/*
 * Copyright (C) 2009 Texas Instruments Inc
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 * TODO : add support for VBI & HBI data service
 *        add static buffer allocation
 */
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/workqueue.h>
#include <linux/string.h>
#include <linux/videodev2.h>
#include <linux/wait.h>
#include <linux/time.h>
#include <linux/i2c.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/version.h>
#include <media/v4l2-device.h>
#include <media/v4l2-ioctl.h>

#include "vpif_capture.h"
#include "vpif.h"

MODULE_DESCRIPTION("TI DaVinci VPIF Capture driver");
MODULE_LICENSE("GPL");

#define vpif_err(fmt, arg...)   v4l2_err(&vpif_obj.v4l2_dev, fmt, ## arg)
#define vpif_dbg(level, debug, fmt, arg...)     \
                v4l2_dbg(level, debug, &vpif_obj.v4l2_dev, fmt, ## arg)

static int debug = 1;
static u32 ch0_numbuffers = 3;
static u32 ch1_numbuffers = 3;
static u32 ch0_bufsize = 1920 * 1080 * 2;
static u32 ch1_bufsize = 720 * 576 * 2;

module_param(debug, int, 0644);
module_param(ch0_numbuffers, uint, S_IRUGO);
module_param(ch1_numbuffers, uint, S_IRUGO);
module_param(ch0_bufsize, uint, S_IRUGO);
module_param(ch1_bufsize, uint, S_IRUGO);

MODULE_PARM_DESC(debug, "Debug level 0-1");
MODULE_PARM_DESC(ch2_numbuffers, "Channel0 buffer count (default:3)");
MODULE_PARM_DESC(ch3_numbuffers, "Channel1 buffer count (default:3)");
MODULE_PARM_DESC(ch2_bufsize, "Channel0 buffer size (default:1920 x 1080 x 2)");
MODULE_PARM_DESC(ch3_bufsize, "Channel1 buffer size (default:720 x 576 x 2)");

static struct vpif_config_params config_params = {
        .min_numbuffers = 3,
        .numbuffers[0] = 3,
        .numbuffers[1] = 3,
        .min_bufsize[0] = 720 * 480 * 2,
        .min_bufsize[1] = 720 * 480 * 2,
        .channel_bufsize[0] = 1920 * 1080 * 2,
        .channel_bufsize[1] = 720 * 576 * 2,
};

/* global variables */
static struct vpif_device vpif_obj = { {NULL} };
static struct device *vpif_dev;

/**
 * ch_params: video standard configuration parameters for vpif
 */
static const struct vpif_channel_config_params ch_params[] = {
        {
                "NTSC_M", 720, 480, 30, 0, 1, 268, 1440, 1, 23, 263, 266,
                286, 525, 525, 0, 1, 0, V4L2_STD_525_60,
        },
        {
                "PAL_BDGHIK", 720, 576, 25, 0, 1, 280, 1440, 1, 23, 311, 313,
                336, 624, 625, 0, 1, 0, V4L2_STD_625_50,
        },
};

/**
 * vpif_uservirt_to_phys : translate user/virtual address to phy address
 * @virtp: user/virtual address
 *
 * This inline function is used to convert user space virtual address to
 * physical address.
 */
static inline u32 vpif_uservirt_to_phys(u32 virtp)
{
        unsigned long physp = 0;
        struct mm_struct *mm = current->mm;
        struct vm_area_struct *vma;

        vma = find_vma(mm, virtp);

        /* For kernel direct-mapped memory, take the easy way */
        if (virtp >= PAGE_OFFSET)
                physp = virt_to_phys((void *)virtp);
        else if (vma && (vma->vm_flags & VM_IO) && (vma->vm_pgoff))
                /**
                 * this will catch, kernel-allocated, mmaped-to-usermode
                 * addresses
                 */
                physp = (vma->vm_pgoff << PAGE_SHIFT) + (virtp - vma->vm_start);
        else {
                /* otherwise, use get_user_pages() for general userland pages */
                int res, nr_pages = 1;
                        struct page *pages;

                down_read(&current->mm->mmap_sem);

                res = get_user_pages(current, current->mm,
                                     virtp, nr_pages, 1, 0, &pages, NULL);
                up_read(&current->mm->mmap_sem);

                if (res == nr_pages)
                        physp = __pa(page_address(&pages[0]) +
                                     (virtp & ~PAGE_MASK));
                else {
                        vpif_err("get_user_pages failed\n");
                        return 0;
                }
        }
        return physp;
}

/**
 * buffer_prepare :  callback function for buffer prepare
 * @q : buffer queue ptr
 * @vb: ptr to video buffer
 * @field: field info
 *
 * This is the callback function for buffer prepare when videobuf_qbuf()
 * function is called. The buffer is prepared and user space virtual address
 * or user address is converted into  physical address
 */
static int vpif_buffer_prepare(struct videobuf_queue *q,
                               struct videobuf_buffer *vb,
                               enum v4l2_field field)
{
        /* Get the file handle object and channel object */
        struct vpif_fh *fh = q->priv_data;
        struct channel_obj *ch = fh->channel;
        struct common_obj *common;
        unsigned long addr;


        vpif_dbg(2, debug, "vpif_buffer_prepare\n");

        common = &ch->common[VPIF_VIDEO_INDEX];

        /* If buffer is not initialized, initialize it */
        if (VIDEOBUF_NEEDS_INIT == vb->state) {
                vb->width = common->width;
                vb->height = common->height;
                vb->size = vb->width * vb->height;
                vb->field = field;
        }
        vb->state = VIDEOBUF_PREPARED;
        /**
         * if user pointer memory mechanism is used, get the physical
         * address of the buffer
         */
        if (V4L2_MEMORY_USERPTR == common->memory) {
                if (0 == vb->baddr) {
                        vpif_dbg(1, debug, "buffer address is 0\n");
                        return -EINVAL;

                }
                vb->boff = vpif_uservirt_to_phys(vb->baddr);
                if (!IS_ALIGNED(vb->boff, 8))
                        goto exit;
        }

        addr = vb->boff;
        if (q->streaming) {
                if (!IS_ALIGNED((addr + common->ytop_off), 8) ||
                    !IS_ALIGNED((addr + common->ybtm_off), 8) ||
                    !IS_ALIGNED((addr + common->ctop_off), 8) ||
                    !IS_ALIGNED((addr + common->cbtm_off), 8))
                        goto exit;
        }
        return 0;
exit:
        vpif_dbg(1, debug, "buffer_prepare:offset is not aligned to 8 bytes\n");
        return -EINVAL;
}

/**
 * vpif_buffer_setup : Callback function for buffer setup.
 * @q: buffer queue ptr
 * @count: number of buffers
 * @size: size of the buffer
 *
 * This callback function is called when reqbuf() is called to adjust
 * the buffer count and buffer size
 */
static int vpif_buffer_setup(struct videobuf_queue *q, unsigned int *count,
                             unsigned int *size)
{
        /* Get the file handle object and channel object */
        struct vpif_fh *fh = q->priv_data;
        struct channel_obj *ch = fh->channel;
        struct common_obj *common;

        common = &ch->common[VPIF_VIDEO_INDEX];

        vpif_dbg(2, debug, "vpif_buffer_setup\n");

        /* If memory type is not mmap, return */
        if (V4L2_MEMORY_MMAP != common->memory)
                return 0;

        /* Calculate the size of the buffer */
        *size = config_params.channel_bufsize[ch->channel_id];

        if (*count < config_params.min_numbuffers)
                *count = config_params.min_numbuffers;
        return 0;
}

/**
 * vpif_buffer_queue : Callback function to add buffer to DMA queue
 * @q: ptr to videobuf_queue
 * @vb: ptr to videobuf_buffer
 */
static void vpif_buffer_queue(struct videobuf_queue *q,
                              struct videobuf_buffer *vb)
{
        /* Get the file handle object and channel object */
        struct vpif_fh *fh = q->priv_data;
        struct channel_obj *ch = fh->channel;
        struct common_obj *common;

        common = &ch->common[VPIF_VIDEO_INDEX];

        vpif_dbg(2, debug, "vpif_buffer_queue\n");

        /* add the buffer to the DMA queue */
        list_add_tail(&vb->queue, &common->dma_queue);
        /* Change state of the buffer */
        vb->state = VIDEOBUF_QUEUED;
}

/**
 * vpif_buffer_release : Callback function to free buffer
 * @q: buffer queue ptr
 * @vb: ptr to video buffer
 *
 * This function is called from the videobuf layer to free memory
 * allocated to  the buffers
 */
static void vpif_buffer_release(struct videobuf_queue *q,
                                struct videobuf_buffer *vb)
{
        /* Get the file handle object and channel object */
        struct vpif_fh *fh = q->priv_data;
        struct channel_obj *ch = fh->channel;
        struct common_obj *common;

        common = &ch->common[VPIF_VIDEO_INDEX];

        videobuf_dma_contig_free(q, vb);
        vb->state = VIDEOBUF_NEEDS_INIT;
}

static struct videobuf_queue_ops video_qops = {
        .buf_setup = vpif_buffer_setup,
        .buf_prepare = vpif_buffer_prepare,
        .buf_queue = vpif_buffer_queue,
        .buf_release = vpif_buffer_release,
};

static u8 channel_first_int[VPIF_NUMBER_OF_OBJECTS][2] =
        { {1, 1} };

