/*
 * V4L2 Driver for SuperH Mobile CEU interface
 *
 * Copyright (C) 2008 Magnus Damm
 *
 * Based on V4L2 Driver for PXA camera host - "pxa_camera.c",
 *
 * Copyright (C) 2006, Sascha Hauer, Pengutronix
 * Copyright (C) 2008, Guennadi Liakhovetski <kernel@pengutronix.de>
 *
 * 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.
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/io.h>
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/moduleparam.h>
#include <linux/of.h>
#include <linux/time.h>
#include <linux/slab.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/videodev2.h>
#include <linux/pm_runtime.h>
#include <linux/sched.h>

#include <media/v4l2-async.h>
#include <media/v4l2-common.h>
#include <media/v4l2-dev.h>
#include <media/soc_camera.h>
#include <media/sh_mobile_ceu.h>
#include <media/sh_mobile_csi2.h>
#include <media/videobuf2-dma-contig.h>
#include <media/v4l2-mediabus.h>
#include <media/soc_mediabus.h>

#include "soc_scale_crop.h"

/* register offsets for sh7722 / sh7723 */

#define CAPSR  0x00 /* Capture start register */
#define CAPCR  0x04 /* Capture control register */
#define CAMCR  0x08 /* Capture interface control register */
#define CMCYR  0x0c /* Capture interface cycle  register */
#define CAMOR  0x10 /* Capture interface offset register */
#define CAPWR  0x14 /* Capture interface width register */
#define CAIFR  0x18 /* Capture interface input format register */
#define CSTCR  0x20 /* Camera strobe control register (<= sh7722) */
#define CSECR  0x24 /* Camera strobe emission count register (<= sh7722) */
#define CRCNTR 0x28 /* CEU register control register */
#define CRCMPR 0x2c /* CEU register forcible control register */
#define CFLCR  0x30 /* Capture filter control register */
#define CFSZR  0x34 /* Capture filter size clip register */
#define CDWDR  0x38 /* Capture destination width register */
#define CDAYR  0x3c /* Capture data address Y register */
#define CDACR  0x40 /* Capture data address C register */
#define CDBYR  0x44 /* Capture data bottom-field address Y register */
#define CDBCR  0x48 /* Capture data bottom-field address C register */
#define CBDSR  0x4c /* Capture bundle destination size register */
#define CFWCR  0x5c /* Firewall operation control register */
#define CLFCR  0x60 /* Capture low-pass filter control register */
#define CDOCR  0x64 /* Capture data output control register */
#define CDDCR  0x68 /* Capture data complexity level register */
#define CDDAR  0x6c /* Capture data complexity level address register */
#define CEIER  0x70 /* Capture event interrupt enable register */
#define CETCR  0x74 /* Capture event flag clear register */
#define CSTSR  0x7c /* Capture status register */
#define CSRTR  0x80 /* Capture software reset register */
#define CDSSR  0x84 /* Capture data size register */
#define CDAYR2 0x90 /* Capture data address Y register 2 */
#define CDACR2 0x94 /* Capture data address C register 2 */
#define CDBYR2 0x98 /* Capture data bottom-field address Y register 2 */
#define CDBCR2 0x9c /* Capture data bottom-field address C register 2 */

#undef DEBUG_GEOMETRY
#ifdef DEBUG_GEOMETRY
#define dev_geo dev_info
#else
#define dev_geo dev_dbg
#endif

/* per video frame buffer */
struct sh_mobile_ceu_buffer {
        struct vb2_buffer vb; /* v4l buffer must be first */
        struct list_head queue;
};

struct sh_mobile_ceu_dev {
        struct soc_camera_host ici;
        /* Asynchronous CSI2 linking */
        struct v4l2_async_subdev *csi2_asd;
        struct v4l2_subdev *csi2_sd;
        /* Synchronous probing compatibility */
        struct platform_device *csi2_pdev;

        unsigned int irq;
        void __iomem *base;
        size_t video_limit;
        size_t buf_total;

        spinlock_t lock;                /* Protects video buffer lists */
        struct list_head capture;
        struct vb2_buffer *active;
        struct vb2_alloc_ctx *alloc_ctx;

        struct sh_mobile_ceu_info *pdata;
        struct completion complete;

        u32 cflcr;

        /* static max sizes either from platform data or default */
        int max_width;
        int max_height;

        enum v4l2_field field;
        int sequence;
        unsigned long flags;

        unsigned int image_mode:1;
        unsigned int is_16bit:1;
        unsigned int frozen:1;
};

struct sh_mobile_ceu_cam {
        /* CEU offsets within the camera output, before the CEU scaler */
        unsigned int ceu_left;
        unsigned int ceu_top;
        /* Client output, as seen by the CEU */
        unsigned int width;
        unsigned int height;
        /*
         * User window from S_CROP / G_CROP, produced by client cropping and
         * scaling, CEU scaling and CEU cropping, mapped back onto the client
         * input window
         */
        struct v4l2_rect subrect;
        /* Camera cropping rectangle */
        struct v4l2_rect rect;
        const struct soc_mbus_pixelfmt *extra_fmt;
        enum v4l2_mbus_pixelcode code;
};

static struct sh_mobile_ceu_buffer *to_ceu_vb(struct vb2_buffer *vb)
{
        return container_of(vb, struct sh_mobile_ceu_buffer, vb);
}

static void ceu_write(struct sh_mobile_ceu_dev *priv,
                      unsigned long reg_offs, u32 data)
{
        iowrite32(data, priv->base + reg_offs);
}

static u32 ceu_read(struct sh_mobile_ceu_dev *priv, unsigned long reg_offs)
{
        return ioread32(priv->base + reg_offs);
}

static int sh_mobile_ceu_soft_reset(struct sh_mobile_ceu_dev *pcdev)
{
        int i, success = 0;

        ceu_write(pcdev, CAPSR, 1 << 16); /* reset */

        /* wait CSTSR.CPTON bit */
        for (i = 0; i < 1000; i++) {
                if (!(ceu_read(pcdev, CSTSR) & 1)) {
                        success++;
                        break;
                }
                udelay(1);
        }

        /* wait CAPSR.CPKIL bit */
        for (i = 0; i < 1000; i++) {
                if (!(ceu_read(pcdev, CAPSR) & (1 << 16))) {
                        success++;
                        break;
                }
                udelay(1);
        }

        if (2 != success) {
                dev_warn(pcdev->ici.v4l2_dev.dev, "soft reset time out\n");
                return -EIO;
        }

        return 0;
}

/*
 *  Videobuf operations
 */

/*
 * .queue_setup() is called to check, whether the driver can accept the
 *                requested number of buffers and to fill in plane sizes
 *                for the current frame format if required
 */
static int sh_mobile_ceu_videobuf_setup(struct vb2_queue *vq,
                        const struct v4l2_format *fmt,
                        unsigned int *count, unsigned int *num_planes,
                        unsigned int sizes[], void *alloc_ctxs[])
{
        struct soc_camera_device *icd = container_of(vq, struct soc_camera_device, vb2_vidq);
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
        struct sh_mobile_ceu_dev *pcdev = ici->priv;

        if (fmt) {
                const struct soc_camera_format_xlate *xlate = soc_camera_xlate_by_fourcc(icd,
                                                                fmt->fmt.pix.pixelformat);
                unsigned int bytes_per_line;
                int ret;

                if (!xlate)
                        return -EINVAL;

                ret = soc_mbus_bytes_per_line(fmt->fmt.pix.width,
                                              xlate->host_fmt);
                if (ret < 0)
                        return ret;

                bytes_per_line = max_t(u32, fmt->fmt.pix.bytesperline, ret);

                ret = soc_mbus_image_size(xlate->host_fmt, bytes_per_line,
                                          fmt->fmt.pix.height);
                if (ret < 0)
                        return ret;

                sizes[0] = max_t(u32, fmt->fmt.pix.sizeimage, ret);
        } else {
                /* Called from VIDIOC_REQBUFS or in compatibility mode */
                sizes[0] = icd->sizeimage;
        }

        alloc_ctxs[0] = pcdev->alloc_ctx;

        if (!vq->num_buffers)
                pcdev->sequence = 0;

        if (!*count)
                *count = 2;

        /* If *num_planes != 0, we have already verified *count. */
        if (pcdev->video_limit && !*num_planes) {
                size_t size = PAGE_ALIGN(sizes[0]) * *count;

                if (size + pcdev->buf_total > pcdev->video_limit)
                        *count = (pcdev->video_limit - pcdev->buf_total) /
                                PAGE_ALIGN(sizes[0]);
        }

        *num_planes = 1;

        dev_dbg(icd->parent, "count=%d, size=%u\n", *count, sizes[0]);

        return 0;
}

#define CEU_CETCR_MAGIC 0x0317f313 /* acknowledge magical interrupt sources */
#define CEU_CETCR_IGRW (1 << 4) /* prohibited register access interrupt bit */
#define CEU_CEIER_CPEIE (1 << 0) /* one-frame capture end interrupt */
#define CEU_CEIER_VBP   (1 << 20) /* vbp error */
#define CEU_CAPCR_CTNCP (1 << 16) /* continuous capture mode (if set) */
#define CEU_CEIER_MASK (CEU_CEIER_CPEIE | CEU_CEIER_VBP)


