[PATCH v3] iio: add Bosch BMA180 acceleration sensor driver

[PATCH v3] iio: add Bosch BMA180 acceleration sensor driver

[Oleksandr Kravchenko]

This patch adds IIO driver for Bosch BMA180 triaxial
acceleration sensor.
http://dlnmh9ip6v2uc.cloudfront.net/datasheets/
		Sensors/Accelerometers/BST-BMA180-DS000-07_2.pdf

Signed-off-by: Oleksandr Kravchenko <o.v.kravchenko@globallogic.com>
---
 .../devicetree/bindings/iio/accel/bma180.txt       |   24 +
 drivers/iio/accel/Kconfig                          |   12 +
 drivers/iio/accel/Makefile                         |    2 +
 drivers/iio/accel/bma180.c                         |  689 ++++++++++++++++++++
 4 files changed, 727 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/accel/bma180.txt
 create mode 100644 drivers/iio/accel/bma180.c

diff --git a/Documentation/devicetree/bindings/iio/accel/bma180.txt b/Documentation/devicetree/bindings/iio/accel/bma180.txt
new file mode 100644
index 0000000..c593357
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/accel/bma180.txt
@@ -0,0 +1,24 @@
+* Bosch BMA180 triaxial acceleration sensor
+
+http://omapworld.com/BMA180_111_1002839.pdf
+
+Required properties:
+
+  - compatible : should be "bosch,bma180"
+  - reg : the I2C address of the sensor
+
+Optional properties:
+
+  - interrupt-parent : should be the phandle for the interrupt controller
+
+  - interrupts : interrupt mapping for GPIO IRQ, it should by configured with
+		flags IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_EDGE_RISING
+
+Example:
+
+bma180@40 {
+	compatible = "bosch,bma180";
+	reg = <0x40>;
+	interrupt-parent = <&gpio6>;
+	interrupts = <18 (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_EDGE_RISING)>;
+};
diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
index 719d83f..bd9d581 100644
--- a/drivers/iio/accel/Kconfig
+++ b/drivers/iio/accel/Kconfig
@@ -3,6 +3,18 @@
 #
 menu "Accelerometers"
 
+config BMA180
+	tristate "Bosch BMA180 3-Axis Accelerometer Driver"
+	depends on I2C
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
+	help
+	  Say Y here if you want to build a driver for the Bosch BMA180
+	  triaxial acceleration sensor.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called bma180.
+
 config HID_SENSOR_ACCEL_3D
 	depends on HID_SENSOR_HUB
 	select IIO_BUFFER
diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile
index 87d8fa2..eb09d72 100644
--- a/drivers/iio/accel/Makefile
+++ b/drivers/iio/accel/Makefile
@@ -2,6 +2,8 @@
 # Makefile for industrial I/O accelerometer drivers
 #
 
+obj-$(CONFIG_BMA180)	+= bma180.o
+
 obj-$(CONFIG_HID_SENSOR_ACCEL_3D) += hid-sensor-accel-3d.o
 
 obj-$(CONFIG_IIO_ST_ACCEL_3AXIS) += st_accel.o
diff --git a/drivers/iio/accel/bma180.c b/drivers/iio/accel/bma180.c
new file mode 100644
index 0000000..23c738f
--- /dev/null
+++ b/drivers/iio/accel/bma180.c
@@ -0,0 +1,689 @@
+/*
+ * bma180.c - IIO driver for Bosch BMA180 triaxial acceleration sensor
+ *
+ * Copyright 2013 Oleksandr Kravchenko <x0199363@ti.com>
+ *
+ * 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.
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/of.h>
+#include <linux/bitops.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+
+#define BMA180_DRV_NAME "bma180"
+#define BMA180_IRQ_NAME "bma180_event"
+
+/* Register set */
+#define BMA180_CHIP_ID		0x00 /* Need to distinguish BMA180 from other */
+#define BMA180_ACC_X_LSB	0x02 /* First of 6 registers of accel data */
+#define BMA180_CTRL_REG0	0x0d
+#define BMA180_RESET		0x10
+#define BMA180_BW_TCS		0x20
+#define BMA180_CTRL_REG3	0x21
+#define BMA180_TCO_Z		0x30
+#define BMA180_OFFSET_LSB1	0x35
+
+/* BMA180_CTRL_REG0 bits */
+#define BMA180_DIS_WAKE_UP	BIT(0) /* Disable wake up mode */
+#define BMA180_SLEEP		BIT(1) /* 1 - chip will sleep */
+#define BMA180_EE_W		BIT(4) /* Unlock writing to addr from 0x20 */
+#define BMA180_RESET_INT	BIT(6) /* Reset pending interrupts */
+
+/* BMA180_CTRL_REG3 bits */
+#define BMA180_NEW_DATA_INT	BIT(1) /* Intr every new accel data is ready */
+
+/* BMA180_OFFSET_LSB1 skipping mode bit */
+#define BMA180_SMP_SKIP		BIT(0)
+
+/* Bit masks for registers bit fields */
+#define BMA180_RANGE		0x0e /* Range of measured accel values*/
+#define BMA180_BW		0xf0 /* Accel bandwidth */
+#define BMA180_MODE_CONFIG	0x03 /* Config operation modes */
+
+/* We have to write this value in reset register to do soft reset */
+#define BMA180_RESET_VAL	0xb6
+
+#define BMA_180_ID_REG_VAL	0x03
+
+/* Chip operation modes */
+#define BMA180_LOW_NOISE	0x00
+#define BMA180_LOW_POWER	0x03
+
+#define BMA180_LOW_NOISE_STR	"low_noise"
+#define BMA180_LOW_POWER_STR	"low_power"
+
+/* Defaults values */
+#define BMA180_DEF_MODE		BMA180_LOW_NOISE_STR
+#define BMA180_DEF_BW		20
+#define BMA180_DEF_SCALE	250
+
+/* Available values */
+#define BMA180_MODE_AVAILABLE \
+	BMA180_LOW_NOISE_STR " " BMA180_LOW_POWER_STR
+#define BMA180_BW_AVAILABLE	"10 20 40 75 150 300"
+#define BMA180_SCALE_AVAILABLE \
+	"0.000130 0.000190 0.000250 0.000380 0.000500 0.000990 0.001980"
+
+struct bma180_data {
+	struct i2c_client *client;
+	struct iio_trigger *trig;
+	struct mutex mutex;
+	int sleep_state;
+	int scale;
+	int bw;
+	int mode;
+	char *buff;
+};
+
+enum bma180_axis {
+	AXIS_X,
+	AXIS_Y,
+	AXIS_Z,
+};
+
+static int bw_table[] = { 10, 20, 40, 75, 150, 300 }; /* Hz */
+static int scale_table[] = { 130, 190, 250, 380, 500, 990, 1980 };
+
+static int bma180_get_acc_reg(struct bma180_data *data, enum bma180_axis axis)
+{
+	u8 reg = BMA180_ACC_X_LSB + axis * 2;
+	int ret;
+
+	if (data->sleep_state)
+		return -EBUSY;
+
+	ret = i2c_smbus_read_word_data(data->client, reg);
+	if (ret < 0)
+		dev_err(&data->client->dev,
+			"failed to read accel_%c registers\n", 'x' + axis);
+
+	return ret;
+}
+
+static int bma180_set_bits(struct bma180_data *data, u8 reg, u8 mask, u8 val)
+{
+	int ret = i2c_smbus_read_byte_data(data->client, reg);
+	u8 reg_val = (ret & ~mask) | (val << (ffs(mask) - 1));
+
+	if (ret < 0)
+		return ret;
+
+	return i2c_smbus_write_byte_data(data->client, reg, reg_val);
+}
+
+static int bma180_reset_intr(struct bma180_data *data)
+{
+	int ret = bma180_set_bits(data, BMA180_CTRL_REG0, BMA180_RESET_INT, 1);
+
+	if (ret)
+		dev_err(&data->client->dev, "failed to reset interrupt\n");
+
+	return ret;
+}
+
+static int bma180_set_new_data_intr_state(struct bma180_data *data, int state)
+{
+	u8 reg_val = state ? BMA180_NEW_DATA_INT : 0x00;
+	int ret = i2c_smbus_write_byte_data(data->client, BMA180_CTRL_REG3,
+			reg_val);
+
+	if (ret)
+		goto err;
+	ret = bma180_reset_intr(data);
+	if (ret)
+		goto err;
+
+	return 0;
+
+err:
+	dev_err(&data->client->dev,
+		"failed to set new data interrupt state %d\n", state);
+	return ret;
+}
+
+static int bma180_set_sleep_state(struct bma180_data *data, int state)
+{
+	int ret = bma180_set_bits(data, BMA180_CTRL_REG0, BMA180_SLEEP, state);
+
+	if (ret) {
+		dev_err(&data->client->dev,
+			"failed to set sleep state %d\n", state);
+		return ret;
+	}
+	data->sleep_state = state;
+
+	return 0;
+}
+
+static int bma180_set_ee_writing_state(struct bma180_data *data, int state)
+{
+	int ret = bma180_set_bits(data, BMA180_CTRL_REG0, BMA180_EE_W, state);
+
+	if (ret)
+		dev_err(&data->client->dev,
+			"failed to set ee writing state %d\n", state);
+
+	return ret;
+}
+
+static int bma180_set_bw(struct bma180_data *data, int val)
+{
+	int ret, i;
+
+	if (data->sleep_state)
+		return -EBUSY;
+
+	for (i = 0; i < ARRAY_SIZE(bw_table); ++i) {
+		if (bw_table[i] == val) {
+			ret = bma180_set_bits(data,
+					BMA180_BW_TCS, BMA180_BW, i);
+			if (ret) {
+				dev_err(&data->client->dev,
+					"failed to set bandwidth\n");
+				return ret;
+			}
+			data->bw = val;
+			return 0;
+		}
+	}
+
+	return -EINVAL;
+}
+
+static int bma180_set_scale(struct bma180_data *data, int val)
+{
+	int ret, i;
+
+	if (data->sleep_state)
+		return -EBUSY;
+
+	for (i = 0; i < ARRAY_SIZE(scale_table); ++i)
+		if (scale_table[i] == val) {
+			ret = bma180_set_bits(data,
+					BMA180_OFFSET_LSB1, BMA180_RANGE, i);
+			if (ret) {
+				dev_err(&data->client->dev,
+					"failed to set scale\n");
+				return ret;
+			}
+			data->scale = val;
+			return 0;
+		}
+
+	return -EINVAL;
+}
+
+static int bma180_set_mode(struct bma180_data *data, const char *str)
+{
+	u8 reg_val;
+	int ret;
+
+	if (!strcmp(str, BMA180_LOW_NOISE_STR "\n"))
+		reg_val = BMA180_LOW_NOISE;
+	else if (!strcmp(str, BMA180_LOW_POWER_STR "\n"))
+		reg_val = BMA180_LOW_POWER;
+	else
+		return -EINVAL;
+
+	ret = bma180_set_bits(data, BMA180_TCO_Z, BMA180_MODE_CONFIG, reg_val);
+	if (ret)
+		dev_err(&data->client->dev, "failed to set mode\n");
+
+	data->mode = reg_val;
+
+	return ret;
+}
+
+static int bma180_soft_reset(struct bma180_data *data)
+{
+	int ret = i2c_smbus_write_byte_data(data->client,
+			BMA180_RESET, BMA180_RESET_VAL);
+
+	if (ret)
+		dev_err(&data->client->dev, "failed to reset the chip\n");
+
+	return ret;
+}
+
+static int bma180_chip_init(struct bma180_data *data)
+{
+	/* Try to read chip_id register. It must return 0x03. */
+	int ret = i2c_smbus_read_byte_data(data->client, BMA180_CHIP_ID);
+
+	if (ret < 0)
+		goto err;
+	if (ret != BMA_180_ID_REG_VAL) {
+		ret = -ENODEV;
+		goto err;
+	}
+
+	ret = bma180_soft_reset(data);
+	if (ret)
+		goto err;
+	/*
+	 * No serial transaction should occur within minimum 10 us
+	 * after soft_reset command
+	 */
+	msleep(20);
+
+	ret = bma180_set_bits(data, BMA180_CTRL_REG0, BMA180_DIS_WAKE_UP, 1);
+	if (ret)
+		goto err;
+	ret = bma180_set_ee_writing_state(data, 1);
+	if (ret)
+		goto err;
+	ret = bma180_set_new_data_intr_state(data, 0);
+	if (ret)
+		goto err;
+	ret = bma180_set_bits(data, BMA180_OFFSET_LSB1, BMA180_SMP_SKIP, 1);
+	if (ret)
+		goto err;
+	ret = bma180_set_mode(data, BMA180_DEF_MODE "\n");
+	if (ret)
+		goto err;
+	ret = bma180_set_bw(data, BMA180_DEF_BW);
+	if (ret)
+		goto err;
+	ret = bma180_set_scale(data, BMA180_DEF_SCALE);
+	if (ret)
+		goto err;
+
+	return 0;
+
+err:
+	dev_err(&data->client->dev, "failed to init the chip\n");
+	return ret;
+}
+
+static void bma180_chip_disable(struct bma180_data *data)
+{
+	if (bma180_set_new_data_intr_state(data, 0))
+		goto err;
+	if (bma180_set_ee_writing_state(data, 0))
+		goto err;
+	if (bma180_set_sleep_state(data, 1))
+		goto err;
+
+	return;
+
+err:
+	dev_err(&data->client->dev, "failed to disable the chip\n");
+}
+
+static ssize_t bma180_read_mode_config(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct bma180_data *data = iio_priv(indio_dev);
+
+	return sprintf(buf, "%s\n",
+			data->mode ?
+			BMA180_LOW_POWER_STR : BMA180_LOW_NOISE_STR);
+}
+
+static ssize_t bma180_write_mode_config(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t len)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct bma180_data *data = iio_priv(indio_dev);
+	int ret;
+
+	mutex_lock(&data->mutex);
+	ret = bma180_set_mode(data, buf);
+	mutex_unlock(&data->mutex);
+
+	return ret ? ret : len;
+}
+
+static ssize_t bma180_read_bw_config(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct bma180_data *data = iio_priv(indio_dev);
+
+	return sprintf(buf, "%d\n", data->bw);
+}
+
+static ssize_t bma180_write_bw_config(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t len)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct bma180_data *data = iio_priv(indio_dev);
+	long val;
+	int ret = kstrtol(buf, 10, &val);
+
+	if (ret)
+		return ret;
+
+	mutex_lock(&data->mutex);
+	ret = bma180_set_bw(data, val);
+	mutex_unlock(&data->mutex);
+
+	return ret ? ret : len;
+}
+
+static IIO_DEVICE_ATTR(mode, S_IRUGO | S_IWUSR, bma180_read_mode_config,
+		bma180_write_mode_config, 0);
+static IIO_CONST_ATTR(mode_available, BMA180_MODE_AVAILABLE);
+static IIO_DEVICE_ATTR(bandwidth, S_IRUGO | S_IWUSR, bma180_read_bw_config,
+		bma180_write_bw_config, 0);
+static IIO_CONST_ATTR(bandwidth_available, BMA180_BW_AVAILABLE);
+static IIO_CONST_ATTR(scale_available, BMA180_SCALE_AVAILABLE);
+
+static struct attribute *bma180_attributes[] = {
+	&iio_dev_attr_mode.dev_attr.attr,
+	&iio_const_attr_mode_available.dev_attr.attr,
+	&iio_dev_attr_bandwidth.dev_attr.attr,
+	&iio_const_attr_bandwidth_available.dev_attr.attr,
+	&iio_const_attr_scale_available.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group bma180_attrs_group = {
+	.attrs = bma180_attributes,
+};
+
+static int bma180_read_raw(struct iio_dev *indio_dev,
+		struct iio_chan_spec const *chan, int *val, int *val2,
+		long mask)
+{
+	struct bma180_data *data = iio_priv(indio_dev);
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		mutex_lock(&data->mutex);
+		if (iio_buffer_enabled(indio_dev))
+			ret = -EBUSY;
+		else
+			ret = bma180_get_acc_reg(data, chan->scan_index);
+		mutex_unlock(&data->mutex);
+		if (ret < 0)
+			return ret;
+		*val = (s16)ret >> chan->scan_type.shift;
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		*val = 0;
+		*val2 = data->scale;
+		return IIO_VAL_INT_PLUS_MICRO;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int bma180_write_raw(struct iio_dev *indio_dev,
+		struct iio_chan_spec const *chan, int val, int val2, long mask)
+{
+	struct bma180_data *data = iio_priv(indio_dev);
+	int ret;
+
+	if (mask != IIO_CHAN_INFO_SCALE || val)
+		return -EINVAL;
+
+	mutex_lock(&data->mutex);
+	ret = bma180_set_scale(data, val2);
+	mutex_unlock(&data->mutex);
+
+	return ret;
+}
+
+static int bma180_update_scan_mode(struct iio_dev *indio_dev,
+		const unsigned long *scan_mask)
+{
+	struct bma180_data *data = iio_priv(indio_dev);
+
+	kfree(data->buff);
+	data->buff = kmalloc(indio_dev->scan_bytes, GFP_KERNEL);
+	if (!data->buff)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static const struct iio_info bma180_info = {
+	.attrs			= &bma180_attrs_group,
+	.read_raw		= bma180_read_raw,
+	.write_raw		= bma180_write_raw,
+	.update_scan_mode	= bma180_update_scan_mode,
+	.driver_module		= THIS_MODULE,
+};
+
+#define BMA180_CHANNEL(_index) {				\
+	.type = IIO_ACCEL,					\
+	.indexed = 1,						\
+	.channel = (_index),					\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
+	.scan_index = (_index),					\
+	.scan_type = IIO_ST('s', 14, 16, 2),			\
+}
+
+static const struct iio_chan_spec bma180_channels[] = {
+	BMA180_CHANNEL(AXIS_X),
+	BMA180_CHANNEL(AXIS_Y),
+	BMA180_CHANNEL(AXIS_Z),
+	IIO_CHAN_SOFT_TIMESTAMP(4),
+};
+
+static irqreturn_t bma180_trigger_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct bma180_data *data = iio_priv(indio_dev);
+	int bit, ret, i = 0;
+
+	mutex_lock(&data->mutex);
+	if (indio_dev->scan_timestamp) {
+		ret = indio_dev->scan_bytes / sizeof(s64) - 1;
+		((s64 *)data->buff)[ret] = iio_get_time_ns();
+	}
+
+	for_each_set_bit(bit, indio_dev->buffer->scan_mask,
+			 indio_dev->masklength) {
+		ret = bma180_get_acc_reg(data, bit);
+		if (ret < 0) {
+			mutex_unlock(&data->mutex);
+			goto err;
+		}
+		((s16 *)data->buff)[i++] = ret;
+	}
+	mutex_unlock(&data->mutex);
+
+	iio_push_to_buffers(indio_dev, (u8 *)data->buff);
+err:
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
+static int bma180_data_rdy_trigger_set_state(struct iio_trigger *trig,
+		bool state)
+{
+	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
+	struct bma180_data *data = iio_priv(indio_dev);
+
+	return bma180_set_new_data_intr_state(data, state);
+}
+
+static int bma180_trig_try_reen(struct iio_trigger *trig)
+{
+	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
+	struct bma180_data *data = iio_priv(indio_dev);
+
+	return bma180_reset_intr(data);
+}
+
+static const struct iio_trigger_ops bma180_trigger_ops = {
+	.set_trigger_state = bma180_data_rdy_trigger_set_state,
+	.try_reenable = bma180_trig_try_reen,
+	.owner = THIS_MODULE,
+};
+
+static int bma180_probe(struct i2c_client *client,
+		const struct i2c_device_id *id)
+{
+	struct bma180_data *data;
+	struct iio_dev *indio_dev;
+	struct iio_trigger *trig;
+	int ret;
+
+	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;
+
+	ret = bma180_chip_init(data);
+	if (ret < 0)
+		goto err_chip_disable;
+
+	mutex_init(&data->mutex);
+
+	indio_dev->dev.parent = &client->dev;
+	indio_dev->channels = bma180_channels;
+	indio_dev->num_channels = ARRAY_SIZE(bma180_channels);
+	indio_dev->name = BMA180_DRV_NAME;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->info = &bma180_info;
+
+	trig = iio_trigger_alloc("%s-dev%d", indio_dev->name, indio_dev->id);
+	if (!trig) {
+		ret = -ENOMEM;
+		goto err_chip_disable;
+	}
+
+	ret = devm_request_irq(&client->dev, client->irq,
+			iio_trigger_generic_data_rdy_poll,
+			IRQF_TRIGGER_RISING, BMA180_IRQ_NAME, trig);
+	if (ret) {
+		dev_err(&client->dev, "unable to request IRQ\n");
+		goto err_trigger_free;
+	}
+
+	trig->dev.parent = &client->dev;
+	trig->ops = &bma180_trigger_ops;
+	iio_trigger_set_drvdata(trig, indio_dev);
+	data->trig = trig;
+	indio_dev->trig = trig;
+
+	ret = iio_trigger_register(trig);
+	if (ret)
+		goto err_trigger_free;
+
+	ret = iio_triggered_buffer_setup(indio_dev, NULL,
+			bma180_trigger_handler, NULL);
+	if (ret < 0) {
+		dev_err(&client->dev, "unable to setup iio triggered buffer\n");
+		goto err_trigger_unregister;
+	}
+
+	ret = iio_device_register(indio_dev);
+	if (ret < 0) {
+		dev_err(&client->dev, "unable to register iio device\n");
+		goto err_buffer_cleanup;
+	}
+
+	return 0;
+
+err_buffer_cleanup:
+	iio_triggered_buffer_cleanup(indio_dev);
+err_trigger_unregister:
+	iio_trigger_unregister(trig);
+err_trigger_free:
+	iio_trigger_free(trig);
+err_chip_disable:
+	bma180_chip_disable(data);
+
+	return ret;
+}
+
+static int bma180_remove(struct i2c_client *client)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(client);
+	struct bma180_data *data = iio_priv(indio_dev);
+
+	iio_device_unregister(indio_dev);
+	iio_triggered_buffer_cleanup(indio_dev);
+	iio_trigger_unregister(data->trig);
+	iio_trigger_free(data->trig);
+	kfree(data->buff);
+
+	mutex_lock(&data->mutex);
+	bma180_chip_disable(data);
+	mutex_unlock(&data->mutex);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int bma180_suspend(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct bma180_data *data = iio_priv(indio_dev);
+	int ret;
+
+	mutex_lock(&data->mutex);
+	ret = bma180_set_sleep_state(data, 1);
+	mutex_unlock(&data->mutex);
+
+	return ret;
+}
+
+static int bma180_resume(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct bma180_data *data = iio_priv(indio_dev);
+	int ret;
+
+	mutex_lock(&data->mutex);
+	ret = bma180_set_sleep_state(data, 0);
+	mutex_unlock(&data->mutex);
+
+	return ret;
+}
+
+static SIMPLE_DEV_PM_OPS(bma180_pm_ops, bma180_suspend, bma180_resume);
+#define BMA180_PM_OPS (&bma180_pm_ops)
+#else
+#define BMA180_PM_OPS NULL
+#endif
+
+static struct i2c_device_id bma180_id[] = {
+	{ BMA180_DRV_NAME, 0 },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(i2c, bma180_id);
+
+static struct i2c_driver bma180_driver = {
+	.driver = {
+		.name	= BMA180_DRV_NAME,
+		.owner	= THIS_MODULE,
+		.pm	= BMA180_PM_OPS,
+	},
+	.probe		= bma180_probe,
+	.remove		= bma180_remove,
+	.id_table	= bma180_id,
+};
+
+module_i2c_driver(bma180_driver);
+
+MODULE_AUTHOR("Kravchenko Oleksandr <x0199363@ti.com>");
+MODULE_AUTHOR("Texas Instruments, Inc.");
+MODULE_DESCRIPTION("Bosch BMA180 triaxial acceleration sensor");
+MODULE_LICENSE("GPL");
-- 
1.7.9.5

Re: [PATCH v3] iio: add Bosch BMA180 acceleration sensor driver

[Jonathan Cameron]

On 08/13/13 16:44, Oleksandr Kravchenko wrote:
> This patch adds IIO driver for Bosch BMA180 triaxial
> acceleration sensor.
> http://dlnmh9ip6v2uc.cloudfront.net/datasheets/
> 		Sensors/Accelerometers/BST-BMA180-DS000-07_2.pdf
> 
> Signed-off-by: Oleksandr Kravchenko <o.v.kravchenko@globallogic.com>
> ---
To play the lazy / busy maintainer.  What changed since v2?

