// SPDX-License-Identifier: GPL-2.0+
/*
 * vsp1_histo.c  --  R-Car VSP1 Histogram API
 *
 * Copyright (C) 2016 Renesas Electronics Corporation
 * Copyright (C) 2016 Laurent Pinchart
 *
 * Contact: Laurent Pinchart (laurent.pinchart@ideasonboard.com)
 */

#include <linux/device.h>
#include <linux/gfp.h>

#include <media/v4l2-ioctl.h>
#include <media/v4l2-subdev.h>
#include <media/videobuf2-vmalloc.h>

#include "vsp1.h"
#include "vsp1_histo.h"
#include "vsp1_pipe.h"

#define HISTO_MIN_SIZE                          4U
#define HISTO_MAX_SIZE                          8192U

/* -----------------------------------------------------------------------------
 * Buffer Operations
 */

static inline struct vsp1_histogram_buffer *
to_vsp1_histogram_buffer(struct vb2_v4l2_buffer *vbuf)
{
        return container_of(vbuf, struct vsp1_histogram_buffer, buf);
}

struct vsp1_histogram_buffer *
vsp1_histogram_buffer_get(struct vsp1_histogram *histo)
{
        struct vsp1_histogram_buffer *buf = NULL;

        spin_lock(&histo->irqlock);

        if (list_empty(&histo->irqqueue))
                goto done;

        buf = list_first_entry(&histo->irqqueue, struct vsp1_histogram_buffer,
                               queue);
        list_del(&buf->queue);
        histo->readout = true;

done:
        spin_unlock(&histo->irqlock);
        return buf;
}

void vsp1_histogram_buffer_complete(struct vsp1_histogram *histo,
                                    struct vsp1_histogram_buffer *buf,
                                    size_t size)
{
        struct vsp1_pipeline *pipe = histo->entity.pipe;

        /*
         * The pipeline pointer is guaranteed to be valid as this function is
         * called from the frame completion interrupt handler, which can only
         * occur when video streaming is active.
         */
        buf->buf.sequence = pipe->sequence;
        buf->buf.vb2_buf.timestamp = ktime_get_ns();
        vb2_set_plane_payload(&buf->buf.vb2_buf, 0, size);
        vb2_buffer_done(&buf->buf.vb2_buf, VB2_BUF_STATE_DONE);

        spin_lock(&histo->irqlock);
        histo->readout = false;
        wake_up(&histo->wait_queue);
        spin_unlock(&histo->irqlock);
}

/* -----------------------------------------------------------------------------
 * videobuf2 Queue Operations
 */

static int histo_queue_setup(struct vb2_queue *vq, unsigned int *nbuffers,
                             unsigned int *nplanes, unsigned int sizes[],
                             struct device *alloc_devs[])
{
        struct vsp1_histogram *histo = vb2_get_drv_priv(vq);

        if (*nplanes) {
                if (*nplanes != 1)
                        return -EINVAL;

                if (sizes[0] < histo->data_size)
                        return -EINVAL;

                return 0;
        }

        *nplanes = 1;
        sizes[0] = histo->data_size;

        return 0;
}

static int histo_buffer_prepare(struct vb2_buffer *vb)
{
        struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
        struct vsp1_histogram *histo = vb2_get_drv_priv(vb->vb2_queue);
        struct vsp1_histogram_buffer *buf = to_vsp1_histogram_buffer(vbuf);

        if (vb->num_planes != 1)
                return -EINVAL;

        if (vb2_plane_size(vb, 0) < histo->data_size)
                return -EINVAL;

        buf->addr = vb2_plane_vaddr(vb, 0);

        return 0;
}

static void histo_buffer_queue(struct vb2_buffer *vb)
{
        struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
        struct vsp1_histogram *histo = vb2_get_drv_priv(vb->vb2_queue);
        struct vsp1_histogram_buffer *buf = to_vsp1_histogram_buffer(vbuf);

        spin_lock_irq(&histo->irqlock);
        list_add_tail(&buf->queue, &histo->irqqueue);
        spin_unlock_irq(&histo->irqlock);
}

static int histo_start_streaming(struct vb2_queue *vq, unsigned int count)
{
        return 0;
}

static void histo_stop_streaming(struct vb2_queue *vq)
{
        struct vsp1_histogram *histo = vb2_get_drv_priv(vq);
        struct vsp1_histogram_buffer *buffer;

        spin_lock_irq(&histo->irqlock);