/*
 * return value doesn't reflex the success/failure to queue the new buffer,
 * but rather the status of the previous buffer.
 */
static int sh_mobile_ceu_capture(struct sh_mobile_ceu_dev *pcdev)
{
        struct soc_camera_device *icd = pcdev->ici.icd;
        dma_addr_t phys_addr_top, phys_addr_bottom;
        unsigned long top1, top2;
        unsigned long bottom1, bottom2;
        u32 status;
        bool planar;
        int ret = 0;

        /*
         * The hardware is _very_ picky about this sequence. Especially
         * the CEU_CETCR_MAGIC value. It seems like we need to acknowledge
         * several not-so-well documented interrupt sources in CETCR.
         */
        ceu_write(pcdev, CEIER, ceu_read(pcdev, CEIER) & ~CEU_CEIER_MASK);
        status = ceu_read(pcdev, CETCR);
        ceu_write(pcdev, CETCR, ~status & CEU_CETCR_MAGIC);
        if (!pcdev->frozen)
                ceu_write(pcdev, CEIER, ceu_read(pcdev, CEIER) | CEU_CEIER_MASK);
        ceu_write(pcdev, CAPCR, ceu_read(pcdev, CAPCR) & ~CEU_CAPCR_CTNCP);
        ceu_write(pcdev, CETCR, CEU_CETCR_MAGIC ^ CEU_CETCR_IGRW);

        /*
         * When a VBP interrupt occurs, a capture end interrupt does not occur
         * and the image of that frame is not captured correctly. So, soft reset
         * is needed here.
         */
        if (status & CEU_CEIER_VBP) {
                sh_mobile_ceu_soft_reset(pcdev);
                ret = -EIO;
        }

        if (pcdev->frozen) {
                complete(&pcdev->complete);
                return ret;
        }

        if (!pcdev->active)
                return ret;

        if (V4L2_FIELD_INTERLACED_BT == pcdev->field) {
                top1    = CDBYR;
                top2    = CDBCR;
                bottom1 = CDAYR;
                bottom2 = CDACR;
        } else {
                top1    = CDAYR;
                top2    = CDACR;
                bottom1 = CDBYR;
                bottom2 = CDBCR;
        }

        phys_addr_top = vb2_dma_contig_plane_dma_addr(pcdev->active, 0);

        switch (icd->current_fmt->host_fmt->fourcc) {
        case V4L2_PIX_FMT_NV12:
        case V4L2_PIX_FMT_NV21:
        case V4L2_PIX_FMT_NV16:
        case V4L2_PIX_FMT_NV61:
                planar = true;
                break;
        default:
                planar = false;
        }

        ceu_write(pcdev, top1, phys_addr_top);
        if (V4L2_FIELD_NONE != pcdev->field) {
                phys_addr_bottom = phys_addr_top + icd->bytesperline;
                ceu_write(pcdev, bottom1, phys_addr_bottom);
        }

        if (planar) {
                phys_addr_top += icd->bytesperline * icd->user_height;
                ceu_write(pcdev, top2, phys_addr_top);
                if (V4L2_FIELD_NONE != pcdev->field) {
                        phys_addr_bottom = phys_addr_top + icd->bytesperline;
                        ceu_write(pcdev, bottom2, phys_addr_bottom);
                }
        }

        ceu_write(pcdev, CAPSR, 0x1); /* start capture */

        return ret;
}

static int sh_mobile_ceu_videobuf_prepare(struct vb2_buffer *vb)
{
        struct sh_mobile_ceu_buffer *buf = to_ceu_vb(vb);

        /* Added list head initialization on alloc */
        WARN(!list_empty(&buf->queue), "Buffer %p on queue!\n", vb);

        return 0;
}

static void sh_mobile_ceu_videobuf_queue(struct vb2_buffer *vb)
{
        struct soc_camera_device *icd = container_of(vb->vb2_queue, struct soc_camera_device, vb2_vidq);
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
        struct sh_mobile_ceu_dev *pcdev = ici->priv;
        struct sh_mobile_ceu_buffer *buf = to_ceu_vb(vb);
        unsigned long size;

        size = icd->sizeimage;

        if (vb2_plane_size(vb, 0) < size) {
                dev_err(icd->parent, "Buffer #%d too small (%lu < %lu)\n",
                        vb->v4l2_buf.index, vb2_plane_size(vb, 0), size);
                goto error;
        }

        vb2_set_plane_payload(vb, 0, size);

        dev_dbg(icd->parent, "%s (vb=0x%p) 0x%p %lu\n", __func__,
                vb, vb2_plane_vaddr(vb, 0), vb2_get_plane_payload(vb, 0));

#ifdef DEBUG
        /*
         * This can be useful if you want to see if we actually fill
         * the buffer with something
         */
        if (vb2_plane_vaddr(vb, 0))
                memset(vb2_plane_vaddr(vb, 0), 0xaa, vb2_get_plane_payload(vb, 0));
#endif

        spin_lock_irq(&pcdev->lock);
        list_add_tail(&buf->queue, &pcdev->capture);

        if (!pcdev->active) {
                /*
                 * Because there were no active buffer at this moment,
                 * we are not interested in the return value of
                 * sh_mobile_ceu_capture here.
                 */
                pcdev->active = vb;
                sh_mobile_ceu_capture(pcdev);
        }
        spin_unlock_irq(&pcdev->lock);

        return;

error:
        vb2_buffer_done(vb, VB2_BUF_STATE_ERROR);
}

static void sh_mobile_ceu_videobuf_release(struct vb2_buffer *vb)
{
        struct soc_camera_device *icd = container_of(vb->vb2_queue, struct soc_camera_device, vb2_vidq);
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
        struct sh_mobile_ceu_buffer *buf = to_ceu_vb(vb);
        struct sh_mobile_ceu_dev *pcdev = ici->priv;

        spin_lock_irq(&pcdev->lock);

        if (pcdev->active == vb) {
                /* disable capture (release DMA buffer), reset */
                ceu_write(pcdev, CAPSR, 1 << 16);
                pcdev->active = NULL;
        }

        /*
         * Doesn't hurt also if the list is empty, but it hurts, if queuing the
         * buffer failed, and .buf_init() hasn't been called
         */
        if (buf->queue.next)
                list_del_init(&buf->queue);

        pcdev->buf_total -= PAGE_ALIGN(vb2_plane_size(vb, 0));
        dev_dbg(icd->parent, "%s() %zu bytes buffers\n", __func__,
                pcdev->buf_total);

        spin_unlock_irq(&pcdev->lock);
}

static int sh_mobile_ceu_videobuf_init(struct vb2_buffer *vb)
{
        struct soc_camera_device *icd = container_of(vb->vb2_queue, struct soc_camera_device, vb2_vidq);
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
        struct sh_mobile_ceu_dev *pcdev = ici->priv;

        pcdev->buf_total += PAGE_ALIGN(vb2_plane_size(vb, 0));
        dev_dbg(icd->parent, "%s() %zu bytes buffers\n", __func__,
                pcdev->buf_total);

        /* This is for locking debugging only */
        INIT_LIST_HEAD(&to_ceu_vb(vb)->queue);
        return 0;
}

static int sh_mobile_ceu_stop_streaming(struct vb2_queue *q)
{
        struct soc_camera_device *icd = container_of(q, struct soc_camera_device, vb2_vidq);
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
        struct sh_mobile_ceu_dev *pcdev = ici->priv;
        struct list_head *buf_head, *tmp;

        spin_lock_irq(&pcdev->lock);

        pcdev->active = NULL;

        list_for_each_safe(buf_head, tmp, &pcdev->capture)
                list_del_init(buf_head);

        spin_unlock_irq(&pcdev->lock);

        return sh_mobile_ceu_soft_reset(pcdev);
}

static struct vb2_ops sh_mobile_ceu_videobuf_ops = {
        .queue_setup    = sh_mobile_ceu_videobuf_setup,
        .buf_prepare    = sh_mobile_ceu_videobuf_prepare,
        .buf_queue      = sh_mobile_ceu_videobuf_queue,
        .buf_cleanup    = sh_mobile_ceu_videobuf_release,
        .buf_init       = sh_mobile_ceu_videobuf_init,
        .wait_prepare   = soc_camera_unlock,
        .wait_finish    = soc_camera_lock,
        .stop_streaming = sh_mobile_ceu_stop_streaming,
};

static irqreturn_t sh_mobile_ceu_irq(int irq, void *data)
{
        struct sh_mobile_ceu_dev *pcdev = data;
        struct vb2_buffer *vb;
        int ret;

        spin_lock(&pcdev->lock);

        vb = pcdev->active;
        if (!vb)
                /* Stale interrupt from a released buffer */
                goto out;

        list_del_init(&to_ceu_vb(vb)->queue);

        if (!list_empty(&pcdev->capture))
                pcdev->active = &list_entry(pcdev->capture.next,
                                            struct sh_mobile_ceu_buffer, queue)->vb;
        else
                pcdev->active = NULL;

