/**
* Sensortek STK8BA50 3-Axis Accelerometer
*
* Copyright (c) 2015, Intel Corporation.
*
* 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.
*
* STK8BA50 7-bit I2C address: 0x18.
*/
#include <linux/acpi.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/iio/buffer.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/trigger.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/iio/trigger_consumer.h>
#define STK8BA50_REG_XOUT 0x02
#define STK8BA50_REG_YOUT 0x04
#define STK8BA50_REG_ZOUT 0x06
#define STK8BA50_REG_RANGE 0x0F
#define STK8BA50_REG_BWSEL 0x10
#define STK8BA50_REG_POWMODE 0x11
#define STK8BA50_REG_SWRST 0x14
#define STK8BA50_REG_INTEN2 0x17
#define STK8BA50_REG_INTMAP2 0x1A
#define STK8BA50_MODE_NORMAL 0
#define STK8BA50_MODE_SUSPEND 1
#define STK8BA50_MODE_POWERBIT BIT(7)
#define STK8BA50_DATA_SHIFT 6
#define STK8BA50_RESET_CMD 0xB6
#define STK8BA50_SR_1792HZ_IDX 7
#define STK8BA50_DREADY_INT_MASK 0x10
#define STK8BA50_DREADY_INT_MAP 0x81
#define STK8BA50_ALL_CHANNEL_MASK 7
#define STK8BA50_ALL_CHANNEL_SIZE 6
#define STK8BA50_DRIVER_NAME "stk8ba50"
#define STK8BA50_IRQ_NAME "stk8ba50_event"
#define STK8BA50_SCALE_AVAIL "0.0384 0.0767 0.1534 0.3069"
/*
* The accelerometer has four measurement ranges:
* +/-2g; +/-4g; +/-8g; +/-16g
*
* Acceleration values are 10-bit, 2's complement.
* Scales are calculated as following:
*
* scale1 = (2 + 2) * 9.81 / (2^10 - 1) = 0.0384
* scale2 = (4 + 4) * 9.81 / (2^10 - 1) = 0.0767
* etc.
*
* Scales are stored in this format:
* { <register value>, <scale value> }
*
* Locally, the range is stored as a table index.
*/
static const struct {
u8 reg_val;
u32 scale_val;
} stk8ba50_scale_table[] = {
{3, 38400}, {5, 76700}, {8, 153400}, {12, 306900}
};
/* Sample rates are stored as { <register value>, <Hz value> } */
static const struct {
u8 reg_val;
u16 samp_freq;
} stk8ba50_samp_freq_table[] = {
{0x08, 14}, {0x09, 25}, {0x0A, 56}, {0x0B, 112},
{0x0C, 224}, {0x0D, 448}, {0x0E, 896}, {0x0F, 1792}
};
/* Used to map scan mask bits to their corresponding channel register. */
static const int stk8ba50_channel_table[] = {
STK8BA50_REG_XOUT,
STK8BA50_REG_YOUT,
STK8BA50_REG_ZOUT
};
struct stk8ba50_data {
struct i2c_client *client;
struct mutex lock;
int range;
u8 sample_rate_idx;
struct iio_trigger *dready_trig;
bool dready_trigger_on;
/*
* 3 x 16-bit channels (10-bit data, 6-bit padding) +
* 1 x 16 padding +
* 4 x 16 64-bit timestamp
*/
s16 buffer[8];
};
#define STK8BA50_ACCEL_CHANNEL(index, reg, axis) { \
.type = IIO_ACCEL, \
.address = reg, \
.modified = 1, \
.channel2 = IIO_MOD_##axis, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
BIT(IIO_CHAN_INFO_SAMP_FREQ), \
.scan_index = index, \
.scan_type = { \
.sign = 's', \
.realbits = 10, \
.storagebits = 16, \
.shift = STK8BA50_DATA_SHIFT, \
.endianness = IIO_CPU, \
}, \
}
static const struct iio_chan_spec stk8ba50_channels[] = {
STK8BA50_ACCEL_CHANNEL(0, STK8BA50_REG_XOUT, X),
STK8BA50_ACCEL_CHANNEL(1, STK8BA50_REG_YOUT, Y),
STK8BA50_ACCEL_CHANNEL(2, STK8BA50_REG_ZOUT, Z),
IIO_CHAN_SOFT_TIMESTAMP(3),
};
static IIO_CONST_ATTR(in_accel_scale_available, STK8BA50_SCALE_AVAIL);
static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("14 25 56 112 224 448 896 1792");
static struct attribute *stk8ba50_attributes[] = {
&iio_const_attr_in_accel_scale_available.dev_attr.attr,
