linuxdebug/drivers/media/platform/st/stm32/dma2d/dma2d.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * STM32 DMA2D - 2D Graphics Accelerator Driver
 *
 * Copyright (c) 2021 Dillon Min
 * Dillon Min, <dillon.minfei@gmail.com>
 *
 * based on s5p-g2d
 *
 * Copyright (c) 2011 Samsung Electronics Co., Ltd.
 * Kamil Debski, <k.debski@samsung.com>
 */

#include <linux/module.h>
#include <linux/fs.h>
#include <linux/timer.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/clk.h>
#include <linux/interrupt.h>
#include <linux/of.h>

#include <linux/platform_device.h>
#include <media/v4l2-mem2mem.h>
#include <media/v4l2-device.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-event.h>
#include <media/videobuf2-v4l2.h>
#include <media/videobuf2-dma-contig.h>

#include "dma2d.h"
#include "dma2d-regs.h"

/*
 * This V4L2 subdev m2m driver enables Chrom-Art Accelerator unit
 * of STMicroelectronics STM32 SoC series.
 *
 * Currently support r2m, m2m, m2m_pfc.
 *
 * - r2m, Filling a part or the whole of a destination image with a specific
 *   color.
 * - m2m, Copying a part or the whole of a source image into a part or the
 *   whole of a destination.
 * - m2m_pfc, Copying a part or the whole of a source image into a part or the
 *   whole of a destination image with a pixel format conversion.
 */

#define fh2ctx(__fh) container_of(__fh, struct dma2d_ctx, fh)

static const struct dma2d_fmt formats[] = {
	{
		.fourcc	= V4L2_PIX_FMT_ARGB32,
		.cmode = DMA2D_CMODE_ARGB8888,
		.depth = 32,
	},
	{
		.fourcc	= V4L2_PIX_FMT_RGB24,
		.cmode = DMA2D_CMODE_RGB888,
		.depth = 24,
	},
	{
		.fourcc	= V4L2_PIX_FMT_RGB565,
		.cmode = DMA2D_CMODE_RGB565,
		.depth = 16,
	},
	{
		.fourcc	= V4L2_PIX_FMT_ARGB555,
		.cmode = DMA2D_CMODE_ARGB1555,
		.depth = 16,
	},
	{
		.fourcc	= V4L2_PIX_FMT_ARGB444,
		.cmode = DMA2D_CMODE_ARGB4444,
		.depth = 16,
	},
};

#define NUM_FORMATS ARRAY_SIZE(formats)

static const struct dma2d_frame def_frame = {
	.width		= DEFAULT_WIDTH,
	.height		= DEFAULT_HEIGHT,
	.line_offset	= 0,
	.a_rgb		= {0x00, 0x00, 0x00, 0xff},
	.a_mode		= DMA2D_ALPHA_MODE_NO_MODIF,
	.fmt		= (struct dma2d_fmt *)&formats[0],
	.size		= DEFAULT_SIZE,
};

static struct dma2d_fmt *find_fmt(int pixelformat)
{
	unsigned int i;

	for (i = 0; i < NUM_FORMATS; i++) {
		if (formats[i].fourcc == pixelformat)
			return (struct dma2d_fmt *)&formats[i];
	}

	return NULL;
}

static struct dma2d_frame *get_frame(struct dma2d_ctx *ctx,
				     enum v4l2_buf_type type)
{
	return V4L2_TYPE_IS_OUTPUT(type) ? &ctx->cap : &ctx->out;
}

static int dma2d_queue_setup(struct vb2_queue *vq,
			     unsigned int *nbuffers, unsigned int *nplanes,
			     unsigned int sizes[], struct device *alloc_devs[])
{
	struct dma2d_ctx *ctx = vb2_get_drv_priv(vq);
	struct dma2d_frame *f = get_frame(ctx, vq->type);

	if (*nplanes)
		return sizes[0] < f->size ? -EINVAL : 0;

	sizes[0] = f->size;
	*nplanes = 1;

	return 0;
}

static int dma2d_buf_out_validate(struct vb2_buffer *vb)
{
	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);

	if (vbuf->field == V4L2_FIELD_ANY)
		vbuf->field = V4L2_FIELD_NONE;
	if (vbuf->field != V4L2_FIELD_NONE)
		return -EINVAL;

	return 0;
}

static int dma2d_buf_prepare(struct vb2_buffer *vb)
{
	struct dma2d_ctx *ctx = vb2_get_drv_priv(vb->vb2_queue);
	struct dma2d_frame *f = get_frame(ctx, vb->vb2_queue->type);

	if (vb2_plane_size(vb, 0) < f->size)
		return -EINVAL;

	vb2_set_plane_payload(vb, 0, f->size);

