/*
   cx231xx_vbi.c - driver for Conexant Cx23100/101/102 USB video capture devices

   Copyright (C) 2008 <srinivasa.deevi at conexant dot com>
        Based on cx88 driver

   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.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/init.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/bitmap.h>
#include <linux/usb.h>
#include <linux/i2c.h>
#include <linux/mm.h>
#include <linux/mutex.h>
#include <linux/slab.h>

#include <media/v4l2-common.h>
#include <media/v4l2-ioctl.h>
#include <media/msp3400.h>
#include <media/tuner.h>

#include "cx231xx.h"
#include "cx231xx-vbi.h"

static inline void print_err_status(struct cx231xx *dev, int packet, int status)
{
        char *errmsg = "Unknown";

        switch (status) {
        case -ENOENT:
                errmsg = "unlinked synchronuously";
                break;
        case -ECONNRESET:
                errmsg = "unlinked asynchronuously";
                break;
        case -ENOSR:
                errmsg = "Buffer error (overrun)";
                break;
        case -EPIPE:
                errmsg = "Stalled (device not responding)";
                break;
        case -EOVERFLOW:
                errmsg = "Babble (bad cable?)";
                break;
        case -EPROTO:
                errmsg = "Bit-stuff error (bad cable?)";
                break;
        case -EILSEQ:
                errmsg = "CRC/Timeout (could be anything)";
                break;
        case -ETIME:
                errmsg = "Device does not respond";
                break;
        }
        if (packet < 0) {
                cx231xx_err("URB status %d [%s].\n", status,
                            errmsg);
        } else {
                cx231xx_err("URB packet %d, status %d [%s].\n",
                            packet, status, errmsg);
        }
}

/*
 * Controls the isoc copy of each urb packet
 */
static inline int cx231xx_isoc_vbi_copy(struct cx231xx *dev, struct urb *urb)
{
        struct cx231xx_dmaqueue *dma_q = urb->context;
        int rc = 1;
        unsigned char *p_buffer;
        u32 bytes_parsed = 0, buffer_size = 0;
        u8 sav_eav = 0;

        if (!dev)
                return 0;

        if (dev->state & DEV_DISCONNECTED)
                return 0;

        if (urb->status < 0) {
                print_err_status(dev, -1, urb->status);
                if (urb->status == -ENOENT)
                        return 0;
        }

        /* get buffer pointer and length */
        p_buffer = urb->transfer_buffer;
        buffer_size = urb->actual_length;

        if (buffer_size > 0) {
                bytes_parsed = 0;

                if (dma_q->is_partial_line) {
                        /* Handle the case where we were working on a partial
                           line */
                        sav_eav = dma_q->last_sav;
                } else {
                        /* Check for a SAV/EAV overlapping the
                           buffer boundary */

                        sav_eav = cx231xx_find_boundary_SAV_EAV(p_buffer,
                                                          dma_q->partial_buf,
                                                          &bytes_parsed);
                }

                sav_eav &= 0xF0;
                /* Get the first line if we have some portion of an SAV/EAV from
                   the last buffer or a partial line */
                if (sav_eav) {
                        bytes_parsed += cx231xx_get_vbi_line(dev, dma_q,
                                sav_eav,                       /* SAV/EAV */
                                p_buffer + bytes_parsed,       /* p_buffer */
                                buffer_size - bytes_parsed);   /* buffer size */
                }

                /* Now parse data that is completely in this buffer */
                dma_q->is_partial_line = 0;

                while (bytes_parsed < buffer_size) {
                        u32 bytes_used = 0;

                        sav_eav = cx231xx_find_next_SAV_EAV(
                                p_buffer + bytes_parsed,        /* p_buffer */
                                buffer_size - bytes_parsed, /* buffer size */
                                &bytes_used);   /* bytes used to get SAV/EAV */

                        bytes_parsed += bytes_used;