        ret = sh_mobile_ceu_capture(pcdev);
        v4l2_get_timestamp(&vb->v4l2_buf.timestamp);
        if (!ret) {
                vb->v4l2_buf.field = pcdev->field;
                vb->v4l2_buf.sequence = pcdev->sequence++;
        }
        vb2_buffer_done(vb, ret < 0 ? VB2_BUF_STATE_ERROR : VB2_BUF_STATE_DONE);

out:
        spin_unlock(&pcdev->lock);

        return IRQ_HANDLED;
}

static struct v4l2_subdev *find_csi2(struct sh_mobile_ceu_dev *pcdev)
{
        struct v4l2_subdev *sd;

        if (pcdev->csi2_sd)
                return pcdev->csi2_sd;

        if (pcdev->csi2_asd) {
                char name[] = "sh-mobile-csi2";
                v4l2_device_for_each_subdev(sd, &pcdev->ici.v4l2_dev)
                        if (!strncmp(name, sd->name, sizeof(name) - 1)) {
                                pcdev->csi2_sd = sd;
                                return sd;
                        }
        }

        return NULL;
}

static struct v4l2_subdev *csi2_subdev(struct sh_mobile_ceu_dev *pcdev,
                                       struct soc_camera_device *icd)
{
        struct v4l2_subdev *sd = pcdev->csi2_sd;

        return sd && sd->grp_id == soc_camera_grp_id(icd) ? sd : NULL;
}

static int sh_mobile_ceu_add_device(struct soc_camera_device *icd)
{
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
        struct sh_mobile_ceu_dev *pcdev = ici->priv;
        struct v4l2_subdev *csi2_sd = find_csi2(pcdev);
        int ret;

        if (csi2_sd) {
                csi2_sd->grp_id = soc_camera_grp_id(icd);
                v4l2_set_subdev_hostdata(csi2_sd, icd);
        }

        ret = v4l2_subdev_call(csi2_sd, core, s_power, 1);
        if (ret < 0 && ret != -ENOIOCTLCMD && ret != -ENODEV)
                return ret;

        /*
         * -ENODEV is special: either csi2_sd == NULL or the CSI-2 driver
         * has not found this soc-camera device among its clients
         */
        if (csi2_sd && ret == -ENODEV)
                csi2_sd->grp_id = 0;

        dev_info(icd->parent,
                 "SuperH Mobile CEU%s driver attached to camera %d\n",
                 csi2_sd && csi2_sd->grp_id ? "/CSI-2" : "", icd->devnum);

        return 0;
}

static void sh_mobile_ceu_remove_device(struct soc_camera_device *icd)
{
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
        struct sh_mobile_ceu_dev *pcdev = ici->priv;
        struct v4l2_subdev *csi2_sd = find_csi2(pcdev);

        dev_info(icd->parent,
                 "SuperH Mobile CEU driver detached from camera %d\n",
                 icd->devnum);

        v4l2_subdev_call(csi2_sd, core, s_power, 0);
}

/* Called with .host_lock held */
static int sh_mobile_ceu_clock_start(struct soc_camera_host *ici)
{
        struct sh_mobile_ceu_dev *pcdev = ici->priv;
        int ret;

        pm_runtime_get_sync(ici->v4l2_dev.dev);

        pcdev->buf_total = 0;

        ret = sh_mobile_ceu_soft_reset(pcdev);

        return 0;
}

/* Called with .host_lock held */
static void sh_mobile_ceu_clock_stop(struct soc_camera_host *ici)
{
        struct sh_mobile_ceu_dev *pcdev = ici->priv;

        /* disable capture, disable interrupts */
        ceu_write(pcdev, CEIER, 0);
        sh_mobile_ceu_soft_reset(pcdev);

        /* make sure active buffer is canceled */
        spin_lock_irq(&pcdev->lock);
        if (pcdev->active) {
                list_del_init(&to_ceu_vb(pcdev->active)->queue);
                vb2_buffer_done(pcdev->active, VB2_BUF_STATE_ERROR);
                pcdev->active = NULL;
        }
        spin_unlock_irq(&pcdev->lock);

        pm_runtime_put(ici->v4l2_dev.dev);
}

/*
 * See chapter 29.4.12 "Capture Filter Control Register (CFLCR)"
 * in SH7722 Hardware Manual
 */
static unsigned int size_dst(unsigned int src, unsigned int scale)
{
        unsigned int mant_pre = scale >> 12;
        if (!src || !scale)
                return src;
        return ((mant_pre + 2 * (src - 1)) / (2 * mant_pre) - 1) *
                mant_pre * 4096 / scale + 1;
}

static u16 calc_scale(unsigned int src, unsigned int *dst)
{
        u16 scale;

        if (src == *dst)
                return 0;

        scale = (src * 4096 / *dst) & ~7;

        while (scale > 4096 && size_dst(src, scale) < *dst)
                scale -= 8;

        *dst = size_dst(src, scale);

        return scale;
}

/* rect is guaranteed to not exceed the scaled camera rectangle */
static void sh_mobile_ceu_set_rect(struct soc_camera_device *icd)
{
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
        struct sh_mobile_ceu_cam *cam = icd->host_priv;
        struct sh_mobile_ceu_dev *pcdev = ici->priv;
        unsigned int height, width, cdwdr_width, in_width, in_height;
        unsigned int left_offset, top_offset;
        u32 camor;

        dev_geo(icd->parent, "Crop %ux%u@%u:%u\n",
                icd->user_width, icd->user_height, cam->ceu_left, cam->ceu_top);

        left_offset     = cam->ceu_left;
        top_offset      = cam->ceu_top;

        WARN_ON(icd->user_width & 3 || icd->user_height & 3);

        width = icd->user_width;

        if (pcdev->image_mode) {
                in_width = cam->width;
                if (!pcdev->is_16bit) {
                        in_width *= 2;
                        left_offset *= 2;
                }
        } else {
                unsigned int w_factor;

                switch (icd->current_fmt->host_fmt->packing) {
                case SOC_MBUS_PACKING_2X8_PADHI:
                        w_factor = 2;
                        break;
                default:
                        w_factor = 1;
                }

                in_width = cam->width * w_factor;
                left_offset *= w_factor;
        }

        cdwdr_width = icd->bytesperline;

        height = icd->user_height;
        in_height = cam->height;
        if (V4L2_FIELD_NONE != pcdev->field) {
                height = (height / 2) & ~3;
                in_height /= 2;
                top_offset /= 2;
                cdwdr_width *= 2;
        }

        /* CSI2 special configuration */
        if (csi2_subdev(pcdev, icd)) {
                in_width = ((in_width - 2) * 2);
                left_offset *= 2;
        }

        /* Set CAMOR, CAPWR, CFSZR, take care of CDWDR */
        camor = left_offset | (top_offset << 16);

        dev_geo(icd->parent,
                "CAMOR 0x%x, CAPWR 0x%x, CFSZR 0x%x, CDWDR 0x%x\n", camor,
                (in_height << 16) | in_width, (height << 16) | width,
                cdwdr_width);

        ceu_write(pcdev, CAMOR, camor);
        ceu_write(pcdev, CAPWR, (in_height << 16) | in_width);
        /* CFSZR clipping is applied _after_ the scaling filter (CFLCR) */
        ceu_write(pcdev, CFSZR, (height << 16) | width);
        ceu_write(pcdev, CDWDR, cdwdr_width);
}

static u32 capture_save_reset(struct sh_mobile_ceu_dev *pcdev)
{
        u32 capsr = ceu_read(pcdev, CAPSR);
        ceu_write(pcdev, CAPSR, 1 << 16); /* reset, stop capture */
        return capsr;
}

static void capture_restore(struct sh_mobile_ceu_dev *pcdev, u32 capsr)
{
        unsigned long timeout = jiffies + 10 * HZ;

        /*
         * Wait until the end of the current frame. It can take a long time,
         * but if it has been aborted by a CAPSR reset, it shoule exit sooner.
         */
        while ((ceu_read(pcdev, CSTSR) & 1) && time_before(jiffies, timeout))
                msleep(1);

        if (time_after(jiffies, timeout)) {
                dev_err(pcdev->ici.v4l2_dev.dev,
                        "Timeout waiting for frame end! Interface problem?\n");
                return;
        }

        /* Wait until reset clears, this shall not hang... */
        while (ceu_read(pcdev, CAPSR) & (1 << 16))
                udelay(10);

        /* Anything to restore? */
        if (capsr & ~(1 << 16))
                ceu_write(pcdev, CAPSR, capsr);
}

/* Find the bus subdevice driver, e.g., CSI2 */
static struct v4l2_subdev *find_bus_subdev(struct sh_mobile_ceu_dev *pcdev,
                                           struct soc_camera_device *icd)
{
        return csi2_subdev(pcdev, icd) ? : soc_camera_to_subdev(icd);
}

#define CEU_BUS_FLAGS (V4L2_MBUS_MASTER |       \
                V4L2_MBUS_PCLK_SAMPLE_RISING |  \
                V4L2_MBUS_HSYNC_ACTIVE_HIGH |   \
                V4L2_MBUS_HSYNC_ACTIVE_LOW |    \
                V4L2_MBUS_VSYNC_ACTIVE_HIGH |   \
                V4L2_MBUS_VSYNC_ACTIVE_LOW |    \
                V4L2_MBUS_DATA_ACTIVE_HIGH)

