linux-sg2042/drivers/media/radio/si470x/radio-si470x-common.c

762 lines
21 KiB
C

/*
* drivers/media/radio/si470x/radio-si470x-common.c
*
* Driver for radios with Silicon Labs Si470x FM Radio Receivers
*
* Copyright (c) 2009 Tobias Lorenz <tobias.lorenz@gmx.net>
* Copyright (c) 2012 Hans de Goede <hdegoede@redhat.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* History:
* 2008-01-12 Tobias Lorenz <tobias.lorenz@gmx.net>
* Version 1.0.0
* - First working version
* 2008-01-13 Tobias Lorenz <tobias.lorenz@gmx.net>
* Version 1.0.1
* - Improved error handling, every function now returns errno
* - Improved multi user access (start/mute/stop)
* - Channel doesn't get lost anymore after start/mute/stop
* - RDS support added (polling mode via interrupt EP 1)
* - marked default module parameters with *value*
* - switched from bit structs to bit masks
* - header file cleaned and integrated
* 2008-01-14 Tobias Lorenz <tobias.lorenz@gmx.net>
* Version 1.0.2
* - hex values are now lower case
* - commented USB ID for ADS/Tech moved on todo list
* - blacklisted si470x in hid-quirks.c
* - rds buffer handling functions integrated into *_work, *_read
* - rds_command in si470x_poll exchanged against simple retval
* - check for firmware version 15
* - code order and prototypes still remain the same
* - spacing and bottom of band codes remain the same
* 2008-01-16 Tobias Lorenz <tobias.lorenz@gmx.net>
* Version 1.0.3
* - code reordered to avoid function prototypes
* - switch/case defaults are now more user-friendly
* - unified comment style
* - applied all checkpatch.pl v1.12 suggestions
* except the warning about the too long lines with bit comments
* - renamed FMRADIO to RADIO to cut line length (checkpatch.pl)
* 2008-01-22 Tobias Lorenz <tobias.lorenz@gmx.net>
* Version 1.0.4
* - avoid poss. locking when doing copy_to_user which may sleep
* - RDS is automatically activated on read now
* - code cleaned of unnecessary rds_commands
* - USB Vendor/Product ID for ADS/Tech FM Radio Receiver verified
* (thanks to Guillaume RAMOUSSE)
* 2008-01-27 Tobias Lorenz <tobias.lorenz@gmx.net>
* Version 1.0.5
* - number of seek_retries changed to tune_timeout
* - fixed problem with incomplete tune operations by own buffers
* - optimization of variables and printf types
* - improved error logging
* 2008-01-31 Tobias Lorenz <tobias.lorenz@gmx.net>
* Oliver Neukum <oliver@neukum.org>
* Version 1.0.6
* - fixed coverity checker warnings in *_usb_driver_disconnect
* - probe()/open() race by correct ordering in probe()
* - DMA coherency rules by separate allocation of all buffers
* - use of endianness macros
* - abuse of spinlock, replaced by mutex
* - racy handling of timer in disconnect,
* replaced by delayed_work
* - racy interruptible_sleep_on(),
* replaced with wait_event_interruptible()
* - handle signals in read()
* 2008-02-08 Tobias Lorenz <tobias.lorenz@gmx.net>
* Oliver Neukum <oliver@neukum.org>
* Version 1.0.7
* - usb autosuspend support
* - unplugging fixed
* 2008-05-07 Tobias Lorenz <tobias.lorenz@gmx.net>
* Version 1.0.8
* - hardware frequency seek support
* - afc indication
* - more safety checks, let si470x_get_freq return errno
* - vidioc behavior corrected according to v4l2 spec
* 2008-10-20 Alexey Klimov <klimov.linux@gmail.com>
* - add support for KWorld USB FM Radio FM700
* - blacklisted KWorld radio in hid-core.c and hid-ids.h
* 2008-12-03 Mark Lord <mlord@pobox.com>
* - add support for DealExtreme USB Radio
* 2009-01-31 Bob Ross <pigiron@gmx.com>
* - correction of stereo detection/setting
* - correction of signal strength indicator scaling
* 2009-01-31 Rick Bronson <rick@efn.org>
* Tobias Lorenz <tobias.lorenz@gmx.net>
* - add LED status output
* - get HW/SW version from scratchpad
* 2009-06-16 Edouard Lafargue <edouard@lafargue.name>
* Version 1.0.10
* - add support for interrupt mode for RDS endpoint,
* instead of polling.
