/*
 * ispvideo.c
 *
 * TI OMAP3 ISP - Generic video node
 *
 * Copyright (C) 2009-2010 Nokia Corporation
 *
 * Contacts: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
 *           Sakari Ailus <sakari.ailus@iki.fi>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * 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., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 */

#include <asm/cacheflush.h>
#include <linux/clk.h>
#include <linux/mm.h>
#include <linux/pagemap.h>
#include <linux/scatterlist.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <media/v4l2-dev.h>
#include <media/v4l2-ioctl.h>
#include <plat/iommu.h>
#include <plat/iovmm.h>
#include <plat/omap-pm.h>

#include "ispvideo.h"
#include "isp.h"


/* -----------------------------------------------------------------------------
 * Helper functions
 */

static struct isp_format_info formats[] = {
        { V4L2_MBUS_FMT_Y8_1X8, V4L2_MBUS_FMT_Y8_1X8,
          V4L2_MBUS_FMT_Y8_1X8, V4L2_MBUS_FMT_Y8_1X8,
          V4L2_PIX_FMT_GREY, 8, },
        { V4L2_MBUS_FMT_Y10_1X10, V4L2_MBUS_FMT_Y10_1X10,
          V4L2_MBUS_FMT_Y10_1X10, V4L2_MBUS_FMT_Y8_1X8,
          V4L2_PIX_FMT_Y10, 10, },
        { V4L2_MBUS_FMT_Y12_1X12, V4L2_MBUS_FMT_Y10_1X10,
          V4L2_MBUS_FMT_Y12_1X12, V4L2_MBUS_FMT_Y8_1X8,
          V4L2_PIX_FMT_Y12, 12, },
        { V4L2_MBUS_FMT_SBGGR8_1X8, V4L2_MBUS_FMT_SBGGR8_1X8,
          V4L2_MBUS_FMT_SBGGR8_1X8, V4L2_MBUS_FMT_SBGGR8_1X8,
          V4L2_PIX_FMT_SBGGR8, 8, },
        { V4L2_MBUS_FMT_SGBRG8_1X8, V4L2_MBUS_FMT_SGBRG8_1X8,
          V4L2_MBUS_FMT_SGBRG8_1X8, V4L2_MBUS_FMT_SGBRG8_1X8,
          V4L2_PIX_FMT_SGBRG8, 8, },
        { V4L2_MBUS_FMT_SGRBG8_1X8, V4L2_MBUS_FMT_SGRBG8_1X8,
          V4L2_MBUS_FMT_SGRBG8_1X8, V4L2_MBUS_FMT_SGRBG8_1X8,
          V4L2_PIX_FMT_SGRBG8, 8, },
        { V4L2_MBUS_FMT_SRGGB8_1X8, V4L2_MBUS_FMT_SRGGB8_1X8,
          V4L2_MBUS_FMT_SRGGB8_1X8, V4L2_MBUS_FMT_SRGGB8_1X8,
          V4L2_PIX_FMT_SRGGB8, 8, },
        { V4L2_MBUS_FMT_SGRBG10_DPCM8_1X8, V4L2_MBUS_FMT_SGRBG10_DPCM8_1X8,
          V4L2_MBUS_FMT_SGRBG10_1X10, 0,
          V4L2_PIX_FMT_SGRBG10DPCM8, 8, },
        { V4L2_MBUS_FMT_SBGGR10_1X10, V4L2_MBUS_FMT_SBGGR10_1X10,
          V4L2_MBUS_FMT_SBGGR10_1X10, V4L2_MBUS_FMT_SBGGR8_1X8,
          V4L2_PIX_FMT_SBGGR10, 10, },
        { V4L2_MBUS_FMT_SGBRG10_1X10, V4L2_MBUS_FMT_SGBRG10_1X10,
          V4L2_MBUS_FMT_SGBRG10_1X10, V4L2_MBUS_FMT_SGBRG8_1X8,
          V4L2_PIX_FMT_SGBRG10, 10, },
        { V4L2_MBUS_FMT_SGRBG10_1X10, V4L2_MBUS_FMT_SGRBG10_1X10,
          V4L2_MBUS_FMT_SGRBG10_1X10, V4L2_MBUS_FMT_SGRBG8_1X8,
          V4L2_PIX_FMT_SGRBG10, 10, },
        { V4L2_MBUS_FMT_SRGGB10_1X10, V4L2_MBUS_FMT_SRGGB10_1X10,
          V4L2_MBUS_FMT_SRGGB10_1X10, V4L2_MBUS_FMT_SRGGB8_1X8,
          V4L2_PIX_FMT_SRGGB10, 10, },
        { V4L2_MBUS_FMT_SBGGR12_1X12, V4L2_MBUS_FMT_SBGGR10_1X10,
          V4L2_MBUS_FMT_SBGGR12_1X12, V4L2_MBUS_FMT_SBGGR8_1X8,
          V4L2_PIX_FMT_SBGGR12, 12, },
        { V4L2_MBUS_FMT_SGBRG12_1X12, V4L2_MBUS_FMT_SGBRG10_1X10,
          V4L2_MBUS_FMT_SGBRG12_1X12, V4L2_MBUS_FMT_SGBRG8_1X8,
          V4L2_PIX_FMT_SGBRG12, 12, },
        { V4L2_MBUS_FMT_SGRBG12_1X12, V4L2_MBUS_FMT_SGRBG10_1X10,
          V4L2_MBUS_FMT_SGRBG12_1X12, V4L2_MBUS_FMT_SGRBG8_1X8,
          V4L2_PIX_FMT_SGRBG12, 12, },
        { V4L2_MBUS_FMT_SRGGB12_1X12, V4L2_MBUS_FMT_SRGGB10_1X10,
          V4L2_MBUS_FMT_SRGGB12_1X12, V4L2_MBUS_FMT_SRGGB8_1X8,
          V4L2_PIX_FMT_SRGGB12, 12, },
        { V4L2_MBUS_FMT_UYVY8_1X16, V4L2_MBUS_FMT_UYVY8_1X16,
          V4L2_MBUS_FMT_UYVY8_1X16, 0,
          V4L2_PIX_FMT_UYVY, 16, },
        { V4L2_MBUS_FMT_YUYV8_1X16, V4L2_MBUS_FMT_YUYV8_1X16,
          V4L2_MBUS_FMT_YUYV8_1X16, 0,
          V4L2_PIX_FMT_YUYV, 16, },
};