                        sav_eav &= 0xF0;
                        if (sav_eav && (bytes_parsed < buffer_size)) {
                                bytes_parsed += cx231xx_get_vbi_line(dev,
                                        dma_q, sav_eav, /* SAV/EAV */
                                        p_buffer+bytes_parsed, /* p_buffer */
                                        buffer_size-bytes_parsed);/*buf size*/
                        }
                }

                /* Save the last four bytes of the buffer so we can
                check the buffer boundary condition next time */
                memcpy(dma_q->partial_buf, p_buffer + buffer_size - 4, 4);
                bytes_parsed = 0;
        }

        return rc;
}

/* ------------------------------------------------------------------
        Vbi buf operations
   ------------------------------------------------------------------*/

static int
vbi_buffer_setup(struct videobuf_queue *vq, unsigned int *count,
                 unsigned int *size)
{
        struct cx231xx_fh *fh = vq->priv_data;
        struct cx231xx *dev = fh->dev;
        u32 height = 0;

        height = ((dev->norm & V4L2_STD_625_50) ?
                  PAL_VBI_LINES : NTSC_VBI_LINES);

        *size = (dev->width * height * 2 * 2);
        if (0 == *count)
                *count = CX231XX_DEF_VBI_BUF;

        if (*count < CX231XX_MIN_BUF)
                *count = CX231XX_MIN_BUF;

        return 0;
}

/* This is called *without* dev->slock held; please keep it that way */
static void free_buffer(struct videobuf_queue *vq, struct cx231xx_buffer *buf)
{
        struct cx231xx_fh *fh = vq->priv_data;
        struct cx231xx *dev = fh->dev;
        unsigned long flags = 0;
        if (in_interrupt())
                BUG();

        /* We used to wait for the buffer to finish here, but this didn't work
           because, as we were keeping the state as VIDEOBUF_QUEUED,
           videobuf_queue_cancel marked it as finished for us.
           (Also, it could wedge forever if the hardware was misconfigured.)

           This should be safe; by the time we get here, the buffer isn't
           queued anymore. If we ever start marking the buffers as
           VIDEOBUF_ACTIVE, it won't be, though.
         */
        spin_lock_irqsave(&dev->vbi_mode.slock, flags);
        if (dev->vbi_mode.bulk_ctl.buf == buf)
                dev->vbi_mode.bulk_ctl.buf = NULL;
        spin_unlock_irqrestore(&dev->vbi_mode.slock, flags);

        videobuf_vmalloc_free(&buf->vb);
        buf->vb.state = VIDEOBUF_NEEDS_INIT;
}

static int
vbi_buffer_prepare(struct videobuf_queue *vq, struct videobuf_buffer *vb,
                   enum v4l2_field field)
{
        struct cx231xx_fh *fh = vq->priv_data;
        struct cx231xx_buffer *buf =
            container_of(vb, struct cx231xx_buffer, vb);
        struct cx231xx *dev = fh->dev;
        int rc = 0, urb_init = 0;
        u32 height = 0;

        height = ((dev->norm & V4L2_STD_625_50) ?
                  PAL_VBI_LINES : NTSC_VBI_LINES);
        buf->vb.size = ((dev->width << 1) * height * 2);

        if (0 != buf->vb.baddr && buf->vb.bsize < buf->vb.size)
                return -EINVAL;

        buf->vb.width = dev->width;
        buf->vb.height = height;
        buf->vb.field = field;
        buf->vb.field = V4L2_FIELD_SEQ_TB;

        if (VIDEOBUF_NEEDS_INIT == buf->vb.state) {
                rc = videobuf_iolock(vq, &buf->vb, NULL);
                if (rc < 0)
                        goto fail;
        }

        if (!dev->vbi_mode.bulk_ctl.num_bufs)
                urb_init = 1;

        if (urb_init) {
                rc = cx231xx_init_vbi_isoc(dev, CX231XX_NUM_VBI_PACKETS,
                                           CX231XX_NUM_VBI_BUFS,
                                           dev->vbi_mode.alt_max_pkt_size[0],
                                           cx231xx_isoc_vbi_copy);
                if (rc < 0)
                        goto fail;
        }