/**
 * vpif_process_buffer_complete: process a completed buffer
 * @common: ptr to common channel object
 *
 * This function time stamp the buffer and mark it as DONE. It also
 * wake up any process waiting on the QUEUE and set the next buffer
 * as current
 */
static void vpif_process_buffer_complete(struct common_obj *common)
{
        do_gettimeofday(&common->cur_frm->ts);
        common->cur_frm->state = VIDEOBUF_DONE;
        wake_up_interruptible(&common->cur_frm->done);
        /* Make curFrm pointing to nextFrm */
        common->cur_frm = common->next_frm;
}

/**
 * vpif_schedule_next_buffer: set next buffer address for capture
 * @common : ptr to common channel object
 *
 * This function will get next buffer from the dma queue and
 * set the buffer address in the vpif register for capture.
 * the buffer is marked active
 */
static void vpif_schedule_next_buffer(struct common_obj *common)
{
        unsigned long addr = 0;

        common->next_frm = list_entry(common->dma_queue.next,
                                     struct videobuf_buffer, queue);
        /* Remove that buffer from the buffer queue */
        list_del(&common->next_frm->queue);
        common->next_frm->state = VIDEOBUF_ACTIVE;
        if (V4L2_MEMORY_USERPTR == common->memory)
                addr = common->next_frm->boff;
        else
                addr = videobuf_to_dma_contig(common->next_frm);

        /* Set top and bottom field addresses in VPIF registers */
        common->set_addr(addr + common->ytop_off,
                         addr + common->ybtm_off,
                         addr + common->ctop_off,
                         addr + common->cbtm_off);
}

/**
 * vpif_channel_isr : ISR handler for vpif capture
 * @irq: irq number
 * @dev_id: dev_id ptr
 *
 * It changes status of the captured buffer, takes next buffer from the queue
 * and sets its address in VPIF  registers
 */
static irqreturn_t vpif_channel_isr(int irq, void *dev_id)
{
        struct vpif_device *dev = &vpif_obj;
        struct common_obj *common;
        struct channel_obj *ch;
        enum v4l2_field field;
        int channel_id = 0;
        int fid = -1, i;

        channel_id = *(int *)(dev_id);
        ch = dev->dev[channel_id];

        field = ch->common[VPIF_VIDEO_INDEX].fmt.fmt.pix.field;

        for (i = 0; i < VPIF_NUMBER_OF_OBJECTS; i++) {
                common = &ch->common[i];
                /* skip If streaming is not started in this channel */
                if (0 == common->started)
                        continue;

                /* Check the field format */
                if (1 == ch->vpifparams.std_info.frm_fmt) {
                        /* Progressive mode */
                        if (list_empty(&common->dma_queue))
                                continue;

                        if (!channel_first_int[i][channel_id])
                                vpif_process_buffer_complete(common);

                        channel_first_int[i][channel_id] = 0;

                        vpif_schedule_next_buffer(common);


                        channel_first_int[i][channel_id] = 0;
                } else {
                        /**
                         * Interlaced mode. If it is first interrupt, ignore
                         * it
                         */
                        if (channel_first_int[i][channel_id]) {
                                channel_first_int[i][channel_id] = 0;
                                continue;
                        }
                        if (0 == i) {
                                ch->field_id ^= 1;
                                /* Get field id from VPIF registers */
                                fid = vpif_channel_getfid(ch->channel_id);
                                if (fid != ch->field_id) {
                                        /**
                                         * If field id does not match stored
                                         * field id, make them in sync
                                         */
                                        if (0 == fid)
                                                ch->field_id = fid;
                                        return IRQ_HANDLED;
                                }
                        }
                        /* device field id and local field id are in sync */
                        if (0 == fid) {
                                /* this is even field */
                                if (common->cur_frm == common->next_frm)
                                        continue;

                                /* mark the current buffer as done */
                                vpif_process_buffer_complete(common);
                        } else if (1 == fid) {
                                /* odd field */
                                if (list_empty(&common->dma_queue) ||
                                    (common->cur_frm != common->next_frm))
                                        continue;

                                vpif_schedule_next_buffer(common);
                        }
                }
        }
        return IRQ_HANDLED;
}

/**
 * vpif_update_std_info() - update standard related info
 * @ch: ptr to channel object
 *
 * For a given standard selected by application, update values
 * in the device data structures
 */
static int vpif_update_std_info(struct channel_obj *ch)
{
        struct common_obj *common = &ch->common[VPIF_VIDEO_INDEX];
        struct vpif_params *vpifparams = &ch->vpifparams;
        const struct vpif_channel_config_params *config;
        struct vpif_channel_config_params *std_info;
        struct video_obj *vid_ch = &ch->video;
        int index;

        vpif_dbg(2, debug, "vpif_update_std_info\n");

        std_info = &vpifparams->std_info;

        for (index = 0; index < ARRAY_SIZE(ch_params); index++) {
                config = &ch_params[index];
                if (config->stdid & vid_ch->stdid) {
                        memcpy(std_info, config, sizeof(*config));
                        break;
                }
        }

        /* standard not found */
        if (index == ARRAY_SIZE(ch_params))
                return -EINVAL;

        common->fmt.fmt.pix.width = std_info->width;
        common->width = std_info->width;
        common->fmt.fmt.pix.height = std_info->height;
        common->height = std_info->height;
        common->fmt.fmt.pix.bytesperline = std_info->width;
        vpifparams->video_params.hpitch = std_info->width;
        vpifparams->video_params.storage_mode = std_info->frm_fmt;
        return 0;
}

/**
 * vpif_calculate_offsets : This function calculates buffers offsets
 * @ch : ptr to channel object
 *
 * This function calculates buffer offsets for Y and C in the top and
 * bottom field
 */
static void vpif_calculate_offsets(struct channel_obj *ch)
{
        unsigned int hpitch, vpitch, sizeimage;
        struct video_obj *vid_ch = &(ch->video);
        struct vpif_params *vpifparams = &ch->vpifparams;
        struct common_obj *common = &ch->common[VPIF_VIDEO_INDEX];
        enum v4l2_field field = common->fmt.fmt.pix.field;

        vpif_dbg(2, debug, "vpif_calculate_offsets\n");

        if (V4L2_FIELD_ANY == field) {
                if (vpifparams->std_info.frm_fmt)
                        vid_ch->buf_field = V4L2_FIELD_NONE;
                else
                        vid_ch->buf_field = V4L2_FIELD_INTERLACED;
        } else
                vid_ch->buf_field = common->fmt.fmt.pix.field;

        if (V4L2_MEMORY_USERPTR == common->memory)
                sizeimage = common->fmt.fmt.pix.sizeimage;
        else
                sizeimage = config_params.channel_bufsize[ch->channel_id];

        hpitch = common->fmt.fmt.pix.bytesperline;
        vpitch = sizeimage / (hpitch * 2);

        if ((V4L2_FIELD_NONE == vid_ch->buf_field) ||
            (V4L2_FIELD_INTERLACED == vid_ch->buf_field)) {
                /* Calculate offsets for Y top, Y Bottom, C top and C Bottom */
                common->ytop_off = 0;
                common->ybtm_off = hpitch;
                common->ctop_off = sizeimage / 2;
                common->cbtm_off = sizeimage / 2 + hpitch;
        } else if (V4L2_FIELD_SEQ_TB == vid_ch->buf_field) {
                /* Calculate offsets for Y top, Y Bottom, C top and C Bottom */
                common->ytop_off = 0;
                common->ybtm_off = sizeimage / 4;
                common->ctop_off = sizeimage / 2;
                common->cbtm_off = common->ctop_off + sizeimage / 4;
        } else if (V4L2_FIELD_SEQ_BT == vid_ch->buf_field) {
                /* Calculate offsets for Y top, Y Bottom, C top and C Bottom */
                common->ybtm_off = 0;
                common->ytop_off = sizeimage / 4;
                common->cbtm_off = sizeimage / 2;
                common->ctop_off = common->cbtm_off + sizeimage / 4;
        }
        if ((V4L2_FIELD_NONE == vid_ch->buf_field) ||
            (V4L2_FIELD_INTERLACED == vid_ch->buf_field))
                vpifparams->video_params.storage_mode = 1;
        else
                vpifparams->video_params.storage_mode = 0;

