dvb_frontend.c

h内核

		 * 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;
			check_wrapped = 0;
		}

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

		/* slow zigzag */
		if (fepriv->state & FESTATE_SEARCHING_SLOW) {
			update_delay(&quality, &delay, fepriv->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) {
		if (dvb_powerdown_on_sleep)
			if (fe->ops->set_voltage)
				fe->ops->set_voltage(fe, SEC_VOLTAGE_OFF);
		if (fe->ops->sleep)
			fe->ops->sleep(fe);
	}

	fepriv->thread_pid = 0;
	mb();

	dvb_frontend_wakeup(fe);
	return 0;
}

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

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

	fepriv->exit = 1;
	mb();

	if (!fepriv->thread_pid)
		return;

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

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

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

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

	if (fepriv->thread_pid) {
		if (!fepriv->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;
	fepriv->exit = 0;
	fepriv->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(&fepriv->sem);
		return ret;
	}
	fepriv->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 *fe = dvbdev->priv;
	struct dvb_frontend_private *fepriv = (struct dvb_frontend_private*) fe->frontend_priv;
	int err = -EOPNOTSUPP;

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

	if (!fe || fepriv->exit)
		return -ENODEV;

	if ((file->f_flags & O_ACCMODE) == O_RDONLY &&
	    (_IOC_DIR(cmd) != _IOC_READ || cmd == FE_GET_EVENT ||
	     cmd == FE_DISEQC_RECV_SLAVE_REPLY))
		return -EPERM;

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

	switch (cmd) {
	case FE_GET_INFO: {
		struct dvb_frontend_info* info = (struct dvb_frontend_info*) parg;
		memcpy(info, &fe->ops->info, sizeof(struct dvb_frontend_info));

		/* Force the CAN_INVERSION_AUTO bit on. If the frontend doesn't
		 * do it, it is done for it. */
		info->caps |= FE_CAN_INVERSION_AUTO;
		err = 0;
		break;
	}

	case FE_READ_STATUS:
		if (fe->ops->read_status)
			err = fe->ops->read_status(fe, (fe_status_t*) parg);
		break;

	case FE_READ_BER:
		if (fe->ops->read_ber)
			err = fe->ops->read_ber(fe, (__u32*) parg);
		break;

	case FE_READ_SIGNAL_STRENGTH:
		if (fe->ops->read_signal_strength)
			err = fe->ops->read_signal_strength(fe, (__u16*) parg);
		break;

	case FE_READ_SNR:
		if (fe->ops->read_snr)
			err = fe->ops->read_snr(fe, (__u16*) parg);
		break;

	case FE_READ_UNCORRECTED_BLOCKS:
		if (fe->ops->read_ucblocks)
			err = fe->ops->read_ucblocks(fe, (__u32*) parg);
		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) {
			err = fe->ops->diseqc_send_master_cmd(fe, (struct dvb_diseqc_master_cmd*) parg);
			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, (fe_sec_mini_cmd_t) parg);
			fepriv->state = FESTATE_DISEQC;
			fepriv->status = 0;
		}
		break;

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

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

	case FE_DISHNETWORK_SEND_LEGACY_CMD:
		if (fe->ops->dishnetwork_send_legacy_command) {
			err = fe->ops->dishnetwork_send_legacy_command(fe, (unsigned int) 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, (struct dvb_diseqc_slave_reply*) parg);
		break;

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

	case FE_SET_FRONTEND: {
		struct dvb_frontend_tune_settings fetunesettings;
	    
		memcpy (&fepriv->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) {
			fepriv->parameters.inversion = INVERSION_AUTO;
			fetunesettings.parameters.inversion = INVERSION_AUTO;
		}
		if (fe->ops->info.type == FE_OFDM) {
			/* without hierachical coding code_rate_LP is irrelevant,
			 * so we tolerate the otherwise invalid FEC_NONE setting */
			if (fepriv->parameters.u.ofdm.hierarchy_information == HIERARCHY_NONE &&
			    fepriv->parameters.u.ofdm.code_rate_LP == FEC_NONE)
				fepriv->parameters.u.ofdm.code_rate_LP = FEC_AUTO;
		}

