/*
 * camera image capture (abstract) bus driver
 *
 * Copyright (C) 2008, Guennadi Liakhovetski <kernel@pengutronix.de>
 *
 * This driver provides an interface between platform-specific camera
 * busses and camera devices. It should be used if the camera is
 * connected not over a "proper" bus like PCI or USB, but over a
 * special bus, like, for example, the Quick Capture interface on PXA270
 * SoCs. Later it should also be used for i.MX31 SoCs from Freescale.
 * It can handle multiple cameras and / or multiple busses, which can
 * be used, e.g., in stereo-vision applications.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/device.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>
#include <linux/pm_runtime.h>
#include <linux/vmalloc.h>

#include <media/soc_camera.h>
#include <media/v4l2-common.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-dev.h>
#include <media/videobuf-core.h>
#include <media/videobuf2-core.h>
#include <media/soc_mediabus.h>

/* Default to VGA resolution */
#define DEFAULT_WIDTH   640
#define DEFAULT_HEIGHT  480

#define is_streaming(ici, icd)                          \
        (((ici)->ops->init_videobuf) ?                  \
         (icd)->vb_vidq.streaming :                     \
         vb2_is_streaming(&(icd)->vb2_vidq))

static LIST_HEAD(hosts);
static LIST_HEAD(devices);
static DEFINE_MUTEX(list_lock);         /* Protects the list of hosts */

static int soc_camera_power_on(struct soc_camera_device *icd,
                               struct soc_camera_link *icl)
{
        struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
        int ret = regulator_bulk_enable(icl->num_regulators,
                                        icl->regulators);
        if (ret < 0) {
                dev_err(icd->pdev, "Cannot enable regulators\n");
                return ret;
        }

        if (icl->power) {
                ret = icl->power(icd->pdev, 1);
                if (ret < 0) {
                        dev_err(icd->pdev,
                                "Platform failed to power-on the camera.\n");
                        goto elinkpwr;
                }
        }

        ret = v4l2_subdev_call(sd, core, s_power, 1);
        if (ret < 0 && ret != -ENOIOCTLCMD && ret != -ENODEV)
                goto esdpwr;

        return 0;

esdpwr:
        if (icl->power)
                icl->power(icd->pdev, 0);
elinkpwr:
        regulator_bulk_disable(icl->num_regulators,
                               icl->regulators);
        return ret;
}

static int soc_camera_power_off(struct soc_camera_device *icd,
                                struct soc_camera_link *icl)
{
        struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
        int ret = v4l2_subdev_call(sd, core, s_power, 0);

        if (ret < 0 && ret != -ENOIOCTLCMD && ret != -ENODEV)
                return ret;

        if (icl->power) {
                ret = icl->power(icd->pdev, 0);
                if (ret < 0) {
                        dev_err(icd->pdev,
                                "Platform failed to power-off the camera.\n");
                        return ret;
                }
        }

        ret = regulator_bulk_disable(icl->num_regulators,
                                     icl->regulators);
        if (ret < 0)
                dev_err(icd->pdev, "Cannot disable regulators\n");

        return ret;
}

const struct soc_camera_format_xlate *soc_camera_xlate_by_fourcc(
        struct soc_camera_device *icd, unsigned int fourcc)
{
        unsigned int i;

        for (i = 0; i < icd->num_user_formats; i++)
                if (icd->user_formats[i].host_fmt->fourcc == fourcc)
                        return icd->user_formats + i;
        return NULL;
}
EXPORT_SYMBOL(soc_camera_xlate_by_fourcc);

/**
 * soc_camera_apply_board_flags() - apply platform SOCAM_SENSOR_INVERT_* flags
 * @icl:        camera platform parameters
 * @cfg:        media bus configuration
 * @return:     resulting flags
 */
unsigned long soc_camera_apply_board_flags(struct soc_camera_link *icl,
                                           const struct v4l2_mbus_config *cfg)
{
        unsigned long f, flags = cfg->flags;

        /* If only one of the two polarities is supported, switch to the opposite */
        if (icl->flags & SOCAM_SENSOR_INVERT_HSYNC) {
                f = flags & (V4L2_MBUS_HSYNC_ACTIVE_HIGH | V4L2_MBUS_HSYNC_ACTIVE_LOW);
                if (f == V4L2_MBUS_HSYNC_ACTIVE_HIGH || f == V4L2_MBUS_HSYNC_ACTIVE_LOW)
                        flags ^= V4L2_MBUS_HSYNC_ACTIVE_HIGH | V4L2_MBUS_HSYNC_ACTIVE_LOW;
        }

        if (icl->flags & SOCAM_SENSOR_INVERT_VSYNC) {
                f = flags & (V4L2_MBUS_VSYNC_ACTIVE_HIGH | V4L2_MBUS_VSYNC_ACTIVE_LOW);
                if (f == V4L2_MBUS_VSYNC_ACTIVE_HIGH || f == V4L2_MBUS_VSYNC_ACTIVE_LOW)
                        flags ^= V4L2_MBUS_VSYNC_ACTIVE_HIGH | V4L2_MBUS_VSYNC_ACTIVE_LOW;
        }

        if (icl->flags & SOCAM_SENSOR_INVERT_PCLK) {
                f = flags & (V4L2_MBUS_PCLK_SAMPLE_RISING | V4L2_MBUS_PCLK_SAMPLE_FALLING);
                if (f == V4L2_MBUS_PCLK_SAMPLE_RISING || f == V4L2_MBUS_PCLK_SAMPLE_FALLING)
                        flags ^= V4L2_MBUS_PCLK_SAMPLE_RISING | V4L2_MBUS_PCLK_SAMPLE_FALLING;
        }

        return flags;
}
EXPORT_SYMBOL(soc_camera_apply_board_flags);

