// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2018 BayLibre, SAS
 * Author: Maxime Jourdan <mjourdan@baylibre.com>
 */

#include <linux/of_device.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/mfd/syscon.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/kthread.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-event.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-mem2mem.h>
#include <media/v4l2-dev.h>
#include <media/videobuf2-dma-contig.h>

#include "vdec.h"
#include "esparser.h"
#include "vdec_helpers.h"

struct dummy_buf {
	struct vb2_v4l2_buffer vb;
	struct list_head list;
};

/* 16 MiB for parsed bitstream swap exchange */
#define SIZE_VIFIFO SZ_16M

static u32 get_output_size(u32 width, u32 height)
{
	return ALIGN(width * height, SZ_64K);
}

u32 amvdec_get_output_size(struct amvdec_session *sess)
{
	return get_output_size(sess->width, sess->height);
}
EXPORT_SYMBOL_GPL(amvdec_get_output_size);

static int vdec_codec_needs_recycle(struct amvdec_session *sess)
{
	struct amvdec_codec_ops *codec_ops = sess->fmt_out->codec_ops;

	return codec_ops->can_recycle && codec_ops->recycle;
}

static int vdec_recycle_thread(void *data)
{
	struct amvdec_session *sess = data;
	struct amvdec_core *core = sess->core;
	struct amvdec_codec_ops *codec_ops = sess->fmt_out->codec_ops;
	struct amvdec_buffer *tmp, *n;

	while (!kthread_should_stop()) {
		mutex_lock(&sess->bufs_recycle_lock);
		list_for_each_entry_safe(tmp, n, &sess->bufs_recycle, list) {
			if (!codec_ops->can_recycle(core))
				break;

			codec_ops->recycle(core, tmp->vb->index);
			list_del(&tmp->list);
			kfree(tmp);
		}
		mutex_unlock(&sess->bufs_recycle_lock);

		usleep_range(5000, 10000);
	}

	return 0;
}

static int vdec_poweron(struct amvdec_session *sess)
{
	int ret;
	struct amvdec_ops *vdec_ops = sess->fmt_out->vdec_ops;

	ret = clk_prepare_enable(sess->core->dos_parser_clk);
	if (ret)
		return ret;

	ret = clk_prepare_enable(sess->core->dos_clk);
	if (ret)
		goto disable_dos_parser;

	ret = vdec_ops->start(sess);
	if (ret)
		goto disable_dos;

	esparser_power_up(sess);

	return 0;

disable_dos:
	clk_disable_unprepare(sess->core->dos_clk);
disable_dos_parser:
	clk_disable_unprepare(sess->core->dos_parser_clk);

	return ret;
}

static void vdec_wait_inactive(struct amvdec_session *sess)
{
	/* We consider 50ms with no IRQ to be inactive. */
	while (time_is_after_jiffies64(sess->last_irq_jiffies +
				       msecs_to_jiffies(50)))
		msleep(25);
}

static void vdec_poweroff(struct amvdec_session *sess)
{
	struct amvdec_ops *vdec_ops = sess->fmt_out->vdec_ops;
	struct amvdec_codec_ops *codec_ops = sess->fmt_out->codec_ops;

	sess->should_stop = 1;
	vdec_wait_inactive(sess);
	if (codec_ops->drain)
		codec_ops->drain(sess);

	vdec_ops->stop(sess);
	clk_disable_unprepare(sess->core->dos_clk);
	clk_disable_unprepare(sess->core->dos_parser_clk);
}

static void
vdec_queue_recycle(struct amvdec_session *sess, struct vb2_buffer *vb)
{
	struct amvdec_buffer *new_buf;

	new_buf = kmalloc(sizeof(*new_buf), GFP_KERNEL);
	new_buf->vb = vb;

	mutex_lock(&sess->bufs_recycle_lock);
	list_add_tail(&new_buf->list, &sess->bufs_recycle);
	mutex_unlock(&sess->bufs_recycle_lock);
}

static void vdec_m2m_device_run(void *priv)
{
	struct amvdec_session *sess = priv;

	schedule_work(&sess->esparser_queue_work);
}

static void vdec_m2m_job_abort(void *priv)
{
	struct amvdec_session *sess = priv;

	v4l2_m2m_job_finish(sess->m2m_dev, sess->m2m_ctx);
}

static const struct v4l2_m2m_ops vdec_m2m_ops = {
	.device_run = vdec_m2m_device_run,
	.job_abort = vdec_m2m_job_abort,
};

static void process_num_buffers(struct vb2_queue *q,
				struct amvdec_session *sess,
				unsigned int *num_buffers,
				bool is_reqbufs)
{
	const struct amvdec_format *fmt_out = sess->fmt_out;
	unsigned int buffers_total = q->num_buffers + *num_buffers;

	if (is_reqbufs && buffers_total < fmt_out->min_buffers)
		*num_buffers = fmt_out->min_buffers - q->num_buffers;
	if (buffers_total > fmt_out->max_buffers)
		*num_buffers = fmt_out->max_buffers - q->num_buffers;