        /* Remove all buffers from the IRQ queue. */
        list_for_each_entry(buffer, &histo->irqqueue, queue)
                vb2_buffer_done(&buffer->buf.vb2_buf, VB2_BUF_STATE_ERROR);
        INIT_LIST_HEAD(&histo->irqqueue);

        /* Wait for the buffer being read out (if any) to complete. */
        wait_event_lock_irq(histo->wait_queue, !histo->readout, histo->irqlock);

        spin_unlock_irq(&histo->irqlock);
}

static const struct vb2_ops histo_video_queue_qops = {
        .queue_setup = histo_queue_setup,
        .buf_prepare = histo_buffer_prepare,
        .buf_queue = histo_buffer_queue,
        .start_streaming = histo_start_streaming,
        .stop_streaming = histo_stop_streaming,
};

/* -----------------------------------------------------------------------------
 * V4L2 Subdevice Operations
 */

static int histo_enum_mbus_code(struct v4l2_subdev *subdev,
                                struct v4l2_subdev_state *sd_state,
                                struct v4l2_subdev_mbus_code_enum *code)
{
        struct vsp1_histogram *histo = subdev_to_histo(subdev);

        if (code->pad == HISTO_PAD_SOURCE) {
                code->code = MEDIA_BUS_FMT_FIXED;
                return 0;
        }

        return vsp1_subdev_enum_mbus_code(subdev, sd_state, code,
                                          histo->formats,
                                          histo->num_formats);
}

static int histo_enum_frame_size(struct v4l2_subdev *subdev,
                                 struct v4l2_subdev_state *sd_state,
                                 struct v4l2_subdev_frame_size_enum *fse)
{
        if (fse->pad != HISTO_PAD_SINK)
                return -EINVAL;

        return vsp1_subdev_enum_frame_size(subdev, sd_state, fse,
                                           HISTO_MIN_SIZE,
                                           HISTO_MIN_SIZE, HISTO_MAX_SIZE,
                                           HISTO_MAX_SIZE);
}

static int histo_get_selection(struct v4l2_subdev *subdev,
                               struct v4l2_subdev_state *sd_state,
                               struct v4l2_subdev_selection *sel)
{
        struct vsp1_histogram *histo = subdev_to_histo(subdev);
        struct v4l2_subdev_state *state;
        struct v4l2_mbus_framefmt *format;
        struct v4l2_rect *crop;
        int ret = 0;

        if (sel->pad != HISTO_PAD_SINK)
                return -EINVAL;

        mutex_lock(&histo->entity.lock);

        state = vsp1_entity_get_state(&histo->entity, sd_state, sel->which);
        if (!state) {
                ret = -EINVAL;
                goto done;
        }

        switch (sel->target) {
        case V4L2_SEL_TGT_COMPOSE_BOUNDS:
        case V4L2_SEL_TGT_COMPOSE_DEFAULT:
                crop = v4l2_subdev_state_get_crop(state, HISTO_PAD_SINK);
                sel->r.left = 0;
                sel->r.top = 0;
                sel->r.width = crop->width;
                sel->r.height = crop->height;
                break;

        case V4L2_SEL_TGT_CROP_BOUNDS:
        case V4L2_SEL_TGT_CROP_DEFAULT:
                format = v4l2_subdev_state_get_format(state, HISTO_PAD_SINK);
                sel->r.left = 0;
                sel->r.top = 0;
                sel->r.width = format->width;
                sel->r.height = format->height;
                break;

        case V4L2_SEL_TGT_COMPOSE:
                sel->r = *v4l2_subdev_state_get_compose(state, sel->pad);
                break;

        case V4L2_SEL_TGT_CROP:
                sel->r = *v4l2_subdev_state_get_crop(state, sel->pad);
                break;

        default:
                ret = -EINVAL;
                break;
        }

done:
        mutex_unlock(&histo->entity.lock);
        return ret;
}

static int histo_set_crop(struct v4l2_subdev *subdev,
                          struct v4l2_subdev_state *sd_state,
                          struct v4l2_subdev_selection *sel)
{
        struct v4l2_mbus_framefmt *format;

