// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * dvb_frontend.c: DVB frontend tuning interface/thread
 *
 * Copyright (C) 1999-2001 Ralph  Metzler
 *                         Marcus Metzler
 *                         Holger Waechtler
 *                                    for convergence integrated media GmbH
 *
 * Copyright (C) 2004 Andrew de Quincey (tuning thread cleanup)
 */

/* Enables DVBv3 compatibility bits at the headers */
#define __DVB_CORE__

#define pr_fmt(fmt) "dvb_frontend: " fmt

#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/sched/signal.h>
#include <linux/wait.h>
#include <linux/slab.h>
#include <linux/poll.h>
#include <linux/semaphore.h>
#include <linux/module.h>
#include <linux/nospec.h>
#include <linux/list.h>
#include <linux/freezer.h>
#include <linux/jiffies.h>
#include <linux/kthread.h>
#include <linux/ktime.h>
#include <linux/compat.h>
#include <asm/processor.h>

#include <media/dvb_frontend.h>
#include <media/dvbdev.h>
#include <linux/dvb/version.h>

static int dvb_frontend_debug;
static int dvb_shutdown_timeout;
static int dvb_force_auto_inversion;
static int dvb_override_tune_delay;
static int dvb_powerdown_on_sleep = 1;
static int dvb_mfe_wait_time = 5;

module_param_named(frontend_debug, dvb_frontend_debug, int, 0644);
MODULE_PARM_DESC(frontend_debug, "Turn on/off frontend core debugging (default:off).");
module_param(dvb_shutdown_timeout, int, 0644);
MODULE_PARM_DESC(dvb_shutdown_timeout, "wait <shutdown_timeout> seconds after close() before suspending hardware");
module_param(dvb_force_auto_inversion, int, 0644);
MODULE_PARM_DESC(dvb_force_auto_inversion, "0: normal (default), 1: INVERSION_AUTO forced always");
module_param(dvb_override_tune_delay, int, 0644);
MODULE_PARM_DESC(dvb_override_tune_delay, "0: normal (default), >0 => delay in milliseconds to wait for lock after a tune attempt");
module_param(dvb_powerdown_on_sleep, int, 0644);
MODULE_PARM_DESC(dvb_powerdown_on_sleep, "0: do not power down, 1: turn LNB voltage off on sleep (default)");
module_param(dvb_mfe_wait_time, int, 0644);
MODULE_PARM_DESC(dvb_mfe_wait_time, "Wait up to <mfe_wait_time> seconds on open() for multi-frontend to become available (default:5 seconds)");

#define dprintk(fmt, arg...) \
        printk(KERN_DEBUG pr_fmt("%s: " fmt), __func__, ##arg)

#define FESTATE_IDLE 1
#define FESTATE_RETUNE 2
#define FESTATE_TUNING_FAST 4
#define FESTATE_TUNING_SLOW 8
#define FESTATE_TUNED 16
#define FESTATE_ZIGZAG_FAST 32
#define FESTATE_ZIGZAG_SLOW 64
#define FESTATE_DISEQC 128
#define FESTATE_ERROR 256
#define FESTATE_WAITFORLOCK (FESTATE_TUNING_FAST | FESTATE_TUNING_SLOW | FESTATE_ZIGZAG_FAST | FESTATE_ZIGZAG_SLOW | FESTATE_DISEQC)
#define FESTATE_SEARCHING_FAST (FESTATE_TUNING_FAST | FESTATE_ZIGZAG_FAST)
#define FESTATE_SEARCHING_SLOW (FESTATE_TUNING_SLOW | FESTATE_ZIGZAG_SLOW)
#define FESTATE_LOSTLOCK (FESTATE_ZIGZAG_FAST | FESTATE_ZIGZAG_SLOW)

/*
 * FESTATE_IDLE. No tuning parameters have been supplied and the loop is idling.
 * FESTATE_RETUNE. Parameters have been supplied, but we have not yet performed the first tune.
 * FESTATE_TUNING_FAST. Tuning parameters have been supplied and fast zigzag scan is in progress.
 * FESTATE_TUNING_SLOW. Tuning parameters have been supplied. Fast zigzag failed, so we're trying again, but slower.
 * FESTATE_TUNED. The frontend has successfully locked on.
 * FESTATE_ZIGZAG_FAST. The lock has been lost, and a fast zigzag has been initiated to try and regain it.
 * FESTATE_ZIGZAG_SLOW. The lock has been lost. Fast zigzag has been failed, so we're trying again, but slower.
 * FESTATE_DISEQC. A DISEQC command has just been issued.
 * FESTATE_WAITFORLOCK. When we're waiting for a lock.
 * FESTATE_SEARCHING_FAST. When we're searching for a signal using a fast zigzag scan.
 * FESTATE_SEARCHING_SLOW. When we're searching for a signal using a slow zigzag scan.
 * FESTATE_LOSTLOCK. When the lock has been lost, and we're searching it again.
 */

static DEFINE_MUTEX(frontend_mutex);

struct dvb_frontend_private {
        /* thread/frontend values */
        struct dvb_device *dvbdev;
        struct dvb_frontend_parameters parameters_out;
        struct dvb_fe_events events;
        struct semaphore sem;
        struct list_head list_head;
        wait_queue_head_t wait_queue;
        struct task_struct *thread;
        unsigned long release_jiffies;
        unsigned int wakeup;
        enum fe_status status;
        unsigned long tune_mode_flags;
        unsigned int delay;
        unsigned int reinitialise;
        int tone;
        int voltage;

        /* swzigzag values */
        unsigned int state;
        unsigned int bending;
        int lnb_drift;
        unsigned int inversion;
        unsigned int auto_step;
        unsigned int auto_sub_step;
        unsigned int started_auto_step;
        unsigned int min_delay;
        unsigned int max_drift;
        unsigned int step_size;
        int quality;
        unsigned int check_wrapped;
        enum dvbfe_search algo_status;

#if defined(CONFIG_MEDIA_CONTROLLER_DVB)
        struct media_pipeline pipe;
#endif
};

static void dvb_frontend_invoke_release(struct dvb_frontend *fe,
                                        void (*release)(struct dvb_frontend *fe));

static void __dvb_frontend_free(struct dvb_frontend *fe)
{
        struct dvb_frontend_private *fepriv = fe->frontend_priv;

        if (fepriv)
                dvb_free_device(fepriv->dvbdev);

        dvb_frontend_invoke_release(fe, fe->ops.release);

        kfree(fepriv);
}

static void dvb_frontend_free(struct kref *ref)
{
        struct dvb_frontend *fe =
                container_of(ref, struct dvb_frontend, refcount);

        __dvb_frontend_free(fe);
}

static void dvb_frontend_put(struct dvb_frontend *fe)
{
        /* call detach before dropping the reference count */
        if (fe->ops.detach)
                fe->ops.detach(fe);
        /*
         * Check if the frontend was registered, as otherwise
         * kref was not initialized yet.
         */
        if (fe->frontend_priv)
                kref_put(&fe->refcount, dvb_frontend_free);
        else
                __dvb_frontend_free(fe);
}

static void dvb_frontend_get(struct dvb_frontend *fe)
{
        kref_get(&fe->refcount);
}

static void dvb_frontend_wakeup(struct dvb_frontend *fe);
static int dtv_get_frontend(struct dvb_frontend *fe,
                            struct dtv_frontend_properties *c,
                            struct dvb_frontend_parameters *p_out);
static int
dtv_property_legacy_params_sync(struct dvb_frontend *fe,
                                const struct dtv_frontend_properties *c,
                                struct dvb_frontend_parameters *p);

static bool has_get_frontend(struct dvb_frontend *fe)
{
        return fe->ops.get_frontend;
}

/*
 * Due to DVBv3 API calls, a delivery system should be mapped into one of
 * the 4 DVBv3 delivery systems (FE_QPSK, FE_QAM, FE_OFDM or FE_ATSC),
 * otherwise, a DVBv3 call will fail.
 */
enum dvbv3_emulation_type {
        DVBV3_UNKNOWN,
        DVBV3_QPSK,
        DVBV3_QAM,
        DVBV3_OFDM,
        DVBV3_ATSC,
};

static enum dvbv3_emulation_type dvbv3_type(u32 delivery_system)
{
        switch (delivery_system) {
        case SYS_DVBC_ANNEX_A:
        case SYS_DVBC_ANNEX_C:
                return DVBV3_QAM;
        case SYS_DVBS:
        case SYS_DVBS2:
        case SYS_TURBO:
        case SYS_ISDBS:
        case SYS_DSS:
                return DVBV3_QPSK;
        case SYS_DVBT:
        case SYS_DVBT2:
        case SYS_ISDBT:
        case SYS_DTMB:
                return DVBV3_OFDM;
        case SYS_ATSC:
        case SYS_ATSCMH:
        case SYS_DVBC_ANNEX_B:
                return DVBV3_ATSC;
        case SYS_UNDEFINED:
        case SYS_ISDBC:
        case SYS_DVBH:
        case SYS_DAB:
        default:
                /*
                 * Doesn't know how to emulate those types and/or
                 * there's no frontend driver from this type yet
                 * with some emulation code, so, we're not sure yet how
                 * to handle them, or they're not compatible with a DVBv3 call.
                 */
                return DVBV3_UNKNOWN;
        }
}

static void dvb_frontend_add_event(struct dvb_frontend *fe,
                                   enum fe_status status)
{
        struct dvb_frontend_private *fepriv = fe->frontend_priv;
        struct dtv_frontend_properties *c = &fe->dtv_property_cache;
        struct dvb_fe_events *events = &fepriv->events;
        struct dvb_frontend_event *e;
        int wp;

        dev_dbg(fe->dvb->device, "%s:\n", __func__);

        if ((status & FE_HAS_LOCK) && has_get_frontend(fe))
                dtv_get_frontend(fe, c, &fepriv->parameters_out);

        mutex_lock(&events->mtx);

        wp = (events->eventw + 1) % MAX_EVENT;
        if (wp == events->eventr) {
                events->overflow = 1;
                events->eventr = (events->eventr + 1) % MAX_EVENT;
        }

        e = &events->events[events->eventw];
        e->status = status;
        e->parameters = fepriv->parameters_out;

        events->eventw = wp;

        mutex_unlock(&events->mtx);

        wake_up_interruptible(&events->wait_queue);
}

static int dvb_frontend_test_event(struct dvb_frontend_private *fepriv,
                                   struct dvb_fe_events *events)
{
        int ret;

        up(&fepriv->sem);
        ret = events->eventw != events->eventr;
        down(&fepriv->sem);

        return ret;
}

static int dvb_frontend_get_event(struct dvb_frontend *fe,
                                  struct dvb_frontend_event *event, int flags)
{
        struct dvb_frontend_private *fepriv = fe->frontend_priv;
        struct dvb_fe_events *events = &fepriv->events;

        dev_dbg(fe->dvb->device, "%s:\n", __func__);

        if (events->overflow) {
                events->overflow = 0;
                return -EOVERFLOW;
        }

        if (events->eventw == events->eventr) {
                int ret;

                if (flags & O_NONBLOCK)
                        return -EWOULDBLOCK;

                ret = wait_event_interruptible(events->wait_queue,
                                               dvb_frontend_test_event(fepriv, events));

                if (ret < 0)
                        return ret;
        }

        mutex_lock(&events->mtx);
        *event = events->events[events->eventr];
        events->eventr = (events->eventr + 1) % MAX_EVENT;
        mutex_unlock(&events->mtx);

        return 0;
}

static void dvb_frontend_clear_events(struct dvb_frontend *fe)
{
        struct dvb_frontend_private *fepriv = fe->frontend_priv;
        struct dvb_fe_events *events = &fepriv->events;

        mutex_lock(&events->mtx);
        events->eventr = events->eventw;
        mutex_unlock(&events->mtx);
}

static void dvb_frontend_init(struct dvb_frontend *fe)
{
        dev_dbg(fe->dvb->device,
                "%s: initialising adapter %i frontend %i (%s)...\n",
                __func__, fe->dvb->num, fe->id, fe->ops.info.name);

        if (fe->ops.init)
                fe->ops.init(fe);
        if (fe->ops.tuner_ops.init) {
                if (fe->ops.i2c_gate_ctrl)
                        fe->ops.i2c_gate_ctrl(fe, 1);
                fe->ops.tuner_ops.init(fe);
                if (fe->ops.i2c_gate_ctrl)
                        fe->ops.i2c_gate_ctrl(fe, 0);
        }
}

void dvb_frontend_reinitialise(struct dvb_frontend *fe)
{
        struct dvb_frontend_private *fepriv = fe->frontend_priv;

        fepriv->reinitialise = 1;
        dvb_frontend_wakeup(fe);
}
EXPORT_SYMBOL(dvb_frontend_reinitialise);

static void dvb_frontend_swzigzag_update_delay(struct dvb_frontend_private *fepriv, int locked)
{
        int q2;
        struct dvb_frontend *fe = fepriv->dvbdev->priv;

        dev_dbg(fe->dvb->device, "%s:\n", __func__);

        if (locked)
                (fepriv->quality) = (fepriv->quality * 220 + 36 * 256) / 256;
        else
                (fepriv->quality) = (fepriv->quality * 220 + 0) / 256;

        q2 = fepriv->quality - 128;
        q2 *= q2;

        fepriv->delay = fepriv->min_delay + q2 * HZ / (128 * 128);
}

/**
 * dvb_frontend_swzigzag_autotune - Performs automatic twiddling of frontend
 *      parameters.
 *
 * @fe: The frontend concerned.
 * @check_wrapped: Checks if an iteration has completed.
 *                 DO NOT SET ON THE FIRST ATTEMPT.
 *
 * return: Number of complete iterations that have been performed.
 */
static int dvb_frontend_swzigzag_autotune(struct dvb_frontend *fe, int check_wrapped)
{
        int autoinversion;
        int ready = 0;
        int fe_set_err = 0;
        struct dvb_frontend_private *fepriv = fe->frontend_priv;
        struct dtv_frontend_properties *c = &fe->dtv_property_cache, tmp;
        int original_inversion = c->inversion;
        u32 original_frequency = c->frequency;