This is where that information should be.
>  .../devicetree/bindings/iio/accel/bma180.txt       |   24 +
>  drivers/iio/accel/Kconfig                          |   12 +
>  drivers/iio/accel/Makefile                         |    2 +
>  drivers/iio/accel/bma180.c                         |  689 ++++++++++++++++++++
>  4 files changed, 727 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/accel/bma180.txt
>  create mode 100644 drivers/iio/accel/bma180.c
> 
> diff --git a/Documentation/devicetree/bindings/iio/accel/bma180.txt b/Documentation/devicetree/bindings/iio/accel/bma180.txt
> new file mode 100644
> index 0000000..c593357
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/accel/bma180.txt
> @@ -0,0 +1,24 @@
> +* Bosch BMA180 triaxial acceleration sensor
> +
> +http://omapworld.com/BMA180_111_1002839.pdf
> +
> +Required properties:
> +
> +  - compatible : should be "bosch,bma180"
> +  - reg : the I2C address of the sensor
> +
> +Optional properties:
> +
> +  - interrupt-parent : should be the phandle for the interrupt controller
> +
> +  - interrupts : interrupt mapping for GPIO IRQ, it should by configured with
> +		flags IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_EDGE_RISING
> +
> +Example:
> +
> +bma180@40 {
> +	compatible = "bosch,bma180";
> +	reg = <0x40>;
> +	interrupt-parent = <&gpio6>;
> +	interrupts = <18 (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_EDGE_RISING)>;
> +};
> diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
> index 719d83f..bd9d581 100644
> --- a/drivers/iio/accel/Kconfig
> +++ b/drivers/iio/accel/Kconfig
> @@ -3,6 +3,18 @@
>  #
>  menu "Accelerometers"
>  
> +config BMA180
> +	tristate "Bosch BMA180 3-Axis Accelerometer Driver"
> +	depends on I2C
> +	select IIO_BUFFER
> +	select IIO_TRIGGERED_BUFFER
> +	help
> +	  Say Y here if you want to build a driver for the Bosch BMA180
> +	  triaxial acceleration sensor.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called bma180.
> +
>  config HID_SENSOR_ACCEL_3D
>  	depends on HID_SENSOR_HUB
>  	select IIO_BUFFER
> diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile
> index 87d8fa2..eb09d72 100644
> --- a/drivers/iio/accel/Makefile
> +++ b/drivers/iio/accel/Makefile
> @@ -2,6 +2,8 @@
>  # Makefile for industrial I/O accelerometer drivers
>  #
>  
> +obj-$(CONFIG_BMA180)	+= bma180.o
> +
>  obj-$(CONFIG_HID_SENSOR_ACCEL_3D) += hid-sensor-accel-3d.o
>  
>  obj-$(CONFIG_IIO_ST_ACCEL_3AXIS) += st_accel.o
> diff --git a/drivers/iio/accel/bma180.c b/drivers/iio/accel/bma180.c
> new file mode 100644
> index 0000000..23c738f
> --- /dev/null
> +++ b/drivers/iio/accel/bma180.c
> @@ -0,0 +1,689 @@
> +/*
> + * bma180.c - IIO driver for Bosch BMA180 triaxial acceleration sensor
> + *
> + * Copyright 2013 Oleksandr Kravchenko <x0199363@ti.com>
> + *
> + * 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.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/i2c.h>
> +#include <linux/interrupt.h>
> +#include <linux/delay.h>
> +#include <linux/of.h>
> +#include <linux/bitops.h>
> +#include <linux/slab.h>
> +#include <linux/string.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +#include <linux/iio/buffer.h>
> +#include <linux/iio/trigger.h>
> +#include <linux/iio/trigger_consumer.h>
> +#include <linux/iio/triggered_buffer.h>
> +
> +#define BMA180_DRV_NAME "bma180"
> +#define BMA180_IRQ_NAME "bma180_event"
> +
> +/* Register set */
> +#define BMA180_CHIP_ID		0x00 /* Need to distinguish BMA180 from other */
> +#define BMA180_ACC_X_LSB	0x02 /* First of 6 registers of accel data */
> +#define BMA180_CTRL_REG0	0x0d
> +#define BMA180_RESET		0x10
> +#define BMA180_BW_TCS		0x20
> +#define BMA180_CTRL_REG3	0x21
> +#define BMA180_TCO_Z		0x30
> +#define BMA180_OFFSET_LSB1	0x35
> +
> +/* BMA180_CTRL_REG0 bits */
> +#define BMA180_DIS_WAKE_UP	BIT(0) /* Disable wake up mode */
> +#define BMA180_SLEEP		BIT(1) /* 1 - chip will sleep */
> +#define BMA180_EE_W		BIT(4) /* Unlock writing to addr from 0x20 */
> +#define BMA180_RESET_INT	BIT(6) /* Reset pending interrupts */
> +
> +/* BMA180_CTRL_REG3 bits */
> +#define BMA180_NEW_DATA_INT	BIT(1) /* Intr every new accel data is ready */
> +
> +/* BMA180_OFFSET_LSB1 skipping mode bit */
> +#define BMA180_SMP_SKIP		BIT(0)
> +
> +/* Bit masks for registers bit fields */
> +#define BMA180_RANGE		0x0e /* Range of measured accel values*/
> +#define BMA180_BW		0xf0 /* Accel bandwidth */
> +#define BMA180_MODE_CONFIG	0x03 /* Config operation modes */
> +
> +/* We have to write this value in reset register to do soft reset */
> +#define BMA180_RESET_VAL	0xb6
> +
> +#define BMA_180_ID_REG_VAL	0x03
> +
> +/* Chip operation modes */
> +#define BMA180_LOW_NOISE	0x00
> +#define BMA180_LOW_POWER	0x03
> +
> +#define BMA180_LOW_NOISE_STR	"low_noise"
> +#define BMA180_LOW_POWER_STR	"low_power"
> +
> +/* Defaults values */
> +#define BMA180_DEF_MODE		BMA180_LOW_NOISE_STR
> +#define BMA180_DEF_BW		20
> +#define BMA180_DEF_SCALE	250
> +
> +/* Available values */
> +#define BMA180_MODE_AVAILABLE \
> +	BMA180_LOW_NOISE_STR " " BMA180_LOW_POWER_STR
> +#define BMA180_BW_AVAILABLE	"10 20 40 75 150 300"
> +#define BMA180_SCALE_AVAILABLE \
> +	"0.000130 0.000190 0.000250 0.000380 0.000500 0.000990 0.001980"
> +
> +struct bma180_data {
> +	struct i2c_client *client;
> +	struct iio_trigger *trig;
> +	struct mutex mutex;
> +	int sleep_state;
> +	int scale;
> +	int bw;
> +	int mode;
> +	char *buff;
> +};
> +
> +enum bma180_axis {
> +	AXIS_X,
> +	AXIS_Y,
> +	AXIS_Z,
> +};
> +
> +static int bw_table[] = { 10, 20, 40, 75, 150, 300 }; /* Hz */
> +static int scale_table[] = { 130, 190, 250, 380, 500, 990, 1980 };
> +
> +static int bma180_get_acc_reg(struct bma180_data *data, enum bma180_axis axis)
> +{
> +	u8 reg = BMA180_ACC_X_LSB + axis * 2;
> +	int ret;
> +
> +	if (data->sleep_state)
> +		return -EBUSY;
> +
> +	ret = i2c_smbus_read_word_data(data->client, reg);
> +	if (ret < 0)
> +		dev_err(&data->client->dev,
> +			"failed to read accel_%c registers\n", 'x' + axis);
> +
> +	return ret;
> +}
> +
> +static int bma180_set_bits(struct bma180_data *data, u8 reg, u8 mask, u8 val)
> +{
> +	int ret = i2c_smbus_read_byte_data(data->client, reg);
> +	u8 reg_val = (ret & ~mask) | (val << (ffs(mask) - 1));
> +
> +	if (ret < 0)
> +		return ret;
> +
> +	return i2c_smbus_write_byte_data(data->client, reg, reg_val);
> +}
> +
> +static int bma180_reset_intr(struct bma180_data *data)
> +{
> +	int ret = bma180_set_bits(data, BMA180_CTRL_REG0, BMA180_RESET_INT, 1);
> +
> +	if (ret)
> +		dev_err(&data->client->dev, "failed to reset interrupt\n");
> +
> +	return ret;
> +}
> +
> +static int bma180_set_new_data_intr_state(struct bma180_data *data, int state)
> +{
> +	u8 reg_val = state ? BMA180_NEW_DATA_INT : 0x00;
> +	int ret = i2c_smbus_write_byte_data(data->client, BMA180_CTRL_REG3,
> +			reg_val);
> +
> +	if (ret)
> +		goto err;
> +	ret = bma180_reset_intr(data);
> +	if (ret)
> +		goto err;
> +
> +	return 0;
> +
> +err:
> +	dev_err(&data->client->dev,
> +		"failed to set new data interrupt state %d\n", state);
> +	return ret;
> +}
> +
> +static int bma180_set_sleep_state(struct bma180_data *data, int state)
> +{
> +	int ret = bma180_set_bits(data, BMA180_CTRL_REG0, BMA180_SLEEP, state);
> +
> +	if (ret) {
> +		dev_err(&data->client->dev,
> +			"failed to set sleep state %d\n", state);
> +		return ret;
> +	}
> +	data->sleep_state = state;
> +
> +	return 0;
> +}
> +
> +static int bma180_set_ee_writing_state(struct bma180_data *data, int state)
> +{
> +	int ret = bma180_set_bits(data, BMA180_CTRL_REG0, BMA180_EE_W, state);
> +
> +	if (ret)
> +		dev_err(&data->client->dev,
> +			"failed to set ee writing state %d\n", state);
> +
> +	return ret;
> +}
> +
> +static int bma180_set_bw(struct bma180_data *data, int val)
> +{
> +	int ret, i;
> +
> +	if (data->sleep_state)
> +		return -EBUSY;
> +
> +	for (i = 0; i < ARRAY_SIZE(bw_table); ++i) {
> +		if (bw_table[i] == val) {
> +			ret = bma180_set_bits(data,
> +					BMA180_BW_TCS, BMA180_BW, i);
> +			if (ret) {
> +				dev_err(&data->client->dev,
> +					"failed to set bandwidth\n");
> +				return ret;
> +			}
> +			data->bw = val;
> +			return 0;
> +		}
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +static int bma180_set_scale(struct bma180_data *data, int val)
> +{
> +	int ret, i;
> +
> +	if (data->sleep_state)
> +		return -EBUSY;
> +
> +	for (i = 0; i < ARRAY_SIZE(scale_table); ++i)
> +		if (scale_table[i] == val) {
> +			ret = bma180_set_bits(data,
> +					BMA180_OFFSET_LSB1, BMA180_RANGE, i);
> +			if (ret) {
> +				dev_err(&data->client->dev,
> +					"failed to set scale\n");
> +				return ret;
> +			}
> +			data->scale = val;
> +			return 0;
> +		}
> +
> +	return -EINVAL;
> +}
> +
> +static int bma180_set_mode(struct bma180_data *data, const char *str)
> +{
> +	u8 reg_val;
> +	int ret;
> +
> +	if (!strcmp(str, BMA180_LOW_NOISE_STR "\n"))
> +		reg_val = BMA180_LOW_NOISE;
> +	else if (!strcmp(str, BMA180_LOW_POWER_STR "\n"))
> +		reg_val = BMA180_LOW_POWER;
> +	else
> +		return -EINVAL;
> +
> +	ret = bma180_set_bits(data, BMA180_TCO_Z, BMA180_MODE_CONFIG, reg_val);
> +	if (ret)
> +		dev_err(&data->client->dev, "failed to set mode\n");
> +
> +	data->mode = reg_val;
> +
> +	return ret;
> +}
> +
> +static int bma180_soft_reset(struct bma180_data *data)
> +{
> +	int ret = i2c_smbus_write_byte_data(data->client,
> +			BMA180_RESET, BMA180_RESET_VAL);
> +
> +	if (ret)
> +		dev_err(&data->client->dev, "failed to reset the chip\n");
> +
> +	return ret;
> +}
> +
> +static int bma180_chip_init(struct bma180_data *data)
> +{
> +	/* Try to read chip_id register. It must return 0x03. */
> +	int ret = i2c_smbus_read_byte_data(data->client, BMA180_CHIP_ID);
> +
> +	if (ret < 0)
> +		goto err;
> +	if (ret != BMA_180_ID_REG_VAL) {
> +		ret = -ENODEV;
> +		goto err;
> +	}
> +
> +	ret = bma180_soft_reset(data);
> +	if (ret)
> +		goto err;
> +	/*
> +	 * No serial transaction should occur within minimum 10 us
> +	 * after soft_reset command
> +	 */
> +	msleep(20);
> +
> +	ret = bma180_set_bits(data, BMA180_CTRL_REG0, BMA180_DIS_WAKE_UP, 1);
> +	if (ret)
> +		goto err;
> +	ret = bma180_set_ee_writing_state(data, 1);
> +	if (ret)
> +		goto err;
> +	ret = bma180_set_new_data_intr_state(data, 0);
> +	if (ret)
> +		goto err;
> +	ret = bma180_set_bits(data, BMA180_OFFSET_LSB1, BMA180_SMP_SKIP, 1);
> +	if (ret)
> +		goto err;
> +	ret = bma180_set_mode(data, BMA180_DEF_MODE "\n");
> +	if (ret)
> +		goto err;
> +	ret = bma180_set_bw(data, BMA180_DEF_BW);
> +	if (ret)
> +		goto err;
> +	ret = bma180_set_scale(data, BMA180_DEF_SCALE);
> +	if (ret)
> +		goto err;
> +
> +	return 0;
> +
> +err:
> +	dev_err(&data->client->dev, "failed to init the chip\n");
> +	return ret;
> +}
> +
> +static void bma180_chip_disable(struct bma180_data *data)
> +{
> +	if (bma180_set_new_data_intr_state(data, 0))
> +		goto err;
> +	if (bma180_set_ee_writing_state(data, 0))
> +		goto err;
> +	if (bma180_set_sleep_state(data, 1))
> +		goto err;
> +
> +	return;
> +
> +err:
> +	dev_err(&data->client->dev, "failed to disable the chip\n");
> +}
> +
> +static ssize_t bma180_read_mode_config(struct device *dev,
> +		struct device_attribute *attr, char *buf)
> +{
> +	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> +	struct bma180_data *data = iio_priv(indio_dev);
> +
> +	return sprintf(buf, "%s\n",
> +			data->mode ?
> +			BMA180_LOW_POWER_STR : BMA180_LOW_NOISE_STR);
> +}
> +
> +static ssize_t bma180_write_mode_config(struct device *dev,
> +		struct device_attribute *attr, const char *buf, size_t len)
> +{
> +	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> +	struct bma180_data *data = iio_priv(indio_dev);
> +	int ret;
> +
> +	mutex_lock(&data->mutex);
> +	ret = bma180_set_mode(data, buf);
> +	mutex_unlock(&data->mutex);
> +
> +	return ret ? ret : len;
> +}
> +
> +static ssize_t bma180_read_bw_config(struct device *dev,
> +		struct device_attribute *attr, char *buf)
> +{
> +	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> +	struct bma180_data *data = iio_priv(indio_dev);
> +
> +	return sprintf(buf, "%d\n", data->bw);
> +}
> +
> +static ssize_t bma180_write_bw_config(struct device *dev,
> +		struct device_attribute *attr, const char *buf, size_t len)
> +{
> +	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> +	struct bma180_data *data = iio_priv(indio_dev);
> +	long val;
> +	int ret = kstrtol(buf, 10, &val);
> +
> +	if (ret)
> +		return ret;
> +
> +	mutex_lock(&data->mutex);
> +	ret = bma180_set_bw(data, val);
> +	mutex_unlock(&data->mutex);
> +
> +	return ret ? ret : len;
> +}
> +
> +static IIO_DEVICE_ATTR(mode, S_IRUGO | S_IWUSR, bma180_read_mode_config,
> +		bma180_write_mode_config, 0);
> +static IIO_CONST_ATTR(mode_available, BMA180_MODE_AVAILABLE);
> +static IIO_DEVICE_ATTR(bandwidth, S_IRUGO | S_IWUSR, bma180_read_bw_config,
> +		bma180_write_bw_config, 0);
> +static IIO_CONST_ATTR(bandwidth_available, BMA180_BW_AVAILABLE);
> +static IIO_CONST_ATTR(scale_available, BMA180_SCALE_AVAILABLE);
> +
> +static struct attribute *bma180_attributes[] = {
> +	&iio_dev_attr_mode.dev_attr.attr,
> +	&iio_const_attr_mode_available.dev_attr.attr,
> +	&iio_dev_attr_bandwidth.dev_attr.attr,
> +	&iio_const_attr_bandwidth_available.dev_attr.attr,
> +	&iio_const_attr_scale_available.dev_attr.attr,
> +	NULL,
> +};
> +
> +static const struct attribute_group bma180_attrs_group = {
> +	.attrs = bma180_attributes,
> +};
> +
> +static int bma180_read_raw(struct iio_dev *indio_dev,
> +		struct iio_chan_spec const *chan, int *val, int *val2,
> +		long mask)
> +{
> +	struct bma180_data *data = iio_priv(indio_dev);
> +	int ret;
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_RAW:
> +		mutex_lock(&data->mutex);
> +		if (iio_buffer_enabled(indio_dev))
> +			ret = -EBUSY;
> +		else
> +			ret = bma180_get_acc_reg(data, chan->scan_index);
> +		mutex_unlock(&data->mutex);
> +		if (ret < 0)
> +			return ret;
> +		*val = (s16)ret >> chan->scan_type.shift;
> +		return IIO_VAL_INT;
> +	case IIO_CHAN_INFO_SCALE:
> +		*val = 0;
> +		*val2 = data->scale;
> +		return IIO_VAL_INT_PLUS_MICRO;
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static int bma180_write_raw(struct iio_dev *indio_dev,
> +		struct iio_chan_spec const *chan, int val, int val2, long mask)
> +{
> +	struct bma180_data *data = iio_priv(indio_dev);
> +	int ret;
> +
> +	if (mask != IIO_CHAN_INFO_SCALE || val)
> +		return -EINVAL;
> +
> +	mutex_lock(&data->mutex);
> +	ret = bma180_set_scale(data, val2);
> +	mutex_unlock(&data->mutex);
> +
> +	return ret;
> +}
> +
> +static int bma180_update_scan_mode(struct iio_dev *indio_dev,
> +		const unsigned long *scan_mask)
> +{
> +	struct bma180_data *data = iio_priv(indio_dev);
> +
> +	kfree(data->buff);
> +	data->buff = kmalloc(indio_dev->scan_bytes, GFP_KERNEL);
> +	if (!data->buff)
> +		return -ENOMEM;
> +
> +	return 0;
> +}
> +
> +static const struct iio_info bma180_info = {
> +	.attrs			= &bma180_attrs_group,
> +	.read_raw		= bma180_read_raw,
> +	.write_raw		= bma180_write_raw,
> +	.update_scan_mode	= bma180_update_scan_mode,
> +	.driver_module		= THIS_MODULE,
> +};
> +
> +#define BMA180_CHANNEL(_index) {				\
> +	.type = IIO_ACCEL,					\
> +	.indexed = 1,						\
> +	.channel = (_index),					\
> +	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
> +	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
> +	.scan_index = (_index),					\
> +	.scan_type = IIO_ST('s', 14, 16, 2),			\
> +}
> +
> +static const struct iio_chan_spec bma180_channels[] = {
> +	BMA180_CHANNEL(AXIS_X),
> +	BMA180_CHANNEL(AXIS_Y),
> +	BMA180_CHANNEL(AXIS_Z),
> +	IIO_CHAN_SOFT_TIMESTAMP(4),
> +};
> +
> +static irqreturn_t bma180_trigger_handler(int irq, void *p)
> +{
> +	struct iio_poll_func *pf = p;
> +	struct iio_dev *indio_dev = pf->indio_dev;
> +	struct bma180_data *data = iio_priv(indio_dev);
> +	int bit, ret, i = 0;
> +
> +	mutex_lock(&data->mutex);
> +	if (indio_dev->scan_timestamp) {
> +		ret = indio_dev->scan_bytes / sizeof(s64) - 1;
> +		((s64 *)data->buff)[ret] = iio_get_time_ns();
> +	}
> +
> +	for_each_set_bit(bit, indio_dev->buffer->scan_mask,
> +			 indio_dev->masklength) {
> +		ret = bma180_get_acc_reg(data, bit);
> +		if (ret < 0) {
> +			mutex_unlock(&data->mutex);
> +			goto err;
> +		}
> +		((s16 *)data->buff)[i++] = ret;
> +	}
> +	mutex_unlock(&data->mutex);
> +
> +	iio_push_to_buffers(indio_dev, (u8 *)data->buff);
> +err:
> +	iio_trigger_notify_done(indio_dev->trig);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int bma180_data_rdy_trigger_set_state(struct iio_trigger *trig,
> +		bool state)
> +{
> +	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
> +	struct bma180_data *data = iio_priv(indio_dev);
> +
> +	return bma180_set_new_data_intr_state(data, state);
> +}
> +
> +static int bma180_trig_try_reen(struct iio_trigger *trig)
> +{
> +	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
> +	struct bma180_data *data = iio_priv(indio_dev);
> +
> +	return bma180_reset_intr(data);
> +}
> +
> +static const struct iio_trigger_ops bma180_trigger_ops = {
> +	.set_trigger_state = bma180_data_rdy_trigger_set_state,
> +	.try_reenable = bma180_trig_try_reen,
> +	.owner = THIS_MODULE,
> +};
> +
> +static int bma180_probe(struct i2c_client *client,
> +		const struct i2c_device_id *id)
> +{
> +	struct bma180_data *data;
> +	struct iio_dev *indio_dev;
> +	struct iio_trigger *trig;
> +	int ret;
> +
> +	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;
> +
> +	ret = bma180_chip_init(data);
> +	if (ret < 0)
> +		goto err_chip_disable;
> +
> +	mutex_init(&data->mutex);
> +
> +	indio_dev->dev.parent = &client->dev;
> +	indio_dev->channels = bma180_channels;
> +	indio_dev->num_channels = ARRAY_SIZE(bma180_channels);
> +	indio_dev->name = BMA180_DRV_NAME;
> +	indio_dev->modes = INDIO_DIRECT_MODE;
> +	indio_dev->info = &bma180_info;
> +
> +	trig = iio_trigger_alloc("%s-dev%d", indio_dev->name, indio_dev->id);
> +	if (!trig) {
> +		ret = -ENOMEM;
> +		goto err_chip_disable;
> +	}
> +
> +	ret = devm_request_irq(&client->dev, client->irq,
> +			iio_trigger_generic_data_rdy_poll,
> +			IRQF_TRIGGER_RISING, BMA180_IRQ_NAME, trig);
> +	if (ret) {
> +		dev_err(&client->dev, "unable to request IRQ\n");
> +		goto err_trigger_free;
> +	}
> +
> +	trig->dev.parent = &client->dev;
> +	trig->ops = &bma180_trigger_ops;
> +	iio_trigger_set_drvdata(trig, indio_dev);
> +	data->trig = trig;
> +	indio_dev->trig = trig;
> +
> +	ret = iio_trigger_register(trig);
> +	if (ret)
> +		goto err_trigger_free;
> +
> +	ret = iio_triggered_buffer_setup(indio_dev, NULL,
> +			bma180_trigger_handler, NULL);
> +	if (ret < 0) {
> +		dev_err(&client->dev, "unable to setup iio triggered buffer\n");
> +		goto err_trigger_unregister;
> +	}
> +
> +	ret = iio_device_register(indio_dev);
> +	if (ret < 0) {
> +		dev_err(&client->dev, "unable to register iio device\n");
> +		goto err_buffer_cleanup;
> +	}
> +
> +	return 0;
> +
> +err_buffer_cleanup:
> +	iio_triggered_buffer_cleanup(indio_dev);
> +err_trigger_unregister:
> +	iio_trigger_unregister(trig);
> +err_trigger_free:
> +	iio_trigger_free(trig);
> +err_chip_disable:
> +	bma180_chip_disable(data);
> +
> +	return ret;
> +}
> +
> +static int bma180_remove(struct i2c_client *client)
> +{
> +	struct iio_dev *indio_dev = i2c_get_clientdata(client);
> +	struct bma180_data *data = iio_priv(indio_dev);
> +
> +	iio_device_unregister(indio_dev);
> +	iio_triggered_buffer_cleanup(indio_dev);
> +	iio_trigger_unregister(data->trig);
> +	iio_trigger_free(data->trig);
> +	kfree(data->buff);
> +
> +	mutex_lock(&data->mutex);
> +	bma180_chip_disable(data);
> +	mutex_unlock(&data->mutex);
> +
> +	return 0;
> +}
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int bma180_suspend(struct device *dev)
> +{
> +	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> +	struct bma180_data *data = iio_priv(indio_dev);
> +	int ret;
> +
> +	mutex_lock(&data->mutex);
> +	ret = bma180_set_sleep_state(data, 1);
> +	mutex_unlock(&data->mutex);
> +
> +	return ret;
> +}
> +
> +static int bma180_resume(struct device *dev)
> +{
> +	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> +	struct bma180_data *data = iio_priv(indio_dev);
> +	int ret;
> +
> +	mutex_lock(&data->mutex);
> +	ret = bma180_set_sleep_state(data, 0);
> +	mutex_unlock(&data->mutex);
> +
> +	return ret;
> +}
> +
> +static SIMPLE_DEV_PM_OPS(bma180_pm_ops, bma180_suspend, bma180_resume);
> +#define BMA180_PM_OPS (&bma180_pm_ops)
> +#else
> +#define BMA180_PM_OPS NULL
> +#endif
> +
> +static struct i2c_device_id bma180_id[] = {
> +	{ BMA180_DRV_NAME, 0 },
> +	{ }
> +};
> +
> +MODULE_DEVICE_TABLE(i2c, bma180_id);
> +
> +static struct i2c_driver bma180_driver = {
> +	.driver = {
> +		.name	= BMA180_DRV_NAME,
> +		.owner	= THIS_MODULE,
> +		.pm	= BMA180_PM_OPS,
> +	},
> +	.probe		= bma180_probe,
> +	.remove		= bma180_remove,
> +	.id_table	= bma180_id,
> +};
> +
> +module_i2c_driver(bma180_driver);
> +
> +MODULE_AUTHOR("Kravchenko Oleksandr <x0199363@ti.com>");
> +MODULE_AUTHOR("Texas Instruments, Inc.");
> +MODULE_DESCRIPTION("Bosch BMA180 triaxial acceleration sensor");
> +MODULE_LICENSE("GPL");
> 

Re: [PATCH v3] iio: add Bosch BMA180 acceleration sensor driver

[Stephen Warren]

On 08/13/2013 09:44 AM, Oleksandr Kravchenko wrote:
> This patch adds IIO driver for Bosch BMA180 triaxial
> acceleration sensor.
> http://dlnmh9ip6v2uc.cloudfront.net/datasheets/
> 		Sensors/Accelerometers/BST-BMA180-DS000-07_2.pdf

The binding document,
Acked-by: Stephen Warren <swarren@nvidia.com>

Re: [PATCH v3] iio: add Bosch BMA180 acceleration sensor driver

[Oleksandr Kravchenko]

On Tue, Aug 13, 2013 at 9:28 PM, Jonathan Cameron <jic23@kernel.org> wrote:
> On 08/13/13 16:44, Oleksandr Kravchenko wrote:
>> This patch adds IIO driver for Bosch BMA180 triaxial
>> acceleration sensor.
>> http://dlnmh9ip6v2uc.cloudfront.net/datasheets/
>>               Sensors/Accelerometers/BST-BMA180-DS000-07_2.pdf
>>
>> Signed-off-by: Oleksandr Kravchenko <o.v.kravchenko@globallogic.com>
>> ---
> To play the lazy / busy maintainer.  What changed since v2?
>
> This is where that information should be.

In general: fixed problem with possible not unlocked mutex in
bma180_trigger_handler() and moved range, bandwidth and mode
from devtree to sysfs attributes.

Re: [PATCH v3] iio: add Bosch BMA180 acceleration sensor driver

[Jonathan Cameron]

On 08/13/13 16:44, Oleksandr Kravchenko wrote:
> This patch adds IIO driver for Bosch BMA180 triaxial
> acceleration sensor.
> http://dlnmh9ip6v2uc.cloudfront.net/datasheets/
> 		Sensors/Accelerometers/BST-BMA180-DS000-07_2.pdf
>
> Signed-off-by: Oleksandr Kravchenko <o.v.kravchenko@globallogic.com>
Hi,

Firstly, just a thought (I haven't made up my mind whether it is a good idea or
not!) but you could use devm_kzalloc for data->buff and hence avoid having
to care about freeing it in the remove function.  Update scan mode isn't
a particularly fast path so I doubt the small overhead will matter.

Otherwise, the abi additions need documenting iff they don't fit within
existing ABI. If they do then they need to match existing ABI.

Of those, 'mode' is rather device specific and could probably do with
a more detailed name.  The only 'generic' way to do it would be to make the
channel type attributes writable and treat it as a resolution control rather
than a noise/power trade off.  Uggly though so perhaps what you have makes
sense.  We can always add a more generic way of controlling this if it
starts turning up in lots of devices (keeping this method of course to avoid
breaking ABI).

'bandwidth' is already (I think) covered by the ABI.  For the bandwidth optoins you have enabled we are talking low pass
filters and presumably their 3db point.
In Documentation/ABI/testing/sysfs-bus-iio you will find in_accel_filter_low_pass_3db_frequency. My filter theory is
rather rusty (not sure it was
every anything else ;). Hence I'm not entirely sure how to work
out the 3db frequency from the 'pole frequency' if they are not infact
the same thing..

Otherwise, the driver looks good to me.

