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/*
 *
 * some helper function for simple DVB cards which simply DMA the
 * complete transport stream and let the computer sort everything else
 * (i.e. we are using the software demux, ...).  Also uses the
 * video-buf to manage DMA buffers.
 *
 * (c) 2004 Gerd Knorr <kraxel@bytesex.org> [SUSE Labs]
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/kthread.h>
#include <linux/file.h>
#include <linux/slab.h>

#include <linux/freezer.h>

#include <media/videobuf-core.h>
#include <media/videobuf-dvb.h>

/* ------------------------------------------------------------------ */

MODULE_AUTHOR("Gerd Knorr <kraxel@bytesex.org> [SuSE Labs]");
MODULE_LICENSE("GPL");

static unsigned int debug;
module_param(debug, int, 0644);
MODULE_PARM_DESC(debug,"enable debug messages");

#define dprintk(fmt, arg...)	if (debug)			\
	printk(KERN_DEBUG "%s/dvb: " fmt, dvb->name , ## arg)

/* ------------------------------------------------------------------ */

static int videobuf_dvb_thread(void *data)
{
	struct videobuf_dvb *dvb = data;
	struct videobuf_buffer *buf;
	unsigned long flags;
	void *outp;

	dprintk("dvb thread started\n");
	set_freezable();
	videobuf_read_start(&dvb->dvbq);

	for (;;) {
		/* fetch next buffer */
		buf = list_entry(dvb->dvbq.stream.next,
				 struct videobuf_buffer, stream);
		list_del(&buf->stream);
		videobuf_waiton(&dvb->dvbq, buf, 0, 1);

		/* no more feeds left or stop_feed() asked us to quit */
		if (0 == dvb->nfeeds)
			break;
		if (kthread_should_stop())
			break;
		try_to_freeze();

		/* feed buffer data to demux */
		outp = videobuf_queue_to_vaddr(&dvb->dvbq, buf);

		if (buf->state == VIDEOBUF_DONE)
			dvb_dmx_swfilter(&dvb->demux, outp,
					 buf->size);

		/* requeue buffer */
		list_add_tail(&buf->stream,&dvb->dvbq.stream);
		spin_lock_irqsave(dvb->dvbq.irqlock,flags);
		dvb->dvbq.ops->buf_queue(&dvb->dvbq,buf);
		spin_unlock_irqrestore(dvb->dvbq.irqlock,flags);
	}

	videobuf_read_stop(&dvb->dvbq);
	dprintk("dvb thread stopped\n");

	/* Hmm, linux becomes *very* unhappy without this ... */
	while (!kthread_should_stop()) {
		set_current_state(TASK_INTERRUPTIBLE);
		schedule();
	}
	return 0;
}

static int videobuf_dvb_start_feed(struct dvb_demux_feed *feed)
{
	struct dvb_demux *demux  = feed->demux;
	struct videobuf_dvb *dvb = demux->priv;
	int rc;

	if (!demux->dmx.frontend)
		return -EINVAL;

	mutex_lock(&dvb->lock);
	dvb->nfeeds++;
	rc = dvb->nfeeds;

	if (NULL != dvb->thread)
		goto out;
	dvb->thread = kthread_run(videobuf_dvb_thread,
				  dvb, "%s dvb", dvb->name);
	if (IS_ERR(dvb->thread)) {
		rc = PTR_ERR(dvb->thread);
		dvb->thread = NULL;
	}

out:
	mutex_unlock(&dvb->lock);
	return rc;
}

static int videobuf_dvb_stop_feed(struct dvb_demux_feed *feed)
{
	struct dvb_demux *demux  = feed->demux;
	struct videobuf_dvb *dvb = demux->priv;
	int err = 0;

	mutex_lock(&dvb->lock);
	dvb->nfeeds--;
	if (0 == dvb->nfeeds  &&  NULL != dvb->thread) {
		err = kthread_stop(dvb->thread);
		dvb->thread = NULL;
	}
	mutex_unlock(&dvb->lock);
	return err;
}

static int videobuf_dvb_register_adapter(struct videobuf_dvb_frontends *fe,
			  struct module *module,
			  void *adapter_priv,
			  struct device *device,
			  char *adapter_name,
			  short *adapter_nr,
			  int mfe_shared)
{
	int result;

	mutex_init(&fe->lock);

