// SPDX-License-Identifier: GPL-2.0
/*
 * A virtual stateless decoder device for stateless uAPI development purposes.
 *
 * This tool's objective is to help the development and testing of userspace
 * applications that use the V4L2 stateless API to decode media.
 *
 * A userspace implementation can use visl to run a decoding loop even when no
 * hardware is available or when the kernel uAPI for the codec has not been
 * upstreamed yet. This can reveal bugs at an early stage.
 *
 * This driver can also trace the contents of the V4L2 controls submitted to it.
 * It can also dump the contents of the vb2 buffers through a debugfs
 * interface. This is in many ways similar to the tracing infrastructure
 * available for other popular encode/decode APIs out there and can help develop
 * a userspace application by using another (working) one as a reference.
 *
 * Note that no actual decoding of video frames is performed by visl. The V4L2
 * test pattern generator is used to write various debug information to the
 * capture buffers instead.
 *
 * Copyright (C) 2022 Collabora, Ltd.
 *
 * Based on the vim2m driver, that is:
 *
 * Copyright (c) 2009-2010 Samsung Electronics Co., Ltd.
 * Pawel Osciak, <pawel@osciak.com>
 * Marek Szyprowski, <m.szyprowski@samsung.com>
 *
 * Based on the vicodec driver, that is:
 *
 * Copyright 2018 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
 *
 * Based on the Cedrus VPU driver, that is:
 *
 * Copyright (C) 2016 Florent Revest <florent.revest@free-electrons.com>
 * Copyright (C) 2018 Paul Kocialkowski <paul.kocialkowski@bootlin.com>
 * Copyright (C) 2018 Bootlin
 */

#include <linux/debugfs.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-device.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-mem2mem.h>

#include "visl.h"
#include "visl-dec.h"
#include "visl-debugfs.h"
#include "visl-video.h"

unsigned int visl_debug;
module_param(visl_debug, uint, 0644);
MODULE_PARM_DESC(visl_debug, " activates debug info");

unsigned int visl_transtime_ms;
module_param(visl_transtime_ms, uint, 0644);
MODULE_PARM_DESC(visl_transtime_ms, " simulated process time in milliseconds.");

/*
 * dprintk can be slow through serial. This lets one limit the tracing to a
 * particular number of frames
 */
int visl_dprintk_frame_start = -1;
module_param(visl_dprintk_frame_start, int, 0444);
MODULE_PARM_DESC(visl_dprintk_frame_start,
                 " a frame number to start tracing with dprintk");

unsigned int visl_dprintk_nframes;
module_param(visl_dprintk_nframes, uint, 0444);
MODULE_PARM_DESC(visl_dprintk_nframes,
                 " the number of frames to trace with dprintk");

bool keep_bitstream_buffers;
module_param(keep_bitstream_buffers, bool, 0444);
MODULE_PARM_DESC(keep_bitstream_buffers,
                 " keep bitstream buffers in debugfs after streaming is stopped");

int bitstream_trace_frame_start = -1;
module_param(bitstream_trace_frame_start, int, 0444);
MODULE_PARM_DESC(bitstream_trace_frame_start,
                 " a frame number to start dumping the bitstream through debugfs");

unsigned int bitstream_trace_nframes;
module_param(bitstream_trace_nframes, uint, 0444);
MODULE_PARM_DESC(bitstream_trace_nframes,
                 " the number of frames to dump the bitstream through debugfs");

bool tpg_verbose;
module_param(tpg_verbose, bool, 0644);
MODULE_PARM_DESC(tpg_verbose,
                 " add more verbose information on the generated output frames");

static const struct visl_ctrl_desc visl_fwht_ctrl_descs[] = {
        {
                .cfg.id = V4L2_CID_STATELESS_FWHT_PARAMS,
        },
};

const struct visl_ctrls visl_fwht_ctrls = {
        .ctrls = visl_fwht_ctrl_descs,
        .num_ctrls = ARRAY_SIZE(visl_fwht_ctrl_descs)
};