/* Capture is not running, no interrupts, no locking needed */
static int sh_mobile_ceu_set_bus_param(struct soc_camera_device *icd)
{
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
        struct sh_mobile_ceu_dev *pcdev = ici->priv;
        struct v4l2_subdev *sd = find_bus_subdev(pcdev, icd);
        struct sh_mobile_ceu_cam *cam = icd->host_priv;
        struct v4l2_mbus_config cfg = {.type = V4L2_MBUS_PARALLEL,};
        unsigned long value, common_flags = CEU_BUS_FLAGS;
        u32 capsr = capture_save_reset(pcdev);
        unsigned int yuv_lineskip;
        int ret;

        /*
         * If the client doesn't implement g_mbus_config, we just use our
         * platform data
         */
        ret = v4l2_subdev_call(sd, video, g_mbus_config, &cfg);
        if (!ret) {
                common_flags = soc_mbus_config_compatible(&cfg,
                                                          common_flags);
                if (!common_flags)
                        return -EINVAL;
        } else if (ret != -ENOIOCTLCMD) {
                return ret;
        }

        /* Make choises, based on platform preferences */
        if ((common_flags & V4L2_MBUS_HSYNC_ACTIVE_HIGH) &&
            (common_flags & V4L2_MBUS_HSYNC_ACTIVE_LOW)) {
                if (pcdev->flags & SH_CEU_FLAG_HSYNC_LOW)
                        common_flags &= ~V4L2_MBUS_HSYNC_ACTIVE_HIGH;
                else
                        common_flags &= ~V4L2_MBUS_HSYNC_ACTIVE_LOW;
        }

        if ((common_flags & V4L2_MBUS_VSYNC_ACTIVE_HIGH) &&
            (common_flags & V4L2_MBUS_VSYNC_ACTIVE_LOW)) {
                if (pcdev->flags & SH_CEU_FLAG_VSYNC_LOW)
                        common_flags &= ~V4L2_MBUS_VSYNC_ACTIVE_HIGH;
                else
                        common_flags &= ~V4L2_MBUS_VSYNC_ACTIVE_LOW;
        }

        cfg.flags = common_flags;
        ret = v4l2_subdev_call(sd, video, s_mbus_config, &cfg);
        if (ret < 0 && ret != -ENOIOCTLCMD)
                return ret;

        if (icd->current_fmt->host_fmt->bits_per_sample > 8)
                pcdev->is_16bit = 1;
        else
                pcdev->is_16bit = 0;

        ceu_write(pcdev, CRCNTR, 0);
        ceu_write(pcdev, CRCMPR, 0);

        value = 0x00000010; /* data fetch by default */
        yuv_lineskip = 0x10;

        switch (icd->current_fmt->host_fmt->fourcc) {
        case V4L2_PIX_FMT_NV12:
        case V4L2_PIX_FMT_NV21:
                /* convert 4:2:2 -> 4:2:0 */
                yuv_lineskip = 0; /* skip for NV12/21, no skip for NV16/61 */
                /* fall-through */
        case V4L2_PIX_FMT_NV16:
        case V4L2_PIX_FMT_NV61:
                switch (cam->code) {
                case V4L2_MBUS_FMT_UYVY8_2X8:
                        value = 0x00000000; /* Cb0, Y0, Cr0, Y1 */
                        break;
                case V4L2_MBUS_FMT_VYUY8_2X8:
                        value = 0x00000100; /* Cr0, Y0, Cb0, Y1 */
                        break;
                case V4L2_MBUS_FMT_YUYV8_2X8:
                        value = 0x00000200; /* Y0, Cb0, Y1, Cr0 */
                        break;
                case V4L2_MBUS_FMT_YVYU8_2X8:
                        value = 0x00000300; /* Y0, Cr0, Y1, Cb0 */
                        break;
                default:
                        BUG();
                }
        }

        if (icd->current_fmt->host_fmt->fourcc == V4L2_PIX_FMT_NV21 ||
            icd->current_fmt->host_fmt->fourcc == V4L2_PIX_FMT_NV61)
                value ^= 0x00000100; /* swap U, V to change from NV1x->NVx1 */

        value |= common_flags & V4L2_MBUS_VSYNC_ACTIVE_LOW ? 1 << 1 : 0;
        value |= common_flags & V4L2_MBUS_HSYNC_ACTIVE_LOW ? 1 << 0 : 0;

        if (csi2_subdev(pcdev, icd)) /* CSI2 mode */
                value |= 3 << 12;
        else if (pcdev->is_16bit)
                value |= 1 << 12;
        else if (pcdev->flags & SH_CEU_FLAG_LOWER_8BIT)
                value |= 2 << 12;

        ceu_write(pcdev, CAMCR, value);

        ceu_write(pcdev, CAPCR, 0x00300000);

        switch (pcdev->field) {
        case V4L2_FIELD_INTERLACED_TB:
                value = 0x101;
                break;
        case V4L2_FIELD_INTERLACED_BT:
                value = 0x102;
                break;
        default:
                value = 0;
                break;
        }
        ceu_write(pcdev, CAIFR, value);

        sh_mobile_ceu_set_rect(icd);
        mdelay(1);

        dev_geo(icd->parent, "CFLCR 0x%x\n", pcdev->cflcr);
        ceu_write(pcdev, CFLCR, pcdev->cflcr);

        /*
         * A few words about byte order (observed in Big Endian mode)
         *
         * In data fetch mode bytes are received in chunks of 8 bytes.
         * D0, D1, D2, D3, D4, D5, D6, D7 (D0 received first)
         *
         * The data is however by default written to memory in reverse order:
         * D7, D6, D5, D4, D3, D2, D1, D0 (D7 written to lowest byte)
         *
         * The lowest three bits of CDOCR allows us to do swapping,
         * using 7 we swap the data bytes to match the incoming order:
         * D0, D1, D2, D3, D4, D5, D6, D7
         */
        value = 0x00000007 | yuv_lineskip;

        ceu_write(pcdev, CDOCR, value);
        ceu_write(pcdev, CFWCR, 0); /* keep "datafetch firewall" disabled */

        capture_restore(pcdev, capsr);

        /* not in bundle mode: skip CBDSR, CDAYR2, CDACR2, CDBYR2, CDBCR2 */
        return 0;
}

static int sh_mobile_ceu_try_bus_param(struct soc_camera_device *icd,
                                       unsigned char buswidth)
{
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
        struct sh_mobile_ceu_dev *pcdev = ici->priv;
        struct v4l2_subdev *sd = find_bus_subdev(pcdev, icd);
        unsigned long common_flags = CEU_BUS_FLAGS;
        struct v4l2_mbus_config cfg = {.type = V4L2_MBUS_PARALLEL,};
        int ret;

        ret = v4l2_subdev_call(sd, video, g_mbus_config, &cfg);
        if (!ret)
                common_flags = soc_mbus_config_compatible(&cfg,
                                                          common_flags);
        else if (ret != -ENOIOCTLCMD)
                return ret;

        if (!common_flags || buswidth > 16)
                return -EINVAL;

        return 0;
}

static const struct soc_mbus_pixelfmt sh_mobile_ceu_formats[] = {
        {
                .fourcc                 = V4L2_PIX_FMT_NV12,
                .name                   = "NV12",
                .bits_per_sample        = 8,
                .packing                = SOC_MBUS_PACKING_1_5X8,
                .order                  = SOC_MBUS_ORDER_LE,
                .layout                 = SOC_MBUS_LAYOUT_PLANAR_2Y_C,
        }, {
                .fourcc                 = V4L2_PIX_FMT_NV21,
                .name                   = "NV21",
                .bits_per_sample        = 8,
                .packing                = SOC_MBUS_PACKING_1_5X8,
                .order                  = SOC_MBUS_ORDER_LE,
                .layout                 = SOC_MBUS_LAYOUT_PLANAR_2Y_C,
        }, {
                .fourcc                 = V4L2_PIX_FMT_NV16,
                .name                   = "NV16",
                .bits_per_sample        = 8,
                .packing                = SOC_MBUS_PACKING_2X8_PADHI,
                .order                  = SOC_MBUS_ORDER_LE,
                .layout                 = SOC_MBUS_LAYOUT_PLANAR_Y_C,
        }, {
                .fourcc                 = V4L2_PIX_FMT_NV61,
                .name                   = "NV61",
                .bits_per_sample        = 8,
                .packing                = SOC_MBUS_PACKING_2X8_PADHI,
                .order                  = SOC_MBUS_ORDER_LE,
                .layout                 = SOC_MBUS_LAYOUT_PLANAR_Y_C,
        },
};

