+static void dvb_frontend_swzigzag(struct dvb_frontend *fe)
+{
+ fe_status_t s;
+ struct dvb_frontend_private *fepriv = fe->frontend_priv;
+
+ /* 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) {
+ if (fe->ops->set_frontend)
+ fe->ops->set_frontend(fe, &fepriv->parameters);
+ 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)) &&
+ (fepriv->parameters.inversion == INVERSION_AUTO)) {
+ fepriv->parameters.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;
+
+ /* peform a tune */
+ if (dvb_frontend_swzigzag_autotune(fe, fepriv->check_wrapped)) {
+ /* 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 retuned, 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);
+ }
+}
+