	return 0;
}

static void dma2d_buf_queue(struct vb2_buffer *vb)
{
	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
	struct dma2d_ctx *ctx = vb2_get_drv_priv(vb->vb2_queue);

	v4l2_m2m_buf_queue(ctx->fh.m2m_ctx, vbuf);
}

static int dma2d_start_streaming(struct vb2_queue *q, unsigned int count)
{
	struct dma2d_ctx *ctx = vb2_get_drv_priv(q);
	struct dma2d_frame *f = get_frame(ctx, q->type);

	f->sequence = 0;
	return 0;
}

static void dma2d_stop_streaming(struct vb2_queue *q)
{
	struct dma2d_ctx *ctx = vb2_get_drv_priv(q);
	struct vb2_v4l2_buffer *vbuf;

	for (;;) {
		if (V4L2_TYPE_IS_OUTPUT(q->type))
			vbuf = v4l2_m2m_src_buf_remove(ctx->fh.m2m_ctx);
		else
			vbuf = v4l2_m2m_dst_buf_remove(ctx->fh.m2m_ctx);
		if (!vbuf)
			return;
		v4l2_m2m_buf_done(vbuf, VB2_BUF_STATE_ERROR);
	}
}

static const struct vb2_ops dma2d_qops = {
	.queue_setup	= dma2d_queue_setup,
	.buf_out_validate	 = dma2d_buf_out_validate,
	.buf_prepare	= dma2d_buf_prepare,
	.buf_queue	= dma2d_buf_queue,
	.start_streaming = dma2d_start_streaming,
	.stop_streaming  = dma2d_stop_streaming,
	.wait_prepare	= vb2_ops_wait_prepare,
	.wait_finish	= vb2_ops_wait_finish,
};

static int queue_init(void *priv, struct vb2_queue *src_vq,
		      struct vb2_queue *dst_vq)
{
	struct dma2d_ctx *ctx = priv;
	int ret;

	src_vq->type = V4L2_BUF_TYPE_VIDEO_OUTPUT;
	src_vq->io_modes = VB2_MMAP | VB2_DMABUF;
	src_vq->drv_priv = ctx;
	src_vq->ops = &dma2d_qops;
	src_vq->mem_ops = &vb2_dma_contig_memops;
	src_vq->buf_struct_size = sizeof(struct v4l2_m2m_buffer);
	src_vq->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
	src_vq->lock = &ctx->dev->mutex;
	src_vq->dev = ctx->dev->v4l2_dev.dev;

	ret = vb2_queue_init(src_vq);
	if (ret)
		return ret;

	dst_vq->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
	dst_vq->io_modes = VB2_MMAP | VB2_DMABUF;
	dst_vq->drv_priv = ctx;
	dst_vq->ops = &dma2d_qops;
	dst_vq->mem_ops = &vb2_dma_contig_memops;
	dst_vq->buf_struct_size = sizeof(struct v4l2_m2m_buffer);
	dst_vq->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
	dst_vq->lock = &ctx->dev->mutex;
	dst_vq->dev = ctx->dev->v4l2_dev.dev;

	return vb2_queue_init(dst_vq);
}

static int dma2d_s_ctrl(struct v4l2_ctrl *ctrl)
{
	struct dma2d_frame *frm;
	struct dma2d_ctx *ctx = container_of(ctrl->handler, struct dma2d_ctx,
								ctrl_handler);
	unsigned long flags;

	spin_lock_irqsave(&ctx->dev->ctrl_lock, flags);
	switch (ctrl->id) {
	case V4L2_CID_COLORFX:
		if (ctrl->val == V4L2_COLORFX_SET_RGB)
			ctx->op_mode = DMA2D_MODE_R2M;
		else if (ctrl->val == V4L2_COLORFX_NONE)
			ctx->op_mode = DMA2D_MODE_M2M;
		break;
	case V4L2_CID_COLORFX_RGB:
		frm = get_frame(ctx, V4L2_BUF_TYPE_VIDEO_CAPTURE);
		frm->a_rgb[2] = (ctrl->val >> 16) & 0xff;
		frm->a_rgb[1] = (ctrl->val >> 8) & 0xff;
		frm->a_rgb[0] = (ctrl->val >> 0) & 0xff;
		break;
	default:
		spin_unlock_irqrestore(&ctx->dev->ctrl_lock, flags);
		return -EINVAL;
	}
	spin_unlock_irqrestore(&ctx->dev->ctrl_lock, flags);

	return 0;
}

static const struct v4l2_ctrl_ops dma2d_ctrl_ops = {
	.s_ctrl	= dma2d_s_ctrl,
};