* Improves RDS reception significantly
*/
/* kernel includes */
#include "radio-si470x.h"
/**************************************************************************
* Module Parameters
**************************************************************************/
/* Spacing (kHz) */
/* 0: 200 kHz (USA, Australia) */
/* 1: 100 kHz (Europe, Japan) */
/* 2: 50 kHz */
static unsigned short space = 2;
module_param(space, ushort, 0444);
MODULE_PARM_DESC(space, "Spacing: 0=200kHz 1=100kHz *2=50kHz*");
/* De-emphasis */
/* 0: 75 us (USA) */
/* 1: 50 us (Europe, Australia, Japan) */
static unsigned short de = 1;
module_param(de, ushort, 0444);
MODULE_PARM_DESC(de, "De-emphasis: 0=75us *1=50us*");
/* Tune timeout */
static unsigned int tune_timeout = 3000;
module_param(tune_timeout, uint, 0644);
MODULE_PARM_DESC(tune_timeout, "Tune timeout: *3000*");
/* Seek timeout */
static unsigned int seek_timeout = 5000;
module_param(seek_timeout, uint, 0644);
MODULE_PARM_DESC(seek_timeout, "Seek timeout: *5000*");
static const struct v4l2_frequency_band bands[] = {
{
.type = V4L2_TUNER_RADIO,
.index = 0,
.capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO |
V4L2_TUNER_CAP_RDS | V4L2_TUNER_CAP_RDS_BLOCK_IO |
V4L2_TUNER_CAP_FREQ_BANDS |
V4L2_TUNER_CAP_HWSEEK_BOUNDED |
V4L2_TUNER_CAP_HWSEEK_WRAP,
.rangelow = 87500 * 16,
.rangehigh = 108000 * 16,
.modulation = V4L2_BAND_MODULATION_FM,
},
{
.type = V4L2_TUNER_RADIO,
.index = 1,
.capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO |
V4L2_TUNER_CAP_RDS | V4L2_TUNER_CAP_RDS_BLOCK_IO |
V4L2_TUNER_CAP_FREQ_BANDS |
V4L2_TUNER_CAP_HWSEEK_BOUNDED |
V4L2_TUNER_CAP_HWSEEK_WRAP,
.rangelow = 76000 * 16,
.rangehigh = 108000 * 16,
.modulation = V4L2_BAND_MODULATION_FM,
},
{
.type = V4L2_TUNER_RADIO,
.index = 2,
.capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO |
V4L2_TUNER_CAP_RDS | V4L2_TUNER_CAP_RDS_BLOCK_IO |
V4L2_TUNER_CAP_FREQ_BANDS |
V4L2_TUNER_CAP_HWSEEK_BOUNDED |
V4L2_TUNER_CAP_HWSEEK_WRAP,
.rangelow = 76000 * 16,
.rangehigh = 90000 * 16,
.modulation = V4L2_BAND_MODULATION_FM,
},
};
/**************************************************************************
* Generic Functions
**************************************************************************/
/*
* si470x_set_band - set the band
*/
static int si470x_set_band(struct si470x_device *radio, int band)
{
if (radio->band == band)
return 0;
radio->band = band;
radio->registers[SYSCONFIG2] &= ~SYSCONFIG2_BAND;
radio->registers[SYSCONFIG2] |= radio->band << 6;
return si470x_set_register(radio, SYSCONFIG2);
}
/*
* si470x_set_chan - set the channel
*/
static int si470x_set_chan(struct si470x_device *radio, unsigned short chan)
{
int retval;
unsigned long time_left;
bool timed_out = false;
/* start tuning */
radio->registers[CHANNEL] &= ~CHANNEL_CHAN;
radio->registers[CHANNEL] |= CHANNEL_TUNE | chan;
retval = si470x_set_register(radio, CHANNEL);
if (retval < 0)
goto done;
/* wait till tune operation has completed */
reinit_completion(&radio->completion);
time_left = wait_for_completion_timeout(&radio->completion,
msecs_to_jiffies(tune_timeout));
if (time_left == 0)
timed_out = true;