	/* register adapter */
	result = dvb_register_adapter(&fe->adapter, adapter_name, module,
		device, adapter_nr);
	if (result < 0) {
		printk(KERN_WARNING "%s: dvb_register_adapter failed (errno = %d)\n",
		       adapter_name, result);
	}
	fe->adapter.priv = adapter_priv;
	fe->adapter.mfe_shared = mfe_shared;

	return result;
}

static int videobuf_dvb_register_frontend(struct dvb_adapter *adapter,
	struct videobuf_dvb *dvb)
{
	int result;

	/* register frontend */
	result = dvb_register_frontend(adapter, dvb->frontend);
	if (result < 0) {
		printk(KERN_WARNING "%s: dvb_register_frontend failed (errno = %d)\n",
		       dvb->name, result);
		goto fail_frontend;
	}

	/* register demux stuff */
	dvb->demux.dmx.capabilities =
		DMX_TS_FILTERING | DMX_SECTION_FILTERING |
		DMX_MEMORY_BASED_FILTERING;
	dvb->demux.priv       = dvb;
	dvb->demux.filternum  = 256;
	dvb->demux.feednum    = 256;
	dvb->demux.start_feed = videobuf_dvb_start_feed;
	dvb->demux.stop_feed  = videobuf_dvb_stop_feed;
	result = dvb_dmx_init(&dvb->demux);
	if (result < 0) {
		printk(KERN_WARNING "%s: dvb_dmx_init failed (errno = %d)\n",
		       dvb->name, result);
		goto fail_dmx;
	}

	dvb->dmxdev.filternum    = 256;
	dvb->dmxdev.demux        = &dvb->demux.dmx;
	dvb->dmxdev.capabilities = 0;
	result = dvb_dmxdev_init(&dvb->dmxdev, adapter);

	if (result < 0) {
		printk(KERN_WARNING "%s: dvb_dmxdev_init failed (errno = %d)\n",
		       dvb->name, result);
		goto fail_dmxdev;
	}

	dvb->fe_hw.source = DMX_FRONTEND_0;
	result = dvb->demux.dmx.add_frontend(&dvb->demux.dmx, &dvb->fe_hw);
	if (result < 0) {
		printk(KERN_WARNING "%s: add_frontend failed (DMX_FRONTEND_0, errno = %d)\n",
		       dvb->name, result);
		goto fail_fe_hw;
	}

	dvb->fe_mem.source = DMX_MEMORY_FE;
	result = dvb->demux.dmx.add_frontend(&dvb->demux.dmx, &dvb->fe_mem);
	if (result < 0) {
		printk(KERN_WARNING "%s: add_frontend failed (DMX_MEMORY_FE, errno = %d)\n",
		       dvb->name, result);
		goto fail_fe_mem;
	}

	result = dvb->demux.dmx.connect_frontend(&dvb->demux.dmx, &dvb->fe_hw);
	if (result < 0) {
		printk(KERN_WARNING "%s: connect_frontend failed (errno = %d)\n",
		       dvb->name, result);
		goto fail_fe_conn;
	}

	/* register network adapter */
	result = dvb_net_init(adapter, &dvb->net, &dvb->demux.dmx);
	if (result < 0) {
		printk(KERN_WARNING "%s: dvb_net_init failed (errno = %d)\n",
		       dvb->name, result);
		goto fail_fe_conn;
	}
	return 0;

fail_fe_conn:
	dvb->demux.dmx.remove_frontend(&dvb->demux.dmx, &dvb->fe_mem);
fail_fe_mem:
	dvb->demux.dmx.remove_frontend(&dvb->demux.dmx, &dvb->fe_hw);
fail_fe_hw:
	dvb_dmxdev_release(&dvb->dmxdev);
fail_dmxdev:
	dvb_dmx_release(&dvb->demux);
fail_dmx:
	dvb_unregister_frontend(dvb->frontend);
fail_frontend:
	dvb_frontend_detach(dvb->frontend);
	dvb->frontend = NULL;

	return result;
}

/* ------------------------------------------------------------------ */
/* Register a single adapter and one or more frontends */
int videobuf_dvb_register_bus(struct videobuf_dvb_frontends *f,
			  struct module *module,
			  void *adapter_priv,
			  struct device *device,
			  short *adapter_nr,
			  int mfe_shared)
{
	struct list_head *list, *q;
	struct videobuf_dvb_frontend *fe;
	int res;

	fe = videobuf_dvb_get_frontend(f, 1);
	if (!fe) {
		printk(KERN_WARNING "Unable to register the adapter which has no frontends\n");
		return -EINVAL;
	}

