blob: 0c2caf3570db9729fadfbeb509e0218b7fd45d8d [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
/*
* System Control and Management Interface(SCMI) based IIO sensor driver
*
* Copyright (C) 2021 Google LLC
*/
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/iio/buffer.h>
#include <linux/iio/iio.h>
#include <linux/iio/kfifo_buf.h>
#include <linux/iio/sysfs.h>
#include <linux/kernel.h>
#include <linux/kthread.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/scmi_protocol.h>
#include <linux/time.h>
#include <linux/types.h>
#include <linux/units.h>
#define SCMI_IIO_NUM_OF_AXIS 3
struct scmi_iio_priv {
const struct scmi_sensor_proto_ops *sensor_ops;
struct scmi_protocol_handle *ph;
const struct scmi_sensor_info *sensor_info;
struct iio_dev *indio_dev;
/* lock to protect against multiple access to the device */
struct mutex lock;
/* adding one additional channel for timestamp */
s64 iio_buf[SCMI_IIO_NUM_OF_AXIS + 1];
struct notifier_block sensor_update_nb;
u32 *freq_avail;
};
static int scmi_iio_sensor_update_cb(struct notifier_block *nb,
unsigned long event, void *data)
{
struct scmi_sensor_update_report *sensor_update = data;
struct iio_dev *scmi_iio_dev;
struct scmi_iio_priv *sensor;
s8 tstamp_scale;
u64 time, time_ns;
int i;
if (sensor_update->readings_count == 0)
return NOTIFY_DONE;
sensor = container_of(nb, struct scmi_iio_priv, sensor_update_nb);
for (i = 0; i < sensor_update->readings_count; i++)
sensor->iio_buf[i] = sensor_update->readings[i].value;
if (!sensor->sensor_info->timestamped) {
time_ns = ktime_to_ns(sensor_update->timestamp);
} else {
/*
* All the axes are supposed to have the same value for timestamp.
* We are just using the values from the Axis 0 here.
*/
time = sensor_update->readings[0].timestamp;
/*
* Timestamp returned by SCMI is in seconds and is equal to
* time * power-of-10 multiplier(tstamp_scale) seconds.
* Converting the timestamp to nanoseconds below.
*/
tstamp_scale = sensor->sensor_info->tstamp_scale +
const_ilog2(NSEC_PER_SEC) / const_ilog2(10);
if (tstamp_scale < 0) {
do_div(time, int_pow(10, abs(tstamp_scale)));
time_ns = time;
} else {
time_ns = time * int_pow(10, tstamp_scale);
}
}
scmi_iio_dev = sensor->indio_dev;
iio_push_to_buffers_with_timestamp(scmi_iio_dev, sensor->iio_buf,
time_ns);
return NOTIFY_OK;
}
static int scmi_iio_buffer_preenable(struct iio_dev *iio_dev)
{
struct scmi_iio_priv *sensor = iio_priv(iio_dev);
u32 sensor_config = 0;
int err;
if (sensor->sensor_info->timestamped)
sensor_config |= FIELD_PREP(SCMI_SENS_CFG_TSTAMP_ENABLED_MASK,
SCMI_SENS_CFG_TSTAMP_ENABLE);
sensor_config |= FIELD_PREP(SCMI_SENS_CFG_SENSOR_ENABLED_MASK,
SCMI_SENS_CFG_SENSOR_ENABLE);
err = sensor->sensor_ops->config_set(sensor->ph,
sensor->sensor_info->id,
sensor_config);
if (err)
dev_err(&iio_dev->dev, "Error in enabling sensor %s err %d",
sensor->sensor_info->name, err);
return err;
}
static int scmi_iio_buffer_postdisable(struct iio_dev *iio_dev)
{
struct scmi_iio_priv *sensor = iio_priv(iio_dev);
u32 sensor_config = 0;
int err;
sensor_config |= FIELD_PREP(SCMI_SENS_CFG_SENSOR_ENABLED_MASK,
SCMI_SENS_CFG_SENSOR_DISABLE);
err = sensor->sensor_ops->config_set(sensor->ph,
sensor->sensor_info->id,
sensor_config);
if (err) {
dev_err(&iio_dev->dev,
"Error in disabling sensor %s with err %d",
sensor->sensor_info->name, err);