#define pixfmtstr(x) (x) & 0xff, ((x) >> 8) & 0xff, ((x) >> 16) & 0xff, \
        ((x) >> 24) & 0xff

static int soc_camera_try_fmt(struct soc_camera_device *icd,
                              struct v4l2_format *f)
{
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
        struct v4l2_pix_format *pix = &f->fmt.pix;
        int ret;

        dev_dbg(icd->pdev, "TRY_FMT(%c%c%c%c, %ux%u)\n",
                pixfmtstr(pix->pixelformat), pix->width, pix->height);

        pix->bytesperline = 0;
        pix->sizeimage = 0;

        ret = ici->ops->try_fmt(icd, f);
        if (ret < 0)
                return ret;

        if (!pix->sizeimage) {
                if (!pix->bytesperline) {
                        const struct soc_camera_format_xlate *xlate;

                        xlate = soc_camera_xlate_by_fourcc(icd, pix->pixelformat);
                        if (!xlate)
                                return -EINVAL;

                        ret = soc_mbus_bytes_per_line(pix->width,
                                                      xlate->host_fmt);
                        if (ret > 0)
                                pix->bytesperline = ret;
                }
                if (pix->bytesperline)
                        pix->sizeimage = pix->bytesperline * pix->height;
        }

        return 0;
}

static int soc_camera_try_fmt_vid_cap(struct file *file, void *priv,
                                      struct v4l2_format *f)
{
        struct soc_camera_device *icd = file->private_data;

        WARN_ON(priv != file->private_data);

        /* Only single-plane capture is supported so far */
        if (f->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
                return -EINVAL;

        /* limit format to hardware capabilities */
        return soc_camera_try_fmt(icd, f);
}

static int soc_camera_enum_input(struct file *file, void *priv,
                                 struct v4l2_input *inp)
{
        if (inp->index != 0)
                return -EINVAL;

        /* default is camera */
        inp->type = V4L2_INPUT_TYPE_CAMERA;
        inp->std  = V4L2_STD_UNKNOWN;
        strcpy(inp->name, "Camera");

        return 0;
}

static int soc_camera_g_input(struct file *file, void *priv, unsigned int *i)
{
        *i = 0;

        return 0;
}

static int soc_camera_s_input(struct file *file, void *priv, unsigned int i)
{
        if (i > 0)
                return -EINVAL;

        return 0;
}

static int soc_camera_s_std(struct file *file, void *priv, v4l2_std_id *a)
{
        struct soc_camera_device *icd = file->private_data;
        struct v4l2_subdev *sd = soc_camera_to_subdev(icd);

        return v4l2_subdev_call(sd, core, s_std, *a);
}

static int soc_camera_g_std(struct file *file, void *priv, v4l2_std_id *a)
{
        struct soc_camera_device *icd = file->private_data;
        struct v4l2_subdev *sd = soc_camera_to_subdev(icd);

        return v4l2_subdev_call(sd, core, g_std, a);
}

static int soc_camera_enum_fsizes(struct file *file, void *fh,
                                         struct v4l2_frmsizeenum *fsize)
{
        struct soc_camera_device *icd = file->private_data;
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);

        return ici->ops->enum_fsizes(icd, fsize);
}

static int soc_camera_reqbufs(struct file *file, void *priv,
                              struct v4l2_requestbuffers *p)
{
        int ret;
        struct soc_camera_device *icd = file->private_data;
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);

        WARN_ON(priv != file->private_data);

        if (icd->streamer && icd->streamer != file)
                return -EBUSY;

        if (ici->ops->init_videobuf) {
                ret = videobuf_reqbufs(&icd->vb_vidq, p);
                if (ret < 0)
                        return ret;

                ret = ici->ops->reqbufs(icd, p);
        } else {
                ret = vb2_reqbufs(&icd->vb2_vidq, p);
        }

        if (!ret && !icd->streamer)
                icd->streamer = file;

        return ret;
}

static int soc_camera_querybuf(struct file *file, void *priv,
                               struct v4l2_buffer *p)
{
        struct soc_camera_device *icd = file->private_data;
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);

        WARN_ON(priv != file->private_data);

        if (ici->ops->init_videobuf)
                return videobuf_querybuf(&icd->vb_vidq, p);
        else
                return vb2_querybuf(&icd->vb2_vidq, p);
}

static int soc_camera_qbuf(struct file *file, void *priv,
                           struct v4l2_buffer *p)
{
        struct soc_camera_device *icd = file->private_data;
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);

        WARN_ON(priv != file->private_data);

        if (icd->streamer != file)
                return -EBUSY;

        if (ici->ops->init_videobuf)
                return videobuf_qbuf(&icd->vb_vidq, p);
        else
                return vb2_qbuf(&icd->vb2_vidq, p);
}

static int soc_camera_dqbuf(struct file *file, void *priv,
                            struct v4l2_buffer *p)
{
        struct soc_camera_device *icd = file->private_data;
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);

        WARN_ON(priv != file->private_data);

        if (icd->streamer != file)
                return -EBUSY;

        if (ici->ops->init_videobuf)
                return videobuf_dqbuf(&icd->vb_vidq, p, file->f_flags & O_NONBLOCK);
        else
                return vb2_dqbuf(&icd->vb2_vidq, p, file->f_flags & O_NONBLOCK);
}

static int soc_camera_create_bufs(struct file *file, void *priv,
                            struct v4l2_create_buffers *create)
{
        struct soc_camera_device *icd = file->private_data;
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);

        /* videobuf2 only */
        if (ici->ops->init_videobuf)
                return -EINVAL;
        else
                return vb2_create_bufs(&icd->vb2_vidq, create);
}

static int soc_camera_prepare_buf(struct file *file, void *priv,
                                  struct v4l2_buffer *b)
{
        struct soc_camera_device *icd = file->private_data;
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);

        /* videobuf2 only */
        if (ici->ops->init_videobuf)
                return -EINVAL;
        else
                return vb2_prepare_buf(&icd->vb2_vidq, b);
}

