stk1160-v4l.c

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/*
 * STK1160 driver
 *
 * Copyright (C) 2012 Ezequiel Garcia
 * <elezegarcia--a.t--gmail.com>
 *
 * Based on Easycap driver by R.M. Thomas
 *  Copyright (C) 2010 R.M. Thomas
 *  <rmthomas--a.t--sciolus.org>
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 */

#include <linux/module.h>
#include <linux/usb.h>
#include <linux/mm.h>
#include <linux/slab.h>

#include <linux/videodev2.h>
#include <media/v4l2-device.h>
#include <media/v4l2-common.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-fh.h>
#include <media/v4l2-event.h>
#include <media/v4l2-chip-ident.h>
#include <media/videobuf2-vmalloc.h>

#include <media/saa7115.h>

#include "stk1160.h"
#include "stk1160-reg.h"

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

static bool keep_buffers;
module_param(keep_buffers, bool, 0644);
MODULE_PARM_DESC(keep_buffers, "don't release buffers upon stop streaming");

/* supported video standards */
static struct stk1160_fmt format[] = {
    {
        .name     = "16 bpp YUY2, 4:2:2, packed",
        .fourcc   = V4L2_PIX_FMT_UYVY,
        .depth    = 16,
    }
};

static void stk1160_set_std(struct stk1160 *dev)
{
    int i;

    static struct regval std525[] = {

        /* 720x480 */

        /* Frame start */
        {STK116_CFSPO_STX_L, 0x0000},
        {STK116_CFSPO_STX_H, 0x0000},
        {STK116_CFSPO_STY_L, 0x0003},
        {STK116_CFSPO_STY_H, 0x0000},

        /* Frame end */
        {STK116_CFEPO_ENX_L, 0x05a0},
        {STK116_CFEPO_ENX_H, 0x0005},
        {STK116_CFEPO_ENY_L, 0x00f3},
        {STK116_CFEPO_ENY_H, 0x0000},

        {0xffff, 0xffff}
    };

    static struct regval std625[] = {

        /* 720x576 */

        /* TODO: Each line of frame has some junk at the end */
        /* Frame start */
        {STK116_CFSPO,   0x0000},
        {STK116_CFSPO+1, 0x0000},
        {STK116_CFSPO+2, 0x0001},
        {STK116_CFSPO+3, 0x0000},

        /* Frame end */
        {STK116_CFEPO,   0x05a0},
        {STK116_CFEPO+1, 0x0005},
        {STK116_CFEPO+2, 0x0121},
        {STK116_CFEPO+3, 0x0001},

        {0xffff, 0xffff}
    };

    if (dev->norm & V4L2_STD_525_60) {
        stk1160_dbg("registers to NTSC like standard\n");
        for (i = 0; std525[i].reg != 0xffff; i++)
            stk1160_write_reg(dev, std525[i].reg, std525[i].val);
    } else {
        stk1160_dbg("registers to PAL like standard\n");
        for (i = 0; std625[i].reg != 0xffff; i++)
            stk1160_write_reg(dev, std625[i].reg, std625[i].val);
    }

}

/*
 * Set a new alternate setting.
 * Returns true is dev->max_pkt_size has changed, false otherwise.
 */
static bool stk1160_set_alternate(struct stk1160 *dev)
{
    int i, prev_alt = dev->alt;
    unsigned int min_pkt_size;
    bool new_pkt_size;

    /*
     * If we don't set right alternate,
     * then we will get a green screen with junk.
     */
    min_pkt_size = STK1160_MIN_PKT_SIZE;

    for (i = 0; i < dev->num_alt; i++) {
        /* stop when the selected alt setting offers enough bandwidth */
        if (dev->alt_max_pkt_size[i] >= min_pkt_size) {
            dev->alt = i;
            break;
        /*
         * otherwise make sure that we end up with the maximum bandwidth
         * because the min_pkt_size equation might be wrong...
         */
        } else if (dev->alt_max_pkt_size[i] >
               dev->alt_max_pkt_size[dev->alt])
            dev->alt = i;
    }