		/* 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(fe->ops->info.type) {
			case FE_QPSK:
				fepriv->min_delay = HZ/20;
				fepriv->step_size = fepriv->parameters.u.qpsk.symbol_rate / 16000;
				fepriv->max_drift = fepriv->parameters.u.qpsk.symbol_rate / 2000;
		break;
			    
			case FE_QAM:
				fepriv->min_delay = HZ/20;
				fepriv->step_size = 0; /* no zigzag */
				fepriv->max_drift = 0;
				break;
			    
			case FE_OFDM:
				fepriv->min_delay = HZ/20;
				fepriv->step_size = fe->ops->info.frequency_stepsize * 2;
				fepriv->max_drift = (fe->ops->info.frequency_stepsize * 2) + 1;
				break;
			case FE_ATSC:
				printk("dvb-core: FE_ATSC not handled yet.\n");
				break;
			}
		}
		if (dvb_override_tune_delay > 0)
			fepriv->min_delay = (dvb_override_tune_delay * HZ) / 1000;

		fepriv->state = FESTATE_RETUNE;
		dvb_frontend_wakeup(fe);
		dvb_frontend_add_event (fe, 0);	    
		fepriv->status = 0;
		err = 0;
		break;
	}

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

	case FE_GET_FRONTEND:
		if (fe->ops->get_frontend) {
			memcpy (parg, &fepriv->parameters, sizeof (struct dvb_frontend_parameters));
			err = fe->ops->get_frontend(fe, (struct dvb_frontend_parameters*) parg);
		}
		break;
	};

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


static unsigned int 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 = (struct dvb_frontend_private*) fe->frontend_priv;

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

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

	if (fepriv->events.eventw != fepriv->events.eventr)
		return (POLLIN | POLLRDNORM | POLLPRI);

	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 = (struct dvb_frontend_private*) fe->frontend_priv;
	int ret;

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

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

	if ((file->f_flags & O_ACCMODE) != O_RDONLY) {
		ret = dvb_frontend_start (fe);
		if (ret)
			dvb_generic_release (inode, file);

		/*  empty event queue */
		fepriv->events.eventr = fepriv->events.eventw = 0;
	}
	
	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 = (struct dvb_frontend_private*) fe->frontend_priv;

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

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

	return dvb_generic_release (inode, file);
}


static struct file_operations dvb_frontend_fops = {
	.owner		= THIS_MODULE,
	.ioctl		= dvb_generic_ioctl,
	.poll		= dvb_frontend_poll,
	.open		= dvb_frontend_open,
	.release	= dvb_frontend_release
};

int dvb_register_frontend(struct dvb_adapter* dvb,
			  struct dvb_frontend* fe)
{
	struct dvb_frontend_private *fepriv;
	static const struct dvb_device dvbdev_template = {
		.users = ~0,
		.writers = 1,
		.readers = (~0)-1,
		.fops = &dvb_frontend_fops,
		.kernel_ioctl = dvb_frontend_ioctl
	};

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

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

	fe->frontend_priv = kmalloc(sizeof(struct dvb_frontend_private), GFP_KERNEL);
	if (fe->frontend_priv == NULL) {
		up(&frontend_mutex);
		return -ENOMEM;
	}
	fepriv = (struct dvb_frontend_private*) fe->frontend_priv;
	memset(fe->frontend_priv, 0, sizeof(struct dvb_frontend_private));

	init_MUTEX (&fepriv->sem);
	init_waitqueue_head (&fepriv->wait_queue);
	init_waitqueue_head (&fepriv->events.wait_queue);
	init_MUTEX (&fepriv->events.sem);
	fe->dvb = dvb;
	fepriv->inversion = INVERSION_OFF;

	printk ("DVB: registering frontend %i (%s)...\n",
		fe->dvb->num,
		fe->ops->info.name);

	dvb_register_device (fe->dvb, &fepriv->dvbdev, &dvbdev_template,
			     fe, DVB_DEVICE_FRONTEND);

	up (&frontend_mutex);
	return 0;
}
EXPORT_SYMBOL(dvb_register_frontend);

int dvb_unregister_frontend(struct dvb_frontend* fe)
{
	struct dvb_frontend_private *fepriv = (struct dvb_frontend_private*) fe->frontend_priv;
	dprintk ("%s\n", __FUNCTION__);

	down (&frontend_mutex);
	dvb_unregister_device (fepriv->dvbdev);
			dvb_frontend_stop (fe);
	if (fe->ops->release)
		fe->ops->release(fe);
	else
		printk("dvb_frontend: Demodulator (%s) does not have a release callback!\n", fe->ops->info.name);
	/* fe is invalid now */
	if (fepriv)
		kfree(fepriv);
	up (&frontend_mutex);
	return 0;
}
EXPORT_SYMBOL(dvb_unregister_frontend);