Date:	Mon, 29 Jul 2013 17:58:13 +0300
From:	Oleksandr Kravchenko <x0199363@...com>
To:	<linux-iio@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
	<linux-doc@...r.kernel.org>
CC:	<grant.likely@...aro.org>, <rob.herring@...xeda.com>,
	<rob@...dley.net>, <jic23@....ac.uk>, <pmeerw@...erw.net>,
	<holler@...oftware.de>, <srinivas.pandruvada@...el.com>,
	<devicetree-discuss@...ts.ozlabs.org>,
	Oleksandr Kravchenko <o.v.kravchenko@...ballogic.com>
Subject: [PATCH 2/2] iio: add Bosch BMA180 acceleration sensor driver

From: Oleksandr Kravchenko <o.v.kravchenko@...ballogic.com>

This patch adds IIO driver for Bosch BMA180 triaxial
acceleration sensor.
http://omapworld.com/BMA180_111_1002839.pdf

Signed-off-by: Oleksandr Kravchenko <o.v.kravchenko@...ballogic.com>
---
 .../devicetree/bindings/iio/accel/bma180.txt       |   53 +++
 drivers/iio/accel/Kconfig                          |   10 +
 drivers/iio/accel/Makefile                         |    2 +
 drivers/iio/accel/bma180.c                         |  462 ++++++++++++++++++++
 4 files changed, 527 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..7c13c84
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/accel/bma180.txt
@@ -0,0 +1,53 @@
+* 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 shuld by configured with
+		flags IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_EDGE_RISING
+
+  - range : select the full scale acceleration range
+		0 : -1g..+1g
+		1 : -1.5g..+1.5g
+		2 : -2g..+2g
+		3 : -3g..+3g
+		4 : -4g..+4g
+		5 : -8g..+8g
+		6 : -16g..+16g
+
+  - bw : select bandwidth bandwidth
+		0 : 10Hz
+		1 : 20Hz
+		2 : 40Hz
+		3 : 75Hz
+		4 : 150Hz
+		5 : 300Hz
+		Don't use bandwidth frequency more than 300Hz couse it
+		influences the frequency of generating new data interrupts
+		and i2c reading phase can be longer than pheriod of interrupt
+		generation.
+
+  - mode_config : 0 - select low noise mode, 1 - select low power mode
+
+  - fuzz : specifies fuzz value that is used to filter noise from the event stream
+
+Example:
+
+bma180@40 {
+	compatible = "bosch,bma180";
+	reg = <0x40>;
+	interrupt-parent = <&gpio6>;
+	interrupts = <18 (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_EDGE_RISING)>;
+	range = <2>;
+	bw = <0>;
+	mode_config = <1>;
+	fuzz = <555>;
+};
diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
index 719d83f..61fd29f 100644
--- a/drivers/iio/accel/Kconfig
+++ b/drivers/iio/accel/Kconfig
@@ -3,6 +3,16 @@
 #
 menu "Accelerometers"
 
+config BMA180
+	tristate "Bosch BMA180 3-Axis Accelerometer Driver"
+	depends on I2C
+	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..31a36fa 100644
--- a/drivers/iio/accel/Makefile
+++ b/drivers/iio/accel/Makefile
@@ -12,3 +12,5 @@ obj-$(CONFIG_IIO_ST_ACCEL_I2C_3AXIS) += st_accel_i2c.o
 obj-$(CONFIG_IIO_ST_ACCEL_SPI_3AXIS) += st_accel_spi.o
 