    stk1160_info("setting alternate %d\n", dev->alt);

    if (dev->alt != prev_alt) {
        stk1160_dbg("minimum isoc packet size: %u (alt=%d)\n",
                min_pkt_size, dev->alt);
        stk1160_dbg("setting alt %d with wMaxPacketSize=%u\n",
                   dev->alt, dev->alt_max_pkt_size[dev->alt]);
        usb_set_interface(dev->udev, 0, dev->alt);
    }

    new_pkt_size = dev->max_pkt_size != dev->alt_max_pkt_size[dev->alt];
    dev->max_pkt_size = dev->alt_max_pkt_size[dev->alt];

    return new_pkt_size;
}

static int stk1160_start_streaming(struct stk1160 *dev)
{
    bool new_pkt_size;
    int rc = 0;
    int i;

    /* Check device presence */
    if (!dev->udev)
        return -ENODEV;

    if (mutex_lock_interruptible(&dev->v4l_lock))
        return -ERESTARTSYS;
    /*
     * For some reason it is mandatory to set alternate *first*
     * and only *then* initialize isoc urbs.
     * Someone please explain me why ;)
     */
    new_pkt_size = stk1160_set_alternate(dev);

    /*
     * We (re)allocate isoc urbs if:
     * there is no allocated isoc urbs, OR
     * a new dev->max_pkt_size is detected
     */
    if (!dev->isoc_ctl.num_bufs || new_pkt_size) {
        rc = stk1160_alloc_isoc(dev);
        if (rc < 0)
            goto out_stop_hw;
    }

    /* submit urbs and enables IRQ */
    for (i = 0; i < dev->isoc_ctl.num_bufs; i++) {
        rc = usb_submit_urb(dev->isoc_ctl.urb[i], GFP_KERNEL);
        if (rc) {
            stk1160_err("cannot submit urb[%d] (%d)\n", i, rc);
            goto out_uninit;
        }
    }

    /* Start saa711x */
    v4l2_device_call_all(&dev->v4l2_dev, 0, video, s_stream, 1);

    /* Start stk1160 */
    stk1160_write_reg(dev, STK1160_DCTRL, 0xb3);
    stk1160_write_reg(dev, STK1160_DCTRL+3, 0x00);

    stk1160_dbg("streaming started\n");

    mutex_unlock(&dev->v4l_lock);

    return 0;

out_uninit:
    stk1160_uninit_isoc(dev);
out_stop_hw:
    usb_set_interface(dev->udev, 0, 0);
    stk1160_clear_queue(dev);

    mutex_unlock(&dev->v4l_lock);

    return rc;
}

/* Must be called with v4l_lock hold */
static void stk1160_stop_hw(struct stk1160 *dev)
{
    /* If the device is not physically present, there is nothing to do */
    if (!dev->udev)
        return;

    /* set alternate 0 */
    dev->alt = 0;
    stk1160_info("setting alternate %d\n", dev->alt);
    usb_set_interface(dev->udev, 0, 0);

    /* Stop stk1160 */
    stk1160_write_reg(dev, STK1160_DCTRL, 0x00);
    stk1160_write_reg(dev, STK1160_DCTRL+3, 0x00);

    /* Stop saa711x */
    v4l2_device_call_all(&dev->v4l2_dev, 0, video, s_stream, 0);
}

static int stk1160_stop_streaming(struct stk1160 *dev)
{
    if (mutex_lock_interruptible(&dev->v4l_lock))
        return -ERESTARTSYS;

    stk1160_cancel_isoc(dev);

    /*
     * It is possible to keep buffers around using a module parameter.
     * This is intended to avoid memory fragmentation.
     */
    if (!keep_buffers)
        stk1160_free_isoc(dev);

    stk1160_stop_hw(dev);

    stk1160_clear_queue(dev);

    stk1160_dbg("streaming stopped\n");

    mutex_unlock(&dev->v4l_lock);

    return 0;
}

static struct v4l2_file_operations stk1160_fops = {
    .owner = THIS_MODULE,
    .open = v4l2_fh_open,
    .release = vb2_fop_release,
    .read = vb2_fop_read,
    .poll = vb2_fop_poll,
    .mmap = vb2_fop_mmap,
    .unlocked_ioctl = video_ioctl2,
};