const struct isp_format_info *
omap3isp_video_format_info(enum v4l2_mbus_pixelcode code)
{
        unsigned int i;

        for (i = 0; i < ARRAY_SIZE(formats); ++i) {
                if (formats[i].code == code)
                        return &formats[i];
        }

        return NULL;
}

/*
 * Decide whether desired output pixel code can be obtained with
 * the lane shifter by shifting the input pixel code.
 * @in: input pixelcode to shifter
 * @out: output pixelcode from shifter
 * @additional_shift: # of bits the sensor's LSB is offset from CAMEXT[0]
 *
 * return true if the combination is possible
 * return false otherwise
 */
static bool isp_video_is_shiftable(enum v4l2_mbus_pixelcode in,
                enum v4l2_mbus_pixelcode out,
                unsigned int additional_shift)
{
        const struct isp_format_info *in_info, *out_info;

        if (in == out)
                return true;

        in_info = omap3isp_video_format_info(in);
        out_info = omap3isp_video_format_info(out);

        if ((in_info->flavor == 0) || (out_info->flavor == 0))
                return false;

        if (in_info->flavor != out_info->flavor)
                return false;

        return in_info->bpp - out_info->bpp + additional_shift <= 6;
}

/*
 * isp_video_mbus_to_pix - Convert v4l2_mbus_framefmt to v4l2_pix_format
 * @video: ISP video instance
 * @mbus: v4l2_mbus_framefmt format (input)
 * @pix: v4l2_pix_format format (output)
 *
 * Fill the output pix structure with information from the input mbus format.
 * The bytesperline and sizeimage fields are computed from the requested bytes
 * per line value in the pix format and information from the video instance.
 *
 * Return the number of padding bytes at end of line.
 */
static unsigned int isp_video_mbus_to_pix(const struct isp_video *video,
                                          const struct v4l2_mbus_framefmt *mbus,
                                          struct v4l2_pix_format *pix)
{
        unsigned int bpl = pix->bytesperline;
        unsigned int min_bpl;
        unsigned int i;

        memset(pix, 0, sizeof(*pix));
        pix->width = mbus->width;
        pix->height = mbus->height;

        for (i = 0; i < ARRAY_SIZE(formats); ++i) {
                if (formats[i].code == mbus->code)
                        break;
        }

        if (WARN_ON(i == ARRAY_SIZE(formats)))
                return 0;

        min_bpl = pix->width * ALIGN(formats[i].bpp, 8) / 8;

        /* Clamp the requested bytes per line value. If the maximum bytes per
         * line value is zero, the module doesn't support user configurable line
         * sizes. Override the requested value with the minimum in that case.
         */
        if (video->bpl_max)
                bpl = clamp(bpl, min_bpl, video->bpl_max);
        else
                bpl = min_bpl;

        if (!video->bpl_zero_padding || bpl != min_bpl)
                bpl = ALIGN(bpl, video->bpl_alignment);

        pix->pixelformat = formats[i].pixelformat;
        pix->bytesperline = bpl;
        pix->sizeimage = pix->bytesperline * pix->height;
        pix->colorspace = mbus->colorspace;
        pix->field = mbus->field;

        return bpl - min_bpl;
}

static void isp_video_pix_to_mbus(const struct v4l2_pix_format *pix,
                                  struct v4l2_mbus_framefmt *mbus)
{
        unsigned int i;

        memset(mbus, 0, sizeof(*mbus));
        mbus->width = pix->width;
        mbus->height = pix->height;

        for (i = 0; i < ARRAY_SIZE(formats); ++i) {
                if (formats[i].pixelformat == pix->pixelformat)
                        break;
        }

        if (WARN_ON(i == ARRAY_SIZE(formats)))
                return;

        mbus->code = formats[i].code;
        mbus->colorspace = pix->colorspace;
        mbus->field = pix->field;
}

static struct v4l2_subdev *
isp_video_remote_subdev(struct isp_video *video, u32 *pad)
{
        struct media_pad *remote;

        remote = media_entity_remote_source(&video->pad);

        if (remote == NULL ||
            media_entity_type(remote->entity) != MEDIA_ENT_T_V4L2_SUBDEV)
                return NULL;

        if (pad)
                *pad = remote->index;

        return media_entity_to_v4l2_subdev(remote->entity);
}

/* Return a pointer to the ISP video instance at the far end of the pipeline. */
static struct isp_video *
isp_video_far_end(struct isp_video *video)
{
        struct media_entity_graph graph;
        struct media_entity *entity = &video->video.entity;
        struct media_device *mdev = entity->parent;
        struct isp_video *far_end = NULL;

        mutex_lock(&mdev->graph_mutex);
        media_entity_graph_walk_start(&graph, entity);

        while ((entity = media_entity_graph_walk_next(&graph))) {
                if (entity == &video->video.entity)
                        continue;

                if (media_entity_type(entity) != MEDIA_ENT_T_DEVNODE)
                        continue;

                far_end = to_isp_video(media_entity_to_video_device(entity));
                if (far_end->type != video->type)
                        break;

                far_end = NULL;
        }

        mutex_unlock(&mdev->graph_mutex);
        return far_end;
}

/*
 * Validate a pipeline by checking both ends of all links for format
 * discrepancies.
 *
 * Compute the minimum time per frame value as the maximum of time per frame
 * limits reported by every block in the pipeline.
 *
 * Return 0 if all formats match, or -EPIPE if at least one link is found with
 * different formats on its two ends.
 */
static int isp_video_validate_pipeline(struct isp_pipeline *pipe)
{
        struct isp_device *isp = pipe->output->isp;
        struct v4l2_subdev_format fmt_source;
        struct v4l2_subdev_format fmt_sink;
        struct media_pad *pad;
        struct v4l2_subdev *subdev;
        int ret;

        pipe->max_rate = pipe->l3_ick;

        subdev = isp_video_remote_subdev(pipe->output, NULL);
        if (subdev == NULL)
                return -EPIPE;

        while (1) {
                unsigned int shifter_link;
                /* Retrieve the sink format */
                pad = &subdev->entity.pads[0];
                if (!(pad->flags & MEDIA_PAD_FL_SINK))
                        break;

                fmt_sink.pad = pad->index;
                fmt_sink.which = V4L2_SUBDEV_FORMAT_ACTIVE;
                ret = v4l2_subdev_call(subdev, pad, get_fmt, NULL, &fmt_sink);
                if (ret < 0 && ret != -ENOIOCTLCMD)
                        return -EPIPE;