	/* We need to program the complete CAPTURE buffer list
	 * in registers during start_streaming, and the firmwares
	 * are free to choose any of them to write frames to. As such,
	 * we need all of them to be queued into the driver
	 */
	sess->num_dst_bufs = q->num_buffers + *num_buffers;
	q->min_buffers_needed = max(fmt_out->min_buffers, sess->num_dst_bufs);
}

static int vdec_queue_setup(struct vb2_queue *q, unsigned int *num_buffers,
			    unsigned int *num_planes, unsigned int sizes[],
			    struct device *alloc_devs[])
{
	struct amvdec_session *sess = vb2_get_drv_priv(q);
	u32 output_size = amvdec_get_output_size(sess);

	if (*num_planes) {
		switch (q->type) {
		case V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE:
			if (*num_planes != 1 || sizes[0] < output_size)
				return -EINVAL;
			break;
		case V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE:
			switch (sess->pixfmt_cap) {
			case V4L2_PIX_FMT_NV12M:
				if (*num_planes != 2 ||
				    sizes[0] < output_size ||
				    sizes[1] < output_size / 2)
					return -EINVAL;
				break;
			case V4L2_PIX_FMT_YUV420M:
				if (*num_planes != 3 ||
				    sizes[0] < output_size ||
				    sizes[1] < output_size / 4 ||
				    sizes[2] < output_size / 4)
					return -EINVAL;
				break;
			default:
				return -EINVAL;
			}

			process_num_buffers(q, sess, num_buffers, false);
			break;
		}

		return 0;
	}

	switch (q->type) {
	case V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE:
		sizes[0] = amvdec_get_output_size(sess);
		*num_planes = 1;
		break;
	case V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE:
		switch (sess->pixfmt_cap) {
		case V4L2_PIX_FMT_NV12M:
			sizes[0] = output_size;
			sizes[1] = output_size / 2;
			*num_planes = 2;
			break;
		case V4L2_PIX_FMT_YUV420M:
			sizes[0] = output_size;
			sizes[1] = output_size / 4;
			sizes[2] = output_size / 4;
			*num_planes = 3;
			break;
		default:
			return -EINVAL;
		}

		process_num_buffers(q, sess, num_buffers, true);
		break;
	default:
		return -EINVAL;
	}

	return 0;
}

static void vdec_vb2_buf_queue(struct vb2_buffer *vb)
{
	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
	struct amvdec_session *sess = vb2_get_drv_priv(vb->vb2_queue);
	struct v4l2_m2m_ctx *m2m_ctx = sess->m2m_ctx;

	v4l2_m2m_buf_queue(m2m_ctx, vbuf);

	if (!sess->streamon_out || !sess->streamon_cap)
		return;

	if (vb->type == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE &&
	    vdec_codec_needs_recycle(sess))
		vdec_queue_recycle(sess, vb);

	schedule_work(&sess->esparser_queue_work);
}

static int vdec_start_streaming(struct vb2_queue *q, unsigned int count)
{
	struct amvdec_session *sess = vb2_get_drv_priv(q);
	struct amvdec_codec_ops *codec_ops = sess->fmt_out->codec_ops;
	struct amvdec_core *core = sess->core;
	struct vb2_v4l2_buffer *buf;
	int ret;

	if (core->cur_sess && core->cur_sess != sess) {
		ret = -EBUSY;
		goto bufs_done;
	}

	if (q->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE)
		sess->streamon_out = 1;
	else
		sess->streamon_cap = 1;

	if (!sess->streamon_out || !sess->streamon_cap)
		return 0;

	if (sess->status == STATUS_NEEDS_RESUME &&
	    q->type == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE) {
		codec_ops->resume(sess);
		sess->status = STATUS_RUNNING;
		return 0;
	}

	sess->vififo_size = SIZE_VIFIFO;
	sess->vififo_vaddr =
		dma_alloc_coherent(sess->core->dev, sess->vififo_size,
				   &sess->vififo_paddr, GFP_KERNEL);
	if (!sess->vififo_vaddr) {
		dev_err(sess->core->dev, "Failed to request VIFIFO buffer\n");
		ret = -ENOMEM;
		goto bufs_done;
	}