/* Always entered with .video_lock held */
static int soc_camera_init_user_formats(struct soc_camera_device *icd)
{
        struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
        unsigned int i, fmts = 0, raw_fmts = 0;
        int ret;
        enum v4l2_mbus_pixelcode code;

        while (!v4l2_subdev_call(sd, video, enum_mbus_fmt, raw_fmts, &code))
                raw_fmts++;

        if (!ici->ops->get_formats)
                /*
                 * Fallback mode - the host will have to serve all
                 * sensor-provided formats one-to-one to the user
                 */
                fmts = raw_fmts;
        else
                /*
                 * First pass - only count formats this host-sensor
                 * configuration can provide
                 */
                for (i = 0; i < raw_fmts; i++) {
                        ret = ici->ops->get_formats(icd, i, NULL);
                        if (ret < 0)
                                return ret;
                        fmts += ret;
                }

        if (!fmts)
                return -ENXIO;

        icd->user_formats =
                vmalloc(fmts * sizeof(struct soc_camera_format_xlate));
        if (!icd->user_formats)
                return -ENOMEM;

        dev_dbg(icd->pdev, "Found %d supported formats.\n", fmts);

        /* Second pass - actually fill data formats */
        fmts = 0;
        for (i = 0; i < raw_fmts; i++)
                if (!ici->ops->get_formats) {
                        v4l2_subdev_call(sd, video, enum_mbus_fmt, i, &code);
                        icd->user_formats[fmts].host_fmt =
                                soc_mbus_get_fmtdesc(code);
                        if (icd->user_formats[fmts].host_fmt)
                                icd->user_formats[fmts++].code = code;
                } else {
                        ret = ici->ops->get_formats(icd, i,
                                                    &icd->user_formats[fmts]);
                        if (ret < 0)
                                goto egfmt;
                        fmts += ret;
                }

        icd->num_user_formats = fmts;
        icd->current_fmt = &icd->user_formats[0];

        return 0;

egfmt:
        vfree(icd->user_formats);
        return ret;
}

/* Always entered with .video_lock held */
static void soc_camera_free_user_formats(struct soc_camera_device *icd)
{
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);

        if (ici->ops->put_formats)
                ici->ops->put_formats(icd);
        icd->current_fmt = NULL;
        icd->num_user_formats = 0;
        vfree(icd->user_formats);
        icd->user_formats = NULL;
}

/* Called with .vb_lock held, or from the first open(2), see comment there */
static int soc_camera_set_fmt(struct soc_camera_device *icd,
                              struct v4l2_format *f)
{
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
        struct v4l2_pix_format *pix = &f->fmt.pix;
        int ret;

        dev_dbg(icd->pdev, "S_FMT(%c%c%c%c, %ux%u)\n",
                pixfmtstr(pix->pixelformat), pix->width, pix->height);

        /* We always call try_fmt() before set_fmt() or set_crop() */
        ret = soc_camera_try_fmt(icd, f);
        if (ret < 0)
                return ret;

        ret = ici->ops->set_fmt(icd, f);
        if (ret < 0) {
                return ret;
        } else if (!icd->current_fmt ||
                   icd->current_fmt->host_fmt->fourcc != pix->pixelformat) {
                dev_err(icd->pdev,
                        "Host driver hasn't set up current format correctly!\n");
                return -EINVAL;
        }

        icd->user_width         = pix->width;
        icd->user_height        = pix->height;
        icd->bytesperline       = pix->bytesperline;
        icd->sizeimage          = pix->sizeimage;
        icd->colorspace         = pix->colorspace;
        icd->field              = pix->field;
        if (ici->ops->init_videobuf)
                icd->vb_vidq.field = pix->field;

        dev_dbg(icd->pdev, "set width: %d height: %d\n",
                icd->user_width, icd->user_height);

        /* set physical bus parameters */
        return ici->ops->set_bus_param(icd, pix->pixelformat);
}

static int soc_camera_open(struct file *file)
{
        struct video_device *vdev = video_devdata(file);
        struct soc_camera_device *icd = dev_get_drvdata(vdev->parent);
        struct soc_camera_link *icl = to_soc_camera_link(icd);
        struct soc_camera_host *ici;
        int ret;

        if (!to_soc_camera_control(icd))
                /* No device driver attached */
                return -ENODEV;

        ici = to_soc_camera_host(icd->parent);

        if (!try_module_get(ici->ops->owner)) {
                dev_err(icd->pdev, "Couldn't lock capture bus driver.\n");
                return -EINVAL;
        }

        icd->use_count++;

        /* Now we really have to activate the camera */
        if (icd->use_count == 1) {
                /* Restore parameters before the last close() per V4L2 API */
                struct v4l2_format f = {
                        .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
                        .fmt.pix = {
                                .width          = icd->user_width,
                                .height         = icd->user_height,
                                .field          = icd->field,
                                .colorspace     = icd->colorspace,
                                .pixelformat    =
                                        icd->current_fmt->host_fmt->fourcc,
                        },
                };

                ret = soc_camera_power_on(icd, icl);
                if (ret < 0)
                        goto epower;

                /* The camera could have been already on, try to reset */
                if (icl->reset)
                        icl->reset(icd->pdev);

                ret = ici->ops->add(icd);
                if (ret < 0) {
                        dev_err(icd->pdev, "Couldn't activate the camera: %d\n", ret);
                        goto eiciadd;
                }

                pm_runtime_enable(&icd->vdev->dev);
                ret = pm_runtime_resume(&icd->vdev->dev);
                if (ret < 0 && ret != -ENOSYS)
                        goto eresume;