        /* are we using autoinversion? */
        autoinversion = ((!(fe->ops.info.caps & FE_CAN_INVERSION_AUTO)) &&
                         (c->inversion == INVERSION_AUTO));

        /* setup parameters correctly */
        while (!ready) {
                /* calculate the lnb_drift */
                fepriv->lnb_drift = fepriv->auto_step * fepriv->step_size;

                /* wrap the auto_step if we've exceeded the maximum drift */
                if (fepriv->lnb_drift > fepriv->max_drift) {
                        fepriv->auto_step = 0;
                        fepriv->auto_sub_step = 0;
                        fepriv->lnb_drift = 0;
                }

                /* perform inversion and +/- zigzag */
                switch (fepriv->auto_sub_step) {
                case 0:
                        /* try with the current inversion and current drift setting */
                        ready = 1;
                        break;

                case 1:
                        if (!autoinversion) break;

                        fepriv->inversion = (fepriv->inversion == INVERSION_OFF) ? INVERSION_ON : INVERSION_OFF;
                        ready = 1;
                        break;

                case 2:
                        if (fepriv->lnb_drift == 0) break;

                        fepriv->lnb_drift = -fepriv->lnb_drift;
                        ready = 1;
                        break;

                case 3:
                        if (fepriv->lnb_drift == 0) break;
                        if (!autoinversion) break;

                        fepriv->inversion = (fepriv->inversion == INVERSION_OFF) ? INVERSION_ON : INVERSION_OFF;
                        fepriv->lnb_drift = -fepriv->lnb_drift;
                        ready = 1;
                        break;

                default:
                        fepriv->auto_step++;
                        fepriv->auto_sub_step = -1; /* it'll be incremented to 0 in a moment */
                        break;
                }

                if (!ready) fepriv->auto_sub_step++;
        }

        /* if this attempt would hit where we started, indicate a complete
         * iteration has occurred */
        if ((fepriv->auto_step == fepriv->started_auto_step) &&
            (fepriv->auto_sub_step == 0) && check_wrapped) {
                return 1;
        }

        dev_dbg(fe->dvb->device,
                "%s: drift:%i inversion:%i auto_step:%i auto_sub_step:%i started_auto_step:%i\n",
                __func__, fepriv->lnb_drift, fepriv->inversion,
                fepriv->auto_step, fepriv->auto_sub_step,
                fepriv->started_auto_step);

        /* set the frontend itself */
        c->frequency += fepriv->lnb_drift;
        if (autoinversion)
                c->inversion = fepriv->inversion;
        tmp = *c;
        if (fe->ops.set_frontend)
                fe_set_err = fe->ops.set_frontend(fe);
        *c = tmp;
        if (fe_set_err < 0) {
                fepriv->state = FESTATE_ERROR;
                return fe_set_err;
        }

        c->frequency = original_frequency;
        c->inversion = original_inversion;

        fepriv->auto_sub_step++;
        return 0;
}

static void dvb_frontend_swzigzag(struct dvb_frontend *fe)
{
        enum fe_status s = FE_NONE;
        int retval = 0;
        struct dvb_frontend_private *fepriv = fe->frontend_priv;
        struct dtv_frontend_properties *c = &fe->dtv_property_cache, tmp;

        if (fepriv->max_drift)
                dev_warn_once(fe->dvb->device,
                              "Frontend requested software zigzag, but didn't set the frequency step size\n");

        /* if we've got no parameters, just keep idling */
        if (fepriv->state & FESTATE_IDLE) {
                fepriv->delay = 3 * HZ;
                fepriv->quality = 0;
                return;
        }

        /* in SCAN mode, we just set the frontend when asked and leave it alone */
        if (fepriv->tune_mode_flags & FE_TUNE_MODE_ONESHOT) {
                if (fepriv->state & FESTATE_RETUNE) {
                        tmp = *c;
                        if (fe->ops.set_frontend)
                                retval = fe->ops.set_frontend(fe);
                        *c = tmp;
                        if (retval < 0)
                                fepriv->state = FESTATE_ERROR;
                        else
                                fepriv->state = FESTATE_TUNED;
                }
                fepriv->delay = 3 * HZ;
                fepriv->quality = 0;
                return;
        }

        /* get the frontend status */
        if (fepriv->state & FESTATE_RETUNE) {
                s = 0;
        } else {
                if (fe->ops.read_status)
                        fe->ops.read_status(fe, &s);
                if (s != fepriv->status) {
                        dvb_frontend_add_event(fe, s);
                        fepriv->status = s;
                }
        }

        /* if we're not tuned, and we have a lock, move to the TUNED state */
        if ((fepriv->state & FESTATE_WAITFORLOCK) && (s & FE_HAS_LOCK)) {
                dvb_frontend_swzigzag_update_delay(fepriv, s & FE_HAS_LOCK);
                fepriv->state = FESTATE_TUNED;

                /* if we're tuned, then we have determined the correct inversion */
                if ((!(fe->ops.info.caps & FE_CAN_INVERSION_AUTO)) &&
                    (c->inversion == INVERSION_AUTO)) {
                        c->inversion = fepriv->inversion;
                }
                return;
        }

        /* if we are tuned already, check we're still locked */
        if (fepriv->state & FESTATE_TUNED) {
                dvb_frontend_swzigzag_update_delay(fepriv, s & FE_HAS_LOCK);

                /* we're tuned, and the lock is still good... */
                if (s & FE_HAS_LOCK) {
                        return;
                } else { /* if we _WERE_ tuned, but now don't have a lock */
                        fepriv->state = FESTATE_ZIGZAG_FAST;
                        fepriv->started_auto_step = fepriv->auto_step;
                        fepriv->check_wrapped = 0;
                }
        }

        /* don't actually do anything if we're in the LOSTLOCK state,
         * the frontend is set to FE_CAN_RECOVER, and the max_drift is 0 */
        if ((fepriv->state & FESTATE_LOSTLOCK) &&
            (fe->ops.info.caps & FE_CAN_RECOVER) && (fepriv->max_drift == 0)) {
                dvb_frontend_swzigzag_update_delay(fepriv, s & FE_HAS_LOCK);
                return;
        }

        /* don't do anything if we're in the DISEQC state, since this
         * might be someone with a motorized dish controlled by DISEQC.
         * If its actually a re-tune, there will be a SET_FRONTEND soon enough. */
        if (fepriv->state & FESTATE_DISEQC) {
                dvb_frontend_swzigzag_update_delay(fepriv, s & FE_HAS_LOCK);
                return;
        }

        /* if we're in the RETUNE state, set everything up for a brand
         * new scan, keeping the current inversion setting, as the next
         * tune is _very_ likely to require the same */
        if (fepriv->state & FESTATE_RETUNE) {
                fepriv->lnb_drift = 0;
                fepriv->auto_step = 0;
                fepriv->auto_sub_step = 0;
                fepriv->started_auto_step = 0;
                fepriv->check_wrapped = 0;
        }

        /* fast zigzag. */
        if ((fepriv->state & FESTATE_SEARCHING_FAST) || (fepriv->state & FESTATE_RETUNE)) {
                fepriv->delay = fepriv->min_delay;

                /* perform a tune */
                retval = dvb_frontend_swzigzag_autotune(fe,
                                                        fepriv->check_wrapped);
                if (retval < 0) {
                        return;
                } else if (retval) {
                        /* OK, if we've run out of trials at the fast speed.
                         * Drop back to slow for the _next_ attempt */
                        fepriv->state = FESTATE_SEARCHING_SLOW;
                        fepriv->started_auto_step = fepriv->auto_step;
                        return;
                }
                fepriv->check_wrapped = 1;

                /* if we've just re-tuned, enter the ZIGZAG_FAST state.
                 * This ensures we cannot return from an
                 * FE_SET_FRONTEND ioctl before the first frontend tune
                 * occurs */
                if (fepriv->state & FESTATE_RETUNE) {
                        fepriv->state = FESTATE_TUNING_FAST;
                }
        }

        /* slow zigzag */
        if (fepriv->state & FESTATE_SEARCHING_SLOW) {
                dvb_frontend_swzigzag_update_delay(fepriv, s & FE_HAS_LOCK);

                /* Note: don't bother checking for wrapping; we stay in this
                 * state until we get a lock */
                dvb_frontend_swzigzag_autotune(fe, 0);
        }
}

static int dvb_frontend_is_exiting(struct dvb_frontend *fe)
{
        struct dvb_frontend_private *fepriv = fe->frontend_priv;

        if (fe->exit != DVB_FE_NO_EXIT)
                return 1;

        if (fepriv->dvbdev->writers == 1)
                if (time_after_eq(jiffies, fepriv->release_jiffies +
                                  dvb_shutdown_timeout * HZ))
                        return 1;

        return 0;
}

static int dvb_frontend_should_wakeup(struct dvb_frontend *fe)
{
        struct dvb_frontend_private *fepriv = fe->frontend_priv;

        if (fepriv->wakeup) {
                fepriv->wakeup = 0;
                return 1;
        }
        return dvb_frontend_is_exiting(fe);
}

static void dvb_frontend_wakeup(struct dvb_frontend *fe)
{
        struct dvb_frontend_private *fepriv = fe->frontend_priv;

        fepriv->wakeup = 1;
        wake_up_interruptible(&fepriv->wait_queue);
}

static int dvb_frontend_thread(void *data)
{
        struct dvb_frontend *fe = data;
        struct dtv_frontend_properties *c = &fe->dtv_property_cache;
        struct dvb_frontend_private *fepriv = fe->frontend_priv;
        enum fe_status s = FE_NONE;
        enum dvbfe_algo algo;
        bool re_tune = false;
        bool semheld = false;

        dev_dbg(fe->dvb->device, "%s:\n", __func__);

        fepriv->check_wrapped = 0;
        fepriv->quality = 0;
        fepriv->delay = 3 * HZ;
        fepriv->status = 0;
        fepriv->wakeup = 0;
        fepriv->reinitialise = 0;

        dvb_frontend_init(fe);

        set_freezable();
        while (1) {
                up(&fepriv->sem);           /* is locked when we enter the thread... */
restart:
                wait_event_interruptible_timeout(fepriv->wait_queue,
                                                 dvb_frontend_should_wakeup(fe) ||
                                                 kthread_should_stop() ||
                                                 freezing(current),
                        fepriv->delay);

                if (kthread_should_stop() || dvb_frontend_is_exiting(fe)) {
                        /* got signal or quitting */
                        if (!down_interruptible(&fepriv->sem))
                                semheld = true;
                        fe->exit = DVB_FE_NORMAL_EXIT;
                        break;
                }

                if (try_to_freeze())
                        goto restart;

                if (down_interruptible(&fepriv->sem))
                        break;

                if (fepriv->reinitialise) {
                        dvb_frontend_init(fe);
                        if (fe->ops.set_tone && fepriv->tone != -1)
                                fe->ops.set_tone(fe, fepriv->tone);
                        if (fe->ops.set_voltage && fepriv->voltage != -1)
                                fe->ops.set_voltage(fe, fepriv->voltage);
                        fepriv->reinitialise = 0;
                }

                /* do an iteration of the tuning loop */
                if (fe->ops.get_frontend_algo) {
                        algo = fe->ops.get_frontend_algo(fe);
                        switch (algo) {
                        case DVBFE_ALGO_HW:
                                dev_dbg(fe->dvb->device, "%s: Frontend ALGO = DVBFE_ALGO_HW\n", __func__);

                                if (fepriv->state & FESTATE_RETUNE) {
                                        dev_dbg(fe->dvb->device, "%s: Retune requested, FESTATE_RETUNE\n", __func__);
                                        re_tune = true;
                                        fepriv->state = FESTATE_TUNED;
                                } else {
                                        re_tune = false;
                                }

                                if (fe->ops.tune)
                                        fe->ops.tune(fe, re_tune, fepriv->tune_mode_flags, &fepriv->delay, &s);