	sess->should_stop = 0;
	sess->keyframe_found = 0;
	sess->last_offset = 0;
	sess->wrap_count = 0;
	sess->pixelaspect.numerator = 1;
	sess->pixelaspect.denominator = 1;
	atomic_set(&sess->esparser_queued_bufs, 0);
	v4l2_ctrl_s_ctrl(sess->ctrl_min_buf_capture, 1);

	ret = vdec_poweron(sess);
	if (ret)
		goto vififo_free;

	sess->sequence_cap = 0;
	if (vdec_codec_needs_recycle(sess))
		sess->recycle_thread = kthread_run(vdec_recycle_thread, sess,
						   "vdec_recycle");

	sess->status = STATUS_RUNNING;
	core->cur_sess = sess;

	return 0;

vififo_free:
	dma_free_coherent(sess->core->dev, sess->vififo_size,
			  sess->vififo_vaddr, sess->vififo_paddr);
bufs_done:
	while ((buf = v4l2_m2m_src_buf_remove(sess->m2m_ctx)))
		v4l2_m2m_buf_done(buf, VB2_BUF_STATE_QUEUED);
	while ((buf = v4l2_m2m_dst_buf_remove(sess->m2m_ctx)))
		v4l2_m2m_buf_done(buf, VB2_BUF_STATE_QUEUED);

	if (q->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE)
		sess->streamon_out = 0;
	else
		sess->streamon_cap = 0;

	return ret;
}

static void vdec_free_canvas(struct amvdec_session *sess)
{
	int i;

	for (i = 0; i < sess->canvas_num; ++i)
		meson_canvas_free(sess->core->canvas, sess->canvas_alloc[i]);

	sess->canvas_num = 0;
}

static void vdec_reset_timestamps(struct amvdec_session *sess)
{
	struct amvdec_timestamp *tmp, *n;

	list_for_each_entry_safe(tmp, n, &sess->timestamps, list) {
		list_del(&tmp->list);
		kfree(tmp);
	}
}

static void vdec_reset_bufs_recycle(struct amvdec_session *sess)
{
	struct amvdec_buffer *tmp, *n;

	list_for_each_entry_safe(tmp, n, &sess->bufs_recycle, list) {
		list_del(&tmp->list);
		kfree(tmp);
	}
}

static void vdec_stop_streaming(struct vb2_queue *q)
{
	struct amvdec_session *sess = vb2_get_drv_priv(q);
	struct amvdec_core *core = sess->core;
	struct vb2_v4l2_buffer *buf;

	if (sess->status == STATUS_RUNNING ||
	    (sess->status == STATUS_NEEDS_RESUME &&
	     (!sess->streamon_out || !sess->streamon_cap))) {
		if (vdec_codec_needs_recycle(sess))
			kthread_stop(sess->recycle_thread);

		vdec_poweroff(sess);
		vdec_free_canvas(sess);
		dma_free_coherent(sess->core->dev, sess->vififo_size,
				  sess->vififo_vaddr, sess->vififo_paddr);
		vdec_reset_timestamps(sess);
		vdec_reset_bufs_recycle(sess);
		kfree(sess->priv);
		sess->priv = NULL;
		core->cur_sess = NULL;
		sess->status = STATUS_STOPPED;
	}

	if (q->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE) {
		while ((buf = v4l2_m2m_src_buf_remove(sess->m2m_ctx)))
			v4l2_m2m_buf_done(buf, VB2_BUF_STATE_ERROR);

		sess->streamon_out = 0;
	} else {
		while ((buf = v4l2_m2m_dst_buf_remove(sess->m2m_ctx)))
			v4l2_m2m_buf_done(buf, VB2_BUF_STATE_ERROR);

		sess->streamon_cap = 0;
	}
}

static int vdec_vb2_buf_prepare(struct vb2_buffer *vb)
{
	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);

	vbuf->field = V4L2_FIELD_NONE;
	return 0;
}

static const struct vb2_ops vdec_vb2_ops = {
	.queue_setup = vdec_queue_setup,
	.start_streaming = vdec_start_streaming,
	.stop_streaming = vdec_stop_streaming,
	.buf_queue = vdec_vb2_buf_queue,
	.buf_prepare = vdec_vb2_buf_prepare,
	.wait_prepare = vb2_ops_wait_prepare,
	.wait_finish = vb2_ops_wait_finish,
};

static int
vdec_querycap(struct file *file, void *fh, struct v4l2_capability *cap)
{
	strscpy(cap->driver, "meson-vdec", sizeof(cap->driver));
	strscpy(cap->card, "Amlogic Video Decoder", sizeof(cap->card));
	strscpy(cap->bus_info, "platform:meson-vdec", sizeof(cap->bus_info));

	return 0;
}

static const struct amvdec_format *
find_format(const struct amvdec_format *fmts, u32 size, u32 pixfmt)
{
	unsigned int i;