Jonathan
> ---
>  .../devicetree/bindings/iio/accel/bma180.txt       |   24 +
>  drivers/iio/accel/Kconfig                          |   12 +
>  drivers/iio/accel/Makefile                         |    2 +
>  drivers/iio/accel/bma180.c                         |  689 ++++++++++++++++++++
>  4 files changed, 727 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/accel/bma180.txt
>  create mode 100644 drivers/iio/accel/bma180.c
>
> diff --git a/Documentation/devicetree/bindings/iio/accel/bma180.txt b/Documentation/devicetree/bindings/iio/accel/bma180.txt
> new file mode 100644
> index 0000000..c593357
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/accel/bma180.txt
> @@ -0,0 +1,24 @@
> +* Bosch BMA180 triaxial acceleration sensor
> +
> +http://omapworld.com/BMA180_111_1002839.pdf
> +
> +Required properties:
> +
> +  - compatible : should be "bosch,bma180"
> +  - reg : the I2C address of the sensor
> +
> +Optional properties:
> +
> +  - interrupt-parent : should be the phandle for the interrupt controller
> +
> +  - interrupts : interrupt mapping for GPIO IRQ, it should by configured with
> +		flags IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_EDGE_RISING
> +
> +Example:
> +
> +bma180@40 {
> +	compatible = "bosch,bma180";
> +	reg = <0x40>;
> +	interrupt-parent = <&gpio6>;
> +	interrupts = <18 (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_EDGE_RISING)>;
> +};
> diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
> index 719d83f..bd9d581 100644
> --- a/drivers/iio/accel/Kconfig
> +++ b/drivers/iio/accel/Kconfig
> @@ -3,6 +3,18 @@
>  #
>  menu "Accelerometers"
>
> +config BMA180
> +	tristate "Bosch BMA180 3-Axis Accelerometer Driver"
> +	depends on I2C
> +	select IIO_BUFFER
> +	select IIO_TRIGGERED_BUFFER
> +	help
> +	  Say Y here if you want to build a driver for the Bosch BMA180
> +	  triaxial acceleration sensor.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called bma180.
> +
>  config HID_SENSOR_ACCEL_3D
>  	depends on HID_SENSOR_HUB
>  	select IIO_BUFFER
> diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile
> index 87d8fa2..eb09d72 100644
> --- a/drivers/iio/accel/Makefile
> +++ b/drivers/iio/accel/Makefile
> @@ -2,6 +2,8 @@
>  # Makefile for industrial I/O accelerometer drivers
>  #
>
> +obj-$(CONFIG_BMA180)	+= bma180.o
> +
>  obj-$(CONFIG_HID_SENSOR_ACCEL_3D) += hid-sensor-accel-3d.o
>
>  obj-$(CONFIG_IIO_ST_ACCEL_3AXIS) += st_accel.o
> diff --git a/drivers/iio/accel/bma180.c b/drivers/iio/accel/bma180.c
> new file mode 100644
> index 0000000..23c738f
> --- /dev/null
> +++ b/drivers/iio/accel/bma180.c
> @@ -0,0 +1,689 @@
> +/*
> + * bma180.c - IIO driver for Bosch BMA180 triaxial acceleration sensor
> + *
> + * Copyright 2013 Oleksandr Kravchenko <x0199363@ti.com>
> + *
> + * 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.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/i2c.h>
> +#include <linux/interrupt.h>
> +#include <linux/delay.h>
> +#include <linux/of.h>
> +#include <linux/bitops.h>
> +#include <linux/slab.h>
> +#include <linux/string.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +#include <linux/iio/buffer.h>
> +#include <linux/iio/trigger.h>
> +#include <linux/iio/trigger_consumer.h>
> +#include <linux/iio/triggered_buffer.h>
> +
> +#define BMA180_DRV_NAME "bma180"
> +#define BMA180_IRQ_NAME "bma180_event"
> +
> +/* Register set */
> +#define BMA180_CHIP_ID		0x00 /* Need to distinguish BMA180 from other */
> +#define BMA180_ACC_X_LSB	0x02 /* First of 6 registers of accel data */
> +#define BMA180_CTRL_REG0	0x0d
> +#define BMA180_RESET		0x10
> +#define BMA180_BW_TCS		0x20
> +#define BMA180_CTRL_REG3	0x21
> +#define BMA180_TCO_Z		0x30
> +#define BMA180_OFFSET_LSB1	0x35
> +
> +/* BMA180_CTRL_REG0 bits */
> +#define BMA180_DIS_WAKE_UP	BIT(0) /* Disable wake up mode */
> +#define BMA180_SLEEP		BIT(1) /* 1 - chip will sleep */
> +#define BMA180_EE_W		BIT(4) /* Unlock writing to addr from 0x20 */
> +#define BMA180_RESET_INT	BIT(6) /* Reset pending interrupts */
> +
> +/* BMA180_CTRL_REG3 bits */
> +#define BMA180_NEW_DATA_INT	BIT(1) /* Intr every new accel data is ready */
> +
> +/* BMA180_OFFSET_LSB1 skipping mode bit */
> +#define BMA180_SMP_SKIP		BIT(0)
> +
> +/* Bit masks for registers bit fields */
> +#define BMA180_RANGE		0x0e /* Range of measured accel values*/
> +#define BMA180_BW		0xf0 /* Accel bandwidth */
> +#define BMA180_MODE_CONFIG	0x03 /* Config operation modes */
> +
> +/* We have to write this value in reset register to do soft reset */
> +#define BMA180_RESET_VAL	0xb6
> +
> +#define BMA_180_ID_REG_VAL	0x03
> +
> +/* Chip operation modes */
> +#define BMA180_LOW_NOISE	0x00
> +#define BMA180_LOW_POWER	0x03
> +
> +#define BMA180_LOW_NOISE_STR	"low_noise"
> +#define BMA180_LOW_POWER_STR	"low_power"
> +
> +/* Defaults values */
> +#define BMA180_DEF_MODE		BMA180_LOW_NOISE_STR
> +#define BMA180_DEF_BW		20
> +#define BMA180_DEF_SCALE	250
> +
> +/* Available values */
> +#define BMA180_MODE_AVAILABLE \
> +	BMA180_LOW_NOISE_STR " " BMA180_LOW_POWER_STR
> +#define BMA180_BW_AVAILABLE	"10 20 40 75 150 300"
> +#define BMA180_SCALE_AVAILABLE \
> +	"0.000130 0.000190 0.000250 0.000380 0.000500 0.000990 0.001980"
> +
> +struct bma180_data {
> +	struct i2c_client *client;
> +	struct iio_trigger *trig;
> +	struct mutex mutex;
> +	int sleep_state;
> +	int scale;
> +	int bw;
> +	int mode;
> +	char *buff;
> +};
> +
> +enum bma180_axis {
> +	AXIS_X,
> +	AXIS_Y,
> +	AXIS_Z,
> +};
> +
> +static int bw_table[] = { 10, 20, 40, 75, 150, 300 }; /* Hz */
> +static int scale_table[] = { 130, 190, 250, 380, 500, 990, 1980 };
> +
> +static int bma180_get_acc_reg(struct bma180_data *data, enum bma180_axis axis)
> +{
> +	u8 reg = BMA180_ACC_X_LSB + axis * 2;
> +	int ret;
> +
> +	if (data->sleep_state)
> +		return -EBUSY;
> +
> +	ret = i2c_smbus_read_word_data(data->client, reg);
> +	if (ret < 0)
> +		dev_err(&data->client->dev,
> +			"failed to read accel_%c registers\n", 'x' + axis);
> +
> +	return ret;
> +}
> +
> +static int bma180_set_bits(struct bma180_data *data, u8 reg, u8 mask, u8 val)
> +{
> +	int ret = i2c_smbus_read_byte_data(data->client, reg);
> +	u8 reg_val = (ret & ~mask) | (val << (ffs(mask) - 1));
> +
> +	if (ret < 0)
> +		return ret;
> +
> +	return i2c_smbus_write_byte_data(data->client, reg, reg_val);
> +}
> +
> +static int bma180_reset_intr(struct bma180_data *data)
> +{
> +	int ret = bma180_set_bits(data, BMA180_CTRL_REG0, BMA180_RESET_INT, 1);
> +
> +	if (ret)
> +		dev_err(&data->client->dev, "failed to reset interrupt\n");
> +
> +	return ret;
> +}
> +
> +static int bma180_set_new_data_intr_state(struct bma180_data *data, int state)
> +{
> +	u8 reg_val = state ? BMA180_NEW_DATA_INT : 0x00;
> +	int ret = i2c_smbus_write_byte_data(data->client, BMA180_CTRL_REG3,
> +			reg_val);
> +
> +	if (ret)
> +		goto err;
> +	ret = bma180_reset_intr(data);
> +	if (ret)
> +		goto err;
> +
> +	return 0;
> +
> +err:
> +	dev_err(&data->client->dev,
> +		"failed to set new data interrupt state %d\n", state);
> +	return ret;
> +}
> +
> +static int bma180_set_sleep_state(struct bma180_data *data, int state)
> +{
> +	int ret = bma180_set_bits(data, BMA180_CTRL_REG0, BMA180_SLEEP, state);
> +
> +	if (ret) {
> +		dev_err(&data->client->dev,
> +			"failed to set sleep state %d\n", state);
> +		return ret;
> +	}
> +	data->sleep_state = state;
> +
> +	return 0;
> +}
> +
> +static int bma180_set_ee_writing_state(struct bma180_data *data, int state)
> +{
> +	int ret = bma180_set_bits(data, BMA180_CTRL_REG0, BMA180_EE_W, state);
> +
> +	if (ret)
> +		dev_err(&data->client->dev,
> +			"failed to set ee writing state %d\n", state);
> +
> +	return ret;
> +}
> +
> +static int bma180_set_bw(struct bma180_data *data, int val)
> +{
> +	int ret, i;
> +
> +	if (data->sleep_state)
> +		return -EBUSY;
> +
> +	for (i = 0; i < ARRAY_SIZE(bw_table); ++i) {
> +		if (bw_table[i] == val) {
> +			ret = bma180_set_bits(data,
> +					BMA180_BW_TCS, BMA180_BW, i);
> +			if (ret) {
> +				dev_err(&data->client->dev,
> +					"failed to set bandwidth\n");
> +				return ret;
> +			}
> +			data->bw = val;
> +			return 0;
> +		}
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +static int bma180_set_scale(struct bma180_data *data, int val)
> +{
> +	int ret, i;
> +
> +	if (data->sleep_state)
> +		return -EBUSY;
> +
> +	for (i = 0; i < ARRAY_SIZE(scale_table); ++i)
> +		if (scale_table[i] == val) {
> +			ret = bma180_set_bits(data,
> +					BMA180_OFFSET_LSB1, BMA180_RANGE, i);
> +			if (ret) {
> +				dev_err(&data->client->dev,
> +					"failed to set scale\n");
> +				return ret;
> +			}
> +			data->scale = val;
> +			return 0;
> +		}
> +
> +	return -EINVAL;
> +}
> +
> +static int bma180_set_mode(struct bma180_data *data, const char *str)
> +{
> +	u8 reg_val;
> +	int ret;
> +
> +	if (!strcmp(str, BMA180_LOW_NOISE_STR "\n"))
> +		reg_val = BMA180_LOW_NOISE;
> +	else if (!strcmp(str, BMA180_LOW_POWER_STR "\n"))
> +		reg_val = BMA180_LOW_POWER;
> +	else
> +		return -EINVAL;
> +
> +	ret = bma180_set_bits(data, BMA180_TCO_Z, BMA180_MODE_CONFIG, reg_val);
> +	if (ret)
> +		dev_err(&data->client->dev, "failed to set mode\n");
> +
> +	data->mode = reg_val;
> +
> +	return ret;
> +}
> +
> +static int bma180_soft_reset(struct bma180_data *data)
> +{
> +	int ret = i2c_smbus_write_byte_data(data->client,
> +			BMA180_RESET, BMA180_RESET_VAL);
> +
> +	if (ret)
> +		dev_err(&data->client->dev, "failed to reset the chip\n");
> +
> +	return ret;
> +}
> +
> +static int bma180_chip_init(struct bma180_data *data)
> +{
> +	/* Try to read chip_id register. It must return 0x03. */
> +	int ret = i2c_smbus_read_byte_data(data->client, BMA180_CHIP_ID);
> +
> +	if (ret < 0)
> +		goto err;
> +	if (ret != BMA_180_ID_REG_VAL) {
> +		ret = -ENODEV;
> +		goto err;
> +	}
> +
> +	ret = bma180_soft_reset(data);
> +	if (ret)
> +		goto err;
> +	/*
> +	 * No serial transaction should occur within minimum 10 us
> +	 * after soft_reset command
> +	 */
> +	msleep(20);
> +
> +	ret = bma180_set_bits(data, BMA180_CTRL_REG0, BMA180_DIS_WAKE_UP, 1);
> +	if (ret)
> +		goto err;
> +	ret = bma180_set_ee_writing_state(data, 1);
> +	if (ret)
> +		goto err;
> +	ret = bma180_set_new_data_intr_state(data, 0);
> +	if (ret)
> +		goto err;
> +	ret = bma180_set_bits(data, BMA180_OFFSET_LSB1, BMA180_SMP_SKIP, 1);
> +	if (ret)
> +		goto err;
> +	ret = bma180_set_mode(data, BMA180_DEF_MODE "\n");
> +	if (ret)
> +		goto err;
> +	ret = bma180_set_bw(data, BMA180_DEF_BW);
> +	if (ret)
> +		goto err;
> +	ret = bma180_set_scale(data, BMA180_DEF_SCALE);
> +	if (ret)
> +		goto err;
> +
> +	return 0;
> +
> +err:
> +	dev_err(&data->client->dev, "failed to init the chip\n");
> +	return ret;
> +}
> +
> +static void bma180_chip_disable(struct bma180_data *data)
> +{
> +	if (bma180_set_new_data_intr_state(data, 0))
> +		goto err;
> +	if (bma180_set_ee_writing_state(data, 0))
> +		goto err;
> +	if (bma180_set_sleep_state(data, 1))
> +		goto err;
> +
> +	return;
> +
> +err:
> +	dev_err(&data->client->dev, "failed to disable the chip\n");
> +}
> +
> +static ssize_t bma180_read_mode_config(struct device *dev,
> +		struct device_attribute *attr, char *buf)
> +{
> +	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> +	struct bma180_data *data = iio_priv(indio_dev);
> +
> +	return sprintf(buf, "%s\n",
> +			data->mode ?
> +			BMA180_LOW_POWER_STR : BMA180_LOW_NOISE_STR);
> +}
> +
> +static ssize_t bma180_write_mode_config(struct device *dev,
> +		struct device_attribute *attr, const char *buf, size_t len)
> +{
> +	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> +	struct bma180_data *data = iio_priv(indio_dev);
> +	int ret;
> +
> +	mutex_lock(&data->mutex);
> +	ret = bma180_set_mode(data, buf);
> +	mutex_unlock(&data->mutex);
> +
> +	return ret ? ret : len;
> +}
> +
> +static ssize_t bma180_read_bw_config(struct device *dev,
> +		struct device_attribute *attr, char *buf)
> +{
> +	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> +	struct bma180_data *data = iio_priv(indio_dev);
> +
> +	return sprintf(buf, "%d\n", data->bw);
> +}
> +
> +static ssize_t bma180_write_bw_config(struct device *dev,
> +		struct device_attribute *attr, const char *buf, size_t len)
> +{
> +	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> +	struct bma180_data *data = iio_priv(indio_dev);
> +	long val;
> +	int ret = kstrtol(buf, 10, &val);
> +
> +	if (ret)
> +		return ret;
> +
> +	mutex_lock(&data->mutex);
> +	ret = bma180_set_bw(data, val);
> +	mutex_unlock(&data->mutex);
> +
> +	return ret ? ret : len;
> +}
> +
> +static IIO_DEVICE_ATTR(mode, S_IRUGO | S_IWUSR, bma180_read_mode_config,
> +		bma180_write_mode_config, 0);
> +static IIO_CONST_ATTR(mode_available, BMA180_MODE_AVAILABLE);
> +static IIO_DEVICE_ATTR(bandwidth, S_IRUGO | S_IWUSR, bma180_read_bw_config,
> +		bma180_write_bw_config, 0);
> +static IIO_CONST_ATTR(bandwidth_available, BMA180_BW_AVAILABLE);
> +static IIO_CONST_ATTR(scale_available, BMA180_SCALE_AVAILABLE);
> +
> +static struct attribute *bma180_attributes[] = {
> +	&iio_dev_attr_mode.dev_attr.attr,
> +	&iio_const_attr_mode_available.dev_attr.attr,
These need documenting if they don't fit within standard abi options.
> +	&iio_dev_attr_bandwidth.dev_attr.attr,
> +	&iio_const_attr_bandwidth_available.dev_attr.attr,
bandwidth = 3db frequency?
> +	&iio_const_attr_scale_available.dev_attr.attr,
> +	NULL,
> +};
> +
> +static const struct attribute_group bma180_attrs_group = {
> +	.attrs = bma180_attributes,
> +};
> +
> +static int bma180_read_raw(struct iio_dev *indio_dev,
> +		struct iio_chan_spec const *chan, int *val, int *val2,
> +		long mask)
> +{
> +	struct bma180_data *data = iio_priv(indio_dev);
> +	int ret;
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_RAW:
> +		mutex_lock(&data->mutex);
> +		if (iio_buffer_enabled(indio_dev))
> +			ret = -EBUSY;
> +		else
> +			ret = bma180_get_acc_reg(data, chan->scan_index);
> +		mutex_unlock(&data->mutex);
> +		if (ret < 0)
> +			return ret;
> +		*val = (s16)ret >> chan->scan_type.shift;
> +		return IIO_VAL_INT;
> +	case IIO_CHAN_INFO_SCALE:
> +		*val = 0;
> +		*val2 = data->scale;
> +		return IIO_VAL_INT_PLUS_MICRO;
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static int bma180_write_raw(struct iio_dev *indio_dev,
> +		struct iio_chan_spec const *chan, int val, int val2, long mask)
> +{
> +	struct bma180_data *data = iio_priv(indio_dev);
> +	int ret;
> +
> +	if (mask != IIO_CHAN_INFO_SCALE || val)
> +		return -EINVAL;
> +
> +	mutex_lock(&data->mutex);
> +	ret = bma180_set_scale(data, val2);
> +	mutex_unlock(&data->mutex);
> +
> +	return ret;
> +}
> +
> +static int bma180_update_scan_mode(struct iio_dev *indio_dev,
> +		const unsigned long *scan_mask)
> +{
> +	struct bma180_data *data = iio_priv(indio_dev);
> +
> +	kfree(data->buff);
> +	data->buff = kmalloc(indio_dev->scan_bytes, GFP_KERNEL);
> +	if (!data->buff)
> +		return -ENOMEM;
> +
> +	return 0;
> +}
> +
> +static const struct iio_info bma180_info = {
> +	.attrs			= &bma180_attrs_group,
> +	.read_raw		= bma180_read_raw,
> +	.write_raw		= bma180_write_raw,
> +	.update_scan_mode	= bma180_update_scan_mode,
> +	.driver_module		= THIS_MODULE,
> +};
> +
> +#define BMA180_CHANNEL(_index) {				\
> +	.type = IIO_ACCEL,					\
> +	.indexed = 1,						\
> +	.channel = (_index),					\
> +	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
> +	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
> +	.scan_index = (_index),					\
> +	.scan_type = IIO_ST('s', 14, 16, 2),			\
> +}
> +
> +static const struct iio_chan_spec bma180_channels[] = {
> +	BMA180_CHANNEL(AXIS_X),
> +	BMA180_CHANNEL(AXIS_Y),
> +	BMA180_CHANNEL(AXIS_Z),
> +	IIO_CHAN_SOFT_TIMESTAMP(4),
> +};
> +
> +static irqreturn_t bma180_trigger_handler(int irq, void *p)
> +{
> +	struct iio_poll_func *pf = p;
> +	struct iio_dev *indio_dev = pf->indio_dev;
> +	struct bma180_data *data = iio_priv(indio_dev);
> +	int bit, ret, i = 0;
> +
> +	mutex_lock(&data->mutex);
> +	if (indio_dev->scan_timestamp) {
> +		ret = indio_dev->scan_bytes / sizeof(s64) - 1;
> +		((s64 *)data->buff)[ret] = iio_get_time_ns();
> +	}
> +
> +	for_each_set_bit(bit, indio_dev->buffer->scan_mask,
> +			 indio_dev->masklength) {
> +		ret = bma180_get_acc_reg(data, bit);
> +		if (ret < 0) {
> +			mutex_unlock(&data->mutex);
> +			goto err;
> +		}
> +		((s16 *)data->buff)[i++] = ret;
> +	}
> +	mutex_unlock(&data->mutex);
> +
> +	iio_push_to_buffers(indio_dev, (u8 *)data->buff);
> +err:
> +	iio_trigger_notify_done(indio_dev->trig);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int bma180_data_rdy_trigger_set_state(struct iio_trigger *trig,
> +		bool state)
> +{
> +	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
> +	struct bma180_data *data = iio_priv(indio_dev);
> +
> +	return bma180_set_new_data_intr_state(data, state);
> +}
> +
> +static int bma180_trig_try_reen(struct iio_trigger *trig)
> +{
> +	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
> +	struct bma180_data *data = iio_priv(indio_dev);
> +
> +	return bma180_reset_intr(data);
> +}
> +
> +static const struct iio_trigger_ops bma180_trigger_ops = {
> +	.set_trigger_state = bma180_data_rdy_trigger_set_state,
> +	.try_reenable = bma180_trig_try_reen,
> +	.owner = THIS_MODULE,
> +};
> +
> +static int bma180_probe(struct i2c_client *client,
> +		const struct i2c_device_id *id)
> +{
> +	struct bma180_data *data;
> +	struct iio_dev *indio_dev;
> +	struct iio_trigger *trig;
> +	int ret;
> +
> +	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;
> +
> +	ret = bma180_chip_init(data);
> +	if (ret < 0)
> +		goto err_chip_disable;
> +
> +	mutex_init(&data->mutex);
> +
> +	indio_dev->dev.parent = &client->dev;
> +	indio_dev->channels = bma180_channels;
> +	indio_dev->num_channels = ARRAY_SIZE(bma180_channels);
> +	indio_dev->name = BMA180_DRV_NAME;
> +	indio_dev->modes = INDIO_DIRECT_MODE;
> +	indio_dev->info = &bma180_info;
> +
> +	trig = iio_trigger_alloc("%s-dev%d", indio_dev->name, indio_dev->id);
> +	if (!trig) {
> +		ret = -ENOMEM;
> +		goto err_chip_disable;
> +	}
> +
> +	ret = devm_request_irq(&client->dev, client->irq,
> +			iio_trigger_generic_data_rdy_poll,
> +			IRQF_TRIGGER_RISING, BMA180_IRQ_NAME, trig);
> +	if (ret) {
> +		dev_err(&client->dev, "unable to request IRQ\n");
> +		goto err_trigger_free;
> +	}
> +
> +	trig->dev.parent = &client->dev;
> +	trig->ops = &bma180_trigger_ops;
> +	iio_trigger_set_drvdata(trig, indio_dev);
> +	data->trig = trig;
> +	indio_dev->trig = trig;
> +
> +	ret = iio_trigger_register(trig);
> +	if (ret)
> +		goto err_trigger_free;
> +
> +	ret = iio_triggered_buffer_setup(indio_dev, NULL,
> +			bma180_trigger_handler, NULL);
> +	if (ret < 0) {
> +		dev_err(&client->dev, "unable to setup iio triggered buffer\n");
> +		goto err_trigger_unregister;
> +	}
> +
> +	ret = iio_device_register(indio_dev);
> +	if (ret < 0) {
> +		dev_err(&client->dev, "unable to register iio device\n");
> +		goto err_buffer_cleanup;
> +	}
> +
> +	return 0;
> +
> +err_buffer_cleanup:
> +	iio_triggered_buffer_cleanup(indio_dev);
> +err_trigger_unregister:
> +	iio_trigger_unregister(trig);
> +err_trigger_free:
> +	iio_trigger_free(trig);
> +err_chip_disable:
> +	bma180_chip_disable(data);
> +
> +	return ret;
> +}
> +
> +static int bma180_remove(struct i2c_client *client)
> +{
> +	struct iio_dev *indio_dev = i2c_get_clientdata(client);
> +	struct bma180_data *data = iio_priv(indio_dev);
> +
> +	iio_device_unregister(indio_dev);
> +	iio_triggered_buffer_cleanup(indio_dev);
> +	iio_trigger_unregister(data->trig);
> +	iio_trigger_free(data->trig);
> +	kfree(data->buff);
> +
> +	mutex_lock(&data->mutex);
> +	bma180_chip_disable(data);
> +	mutex_unlock(&data->mutex);
> +
> +	return 0;
> +}
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int bma180_suspend(struct device *dev)
> +{
> +	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> +	struct bma180_data *data = iio_priv(indio_dev);
> +	int ret;
> +
> +	mutex_lock(&data->mutex);
> +	ret = bma180_set_sleep_state(data, 1);
> +	mutex_unlock(&data->mutex);
> +
> +	return ret;
> +}
> +
> +static int bma180_resume(struct device *dev)
> +{
> +	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> +	struct bma180_data *data = iio_priv(indio_dev);
> +	int ret;
> +
> +	mutex_lock(&data->mutex);
> +	ret = bma180_set_sleep_state(data, 0);
> +	mutex_unlock(&data->mutex);
> +
> +	return ret;
> +}
> +
> +static SIMPLE_DEV_PM_OPS(bma180_pm_ops, bma180_suspend, bma180_resume);
> +#define BMA180_PM_OPS (&bma180_pm_ops)
> +#else
> +#define BMA180_PM_OPS NULL
> +#endif
> +
> +static struct i2c_device_id bma180_id[] = {
> +	{ BMA180_DRV_NAME, 0 },
> +	{ }
> +};
> +
> +MODULE_DEVICE_TABLE(i2c, bma180_id);
> +
> +static struct i2c_driver bma180_driver = {
> +	.driver = {
> +		.name	= BMA180_DRV_NAME,
> +		.owner	= THIS_MODULE,
> +		.pm	= BMA180_PM_OPS,
> +	},
> +	.probe		= bma180_probe,
> +	.remove		= bma180_remove,
> +	.id_table	= bma180_id,
> +};
> +
> +module_i2c_driver(bma180_driver);
> +
> +MODULE_AUTHOR("Kravchenko Oleksandr <x0199363@ti.com>");
> +MODULE_AUTHOR("Texas Instruments, Inc.");
> +MODULE_DESCRIPTION("Bosch BMA180 triaxial acceleration sensor");
> +MODULE_LICENSE("GPL");
>

Re: [PATCH v3] iio: add Bosch BMA180 acceleration sensor driver

[Oleksandr Kravchenko]

On Thu, Aug 15, 2013 at 1:22 PM, Jonathan Cameron <jic23@kernel.org> wrote:
> On 08/13/13 16:44, Oleksandr Kravchenko wrote:
>> This patch adds IIO driver for Bosch BMA180 triaxial
>> acceleration sensor.
>> http://dlnmh9ip6v2uc.cloudfront.net/datasheets/
>>               Sensors/Accelerometers/BST-BMA180-DS000-07_2.pdf
>>
>> Signed-off-by: Oleksandr Kravchenko <o.v.kravchenko@globallogic.com>
> Hi,
>
> Firstly, just a thought (I haven't made up my mind whether it is a good idea or
> not!) but you could use devm_kzalloc for data->buff and hence avoid having
> to care about freeing it in the remove function.  Update scan mode isn't
> a particularly fast path so I doubt the small overhead will matter.
Thanks, it is a good idea.

>
> Otherwise, the abi additions need documenting iff they don't fit within
> existing ABI. If they do then they need to match existing ABI.
>
> Of those, 'mode' is rather device specific and could probably do with
> a more detailed name.  The only 'generic' way to do it would be to make the
> channel type attributes writable and treat it as a resolution control rather
> than a noise/power trade off.  Uggly though so perhaps what you have makes
> sense.  We can always add a more generic way of controlling this if it
> starts turning up in lots of devices (keeping this method of course to avoid
> breaking ABI).
Ok, I'll change 'mode' to 'power_mode' and document it in ABI.
>
> 'bandwidth' is already (I think) covered by the ABI.  For the bandwidth optoins you have enabled we are talking low pass
> filters and presumably their 3db point.
> In Documentation/ABI/testing/sysfs-bus-iio you will find in_accel_filter_low_pass_3db_frequency. My filter theory is
> rather rusty (not sure it was
> every anything else ;). Hence I'm not entirely sure how to work
> out the 3db frequency from the 'pole frequency' if they are not infact
> the same thing..
You are right. In my case 'bandwidth' is low path filter. I'll change my driver
accordingly. But how can I declare available values?
If I do it in next way:
    static IIO_CONST_ATTR(in_accel0_filter_low_pass_3db_frequency_available,
BMA180_BW_AVAILABLE);
it will lock so ugly in the code and sysfs...