        /* The crop rectangle must be inside the input frame. */
        format = v4l2_subdev_state_get_format(sd_state, HISTO_PAD_SINK);
        sel->r.left = clamp_t(unsigned int, sel->r.left, 0, format->width - 1);
        sel->r.top = clamp_t(unsigned int, sel->r.top, 0, format->height - 1);
        sel->r.width = clamp_t(unsigned int, sel->r.width, HISTO_MIN_SIZE,
                               format->width - sel->r.left);
        sel->r.height = clamp_t(unsigned int, sel->r.height, HISTO_MIN_SIZE,
                                format->height - sel->r.top);

        /* Set the crop rectangle and reset the compose rectangle. */
        *v4l2_subdev_state_get_crop(sd_state, sel->pad) = sel->r;
        *v4l2_subdev_state_get_compose(sd_state, sel->pad) = sel->r;

        return 0;
}

static int histo_set_compose(struct v4l2_subdev *subdev,
                             struct v4l2_subdev_state *sd_state,
                             struct v4l2_subdev_selection *sel)
{
        struct v4l2_rect *compose;
        struct v4l2_rect *crop;
        unsigned int ratio;

        /*
         * The compose rectangle is used to configure downscaling, the top left
         * corner is fixed to (0,0) and the size to 1/2 or 1/4 of the crop
         * rectangle.
         */
        sel->r.left = 0;
        sel->r.top = 0;

        crop = v4l2_subdev_state_get_crop(sd_state, sel->pad);

        /*
         * Clamp the width and height to acceptable values first and then
         * compute the closest rounded dividing ratio.
         *
         * Ratio        Rounded ratio
         * --------------------------
         * [1.0 1.5[    1
         * [1.5 3.0[    2
         * [3.0 4.0]    4
         *
         * The rounded ratio can be computed using
         *
         * 1 << (ceil(ratio * 2) / 3)
         */
        sel->r.width = clamp(sel->r.width, crop->width / 4, crop->width);
        ratio = 1 << (crop->width * 2 / sel->r.width / 3);
        sel->r.width = crop->width / ratio;


        sel->r.height = clamp(sel->r.height, crop->height / 4, crop->height);
        ratio = 1 << (crop->height * 2 / sel->r.height / 3);
        sel->r.height = crop->height / ratio;

        compose = v4l2_subdev_state_get_compose(sd_state, sel->pad);
        *compose = sel->r;

        return 0;
}

static int histo_set_selection(struct v4l2_subdev *subdev,
                               struct v4l2_subdev_state *sd_state,
                               struct v4l2_subdev_selection *sel)
{
        struct vsp1_histogram *histo = subdev_to_histo(subdev);
        struct v4l2_subdev_state *state;
        int ret;

        if (sel->pad != HISTO_PAD_SINK)
                return -EINVAL;

        mutex_lock(&histo->entity.lock);

        state = vsp1_entity_get_state(&histo->entity, sd_state, sel->which);
        if (!state) {
                ret = -EINVAL;
                goto done;
        }

        if (sel->target == V4L2_SEL_TGT_CROP)
                ret = histo_set_crop(subdev, state, sel);
        else if (sel->target == V4L2_SEL_TGT_COMPOSE)
                ret = histo_set_compose(subdev, state, sel);
        else
                ret = -EINVAL;

done:
        mutex_unlock(&histo->entity.lock);
        return ret;
}

static int histo_set_format(struct v4l2_subdev *subdev,
                            struct v4l2_subdev_state *sd_state,
                            struct v4l2_subdev_format *fmt)
{
        struct vsp1_histogram *histo = subdev_to_histo(subdev);