                                if (s != fepriv->status && !(fepriv->tune_mode_flags & FE_TUNE_MODE_ONESHOT)) {
                                        dev_dbg(fe->dvb->device, "%s: state changed, adding current state\n", __func__);
                                        dvb_frontend_add_event(fe, s);
                                        fepriv->status = s;
                                }
                                break;
                        case DVBFE_ALGO_SW:
                                dev_dbg(fe->dvb->device, "%s: Frontend ALGO = DVBFE_ALGO_SW\n", __func__);
                                dvb_frontend_swzigzag(fe);
                                break;
                        case DVBFE_ALGO_CUSTOM:
                                dev_dbg(fe->dvb->device, "%s: Frontend ALGO = DVBFE_ALGO_CUSTOM, state=%d\n", __func__, fepriv->state);
                                if (fepriv->state & FESTATE_RETUNE) {
                                        dev_dbg(fe->dvb->device, "%s: Retune requested, FESTAT_RETUNE\n", __func__);
                                        fepriv->state = FESTATE_TUNED;
                                }
                                /* Case where we are going to search for a carrier
                                 * User asked us to retune again for some reason, possibly
                                 * requesting a search with a new set of parameters
                                 */
                                if (fepriv->algo_status & DVBFE_ALGO_SEARCH_AGAIN) {
                                        if (fe->ops.search) {
                                                fepriv->algo_status = fe->ops.search(fe);
                                                /* We did do a search as was requested, the flags are
                                                 * now unset as well and has the flags wrt to search.
                                                 */
                                        } else {
                                                fepriv->algo_status &= ~DVBFE_ALGO_SEARCH_AGAIN;
                                        }
                                }
                                /* Track the carrier if the search was successful */
                                if (fepriv->algo_status != DVBFE_ALGO_SEARCH_SUCCESS) {
                                        fepriv->algo_status |= DVBFE_ALGO_SEARCH_AGAIN;
                                        fepriv->delay = HZ / 2;
                                }
                                dtv_property_legacy_params_sync(fe, c, &fepriv->parameters_out);
                                fe->ops.read_status(fe, &s);
                                if (s != fepriv->status) {
                                        dvb_frontend_add_event(fe, s); /* update event list */
                                        fepriv->status = s;
                                        if (!(s & FE_HAS_LOCK)) {
                                                fepriv->delay = HZ / 10;
                                                fepriv->algo_status |= DVBFE_ALGO_SEARCH_AGAIN;
                                        } else {
                                                fepriv->delay = 60 * HZ;
                                        }
                                }
                                break;
                        default:
                                dev_dbg(fe->dvb->device, "%s: UNDEFINED ALGO !\n", __func__);
                                break;
                        }
                } else {
                        dvb_frontend_swzigzag(fe);
                }
        }

        if (dvb_powerdown_on_sleep) {
                if (fe->ops.set_voltage)
                        fe->ops.set_voltage(fe, SEC_VOLTAGE_OFF);
                if (fe->ops.tuner_ops.sleep) {
                        if (fe->ops.i2c_gate_ctrl)
                                fe->ops.i2c_gate_ctrl(fe, 1);
                        fe->ops.tuner_ops.sleep(fe);
                        if (fe->ops.i2c_gate_ctrl)
                                fe->ops.i2c_gate_ctrl(fe, 0);
                }
                if (fe->ops.sleep)
                        fe->ops.sleep(fe);
        }

        fepriv->thread = NULL;
        if (kthread_should_stop())
                fe->exit = DVB_FE_DEVICE_REMOVED;
        else
                fe->exit = DVB_FE_NO_EXIT;
        mb();

        if (semheld)
                up(&fepriv->sem);
        dvb_frontend_wakeup(fe);
        return 0;
}

static void dvb_frontend_stop(struct dvb_frontend *fe)
{
        struct dvb_frontend_private *fepriv = fe->frontend_priv;

        dev_dbg(fe->dvb->device, "%s:\n", __func__);

        if (fe->exit != DVB_FE_DEVICE_REMOVED)
                fe->exit = DVB_FE_NORMAL_EXIT;
        mb();

        if (!fepriv->thread)
                return;

        kthread_stop(fepriv->thread);

        sema_init(&fepriv->sem, 1);
        fepriv->state = FESTATE_IDLE;

        /* paranoia check in case a signal arrived */
        if (fepriv->thread)
                dev_warn(fe->dvb->device,
                         "dvb_frontend_stop: warning: thread %p won't exit\n",
                         fepriv->thread);
}

/*
 * Sleep for the amount of time given by add_usec parameter
 *
 * This needs to be as precise as possible, as it affects the detection of
 * the dish tone command at the satellite subsystem. The precision is improved
 * by using a scheduled msleep followed by udelay for the remainder.
 */
void dvb_frontend_sleep_until(ktime_t *waketime, u32 add_usec)
{
        s32 delta;

        *waketime = ktime_add_us(*waketime, add_usec);
        delta = ktime_us_delta(ktime_get_boottime(), *waketime);
        if (delta > 2500) {
                msleep((delta - 1500) / 1000);
                delta = ktime_us_delta(ktime_get_boottime(), *waketime);
        }
        if (delta > 0)
                udelay(delta);
}
EXPORT_SYMBOL(dvb_frontend_sleep_until);

static int dvb_frontend_start(struct dvb_frontend *fe)
{
        int ret;
        struct dvb_frontend_private *fepriv = fe->frontend_priv;
        struct task_struct *fe_thread;

        dev_dbg(fe->dvb->device, "%s:\n", __func__);

        if (fepriv->thread) {
                if (fe->exit == DVB_FE_NO_EXIT)
                        return 0;
                else
                        dvb_frontend_stop(fe);
        }

        if (signal_pending(current))
                return -EINTR;
        if (down_interruptible(&fepriv->sem))
                return -EINTR;

        fepriv->state = FESTATE_IDLE;
        fe->exit = DVB_FE_NO_EXIT;
        fepriv->thread = NULL;
        mb();

        fe_thread = kthread_run(dvb_frontend_thread, fe,
                                "kdvb-ad-%i-fe-%i", fe->dvb->num, fe->id);
        if (IS_ERR(fe_thread)) {
                ret = PTR_ERR(fe_thread);
                dev_warn(fe->dvb->device,
                         "dvb_frontend_start: failed to start kthread (%d)\n",
                         ret);
                up(&fepriv->sem);
                return ret;
        }
        fepriv->thread = fe_thread;
        return 0;
}

static void dvb_frontend_get_frequency_limits(struct dvb_frontend *fe,
                                              u32 *freq_min, u32 *freq_max,
                                              u32 *tolerance)
{
        struct dtv_frontend_properties *c = &fe->dtv_property_cache;
        u32 tuner_min = fe->ops.tuner_ops.info.frequency_min_hz;
        u32 tuner_max = fe->ops.tuner_ops.info.frequency_max_hz;
        u32 frontend_min = fe->ops.info.frequency_min_hz;
        u32 frontend_max = fe->ops.info.frequency_max_hz;

        *freq_min = max(frontend_min, tuner_min);

        if (frontend_max == 0)
                *freq_max = tuner_max;
        else if (tuner_max == 0)
                *freq_max = frontend_max;
        else
                *freq_max = min(frontend_max, tuner_max);

        if (*freq_min == 0 || *freq_max == 0)
                dev_warn(fe->dvb->device,
                         "DVB: adapter %i frontend %u frequency limits undefined - fix the driver\n",
                         fe->dvb->num, fe->id);

        dev_dbg(fe->dvb->device, "frequency interval: tuner: %u...%u, frontend: %u...%u",
                tuner_min, tuner_max, frontend_min, frontend_max);

        /* If the standard is for satellite, convert frequencies to kHz */
        switch (c->delivery_system) {
        case SYS_DVBS:
        case SYS_DVBS2:
        case SYS_TURBO:
        case SYS_ISDBS:
                *freq_min /= kHz;
                *freq_max /= kHz;
                if (tolerance)
                        *tolerance = fe->ops.info.frequency_tolerance_hz / kHz;

                break;
        default:
                if (tolerance)
                        *tolerance = fe->ops.info.frequency_tolerance_hz;
                break;
        }
}

static u32 dvb_frontend_get_stepsize(struct dvb_frontend *fe)
{
        struct dtv_frontend_properties *c = &fe->dtv_property_cache;
        u32 fe_step = fe->ops.info.frequency_stepsize_hz;
        u32 tuner_step = fe->ops.tuner_ops.info.frequency_step_hz;
        u32 step = max(fe_step, tuner_step);

        switch (c->delivery_system) {
        case SYS_DVBS:
        case SYS_DVBS2:
        case SYS_TURBO:
        case SYS_ISDBS:
                step /= kHz;
                break;
        default:
                break;
        }

        return step;
}

static int dvb_frontend_check_parameters(struct dvb_frontend *fe)
{
        struct dtv_frontend_properties *c = &fe->dtv_property_cache;
        u32 freq_min;
        u32 freq_max;

        /* range check: frequency */
        dvb_frontend_get_frequency_limits(fe, &freq_min, &freq_max, NULL);
        if ((freq_min && c->frequency < freq_min) ||
            (freq_max && c->frequency > freq_max)) {
                dev_warn(fe->dvb->device, "DVB: adapter %i frontend %i frequency %u out of range (%u..%u)\n",
                         fe->dvb->num, fe->id, c->frequency,
                         freq_min, freq_max);
                return -EINVAL;
        }

        /* range check: symbol rate */
        switch (c->delivery_system) {
        case SYS_DVBS:
        case SYS_DVBS2:
        case SYS_TURBO:
        case SYS_DVBC_ANNEX_A:
        case SYS_DVBC_ANNEX_C:
                if ((fe->ops.info.symbol_rate_min &&
                     c->symbol_rate < fe->ops.info.symbol_rate_min) ||
                    (fe->ops.info.symbol_rate_max &&
                     c->symbol_rate > fe->ops.info.symbol_rate_max)) {
                        dev_warn(fe->dvb->device, "DVB: adapter %i frontend %i symbol rate %u out of range (%u..%u)\n",
                                 fe->dvb->num, fe->id, c->symbol_rate,
                                 fe->ops.info.symbol_rate_min,
                                 fe->ops.info.symbol_rate_max);
                        return -EINVAL;
                }
                break;
        default:
                break;
        }

        return 0;
}

static int dvb_frontend_clear_cache(struct dvb_frontend *fe)

{
        struct dtv_frontend_properties *c = &fe->dtv_property_cache;
        int i;
        u32 delsys;

        delsys = c->delivery_system;
        memset(c, 0, offsetof(struct dtv_frontend_properties, strength));
        c->delivery_system = delsys;

        dev_dbg(fe->dvb->device, "%s: Clearing cache for delivery system %d\n",
                __func__, c->delivery_system);

        c->transmission_mode = TRANSMISSION_MODE_AUTO;
        c->bandwidth_hz = 0;    /* AUTO */
        c->guard_interval = GUARD_INTERVAL_AUTO;
        c->hierarchy = HIERARCHY_AUTO;
        c->symbol_rate = 0;
        c->code_rate_HP = FEC_AUTO;
        c->code_rate_LP = FEC_AUTO;
        c->fec_inner = FEC_AUTO;
        c->rolloff = ROLLOFF_AUTO;
        c->voltage = SEC_VOLTAGE_OFF;
        c->sectone = SEC_TONE_OFF;
        c->pilot = PILOT_AUTO;

        c->isdbt_partial_reception = 0;
        c->isdbt_sb_mode = 0;
        c->isdbt_sb_subchannel = 0;
        c->isdbt_sb_segment_idx = 0;
        c->isdbt_sb_segment_count = 0;
        c->isdbt_layer_enabled = 7;     /* All layers (A,B,C) */
        for (i = 0; i < 3; i++) {
                c->layer[i].fec = FEC_AUTO;
                c->layer[i].modulation = QAM_AUTO;
                c->layer[i].interleaving = 0;
                c->layer[i].segment_count = 0;
        }

        c->stream_id = NO_STREAM_ID_FILTER;
        c->scrambling_sequence_index = 0;/* default sequence */

        switch (c->delivery_system) {
        case SYS_DVBS:
        case SYS_DVBS2:
        case SYS_TURBO:
                c->modulation = QPSK;   /* implied for DVB-S in legacy API */
                c->rolloff = ROLLOFF_35;/* implied for DVB-S */
                break;
        case SYS_ATSC:
                c->modulation = VSB_8;
                break;
        case SYS_ISDBS:
                c->symbol_rate = 28860000;
                c->rolloff = ROLLOFF_35;
                c->bandwidth_hz = c->symbol_rate / 100 * 135;
                break;
        default:
                c->modulation = QAM_AUTO;
                break;
        }

        c->lna = LNA_AUTO;

        return 0;
}

#define _DTV_CMD(n) \
        [n] =  #n

static char *dtv_cmds[DTV_MAX_COMMAND + 1] = {
        _DTV_CMD(DTV_TUNE),
        _DTV_CMD(DTV_CLEAR),

        /* Set */
        _DTV_CMD(DTV_FREQUENCY),
        _DTV_CMD(DTV_BANDWIDTH_HZ),
        _DTV_CMD(DTV_MODULATION),
        _DTV_CMD(DTV_INVERSION),
        _DTV_CMD(DTV_DISEQC_MASTER),
        _DTV_CMD(DTV_SYMBOL_RATE),
        _DTV_CMD(DTV_INNER_FEC),
        _DTV_CMD(DTV_VOLTAGE),
        _DTV_CMD(DTV_TONE),
        _DTV_CMD(DTV_PILOT),
        _DTV_CMD(DTV_ROLLOFF),
        _DTV_CMD(DTV_DELIVERY_SYSTEM),
        _DTV_CMD(DTV_HIERARCHY),
        _DTV_CMD(DTV_CODE_RATE_HP),
        _DTV_CMD(DTV_CODE_RATE_LP),
        _DTV_CMD(DTV_GUARD_INTERVAL),
        _DTV_CMD(DTV_TRANSMISSION_MODE),
        _DTV_CMD(DTV_INTERLEAVING),

        _DTV_CMD(DTV_ISDBT_PARTIAL_RECEPTION),
        _DTV_CMD(DTV_ISDBT_SOUND_BROADCASTING),
        _DTV_CMD(DTV_ISDBT_SB_SUBCHANNEL_ID),
        _DTV_CMD(DTV_ISDBT_SB_SEGMENT_IDX),
        _DTV_CMD(DTV_ISDBT_SB_SEGMENT_COUNT),
        _DTV_CMD(DTV_ISDBT_LAYER_ENABLED),
        _DTV_CMD(DTV_ISDBT_LAYERA_FEC),
        _DTV_CMD(DTV_ISDBT_LAYERA_MODULATION),
        _DTV_CMD(DTV_ISDBT_LAYERA_SEGMENT_COUNT),
        _DTV_CMD(DTV_ISDBT_LAYERA_TIME_INTERLEAVING),
        _DTV_CMD(DTV_ISDBT_LAYERB_FEC),
        _DTV_CMD(DTV_ISDBT_LAYERB_MODULATION),
        _DTV_CMD(DTV_ISDBT_LAYERB_SEGMENT_COUNT),
        _DTV_CMD(DTV_ISDBT_LAYERB_TIME_INTERLEAVING),
        _DTV_CMD(DTV_ISDBT_LAYERC_FEC),
        _DTV_CMD(DTV_ISDBT_LAYERC_MODULATION),
        _DTV_CMD(DTV_ISDBT_LAYERC_SEGMENT_COUNT),
        _DTV_CMD(DTV_ISDBT_LAYERC_TIME_INTERLEAVING),