>
> Otherwise, the driver looks good to me.
>
> Jonathan
>> ---
>>  .../devicetree/bindings/iio/accel/bma180.txt       |   24 +
>>  drivers/iio/accel/Kconfig                          |   12 +
>>  drivers/iio/accel/Makefile                         |    2 +
>>  drivers/iio/accel/bma180.c                         |  689 ++++++++++++++++++++
>>  4 files changed, 727 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/iio/accel/bma180.txt
>>  create mode 100644 drivers/iio/accel/bma180.c
>>
>> diff --git a/Documentation/devicetree/bindings/iio/accel/bma180.txt b/Documentation/devicetree/bindings/iio/accel/bma180.txt
>> new file mode 100644
>> index 0000000..c593357
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/iio/accel/bma180.txt
>> @@ -0,0 +1,24 @@
>> +* Bosch BMA180 triaxial acceleration sensor
>> +
>> +http://omapworld.com/BMA180_111_1002839.pdf
>> +
>> +Required properties:
>> +
>> +  - compatible : should be "bosch,bma180"
>> +  - reg : the I2C address of the sensor
>> +
>> +Optional properties:
>> +
>> +  - interrupt-parent : should be the phandle for the interrupt controller
>> +
>> +  - interrupts : interrupt mapping for GPIO IRQ, it should by configured with
>> +             flags IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_EDGE_RISING
>> +
>> +Example:
>> +
>> +bma180@40 {
>> +     compatible = "bosch,bma180";
>> +     reg = <0x40>;
>> +     interrupt-parent = <&gpio6>;
>> +     interrupts = <18 (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_EDGE_RISING)>;
>> +};
>> diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
>> index 719d83f..bd9d581 100644
>> --- a/drivers/iio/accel/Kconfig
>> +++ b/drivers/iio/accel/Kconfig
>> @@ -3,6 +3,18 @@
>>  #
>>  menu "Accelerometers"
>>
>> +config BMA180
>> +     tristate "Bosch BMA180 3-Axis Accelerometer Driver"
>> +     depends on I2C
>> +     select IIO_BUFFER
>> +     select IIO_TRIGGERED_BUFFER
>> +     help
>> +       Say Y here if you want to build a driver for the Bosch BMA180
>> +       triaxial acceleration sensor.
>> +
>> +       To compile this driver as a module, choose M here: the
>> +       module will be called bma180.
>> +
>>  config HID_SENSOR_ACCEL_3D
>>       depends on HID_SENSOR_HUB
>>       select IIO_BUFFER
>> diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile
>> index 87d8fa2..eb09d72 100644
>> --- a/drivers/iio/accel/Makefile
>> +++ b/drivers/iio/accel/Makefile
>> @@ -2,6 +2,8 @@
>>  # Makefile for industrial I/O accelerometer drivers
>>  #
>>
>> +obj-$(CONFIG_BMA180) += bma180.o
>> +
>>  obj-$(CONFIG_HID_SENSOR_ACCEL_3D) += hid-sensor-accel-3d.o
>>
>>  obj-$(CONFIG_IIO_ST_ACCEL_3AXIS) += st_accel.o
>> diff --git a/drivers/iio/accel/bma180.c b/drivers/iio/accel/bma180.c
>> new file mode 100644
>> index 0000000..23c738f
>> --- /dev/null
>> +++ b/drivers/iio/accel/bma180.c
>> @@ -0,0 +1,689 @@
>> +/*
>> + * bma180.c - IIO driver for Bosch BMA180 triaxial acceleration sensor
>> + *
>> + * Copyright 2013 Oleksandr Kravchenko <x0199363@ti.com>
>> + *
>> + * 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.
>> + */
>> +
>> +#include <linux/module.h>
>> +#include <linux/i2c.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/delay.h>
>> +#include <linux/of.h>
>> +#include <linux/bitops.h>
>> +#include <linux/slab.h>
>> +#include <linux/string.h>
>> +#include <linux/iio/iio.h>
>> +#include <linux/iio/sysfs.h>
>> +#include <linux/iio/buffer.h>
>> +#include <linux/iio/trigger.h>
>> +#include <linux/iio/trigger_consumer.h>
>> +#include <linux/iio/triggered_buffer.h>
>> +
>> +#define BMA180_DRV_NAME "bma180"
>> +#define BMA180_IRQ_NAME "bma180_event"
>> +
>> +/* Register set */
>> +#define BMA180_CHIP_ID               0x00 /* Need to distinguish BMA180 from other */
>> +#define BMA180_ACC_X_LSB     0x02 /* First of 6 registers of accel data */
>> +#define BMA180_CTRL_REG0     0x0d
>> +#define BMA180_RESET         0x10
>> +#define BMA180_BW_TCS                0x20
>> +#define BMA180_CTRL_REG3     0x21
>> +#define BMA180_TCO_Z         0x30
>> +#define BMA180_OFFSET_LSB1   0x35
>> +
>> +/* BMA180_CTRL_REG0 bits */
>> +#define BMA180_DIS_WAKE_UP   BIT(0) /* Disable wake up mode */
>> +#define BMA180_SLEEP         BIT(1) /* 1 - chip will sleep */
>> +#define BMA180_EE_W          BIT(4) /* Unlock writing to addr from 0x20 */
>> +#define BMA180_RESET_INT     BIT(6) /* Reset pending interrupts */
>> +
>> +/* BMA180_CTRL_REG3 bits */
>> +#define BMA180_NEW_DATA_INT  BIT(1) /* Intr every new accel data is ready */
>> +
>> +/* BMA180_OFFSET_LSB1 skipping mode bit */
>> +#define BMA180_SMP_SKIP              BIT(0)
>> +
>> +/* Bit masks for registers bit fields */
>> +#define BMA180_RANGE         0x0e /* Range of measured accel values*/
>> +#define BMA180_BW            0xf0 /* Accel bandwidth */
>> +#define BMA180_MODE_CONFIG   0x03 /* Config operation modes */
>> +
>> +/* We have to write this value in reset register to do soft reset */
>> +#define BMA180_RESET_VAL     0xb6
>> +
>> +#define BMA_180_ID_REG_VAL   0x03
>> +
>> +/* Chip operation modes */
>> +#define BMA180_LOW_NOISE     0x00
>> +#define BMA180_LOW_POWER     0x03
>> +
>> +#define BMA180_LOW_NOISE_STR "low_noise"
>> +#define BMA180_LOW_POWER_STR "low_power"
>> +
>> +/* Defaults values */
>> +#define BMA180_DEF_MODE              BMA180_LOW_NOISE_STR
>> +#define BMA180_DEF_BW                20
>> +#define BMA180_DEF_SCALE     250
>> +
>> +/* Available values */
>> +#define BMA180_MODE_AVAILABLE \
>> +     BMA180_LOW_NOISE_STR " " BMA180_LOW_POWER_STR
>> +#define BMA180_BW_AVAILABLE  "10 20 40 75 150 300"
>> +#define BMA180_SCALE_AVAILABLE \
>> +     "0.000130 0.000190 0.000250 0.000380 0.000500 0.000990 0.001980"
>> +
>> +struct bma180_data {
>> +     struct i2c_client *client;
>> +     struct iio_trigger *trig;
>> +     struct mutex mutex;
>> +     int sleep_state;
>> +     int scale;
>> +     int bw;
>> +     int mode;
>> +     char *buff;
>> +};
>> +
>> +enum bma180_axis {
>> +     AXIS_X,
>> +     AXIS_Y,
>> +     AXIS_Z,
>> +};
>> +
>> +static int bw_table[] = { 10, 20, 40, 75, 150, 300 }; /* Hz */
>> +static int scale_table[] = { 130, 190, 250, 380, 500, 990, 1980 };
>> +
>> +static int bma180_get_acc_reg(struct bma180_data *data, enum bma180_axis axis)
>> +{
>> +     u8 reg = BMA180_ACC_X_LSB + axis * 2;
>> +     int ret;
>> +
>> +     if (data->sleep_state)
>> +             return -EBUSY;
>> +
>> +     ret = i2c_smbus_read_word_data(data->client, reg);
>> +     if (ret < 0)
>> +             dev_err(&data->client->dev,
>> +                     "failed to read accel_%c registers\n", 'x' + axis);
>> +
>> +     return ret;
>> +}
>> +
>> +static int bma180_set_bits(struct bma180_data *data, u8 reg, u8 mask, u8 val)
>> +{
>> +     int ret = i2c_smbus_read_byte_data(data->client, reg);
>> +     u8 reg_val = (ret & ~mask) | (val << (ffs(mask) - 1));
>> +
>> +     if (ret < 0)
>> +             return ret;
>> +
>> +     return i2c_smbus_write_byte_data(data->client, reg, reg_val);
>> +}
>> +
>> +static int bma180_reset_intr(struct bma180_data *data)
>> +{
>> +     int ret = bma180_set_bits(data, BMA180_CTRL_REG0, BMA180_RESET_INT, 1);
>> +
>> +     if (ret)
>> +             dev_err(&data->client->dev, "failed to reset interrupt\n");
>> +
>> +     return ret;
>> +}
>> +
>> +static int bma180_set_new_data_intr_state(struct bma180_data *data, int state)
>> +{
>> +     u8 reg_val = state ? BMA180_NEW_DATA_INT : 0x00;
>> +     int ret = i2c_smbus_write_byte_data(data->client, BMA180_CTRL_REG3,
>> +                     reg_val);
>> +
>> +     if (ret)
>> +             goto err;
>> +     ret = bma180_reset_intr(data);
>> +     if (ret)
>> +             goto err;
>> +
>> +     return 0;
>> +
>> +err:
>> +     dev_err(&data->client->dev,
>> +             "failed to set new data interrupt state %d\n", state);
>> +     return ret;
>> +}
>> +
>> +static int bma180_set_sleep_state(struct bma180_data *data, int state)
>> +{
>> +     int ret = bma180_set_bits(data, BMA180_CTRL_REG0, BMA180_SLEEP, state);
>> +
>> +     if (ret) {
>> +             dev_err(&data->client->dev,
>> +                     "failed to set sleep state %d\n", state);
>> +             return ret;
>> +     }
>> +     data->sleep_state = state;
>> +
>> +     return 0;
>> +}
>> +
>> +static int bma180_set_ee_writing_state(struct bma180_data *data, int state)
>> +{
>> +     int ret = bma180_set_bits(data, BMA180_CTRL_REG0, BMA180_EE_W, state);
>> +
>> +     if (ret)
>> +             dev_err(&data->client->dev,
>> +                     "failed to set ee writing state %d\n", state);
>> +
>> +     return ret;
>> +}
>> +
>> +static int bma180_set_bw(struct bma180_data *data, int val)
>> +{
>> +     int ret, i;
>> +
>> +     if (data->sleep_state)
>> +             return -EBUSY;
>> +
>> +     for (i = 0; i < ARRAY_SIZE(bw_table); ++i) {
>> +             if (bw_table[i] == val) {
>> +                     ret = bma180_set_bits(data,
>> +                                     BMA180_BW_TCS, BMA180_BW, i);
>> +                     if (ret) {
>> +                             dev_err(&data->client->dev,
>> +                                     "failed to set bandwidth\n");
>> +                             return ret;
>> +                     }
>> +                     data->bw = val;
>> +                     return 0;
>> +             }
>> +     }
>> +
>> +     return -EINVAL;
>> +}
>> +
>> +static int bma180_set_scale(struct bma180_data *data, int val)
>> +{
>> +     int ret, i;
>> +
>> +     if (data->sleep_state)
>> +             return -EBUSY;
>> +
>> +     for (i = 0; i < ARRAY_SIZE(scale_table); ++i)
>> +             if (scale_table[i] == val) {
>> +                     ret = bma180_set_bits(data,
>> +                                     BMA180_OFFSET_LSB1, BMA180_RANGE, i);
>> +                     if (ret) {
>> +                             dev_err(&data->client->dev,
>> +                                     "failed to set scale\n");
>> +                             return ret;
>> +                     }
>> +                     data->scale = val;
>> +                     return 0;
>> +             }
>> +
>> +     return -EINVAL;
>> +}
>> +
>> +static int bma180_set_mode(struct bma180_data *data, const char *str)
>> +{
>> +     u8 reg_val;
>> +     int ret;
>> +
>> +     if (!strcmp(str, BMA180_LOW_NOISE_STR "\n"))
>> +             reg_val = BMA180_LOW_NOISE;
>> +     else if (!strcmp(str, BMA180_LOW_POWER_STR "\n"))
>> +             reg_val = BMA180_LOW_POWER;
>> +     else
>> +             return -EINVAL;
>> +
>> +     ret = bma180_set_bits(data, BMA180_TCO_Z, BMA180_MODE_CONFIG, reg_val);
>> +     if (ret)
>> +             dev_err(&data->client->dev, "failed to set mode\n");
>> +
>> +     data->mode = reg_val;
>> +
>> +     return ret;
>> +}
>> +
>> +static int bma180_soft_reset(struct bma180_data *data)
>> +{
>> +     int ret = i2c_smbus_write_byte_data(data->client,
>> +                     BMA180_RESET, BMA180_RESET_VAL);
>> +
>> +     if (ret)
>> +             dev_err(&data->client->dev, "failed to reset the chip\n");
>> +
>> +     return ret;
>> +}
>> +
>> +static int bma180_chip_init(struct bma180_data *data)
>> +{
>> +     /* Try to read chip_id register. It must return 0x03. */
>> +     int ret = i2c_smbus_read_byte_data(data->client, BMA180_CHIP_ID);
>> +
>> +     if (ret < 0)
>> +             goto err;
>> +     if (ret != BMA_180_ID_REG_VAL) {
>> +             ret = -ENODEV;
>> +             goto err;
>> +     }
>> +
>> +     ret = bma180_soft_reset(data);
>> +     if (ret)
>> +             goto err;
>> +     /*
>> +      * No serial transaction should occur within minimum 10 us
>> +      * after soft_reset command
>> +      */
>> +     msleep(20);
>> +
>> +     ret = bma180_set_bits(data, BMA180_CTRL_REG0, BMA180_DIS_WAKE_UP, 1);
>> +     if (ret)
>> +             goto err;
>> +     ret = bma180_set_ee_writing_state(data, 1);
>> +     if (ret)
>> +             goto err;
>> +     ret = bma180_set_new_data_intr_state(data, 0);
>> +     if (ret)
>> +             goto err;
>> +     ret = bma180_set_bits(data, BMA180_OFFSET_LSB1, BMA180_SMP_SKIP, 1);
>> +     if (ret)
>> +             goto err;
>> +     ret = bma180_set_mode(data, BMA180_DEF_MODE "\n");
>> +     if (ret)
>> +             goto err;
>> +     ret = bma180_set_bw(data, BMA180_DEF_BW);
>> +     if (ret)
>> +             goto err;
>> +     ret = bma180_set_scale(data, BMA180_DEF_SCALE);
>> +     if (ret)
>> +             goto err;
>> +
>> +     return 0;
>> +
>> +err:
>> +     dev_err(&data->client->dev, "failed to init the chip\n");
>> +     return ret;
>> +}
>> +
>> +static void bma180_chip_disable(struct bma180_data *data)
>> +{
>> +     if (bma180_set_new_data_intr_state(data, 0))
>> +             goto err;
>> +     if (bma180_set_ee_writing_state(data, 0))
>> +             goto err;
>> +     if (bma180_set_sleep_state(data, 1))
>> +             goto err;
>> +
>> +     return;
>> +
>> +err:
>> +     dev_err(&data->client->dev, "failed to disable the chip\n");
>> +}
>> +
>> +static ssize_t bma180_read_mode_config(struct device *dev,
>> +             struct device_attribute *attr, char *buf)
>> +{
>> +     struct iio_dev *indio_dev = dev_to_iio_dev(dev);
>> +     struct bma180_data *data = iio_priv(indio_dev);
>> +
>> +     return sprintf(buf, "%s\n",
>> +                     data->mode ?
>> +                     BMA180_LOW_POWER_STR : BMA180_LOW_NOISE_STR);
>> +}
>> +
>> +static ssize_t bma180_write_mode_config(struct device *dev,
>> +             struct device_attribute *attr, const char *buf, size_t len)
>> +{
>> +     struct iio_dev *indio_dev = dev_to_iio_dev(dev);
>> +     struct bma180_data *data = iio_priv(indio_dev);
>> +     int ret;
>> +
>> +     mutex_lock(&data->mutex);
>> +     ret = bma180_set_mode(data, buf);
>> +     mutex_unlock(&data->mutex);
>> +
>> +     return ret ? ret : len;
>> +}
>> +
>> +static ssize_t bma180_read_bw_config(struct device *dev,
>> +             struct device_attribute *attr, char *buf)
>> +{
>> +     struct iio_dev *indio_dev = dev_to_iio_dev(dev);
>> +     struct bma180_data *data = iio_priv(indio_dev);
>> +
>> +     return sprintf(buf, "%d\n", data->bw);
>> +}
>> +
>> +static ssize_t bma180_write_bw_config(struct device *dev,
>> +             struct device_attribute *attr, const char *buf, size_t len)
>> +{
>> +     struct iio_dev *indio_dev = dev_to_iio_dev(dev);
>> +     struct bma180_data *data = iio_priv(indio_dev);
>> +     long val;
>> +     int ret = kstrtol(buf, 10, &val);
>> +
>> +     if (ret)
>> +             return ret;
>> +
>> +     mutex_lock(&data->mutex);
>> +     ret = bma180_set_bw(data, val);
>> +     mutex_unlock(&data->mutex);
>> +
>> +     return ret ? ret : len;
>> +}
>> +
>> +static IIO_DEVICE_ATTR(mode, S_IRUGO | S_IWUSR, bma180_read_mode_config,
>> +             bma180_write_mode_config, 0);
>> +static IIO_CONST_ATTR(mode_available, BMA180_MODE_AVAILABLE);
>> +static IIO_DEVICE_ATTR(bandwidth, S_IRUGO | S_IWUSR, bma180_read_bw_config,
>> +             bma180_write_bw_config, 0);
>> +static IIO_CONST_ATTR(bandwidth_available, BMA180_BW_AVAILABLE);
>> +static IIO_CONST_ATTR(scale_available, BMA180_SCALE_AVAILABLE);
>> +
>> +static struct attribute *bma180_attributes[] = {
>> +     &iio_dev_attr_mode.dev_attr.attr,
>> +     &iio_const_attr_mode_available.dev_attr.attr,
> These need documenting if they don't fit within standard abi options.
>> +     &iio_dev_attr_bandwidth.dev_attr.attr,
>> +     &iio_const_attr_bandwidth_available.dev_attr.attr,
> bandwidth = 3db frequency?
>> +     &iio_const_attr_scale_available.dev_attr.attr,
>> +     NULL,
>> +};
>> +
>> +static const struct attribute_group bma180_attrs_group = {
>> +     .attrs = bma180_attributes,
>> +};
>> +
>> +static int bma180_read_raw(struct iio_dev *indio_dev,
>> +             struct iio_chan_spec const *chan, int *val, int *val2,
>> +             long mask)
>> +{
>> +     struct bma180_data *data = iio_priv(indio_dev);
>> +     int ret;
>> +
>> +     switch (mask) {
>> +     case IIO_CHAN_INFO_RAW:
>> +             mutex_lock(&data->mutex);
>> +             if (iio_buffer_enabled(indio_dev))
>> +                     ret = -EBUSY;
>> +             else
>> +                     ret = bma180_get_acc_reg(data, chan->scan_index);
>> +             mutex_unlock(&data->mutex);
>> +             if (ret < 0)
>> +                     return ret;
>> +             *val = (s16)ret >> chan->scan_type.shift;
>> +             return IIO_VAL_INT;
>> +     case IIO_CHAN_INFO_SCALE:
>> +             *val = 0;
>> +             *val2 = data->scale;
>> +             return IIO_VAL_INT_PLUS_MICRO;
>> +     default:
>> +             return -EINVAL;
>> +     }
>> +}
>> +
>> +static int bma180_write_raw(struct iio_dev *indio_dev,
>> +             struct iio_chan_spec const *chan, int val, int val2, long mask)
>> +{
>> +     struct bma180_data *data = iio_priv(indio_dev);
>> +     int ret;
>> +
>> +     if (mask != IIO_CHAN_INFO_SCALE || val)
>> +             return -EINVAL;
>> +
>> +     mutex_lock(&data->mutex);
>> +     ret = bma180_set_scale(data, val2);
>> +     mutex_unlock(&data->mutex);
>> +
>> +     return ret;
>> +}
>> +
>> +static int bma180_update_scan_mode(struct iio_dev *indio_dev,
>> +             const unsigned long *scan_mask)
>> +{
>> +     struct bma180_data *data = iio_priv(indio_dev);
>> +
>> +     kfree(data->buff);
>> +     data->buff = kmalloc(indio_dev->scan_bytes, GFP_KERNEL);
>> +     if (!data->buff)
>> +             return -ENOMEM;
>> +
>> +     return 0;
>> +}
>> +
>> +static const struct iio_info bma180_info = {
>> +     .attrs                  = &bma180_attrs_group,
>> +     .read_raw               = bma180_read_raw,
>> +     .write_raw              = bma180_write_raw,
>> +     .update_scan_mode       = bma180_update_scan_mode,
>> +     .driver_module          = THIS_MODULE,
>> +};
>> +
>> +#define BMA180_CHANNEL(_index) {                             \
>> +     .type = IIO_ACCEL,                                      \
>> +     .indexed = 1,                                           \
>> +     .channel = (_index),                                    \
>> +     .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),           \
>> +     .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),   \
>> +     .scan_index = (_index),                                 \
>> +     .scan_type = IIO_ST('s', 14, 16, 2),                    \
>> +}
>> +
>> +static const struct iio_chan_spec bma180_channels[] = {
>> +     BMA180_CHANNEL(AXIS_X),
>> +     BMA180_CHANNEL(AXIS_Y),
>> +     BMA180_CHANNEL(AXIS_Z),
>> +     IIO_CHAN_SOFT_TIMESTAMP(4),
>> +};
>> +
>> +static irqreturn_t bma180_trigger_handler(int irq, void *p)
>> +{
>> +     struct iio_poll_func *pf = p;
>> +     struct iio_dev *indio_dev = pf->indio_dev;
>> +     struct bma180_data *data = iio_priv(indio_dev);
>> +     int bit, ret, i = 0;
>> +
>> +     mutex_lock(&data->mutex);
>> +     if (indio_dev->scan_timestamp) {
>> +             ret = indio_dev->scan_bytes / sizeof(s64) - 1;
>> +             ((s64 *)data->buff)[ret] = iio_get_time_ns();
>> +     }
>> +
>> +     for_each_set_bit(bit, indio_dev->buffer->scan_mask,
>> +                      indio_dev->masklength) {
>> +             ret = bma180_get_acc_reg(data, bit);
>> +             if (ret < 0) {
>> +                     mutex_unlock(&data->mutex);
>> +                     goto err;
>> +             }
>> +             ((s16 *)data->buff)[i++] = ret;
>> +     }
>> +     mutex_unlock(&data->mutex);
>> +
>> +     iio_push_to_buffers(indio_dev, (u8 *)data->buff);
>> +err:
>> +     iio_trigger_notify_done(indio_dev->trig);
>> +
>> +     return IRQ_HANDLED;
>> +}
>> +
>> +static int bma180_data_rdy_trigger_set_state(struct iio_trigger *trig,
>> +             bool state)
>> +{
>> +     struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
>> +     struct bma180_data *data = iio_priv(indio_dev);
>> +
>> +     return bma180_set_new_data_intr_state(data, state);
>> +}
>> +
>> +static int bma180_trig_try_reen(struct iio_trigger *trig)
>> +{
>> +     struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
>> +     struct bma180_data *data = iio_priv(indio_dev);
>> +
>> +     return bma180_reset_intr(data);
>> +}
>> +
>> +static const struct iio_trigger_ops bma180_trigger_ops = {
>> +     .set_trigger_state = bma180_data_rdy_trigger_set_state,
>> +     .try_reenable = bma180_trig_try_reen,
>> +     .owner = THIS_MODULE,
>> +};
>> +
>> +static int bma180_probe(struct i2c_client *client,
>> +             const struct i2c_device_id *id)
>> +{
>> +     struct bma180_data *data;
>> +     struct iio_dev *indio_dev;
>> +     struct iio_trigger *trig;
>> +     int ret;
>> +
>> +     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;
>> +
>> +     ret = bma180_chip_init(data);
>> +     if (ret < 0)
>> +             goto err_chip_disable;
>> +
>> +     mutex_init(&data->mutex);
>> +
>> +     indio_dev->dev.parent = &client->dev;
>> +     indio_dev->channels = bma180_channels;
>> +     indio_dev->num_channels = ARRAY_SIZE(bma180_channels);
>> +     indio_dev->name = BMA180_DRV_NAME;
>> +     indio_dev->modes = INDIO_DIRECT_MODE;
>> +     indio_dev->info = &bma180_info;
>> +
>> +     trig = iio_trigger_alloc("%s-dev%d", indio_dev->name, indio_dev->id);
>> +     if (!trig) {
>> +             ret = -ENOMEM;
>> +             goto err_chip_disable;
>> +     }
>> +
>> +     ret = devm_request_irq(&client->dev, client->irq,
>> +                     iio_trigger_generic_data_rdy_poll,
>> +                     IRQF_TRIGGER_RISING, BMA180_IRQ_NAME, trig);
>> +     if (ret) {
>> +             dev_err(&client->dev, "unable to request IRQ\n");
>> +             goto err_trigger_free;
>> +     }
>> +
>> +     trig->dev.parent = &client->dev;
>> +     trig->ops = &bma180_trigger_ops;
>> +     iio_trigger_set_drvdata(trig, indio_dev);
>> +     data->trig = trig;
>> +     indio_dev->trig = trig;
>> +
>> +     ret = iio_trigger_register(trig);
>> +     if (ret)
>> +             goto err_trigger_free;
>> +
>> +     ret = iio_triggered_buffer_setup(indio_dev, NULL,
>> +                     bma180_trigger_handler, NULL);
>> +     if (ret < 0) {
>> +             dev_err(&client->dev, "unable to setup iio triggered buffer\n");
>> +             goto err_trigger_unregister;
>> +     }
>> +
>> +     ret = iio_device_register(indio_dev);
>> +     if (ret < 0) {
>> +             dev_err(&client->dev, "unable to register iio device\n");
>> +             goto err_buffer_cleanup;
>> +     }
>> +
>> +     return 0;
>> +
>> +err_buffer_cleanup:
>> +     iio_triggered_buffer_cleanup(indio_dev);
>> +err_trigger_unregister:
>> +     iio_trigger_unregister(trig);
>> +err_trigger_free:
>> +     iio_trigger_free(trig);
>> +err_chip_disable:
>> +     bma180_chip_disable(data);
>> +
>> +     return ret;
>> +}
>> +
>> +static int bma180_remove(struct i2c_client *client)
>> +{
>> +     struct iio_dev *indio_dev = i2c_get_clientdata(client);
>> +     struct bma180_data *data = iio_priv(indio_dev);
>> +
>> +     iio_device_unregister(indio_dev);
>> +     iio_triggered_buffer_cleanup(indio_dev);
>> +     iio_trigger_unregister(data->trig);
>> +     iio_trigger_free(data->trig);
>> +     kfree(data->buff);
>> +
>> +     mutex_lock(&data->mutex);
>> +     bma180_chip_disable(data);
>> +     mutex_unlock(&data->mutex);
>> +
>> +     return 0;
>> +}
>> +
>> +#ifdef CONFIG_PM_SLEEP
>> +static int bma180_suspend(struct device *dev)
>> +{
>> +     struct iio_dev *indio_dev = dev_to_iio_dev(dev);
>> +     struct bma180_data *data = iio_priv(indio_dev);
>> +     int ret;
>> +
>> +     mutex_lock(&data->mutex);
>> +     ret = bma180_set_sleep_state(data, 1);
>> +     mutex_unlock(&data->mutex);
>> +
>> +     return ret;
>> +}
>> +
>> +static int bma180_resume(struct device *dev)
>> +{
>> +     struct iio_dev *indio_dev = dev_to_iio_dev(dev);
>> +     struct bma180_data *data = iio_priv(indio_dev);
>> +     int ret;
>> +
>> +     mutex_lock(&data->mutex);
>> +     ret = bma180_set_sleep_state(data, 0);
>> +     mutex_unlock(&data->mutex);
>> +
>> +     return ret;
>> +}
>> +
>> +static SIMPLE_DEV_PM_OPS(bma180_pm_ops, bma180_suspend, bma180_resume);
>> +#define BMA180_PM_OPS (&bma180_pm_ops)
>> +#else
>> +#define BMA180_PM_OPS NULL
>> +#endif
>> +
>> +static struct i2c_device_id bma180_id[] = {
>> +     { BMA180_DRV_NAME, 0 },
>> +     { }
>> +};
>> +
>> +MODULE_DEVICE_TABLE(i2c, bma180_id);
>> +
>> +static struct i2c_driver bma180_driver = {
>> +     .driver = {
>> +             .name   = BMA180_DRV_NAME,
>> +             .owner  = THIS_MODULE,
>> +             .pm     = BMA180_PM_OPS,
>> +     },
>> +     .probe          = bma180_probe,
>> +     .remove         = bma180_remove,
>> +     .id_table       = bma180_id,
>> +};
>> +
>> +module_i2c_driver(bma180_driver);
>> +
>> +MODULE_AUTHOR("Kravchenko Oleksandr <x0199363@ti.com>");
>> +MODULE_AUTHOR("Texas Instruments, Inc.");
>> +MODULE_DESCRIPTION("Bosch BMA180 triaxial acceleration sensor");
>> +MODULE_LICENSE("GPL");

Re: [PATCH v3] iio: add Bosch BMA180 acceleration sensor driver

[Jonathan Cameron]

On 08/15/13 14:41, Oleksandr Kravchenko wrote:
> On Thu, Aug 15, 2013 at 1:22 PM, Jonathan Cameron <jic23@kernel.org> wrote:
>> On 08/13/13 16:44, Oleksandr Kravchenko wrote:
>>> This patch adds IIO driver for Bosch BMA180 triaxial
>>> acceleration sensor.
>>> http://dlnmh9ip6v2uc.cloudfront.net/datasheets/
>>>               Sensors/Accelerometers/BST-BMA180-DS000-07_2.pdf
>>>
>>> Signed-off-by: Oleksandr Kravchenko <o.v.kravchenko@globallogic.com>
>> Hi,
>>
>> Firstly, just a thought (I haven't made up my mind whether it is a good idea or
>> not!) but you could use devm_kzalloc for data->buff and hence avoid having
>> to care about freeing it in the remove function.  Update scan mode isn't
>> a particularly fast path so I doubt the small overhead will matter.
> Thanks, it is a good idea.
> 
>>
>> Otherwise, the abi additions need documenting iff they don't fit within
>> existing ABI. If they do then they need to match existing ABI.
>>
>> Of those, 'mode' is rather device specific and could probably do with
>> a more detailed name.  The only 'generic' way to do it would be to make the
>> channel type attributes writable and treat it as a resolution control rather
>> than a noise/power trade off.  Uggly though so perhaps what you have makes
>> sense.  We can always add a more generic way of controlling this if it
>> starts turning up in lots of devices (keeping this method of course to avoid
>> breaking ABI).
> Ok, I'll change 'mode' to 'power_mode' and document it in ABI.
>>
>> 'bandwidth' is already (I think) covered by the ABI.  For the bandwidth optoins you have enabled we are talking low pass
>> filters and presumably their 3db point.
>> In Documentation/ABI/testing/sysfs-bus-iio you will find in_accel_filter_low_pass_3db_frequency. My filter theory is
>> rather rusty (not sure it was
>> every anything else ;). Hence I'm not entirely sure how to work
>> out the 3db frequency from the 'pole frequency' if they are not infact
>> the same thing..
> You are right. In my case 'bandwidth' is low path filter. I'll change my driver
> accordingly. But how can I declare available values?
> If I do it in next way:
>     static IIO_CONST_ATTR(in_accel0_filter_low_pass_3db_frequency_available,
> BMA180_BW_AVAILABLE);
Not shared across all channels?  If it is then
in_accel_filter_low_pass_3db_frequency_available it is...
> it will lock so ugly in the code and sysfs...

yeah.  There are plans to clean that sort of thing up.   I keep mentioning them
and never getting them done though.