static int dma2d_setup_ctrls(struct dma2d_ctx *ctx)
{
	struct v4l2_ctrl_handler *handler = &ctx->ctrl_handler;

	v4l2_ctrl_handler_init(handler, 2);

	v4l2_ctrl_new_std_menu(handler, &dma2d_ctrl_ops, V4L2_CID_COLORFX,
			       V4L2_COLORFX_SET_RGB, ~0x10001,
			       V4L2_COLORFX_NONE);

	v4l2_ctrl_new_std(handler, &dma2d_ctrl_ops, V4L2_CID_COLORFX_RGB, 0,
			  0xffffff, 1, 0);

	return 0;
}

static int dma2d_open(struct file *file)
{
	struct dma2d_dev *dev = video_drvdata(file);
	struct dma2d_ctx *ctx = NULL;
	int ret = 0;

	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
	if (!ctx)
		return -ENOMEM;
	ctx->dev = dev;
	/* Set default formats */
	ctx->cap		= def_frame;
	ctx->bg		= def_frame;
	ctx->out	= def_frame;
	ctx->op_mode	= DMA2D_MODE_M2M_FPC;
	ctx->colorspace = V4L2_COLORSPACE_REC709;
	if (mutex_lock_interruptible(&dev->mutex)) {
		kfree(ctx);
		return -ERESTARTSYS;
	}

	ctx->fh.m2m_ctx = v4l2_m2m_ctx_init(dev->m2m_dev, ctx, &queue_init);
	if (IS_ERR(ctx->fh.m2m_ctx)) {
		ret = PTR_ERR(ctx->fh.m2m_ctx);
		mutex_unlock(&dev->mutex);
		kfree(ctx);
		return ret;
	}

	v4l2_fh_init(&ctx->fh, video_devdata(file));
	file->private_data = &ctx->fh;
	v4l2_fh_add(&ctx->fh);

	dma2d_setup_ctrls(ctx);

	/* Write the default values to the ctx struct */
	v4l2_ctrl_handler_setup(&ctx->ctrl_handler);

	ctx->fh.ctrl_handler = &ctx->ctrl_handler;
	mutex_unlock(&dev->mutex);

	return 0;
}

static int dma2d_release(struct file *file)
{
	struct dma2d_dev *dev = video_drvdata(file);
	struct dma2d_ctx *ctx = fh2ctx(file->private_data);

	mutex_lock(&dev->mutex);
	v4l2_m2m_ctx_release(ctx->fh.m2m_ctx);
	mutex_unlock(&dev->mutex);
	v4l2_ctrl_handler_free(&ctx->ctrl_handler);
	v4l2_fh_del(&ctx->fh);
	v4l2_fh_exit(&ctx->fh);
	kfree(ctx);

	return 0;
}

static int vidioc_querycap(struct file *file, void *priv,
			   struct v4l2_capability *cap)
{
	strscpy(cap->driver, DMA2D_NAME, sizeof(cap->driver));
	strscpy(cap->card, DMA2D_NAME, sizeof(cap->card));
	strscpy(cap->bus_info, BUS_INFO, sizeof(cap->bus_info));

	return 0;
}

static int vidioc_enum_fmt(struct file *file, void *prv, struct v4l2_fmtdesc *f)
{
	if (f->index >= NUM_FORMATS)
		return -EINVAL;

	f->pixelformat = formats[f->index].fourcc;
	return 0;
}

static int vidioc_g_fmt(struct file *file, void *prv, struct v4l2_format *f)
{
	struct dma2d_ctx *ctx = prv;
	struct vb2_queue *vq;
	struct dma2d_frame *frm;

	vq = v4l2_m2m_get_vq(ctx->fh.m2m_ctx, f->type);
	if (!vq)
		return -EINVAL;

	frm = get_frame(ctx, f->type);
	f->fmt.pix.width		= frm->width;
	f->fmt.pix.height		= frm->height;
	f->fmt.pix.field		= V4L2_FIELD_NONE;
	f->fmt.pix.pixelformat		= frm->fmt->fourcc;
	f->fmt.pix.bytesperline		= (frm->width * frm->fmt->depth) >> 3;
	f->fmt.pix.sizeimage		= frm->size;
	f->fmt.pix.colorspace		= ctx->colorspace;
	f->fmt.pix.xfer_func		= ctx->xfer_func;
	f->fmt.pix.ycbcr_enc		= ctx->ycbcr_enc;
	f->fmt.pix.quantization		= ctx->quant;

	return 0;
}

static int vidioc_try_fmt(struct file *file, void *prv, struct v4l2_format *f)
{
	struct dma2d_ctx *ctx = prv;
	struct dma2d_fmt *fmt;
	enum v4l2_field *field;
	u32 fourcc = f->fmt.pix.pixelformat;