static const struct visl_ctrl_desc visl_mpeg2_ctrl_descs[] = {
        {
                .cfg.id = V4L2_CID_STATELESS_MPEG2_SEQUENCE,
        },
        {
                .cfg.id = V4L2_CID_STATELESS_MPEG2_PICTURE,
        },
        {
                .cfg.id = V4L2_CID_STATELESS_MPEG2_QUANTISATION,
        },
};

const struct visl_ctrls visl_mpeg2_ctrls = {
        .ctrls = visl_mpeg2_ctrl_descs,
        .num_ctrls = ARRAY_SIZE(visl_mpeg2_ctrl_descs),
};

static const struct visl_ctrl_desc visl_vp8_ctrl_descs[] = {
        {
                .cfg.id = V4L2_CID_STATELESS_VP8_FRAME,
        },
};

const struct visl_ctrls visl_vp8_ctrls = {
        .ctrls = visl_vp8_ctrl_descs,
        .num_ctrls = ARRAY_SIZE(visl_vp8_ctrl_descs),
};

static const struct visl_ctrl_desc visl_vp9_ctrl_descs[] = {
        {
                .cfg.id = V4L2_CID_STATELESS_VP9_FRAME,
        },
        {
                .cfg.id = V4L2_CID_STATELESS_VP9_COMPRESSED_HDR,
        },
};

const struct visl_ctrls visl_vp9_ctrls = {
        .ctrls = visl_vp9_ctrl_descs,
        .num_ctrls = ARRAY_SIZE(visl_vp9_ctrl_descs),
};

static const struct visl_ctrl_desc visl_h264_ctrl_descs[] = {
        {
                .cfg.id = V4L2_CID_STATELESS_H264_DECODE_PARAMS,
        },
        {
                .cfg.id = V4L2_CID_STATELESS_H264_SPS,
        },
        {
                .cfg.id = V4L2_CID_STATELESS_H264_PPS,
        },
        {
                .cfg.id = V4L2_CID_STATELESS_H264_SCALING_MATRIX,
        },
        {
                .cfg.id = V4L2_CID_STATELESS_H264_DECODE_MODE,
                .cfg.min = V4L2_STATELESS_H264_DECODE_MODE_SLICE_BASED,
                .cfg.max = V4L2_STATELESS_H264_DECODE_MODE_FRAME_BASED,
                .cfg.def = V4L2_STATELESS_H264_DECODE_MODE_SLICE_BASED,
        },
        {
                .cfg.id = V4L2_CID_STATELESS_H264_START_CODE,
                .cfg.min = V4L2_STATELESS_H264_START_CODE_NONE,
                .cfg.max = V4L2_STATELESS_H264_START_CODE_ANNEX_B,
                .cfg.def = V4L2_STATELESS_H264_START_CODE_NONE,
        },
        {
                .cfg.id = V4L2_CID_STATELESS_H264_SLICE_PARAMS,
        },
        {
                .cfg.id = V4L2_CID_STATELESS_H264_PRED_WEIGHTS,
        },
};

const struct visl_ctrls visl_h264_ctrls = {
        .ctrls = visl_h264_ctrl_descs,
        .num_ctrls = ARRAY_SIZE(visl_h264_ctrl_descs),
};

static const struct visl_ctrl_desc visl_hevc_ctrl_descs[] = {
        {
                .cfg.id = V4L2_CID_STATELESS_HEVC_SPS,
        },
        {
                .cfg.id = V4L2_CID_STATELESS_HEVC_PPS,
        },
        {
                .cfg.id = V4L2_CID_STATELESS_HEVC_SLICE_PARAMS,
                /* The absolute maximum for level > 6 */
                .cfg.dims = { 600 },
        },
        {
                .cfg.id = V4L2_CID_STATELESS_HEVC_SCALING_MATRIX,
        },
        {
                .cfg.id = V4L2_CID_STATELESS_HEVC_DECODE_PARAMS,
        },
        {
                .cfg.id = V4L2_CID_STATELESS_HEVC_DECODE_MODE,
                .cfg.min = V4L2_STATELESS_HEVC_DECODE_MODE_SLICE_BASED,
                .cfg.max = V4L2_STATELESS_HEVC_DECODE_MODE_FRAME_BASED,
                .cfg.def = V4L2_STATELESS_HEVC_DECODE_MODE_SLICE_BASED,
        },
        {
                .cfg.id = V4L2_CID_STATELESS_HEVC_START_CODE,
                .cfg.min = V4L2_STATELESS_HEVC_START_CODE_NONE,
                .cfg.max = V4L2_STATELESS_HEVC_START_CODE_ANNEX_B,
                .cfg.def = V4L2_STATELESS_HEVC_START_CODE_NONE,
        },
        {
                .cfg.id = V4L2_CID_STATELESS_HEVC_ENTRY_POINT_OFFSETS,
                .cfg.dims = { 256 },
                .cfg.max = 0xffffffff,
                .cfg.step = 1,
        },