/*
 * vidioc ioctls
 */
static int vidioc_querycap(struct file *file,
        void *priv, struct v4l2_capability *cap)
{
    struct stk1160 *dev = video_drvdata(file);

    strcpy(cap->driver, "stk1160");
    strcpy(cap->card, "stk1160");
    usb_make_path(dev->udev, cap->bus_info, sizeof(cap->bus_info));
    cap->device_caps =
        V4L2_CAP_VIDEO_CAPTURE |
        V4L2_CAP_STREAMING |
        V4L2_CAP_READWRITE;
    cap->capabilities = cap->device_caps | V4L2_CAP_DEVICE_CAPS;
    return 0;
}

static int vidioc_enum_fmt_vid_cap(struct file *file, void  *priv,
        struct v4l2_fmtdesc *f)
{
    if (f->index != 0)
        return -EINVAL;

    strlcpy(f->description, format[f->index].name, sizeof(f->description));
    f->pixelformat = format[f->index].fourcc;
    return 0;
}

static int vidioc_g_fmt_vid_cap(struct file *file, void *priv,
                    struct v4l2_format *f)
{
    struct stk1160 *dev = video_drvdata(file);

    f->fmt.pix.width = dev->width;
    f->fmt.pix.height = dev->height;
    f->fmt.pix.field = V4L2_FIELD_INTERLACED;
    f->fmt.pix.pixelformat = dev->fmt->fourcc;
    f->fmt.pix.bytesperline = dev->width * 2;
    f->fmt.pix.sizeimage = dev->height * f->fmt.pix.bytesperline;
    f->fmt.pix.colorspace = V4L2_COLORSPACE_SMPTE170M;

    return 0;
}

static int vidioc_try_fmt_vid_cap(struct file *file, void *priv,
            struct v4l2_format *f)
{
    struct stk1160 *dev = video_drvdata(file);

    /*
     * User can't choose size at his own will,
     * so we just return him the current size chosen
     * at standard selection.
     * TODO: Implement frame scaling?
     */

    f->fmt.pix.pixelformat = dev->fmt->fourcc;
    f->fmt.pix.width = dev->width;
    f->fmt.pix.height = dev->height;
    f->fmt.pix.field = V4L2_FIELD_INTERLACED;
    f->fmt.pix.bytesperline = dev->width * 2;
    f->fmt.pix.sizeimage = dev->height * f->fmt.pix.bytesperline;
    f->fmt.pix.colorspace = V4L2_COLORSPACE_SMPTE170M;

    return 0;
}

static int vidioc_s_fmt_vid_cap(struct file *file, void *priv,
                    struct v4l2_format *f)
{
    struct stk1160 *dev = video_drvdata(file);
    struct vb2_queue *q = &dev->vb_vidq;

    if (vb2_is_busy(q))
        return -EBUSY;

    vidioc_try_fmt_vid_cap(file, priv, f);

    /* We don't support any format changes */

    return 0;
}

static int vidioc_querystd(struct file *file, void *priv, v4l2_std_id *norm)
{
    struct stk1160 *dev = video_drvdata(file);
    v4l2_device_call_all(&dev->v4l2_dev, 0, video, querystd, norm);
    return 0;
}

static int vidioc_g_std(struct file *file, void *priv, v4l2_std_id *norm)
{
    struct stk1160 *dev = video_drvdata(file);

    *norm = dev->norm;
    return 0;
}

static int vidioc_s_std(struct file *file, void *priv, v4l2_std_id *norm)
{
    struct stk1160 *dev = video_drvdata(file);
    struct vb2_queue *q = &dev->vb_vidq;

    if (vb2_is_busy(q))
        return -EBUSY;

    /* Check device presence */
    if (!dev->udev)
        return -ENODEV;