&iio_const_attr_sampling_frequency_available.dev_attr.attr,
NULL,
};
static const struct attribute_group stk8ba50_attribute_group = {
.attrs = stk8ba50_attributes
};
static int stk8ba50_read_accel(struct stk8ba50_data *data, u8 reg)
{
int ret;
struct i2c_client *client = data->client;
ret = i2c_smbus_read_word_data(client, reg);
if (ret < 0) {
dev_err(&client->dev, "register read failed\n");
return ret;
}
return ret;
}
static int stk8ba50_data_rdy_trigger_set_state(struct iio_trigger *trig,
bool state)
{
struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
struct stk8ba50_data *data = iio_priv(indio_dev);
int ret;
if (state)
ret = i2c_smbus_write_byte_data(data->client,
STK8BA50_REG_INTEN2, STK8BA50_DREADY_INT_MASK);
else
ret = i2c_smbus_write_byte_data(data->client,
STK8BA50_REG_INTEN2, 0x00);
if (ret < 0)
dev_err(&data->client->dev, "failed to set trigger state\n");
else
data->dready_trigger_on = state;
return ret;
}
static const struct iio_trigger_ops stk8ba50_trigger_ops = {
.set_trigger_state = stk8ba50_data_rdy_trigger_set_state,
.owner = THIS_MODULE,
};
static int stk8ba50_set_power(struct stk8ba50_data *data, bool mode)
{
int ret;
u8 masked_reg;
struct i2c_client *client = data->client;
ret = i2c_smbus_read_byte_data(client, STK8BA50_REG_POWMODE);
if (ret < 0)
goto exit_err;
if (mode)
masked_reg = ret | STK8BA50_MODE_POWERBIT;
else
masked_reg = ret & (~STK8BA50_MODE_POWERBIT);
ret = i2c_smbus_write_byte_data(client, STK8BA50_REG_POWMODE,
masked_reg);
if (ret < 0)
goto exit_err;
return ret;
exit_err:
dev_err(&client->dev, "failed to change sensor mode\n");
return ret;
}
static int stk8ba50_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct stk8ba50_data *data = iio_priv(indio_dev);
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
if (iio_buffer_enabled(indio_dev))
return -EBUSY;
mutex_lock(&data->lock);
ret = stk8ba50_set_power(data, STK8BA50_MODE_NORMAL);
if (ret < 0) {
mutex_unlock(&data->lock);
return -EINVAL;
}
ret = stk8ba50_read_accel(data, chan->address);
if (ret < 0) {
stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
mutex_unlock(&data->lock);
return -EINVAL;
}
*val = sign_extend32(ret >> STK8BA50_DATA_SHIFT, 9);
stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
mutex_unlock(&data->lock);
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
*val = 0;
*val2 = stk8ba50_scale_table[data->range].scale_val;
return IIO_VAL_INT_PLUS_MICRO;
case IIO_CHAN_INFO_SAMP_FREQ:
*val = stk8ba50_samp_freq_table
[data->sample_rate_idx].samp_freq;
*val2 = 0;
return IIO_VAL_INT;
}
return -EINVAL;
}
static int stk8ba50_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val, int val2, long mask)
{
int ret;
int i;
int index = -1;
struct stk8ba50_data *data = iio_priv(indio_dev);
switch (mask) {
case IIO_CHAN_INFO_SCALE:
if (val != 0)
return -EINVAL;
for (i = 0; i < ARRAY_SIZE(stk8ba50_scale_table); i++)
if (val2 == stk8ba50_scale_table[i].scale_val) {
index = i;
break;
}
if (index < 0)
return -EINVAL;
ret = i2c_smbus_write_byte_data(data->client,
STK8BA50_REG_RANGE,
stk8ba50_scale_table[index].reg_val);
if (ret < 0)
dev_err(&data->client->dev,
"failed to set measurement range\n");
else
data->range = index;
return ret;
case IIO_CHAN_INFO_SAMP_FREQ:
for (i = 0; i < ARRAY_SIZE(stk8ba50_samp_freq_table); i++)
if (val == stk8ba50_samp_freq_table[i].samp_freq) {