}
return err;
}
static const struct iio_buffer_setup_ops scmi_iio_buffer_ops = {
.preenable = scmi_iio_buffer_preenable,
.postdisable = scmi_iio_buffer_postdisable,
};
static int scmi_iio_set_odr_val(struct iio_dev *iio_dev, int val, int val2)
{
struct scmi_iio_priv *sensor = iio_priv(iio_dev);
u64 sec, mult, uHz, sf;
u32 sensor_config;
char buf[32];
int err = sensor->sensor_ops->config_get(sensor->ph,
sensor->sensor_info->id,
&sensor_config);
if (err) {
dev_err(&iio_dev->dev,
"Error in getting sensor config for sensor %s err %d",
sensor->sensor_info->name, err);
return err;
}
uHz = val * MICROHZ_PER_HZ + val2;
/*
* The seconds field in the sensor interval in SCMI is 16 bits long
* Therefore seconds = 1/Hz <= 0xFFFF. As floating point calculations are
* discouraged in the kernel driver code, to calculate the scale factor (sf)
* (1* 1000000 * sf)/uHz <= 0xFFFF. Therefore, sf <= (uHz * 0xFFFF)/1000000
* To calculate the multiplier,we convert the sf into char string and
* count the number of characters
*/
sf = (u64)uHz * 0xFFFF;
do_div(sf, MICROHZ_PER_HZ);
mult = scnprintf(buf, sizeof(buf), "%llu", sf) - 1;
sec = int_pow(10, mult) * MICROHZ_PER_HZ;
do_div(sec, uHz);
if (sec == 0) {
dev_err(&iio_dev->dev,
"Trying to set invalid sensor update value for sensor %s",
sensor->sensor_info->name);
return -EINVAL;
}
sensor_config &= ~SCMI_SENS_CFG_UPDATE_SECS_MASK;
sensor_config |= FIELD_PREP(SCMI_SENS_CFG_UPDATE_SECS_MASK, sec);
sensor_config &= ~SCMI_SENS_CFG_UPDATE_EXP_MASK;
sensor_config |= FIELD_PREP(SCMI_SENS_CFG_UPDATE_EXP_MASK, -mult);
if (sensor->sensor_info->timestamped) {
sensor_config &= ~SCMI_SENS_CFG_TSTAMP_ENABLED_MASK;
sensor_config |= FIELD_PREP(SCMI_SENS_CFG_TSTAMP_ENABLED_MASK,
SCMI_SENS_CFG_TSTAMP_ENABLE);
}
sensor_config &= ~SCMI_SENS_CFG_ROUND_MASK;
sensor_config |=
FIELD_PREP(SCMI_SENS_CFG_ROUND_MASK, SCMI_SENS_CFG_ROUND_AUTO);
err = sensor->sensor_ops->config_set(sensor->ph,
sensor->sensor_info->id,
sensor_config);
if (err)
dev_err(&iio_dev->dev,
"Error in setting sensor update interval for sensor %s value %u err %d",
sensor->sensor_info->name, sensor_config, err);
return err;
}
static int scmi_iio_write_raw(struct iio_dev *iio_dev,
struct iio_chan_spec const *chan, int val,
int val2, long mask)
{
struct scmi_iio_priv *sensor = iio_priv(iio_dev);
int err;
switch (mask) {
case IIO_CHAN_INFO_SAMP_FREQ:
mutex_lock(&sensor->lock);
err = scmi_iio_set_odr_val(iio_dev, val, val2);
mutex_unlock(&sensor->lock);
return err;
default:
return -EINVAL;
}
}
static int scmi_iio_read_avail(struct iio_dev *iio_dev,
struct iio_chan_spec const *chan,
const int **vals, int *type, int *length,
long mask)
{
struct scmi_iio_priv *sensor = iio_priv(iio_dev);
switch (mask) {
case IIO_CHAN_INFO_SAMP_FREQ:
*vals = sensor->freq_avail;
*type = IIO_VAL_INT_PLUS_MICRO;
*length = sensor->sensor_info->intervals.count * 2;
if (sensor->sensor_info->intervals.segmented)
return IIO_AVAIL_RANGE;
else
return IIO_AVAIL_LIST;
default:
return -EINVAL;
}
}
static void convert_ns_to_freq(u64 interval_ns, u64 *hz, u64 *uhz)
{
u64 rem, freq;
freq = NSEC_PER_SEC;
rem = do_div(freq, interval_ns);
*hz = freq;
*uhz = rem * 1000000UL;
do_div(*uhz, interval_ns);
}
static int scmi_iio_get_odr_val(struct iio_dev *iio_dev, int *val, int *val2)
{
u64 sensor_update_interval, sensor_interval_mult, hz, uhz;