        if (1 == vpifparams->std_info.frm_fmt)
                vpifparams->video_params.hpitch =
                    common->fmt.fmt.pix.bytesperline;
        else {
                if ((field == V4L2_FIELD_ANY)
                    || (field == V4L2_FIELD_INTERLACED))
                        vpifparams->video_params.hpitch =
                            common->fmt.fmt.pix.bytesperline * 2;
                else
                        vpifparams->video_params.hpitch =
                            common->fmt.fmt.pix.bytesperline;
        }

        ch->vpifparams.video_params.stdid = vpifparams->std_info.stdid;
}

/**
 * vpif_config_format: configure default frame format in the device
 * ch : ptr to channel object
 */
static void vpif_config_format(struct channel_obj *ch)
{
        struct common_obj *common = &ch->common[VPIF_VIDEO_INDEX];

        vpif_dbg(2, debug, "vpif_config_format\n");

        common->fmt.fmt.pix.field = V4L2_FIELD_ANY;
        if (config_params.numbuffers[ch->channel_id] == 0)
                common->memory = V4L2_MEMORY_USERPTR;
        else
                common->memory = V4L2_MEMORY_MMAP;

        common->fmt.fmt.pix.sizeimage
            = config_params.channel_bufsize[ch->channel_id];

        if (ch->vpifparams.iface.if_type == VPIF_IF_RAW_BAYER)
                common->fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_SBGGR8;
        else
                common->fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_YUV422P;
        common->fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
}

/**
 * vpif_get_default_field() - Get default field type based on interface
 * @vpif_params - ptr to vpif params
 */
static inline enum v4l2_field vpif_get_default_field(
                                struct vpif_interface *iface)
{
        return (iface->if_type == VPIF_IF_RAW_BAYER) ? V4L2_FIELD_NONE :
                                                V4L2_FIELD_INTERLACED;
}

/**
 * vpif_check_format()  - check given pixel format for compatibility
 * @ch - channel  ptr
 * @pixfmt - Given pixel format
 * @update - update the values as per hardware requirement
 *
 * Check the application pixel format for S_FMT and update the input
 * values as per hardware limits for TRY_FMT. The default pixel and
 * field format is selected based on interface type.
 */
static int vpif_check_format(struct channel_obj *ch,
                             struct v4l2_pix_format *pixfmt,
                             int update)
{
        struct common_obj *common = &(ch->common[VPIF_VIDEO_INDEX]);
        struct vpif_params *vpif_params = &ch->vpifparams;
        enum v4l2_field field = pixfmt->field;
        u32 sizeimage, hpitch, vpitch;
        int ret = -EINVAL;

        vpif_dbg(2, debug, "vpif_check_format\n");
        /**
         * first check for the pixel format. If if_type is Raw bayer,
         * only V4L2_PIX_FMT_SBGGR8 format is supported. Otherwise only
         * V4L2_PIX_FMT_YUV422P is supported
         */
        if (vpif_params->iface.if_type == VPIF_IF_RAW_BAYER) {
                if (pixfmt->pixelformat != V4L2_PIX_FMT_SBGGR8) {
                        if (!update) {
                                vpif_dbg(2, debug, "invalid pix format\n");
                                goto exit;
                        }
                        pixfmt->pixelformat = V4L2_PIX_FMT_SBGGR8;
                }
        } else {
                if (pixfmt->pixelformat != V4L2_PIX_FMT_YUV422P) {
                        if (!update) {
                                vpif_dbg(2, debug, "invalid pixel format\n");
                                goto exit;
                        }
                        pixfmt->pixelformat = V4L2_PIX_FMT_YUV422P;
                }
        }

        if (!(VPIF_VALID_FIELD(field))) {
                if (!update) {
                        vpif_dbg(2, debug, "invalid field format\n");
                        goto exit;
                }
                /**
                 * By default use FIELD_NONE for RAW Bayer capture
                 * and FIELD_INTERLACED for other interfaces
                 */
                field = vpif_get_default_field(&vpif_params->iface);
        } else if (field == V4L2_FIELD_ANY)
                /* unsupported field. Use default */
                field = vpif_get_default_field(&vpif_params->iface);

        /* validate the hpitch */
        hpitch = pixfmt->bytesperline;
        if (hpitch < vpif_params->std_info.width) {
                if (!update) {
                        vpif_dbg(2, debug, "invalid hpitch\n");
                        goto exit;
                }
                hpitch = vpif_params->std_info.width;
        }

        if (V4L2_MEMORY_USERPTR == common->memory)
                sizeimage = pixfmt->sizeimage;
        else
                sizeimage = config_params.channel_bufsize[ch->channel_id];

        vpitch = sizeimage / (hpitch * 2);

        /* validate the vpitch */
        if (vpitch < vpif_params->std_info.height) {
                if (!update) {
                        vpif_dbg(2, debug, "Invalid vpitch\n");
                        goto exit;
                }
                vpitch = vpif_params->std_info.height;
        }

        /* Check for 8 byte alignment */
        if (!ALIGN(hpitch, 8)) {
                if (!update) {
                        vpif_dbg(2, debug, "invalid pitch alignment\n");
                        goto exit;
                }
                /* adjust to next 8 byte boundary */
                hpitch = (((hpitch + 7) / 8) * 8);
        }
        /* if update is set, modify the bytesperline and sizeimage */
        if (update) {
                pixfmt->bytesperline = hpitch;
                pixfmt->sizeimage = hpitch * vpitch * 2;
        }
        /**
         * Image width and height is always based on current standard width and
         * height
         */
        pixfmt->width = common->fmt.fmt.pix.width;
        pixfmt->height = common->fmt.fmt.pix.height;
        return 0;
exit:
        return ret;
}

/**
 * vpif_config_addr() - function to configure buffer address in vpif
 * @ch - channel ptr
 * @muxmode - channel mux mode
 */
static void vpif_config_addr(struct channel_obj *ch, int muxmode)
{
        struct common_obj *common;

        vpif_dbg(2, debug, "vpif_config_addr\n");

        common = &(ch->common[VPIF_VIDEO_INDEX]);

        if (VPIF_CHANNEL1_VIDEO == ch->channel_id)
                common->set_addr = ch1_set_videobuf_addr;
        else if (2 == muxmode)
                common->set_addr = ch0_set_videobuf_addr_yc_nmux;
        else
                common->set_addr = ch0_set_videobuf_addr;
}

/**
 * vpfe_mmap : It is used to map kernel space buffers into user spaces
 * @filep: file pointer
 * @vma: ptr to vm_area_struct
 */
static int vpif_mmap(struct file *filep, struct vm_area_struct *vma)
{
        /* Get the channel object and file handle object */
        struct vpif_fh *fh = filep->private_data;
        struct channel_obj *ch = fh->channel;
        struct common_obj *common = &(ch->common[VPIF_VIDEO_INDEX]);

        vpif_dbg(2, debug, "vpif_mmap\n");

        return videobuf_mmap_mapper(&common->buffer_queue, vma);
}

/**
 * vpif_poll: It is used for select/poll system call
 * @filep: file pointer
 * @wait: poll table to wait
 */
static unsigned int vpif_poll(struct file *filep, poll_table * wait)
{
        int err = 0;
        struct vpif_fh *fh = filep->private_data;
        struct channel_obj *channel = fh->channel;
        struct common_obj *common = &(channel->common[VPIF_VIDEO_INDEX]);

        vpif_dbg(2, debug, "vpif_poll\n");

        if (common->started)
                err = videobuf_poll_stream(filep, &common->buffer_queue, wait);

        return 0;
}

/**
 * vpif_open : vpif open handler
 * @filep: file ptr
 *
 * It creates object of file handle structure and stores it in private_data
 * member of filepointer
 */
static int vpif_open(struct file *filep)
{
        struct vpif_capture_config *config = vpif_dev->platform_data;
        struct video_device *vdev = video_devdata(filep);
        struct common_obj *common;
        struct video_obj *vid_ch;
        struct channel_obj *ch;
        struct vpif_fh *fh;
        int i, ret = 0;

        vpif_dbg(2, debug, "vpif_open\n");

        ch = video_get_drvdata(vdev);

        vid_ch = &ch->video;
        common = &ch->common[VPIF_VIDEO_INDEX];

        if (mutex_lock_interruptible(&common->lock))
                return -ERESTARTSYS;

        if (NULL == ch->curr_subdev_info) {
                /**
                 * search through the sub device to see a registered
                 * sub device and make it as current sub device
                 */
                for (i = 0; i < config->subdev_count; i++) {
                        if (vpif_obj.sd[i]) {
                                /* the sub device is registered */
                                ch->curr_subdev_info = &config->subdev_info[i];
                                /* make first input as the current input */
                                vid_ch->input_idx = 0;
                                break;
                        }
                }
                if (i == config->subdev_count) {
                        vpif_err("No sub device registered\n");
                        ret = -ENOENT;
                        goto exit;
                }
        }