};

const struct visl_ctrls visl_hevc_ctrls = {
        .ctrls = visl_hevc_ctrl_descs,
        .num_ctrls = ARRAY_SIZE(visl_hevc_ctrl_descs),
};

static const struct visl_ctrl_desc visl_av1_ctrl_descs[] = {
        {
                .cfg.id = V4L2_CID_STATELESS_AV1_FRAME,
        },
        {
                .cfg.id = V4L2_CID_STATELESS_AV1_TILE_GROUP_ENTRY,
                .cfg.dims = { V4L2_AV1_MAX_TILE_COUNT },
        },
        {
                .cfg.id = V4L2_CID_STATELESS_AV1_SEQUENCE,
        },
        {
                .cfg.id = V4L2_CID_STATELESS_AV1_FILM_GRAIN,
        },
};

const struct visl_ctrls visl_av1_ctrls = {
        .ctrls = visl_av1_ctrl_descs,
        .num_ctrls = ARRAY_SIZE(visl_av1_ctrl_descs),
};

struct v4l2_ctrl *visl_find_control(struct visl_ctx *ctx, u32 id)
{
        struct v4l2_ctrl_handler *hdl = &ctx->hdl;

        return v4l2_ctrl_find(hdl, id);
}

void *visl_find_control_data(struct visl_ctx *ctx, u32 id)
{
        struct v4l2_ctrl *ctrl;

        ctrl = visl_find_control(ctx, id);
        if (ctrl)
                return ctrl->p_cur.p;

        return NULL;
}

u32 visl_control_num_elems(struct visl_ctx *ctx, u32 id)
{
        struct v4l2_ctrl *ctrl;

        ctrl = visl_find_control(ctx, id);
        if (ctrl)
                return ctrl->elems;

        return 0;
}

static void visl_device_release(struct video_device *vdev)
{
        struct visl_dev *dev = container_of(vdev, struct visl_dev, vfd);

        v4l2_device_unregister(&dev->v4l2_dev);
        v4l2_m2m_release(dev->m2m_dev);
        media_device_cleanup(&dev->mdev);
        visl_debugfs_deinit(dev);
        kfree(dev);
}

#define VISL_CONTROLS_COUNT     ARRAY_SIZE(visl_controls)

static int visl_init_ctrls(struct visl_ctx *ctx)
{
        struct visl_dev *dev = ctx->dev;
        struct v4l2_ctrl_handler *hdl = &ctx->hdl;
        unsigned int ctrl_cnt = 0;
        unsigned int i;
        unsigned int j;
        const struct visl_ctrls *ctrls;

        for (i = 0; i < num_coded_fmts; i++)
                ctrl_cnt += visl_coded_fmts[i].ctrls->num_ctrls;

        v4l2_ctrl_handler_init(hdl, ctrl_cnt);

        for (i = 0; i < num_coded_fmts; i++) {
                ctrls = visl_coded_fmts[i].ctrls;
                for (j = 0; j < ctrls->num_ctrls; j++)
                        v4l2_ctrl_new_custom(hdl, &ctrls->ctrls[j].cfg, NULL);
        }

        if (hdl->error) {
                v4l2_err(&dev->v4l2_dev,
                         "Failed to initialize control handler\n");
                v4l2_ctrl_handler_free(hdl);
                return hdl->error;
        }

        ctx->fh.ctrl_handler = hdl;
        v4l2_ctrl_handler_setup(hdl);