struct scmi_iio_priv *sensor = iio_priv(iio_dev);
u32 sensor_config;
int mult;
int err = sensor->sensor_ops->config_get(sensor->ph,
sensor->sensor_info->id,
&sensor_config);
if (err) {
dev_err(&iio_dev->dev,
"Error in getting sensor config for sensor %s err %d",
sensor->sensor_info->name, err);
return err;
}
sensor_update_interval =
SCMI_SENS_CFG_GET_UPDATE_SECS(sensor_config) * NSEC_PER_SEC;
mult = SCMI_SENS_CFG_GET_UPDATE_EXP(sensor_config);
if (mult < 0) {
sensor_interval_mult = int_pow(10, abs(mult));
do_div(sensor_update_interval, sensor_interval_mult);
} else {
sensor_interval_mult = int_pow(10, mult);
sensor_update_interval =
sensor_update_interval * sensor_interval_mult;
}
convert_ns_to_freq(sensor_update_interval, &hz, &uhz);
*val = hz;
*val2 = uhz;
return 0;
}
static int scmi_iio_read_channel_data(struct iio_dev *iio_dev,
struct iio_chan_spec const *ch, int *val, int *val2)
{
struct scmi_iio_priv *sensor = iio_priv(iio_dev);
u32 sensor_config;
struct scmi_sensor_reading readings[SCMI_IIO_NUM_OF_AXIS];
int err;
sensor_config = FIELD_PREP(SCMI_SENS_CFG_SENSOR_ENABLED_MASK,
SCMI_SENS_CFG_SENSOR_ENABLE);
err = sensor->sensor_ops->config_set(
sensor->ph, sensor->sensor_info->id, sensor_config);
if (err) {
dev_err(&iio_dev->dev,
"Error in enabling sensor %s err %d",
sensor->sensor_info->name, err);
return err;
}
err = sensor->sensor_ops->reading_get_timestamped(
sensor->ph, sensor->sensor_info->id,
sensor->sensor_info->num_axis, readings);
if (err) {
dev_err(&iio_dev->dev,
"Error in reading raw attribute for sensor %s err %d",
sensor->sensor_info->name, err);
return err;
}
sensor_config = FIELD_PREP(SCMI_SENS_CFG_SENSOR_ENABLED_MASK,
SCMI_SENS_CFG_SENSOR_DISABLE);
err = sensor->sensor_ops->config_set(
sensor->ph, sensor->sensor_info->id, sensor_config);
if (err) {
dev_err(&iio_dev->dev,
"Error in disabling sensor %s err %d",
sensor->sensor_info->name, err);
return err;
}
*val = lower_32_bits(readings[ch->scan_index].value);
*val2 = upper_32_bits(readings[ch->scan_index].value);
return IIO_VAL_INT_64;
}
static int scmi_iio_read_raw(struct iio_dev *iio_dev,
struct iio_chan_spec const *ch, int *val,
int *val2, long mask)
{
struct scmi_iio_priv *sensor = iio_priv(iio_dev);
s8 scale;
int ret;
switch (mask) {
case IIO_CHAN_INFO_SCALE:
scale = sensor->sensor_info->axis[ch->scan_index].scale;
if (scale < 0) {
*val = 1;
*val2 = int_pow(10, abs(scale));
return IIO_VAL_FRACTIONAL;
}
*val = int_pow(10, scale);
return IIO_VAL_INT;
case IIO_CHAN_INFO_SAMP_FREQ:
ret = scmi_iio_get_odr_val(iio_dev, val, val2);
return ret ? ret : IIO_VAL_INT_PLUS_MICRO;
case IIO_CHAN_INFO_RAW:
ret = iio_device_claim_direct_mode(iio_dev);
if (ret)
return ret;
ret = scmi_iio_read_channel_data(iio_dev, ch, val, val2);
iio_device_release_direct_mode(iio_dev);
return ret;
default:
return -EINVAL;
}
}
static const struct iio_info scmi_iio_info = {
.read_raw = scmi_iio_read_raw,
.read_avail = scmi_iio_read_avail,
.write_raw = scmi_iio_write_raw,
};
static ssize_t scmi_iio_get_raw_available(struct iio_dev *iio_dev,
uintptr_t private,
const struct iio_chan_spec *chan,
char *buf)
{
struct scmi_iio_priv *sensor = iio_priv(iio_dev);
u64 resolution, rem;
s64 min_range, max_range;
s8 exponent, scale;
int len = 0;
/*
* All the axes are supposed to have the same value for range and resolution.
