_OPS NULL
+#endif
+
+static const struct i2c_device_id stk8312_i2c_id[] = {
+	{"STK8312", 0},
+	{}
+};
+
+static const struct acpi_device_id stk8312_acpi_id[] = {
+	{"STK8312", 0},
+	{}
+};
+
+MODULE_DEVICE_TABLE(acpi, stk8312_acpi_id);
+
+static struct i2c_driver stk8312_driver = {
+	.driver = {
+		.name = "stk8312",
+		.pm = STK8312_PM_OPS,
+		.acpi_match_table = ACPI_PTR(stk8312_acpi_id),
+	},
+	.probe =            stk8312_probe,
+	.remove =           stk8312_remove,
+	.id_table =         stk8312_i2c_id,
+};
+
+module_i2c_driver(stk8312_driver);
+
+MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>");
+MODULE_DESCRIPTION("STK8312 3-Axis Accelerometer driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/accel/stk8ba50.c b/drivers/iio/accel/stk8ba50.c
new file mode 100644
index 000000000000..30950c6b36de
--- /dev/null
+++ b/drivers/iio/accel/stk8ba50.c
@@ -0,0 +1,302 @@
+/**
+ * Sensortek STK8BA50 3-Axis Accelerometer
+ *
+ * Copyright (c) 2015, Intel Corporation.
+ *
+ * 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.
+ *
+ * STK8BA50 7-bit I2C address: 0x18.
+ */
+
+#include <linux/acpi.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#define STK8BA50_REG_XOUT			0x02
+#define STK8BA50_REG_YOUT			0x04
+#define STK8BA50_REG_ZOUT			0x06
+#define STK8BA50_REG_RANGE			0x0F
+#define STK8BA50_REG_POWMODE			0x11
+#define STK8BA50_REG_SWRST			0x14
+
+#define STK8BA50_MODE_NORMAL			0
+#define STK8BA50_MODE_SUSPEND			1
+#define STK8BA50_MODE_POWERBIT			BIT(7)
+#define STK8BA50_DATA_SHIFT			6
+#define STK8BA50_RESET_CMD			0xB6
+
+#define STK8BA50_DRIVER_NAME			"stk8ba50"
+
+#define STK8BA50_SCALE_AVAIL			"0.0384 0.0767 0.1534 0.3069"
+
+/*
+ * The accelerometer has four measurement ranges:
+ * +/-2g; +/-4g; +/-8g; +/-16g
+ *
+ * Acceleration values are 10-bit, 2's complement.
+ * Scales are calculated as following:
+ *
+ * scale1 = (2 + 2) * 9.81 / (2^10 - 1)   = 0.0384
+ * scale2 = (4 + 4) * 9.81 / (2^10 - 1)   = 0.0767
+ * etc.
+ *
+ * Scales are stored in this format:
+ * { <register value>, <scale value> }
+ *
+ * Locally, the range is stored as a table index.
+ */
+static const int stk8ba50_scale_table[][2] = {
+	{3, 38400}, {5, 76700}, {8, 153400}, {12, 306900}
+};
+
+struct stk8ba50_data {
+	struct i2c_client *client;
+	struct mutex lock;
+	int range;
+};
+
+#define STK8BA50_ACCEL_CHANNEL(reg, axis) {			\
+	.type = IIO_ACCEL,					\
+	.address = reg,						\
+	.modified = 1,						\
+	.channel2 = IIO_MOD_##axis,				\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
+}
+
+static const struct iio_chan_spec stk8ba50_channels[] = {
+	STK8BA50_ACCEL_CHANNEL(STK8BA50_REG_XOUT, X),
+	STK8BA50_ACCEL_CHANNEL(STK8BA50_REG_YOUT, Y),
+	STK8BA50_ACCEL_CHANNEL(STK8BA50_REG_ZOUT, Z),
+};
+
+static IIO_CONST_ATTR(in_accel_scale_available, STK8BA50_SCALE_AVAIL);
+
+static struct attribute *stk8ba50_attributes[] = {
+	&iio_const_attr_in_accel_scale_available.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group stk8ba50_attribute_group = {
+	.attrs = stk8ba50_attributes
+};
+
+static int stk8ba50_read_accel(struct stk8ba50_data *data, u8 reg)
+{
+	int ret;
+	struct i2c_client *client = data->client;
+
+	ret = i2c_smbus_read_word_data(client, reg);
+	if (ret < 0) {
+		dev_err(&client->dev, "register read failed\n");
+		return ret;
+	}
+
+	return sign_extend32(ret >> STK8BA50_DATA_SHIFT, 9);
+}
+
+static int stk8ba50_read_raw(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan,
+			     int *val, int *val2, long mask)
+{
+	struct stk8ba50_data *data = iio_priv(indio_dev);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		mutex_lock(&data->lock);
+		*val = stk8ba50_read_accel(data, chan->address);
+		mutex_unlock(&data->lock);
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		*val = 0;
+		*val2 = stk8ba50_scale_table[data->range][1];
+		return IIO_VAL_INT_PLUS_MICRO;
+	}
+
+	return -EINVAL;
+}
+
+static int stk8ba50_write_raw(struct iio_dev *indio_dev,
+			      struct iio_chan_spec const *chan,
+			      int val, int val2, long mask)
+{
+	int ret;
+	int i;
+	int index = -1;