	for (i = 0; i < size; i++) {
		if (fmts[i].pixfmt == pixfmt)
			return &fmts[i];
	}

	return NULL;
}

static unsigned int
vdec_supports_pixfmt_cap(const struct amvdec_format *fmt_out, u32 pixfmt_cap)
{
	int i;

	for (i = 0; fmt_out->pixfmts_cap[i]; i++)
		if (fmt_out->pixfmts_cap[i] == pixfmt_cap)
			return 1;

	return 0;
}

static const struct amvdec_format *
vdec_try_fmt_common(struct amvdec_session *sess, u32 size,
		    struct v4l2_format *f)
{
	struct v4l2_pix_format_mplane *pixmp = &f->fmt.pix_mp;
	struct v4l2_plane_pix_format *pfmt = pixmp->plane_fmt;
	const struct amvdec_format *fmts = sess->core->platform->formats;
	const struct amvdec_format *fmt_out;

	memset(pfmt[0].reserved, 0, sizeof(pfmt[0].reserved));
	memset(pixmp->reserved, 0, sizeof(pixmp->reserved));

	if (f->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE) {
		fmt_out = find_format(fmts, size, pixmp->pixelformat);
		if (!fmt_out) {
			pixmp->pixelformat = V4L2_PIX_FMT_MPEG2;
			fmt_out = find_format(fmts, size, pixmp->pixelformat);
		}

		pfmt[0].sizeimage =
			get_output_size(pixmp->width, pixmp->height);
		pfmt[0].bytesperline = 0;
		pixmp->num_planes = 1;
	} else if (f->type == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE) {
		fmt_out = sess->fmt_out;
		if (!vdec_supports_pixfmt_cap(fmt_out, pixmp->pixelformat))
			pixmp->pixelformat = fmt_out->pixfmts_cap[0];

		memset(pfmt[1].reserved, 0, sizeof(pfmt[1].reserved));
		if (pixmp->pixelformat == V4L2_PIX_FMT_NV12M) {
			pfmt[0].sizeimage =
				get_output_size(pixmp->width, pixmp->height);
			pfmt[0].bytesperline = ALIGN(pixmp->width, 64);

			pfmt[1].sizeimage =
			      get_output_size(pixmp->width, pixmp->height) / 2;
			pfmt[1].bytesperline = ALIGN(pixmp->width, 64);
			pixmp->num_planes = 2;
		} else if (pixmp->pixelformat == V4L2_PIX_FMT_YUV420M) {
			pfmt[0].sizeimage =
				get_output_size(pixmp->width, pixmp->height);
			pfmt[0].bytesperline = ALIGN(pixmp->width, 64);

			pfmt[1].sizeimage =
			      get_output_size(pixmp->width, pixmp->height) / 4;
			pfmt[1].bytesperline = ALIGN(pixmp->width, 64) / 2;

			pfmt[2].sizeimage =
			      get_output_size(pixmp->width, pixmp->height) / 4;
			pfmt[2].bytesperline = ALIGN(pixmp->width, 64) / 2;
			pixmp->num_planes = 3;
		}
	} else {
		return NULL;
	}

	pixmp->width  = clamp(pixmp->width,  (u32)256, fmt_out->max_width);
	pixmp->height = clamp(pixmp->height, (u32)144, fmt_out->max_height);

	if (pixmp->field == V4L2_FIELD_ANY)
		pixmp->field = V4L2_FIELD_NONE;

	return fmt_out;
}

static int vdec_try_fmt(struct file *file, void *fh, struct v4l2_format *f)
{
	struct amvdec_session *sess =
		container_of(file->private_data, struct amvdec_session, fh);

	vdec_try_fmt_common(sess, sess->core->platform->num_formats, f);

	return 0;
}

static int vdec_g_fmt(struct file *file, void *fh, struct v4l2_format *f)
{
	struct amvdec_session *sess =
		container_of(file->private_data, struct amvdec_session, fh);
	struct v4l2_pix_format_mplane *pixmp = &f->fmt.pix_mp;

	if (f->type == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE)
		pixmp->pixelformat = sess->pixfmt_cap;
	else if (f->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE)
		pixmp->pixelformat = sess->fmt_out->pixfmt;

	if (f->type == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE) {
		pixmp->width = sess->width;
		pixmp->height = sess->height;
		pixmp->colorspace = sess->colorspace;
		pixmp->ycbcr_enc = sess->ycbcr_enc;
		pixmp->quantization = sess->quantization;
		pixmp->xfer_func = sess->xfer_func;
	} else if (f->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE) {
		pixmp->width = sess->width;
		pixmp->height = sess->height;
	}

	vdec_try_fmt_common(sess, sess->core->platform->num_formats, f);