        /* Allocate memory for the file handle object */
        fh = kmalloc(sizeof(struct vpif_fh), GFP_KERNEL);
        if (NULL == fh) {
                vpif_err("unable to allocate memory for file handle object\n");
                ret = -ENOMEM;
                goto exit;
        }

        /* store pointer to fh in private_data member of filep */
        filep->private_data = fh;
        fh->channel = ch;
        fh->initialized = 0;
        /* If decoder is not initialized. initialize it */
        if (!ch->initialized) {
                fh->initialized = 1;
                ch->initialized = 1;
                memset(&(ch->vpifparams), 0, sizeof(struct vpif_params));
        }
        /* Increment channel usrs counter */
        ch->usrs++;
        /* Set io_allowed member to false */
        fh->io_allowed[VPIF_VIDEO_INDEX] = 0;
        /* Initialize priority of this instance to default priority */
        fh->prio = V4L2_PRIORITY_UNSET;
        v4l2_prio_open(&ch->prio, &fh->prio);
exit:
        mutex_unlock(&common->lock);
        return ret;
}

/**
 * vpif_release : function to clean up file close
 * @filep: file pointer
 *
 * This function deletes buffer queue, frees the buffers and the vpfe file
 * handle
 */
static int vpif_release(struct file *filep)
{
        struct vpif_fh *fh = filep->private_data;
        struct channel_obj *ch = fh->channel;
        struct common_obj *common;

        vpif_dbg(2, debug, "vpif_release\n");

        common = &ch->common[VPIF_VIDEO_INDEX];

        if (mutex_lock_interruptible(&common->lock))
                return -ERESTARTSYS;

        /* if this instance is doing IO */
        if (fh->io_allowed[VPIF_VIDEO_INDEX]) {
                /* Reset io_usrs member of channel object */
                common->io_usrs = 0;
                /* Disable channel as per its device type and channel id */
                if (VPIF_CHANNEL0_VIDEO == ch->channel_id) {
                        enable_channel0(0);
                        channel0_intr_enable(0);
                }
                if ((VPIF_CHANNEL1_VIDEO == ch->channel_id) ||
                    (2 == common->started)) {
                        enable_channel1(0);
                        channel1_intr_enable(0);
                }
                common->started = 0;
                /* Free buffers allocated */
                videobuf_queue_cancel(&common->buffer_queue);
                videobuf_mmap_free(&common->buffer_queue);
        }

        /* Decrement channel usrs counter */
        ch->usrs--;

        /* unlock mutex on channel object */
        mutex_unlock(&common->lock);

        /* Close the priority */
        v4l2_prio_close(&ch->prio, &fh->prio);

        if (fh->initialized)
                ch->initialized = 0;

        filep->private_data = NULL;
        kfree(fh);
        return 0;
}

/**
 * vpif_reqbufs() - request buffer handler
 * @file: file ptr
 * @priv: file handle
 * @reqbuf: request buffer structure ptr
 */
static int vpif_reqbufs(struct file *file, void *priv,
                        struct v4l2_requestbuffers *reqbuf)
{
        struct vpif_fh *fh = priv;
        struct channel_obj *ch = fh->channel;
        struct common_obj *common;
        u8 index = 0;
        int ret = 0;

        vpif_dbg(2, debug, "vpif_reqbufs\n");

        /**
         * This file handle has not initialized the channel,
         * It is not allowed to do settings
         */
        if ((VPIF_CHANNEL0_VIDEO == ch->channel_id)
            || (VPIF_CHANNEL1_VIDEO == ch->channel_id)) {
                if (!fh->initialized) {
                        vpif_dbg(1, debug, "Channel Busy\n");
                        return -EBUSY;
                }
        }

        if (V4L2_BUF_TYPE_VIDEO_CAPTURE != reqbuf->type)
                return -EINVAL;

        index = VPIF_VIDEO_INDEX;

        common = &ch->common[index];

        if (mutex_lock_interruptible(&common->lock))
                return -ERESTARTSYS;

        if (0 != common->io_usrs) {
                ret = -EBUSY;
                goto reqbuf_exit;
        }

        /* Initialize videobuf queue as per the buffer type */
        videobuf_queue_dma_contig_init(&common->buffer_queue,
                                            &video_qops, NULL,
                                            &common->irqlock,
                                            reqbuf->type,
                                            common->fmt.fmt.pix.field,
                                            sizeof(struct videobuf_buffer), fh);

        /* Set io allowed member of file handle to TRUE */
        fh->io_allowed[index] = 1;
        /* Increment io usrs member of channel object to 1 */
        common->io_usrs = 1;
        /* Store type of memory requested in channel object */
        common->memory = reqbuf->memory;
        INIT_LIST_HEAD(&common->dma_queue);

        /* Allocate buffers */
        ret = videobuf_reqbufs(&common->buffer_queue, reqbuf);

reqbuf_exit:
        mutex_unlock(&common->lock);
        return ret;
}

/**
 * vpif_querybuf() - query buffer handler
 * @file: file ptr
 * @priv: file handle
 * @buf: v4l2 buffer structure ptr
 */
static int vpif_querybuf(struct file *file, void *priv,
                                struct v4l2_buffer *buf)
{
        struct vpif_fh *fh = priv;
        struct channel_obj *ch = fh->channel;
        struct common_obj *common = &ch->common[VPIF_VIDEO_INDEX];

        vpif_dbg(2, debug, "vpif_querybuf\n");

        if (common->fmt.type != buf->type)
                return -EINVAL;

        if (common->memory != V4L2_MEMORY_MMAP) {
                vpif_dbg(1, debug, "Invalid memory\n");
                return -EINVAL;
        }

        return videobuf_querybuf(&common->buffer_queue, buf);
}

/**
 * vpif_qbuf() - query buffer handler
 * @file: file ptr
 * @priv: file handle
 * @buf: v4l2 buffer structure ptr
 */
static int vpif_qbuf(struct file *file, void *priv, struct v4l2_buffer *buf)
{

        struct vpif_fh *fh = priv;
        struct channel_obj *ch = fh->channel;
        struct common_obj *common = &ch->common[VPIF_VIDEO_INDEX];
        struct v4l2_buffer tbuf = *buf;
        struct videobuf_buffer *buf1;
        unsigned long addr = 0;
        unsigned long flags;
        int ret = 0;

        vpif_dbg(2, debug, "vpif_qbuf\n");

        if (common->fmt.type != tbuf.type) {
                vpif_err("invalid buffer type\n");
                return -EINVAL;
        }

        if (!fh->io_allowed[VPIF_VIDEO_INDEX]) {

                vpif_err("fh io not allowed \n");
                return -EACCES;
        }

        if (!(list_empty(&common->dma_queue)) ||
            (common->cur_frm != common->next_frm) ||
            !common->started ||
            (common->started && (0 == ch->field_id)))
                return videobuf_qbuf(&common->buffer_queue, buf);

        /* bufferqueue is empty store buffer address in VPIF registers */
        mutex_lock(&common->buffer_queue.vb_lock);
        buf1 = common->buffer_queue.bufs[tbuf.index];

        if ((buf1->state == VIDEOBUF_QUEUED) ||
            (buf1->state == VIDEOBUF_ACTIVE)) {
                vpif_err("invalid state\n");
                goto qbuf_exit;
        }

        switch (buf1->memory) {
        case V4L2_MEMORY_MMAP:
                if (buf1->baddr == 0)
                        goto qbuf_exit;
                break;

        case V4L2_MEMORY_USERPTR:
                if (tbuf.length < buf1->bsize)
                        goto qbuf_exit;

                if ((VIDEOBUF_NEEDS_INIT != buf1->state)
                            && (buf1->baddr != tbuf.m.userptr))
                        vpif_buffer_release(&common->buffer_queue, buf1);
                        buf1->baddr = tbuf.m.userptr;
                break;

        default:
                goto qbuf_exit;
        }

        local_irq_save(flags);
        ret = vpif_buffer_prepare(&common->buffer_queue, buf1,
                                        common->buffer_queue.field);
        if (ret < 0) {
                local_irq_restore(flags);
                goto qbuf_exit;
        }

        buf1->state = VIDEOBUF_ACTIVE;

        if (V4L2_MEMORY_USERPTR == common->memory)
                addr = buf1->boff;
        else
                addr = videobuf_to_dma_contig(buf1);

        common->next_frm = buf1;
        common->set_addr(addr + common->ytop_off,
                         addr + common->ybtm_off,
                         addr + common->ctop_off,
                         addr + common->cbtm_off);

        local_irq_restore(flags);
        list_add_tail(&buf1->stream, &common->buffer_queue.stream);
        mutex_unlock(&common->buffer_queue.vb_lock);
        return 0;

qbuf_exit:
        mutex_unlock(&common->buffer_queue.vb_lock);
        return -EINVAL;
}