/* This will be corrected as we get more formats */
static bool sh_mobile_ceu_packing_supported(const struct soc_mbus_pixelfmt *fmt)
{

        return  fmt->packing == SOC_MBUS_PACKING_NONE ||
                (fmt->bits_per_sample == 8 &&
                 fmt->packing == SOC_MBUS_PACKING_1_5X8) ||
                (fmt->bits_per_sample == 8 &&
                 fmt->packing == SOC_MBUS_PACKING_2X8_PADHI) ||
                (fmt->bits_per_sample > 8 &&
                 fmt->packing == SOC_MBUS_PACKING_EXTEND16);
}

static struct soc_camera_device *ctrl_to_icd(struct v4l2_ctrl *ctrl)
{
        return container_of(ctrl->handler, struct soc_camera_device,
                                                        ctrl_handler);
}

static int sh_mobile_ceu_s_ctrl(struct v4l2_ctrl *ctrl)
{
        struct soc_camera_device *icd = ctrl_to_icd(ctrl);
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
        struct sh_mobile_ceu_dev *pcdev = ici->priv;

        switch (ctrl->id) {
        case V4L2_CID_SHARPNESS:
                switch (icd->current_fmt->host_fmt->fourcc) {
                case V4L2_PIX_FMT_NV12:
                case V4L2_PIX_FMT_NV21:
                case V4L2_PIX_FMT_NV16:
                case V4L2_PIX_FMT_NV61:
                        ceu_write(pcdev, CLFCR, !ctrl->val);
                        return 0;
                }
                break;
        }

        return -EINVAL;
}

static const struct v4l2_ctrl_ops sh_mobile_ceu_ctrl_ops = {
        .s_ctrl = sh_mobile_ceu_s_ctrl,
};

static int sh_mobile_ceu_get_formats(struct soc_camera_device *icd, unsigned int idx,
                                     struct soc_camera_format_xlate *xlate)
{
        struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
        struct device *dev = icd->parent;
        struct soc_camera_host *ici = to_soc_camera_host(dev);
        struct sh_mobile_ceu_dev *pcdev = ici->priv;
        int ret, k, n;
        int formats = 0;
        struct sh_mobile_ceu_cam *cam;
        enum v4l2_mbus_pixelcode code;
        const struct soc_mbus_pixelfmt *fmt;

        ret = v4l2_subdev_call(sd, video, enum_mbus_fmt, idx, &code);
        if (ret < 0)
                /* No more formats */
                return 0;

        fmt = soc_mbus_get_fmtdesc(code);
        if (!fmt) {
                dev_warn(dev, "unsupported format code #%u: %d\n", idx, code);
                return 0;
        }

        if (!csi2_subdev(pcdev, icd)) {
                /* Are there any restrictions in the CSI-2 case? */
                ret = sh_mobile_ceu_try_bus_param(icd, fmt->bits_per_sample);
                if (ret < 0)
                        return 0;
        }

        if (!icd->host_priv) {
                struct v4l2_mbus_framefmt mf;
                struct v4l2_rect rect;
                int shift = 0;

                /* Add our control */
                v4l2_ctrl_new_std(&icd->ctrl_handler, &sh_mobile_ceu_ctrl_ops,
                                  V4L2_CID_SHARPNESS, 0, 1, 1, 1);
                if (icd->ctrl_handler.error)
                        return icd->ctrl_handler.error;

                /* FIXME: subwindow is lost between close / open */

                /* Cache current client geometry */
                ret = soc_camera_client_g_rect(sd, &rect);
                if (ret < 0)
                        return ret;

                /* First time */
                ret = v4l2_subdev_call(sd, video, g_mbus_fmt, &mf);
                if (ret < 0)
                        return ret;

                /*
                 * All currently existing CEU implementations support 2560x1920
                 * or larger frames. If the sensor is proposing too big a frame,
                 * don't bother with possibly supportred by the CEU larger
                 * sizes, just try VGA multiples. If needed, this can be
                 * adjusted in the future.
                 */
                while ((mf.width > pcdev->max_width ||
                        mf.height > pcdev->max_height) && shift < 4) {
                        /* Try 2560x1920, 1280x960, 640x480, 320x240 */
                        mf.width        = 2560 >> shift;
                        mf.height       = 1920 >> shift;
                        ret = v4l2_device_call_until_err(sd->v4l2_dev,
                                        soc_camera_grp_id(icd), video,
                                        s_mbus_fmt, &mf);
                        if (ret < 0)
                                return ret;
                        shift++;
                }

                if (shift == 4) {
                        dev_err(dev, "Failed to configure the client below %ux%x\n",
                                mf.width, mf.height);
                        return -EIO;
                }

                dev_geo(dev, "camera fmt %ux%u\n", mf.width, mf.height);

                cam = kzalloc(sizeof(*cam), GFP_KERNEL);
                if (!cam)
                        return -ENOMEM;

                /* We are called with current camera crop, initialise subrect with it */
                cam->rect       = rect;
                cam->subrect    = rect;

                cam->width      = mf.width;
                cam->height     = mf.height;

                icd->host_priv = cam;
        } else {
                cam = icd->host_priv;
        }

        /* Beginning of a pass */
        if (!idx)
                cam->extra_fmt = NULL;

        switch (code) {
        case V4L2_MBUS_FMT_UYVY8_2X8:
        case V4L2_MBUS_FMT_VYUY8_2X8:
        case V4L2_MBUS_FMT_YUYV8_2X8:
        case V4L2_MBUS_FMT_YVYU8_2X8:
                if (cam->extra_fmt)
                        break;

                /*
                 * Our case is simple so far: for any of the above four camera
                 * formats we add all our four synthesized NV* formats, so,
                 * just marking the device with a single flag suffices. If
                 * the format generation rules are more complex, you would have
                 * to actually hang your already added / counted formats onto
                 * the host_priv pointer and check whether the format you're
                 * going to add now is already there.
                 */
                cam->extra_fmt = sh_mobile_ceu_formats;

                n = ARRAY_SIZE(sh_mobile_ceu_formats);
                formats += n;
                for (k = 0; xlate && k < n; k++) {
                        xlate->host_fmt = &sh_mobile_ceu_formats[k];
                        xlate->code     = code;
                        xlate++;
                        dev_dbg(dev, "Providing format %s using code %d\n",
                                sh_mobile_ceu_formats[k].name, code);
                }
                break;
        default:
                if (!sh_mobile_ceu_packing_supported(fmt))
                        return 0;
        }

        /* Generic pass-through */
        formats++;
        if (xlate) {
                xlate->host_fmt = fmt;
                xlate->code     = code;
                xlate++;
                dev_dbg(dev, "Providing format %s in pass-through mode\n",
                        fmt->name);
        }

        return formats;
}

static void sh_mobile_ceu_put_formats(struct soc_camera_device *icd)
{
        kfree(icd->host_priv);
        icd->host_priv = NULL;
}

#define scale_down(size, scale) soc_camera_shift_scale(size, 12, scale)
#define calc_generic_scale(in, out) soc_camera_calc_scale(in, 12, out)

/*
 * CEU can scale and crop, but we don't want to waste bandwidth and kill the
 * framerate by always requesting the maximum image from the client. See
 * Documentation/video4linux/sh_mobile_ceu_camera.txt for a description of
 * scaling and cropping algorithms and for the meaning of referenced here steps.
 */
static int sh_mobile_ceu_set_crop(struct soc_camera_device *icd,
                                  const struct v4l2_crop *a)
{
        struct v4l2_crop a_writable = *a;
        const struct v4l2_rect *rect = &a_writable.c;
        struct device *dev = icd->parent;
        struct soc_camera_host *ici = to_soc_camera_host(dev);
        struct sh_mobile_ceu_dev *pcdev = ici->priv;
        struct v4l2_crop cam_crop;
        struct sh_mobile_ceu_cam *cam = icd->host_priv;
        struct v4l2_rect *cam_rect = &cam_crop.c;
        struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
        struct v4l2_mbus_framefmt mf;
        unsigned int scale_cam_h, scale_cam_v, scale_ceu_h, scale_ceu_v,
                out_width, out_height;
        int interm_width, interm_height;
        u32 capsr, cflcr;
        int ret;

        dev_geo(dev, "S_CROP(%ux%u@%u:%u)\n", rect->width, rect->height,
                rect->left, rect->top);

        /* During camera cropping its output window can change too, stop CEU */
        capsr = capture_save_reset(pcdev);
        dev_dbg(dev, "CAPSR 0x%x, CFLCR 0x%x\n", capsr, pcdev->cflcr);

        /*
         * 1. - 2. Apply iterative camera S_CROP for new input window, read back
         * actual camera rectangle.
         */
        ret = soc_camera_client_s_crop(sd, &a_writable, &cam_crop,
                                       &cam->rect, &cam->subrect);
        if (ret < 0)
                return ret;

        dev_geo(dev, "1-2: camera cropped to %ux%u@%u:%u\n",
                cam_rect->width, cam_rect->height,
                cam_rect->left, cam_rect->top);

        /* On success cam_crop contains current camera crop */

        /* 3. Retrieve camera output window */
        ret = v4l2_subdev_call(sd, video, g_mbus_fmt, &mf);
        if (ret < 0)
                return ret;

        if (mf.width > pcdev->max_width || mf.height > pcdev->max_height)
                return -EINVAL;

        /* 4. Calculate camera scales */
        scale_cam_h     = calc_generic_scale(cam_rect->width, mf.width);
        scale_cam_v     = calc_generic_scale(cam_rect->height, mf.height);