In brief drivers will  be able to provide and additional callback
which will then return pointers to arrays containing all the numbers to
specify the 'range' of values any parameter in info_mask can take
(note this includes the raw and processed values as well as the other bits).

I sketch out how we could do this from time to time and dont' quite get around to
doing it.
> 
>>
>> Otherwise, the driver looks good to me.
>>
>> Jonathan
>>> ---
>>>  .../devicetree/bindings/iio/accel/bma180.txt       |   24 +
>>>  drivers/iio/accel/Kconfig                          |   12 +
>>>  drivers/iio/accel/Makefile                         |    2 +
>>>  drivers/iio/accel/bma180.c                         |  689 ++++++++++++++++++++
>>>  4 files changed, 727 insertions(+)
>>>  create mode 100644 Documentation/devicetree/bindings/iio/accel/bma180.txt
>>>  create mode 100644 drivers/iio/accel/bma180.c
>>>
>>> diff --git a/Documentation/devicetree/bindings/iio/accel/bma180.txt b/Documentation/devicetree/bindings/iio/accel/bma180.txt
>>> new file mode 100644
>>> index 0000000..c593357
>>> --- /dev/null
>>> +++ b/Documentation/devicetree/bindings/iio/accel/bma180.txt
>>> @@ -0,0 +1,24 @@
>>> +* Bosch BMA180 triaxial acceleration sensor
>>> +
>>> +http://omapworld.com/BMA180_111_1002839.pdf
>>> +
>>> +Required properties:
>>> +
>>> +  - compatible : should be "bosch,bma180"
>>> +  - reg : the I2C address of the sensor
>>> +
>>> +Optional properties:
>>> +
>>> +  - interrupt-parent : should be the phandle for the interrupt controller
>>> +
>>> +  - interrupts : interrupt mapping for GPIO IRQ, it should by configured with
>>> +             flags IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_EDGE_RISING
>>> +
>>> +Example:
>>> +
>>> +bma180@40 {
>>> +     compatible = "bosch,bma180";
>>> +     reg = <0x40>;
>>> +     interrupt-parent = <&gpio6>;
>>> +     interrupts = <18 (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_EDGE_RISING)>;
>>> +};
>>> diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
>>> index 719d83f..bd9d581 100644
>>> --- a/drivers/iio/accel/Kconfig
>>> +++ b/drivers/iio/accel/Kconfig
>>> @@ -3,6 +3,18 @@
>>>  #
>>>  menu "Accelerometers"
>>>
>>> +config BMA180
>>> +     tristate "Bosch BMA180 3-Axis Accelerometer Driver"
>>> +     depends on I2C
>>> +     select IIO_BUFFER
>>> +     select IIO_TRIGGERED_BUFFER
>>> +     help
>>> +       Say Y here if you want to build a driver for the Bosch BMA180
>>> +       triaxial acceleration sensor.
>>> +
>>> +       To compile this driver as a module, choose M here: the
>>> +       module will be called bma180.
>>> +
>>>  config HID_SENSOR_ACCEL_3D
>>>       depends on HID_SENSOR_HUB
>>>       select IIO_BUFFER
>>> diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile
>>> index 87d8fa2..eb09d72 100644
>>> --- a/drivers/iio/accel/Makefile
>>> +++ b/drivers/iio/accel/Makefile
>>> @@ -2,6 +2,8 @@
>>>  # Makefile for industrial I/O accelerometer drivers
>>>  #
>>>
>>> +obj-$(CONFIG_BMA180) += bma180.o
>>> +
>>>  obj-$(CONFIG_HID_SENSOR_ACCEL_3D) += hid-sensor-accel-3d.o
>>>
>>>  obj-$(CONFIG_IIO_ST_ACCEL_3AXIS) += st_accel.o
>>> diff --git a/drivers/iio/accel/bma180.c b/drivers/iio/accel/bma180.c
>>> new file mode 100644
>>> index 0000000..23c738f
>>> --- /dev/null
>>> +++ b/drivers/iio/accel/bma180.c
>>> @@ -0,0 +1,689 @@
>>> +/*
>>> + * bma180.c - IIO driver for Bosch BMA180 triaxial acceleration sensor
>>> + *
>>> + * Copyright 2013 Oleksandr Kravchenko <x0199363@ti.com>
>>> + *
>>> + * 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.
>>> + */
>>> +
>>> +#include <linux/module.h>
>>> +#include <linux/i2c.h>
>>> +#include <linux/interrupt.h>
>>> +#include <linux/delay.h>
>>> +#include <linux/of.h>
>>> +#include <linux/bitops.h>
>>> +#include <linux/slab.h>
>>> +#include <linux/string.h>
>>> +#include <linux/iio/iio.h>
>>> +#include <linux/iio/sysfs.h>
>>> +#include <linux/iio/buffer.h>
>>> +#include <linux/iio/trigger.h>
>>> +#include <linux/iio/trigger_consumer.h>
>>> +#include <linux/iio/triggered_buffer.h>
>>> +
>>> +#define BMA180_DRV_NAME "bma180"
>>> +#define BMA180_IRQ_NAME "bma180_event"
>>> +
>>> +/* Register set */
>>> +#define BMA180_CHIP_ID               0x00 /* Need to distinguish BMA180 from other */
>>> +#define BMA180_ACC_X_LSB     0x02 /* First of 6 registers of accel data */
>>> +#define BMA180_CTRL_REG0     0x0d
>>> +#define BMA180_RESET         0x10
>>> +#define BMA180_BW_TCS                0x20
>>> +#define BMA180_CTRL_REG3     0x21
>>> +#define BMA180_TCO_Z         0x30
>>> +#define BMA180_OFFSET_LSB1   0x35
>>> +
>>> +/* BMA180_CTRL_REG0 bits */
>>> +#define BMA180_DIS_WAKE_UP   BIT(0) /* Disable wake up mode */
>>> +#define BMA180_SLEEP         BIT(1) /* 1 - chip will sleep */
>>> +#define BMA180_EE_W          BIT(4) /* Unlock writing to addr from 0x20 */
>>> +#define BMA180_RESET_INT     BIT(6) /* Reset pending interrupts */
>>> +
>>> +/* BMA180_CTRL_REG3 bits */
>>> +#define BMA180_NEW_DATA_INT  BIT(1) /* Intr every new accel data is ready */
>>> +
>>> +/* BMA180_OFFSET_LSB1 skipping mode bit */
>>> +#define BMA180_SMP_SKIP              BIT(0)
>>> +
>>> +/* Bit masks for registers bit fields */
>>> +#define BMA180_RANGE         0x0e /* Range of measured accel values*/
>>> +#define BMA180_BW            0xf0 /* Accel bandwidth */
>>> +#define BMA180_MODE_CONFIG   0x03 /* Config operation modes */
>>> +
>>> +/* We have to write this value in reset register to do soft reset */
>>> +#define BMA180_RESET_VAL     0xb6
>>> +
>>> +#define BMA_180_ID_REG_VAL   0x03
>>> +
>>> +/* Chip operation modes */
>>> +#define BMA180_LOW_NOISE     0x00
>>> +#define BMA180_LOW_POWER     0x03
>>> +
>>> +#define BMA180_LOW_NOISE_STR "low_noise"
>>> +#define BMA180_LOW_POWER_STR "low_power"
>>> +
>>> +/* Defaults values */
>>> +#define BMA180_DEF_MODE              BMA180_LOW_NOISE_STR
>>> +#define BMA180_DEF_BW                20
>>> +#define BMA180_DEF_SCALE     250
>>> +
>>> +/* Available values */
>>> +#define BMA180_MODE_AVAILABLE \
>>> +     BMA180_LOW_NOISE_STR " " BMA180_LOW_POWER_STR
>>> +#define BMA180_BW_AVAILABLE  "10 20 40 75 150 300"
>>> +#define BMA180_SCALE_AVAILABLE \
>>> +     "0.000130 0.000190 0.000250 0.000380 0.000500 0.000990 0.001980"
>>> +
>>> +struct bma180_data {
>>> +     struct i2c_client *client;
>>> +     struct iio_trigger *trig;
>>> +     struct mutex mutex;
>>> +     int sleep_state;
>>> +     int scale;
>>> +     int bw;
>>> +     int mode;
>>> +     char *buff;
>>> +};
>>> +
>>> +enum bma180_axis {
>>> +     AXIS_X,
>>> +     AXIS_Y,
>>> +     AXIS_Z,
>>> +};
>>> +
>>> +static int bw_table[] = { 10, 20, 40, 75, 150, 300 }; /* Hz */
>>> +static int scale_table[] = { 130, 190, 250, 380, 500, 990, 1980 };
>>> +
>>> +static int bma180_get_acc_reg(struct bma180_data *data, enum bma180_axis axis)
>>> +{
>>> +     u8 reg = BMA180_ACC_X_LSB + axis * 2;
>>> +     int ret;
>>> +
>>> +     if (data->sleep_state)
>>> +             return -EBUSY;
>>> +
>>> +     ret = i2c_smbus_read_word_data(data->client, reg);
>>> +     if (ret < 0)
>>> +             dev_err(&data->client->dev,
>>> +                     "failed to read accel_%c registers\n", 'x' + axis);
>>> +
>>> +     return ret;
>>> +}
>>> +
>>> +static int bma180_set_bits(struct bma180_data *data, u8 reg, u8 mask, u8 val)
>>> +{
>>> +     int ret = i2c_smbus_read_byte_data(data->client, reg);
>>> +     u8 reg_val = (ret & ~mask) | (val << (ffs(mask) - 1));
>>> +
>>> +     if (ret < 0)
>>> +             return ret;
>>> +
>>> +     return i2c_smbus_write_byte_data(data->client, reg, reg_val);
>>> +}
>>> +
>>> +static int bma180_reset_intr(struct bma180_data *data)
>>> +{
>>> +     int ret = bma180_set_bits(data, BMA180_CTRL_REG0, BMA180_RESET_INT, 1);
>>> +
>>> +     if (ret)
>>> +             dev_err(&data->client->dev, "failed to reset interrupt\n");
>>> +
>>> +     return ret;
>>> +}
>>> +
>>> +static int bma180_set_new_data_intr_state(struct bma180_data *data, int state)
>>> +{
>>> +     u8 reg_val = state ? BMA180_NEW_DATA_INT : 0x00;
>>> +     int ret = i2c_smbus_write_byte_data(data->client, BMA180_CTRL_REG3,
>>> +                     reg_val);
>>> +
>>> +     if (ret)
>>> +             goto err;
>>> +     ret = bma180_reset_intr(data);
>>> +     if (ret)
>>> +             goto err;
>>> +
>>> +     return 0;
>>> +
>>> +err:
>>> +     dev_err(&data->client->dev,
>>> +             "failed to set new data interrupt state %d\n", state);
>>> +     return ret;
>>> +}
>>> +
>>> +static int bma180_set_sleep_state(struct bma180_data *data, int state)
>>> +{
>>> +     int ret = bma180_set_bits(data, BMA180_CTRL_REG0, BMA180_SLEEP, state);
>>> +
>>> +     if (ret) {
>>> +             dev_err(&data->client->dev,
>>> +                     "failed to set sleep state %d\n", state);
>>> +             return ret;
>>> +     }
>>> +     data->sleep_state = state;
>>> +
>>> +     return 0;
>>> +}
>>> +
>>> +static int bma180_set_ee_writing_state(struct bma180_data *data, int state)
>>> +{
>>> +     int ret = bma180_set_bits(data, BMA180_CTRL_REG0, BMA180_EE_W, state);
>>> +
>>> +     if (ret)
>>> +             dev_err(&data->client->dev,
>>> +                     "failed to set ee writing state %d\n", state);
>>> +
>>> +     return ret;
>>> +}
>>> +
>>> +static int bma180_set_bw(struct bma180_data *data, int val)
>>> +{
>>> +     int ret, i;
>>> +
>>> +     if (data->sleep_state)
>>> +             return -EBUSY;
>>> +
>>> +     for (i = 0; i < ARRAY_SIZE(bw_table); ++i) {
>>> +             if (bw_table[i] == val) {
>>> +                     ret = bma180_set_bits(data,
>>> +                                     BMA180_BW_TCS, BMA180_BW, i);
>>> +                     if (ret) {
>>> +                             dev_err(&data->client->dev,
>>> +                                     "failed to set bandwidth\n");
>>> +                             return ret;
>>> +                     }
>>> +                     data->bw = val;
>>> +                     return 0;
>>> +             }
>>> +     }
>>> +
>>> +     return -EINVAL;
>>> +}
>>> +
>>> +static int bma180_set_scale(struct bma180_data *data, int val)
>>> +{
>>> +     int ret, i;
>>> +
>>> +     if (data->sleep_state)
>>> +             return -EBUSY;
>>> +
>>> +     for (i = 0; i < ARRAY_SIZE(scale_table); ++i)
>>> +             if (scale_table[i] == val) {
>>> +                     ret = bma180_set_bits(data,
>>> +                                     BMA180_OFFSET_LSB1, BMA180_RANGE, i);
>>> +                     if (ret) {
>>> +                             dev_err(&data->client->dev,
>>> +                                     "failed to set scale\n");
>>> +                             return ret;
>>> +                     }
>>> +                     data->scale = val;
>>> +                     return 0;
>>> +             }
>>> +
>>> +     return -EINVAL;
>>> +}
>>> +
>>> +static int bma180_set_mode(struct bma180_data *data, const char *str)
>>> +{
>>> +     u8 reg_val;
>>> +     int ret;
>>> +
>>> +     if (!strcmp(str, BMA180_LOW_NOISE_STR "\n"))
>>> +             reg_val = BMA180_LOW_NOISE;
>>> +     else if (!strcmp(str, BMA180_LOW_POWER_STR "\n"))
>>> +             reg_val = BMA180_LOW_POWER;
>>> +     else
>>> +             return -EINVAL;
>>> +
>>> +     ret = bma180_set_bits(data, BMA180_TCO_Z, BMA180_MODE_CONFIG, reg_val);
>>> +     if (ret)
>>> +             dev_err(&data->client->dev, "failed to set mode\n");
>>> +
>>> +     data->mode = reg_val;
>>> +
>>> +     return ret;
>>> +}
>>> +
>>> +static int bma180_soft_reset(struct bma180_data *data)
>>> +{
>>> +     int ret = i2c_smbus_write_byte_data(data->client,
>>> +                     BMA180_RESET, BMA180_RESET_VAL);
>>> +
>>> +     if (ret)
>>> +             dev_err(&data->client->dev, "failed to reset the chip\n");
>>> +
>>> +     return ret;
>>> +}
>>> +
>>> +static int bma180_chip_init(struct bma180_data *data)
>>> +{
>>> +     /* Try to read chip_id register. It must return 0x03. */
>>> +     int ret = i2c_smbus_read_byte_data(data->client, BMA180_CHIP_ID);
>>> +
>>> +     if (ret < 0)
>>> +             goto err;
>>> +     if (ret != BMA_180_ID_REG_VAL) {
>>> +             ret = -ENODEV;
>>> +             goto err;
>>> +     }
>>> +
>>> +     ret = bma180_soft_reset(data);
>>> +     if (ret)
>>> +             goto err;
>>> +     /*
>>> +      * No serial transaction should occur within minimum 10 us
>>> +      * after soft_reset command
>>> +      */
>>> +     msleep(20);
>>> +
>>> +     ret = bma180_set_bits(data, BMA180_CTRL_REG0, BMA180_DIS_WAKE_UP, 1);
>>> +     if (ret)
>>> +             goto err;
>>> +     ret = bma180_set_ee_writing_state(data, 1);
>>> +     if (ret)
>>> +             goto err;
>>> +     ret = bma180_set_new_data_intr_state(data, 0);
>>> +     if (ret)
>>> +             goto err;
>>> +     ret = bma180_set_bits(data, BMA180_OFFSET_LSB1, BMA180_SMP_SKIP, 1);
>>> +     if (ret)
>>> +             goto err;
>>> +     ret = bma180_set_mode(data, BMA180_DEF_MODE "\n");
>>> +     if (ret)
>>> +             goto err;
>>> +     ret = bma180_set_bw(data, BMA180_DEF_BW);
>>> +     if (ret)
>>> +             goto err;
>>> +     ret = bma180_set_scale(data, BMA180_DEF_SCALE);
>>> +     if (ret)
>>> +             goto err;
>>> +
>>> +     return 0;
>>> +
>>> +err:
>>> +     dev_err(&data->client->dev, "failed to init the chip\n");
>>> +     return ret;
>>> +}
>>> +
>>> +static void bma180_chip_disable(struct bma180_data *data)
>>> +{
>>> +     if (bma180_set_new_data_intr_state(data, 0))
>>> +             goto err;
>>> +     if (bma180_set_ee_writing_state(data, 0))
>>> +             goto err;
>>> +     if (bma180_set_sleep_state(data, 1))
>>> +             goto err;
>>> +
>>> +     return;
>>> +
>>> +err:
>>> +     dev_err(&data->client->dev, "failed to disable the chip\n");
>>> +}
>>> +
>>> +static ssize_t bma180_read_mode_config(struct device *dev,
>>> +             struct device_attribute *attr, char *buf)
>>> +{
>>> +     struct iio_dev *indio_dev = dev_to_iio_dev(dev);
>>> +     struct bma180_data *data = iio_priv(indio_dev);
>>> +
>>> +     return sprintf(buf, "%s\n",
>>> +                     data->mode ?
>>> +                     BMA180_LOW_POWER_STR : BMA180_LOW_NOISE_STR);
>>> +}
>>> +
>>> +static ssize_t bma180_write_mode_config(struct device *dev,
>>> +             struct device_attribute *attr, const char *buf, size_t len)
>>> +{
>>> +     struct iio_dev *indio_dev = dev_to_iio_dev(dev);
>>> +     struct bma180_data *data = iio_priv(indio_dev);
>>> +     int ret;
>>> +
>>> +     mutex_lock(&data->mutex);
>>> +     ret = bma180_set_mode(data, buf);
>>> +     mutex_unlock(&data->mutex);
>>> +
>>> +     return ret ? ret : len;
>>> +}
>>> +
>>> +static ssize_t bma180_read_bw_config(struct device *dev,
>>> +             struct device_attribute *attr, char *buf)
>>> +{
>>> +     struct iio_dev *indio_dev = dev_to_iio_dev(dev);
>>> +     struct bma180_data *data = iio_priv(indio_dev);
>>> +
>>> +     return sprintf(buf, "%d\n", data->bw);
>>> +}
>>> +
>>> +static ssize_t bma180_write_bw_config(struct device *dev,
>>> +             struct device_attribute *attr, const char *buf, size_t len)
>>> +{
>>> +     struct iio_dev *indio_dev = dev_to_iio_dev(dev);
>>> +     struct bma180_data *data = iio_priv(indio_dev);
>>> +     long val;
>>> +     int ret = kstrtol(buf, 10, &val);
>>> +
>>> +     if (ret)
>>> +             return ret;
>>> +
>>> +     mutex_lock(&data->mutex);
>>> +     ret = bma180_set_bw(data, val);
>>> +     mutex_unlock(&data->mutex);
>>> +
>>> +     return ret ? ret : len;
>>> +}
>>> +
>>> +static IIO_DEVICE_ATTR(mode, S_IRUGO | S_IWUSR, bma180_read_mode_config,
>>> +             bma180_write_mode_config, 0);
>>> +static IIO_CONST_ATTR(mode_available, BMA180_MODE_AVAILABLE);
>>> +static IIO_DEVICE_ATTR(bandwidth, S_IRUGO | S_IWUSR, bma180_read_bw_config,
>>> +             bma180_write_bw_config, 0);
>>> +static IIO_CONST_ATTR(bandwidth_available, BMA180_BW_AVAILABLE);
>>> +static IIO_CONST_ATTR(scale_available, BMA180_SCALE_AVAILABLE);
>>> +
>>> +static struct attribute *bma180_attributes[] = {
>>> +     &iio_dev_attr_mode.dev_attr.attr,
>>> +     &iio_const_attr_mode_available.dev_attr.attr,
>> These need documenting if they don't fit within standard abi options.
>>> +     &iio_dev_attr_bandwidth.dev_attr.attr,
>>> +     &iio_const_attr_bandwidth_available.dev_attr.attr,
>> bandwidth = 3db frequency?
>>> +     &iio_const_attr_scale_available.dev_attr.attr,
>>> +     NULL,
>>> +};
>>> +
>>> +static const struct attribute_group bma180_attrs_group = {
>>> +     .attrs = bma180_attributes,
>>> +};
>>> +
>>> +static int bma180_read_raw(struct iio_dev *indio_dev,
>>> +             struct iio_chan_spec const *chan, int *val, int *val2,
>>> +             long mask)
>>> +{
>>> +     struct bma180_data *data = iio_priv(indio_dev);
>>> +     int ret;
>>> +
>>> +     switch (mask) {
>>> +     case IIO_CHAN_INFO_RAW:
>>> +             mutex_lock(&data->mutex);
>>> +             if (iio_buffer_enabled(indio_dev))
>>> +                     ret = -EBUSY;
>>> +             else
>>> +                     ret = bma180_get_acc_reg(data, chan->scan_index);
>>> +             mutex_unlock(&data->mutex);
>>> +             if (ret < 0)
>>> +                     return ret;
>>> +             *val = (s16)ret >> chan->scan_type.shift;
>>> +             return IIO_VAL_INT;
>>> +     case IIO_CHAN_INFO_SCALE:
>>> +             *val = 0;
>>> +             *val2 = data->scale;
>>> +             return IIO_VAL_INT_PLUS_MICRO;
>>> +     default:
>>> +             return -EINVAL;
>>> +     }
>>> +}
>>> +
>>> +static int bma180_write_raw(struct iio_dev *indio_dev,
>>> +             struct iio_chan_spec const *chan, int val, int val2, long mask)
>>> +{
>>> +     struct bma180_data *data = iio_priv(indio_dev);
>>> +     int ret;
>>> +
>>> +     if (mask != IIO_CHAN_INFO_SCALE || val)
>>> +             return -EINVAL;
>>> +
>>> +     mutex_lock(&data->mutex);
>>> +     ret = bma180_set_scale(data, val2);
>>> +     mutex_unlock(&data->mutex);
>>> +
>>> +     return ret;
>>> +}
>>> +
>>> +static int bma180_update_scan_mode(struct iio_dev *indio_dev,
>>> +             const unsigned long *scan_mask)
>>> +{
>>> +     struct bma180_data *data = iio_priv(indio_dev);
>>> +
>>> +     kfree(data->buff);
>>> +     data->buff = kmalloc(indio_dev->scan_bytes, GFP_KERNEL);
>>> +     if (!data->buff)
>>> +             return -ENOMEM;
>>> +
>>> +     return 0;
>>> +}
>>> +
>>> +static const struct iio_info bma180_info = {
>>> +     .attrs                  = &bma180_attrs_group,
>>> +     .read_raw               = bma180_read_raw,
>>> +     .write_raw              = bma180_write_raw,
>>> +     .update_scan_mode       = bma180_update_scan_mode,
>>> +     .driver_module          = THIS_MODULE,
>>> +};
>>> +
>>> +#define BMA180_CHANNEL(_index) {                             \
>>> +     .type = IIO_ACCEL,                                      \
>>> +     .indexed = 1,                                           \
>>> +     .channel = (_index),                                    \
>>> +     .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),           \
>>> +     .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),   \
>>> +     .scan_index = (_index),                                 \
>>> +     .scan_type = IIO_ST('s', 14, 16, 2),                    \
>>> +}
>>> +
>>> +static const struct iio_chan_spec bma180_channels[] = {
>>> +     BMA180_CHANNEL(AXIS_X),
>>> +     BMA180_CHANNEL(AXIS_Y),
>>> +     BMA180_CHANNEL(AXIS_Z),
>>> +     IIO_CHAN_SOFT_TIMESTAMP(4),
>>> +};
>>> +
>>> +static irqreturn_t bma180_trigger_handler(int irq, void *p)
>>> +{
>>> +     struct iio_poll_func *pf = p;
>>> +     struct iio_dev *indio_dev = pf->indio_dev;
>>> +     struct bma180_data *data = iio_priv(indio_dev);
>>> +     int bit, ret, i = 0;
>>> +
>>> +     mutex_lock(&data->mutex);
>>> +     if (indio_dev->scan_timestamp) {
>>> +             ret = indio_dev->scan_bytes / sizeof(s64) - 1;
>>> +             ((s64 *)data->buff)[ret] = iio_get_time_ns();
>>> +     }
>>> +
>>> +     for_each_set_bit(bit, indio_dev->buffer->scan_mask,
>>> +                      indio_dev->masklength) {
>>> +             ret = bma180_get_acc_reg(data, bit);
>>> +             if (ret < 0) {
>>> +                     mutex_unlock(&data->mutex);
>>> +                     goto err;
>>> +             }
>>> +             ((s16 *)data->buff)[i++] = ret;
>>> +     }
>>> +     mutex_unlock(&data->mutex);
>>> +
>>> +     iio_push_to_buffers(indio_dev, (u8 *)data->buff);
>>> +err:
>>> +     iio_trigger_notify_done(indio_dev->trig);
>>> +
>>> +     return IRQ_HANDLED;
>>> +}
>>> +
>>> +static int bma180_data_rdy_trigger_set_state(struct iio_trigger *trig,
>>> +             bool state)
>>> +{
>>> +     struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
>>> +     struct bma180_data *data = iio_priv(indio_dev);
>>> +
>>> +     return bma180_set_new_data_intr_state(data, state);
>>> +}
>>> +
>>> +static int bma180_trig_try_reen(struct iio_trigger *trig)
>>> +{
>>> +     struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
>>> +     struct bma180_data *data = iio_priv(indio_dev);
>>> +
>>> +     return bma180_reset_intr(data);
>>> +}
>>> +
>>> +static const struct iio_trigger_ops bma180_trigger_ops = {
>>> +     .set_trigger_state = bma180_data_rdy_trigger_set_state,
>>> +     .try_reenable = bma180_trig_try_reen,
>>> +     .owner = THIS_MODULE,
>>> +};
>>> +
>>> +static int bma180_probe(struct i2c_client *client,
>>> +             const struct i2c_device_id *id)
>>> +{
>>> +     struct bma180_data *data;
>>> +     struct iio_dev *indio_dev;
>>> +     struct iio_trigger *trig;
>>> +     int ret;
>>> +
>>> +     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;
>>> +
>>> +     ret = bma180_chip_init(data);
>>> +     if (ret < 0)
>>> +             goto err_chip_disable;
>>> +
>>> +     mutex_init(&data->mutex);
>>> +
>>> +     indio_dev->dev.parent = &client->dev;
>>> +     indio_dev->channels = bma180_channels;
>>> +     indio_dev->num_channels = ARRAY_SIZE(bma180_channels);
>>> +     indio_dev->name = BMA180_DRV_NAME;
>>> +     indio_dev->modes = INDIO_DIRECT_MODE;
>>> +     indio_dev->info = &bma180_info;
>>> +
>>> +     trig = iio_trigger_alloc("%s-dev%d", indio_dev->name, indio_dev->id);
>>> +     if (!trig) {
>>> +             ret = -ENOMEM;
>>> +             goto err_chip_disable;
>>> +     }
>>> +
>>> +     ret = devm_request_irq(&client->dev, client->irq,
>>> +                     iio_trigger_generic_data_rdy_poll,
>>> +                     IRQF_TRIGGER_RISING, BMA180_IRQ_NAME, trig);
>>> +     if (ret) {
>>> +             dev_err(&client->dev, "unable to request IRQ\n");
>>> +             goto err_trigger_free;
>>> +     }
>>> +
>>> +     trig->dev.parent = &client->dev;
>>> +     trig->ops = &bma180_trigger_ops;
>>> +     iio_trigger_set_drvdata(trig, indio_dev);
>>> +     data->trig = trig;
>>> +     indio_dev->trig = trig;
>>> +
>>> +     ret = iio_trigger_register(trig);
>>> +     if (ret)
>>> +             goto err_trigger_free;
>>> +
>>> +     ret = iio_triggered_buffer_setup(indio_dev, NULL,
>>> +                     bma180_trigger_handler, NULL);
>>> +     if (ret < 0) {
>>> +             dev_err(&client->dev, "unable to setup iio triggered buffer\n");
>>> +             goto err_trigger_unregister;
>>> +     }
>>> +
>>> +     ret = iio_device_register(indio_dev);
>>> +     if (ret < 0) {
>>> +             dev_err(&client->dev, "unable to register iio device\n");
>>> +             goto err_buffer_cleanup;
>>> +     }
>>> +
>>> +     return 0;
>>> +
>>> +err_buffer_cleanup:
>>> +     iio_triggered_buffer_cleanup(indio_dev);
>>> +err_trigger_unregister:
>>> +     iio_trigger_unregister(trig);
>>> +err_trigger_free:
>>> +     iio_trigger_free(trig);
>>> +err_chip_disable:
>>> +     bma180_chip_disable(data);
>>> +
>>> +     return ret;
>>> +}
>>> +
>>> +static int bma180_remove(struct i2c_client *client)
>>> +{
>>> +     struct iio_dev *indio_dev = i2c_get_clientdata(client);
>>> +     struct bma180_data *data = iio_priv(indio_dev);
>>> +
>>> +     iio_device_unregister(indio_dev);
>>> +     iio_triggered_buffer_cleanup(indio_dev);
>>> +     iio_trigger_unregister(data->trig);
>>> +     iio_trigger_free(data->trig);
>>> +     kfree(data->buff);
>>> +
>>> +     mutex_lock(&data->mutex);
>>> +     bma180_chip_disable(data);
>>> +     mutex_unlock(&data->mutex);
>>> +
>>> +     return 0;
>>> +}
>>> +
>>> +#ifdef CONFIG_PM_SLEEP
>>> +static int bma180_suspend(struct device *dev)
>>> +{
>>> +     struct iio_dev *indio_dev = dev_to_iio_dev(dev);
>>> +     struct bma180_data *data = iio_priv(indio_dev);
>>> +     int ret;
>>> +
>>> +     mutex_lock(&data->mutex);
>>> +     ret = bma180_set_sleep_state(data, 1);
>>> +     mutex_unlock(&data->mutex);
>>> +
>>> +     return ret;
>>> +}
>>> +
>>> +static int bma180_resume(struct device *dev)
>>> +{
>>> +     struct iio_dev *indio_dev = dev_to_iio_dev(dev);
>>> +     struct bma180_data *data = iio_priv(indio_dev);
>>> +     int ret;
>>> +
>>> +     mutex_lock(&data->mutex);
>>> +     ret = bma180_set_sleep_state(data, 0);
>>> +     mutex_unlock(&data->mutex);
>>> +
>>> +     return ret;
>>> +}
>>> +
>>> +static SIMPLE_DEV_PM_OPS(bma180_pm_ops, bma180_suspend, bma180_resume);
>>> +#define BMA180_PM_OPS (&bma180_pm_ops)
>>> +#else
>>> +#define BMA180_PM_OPS NULL
>>> +#endif
>>> +
>>> +static struct i2c_device_id bma180_id[] = {
>>> +     { BMA180_DRV_NAME, 0 },
>>> +     { }
>>> +};
>>> +
>>> +MODULE_DEVICE_TABLE(i2c, bma180_id);
>>> +
>>> +static struct i2c_driver bma180_driver = {
>>> +     .driver = {
>>> +             .name   = BMA180_DRV_NAME,
>>> +             .owner  = THIS_MODULE,
>>> +             .pm     = BMA180_PM_OPS,
>>> +     },
>>> +     .probe          = bma180_probe,
>>> +     .remove         = bma180_remove,
>>> +     .id_table       = bma180_id,
>>> +};
>>> +
>>> +module_i2c_driver(bma180_driver);
>>> +
>>> +MODULE_AUTHOR("Kravchenko Oleksandr <x0199363@ti.com>");
>>> +MODULE_AUTHOR("Texas Instruments, Inc.");
>>> +MODULE_DESCRIPTION("Bosch BMA180 triaxial acceleration sensor");
>>> +MODULE_LICENSE("GPL");
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> 

