dvb_frontend.c

来自「优龙2410linux2.6.8内核源代码」· C语言 代码 · 共 1,190 行 · 第 1/3 页

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

		case 2:
			if (fe->lnb_drift == 0) break;
		    
			fe->lnb_drift = -fe->lnb_drift;
			ready = 1;
			break;
	    
		case 3:
			if (fe->lnb_drift == 0) break;
			if (!autoinversion) break;
		    
			fe->inversion = (fe->inversion == INVERSION_OFF) ? INVERSION_ON : INVERSION_OFF;
			fe->lnb_drift = -fe->lnb_drift;
			ready = 1;
			break;
		    
		default:
			fe->auto_step++;
			fe->auto_sub_step = -1; // it'll be incremented to 0 in a moment
			break;
		}
	    
		if (!ready) fe->auto_sub_step++;
	}

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

	// perform frequency bending if necessary
	if ((dvb_override_frequency_bending != 1) && do_frequency_bending)
		dvb_bend_frequency(fe, 0);

	// instrumentation
	dprintk("%s: drift:%i bending:%i inversion:%i auto_step:%i auto_sub_step:%i started_auto_step:%i\n", 
		__FUNCTION__, fe->lnb_drift, fe->bending, fe->inversion, fe->auto_step, fe->auto_sub_step,
		fe->started_auto_step);
    
	// set the frontend itself
	fe->parameters.frequency += fe->lnb_drift + fe->bending;
	if (autoinversion) fe->parameters.inversion = fe->inversion;
	dvb_frontend_internal_ioctl (&fe->frontend, FE_SET_FRONTEND, &fe->parameters);
	fe->parameters.frequency = original_frequency;
	fe->parameters.inversion = original_inversion;

	// normal return
	fe->auto_sub_step++;
	return 0;
}



static int dvb_frontend_is_exiting (struct dvb_frontend_data *fe)
{
	if (fe->exit)
		return 1;

	if (fe->dvbdev->writers == 1)
		if (jiffies - fe->release_jiffies > dvb_shutdown_timeout * HZ)
			return 1;

	return 0;
}

static int dvb_frontend_should_wakeup (struct dvb_frontend_data *fe)
{
	if (fe->wakeup) {
		fe->wakeup = 0;
		return 1;
	}
	return dvb_frontend_is_exiting(fe);
}

static void dvb_frontend_wakeup (struct dvb_frontend_data *fe) {
	fe->wakeup = 1;
	wake_up_interruptible(&fe->wait_queue);
}

static int dvb_frontend_thread (void *data)
{
	struct dvb_frontend_data *fe = (struct dvb_frontend_data *) data;
	unsigned long timeout;
	char name [15];
	int quality = 0, delay = 3*HZ;
	fe_status_t s;
	int check_wrapped = 0;

	dprintk ("%s\n", __FUNCTION__);

	snprintf (name, sizeof(name), "kdvb-fe-%i:%i",
		  fe->frontend.i2c->adapter->num, fe->frontend.i2c->id);

	dvb_kernel_thread_setup (name);

	dvb_call_frontend_notifiers (fe, 0);
	dvb_frontend_init (fe);
	fe->wakeup = 0;

	while (1) {
		up (&fe->sem);      /* is locked when we enter the thread... */

		timeout = wait_event_interruptible_timeout(fe->wait_queue,0 != dvb_frontend_should_wakeup (fe), delay);
		if (-ERESTARTSYS == timeout || 0 != dvb_frontend_is_exiting (fe)) {
			/* got signal or quitting */
			break;
		}

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

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

		// get the frontend status
		dvb_frontend_internal_ioctl (&fe->frontend, FE_READ_STATUS, &s);
		if (s != fe->status)
			dvb_frontend_add_event (fe, s);