        buf->vb.state = VIDEOBUF_PREPARED;
        return 0;

fail:
        free_buffer(vq, buf);
        return rc;
}

static void
vbi_buffer_queue(struct videobuf_queue *vq, struct videobuf_buffer *vb)
{
        struct cx231xx_buffer *buf =
            container_of(vb, struct cx231xx_buffer, vb);
        struct cx231xx_fh *fh = vq->priv_data;
        struct cx231xx *dev = fh->dev;
        struct cx231xx_dmaqueue *vidq = &dev->vbi_mode.vidq;

        buf->vb.state = VIDEOBUF_QUEUED;
        list_add_tail(&buf->vb.queue, &vidq->active);

}

static void vbi_buffer_release(struct videobuf_queue *vq,
                               struct videobuf_buffer *vb)
{
        struct cx231xx_buffer *buf =
            container_of(vb, struct cx231xx_buffer, vb);


        free_buffer(vq, buf);
}

struct videobuf_queue_ops cx231xx_vbi_qops = {
        .buf_setup   = vbi_buffer_setup,
        .buf_prepare = vbi_buffer_prepare,
        .buf_queue   = vbi_buffer_queue,
        .buf_release = vbi_buffer_release,
};

/* ------------------------------------------------------------------
        URB control
   ------------------------------------------------------------------*/

/*
 * IRQ callback, called by URB callback
 */
static void cx231xx_irq_vbi_callback(struct urb *urb)
{
        struct cx231xx_dmaqueue *dma_q = urb->context;
        struct cx231xx_video_mode *vmode =
            container_of(dma_q, struct cx231xx_video_mode, vidq);
        struct cx231xx *dev = container_of(vmode, struct cx231xx, vbi_mode);

        switch (urb->status) {
        case 0:         /* success */
        case -ETIMEDOUT:        /* NAK */
                break;
        case -ECONNRESET:       /* kill */
        case -ENOENT:
        case -ESHUTDOWN:
                return;
        default:                /* error */
                cx231xx_err("urb completition error %d.\n",
                            urb->status);
                break;
        }

        /* Copy data from URB */
        spin_lock(&dev->vbi_mode.slock);
        dev->vbi_mode.bulk_ctl.bulk_copy(dev, urb);
        spin_unlock(&dev->vbi_mode.slock);

        /* Reset status */
        urb->status = 0;

        urb->status = usb_submit_urb(urb, GFP_ATOMIC);
        if (urb->status) {
                cx231xx_err("urb resubmit failed (error=%i)\n",
                            urb->status);
        }
}

/*
 * Stop and Deallocate URBs
 */
void cx231xx_uninit_vbi_isoc(struct cx231xx *dev)
{
        struct urb *urb;
        int i;

        cx231xx_info("called cx231xx_uninit_vbi_isoc\n");

        dev->vbi_mode.bulk_ctl.nfields = -1;
        for (i = 0; i < dev->vbi_mode.bulk_ctl.num_bufs; i++) {
                urb = dev->vbi_mode.bulk_ctl.urb[i];
                if (urb) {
                        if (!irqs_disabled())
                                usb_kill_urb(urb);
                        else
                                usb_unlink_urb(urb);

                        if (dev->vbi_mode.bulk_ctl.transfer_buffer[i]) {

                                kfree(dev->vbi_mode.bulk_ctl.
                                      transfer_buffer[i]);
                                dev->vbi_mode.bulk_ctl.transfer_buffer[i] =
                                    NULL;
                        }
                        usb_free_urb(urb);
                        dev->vbi_mode.bulk_ctl.urb[i] = NULL;
                }
                dev->vbi_mode.bulk_ctl.transfer_buffer[i] = NULL;
        }

        kfree(dev->vbi_mode.bulk_ctl.urb);
        kfree(dev->vbi_mode.bulk_ctl.transfer_buffer);

        dev->vbi_mode.bulk_ctl.urb = NULL;
        dev->vbi_mode.bulk_ctl.transfer_buffer = NULL;
        dev->vbi_mode.bulk_ctl.num_bufs = 0;

        cx231xx_capture_start(dev, 0, Vbi);
}
EXPORT_SYMBOL_GPL(cx231xx_uninit_vbi_isoc);

