// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * vimc-capture.c Virtual Media Controller Driver
 *
 * Copyright (C) 2015-2017 Helen Koike <helen.fornazier@gmail.com>
 */

#include <media/v4l2-ioctl.h>
#include <media/videobuf2-core.h>
#include <media/videobuf2-dma-contig.h>
#include <media/videobuf2-vmalloc.h>

#include "vimc-common.h"
#include "vimc-streamer.h"

struct vimc_capture_device {
        struct vimc_ent_device ved;
        struct video_device vdev;
        struct v4l2_pix_format format;
        struct vb2_queue queue;
        struct list_head buf_list;
        /*
         * NOTE: in a real driver, a spin lock must be used to access the
         * queue because the frames are generated from a hardware interruption
         * and the isr is not allowed to sleep.
         * Even if it is not necessary a spinlock in the vimc driver, we
         * use it here as a code reference
         */
        spinlock_t qlock;
        struct mutex lock;
        u32 sequence;
        struct vimc_stream stream;
        struct media_pad pad;
};

static const struct v4l2_pix_format fmt_default = {
        .width = 640,
        .height = 480,
        .pixelformat = V4L2_PIX_FMT_RGB24,
        .field = V4L2_FIELD_NONE,
        .colorspace = V4L2_COLORSPACE_SRGB,
};

struct vimc_capture_buffer {
        /*
         * struct vb2_v4l2_buffer must be the first element
         * the videobuf2 framework will allocate this struct based on
         * buf_struct_size and use the first sizeof(struct vb2_buffer) bytes of
         * memory as a vb2_buffer
         */
        struct vb2_v4l2_buffer vb2;
        struct list_head list;
};

static int vimc_capture_querycap(struct file *file, void *priv,
                             struct v4l2_capability *cap)
{
        strscpy(cap->driver, VIMC_PDEV_NAME, sizeof(cap->driver));
        strscpy(cap->card, KBUILD_MODNAME, sizeof(cap->card));

        return 0;
}

static void vimc_capture_get_format(struct vimc_ent_device *ved,
                                struct v4l2_pix_format *fmt)
{
        struct vimc_capture_device *vcapture = container_of(ved, struct vimc_capture_device,
                                                    ved);

        *fmt = vcapture->format;
}

static int vimc_capture_g_fmt_vid_cap(struct file *file, void *priv,
                                  struct v4l2_format *f)
{
        struct vimc_capture_device *vcapture = video_drvdata(file);

        f->fmt.pix = vcapture->format;

        return 0;
}

static int vimc_capture_try_fmt_vid_cap(struct file *file, void *priv,
                                    struct v4l2_format *f)
{
        struct v4l2_pix_format *format = &f->fmt.pix;
        const struct vimc_pix_map *vpix;

        format->width = clamp_t(u32, format->width, VIMC_FRAME_MIN_WIDTH,
                                VIMC_FRAME_MAX_WIDTH) & ~1;
        format->height = clamp_t(u32, format->height, VIMC_FRAME_MIN_HEIGHT,
                                 VIMC_FRAME_MAX_HEIGHT) & ~1;

        /* Don't accept a pixelformat that is not on the table */
        vpix = vimc_pix_map_by_pixelformat(format->pixelformat);
        if (!vpix) {
                format->pixelformat = fmt_default.pixelformat;
                vpix = vimc_pix_map_by_pixelformat(format->pixelformat);
        }
        /* TODO: Add support for custom bytesperline values */
        format->bytesperline = format->width * vpix->bpp;
        format->sizeimage = format->bytesperline * format->height;

        if (format->field == V4L2_FIELD_ANY)
                format->field = fmt_default.field;

        vimc_colorimetry_clamp(format);

        if (format->colorspace == V4L2_COLORSPACE_DEFAULT)
                format->colorspace = fmt_default.colorspace;

        return 0;
}

static int vimc_capture_s_fmt_vid_cap(struct file *file, void *priv,
                                  struct v4l2_format *f)
{
        struct vimc_capture_device *vcapture = video_drvdata(file);
        int ret;