    /* We need to set this now, before we call stk1160_set_std */
    dev->norm = *norm;

    /* This is taken from saa7115 video decoder */
    if (dev->norm & V4L2_STD_525_60) {
        dev->width = 720;
        dev->height = 480;
    } else if (dev->norm & V4L2_STD_625_50) {
        dev->width = 720;
        dev->height = 576;
    } else {
        stk1160_err("invalid standard\n");
        return -EINVAL;
    }

    stk1160_set_std(dev);

    v4l2_device_call_all(&dev->v4l2_dev, 0, core, s_std,
            dev->norm);

    return 0;
}


static int vidioc_enum_input(struct file *file, void *priv,
                struct v4l2_input *i)
{
    struct stk1160 *dev = video_drvdata(file);

    if (i->index > STK1160_MAX_INPUT)
        return -EINVAL;

    /* S-Video special handling */
    if (i->index == STK1160_SVIDEO_INPUT)
        sprintf(i->name, "S-Video");
    else
        sprintf(i->name, "Composite%d", i->index);

    i->type = V4L2_INPUT_TYPE_CAMERA;
    i->std = dev->vdev.tvnorms;
    return 0;
}

static int vidioc_g_input(struct file *file, void *priv, unsigned int *i)
{
    struct stk1160 *dev = video_drvdata(file);
    *i = dev->ctl_input;
    return 0;
}

static int vidioc_s_input(struct file *file, void *priv, unsigned int i)
{
    struct stk1160 *dev = video_drvdata(file);

    if (vb2_is_busy(&dev->vb_vidq))
        return -EBUSY;

    if (i > STK1160_MAX_INPUT)
        return -EINVAL;

    dev->ctl_input = i;

    stk1160_select_input(dev);

    return 0;
}

static int vidioc_g_chip_ident(struct file *file, void *priv,
           struct v4l2_dbg_chip_ident *chip)
{
    switch (chip->match.type) {
    case V4L2_CHIP_MATCH_HOST:
        chip->ident = V4L2_IDENT_NONE;
        chip->revision = 0;
        return 0;
    default:
        return -EINVAL;
    }
}

#ifdef CONFIG_VIDEO_ADV_DEBUG
static int vidioc_g_register(struct file *file, void *priv,
                 struct v4l2_dbg_register *reg)
{
    struct stk1160 *dev = video_drvdata(file);
    int rc;
    u8 val;

    switch (reg->match.type) {
    case V4L2_CHIP_MATCH_AC97:
        /* TODO: Support me please :-( */
        return -EINVAL;
    case V4L2_CHIP_MATCH_I2C_DRIVER:
        v4l2_device_call_all(&dev->v4l2_dev, 0, core, g_register, reg);
        return 0;
    case V4L2_CHIP_MATCH_I2C_ADDR:
        /* TODO: is this correct? */
        v4l2_device_call_all(&dev->v4l2_dev, 0, core, g_register, reg);
        return 0;
    default:
        if (!v4l2_chip_match_host(&reg->match))
            return -EINVAL;
    }

    /* Match host */
    rc = stk1160_read_reg(dev, reg->reg, &val);
    reg->val = val;
    reg->size = 1;

    return rc;
}

static int vidioc_s_register(struct file *file, void *priv,
                 struct v4l2_dbg_register *reg)
{
    struct stk1160 *dev = video_drvdata(file);

    switch (reg->match.type) {
    case V4L2_CHIP_MATCH_AC97:
        return -EINVAL;
    case V4L2_CHIP_MATCH_I2C_DRIVER:
        v4l2_device_call_all(&dev->v4l2_dev, 0, core, s_register, reg);
        return 0;
    case V4L2_CHIP_MATCH_I2C_ADDR:
        /* TODO: is this correct? */
        v4l2_device_call_all(&dev->v4l2_dev, 0, core, s_register, reg);
        return 0;
    default:
        if (!v4l2_chip_match_host(&reg->match))
            return -EINVAL;
    }