Re: [PATCH v3] iio: add Bosch BMA180 acceleration sensor driver

[Oleksandr Kravchenko]

On Thu, Aug 15, 2013 at 8:57 PM, Jonathan Cameron <jic23@kernel.org> wrote:
> On 08/15/13 14:41, Oleksandr Kravchenko wrote:
>> On Thu, Aug 15, 2013 at 1:22 PM, Jonathan Cameron <jic23@kernel.org> wrote:
>>> On 08/13/13 16:44, Oleksandr Kravchenko wrote:
>>>> This patch adds IIO driver for Bosch BMA180 triaxial
>>>> acceleration sensor.
>>>> http://dlnmh9ip6v2uc.cloudfront.net/datasheets/
>>>>               Sensors/Accelerometers/BST-BMA180-DS000-07_2.pdf
>>>>
>>>> Signed-off-by: Oleksandr Kravchenko <o.v.kravchenko@globallogic.com>
>>> Hi,
>>>
>>> Firstly, just a thought (I haven't made up my mind whether it is a good idea or
>>> not!) but you could use devm_kzalloc for data->buff and hence avoid having
>>> to care about freeing it in the remove function.  Update scan mode isn't
>>> a particularly fast path so I doubt the small overhead will matter.
>> Thanks, it is a good idea.
>>
>>>
>>> Otherwise, the abi additions need documenting iff they don't fit within
>>> existing ABI. If they do then they need to match existing ABI.
>>>
>>> Of those, 'mode' is rather device specific and could probably do with
>>> a more detailed name.  The only 'generic' way to do it would be to make the
>>> channel type attributes writable and treat it as a resolution control rather
>>> than a noise/power trade off.  Uggly though so perhaps what you have makes
>>> sense.  We can always add a more generic way of controlling this if it
>>> starts turning up in lots of devices (keeping this method of course to avoid
>>> breaking ABI).
>> Ok, I'll change 'mode' to 'power_mode' and document it in ABI.
Can I use ext_info and iio_chan_spec_ext_info to provide my "power_mode"
in my driver like "powerdown_mode" in some other drivers?

>>>
>>> 'bandwidth' is already (I think) covered by the ABI.  For the bandwidth optoins you have enabled we are talking low pass
>>> filters and presumably their 3db point.
>>> In Documentation/ABI/testing/sysfs-bus-iio you will find in_accel_filter_low_pass_3db_frequency. My filter theory is
>>> rather rusty (not sure it was
>>> every anything else ;). Hence I'm not entirely sure how to work
>>> out the 3db frequency from the 'pole frequency' if they are not infact
>>> the same thing..
>> You are right. In my case 'bandwidth' is low path filter. I'll change my driver
>> accordingly. But how can I declare available values?
>> If I do it in next way:
>>     static IIO_CONST_ATTR(in_accel0_filter_low_pass_3db_frequency_available,
>> BMA180_BW_AVAILABLE);
> Not shared across all channels?  If it is then
> in_accel_filter_low_pass_3db_frequency_available it is...
>> it will lock so ugly in the code and sysfs...
>
> yeah.  There are plans to clean that sort of thing up.   I keep mentioning them
> and never getting them done though.
>
> In brief drivers will  be able to provide and additional callback
> which will then return pointers to arrays containing all the numbers to
> specify the 'range' of values any parameter in info_mask can take
> (note this includes the raw and processed values as well as the other bits).
>
> I sketch out how we could do this from time to time and dont' quite get around to
> doing it.
>>
>>>
>>> Otherwise, the driver looks good to me.
>>>
>>> Jonathan
>>>> ---
>>>>  .../devicetree/bindings/iio/accel/bma180.txt       |   24 +
>>>>  drivers/iio/accel/Kconfig                          |   12 +
>>>>  drivers/iio/accel/Makefile                         |    2 +
>>>>  drivers/iio/accel/bma180.c                         |  689 ++++++++++++++++++++
>>>>  4 files changed, 727 insertions(+)
>>>>  create mode 100644 Documentation/devicetree/bindings/iio/accel/bma180.txt
>>>>  create mode 100644 drivers/iio/accel/bma180.c
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/iio/accel/bma180.txt b/Documentation/devicetree/bindings/iio/accel/bma180.txt
>>>> new file mode 100644
>>>> index 0000000..c593357
>>>> --- /dev/null
>>>> +++ b/Documentation/devicetree/bindings/iio/accel/bma180.txt
>>>> @@ -0,0 +1,24 @@
>>>> +* Bosch BMA180 triaxial acceleration sensor
>>>> +
>>>> +http://omapworld.com/BMA180_111_1002839.pdf
>>>> +
>>>> +Required properties:
>>>> +
>>>> +  - compatible : should be "bosch,bma180"
>>>> +  - reg : the I2C address of the sensor
>>>> +
>>>> +Optional properties:
>>>> +
>>>> +  - interrupt-parent : should be the phandle for the interrupt controller
>>>> +
>>>> +  - interrupts : interrupt mapping for GPIO IRQ, it should by configured with
>>>> +             flags IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_EDGE_RISING
>>>> +
>>>> +Example:
>>>> +
>>>> +bma180@40 {
>>>> +     compatible = "bosch,bma180";
>>>> +     reg = <0x40>;
>>>> +     interrupt-parent = <&gpio6>;
>>>> +     interrupts = <18 (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_EDGE_RISING)>;
>>>> +};
>>>> diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
>>>> index 719d83f..bd9d581 100644
>>>> --- a/drivers/iio/accel/Kconfig
>>>> +++ b/drivers/iio/accel/Kconfig
>>>> @@ -3,6 +3,18 @@
>>>>  #
>>>>  menu "Accelerometers"
>>>>
>>>> +config BMA180
>>>> +     tristate "Bosch BMA180 3-Axis Accelerometer Driver"
>>>> +     depends on I2C
>>>> +     select IIO_BUFFER
>>>> +     select IIO_TRIGGERED_BUFFER
>>>> +     help
>>>> +       Say Y here if you want to build a driver for the Bosch BMA180
>>>> +       triaxial acceleration sensor.
>>>> +
>>>> +       To compile this driver as a module, choose M here: the
>>>> +       module will be called bma180.
>>>> +
>>>>  config HID_SENSOR_ACCEL_3D
>>>>       depends on HID_SENSOR_HUB
>>>>       select IIO_BUFFER
>>>> diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile
>>>> index 87d8fa2..eb09d72 100644
>>>> --- a/drivers/iio/accel/Makefile
>>>> +++ b/drivers/iio/accel/Makefile
>>>> @@ -2,6 +2,8 @@
>>>>  # Makefile for industrial I/O accelerometer drivers
>>>>  #
>>>>
>>>> +obj-$(CONFIG_BMA180) += bma180.o
>>>> +
>>>>  obj-$(CONFIG_HID_SENSOR_ACCEL_3D) += hid-sensor-accel-3d.o
>>>>
>>>>  obj-$(CONFIG_IIO_ST_ACCEL_3AXIS) += st_accel.o
>>>> diff --git a/drivers/iio/accel/bma180.c b/drivers/iio/accel/bma180.c
>>>> new file mode 100644
>>>> index 0000000..23c738f
>>>> --- /dev/null
>>>> +++ b/drivers/iio/accel/bma180.c
>>>> @@ -0,0 +1,689 @@
>>>> +/*
>>>> + * bma180.c - IIO driver for Bosch BMA180 triaxial acceleration sensor
>>>> + *
>>>> + * Copyright 2013 Oleksandr Kravchenko <x0199363@ti.com>
>>>> + *
>>>> + * 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.
>>>> + */
>>>> +
>>>> +#include <linux/module.h>
>>>> +#include <linux/i2c.h>
>>>> +#include <linux/interrupt.h>
>>>> +#include <linux/delay.h>
>>>> +#include <linux/of.h>
>>>> +#include <linux/bitops.h>
>>>> +#include <linux/slab.h>
>>>> +#include <linux/string.h>
>>>> +#include <linux/iio/iio.h>
>>>> +#include <linux/iio/sysfs.h>
>>>> +#include <linux/iio/buffer.h>
>>>> +#include <linux/iio/trigger.h>
>>>> +#include <linux/iio/trigger_consumer.h>
>>>> +#include <linux/iio/triggered_buffer.h>
>>>> +
>>>> +#define BMA180_DRV_NAME "bma180"
>>>> +#define BMA180_IRQ_NAME "bma180_event"
>>>> +
>>>> +/* Register set */
>>>> +#define BMA180_CHIP_ID               0x00 /* Need to distinguish BMA180 from other */
>>>> +#define BMA180_ACC_X_LSB     0x02 /* First of 6 registers of accel data */
>>>> +#define BMA180_CTRL_REG0     0x0d
>>>> +#define BMA180_RESET         0x10
>>>> +#define BMA180_BW_TCS                0x20
>>>> +#define BMA180_CTRL_REG3     0x21
>>>> +#define BMA180_TCO_Z         0x30
>>>> +#define BMA180_OFFSET_LSB1   0x35
>>>> +
>>>> +/* BMA180_CTRL_REG0 bits */
>>>> +#define BMA180_DIS_WAKE_UP   BIT(0) /* Disable wake up mode */
>>>> +#define BMA180_SLEEP         BIT(1) /* 1 - chip will sleep */
>>>> +#define BMA180_EE_W          BIT(4) /* Unlock writing to addr from 0x20 */
>>>> +#define BMA180_RESET_INT     BIT(6) /* Reset pending interrupts */
>>>> +
>>>> +/* BMA180_CTRL_REG3 bits */
>>>> +#define BMA180_NEW_DATA_INT  BIT(1) /* Intr every new accel data is ready */
>>>> +
>>>> +/* BMA180_OFFSET_LSB1 skipping mode bit */
>>>> +#define BMA180_SMP_SKIP              BIT(0)
>>>> +
>>>> +/* Bit masks for registers bit fields */
>>>> +#define BMA180_RANGE         0x0e /* Range of measured accel values*/
>>>> +#define BMA180_BW            0xf0 /* Accel bandwidth */
>>>> +#define BMA180_MODE_CONFIG   0x03 /* Config operation modes */
>>>> +
>>>> +/* We have to write this value in reset register to do soft reset */
>>>> +#define BMA180_RESET_VAL     0xb6
>>>> +
>>>> +#define BMA_180_ID_REG_VAL   0x03
>>>> +
>>>> +/* Chip operation modes */
>>>> +#define BMA180_LOW_NOISE     0x00
>>>> +#define BMA180_LOW_POWER     0x03
>>>> +
>>>> +#define BMA180_LOW_NOISE_STR "low_noise"
>>>> +#define BMA180_LOW_POWER_STR "low_power"
>>>> +
>>>> +/* Defaults values */
>>>> +#define BMA180_DEF_MODE              BMA180_LOW_NOISE_STR
>>>> +#define BMA180_DEF_BW                20
>>>> +#define BMA180_DEF_SCALE     250
>>>> +
>>>> +/* Available values */
>>>> +#define BMA180_MODE_AVAILABLE \
>>>> +     BMA180_LOW_NOISE_STR " " BMA180_LOW_POWER_STR
>>>> +#define BMA180_BW_AVAILABLE  "10 20 40 75 150 300"
>>>> +#define BMA180_SCALE_AVAILABLE \
>>>> +     "0.000130 0.000190 0.000250 0.000380 0.000500 0.000990 0.001980"
>>>> +
>>>> +struct bma180_data {
>>>> +     struct i2c_client *client;
>>>> +     struct iio_trigger *trig;
>>>> +     struct mutex mutex;
>>>> +     int sleep_state;
>>>> +     int scale;
>>>> +     int bw;
>>>> +     int mode;
>>>> +     char *buff;
>>>> +};
>>>> +
>>>> +enum bma180_axis {
>>>> +     AXIS_X,
>>>> +     AXIS_Y,
>>>> +     AXIS_Z,
>>>> +};
>>>> +
>>>> +static int bw_table[] = { 10, 20, 40, 75, 150, 300 }; /* Hz */
>>>> +static int scale_table[] = { 130, 190, 250, 380, 500, 990, 1980 };
>>>> +
>>>> +static int bma180_get_acc_reg(struct bma180_data *data, enum bma180_axis axis)
>>>> +{
>>>> +     u8 reg = BMA180_ACC_X_LSB + axis * 2;
>>>> +     int ret;
>>>> +
>>>> +     if (data->sleep_state)
>>>> +             return -EBUSY;
>>>> +
>>>> +     ret = i2c_smbus_read_word_data(data->client, reg);
>>>> +     if (ret < 0)
>>>> +             dev_err(&data->client->dev,
>>>> +                     "failed to read accel_%c registers\n", 'x' + axis);
>>>> +
>>>> +     return ret;
>>>> +}
>>>> +
>>>> +static int bma180_set_bits(struct bma180_data *data, u8 reg, u8 mask, u8 val)
>>>> +{
>>>> +     int ret = i2c_smbus_read_byte_data(data->client, reg);
>>>> +     u8 reg_val = (ret & ~mask) | (val << (ffs(mask) - 1));
>>>> +
>>>> +     if (ret < 0)
>>>> +             return ret;
>>>> +
>>>> +     return i2c_smbus_write_byte_data(data->client, reg, reg_val);
>>>> +}
>>>> +
>>>> +static int bma180_reset_intr(struct bma180_data *data)
>>>> +{
>>>> +     int ret = bma180_set_bits(data, BMA180_CTRL_REG0, BMA180_RESET_INT, 1);
>>>> +
>>>> +     if (ret)
>>>> +             dev_err(&data->client->dev, "failed to reset interrupt\n");
>>>> +
>>>> +     return ret;
>>>> +}
>>>> +
>>>> +static int bma180_set_new_data_intr_state(struct bma180_data *data, int state)
>>>> +{
>>>> +     u8 reg_val = state ? BMA180_NEW_DATA_INT : 0x00;
>>>> +     int ret = i2c_smbus_write_byte_data(data->client, BMA180_CTRL_REG3,
>>>> +                     reg_val);
>>>> +
>>>> +     if (ret)
>>>> +             goto err;
>>>> +     ret = bma180_reset_intr(data);
>>>> +     if (ret)
>>>> +             goto err;
>>>> +
>>>> +     return 0;
>>>> +
>>>> +err:
>>>> +     dev_err(&data->client->dev,
>>>> +             "failed to set new data interrupt state %d\n", state);
>>>> +     return ret;
>>>> +}
>>>> +
>>>> +static int bma180_set_sleep_state(struct bma180_data *data, int state)
>>>> +{
>>>> +     int ret = bma180_set_bits(data, BMA180_CTRL_REG0, BMA180_SLEEP, state);
>>>> +
>>>> +     if (ret) {
>>>> +             dev_err(&data->client->dev,
>>>> +                     "failed to set sleep state %d\n", state);
>>>> +             return ret;
>>>> +     }
>>>> +     data->sleep_state = state;
>>>> +
>>>> +     return 0;
>>>> +}
>>>> +
>>>> +static int bma180_set_ee_writing_state(struct bma180_data *data, int state)
>>>> +{
>>>> +     int ret = bma180_set_bits(data, BMA180_CTRL_REG0, BMA180_EE_W, state);
>>>> +
>>>> +     if (ret)
>>>> +             dev_err(&data->client->dev,
>>>> +                     "failed to set ee writing state %d\n", state);
>>>> +
>>>> +     return ret;
>>>> +}
>>>> +
>>>> +static int bma180_set_bw(struct bma180_data *data, int val)
>>>> +{
>>>> +     int ret, i;
>>>> +
>>>> +     if (data->sleep_state)
>>>> +             return -EBUSY;
>>>> +
>>>> +     for (i = 0; i < ARRAY_SIZE(bw_table); ++i) {
>>>> +             if (bw_table[i] == val) {
>>>> +                     ret = bma180_set_bits(data,
>>>> +                                     BMA180_BW_TCS, BMA180_BW, i);
>>>> +                     if (ret) {
>>>> +                             dev_err(&data->client->dev,
>>>> +                                     "failed to set bandwidth\n");
>>>> +                             return ret;
>>>> +                     }
>>>> +                     data->bw = val;
>>>> +                     return 0;
>>>> +             }
>>>> +     }
>>>> +
>>>> +     return -EINVAL;
>>>> +}
>>>> +
>>>> +static int bma180_set_scale(struct bma180_data *data, int val)
>>>> +{
>>>> +     int ret, i;
>>>> +
>>>> +     if (data->sleep_state)
>>>> +             return -EBUSY;
>>>> +
>>>> +     for (i = 0; i < ARRAY_SIZE(scale_table); ++i)
>>>> +             if (scale_table[i] == val) {
>>>> +                     ret = bma180_set_bits(data,
>>>> +                                     BMA180_OFFSET_LSB1, BMA180_RANGE, i);
>>>> +                     if (ret) {
>>>> +                             dev_err(&data->client->dev,
>>>> +                                     "failed to set scale\n");
>>>> +                             return ret;
>>>> +                     }
>>>> +                     data->scale = val;
>>>> +                     return 0;
>>>> +             }
>>>> +
>>>> +     return -EINVAL;
>>>> +}
>>>> +
>>>> +static int bma180_set_mode(struct bma180_data *data, const char *str)
>>>> +{
>>>> +     u8 reg_val;
>>>> +     int ret;
>>>> +
>>>> +     if (!strcmp(str, BMA180_LOW_NOISE_STR "\n"))
>>>> +             reg_val = BMA180_LOW_NOISE;
>>>> +     else if (!strcmp(str, BMA180_LOW_POWER_STR "\n"))
>>>> +             reg_val = BMA180_LOW_POWER;
>>>> +     else
>>>> +             return -EINVAL;
>>>> +
>>>> +     ret = bma180_set_bits(data, BMA180_TCO_Z, BMA180_MODE_CONFIG, reg_val);
>>>> +     if (ret)
>>>> +             dev_err(&data->client->dev, "failed to set mode\n");
>>>> +
>>>> +     data->mode = reg_val;
>>>> +
>>>> +     return ret;
>>>> +}
>>>> +
>>>> +static int bma180_soft_reset(struct bma180_data *data)
>>>> +{
>>>> +     int ret = i2c_smbus_write_byte_data(data->client,
>>>> +                     BMA180_RESET, BMA180_RESET_VAL);
>>>> +
>>>> +     if (ret)
>>>> +             dev_err(&data->client->dev, "failed to reset the chip\n");
>>>> +
>>>> +     return ret;
>>>> +}
>>>> +
>>>> +static int bma180_chip_init(struct bma180_data *data)
>>>> +{
>>>> +     /* Try to read chip_id register. It must return 0x03. */
>>>> +     int ret = i2c_smbus_read_byte_data(data->client, BMA180_CHIP_ID);
>>>> +
>>>> +     if (ret < 0)
>>>> +             goto err;
>>>> +     if (ret != BMA_180_ID_REG_VAL) {
>>>> +             ret = -ENODEV;
>>>> +             goto err;
>>>> +     }
>>>> +
>>>> +     ret = bma180_soft_reset(data);
>>>> +     if (ret)
>>>> +             goto err;
>>>> +     /*
>>>> +      * No serial transaction should occur within minimum 10 us
>>>> +      * after soft_reset command
>>>> +      */
>>>> +     msleep(20);
>>>> +
>>>> +     ret = bma180_set_bits(data, BMA180_CTRL_REG0, BMA180_DIS_WAKE_UP, 1);
>>>> +     if (ret)
>>>> +             goto err;
>>>> +     ret = bma180_set_ee_writing_state(data, 1);
>>>> +     if (ret)
>>>> +             goto err;
>>>> +     ret = bma180_set_new_data_intr_state(data, 0);
>>>> +     if (ret)
>>>> +             goto err;
>>>> +     ret = bma180_set_bits(data, BMA180_OFFSET_LSB1, BMA180_SMP_SKIP, 1);
>>>> +     if (ret)
>>>> +             goto err;
>>>> +     ret = bma180_set_mode(data, BMA180_DEF_MODE "\n");
>>>> +     if (ret)
>>>> +             goto err;
>>>> +     ret = bma180_set_bw(data, BMA180_DEF_BW);
>>>> +     if (ret)
>>>> +             goto err;
>>>> +     ret = bma180_set_scale(data, BMA180_DEF_SCALE);
>>>> +     if (ret)
>>>> +             goto err;
>>>> +
>>>> +     return 0;
>>>> +
>>>> +err:
>>>> +     dev_err(&data->client->dev, "failed to init the chip\n");
>>>> +     return ret;
>>>> +}
>>>> +
>>>> +static void bma180_chip_disable(struct bma180_data *data)
>>>> +{
>>>> +     if (bma180_set_new_data_intr_state(data, 0))
>>>> +             goto err;
>>>> +     if (bma180_set_ee_writing_state(data, 0))
>>>> +             goto err;
>>>> +     if (bma180_set_sleep_state(data, 1))
>>>> +             goto err;
>>>> +
>>>> +     return;
>>>> +
>>>> +err:
>>>> +     dev_err(&data->client->dev, "failed to disable the chip\n");
>>>> +}
>>>> +
>>>> +static ssize_t bma180_read_mode_config(struct device *dev,
>>>> +             struct device_attribute *attr, char *buf)
>>>> +{
>>>> +     struct iio_dev *indio_dev = dev_to_iio_dev(dev);
>>>> +     struct bma180_data *data = iio_priv(indio_dev);
>>>> +
>>>> +     return sprintf(buf, "%s\n",
>>>> +                     data->mode ?
>>>> +                     BMA180_LOW_POWER_STR : BMA180_LOW_NOISE_STR);
>>>> +}
>>>> +
>>>> +static ssize_t bma180_write_mode_config(struct device *dev,
>>>> +             struct device_attribute *attr, const char *buf, size_t len)
>>>> +{
>>>> +     struct iio_dev *indio_dev = dev_to_iio_dev(dev);
>>>> +     struct bma180_data *data = iio_priv(indio_dev);
>>>> +     int ret;
>>>> +
>>>> +     mutex_lock(&data->mutex);
>>>> +     ret = bma180_set_mode(data, buf);
>>>> +     mutex_unlock(&data->mutex);
>>>> +
>>>> +     return ret ? ret : len;
>>>> +}
>>>> +
>>>> +static ssize_t bma180_read_bw_config(struct device *dev,
>>>> +             struct device_attribute *attr, char *buf)
>>>> +{
>>>> +     struct iio_dev *indio_dev = dev_to_iio_dev(dev);
>>>> +     struct bma180_data *data = iio_priv(indio_dev);
>>>> +
>>>> +     return sprintf(buf, "%d\n", data->bw);
>>>> +}
>>>> +
>>>> +static ssize_t bma180_write_bw_config(struct device *dev,
>>>> +             struct device_attribute *attr, const char *buf, size_t len)
>>>> +{
>>>> +     struct iio_dev *indio_dev = dev_to_iio_dev(dev);
>>>> +     struct bma180_data *data = iio_priv(indio_dev);
>>>> +     long val;
>>>> +     int ret = kstrtol(buf, 10, &val);
>>>> +
>>>> +     if (ret)
>>>> +             return ret;
>>>> +
>>>> +     mutex_lock(&data->mutex);
>>>> +     ret = bma180_set_bw(data, val);
>>>> +     mutex_unlock(&data->mutex);
>>>> +
>>>> +     return ret ? ret : len;
>>>> +}
>>>> +
>>>> +static IIO_DEVICE_ATTR(mode, S_IRUGO | S_IWUSR, bma180_read_mode_config,
>>>> +             bma180_write_mode_config, 0);
>>>> +static IIO_CONST_ATTR(mode_available, BMA180_MODE_AVAILABLE);
>>>> +static IIO_DEVICE_ATTR(bandwidth, S_IRUGO | S_IWUSR, bma180_read_bw_config,
>>>> +             bma180_write_bw_config, 0);
>>>> +static IIO_CONST_ATTR(bandwidth_available, BMA180_BW_AVAILABLE);
>>>> +static IIO_CONST_ATTR(scale_available, BMA180_SCALE_AVAILABLE);
>>>> +
>>>> +static struct attribute *bma180_attributes[] = {
>>>> +     &iio_dev_attr_mode.dev_attr.attr,
>>>> +     &iio_const_attr_mode_available.dev_attr.attr,
>>> These need documenting if they don't fit within standard abi options.
>>>> +     &iio_dev_attr_bandwidth.dev_attr.attr,
>>>> +     &iio_const_attr_bandwidth_available.dev_attr.attr,
>>> bandwidth = 3db frequency?
>>>> +     &iio_const_attr_scale_available.dev_attr.attr,
>>>> +     NULL,
>>>> +};
>>>> +
>>>> +static const struct attribute_group bma180_attrs_group = {
>>>> +     .attrs = bma180_attributes,
>>>> +};
>>>> +
>>>> +static int bma180_read_raw(struct iio_dev *indio_dev,
>>>> +             struct iio_chan_spec const *chan, int *val, int *val2,
>>>> +             long mask)
>>>> +{
>>>> +     struct bma180_data *data = iio_priv(indio_dev);
>>>> +     int ret;
>>>> +
>>>> +     switch (mask) {
>>>> +     case IIO_CHAN_INFO_RAW:
>>>> +             mutex_lock(&data->mutex);
>>>> +             if (iio_buffer_enabled(indio_dev))
>>>> +                     ret = -EBUSY;
>>>> +             else
>>>> +                     ret = bma180_get_acc_reg(data, chan->scan_index);
>>>> +             mutex_unlock(&data->mutex);
>>>> +             if (ret < 0)
>>>> +                     return ret;
>>>> +             *val = (s16)ret >> chan->scan_type.shift;
>>>> +             return IIO_VAL_INT;
>>>> +     case IIO_CHAN_INFO_SCALE:
>>>> +             *val = 0;
>>>> +             *val2 = data->scale;
>>>> +             return IIO_VAL_INT_PLUS_MICRO;
>>>> +     default:
>>>> +             return -EINVAL;
>>>> +     }
>>>> +}
>>>> +
>>>> +static int bma180_write_raw(struct iio_dev *indio_dev,
>>>> +             struct iio_chan_spec const *chan, int val, int val2, long mask)
>>>> +{
>>>> +     struct bma180_data *data = iio_priv(indio_dev);
>>>> +     int ret;
>>>> +
>>>> +     if (mask != IIO_CHAN_INFO_SCALE || val)
>>>> +             return -EINVAL;
>>>> +
>>>> +     mutex_lock(&data->mutex);
>>>> +     ret = bma180_set_scale(data, val2);
>>>> +     mutex_unlock(&data->mutex);
>>>> +
>>>> +     return ret;
>>>> +}
>>>> +
>>>> +static int bma180_update_scan_mode(struct iio_dev *indio_dev,
>>>> +             const unsigned long *scan_mask)
>>>> +{
>>>> +     struct bma180_data *data = iio_priv(indio_dev);
>>>> +
>>>> +     kfree(data->buff);
>>>> +     data->buff = kmalloc(indio_dev->scan_bytes, GFP_KERNEL);
>>>> +     if (!data->buff)
>>>> +             return -ENOMEM;
>>>> +
>>>> +     return 0;
>>>> +}
>>>> +
>>>> +static const struct iio_info bma180_info = {
>>>> +     .attrs                  = &bma180_attrs_group,
>>>> +     .read_raw               = bma180_read_raw,
>>>> +     .write_raw              = bma180_write_raw,
>>>> +     .update_scan_mode       = bma180_update_scan_mode,
>>>> +     .driver_module          = THIS_MODULE,
>>>> +};
>>>> +
>>>> +#define BMA180_CHANNEL(_index) {                             \
>>>> +     .type = IIO_ACCEL,                                      \
>>>> +     .indexed = 1,                                           \
>>>> +     .channel = (_index),                                    \
>>>> +     .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),           \
>>>> +     .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),   \
>>>> +     .scan_index = (_index),                                 \
>>>> +     .scan_type = IIO_ST('s', 14, 16, 2),                    \
>>>> +}
>>>> +
>>>> +static const struct iio_chan_spec bma180_channels[] = {
>>>> +     BMA180_CHANNEL(AXIS_X),
>>>> +     BMA180_CHANNEL(AXIS_Y),
>>>> +     BMA180_CHANNEL(AXIS_Z),
>>>> +     IIO_CHAN_SOFT_TIMESTAMP(4),
>>>> +};
>>>> +
>>>> +static irqreturn_t bma180_trigger_handler(int irq, void *p)
>>>> +{
>>>> +     struct iio_poll_func *pf = p;
>>>> +     struct iio_dev *indio_dev = pf->indio_dev;
>>>> +     struct bma180_data *data = iio_priv(indio_dev);
>>>> +     int bit, ret, i = 0;
>>>> +
>>>> +     mutex_lock(&data->mutex);
>>>> +     if (indio_dev->scan_timestamp) {
>>>> +             ret = indio_dev->scan_bytes / sizeof(s64) - 1;
>>>> +             ((s64 *)data->buff)[ret] = iio_get_time_ns();
>>>> +     }
>>>> +
>>>> +     for_each_set_bit(bit, indio_dev->buffer->scan_mask,
>>>> +                      indio_dev->masklength) {
>>>> +             ret = bma180_get_acc_reg(data, bit);
>>>> +             if (ret < 0) {
>>>> +                     mutex_unlock(&data->mutex);
>>>> +                     goto err;
>>>> +             }
>>>> +             ((s16 *)data->buff)[i++] = ret;
>>>> +     }
>>>> +     mutex_unlock(&data->mutex);
>>>> +
>>>> +     iio_push_to_buffers(indio_dev, (u8 *)data->buff);
>>>> +err:
>>>> +     iio_trigger_notify_done(indio_dev->trig);
>>>> +
>>>> +     return IRQ_HANDLED;
>>>> +}
>>>> +
>>>> +static int bma180_data_rdy_trigger_set_state(struct iio_trigger *trig,
>>>> +             bool state)
>>>> +{
>>>> +     struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
>>>> +     struct bma180_data *data = iio_priv(indio_dev);
>>>> +
>>>> +     return bma180_set_new_data_intr_state(data, state);
>>>> +}
>>>> +
>>>> +static int bma180_trig_try_reen(struct iio_trigger *trig)
>>>> +{
>>>> +     struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
>>>> +     struct bma180_data *data = iio_priv(indio_dev);
>>>> +
>>>> +     return bma180_reset_intr(data);
>>>> +}
>>>> +
>>>> +static const struct iio_trigger_ops bma180_trigger_ops = {
>>>> +     .set_trigger_state = bma180_data_rdy_trigger_set_state,
>>>> +     .try_reenable = bma180_trig_try_reen,
>>>> +     .owner = THIS_MODULE,
>>>> +};
>>>> +
>>>> +static int bma180_probe(struct i2c_client *client,
>>>> +             const struct i2c_device_id *id)
>>>> +{
>>>> +     struct bma180_data *data;
>>>> +     struct iio_dev *indio_dev;
>>>> +     struct iio_trigger *trig;
>>>> +     int ret;
>>>> +
>>>> +     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;
>>>> +
>>>> +     ret = bma180_chip_init(data);
>>>> +     if (ret < 0)
>>>> +             goto err_chip_disable;
>>>> +
>>>> +     mutex_init(&data->mutex);
>>>> +
>>>> +     indio_dev->dev.parent = &client->dev;
>>>> +     indio_dev->channels = bma180_channels;
>>>> +     indio_dev->num_channels = ARRAY_SIZE(bma180_channels);
>>>> +     indio_dev->name = BMA180_DRV_NAME;
>>>> +     indio_dev->modes = INDIO_DIRECT_MODE;
>>>> +     indio_dev->info = &bma180_info;
>>>> +
>>>> +     trig = iio_trigger_alloc("%s-dev%d", indio_dev->name, indio_dev->id);
>>>> +     if (!trig) {
>>>> +             ret = -ENOMEM;
>>>> +             goto err_chip_disable;
>>>> +     }
>>>> +
>>>> +     ret = devm_request_irq(&client->dev, client->irq,
>>>> +                     iio_trigger_generic_data_rdy_poll,
>>>> +                     IRQF_TRIGGER_RISING, BMA180_IRQ_NAME, trig);
>>>> +     if (ret) {
>>>> +             dev_err(&client->dev, "unable to request IRQ\n");
>>>> +             goto err_trigger_free;
>>>> +     }
>>>> +
>>>> +     trig->dev.parent = &client->dev;
>>>> +     trig->ops = &bma180_trigger_ops;
>>>> +     iio_trigger_set_drvdata(trig, indio_dev);
>>>> +     data->trig = trig;
>>>> +     indio_dev->trig = trig;
>>>> +
>>>> +     ret = iio_trigger_register(trig);
>>>> +     if (ret)
>>>> +             goto err_trigger_free;
>>>> +
>>>> +     ret = iio_triggered_buffer_setup(indio_dev, NULL,
>>>> +                     bma180_trigger_handler, NULL);
>>>> +     if (ret < 0) {
>>>> +             dev_err(&client->dev, "unable to setup iio triggered buffer\n");
>>>> +             goto err_trigger_unregister;
>>>> +     }
>>>> +
>>>> +     ret = iio_device_register(indio_dev);
>>>> +     if (ret < 0) {
>>>> +             dev_err(&client->dev, "unable to register iio device\n");
>>>> +             goto err_buffer_cleanup;
>>>> +     }
>>>> +
>>>> +     return 0;
>>>> +
>>>> +err_buffer_cleanup:
>>>> +     iio_triggered_buffer_cleanup(indio_dev);
>>>> +err_trigger_unregister:
>>>> +     iio_trigger_unregister(trig);
>>>> +err_trigger_free:
>>>> +     iio_trigger_free(trig);
>>>> +err_chip_disable:
>>>> +     bma180_chip_disable(data);
>>>> +
>>>> +     return ret;
>>>> +}
>>>> +
>>>> +static int bma180_remove(struct i2c_client *client)
>>>> +{
>>>> +     struct iio_dev *indio_dev = i2c_get_clientdata(client);
>>>> +     struct bma180_data *data = iio_priv(indio_dev);
>>>> +
>>>> +     iio_device_unregister(indio_dev);
>>>> +     iio_triggered_buffer_cleanup(indio_dev);
>>>> +     iio_trigger_unregister(data->trig);
>>>> +     iio_trigger_free(data->trig);
>>>> +     kfree(data->buff);
>>>> +
>>>> +     mutex_lock(&data->mutex);
>>>> +     bma180_chip_disable(data);
>>>> +     mutex_unlock(&data->mutex);
>>>> +
>>>> +     return 0;
>>>> +}
>>>> +
>>>> +#ifdef CONFIG_PM_SLEEP
>>>> +static int bma180_suspend(struct device *dev)
>>>> +{
>>>> +     struct iio_dev *indio_dev = dev_to_iio_dev(dev);
>>>> +     struct bma180_data *data = iio_priv(indio_dev);
>>>> +     int ret;
>>>> +
>>>> +     mutex_lock(&data->mutex);
>>>> +     ret = bma180_set_sleep_state(data, 1);
>>>> +     mutex_unlock(&data->mutex);
>>>> +
>>>> +     return ret;
>>>> +}
>>>> +
>>>> +static int bma180_resume(struct device *dev)
>>>> +{
>>>> +     struct iio_dev *indio_dev = dev_to_iio_dev(dev);
>>>> +     struct bma180_data *data = iio_priv(indio_dev);
>>>> +     int ret;
>>>> +
>>>> +     mutex_lock(&data->mutex);
>>>> +     ret = bma180_set_sleep_state(data, 0);
>>>> +     mutex_unlock(&data->mutex);
>>>> +
>>>> +     return ret;
>>>> +}
>>>> +
>>>> +static SIMPLE_DEV_PM_OPS(bma180_pm_ops, bma180_suspend, bma180_resume);
>>>> +#define BMA180_PM_OPS (&bma180_pm_ops)
>>>> +#else
>>>> +#define BMA180_PM_OPS NULL
>>>> +#endif
>>>> +
>>>> +static struct i2c_device_id bma180_id[] = {
>>>> +     { BMA180_DRV_NAME, 0 },
>>>> +     { }
>>>> +};
>>>> +
>>>> +MODULE_DEVICE_TABLE(i2c, bma180_id);
>>>> +
>>>> +static struct i2c_driver bma180_driver = {
>>>> +     .driver = {
>>>> +             .name   = BMA180_DRV_NAME,
>>>> +             .owner  = THIS_MODULE,
>>>> +             .pm     = BMA180_PM_OPS,
>>>> +     },
>>>> +     .probe          = bma180_probe,
>>>> +     .remove         = bma180_remove,
>>>> +     .id_table       = bma180_id,
>>>> +};
>>>> +
>>>> +module_i2c_driver(bma180_driver);
>>>> +
>>>> +MODULE_AUTHOR("Kravchenko Oleksandr <x0199363@ti.com>");
>>>> +MODULE_AUTHOR("Texas Instruments, Inc.");
>>>> +MODULE_DESCRIPTION("Bosch BMA180 triaxial acceleration sensor");
>>>> +MODULE_LICENSE("GPL");
>> --
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>> the body of a message to majordomo@vger.kernel.org
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>>