        /* Do not change the format while stream is on */
        if (vb2_is_busy(&vcapture->queue))
                return -EBUSY;

        ret = vimc_capture_try_fmt_vid_cap(file, priv, f);
        if (ret)
                return ret;

        dev_dbg(vcapture->ved.dev, "%s: format update: "
                "old:%dx%d (0x%x, %d, %d, %d, %d) "
                "new:%dx%d (0x%x, %d, %d, %d, %d)\n", vcapture->vdev.name,
                /* old */
                vcapture->format.width, vcapture->format.height,
                vcapture->format.pixelformat, vcapture->format.colorspace,
                vcapture->format.quantization, vcapture->format.xfer_func,
                vcapture->format.ycbcr_enc,
                /* new */
                f->fmt.pix.width, f->fmt.pix.height,
                f->fmt.pix.pixelformat, f->fmt.pix.colorspace,
                f->fmt.pix.quantization, f->fmt.pix.xfer_func,
                f->fmt.pix.ycbcr_enc);

        vcapture->format = f->fmt.pix;

        return 0;
}

static int vimc_capture_enum_fmt_vid_cap(struct file *file, void *priv,
                                     struct v4l2_fmtdesc *f)
{
        const struct vimc_pix_map *vpix;

        if (f->mbus_code) {
                if (f->index > 0)
                        return -EINVAL;

                vpix = vimc_pix_map_by_code(f->mbus_code);
        } else {
                vpix = vimc_pix_map_by_index(f->index);
        }

        if (!vpix)
                return -EINVAL;

        f->pixelformat = vpix->pixelformat;

        return 0;
}

static int vimc_capture_enum_framesizes(struct file *file, void *priv,
                                    struct v4l2_frmsizeenum *fsize)
{
        const struct vimc_pix_map *vpix;

        if (fsize->index)
                return -EINVAL;

        /* Only accept code in the pix map table */
        vpix = vimc_pix_map_by_code(fsize->pixel_format);
        if (!vpix)
                return -EINVAL;

        fsize->type = V4L2_FRMSIZE_TYPE_CONTINUOUS;
        fsize->stepwise.min_width = VIMC_FRAME_MIN_WIDTH;
        fsize->stepwise.max_width = VIMC_FRAME_MAX_WIDTH;
        fsize->stepwise.min_height = VIMC_FRAME_MIN_HEIGHT;
        fsize->stepwise.max_height = VIMC_FRAME_MAX_HEIGHT;
        fsize->stepwise.step_width = 1;
        fsize->stepwise.step_height = 1;

        return 0;
}

static const struct v4l2_file_operations vimc_capture_fops = {
        .owner          = THIS_MODULE,
        .open           = v4l2_fh_open,
        .release        = vb2_fop_release,
        .read           = vb2_fop_read,
        .poll           = vb2_fop_poll,
        .unlocked_ioctl = video_ioctl2,
        .mmap           = vb2_fop_mmap,
};

static const struct v4l2_ioctl_ops vimc_capture_ioctl_ops = {
        .vidioc_querycap = vimc_capture_querycap,

        .vidioc_g_fmt_vid_cap = vimc_capture_g_fmt_vid_cap,
        .vidioc_s_fmt_vid_cap = vimc_capture_s_fmt_vid_cap,
        .vidioc_try_fmt_vid_cap = vimc_capture_try_fmt_vid_cap,
        .vidioc_enum_fmt_vid_cap = vimc_capture_enum_fmt_vid_cap,
        .vidioc_enum_framesizes = vimc_capture_enum_framesizes,

        .vidioc_reqbufs = vb2_ioctl_reqbufs,
        .vidioc_create_bufs = vb2_ioctl_create_bufs,
        .vidioc_prepare_buf = vb2_ioctl_prepare_buf,
        .vidioc_querybuf = vb2_ioctl_querybuf,
        .vidioc_qbuf = vb2_ioctl_qbuf,
        .vidioc_dqbuf = vb2_ioctl_dqbuf,
        .vidioc_expbuf = vb2_ioctl_expbuf,
        .vidioc_streamon = vb2_ioctl_streamon,
        .vidioc_streamoff = vb2_ioctl_streamoff,
        .vidioc_remove_bufs = vb2_ioctl_remove_bufs,
};

static void vimc_capture_return_all_buffers(struct vimc_capture_device *vcapture,
                                        enum vb2_buffer_state state)
{
        struct vimc_capture_buffer *vbuf, *node;

        spin_lock(&vcapture->qlock);

        list_for_each_entry_safe(vbuf, node, &vcapture->buf_list, list) {
                list_del(&vbuf->list);
                vb2_buffer_done(&vbuf->vb2.vb2_buf, state);
        }

        spin_unlock(&vcapture->qlock);
}

static int vimc_capture_start_streaming(struct vb2_queue *vq, unsigned int count)
{
        struct vimc_capture_device *vcapture = vb2_get_drv_priv(vq);
        int ret;

        vcapture->sequence = 0;

