From: Oleksandr Kravchenko <o.v.kravche...@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.kravche...@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 <x0199...@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 <x0199...@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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