    /* Match host */
    return stk1160_write_reg(dev, reg->reg, cpu_to_le16(reg->val));
}
#endif

static const struct v4l2_ioctl_ops stk1160_ioctl_ops = {
    .vidioc_querycap      = vidioc_querycap,
    .vidioc_enum_fmt_vid_cap  = vidioc_enum_fmt_vid_cap,
    .vidioc_g_fmt_vid_cap     = vidioc_g_fmt_vid_cap,
    .vidioc_try_fmt_vid_cap   = vidioc_try_fmt_vid_cap,
    .vidioc_s_fmt_vid_cap     = vidioc_s_fmt_vid_cap,
    .vidioc_querystd      = vidioc_querystd,
    .vidioc_g_std         = vidioc_g_std,
    .vidioc_s_std         = vidioc_s_std,
    .vidioc_enum_input    = vidioc_enum_input,
    .vidioc_g_input       = vidioc_g_input,
    .vidioc_s_input       = vidioc_s_input,

    /* vb2 takes care of these */
    .vidioc_reqbufs       = vb2_ioctl_reqbufs,
    .vidioc_querybuf      = vb2_ioctl_querybuf,
    .vidioc_qbuf          = vb2_ioctl_qbuf,
    .vidioc_dqbuf         = vb2_ioctl_dqbuf,
    .vidioc_streamon      = vb2_ioctl_streamon,
    .vidioc_streamoff     = vb2_ioctl_streamoff,

    .vidioc_log_status  = v4l2_ctrl_log_status,
    .vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
    .vidioc_unsubscribe_event = v4l2_event_unsubscribe,
    .vidioc_g_chip_ident = vidioc_g_chip_ident,

#ifdef CONFIG_VIDEO_ADV_DEBUG
    .vidioc_g_register = vidioc_g_register,
    .vidioc_s_register = vidioc_s_register,
#endif
};

/********************************************************************/

/*
 * Videobuf2 operations
 */
static int queue_setup(struct vb2_queue *vq, const struct v4l2_format *v4l_fmt,
                unsigned int *nbuffers, unsigned int *nplanes,
                unsigned int sizes[], void *alloc_ctxs[])
{
    struct stk1160 *dev = vb2_get_drv_priv(vq);
    unsigned long size;

    size = dev->width * dev->height * 2;

    /*
     * Here we can change the number of buffers being requested.
     * So, we set a minimum and a maximum like this:
     */
    *nbuffers = clamp_t(unsigned int, *nbuffers,
            STK1160_MIN_VIDEO_BUFFERS, STK1160_MAX_VIDEO_BUFFERS);

    /* This means a packed colorformat */
    *nplanes = 1;

    sizes[0] = size;

    stk1160_info("%s: buffer count %d, each %ld bytes\n",
            __func__, *nbuffers, size);

    return 0;
}

static void buffer_queue(struct vb2_buffer *vb)
{
    unsigned long flags;
    struct stk1160 *dev = vb2_get_drv_priv(vb->vb2_queue);
    struct stk1160_buffer *buf =
        container_of(vb, struct stk1160_buffer, vb);

    spin_lock_irqsave(&dev->buf_lock, flags);
    if (!dev->udev) {
        /*
         * If the device is disconnected return the buffer to userspace
         * directly. The next QBUF call will fail with -ENODEV.
         */
        vb2_buffer_done(&buf->vb, VB2_BUF_STATE_ERROR);
    } else {

        buf->mem = vb2_plane_vaddr(vb, 0);
        buf->length = vb2_plane_size(vb, 0);
        buf->bytesused = 0;
        buf->pos = 0;

        /*
         * If buffer length is less from expected then we return
         * the buffer to userspace directly.
         */
        if (buf->length < dev->width * dev->height * 2)
            vb2_buffer_done(&buf->vb, VB2_BUF_STATE_ERROR);
        else
            list_add_tail(&buf->list, &dev->avail_bufs);

    }
    spin_unlock_irqrestore(&dev->buf_lock, flags);
}

static int start_streaming(struct vb2_queue *vq, unsigned int count)
{
    struct stk1160 *dev = vb2_get_drv_priv(vq);
    return stk1160_start_streaming(dev);
}