Re: [PATCH v3] iio: add Bosch BMA180 acceleration sensor driver

[Jonathan Cameron]

On 08/16/13 10:29, Oleksandr Kravchenko wrote:
> On Thu, Aug 15, 2013 at 8:57 PM, Jonathan Cameron <jic23@kernel.org> wrote:
>> On 08/15/13 14:41, Oleksandr Kravchenko wrote:
>>> On Thu, Aug 15, 2013 at 1:22 PM, Jonathan Cameron <jic23@kernel.org> wrote:
>>>> On 08/13/13 16:44, Oleksandr Kravchenko wrote:
>>>>> This patch adds IIO driver for Bosch BMA180 triaxial
>>>>> acceleration sensor.
>>>>> http://dlnmh9ip6v2uc.cloudfront.net/datasheets/
>>>>>               Sensors/Accelerometers/BST-BMA180-DS000-07_2.pdf
>>>>>
>>>>> Signed-off-by: Oleksandr Kravchenko <o.v.kravchenko@globallogic.com>
>>>> Hi,
>>>>
>>>> Firstly, just a thought (I haven't made up my mind whether it is a good idea or
>>>> not!) but you could use devm_kzalloc for data->buff and hence avoid having
>>>> to care about freeing it in the remove function.  Update scan mode isn't
>>>> a particularly fast path so I doubt the small overhead will matter.
>>> Thanks, it is a good idea.
>>>
>>>>
>>>> Otherwise, the abi additions need documenting iff they don't fit within
>>>> existing ABI. If they do then they need to match existing ABI.
>>>>
>>>> Of those, 'mode' is rather device specific and could probably do with
>>>> a more detailed name.  The only 'generic' way to do it would be to make the
>>>> channel type attributes writable and treat it as a resolution control rather
>>>> than a noise/power trade off.  Uggly though so perhaps what you have makes
>>>> sense.  We can always add a more generic way of controlling this if it
>>>> starts turning up in lots of devices (keeping this method of course to avoid
>>>> breaking ABI).
>>> Ok, I'll change 'mode' to 'power_mode' and document it in ABI.
> Can I use ext_info and iio_chan_spec_ext_info to provide my "power_mode"
> in my driver like "powerdown_mode" in some other drivers?
Yes.
> 
>>>>
>>>> 'bandwidth' is already (I think) covered by the ABI.  For the bandwidth optoins you have enabled we are talking low pass
>>>> filters and presumably their 3db point.
>>>> In Documentation/ABI/testing/sysfs-bus-iio you will find in_accel_filter_low_pass_3db_frequency. My filter theory is
>>>> rather rusty (not sure it was
>>>> every anything else ;). Hence I'm not entirely sure how to work
>>>> out the 3db frequency from the 'pole frequency' if they are not infact
>>>> the same thing..
>>> You are right. In my case 'bandwidth' is low path filter. I'll change my driver
>>> accordingly. But how can I declare available values?
>>> If I do it in next way:
>>>     static IIO_CONST_ATTR(in_accel0_filter_low_pass_3db_frequency_available,
>>> BMA180_BW_AVAILABLE);
>> Not shared across all channels?  If it is then
>> in_accel_filter_low_pass_3db_frequency_available it is...
>>> it will lock so ugly in the code and sysfs...
>>
>> yeah.  There are plans to clean that sort of thing up.   I keep mentioning them
>> and never getting them done though.
>>
>> In brief drivers will  be able to provide and additional callback
>> which will then return pointers to arrays containing all the numbers to
>> specify the 'range' of values any parameter in info_mask can take
>> (note this includes the raw and processed values as well as the other bits).
>>
>> I sketch out how we could do this from time to time and dont' quite get around to
>> doing it.
>>>
>>>>
>>>> Otherwise, the driver looks good to me.
>>>>
>>>> Jonathan
>>>>> ---
>>>>>  .../devicetree/bindings/iio/accel/bma180.txt       |   24 +
>>>>>  drivers/iio/accel/Kconfig                          |   12 +
>>>>>  drivers/iio/accel/Makefile                         |    2 +
>>>>>  drivers/iio/accel/bma180.c                         |  689 ++++++++++++++++++++
>>>>>  4 files changed, 727 insertions(+)
>>>>>  create mode 100644 Documentation/devicetree/bindings/iio/accel/bma180.txt
>>>>>  create mode 100644 drivers/iio/accel/bma180.c
>>>>>
>>>>> diff --git a/Documentation/devicetree/bindings/iio/accel/bma180.txt b/Documentation/devicetree/bindings/iio/accel/bma180.txt
>>>>> new file mode 100644
>>>>> index 0000000..c593357
>>>>> --- /dev/null
>>>>> +++ b/Documentation/devicetree/bindings/iio/accel/bma180.txt
>>>>> @@ -0,0 +1,24 @@
>>>>> +* Bosch BMA180 triaxial acceleration sensor
>>>>> +
>>>>> +http://omapworld.com/BMA180_111_1002839.pdf
>>>>> +
>>>>> +Required properties:
>>>>> +
>>>>> +  - compatible : should be "bosch,bma180"
>>>>> +  - reg : the I2C address of the sensor
>>>>> +
>>>>> +Optional properties:
>>>>> +
>>>>> +  - interrupt-parent : should be the phandle for the interrupt controller
>>>>> +
>>>>> +  - interrupts : interrupt mapping for GPIO IRQ, it should by configured with
>>>>> +             flags IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_EDGE_RISING
>>>>> +
>>>>> +Example:
>>>>> +
>>>>> +bma180@40 {
>>>>> +     compatible = "bosch,bma180";
>>>>> +     reg = <0x40>;
>>>>> +     interrupt-parent = <&gpio6>;
>>>>> +     interrupts = <18 (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_EDGE_RISING)>;
>>>>> +};
>>>>> diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
>>>>> index 719d83f..bd9d581 100644
>>>>> --- a/drivers/iio/accel/Kconfig
>>>>> +++ b/drivers/iio/accel/Kconfig
>>>>> @@ -3,6 +3,18 @@
>>>>>  #
>>>>>  menu "Accelerometers"
>>>>>
>>>>> +config BMA180
>>>>> +     tristate "Bosch BMA180 3-Axis Accelerometer Driver"
>>>>> +     depends on I2C
>>>>> +     select IIO_BUFFER
>>>>> +     select IIO_TRIGGERED_BUFFER
>>>>> +     help
>>>>> +       Say Y here if you want to build a driver for the Bosch BMA180
>>>>> +       triaxial acceleration sensor.
>>>>> +
>>>>> +       To compile this driver as a module, choose M here: the
>>>>> +       module will be called bma180.
>>>>> +
>>>>>  config HID_SENSOR_ACCEL_3D
>>>>>       depends on HID_SENSOR_HUB
>>>>>       select IIO_BUFFER
>>>>> diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile
>>>>> index 87d8fa2..eb09d72 100644
>>>>> --- a/drivers/iio/accel/Makefile
>>>>> +++ b/drivers/iio/accel/Makefile
>>>>> @@ -2,6 +2,8 @@
>>>>>  # Makefile for industrial I/O accelerometer drivers
>>>>>  #
>>>>>
>>>>> +obj-$(CONFIG_BMA180) += bma180.o
>>>>> +
>>>>>  obj-$(CONFIG_HID_SENSOR_ACCEL_3D) += hid-sensor-accel-3d.o
>>>>>
>>>>>  obj-$(CONFIG_IIO_ST_ACCEL_3AXIS) += st_accel.o
>>>>> diff --git a/drivers/iio/accel/bma180.c b/drivers/iio/accel/bma180.c
>>>>> new file mode 100644
>>>>> index 0000000..23c738f
>>>>> --- /dev/null
>>>>> +++ b/drivers/iio/accel/bma180.c
>>>>> @@ -0,0 +1,689 @@
>>>>> +/*
>>>>> + * bma180.c - IIO driver for Bosch BMA180 triaxial acceleration sensor
>>>>> + *
>>>>> + * Copyright 2013 Oleksandr Kravchenko <x0199363@ti.com>
>>>>> + *
>>>>> + * 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.
>>>>> + */
>>>>> +
>>>>> +#include <linux/module.h>
>>>>> +#include <linux/i2c.h>
>>>>> +#include <linux/interrupt.h>
>>>>> +#include <linux/delay.h>
>>>>> +#include <linux/of.h>
>>>>> +#include <linux/bitops.h>
>>>>> +#include <linux/slab.h>
>>>>> +#include <linux/string.h>
>>>>> +#include <linux/iio/iio.h>
>>>>> +#include <linux/iio/sysfs.h>
>>>>> +#include <linux/iio/buffer.h>
>>>>> +#include <linux/iio/trigger.h>
>>>>> +#include <linux/iio/trigger_consumer.h>
>>>>> +#include <linux/iio/triggered_buffer.h>
>>>>> +
>>>>> +#define BMA180_DRV_NAME "bma180"
>>>>> +#define BMA180_IRQ_NAME "bma180_event"
>>>>> +
>>>>> +/* Register set */
>>>>> +#define BMA180_CHIP_ID               0x00 /* Need to distinguish BMA180 from other */
>>>>> +#define BMA180_ACC_X_LSB     0x02 /* First of 6 registers of accel data */
>>>>> +#define BMA180_CTRL_REG0     0x0d
>>>>> +#define BMA180_RESET         0x10
>>>>> +#define BMA180_BW_TCS                0x20
>>>>> +#define BMA180_CTRL_REG3     0x21
>>>>> +#define BMA180_TCO_Z         0x30
>>>>> +#define BMA180_OFFSET_LSB1   0x35
>>>>> +
>>>>> +/* BMA180_CTRL_REG0 bits */
>>>>> +#define BMA180_DIS_WAKE_UP   BIT(0) /* Disable wake up mode */
>>>>> +#define BMA180_SLEEP         BIT(1) /* 1 - chip will sleep */
>>>>> +#define BMA180_EE_W          BIT(4) /* Unlock writing to addr from 0x20 */
>>>>> +#define BMA180_RESET_INT     BIT(6) /* Reset pending interrupts */
>>>>> +
>>>>> +/* BMA180_CTRL_REG3 bits */
>>>>> +#define BMA180_NEW_DATA_INT  BIT(1) /* Intr every new accel data is ready */
>>>>> +
>>>>> +/* BMA180_OFFSET_LSB1 skipping mode bit */
>>>>> +#define BMA180_SMP_SKIP              BIT(0)
>>>>> +
>>>>> +/* Bit masks for registers bit fields */
>>>>> +#define BMA180_RANGE         0x0e /* Range of measured accel values*/
>>>>> +#define BMA180_BW            0xf0 /* Accel bandwidth */
>>>>> +#define BMA180_MODE_CONFIG   0x03 /* Config operation modes */
>>>>> +
>>>>> +/* We have to write this value in reset register to do soft reset */
>>>>> +#define BMA180_RESET_VAL     0xb6
>>>>> +
>>>>> +#define BMA_180_ID_REG_VAL   0x03
>>>>> +
>>>>> +/* Chip operation modes */
>>>>> +#define BMA180_LOW_NOISE     0x00
>>>>> +#define BMA180_LOW_POWER     0x03
>>>>> +
>>>>> +#define BMA180_LOW_NOISE_STR "low_noise"
>>>>> +#define BMA180_LOW_POWER_STR "low_power"
>>>>> +
>>>>> +/* Defaults values */
>>>>> +#define BMA180_DEF_MODE              BMA180_LOW_NOISE_STR
>>>>> +#define BMA180_DEF_BW                20
>>>>> +#define BMA180_DEF_SCALE     250
>>>>> +
>>>>> +/* Available values */
>>>>> +#define BMA180_MODE_AVAILABLE \
>>>>> +     BMA180_LOW_NOISE_STR " " BMA180_LOW_POWER_STR
>>>>> +#define BMA180_BW_AVAILABLE  "10 20 40 75 150 300"
>>>>> +#define BMA180_SCALE_AVAILABLE \
>>>>> +     "0.000130 0.000190 0.000250 0.000380 0.000500 0.000990 0.001980"
>>>>> +
>>>>> +struct bma180_data {
>>>>> +     struct i2c_client *client;
>>>>> +     struct iio_trigger *trig;
>>>>> +     struct mutex mutex;
>>>>> +     int sleep_state;
>>>>> +     int scale;
>>>>> +     int bw;
>>>>> +     int mode;
>>>>> +     char *buff;
>>>>> +};
>>>>> +
>>>>> +enum bma180_axis {
>>>>> +     AXIS_X,
>>>>> +     AXIS_Y,
>>>>> +     AXIS_Z,
>>>>> +};
>>>>> +
>>>>> +static int bw_table[] = { 10, 20, 40, 75, 150, 300 }; /* Hz */
>>>>> +static int scale_table[] = { 130, 190, 250, 380, 500, 990, 1980 };
>>>>> +
>>>>> +static int bma180_get_acc_reg(struct bma180_data *data, enum bma180_axis axis)
>>>>> +{
>>>>> +     u8 reg = BMA180_ACC_X_LSB + axis * 2;
>>>>> +     int ret;
>>>>> +
>>>>> +     if (data->sleep_state)
>>>>> +             return -EBUSY;
>>>>> +
>>>>> +     ret = i2c_smbus_read_word_data(data->client, reg);
>>>>> +     if (ret < 0)
>>>>> +             dev_err(&data->client->dev,
>>>>> +                     "failed to read accel_%c registers\n", 'x' + axis);
>>>>> +
>>>>> +     return ret;
>>>>> +}
>>>>> +
>>>>> +static int bma180_set_bits(struct bma180_data *data, u8 reg, u8 mask, u8 val)
>>>>> +{
>>>>> +     int ret = i2c_smbus_read_byte_data(data->client, reg);
>>>>> +     u8 reg_val = (ret & ~mask) | (val << (ffs(mask) - 1));
>>>>> +
>>>>> +     if (ret < 0)
>>>>> +             return ret;
>>>>> +
>>>>> +     return i2c_smbus_write_byte_data(data->client, reg, reg_val);
>>>>> +}
>>>>> +
>>>>> +static int bma180_reset_intr(struct bma180_data *data)
>>>>> +{
>>>>> +     int ret = bma180_set_bits(data, BMA180_CTRL_REG0, BMA180_RESET_INT, 1);
>>>>> +
>>>>> +     if (ret)
>>>>> +             dev_err(&data->client->dev, "failed to reset interrupt\n");
>>>>> +
>>>>> +     return ret;
>>>>> +}
>>>>> +
>>>>> +static int bma180_set_new_data_intr_state(struct bma180_data *data, int state)
>>>>> +{
>>>>> +     u8 reg_val = state ? BMA180_NEW_DATA_INT : 0x00;
>>>>> +     int ret = i2c_smbus_write_byte_data(data->client, BMA180_CTRL_REG3,
>>>>> +                     reg_val);
>>>>> +
>>>>> +     if (ret)
>>>>> +             goto err;
>>>>> +     ret = bma180_reset_intr(data);
>>>>> +     if (ret)
>>>>> +             goto err;
>>>>> +
>>>>> +     return 0;
>>>>> +
>>>>> +err:
>>>>> +     dev_err(&data->client->dev,
>>>>> +             "failed to set new data interrupt state %d\n", state);
>>>>> +     return ret;
>>>>> +}
>>>>> +
>>>>> +static int bma180_set_sleep_state(struct bma180_data *data, int state)
>>>>> +{
>>>>> +     int ret = bma180_set_bits(data, BMA180_CTRL_REG0, BMA180_SLEEP, state);
>>>>> +
>>>>> +     if (ret) {
>>>>> +             dev_err(&data->client->dev,
>>>>> +                     "failed to set sleep state %d\n", state);
>>>>> +             return ret;
>>>>> +     }
>>>>> +     data->sleep_state = state;
>>>>> +
>>>>> +     return 0;
>>>>> +}
>>>>> +
>>>>> +static int bma180_set_ee_writing_state(struct bma180_data *data, int state)
>>>>> +{
>>>>> +     int ret = bma180_set_bits(data, BMA180_CTRL_REG0, BMA180_EE_W, state);
>>>>> +
>>>>> +     if (ret)
>>>>> +             dev_err(&data->client->dev,
>>>>> +                     "failed to set ee writing state %d\n", state);
>>>>> +
>>>>> +     return ret;
>>>>> +}
>>>>> +
>>>>> +static int bma180_set_bw(struct bma180_data *data, int val)
>>>>> +{
>>>>> +     int ret, i;
>>>>> +
>>>>> +     if (data->sleep_state)
>>>>> +             return -EBUSY;
>>>>> +
>>>>> +     for (i = 0; i < ARRAY_SIZE(bw_table); ++i) {
>>>>> +             if (bw_table[i] == val) {
>>>>> +                     ret = bma180_set_bits(data,
>>>>> +                                     BMA180_BW_TCS, BMA180_BW, i);
>>>>> +                     if (ret) {
>>>>> +                             dev_err(&data->client->dev,
>>>>> +                                     "failed to set bandwidth\n");
>>>>> +                             return ret;
>>>>> +                     }
>>>>> +                     data->bw = val;
>>>>> +                     return 0;
>>>>> +             }
>>>>> +     }
>>>>> +
>>>>> +     return -EINVAL;
>>>>> +}
>>>>> +
>>>>> +static int bma180_set_scale(struct bma180_data *data, int val)
>>>>> +{
>>>>> +     int ret, i;
>>>>> +
>>>>> +     if (data->sleep_state)
>>>>> +             return -EBUSY;
>>>>> +
>>>>> +     for (i = 0; i < ARRAY_SIZE(scale_table); ++i)
>>>>> +             if (scale_table[i] == val) {
>>>>> +                     ret = bma180_set_bits(data,
>>>>> +                                     BMA180_OFFSET_LSB1, BMA180_RANGE, i);
>>>>> +                     if (ret) {
>>>>> +                             dev_err(&data->client->dev,
>>>>> +                                     "failed to set scale\n");
>>>>> +                             return ret;
>>>>> +                     }
>>>>> +                     data->scale = val;
>>>>> +                     return 0;
>>>>> +             }
>>>>> +
>>>>> +     return -EINVAL;
>>>>> +}
>>>>> +
>>>>> +static int bma180_set_mode(struct bma180_data *data, const char *str)
>>>>> +{
>>>>> +     u8 reg_val;
>>>>> +     int ret;
>>>>> +
>>>>> +     if (!strcmp(str, BMA180_LOW_NOISE_STR "\n"))
>>>>> +             reg_val = BMA180_LOW_NOISE;
>>>>> +     else if (!strcmp(str, BMA180_LOW_POWER_STR "\n"))
>>>>> +             reg_val = BMA180_LOW_POWER;
>>>>> +     else
>>>>> +             return -EINVAL;
>>>>> +
>>>>> +     ret = bma180_set_bits(data, BMA180_TCO_Z, BMA180_MODE_CONFIG, reg_val);
>>>>> +     if (ret)
>>>>> +             dev_err(&data->client->dev, "failed to set mode\n");
>>>>> +
>>>>> +     data->mode = reg_val;
>>>>> +
>>>>> +     return ret;
>>>>> +}
>>>>> +
>>>>> +static int bma180_soft_reset(struct bma180_data *data)
>>>>> +{
>>>>> +     int ret = i2c_smbus_write_byte_data(data->client,
>>>>> +                     BMA180_RESET, BMA180_RESET_VAL);
>>>>> +
>>>>> +     if (ret)