* We are just using the values from the Axis 0 here.
*/
if (sensor->sensor_info->axis[0].extended_attrs) {
min_range = sensor->sensor_info->axis[0].attrs.min_range;
max_range = sensor->sensor_info->axis[0].attrs.max_range;
resolution = sensor->sensor_info->axis[0].resolution;
exponent = sensor->sensor_info->axis[0].exponent;
scale = sensor->sensor_info->axis[0].scale;
/*
* To provide the raw value for the resolution to the userspace,
* need to divide the resolution exponent by the sensor scale
*/
exponent = exponent - scale;
if (exponent < 0) {
rem = do_div(resolution,
int_pow(10, abs(exponent))
);
len = sysfs_emit(buf,
"[%lld %llu.%llu %lld]\n", min_range,
resolution, rem, max_range);
} else {
resolution = resolution * int_pow(10, exponent);
len = sysfs_emit(buf, "[%lld %llu %lld]\n",
min_range, resolution, max_range);
}
}
return len;
}
static const struct iio_chan_spec_ext_info scmi_iio_ext_info[] = {
{
.name = "raw_available",
.read = scmi_iio_get_raw_available,
.shared = IIO_SHARED_BY_TYPE,
},
{},
};
static void scmi_iio_set_timestamp_channel(struct iio_chan_spec *iio_chan,
int scan_index)
{
iio_chan->type = IIO_TIMESTAMP;
iio_chan->channel = -1;
iio_chan->scan_index = scan_index;
iio_chan->scan_type.sign = 'u';
iio_chan->scan_type.realbits = 64;
iio_chan->scan_type.storagebits = 64;
}
static void scmi_iio_set_data_channel(struct iio_chan_spec *iio_chan,
enum iio_chan_type type,
enum iio_modifier mod, int scan_index)
{
iio_chan->type = type;
iio_chan->modified = 1;
iio_chan->channel2 = mod;
iio_chan->info_mask_separate =
BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_RAW);
iio_chan->info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ);
iio_chan->info_mask_shared_by_type_available =
BIT(IIO_CHAN_INFO_SAMP_FREQ);
iio_chan->scan_index = scan_index;
iio_chan->scan_type.sign = 's';
iio_chan->scan_type.realbits = 64;
iio_chan->scan_type.storagebits = 64;
iio_chan->scan_type.endianness = IIO_LE;
iio_chan->ext_info = scmi_iio_ext_info;
}
static int scmi_iio_get_chan_modifier(const char *name,
enum iio_modifier *modifier)
{
char *pch, mod;
if (!name)
return -EINVAL;
pch = strrchr(name, '_');
if (!pch)
return -EINVAL;
mod = *(pch + 1);
switch (mod) {
case 'X':
*modifier = IIO_MOD_X;
return 0;
case 'Y':
*modifier = IIO_MOD_Y;
return 0;
case 'Z':
*modifier = IIO_MOD_Z;
return 0;
default:
return -EINVAL;
}
}
static int scmi_iio_get_chan_type(u8 scmi_type, enum iio_chan_type *iio_type)
{
switch (scmi_type) {
case METERS_SEC_SQUARED:
*iio_type = IIO_ACCEL;
return 0;
case RADIANS_SEC:
*iio_type = IIO_ANGL_VEL;
return 0;
default:
return -EINVAL;
}
}
static u64 scmi_iio_convert_interval_to_ns(u32 val)
{
u64 sensor_update_interval =
SCMI_SENS_INTVL_GET_SECS(val) * NSEC_PER_SEC;
u64 sensor_interval_mult;
int mult;
mult = SCMI_SENS_INTVL_GET_EXP(val);
if (mult < 0) {
sensor_interval_mult = int_pow(10, abs(mult));
do_div(sensor_update_interval, sensor_interval_mult);
} else {