                /* Update the maximum frame rate */
                if (subdev == &isp->isp_res.subdev)
                        omap3isp_resizer_max_rate(&isp->isp_res,
                                                  &pipe->max_rate);

                /* Check ccdc maximum data rate when data comes from sensor
                 * TODO: Include ccdc rate in pipe->max_rate and compare the
                 *       total pipe rate with the input data rate from sensor.
                 */
                if (subdev == &isp->isp_ccdc.subdev && pipe->input == NULL) {
                        unsigned int rate = UINT_MAX;

                        omap3isp_ccdc_max_rate(&isp->isp_ccdc, &rate);
                        if (isp->isp_ccdc.vpcfg.pixelclk > rate)
                                return -ENOSPC;
                }

                /* If sink pad is on CCDC, the link has the lane shifter
                 * in the middle of it. */
                shifter_link = subdev == &isp->isp_ccdc.subdev;

                /* Retrieve the source format */
                pad = media_entity_remote_source(pad);
                if (pad == NULL ||
                    media_entity_type(pad->entity) != MEDIA_ENT_T_V4L2_SUBDEV)
                        break;

                subdev = media_entity_to_v4l2_subdev(pad->entity);

                fmt_source.pad = pad->index;
                fmt_source.which = V4L2_SUBDEV_FORMAT_ACTIVE;
                ret = v4l2_subdev_call(subdev, pad, get_fmt, NULL, &fmt_source);
                if (ret < 0 && ret != -ENOIOCTLCMD)
                        return -EPIPE;

                /* Check if the two ends match */
                if (fmt_source.format.width != fmt_sink.format.width ||
                    fmt_source.format.height != fmt_sink.format.height)
                        return -EPIPE;

                if (shifter_link) {
                        unsigned int parallel_shift = 0;
                        if (isp->isp_ccdc.input == CCDC_INPUT_PARALLEL) {
                                struct isp_parallel_platform_data *pdata =
                                        &((struct isp_v4l2_subdevs_group *)
                                              subdev->host_priv)->bus.parallel;
                                parallel_shift = pdata->data_lane_shift * 2;
                        }
                        if (!isp_video_is_shiftable(fmt_source.format.code,
                                                fmt_sink.format.code,
                                                parallel_shift))
                                return -EPIPE;
                } else if (fmt_source.format.code != fmt_sink.format.code)
                        return -EPIPE;
        }

        return 0;
}

static int
__isp_video_get_format(struct isp_video *video, struct v4l2_format *format)
{
        struct v4l2_subdev_format fmt;
        struct v4l2_subdev *subdev;
        u32 pad;
        int ret;

        subdev = isp_video_remote_subdev(video, &pad);
        if (subdev == NULL)
                return -EINVAL;

        mutex_lock(&video->mutex);

        fmt.pad = pad;
        fmt.which = V4L2_SUBDEV_FORMAT_ACTIVE;
        ret = v4l2_subdev_call(subdev, pad, get_fmt, NULL, &fmt);
        if (ret == -ENOIOCTLCMD)
                ret = -EINVAL;

        mutex_unlock(&video->mutex);

        if (ret)
                return ret;

        format->type = video->type;
        return isp_video_mbus_to_pix(video, &fmt.format, &format->fmt.pix);
}

static int
isp_video_check_format(struct isp_video *video, struct isp_video_fh *vfh)
{
        struct v4l2_format format;
        int ret;

        memcpy(&format, &vfh->format, sizeof(format));
        ret = __isp_video_get_format(video, &format);
        if (ret < 0)
                return ret;

        if (vfh->format.fmt.pix.pixelformat != format.fmt.pix.pixelformat ||
            vfh->format.fmt.pix.height != format.fmt.pix.height ||
            vfh->format.fmt.pix.width != format.fmt.pix.width ||
            vfh->format.fmt.pix.bytesperline != format.fmt.pix.bytesperline ||
            vfh->format.fmt.pix.sizeimage != format.fmt.pix.sizeimage)
                return -EINVAL;

        return ret;
}

/* -----------------------------------------------------------------------------
 * IOMMU management
 */

#define IOMMU_FLAG      (IOVMF_ENDIAN_LITTLE | IOVMF_ELSZ_8)

/*
 * ispmmu_vmap - Wrapper for Virtual memory mapping of a scatter gather list
 * @dev: Device pointer specific to the OMAP3 ISP.
 * @sglist: Pointer to source Scatter gather list to allocate.
 * @sglen: Number of elements of the scatter-gatter list.
 *
 * Returns a resulting mapped device address by the ISP MMU, or -ENOMEM if
 * we ran out of memory.
 */
static dma_addr_t
ispmmu_vmap(struct isp_device *isp, const struct scatterlist *sglist, int sglen)
{
        struct sg_table *sgt;
        u32 da;

        sgt = kmalloc(sizeof(*sgt), GFP_KERNEL);
        if (sgt == NULL)
                return -ENOMEM;

        sgt->sgl = (struct scatterlist *)sglist;
        sgt->nents = sglen;
        sgt->orig_nents = sglen;

        da = iommu_vmap(isp->iommu, 0, sgt, IOMMU_FLAG);
        if (IS_ERR_VALUE(da))
                kfree(sgt);

        return da;
}

/*
 * ispmmu_vunmap - Unmap a device address from the ISP MMU
 * @dev: Device pointer specific to the OMAP3 ISP.
 * @da: Device address generated from a ispmmu_vmap call.
 */
static void ispmmu_vunmap(struct isp_device *isp, dma_addr_t da)
{
        struct sg_table *sgt;

        sgt = iommu_vunmap(isp->iommu, (u32)da);
        kfree(sgt);
}

/* -----------------------------------------------------------------------------
 * Video queue operations
 */

static void isp_video_queue_prepare(struct isp_video_queue *queue,
                                    unsigned int *nbuffers, unsigned int *size)
{
        struct isp_video_fh *vfh =
                container_of(queue, struct isp_video_fh, queue);
        struct isp_video *video = vfh->video;

