root/drivers/media/pci/saa7134/saa7134-vbi.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *
 * device driver for philips saa7134 based TV cards
 * video4linux video interface
 *
 * (c) 2001,02 Gerd Knorr <kraxel@bytesex.org> [SuSE Labs]
 */

#include "saa7134.h"
#include "saa7134-reg.h"

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

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

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

static unsigned int vbibufs = 4;
module_param(vbibufs, int, 0444);
MODULE_PARM_DESC(vbibufs,"number of vbi buffers, range 2-32");

#define vbi_dbg(fmt, arg...) do { \
        if (vbi_debug) \
                printk(KERN_DEBUG pr_fmt("vbi: " fmt), ## arg); \
        } while (0)

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

#define VBI_LINE_COUNT     17
#define VBI_LINE_LENGTH  2048
#define VBI_SCALE       0x200

static void task_init(struct saa7134_dev *dev, struct saa7134_buf *buf,
                      int task)
{
        struct saa7134_tvnorm *norm = dev->tvnorm;

        /* setup video scaler */
        saa_writeb(SAA7134_VBI_H_START1(task), norm->h_start     &  0xff);
        saa_writeb(SAA7134_VBI_H_START2(task), norm->h_start     >> 8);
        saa_writeb(SAA7134_VBI_H_STOP1(task),  norm->h_stop      &  0xff);
        saa_writeb(SAA7134_VBI_H_STOP2(task),  norm->h_stop      >> 8);
        saa_writeb(SAA7134_VBI_V_START1(task), norm->vbi_v_start_0 &  0xff);
        saa_writeb(SAA7134_VBI_V_START2(task), norm->vbi_v_start_0 >> 8);
        saa_writeb(SAA7134_VBI_V_STOP1(task),  norm->vbi_v_stop_0  &  0xff);
        saa_writeb(SAA7134_VBI_V_STOP2(task),  norm->vbi_v_stop_0  >> 8);

        saa_writeb(SAA7134_VBI_H_SCALE_INC1(task),        VBI_SCALE & 0xff);
        saa_writeb(SAA7134_VBI_H_SCALE_INC2(task),        VBI_SCALE >> 8);
        saa_writeb(SAA7134_VBI_PHASE_OFFSET_LUMA(task),   0x00);
        saa_writeb(SAA7134_VBI_PHASE_OFFSET_CHROMA(task), 0x00);

        saa_writeb(SAA7134_VBI_H_LEN1(task), dev->vbi_hlen & 0xff);
        saa_writeb(SAA7134_VBI_H_LEN2(task), dev->vbi_hlen >> 8);
        saa_writeb(SAA7134_VBI_V_LEN1(task), dev->vbi_vlen & 0xff);
        saa_writeb(SAA7134_VBI_V_LEN2(task), dev->vbi_vlen >> 8);

        saa_andorb(SAA7134_DATA_PATH(task), 0xc0, 0x00);
}

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

static int buffer_activate(struct saa7134_dev *dev,
                           struct saa7134_buf *buf,
                           struct saa7134_buf *next)
{
        struct saa7134_dmaqueue *dmaq = buf->vb2.vb2_buf.vb2_queue->drv_priv;
        unsigned long control, base;

        vbi_dbg("buffer_activate [%p]\n", buf);
        buf->top_seen = 0;

        task_init(dev, buf, TASK_A);
        task_init(dev, buf, TASK_B);
        saa_writeb(SAA7134_OFMT_DATA_A, 0x06);
        saa_writeb(SAA7134_OFMT_DATA_B, 0x06);

        /* DMA: setup channel 2+3 (= VBI Task A+B) */
        base    = saa7134_buffer_base(buf);
        control = SAA7134_RS_CONTROL_BURST_16 |
                SAA7134_RS_CONTROL_ME |
                (dmaq->pt.dma >> 12);
        saa_writel(SAA7134_RS_BA1(2), base);
        saa_writel(SAA7134_RS_BA2(2), base + dev->vbi_hlen * dev->vbi_vlen);
        saa_writel(SAA7134_RS_PITCH(2), dev->vbi_hlen);
        saa_writel(SAA7134_RS_CONTROL(2), control);
        saa_writel(SAA7134_RS_BA1(3), base);
        saa_writel(SAA7134_RS_BA2(3), base + dev->vbi_hlen * dev->vbi_vlen);
        saa_writel(SAA7134_RS_PITCH(3), dev->vbi_hlen);
        saa_writel(SAA7134_RS_CONTROL(3), control);