                /*
                 * Try to configure with default parameters. Notice: this is the
                 * very first open, so, we cannot race against other calls,
                 * apart from someone else calling open() simultaneously, but
                 * .video_lock is protecting us against it.
                 */
                ret = soc_camera_set_fmt(icd, &f);
                if (ret < 0)
                        goto esfmt;

                if (ici->ops->init_videobuf) {
                        ici->ops->init_videobuf(&icd->vb_vidq, icd);
                } else {
                        ret = ici->ops->init_videobuf2(&icd->vb2_vidq, icd);
                        if (ret < 0)
                                goto einitvb;
                }
                v4l2_ctrl_handler_setup(&icd->ctrl_handler);
        }

        file->private_data = icd;
        dev_dbg(icd->pdev, "camera device open\n");

        return 0;

        /*
         * First four errors are entered with the .video_lock held
         * and use_count == 1
         */
einitvb:
esfmt:
        pm_runtime_disable(&icd->vdev->dev);
eresume:
        ici->ops->remove(icd);
eiciadd:
        soc_camera_power_off(icd, icl);
epower:
        icd->use_count--;
        module_put(ici->ops->owner);

        return ret;
}

static int soc_camera_close(struct file *file)
{
        struct soc_camera_device *icd = file->private_data;
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);

        icd->use_count--;
        if (!icd->use_count) {
                struct soc_camera_link *icl = to_soc_camera_link(icd);

                pm_runtime_suspend(&icd->vdev->dev);
                pm_runtime_disable(&icd->vdev->dev);

                ici->ops->remove(icd);
                if (ici->ops->init_videobuf2)
                        vb2_queue_release(&icd->vb2_vidq);

                soc_camera_power_off(icd, icl);
        }

        if (icd->streamer == file)
                icd->streamer = NULL;

        module_put(ici->ops->owner);

        dev_dbg(icd->pdev, "camera device close\n");

        return 0;
}

static ssize_t soc_camera_read(struct file *file, char __user *buf,
                               size_t count, loff_t *ppos)
{
        struct soc_camera_device *icd = file->private_data;
        int err = -EINVAL;

        dev_err(icd->pdev, "camera device read not implemented\n");

        return err;
}

static int soc_camera_mmap(struct file *file, struct vm_area_struct *vma)
{
        struct soc_camera_device *icd = file->private_data;
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
        int err;

        dev_dbg(icd->pdev, "mmap called, vma=0x%08lx\n", (unsigned long)vma);

        if (icd->streamer != file)
                return -EBUSY;

        if (ici->ops->init_videobuf)
                err = videobuf_mmap_mapper(&icd->vb_vidq, vma);
        else
                err = vb2_mmap(&icd->vb2_vidq, vma);

        dev_dbg(icd->pdev, "vma start=0x%08lx, size=%ld, ret=%d\n",
                (unsigned long)vma->vm_start,
                (unsigned long)vma->vm_end - (unsigned long)vma->vm_start,
                err);

        return err;
}

static unsigned int soc_camera_poll(struct file *file, poll_table *pt)
{
        struct soc_camera_device *icd = file->private_data;
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);

        if (icd->streamer != file)
                return -EBUSY;

        if (ici->ops->init_videobuf && list_empty(&icd->vb_vidq.stream)) {
                dev_err(icd->pdev, "Trying to poll with no queued buffers!\n");
                return POLLERR;
        }

        return ici->ops->poll(file, pt);
}

void soc_camera_lock(struct vb2_queue *vq)
{
        struct soc_camera_device *icd = vb2_get_drv_priv(vq);
        mutex_lock(&icd->video_lock);
}
EXPORT_SYMBOL(soc_camera_lock);

void soc_camera_unlock(struct vb2_queue *vq)
{
        struct soc_camera_device *icd = vb2_get_drv_priv(vq);
        mutex_unlock(&icd->video_lock);
}
EXPORT_SYMBOL(soc_camera_unlock);

static struct v4l2_file_operations soc_camera_fops = {
        .owner          = THIS_MODULE,
        .open           = soc_camera_open,
        .release        = soc_camera_close,
        .unlocked_ioctl = video_ioctl2,
        .read           = soc_camera_read,
        .mmap           = soc_camera_mmap,
        .poll           = soc_camera_poll,
};

static int soc_camera_s_fmt_vid_cap(struct file *file, void *priv,
                                    struct v4l2_format *f)
{
        struct soc_camera_device *icd = file->private_data;
        int ret;

        WARN_ON(priv != file->private_data);

        if (f->type != V4L2_BUF_TYPE_VIDEO_CAPTURE) {
                dev_warn(icd->pdev, "Wrong buf-type %d\n", f->type);
                return -EINVAL;
        }

        if (icd->streamer && icd->streamer != file)
                return -EBUSY;

        if (is_streaming(to_soc_camera_host(icd->parent), icd)) {
                dev_err(icd->pdev, "S_FMT denied: queue initialised\n");
                return -EBUSY;
        }

        ret = soc_camera_set_fmt(icd, f);

        if (!ret && !icd->streamer)
                icd->streamer = file;

        return ret;
}

static int soc_camera_enum_fmt_vid_cap(struct file *file, void  *priv,
                                       struct v4l2_fmtdesc *f)
{
        struct soc_camera_device *icd = file->private_data;
        const struct soc_mbus_pixelfmt *format;

        WARN_ON(priv != file->private_data);

        if (f->index >= icd->num_user_formats)
                return -EINVAL;

        format = icd->user_formats[f->index].host_fmt;

        if (format->name)
                strlcpy(f->description, format->name, sizeof(f->description));
        f->pixelformat = format->fourcc;
        return 0;
}

static int soc_camera_g_fmt_vid_cap(struct file *file, void *priv,
                                    struct v4l2_format *f)
{
        struct soc_camera_device *icd = file->private_data;
        struct v4l2_pix_format *pix = &f->fmt.pix;

        WARN_ON(priv != file->private_data);