/* abort streaming and wait for last buffer */
static int stop_streaming(struct vb2_queue *vq)
{
    struct stk1160 *dev = vb2_get_drv_priv(vq);
    return stk1160_stop_streaming(dev);
}

static struct vb2_ops stk1160_video_qops = {
    .queue_setup        = queue_setup,
    .buf_queue      = buffer_queue,
    .start_streaming    = start_streaming,
    .stop_streaming     = stop_streaming,
    .wait_prepare       = vb2_ops_wait_prepare,
    .wait_finish        = vb2_ops_wait_finish,
};

static struct video_device v4l_template = {
    .name = "stk1160",
    .tvnorms = V4L2_STD_525_60 | V4L2_STD_625_50,
    .fops = &stk1160_fops,
    .ioctl_ops = &stk1160_ioctl_ops,
    .release = video_device_release_empty,
};

/********************************************************************/

/* Must be called with both v4l_lock and vb_queue_lock hold */
void stk1160_clear_queue(struct stk1160 *dev)
{
    struct stk1160_buffer *buf;
    unsigned long flags;

    /* Release all active buffers */
    spin_lock_irqsave(&dev->buf_lock, flags);
    while (!list_empty(&dev->avail_bufs)) {
        buf = list_first_entry(&dev->avail_bufs,
            struct stk1160_buffer, list);
        list_del(&buf->list);
        vb2_buffer_done(&buf->vb, VB2_BUF_STATE_ERROR);
        stk1160_info("buffer [%p/%d] aborted\n",
                buf, buf->vb.v4l2_buf.index);
    }
    /* It's important to clear current buffer */
    dev->isoc_ctl.buf = NULL;
    spin_unlock_irqrestore(&dev->buf_lock, flags);
}

int stk1160_vb2_setup(struct stk1160 *dev)
{
    int rc;
    struct vb2_queue *q;

    q = &dev->vb_vidq;
    q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
    q->io_modes = VB2_READ | VB2_MMAP | VB2_USERPTR;
    q->drv_priv = dev;
    q->buf_struct_size = sizeof(struct stk1160_buffer);
    q->ops = &stk1160_video_qops;
    q->mem_ops = &vb2_vmalloc_memops;

    rc = vb2_queue_init(q);
    if (rc < 0)
        return rc;

    /* initialize video dma queue */
    INIT_LIST_HEAD(&dev->avail_bufs);

    return 0;
}

int stk1160_video_register(struct stk1160 *dev)
{
    int rc;

    /* Initialize video_device with a template structure */
    dev->vdev = v4l_template;
    dev->vdev.debug = vidioc_debug;
    dev->vdev.queue = &dev->vb_vidq;

    /*
     * Provide mutexes for v4l2 core and for videobuf2 queue.
     * It will be used to protect *only* v4l2 ioctls.
     */
    dev->vdev.lock = &dev->v4l_lock;
    dev->vdev.queue->lock = &dev->vb_queue_lock;

    /* This will be used to set video_device parent */
    dev->vdev.v4l2_dev = &dev->v4l2_dev;
    set_bit(V4L2_FL_USE_FH_PRIO, &dev->vdev.flags);

    /* NTSC is default */
    dev->norm = V4L2_STD_NTSC_M;
    dev->width = 720;
    dev->height = 480;

    /* set default format */
    dev->fmt = &format[0];
    stk1160_set_std(dev);

    v4l2_device_call_all(&dev->v4l2_dev, 0, core, s_std,
            dev->norm);

    video_set_drvdata(&dev->vdev, dev);
    rc = video_register_device(&dev->vdev, VFL_TYPE_GRABBER, -1);
    if (rc < 0) {
        stk1160_err("video_register_device failed (%d)\n", rc);
        return rc;
    }

    v4l2_info(&dev->v4l2_dev, "V4L2 device registered as %s\n",
          video_device_node_name(&dev->vdev));

    return 0;
}