        *size = vfh->format.fmt.pix.sizeimage;
        if (*size == 0)
                return;

        *nbuffers = min(*nbuffers, video->capture_mem / PAGE_ALIGN(*size));
}

static void isp_video_buffer_cleanup(struct isp_video_buffer *buf)
{
        struct isp_video_fh *vfh = isp_video_queue_to_isp_video_fh(buf->queue);
        struct isp_buffer *buffer = to_isp_buffer(buf);
        struct isp_video *video = vfh->video;

        if (buffer->isp_addr) {
                ispmmu_vunmap(video->isp, buffer->isp_addr);
                buffer->isp_addr = 0;
        }
}

static int isp_video_buffer_prepare(struct isp_video_buffer *buf)
{
        struct isp_video_fh *vfh = isp_video_queue_to_isp_video_fh(buf->queue);
        struct isp_buffer *buffer = to_isp_buffer(buf);
        struct isp_video *video = vfh->video;
        unsigned long addr;

        addr = ispmmu_vmap(video->isp, buf->sglist, buf->sglen);
        if (IS_ERR_VALUE(addr))
                return -EIO;

        if (!IS_ALIGNED(addr, 32)) {
                dev_dbg(video->isp->dev, "Buffer address must be "
                        "aligned to 32 bytes boundary.\n");
                ispmmu_vunmap(video->isp, buffer->isp_addr);
                return -EINVAL;
        }

        buf->vbuf.bytesused = vfh->format.fmt.pix.sizeimage;
        buffer->isp_addr = addr;
        return 0;
}

/*
 * isp_video_buffer_queue - Add buffer to streaming queue
 * @buf: Video buffer
 *
 * In memory-to-memory mode, start streaming on the pipeline if buffers are
 * queued on both the input and the output, if the pipeline isn't already busy.
 * If the pipeline is busy, it will be restarted in the output module interrupt
 * handler.
 */
static void isp_video_buffer_queue(struct isp_video_buffer *buf)
{
        struct isp_video_fh *vfh = isp_video_queue_to_isp_video_fh(buf->queue);
        struct isp_buffer *buffer = to_isp_buffer(buf);
        struct isp_video *video = vfh->video;
        struct isp_pipeline *pipe = to_isp_pipeline(&video->video.entity);
        enum isp_pipeline_state state;
        unsigned long flags;
        unsigned int empty;
        unsigned int start;

        empty = list_empty(&video->dmaqueue);
        list_add_tail(&buffer->buffer.irqlist, &video->dmaqueue);

        if (empty) {
                if (video->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
                        state = ISP_PIPELINE_QUEUE_OUTPUT;
                else
                        state = ISP_PIPELINE_QUEUE_INPUT;

                spin_lock_irqsave(&pipe->lock, flags);
                pipe->state |= state;
                video->ops->queue(video, buffer);
                video->dmaqueue_flags |= ISP_VIDEO_DMAQUEUE_QUEUED;

                start = isp_pipeline_ready(pipe);
                if (start)
                        pipe->state |= ISP_PIPELINE_STREAM;
                spin_unlock_irqrestore(&pipe->lock, flags);

                if (start)
                        omap3isp_pipeline_set_stream(pipe,
                                                ISP_PIPELINE_STREAM_SINGLESHOT);
        }
}

static const struct isp_video_queue_operations isp_video_queue_ops = {
        .queue_prepare = &isp_video_queue_prepare,
        .buffer_prepare = &isp_video_buffer_prepare,
        .buffer_queue = &isp_video_buffer_queue,
        .buffer_cleanup = &isp_video_buffer_cleanup,
};

/*
 * omap3isp_video_buffer_next - Complete the current buffer and return the next
 * @video: ISP video object
 * @error: Whether an error occurred during capture
 *
 * Remove the current video buffer from the DMA queue and fill its timestamp,
 * field count and state fields before waking up its completion handler.
 *
 * The buffer state is set to VIDEOBUF_DONE if no error occurred (@error is 0)
 * or VIDEOBUF_ERROR otherwise (@error is non-zero).
 *
 * The DMA queue is expected to contain at least one buffer.
 *
 * Return a pointer to the next buffer in the DMA queue, or NULL if the queue is
 * empty.
 */
struct isp_buffer *omap3isp_video_buffer_next(struct isp_video *video,
                                              unsigned int error)
{
        struct isp_pipeline *pipe = to_isp_pipeline(&video->video.entity);
        struct isp_video_queue *queue = video->queue;
        enum isp_pipeline_state state;
        struct isp_video_buffer *buf;
        unsigned long flags;
        struct timespec ts;

        spin_lock_irqsave(&queue->irqlock, flags);
        if (WARN_ON(list_empty(&video->dmaqueue))) {
                spin_unlock_irqrestore(&queue->irqlock, flags);
                return NULL;
        }

        buf = list_first_entry(&video->dmaqueue, struct isp_video_buffer,
                               irqlist);
        list_del(&buf->irqlist);
        spin_unlock_irqrestore(&queue->irqlock, flags);

        ktime_get_ts(&ts);
        buf->vbuf.timestamp.tv_sec = ts.tv_sec;
        buf->vbuf.timestamp.tv_usec = ts.tv_nsec / NSEC_PER_USEC;