/**
 * vpif_dqbuf() - query buffer handler
 * @file: file ptr
 * @priv: file handle
 * @buf: v4l2 buffer structure ptr
 */
static int vpif_dqbuf(struct file *file, void *priv, struct v4l2_buffer *buf)
{
        struct vpif_fh *fh = priv;
        struct channel_obj *ch = fh->channel;
        struct common_obj *common = &ch->common[VPIF_VIDEO_INDEX];

        vpif_dbg(2, debug, "vpif_dqbuf\n");

        return videobuf_dqbuf(&common->buffer_queue, buf,
                                        file->f_flags & O_NONBLOCK);
}

/**
 * vpif_streamon() - streamon handler
 * @file: file ptr
 * @priv: file handle
 * @buftype: v4l2 buffer type
 */
static int vpif_streamon(struct file *file, void *priv,
                                enum v4l2_buf_type buftype)
{

        struct vpif_capture_config *config = vpif_dev->platform_data;
        struct vpif_fh *fh = priv;
        struct channel_obj *ch = fh->channel;
        struct common_obj *common = &ch->common[VPIF_VIDEO_INDEX];
        struct channel_obj *oth_ch = vpif_obj.dev[!ch->channel_id];
        struct vpif_params *vpif;
        unsigned long addr = 0;
        int ret = 0;

        vpif_dbg(2, debug, "vpif_streamon\n");

        vpif = &ch->vpifparams;

        if (buftype != V4L2_BUF_TYPE_VIDEO_CAPTURE) {
                vpif_dbg(1, debug, "buffer type not supported\n");
                return -EINVAL;
        }

        /* If file handle is not allowed IO, return error */
        if (!fh->io_allowed[VPIF_VIDEO_INDEX]) {
                vpif_dbg(1, debug, "io not allowed\n");
                return -EACCES;
        }

        /* If Streaming is already started, return error */
        if (common->started) {
                vpif_dbg(1, debug, "channel->started\n");
                return -EBUSY;
        }

        if ((ch->channel_id == VPIF_CHANNEL0_VIDEO &&
            oth_ch->common[VPIF_VIDEO_INDEX].started &&
            vpif->std_info.ycmux_mode == 0) ||
           ((ch->channel_id == VPIF_CHANNEL1_VIDEO) &&
            (2 == oth_ch->common[VPIF_VIDEO_INDEX].started))) {
                vpif_dbg(1, debug, "other channel is being used\n");
                return -EBUSY;
        }

        ret = vpif_check_format(ch, &common->fmt.fmt.pix, 0);
        if (ret)
                return ret;

        /* Enable streamon on the sub device */
        ret = v4l2_subdev_call(vpif_obj.sd[ch->curr_sd_index], video,
                                s_stream, 1);

        if (ret && (ret != -ENOIOCTLCMD)) {
                vpif_dbg(1, debug, "stream on failed in subdev\n");
                return ret;
        }

        /* Call videobuf_streamon to start streaming in videobuf */
        ret = videobuf_streamon(&common->buffer_queue);
        if (ret) {
                vpif_dbg(1, debug, "videobuf_streamon\n");
                return ret;
        }

        if (mutex_lock_interruptible(&common->lock)) {
                ret = -ERESTARTSYS;
                goto streamoff_exit;
        }

        /* If buffer queue is empty, return error */
        if (list_empty(&common->dma_queue)) {
                vpif_dbg(1, debug, "buffer queue is empty\n");
                ret = -EIO;
                goto exit;
        }

        /* Get the next frame from the buffer queue */
        common->cur_frm = list_entry(common->dma_queue.next,
                                    struct videobuf_buffer, queue);
        common->next_frm = common->cur_frm;

        /* Remove buffer from the buffer queue */
        list_del(&common->cur_frm->queue);
        /* Mark state of the current frame to active */
        common->cur_frm->state = VIDEOBUF_ACTIVE;
        /* Initialize field_id and started member */
        ch->field_id = 0;
        common->started = 1;

        if (V4L2_MEMORY_USERPTR == common->memory)
                addr = common->cur_frm->boff;
        else
                addr = videobuf_to_dma_contig(common->cur_frm);

        /* Calculate the offset for Y and C data in the buffer */
        vpif_calculate_offsets(ch);

        if ((vpif->std_info.frm_fmt &&
            ((common->fmt.fmt.pix.field != V4L2_FIELD_NONE) &&
             (common->fmt.fmt.pix.field != V4L2_FIELD_ANY))) ||
            (!vpif->std_info.frm_fmt &&
             (common->fmt.fmt.pix.field == V4L2_FIELD_NONE))) {
                vpif_dbg(1, debug, "conflict in field format and std format\n");
                ret = -EINVAL;
                goto exit;
        }

        /* configure 1 or 2 channel mode */
        ret = config->setup_input_channel_mode(vpif->std_info.ycmux_mode);

        if (ret < 0) {
                vpif_dbg(1, debug, "can't set vpif channel mode\n");
                goto exit;
        }

        /* Call vpif_set_params function to set the parameters and addresses */
        ret = vpif_set_video_params(vpif, ch->channel_id);

        if (ret < 0) {
                vpif_dbg(1, debug, "can't set video params\n");
                goto exit;
        }

        common->started = ret;
        vpif_config_addr(ch, ret);

        common->set_addr(addr + common->ytop_off,
                         addr + common->ybtm_off,
                         addr + common->ctop_off,
                         addr + common->cbtm_off);

        /**
         * Set interrupt for both the fields in VPIF Register enable channel in
         * VPIF register
         */
        if ((VPIF_CHANNEL0_VIDEO == ch->channel_id)) {
                channel0_intr_assert();
                channel0_intr_enable(1);
                enable_channel0(1);
        }
        if ((VPIF_CHANNEL1_VIDEO == ch->channel_id) ||
            (common->started == 2)) {
                channel1_intr_assert();
                channel1_intr_enable(1);
                enable_channel1(1);
        }
        channel_first_int[VPIF_VIDEO_INDEX][ch->channel_id] = 1;
        mutex_unlock(&common->lock);
        return ret;

exit:
        mutex_unlock(&common->lock);
streamoff_exit:
        ret = videobuf_streamoff(&common->buffer_queue);
        return ret;
}

/**
 * vpif_streamoff() - streamoff handler
 * @file: file ptr
 * @priv: file handle
 * @buftype: v4l2 buffer type
 */
static int vpif_streamoff(struct file *file, void *priv,
                                enum v4l2_buf_type buftype)
{

        struct vpif_fh *fh = priv;
        struct channel_obj *ch = fh->channel;
        struct common_obj *common = &ch->common[VPIF_VIDEO_INDEX];
        int ret;

        vpif_dbg(2, debug, "vpif_streamoff\n");

        if (buftype != V4L2_BUF_TYPE_VIDEO_CAPTURE) {
                vpif_dbg(1, debug, "buffer type not supported\n");
                return -EINVAL;
        }

        /* If io is allowed for this file handle, return error */
        if (!fh->io_allowed[VPIF_VIDEO_INDEX]) {
                vpif_dbg(1, debug, "io not allowed\n");
                return -EACCES;
        }

        /* If streaming is not started, return error */
        if (!common->started) {
                vpif_dbg(1, debug, "channel->started\n");
                return -EINVAL;
        }

        if (mutex_lock_interruptible(&common->lock))
                return -ERESTARTSYS;

        /* disable channel */
        if (VPIF_CHANNEL0_VIDEO == ch->channel_id) {
                enable_channel0(0);
                channel0_intr_enable(0);
        } else {
                enable_channel1(0);
                channel1_intr_enable(0);
        }

        common->started = 0;

        ret = v4l2_subdev_call(vpif_obj.sd[ch->curr_sd_index], video,
                                s_stream, 0);

        if (ret && (ret != -ENOIOCTLCMD))
                vpif_dbg(1, debug, "stream off failed in subdev\n");

        mutex_unlock(&common->lock);

        return videobuf_streamoff(&common->buffer_queue);
}

/**
 * vpif_map_sub_device_to_input() - Maps sub device to input
 * @ch - ptr to channel
 * @config - ptr to capture configuration
 * @input_index - Given input index from application
 * @sub_device_index - index into sd table
 *
 * lookup the sub device information for a given input index.
 * we report all the inputs to application. inputs table also
 * has sub device name for the each input
 */
static struct vpif_subdev_info *vpif_map_sub_device_to_input(
                                struct channel_obj *ch,
                                struct vpif_capture_config *vpif_cfg,
                                int input_index,
                                int *sub_device_index)
{
        struct vpif_capture_chan_config *chan_cfg;
        struct vpif_subdev_info *subdev_info = NULL;
        const char *subdev_name = NULL;
        int i;

        vpif_dbg(2, debug, "vpif_map_sub_device_to_input\n");

        chan_cfg = &vpif_cfg->chan_config[ch->channel_id];