        /* Calculate intermediate window */
        interm_width    = scale_down(rect->width, scale_cam_h);
        interm_height   = scale_down(rect->height, scale_cam_v);

        if (interm_width < icd->user_width) {
                u32 new_scale_h;

                new_scale_h = calc_generic_scale(rect->width, icd->user_width);

                mf.width = scale_down(cam_rect->width, new_scale_h);
        }

        if (interm_height < icd->user_height) {
                u32 new_scale_v;

                new_scale_v = calc_generic_scale(rect->height, icd->user_height);

                mf.height = scale_down(cam_rect->height, new_scale_v);
        }

        if (interm_width < icd->user_width || interm_height < icd->user_height) {
                ret = v4l2_device_call_until_err(sd->v4l2_dev,
                                        soc_camera_grp_id(icd), video,
                                        s_mbus_fmt, &mf);
                if (ret < 0)
                        return ret;

                dev_geo(dev, "New camera output %ux%u\n", mf.width, mf.height);
                scale_cam_h     = calc_generic_scale(cam_rect->width, mf.width);
                scale_cam_v     = calc_generic_scale(cam_rect->height, mf.height);
                interm_width    = scale_down(rect->width, scale_cam_h);
                interm_height   = scale_down(rect->height, scale_cam_v);
        }

        /* Cache camera output window */
        cam->width      = mf.width;
        cam->height     = mf.height;

        if (pcdev->image_mode) {
                out_width       = min(interm_width, icd->user_width);
                out_height      = min(interm_height, icd->user_height);
        } else {
                out_width       = interm_width;
                out_height      = interm_height;
        }

        /*
         * 5. Calculate CEU scales from camera scales from results of (5) and
         *    the user window
         */
        scale_ceu_h     = calc_scale(interm_width, &out_width);
        scale_ceu_v     = calc_scale(interm_height, &out_height);

        dev_geo(dev, "5: CEU scales %u:%u\n", scale_ceu_h, scale_ceu_v);

        /* Apply CEU scales. */
        cflcr = scale_ceu_h | (scale_ceu_v << 16);
        if (cflcr != pcdev->cflcr) {
                pcdev->cflcr = cflcr;
                ceu_write(pcdev, CFLCR, cflcr);
        }

        icd->user_width  = out_width & ~3;
        icd->user_height = out_height & ~3;
        /* Offsets are applied at the CEU scaling filter input */
        cam->ceu_left    = scale_down(rect->left - cam_rect->left, scale_cam_h) & ~1;
        cam->ceu_top     = scale_down(rect->top - cam_rect->top, scale_cam_v) & ~1;

        /* 6. Use CEU cropping to crop to the new window. */
        sh_mobile_ceu_set_rect(icd);

        cam->subrect = *rect;

        dev_geo(dev, "6: CEU cropped to %ux%u@%u:%u\n",
                icd->user_width, icd->user_height,
                cam->ceu_left, cam->ceu_top);

        /* Restore capture. The CE bit can be cleared by the hardware */
        if (pcdev->active)
                capsr |= 1;
        capture_restore(pcdev, capsr);

        /* Even if only camera cropping succeeded */
        return ret;
}

static int sh_mobile_ceu_get_crop(struct soc_camera_device *icd,
                                  struct v4l2_crop *a)
{
        struct sh_mobile_ceu_cam *cam = icd->host_priv;

        a->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
        a->c = cam->subrect;

        return 0;
}

/* Similar to set_crop multistage iterative algorithm */
static int sh_mobile_ceu_set_fmt(struct soc_camera_device *icd,
                                 struct v4l2_format *f)
{
        struct device *dev = icd->parent;
        struct soc_camera_host *ici = to_soc_camera_host(dev);
        struct sh_mobile_ceu_dev *pcdev = ici->priv;
        struct sh_mobile_ceu_cam *cam = icd->host_priv;
        struct v4l2_pix_format *pix = &f->fmt.pix;
        struct v4l2_mbus_framefmt mf;
        __u32 pixfmt = pix->pixelformat;
        const struct soc_camera_format_xlate *xlate;
        unsigned int ceu_sub_width = pcdev->max_width,
                ceu_sub_height = pcdev->max_height;
        u16 scale_v, scale_h;
        int ret;
        bool image_mode;
        enum v4l2_field field;

        switch (pix->field) {
        default:
                pix->field = V4L2_FIELD_NONE;
                /* fall-through */
        case V4L2_FIELD_INTERLACED_TB:
        case V4L2_FIELD_INTERLACED_BT:
        case V4L2_FIELD_NONE:
                field = pix->field;
                break;
        case V4L2_FIELD_INTERLACED:
                field = V4L2_FIELD_INTERLACED_TB;
                break;
        }

        xlate = soc_camera_xlate_by_fourcc(icd, pixfmt);
        if (!xlate) {
                dev_warn(dev, "Format %x not found\n", pixfmt);
                return -EINVAL;
        }

        /* 1.-4. Calculate desired client output geometry */
        soc_camera_calc_client_output(icd, &cam->rect, &cam->subrect, pix, &mf, 12);
        mf.field        = pix->field;
        mf.colorspace   = pix->colorspace;
        mf.code         = xlate->code;

        switch (pixfmt) {
        case V4L2_PIX_FMT_NV12:
        case V4L2_PIX_FMT_NV21:
        case V4L2_PIX_FMT_NV16:
        case V4L2_PIX_FMT_NV61:
                image_mode = true;
                break;
        default:
                image_mode = false;
        }

        dev_geo(dev, "S_FMT(pix=0x%x, fld 0x%x, code 0x%x, %ux%u)\n", pixfmt, mf.field, mf.code,
                pix->width, pix->height);

        dev_geo(dev, "4: request camera output %ux%u\n", mf.width, mf.height);

        /* 5. - 9. */
        ret = soc_camera_client_scale(icd, &cam->rect, &cam->subrect,
                                &mf, &ceu_sub_width, &ceu_sub_height,
                                image_mode && V4L2_FIELD_NONE == field, 12);

        dev_geo(dev, "5-9: client scale return %d\n", ret);

        /* Done with the camera. Now see if we can improve the result */

        dev_geo(dev, "fmt %ux%u, requested %ux%u\n",
                mf.width, mf.height, pix->width, pix->height);
        if (ret < 0)
                return ret;

        if (mf.code != xlate->code)
                return -EINVAL;

        /* 9. Prepare CEU crop */
        cam->width = mf.width;
        cam->height = mf.height;

        /* 10. Use CEU scaling to scale to the requested user window. */

        /* We cannot scale up */
        if (pix->width > ceu_sub_width)
                ceu_sub_width = pix->width;

        if (pix->height > ceu_sub_height)
                ceu_sub_height = pix->height;

        pix->colorspace = mf.colorspace;

        if (image_mode) {
                /* Scale pix->{width x height} down to width x height */
                scale_h         = calc_scale(ceu_sub_width, &pix->width);
                scale_v         = calc_scale(ceu_sub_height, &pix->height);
        } else {
                pix->width      = ceu_sub_width;
                pix->height     = ceu_sub_height;
                scale_h         = 0;
                scale_v         = 0;
        }

        pcdev->cflcr = scale_h | (scale_v << 16);

        /*
         * We have calculated CFLCR, the actual configuration will be performed
         * in sh_mobile_ceu_set_bus_param()
         */

        dev_geo(dev, "10: W: %u : 0x%x = %u, H: %u : 0x%x = %u\n",
                ceu_sub_width, scale_h, pix->width,
                ceu_sub_height, scale_v, pix->height);

        cam->code               = xlate->code;
        icd->current_fmt        = xlate;

        pcdev->field = field;
        pcdev->image_mode = image_mode;

        /* CFSZR requirement */
        pix->width      &= ~3;
        pix->height     &= ~3;

        return 0;
}

#define CEU_CHDW_MAX    8188U   /* Maximum line stride */

static int sh_mobile_ceu_try_fmt(struct soc_camera_device *icd,
                                 struct v4l2_format *f)
{
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
        struct sh_mobile_ceu_dev *pcdev = ici->priv;
        const struct soc_camera_format_xlate *xlate;
        struct v4l2_pix_format *pix = &f->fmt.pix;
        struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
        struct v4l2_mbus_framefmt mf;
        __u32 pixfmt = pix->pixelformat;
        int width, height;
        int ret;

        dev_geo(icd->parent, "TRY_FMT(pix=0x%x, %ux%u)\n",
                 pixfmt, pix->width, pix->height);

        xlate = soc_camera_xlate_by_fourcc(icd, pixfmt);
        if (!xlate) {
                xlate = icd->current_fmt;
                dev_dbg(icd->parent, "Format %x not found, keeping %x\n",
                        pixfmt, xlate->host_fmt->fourcc);
                pixfmt = xlate->host_fmt->fourcc;
                pix->pixelformat = pixfmt;
                pix->colorspace = icd->colorspace;
        }

        /* FIXME: calculate using depth and bus width */

        /* CFSZR requires height and width to be 4-pixel aligned */
        v4l_bound_align_image(&pix->width, 2, pcdev->max_width, 2,
                              &pix->height, 4, pcdev->max_height, 2, 0);

        width = pix->width;
        height = pix->height;