index = i;
break;
}
if (index < 0)
return -EINVAL;
ret = i2c_smbus_write_byte_data(data->client,
STK8BA50_REG_BWSEL,
stk8ba50_samp_freq_table[index].reg_val);
if (ret < 0)
dev_err(&data->client->dev,
"failed to set sampling rate\n");
else
data->sample_rate_idx = index;
return ret;
}
return -EINVAL;
}
static const struct iio_info stk8ba50_info = {
.driver_module = THIS_MODULE,
.read_raw = stk8ba50_read_raw,
.write_raw = stk8ba50_write_raw,
.attrs = &stk8ba50_attribute_group,
};
static irqreturn_t stk8ba50_trigger_handler(int irq, void *p)
{
struct iio_poll_func *pf = p;
struct iio_dev *indio_dev = pf->indio_dev;
struct stk8ba50_data *data = iio_priv(indio_dev);
int bit, ret, i = 0;
mutex_lock(&data->lock);
/*
* Do a bulk read if all channels are requested,
* from 0x02 (XOUT1) to 0x07 (ZOUT2)
*/
if (*(indio_dev->active_scan_mask) == STK8BA50_ALL_CHANNEL_MASK) {
ret = i2c_smbus_read_i2c_block_data(data->client,
STK8BA50_REG_XOUT,
STK8BA50_ALL_CHANNEL_SIZE,
(u8 *)data->buffer);
if (ret < STK8BA50_ALL_CHANNEL_SIZE) {
dev_err(&data->client->dev, "register read failed\n");
goto err;
}
} else {
for_each_set_bit(bit, indio_dev->active_scan_mask,
indio_dev->masklength) {
ret = stk8ba50_read_accel(data,
stk8ba50_channel_table[bit]);
if (ret < 0)
goto err;
data->buffer[i++] = ret;
}
}
iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
pf->timestamp);
err:
mutex_unlock(&data->lock);
iio_trigger_notify_done(indio_dev->trig);
return IRQ_HANDLED;
}
static irqreturn_t stk8ba50_data_rdy_trig_poll(int irq, void *private)
{
struct iio_dev *indio_dev = private;
struct stk8ba50_data *data = iio_priv(indio_dev);
if (data->dready_trigger_on)
iio_trigger_poll(data->dready_trig);
return IRQ_HANDLED;
}
static int stk8ba50_buffer_preenable(struct iio_dev *indio_dev)
{
struct stk8ba50_data *data = iio_priv(indio_dev);
return stk8ba50_set_power(data, STK8BA50_MODE_NORMAL);
}
static int stk8ba50_buffer_postdisable(struct iio_dev *indio_dev)
{
struct stk8ba50_data *data = iio_priv(indio_dev);
return stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
}
static const struct iio_buffer_setup_ops stk8ba50_buffer_setup_ops = {
.preenable = stk8ba50_buffer_preenable,
.postenable = iio_triggered_buffer_postenable,
.predisable = iio_triggered_buffer_predisable,
.postdisable = stk8ba50_buffer_postdisable,
};
static int stk8ba50_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
int ret;
struct iio_dev *indio_dev;
struct stk8ba50_data *data;
indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
if (!indio_dev) {
dev_err(&client->dev, "iio allocation failed!\n");
return -ENOMEM;
}
data = iio_priv(indio_dev);
data->client = client;
i2c_set_clientdata(client, indio_dev);
mutex_init(&data->lock);
indio_dev->dev.parent = &client->dev;
indio_dev->info = &stk8ba50_info;
indio_dev->name = STK8BA50_DRIVER_NAME;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = stk8ba50_channels;
indio_dev->num_channels = ARRAY_SIZE(stk8ba50_channels);
/* Reset all registers on startup */
ret = i2c_smbus_write_byte_data(client,
STK8BA50_REG_SWRST, STK8BA50_RESET_CMD);
if (ret < 0) {
dev_err(&client->dev, "failed to reset sensor\n");
goto err_power_off;
}
/* The default range is +/-2g */
data->range = 0;
/* The default sampling rate is 1792 Hz (maximum) */
data->sample_rate_idx = STK8BA50_SR_1792HZ_IDX;