        /**
         * search through the inputs to find the sub device supporting
         * the input
         */
        for (i = 0; i < chan_cfg->input_count; i++) {
                /* For each sub device, loop through input */
                if (i == input_index) {
                        subdev_name = chan_cfg->inputs[i].subdev_name;
                        break;
                }
        }

        /* if reached maximum. return null */
        if (i == chan_cfg->input_count || (NULL == subdev_name))
                return subdev_info;

        /* loop through the sub device list to get the sub device info */
        for (i = 0; i < vpif_cfg->subdev_count; i++) {
                subdev_info = &vpif_cfg->subdev_info[i];
                if (!strcmp(subdev_info->name, subdev_name))
                        break;
        }

        if (i == vpif_cfg->subdev_count)
                return subdev_info;

        /* check if the sub device is registered */
        if (NULL == vpif_obj.sd[i])
                return NULL;

        *sub_device_index = i;
        return subdev_info;
}

/**
 * vpif_querystd() - querystd handler
 * @file: file ptr
 * @priv: file handle
 * @std_id: ptr to std id
 *
 * This function is called to detect standard at the selected input
 */
static int vpif_querystd(struct file *file, void *priv, v4l2_std_id *std_id)
{
        struct vpif_fh *fh = priv;
        struct channel_obj *ch = fh->channel;
        struct common_obj *common = &ch->common[VPIF_VIDEO_INDEX];
        int ret = 0;

        vpif_dbg(2, debug, "vpif_querystd\n");

        if (mutex_lock_interruptible(&common->lock))
                return -ERESTARTSYS;

        /* Call querystd function of decoder device */
        ret = v4l2_subdev_call(vpif_obj.sd[ch->curr_sd_index], video,
                                querystd, std_id);
        if (ret < 0)
                vpif_dbg(1, debug, "Failed to set standard for sub devices\n");

        mutex_unlock(&common->lock);
        return ret;
}

/**
 * vpif_g_std() - get STD handler
 * @file: file ptr
 * @priv: file handle
 * @std_id: ptr to std id
 */
static int vpif_g_std(struct file *file, void *priv, v4l2_std_id *std)
{
        struct vpif_fh *fh = priv;
        struct channel_obj *ch = fh->channel;

        vpif_dbg(2, debug, "vpif_g_std\n");

        *std = ch->video.stdid;
        return 0;
}

/**
 * vpif_s_std() - set STD handler
 * @file: file ptr
 * @priv: file handle
 * @std_id: ptr to std id
 */
static int vpif_s_std(struct file *file, void *priv, v4l2_std_id *std_id)
{
        struct vpif_fh *fh = priv;
        struct channel_obj *ch = fh->channel;
        struct common_obj *common = &ch->common[VPIF_VIDEO_INDEX];
        int ret = 0;

        vpif_dbg(2, debug, "vpif_s_std\n");

        if (common->started) {
                vpif_err("streaming in progress\n");
                return -EBUSY;
        }

        if ((VPIF_CHANNEL0_VIDEO == ch->channel_id) ||
            (VPIF_CHANNEL1_VIDEO == ch->channel_id)) {
                if (!fh->initialized) {
                        vpif_dbg(1, debug, "Channel Busy\n");
                        return -EBUSY;
                }
        }

        ret = v4l2_prio_check(&ch->prio, &fh->prio);
        if (0 != ret)
                return ret;

        fh->initialized = 1;

        /* Call encoder subdevice function to set the standard */
        if (mutex_lock_interruptible(&common->lock))
                return -ERESTARTSYS;

        ch->video.stdid = *std_id;

        /* Get the information about the standard */
        if (vpif_update_std_info(ch)) {
                ret = -EINVAL;
                vpif_err("Error getting the standard info\n");
                goto s_std_exit;
        }

        /* Configure the default format information */
        vpif_config_format(ch);

        /* set standard in the sub device */
        ret = v4l2_subdev_call(vpif_obj.sd[ch->curr_sd_index], core,
                                s_std, *std_id);
        if (ret < 0)
                vpif_dbg(1, debug, "Failed to set standard for sub devices\n");

s_std_exit:
        mutex_unlock(&common->lock);
        return ret;
}

/**
 * vpif_enum_input() - ENUMINPUT handler
 * @file: file ptr
 * @priv: file handle
 * @input: ptr to input structure
 */
static int vpif_enum_input(struct file *file, void *priv,
                                struct v4l2_input *input)
{

        struct vpif_capture_config *config = vpif_dev->platform_data;
        struct vpif_capture_chan_config *chan_cfg;
        struct vpif_fh *fh = priv;
        struct channel_obj *ch = fh->channel;

        chan_cfg = &config->chan_config[ch->channel_id];

        if (input->index >= chan_cfg->input_count) {
                vpif_dbg(1, debug, "Invalid input index\n");
                return -EINVAL;
        }

        memcpy(input, &chan_cfg->inputs[input->index].input,
                sizeof(*input));
        return 0;
}

/**
 * vpif_g_input() - Get INPUT handler
 * @file: file ptr
 * @priv: file handle
 * @index: ptr to input index
 */
static int vpif_g_input(struct file *file, void *priv, unsigned int *index)
{
        struct vpif_fh *fh = priv;
        struct channel_obj *ch = fh->channel;
        struct video_obj *vid_ch = &ch->video;

        *index = vid_ch->input_idx;

        return 0;
}

/**
 * vpif_s_input() - Set INPUT handler
 * @file: file ptr
 * @priv: file handle
 * @index: input index
 */
static int vpif_s_input(struct file *file, void *priv, unsigned int index)
{
        struct vpif_capture_config *config = vpif_dev->platform_data;
        struct vpif_capture_chan_config *chan_cfg;
        struct vpif_fh *fh = priv;
        struct channel_obj *ch = fh->channel;
        struct common_obj *common = &ch->common[VPIF_VIDEO_INDEX];
        struct video_obj *vid_ch = &ch->video;
        struct vpif_subdev_info *subdev_info;
        int ret = 0, sd_index = 0;
        u32 input = 0, output = 0;

        chan_cfg = &config->chan_config[ch->channel_id];

        if (common->started) {
                vpif_err("Streaming in progress\n");
                return -EBUSY;
        }

        if ((VPIF_CHANNEL0_VIDEO == ch->channel_id) ||
            (VPIF_CHANNEL1_VIDEO == ch->channel_id)) {
                if (!fh->initialized) {
                        vpif_dbg(1, debug, "Channel Busy\n");
                        return -EBUSY;
                }
        }

        ret = v4l2_prio_check(&ch->prio, &fh->prio);
        if (0 != ret)
                return ret;

        fh->initialized = 1;
        subdev_info = vpif_map_sub_device_to_input(ch, config, index,
                                                   &sd_index);
        if (NULL == subdev_info) {
                vpif_dbg(1, debug,
                        "couldn't lookup sub device for the input index\n");
                return -EINVAL;
        }

        if (mutex_lock_interruptible(&common->lock))
                return -ERESTARTSYS;

        /* first setup input path from sub device to vpif */
        if (config->setup_input_path) {
                ret = config->setup_input_path(ch->channel_id,
                                               subdev_info->name);
                if (ret < 0) {
                        vpif_dbg(1, debug, "couldn't setup input path for the"
                                " sub device %s, for input index %d\n",
                                subdev_info->name, index);
                        goto exit;
                }
        }

        if (subdev_info->can_route) {
                input = subdev_info->input;
                output = subdev_info->output;
                ret = v4l2_subdev_call(vpif_obj.sd[sd_index], video, s_routing,
                                        input, output, 0);
                if (ret < 0) {
                        vpif_dbg(1, debug, "Failed to set input\n");
                        goto exit;
                }
        }
        vid_ch->input_idx = index;
        ch->curr_subdev_info = subdev_info;
        ch->curr_sd_index = sd_index;
        /* copy interface parameters to vpif */
        ch->vpifparams.iface = subdev_info->vpif_if;

        /* update tvnorms from the sub device input info */
        ch->video_dev->tvnorms = chan_cfg->inputs[index].input.std;

exit:
        mutex_unlock(&common->lock);
        return ret;
}

/**
 * vpif_enum_fmt_vid_cap() - ENUM_FMT handler
 * @file: file ptr
 * @priv: file handle
 * @index: input index
 */
static int vpif_enum_fmt_vid_cap(struct file *file, void  *priv,
                                        struct v4l2_fmtdesc *fmt)
{
        struct vpif_fh *fh = priv;
        struct channel_obj *ch = fh->channel;

        if (fmt->index != 0) {
                vpif_dbg(1, debug, "Invalid format index\n");
                return -EINVAL;
        }

        /* Fill in the information about format */
        if (ch->vpifparams.iface.if_type == VPIF_IF_RAW_BAYER) {
                fmt->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
                strcpy(fmt->description, "Raw Mode -Bayer Pattern GrRBGb");
                fmt->pixelformat = V4L2_PIX_FMT_SBGGR8;
        } else {
                fmt->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
                strcpy(fmt->description, "YCbCr4:2:2 YC Planar");
                fmt->pixelformat = V4L2_PIX_FMT_YUV422P;
        }
        return 0;
}