        /* limit to sensor capabilities */
        mf.width        = pix->width;
        mf.height       = pix->height;
        mf.field        = pix->field;
        mf.code         = xlate->code;
        mf.colorspace   = pix->colorspace;

        ret = v4l2_device_call_until_err(sd->v4l2_dev, soc_camera_grp_id(icd),
                                         video, try_mbus_fmt, &mf);
        if (ret < 0)
                return ret;

        pix->width      = mf.width;
        pix->height     = mf.height;
        pix->field      = mf.field;
        pix->colorspace = mf.colorspace;

        switch (pixfmt) {
        case V4L2_PIX_FMT_NV12:
        case V4L2_PIX_FMT_NV21:
        case V4L2_PIX_FMT_NV16:
        case V4L2_PIX_FMT_NV61:
                /* FIXME: check against rect_max after converting soc-camera */
                /* We can scale precisely, need a bigger image from camera */
                if (pix->width < width || pix->height < height) {
                        /*
                         * We presume, the sensor behaves sanely, i.e., if
                         * requested a bigger rectangle, it will not return a
                         * smaller one.
                         */
                        mf.width = pcdev->max_width;
                        mf.height = pcdev->max_height;
                        ret = v4l2_device_call_until_err(sd->v4l2_dev,
                                        soc_camera_grp_id(icd), video,
                                        try_mbus_fmt, &mf);
                        if (ret < 0) {
                                /* Shouldn't actually happen... */
                                dev_err(icd->parent,
                                        "FIXME: client try_fmt() = %d\n", ret);
                                return ret;
                        }
                }
                /* We will scale exactly */
                if (mf.width > width)
                        pix->width = width;
                if (mf.height > height)
                        pix->height = height;

                pix->bytesperline = max(pix->bytesperline, pix->width);
                pix->bytesperline = min(pix->bytesperline, CEU_CHDW_MAX);
                pix->bytesperline &= ~3;
                break;

        default:
                /* Configurable stride isn't supported in pass-through mode. */
                pix->bytesperline  = 0;
        }

        pix->width      &= ~3;
        pix->height     &= ~3;
        pix->sizeimage  = 0;

        dev_geo(icd->parent, "%s(): return %d, fmt 0x%x, %ux%u\n",
                __func__, ret, pix->pixelformat, pix->width, pix->height);

        return ret;
}

static int sh_mobile_ceu_set_livecrop(struct soc_camera_device *icd,
                                      const struct v4l2_crop *a)
{
        struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
        struct sh_mobile_ceu_dev *pcdev = ici->priv;
        u32 out_width = icd->user_width, out_height = icd->user_height;
        int ret;

        /* Freeze queue */
        pcdev->frozen = 1;
        /* Wait for frame */
        ret = wait_for_completion_interruptible(&pcdev->complete);
        /* Stop the client */
        ret = v4l2_subdev_call(sd, video, s_stream, 0);
        if (ret < 0)
                dev_warn(icd->parent,
                         "Client failed to stop the stream: %d\n", ret);
        else
                /* Do the crop, if it fails, there's nothing more we can do */
                sh_mobile_ceu_set_crop(icd, a);

        dev_geo(icd->parent, "Output after crop: %ux%u\n", icd->user_width, icd->user_height);

        if (icd->user_width != out_width || icd->user_height != out_height) {
                struct v4l2_format f = {
                        .type   = V4L2_BUF_TYPE_VIDEO_CAPTURE,
                        .fmt.pix        = {
                                .width          = out_width,
                                .height         = out_height,
                                .pixelformat    = icd->current_fmt->host_fmt->fourcc,
                                .field          = pcdev->field,
                                .colorspace     = icd->colorspace,
                        },
                };
                ret = sh_mobile_ceu_set_fmt(icd, &f);
                if (!ret && (out_width != f.fmt.pix.width ||
                             out_height != f.fmt.pix.height))
                        ret = -EINVAL;
                if (!ret) {
                        icd->user_width         = out_width & ~3;
                        icd->user_height        = out_height & ~3;
                        ret = sh_mobile_ceu_set_bus_param(icd);
                }
        }

        /* Thaw the queue */
        pcdev->frozen = 0;
        spin_lock_irq(&pcdev->lock);
        sh_mobile_ceu_capture(pcdev);
        spin_unlock_irq(&pcdev->lock);
        /* Start the client */
        ret = v4l2_subdev_call(sd, video, s_stream, 1);
        return ret;
}

static unsigned int sh_mobile_ceu_poll(struct file *file, poll_table *pt)
{
        struct soc_camera_device *icd = file->private_data;

        return vb2_poll(&icd->vb2_vidq, file, pt);
}

static int sh_mobile_ceu_querycap(struct soc_camera_host *ici,
                                  struct v4l2_capability *cap)
{
        strlcpy(cap->card, "SuperH_Mobile_CEU", sizeof(cap->card));
        cap->capabilities = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING;
        return 0;
}

static int sh_mobile_ceu_init_videobuf(struct vb2_queue *q,
                                       struct soc_camera_device *icd)
{
        q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
        q->io_modes = VB2_MMAP | VB2_USERPTR;
        q->drv_priv = icd;
        q->ops = &sh_mobile_ceu_videobuf_ops;
        q->mem_ops = &vb2_dma_contig_memops;
        q->buf_struct_size = sizeof(struct sh_mobile_ceu_buffer);
        q->timestamp_type = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;

        return vb2_queue_init(q);
}

static struct soc_camera_host_ops sh_mobile_ceu_host_ops = {
        .owner          = THIS_MODULE,
        .add            = sh_mobile_ceu_add_device,
        .remove         = sh_mobile_ceu_remove_device,
        .clock_start    = sh_mobile_ceu_clock_start,
        .clock_stop     = sh_mobile_ceu_clock_stop,
        .get_formats    = sh_mobile_ceu_get_formats,
        .put_formats    = sh_mobile_ceu_put_formats,
        .get_crop       = sh_mobile_ceu_get_crop,
        .set_crop       = sh_mobile_ceu_set_crop,
        .set_livecrop   = sh_mobile_ceu_set_livecrop,
        .set_fmt        = sh_mobile_ceu_set_fmt,
        .try_fmt        = sh_mobile_ceu_try_fmt,
        .poll           = sh_mobile_ceu_poll,
        .querycap       = sh_mobile_ceu_querycap,
        .set_bus_param  = sh_mobile_ceu_set_bus_param,
        .init_videobuf2 = sh_mobile_ceu_init_videobuf,
};

struct bus_wait {
        struct notifier_block   notifier;
        struct completion       completion;
        struct device           *dev;
};

static int bus_notify(struct notifier_block *nb,
                      unsigned long action, void *data)
{
        struct device *dev = data;
        struct bus_wait *wait = container_of(nb, struct bus_wait, notifier);

        if (wait->dev != dev)
                return NOTIFY_DONE;

        switch (action) {
        case BUS_NOTIFY_UNBOUND_DRIVER:
                /* Protect from module unloading */
                wait_for_completion(&wait->completion);
                return NOTIFY_OK;
        }
        return NOTIFY_DONE;
}

static int sh_mobile_ceu_probe(struct platform_device *pdev)
{
        struct sh_mobile_ceu_dev *pcdev;
        struct resource *res;
        void __iomem *base;
        unsigned int irq;
        int err, i;
        struct bus_wait wait = {
                .completion = COMPLETION_INITIALIZER_ONSTACK(wait.completion),
                .notifier.notifier_call = bus_notify,
        };
        struct sh_mobile_ceu_companion *csi2;

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        irq = platform_get_irq(pdev, 0);
        if (!res || (int)irq <= 0) {
                dev_err(&pdev->dev, "Not enough CEU platform resources.\n");
                return -ENODEV;
        }

        pcdev = devm_kzalloc(&pdev->dev, sizeof(*pcdev), GFP_KERNEL);
        if (!pcdev) {
                dev_err(&pdev->dev, "Could not allocate pcdev\n");
                return -ENOMEM;
        }

        INIT_LIST_HEAD(&pcdev->capture);
        spin_lock_init(&pcdev->lock);
        init_completion(&pcdev->complete);

        pcdev->pdata = pdev->dev.platform_data;
        if (!pcdev->pdata && !pdev->dev.of_node) {
                dev_err(&pdev->dev, "CEU platform data not set.\n");
                return -EINVAL;
        }