if ((radio->registers[STATUSRSSI] & STATUSRSSI_STC) == 0)
dev_warn(&radio->videodev.dev, "tune does not complete\n");
if (timed_out)
dev_warn(&radio->videodev.dev,
"tune timed out after %u ms\n", tune_timeout);
/* stop tuning */
radio->registers[CHANNEL] &= ~CHANNEL_TUNE;
retval = si470x_set_register(radio, CHANNEL);
done:
return retval;
}
/*
* si470x_get_step - get channel spacing
*/
static unsigned int si470x_get_step(struct si470x_device *radio)
{
/* Spacing (kHz) */
switch ((radio->registers[SYSCONFIG2] & SYSCONFIG2_SPACE) >> 4) {
/* 0: 200 kHz (USA, Australia) */
case 0:
return 200 * 16;
/* 1: 100 kHz (Europe, Japan) */
case 1:
return 100 * 16;
/* 2: 50 kHz */
default:
return 50 * 16;
}
}
/*
* si470x_get_freq - get the frequency
*/
static int si470x_get_freq(struct si470x_device *radio, unsigned int *freq)
{
int chan, retval;
/* read channel */
retval = si470x_get_register(radio, READCHAN);
chan = radio->registers[READCHAN] & READCHAN_READCHAN;
/* Frequency (MHz) = Spacing (kHz) x Channel + Bottom of Band (MHz) */
*freq = chan * si470x_get_step(radio) + bands[radio->band].rangelow;
return retval;
}
/*
* si470x_set_freq - set the frequency
*/
int si470x_set_freq(struct si470x_device *radio, unsigned int freq)
{
unsigned short chan;
freq = clamp(freq, bands[radio->band].rangelow,
bands[radio->band].rangehigh);
/* Chan = [ Freq (Mhz) - Bottom of Band (MHz) ] / Spacing (kHz) */
chan = (freq - bands[radio->band].rangelow) / si470x_get_step(radio);
return si470x_set_chan(radio, chan);
}
/*
* si470x_set_seek - set seek
*/
static int si470x_set_seek(struct si470x_device *radio,
const struct v4l2_hw_freq_seek *seek)
{
int band, retval;
unsigned int freq;
bool timed_out = false;
unsigned long time_left;
/* set band */
if (seek->rangelow || seek->rangehigh) {
for (band = 0; band < ARRAY_SIZE(bands); band++) {
if (bands[band].rangelow == seek->rangelow &&
bands[band].rangehigh == seek->rangehigh)
break;
}
if (band == ARRAY_SIZE(bands))
return -EINVAL; /* No matching band found */
} else
band = 1; /* If nothing is specified seek 76 - 108 Mhz */
if (radio->band != band) {
retval = si470x_get_freq(radio, &freq);
if (retval)
return retval;
retval = si470x_set_band(radio, band);
if (retval)
return retval;
retval = si470x_set_freq(radio, freq);
if (retval)
return retval;
}
/* start seeking */
radio->registers[POWERCFG] |= POWERCFG_SEEK;
if (seek->wrap_around)
radio->registers[POWERCFG] &= ~POWERCFG_SKMODE;
else
radio->registers[POWERCFG] |= POWERCFG_SKMODE;
if (seek->seek_upward)
radio->registers[POWERCFG] |= POWERCFG_SEEKUP;
else
radio->registers[POWERCFG] &= ~POWERCFG_SEEKUP;
retval = si470x_set_register(radio, POWERCFG);
if (retval < 0)
return retval;
/* wait till tune operation has completed */
reinit_completion(&radio->completion);
time_left = wait_for_completion_timeout(&radio->completion,
msecs_to_jiffies(seek_timeout));
if (time_left == 0)
timed_out = true;
if ((radio->registers[STATUSRSSI] & STATUSRSSI_STC) == 0)
dev_warn(&radio->videodev.dev, "seek does not complete\n");
if (radio->registers[STATUSRSSI] & STATUSRSSI_SF)
dev_warn(&radio->videodev.dev,
"seek failed / band limit reached\n");
/* stop seeking */