/**
 * vpif_try_fmt_vid_cap() - TRY_FMT handler
 * @file: file ptr
 * @priv: file handle
 * @fmt: ptr to v4l2 format structure
 */
static int vpif_try_fmt_vid_cap(struct file *file, void *priv,
                                struct v4l2_format *fmt)
{
        struct vpif_fh *fh = priv;
        struct channel_obj *ch = fh->channel;
        struct v4l2_pix_format *pixfmt = &fmt->fmt.pix;

        return vpif_check_format(ch, pixfmt, 1);
}


/**
 * vpif_g_fmt_vid_cap() - Set INPUT handler
 * @file: file ptr
 * @priv: file handle
 * @fmt: ptr to v4l2 format structure
 */
static int vpif_g_fmt_vid_cap(struct file *file, void *priv,
                                struct v4l2_format *fmt)
{
        struct vpif_fh *fh = priv;
        struct channel_obj *ch = fh->channel;
        struct common_obj *common = &ch->common[VPIF_VIDEO_INDEX];

        /* Check the validity of the buffer type */
        if (common->fmt.type != fmt->type)
                return -EINVAL;

        /* Fill in the information about format */
        if (mutex_lock_interruptible(&common->lock))
                return -ERESTARTSYS;

        *fmt = common->fmt;
        mutex_unlock(&common->lock);
        return 0;
}

/**
 * vpif_s_fmt_vid_cap() - Set FMT handler
 * @file: file ptr
 * @priv: file handle
 * @fmt: ptr to v4l2 format structure
 */
static int vpif_s_fmt_vid_cap(struct file *file, void *priv,
                                struct v4l2_format *fmt)
{
        struct vpif_fh *fh = priv;
        struct channel_obj *ch = fh->channel;
        struct common_obj *common = &ch->common[VPIF_VIDEO_INDEX];
        struct v4l2_pix_format *pixfmt;
        int ret = 0;

        vpif_dbg(2, debug, "VIDIOC_S_FMT\n");

        /* If streaming is started, return error */
        if (common->started) {
                vpif_dbg(1, debug, "Streaming is started\n");
                return -EBUSY;
        }

        if ((VPIF_CHANNEL0_VIDEO == ch->channel_id) ||
            (VPIF_CHANNEL1_VIDEO == ch->channel_id)) {
                if (!fh->initialized) {
                        vpif_dbg(1, debug, "Channel Busy\n");
                        return -EBUSY;
                }
        }

        ret = v4l2_prio_check(&ch->prio, &fh->prio);
        if (0 != ret)
                return ret;

        fh->initialized = 1;

        pixfmt = &fmt->fmt.pix;
        /* Check for valid field format */
        ret = vpif_check_format(ch, pixfmt, 0);

        if (ret)
                return ret;
        /* store the format in the channel object */
        if (mutex_lock_interruptible(&common->lock))
                return -ERESTARTSYS;

        common->fmt = *fmt;
        mutex_unlock(&common->lock);

        return 0;
}

/**
 * vpif_querycap() - QUERYCAP handler
 * @file: file ptr
 * @priv: file handle
 * @cap: ptr to v4l2_capability structure
 */
static int vpif_querycap(struct file *file, void  *priv,
                                struct v4l2_capability *cap)
{
        struct vpif_capture_config *config = vpif_dev->platform_data;

        cap->version = VPIF_CAPTURE_VERSION_CODE;
        cap->capabilities = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING;
        strlcpy(cap->driver, "vpif capture", sizeof(cap->driver));
        strlcpy(cap->bus_info, "DM646x Platform", sizeof(cap->bus_info));
        strlcpy(cap->card, config->card_name, sizeof(cap->card));

        return 0;
}

/**
 * vpif_g_priority() - get priority handler
 * @file: file ptr
 * @priv: file handle
 * @prio: ptr to v4l2_priority structure
 */
static int vpif_g_priority(struct file *file, void *priv,
                           enum v4l2_priority *prio)
{
        struct vpif_fh *fh = priv;
        struct channel_obj *ch = fh->channel;

        *prio = v4l2_prio_max(&ch->prio);

        return 0;
}

/**
 * vpif_s_priority() - set priority handler
 * @file: file ptr
 * @priv: file handle
 * @prio: ptr to v4l2_priority structure
 */
static int vpif_s_priority(struct file *file, void *priv, enum v4l2_priority p)
{
        struct vpif_fh *fh = priv;
        struct channel_obj *ch = fh->channel;

        return v4l2_prio_change(&ch->prio, &fh->prio, p);
}

/**
 * vpif_cropcap() - cropcap handler
 * @file: file ptr
 * @priv: file handle
 * @crop: ptr to v4l2_cropcap structure
 */
static int vpif_cropcap(struct file *file, void *priv,
                        struct v4l2_cropcap *crop)
{
        struct vpif_fh *fh = priv;
        struct channel_obj *ch = fh->channel;
        struct common_obj *common = &ch->common[VPIF_VIDEO_INDEX];

        if (V4L2_BUF_TYPE_VIDEO_CAPTURE != crop->type)
                return -EINVAL;

        crop->bounds.left = 0;
        crop->bounds.top = 0;
        crop->bounds.height = common->height;
        crop->bounds.width = common->width;
        crop->defrect = crop->bounds;
        return 0;
}

/* vpif capture ioctl operations */
static const struct v4l2_ioctl_ops vpif_ioctl_ops = {
        .vidioc_querycap                = vpif_querycap,
        .vidioc_g_priority              = vpif_g_priority,
        .vidioc_s_priority              = vpif_s_priority,
        .vidioc_enum_fmt_vid_cap        = vpif_enum_fmt_vid_cap,
        .vidioc_g_fmt_vid_cap           = vpif_g_fmt_vid_cap,
        .vidioc_s_fmt_vid_cap           = vpif_s_fmt_vid_cap,
        .vidioc_try_fmt_vid_cap         = vpif_try_fmt_vid_cap,
        .vidioc_enum_input              = vpif_enum_input,
        .vidioc_s_input                 = vpif_s_input,
        .vidioc_g_input                 = vpif_g_input,
        .vidioc_reqbufs                 = vpif_reqbufs,
        .vidioc_querybuf                = vpif_querybuf,
        .vidioc_querystd                = vpif_querystd,
        .vidioc_s_std                   = vpif_s_std,
        .vidioc_g_std                   = vpif_g_std,
        .vidioc_qbuf                    = vpif_qbuf,
        .vidioc_dqbuf                   = vpif_dqbuf,
        .vidioc_streamon                = vpif_streamon,
        .vidioc_streamoff               = vpif_streamoff,
        .vidioc_cropcap                 = vpif_cropcap,
};

/* vpif file operations */
static struct v4l2_file_operations vpif_fops = {
        .owner = THIS_MODULE,
        .open = vpif_open,
        .release = vpif_release,
        .ioctl = video_ioctl2,
        .mmap = vpif_mmap,
        .poll = vpif_poll
};

/* vpif video template */
static struct video_device vpif_video_template = {
        .name           = "vpif",
        .fops           = &vpif_fops,
        .minor          = -1,
        .ioctl_ops      = &vpif_ioctl_ops,
};

/**
 * initialize_vpif() - Initialize vpif data structures
 *
 * Allocate memory for data structures and initialize them
 */
static int initialize_vpif(void)
{
        int err = 0, i, j;
        int free_channel_objects_index;

        /* Default number of buffers should be 3 */
        if ((ch0_numbuffers > 0) &&
            (ch0_numbuffers < config_params.min_numbuffers))
                ch0_numbuffers = config_params.min_numbuffers;
        if ((ch1_numbuffers > 0) &&
            (ch1_numbuffers < config_params.min_numbuffers))
                ch1_numbuffers = config_params.min_numbuffers;

        /* Set buffer size to min buffers size if it is invalid */
        if (ch0_bufsize < config_params.min_bufsize[VPIF_CHANNEL0_VIDEO])
                ch0_bufsize =
                    config_params.min_bufsize[VPIF_CHANNEL0_VIDEO];
        if (ch1_bufsize < config_params.min_bufsize[VPIF_CHANNEL1_VIDEO])
                ch1_bufsize =
                    config_params.min_bufsize[VPIF_CHANNEL1_VIDEO];

        config_params.numbuffers[VPIF_CHANNEL0_VIDEO] = ch0_numbuffers;
        config_params.numbuffers[VPIF_CHANNEL1_VIDEO] = ch1_numbuffers;
        if (ch0_numbuffers) {
                config_params.channel_bufsize[VPIF_CHANNEL0_VIDEO]
                    = ch0_bufsize;
        }
        if (ch1_numbuffers) {
                config_params.channel_bufsize[VPIF_CHANNEL1_VIDEO]
                    = ch1_bufsize;
        }