/*
 * Allocate URBs and start IRQ
 */
int cx231xx_init_vbi_isoc(struct cx231xx *dev, int max_packets,
                          int num_bufs, int max_pkt_size,
                          int (*bulk_copy) (struct cx231xx *dev,
                                            struct urb *urb))
{
        struct cx231xx_dmaqueue *dma_q = &dev->vbi_mode.vidq;
        int i;
        int sb_size, pipe;
        struct urb *urb;
        int rc;

        cx231xx_info("called cx231xx_vbi_isoc\n");

        /* De-allocates all pending stuff */
        cx231xx_uninit_vbi_isoc(dev);

        /* clear if any halt */
        usb_clear_halt(dev->udev,
                       usb_rcvbulkpipe(dev->udev,
                                       dev->vbi_mode.end_point_addr));

        dev->vbi_mode.bulk_ctl.bulk_copy = bulk_copy;
        dev->vbi_mode.bulk_ctl.num_bufs = num_bufs;
        dma_q->pos = 0;
        dma_q->is_partial_line = 0;
        dma_q->last_sav = 0;
        dma_q->current_field = -1;
        dma_q->bytes_left_in_line = dev->width << 1;
        dma_q->lines_per_field = ((dev->norm & V4L2_STD_625_50) ?
                                  PAL_VBI_LINES : NTSC_VBI_LINES);
        dma_q->lines_completed = 0;
        for (i = 0; i < 8; i++)
                dma_q->partial_buf[i] = 0;

        dev->vbi_mode.bulk_ctl.urb = kzalloc(sizeof(void *) * num_bufs,
                                             GFP_KERNEL);
        if (!dev->vbi_mode.bulk_ctl.urb) {
                cx231xx_errdev("cannot alloc memory for usb buffers\n");
                return -ENOMEM;
        }

        dev->vbi_mode.bulk_ctl.transfer_buffer =
            kzalloc(sizeof(void *) * num_bufs, GFP_KERNEL);
        if (!dev->vbi_mode.bulk_ctl.transfer_buffer) {
                cx231xx_errdev("cannot allocate memory for usbtransfer\n");
                kfree(dev->vbi_mode.bulk_ctl.urb);
                return -ENOMEM;
        }

        dev->vbi_mode.bulk_ctl.max_pkt_size = max_pkt_size;
        dev->vbi_mode.bulk_ctl.buf = NULL;

        sb_size = max_packets * dev->vbi_mode.bulk_ctl.max_pkt_size;

        /* allocate urbs and transfer buffers */
        for (i = 0; i < dev->vbi_mode.bulk_ctl.num_bufs; i++) {

                urb = usb_alloc_urb(0, GFP_KERNEL);
                if (!urb) {
                        cx231xx_err("cannot alloc bulk_ctl.urb %i\n", i);
                        cx231xx_uninit_vbi_isoc(dev);
                        return -ENOMEM;
                }
                dev->vbi_mode.bulk_ctl.urb[i] = urb;
                urb->transfer_flags = 0;

                dev->vbi_mode.bulk_ctl.transfer_buffer[i] =
                    kzalloc(sb_size, GFP_KERNEL);
                if (!dev->vbi_mode.bulk_ctl.transfer_buffer[i]) {
                        cx231xx_err("unable to allocate %i bytes for transfer"
                                    " buffer %i%s\n", sb_size, i,
                                    in_interrupt() ? " while in int" : "");
                        cx231xx_uninit_vbi_isoc(dev);
                        return -ENOMEM;
                }

                pipe = usb_rcvbulkpipe(dev->udev, dev->vbi_mode.end_point_addr);
                usb_fill_bulk_urb(urb, dev->udev, pipe,
                                  dev->vbi_mode.bulk_ctl.transfer_buffer[i],
                                  sb_size, cx231xx_irq_vbi_callback, dma_q);
        }

        init_waitqueue_head(&dma_q->wq);