        if (fmt->pad == HISTO_PAD_SOURCE) {
                fmt->format.code = MEDIA_BUS_FMT_FIXED;
                fmt->format.width = 0;
                fmt->format.height = 0;
                fmt->format.field = V4L2_FIELD_NONE;
                fmt->format.colorspace = V4L2_COLORSPACE_RAW;

                return 0;
        }

        return vsp1_subdev_set_pad_format(subdev, sd_state, fmt,
                                          histo->formats, histo->num_formats,
                                          HISTO_MIN_SIZE, HISTO_MIN_SIZE,
                                          HISTO_MAX_SIZE, HISTO_MAX_SIZE);
}

static const struct v4l2_subdev_pad_ops histo_pad_ops = {
        .enum_mbus_code = histo_enum_mbus_code,
        .enum_frame_size = histo_enum_frame_size,
        .get_fmt = vsp1_subdev_get_pad_format,
        .set_fmt = histo_set_format,
        .get_selection = histo_get_selection,
        .set_selection = histo_set_selection,
};

static const struct v4l2_subdev_ops histo_ops = {
        .pad    = &histo_pad_ops,
};

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

static int histo_v4l2_querycap(struct file *file, void *fh,
                               struct v4l2_capability *cap)
{
        struct v4l2_fh *vfh = file_to_v4l2_fh(file);
        struct vsp1_histogram *histo = vdev_to_histo(vfh->vdev);

        cap->capabilities = V4L2_CAP_DEVICE_CAPS | V4L2_CAP_STREAMING
                          | V4L2_CAP_VIDEO_CAPTURE_MPLANE
                          | V4L2_CAP_VIDEO_OUTPUT_MPLANE
                          | V4L2_CAP_META_CAPTURE;

        strscpy(cap->driver, "vsp1", sizeof(cap->driver));
        strscpy(cap->card, histo->video.name, sizeof(cap->card));

        return 0;
}

static int histo_v4l2_enum_format(struct file *file, void *fh,
                                  struct v4l2_fmtdesc *f)
{
        struct v4l2_fh *vfh = file_to_v4l2_fh(file);
        struct vsp1_histogram *histo = vdev_to_histo(vfh->vdev);

        if (f->index > 0 || f->type != histo->queue.type)
                return -EINVAL;

        f->pixelformat = histo->meta_format;

        return 0;
}

static int histo_v4l2_get_format(struct file *file, void *fh,
                                 struct v4l2_format *format)
{
        struct v4l2_fh *vfh = file_to_v4l2_fh(file);
        struct vsp1_histogram *histo = vdev_to_histo(vfh->vdev);
        struct v4l2_meta_format *meta = &format->fmt.meta;

        if (format->type != histo->queue.type)
                return -EINVAL;

        memset(meta, 0, sizeof(*meta));

        meta->dataformat = histo->meta_format;
        meta->buffersize = histo->data_size;

        return 0;
}

static const struct v4l2_ioctl_ops histo_v4l2_ioctl_ops = {
        .vidioc_querycap                = histo_v4l2_querycap,
        .vidioc_enum_fmt_meta_cap       = histo_v4l2_enum_format,
        .vidioc_g_fmt_meta_cap          = histo_v4l2_get_format,
        .vidioc_s_fmt_meta_cap          = histo_v4l2_get_format,
        .vidioc_try_fmt_meta_cap        = histo_v4l2_get_format,
        .vidioc_reqbufs                 = vb2_ioctl_reqbufs,
        .vidioc_querybuf                = vb2_ioctl_querybuf,
        .vidioc_qbuf                    = vb2_ioctl_qbuf,
        .vidioc_dqbuf                   = vb2_ioctl_dqbuf,
        .vidioc_create_bufs             = vb2_ioctl_create_bufs,
        .vidioc_prepare_buf             = vb2_ioctl_prepare_buf,
        .vidioc_streamon                = vb2_ioctl_streamon,
        .vidioc_streamoff               = vb2_ioctl_streamoff,
};