	return 0;
}

static int vdec_s_fmt(struct file *file, void *fh, struct v4l2_format *f)
{
	struct amvdec_session *sess =
		container_of(file->private_data, struct amvdec_session, fh);
	struct v4l2_pix_format_mplane *pixmp = &f->fmt.pix_mp;
	u32 num_formats = sess->core->platform->num_formats;
	const struct amvdec_format *fmt_out;
	struct v4l2_pix_format_mplane orig_pixmp;
	struct v4l2_format format;
	u32 pixfmt_out = 0, pixfmt_cap = 0;

	orig_pixmp = *pixmp;

	fmt_out = vdec_try_fmt_common(sess, num_formats, f);

	if (f->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE) {
		pixfmt_out = pixmp->pixelformat;
		pixfmt_cap = sess->pixfmt_cap;
	} else if (f->type == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE) {
		pixfmt_cap = pixmp->pixelformat;
		pixfmt_out = sess->fmt_out->pixfmt;
	}

	memset(&format, 0, sizeof(format));

	format.type = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE;
	format.fmt.pix_mp.pixelformat = pixfmt_out;
	format.fmt.pix_mp.width = orig_pixmp.width;
	format.fmt.pix_mp.height = orig_pixmp.height;
	vdec_try_fmt_common(sess, num_formats, &format);

	if (f->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE) {
		sess->width = format.fmt.pix_mp.width;
		sess->height = format.fmt.pix_mp.height;
		sess->colorspace = pixmp->colorspace;
		sess->ycbcr_enc = pixmp->ycbcr_enc;
		sess->quantization = pixmp->quantization;
		sess->xfer_func = pixmp->xfer_func;
	}

	memset(&format, 0, sizeof(format));

	format.type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
	format.fmt.pix_mp.pixelformat = pixfmt_cap;
	format.fmt.pix_mp.width = orig_pixmp.width;
	format.fmt.pix_mp.height = orig_pixmp.height;
	vdec_try_fmt_common(sess, num_formats, &format);

	sess->width = format.fmt.pix_mp.width;
	sess->height = format.fmt.pix_mp.height;

	if (f->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE)
		sess->fmt_out = fmt_out;
	else if (f->type == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE)
		sess->pixfmt_cap = format.fmt.pix_mp.pixelformat;

	return 0;
}

static int vdec_enum_fmt(struct file *file, void *fh, struct v4l2_fmtdesc *f)
{
	struct amvdec_session *sess =
		container_of(file->private_data, struct amvdec_session, fh);
	const struct vdec_platform *platform = sess->core->platform;
	const struct amvdec_format *fmt_out;

	memset(f->reserved, 0, sizeof(f->reserved));

	if (f->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE) {
		if (f->index >= platform->num_formats)
			return -EINVAL;

		fmt_out = &platform->formats[f->index];
		f->pixelformat = fmt_out->pixfmt;
		f->flags = fmt_out->flags;
	} else if (f->type == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE) {
		fmt_out = sess->fmt_out;
		if (f->index >= 4 || !fmt_out->pixfmts_cap[f->index])
			return -EINVAL;

		f->pixelformat = fmt_out->pixfmts_cap[f->index];
	} else {
		return -EINVAL;
	}

	return 0;
}

static int vdec_enum_framesizes(struct file *file, void *fh,
				struct v4l2_frmsizeenum *fsize)
{
	struct amvdec_session *sess =
		container_of(file->private_data, struct amvdec_session, fh);
	const struct amvdec_format *formats = sess->core->platform->formats;
	const struct amvdec_format *fmt;
	u32 num_formats = sess->core->platform->num_formats;

	fmt = find_format(formats, num_formats, fsize->pixel_format);
	if (!fmt || fsize->index)
		return -EINVAL;

	fsize->type = V4L2_FRMSIZE_TYPE_CONTINUOUS;

	fsize->stepwise.min_width = 256;
	fsize->stepwise.max_width = fmt->max_width;
	fsize->stepwise.step_width = 1;
	fsize->stepwise.min_height = 144;
	fsize->stepwise.max_height = fmt->max_height;
	fsize->stepwise.step_height = 1;

	return 0;
}

static int
vdec_decoder_cmd(struct file *file, void *fh, struct v4l2_decoder_cmd *cmd)
{
	struct amvdec_session *sess =
		container_of(file->private_data, struct amvdec_session, fh);
	struct amvdec_codec_ops *codec_ops = sess->fmt_out->codec_ops;
	struct device *dev = sess->core->dev;
	int ret;

	ret = v4l2_m2m_ioctl_try_decoder_cmd(file, fh, cmd);
	if (ret)
		return ret;

	if (!(sess->streamon_out & sess->streamon_cap))
		return 0;