 obj-$(CONFIG_KXSD9)	+= kxsd9.o
+
+obj-$(CONFIG_BMA180)	+= bma180.o
diff --git a/drivers/iio/accel/bma180.c b/drivers/iio/accel/bma180.c
new file mode 100644
index 0000000..9f5341f
--- /dev/null
+++ b/drivers/iio/accel/bma180.c
@@ -0,0 +1,462 @@
+/*
+ * bma180.c - IIO driver for Bosch BMA180 triaxial acceleration sensor
+ *
+ * Copyright 2013 Oleksandr Kravchenko <x0199363@...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/input.h>
+#include <linux/of.h>
+#include <linux/bitops.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/events.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
+
+/* Control bits */
+#define BMA180_SLEEP		BIT(1) /* 1 - chip will sleep */
+#define BMA180_DIS_WAKE_UP	BIT(0) /* Disable wake up mode */
+#define BMA180_EE_W		BIT(4) /* Unlock writing to addr. from 0x20 */
+#define BMA180_NEW_DATA_INT	BIT(1) /* Intr every new accel data is ready */
+#define BMA180_SMP_SKIP		BIT(0) /* Sample skipping mode */
+
+/* Bit masks fo registerts bit fields */
+#define BMA180_RANGE		0x0e /* Range of accel measurment */
+#define BMA180_BW		0xf0 /* Accel measurmend bandwidth */
+#define BMA180_MODE_CONFIG	0x03 /* Config operation modes */
+
+/* We have write this value in reset register to do soft reset */
+#define BMA180_RESET_VAL	0xb6
+
+/* Chip operation modes */
+#define BMA180_LOW_NOISE	0x00
+#define BMA180_LOW_POWER	0x03
+
+struct bma180_data {
+	struct i2c_client *client;
+	struct input_dev *input_dev;
+	struct mutex mutex;
+	int sleep_state;
+	int range;
+	int bw;
+	int mode;
+	int fuzz;
+	int acc_reg[3];
+};
+
+enum bma180_axis {
+	AXIS_X,
+	AXIS_Y,
+	AXIS_Z,
+};
+
+struct bma180_range {
+	int g_range;
+	int ratio;
+};
+
+static struct bma180_range bma180_range_table[7] = {
+	{ 1000, 130 },
+	{ 1500, 190 },
+	{ 2000, 250 },
+	{ 3000, 380 },
+	{ 4000, 500 },
+	{ 8000, 990 },
+	{ 16000, 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_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)
+		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_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 != 0x03) {
+		ret = -ENODEV;
+		goto err;
+	}
+
+	ret = bma180_soft_reset(data);
+	if (ret)
+		goto err;
+	/*
+	 * No serial transaction should occur within minimum 10 μs
+	 * 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_BW_TCS, BMA180_BW, data->bw);
+	if (ret)
+		goto err;
+	ret = bma180_set_bits(data,
+			BMA180_OFFSET_LSB1, BMA180_RANGE, data->range);
+	if (ret)
+		goto err;
+	ret = bma180_set_bits(data, BMA180_TCO_Z, BMA180_MODE_CONFIG,
+			data->mode ? BMA180_LOW_POWER : BMA180_LOW_NOISE);
+	if (ret)
+		goto err;
+	ret = bma180_set_bits(data, BMA180_OFFSET_LSB1, BMA180_SMP_SKIP, 1);
+	if (ret)
+		goto err;
+	ret = bma180_set_new_data_intr_state(data, 1);
+	if (ret)
+		goto err;
+	ret = bma180_set_ee_writing_state(data, 0);
+	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_ee_writing_state(data, 1))
+		goto err;
+	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 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);
+	long tmp = ((s16)data->acc_reg[chan->channel] >> 2)
+		* bma180_range_table[data->range].ratio;
+
+	if (data->acc_reg[chan->channel] < 0)
+		return data->acc_reg[chan->channel];
+
+	*val = tmp / 1000000;
+	*val2 = (tmp % 1000000);
+
+	return IIO_VAL_INT_PLUS_MICRO;
+}
+
+static const struct iio_info bma180_info = {
+	.driver_module	= THIS_MODULE,
+	.read_raw	= &bma180_read_raw,
+};
+
+static const struct iio_chan_spec bma180_channels[] = {
+	{
+		.type = IIO_ACCEL,