        return 0;
}

static int visl_open(struct file *file)
{
        struct visl_dev *dev = video_drvdata(file);
        struct visl_ctx *ctx = NULL;
        int rc = 0;

        if (mutex_lock_interruptible(&dev->dev_mutex))
                return -ERESTARTSYS;
        ctx = kzalloc_obj(*ctx);
        if (!ctx) {
                rc = -ENOMEM;
                goto unlock;
        }

        ctx->tpg_str_buf = kzalloc(TPG_STR_BUF_SZ, GFP_KERNEL);

        v4l2_fh_init(&ctx->fh, video_devdata(file));
        ctx->dev = dev;

        rc = visl_init_ctrls(ctx);
        if (rc)
                goto free_ctx;

        ctx->fh.m2m_ctx = v4l2_m2m_ctx_init(dev->m2m_dev, ctx, &visl_queue_init);

        mutex_init(&ctx->vb_mutex);

        if (IS_ERR(ctx->fh.m2m_ctx)) {
                rc = PTR_ERR(ctx->fh.m2m_ctx);
                goto free_hdl;
        }

        rc = visl_set_default_format(ctx);
        if (rc)
                goto free_m2m_ctx;

        v4l2_fh_add(&ctx->fh, file);

        dprintk(dev, "Created instance: %p, m2m_ctx: %p\n",
                ctx, ctx->fh.m2m_ctx);

        mutex_unlock(&dev->dev_mutex);
        return rc;

free_m2m_ctx:
        v4l2_m2m_ctx_release(ctx->fh.m2m_ctx);
free_hdl:
        v4l2_ctrl_handler_free(&ctx->hdl);
        v4l2_fh_exit(&ctx->fh);
free_ctx:
        kfree(ctx->tpg_str_buf);
        kfree(ctx);
unlock:
        mutex_unlock(&dev->dev_mutex);
        return rc;
}

static int visl_release(struct file *file)
{
        struct visl_dev *dev = video_drvdata(file);
        struct visl_ctx *ctx = visl_file_to_ctx(file);

        dprintk(dev, "Releasing instance %p\n", ctx);

        tpg_free(&ctx->tpg);
        v4l2_fh_del(&ctx->fh, file);
        v4l2_fh_exit(&ctx->fh);
        v4l2_ctrl_handler_free(&ctx->hdl);
        mutex_lock(&dev->dev_mutex);
        v4l2_m2m_ctx_release(ctx->fh.m2m_ctx);
        mutex_unlock(&dev->dev_mutex);

        kfree(ctx->tpg_str_buf);
        kfree(ctx);

        return 0;
}

static const struct v4l2_file_operations visl_fops = {
        .owner          = THIS_MODULE,
        .open           = visl_open,
        .release        = visl_release,
        .poll           = v4l2_m2m_fop_poll,
        .unlocked_ioctl = video_ioctl2,
        .mmap           = v4l2_m2m_fop_mmap,
};

static const struct video_device visl_videodev = {
        .name           = VISL_NAME,
        .vfl_dir        = VFL_DIR_M2M,
        .fops           = &visl_fops,
        .ioctl_ops      = &visl_ioctl_ops,
        .minor          = -1,
        .release        = visl_device_release,
        .device_caps    = V4L2_CAP_VIDEO_M2M_MPLANE | V4L2_CAP_STREAMING,
};

static const struct v4l2_m2m_ops visl_m2m_ops = {
        .device_run     = visl_device_run,
};

static const struct media_device_ops visl_m2m_media_ops = {
        .req_validate   = visl_request_validate,
        .req_queue      = v4l2_m2m_request_queue,
};

static int visl_probe(struct platform_device *pdev)
{
        struct visl_dev *dev;
        struct video_device *vfd;
        int ret;
        int rc;

        dev = kzalloc_obj(*dev);
        if (!dev)
                return -ENOMEM;

        ret = v4l2_device_register(&pdev->dev, &dev->v4l2_dev);
        if (ret)
                goto error_visl_dev;

        mutex_init(&dev->dev_mutex);