        _DTV_CMD(DTV_STREAM_ID),
        _DTV_CMD(DTV_DVBT2_PLP_ID_LEGACY),
        _DTV_CMD(DTV_SCRAMBLING_SEQUENCE_INDEX),
        _DTV_CMD(DTV_LNA),

        /* Get */
        _DTV_CMD(DTV_DISEQC_SLAVE_REPLY),
        _DTV_CMD(DTV_API_VERSION),

        _DTV_CMD(DTV_ENUM_DELSYS),

        _DTV_CMD(DTV_ATSCMH_PARADE_ID),
        _DTV_CMD(DTV_ATSCMH_RS_FRAME_ENSEMBLE),

        _DTV_CMD(DTV_ATSCMH_FIC_VER),
        _DTV_CMD(DTV_ATSCMH_NOG),
        _DTV_CMD(DTV_ATSCMH_TNOG),
        _DTV_CMD(DTV_ATSCMH_SGN),
        _DTV_CMD(DTV_ATSCMH_PRC),
        _DTV_CMD(DTV_ATSCMH_RS_FRAME_MODE),
        _DTV_CMD(DTV_ATSCMH_RS_CODE_MODE_PRI),
        _DTV_CMD(DTV_ATSCMH_RS_CODE_MODE_SEC),
        _DTV_CMD(DTV_ATSCMH_SCCC_BLOCK_MODE),
        _DTV_CMD(DTV_ATSCMH_SCCC_CODE_MODE_A),
        _DTV_CMD(DTV_ATSCMH_SCCC_CODE_MODE_B),
        _DTV_CMD(DTV_ATSCMH_SCCC_CODE_MODE_C),
        _DTV_CMD(DTV_ATSCMH_SCCC_CODE_MODE_D),

        /* Statistics API */
        _DTV_CMD(DTV_STAT_SIGNAL_STRENGTH),
        _DTV_CMD(DTV_STAT_CNR),
        _DTV_CMD(DTV_STAT_PRE_ERROR_BIT_COUNT),
        _DTV_CMD(DTV_STAT_PRE_TOTAL_BIT_COUNT),
        _DTV_CMD(DTV_STAT_POST_ERROR_BIT_COUNT),
        _DTV_CMD(DTV_STAT_POST_TOTAL_BIT_COUNT),
        _DTV_CMD(DTV_STAT_ERROR_BLOCK_COUNT),
        _DTV_CMD(DTV_STAT_TOTAL_BLOCK_COUNT),
};

static char *dtv_cmd_name(u32 cmd)
{
        cmd = array_index_nospec(cmd, DTV_MAX_COMMAND);
        return dtv_cmds[cmd];
}

/* Synchronise the legacy tuning parameters into the cache, so that demodulator
 * drivers can use a single set_frontend tuning function, regardless of whether
 * it's being used for the legacy or new API, reducing code and complexity.
 */
static int dtv_property_cache_sync(struct dvb_frontend *fe,
                                   struct dtv_frontend_properties *c,
                                   const struct dvb_frontend_parameters *p)
{
        c->frequency = p->frequency;
        c->inversion = p->inversion;

        switch (dvbv3_type(c->delivery_system)) {
        case DVBV3_QPSK:
                dev_dbg(fe->dvb->device, "%s: Preparing QPSK req\n", __func__);
                c->symbol_rate = p->u.qpsk.symbol_rate;
                c->fec_inner = p->u.qpsk.fec_inner;
                break;
        case DVBV3_QAM:
                dev_dbg(fe->dvb->device, "%s: Preparing QAM req\n", __func__);
                c->symbol_rate = p->u.qam.symbol_rate;
                c->fec_inner = p->u.qam.fec_inner;
                c->modulation = p->u.qam.modulation;
                break;
        case DVBV3_OFDM:
                dev_dbg(fe->dvb->device, "%s: Preparing OFDM req\n", __func__);

                switch (p->u.ofdm.bandwidth) {
                case BANDWIDTH_10_MHZ:
                        c->bandwidth_hz = 10000000;
                        break;
                case BANDWIDTH_8_MHZ:
                        c->bandwidth_hz = 8000000;
                        break;
                case BANDWIDTH_7_MHZ:
                        c->bandwidth_hz = 7000000;
                        break;
                case BANDWIDTH_6_MHZ:
                        c->bandwidth_hz = 6000000;
                        break;
                case BANDWIDTH_5_MHZ:
                        c->bandwidth_hz = 5000000;
                        break;
                case BANDWIDTH_1_712_MHZ:
                        c->bandwidth_hz = 1712000;
                        break;
                case BANDWIDTH_AUTO:
                        c->bandwidth_hz = 0;
                }

                c->code_rate_HP = p->u.ofdm.code_rate_HP;
                c->code_rate_LP = p->u.ofdm.code_rate_LP;
                c->modulation = p->u.ofdm.constellation;
                c->transmission_mode = p->u.ofdm.transmission_mode;
                c->guard_interval = p->u.ofdm.guard_interval;
                c->hierarchy = p->u.ofdm.hierarchy_information;
                break;
        case DVBV3_ATSC:
                dev_dbg(fe->dvb->device, "%s: Preparing ATSC req\n", __func__);
                c->modulation = p->u.vsb.modulation;
                if (c->delivery_system == SYS_ATSCMH)
                        break;
                if ((c->modulation == VSB_8) || (c->modulation == VSB_16))
                        c->delivery_system = SYS_ATSC;
                else
                        c->delivery_system = SYS_DVBC_ANNEX_B;
                break;
        case DVBV3_UNKNOWN:
                dev_err(fe->dvb->device,
                        "%s: doesn't know how to handle a DVBv3 call to delivery system %i\n",
                        __func__, c->delivery_system);
                return -EINVAL;
        }

        return 0;
}

/* Ensure the cached values are set correctly in the frontend
 * legacy tuning structures, for the advanced tuning API.
 */
static int
dtv_property_legacy_params_sync(struct dvb_frontend *fe,
                                const struct dtv_frontend_properties *c,
                                struct dvb_frontend_parameters *p)
{
        p->frequency = c->frequency;
        p->inversion = c->inversion;

        switch (dvbv3_type(c->delivery_system)) {
        case DVBV3_UNKNOWN:
                dev_err(fe->dvb->device,
                        "%s: doesn't know how to handle a DVBv3 call to delivery system %i\n",
                        __func__, c->delivery_system);
                return -EINVAL;
        case DVBV3_QPSK:
                dev_dbg(fe->dvb->device, "%s: Preparing QPSK req\n", __func__);
                p->u.qpsk.symbol_rate = c->symbol_rate;
                p->u.qpsk.fec_inner = c->fec_inner;
                break;
        case DVBV3_QAM:
                dev_dbg(fe->dvb->device, "%s: Preparing QAM req\n", __func__);
                p->u.qam.symbol_rate = c->symbol_rate;
                p->u.qam.fec_inner = c->fec_inner;
                p->u.qam.modulation = c->modulation;
                break;
        case DVBV3_OFDM:
                dev_dbg(fe->dvb->device, "%s: Preparing OFDM req\n", __func__);
                switch (c->bandwidth_hz) {
                case 10000000:
                        p->u.ofdm.bandwidth = BANDWIDTH_10_MHZ;
                        break;
                case 8000000:
                        p->u.ofdm.bandwidth = BANDWIDTH_8_MHZ;
                        break;
                case 7000000:
                        p->u.ofdm.bandwidth = BANDWIDTH_7_MHZ;
                        break;
                case 6000000:
                        p->u.ofdm.bandwidth = BANDWIDTH_6_MHZ;
                        break;
                case 5000000:
                        p->u.ofdm.bandwidth = BANDWIDTH_5_MHZ;
                        break;
                case 1712000:
                        p->u.ofdm.bandwidth = BANDWIDTH_1_712_MHZ;
                        break;
                case 0:
                default:
                        p->u.ofdm.bandwidth = BANDWIDTH_AUTO;
                }
                p->u.ofdm.code_rate_HP = c->code_rate_HP;
                p->u.ofdm.code_rate_LP = c->code_rate_LP;
                p->u.ofdm.constellation = c->modulation;
                p->u.ofdm.transmission_mode = c->transmission_mode;
                p->u.ofdm.guard_interval = c->guard_interval;
                p->u.ofdm.hierarchy_information = c->hierarchy;
                break;
        case DVBV3_ATSC:
                dev_dbg(fe->dvb->device, "%s: Preparing VSB req\n", __func__);
                p->u.vsb.modulation = c->modulation;
                break;
        }
        return 0;
}

/**
 * dtv_get_frontend - calls a callback for retrieving DTV parameters
 * @fe:         struct dvb_frontend pointer
 * @c:          struct dtv_frontend_properties pointer (DVBv5 cache)
 * @p_out:      struct dvb_frontend_parameters pointer (DVBv3 FE struct)
 *
 * This routine calls either the DVBv3 or DVBv5 get_frontend call.
 * If c is not null, it will update the DVBv5 cache struct pointed by it.
 * If p_out is not null, it will update the DVBv3 params pointed by it.
 */
static int dtv_get_frontend(struct dvb_frontend *fe,
                            struct dtv_frontend_properties *c,
                            struct dvb_frontend_parameters *p_out)
{
        int r;

        if (fe->ops.get_frontend) {
                r = fe->ops.get_frontend(fe, c);
                if (unlikely(r < 0))
                        return r;
                if (p_out)
                        dtv_property_legacy_params_sync(fe, c, p_out);
                return 0;
        }

        /* As everything is in cache, get_frontend fops are always supported */
        return 0;
}

static int dvb_frontend_handle_ioctl(struct file *file,
                                     unsigned int cmd, void *parg);

static int dtv_property_process_get(struct dvb_frontend *fe,
                                    const struct dtv_frontend_properties *c,
                                    struct dtv_property *tvp,
                                    struct file *file)
{
        int ncaps;
        unsigned int len = 1;

        switch (tvp->cmd) {
        case DTV_ENUM_DELSYS:
                ncaps = 0;
                while (ncaps < MAX_DELSYS && fe->ops.delsys[ncaps]) {
                        tvp->u.buffer.data[ncaps] = fe->ops.delsys[ncaps];
                        ncaps++;
                }
                tvp->u.buffer.len = ncaps;
                len = ncaps;
                break;
        case DTV_FREQUENCY:
                tvp->u.data = c->frequency;
                break;
        case DTV_MODULATION:
                tvp->u.data = c->modulation;
                break;
        case DTV_BANDWIDTH_HZ:
                tvp->u.data = c->bandwidth_hz;
                break;
        case DTV_INVERSION:
                tvp->u.data = c->inversion;
                break;
        case DTV_SYMBOL_RATE:
                tvp->u.data = c->symbol_rate;
                break;
        case DTV_INNER_FEC:
                tvp->u.data = c->fec_inner;
                break;
        case DTV_PILOT:
                tvp->u.data = c->pilot;
                break;
        case DTV_ROLLOFF:
                tvp->u.data = c->rolloff;
                break;
        case DTV_DELIVERY_SYSTEM:
                tvp->u.data = c->delivery_system;
                break;
        case DTV_VOLTAGE:
                tvp->u.data = c->voltage;
                break;
        case DTV_TONE:
                tvp->u.data = c->sectone;
                break;
        case DTV_API_VERSION:
                tvp->u.data = (DVB_API_VERSION << 8) | DVB_API_VERSION_MINOR;
                break;
        case DTV_CODE_RATE_HP:
                tvp->u.data = c->code_rate_HP;
                break;
        case DTV_CODE_RATE_LP:
                tvp->u.data = c->code_rate_LP;
                break;
        case DTV_GUARD_INTERVAL:
                tvp->u.data = c->guard_interval;
                break;
        case DTV_TRANSMISSION_MODE:
                tvp->u.data = c->transmission_mode;
                break;
        case DTV_HIERARCHY:
                tvp->u.data = c->hierarchy;
                break;
        case DTV_INTERLEAVING:
                tvp->u.data = c->interleaving;
                break;

        /* ISDB-T Support here */
        case DTV_ISDBT_PARTIAL_RECEPTION:
                tvp->u.data = c->isdbt_partial_reception;
                break;
        case DTV_ISDBT_SOUND_BROADCASTING:
                tvp->u.data = c->isdbt_sb_mode;
                break;
        case DTV_ISDBT_SB_SUBCHANNEL_ID:
                tvp->u.data = c->isdbt_sb_subchannel;
                break;
        case DTV_ISDBT_SB_SEGMENT_IDX:
                tvp->u.data = c->isdbt_sb_segment_idx;
                break;
        case DTV_ISDBT_SB_SEGMENT_COUNT:
                tvp->u.data = c->isdbt_sb_segment_count;
                break;
        case DTV_ISDBT_LAYER_ENABLED:
                tvp->u.data = c->isdbt_layer_enabled;
                break;
        case DTV_ISDBT_LAYERA_FEC:
                tvp->u.data = c->layer[0].fec;
                break;
        case DTV_ISDBT_LAYERA_MODULATION:
                tvp->u.data = c->layer[0].modulation;
                break;
        case DTV_ISDBT_LAYERA_SEGMENT_COUNT:
                tvp->u.data = c->layer[0].segment_count;
                break;
        case DTV_ISDBT_LAYERA_TIME_INTERLEAVING:
                tvp->u.data = c->layer[0].interleaving;
                break;
        case DTV_ISDBT_LAYERB_FEC:
                tvp->u.data = c->layer[1].fec;
                break;
        case DTV_ISDBT_LAYERB_MODULATION:
                tvp->u.data = c->layer[1].modulation;
                break;
        case DTV_ISDBT_LAYERB_SEGMENT_COUNT:
                tvp->u.data = c->layer[1].segment_count;
                break;
        case DTV_ISDBT_LAYERB_TIME_INTERLEAVING:
                tvp->u.data = c->layer[1].interleaving;
                break;
        case DTV_ISDBT_LAYERC_FEC:
                tvp->u.data = c->layer[2].fec;
                break;
        case DTV_ISDBT_LAYERC_MODULATION:
                tvp->u.data = c->layer[2].modulation;
                break;
        case DTV_ISDBT_LAYERC_SEGMENT_COUNT:
                tvp->u.data = c->layer[2].segment_count;
                break;
        case DTV_ISDBT_LAYERC_TIME_INTERLEAVING:
                tvp->u.data = c->layer[2].interleaving;
                break;