        /* Do frame number propagation only if this is the output video node.
         * Frame number either comes from the CSI receivers or it gets
         * incremented here if H3A is not active.
         * Note: There is no guarantee that the output buffer will finish
         * first, so the input number might lag behind by 1 in some cases.
         */
        if (video == pipe->output && !pipe->do_propagation)
                buf->vbuf.sequence = atomic_inc_return(&pipe->frame_number);
        else
                buf->vbuf.sequence = atomic_read(&pipe->frame_number);

        buf->state = error ? ISP_BUF_STATE_ERROR : ISP_BUF_STATE_DONE;

        wake_up(&buf->wait);

        if (list_empty(&video->dmaqueue)) {
                if (queue->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
                        state = ISP_PIPELINE_QUEUE_OUTPUT
                              | ISP_PIPELINE_STREAM;
                else
                        state = ISP_PIPELINE_QUEUE_INPUT
                              | ISP_PIPELINE_STREAM;

                spin_lock_irqsave(&pipe->lock, flags);
                pipe->state &= ~state;
                if (video->pipe.stream_state == ISP_PIPELINE_STREAM_CONTINUOUS)
                        video->dmaqueue_flags |= ISP_VIDEO_DMAQUEUE_UNDERRUN;
                spin_unlock_irqrestore(&pipe->lock, flags);
                return NULL;
        }

        if (queue->type == V4L2_BUF_TYPE_VIDEO_CAPTURE && pipe->input != NULL) {
                spin_lock_irqsave(&pipe->lock, flags);
                pipe->state &= ~ISP_PIPELINE_STREAM;
                spin_unlock_irqrestore(&pipe->lock, flags);
        }

        buf = list_first_entry(&video->dmaqueue, struct isp_video_buffer,
                               irqlist);
        buf->state = ISP_BUF_STATE_ACTIVE;
        return to_isp_buffer(buf);
}

/*
 * omap3isp_video_resume - Perform resume operation on the buffers
 * @video: ISP video object
 * @continuous: Pipeline is in single shot mode if 0 or continuous mode otherwise
 *
 * This function is intended to be used on suspend/resume scenario. It
 * requests video queue layer to discard buffers marked as DONE if it's in
 * continuous mode and requests ISP modules to queue again the ACTIVE buffer
 * if there's any.
 */
void omap3isp_video_resume(struct isp_video *video, int continuous)
{
        struct isp_buffer *buf = NULL;

        if (continuous && video->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
                omap3isp_video_queue_discard_done(video->queue);

        if (!list_empty(&video->dmaqueue)) {
                buf = list_first_entry(&video->dmaqueue,
                                       struct isp_buffer, buffer.irqlist);
                video->ops->queue(video, buf);
                video->dmaqueue_flags |= ISP_VIDEO_DMAQUEUE_QUEUED;
        } else {
                if (continuous)
                        video->dmaqueue_flags |= ISP_VIDEO_DMAQUEUE_UNDERRUN;
        }
}

/* -----------------------------------------------------------------------------
 * V4L2 ioctls
 */

static int
isp_video_querycap(struct file *file, void *fh, struct v4l2_capability *cap)
{
        struct isp_video *video = video_drvdata(file);

        strlcpy(cap->driver, ISP_VIDEO_DRIVER_NAME, sizeof(cap->driver));
        strlcpy(cap->card, video->video.name, sizeof(cap->card));
        strlcpy(cap->bus_info, "media", sizeof(cap->bus_info));

        if (video->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
                cap->capabilities = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING;
        else
                cap->capabilities = V4L2_CAP_VIDEO_OUTPUT | V4L2_CAP_STREAMING;

        return 0;
}

static int
isp_video_get_format(struct file *file, void *fh, struct v4l2_format *format)
{
        struct isp_video_fh *vfh = to_isp_video_fh(fh);
        struct isp_video *video = video_drvdata(file);

        if (format->type != video->type)
                return -EINVAL;

        mutex_lock(&video->mutex);
        *format = vfh->format;
        mutex_unlock(&video->mutex);

        return 0;
}

static int
isp_video_set_format(struct file *file, void *fh, struct v4l2_format *format)
{
        struct isp_video_fh *vfh = to_isp_video_fh(fh);
        struct isp_video *video = video_drvdata(file);
        struct v4l2_mbus_framefmt fmt;

        if (format->type != video->type)
                return -EINVAL;

        mutex_lock(&video->mutex);

        /* Fill the bytesperline and sizeimage fields by converting to media bus
         * format and back to pixel format.
         */
        isp_video_pix_to_mbus(&format->fmt.pix, &fmt);
        isp_video_mbus_to_pix(video, &fmt, &format->fmt.pix);

        vfh->format = *format;

        mutex_unlock(&video->mutex);
        return 0;
}

static int
isp_video_try_format(struct file *file, void *fh, struct v4l2_format *format)
{
        struct isp_video *video = video_drvdata(file);
        struct v4l2_subdev_format fmt;
        struct v4l2_subdev *subdev;
        u32 pad;
        int ret;

        if (format->type != video->type)
                return -EINVAL;

        subdev = isp_video_remote_subdev(video, &pad);
        if (subdev == NULL)
                return -EINVAL;

        isp_video_pix_to_mbus(&format->fmt.pix, &fmt.format);

        fmt.pad = pad;
        fmt.which = V4L2_SUBDEV_FORMAT_ACTIVE;
        ret = v4l2_subdev_call(subdev, pad, get_fmt, NULL, &fmt);
        if (ret)
                return ret == -ENOIOCTLCMD ? -EINVAL : ret;

        isp_video_mbus_to_pix(video, &fmt.format, &format->fmt.pix);
        return 0;
}

static int
isp_video_cropcap(struct file *file, void *fh, struct v4l2_cropcap *cropcap)
{
        struct isp_video *video = video_drvdata(file);
        struct v4l2_subdev *subdev;
        int ret;

        subdev = isp_video_remote_subdev(video, NULL);
        if (subdev == NULL)
                return -EINVAL;

        mutex_lock(&video->mutex);
        ret = v4l2_subdev_call(subdev, video, cropcap, cropcap);
        mutex_unlock(&video->mutex);

        return ret == -ENOIOCTLCMD ? -EINVAL : ret;
}

static int
isp_video_get_crop(struct file *file, void *fh, struct v4l2_crop *crop)
{
        struct isp_video *video = video_drvdata(file);
        struct v4l2_subdev_format format;
        struct v4l2_subdev *subdev;
        u32 pad;
        int ret;

        subdev = isp_video_remote_subdev(video, &pad);
        if (subdev == NULL)
                return -EINVAL;