        dev->vfd = visl_videodev;
        vfd = &dev->vfd;
        vfd->lock = &dev->dev_mutex;
        vfd->v4l2_dev = &dev->v4l2_dev;

        video_set_drvdata(vfd, dev);

        platform_set_drvdata(pdev, dev);

        dev->m2m_dev = v4l2_m2m_init(&visl_m2m_ops);
        if (IS_ERR(dev->m2m_dev)) {
                v4l2_err(&dev->v4l2_dev, "Failed to init mem2mem device\n");
                ret = PTR_ERR(dev->m2m_dev);
                dev->m2m_dev = NULL;
                goto error_dev;
        }

        dev->mdev.dev = &pdev->dev;
        strscpy(dev->mdev.model, "visl", sizeof(dev->mdev.model));
        strscpy(dev->mdev.bus_info, "platform:visl",
                sizeof(dev->mdev.bus_info));
        media_device_init(&dev->mdev);
        dev->mdev.ops = &visl_m2m_media_ops;
        dev->v4l2_dev.mdev = &dev->mdev;

        ret = video_register_device(vfd, VFL_TYPE_VIDEO, -1);
        if (ret) {
                v4l2_err(&dev->v4l2_dev, "Failed to register video device\n");
                goto error_m2m;
        }

        v4l2_info(&dev->v4l2_dev,
                  "Device registered as /dev/video%d\n", vfd->num);

        ret = v4l2_m2m_register_media_controller(dev->m2m_dev, vfd,
                                                 MEDIA_ENT_F_PROC_VIDEO_DECODER);
        if (ret) {
                v4l2_err(&dev->v4l2_dev, "Failed to init mem2mem media controller\n");
                goto error_v4l2;
        }

        ret = media_device_register(&dev->mdev);
        if (ret) {
                v4l2_err(&dev->v4l2_dev, "Failed to register mem2mem media device\n");
                goto error_m2m_mc;
        }

        rc = visl_debugfs_init(dev);
        if (rc)
                dprintk(dev, "visl_debugfs_init failed: %d\n"
                        "Continuing without debugfs support\n", rc);

        return 0;

error_m2m_mc:
        v4l2_m2m_unregister_media_controller(dev->m2m_dev);
error_v4l2:
        video_unregister_device(&dev->vfd);
        /* visl_device_release called by video_unregister_device to release various objects */
        return ret;
error_m2m:
        v4l2_m2m_release(dev->m2m_dev);
error_dev:
        v4l2_device_unregister(&dev->v4l2_dev);
error_visl_dev:
        kfree(dev);

        return ret;
}

static void visl_remove(struct platform_device *pdev)
{
        struct visl_dev *dev = platform_get_drvdata(pdev);

        v4l2_info(&dev->v4l2_dev, "Removing " VISL_NAME);

#ifdef CONFIG_MEDIA_CONTROLLER
        if (media_devnode_is_registered(dev->mdev.devnode)) {
                media_device_unregister(&dev->mdev);
                v4l2_m2m_unregister_media_controller(dev->m2m_dev);
        }
#endif
        video_unregister_device(&dev->vfd);
}

static struct platform_driver visl_pdrv = {
        .probe          = visl_probe,
        .remove         = visl_remove,
        .driver         = {
                .name   = VISL_NAME,
        },
};

static void visl_dev_release(struct device *dev) {}

static struct platform_device visl_pdev = {
        .name           = VISL_NAME,
        .dev.release    = visl_dev_release,
};

static void __exit visl_exit(void)
{
        platform_driver_unregister(&visl_pdrv);
        platform_device_unregister(&visl_pdev);
}

static int __init visl_init(void)
{
        int ret;

        ret = platform_device_register(&visl_pdev);
        if (ret)
                return ret;

        ret = platform_driver_register(&visl_pdrv);
        if (ret)
                platform_device_unregister(&visl_pdev);

        return ret;
}

MODULE_DESCRIPTION("Virtual stateless decoder device");
MODULE_AUTHOR("Daniel Almeida <daniel.almeida@collabora.com>");
MODULE_LICENSE("GPL");

module_init(visl_init);
module_exit(visl_exit);