drivers/media/pci/cx23885/cx23885-vbi.c

Source file repositories/reference/linux-study-clean/drivers/media/pci/cx23885/cx23885-vbi.c

File Facts

System
Linux kernel
Corpus path
drivers/media/pci/cx23885/cx23885-vbi.c
Extension
.c
Size
7563 bytes
Lines
255
Domain
Driver Families
Bucket
drivers/media
Inferred role
Driver Families: implementation source
Status
source 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

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Driver for the Conexant CX23885 PCIe bridge
 *
 *  Copyright (c) 2007 Steven Toth <stoth@linuxtv.org>
 */

#include "cx23885.h"

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>

static unsigned int vbibufs = 4;
module_param(vbibufs, int, 0644);
MODULE_PARM_DESC(vbibufs, "number of vbi buffers, range 2-32");

static unsigned int vbi_debug;
module_param(vbi_debug, int, 0644);
MODULE_PARM_DESC(vbi_debug, "enable debug messages [vbi]");

#define dprintk(level, fmt, arg...)\
	do { if (vbi_debug >= level)\
		printk(KERN_DEBUG pr_fmt("%s: vbi:" fmt), \
			__func__, ##arg); \
	} while (0)

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

#define VBI_LINE_LENGTH 1440
#define VBI_NTSC_LINE_COUNT 12
#define VBI_PAL_LINE_COUNT 18


int cx23885_vbi_fmt(struct file *file, void *priv,
	struct v4l2_format *f)
{
	struct cx23885_dev *dev = video_drvdata(file);

	f->fmt.vbi.sampling_rate = 27000000;
	f->fmt.vbi.samples_per_line = VBI_LINE_LENGTH;
	f->fmt.vbi.sample_format = V4L2_PIX_FMT_GREY;
	f->fmt.vbi.offset = 0;
	f->fmt.vbi.flags = 0;
	if (dev->tvnorm & V4L2_STD_525_60) {
		/* ntsc */
		f->fmt.vbi.start[0] = V4L2_VBI_ITU_525_F1_START + 9;
		f->fmt.vbi.start[1] = V4L2_VBI_ITU_525_F2_START + 9;
		f->fmt.vbi.count[0] = VBI_NTSC_LINE_COUNT;
		f->fmt.vbi.count[1] = VBI_NTSC_LINE_COUNT;
	} else if (dev->tvnorm & V4L2_STD_625_50) {
		/* pal */
		f->fmt.vbi.start[0] = V4L2_VBI_ITU_625_F1_START + 5;
		f->fmt.vbi.start[1] = V4L2_VBI_ITU_625_F2_START + 5;
		f->fmt.vbi.count[0] = VBI_PAL_LINE_COUNT;
		f->fmt.vbi.count[1] = VBI_PAL_LINE_COUNT;
	}

	return 0;
}

/* We're given the Video Interrupt status register.
 * The cx23885_video_irq() func has already validated
 * the potential error bits, we just need to
 * deal with vbi payload and return indication if
 * we actually processed any payload.
 */
int cx23885_vbi_irq(struct cx23885_dev *dev, u32 status)
{
	u32 count;
	int handled = 0;

	if (status & VID_BC_MSK_VBI_RISCI1) {
		dprintk(1, "%s() VID_BC_MSK_VBI_RISCI1\n", __func__);
		spin_lock(&dev->slock);
		count = cx_read(VBI_A_GPCNT);
		cx23885_video_wakeup(dev, &dev->vbiq, count);
		spin_unlock(&dev->slock);
		handled++;
	}

	return handled;
}

static int cx23885_start_vbi_dma(struct cx23885_dev    *dev,
			 struct cx23885_dmaqueue *q,
			 struct cx23885_buffer   *buf)
{
	dprintk(1, "%s()\n", __func__);

Annotation

Implementation Notes