        /* Try the get crop operation first and fallback to get format if not
         * implemented.
         */
        ret = v4l2_subdev_call(subdev, video, g_crop, crop);
        if (ret != -ENOIOCTLCMD)
                return ret;

        format.pad = pad;
        format.which = V4L2_SUBDEV_FORMAT_ACTIVE;
        ret = v4l2_subdev_call(subdev, pad, get_fmt, NULL, &format);
        if (ret < 0)
                return ret == -ENOIOCTLCMD ? -EINVAL : ret;

        crop->c.left = 0;
        crop->c.top = 0;
        crop->c.width = format.format.width;
        crop->c.height = format.format.height;

        return 0;
}

static int
isp_video_set_crop(struct file *file, void *fh, struct v4l2_crop *crop)
{
        struct isp_video *video = video_drvdata(file);
        struct v4l2_subdev *subdev;
        int ret;

        subdev = isp_video_remote_subdev(video, NULL);
        if (subdev == NULL)
                return -EINVAL;

        mutex_lock(&video->mutex);
        ret = v4l2_subdev_call(subdev, video, s_crop, crop);
        mutex_unlock(&video->mutex);

        return ret == -ENOIOCTLCMD ? -EINVAL : ret;
}

static int
isp_video_get_param(struct file *file, void *fh, struct v4l2_streamparm *a)
{
        struct isp_video_fh *vfh = to_isp_video_fh(fh);
        struct isp_video *video = video_drvdata(file);

        if (video->type != V4L2_BUF_TYPE_VIDEO_OUTPUT ||
            video->type != a->type)
                return -EINVAL;

        memset(a, 0, sizeof(*a));
        a->type = V4L2_BUF_TYPE_VIDEO_OUTPUT;
        a->parm.output.capability = V4L2_CAP_TIMEPERFRAME;
        a->parm.output.timeperframe = vfh->timeperframe;

        return 0;
}

static int
isp_video_set_param(struct file *file, void *fh, struct v4l2_streamparm *a)
{
        struct isp_video_fh *vfh = to_isp_video_fh(fh);
        struct isp_video *video = video_drvdata(file);

        if (video->type != V4L2_BUF_TYPE_VIDEO_OUTPUT ||
            video->type != a->type)
                return -EINVAL;

        if (a->parm.output.timeperframe.denominator == 0)
                a->parm.output.timeperframe.denominator = 1;

        vfh->timeperframe = a->parm.output.timeperframe;

        return 0;
}

static int
isp_video_reqbufs(struct file *file, void *fh, struct v4l2_requestbuffers *rb)
{
        struct isp_video_fh *vfh = to_isp_video_fh(fh);

        return omap3isp_video_queue_reqbufs(&vfh->queue, rb);
}

static int
isp_video_querybuf(struct file *file, void *fh, struct v4l2_buffer *b)
{
        struct isp_video_fh *vfh = to_isp_video_fh(fh);

        return omap3isp_video_queue_querybuf(&vfh->queue, b);
}

static int
isp_video_qbuf(struct file *file, void *fh, struct v4l2_buffer *b)
{
        struct isp_video_fh *vfh = to_isp_video_fh(fh);

        return omap3isp_video_queue_qbuf(&vfh->queue, b);
}

static int
isp_video_dqbuf(struct file *file, void *fh, struct v4l2_buffer *b)
{
        struct isp_video_fh *vfh = to_isp_video_fh(fh);

        return omap3isp_video_queue_dqbuf(&vfh->queue, b,
                                          file->f_flags & O_NONBLOCK);
}

/*
 * Stream management
 *
 * Every ISP pipeline has a single input and a single output. The input can be
 * either a sensor or a video node. The output is always a video node.
 *
 * As every pipeline has an output video node, the ISP video objects at the
 * pipeline output stores the pipeline state. It tracks the streaming state of
 * both the input and output, as well as the availability of buffers.
 *
 * In sensor-to-memory mode, frames are always available at the pipeline input.
 * Starting the sensor usually requires I2C transfers and must be done in
 * interruptible context. The pipeline is started and stopped synchronously
 * to the stream on/off commands. All modules in the pipeline will get their
 * subdev set stream handler called. The module at the end of the pipeline must
 * delay starting the hardware until buffers are available at its output.
 *
 * In memory-to-memory mode, starting/stopping the stream requires
 * synchronization between the input and output. ISP modules can't be stopped
 * in the middle of a frame, and at least some of the modules seem to become
 * busy as soon as they're started, even if they don't receive a frame start
 * event. For that reason frames need to be processed in single-shot mode. The
 * driver needs to wait until a frame is completely processed and written to
 * memory before restarting the pipeline for the next frame. Pipelined
 * processing might be possible but requires more testing.
 *
 * Stream start must be delayed until buffers are available at both the input
 * and output. The pipeline must be started in the videobuf queue callback with
 * the buffers queue spinlock held. The modules subdev set stream operation must
 * not sleep.
 */
static int
isp_video_streamon(struct file *file, void *fh, enum v4l2_buf_type type)
{
        struct isp_video_fh *vfh = to_isp_video_fh(fh);
        struct isp_video *video = video_drvdata(file);
        enum isp_pipeline_state state;
        struct isp_pipeline *pipe;
        struct isp_video *far_end;
        unsigned long flags;
        int ret;

        if (type != video->type)
                return -EINVAL;

        mutex_lock(&video->stream_lock);

        if (video->streaming) {
                mutex_unlock(&video->stream_lock);
                return -EBUSY;
        }