	/* Bring up the adapter */
	res = videobuf_dvb_register_adapter(f, module, adapter_priv, device,
		fe->dvb.name, adapter_nr, mfe_shared);
	if (res < 0) {
		printk(KERN_WARNING "videobuf_dvb_register_adapter failed (errno = %d)\n", res);
		return res;
	}

	/* Attach all of the frontends to the adapter */
	mutex_lock(&f->lock);
	list_for_each_safe(list, q, &f->felist) {
		fe = list_entry(list, struct videobuf_dvb_frontend, felist);
		res = videobuf_dvb_register_frontend(&f->adapter, &fe->dvb);
		if (res < 0) {
			printk(KERN_WARNING "%s: videobuf_dvb_register_frontend failed (errno = %d)\n",
				fe->dvb.name, res);
			goto err;
		}
	}
	mutex_unlock(&f->lock);
	return 0;

err:
	mutex_unlock(&f->lock);
	videobuf_dvb_unregister_bus(f);
	return res;
}
EXPORT_SYMBOL(videobuf_dvb_register_bus);

void videobuf_dvb_unregister_bus(struct videobuf_dvb_frontends *f)
{
	videobuf_dvb_dealloc_frontends(f);

	dvb_unregister_adapter(&f->adapter);
}
EXPORT_SYMBOL(videobuf_dvb_unregister_bus);

struct videobuf_dvb_frontend *videobuf_dvb_get_frontend(
	struct videobuf_dvb_frontends *f, int id)
{
	struct list_head *list, *q;
	struct videobuf_dvb_frontend *fe, *ret = NULL;

	mutex_lock(&f->lock);

	list_for_each_safe(list, q, &f->felist) {
		fe = list_entry(list, struct videobuf_dvb_frontend, felist);
		if (fe->id == id) {
			ret = fe;
			break;
		}
	}

	mutex_unlock(&f->lock);

	return ret;
}
EXPORT_SYMBOL(videobuf_dvb_get_frontend);

int videobuf_dvb_find_frontend(struct videobuf_dvb_frontends *f,
	struct dvb_frontend *p)
{
	struct list_head *list, *q;
	struct videobuf_dvb_frontend *fe = NULL;
	int ret = 0;

	mutex_lock(&f->lock);

	list_for_each_safe(list, q, &f->felist) {
		fe = list_entry(list, struct videobuf_dvb_frontend, felist);
		if (fe->dvb.frontend == p) {
			ret = fe->id;
			break;
		}
	}

	mutex_unlock(&f->lock);

	return ret;
}
EXPORT_SYMBOL(videobuf_dvb_find_frontend);

struct videobuf_dvb_frontend *videobuf_dvb_alloc_frontend(
	struct videobuf_dvb_frontends *f, int id)
{
	struct videobuf_dvb_frontend *fe;

	fe = kzalloc(sizeof(struct videobuf_dvb_frontend), GFP_KERNEL);
	if (fe == NULL)
		goto fail_alloc;

	fe->id = id;
	mutex_init(&fe->dvb.lock);

	mutex_lock(&f->lock);
	list_add_tail(&fe->felist, &f->felist);
	mutex_unlock(&f->lock);

fail_alloc:
	return fe;
}
EXPORT_SYMBOL(videobuf_dvb_alloc_frontend);

void videobuf_dvb_dealloc_frontends(struct videobuf_dvb_frontends *f)
{
	struct list_head *list, *q;
	struct videobuf_dvb_frontend *fe;

	mutex_lock(&f->lock);
	list_for_each_safe(list, q, &f->felist) {
		fe = list_entry(list, struct videobuf_dvb_frontend, felist);
		if (fe->dvb.net.dvbdev) {
			dvb_net_release(&fe->dvb.net);
			fe->dvb.demux.dmx.remove_frontend(&fe->dvb.demux.dmx,
				&fe->dvb.fe_mem);
			fe->dvb.demux.dmx.remove_frontend(&fe->dvb.demux.dmx,
				&fe->dvb.fe_hw);
			dvb_dmxdev_release(&fe->dvb.dmxdev);
			dvb_dmx_release(&fe->dvb.demux);
			dvb_unregister_frontend(fe->dvb.frontend);
		}
		if (fe->dvb.frontend)
			/* always allocated, may have been reset */
			dvb_frontend_detach(fe->dvb.frontend);
		list_del(list); /* remove list entry */
		kfree(fe);	/* free frontend allocation */
	}
	mutex_unlock(&f->lock);
}
EXPORT_SYMBOL(videobuf_dvb_dealloc_frontends);