        /* Start the media pipeline */
        ret = video_device_pipeline_start(&vcapture->vdev, &vcapture->stream.pipe);
        if (ret) {
                vimc_capture_return_all_buffers(vcapture, VB2_BUF_STATE_QUEUED);
                return ret;
        }

        ret = vimc_streamer_s_stream(&vcapture->stream, &vcapture->ved, 1);
        if (ret) {
                video_device_pipeline_stop(&vcapture->vdev);
                vimc_capture_return_all_buffers(vcapture, VB2_BUF_STATE_QUEUED);
                return ret;
        }

        return 0;
}

/*
 * Stop the stream engine. Any remaining buffers in the stream queue are
 * dequeued and passed on to the vb2 framework marked as STATE_ERROR.
 */
static void vimc_capture_stop_streaming(struct vb2_queue *vq)
{
        struct vimc_capture_device *vcapture = vb2_get_drv_priv(vq);

        vimc_streamer_s_stream(&vcapture->stream, &vcapture->ved, 0);

        /* Stop the media pipeline */
        video_device_pipeline_stop(&vcapture->vdev);

        /* Release all active buffers */
        vimc_capture_return_all_buffers(vcapture, VB2_BUF_STATE_ERROR);
}

static void vimc_capture_buf_queue(struct vb2_buffer *vb2_buf)
{
        struct vimc_capture_device *vcapture = vb2_get_drv_priv(vb2_buf->vb2_queue);
        struct vimc_capture_buffer *buf = container_of(vb2_buf,
                                                   struct vimc_capture_buffer,
                                                   vb2.vb2_buf);

        spin_lock(&vcapture->qlock);
        list_add_tail(&buf->list, &vcapture->buf_list);
        spin_unlock(&vcapture->qlock);
}

static int vimc_capture_queue_setup(struct vb2_queue *vq, unsigned int *nbuffers,
                                unsigned int *nplanes, unsigned int sizes[],
                                struct device *alloc_devs[])
{
        struct vimc_capture_device *vcapture = vb2_get_drv_priv(vq);

        if (*nplanes)
                return sizes[0] < vcapture->format.sizeimage ? -EINVAL : 0;
        /* We don't support multiplanes for now */
        *nplanes = 1;
        sizes[0] = vcapture->format.sizeimage;

        return 0;
}

static int vimc_capture_buffer_prepare(struct vb2_buffer *vb)
{
        struct vimc_capture_device *vcapture = vb2_get_drv_priv(vb->vb2_queue);
        unsigned long size = vcapture->format.sizeimage;

        if (vb2_plane_size(vb, 0) < size) {
                dev_err(vcapture->ved.dev, "%s: buffer too small (%lu < %lu)\n",
                        vcapture->vdev.name, vb2_plane_size(vb, 0), size);
                return -EINVAL;
        }
        return 0;
}

static const struct vb2_ops vimc_capture_qops = {
        .start_streaming        = vimc_capture_start_streaming,
        .stop_streaming         = vimc_capture_stop_streaming,
        .buf_queue              = vimc_capture_buf_queue,
        .queue_setup            = vimc_capture_queue_setup,
        .buf_prepare            = vimc_capture_buffer_prepare,
};

static const struct media_entity_operations vimc_capture_mops = {
        .link_validate          = vimc_vdev_link_validate,
};

static void vimc_capture_release(struct vimc_ent_device *ved)
{
        struct vimc_capture_device *vcapture =
                container_of(ved, struct vimc_capture_device, ved);

        media_entity_cleanup(vcapture->ved.ent);
        kfree(vcapture);
}

static void vimc_capture_unregister(struct vimc_ent_device *ved)
{
        struct vimc_capture_device *vcapture =
                container_of(ved, struct vimc_capture_device, ved);

        vb2_video_unregister_device(&vcapture->vdev);
}

static void *vimc_capture_process_frame(struct vimc_ent_device *ved,
                                    const void *frame)
{
        struct vimc_capture_device *vcapture = container_of(ved, struct vimc_capture_device,
                                                    ved);
        struct vimc_capture_buffer *vimc_buf;
        void *vbuf;

        spin_lock(&vcapture->qlock);

        /* Get the first entry of the list */
        vimc_buf = list_first_entry_or_null(&vcapture->buf_list,
                                            typeof(*vimc_buf), list);
        if (!vimc_buf) {
                spin_unlock(&vcapture->qlock);
                return ERR_PTR(-EAGAIN);
        }

        /* Remove this entry from the list */
        list_del(&vimc_buf->list);

        spin_unlock(&vcapture->qlock);

        /* Fill the buffer */
        vimc_buf->vb2.vb2_buf.timestamp = ktime_get_ns();
        vimc_buf->vb2.sequence = vcapture->sequence++;
        vimc_buf->vb2.field = vcapture->format.field;

        vbuf = vb2_plane_vaddr(&vimc_buf->vb2.vb2_buf, 0);

        memcpy(vbuf, frame, vcapture->format.sizeimage);