        /* Allocate memory for six channel objects */
        for (i = 0; i < VPIF_CAPTURE_MAX_DEVICES; i++) {
                vpif_obj.dev[i] =
                    kzalloc(sizeof(*vpif_obj.dev[i]), GFP_KERNEL);
                /* If memory allocation fails, return error */
                if (!vpif_obj.dev[i]) {
                        free_channel_objects_index = i;
                        err = -ENOMEM;
                        goto vpif_init_free_channel_objects;
                }
        }
        return 0;

vpif_init_free_channel_objects:
        for (j = 0; j < free_channel_objects_index; j++)
                kfree(vpif_obj.dev[j]);
        return err;
}

/**
 * vpif_probe : This function probes the vpif capture driver
 * @pdev: platform device pointer
 *
 * This creates device entries by register itself to the V4L2 driver and
 * initializes fields of each channel objects
 */
static __init int vpif_probe(struct platform_device *pdev)
{
        struct vpif_subdev_info *subdevdata;
        struct vpif_capture_config *config;
        int i, j, k, m, q, err;
        struct i2c_adapter *i2c_adap;
        struct channel_obj *ch;
        struct common_obj *common;
        struct video_device *vfd;
        struct resource *res;
        int subdev_count;

        vpif_dev = &pdev->dev;

        err = initialize_vpif();
        if (err) {
                v4l2_err(vpif_dev->driver, "Error initializing vpif\n");
                return err;
        }

        k = 0;
        while ((res = platform_get_resource(pdev, IORESOURCE_IRQ, k))) {
                for (i = res->start; i <= res->end; i++) {
                        if (request_irq(i, vpif_channel_isr, IRQF_DISABLED,
                                        "DM646x_Capture",
                                (void *)(&vpif_obj.dev[k]->channel_id))) {
                                err = -EBUSY;
                                i--;
                                goto vpif_int_err;
                        }
                }
                k++;
        }

        for (i = 0; i < VPIF_CAPTURE_MAX_DEVICES; i++) {
                /* Get the pointer to the channel object */
                ch = vpif_obj.dev[i];
                /* Allocate memory for video device */
                vfd = video_device_alloc();
                if (NULL == vfd) {
                        for (j = 0; j < i; j++) {
                                ch = vpif_obj.dev[j];
                                video_device_release(ch->video_dev);
                        }
                        err = -ENOMEM;
                        goto vpif_dev_alloc_err;
                }

                /* Initialize field of video device */
                *vfd = vpif_video_template;
                vfd->v4l2_dev = &vpif_obj.v4l2_dev;
                vfd->release = video_device_release;
                snprintf(vfd->name, sizeof(vfd->name),
                         "DM646x_VPIFCapture_DRIVER_V%d.%d.%d",
                         (VPIF_CAPTURE_VERSION_CODE >> 16) & 0xff,
                         (VPIF_CAPTURE_VERSION_CODE >> 8) & 0xff,
                         (VPIF_CAPTURE_VERSION_CODE) & 0xff);
                /* Set video_dev to the video device */
                ch->video_dev = vfd;
        }

        for (j = 0; j < VPIF_CAPTURE_MAX_DEVICES; j++) {
                ch = vpif_obj.dev[j];
                ch->channel_id = j;
                common = &(ch->common[VPIF_VIDEO_INDEX]);
                spin_lock_init(&common->irqlock);
                mutex_init(&common->lock);
                /* Initialize prio member of channel object */
                v4l2_prio_init(&ch->prio);
                err = video_register_device(ch->video_dev,
                                            VFL_TYPE_GRABBER, (j ? 1 : 0));
                if (err)
                        goto probe_out;

                video_set_drvdata(ch->video_dev, ch);

        }

        i2c_adap = i2c_get_adapter(1);
        config = pdev->dev.platform_data;

        subdev_count = config->subdev_count;
        vpif_obj.sd = kmalloc(sizeof(struct v4l2_subdev *) * subdev_count,
                                GFP_KERNEL);
        if (vpif_obj.sd == NULL) {
                vpif_err("unable to allocate memory for subdevice pointers\n");
                err = -ENOMEM;

                goto probe_out;
        }

        err = v4l2_device_register(vpif_dev, &vpif_obj.v4l2_dev);
        if (err) {
                v4l2_err(vpif_dev->driver, "Error registering v4l2 device\n");
                goto probe_subdev_out;
        }

        for (i = 0; i < subdev_count; i++) {
                subdevdata = &config->subdev_info[i];
                vpif_obj.sd[i] =
                        v4l2_i2c_new_subdev_board(&vpif_obj.v4l2_dev,
                                                  i2c_adap,
                                                  subdevdata->name,
                                                  &subdevdata->board_info,
                                                  NULL);

                if (!vpif_obj.sd[i]) {
                        vpif_err("Error registering v4l2 subdevice\n");
                        goto probe_subdev_out;
                }
                v4l2_info(&vpif_obj.v4l2_dev, "registered sub device %s\n",
                          subdevdata->name);

                if (vpif_obj.sd[i])
                        vpif_obj.sd[i]->grp_id = 1 << i;
        }
        v4l2_info(&vpif_obj.v4l2_dev, "DM646x VPIF Capture driver"
                  " initialized\n");

        return 0;

probe_subdev_out:
        /* free sub devices memory */
        kfree(vpif_obj.sd);

        j = VPIF_CAPTURE_MAX_DEVICES;
probe_out:
        v4l2_device_unregister(&vpif_obj.v4l2_dev);
        for (k = 0; k < j; k++) {
                /* Get the pointer to the channel object */
                ch = vpif_obj.dev[k];
                /* Unregister video device */
                video_unregister_device(ch->video_dev);
        }

vpif_dev_alloc_err:
        k = VPIF_CAPTURE_MAX_DEVICES-1;
        res = platform_get_resource(pdev, IORESOURCE_IRQ, k);
        i = res->end;

vpif_int_err:
        for (q = k; q >= 0; q--) {
                for (m = i; m >= (int)res->start; m--)
                        free_irq(m, (void *)(&vpif_obj.dev[q]->channel_id));

                res = platform_get_resource(pdev, IORESOURCE_IRQ, q-1);
                if (res)
                        i = res->end;
        }
        return err;
}

/**
 * vpif_remove() - driver remove handler
 * @device: ptr to platform device structure
 *
 * The vidoe device is unregistered
 */
static int vpif_remove(struct platform_device *device)
{
        int i;
        struct channel_obj *ch;

        v4l2_device_unregister(&vpif_obj.v4l2_dev);

        /* un-register device */
        for (i = 0; i < VPIF_CAPTURE_MAX_DEVICES; i++) {
                /* Get the pointer to the channel object */
                ch = vpif_obj.dev[i];
                /* Unregister video device */
                video_unregister_device(ch->video_dev);
        }
        return 0;
}

/**
 * vpif_suspend: vpif device suspend
 *
 * TODO: Add suspend code here
 */
static int
vpif_suspend(struct device *dev)
{
        return -1;
}

/**
 * vpif_resume: vpif device suspend
 *
 * TODO: Add resume code here
 */
static int
vpif_resume(struct device *dev)
{
        return -1;
}

static struct dev_pm_ops vpif_dev_pm_ops = {
        .suspend = vpif_suspend,
        .resume = vpif_resume,
};

static struct platform_driver vpif_driver = {
        .driver = {
                .name   = "vpif_capture",
                .owner  = THIS_MODULE,
                .pm = &vpif_dev_pm_ops,
        },
        .probe = vpif_probe,
        .remove = vpif_remove,
};

/**
 * vpif_init: initialize the vpif driver
 *
 * This function registers device and driver to the kernel, requests irq
 * handler and allocates memory
 * for channel objects
 */
static __init int vpif_init(void)
{
        return platform_driver_register(&vpif_driver);
}

/**
 * vpif_cleanup : This function clean up the vpif capture resources
 *
 * This will un-registers device and driver to the kernel, frees
 * requested irq handler and de-allocates memory allocated for channel
 * objects.
 */
static void vpif_cleanup(void)
{
        struct platform_device *pdev;
        struct resource *res;
        int irq_num;
        int i = 0;

        pdev = container_of(vpif_dev, struct platform_device, dev);
        while ((res = platform_get_resource(pdev, IORESOURCE_IRQ, i))) {
                for (irq_num = res->start; irq_num <= res->end; irq_num++)
                        free_irq(irq_num,
                                 (void *)(&vpif_obj.dev[i]->channel_id));
                i++;
        }

        platform_driver_unregister(&vpif_driver);

        kfree(vpif_obj.sd);
        for (i = 0; i < VPIF_CAPTURE_MAX_DEVICES; i++)
                kfree(vpif_obj.dev[i]);
}

/* Function for module initialization and cleanup */
module_init(vpif_init);
module_exit(vpif_cleanup);