radio->registers[POWERCFG] &= ~POWERCFG_SEEK;
retval = si470x_set_register(radio, POWERCFG);
/* try again, if timed out */
if (retval == 0 && timed_out)
return -ENODATA;
return retval;
}
/*
* si470x_start - switch on radio
*/
int si470x_start(struct si470x_device *radio)
{
int retval;
/* powercfg */
radio->registers[POWERCFG] =
POWERCFG_DMUTE | POWERCFG_ENABLE | POWERCFG_RDSM;
retval = si470x_set_register(radio, POWERCFG);
if (retval < 0)
goto done;
/* sysconfig 1 */
radio->registers[SYSCONFIG1] =
(de << 11) & SYSCONFIG1_DE; /* DE*/
retval = si470x_set_register(radio, SYSCONFIG1);
if (retval < 0)
goto done;
/* sysconfig 2 */
radio->registers[SYSCONFIG2] =
(0x1f << 8) | /* SEEKTH */
((radio->band << 6) & SYSCONFIG2_BAND) |/* BAND */
((space << 4) & SYSCONFIG2_SPACE) | /* SPACE */
15; /* VOLUME (max) */
retval = si470x_set_register(radio, SYSCONFIG2);
if (retval < 0)
goto done;
/* reset last channel */
retval = si470x_set_chan(radio,
radio->registers[CHANNEL] & CHANNEL_CHAN);
done:
return retval;
}
/*
* si470x_stop - switch off radio
*/
int si470x_stop(struct si470x_device *radio)
{
int retval;
/* sysconfig 1 */
radio->registers[SYSCONFIG1] &= ~SYSCONFIG1_RDS;
retval = si470x_set_register(radio, SYSCONFIG1);
if (retval < 0)
goto done;
/* powercfg */
radio->registers[POWERCFG] &= ~POWERCFG_DMUTE;
/* POWERCFG_ENABLE has to automatically go low */
radio->registers[POWERCFG] |= POWERCFG_ENABLE | POWERCFG_DISABLE;
retval = si470x_set_register(radio, POWERCFG);
done:
return retval;
}
/*
* si470x_rds_on - switch on rds reception
*/
static int si470x_rds_on(struct si470x_device *radio)
{
int retval;
/* sysconfig 1 */
radio->registers[SYSCONFIG1] |= SYSCONFIG1_RDS;
retval = si470x_set_register(radio, SYSCONFIG1);
if (retval < 0)
radio->registers[SYSCONFIG1] &= ~SYSCONFIG1_RDS;
return retval;
}
/**************************************************************************
* File Operations Interface
**************************************************************************/
/*
* si470x_fops_read - read RDS data
*/
static ssize_t si470x_fops_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
struct si470x_device *radio = video_drvdata(file);
int retval = 0;
unsigned int block_count = 0;
/* switch on rds reception */
if ((radio->registers[SYSCONFIG1] & SYSCONFIG1_RDS) == 0)
si470x_rds_on(radio);
/* block if no new data available */
while (radio->wr_index == radio->rd_index) {
if (file->f_flags & O_NONBLOCK) {
retval = -EWOULDBLOCK;
goto done;
}
if (wait_event_interruptible(radio->read_queue,
radio->wr_index != radio->rd_index) < 0) {
retval = -EINTR;
goto done;
}
}
/* calculate block count from byte count */
count /= 3;
/* copy RDS block out of internal buffer and to user buffer */
while (block_count < count) {
if (radio->rd_index == radio->wr_index)
break;
/* always transfer rds complete blocks */
if (copy_to_user(buf, &radio->buffer[radio->rd_index], 3))
/* retval = -EFAULT; */
break;
/* increment and wrap read pointer */
radio->rd_index += 3;
if (radio->rd_index >= radio->buf_size)
radio->rd_index = 0;
/* increment counters */
block_count++;
buf += 3;
retval += 3;
}
done:
return retval;
}
/*