/* -----------------------------------------------------------------------------
 * V4L2 File Operations
 */

static const struct v4l2_file_operations histo_v4l2_fops = {
        .owner = THIS_MODULE,
        .unlocked_ioctl = video_ioctl2,
        .open = v4l2_fh_open,
        .release = vb2_fop_release,
        .poll = vb2_fop_poll,
        .mmap = vb2_fop_mmap,
};

static void vsp1_histogram_cleanup(struct vsp1_histogram *histo)
{
        if (video_is_registered(&histo->video))
                video_unregister_device(&histo->video);

        media_entity_cleanup(&histo->video.entity);
}

void vsp1_histogram_destroy(struct vsp1_entity *entity)
{
        struct vsp1_histogram *histo = subdev_to_histo(&entity->subdev);

        vsp1_histogram_cleanup(histo);
}

int vsp1_histogram_init(struct vsp1_device *vsp1, struct vsp1_histogram *histo,
                        enum vsp1_entity_type type, const char *name,
                        const struct vsp1_entity_operations *ops,
                        const unsigned int *formats, unsigned int num_formats,
                        size_t data_size, u32 meta_format)
{
        int ret;

        histo->formats = formats;
        histo->num_formats = num_formats;
        histo->data_size = data_size;
        histo->meta_format = meta_format;

        histo->pad.flags = MEDIA_PAD_FL_SINK;
        histo->video.vfl_dir = VFL_DIR_RX;

        mutex_init(&histo->lock);
        spin_lock_init(&histo->irqlock);
        INIT_LIST_HEAD(&histo->irqqueue);
        init_waitqueue_head(&histo->wait_queue);

        /* Initialize the VSP entity... */
        histo->entity.ops = ops;
        histo->entity.type = type;

        ret = vsp1_entity_init(vsp1, &histo->entity, name, 2, &histo_ops,
                               MEDIA_ENT_F_PROC_VIDEO_STATISTICS);
        if (ret < 0)
                return ret;

        /* ... and the media entity... */
        ret = media_entity_pads_init(&histo->video.entity, 1, &histo->pad);
        if (ret < 0)
                return ret;

        /* ... and the video node... */
        histo->video.v4l2_dev = &vsp1->v4l2_dev;
        histo->video.fops = &histo_v4l2_fops;
        snprintf(histo->video.name, sizeof(histo->video.name),
                 "%s histo", histo->entity.subdev.name);
        histo->video.vfl_type = VFL_TYPE_VIDEO;
        histo->video.release = video_device_release_empty;
        histo->video.ioctl_ops = &histo_v4l2_ioctl_ops;
        histo->video.device_caps = V4L2_CAP_META_CAPTURE | V4L2_CAP_STREAMING;

        video_set_drvdata(&histo->video, histo);

        /* ... and the buffers queue... */
        histo->queue.type = V4L2_BUF_TYPE_META_CAPTURE;
        histo->queue.io_modes = VB2_MMAP | VB2_USERPTR | VB2_DMABUF;
        histo->queue.lock = &histo->lock;
        histo->queue.drv_priv = histo;
        histo->queue.buf_struct_size = sizeof(struct vsp1_histogram_buffer);
        histo->queue.ops = &histo_video_queue_qops;
        histo->queue.mem_ops = &vb2_vmalloc_memops;
        histo->queue.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
        histo->queue.dev = vsp1->dev;
        ret = vb2_queue_init(&histo->queue);
        if (ret < 0) {
                dev_err(vsp1->dev, "failed to initialize vb2 queue\n");
                goto error;
        }

        /* ... and register the video device. */
        histo->video.queue = &histo->queue;
        ret = video_register_device(&histo->video, VFL_TYPE_VIDEO, -1);
        if (ret < 0) {
                dev_err(vsp1->dev, "failed to register video device\n");
                goto error;
        }

        return 0;

error:
        vsp1_histogram_cleanup(histo);
        return ret;
}