+	struct stk8ba50_data *data = iio_priv(indio_dev);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_SCALE:
+		if (val != 0)
+			return -EINVAL;
+
+		for (i = 0; i < ARRAY_SIZE(stk8ba50_scale_table); i++)
+			if (val2 == stk8ba50_scale_table[i][1]) {
+				index = i;
+				break;
+			}
+		if (index < 0)
+			return -EINVAL;
+
+		ret = i2c_smbus_write_byte_data(data->client,
+				STK8BA50_REG_RANGE,
+				stk8ba50_scale_table[index][0]);
+		if (ret < 0)
+			dev_err(&data->client->dev,
+					"failed to set measurement range\n");
+		else
+			data->range = index;
+
+		return ret;
+	}
+
+	return -EINVAL;
+}
+
+static const struct iio_info stk8ba50_info = {
+	.driver_module		= THIS_MODULE,
+	.read_raw		= stk8ba50_read_raw,
+	.write_raw		= stk8ba50_write_raw,
+	.attrs			= &stk8ba50_attribute_group,
+};
+
+static int stk8ba50_set_power(struct stk8ba50_data *data, bool mode)
+{
+	int ret;
+	u8 masked_reg;
+	struct i2c_client *client = data->client;
+
+	ret = i2c_smbus_read_byte_data(client, STK8BA50_REG_POWMODE);
+	if (ret < 0)
+		goto exit_err;
+
+	if (mode)
+		masked_reg = ret | STK8BA50_MODE_POWERBIT;
+	else
+		masked_reg = ret & (~STK8BA50_MODE_POWERBIT);
+
+	ret = i2c_smbus_write_byte_data(client, STK8BA50_REG_POWMODE,
+					masked_reg);
+	if (ret < 0)
+		goto exit_err;
+
+	return ret;
+
+exit_err:
+	dev_err(&client->dev, "failed to change sensor mode\n");
+	return ret;
+}
+
+static int stk8ba50_probe(struct i2c_client *client,
+			  const struct i2c_device_id *id)
+{
+	int ret;
+	struct iio_dev *indio_dev;
+	struct stk8ba50_data *data;
+
+	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+	if (!indio_dev) {
+		dev_err(&client->dev, "iio allocation failed!\n");
+		return -ENOMEM;
+	}
+
+	data = iio_priv(indio_dev);
+	data->client = client;
+	i2c_set_clientdata(client, indio_dev);
+	mutex_init(&data->lock);
+
+	indio_dev->dev.parent = &client->dev;
+	indio_dev->info = &stk8ba50_info;
+	indio_dev->name = STK8BA50_DRIVER_NAME;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = stk8ba50_channels;
+	indio_dev->num_channels = ARRAY_SIZE(stk8ba50_channels);
+
+	/* Reset all registers on startup */
+	ret = i2c_smbus_write_byte_data(client,
+			STK8BA50_REG_SWRST, STK8BA50_RESET_CMD);
+	if (ret < 0) {
+		dev_err(&client->dev, "failed to reset sensor\n");
+		return ret;
+	}
+
+	/* The default range is +/-2g */
+	data->range = 0;
+
+	ret = iio_device_register(indio_dev);
+	if (ret < 0) {
+		dev_err(&client->dev, "device_register failed\n");
+		stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
+	}
+
+	return ret;
+}
+
+static int stk8ba50_remove(struct i2c_client *client)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(client);
+
+	iio_device_unregister(indio_dev);
+
+	return stk8ba50_set_power(iio_priv(indio_dev), STK8BA50_MODE_SUSPEND);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int stk8ba50_suspend(struct device *dev)
+{
+	struct stk8ba50_data *data;
+
+	data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
+
+	return stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
+}
+
+static int stk8ba50_resume(struct device *dev)
+{
+	struct stk8ba50_data *data;
+
+	data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
+
+	return stk8ba50_set_power(data, STK8BA50_MODE_NORMAL);
+}
+
+static SIMPLE_DEV_PM_OPS(stk8ba50_pm_ops, stk8ba50_suspend, stk8ba50_resume);
+
+#define STK8BA50_PM_OPS (&stk8ba50_pm_ops)
+#else
+#define STK8BA50_PM_OPS NULL
+#endif
+
+static const struct i2c_device_id stk8ba50_i2c_id[] = {
+	{"stk8ba50", 0},
+	{}
+};
+
+static const struct acpi_device_id stk8ba50_acpi_id[] = {
+	{"STK8BA50", 0},
+	{}
+};
+
+MODULE_DEVICE_TABLE(acpi, stk8ba50_acpi_id);
+
+static struct i2c_driver stk8ba50_driver = {
+	.driver = {
+		.name = "stk8ba50",
+		.pm = STK8BA50_PM_OPS,
+		.acpi_match_table = ACPI_PTR(stk8ba50_acpi_id),
+	},
+	.probe =            stk8ba50_probe,
+	.remove =           stk8ba50_remove,
+	.id_table =         stk8ba50_i2c_id,
+};
+
+module_i2c_driver(stk8ba50_driver);
+
+MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>");
+MODULE_DESCRIPTION("STK8BA50 3-Axis Accelerometer driver");
+MODULE_LICENSE("GPL v2");