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Subject[PATCH 2/2] iio: add Bosch BMA180 acceleration sensor driver
Date
From: Oleksandr Kravchenko <o.v.kravchenko@globallogic.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@globallogic.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@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/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@ti.com>");
+MODULE_AUTHOR("Texas Instruments, Inc.");
+MODULE_DESCRIPTION("Bosch BMA180 triaxial acceleration sensor");
+MODULE_LICENSE("GPL");
--
1.7.9.5
--
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