--- /dev/null
+/*
+ * 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 power 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_PMODE 0
+#define BMA180_DEF_BW 20
+#define BMA180_DEF_SCALE 250
+
+/* Available values for sysfs */
+#define BMA180_FLP_FREQ_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 pmode;
+ 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_pmode(struct bma180_data *data, int mode)
+{
+ u8 reg_val = mode ? BMA180_LOW_POWER : BMA180_LOW_NOISE;
+ int ret = bma180_set_bits(data, BMA180_TCO_Z, BMA180_MODE_CONFIG,
+ reg_val);
+
+ if (ret) {
+ dev_err(&data->client->dev, "failed to set power mode\n");
+ return ret;
+ }
+ data->pmode = mode;
+
+ return 0;
+}
+
+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_pmode(data, BMA180_DEF_PMODE);
+ 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 IIO_CONST_ATTR(in_accel_filter_low_pass_3db_frequency_available,
+ BMA180_FLP_FREQ_AVAILABLE);
+static IIO_CONST_ATTR(in_accel_scale_available, BMA180_SCALE_AVAILABLE);
+
+static struct attribute *bma180_attributes[] = {
+ &iio_const_attr_in_accel_filter_low_pass_3db_frequency_available.dev_attr.attr,
+ &iio_const_attr_in_accel_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_LOW_PASS_FILTER_3DB_FREQUENCY:
+ *val = data->bw;
+ 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;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_SCALE:
+ if (val)
+ return -EINVAL;
+ mutex_lock(&data->mutex);
+ ret = bma180_set_scale(data, val2);
+ mutex_unlock(&data->mutex);
+ return ret;
+ case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
+ mutex_lock(&data->mutex);
+ ret = bma180_set_bw(data, val);
+ mutex_unlock(&data->mutex);
+ return ret;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int bma180_update_scan_mode(struct iio_dev *indio_dev,
+ const unsigned long *scan_mask)
+{
+ struct bma180_data *data = iio_priv(indio_dev);
+
+ if (data->buff)
+ devm_kfree(&indio_dev->dev, data->buff);
+ data->buff = devm_kzalloc(&indio_dev->dev,
+ 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,
+};
+
+static const char * const bma180_power_modes[] = {
+ BMA180_LOW_NOISE_STR,
+ BMA180_LOW_POWER_STR,
+};
+
+static int bma180_get_power_mode(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan)
+{
+ struct bma180_data *data = iio_priv(indio_dev);
+
+ return data->pmode;
+}
+
+static int bma180_set_power_mode(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan, unsigned int mode)
+{
+ struct bma180_data *data = iio_priv(indio_dev);
+ int ret;
+
+ mutex_lock(&data->mutex);
+ ret = bma180_set_pmode(data, mode);
+ mutex_unlock(&data->mutex);
+
+ return ret;
+}
+
+static const struct iio_enum bma180_power_mode_enum = {
+ .items = bma180_power_modes,
+ .num_items = ARRAY_SIZE(bma180_power_modes),
+ .get = bma180_get_power_mode,
+ .set = bma180_set_power_mode,
+};
+
+static const struct iio_chan_spec_ext_info bma180_ext_info[] = {
+ IIO_ENUM("power_mode", true, &bma180_power_mode_enum),
+ IIO_ENUM_AVAILABLE("power_mode", &bma180_power_mode_enum),
+ { },
+};
+
+#define BMA180_CHANNEL(_index) { \
+ .type = IIO_ACCEL, \
+ .indexed = 1, \
+ .channel = (_index), \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
+ BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY), \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
+ .scan_index = (_index), \
+ .scan_type = IIO_ST('s', 14, 16, 2), \
+ .ext_info = bma180_ext_info, \
+}
+
+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);
+
+ 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");
projects / ~andy / linux / commitdiff