        /* Multistream support */
        case DTV_STREAM_ID:
        case DTV_DVBT2_PLP_ID_LEGACY:
                tvp->u.data = c->stream_id;
                break;

        /* Physical layer scrambling support */
        case DTV_SCRAMBLING_SEQUENCE_INDEX:
                tvp->u.data = c->scrambling_sequence_index;
                break;

        /* ATSC-MH */
        case DTV_ATSCMH_FIC_VER:
                tvp->u.data = fe->dtv_property_cache.atscmh_fic_ver;
                break;
        case DTV_ATSCMH_PARADE_ID:
                tvp->u.data = fe->dtv_property_cache.atscmh_parade_id;
                break;
        case DTV_ATSCMH_NOG:
                tvp->u.data = fe->dtv_property_cache.atscmh_nog;
                break;
        case DTV_ATSCMH_TNOG:
                tvp->u.data = fe->dtv_property_cache.atscmh_tnog;
                break;
        case DTV_ATSCMH_SGN:
                tvp->u.data = fe->dtv_property_cache.atscmh_sgn;
                break;
        case DTV_ATSCMH_PRC:
                tvp->u.data = fe->dtv_property_cache.atscmh_prc;
                break;
        case DTV_ATSCMH_RS_FRAME_MODE:
                tvp->u.data = fe->dtv_property_cache.atscmh_rs_frame_mode;
                break;
        case DTV_ATSCMH_RS_FRAME_ENSEMBLE:
                tvp->u.data = fe->dtv_property_cache.atscmh_rs_frame_ensemble;
                break;
        case DTV_ATSCMH_RS_CODE_MODE_PRI:
                tvp->u.data = fe->dtv_property_cache.atscmh_rs_code_mode_pri;
                break;
        case DTV_ATSCMH_RS_CODE_MODE_SEC:
                tvp->u.data = fe->dtv_property_cache.atscmh_rs_code_mode_sec;
                break;
        case DTV_ATSCMH_SCCC_BLOCK_MODE:
                tvp->u.data = fe->dtv_property_cache.atscmh_sccc_block_mode;
                break;
        case DTV_ATSCMH_SCCC_CODE_MODE_A:
                tvp->u.data = fe->dtv_property_cache.atscmh_sccc_code_mode_a;
                break;
        case DTV_ATSCMH_SCCC_CODE_MODE_B:
                tvp->u.data = fe->dtv_property_cache.atscmh_sccc_code_mode_b;
                break;
        case DTV_ATSCMH_SCCC_CODE_MODE_C:
                tvp->u.data = fe->dtv_property_cache.atscmh_sccc_code_mode_c;
                break;
        case DTV_ATSCMH_SCCC_CODE_MODE_D:
                tvp->u.data = fe->dtv_property_cache.atscmh_sccc_code_mode_d;
                break;

        case DTV_LNA:
                tvp->u.data = c->lna;
                break;

        /* Fill quality measures */
        case DTV_STAT_SIGNAL_STRENGTH:
                tvp->u.st = c->strength;
                if (tvp->u.buffer.len > MAX_DTV_STATS * sizeof(u32))
                        tvp->u.buffer.len = MAX_DTV_STATS * sizeof(u32);
                len = tvp->u.buffer.len;
                break;
        case DTV_STAT_CNR:
                tvp->u.st = c->cnr;
                if (tvp->u.buffer.len > MAX_DTV_STATS * sizeof(u32))
                        tvp->u.buffer.len = MAX_DTV_STATS * sizeof(u32);
                len = tvp->u.buffer.len;
                break;
        case DTV_STAT_PRE_ERROR_BIT_COUNT:
                tvp->u.st = c->pre_bit_error;
                if (tvp->u.buffer.len > MAX_DTV_STATS * sizeof(u32))
                        tvp->u.buffer.len = MAX_DTV_STATS * sizeof(u32);
                len = tvp->u.buffer.len;
                break;
        case DTV_STAT_PRE_TOTAL_BIT_COUNT:
                tvp->u.st = c->pre_bit_count;
                if (tvp->u.buffer.len > MAX_DTV_STATS * sizeof(u32))
                        tvp->u.buffer.len = MAX_DTV_STATS * sizeof(u32);
                len = tvp->u.buffer.len;
                break;
        case DTV_STAT_POST_ERROR_BIT_COUNT:
                tvp->u.st = c->post_bit_error;
                if (tvp->u.buffer.len > MAX_DTV_STATS * sizeof(u32))
                        tvp->u.buffer.len = MAX_DTV_STATS * sizeof(u32);
                len = tvp->u.buffer.len;
                break;
        case DTV_STAT_POST_TOTAL_BIT_COUNT:
                tvp->u.st = c->post_bit_count;
                if (tvp->u.buffer.len > MAX_DTV_STATS * sizeof(u32))
                        tvp->u.buffer.len = MAX_DTV_STATS * sizeof(u32);
                len = tvp->u.buffer.len;
                break;
        case DTV_STAT_ERROR_BLOCK_COUNT:
                tvp->u.st = c->block_error;
                if (tvp->u.buffer.len > MAX_DTV_STATS * sizeof(u32))
                        tvp->u.buffer.len = MAX_DTV_STATS * sizeof(u32);
                len = tvp->u.buffer.len;
                break;
        case DTV_STAT_TOTAL_BLOCK_COUNT:
                tvp->u.st = c->block_count;
                if (tvp->u.buffer.len > MAX_DTV_STATS * sizeof(u32))
                        tvp->u.buffer.len = MAX_DTV_STATS * sizeof(u32);
                len = tvp->u.buffer.len;
                break;
        default:
                dev_dbg(fe->dvb->device,
                        "%s: FE property %d doesn't exist\n",
                        __func__, tvp->cmd);
                return -EINVAL;
        }

        if (len < 1)
                len = 1;

        dev_dbg(fe->dvb->device,
                "%s: GET cmd 0x%08x (%s) len %d: %*ph\n",
                __func__, tvp->cmd, dtv_cmd_name(tvp->cmd),
                tvp->u.buffer.len, tvp->u.buffer.len, tvp->u.buffer.data);

        return 0;
}

static int dtv_set_frontend(struct dvb_frontend *fe);

static bool is_dvbv3_delsys(u32 delsys)
{
        return (delsys == SYS_DVBT) || (delsys == SYS_DVBC_ANNEX_A) ||
               (delsys == SYS_DVBS) || (delsys == SYS_ATSC);
}

/**
 * emulate_delivery_system - emulate a DVBv5 delivery system with a DVBv3 type
 * @fe:                 struct frontend;
 * @delsys:                     DVBv5 type that will be used for emulation
 *
 * Provides emulation for delivery systems that are compatible with the old
 * DVBv3 call. Among its usages, it provices support for ISDB-T, and allows
 * using a DVB-S2 only frontend just like it were a DVB-S, if the frontend
 * parameters are compatible with DVB-S spec.
 */
static int emulate_delivery_system(struct dvb_frontend *fe, u32 delsys)
{
        int i;
        struct dtv_frontend_properties *c = &fe->dtv_property_cache;

        c->delivery_system = delsys;

        /*
         * If the call is for ISDB-T, put it into full-seg, auto mode, TV
         */
        if (c->delivery_system == SYS_ISDBT) {
                dev_dbg(fe->dvb->device,
                        "%s: Using defaults for SYS_ISDBT\n",
                        __func__);

                if (!c->bandwidth_hz)
                        c->bandwidth_hz = 6000000;

                c->isdbt_partial_reception = 0;
                c->isdbt_sb_mode = 0;
                c->isdbt_sb_subchannel = 0;
                c->isdbt_sb_segment_idx = 0;
                c->isdbt_sb_segment_count = 0;
                c->isdbt_layer_enabled = 7;
                for (i = 0; i < 3; i++) {
                        c->layer[i].fec = FEC_AUTO;
                        c->layer[i].modulation = QAM_AUTO;
                        c->layer[i].interleaving = 0;
                        c->layer[i].segment_count = 0;
                }
        }
        dev_dbg(fe->dvb->device, "%s: change delivery system on cache to %d\n",
                __func__, c->delivery_system);

        return 0;
}

/**
 * dvbv5_set_delivery_system - Sets the delivery system for a DVBv5 API call
 * @fe:                 frontend struct
 * @desired_system:     delivery system requested by the user
 *
 * A DVBv5 call know what's the desired system it wants. So, set it.
 *
 * There are, however, a few known issues with early DVBv5 applications that
 * are also handled by this logic:
 *
 * 1) Some early apps use SYS_UNDEFINED as the desired delivery system.
 *    This is an API violation, but, as we don't want to break userspace,
 *    convert it to the first supported delivery system.
 * 2) Some apps might be using a DVBv5 call in a wrong way, passing, for
 *    example, SYS_DVBT instead of SYS_ISDBT. This is because early usage of
 *    ISDB-T provided backward compat with DVB-T.
 */
static int dvbv5_set_delivery_system(struct dvb_frontend *fe,
                                     u32 desired_system)
{
        int ncaps;
        u32 delsys = SYS_UNDEFINED;
        struct dtv_frontend_properties *c = &fe->dtv_property_cache;
        enum dvbv3_emulation_type type;

        /*
         * It was reported that some old DVBv5 applications were
         * filling delivery_system with SYS_UNDEFINED. If this happens,
         * assume that the application wants to use the first supported
         * delivery system.
         */
        if (desired_system == SYS_UNDEFINED)
                desired_system = fe->ops.delsys[0];

        /*
         * This is a DVBv5 call. So, it likely knows the supported
         * delivery systems. So, check if the desired delivery system is
         * supported
         */
        ncaps = 0;
        while (ncaps < MAX_DELSYS && fe->ops.delsys[ncaps]) {
                if (fe->ops.delsys[ncaps] == desired_system) {
                        c->delivery_system = desired_system;
                        dev_dbg(fe->dvb->device,
                                "%s: Changing delivery system to %d\n",
                                __func__, desired_system);
                        return 0;
                }
                ncaps++;
        }

        /*
         * The requested delivery system isn't supported. Maybe userspace
         * is requesting a DVBv3 compatible delivery system.
         *
         * The emulation only works if the desired system is one of the
         * delivery systems supported by DVBv3 API
         */
        if (!is_dvbv3_delsys(desired_system)) {
                dev_dbg(fe->dvb->device,
                        "%s: Delivery system %d not supported.\n",
                        __func__, desired_system);
                return -EINVAL;
        }

        type = dvbv3_type(desired_system);

        /*
        * Get the last non-DVBv3 delivery system that has the same type
        * of the desired system
        */
        ncaps = 0;
        while (ncaps < MAX_DELSYS && fe->ops.delsys[ncaps]) {
                if (dvbv3_type(fe->ops.delsys[ncaps]) == type)
                        delsys = fe->ops.delsys[ncaps];
                ncaps++;
        }

        /* There's nothing compatible with the desired delivery system */
        if (delsys == SYS_UNDEFINED) {
                dev_dbg(fe->dvb->device,
                        "%s: Delivery system %d not supported on emulation mode.\n",
                        __func__, desired_system);
                return -EINVAL;
        }

        dev_dbg(fe->dvb->device,
                "%s: Using delivery system %d emulated as if it were %d\n",
                __func__, delsys, desired_system);

        return emulate_delivery_system(fe, desired_system);
}

/**
 * dvbv3_set_delivery_system - Sets the delivery system for a DVBv3 API call
 * @fe: frontend struct
 *
 * A DVBv3 call doesn't know what's the desired system it wants. It also
 * doesn't allow to switch between different types. Due to that, userspace
 * should use DVBv5 instead.
 * However, in order to avoid breaking userspace API, limited backward
 * compatibility support is provided.
 *
 * There are some delivery systems that are incompatible with DVBv3 calls.
 *
 * This routine should work fine for frontends that support just one delivery
 * system.
 *
 * For frontends that support multiple frontends:
 * 1) It defaults to use the first supported delivery system. There's an
 *    userspace application that allows changing it at runtime;
 *
 * 2) If the current delivery system is not compatible with DVBv3, it gets
 *    the first one that it is compatible.
 *
 * NOTE: in order for this to work with applications like Kaffeine that
 *      uses a DVBv5 call for DVB-S2 and a DVBv3 call to go back to
 *      DVB-S, drivers that support both DVB-S and DVB-S2 should have the
 *      SYS_DVBS entry before the SYS_DVBS2, otherwise it won't switch back
 *      to DVB-S.
 */
static int dvbv3_set_delivery_system(struct dvb_frontend *fe)
{
        int ncaps;
        u32 delsys = SYS_UNDEFINED;
        struct dtv_frontend_properties *c = &fe->dtv_property_cache;

        /* If not set yet, defaults to the first supported delivery system */
        if (c->delivery_system == SYS_UNDEFINED)
                c->delivery_system = fe->ops.delsys[0];

        /*
         * Trivial case: just use the current one, if it already a DVBv3
         * delivery system
         */
        if (is_dvbv3_delsys(c->delivery_system)) {
                dev_dbg(fe->dvb->device,
                        "%s: Using delivery system to %d\n",
                        __func__, c->delivery_system);
                return 0;
        }