sensor_interval_mult = int_pow(10, mult);
sensor_update_interval =
sensor_update_interval * sensor_interval_mult;
}
return sensor_update_interval;
}
static int scmi_iio_set_sampling_freq_avail(struct iio_dev *iio_dev)
{
u64 cur_interval_ns, low_interval_ns, high_interval_ns, step_size_ns,
hz, uhz;
unsigned int cur_interval, low_interval, high_interval, step_size;
struct scmi_iio_priv *sensor = iio_priv(iio_dev);
int i;
sensor->freq_avail =
devm_kzalloc(&iio_dev->dev,
sizeof(*sensor->freq_avail) *
(sensor->sensor_info->intervals.count * 2),
GFP_KERNEL);
if (!sensor->freq_avail)
return -ENOMEM;
if (sensor->sensor_info->intervals.segmented) {
low_interval = sensor->sensor_info->intervals
.desc[SCMI_SENS_INTVL_SEGMENT_LOW];
low_interval_ns = scmi_iio_convert_interval_to_ns(low_interval);
convert_ns_to_freq(low_interval_ns, &hz, &uhz);
sensor->freq_avail[0] = hz;
sensor->freq_avail[1] = uhz;
step_size = sensor->sensor_info->intervals
.desc[SCMI_SENS_INTVL_SEGMENT_STEP];
step_size_ns = scmi_iio_convert_interval_to_ns(step_size);
convert_ns_to_freq(step_size_ns, &hz, &uhz);
sensor->freq_avail[2] = hz;
sensor->freq_avail[3] = uhz;
high_interval = sensor->sensor_info->intervals
.desc[SCMI_SENS_INTVL_SEGMENT_HIGH];
high_interval_ns =
scmi_iio_convert_interval_to_ns(high_interval);
convert_ns_to_freq(high_interval_ns, &hz, &uhz);
sensor->freq_avail[4] = hz;
sensor->freq_avail[5] = uhz;
} else {
for (i = 0; i < sensor->sensor_info->intervals.count; i++) {
cur_interval = sensor->sensor_info->intervals.desc[i];
cur_interval_ns =
scmi_iio_convert_interval_to_ns(cur_interval);
convert_ns_to_freq(cur_interval_ns, &hz, &uhz);
sensor->freq_avail[i * 2] = hz;
sensor->freq_avail[i * 2 + 1] = uhz;
}
}
return 0;
}
static struct iio_dev *
scmi_alloc_iiodev(struct scmi_device *sdev,
const struct scmi_sensor_proto_ops *ops,
struct scmi_protocol_handle *ph,
const struct scmi_sensor_info *sensor_info)
{
struct iio_chan_spec *iio_channels;
struct scmi_iio_priv *sensor;
enum iio_modifier modifier;
enum iio_chan_type type;
struct iio_dev *iiodev;
struct device *dev = &sdev->dev;
const struct scmi_handle *handle = sdev->handle;
int i, ret;
iiodev = devm_iio_device_alloc(dev, sizeof(*sensor));
if (!iiodev)
return ERR_PTR(-ENOMEM);
iiodev->modes = INDIO_DIRECT_MODE;
sensor = iio_priv(iiodev);
sensor->sensor_ops = ops;
sensor->ph = ph;
sensor->sensor_info = sensor_info;
sensor->sensor_update_nb.notifier_call = scmi_iio_sensor_update_cb;
sensor->indio_dev = iiodev;
mutex_init(&sensor->lock);
/* adding one additional channel for timestamp */
iiodev->num_channels = sensor_info->num_axis + 1;
iiodev->name = sensor_info->name;
iiodev->info = &scmi_iio_info;
iio_channels =
devm_kzalloc(dev,
sizeof(*iio_channels) * (iiodev->num_channels),
GFP_KERNEL);
if (!iio_channels)
return ERR_PTR(-ENOMEM);
ret = scmi_iio_set_sampling_freq_avail(iiodev);
if (ret < 0)
return ERR_PTR(ret);
for (i = 0; i < sensor_info->num_axis; i++) {