	/* Currently not handled since we do not support dynamic resolution
	 * for MPEG2. We consider both queues streaming to mean that the
	 * decoding session is started
	 */
	if (cmd->cmd == V4L2_DEC_CMD_START)
		return 0;

	/* Should not happen */
	if (cmd->cmd != V4L2_DEC_CMD_STOP)
		return -EINVAL;

	dev_dbg(dev, "Received V4L2_DEC_CMD_STOP\n");
	sess->should_stop = 1;

	vdec_wait_inactive(sess);

	if (codec_ops->drain) {
		codec_ops->drain(sess);
	} else if (codec_ops->eos_sequence) {
		u32 len;
		const u8 *data = codec_ops->eos_sequence(&len);

		esparser_queue_eos(sess->core, data, len);
	}

	return ret;
}

static int vdec_subscribe_event(struct v4l2_fh *fh,
				const struct v4l2_event_subscription *sub)
{
	switch (sub->type) {
	case V4L2_EVENT_EOS:
	case V4L2_EVENT_SOURCE_CHANGE:
		return v4l2_event_subscribe(fh, sub, 0, NULL);
	case V4L2_EVENT_CTRL:
		return v4l2_ctrl_subscribe_event(fh, sub);
	default:
		return -EINVAL;
	}
}

static int vdec_g_pixelaspect(struct file *file, void *fh, int type,
			      struct v4l2_fract *f)
{
	struct amvdec_session *sess =
		container_of(file->private_data, struct amvdec_session, fh);

	if (type != V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE)
		return -EINVAL;

	*f = sess->pixelaspect;
	return 0;
}

static const struct v4l2_ioctl_ops vdec_ioctl_ops = {
	.vidioc_querycap = vdec_querycap,
	.vidioc_enum_fmt_vid_cap = vdec_enum_fmt,
	.vidioc_enum_fmt_vid_out = vdec_enum_fmt,
	.vidioc_s_fmt_vid_cap_mplane = vdec_s_fmt,
	.vidioc_s_fmt_vid_out_mplane = vdec_s_fmt,
	.vidioc_g_fmt_vid_cap_mplane = vdec_g_fmt,
	.vidioc_g_fmt_vid_out_mplane = vdec_g_fmt,
	.vidioc_try_fmt_vid_cap_mplane = vdec_try_fmt,
	.vidioc_try_fmt_vid_out_mplane = vdec_try_fmt,
	.vidioc_reqbufs = v4l2_m2m_ioctl_reqbufs,
	.vidioc_querybuf = v4l2_m2m_ioctl_querybuf,
	.vidioc_prepare_buf = v4l2_m2m_ioctl_prepare_buf,
	.vidioc_qbuf = v4l2_m2m_ioctl_qbuf,
	.vidioc_expbuf = v4l2_m2m_ioctl_expbuf,
	.vidioc_dqbuf = v4l2_m2m_ioctl_dqbuf,
	.vidioc_create_bufs = v4l2_m2m_ioctl_create_bufs,
	.vidioc_streamon = v4l2_m2m_ioctl_streamon,
	.vidioc_streamoff = v4l2_m2m_ioctl_streamoff,
	.vidioc_enum_framesizes = vdec_enum_framesizes,
	.vidioc_subscribe_event = vdec_subscribe_event,
	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
	.vidioc_try_decoder_cmd = v4l2_m2m_ioctl_try_decoder_cmd,
	.vidioc_decoder_cmd = vdec_decoder_cmd,
	.vidioc_g_pixelaspect = vdec_g_pixelaspect,
};

static int m2m_queue_init(void *priv, struct vb2_queue *src_vq,
			  struct vb2_queue *dst_vq)
{
	struct amvdec_session *sess = priv;
	int ret;

	src_vq->type = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE;
	src_vq->io_modes = VB2_MMAP | VB2_DMABUF;
	src_vq->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
	src_vq->ops = &vdec_vb2_ops;
	src_vq->mem_ops = &vb2_dma_contig_memops;
	src_vq->drv_priv = sess;
	src_vq->buf_struct_size = sizeof(struct dummy_buf);
	src_vq->min_buffers_needed = 1;
	src_vq->dev = sess->core->dev;
	src_vq->lock = &sess->lock;
	ret = vb2_queue_init(src_vq);
	if (ret)
		return ret;

	dst_vq->type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
	dst_vq->io_modes = VB2_MMAP | VB2_DMABUF;
	dst_vq->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
	dst_vq->ops = &vdec_vb2_ops;
	dst_vq->mem_ops = &vb2_dma_contig_memops;
	dst_vq->drv_priv = sess;
	dst_vq->buf_struct_size = sizeof(struct dummy_buf);
	dst_vq->min_buffers_needed = 1;
	dst_vq->dev = sess->core->dev;
	dst_vq->lock = &sess->lock;
	ret = vb2_queue_init(dst_vq);
	if (ret) {
		vb2_queue_release(src_vq);
		return ret;
	}