>>>>> +             dev_err(&data->client->dev, "failed to reset the chip\n");
>>>>> +
>>>>> +     return ret;
>>>>> +}
>>>>> +
>>>>> +static int bma180_chip_init(struct bma180_data *data)
>>>>> +{
>>>>> +     /* Try to read chip_id register. It must return 0x03. */
>>>>> +     int ret = i2c_smbus_read_byte_data(data->client, BMA180_CHIP_ID);
>>>>> +
>>>>> +     if (ret < 0)
>>>>> +             goto err;
>>>>> +     if (ret != BMA_180_ID_REG_VAL) {
>>>>> +             ret = -ENODEV;
>>>>> +             goto err;
>>>>> +     }
>>>>> +
>>>>> +     ret = bma180_soft_reset(data);
>>>>> +     if (ret)
>>>>> +             goto err;
>>>>> +     /*
>>>>> +      * No serial transaction should occur within minimum 10 us
>>>>> +      * after soft_reset command
>>>>> +      */
>>>>> +     msleep(20);
>>>>> +
>>>>> +     ret = bma180_set_bits(data, BMA180_CTRL_REG0, BMA180_DIS_WAKE_UP, 1);
>>>>> +     if (ret)
>>>>> +             goto err;
>>>>> +     ret = bma180_set_ee_writing_state(data, 1);
>>>>> +     if (ret)
>>>>> +             goto err;
>>>>> +     ret = bma180_set_new_data_intr_state(data, 0);
>>>>> +     if (ret)
>>>>> +             goto err;
>>>>> +     ret = bma180_set_bits(data, BMA180_OFFSET_LSB1, BMA180_SMP_SKIP, 1);
>>>>> +     if (ret)
>>>>> +             goto err;
>>>>> +     ret = bma180_set_mode(data, BMA180_DEF_MODE "\n");
>>>>> +     if (ret)
>>>>> +             goto err;
>>>>> +     ret = bma180_set_bw(data, BMA180_DEF_BW);
>>>>> +     if (ret)
>>>>> +             goto err;
>>>>> +     ret = bma180_set_scale(data, BMA180_DEF_SCALE);
>>>>> +     if (ret)
>>>>> +             goto err;
>>>>> +
>>>>> +     return 0;
>>>>> +
>>>>> +err:
>>>>> +     dev_err(&data->client->dev, "failed to init the chip\n");
>>>>> +     return ret;
>>>>> +}
>>>>> +
>>>>> +static void bma180_chip_disable(struct bma180_data *data)
>>>>> +{
>>>>> +     if (bma180_set_new_data_intr_state(data, 0))
>>>>> +             goto err;
>>>>> +     if (bma180_set_ee_writing_state(data, 0))
>>>>> +             goto err;
>>>>> +     if (bma180_set_sleep_state(data, 1))
>>>>> +             goto err;
>>>>> +
>>>>> +     return;
>>>>> +
>>>>> +err:
>>>>> +     dev_err(&data->client->dev, "failed to disable the chip\n");
>>>>> +}
>>>>> +
>>>>> +static ssize_t bma180_read_mode_config(struct device *dev,
>>>>> +             struct device_attribute *attr, char *buf)
>>>>> +{
>>>>> +     struct iio_dev *indio_dev = dev_to_iio_dev(dev);
>>>>> +     struct bma180_data *data = iio_priv(indio_dev);
>>>>> +
>>>>> +     return sprintf(buf, "%s\n",
>>>>> +                     data->mode ?
>>>>> +                     BMA180_LOW_POWER_STR : BMA180_LOW_NOISE_STR);
>>>>> +}
>>>>> +
>>>>> +static ssize_t bma180_write_mode_config(struct device *dev,
>>>>> +             struct device_attribute *attr, const char *buf, size_t len)
>>>>> +{
>>>>> +     struct iio_dev *indio_dev = dev_to_iio_dev(dev);
>>>>> +     struct bma180_data *data = iio_priv(indio_dev);
>>>>> +     int ret;
>>>>> +
>>>>> +     mutex_lock(&data->mutex);
>>>>> +     ret = bma180_set_mode(data, buf);
>>>>> +     mutex_unlock(&data->mutex);
>>>>> +
>>>>> +     return ret ? ret : len;
>>>>> +}
>>>>> +
>>>>> +static ssize_t bma180_read_bw_config(struct device *dev,
>>>>> +             struct device_attribute *attr, char *buf)
>>>>> +{
>>>>> +     struct iio_dev *indio_dev = dev_to_iio_dev(dev);
>>>>> +     struct bma180_data *data = iio_priv(indio_dev);
>>>>> +
>>>>> +     return sprintf(buf, "%d\n", data->bw);
>>>>> +}
>>>>> +
>>>>> +static ssize_t bma180_write_bw_config(struct device *dev,
>>>>> +             struct device_attribute *attr, const char *buf, size_t len)
>>>>> +{
>>>>> +     struct iio_dev *indio_dev = dev_to_iio_dev(dev);
>>>>> +     struct bma180_data *data = iio_priv(indio_dev);
>>>>> +     long val;
>>>>> +     int ret = kstrtol(buf, 10, &val);
>>>>> +
>>>>> +     if (ret)
>>>>> +             return ret;
>>>>> +
>>>>> +     mutex_lock(&data->mutex);
>>>>> +     ret = bma180_set_bw(data, val);
>>>>> +     mutex_unlock(&data->mutex);
>>>>> +
>>>>> +     return ret ? ret : len;
>>>>> +}
>>>>> +
>>>>> +static IIO_DEVICE_ATTR(mode, S_IRUGO | S_IWUSR, bma180_read_mode_config,
>>>>> +             bma180_write_mode_config, 0);
>>>>> +static IIO_CONST_ATTR(mode_available, BMA180_MODE_AVAILABLE);
>>>>> +static IIO_DEVICE_ATTR(bandwidth, S_IRUGO | S_IWUSR, bma180_read_bw_config,
>>>>> +             bma180_write_bw_config, 0);
>>>>> +static IIO_CONST_ATTR(bandwidth_available, BMA180_BW_AVAILABLE);
>>>>> +static IIO_CONST_ATTR(scale_available, BMA180_SCALE_AVAILABLE);
>>>>> +
>>>>> +static struct attribute *bma180_attributes[] = {
>>>>> +     &iio_dev_attr_mode.dev_attr.attr,
>>>>> +     &iio_const_attr_mode_available.dev_attr.attr,
>>>> These need documenting if they don't fit within standard abi options.
>>>>> +     &iio_dev_attr_bandwidth.dev_attr.attr,
>>>>> +     &iio_const_attr_bandwidth_available.dev_attr.attr,
>>>> bandwidth = 3db frequency?
>>>>> +     &iio_const_attr_scale_available.dev_attr.attr,
>>>>> +     NULL,
>>>>> +};
>>>>> +
>>>>> +static const struct attribute_group bma180_attrs_group = {
>>>>> +     .attrs = bma180_attributes,
>>>>> +};
>>>>> +
>>>>> +static int bma180_read_raw(struct iio_dev *indio_dev,
>>>>> +             struct iio_chan_spec const *chan, int *val, int *val2,
>>>>> +             long mask)
>>>>> +{
>>>>> +     struct bma180_data *data = iio_priv(indio_dev);
>>>>> +     int ret;
>>>>> +
>>>>> +     switch (mask) {
>>>>> +     case IIO_CHAN_INFO_RAW:
>>>>> +             mutex_lock(&data->mutex);
>>>>> +             if (iio_buffer_enabled(indio_dev))
>>>>> +                     ret = -EBUSY;
>>>>> +             else
>>>>> +                     ret = bma180_get_acc_reg(data, chan->scan_index);
>>>>> +             mutex_unlock(&data->mutex);
>>>>> +             if (ret < 0)
>>>>> +                     return ret;
>>>>> +             *val = (s16)ret >> chan->scan_type.shift;
>>>>> +             return IIO_VAL_INT;
>>>>> +     case IIO_CHAN_INFO_SCALE:
>>>>> +             *val = 0;
>>>>> +             *val2 = data->scale;
>>>>> +             return IIO_VAL_INT_PLUS_MICRO;
>>>>> +     default:
>>>>> +             return -EINVAL;
>>>>> +     }
>>>>> +}
>>>>> +
>>>>> +static int bma180_write_raw(struct iio_dev *indio_dev,
>>>>> +             struct iio_chan_spec const *chan, int val, int val2, long mask)
>>>>> +{
>>>>> +     struct bma180_data *data = iio_priv(indio_dev);
>>>>> +     int ret;
>>>>> +
>>>>> +     if (mask != IIO_CHAN_INFO_SCALE || val)
>>>>> +             return -EINVAL;
>>>>> +
>>>>> +     mutex_lock(&data->mutex);
>>>>> +     ret = bma180_set_scale(data, val2);
>>>>> +     mutex_unlock(&data->mutex);
>>>>> +
>>>>> +     return ret;
>>>>> +}
>>>>> +
>>>>> +static int bma180_update_scan_mode(struct iio_dev *indio_dev,
>>>>> +             const unsigned long *scan_mask)
>>>>> +{
>>>>> +     struct bma180_data *data = iio_priv(indio_dev);
>>>>> +
>>>>> +     kfree(data->buff);
>>>>> +     data->buff = kmalloc(indio_dev->scan_bytes, GFP_KERNEL);
>>>>> +     if (!data->buff)
>>>>> +             return -ENOMEM;
>>>>> +
>>>>> +     return 0;
>>>>> +}
>>>>> +
>>>>> +static const struct iio_info bma180_info = {
>>>>> +     .attrs                  = &bma180_attrs_group,
>>>>> +     .read_raw               = bma180_read_raw,
>>>>> +     .write_raw              = bma180_write_raw,
>>>>> +     .update_scan_mode       = bma180_update_scan_mode,
>>>>> +     .driver_module          = THIS_MODULE,
>>>>> +};
>>>>> +
>>>>> +#define BMA180_CHANNEL(_index) {                             \
>>>>> +     .type = IIO_ACCEL,                                      \
>>>>> +     .indexed = 1,                                           \
>>>>> +     .channel = (_index),                                    \
>>>>> +     .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),           \
>>>>> +     .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),   \
>>>>> +     .scan_index = (_index),                                 \
>>>>> +     .scan_type = IIO_ST('s', 14, 16, 2),                    \
>>>>> +}
>>>>> +
>>>>> +static const struct iio_chan_spec bma180_channels[] = {
>>>>> +     BMA180_CHANNEL(AXIS_X),
>>>>> +     BMA180_CHANNEL(AXIS_Y),
>>>>> +     BMA180_CHANNEL(AXIS_Z),
>>>>> +     IIO_CHAN_SOFT_TIMESTAMP(4),
>>>>> +};
>>>>> +
>>>>> +static irqreturn_t bma180_trigger_handler(int irq, void *p)
>>>>> +{
>>>>> +     struct iio_poll_func *pf = p;
>>>>> +     struct iio_dev *indio_dev = pf->indio_dev;
>>>>> +     struct bma180_data *data = iio_priv(indio_dev);
>>>>> +     int bit, ret, i = 0;
>>>>> +
>>>>> +     mutex_lock(&data->mutex);
>>>>> +     if (indio_dev->scan_timestamp) {
>>>>> +             ret = indio_dev->scan_bytes / sizeof(s64) - 1;
>>>>> +             ((s64 *)data->buff)[ret] = iio_get_time_ns();
>>>>> +     }
>>>>> +
>>>>> +     for_each_set_bit(bit, indio_dev->buffer->scan_mask,
>>>>> +                      indio_dev->masklength) {
>>>>> +             ret = bma180_get_acc_reg(data, bit);
>>>>> +             if (ret < 0) {
>>>>> +                     mutex_unlock(&data->mutex);
>>>>> +                     goto err;
>>>>> +             }
>>>>> +             ((s16 *)data->buff)[i++] = ret;
>>>>> +     }
>>>>> +     mutex_unlock(&data->mutex);
>>>>> +
>>>>> +     iio_push_to_buffers(indio_dev, (u8 *)data->buff);
>>>>> +err:
>>>>> +     iio_trigger_notify_done(indio_dev->trig);
>>>>> +
>>>>> +     return IRQ_HANDLED;
>>>>> +}
>>>>> +
>>>>> +static int bma180_data_rdy_trigger_set_state(struct iio_trigger *trig,
>>>>> +             bool state)
>>>>> +{
>>>>> +     struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
>>>>> +     struct bma180_data *data = iio_priv(indio_dev);
>>>>> +
>>>>> +     return bma180_set_new_data_intr_state(data, state);
>>>>> +}
>>>>> +
>>>>> +static int bma180_trig_try_reen(struct iio_trigger *trig)
>>>>> +{
>>>>> +     struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
>>>>> +     struct bma180_data *data = iio_priv(indio_dev);
>>>>> +
>>>>> +     return bma180_reset_intr(data);
>>>>> +}
>>>>> +
>>>>> +static const struct iio_trigger_ops bma180_trigger_ops = {
>>>>> +     .set_trigger_state = bma180_data_rdy_trigger_set_state,
>>>>> +     .try_reenable = bma180_trig_try_reen,
>>>>> +     .owner = THIS_MODULE,
>>>>> +};
>>>>> +
>>>>> +static int bma180_probe(struct i2c_client *client,
>>>>> +             const struct i2c_device_id *id)
>>>>> +{
>>>>> +     struct bma180_data *data;
>>>>> +     struct iio_dev *indio_dev;
>>>>> +     struct iio_trigger *trig;
>>>>> +     int ret;
>>>>> +
>>>>> +     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;
>>>>> +
>>>>> +     ret = bma180_chip_init(data);
>>>>> +     if (ret < 0)
>>>>> +             goto err_chip_disable;
>>>>> +
>>>>> +     mutex_init(&data->mutex);
>>>>> +
>>>>> +     indio_dev->dev.parent = &client->dev;
>>>>> +     indio_dev->channels = bma180_channels;
>>>>> +     indio_dev->num_channels = ARRAY_SIZE(bma180_channels);
>>>>> +     indio_dev->name = BMA180_DRV_NAME;
>>>>> +     indio_dev->modes = INDIO_DIRECT_MODE;
>>>>> +     indio_dev->info = &bma180_info;
>>>>> +
>>>>> +     trig = iio_trigger_alloc("%s-dev%d", indio_dev->name, indio_dev->id);
>>>>> +     if (!trig) {
>>>>> +             ret = -ENOMEM;
>>>>> +             goto err_chip_disable;
>>>>> +     }
>>>>> +
>>>>> +     ret = devm_request_irq(&client->dev, client->irq,
>>>>> +                     iio_trigger_generic_data_rdy_poll,
>>>>> +                     IRQF_TRIGGER_RISING, BMA180_IRQ_NAME, trig);
>>>>> +     if (ret) {
>>>>> +             dev_err(&client->dev, "unable to request IRQ\n");
>>>>> +             goto err_trigger_free;
>>>>> +     }
>>>>> +
>>>>> +     trig->dev.parent = &client->dev;
>>>>> +     trig->ops = &bma180_trigger_ops;
>>>>> +     iio_trigger_set_drvdata(trig, indio_dev);
>>>>> +     data->trig = trig;
>>>>> +     indio_dev->trig = trig;
>>>>> +
>>>>> +     ret = iio_trigger_register(trig);
>>>>> +     if (ret)
>>>>> +             goto err_trigger_free;
>>>>> +
>>>>> +     ret = iio_triggered_buffer_setup(indio_dev, NULL,
>>>>> +                     bma180_trigger_handler, NULL);
>>>>> +     if (ret < 0) {
>>>>> +             dev_err(&client->dev, "unable to setup iio triggered buffer\n");
>>>>> +             goto err_trigger_unregister;
>>>>> +     }
>>>>> +
>>>>> +     ret = iio_device_register(indio_dev);
>>>>> +     if (ret < 0) {
>>>>> +             dev_err(&client->dev, "unable to register iio device\n");
>>>>> +             goto err_buffer_cleanup;
>>>>> +     }
>>>>> +
>>>>> +     return 0;
>>>>> +
>>>>> +err_buffer_cleanup:
>>>>> +     iio_triggered_buffer_cleanup(indio_dev);
>>>>> +err_trigger_unregister:
>>>>> +     iio_trigger_unregister(trig);
>>>>> +err_trigger_free:
>>>>> +     iio_trigger_free(trig);
>>>>> +err_chip_disable:
>>>>> +     bma180_chip_disable(data);
>>>>> +
>>>>> +     return ret;
>>>>> +}
>>>>> +
>>>>> +static int bma180_remove(struct i2c_client *client)
>>>>> +{
>>>>> +     struct iio_dev *indio_dev = i2c_get_clientdata(client);
>>>>> +     struct bma180_data *data = iio_priv(indio_dev);
>>>>> +
>>>>> +     iio_device_unregister(indio_dev);
>>>>> +     iio_triggered_buffer_cleanup(indio_dev);
>>>>> +     iio_trigger_unregister(data->trig);
>>>>> +     iio_trigger_free(data->trig);
>>>>> +     kfree(data->buff);
>>>>> +
>>>>> +     mutex_lock(&data->mutex);
>>>>> +     bma180_chip_disable(data);
>>>>> +     mutex_unlock(&data->mutex);
>>>>> +
>>>>> +     return 0;
>>>>> +}
>>>>> +
>>>>> +#ifdef CONFIG_PM_SLEEP
>>>>> +static int bma180_suspend(struct device *dev)
>>>>> +{
>>>>> +     struct iio_dev *indio_dev = dev_to_iio_dev(dev);
>>>>> +     struct bma180_data *data = iio_priv(indio_dev);
>>>>> +     int ret;
>>>>> +
>>>>> +     mutex_lock(&data->mutex);
>>>>> +     ret = bma180_set_sleep_state(data, 1);
>>>>> +     mutex_unlock(&data->mutex);
>>>>> +
>>>>> +     return ret;
>>>>> +}
>>>>> +
>>>>> +static int bma180_resume(struct device *dev)
>>>>> +{
>>>>> +     struct iio_dev *indio_dev = dev_to_iio_dev(dev);
>>>>> +     struct bma180_data *data = iio_priv(indio_dev);
>>>>> +     int ret;
>>>>> +
>>>>> +     mutex_lock(&data->mutex);
>>>>> +     ret = bma180_set_sleep_state(data, 0);
>>>>> +     mutex_unlock(&data->mutex);
>>>>> +
>>>>> +     return ret;
>>>>> +}
>>>>> +
>>>>> +static SIMPLE_DEV_PM_OPS(bma180_pm_ops, bma180_suspend, bma180_resume);
>>>>> +#define BMA180_PM_OPS (&bma180_pm_ops)
>>>>> +#else
>>>>> +#define BMA180_PM_OPS NULL
>>>>> +#endif
>>>>> +
>>>>> +static struct i2c_device_id bma180_id[] = {
>>>>> +     { BMA180_DRV_NAME, 0 },
>>>>> +     { }
>>>>> +};
>>>>> +
>>>>> +MODULE_DEVICE_TABLE(i2c, bma180_id);
>>>>> +
>>>>> +static struct i2c_driver bma180_driver = {
>>>>> +     .driver = {
>>>>> +             .name   = BMA180_DRV_NAME,
>>>>> +             .owner  = THIS_MODULE,
>>>>> +             .pm     = BMA180_PM_OPS,
>>>>> +     },
>>>>> +     .probe          = bma180_probe,
>>>>> +     .remove         = bma180_remove,
>>>>> +     .id_table       = bma180_id,
>>>>> +};
>>>>> +
>>>>> +module_i2c_driver(bma180_driver);
>>>>> +
>>>>> +MODULE_AUTHOR("Kravchenko Oleksandr <x0199363@ti.com>");
>>>>> +MODULE_AUTHOR("Texas Instruments, Inc.");
>>>>> +MODULE_DESCRIPTION("Bosch BMA180 triaxial acceleration sensor");
>>>>> +MODULE_LICENSE("GPL");
>>> --
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