        /* start DMA */
        saa7134_set_dmabits(dev);
        mod_timer(&dmaq->timeout, jiffies + BUFFER_TIMEOUT);

        return 0;
}

static int buffer_prepare(struct vb2_buffer *vb2)
{
        struct saa7134_dmaqueue *dmaq = vb2->vb2_queue->drv_priv;
        struct saa7134_dev *dev = dmaq->dev;
        struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb2);
        struct saa7134_buf *buf = container_of(vbuf, struct saa7134_buf, vb2);
        struct sg_table *dma = vb2_dma_sg_plane_desc(vb2, 0);
        unsigned int size;

        if (dma->sgl->offset) {
                pr_err("The buffer is not page-aligned\n");
                return -EINVAL;
        }
        size = dev->vbi_hlen * dev->vbi_vlen * 2;
        if (vb2_plane_size(vb2, 0) < size)
                return -EINVAL;

        vb2_set_plane_payload(vb2, 0, size);

        return saa7134_pgtable_build(dev->pci, &dmaq->pt, dma->sgl, dma->nents,
                                    saa7134_buffer_startpage(buf));
}

static int queue_setup(struct vb2_queue *q,
                           unsigned int *nbuffers, unsigned int *nplanes,
                           unsigned int sizes[], struct device *alloc_devs[])
{
        struct saa7134_dmaqueue *dmaq = q->drv_priv;
        struct saa7134_dev *dev = dmaq->dev;
        unsigned int size;

        dev->vbi_vlen = dev->tvnorm->vbi_v_stop_0 - dev->tvnorm->vbi_v_start_0 + 1;
        if (dev->vbi_vlen > VBI_LINE_COUNT)
                dev->vbi_vlen = VBI_LINE_COUNT;
        dev->vbi_hlen = VBI_LINE_LENGTH;
        size = dev->vbi_hlen * dev->vbi_vlen * 2;

        *nbuffers = saa7134_buffer_count(size, *nbuffers);
        *nplanes = 1;
        sizes[0] = size;
        return 0;
}

static int buffer_init(struct vb2_buffer *vb2)
{
        struct saa7134_dmaqueue *dmaq = vb2->vb2_queue->drv_priv;
        struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb2);
        struct saa7134_buf *buf = container_of(vbuf, struct saa7134_buf, vb2);

        dmaq->curr = NULL;
        buf->activate = buffer_activate;
        return 0;
}

const struct vb2_ops saa7134_vbi_qops = {
        .queue_setup    = queue_setup,
        .buf_init       = buffer_init,
        .buf_prepare    = buffer_prepare,
        .buf_queue      = saa7134_vb2_buffer_queue,
        .start_streaming = saa7134_vb2_start_streaming,
        .stop_streaming = saa7134_vb2_stop_streaming,
};

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

int saa7134_vbi_init1(struct saa7134_dev *dev)
{
        INIT_LIST_HEAD(&dev->vbi_q.queue);
        timer_setup(&dev->vbi_q.timeout, saa7134_buffer_timeout, 0);
        dev->vbi_q.dev              = dev;

        if (vbibufs < 2)
                vbibufs = 2;
        if (vbibufs > VIDEO_MAX_FRAME)
                vbibufs = VIDEO_MAX_FRAME;
        return 0;
}

int saa7134_vbi_fini(struct saa7134_dev *dev)
{
        /* nothing */
        timer_delete_sync(&dev->vbi_q.timeout);
        return 0;
}

void saa7134_irq_vbi_done(struct saa7134_dev *dev, unsigned long status)
{
        spin_lock(&dev->slock);
        if (dev->vbi_q.curr) {
                /* make sure we have seen both fields */
                if ((status & 0x10) == 0x00) {
                        dev->vbi_q.curr->top_seen = 1;
                        goto done;
                }
                if (!dev->vbi_q.curr->top_seen)
                        goto done;

                saa7134_buffer_finish(dev, &dev->vbi_q, VB2_BUF_STATE_DONE);
        }
        saa7134_buffer_next(dev, &dev->vbi_q);

 done:
        spin_unlock(&dev->slock);
}