        /* Set it as ready */
        vb2_set_plane_payload(&vimc_buf->vb2.vb2_buf, 0,
                              vcapture->format.sizeimage);
        vb2_buffer_done(&vimc_buf->vb2.vb2_buf, VB2_BUF_STATE_DONE);
        return NULL;
}

static struct vimc_ent_device *vimc_capture_add(struct vimc_device *vimc,
                                            const char *vcfg_name)
{
        struct v4l2_device *v4l2_dev = &vimc->v4l2_dev;
        const struct vimc_pix_map *vpix;
        struct vimc_capture_device *vcapture;
        struct video_device *vdev;
        struct vb2_queue *q;
        int ret;

        /* Allocate the vimc_capture_device struct */
        vcapture = kzalloc_obj(*vcapture);
        if (!vcapture)
                return ERR_PTR(-ENOMEM);

        /* Initialize the media entity */
        vcapture->vdev.entity.name = vcfg_name;
        vcapture->vdev.entity.function = MEDIA_ENT_F_IO_V4L;
        vcapture->pad.flags = MEDIA_PAD_FL_SINK;
        ret = media_entity_pads_init(&vcapture->vdev.entity,
                                     1, &vcapture->pad);
        if (ret)
                goto err_free_vcapture;

        /* Initialize the lock */
        mutex_init(&vcapture->lock);

        /* Initialize the vb2 queue */
        q = &vcapture->queue;
        q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
        q->io_modes = VB2_MMAP | VB2_DMABUF;
        if (vimc_allocator == VIMC_ALLOCATOR_VMALLOC)
                q->io_modes |= VB2_USERPTR;
        q->drv_priv = vcapture;
        q->buf_struct_size = sizeof(struct vimc_capture_buffer);
        q->ops = &vimc_capture_qops;
        q->mem_ops = vimc_allocator == VIMC_ALLOCATOR_DMA_CONTIG
                   ? &vb2_dma_contig_memops : &vb2_vmalloc_memops;
        q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
        q->min_reqbufs_allocation = 2;
        q->lock = &vcapture->lock;
        q->dev = v4l2_dev->dev;

        ret = vb2_queue_init(q);
        if (ret) {
                dev_err(vimc->mdev.dev, "%s: vb2 queue init failed (err=%d)\n",
                        vcfg_name, ret);
                goto err_clean_m_ent;
        }

        /* Initialize buffer list and its lock */
        INIT_LIST_HEAD(&vcapture->buf_list);
        spin_lock_init(&vcapture->qlock);

        /* Set default frame format */
        vcapture->format = fmt_default;
        vpix = vimc_pix_map_by_pixelformat(vcapture->format.pixelformat);
        vcapture->format.bytesperline = vcapture->format.width * vpix->bpp;
        vcapture->format.sizeimage = vcapture->format.bytesperline *
                                 vcapture->format.height;

        /* Fill the vimc_ent_device struct */
        vcapture->ved.ent = &vcapture->vdev.entity;
        vcapture->ved.process_frame = vimc_capture_process_frame;
        vcapture->ved.vdev_get_format = vimc_capture_get_format;
        vcapture->ved.dev = vimc->mdev.dev;

        /* Initialize the video_device struct */
        vdev = &vcapture->vdev;
        vdev->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING
                          | V4L2_CAP_IO_MC;
        vdev->entity.ops = &vimc_capture_mops;
        vdev->release = video_device_release_empty;
        vdev->fops = &vimc_capture_fops;
        vdev->ioctl_ops = &vimc_capture_ioctl_ops;
        vdev->lock = &vcapture->lock;
        vdev->queue = q;
        vdev->v4l2_dev = v4l2_dev;
        vdev->vfl_dir = VFL_DIR_RX;
        strscpy(vdev->name, vcfg_name, sizeof(vdev->name));
        video_set_drvdata(vdev, &vcapture->ved);

        /* Register the video_device with the v4l2 and the media framework */
        ret = video_register_device(vdev, VFL_TYPE_VIDEO, -1);
        if (ret) {
                dev_err(vimc->mdev.dev, "%s: video register failed (err=%d)\n",
                        vcapture->vdev.name, ret);
                goto err_clean_m_ent;
        }

        return &vcapture->ved;

err_clean_m_ent:
        media_entity_cleanup(&vcapture->vdev.entity);
err_free_vcapture:
        kfree(vcapture);

        return ERR_PTR(ret);
}

const struct vimc_ent_type vimc_capture_type = {
        .add = vimc_capture_add,
        .unregister = vimc_capture_unregister,
        .release = vimc_capture_release
};