        /*
         * Seek for the first delivery system that it is compatible with a
         * DVBv3 standard
         */
        ncaps = 0;
        while (ncaps < MAX_DELSYS && fe->ops.delsys[ncaps]) {
                if (dvbv3_type(fe->ops.delsys[ncaps]) != DVBV3_UNKNOWN) {
                        delsys = fe->ops.delsys[ncaps];
                        break;
                }
                ncaps++;
        }
        if (delsys == SYS_UNDEFINED) {
                dev_dbg(fe->dvb->device,
                        "%s: Couldn't find a delivery system that works with FE_SET_FRONTEND\n",
                        __func__);
                return -EINVAL;
        }
        return emulate_delivery_system(fe, delsys);
}

static void prepare_tuning_algo_parameters(struct dvb_frontend *fe)
{
        struct dtv_frontend_properties *c = &fe->dtv_property_cache;
        struct dvb_frontend_private *fepriv = fe->frontend_priv;
        struct dvb_frontend_tune_settings fetunesettings = { 0 };

        /* get frontend-specific tuning settings */
        if (fe->ops.get_tune_settings && (fe->ops.get_tune_settings(fe, &fetunesettings) == 0)) {
                fepriv->min_delay = (fetunesettings.min_delay_ms * HZ) / 1000;
                fepriv->max_drift = fetunesettings.max_drift;
                fepriv->step_size = fetunesettings.step_size;
        } else {
                /* default values */
                switch (c->delivery_system) {
                case SYS_DVBS:
                case SYS_DVBS2:
                case SYS_ISDBS:
                case SYS_TURBO:
                case SYS_DVBC_ANNEX_A:
                case SYS_DVBC_ANNEX_C:
                        fepriv->min_delay = HZ / 20;
                        fepriv->step_size = c->symbol_rate / 16000;
                        fepriv->max_drift = c->symbol_rate / 2000;
                        break;
                case SYS_DVBT:
                case SYS_DVBT2:
                case SYS_ISDBT:
                case SYS_DTMB:
                        fepriv->min_delay = HZ / 20;
                        fepriv->step_size = dvb_frontend_get_stepsize(fe) * 2;
                        fepriv->max_drift = fepriv->step_size + 1;
                        break;
                default:
                        /*
                         * FIXME: This sounds wrong! if freqency_stepsize is
                         * defined by the frontend, why not use it???
                         */
                        fepriv->min_delay = HZ / 20;
                        fepriv->step_size = 0; /* no zigzag */
                        fepriv->max_drift = 0;
                        break;
                }
        }
        if (dvb_override_tune_delay > 0)
                fepriv->min_delay = (dvb_override_tune_delay * HZ) / 1000;
}

/**
 * dtv_property_process_set -  Sets a single DTV property
 * @fe:         Pointer to &struct dvb_frontend
 * @file:       Pointer to &struct file
 * @cmd:        Digital TV command
 * @data:       An unsigned 32-bits number
 *
 * This routine assigns the property
 * value to the corresponding member of
 * &struct dtv_frontend_properties
 *
 * Returns:
 * Zero on success, negative errno on failure.
 */
static int dtv_property_process_set(struct dvb_frontend *fe,
                                    struct file *file,
                                    u32 cmd, u32 data)
{
        int r = 0;
        struct dtv_frontend_properties *c = &fe->dtv_property_cache;

        /** Dump DTV command name and value*/
        if (!cmd || cmd > DTV_MAX_COMMAND)
                dev_warn(fe->dvb->device, "%s: SET cmd 0x%08x undefined\n",
                         __func__, cmd);
        else
                dev_dbg(fe->dvb->device,
                        "%s: SET cmd 0x%08x (%s) to 0x%08x\n",
                        __func__, cmd, dtv_cmd_name(cmd), data);
        switch (cmd) {
        case DTV_CLEAR:
                /*
                 * Reset a cache of data specific to the frontend here. This does
                 * not effect hardware.
                 */
                dvb_frontend_clear_cache(fe);
                break;
        case DTV_TUNE:
                /*
                 * Use the cached Digital TV properties to tune the
                 * frontend
                 */
                dev_dbg(fe->dvb->device,
                        "%s: Setting the frontend from property cache\n",
                        __func__);

                r = dtv_set_frontend(fe);
                break;
        case DTV_FREQUENCY:
                c->frequency = data;
                break;
        case DTV_MODULATION:
                c->modulation = data;
                break;
        case DTV_BANDWIDTH_HZ:
                c->bandwidth_hz = data;
                break;
        case DTV_INVERSION:
                c->inversion = data;
                break;
        case DTV_SYMBOL_RATE:
                c->symbol_rate = data;
                break;
        case DTV_INNER_FEC:
                c->fec_inner = data;
                break;
        case DTV_PILOT:
                c->pilot = data;
                break;
        case DTV_ROLLOFF:
                c->rolloff = data;
                break;
        case DTV_DELIVERY_SYSTEM:
                r = dvbv5_set_delivery_system(fe, data);
                break;
        case DTV_VOLTAGE:
                c->voltage = data;
                r = dvb_frontend_handle_ioctl(file, FE_SET_VOLTAGE,
                                              (void *)c->voltage);
                break;
        case DTV_TONE:
                c->sectone = data;
                r = dvb_frontend_handle_ioctl(file, FE_SET_TONE,
                                              (void *)c->sectone);
                break;
        case DTV_CODE_RATE_HP:
                c->code_rate_HP = data;
                break;
        case DTV_CODE_RATE_LP:
                c->code_rate_LP = data;
                break;
        case DTV_GUARD_INTERVAL:
                c->guard_interval = data;
                break;
        case DTV_TRANSMISSION_MODE:
                c->transmission_mode = data;
                break;
        case DTV_HIERARCHY:
                c->hierarchy = data;
                break;
        case DTV_INTERLEAVING:
                c->interleaving = data;
                break;

        /* ISDB-T Support here */
        case DTV_ISDBT_PARTIAL_RECEPTION:
                c->isdbt_partial_reception = data;
                break;
        case DTV_ISDBT_SOUND_BROADCASTING:
                c->isdbt_sb_mode = data;
                break;
        case DTV_ISDBT_SB_SUBCHANNEL_ID:
                c->isdbt_sb_subchannel = data;
                break;
        case DTV_ISDBT_SB_SEGMENT_IDX:
                c->isdbt_sb_segment_idx = data;
                break;
        case DTV_ISDBT_SB_SEGMENT_COUNT:
                c->isdbt_sb_segment_count = data;
                break;
        case DTV_ISDBT_LAYER_ENABLED:
                c->isdbt_layer_enabled = data;
                break;
        case DTV_ISDBT_LAYERA_FEC:
                c->layer[0].fec = data;
                break;
        case DTV_ISDBT_LAYERA_MODULATION:
                c->layer[0].modulation = data;
                break;
        case DTV_ISDBT_LAYERA_SEGMENT_COUNT:
                c->layer[0].segment_count = data;
                break;
        case DTV_ISDBT_LAYERA_TIME_INTERLEAVING:
                c->layer[0].interleaving = data;
                break;
        case DTV_ISDBT_LAYERB_FEC:
                c->layer[1].fec = data;
                break;
        case DTV_ISDBT_LAYERB_MODULATION:
                c->layer[1].modulation = data;
                break;
        case DTV_ISDBT_LAYERB_SEGMENT_COUNT:
                c->layer[1].segment_count = data;
                break;

        case DTV_ISDBT_LAYERB_TIME_INTERLEAVING:
                c->layer[1].interleaving = data;
                break;
        case DTV_ISDBT_LAYERC_FEC:
                c->layer[2].fec = data;
                break;
        case DTV_ISDBT_LAYERC_MODULATION:
                c->layer[2].modulation = data;
                break;
        case DTV_ISDBT_LAYERC_SEGMENT_COUNT:
                c->layer[2].segment_count = data;
                break;
        case DTV_ISDBT_LAYERC_TIME_INTERLEAVING:
                c->layer[2].interleaving = data;
                break;

        /* Multistream support */
        case DTV_STREAM_ID:
        case DTV_DVBT2_PLP_ID_LEGACY:
                c->stream_id = data;
                break;

        /* Physical layer scrambling support */
        case DTV_SCRAMBLING_SEQUENCE_INDEX:
                c->scrambling_sequence_index = data;
                break;

        /* ATSC-MH */
        case DTV_ATSCMH_PARADE_ID:
                fe->dtv_property_cache.atscmh_parade_id = data;
                break;
        case DTV_ATSCMH_RS_FRAME_ENSEMBLE:
                fe->dtv_property_cache.atscmh_rs_frame_ensemble = data;
                break;

        case DTV_LNA:
                c->lna = data;
                if (fe->ops.set_lna)
                        r = fe->ops.set_lna(fe);
                if (r < 0)
                        c->lna = LNA_AUTO;
                break;

        default:
                return -EINVAL;
        }

        return r;
}

static int dvb_frontend_do_ioctl(struct file *file, unsigned int cmd,
                                 void *parg)
{
        struct dvb_device *dvbdev = file->private_data;
        struct dvb_frontend *fe = dvbdev->priv;
        struct dvb_frontend_private *fepriv = fe->frontend_priv;
        int err;

        dev_dbg(fe->dvb->device, "%s: (%d)\n", __func__, _IOC_NR(cmd));
        if (down_interruptible(&fepriv->sem))
                return -ERESTARTSYS;

        if (fe->exit != DVB_FE_NO_EXIT) {
                up(&fepriv->sem);
                return -ENODEV;
        }

        /*
         * If the frontend is opened in read-only mode, only the ioctls
         * that don't interfere with the tune logic should be accepted.
         * That allows an external application to monitor the DVB QoS and
         * statistics parameters.
         *
         * That matches all _IOR() ioctls, except for two special cases:
         *   - FE_GET_EVENT is part of the tuning logic on a DVB application;
         *   - FE_DISEQC_RECV_SLAVE_REPLY is part of DiSEqC 2.0
         *     setup
         * So, those two ioctls should also return -EPERM, as otherwise
         * reading from them would interfere with a DVB tune application
         */
        if ((file->f_flags & O_ACCMODE) == O_RDONLY
            && (_IOC_DIR(cmd) != _IOC_READ
                || cmd == FE_GET_EVENT
                || cmd == FE_DISEQC_RECV_SLAVE_REPLY)) {
                up(&fepriv->sem);
                return -EPERM;
        }

        err = dvb_frontend_handle_ioctl(file, cmd, parg);

        up(&fepriv->sem);
        return err;
}

static long dvb_frontend_ioctl(struct file *file, unsigned int cmd,
                               unsigned long arg)
{
        struct dvb_device *dvbdev = file->private_data;

        if (!dvbdev)
                return -ENODEV;

        return dvb_usercopy(file, cmd, arg, dvb_frontend_do_ioctl);
}

#ifdef CONFIG_COMPAT
struct compat_dtv_property {
        __u32 cmd;
        __u32 reserved[3];
        union {
                __u32 data;
                struct dtv_fe_stats st;
                struct {
                        __u8 data[32];
                        __u32 len;
                        __u32 reserved1[3];
                        compat_uptr_t reserved2;
                } buffer;
        } u;
        int result;
} __attribute__ ((packed));

struct compat_dtv_properties {
        __u32 num;
        compat_uptr_t props;
};

#define COMPAT_FE_SET_PROPERTY     _IOW('o', 82, struct compat_dtv_properties)
#define COMPAT_FE_GET_PROPERTY     _IOR('o', 83, struct compat_dtv_properties)

static int dvb_frontend_handle_compat_ioctl(struct file *file, unsigned int cmd,
                                            unsigned long arg)
{
        struct dvb_device *dvbdev = file->private_data;
        struct dvb_frontend *fe = dvbdev->priv;
        struct dvb_frontend_private *fepriv = fe->frontend_priv;
        int i, err = 0;

        if (cmd == COMPAT_FE_SET_PROPERTY) {
                struct compat_dtv_properties prop, *tvps = NULL;
                struct compat_dtv_property *tvp = NULL;

                if (copy_from_user(&prop, compat_ptr(arg), sizeof(prop)))
                        return -EFAULT;

                tvps = &prop;

                /*
                 * Put an arbitrary limit on the number of messages that can
                 * be sent at once
                 */
                if (!tvps->num || (tvps->num > DTV_IOCTL_MAX_MSGS))
                        return -EINVAL;

                tvp = memdup_user(compat_ptr(tvps->props), tvps->num * sizeof(*tvp));
                if (IS_ERR(tvp))
                        return PTR_ERR(tvp);

                for (i = 0; i < tvps->num; i++) {
                        err = dtv_property_process_set(fe, file,
                                                       (tvp + i)->cmd,
                                                       (tvp + i)->u.data);
                        if (err < 0) {
                                kfree(tvp);
                                return err;
                        }
                }
                kfree(tvp);
        } else if (cmd == COMPAT_FE_GET_PROPERTY) {
                struct compat_dtv_properties prop, *tvps = NULL;
                struct compat_dtv_property *tvp = NULL;
                struct dtv_frontend_properties getp = fe->dtv_property_cache;

                if (copy_from_user(&prop, compat_ptr(arg), sizeof(prop)))
                        return -EFAULT;

                tvps = &prop;

                /*
                 * Put an arbitrary limit on the number of messages that can
                 * be sent at once
                 */
                if (!tvps->num || (tvps->num > DTV_IOCTL_MAX_MSGS))
                        return -EINVAL;

                tvp = memdup_user(compat_ptr(tvps->props), tvps->num * sizeof(*tvp));
                if (IS_ERR(tvp))
                        return PTR_ERR(tvp);