		// if we're not tuned, and we have a lock, move to the TUNED state
		if ((fe->state & FESTATE_WAITFORLOCK) && (s & FE_HAS_LOCK)) {
			update_delay(&quality, &delay, fe->min_delay, s & FE_HAS_LOCK);
			fe->state = FESTATE_TUNED;

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

		// if we are tuned already, check we're still locked
		if (fe->state & FESTATE_TUNED) {
			update_delay(&quality, &delay, fe->min_delay, s & FE_HAS_LOCK);

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

		// 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 ((fe->state & FESTATE_LOSTLOCK) && 
		    (fe->info->caps & FE_CAN_RECOVER) && (fe->max_drift == 0)) {
			update_delay(&quality, &delay, fe->min_delay, s & FE_HAS_LOCK);
						continue;
				}
	    
		// 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 (fe->state & FESTATE_DISEQC) {
			update_delay(&quality, &delay, fe->min_delay, s & FE_HAS_LOCK);
			continue;
				}

		// 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 (fe->state & FESTATE_RETUNE) {
			fe->lnb_drift = 0;
			fe->auto_step = 0;
			fe->auto_sub_step = 0;
			fe->started_auto_step = 0;
			check_wrapped = 0;
		}

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

			// peform a tune
			if (dvb_frontend_autotune(fe, check_wrapped)) {
				// OK, if we've run out of trials at the fast speed. Drop back to
				// slow for the _next_ attempt
				fe->state = FESTATE_SEARCHING_SLOW;
				fe->started_auto_step = fe->auto_step;
				continue;
			}
			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 (fe->state & FESTATE_RETUNE) {
				fe->state = FESTATE_TUNING_FAST;
				wake_up_interruptible(&fe->wait_queue);
			}
		}

		// slow zigzag
		if (fe->state & FESTATE_SEARCHING_SLOW) {
			update_delay(&quality, &delay, fe->min_delay, s & FE_HAS_LOCK);
		    
			// Note: don't bother checking for wrapping; we stay in this state 
			// until we get a lock
			dvb_frontend_autotune(fe, 0);
		}
	};

	if (dvb_shutdown_timeout)
		dvb_frontend_internal_ioctl (&fe->frontend, FE_SLEEP, NULL); 

	up (&fe->sem);

	fe->thread_pid = 0;
	mb();

	dvb_frontend_wakeup(fe);
	return 0;
}


static void dvb_frontend_stop (struct dvb_frontend_data *fe)
{
	unsigned long ret;

	dprintk ("%s\n", __FUNCTION__);

		fe->exit = 1;
	mb();

	if (!fe->thread_pid)
		return;

	/* check if the thread is really alive */
	if (kill_proc(fe->thread_pid, 0, 1) == -ESRCH) {
		printk("dvb_frontend_stop: thread PID %d already died\n",
				fe->thread_pid);
		/* make sure the mutex was not held by the thread */
		init_MUTEX (&fe->sem);
		return;
	}

	/* wake up the frontend thread, so it notices that fe->exit == 1 */
	dvb_frontend_wakeup(fe);

	/* wait until the frontend thread has exited */
	ret = wait_event_interruptible(fe->wait_queue,0 == fe->thread_pid);
	if (-ERESTARTSYS != ret) {
		fe->state = FESTATE_IDLE;
		return;
	}
	fe->state = FESTATE_IDLE;

	/* paranoia check in case a signal arrived */
	if (fe->thread_pid)
		printk("dvb_frontend_stop: warning: thread PID %d won't exit\n",
				fe->thread_pid);
}


static int dvb_frontend_start (struct dvb_frontend_data *fe)
{
	int ret;

	dprintk ("%s\n", __FUNCTION__);

	if (fe->thread_pid) {
		if (!fe->exit)
			return 0;
		else
		dvb_frontend_stop (fe);
	}