* si470x_fops_poll - poll RDS data
*/
static unsigned int si470x_fops_poll(struct file *file,
struct poll_table_struct *pts)
{
struct si470x_device *radio = video_drvdata(file);
unsigned long req_events = poll_requested_events(pts);
int retval = v4l2_ctrl_poll(file, pts);
if (req_events & (POLLIN | POLLRDNORM)) {
/* switch on rds reception */
if ((radio->registers[SYSCONFIG1] & SYSCONFIG1_RDS) == 0)
si470x_rds_on(radio);
poll_wait(file, &radio->read_queue, pts);
if (radio->rd_index != radio->wr_index)
retval |= POLLIN | POLLRDNORM;
}
return retval;
}
/*
* si470x_fops - file operations interface
*/
static const struct v4l2_file_operations si470x_fops = {
.owner = THIS_MODULE,
.read = si470x_fops_read,
.poll = si470x_fops_poll,
.unlocked_ioctl = video_ioctl2,
.open = si470x_fops_open,
.release = si470x_fops_release,
};
/**************************************************************************
* Video4Linux Interface
**************************************************************************/
static int si470x_s_ctrl(struct v4l2_ctrl *ctrl)
{
struct si470x_device *radio =
container_of(ctrl->handler, struct si470x_device, hdl);
switch (ctrl->id) {
case V4L2_CID_AUDIO_VOLUME:
radio->registers[SYSCONFIG2] &= ~SYSCONFIG2_VOLUME;
radio->registers[SYSCONFIG2] |= ctrl->val;
return si470x_set_register(radio, SYSCONFIG2);
case V4L2_CID_AUDIO_MUTE:
if (ctrl->val)
radio->registers[POWERCFG] &= ~POWERCFG_DMUTE;
else
radio->registers[POWERCFG] |= POWERCFG_DMUTE;
return si470x_set_register(radio, POWERCFG);
default:
return -EINVAL;
}
}
/*
* si470x_vidioc_g_tuner - get tuner attributes
*/
static int si470x_vidioc_g_tuner(struct file *file, void *priv,
struct v4l2_tuner *tuner)
{
struct si470x_device *radio = video_drvdata(file);
int retval = 0;
if (tuner->index != 0)
return -EINVAL;
if (!radio->status_rssi_auto_update) {
retval = si470x_get_register(radio, STATUSRSSI);
if (retval < 0)
return retval;
}
/* driver constants */
strcpy(tuner->name, "FM");
tuner->type = V4L2_TUNER_RADIO;
tuner->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO |
V4L2_TUNER_CAP_RDS | V4L2_TUNER_CAP_RDS_BLOCK_IO |
V4L2_TUNER_CAP_HWSEEK_BOUNDED |
V4L2_TUNER_CAP_HWSEEK_WRAP;
tuner->rangelow = 76 * FREQ_MUL;
tuner->rangehigh = 108 * FREQ_MUL;
/* stereo indicator == stereo (instead of mono) */
if ((radio->registers[STATUSRSSI] & STATUSRSSI_ST) == 0)
tuner->rxsubchans = V4L2_TUNER_SUB_MONO;
else
tuner->rxsubchans = V4L2_TUNER_SUB_STEREO;
/* If there is a reliable method of detecting an RDS channel,
then this code should check for that before setting this
RDS subchannel. */
tuner->rxsubchans |= V4L2_TUNER_SUB_RDS;
/* mono/stereo selector */
if ((radio->registers[POWERCFG] & POWERCFG_MONO) == 0)
tuner->audmode = V4L2_TUNER_MODE_STEREO;
else
tuner->audmode = V4L2_TUNER_MODE_MONO;
/* min is worst, max is best; signal:0..0xffff; rssi: 0..0xff */
/* measured in units of dbµV in 1 db increments (max at ~75 dbµV) */
tuner->signal = (radio->registers[STATUSRSSI] & STATUSRSSI_RSSI);
/* the ideal factor is 0xffff/75 = 873,8 */
tuner->signal = (tuner->signal * 873) + (8 * tuner->signal / 10);
if (tuner->signal > 0xffff)
tuner->signal = 0xffff;