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

        pix->width              = icd->user_width;
        pix->height             = icd->user_height;
        pix->bytesperline       = icd->bytesperline;
        pix->sizeimage          = icd->sizeimage;
        pix->field              = icd->field;
        pix->pixelformat        = icd->current_fmt->host_fmt->fourcc;
        pix->colorspace         = icd->colorspace;
        dev_dbg(icd->pdev, "current_fmt->fourcc: 0x%08x\n",
                icd->current_fmt->host_fmt->fourcc);
        return 0;
}

static int soc_camera_querycap(struct file *file, void  *priv,
                               struct v4l2_capability *cap)
{
        struct soc_camera_device *icd = file->private_data;
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);

        WARN_ON(priv != file->private_data);

        strlcpy(cap->driver, ici->drv_name, sizeof(cap->driver));
        return ici->ops->querycap(ici, cap);
}

static int soc_camera_streamon(struct file *file, void *priv,
                               enum v4l2_buf_type i)
{
        struct soc_camera_device *icd = file->private_data;
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
        struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
        int ret;

        WARN_ON(priv != file->private_data);

        if (i != V4L2_BUF_TYPE_VIDEO_CAPTURE)
                return -EINVAL;

        if (icd->streamer != file)
                return -EBUSY;

        /* This calls buf_queue from host driver's videobuf_queue_ops */
        if (ici->ops->init_videobuf)
                ret = videobuf_streamon(&icd->vb_vidq);
        else
                ret = vb2_streamon(&icd->vb2_vidq, i);

        if (!ret)
                v4l2_subdev_call(sd, video, s_stream, 1);

        return ret;
}

static int soc_camera_streamoff(struct file *file, void *priv,
                                enum v4l2_buf_type i)
{
        struct soc_camera_device *icd = file->private_data;
        struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);

        WARN_ON(priv != file->private_data);

        if (i != V4L2_BUF_TYPE_VIDEO_CAPTURE)
                return -EINVAL;

        if (icd->streamer != file)
                return -EBUSY;

        /*
         * This calls buf_release from host driver's videobuf_queue_ops for all
         * remaining buffers. When the last buffer is freed, stop capture
         */
        if (ici->ops->init_videobuf)
                videobuf_streamoff(&icd->vb_vidq);
        else
                vb2_streamoff(&icd->vb2_vidq, i);

        v4l2_subdev_call(sd, video, s_stream, 0);

        return 0;
}

static int soc_camera_cropcap(struct file *file, void *fh,
                              struct v4l2_cropcap *a)
{
        struct soc_camera_device *icd = file->private_data;
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);

        return ici->ops->cropcap(icd, a);
}

static int soc_camera_g_crop(struct file *file, void *fh,
                             struct v4l2_crop *a)
{
        struct soc_camera_device *icd = file->private_data;
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
        int ret;

        ret = ici->ops->get_crop(icd, a);

        return ret;
}

/*
 * According to the V4L2 API, drivers shall not update the struct v4l2_crop
 * argument with the actual geometry, instead, the user shall use G_CROP to
 * retrieve it.
 */
static int soc_camera_s_crop(struct file *file, void *fh,
                             struct v4l2_crop *a)
{
        struct soc_camera_device *icd = file->private_data;
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
        struct v4l2_rect *rect = &a->c;
        struct v4l2_crop current_crop;
        int ret;

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

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

        /* If get_crop fails, we'll let host and / or client drivers decide */
        ret = ici->ops->get_crop(icd, &current_crop);

        /* Prohibit window size change with initialised buffers */
        if (ret < 0) {
                dev_err(icd->pdev,
                        "S_CROP denied: getting current crop failed\n");
        } else if ((a->c.width == current_crop.c.width &&
                    a->c.height == current_crop.c.height) ||
                   !is_streaming(ici, icd)) {
                /* same size or not streaming - use .set_crop() */
                ret = ici->ops->set_crop(icd, a);
        } else if (ici->ops->set_livecrop) {
                ret = ici->ops->set_livecrop(icd, a);
        } else {
                dev_err(icd->pdev,
                        "S_CROP denied: queue initialised and sizes differ\n");
                ret = -EBUSY;
        }

        return ret;
}

static int soc_camera_g_parm(struct file *file, void *fh,
                             struct v4l2_streamparm *a)
{
        struct soc_camera_device *icd = file->private_data;
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);

        if (ici->ops->get_parm)
                return ici->ops->get_parm(icd, a);

        return -ENOIOCTLCMD;
}

static int soc_camera_s_parm(struct file *file, void *fh,
                             struct v4l2_streamparm *a)
{
        struct soc_camera_device *icd = file->private_data;
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);

        if (ici->ops->set_parm)
                return ici->ops->set_parm(icd, a);

        return -ENOIOCTLCMD;
}

static int soc_camera_g_chip_ident(struct file *file, void *fh,
                                   struct v4l2_dbg_chip_ident *id)
{
        struct soc_camera_device *icd = file->private_data;
        struct v4l2_subdev *sd = soc_camera_to_subdev(icd);

        return v4l2_subdev_call(sd, core, g_chip_ident, id);
}

#ifdef CONFIG_VIDEO_ADV_DEBUG
static int soc_camera_g_register(struct file *file, void *fh,
                                 struct v4l2_dbg_register *reg)
{
        struct soc_camera_device *icd = file->private_data;
        struct v4l2_subdev *sd = soc_camera_to_subdev(icd);

        return v4l2_subdev_call(sd, core, g_register, reg);
}

static int soc_camera_s_register(struct file *file, void *fh,
                                 struct v4l2_dbg_register *reg)
{
        struct soc_camera_device *icd = file->private_data;
        struct v4l2_subdev *sd = soc_camera_to_subdev(icd);

        return v4l2_subdev_call(sd, core, s_register, reg);
}
#endif

static int soc_camera_probe(struct soc_camera_device *icd);

/* So far this function cannot fail */
static void scan_add_host(struct soc_camera_host *ici)
{
        struct soc_camera_device *icd;

        mutex_lock(&list_lock);

        list_for_each_entry(icd, &devices, list) {
                if (icd->iface == ici->nr) {
                        int ret;