	return 0;
}

static int vdec_init_ctrls(struct amvdec_session *sess)
{
	struct v4l2_ctrl_handler *ctrl_handler = &sess->ctrl_handler;
	int ret;

	ret = v4l2_ctrl_handler_init(ctrl_handler, 1);
	if (ret)
		return ret;

	sess->ctrl_min_buf_capture =
		v4l2_ctrl_new_std(ctrl_handler, NULL,
				  V4L2_CID_MIN_BUFFERS_FOR_CAPTURE, 1, 32, 1,
				  1);

	ret = ctrl_handler->error;
	if (ret) {
		v4l2_ctrl_handler_free(ctrl_handler);
		return ret;
	}

	return 0;
}

static int vdec_open(struct file *file)
{
	struct amvdec_core *core = video_drvdata(file);
	struct device *dev = core->dev;
	const struct amvdec_format *formats = core->platform->formats;
	struct amvdec_session *sess;
	int ret;

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

	sess->core = core;

	sess->m2m_dev = v4l2_m2m_init(&vdec_m2m_ops);
	if (IS_ERR(sess->m2m_dev)) {
		dev_err(dev, "Fail to v4l2_m2m_init\n");
		ret = PTR_ERR(sess->m2m_dev);
		goto err_free_sess;
	}

	sess->m2m_ctx = v4l2_m2m_ctx_init(sess->m2m_dev, sess, m2m_queue_init);
	if (IS_ERR(sess->m2m_ctx)) {
		dev_err(dev, "Fail to v4l2_m2m_ctx_init\n");
		ret = PTR_ERR(sess->m2m_ctx);
		goto err_m2m_release;
	}

	ret = vdec_init_ctrls(sess);
	if (ret)
		goto err_m2m_release;

	sess->pixfmt_cap = formats[0].pixfmts_cap[0];
	sess->fmt_out = &formats[0];
	sess->width = 1280;
	sess->height = 720;
	sess->pixelaspect.numerator = 1;
	sess->pixelaspect.denominator = 1;

	INIT_LIST_HEAD(&sess->timestamps);
	INIT_LIST_HEAD(&sess->bufs_recycle);
	INIT_WORK(&sess->esparser_queue_work, esparser_queue_all_src);
	mutex_init(&sess->lock);
	mutex_init(&sess->bufs_recycle_lock);
	spin_lock_init(&sess->ts_spinlock);

	v4l2_fh_init(&sess->fh, core->vdev_dec);
	sess->fh.ctrl_handler = &sess->ctrl_handler;
	v4l2_fh_add(&sess->fh);
	sess->fh.m2m_ctx = sess->m2m_ctx;
	file->private_data = &sess->fh;

	return 0;

err_m2m_release:
	v4l2_m2m_release(sess->m2m_dev);
err_free_sess:
	kfree(sess);
	return ret;
}

static int vdec_close(struct file *file)
{
	struct amvdec_session *sess =
		container_of(file->private_data, struct amvdec_session, fh);

	v4l2_m2m_ctx_release(sess->m2m_ctx);
	v4l2_m2m_release(sess->m2m_dev);
	v4l2_fh_del(&sess->fh);
	v4l2_fh_exit(&sess->fh);

	mutex_destroy(&sess->lock);
	mutex_destroy(&sess->bufs_recycle_lock);

	kfree(sess);

	return 0;
}

static const struct v4l2_file_operations vdec_fops = {
	.owner = THIS_MODULE,
	.open = vdec_open,
	.release = vdec_close,
	.unlocked_ioctl = video_ioctl2,
	.poll = v4l2_m2m_fop_poll,
	.mmap = v4l2_m2m_fop_mmap,
};

static irqreturn_t vdec_isr(int irq, void *data)
{
	struct amvdec_core *core = data;
	struct amvdec_session *sess = core->cur_sess;

	sess->last_irq_jiffies = get_jiffies_64();

	return sess->fmt_out->codec_ops->isr(sess);
}

static irqreturn_t vdec_threaded_isr(int irq, void *data)
{
	struct amvdec_core *core = data;
	struct amvdec_session *sess = core->cur_sess;

	return sess->fmt_out->codec_ops->threaded_isr(sess);
}

static const struct of_device_id vdec_dt_match[] = {
	{ .compatible = "amlogic,gxbb-vdec",
	  .data = &vdec_platform_gxbb },
	{ .compatible = "amlogic,gxm-vdec",
	  .data = &vdec_platform_gxm },
	{ .compatible = "amlogic,gxl-vdec",
	  .data = &vdec_platform_gxl },
	{}
};
MODULE_DEVICE_TABLE(of, vdec_dt_match);

