drivers/media/pci/saa7134/saa7134-ts.c

Source file repositories/reference/linux-study-clean/drivers/media/pci/saa7134/saa7134-ts.c

File Facts

System
Linux kernel
Corpus path
drivers/media/pci/saa7134/saa7134-ts.c
Extension
.c
Size
8642 bytes
Lines
327
Domain
Driver Families
Bucket
drivers/media
Inferred role
Driver Families: exported/initcall integration point
Status
integration implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

list_for_each_entry_safe(buf, tmp, &dmaq->queue, entry) {
			list_del(&buf->entry);
			vb2_buffer_done(&buf->vb2.vb2_buf,
					VB2_BUF_STATE_QUEUED);
		}
		if (dmaq->curr) {
			vb2_buffer_done(&dmaq->curr->vb2.vb2_buf,
					VB2_BUF_STATE_QUEUED);
			dmaq->curr = NULL;
		}
		return -EBUSY;
	}
	dmaq->seq_nr = 0;
	return 0;
}
EXPORT_SYMBOL_GPL(saa7134_ts_start_streaming);

void saa7134_ts_stop_streaming(struct vb2_queue *vq)
{
	struct saa7134_dmaqueue *dmaq = vq->drv_priv;
	struct saa7134_dev *dev = dmaq->dev;

	saa7134_ts_stop(dev);
	saa7134_stop_streaming(dev, dmaq);
}
EXPORT_SYMBOL_GPL(saa7134_ts_stop_streaming);

struct vb2_ops saa7134_ts_qops = {
	.queue_setup	= saa7134_ts_queue_setup,
	.buf_init	= saa7134_ts_buffer_init,
	.buf_prepare	= saa7134_ts_buffer_prepare,
	.buf_queue	= saa7134_vb2_buffer_queue,
	.stop_streaming = saa7134_ts_stop_streaming,
};
EXPORT_SYMBOL_GPL(saa7134_ts_qops);

/* ----------------------------------------------------------- */
/* exported stuff                                              */

static unsigned int tsbufs = 8;
module_param(tsbufs, int, 0444);
MODULE_PARM_DESC(tsbufs, "number of ts buffers for read/write IO, range 2-32");

static unsigned int ts_nr_packets = 64;
module_param(ts_nr_packets, int, 0444);
MODULE_PARM_DESC(ts_nr_packets,"size of a ts buffers (in ts packets)");

int saa7134_ts_init_hw(struct saa7134_dev *dev)
{
	/* deactivate TS softreset */
	saa_writeb(SAA7134_TS_SERIAL1, 0x00);
	/* TSSOP high active, TSVAL high active, TSLOCK ignored */
	saa_writeb(SAA7134_TS_PARALLEL, 0x6c);
	saa_writeb(SAA7134_TS_PARALLEL_SERIAL, (TS_PACKET_SIZE-1));
	saa_writeb(SAA7134_TS_DMA0, ((dev->ts.nr_packets-1)&0xff));
	saa_writeb(SAA7134_TS_DMA1, (((dev->ts.nr_packets-1)>>8)&0xff));
	/* TSNOPIT=0, TSCOLAP=0 */
	saa_writeb(SAA7134_TS_DMA2,
		((((dev->ts.nr_packets-1)>>16)&0x3f) | 0x00));

	return 0;
}

int saa7134_ts_init1(struct saa7134_dev *dev)
{
	/* sanitycheck insmod options */
	if (tsbufs < 2)
		tsbufs = 2;
	if (tsbufs > VIDEO_MAX_FRAME)
		tsbufs = VIDEO_MAX_FRAME;
	if (ts_nr_packets < 4)
		ts_nr_packets = 4;
	if (ts_nr_packets > 312)
		ts_nr_packets = 312;
	dev->ts.nr_bufs    = tsbufs;
	dev->ts.nr_packets = ts_nr_packets;

	INIT_LIST_HEAD(&dev->ts_q.queue);
	timer_setup(&dev->ts_q.timeout, saa7134_buffer_timeout, 0);
	dev->ts_q.dev              = dev;
	dev->ts_q.need_two         = 1;
	dev->ts_started            = 0;
	saa7134_pgtable_alloc(dev->pci, &dev->ts_q.pt);

	/* init TS hw */
	saa7134_ts_init_hw(dev);

	return 0;
}

Annotation

Implementation Notes