                        icd->parent = ici->v4l2_dev.dev;
                        ret = soc_camera_probe(icd);
                }
        }

        mutex_unlock(&list_lock);
}

#ifdef CONFIG_I2C_BOARDINFO
static int soc_camera_init_i2c(struct soc_camera_device *icd,
                               struct soc_camera_link *icl)
{
        struct i2c_client *client;
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
        struct i2c_adapter *adap = i2c_get_adapter(icl->i2c_adapter_id);
        struct v4l2_subdev *subdev;

        if (!adap) {
                dev_err(icd->pdev, "Cannot get I2C adapter #%d. No driver?\n",
                        icl->i2c_adapter_id);
                goto ei2cga;
        }

        icl->board_info->platform_data = icl;

        subdev = v4l2_i2c_new_subdev_board(&ici->v4l2_dev, adap,
                                icl->board_info, NULL);
        if (!subdev)
                goto ei2cnd;

        client = v4l2_get_subdevdata(subdev);

        /* Use to_i2c_client(dev) to recover the i2c client */
        icd->control = &client->dev;

        return 0;

ei2cnd:
        i2c_put_adapter(adap);
ei2cga:
        return -ENODEV;
}

static void soc_camera_free_i2c(struct soc_camera_device *icd)
{
        struct i2c_client *client =
                to_i2c_client(to_soc_camera_control(icd));
        struct i2c_adapter *adap = client->adapter;

        icd->control = NULL;
        v4l2_device_unregister_subdev(i2c_get_clientdata(client));
        i2c_unregister_device(client);
        i2c_put_adapter(adap);
}
#else
#define soc_camera_init_i2c(icd, icl)   (-ENODEV)
#define soc_camera_free_i2c(icd)        do {} while (0)
#endif

static int soc_camera_video_start(struct soc_camera_device *icd);
static int video_dev_create(struct soc_camera_device *icd);
/* Called during host-driver probe */
static int soc_camera_probe(struct soc_camera_device *icd)
{
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
        struct soc_camera_link *icl = to_soc_camera_link(icd);
        struct device *control = NULL;
        struct v4l2_subdev *sd;
        struct v4l2_mbus_framefmt mf;
        int ret;

        dev_info(icd->pdev, "Probing %s\n", dev_name(icd->pdev));

        /*
         * Currently the subdev with the largest number of controls (13) is
         * ov6550. So let's pick 16 as a hint for the control handler. Note
         * that this is a hint only: too large and you waste some memory, too
         * small and there is a (very) small performance hit when looking up
         * controls in the internal hash.
         */
        ret = v4l2_ctrl_handler_init(&icd->ctrl_handler, 16);
        if (ret < 0)
                return ret;

        ret = regulator_bulk_get(icd->pdev, icl->num_regulators,
                                 icl->regulators);
        if (ret < 0)
                goto ereg;

        /*
         * This will not yet call v4l2_subdev_core_ops::s_power(1), because the
         * subdevice has not been initialised yet. We'll have to call it once
         * again after initialisation, even though it shouldn't be needed, we
         * don't do any IO here.
         */
        ret = soc_camera_power_on(icd, icl);
        if (ret < 0)
                goto epower;

        /* The camera could have been already on, try to reset */
        if (icl->reset)
                icl->reset(icd->pdev);

        ret = ici->ops->add(icd);
        if (ret < 0)
                goto eadd;

        /* Must have icd->vdev before registering the device */
        ret = video_dev_create(icd);
        if (ret < 0)
                goto evdc;

        /* Non-i2c cameras, e.g., soc_camera_platform, have no board_info */
        if (icl->board_info) {
                ret = soc_camera_init_i2c(icd, icl);
                if (ret < 0)
                        goto eadddev;
        } else if (!icl->add_device || !icl->del_device) {
                ret = -EINVAL;
                goto eadddev;
        } else {
                if (icl->module_name)
                        ret = request_module(icl->module_name);

                ret = icl->add_device(icd);
                if (ret < 0)
                        goto eadddev;

                /*
                 * FIXME: this is racy, have to use driver-binding notification,
                 * when it is available
                 */
                control = to_soc_camera_control(icd);
                if (!control || !control->driver || !dev_get_drvdata(control) ||
                    !try_module_get(control->driver->owner)) {
                        icl->del_device(icd);
                        ret = -ENODEV;
                        goto enodrv;
                }
        }

        sd = soc_camera_to_subdev(icd);
        sd->grp_id = soc_camera_grp_id(icd);
        v4l2_set_subdev_hostdata(sd, icd);

        if (v4l2_ctrl_add_handler(&icd->ctrl_handler, sd->ctrl_handler))
                goto ectrl;

        /* At this point client .probe() should have run already */
        ret = soc_camera_init_user_formats(icd);
        if (ret < 0)
                goto eiufmt;

        icd->field = V4L2_FIELD_ANY;

        /*
         * ..._video_start() will create a device node, video_register_device()
         * itself is protected against concurrent open() calls, but we also have
         * to protect our data.
         */
        mutex_lock(&icd->video_lock);

        ret = soc_camera_video_start(icd);
        if (ret < 0)
                goto evidstart;

        ret = v4l2_subdev_call(sd, core, s_power, 1);
        if (ret < 0 && ret != -ENOIOCTLCMD)
                goto esdpwr;