ret = scmi_iio_get_chan_type(sensor_info->axis[i].type, &type);
if (ret < 0)
return ERR_PTR(ret);
ret = scmi_iio_get_chan_modifier(sensor_info->axis[i].name,
&modifier);
if (ret < 0)
return ERR_PTR(ret);
scmi_iio_set_data_channel(&iio_channels[i], type, modifier,
sensor_info->axis[i].id);
}
ret = handle->notify_ops->devm_event_notifier_register(sdev,
SCMI_PROTOCOL_SENSOR, SCMI_EVENT_SENSOR_UPDATE,
&sensor->sensor_info->id,
&sensor->sensor_update_nb);
if (ret) {
dev_err(&iiodev->dev,
"Error in registering sensor update notifier for sensor %s err %d",
sensor->sensor_info->name, ret);
return ERR_PTR(ret);
}
scmi_iio_set_timestamp_channel(&iio_channels[i], i);
iiodev->channels = iio_channels;
return iiodev;
}
static int scmi_iio_dev_probe(struct scmi_device *sdev)
{
const struct scmi_sensor_info *sensor_info;
struct scmi_handle *handle = sdev->handle;
const struct scmi_sensor_proto_ops *sensor_ops;
struct scmi_protocol_handle *ph;
struct device *dev = &sdev->dev;
struct iio_dev *scmi_iio_dev;
u16 nr_sensors;
int err = -ENODEV, i;
if (!handle)
return -ENODEV;
sensor_ops = handle->devm_protocol_get(sdev, SCMI_PROTOCOL_SENSOR, &ph);
if (IS_ERR(sensor_ops)) {
dev_err(dev, "SCMI device has no sensor interface\n");
return PTR_ERR(sensor_ops);
}
nr_sensors = sensor_ops->count_get(ph);
if (!nr_sensors) {
dev_dbg(dev, "0 sensors found via SCMI bus\n");
return -ENODEV;
}
for (i = 0; i < nr_sensors; i++) {
sensor_info = sensor_ops->info_get(ph, i);
if (!sensor_info) {
dev_err(dev, "SCMI sensor %d has missing info\n", i);
return -EINVAL;
}
/* This driver only supports 3-axis accel and gyro, skipping other sensors */
if (sensor_info->num_axis != SCMI_IIO_NUM_OF_AXIS)
continue;
/* This driver only supports 3-axis accel and gyro, skipping other sensors */
if (sensor_info->axis[0].type != METERS_SEC_SQUARED &&
sensor_info->axis[0].type != RADIANS_SEC)
continue;
scmi_iio_dev = scmi_alloc_iiodev(sdev, sensor_ops, ph,
sensor_info);
if (IS_ERR(scmi_iio_dev)) {
dev_err(dev,
"failed to allocate IIO device for sensor %s: %ld\n",
sensor_info->name, PTR_ERR(scmi_iio_dev));
return PTR_ERR(scmi_iio_dev);
}
err = devm_iio_kfifo_buffer_setup(&scmi_iio_dev->dev,
scmi_iio_dev,
&scmi_iio_buffer_ops);
if (err < 0) {
dev_err(dev,
"IIO buffer setup error at sensor %s: %d\n",
sensor_info->name, err);
return err;
}
err = devm_iio_device_register(dev, scmi_iio_dev);
if (err) {
dev_err(dev,
"IIO device registration failed at sensor %s: %d\n",
sensor_info->name, err);
return err;
}
}
return err;
}
static const struct scmi_device_id scmi_id_table[] = {
{ SCMI_PROTOCOL_SENSOR, "iiodev" },
{},
};
MODULE_DEVICE_TABLE(scmi, scmi_id_table);
static struct scmi_driver scmi_iiodev_driver = {
.name = "scmi-sensor-iiodev",
.probe = scmi_iio_dev_probe,
.id_table = scmi_id_table,
};
module_scmi_driver(scmi_iiodev_driver);
MODULE_AUTHOR("Jyoti Bhayana <jbhayana@google.com>");
MODULE_DESCRIPTION("SCMI IIO Driver");
MODULE_LICENSE("GPL v2");