static int vdec_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct video_device *vdev;
	struct amvdec_core *core;
	struct resource *r;
	const struct of_device_id *of_id;
	int irq;
	int ret;

	core = devm_kzalloc(dev, sizeof(*core), GFP_KERNEL);
	if (!core)
		return -ENOMEM;

	core->dev = dev;
	platform_set_drvdata(pdev, core);

	r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dos");
	core->dos_base = devm_ioremap_resource(dev, r);
	if (IS_ERR(core->dos_base)) {
		dev_err(dev, "Couldn't remap DOS memory\n");
		return PTR_ERR(core->dos_base);
	}

	r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "esparser");
	core->esparser_base = devm_ioremap_resource(dev, r);
	if (IS_ERR(core->esparser_base)) {
		dev_err(dev, "Couldn't remap ESPARSER memory\n");
		return PTR_ERR(core->esparser_base);
	}

	core->regmap_ao =
		syscon_regmap_lookup_by_phandle(dev->of_node,
						"amlogic,ao-sysctrl");
	if (IS_ERR(core->regmap_ao)) {
		dev_err(dev, "Couldn't regmap AO sysctrl\n");
		return PTR_ERR(core->regmap_ao);
	}

	core->canvas = meson_canvas_get(dev);
	if (IS_ERR(core->canvas))
		return PTR_ERR(core->canvas);

	core->dos_parser_clk = devm_clk_get(dev, "dos_parser");
	if (IS_ERR(core->dos_parser_clk))
		return -EPROBE_DEFER;

	core->dos_clk = devm_clk_get(dev, "dos");
	if (IS_ERR(core->dos_clk))
		return -EPROBE_DEFER;

	core->vdec_1_clk = devm_clk_get(dev, "vdec_1");
	if (IS_ERR(core->vdec_1_clk))
		return -EPROBE_DEFER;

	core->vdec_hevc_clk = devm_clk_get(dev, "vdec_hevc");
	if (IS_ERR(core->vdec_hevc_clk))
		return -EPROBE_DEFER;

	irq = platform_get_irq_byname(pdev, "vdec");
	if (irq < 0)
		return irq;

	ret = devm_request_threaded_irq(core->dev, irq, vdec_isr,
					vdec_threaded_isr, IRQF_ONESHOT,
					"vdec", core);
	if (ret)
		return ret;

	ret = esparser_init(pdev, core);
	if (ret)
		return ret;

	ret = v4l2_device_register(dev, &core->v4l2_dev);
	if (ret) {
		dev_err(dev, "Couldn't register v4l2 device\n");
		return -ENOMEM;
	}

	vdev = video_device_alloc();
	if (!vdev) {
		ret = -ENOMEM;
		goto err_vdev_release;
	}

	of_id = of_match_node(vdec_dt_match, dev->of_node);
	core->platform = of_id->data;
	core->vdev_dec = vdev;
	core->dev_dec = dev;
	mutex_init(&core->lock);

	strscpy(vdev->name, "meson-video-decoder", sizeof(vdev->name));
	vdev->release = video_device_release;
	vdev->fops = &vdec_fops;
	vdev->ioctl_ops = &vdec_ioctl_ops;
	vdev->vfl_dir = VFL_DIR_M2M;
	vdev->v4l2_dev = &core->v4l2_dev;
	vdev->lock = &core->lock;
	vdev->device_caps = V4L2_CAP_VIDEO_M2M_MPLANE | V4L2_CAP_STREAMING;

	video_set_drvdata(vdev, core);

	ret = video_register_device(vdev, VFL_TYPE_GRABBER, -1);
	if (ret) {
		dev_err(dev, "Failed registering video device\n");
		goto err_vdev_release;
	}

	return 0;

err_vdev_release:
	video_device_release(vdev);
	return ret;
}

static int vdec_remove(struct platform_device *pdev)
{
	struct amvdec_core *core = platform_get_drvdata(pdev);

	video_unregister_device(core->vdev_dec);

	return 0;
}

static struct platform_driver meson_vdec_driver = {
	.probe = vdec_probe,
	.remove = vdec_remove,
	.driver = {
		.name = "meson-vdec",
		.of_match_table = vdec_dt_match,
	},
};
module_platform_driver(meson_vdec_driver);

MODULE_DESCRIPTION("Meson video decoder driver for GXBB/GXL/GXM");
MODULE_AUTHOR("Maxime Jourdan <mjourdan@baylibre.com>");
MODULE_LICENSE("GPL");