        /* Start streaming on the pipeline. No link touching an entity in the
         * pipeline can be activated or deactivated once streaming is started.
         */
        pipe = video->video.entity.pipe
             ? to_isp_pipeline(&video->video.entity) : &video->pipe;
        media_entity_pipeline_start(&video->video.entity, &pipe->pipe);

        /* Verify that the currently configured format matches the output of
         * the connected subdev.
         */
        ret = isp_video_check_format(video, vfh);
        if (ret < 0)
                goto error;

        video->bpl_padding = ret;
        video->bpl_value = vfh->format.fmt.pix.bytesperline;

        /* Find the ISP video node connected at the far end of the pipeline and
         * update the pipeline.
         */
        far_end = isp_video_far_end(video);

        if (video->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) {
                state = ISP_PIPELINE_STREAM_OUTPUT | ISP_PIPELINE_IDLE_OUTPUT;
                pipe->input = far_end;
                pipe->output = video;
        } else {
                if (far_end == NULL) {
                        ret = -EPIPE;
                        goto error;
                }

                state = ISP_PIPELINE_STREAM_INPUT | ISP_PIPELINE_IDLE_INPUT;
                pipe->input = video;
                pipe->output = far_end;

        }

        if (video->isp->pdata->set_constraints)
                video->isp->pdata->set_constraints(video->isp, true);
        pipe->l3_ick = clk_get_rate(video->isp->clock[ISP_CLK_L3_ICK]);

        /* Validate the pipeline and update its state. */
        ret = isp_video_validate_pipeline(pipe);
        if (ret < 0)
                goto error;

        spin_lock_irqsave(&pipe->lock, flags);
        pipe->state &= ~ISP_PIPELINE_STREAM;
        pipe->state |= state;
        spin_unlock_irqrestore(&pipe->lock, flags);

        /* Set the maximum time per frame as the value requested by userspace.
         * This is a soft limit that can be overridden if the hardware doesn't
         * support the request limit.
         */
        if (video->type == V4L2_BUF_TYPE_VIDEO_OUTPUT)
                pipe->max_timeperframe = vfh->timeperframe;

        video->queue = &vfh->queue;
        INIT_LIST_HEAD(&video->dmaqueue);
        atomic_set(&pipe->frame_number, -1);

        ret = omap3isp_video_queue_streamon(&vfh->queue);
        if (ret < 0)
                goto error;

        /* In sensor-to-memory mode, the stream can be started synchronously
         * to the stream on command. In memory-to-memory mode, it will be
         * started when buffers are queued on both the input and output.
         */
        if (pipe->input == NULL) {
                ret = omap3isp_pipeline_set_stream(pipe,
                                              ISP_PIPELINE_STREAM_CONTINUOUS);
                if (ret < 0)
                        goto error;
                spin_lock_irqsave(&video->queue->irqlock, flags);
                if (list_empty(&video->dmaqueue))
                        video->dmaqueue_flags |= ISP_VIDEO_DMAQUEUE_UNDERRUN;
                spin_unlock_irqrestore(&video->queue->irqlock, flags);
        }

error:
        if (ret < 0) {
                omap3isp_video_queue_streamoff(&vfh->queue);
                if (video->isp->pdata->set_constraints)
                        video->isp->pdata->set_constraints(video->isp, false);
                media_entity_pipeline_stop(&video->video.entity);
                video->queue = NULL;
        }

        if (!ret)
                video->streaming = 1;

        mutex_unlock(&video->stream_lock);
        return ret;
}

static int
isp_video_streamoff(struct file *file, void *fh, enum v4l2_buf_type type)
{
        struct isp_video_fh *vfh = to_isp_video_fh(fh);
        struct isp_video *video = video_drvdata(file);
        struct isp_pipeline *pipe = to_isp_pipeline(&video->video.entity);
        enum isp_pipeline_state state;
        unsigned int streaming;
        unsigned long flags;

        if (type != video->type)
                return -EINVAL;

        mutex_lock(&video->stream_lock);

        /* Make sure we're not streaming yet. */
        mutex_lock(&vfh->queue.lock);
        streaming = vfh->queue.streaming;
        mutex_unlock(&vfh->queue.lock);

        if (!streaming)
                goto done;

        /* Update the pipeline state. */
        if (video->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
                state = ISP_PIPELINE_STREAM_OUTPUT
                      | ISP_PIPELINE_QUEUE_OUTPUT;
        else
                state = ISP_PIPELINE_STREAM_INPUT
                      | ISP_PIPELINE_QUEUE_INPUT;

        spin_lock_irqsave(&pipe->lock, flags);
        pipe->state &= ~state;
        spin_unlock_irqrestore(&pipe->lock, flags);

        /* Stop the stream. */
        omap3isp_pipeline_set_stream(pipe, ISP_PIPELINE_STREAM_STOPPED);
        omap3isp_video_queue_streamoff(&vfh->queue);
        video->queue = NULL;
        video->streaming = 0;

        if (video->isp->pdata->set_constraints)
                video->isp->pdata->set_constraints(video->isp, false);
        media_entity_pipeline_stop(&video->video.entity);

done:
        mutex_unlock(&video->stream_lock);
        return 0;
}

static int
isp_video_enum_input(struct file *file, void *fh, struct v4l2_input *input)
{
        if (input->index > 0)
                return -EINVAL;

        strlcpy(input->name, "camera", sizeof(input->name));
        input->type = V4L2_INPUT_TYPE_CAMERA;

        return 0;
}

static int
isp_video_g_input(struct file *file, void *fh, unsigned int *input)
{
        *input = 0;

        return 0;
}

static int
isp_video_s_input(struct file *file, void *fh, unsigned int input)
{
        return input == 0 ? 0 : -EINVAL;
}