/* automatic frequency control: -1: freq to low, 1 freq to high */
/* AFCRL does only indicate that freq. differs, not if too low/high */
tuner->afc = (radio->registers[STATUSRSSI] & STATUSRSSI_AFCRL) ? 1 : 0;
return retval;
}
/*
* si470x_vidioc_s_tuner - set tuner attributes
*/
static int si470x_vidioc_s_tuner(struct file *file, void *priv,
const struct v4l2_tuner *tuner)
{
struct si470x_device *radio = video_drvdata(file);
if (tuner->index != 0)
return -EINVAL;
/* mono/stereo selector */
switch (tuner->audmode) {
case V4L2_TUNER_MODE_MONO:
radio->registers[POWERCFG] |= POWERCFG_MONO; /* force mono */
break;
case V4L2_TUNER_MODE_STEREO:
default:
radio->registers[POWERCFG] &= ~POWERCFG_MONO; /* try stereo */
break;
}
return si470x_set_register(radio, POWERCFG);
}
/*
* si470x_vidioc_g_frequency - get tuner or modulator radio frequency
*/
static int si470x_vidioc_g_frequency(struct file *file, void *priv,
struct v4l2_frequency *freq)
{
struct si470x_device *radio = video_drvdata(file);
if (freq->tuner != 0)
return -EINVAL;
freq->type = V4L2_TUNER_RADIO;
return si470x_get_freq(radio, &freq->frequency);
}
/*
* si470x_vidioc_s_frequency - set tuner or modulator radio frequency
*/
static int si470x_vidioc_s_frequency(struct file *file, void *priv,
const struct v4l2_frequency *freq)
{
struct si470x_device *radio = video_drvdata(file);
int retval;
if (freq->tuner != 0)
return -EINVAL;
if (freq->frequency < bands[radio->band].rangelow ||
freq->frequency > bands[radio->band].rangehigh) {
/* Switch to band 1 which covers everything we support */
retval = si470x_set_band(radio, 1);
if (retval)
return retval;
}
return si470x_set_freq(radio, freq->frequency);
}
/*
* si470x_vidioc_s_hw_freq_seek - set hardware frequency seek
*/
static int si470x_vidioc_s_hw_freq_seek(struct file *file, void *priv,
const struct v4l2_hw_freq_seek *seek)
{
struct si470x_device *radio = video_drvdata(file);
if (seek->tuner != 0)
return -EINVAL;
if (file->f_flags & O_NONBLOCK)
return -EWOULDBLOCK;
return si470x_set_seek(radio, seek);
}
/*
* si470x_vidioc_enum_freq_bands - enumerate supported bands
*/
static int si470x_vidioc_enum_freq_bands(struct file *file, void *priv,
struct v4l2_frequency_band *band)
{
if (band->tuner != 0)
return -EINVAL;
if (band->index >= ARRAY_SIZE(bands))
return -EINVAL;
*band = bands[band->index];
return 0;
}
const struct v4l2_ctrl_ops si470x_ctrl_ops = {
.s_ctrl = si470x_s_ctrl,
};
/*
* si470x_ioctl_ops - video device ioctl operations
*/
static const struct v4l2_ioctl_ops si470x_ioctl_ops = {
.vidioc_querycap = si470x_vidioc_querycap,
.vidioc_g_tuner = si470x_vidioc_g_tuner,
.vidioc_s_tuner = si470x_vidioc_s_tuner,
.vidioc_g_frequency = si470x_vidioc_g_frequency,
.vidioc_s_frequency = si470x_vidioc_s_frequency,
.vidioc_s_hw_freq_seek = si470x_vidioc_s_hw_freq_seek,
.vidioc_enum_freq_bands = si470x_vidioc_enum_freq_bands,
.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
};
/*
* si470x_viddev_template - video device interface
*/
struct video_device si470x_viddev_template = {
.fops = &si470x_fops,
.name = DRIVER_NAME,
.release = video_device_release_empty,
.ioctl_ops = &si470x_ioctl_ops,
};