/* Set up interrupts */
ret = i2c_smbus_write_byte_data(client,
STK8BA50_REG_INTEN2, STK8BA50_DREADY_INT_MASK);
if (ret < 0) {
dev_err(&client->dev, "failed to set up interrupts\n");
goto err_power_off;
}
ret = i2c_smbus_write_byte_data(client,
STK8BA50_REG_INTMAP2, STK8BA50_DREADY_INT_MAP);
if (ret < 0) {
dev_err(&client->dev, "failed to set up interrupts\n");
goto err_power_off;
}
if (client->irq > 0) {
ret = devm_request_threaded_irq(&client->dev, client->irq,
stk8ba50_data_rdy_trig_poll,
NULL,
IRQF_TRIGGER_RISING |
IRQF_ONESHOT,
STK8BA50_IRQ_NAME,
indio_dev);
if (ret < 0) {
dev_err(&client->dev, "request irq %d failed\n",
client->irq);
goto err_power_off;
}
data->dready_trig = devm_iio_trigger_alloc(&client->dev,
"%s-dev%d",
indio_dev->name,
indio_dev->id);
if (!data->dready_trig) {
ret = -ENOMEM;
goto err_power_off;
}
data->dready_trig->dev.parent = &client->dev;
data->dready_trig->ops = &stk8ba50_trigger_ops;
iio_trigger_set_drvdata(data->dready_trig, indio_dev);
ret = iio_trigger_register(data->dready_trig);
if (ret) {
dev_err(&client->dev, "iio trigger register failed\n");
goto err_power_off;
}
}
ret = iio_triggered_buffer_setup(indio_dev,
iio_pollfunc_store_time,
stk8ba50_trigger_handler,
&stk8ba50_buffer_setup_ops);
if (ret < 0) {
dev_err(&client->dev, "iio triggered buffer setup failed\n");
goto err_trigger_unregister;
}
ret = iio_device_register(indio_dev);
if (ret < 0) {
dev_err(&client->dev, "device_register failed\n");
goto err_buffer_cleanup;
}
return ret;
err_buffer_cleanup:
iio_triggered_buffer_cleanup(indio_dev);
err_trigger_unregister:
if (data->dready_trig)
iio_trigger_unregister(data->dready_trig);
err_power_off:
stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
return ret;
}
static int stk8ba50_remove(struct i2c_client *client)
{
struct iio_dev *indio_dev = i2c_get_clientdata(client);
struct stk8ba50_data *data = iio_priv(indio_dev);
iio_device_unregister(indio_dev);
iio_triggered_buffer_cleanup(indio_dev);
if (data->dready_trig)
iio_trigger_unregister(data->dready_trig);
return stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
}
#ifdef CONFIG_PM_SLEEP
static int stk8ba50_suspend(struct device *dev)
{
struct stk8ba50_data *data;
data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
return stk8ba50_set_power(data, STK8BA50_MODE_SUSPEND);
}
static int stk8ba50_resume(struct device *dev)
{
struct stk8ba50_data *data;
data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
return stk8ba50_set_power(data, STK8BA50_MODE_NORMAL);
}
static SIMPLE_DEV_PM_OPS(stk8ba50_pm_ops, stk8ba50_suspend, stk8ba50_resume);
#define STK8BA50_PM_OPS (&stk8ba50_pm_ops)
#else
#define STK8BA50_PM_OPS NULL
#endif
static const struct i2c_device_id stk8ba50_i2c_id[] = {
{"stk8ba50", 0},
{}
};
MODULE_DEVICE_TABLE(i2c, stk8ba50_i2c_id);
static const struct acpi_device_id stk8ba50_acpi_id[] = {
{"STK8BA50", 0},
{}
};
MODULE_DEVICE_TABLE(acpi, stk8ba50_acpi_id);
static struct i2c_driver stk8ba50_driver = {
.driver = {
.name = "stk8ba50",
.pm = STK8BA50_PM_OPS,
.acpi_match_table = ACPI_PTR(stk8ba50_acpi_id),
},
.probe = stk8ba50_probe,
.remove = stk8ba50_remove,
.id_table = stk8ba50_i2c_id,
};
module_i2c_driver(stk8ba50_driver);
MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>");
MODULE_DESCRIPTION("STK8BA50 3-Axis Accelerometer driver");
MODULE_LICENSE("GPL v2");
