/*
 *  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;
        bool timed_out = 0;

        /* 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 */
        INIT_COMPLETION(radio->completion);
        retval = wait_for_completion_timeout(&radio->completion,
                        msecs_to_jiffies(tune_timeout));
        if (!retval)
                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 = 0;

        /* 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 */
        INIT_COMPLETION(radio->completion);
        retval = wait_for_completion_timeout(&radio->completion,
                        msecs_to_jiffies(seek_timeout));
        if (!retval)
                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,
};