                /*
                 * Let's use our own copy of property cache, in order to
                 * avoid mangling with DTV zigzag logic, as drivers might
                 * return crap, if they don't check if the data is available
                 * before updating the properties cache.
                 */
                if (fepriv->state != FESTATE_IDLE) {
                        err = dtv_get_frontend(fe, &getp, NULL);
                        if (err < 0) {
                                kfree(tvp);
                                return err;
                        }
                }
                for (i = 0; i < tvps->num; i++) {
                        err = dtv_property_process_get(
                            fe, &getp, (struct dtv_property *)(tvp + i), file);
                        if (err < 0) {
                                kfree(tvp);
                                return err;
                        }
                }

                if (copy_to_user((void __user *)compat_ptr(tvps->props), tvp,
                                 tvps->num * sizeof(struct compat_dtv_property))) {
                        kfree(tvp);
                        return -EFAULT;
                }
                kfree(tvp);
        }

        return err;
}

static long dvb_frontend_compat_ioctl(struct file *file, unsigned int cmd,
                                      unsigned long arg)
{
        struct dvb_device *dvbdev = file->private_data;
        struct dvb_frontend *fe = dvbdev->priv;
        struct dvb_frontend_private *fepriv = fe->frontend_priv;
        int err;

        if (cmd == COMPAT_FE_SET_PROPERTY || cmd == COMPAT_FE_GET_PROPERTY) {
                if (down_interruptible(&fepriv->sem))
                        return -ERESTARTSYS;

                err = dvb_frontend_handle_compat_ioctl(file, cmd, arg);

                up(&fepriv->sem);
                return err;
        }

        return dvb_frontend_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
}
#endif

static int dtv_set_frontend(struct dvb_frontend *fe)
{
        struct dvb_frontend_private *fepriv = fe->frontend_priv;
        struct dtv_frontend_properties *c = &fe->dtv_property_cache;
        u32 rolloff = 0;

        if (dvb_frontend_check_parameters(fe) < 0)
                return -EINVAL;

        /*
         * Initialize output parameters to match the values given by
         * the user. FE_SET_FRONTEND triggers an initial frontend event
         * with status = 0, which copies output parameters to userspace.
         */
        dtv_property_legacy_params_sync(fe, c, &fepriv->parameters_out);

        /*
         * Be sure that the bandwidth will be filled for all
         * non-satellite systems, as tuners need to know what
         * low pass/Nyquist half filter should be applied, in
         * order to avoid inter-channel noise.
         *
         * ISDB-T and DVB-T/T2 already sets bandwidth.
         * ATSC and DVB-C don't set, so, the core should fill it.
         *
         * On DVB-C Annex A and C, the bandwidth is a function of
         * the roll-off and symbol rate. Annex B defines different
         * roll-off factors depending on the modulation. Fortunately,
         * Annex B is only used with 6MHz, so there's no need to
         * calculate it.
         *
         * While not officially supported, a side effect of handling it at
         * the cache level is that a program could retrieve the bandwidth
         * via DTV_BANDWIDTH_HZ, which may be useful for test programs.
         */
        switch (c->delivery_system) {
        case SYS_ATSC:
        case SYS_DVBC_ANNEX_B:
                c->bandwidth_hz = 6000000;
                break;
        case SYS_DVBC_ANNEX_A:
                rolloff = 115;
                break;
        case SYS_DVBC_ANNEX_C:
                rolloff = 113;
                break;
        case SYS_DVBS:
        case SYS_TURBO:
        case SYS_ISDBS:
                rolloff = 135;
                break;
        case SYS_DVBS2:
                switch (c->rolloff) {
                case ROLLOFF_20:
                        rolloff = 120;
                        break;
                case ROLLOFF_25:
                        rolloff = 125;
                        break;
                default:
                case ROLLOFF_35:
                        rolloff = 135;
                }
                break;
        default:
                break;
        }
        if (rolloff)
                c->bandwidth_hz = mult_frac(c->symbol_rate, rolloff, 100);

        /* force auto frequency inversion if requested */
        if (dvb_force_auto_inversion)
                c->inversion = INVERSION_AUTO;

        /*
         * without hierarchical coding code_rate_LP is irrelevant,
         * so we tolerate the otherwise invalid FEC_NONE setting
         */
        if (c->hierarchy == HIERARCHY_NONE && c->code_rate_LP == FEC_NONE)
                c->code_rate_LP = FEC_AUTO;

        prepare_tuning_algo_parameters(fe);

        fepriv->state = FESTATE_RETUNE;

        /* Request the search algorithm to search */
        fepriv->algo_status |= DVBFE_ALGO_SEARCH_AGAIN;

        dvb_frontend_clear_events(fe);
        dvb_frontend_add_event(fe, 0);
        dvb_frontend_wakeup(fe);
        fepriv->status = 0;

        return 0;
}

static int dvb_get_property(struct dvb_frontend *fe, struct file *file,
                            struct dtv_properties *tvps)
{
        struct dvb_frontend_private *fepriv = fe->frontend_priv;
        struct dtv_property *tvp = NULL;
        struct dtv_frontend_properties getp;
        int i, err;

        memcpy(&getp, &fe->dtv_property_cache, sizeof(getp));

        dev_dbg(fe->dvb->device, "%s: properties.num = %d\n",
                __func__, tvps->num);
        dev_dbg(fe->dvb->device, "%s: properties.props = %p\n",
                __func__, tvps->props);

        /*
         * Put an arbitrary limit on the number of messages that can
         * be sent at once
         */
        if (!tvps->num || tvps->num > DTV_IOCTL_MAX_MSGS)
                return -EINVAL;

        tvp = memdup_user((void __user *)tvps->props, tvps->num * sizeof(*tvp));
        if (IS_ERR(tvp))
                return PTR_ERR(tvp);

        /*
         * Let's use our own copy of property cache, in order to
         * avoid mangling with DTV zigzag logic, as drivers might
         * return crap, if they don't check if the data is available
         * before updating the properties cache.
         */
        if (fepriv->state != FESTATE_IDLE) {
                err = dtv_get_frontend(fe, &getp, NULL);
                if (err < 0)
                        goto out;
        }
        for (i = 0; i < tvps->num; i++) {
                err = dtv_property_process_get(fe, &getp,
                                               tvp + i, file);
                if (err < 0)
                        goto out;
        }

        if (copy_to_user((void __user *)tvps->props, tvp,
                         tvps->num * sizeof(struct dtv_property))) {
                err = -EFAULT;
                goto out;
        }

        err = 0;
out:
        kfree(tvp);
        return err;
}

static int dvb_get_frontend(struct dvb_frontend *fe,
                            struct dvb_frontend_parameters *p_out)
{
        struct dtv_frontend_properties getp;

        /*
         * Let's use our own copy of property cache, in order to
         * avoid mangling with DTV zigzag logic, as drivers might
         * return crap, if they don't check if the data is available
         * before updating the properties cache.
         */
        memcpy(&getp, &fe->dtv_property_cache, sizeof(getp));

        return dtv_get_frontend(fe, &getp, p_out);
}

static int dvb_frontend_handle_ioctl(struct file *file,
                                     unsigned int cmd, void *parg)
{
        struct dvb_device *dvbdev = file->private_data;
        struct dvb_frontend *fe = dvbdev->priv;
        struct dvb_frontend_private *fepriv = fe->frontend_priv;
        struct dtv_frontend_properties *c = &fe->dtv_property_cache;
        int i, err = -ENOTSUPP;

        dev_dbg(fe->dvb->device, "%s:\n", __func__);

        switch (cmd) {
        case FE_SET_PROPERTY: {
                struct dtv_properties *tvps = parg;
                struct dtv_property *tvp = NULL;

                dev_dbg(fe->dvb->device, "%s: properties.num = %d\n",
                        __func__, tvps->num);
                dev_dbg(fe->dvb->device, "%s: properties.props = %p\n",
                        __func__, tvps->props);

                /*
                 * Put an arbitrary limit on the number of messages that can
                 * be sent at once
                 */
                if (!tvps->num || (tvps->num > DTV_IOCTL_MAX_MSGS))
                        return -EINVAL;

                tvp = memdup_user((void __user *)tvps->props, tvps->num * sizeof(*tvp));
                if (IS_ERR(tvp))
                        return PTR_ERR(tvp);

                for (i = 0; i < tvps->num; i++) {
                        err = dtv_property_process_set(fe, file,
                                                       (tvp + i)->cmd,
                                                       (tvp + i)->u.data);
                        if (err < 0) {
                                kfree(tvp);
                                return err;
                        }
                }
                kfree(tvp);
                err = 0;
                break;
        }
        case FE_GET_PROPERTY:
                err = dvb_get_property(fe, file, parg);
                break;

        case FE_GET_INFO: {
                struct dvb_frontend_info *info = parg;
                memset(info, 0, sizeof(*info));

                strscpy(info->name, fe->ops.info.name, sizeof(info->name));
                info->symbol_rate_min = fe->ops.info.symbol_rate_min;
                info->symbol_rate_max = fe->ops.info.symbol_rate_max;
                info->symbol_rate_tolerance = fe->ops.info.symbol_rate_tolerance;
                info->caps = fe->ops.info.caps;
                info->frequency_stepsize = dvb_frontend_get_stepsize(fe);
                dvb_frontend_get_frequency_limits(fe, &info->frequency_min,
                                                  &info->frequency_max,
                                                  &info->frequency_tolerance);

                /*
                 * Associate the 4 delivery systems supported by DVBv3
                 * API with their DVBv5 counterpart. For the other standards,
                 * use the closest type, assuming that it would hopefully
                 * work with a DVBv3 application.
                 * It should be noticed that, on multi-frontend devices with
                 * different types (terrestrial and cable, for example),
                 * a pure DVBv3 application won't be able to use all delivery
                 * systems. Yet, changing the DVBv5 cache to the other delivery
                 * system should be enough for making it work.
                 */
                switch (dvbv3_type(c->delivery_system)) {
                case DVBV3_QPSK:
                        info->type = FE_QPSK;
                        break;
                case DVBV3_ATSC:
                        info->type = FE_ATSC;
                        break;
                case DVBV3_QAM:
                        info->type = FE_QAM;
                        break;
                case DVBV3_OFDM:
                        info->type = FE_OFDM;
                        break;
                default:
                        dev_err(fe->dvb->device,
                                "%s: doesn't know how to handle a DVBv3 call to delivery system %i\n",
                                __func__, c->delivery_system);
                        info->type = FE_OFDM;
                }
                dev_dbg(fe->dvb->device, "%s: current delivery system on cache: %d, V3 type: %d\n",
                        __func__, c->delivery_system, info->type);

                /* Set CAN_INVERSION_AUTO bit on in other than oneshot mode */
                if (!(fepriv->tune_mode_flags & FE_TUNE_MODE_ONESHOT))
                        info->caps |= FE_CAN_INVERSION_AUTO;
                err = 0;
                break;
        }

        case FE_READ_STATUS: {
                enum fe_status *status = parg;

                /* if retune was requested but hasn't occurred yet, prevent
                 * that user get signal state from previous tuning */
                if (fepriv->state == FESTATE_RETUNE ||
                    fepriv->state == FESTATE_ERROR) {
                        err = 0;
                        *status = 0;
                        break;
                }

                if (fe->ops.read_status)
                        err = fe->ops.read_status(fe, status);
                break;
        }

        case FE_DISEQC_RESET_OVERLOAD:
                if (fe->ops.diseqc_reset_overload) {
                        err = fe->ops.diseqc_reset_overload(fe);
                        fepriv->state = FESTATE_DISEQC;
                        fepriv->status = 0;
                }
                break;

        case FE_DISEQC_SEND_MASTER_CMD:
                if (fe->ops.diseqc_send_master_cmd) {
                        struct dvb_diseqc_master_cmd *cmd = parg;

                        if (cmd->msg_len > sizeof(cmd->msg)) {
                                err = -EINVAL;
                                break;
                        }
                        err = fe->ops.diseqc_send_master_cmd(fe, cmd);
                        fepriv->state = FESTATE_DISEQC;
                        fepriv->status = 0;
                }
                break;

        case FE_DISEQC_SEND_BURST:
                if (fe->ops.diseqc_send_burst) {
                        err = fe->ops.diseqc_send_burst(fe,
                                                (enum fe_sec_mini_cmd)parg);
                        fepriv->state = FESTATE_DISEQC;
                        fepriv->status = 0;
                }
                break;

        case FE_SET_TONE:
                if (fe->ops.set_tone) {
                        err = fe->ops.set_tone(fe,
                                               (enum fe_sec_tone_mode)parg);
                        fepriv->tone = (enum fe_sec_tone_mode)parg;
                        fepriv->state = FESTATE_DISEQC;
                        fepriv->status = 0;
                }
                break;

        case FE_SET_VOLTAGE:
                if (fe->ops.set_voltage) {
                        err = fe->ops.set_voltage(fe,
                                                  (enum fe_sec_voltage)parg);
                        fepriv->voltage = (enum fe_sec_voltage)parg;
                        fepriv->state = FESTATE_DISEQC;
                        fepriv->status = 0;
                }
                break;

        case FE_DISEQC_RECV_SLAVE_REPLY:
                if (fe->ops.diseqc_recv_slave_reply)
                        err = fe->ops.diseqc_recv_slave_reply(fe, parg);
                break;

        case FE_ENABLE_HIGH_LNB_VOLTAGE:
                if (fe->ops.enable_high_lnb_voltage)
                        err = fe->ops.enable_high_lnb_voltage(fe, (long)parg);
                break;

        case FE_SET_FRONTEND_TUNE_MODE:
                fepriv->tune_mode_flags = (unsigned long)parg;
                err = 0;
                break;
        /* DEPRECATED dish control ioctls */

        case FE_DISHNETWORK_SEND_LEGACY_CMD:
                if (fe->ops.dishnetwork_send_legacy_command) {
                        err = fe->ops.dishnetwork_send_legacy_command(fe,
                                                         (unsigned long)parg);
                        fepriv->state = FESTATE_DISEQC;
                        fepriv->status = 0;
                } else if (fe->ops.set_voltage) {
                        /*
                         * NOTE: This is a fallback condition.  Some frontends
                         * (stv0299 for instance) take longer than 8msec to
                         * respond to a set_voltage command.  Those switches
                         * need custom routines to switch properly.  For all
                         * other frontends, the following should work ok.
                         * Dish network legacy switches (as used by Dish500)
                         * are controlled by sending 9-bit command words
                         * spaced 8msec apart.
                         * the actual command word is switch/port dependent
                         * so it is up to the userspace application to send
                         * the right command.
                         * The command must always start with a '0' after
                         * initialization, so parg is 8 bits and does not
                         * include the initialization or start bit
                         */
                        unsigned long swcmd = ((unsigned long)parg) << 1;
                        ktime_t nexttime;
                        ktime_t tv[10];
                        int i;
                        u8 last = 1;