        /* submit urbs and enables IRQ */
        for (i = 0; i < dev->vbi_mode.bulk_ctl.num_bufs; i++) {
                rc = usb_submit_urb(dev->vbi_mode.bulk_ctl.urb[i], GFP_ATOMIC);
                if (rc) {
                        cx231xx_err("submit of urb %i failed (error=%i)\n", i,
                                    rc);
                        cx231xx_uninit_vbi_isoc(dev);
                        return rc;
                }
        }

        cx231xx_capture_start(dev, 1, Vbi);

        return 0;
}
EXPORT_SYMBOL_GPL(cx231xx_init_vbi_isoc);

u32 cx231xx_get_vbi_line(struct cx231xx *dev, struct cx231xx_dmaqueue *dma_q,
                         u8 sav_eav, u8 *p_buffer, u32 buffer_size)
{
        u32 bytes_copied = 0;
        int current_field = -1;

        switch (sav_eav) {

        case SAV_VBI_FIELD1:
                current_field = 1;
                break;

        case SAV_VBI_FIELD2:
                current_field = 2;
                break;
        default:
                break;
        }

        if (current_field < 0)
                return bytes_copied;

        dma_q->last_sav = sav_eav;

        bytes_copied =
            cx231xx_copy_vbi_line(dev, dma_q, p_buffer, buffer_size,
                                  current_field);

        return bytes_copied;
}

/*
 * Announces that a buffer were filled and request the next
 */
static inline void vbi_buffer_filled(struct cx231xx *dev,
                                     struct cx231xx_dmaqueue *dma_q,
                                     struct cx231xx_buffer *buf)
{
        /* Advice that buffer was filled */
        /* cx231xx_info("[%p/%d] wakeup\n", buf, buf->vb.i); */

        buf->vb.state = VIDEOBUF_DONE;
        buf->vb.field_count++;
        v4l2_get_timestamp(&buf->vb.ts);

        dev->vbi_mode.bulk_ctl.buf = NULL;

        list_del(&buf->vb.queue);
        wake_up(&buf->vb.done);
}

u32 cx231xx_copy_vbi_line(struct cx231xx *dev, struct cx231xx_dmaqueue *dma_q,
                          u8 *p_line, u32 length, int field_number)
{
        u32 bytes_to_copy;
        struct cx231xx_buffer *buf;
        u32 _line_size = dev->width * 2;

        if (dma_q->current_field == -1) {
                /* Just starting up */
                cx231xx_reset_vbi_buffer(dev, dma_q);
        }

        if (dma_q->current_field != field_number)
                dma_q->lines_completed = 0;

        /* get the buffer pointer */
        buf = dev->vbi_mode.bulk_ctl.buf;

        /* Remember the field number for next time */
        dma_q->current_field = field_number;

        bytes_to_copy = dma_q->bytes_left_in_line;
        if (bytes_to_copy > length)
                bytes_to_copy = length;

        if (dma_q->lines_completed >= dma_q->lines_per_field) {
                dma_q->bytes_left_in_line -= bytes_to_copy;
                dma_q->is_partial_line =
                    (dma_q->bytes_left_in_line == 0) ? 0 : 1;
                return 0;
        }

        dma_q->is_partial_line = 1;

        /* If we don't have a buffer, just return the number of bytes we would
           have copied if we had a buffer. */
        if (!buf) {
                dma_q->bytes_left_in_line -= bytes_to_copy;
                dma_q->is_partial_line =
                    (dma_q->bytes_left_in_line == 0) ? 0 : 1;
                return bytes_to_copy;
        }