+		.channel = AXIS_X,
+		.channel2 = IIO_MOD_X,
+		.indexed = true,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+	}, {
+		.type = IIO_ACCEL,
+		.channel = AXIS_Y,
+		.channel2 = IIO_MOD_Y,
+		.indexed = true,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+	}, {
+		.type = IIO_ACCEL,
+		.channel = AXIS_Z,
+		.channel2 = IIO_MOD_Z,
+		.indexed = true,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+	},
+};
+
+static irqreturn_t bma180_interrupt_handler(int irq, void *private)
+{
+	struct iio_dev *dev_info = private;
+	struct bma180_data *data = iio_priv(dev_info);
+	int i;
+
+	mutex_lock(&data->mutex);
+	for (i = AXIS_X; i <= AXIS_Z; ++i)
+		data->acc_reg[i] = bma180_get_acc_reg(data, i);
+	mutex_unlock(&data->mutex);
+
+	input_report_abs(data->input_dev, ABS_X, data->acc_reg[AXIS_X]);
+	input_report_abs(data->input_dev, ABS_Y, data->acc_reg[AXIS_Y]);
+	input_report_abs(data->input_dev, ABS_Z, data->acc_reg[AXIS_Z]);
+	input_sync(data->input_dev);
+
+	return IRQ_HANDLED;
+}
+
+static int bma180_probe(struct i2c_client *client,
+		const struct i2c_device_id *id)
+{
+	struct input_dev *input_dev;
+	struct bma180_data *data;
+	struct iio_dev *indio_dev;
+	struct device_node *np = client->dev.of_node;
+	int i, ret;
+
+	if (!client->irq) {
+		dev_err(&client->dev, "this driver cann't work without IRQ\n");
+		return -ENODEV;
+	}
+
+	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	input_dev = input_allocate_device();
+	if (!input_dev)
+		return -ENOMEM;
+
+	data = iio_priv(indio_dev);
+	i2c_set_clientdata(client, indio_dev);
+	data->client = client;
+
+	of_property_read_u32(np, "bw", &data->bw);
+	of_property_read_u32(np, "range", &data->range);
+	of_property_read_u32(np, "mode", &data->mode);
+	of_property_read_u32(np, "fuzz", &data->fuzz);
+
+	ret = bma180_chip_init(data);
+	if (ret < 0)
+		goto err_1;
+
+	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;
+
+	input_dev->name = BMA180_DRV_NAME;
+	input_dev->id.bustype = BUS_I2C;
+	__set_bit(EV_ABS, input_dev->evbit);
+	for (i = ABS_X; i <= ABS_Z; ++i)
+		input_set_abs_params(input_dev, i,
+				     -bma180_range_table[data->range].g_range,
+				     bma180_range_table[data->range].g_range,
+				     data->fuzz, 0);
+	input_dev->dev.parent = &client->dev;
+	input_set_drvdata(input_dev, data);
+
+	data->input_dev = input_dev;
+
+	ret = devm_request_threaded_irq(&client->dev, client->irq,
+			NULL, bma180_interrupt_handler, IRQF_ONESHOT,
+			BMA180_IRQ_NAME, indio_dev);
+	if (ret < 0) {
+		dev_err(&client->dev, "irq request error %d\n", -ret);
+		goto err_1;
+	}
+
+	ret = input_register_device(input_dev);
+	if (ret) {
+		dev_err(&client->dev, "unable to register input device\n");
+		goto err_1;
+	}
+
+
+	ret = iio_device_register(indio_dev);
+	if (ret < 0) {
+		dev_err(&client->dev, "unable to register iio device\n");
+		goto err_2;
+	}
+
+	return 0;
+
+err_2:
+	input_unregister_device(input_dev);
+err_1:
+	input_free_device(input_dev);
+
+	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);
+	input_unregister_device(data->input_dev);
+
+	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 = i2c_get_clientdata(to_i2c_client(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 = i2c_get_clientdata(to_i2c_client(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@...com>");
+MODULE_AUTHOR("Texas Instruments, Inc.");
+MODULE_DESCRIPTION("Bosch BMA180 triaxial acceleration sensor");
+MODULE_LICENSE("GPL");
-- 
1.7.9.5

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