        /* TODO: implement per-device bus flags */
        if (pcdev->pdata) {
                pcdev->max_width = pcdev->pdata->max_width;
                pcdev->max_height = pcdev->pdata->max_height;
                pcdev->flags = pcdev->pdata->flags;
        }

        if (!pcdev->max_width) {
                unsigned int v;
                err = of_property_read_u32(pdev->dev.of_node, "renesas,max-width", &v);
                if (!err)
                        pcdev->max_width = v;

                if (!pcdev->max_width)
                        pcdev->max_width = 2560;
        }
        if (!pcdev->max_height) {
                unsigned int v;
                err = of_property_read_u32(pdev->dev.of_node, "renesas,max-height", &v);
                if (!err)
                        pcdev->max_height = v;

                if (!pcdev->max_height)
                        pcdev->max_height = 1920;
        }

        base = devm_ioremap_resource(&pdev->dev, res);
        if (IS_ERR(base))
                return PTR_ERR(base);

        pcdev->irq = irq;
        pcdev->base = base;
        pcdev->video_limit = 0; /* only enabled if second resource exists */

        res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
        if (res) {
                err = dma_declare_coherent_memory(&pdev->dev, res->start,
                                                  res->start,
                                                  resource_size(res),
                                                  DMA_MEMORY_MAP |
                                                  DMA_MEMORY_EXCLUSIVE);
                if (!err) {
                        dev_err(&pdev->dev, "Unable to declare CEU memory.\n");
                        return -ENXIO;
                }

                pcdev->video_limit = resource_size(res);
        }

        /* request irq */
        err = devm_request_irq(&pdev->dev, pcdev->irq, sh_mobile_ceu_irq,
                               IRQF_DISABLED, dev_name(&pdev->dev), pcdev);
        if (err) {
                dev_err(&pdev->dev, "Unable to register CEU interrupt.\n");
                goto exit_release_mem;
        }

        pm_suspend_ignore_children(&pdev->dev, true);
        pm_runtime_enable(&pdev->dev);
        pm_runtime_resume(&pdev->dev);

        pcdev->ici.priv = pcdev;
        pcdev->ici.v4l2_dev.dev = &pdev->dev;
        pcdev->ici.nr = pdev->id;
        pcdev->ici.drv_name = dev_name(&pdev->dev);
        pcdev->ici.ops = &sh_mobile_ceu_host_ops;
        pcdev->ici.capabilities = SOCAM_HOST_CAP_STRIDE;

        pcdev->alloc_ctx = vb2_dma_contig_init_ctx(&pdev->dev);
        if (IS_ERR(pcdev->alloc_ctx)) {
                err = PTR_ERR(pcdev->alloc_ctx);
                goto exit_free_clk;
        }

        if (pcdev->pdata && pcdev->pdata->asd_sizes) {
                struct v4l2_async_subdev **asd;
                char name[] = "sh-mobile-csi2";
                int j;

                /*
                 * CSI2 interfacing: several groups can use CSI2, pick up the
                 * first one
                 */
                asd = pcdev->pdata->asd;
                for (j = 0; pcdev->pdata->asd_sizes[j]; j++) {
                        for (i = 0; i < pcdev->pdata->asd_sizes[j]; i++, asd++) {
                                dev_dbg(&pdev->dev, "%s(): subdev #%d, type %u\n",
                                        __func__, i, (*asd)->bus_type);
                                if ((*asd)->bus_type == V4L2_ASYNC_BUS_PLATFORM &&
                                    !strncmp(name, (*asd)->match.platform.name,
                                             sizeof(name) - 1)) {
                                        pcdev->csi2_asd = *asd;
                                        break;
                                }
                        }
                        if (pcdev->csi2_asd)
                                break;
                }

                pcdev->ici.asd = pcdev->pdata->asd;
                pcdev->ici.asd_sizes = pcdev->pdata->asd_sizes;
        }

        /* Legacy CSI2 interfacing */
        csi2 = pcdev->pdata ? pcdev->pdata->csi2 : NULL;
        if (csi2) {
                /*
                 * TODO: remove this once all users are converted to
                 * asynchronous CSI2 probing. If it has to be kept, csi2
                 * platform device resources have to be added, using
                 * platform_device_add_resources()
                 */
                struct platform_device *csi2_pdev =
                        platform_device_alloc("sh-mobile-csi2", csi2->id);
                struct sh_csi2_pdata *csi2_pdata = csi2->platform_data;

                if (!csi2_pdev) {
                        err = -ENOMEM;
                        goto exit_free_ctx;
                }

                pcdev->csi2_pdev                = csi2_pdev;

                err = platform_device_add_data(csi2_pdev, csi2_pdata,
                                               sizeof(*csi2_pdata));
                if (err < 0)
                        goto exit_pdev_put;

                csi2_pdev->resource             = csi2->resource;
                csi2_pdev->num_resources        = csi2->num_resources;

                err = platform_device_add(csi2_pdev);
                if (err < 0)
                        goto exit_pdev_put;

                wait.dev = &csi2_pdev->dev;

                err = bus_register_notifier(&platform_bus_type, &wait.notifier);
                if (err < 0)
                        goto exit_pdev_unregister;

                /*
                 * From this point the driver module will not unload, until
                 * we complete the completion.
                 */

                if (!csi2_pdev->dev.driver) {
                        complete(&wait.completion);
                        /* Either too late, or probing failed */
                        bus_unregister_notifier(&platform_bus_type, &wait.notifier);
                        err = -ENXIO;
                        goto exit_pdev_unregister;
                }

                /*
                 * The module is still loaded, in the worst case it is hanging
                 * in device release on our completion. So, _now_ dereferencing
                 * the "owner" is safe!
                 */

                err = try_module_get(csi2_pdev->dev.driver->owner);

                /* Let notifier complete, if it has been locked */
                complete(&wait.completion);
                bus_unregister_notifier(&platform_bus_type, &wait.notifier);
                if (!err) {
                        err = -ENODEV;
                        goto exit_pdev_unregister;
                }

                pcdev->csi2_sd = platform_get_drvdata(csi2_pdev);
        }

        err = soc_camera_host_register(&pcdev->ici);
        if (err)
                goto exit_csi2_unregister;

        if (csi2) {
                err = v4l2_device_register_subdev(&pcdev->ici.v4l2_dev,
                                                  pcdev->csi2_sd);
                dev_dbg(&pdev->dev, "%s(): ret(register_subdev) = %d\n",
                        __func__, err);
                if (err < 0)
                        goto exit_host_unregister;
                /* v4l2_device_register_subdev() took a reference too */
                module_put(pcdev->csi2_sd->owner);
        }

        return 0;

exit_host_unregister:
        soc_camera_host_unregister(&pcdev->ici);
exit_csi2_unregister:
        if (csi2) {
                module_put(pcdev->csi2_pdev->dev.driver->owner);
exit_pdev_unregister:
                platform_device_del(pcdev->csi2_pdev);
exit_pdev_put:
                pcdev->csi2_pdev->resource = NULL;
                platform_device_put(pcdev->csi2_pdev);
        }
exit_free_ctx:
        vb2_dma_contig_cleanup_ctx(pcdev->alloc_ctx);
exit_free_clk:
        pm_runtime_disable(&pdev->dev);
exit_release_mem:
        if (platform_get_resource(pdev, IORESOURCE_MEM, 1))
                dma_release_declared_memory(&pdev->dev);
        return err;
}

static int sh_mobile_ceu_remove(struct platform_device *pdev)
{
        struct soc_camera_host *soc_host = to_soc_camera_host(&pdev->dev);
        struct sh_mobile_ceu_dev *pcdev = container_of(soc_host,
                                        struct sh_mobile_ceu_dev, ici);
        struct platform_device *csi2_pdev = pcdev->csi2_pdev;

        soc_camera_host_unregister(soc_host);
        pm_runtime_disable(&pdev->dev);
        if (platform_get_resource(pdev, IORESOURCE_MEM, 1))
                dma_release_declared_memory(&pdev->dev);
        vb2_dma_contig_cleanup_ctx(pcdev->alloc_ctx);
        if (csi2_pdev && csi2_pdev->dev.driver) {
                struct module *csi2_drv = csi2_pdev->dev.driver->owner;
                platform_device_del(csi2_pdev);
                csi2_pdev->resource = NULL;
                platform_device_put(csi2_pdev);
                module_put(csi2_drv);
        }

        return 0;
}

static int sh_mobile_ceu_runtime_nop(struct device *dev)
{
        /* Runtime PM callback shared between ->runtime_suspend()
         * and ->runtime_resume(). Simply returns success.
         *
         * This driver re-initializes all registers after
         * pm_runtime_get_sync() anyway so there is no need
         * to save and restore registers here.
         */
        return 0;
}

static const struct dev_pm_ops sh_mobile_ceu_dev_pm_ops = {
        .runtime_suspend = sh_mobile_ceu_runtime_nop,

        .runtime_resume = sh_mobile_ceu_runtime_nop,
};

static const struct of_device_id sh_mobile_ceu_of_match[] = {
        { .compatible = "renesas,sh-mobile-ceu" },
        { }
};
MODULE_DEVICE_TABLE(of, sh_mobile_ceu_of_match);

static struct platform_driver sh_mobile_ceu_driver = {
        .driver         = {
                .name   = "sh_mobile_ceu",
                .owner  = THIS_MODULE,
                .pm     = &sh_mobile_ceu_dev_pm_ops,
                .of_match_table = sh_mobile_ceu_of_match,
        },
        .probe          = sh_mobile_ceu_probe,
        .remove         = sh_mobile_ceu_remove,
};

static int __init sh_mobile_ceu_init(void)
{
        /* Whatever return code */
        request_module("sh_mobile_csi2");
        return platform_driver_register(&sh_mobile_ceu_driver);
}

static void __exit sh_mobile_ceu_exit(void)
{
        platform_driver_unregister(&sh_mobile_ceu_driver);
}

module_init(sh_mobile_ceu_init);
module_exit(sh_mobile_ceu_exit);

MODULE_DESCRIPTION("SuperH Mobile CEU driver");
MODULE_AUTHOR("Magnus Damm");
MODULE_LICENSE("GPL");
MODULE_VERSION("0.1.0");
MODULE_ALIAS("platform:sh_mobile_ceu");