        /* copy the data to video buffer */
        cx231xx_do_vbi_copy(dev, dma_q, p_line, bytes_to_copy);

        dma_q->pos += bytes_to_copy;
        dma_q->bytes_left_in_line -= bytes_to_copy;

        if (dma_q->bytes_left_in_line == 0) {

                dma_q->bytes_left_in_line = _line_size;
                dma_q->lines_completed++;
                dma_q->is_partial_line = 0;

                if (cx231xx_is_vbi_buffer_done(dev, dma_q) && buf) {

                        vbi_buffer_filled(dev, dma_q, buf);

                        dma_q->pos = 0;
                        dma_q->lines_completed = 0;
                        cx231xx_reset_vbi_buffer(dev, dma_q);
                }
        }

        return bytes_to_copy;
}

/*
 * video-buf generic routine to get the next available buffer
 */
static inline void get_next_vbi_buf(struct cx231xx_dmaqueue *dma_q,
                                    struct cx231xx_buffer **buf)
{
        struct cx231xx_video_mode *vmode =
            container_of(dma_q, struct cx231xx_video_mode, vidq);
        struct cx231xx *dev = container_of(vmode, struct cx231xx, vbi_mode);
        char *outp;

        if (list_empty(&dma_q->active)) {
                cx231xx_err("No active queue to serve\n");
                dev->vbi_mode.bulk_ctl.buf = NULL;
                *buf = NULL;
                return;
        }

        /* Get the next buffer */
        *buf = list_entry(dma_q->active.next, struct cx231xx_buffer, vb.queue);

        /* Cleans up buffer - Useful for testing for frame/URB loss */
        outp = videobuf_to_vmalloc(&(*buf)->vb);
        memset(outp, 0, (*buf)->vb.size);

        dev->vbi_mode.bulk_ctl.buf = *buf;

        return;
}

void cx231xx_reset_vbi_buffer(struct cx231xx *dev,
                              struct cx231xx_dmaqueue *dma_q)
{
        struct cx231xx_buffer *buf;

        buf = dev->vbi_mode.bulk_ctl.buf;

        if (buf == NULL) {
                /* first try to get the buffer */
                get_next_vbi_buf(dma_q, &buf);

                dma_q->pos = 0;
                dma_q->current_field = -1;
        }

        dma_q->bytes_left_in_line = dev->width << 1;
        dma_q->lines_completed = 0;
}

int cx231xx_do_vbi_copy(struct cx231xx *dev, struct cx231xx_dmaqueue *dma_q,
                        u8 *p_buffer, u32 bytes_to_copy)
{
        u8 *p_out_buffer = NULL;
        u32 current_line_bytes_copied = 0;
        struct cx231xx_buffer *buf;
        u32 _line_size = dev->width << 1;
        void *startwrite;
        int offset, lencopy;

        buf = dev->vbi_mode.bulk_ctl.buf;

        if (buf == NULL)
                return -EINVAL;

        p_out_buffer = videobuf_to_vmalloc(&buf->vb);

        if (dma_q->bytes_left_in_line != _line_size) {
                current_line_bytes_copied =
                    _line_size - dma_q->bytes_left_in_line;
        }

        offset = (dma_q->lines_completed * _line_size) +
                 current_line_bytes_copied;

        if (dma_q->current_field == 2) {
                /* Populate the second half of the frame */
                offset += (dev->width * 2 * dma_q->lines_per_field);
        }

        /* prepare destination address */
        startwrite = p_out_buffer + offset;

        lencopy = dma_q->bytes_left_in_line > bytes_to_copy ?
                  bytes_to_copy : dma_q->bytes_left_in_line;

        memcpy(startwrite, p_buffer, lencopy);

        return 0;
}

u8 cx231xx_is_vbi_buffer_done(struct cx231xx *dev,
                              struct cx231xx_dmaqueue *dma_q)
{
        u32 height = 0;

        height = ((dev->norm & V4L2_STD_625_50) ?
                  PAL_VBI_LINES : NTSC_VBI_LINES);
        if (dma_q->lines_completed == height && dma_q->current_field == 2)
                return 1;
        else
                return 0;
}