static const struct v4l2_ioctl_ops isp_video_ioctl_ops = {
        .vidioc_querycap                = isp_video_querycap,
        .vidioc_g_fmt_vid_cap           = isp_video_get_format,
        .vidioc_s_fmt_vid_cap           = isp_video_set_format,
        .vidioc_try_fmt_vid_cap         = isp_video_try_format,
        .vidioc_g_fmt_vid_out           = isp_video_get_format,
        .vidioc_s_fmt_vid_out           = isp_video_set_format,
        .vidioc_try_fmt_vid_out         = isp_video_try_format,
        .vidioc_cropcap                 = isp_video_cropcap,
        .vidioc_g_crop                  = isp_video_get_crop,
        .vidioc_s_crop                  = isp_video_set_crop,
        .vidioc_g_parm                  = isp_video_get_param,
        .vidioc_s_parm                  = isp_video_set_param,
        .vidioc_reqbufs                 = isp_video_reqbufs,
        .vidioc_querybuf                = isp_video_querybuf,
        .vidioc_qbuf                    = isp_video_qbuf,
        .vidioc_dqbuf                   = isp_video_dqbuf,
        .vidioc_streamon                = isp_video_streamon,
        .vidioc_streamoff               = isp_video_streamoff,
        .vidioc_enum_input              = isp_video_enum_input,
        .vidioc_g_input                 = isp_video_g_input,
        .vidioc_s_input                 = isp_video_s_input,
};

/* -----------------------------------------------------------------------------
 * V4L2 file operations
 */

static int isp_video_open(struct file *file)
{
        struct isp_video *video = video_drvdata(file);
        struct isp_video_fh *handle;
        int ret = 0;

        handle = kzalloc(sizeof(*handle), GFP_KERNEL);
        if (handle == NULL)
                return -ENOMEM;

        v4l2_fh_init(&handle->vfh, &video->video);
        v4l2_fh_add(&handle->vfh);

        /* If this is the first user, initialise the pipeline. */
        if (omap3isp_get(video->isp) == NULL) {
                ret = -EBUSY;
                goto done;
        }

        ret = omap3isp_pipeline_pm_use(&video->video.entity, 1);
        if (ret < 0) {
                omap3isp_put(video->isp);
                goto done;
        }

        omap3isp_video_queue_init(&handle->queue, video->type,
                                  &isp_video_queue_ops, video->isp->dev,
                                  sizeof(struct isp_buffer));

        memset(&handle->format, 0, sizeof(handle->format));
        handle->format.type = video->type;
        handle->timeperframe.denominator = 1;

        handle->video = video;
        file->private_data = &handle->vfh;

done:
        if (ret < 0) {
                v4l2_fh_del(&handle->vfh);
                kfree(handle);
        }

        return ret;
}

static int isp_video_release(struct file *file)
{
        struct isp_video *video = video_drvdata(file);
        struct v4l2_fh *vfh = file->private_data;
        struct isp_video_fh *handle = to_isp_video_fh(vfh);

        /* Disable streaming and free the buffers queue resources. */
        isp_video_streamoff(file, vfh, video->type);

        mutex_lock(&handle->queue.lock);
        omap3isp_video_queue_cleanup(&handle->queue);
        mutex_unlock(&handle->queue.lock);

        omap3isp_pipeline_pm_use(&video->video.entity, 0);

        /* Release the file handle. */
        v4l2_fh_del(vfh);
        kfree(handle);
        file->private_data = NULL;

        omap3isp_put(video->isp);

        return 0;
}

static unsigned int isp_video_poll(struct file *file, poll_table *wait)
{
        struct isp_video_fh *vfh = to_isp_video_fh(file->private_data);
        struct isp_video_queue *queue = &vfh->queue;

        return omap3isp_video_queue_poll(queue, file, wait);
}

static int isp_video_mmap(struct file *file, struct vm_area_struct *vma)
{
        struct isp_video_fh *vfh = to_isp_video_fh(file->private_data);

        return omap3isp_video_queue_mmap(&vfh->queue, vma);
}

static struct v4l2_file_operations isp_video_fops = {
        .owner = THIS_MODULE,
        .unlocked_ioctl = video_ioctl2,
        .open = isp_video_open,
        .release = isp_video_release,
        .poll = isp_video_poll,
        .mmap = isp_video_mmap,
};

/* -----------------------------------------------------------------------------
 * ISP video core
 */

static const struct isp_video_operations isp_video_dummy_ops = {
};

int omap3isp_video_init(struct isp_video *video, const char *name)
{
        const char *direction;
        int ret;

        switch (video->type) {
        case V4L2_BUF_TYPE_VIDEO_CAPTURE:
                direction = "output";
                video->pad.flags = MEDIA_PAD_FL_SINK;
                break;
        case V4L2_BUF_TYPE_VIDEO_OUTPUT:
                direction = "input";
                video->pad.flags = MEDIA_PAD_FL_SOURCE;
                break;

        default:
                return -EINVAL;
        }

        ret = media_entity_init(&video->video.entity, 1, &video->pad, 0);
        if (ret < 0)
                return ret;

        mutex_init(&video->mutex);
        atomic_set(&video->active, 0);

        spin_lock_init(&video->pipe.lock);
        mutex_init(&video->stream_lock);

        /* Initialize the video device. */
        if (video->ops == NULL)
                video->ops = &isp_video_dummy_ops;

        video->video.fops = &isp_video_fops;
        snprintf(video->video.name, sizeof(video->video.name),
                 "OMAP3 ISP %s %s", name, direction);
        video->video.vfl_type = VFL_TYPE_GRABBER;
        video->video.release = video_device_release_empty;
        video->video.ioctl_ops = &isp_video_ioctl_ops;
        video->pipe.stream_state = ISP_PIPELINE_STREAM_STOPPED;

        video_set_drvdata(&video->video, video);

        return 0;
}

int omap3isp_video_register(struct isp_video *video, struct v4l2_device *vdev)
{
        int ret;

        video->video.v4l2_dev = vdev;

        ret = video_register_device(&video->video, VFL_TYPE_GRABBER, -1);
        if (ret < 0)
                printk(KERN_ERR "%s: could not register video device (%d)\n",
                        __func__, ret);

        return ret;
}

void omap3isp_video_unregister(struct isp_video *video)
{
        if (video_is_registered(&video->video)) {
                media_entity_cleanup(&video->video.entity);
                video_unregister_device(&video->video);
        }
}