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

	fe->state = FESTATE_IDLE;
	fe->exit = 0;
	fe->thread_pid = 0;
	mb();

	ret = kernel_thread (dvb_frontend_thread, fe, 0);
	if (ret < 0) {
		printk("dvb_frontend_start: failed to start kernel_thread (%d)\n", ret);
		up(&fe->sem);
		return ret;
	}
	fe->thread_pid = ret;

	return 0;
}


static int dvb_frontend_ioctl (struct inode *inode, struct file *file,
			unsigned int cmd, void *parg)
{
	struct dvb_device *dvbdev = file->private_data;
	struct dvb_frontend_data *fe = dvbdev->priv;
	struct dvb_frontend_tune_settings fetunesettings;
	int err = 0;

	dprintk ("%s\n", __FUNCTION__);

	if (!fe || !fe->frontend.ioctl || fe->exit)
		return -ENODEV;

	if (down_interruptible (&fe->sem))
		return -ERESTARTSYS;

	switch (cmd) {
	case FE_DISEQC_SEND_MASTER_CMD:
	case FE_DISEQC_SEND_BURST:
	case FE_SET_TONE:
		if (fe->status)
			dvb_call_frontend_notifiers (fe, 0);
		dvb_frontend_internal_ioctl (&fe->frontend, cmd, parg);
		fe->state = FESTATE_DISEQC;
		break;

	case FE_SET_FRONTEND:
		fe->state = FESTATE_RETUNE;
	    
		memcpy (&fe->parameters, parg,
			sizeof (struct dvb_frontend_parameters));

		memset(&fetunesettings, 0, sizeof(struct dvb_frontend_tune_settings));
		memcpy(&fetunesettings.parameters, parg,
		       sizeof (struct dvb_frontend_parameters));
		    
		// force auto frequency inversion if requested
		if (dvb_force_auto_inversion) {
			fe->parameters.inversion = INVERSION_AUTO;
			fetunesettings.parameters.inversion = INVERSION_AUTO;
		}

		// get frontend-specific tuning settings
		if (dvb_frontend_internal_ioctl(&fe->frontend, FE_GET_TUNE_SETTINGS, &fetunesettings) == 0) {
			fe->min_delay = (fetunesettings.min_delay_ms * HZ) / 1000;
			fe->max_drift = fetunesettings.max_drift;
			fe->step_size = fetunesettings.step_size;
		} else {
			// default values
			switch(fe->info->type) {
			case FE_QPSK:
				fe->min_delay = HZ/20; // default mindelay of 50ms
				fe->step_size = fe->parameters.u.qpsk.symbol_rate / 16000;
				fe->max_drift = fe->parameters.u.qpsk.symbol_rate / 2000;
		break;
			    
			case FE_QAM:
				fe->min_delay = HZ/20; // default mindelay of 50ms
				fe->step_size = 0;
				fe->max_drift = 0; // don't want any zigzagging under DVB-C frontends
				break;
			    
			case FE_OFDM:
				fe->min_delay = HZ/20; // default mindelay of 50ms
				fe->step_size = fe->info->frequency_stepsize * 2;
				fe->max_drift = (fe->info->frequency_stepsize * 2) + 1;
				break;
			}
		}
		if (dvb_override_tune_delay > 0) {
		       fe->min_delay = (dvb_override_tune_delay * HZ) / 1000;
		}

		dvb_frontend_add_event (fe, 0);	    
		break;

	case FE_GET_EVENT:
		err = dvb_frontend_get_event (fe, parg, file->f_flags);
		break;
	case FE_GET_FRONTEND:
		memcpy (parg, &fe->parameters,
			sizeof (struct dvb_frontend_parameters));
		/*  fall-through... */
	default:
		err = dvb_frontend_internal_ioctl (&fe->frontend, cmd, parg);
	};

	up (&fe->sem);
	if (err < 0)
		return err;

	// Force the CAN_INVERSION_AUTO bit on. If the frontend doesn't do it, it is done for it.
	if ((cmd == FE_GET_INFO) && (err == 0)) {
		struct dvb_frontend_info* tmp = (struct dvb_frontend_info*) parg;