                        if (dvb_frontend_debug)
                                dprintk("switch command: 0x%04lx\n",
                                        swcmd);
                        nexttime = ktime_get_boottime();
                        if (dvb_frontend_debug)
                                tv[0] = nexttime;
                        /* before sending a command, initialize by sending
                         * a 32ms 18V to the switch
                         */
                        fe->ops.set_voltage(fe, SEC_VOLTAGE_18);
                        dvb_frontend_sleep_until(&nexttime, 32000);

                        for (i = 0; i < 9; i++) {
                                if (dvb_frontend_debug)
                                        tv[i + 1] = ktime_get_boottime();
                                if ((swcmd & 0x01) != last) {
                                        /* set voltage to (last ? 13V : 18V) */
                                        fe->ops.set_voltage(fe, (last) ? SEC_VOLTAGE_13 : SEC_VOLTAGE_18);
                                        last = (last) ? 0 : 1;
                                }
                                swcmd = swcmd >> 1;
                                if (i != 8)
                                        dvb_frontend_sleep_until(&nexttime, 8000);
                        }
                        if (dvb_frontend_debug) {
                                dprintk("(adapter %d): switch delay (should be 32k followed by all 8k)\n",
                                        fe->dvb->num);
                                for (i = 1; i < 10; i++)
                                        pr_info("%d: %d\n", i,
                                                (int)ktime_us_delta(tv[i], tv[i - 1]));
                        }
                        err = 0;
                        fepriv->state = FESTATE_DISEQC;
                        fepriv->status = 0;
                }
                break;

        /* DEPRECATED statistics ioctls */

        case FE_READ_BER:
                if (fe->ops.read_ber) {
                        if (fepriv->thread)
                                err = fe->ops.read_ber(fe, parg);
                        else
                                err = -EAGAIN;
                }
                break;

        case FE_READ_SIGNAL_STRENGTH:
                if (fe->ops.read_signal_strength) {
                        if (fepriv->thread)
                                err = fe->ops.read_signal_strength(fe, parg);
                        else
                                err = -EAGAIN;
                }
                break;

        case FE_READ_SNR:
                if (fe->ops.read_snr) {
                        if (fepriv->thread)
                                err = fe->ops.read_snr(fe, parg);
                        else
                                err = -EAGAIN;
                }
                break;

        case FE_READ_UNCORRECTED_BLOCKS:
                if (fe->ops.read_ucblocks) {
                        if (fepriv->thread)
                                err = fe->ops.read_ucblocks(fe, parg);
                        else
                                err = -EAGAIN;
                }
                break;

        /* DEPRECATED DVBv3 ioctls */

        case FE_SET_FRONTEND:
                err = dvbv3_set_delivery_system(fe);
                if (err)
                        break;

                err = dtv_property_cache_sync(fe, c, parg);
                if (err)
                        break;
                err = dtv_set_frontend(fe);
                break;

        case FE_GET_EVENT:
                err = dvb_frontend_get_event(fe, parg, file->f_flags);
                break;

        case FE_GET_FRONTEND:
                err = dvb_get_frontend(fe, parg);
                break;

        default:
                return -ENOTSUPP;
        } /* switch */

        return err;
}

static __poll_t dvb_frontend_poll(struct file *file, struct poll_table_struct *wait)
{
        struct dvb_device *dvbdev = file->private_data;
        struct dvb_frontend *fe = dvbdev->priv;
        struct dvb_frontend_private *fepriv = fe->frontend_priv;

        dev_dbg_ratelimited(fe->dvb->device, "%s:\n", __func__);

        poll_wait(file, &fepriv->events.wait_queue, wait);

        if (fepriv->events.eventw != fepriv->events.eventr)
                return (EPOLLIN | EPOLLRDNORM | EPOLLPRI);

        return 0;
}

static int dvb_frontend_open(struct inode *inode, struct file *file)
{
        struct dvb_device *dvbdev = file->private_data;
        struct dvb_frontend *fe = dvbdev->priv;
        struct dvb_frontend_private *fepriv = fe->frontend_priv;
        struct dvb_adapter *adapter = fe->dvb;
        int ret;

        dev_dbg(fe->dvb->device, "%s:\n", __func__);
        if (fe->exit == DVB_FE_DEVICE_REMOVED)
                return -ENODEV;

        if (adapter->mfe_shared) {
                mutex_lock(&adapter->mfe_lock);

                if (!adapter->mfe_dvbdev)
                        adapter->mfe_dvbdev = dvbdev;

                else if (adapter->mfe_dvbdev != dvbdev) {
                        struct dvb_device
                                *mfedev = adapter->mfe_dvbdev;
                        struct dvb_frontend
                                *mfe = mfedev->priv;
                        struct dvb_frontend_private
                                *mfepriv = mfe->frontend_priv;
                        int mferetry = (dvb_mfe_wait_time << 1);

                        mutex_unlock(&adapter->mfe_lock);
                        while (mferetry-- && (mfedev->users != -1 ||
                                              mfepriv->thread)) {
                                if (msleep_interruptible(500)) {
                                        if (signal_pending(current))
                                                return -EINTR;
                                }
                        }

                        mutex_lock(&adapter->mfe_lock);
                        if (adapter->mfe_dvbdev != dvbdev) {
                                mfedev = adapter->mfe_dvbdev;
                                mfe = mfedev->priv;
                                mfepriv = mfe->frontend_priv;
                                if (mfedev->users != -1 ||
                                    mfepriv->thread) {
                                        mutex_unlock(&adapter->mfe_lock);
                                        return -EBUSY;
                                }
                                adapter->mfe_dvbdev = dvbdev;
                        }
                }
        }

        if (dvbdev->users == -1 && fe->ops.ts_bus_ctrl) {
                if ((ret = fe->ops.ts_bus_ctrl(fe, 1)) < 0)
                        goto err0;

                /* If we took control of the bus, we need to force
                   reinitialization.  This is because many ts_bus_ctrl()
                   functions strobe the RESET pin on the demod, and if the
                   frontend thread already exists then the dvb_init() routine
                   won't get called (which is what usually does initial
                   register configuration). */
                fepriv->reinitialise = 1;
        }

        if ((ret = dvb_generic_open(inode, file)) < 0)
                goto err1;

        if ((file->f_flags & O_ACCMODE) != O_RDONLY) {
                /* normal tune mode when opened R/W */
                fepriv->tune_mode_flags &= ~FE_TUNE_MODE_ONESHOT;
                fepriv->tone = -1;
                fepriv->voltage = -1;

#ifdef CONFIG_MEDIA_CONTROLLER_DVB
                mutex_lock(&fe->dvb->mdev_lock);
                if (fe->dvb->mdev) {
                        mutex_lock(&fe->dvb->mdev->graph_mutex);
                        if (fe->dvb->mdev->enable_source)
                                ret = fe->dvb->mdev->enable_source(
                                                           dvbdev->entity,
                                                           &fepriv->pipe);
                        mutex_unlock(&fe->dvb->mdev->graph_mutex);
                        if (ret) {
                                mutex_unlock(&fe->dvb->mdev_lock);
                                dev_err(fe->dvb->device,
                                        "Tuner is busy. Error %d\n", ret);
                                goto err2;
                        }
                }
                mutex_unlock(&fe->dvb->mdev_lock);
#endif
                ret = dvb_frontend_start(fe);
                if (ret)
                        goto err3;

                /*  empty event queue */
                fepriv->events.eventr = fepriv->events.eventw = 0;
        }

        dvb_frontend_get(fe);

        if (adapter->mfe_shared)
                mutex_unlock(&adapter->mfe_lock);
        return ret;

err3:
#ifdef CONFIG_MEDIA_CONTROLLER_DVB
        mutex_lock(&fe->dvb->mdev_lock);
        if (fe->dvb->mdev) {
                mutex_lock(&fe->dvb->mdev->graph_mutex);
                if (fe->dvb->mdev->disable_source)
                        fe->dvb->mdev->disable_source(dvbdev->entity);
                mutex_unlock(&fe->dvb->mdev->graph_mutex);
        }
        mutex_unlock(&fe->dvb->mdev_lock);
err2:
#endif
        dvb_generic_release(inode, file);
err1:
        if (dvbdev->users == -1 && fe->ops.ts_bus_ctrl)
                fe->ops.ts_bus_ctrl(fe, 0);
err0:
        if (adapter->mfe_shared)
                mutex_unlock(&adapter->mfe_lock);
        return ret;
}

static int dvb_frontend_release(struct inode *inode, struct file *file)
{
        struct dvb_device *dvbdev = file->private_data;
        struct dvb_frontend *fe = dvbdev->priv;
        struct dvb_frontend_private *fepriv = fe->frontend_priv;
        int ret;

        dev_dbg(fe->dvb->device, "%s:\n", __func__);

        if ((file->f_flags & O_ACCMODE) != O_RDONLY) {
                fepriv->release_jiffies = jiffies;
                mb();
        }

        ret = dvb_generic_release(inode, file);

        if (dvbdev->users == -1) {
                wake_up(&fepriv->wait_queue);
#ifdef CONFIG_MEDIA_CONTROLLER_DVB
                mutex_lock(&fe->dvb->mdev_lock);
                if (fe->dvb->mdev) {
                        mutex_lock(&fe->dvb->mdev->graph_mutex);
                        if (fe->dvb->mdev->disable_source)
                                fe->dvb->mdev->disable_source(dvbdev->entity);
                        mutex_unlock(&fe->dvb->mdev->graph_mutex);
                }
                mutex_unlock(&fe->dvb->mdev_lock);
#endif
                if (fe->exit != DVB_FE_NO_EXIT)
                        wake_up(&dvbdev->wait_queue);
                if (fe->ops.ts_bus_ctrl)
                        fe->ops.ts_bus_ctrl(fe, 0);
        }

        dvb_frontend_put(fe);

        return ret;
}

static const struct file_operations dvb_frontend_fops = {
        .owner          = THIS_MODULE,
        .unlocked_ioctl = dvb_frontend_ioctl,
#ifdef CONFIG_COMPAT
        .compat_ioctl   = dvb_frontend_compat_ioctl,
#endif
        .poll           = dvb_frontend_poll,
        .open           = dvb_frontend_open,
        .release        = dvb_frontend_release,
        .llseek         = noop_llseek,
};

int dvb_frontend_suspend(struct dvb_frontend *fe)
{
        int ret = 0;

        dev_dbg(fe->dvb->device, "%s: adap=%d fe=%d\n", __func__, fe->dvb->num,
                fe->id);

        if (fe->ops.tuner_ops.suspend)
                ret = fe->ops.tuner_ops.suspend(fe);
        else if (fe->ops.tuner_ops.sleep)
                ret = fe->ops.tuner_ops.sleep(fe);

        if (fe->ops.sleep)
                ret = fe->ops.sleep(fe);

        return ret;
}
EXPORT_SYMBOL(dvb_frontend_suspend);

int dvb_frontend_resume(struct dvb_frontend *fe)
{
        struct dvb_frontend_private *fepriv = fe->frontend_priv;
        int ret = 0;

        dev_dbg(fe->dvb->device, "%s: adap=%d fe=%d\n", __func__, fe->dvb->num,
                fe->id);

        fe->exit = DVB_FE_DEVICE_RESUME;
        if (fe->ops.init)
                ret = fe->ops.init(fe);

        if (fe->ops.tuner_ops.resume)
                ret = fe->ops.tuner_ops.resume(fe);
        else if (fe->ops.tuner_ops.init)
                ret = fe->ops.tuner_ops.init(fe);

        if (fe->ops.set_tone && fepriv->tone != -1)
                fe->ops.set_tone(fe, fepriv->tone);
        if (fe->ops.set_voltage && fepriv->voltage != -1)
                fe->ops.set_voltage(fe, fepriv->voltage);

        fe->exit = DVB_FE_NO_EXIT;
        fepriv->state = FESTATE_RETUNE;
        dvb_frontend_wakeup(fe);

        return ret;
}
EXPORT_SYMBOL(dvb_frontend_resume);

int dvb_register_frontend(struct dvb_adapter *dvb,
                          struct dvb_frontend *fe)
{
        struct dvb_frontend_private *fepriv;
        const struct dvb_device dvbdev_template = {
                .users = ~0,
                .writers = 1,
                .readers = (~0) - 1,
                .fops = &dvb_frontend_fops,
#if defined(CONFIG_MEDIA_CONTROLLER_DVB)
                .name = fe->ops.info.name,
#endif
        };

        dev_dbg(dvb->device, "%s:\n", __func__);

        if (mutex_lock_interruptible(&frontend_mutex))
                return -ERESTARTSYS;

        fe->frontend_priv = kzalloc(sizeof(struct dvb_frontend_private), GFP_KERNEL);
        if (!fe->frontend_priv) {
                mutex_unlock(&frontend_mutex);
                return -ENOMEM;
        }
        fepriv = fe->frontend_priv;