        /* Try to improve our guess of a reasonable window format */
        if (!v4l2_subdev_call(sd, video, g_mbus_fmt, &mf)) {
                icd->user_width         = mf.width;
                icd->user_height        = mf.height;
                icd->colorspace         = mf.colorspace;
                icd->field              = mf.field;
        }

        ici->ops->remove(icd);

        soc_camera_power_off(icd, icl);

        mutex_unlock(&icd->video_lock);

        return 0;

esdpwr:
        video_unregister_device(icd->vdev);
evidstart:
        mutex_unlock(&icd->video_lock);
        soc_camera_free_user_formats(icd);
eiufmt:
ectrl:
        if (icl->board_info) {
                soc_camera_free_i2c(icd);
        } else {
                icl->del_device(icd);
                module_put(control->driver->owner);
        }
enodrv:
eadddev:
        video_device_release(icd->vdev);
        icd->vdev = NULL;
evdc:
        ici->ops->remove(icd);
eadd:
        soc_camera_power_off(icd, icl);
epower:
        regulator_bulk_free(icl->num_regulators, icl->regulators);
ereg:
        v4l2_ctrl_handler_free(&icd->ctrl_handler);
        return ret;
}

/*
 * This is called on device_unregister, which only means we have to disconnect
 * from the host, but not remove ourselves from the device list
 */
static int soc_camera_remove(struct soc_camera_device *icd)
{
        struct soc_camera_link *icl = to_soc_camera_link(icd);
        struct video_device *vdev = icd->vdev;

        BUG_ON(!icd->parent);

        v4l2_ctrl_handler_free(&icd->ctrl_handler);
        if (vdev) {
                video_unregister_device(vdev);
                icd->vdev = NULL;
        }

        if (icl->board_info) {
                soc_camera_free_i2c(icd);
        } else {
                struct device_driver *drv = to_soc_camera_control(icd)->driver;
                if (drv) {
                        icl->del_device(icd);
                        module_put(drv->owner);
                }
        }
        soc_camera_free_user_formats(icd);

        regulator_bulk_free(icl->num_regulators, icl->regulators);

        return 0;
}

static int default_cropcap(struct soc_camera_device *icd,
                           struct v4l2_cropcap *a)
{
        struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
        return v4l2_subdev_call(sd, video, cropcap, a);
}

static int default_g_crop(struct soc_camera_device *icd, struct v4l2_crop *a)
{
        struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
        return v4l2_subdev_call(sd, video, g_crop, a);
}

static int default_s_crop(struct soc_camera_device *icd, struct v4l2_crop *a)
{
        struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
        return v4l2_subdev_call(sd, video, s_crop, a);
}

static int default_g_parm(struct soc_camera_device *icd,
                          struct v4l2_streamparm *parm)
{
        struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
        return v4l2_subdev_call(sd, video, g_parm, parm);
}

static int default_s_parm(struct soc_camera_device *icd,
                          struct v4l2_streamparm *parm)
{
        struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
        return v4l2_subdev_call(sd, video, s_parm, parm);
}

static int default_enum_fsizes(struct soc_camera_device *icd,
                          struct v4l2_frmsizeenum *fsize)
{
        int ret;
        struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
        const struct soc_camera_format_xlate *xlate;
        __u32 pixfmt = fsize->pixel_format;
        struct v4l2_frmsizeenum fsize_mbus = *fsize;

        xlate = soc_camera_xlate_by_fourcc(icd, pixfmt);
        if (!xlate)
                return -EINVAL;
        /* map xlate-code to pixel_format, sensor only handle xlate-code*/
        fsize_mbus.pixel_format = xlate->code;

        ret = v4l2_subdev_call(sd, video, enum_mbus_fsizes, &fsize_mbus);
        if (ret < 0)
                return ret;

        *fsize = fsize_mbus;
        fsize->pixel_format = pixfmt;

        return 0;
}

int soc_camera_host_register(struct soc_camera_host *ici)
{
        struct soc_camera_host *ix;
        int ret;

        if (!ici || !ici->ops ||
            !ici->ops->try_fmt ||
            !ici->ops->set_fmt ||
            !ici->ops->set_bus_param ||
            !ici->ops->querycap ||
            ((!ici->ops->init_videobuf ||
              !ici->ops->reqbufs) &&
             !ici->ops->init_videobuf2) ||
            !ici->ops->add ||
            !ici->ops->remove ||
            !ici->ops->poll ||
            !ici->v4l2_dev.dev)
                return -EINVAL;

        if (!ici->ops->set_crop)
                ici->ops->set_crop = default_s_crop;
        if (!ici->ops->get_crop)
                ici->ops->get_crop = default_g_crop;
        if (!ici->ops->cropcap)
                ici->ops->cropcap = default_cropcap;
        if (!ici->ops->set_parm)
                ici->ops->set_parm = default_s_parm;
        if (!ici->ops->get_parm)
                ici->ops->get_parm = default_g_parm;
        if (!ici->ops->enum_fsizes)
                ici->ops->enum_fsizes = default_enum_fsizes;

        mutex_lock(&list_lock);
        list_for_each_entry(ix, &hosts, list) {
                if (ix->nr == ici->nr) {
                        ret = -EBUSY;
                        goto edevreg;
                }
        }

        ret = v4l2_device_register(ici->v4l2_dev.dev, &ici->v4l2_dev);
        if (ret < 0)
                goto edevreg;

        list_add_tail(&ici->list, &hosts);
        mutex_unlock(&list_lock);

        scan_add_host(ici);

        return 0;

edevreg:
        mutex_unlock(&list_lock);
        return ret;
}
EXPORT_SYMBOL(soc_camera_host_register);

/* Unregister all clients! */
void soc_camera_host_unregister(struct soc_camera_host *ici)
{
        struct soc_camera_device *icd;

        mutex_lock(&list_lock);

        list_del(&ici->list);
        list_for_each_entry(icd, &devices, list)
                if (icd->iface == ici->nr && to_soc_camera_control(icd))
                        soc_camera_remove(icd);

        mutex_unlock(&list_lock);

        v4l2_device_unregister(&ici->v4l2_dev);
}
EXPORT_SYMBOL(soc_camera_host_unregister);

/* Image capture device */
static int soc_camera_device_register(struct soc_camera_device *icd)
{
        struct soc_camera_device *ix;
        int num = -1, i;

        for (i = 0; i < 256 && num < 0; i++) {
                num = i;
                /* Check if this index is available on this interface */
                list_for_each_entry(ix, &devices, list) {
                        if (ix->iface == icd->iface && ix->devnum == i) {
                                num = -1;
                                break;
                        }
                }
        }

        if (num < 0)
                /*
                 * ok, we have 256 cameras on this host...
                 * man, stay reasonable...
                 */
                return -ENOMEM;

        icd->devnum             = num;
        icd->use_count          = 0;
        icd->host_priv          = NULL;
        mutex_init(&icd->video_lock);

        list_add_tail(&icd->list, &devices);

        return 0;
}

static const struct v4l2_ioctl_ops soc_camera_ioctl_ops = {
        .vidioc_querycap         = soc_camera_querycap,
        .vidioc_try_fmt_vid_cap  = soc_camera_try_fmt_vid_cap,
        .vidioc_g_fmt_vid_cap    = soc_camera_g_fmt_vid_cap,
        .vidioc_s_fmt_vid_cap    = soc_camera_s_fmt_vid_cap,
        .vidioc_enum_fmt_vid_cap = soc_camera_enum_fmt_vid_cap,
        .vidioc_enum_input       = soc_camera_enum_input,
        .vidioc_g_input          = soc_camera_g_input,
        .vidioc_s_input          = soc_camera_s_input,
        .vidioc_s_std            = soc_camera_s_std,
        .vidioc_g_std            = soc_camera_g_std,
        .vidioc_enum_framesizes  = soc_camera_enum_fsizes,
        .vidioc_reqbufs          = soc_camera_reqbufs,
        .vidioc_querybuf         = soc_camera_querybuf,
        .vidioc_qbuf             = soc_camera_qbuf,
        .vidioc_dqbuf            = soc_camera_dqbuf,
        .vidioc_create_bufs      = soc_camera_create_bufs,
        .vidioc_prepare_buf      = soc_camera_prepare_buf,
        .vidioc_streamon         = soc_camera_streamon,
        .vidioc_streamoff        = soc_camera_streamoff,
        .vidioc_cropcap          = soc_camera_cropcap,
        .vidioc_g_crop           = soc_camera_g_crop,
        .vidioc_s_crop           = soc_camera_s_crop,
        .vidioc_g_parm           = soc_camera_g_parm,
        .vidioc_s_parm           = soc_camera_s_parm,
        .vidioc_g_chip_ident     = soc_camera_g_chip_ident,
#ifdef CONFIG_VIDEO_ADV_DEBUG
        .vidioc_g_register       = soc_camera_g_register,
        .vidioc_s_register       = soc_camera_s_register,
#endif
};

static int video_dev_create(struct soc_camera_device *icd)
{
        struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
        struct video_device *vdev = video_device_alloc();

        if (!vdev)
                return -ENOMEM;

        strlcpy(vdev->name, ici->drv_name, sizeof(vdev->name));

        vdev->parent            = icd->pdev;
        vdev->current_norm      = V4L2_STD_UNKNOWN;
        vdev->fops              = &soc_camera_fops;
        vdev->ioctl_ops         = &soc_camera_ioctl_ops;
        vdev->release           = video_device_release;
        vdev->tvnorms           = V4L2_STD_UNKNOWN;
        vdev->ctrl_handler      = &icd->ctrl_handler;
        vdev->lock              = &icd->video_lock;

        icd->vdev = vdev;

        return 0;
}

/*
 * Called from soc_camera_probe() above (with .video_lock held???)
 */
static int soc_camera_video_start(struct soc_camera_device *icd)
{
        const struct device_type *type = icd->vdev->dev.type;
        int ret;

        if (!icd->parent)
                return -ENODEV;

        ret = video_register_device(icd->vdev, VFL_TYPE_GRABBER, -1);
        if (ret < 0) {
                dev_err(icd->pdev, "video_register_device failed: %d\n", ret);
                return ret;
        }

        /* Restore device type, possibly set by the subdevice driver */
        icd->vdev->dev.type = type;

        return 0;
}

static int __devinit soc_camera_pdrv_probe(struct platform_device *pdev)
{
        struct soc_camera_link *icl = pdev->dev.platform_data;
        struct soc_camera_device *icd;
        int ret;

        if (!icl)
                return -EINVAL;

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

        icd->iface = icl->bus_id;
        icd->link = icl;
        icd->pdev = &pdev->dev;
        platform_set_drvdata(pdev, icd);

        ret = soc_camera_device_register(icd);
        if (ret < 0)
                goto escdevreg;

        icd->user_width         = DEFAULT_WIDTH;
        icd->user_height        = DEFAULT_HEIGHT;

        return 0;

escdevreg:
        kfree(icd);

        return ret;
}

/*
 * Only called on rmmod for each platform device, since they are not
 * hot-pluggable. Now we know, that all our users - hosts and devices have
 * been unloaded already
 */
static int __devexit soc_camera_pdrv_remove(struct platform_device *pdev)
{
        struct soc_camera_device *icd = platform_get_drvdata(pdev);

        if (!icd)
                return -EINVAL;

        list_del(&icd->list);

        kfree(icd);

        return 0;
}

static struct platform_driver __refdata soc_camera_pdrv = {
        .remove  = __devexit_p(soc_camera_pdrv_remove),
        .driver  = {
                .name   = "soc-camera-pdrv",
                .owner  = THIS_MODULE,
        },
};

static int __init soc_camera_init(void)
{
        return platform_driver_probe(&soc_camera_pdrv, soc_camera_pdrv_probe);
}

static void __exit soc_camera_exit(void)
{
        platform_driver_unregister(&soc_camera_pdrv);
}

module_init(soc_camera_init);
module_exit(soc_camera_exit);

MODULE_DESCRIPTION("Image capture bus driver");
MODULE_AUTHOR("Guennadi Liakhovetski <kernel@pengutronix.de>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:soc-camera-pdrv");