	fmt = find_fmt(fourcc);
	if (!fmt) {
		f->fmt.pix.pixelformat = formats[0].fourcc;
		fmt = find_fmt(f->fmt.pix.pixelformat);
	}

	field = &f->fmt.pix.field;
	if (*field == V4L2_FIELD_ANY)
		*field = V4L2_FIELD_NONE;
	else if (*field != V4L2_FIELD_NONE)
		return -EINVAL;

	if (f->fmt.pix.width > MAX_WIDTH)
		f->fmt.pix.width = MAX_WIDTH;
	if (f->fmt.pix.height > MAX_HEIGHT)
		f->fmt.pix.height = MAX_HEIGHT;

	if (f->fmt.pix.width < 1)
		f->fmt.pix.width = 1;
	if (f->fmt.pix.height < 1)
		f->fmt.pix.height = 1;

	if (f->type == V4L2_BUF_TYPE_VIDEO_OUTPUT && !f->fmt.pix.colorspace) {
		f->fmt.pix.colorspace = V4L2_COLORSPACE_REC709;
	} else if (f->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) {
		f->fmt.pix.colorspace	= ctx->colorspace;
		f->fmt.pix.xfer_func = ctx->xfer_func;
		f->fmt.pix.ycbcr_enc = ctx->ycbcr_enc;
		f->fmt.pix.quantization = ctx->quant;
	}
	f->fmt.pix.bytesperline = (f->fmt.pix.width * fmt->depth) >> 3;
	f->fmt.pix.sizeimage = f->fmt.pix.height * f->fmt.pix.bytesperline;

	return 0;
}

static int vidioc_s_fmt(struct file *file, void *prv, struct v4l2_format *f)
{
	struct dma2d_ctx *ctx = prv;
	struct vb2_queue *vq;
	struct dma2d_frame *frm;
	struct dma2d_fmt *fmt;
	int ret = 0;

	/* Adjust all values accordingly to the hardware capabilities
	 * and chosen format.
	 */
	ret = vidioc_try_fmt(file, prv, f);
	if (ret)
		return ret;

	vq = v4l2_m2m_get_vq(ctx->fh.m2m_ctx, f->type);
	if (vb2_is_busy(vq))
		return -EBUSY;

	fmt = find_fmt(f->fmt.pix.pixelformat);
	if (!fmt)
		return -EINVAL;

	if (f->type == V4L2_BUF_TYPE_VIDEO_OUTPUT) {
		ctx->colorspace = f->fmt.pix.colorspace;
		ctx->xfer_func = f->fmt.pix.xfer_func;
		ctx->ycbcr_enc = f->fmt.pix.ycbcr_enc;
		ctx->quant = f->fmt.pix.quantization;
	}

	frm = get_frame(ctx, f->type);
	frm->width = f->fmt.pix.width;
	frm->height = f->fmt.pix.height;
	frm->size = f->fmt.pix.sizeimage;
	/* Reset crop settings */
	frm->o_width = 0;
	frm->o_height = 0;
	frm->c_width = frm->width;
	frm->c_height = frm->height;
	frm->right = frm->width;
	frm->bottom = frm->height;
	frm->fmt = fmt;
	frm->line_offset = 0;

	return 0;
}

static void device_run(void *prv)
{
	struct dma2d_ctx *ctx = prv;
	struct dma2d_dev *dev = ctx->dev;
	struct dma2d_frame *frm_out, *frm_cap;
	struct vb2_v4l2_buffer *src, *dst;
	unsigned long flags;

	spin_lock_irqsave(&dev->ctrl_lock, flags);
	dev->curr = ctx;

	src = v4l2_m2m_next_src_buf(ctx->fh.m2m_ctx);
	dst = v4l2_m2m_next_dst_buf(ctx->fh.m2m_ctx);
	if (!dst || !src)
		goto end;

	frm_cap = get_frame(ctx, V4L2_BUF_TYPE_VIDEO_CAPTURE);
	frm_out = get_frame(ctx, V4L2_BUF_TYPE_VIDEO_OUTPUT);
	if (!frm_cap || !frm_out)
		goto end;

	src->sequence = frm_out->sequence++;
	dst->sequence = frm_cap->sequence++;
	v4l2_m2m_buf_copy_metadata(src, dst, true);

	clk_enable(dev->gate);

	dma2d_config_fg(dev, frm_out,
			vb2_dma_contig_plane_dma_addr(&src->vb2_buf, 0));

	/* TODO: add M2M_BLEND handler here */

	if (ctx->op_mode != DMA2D_MODE_R2M) {
		if (frm_out->fmt->fourcc == frm_cap->fmt->fourcc)
			ctx->op_mode = DMA2D_MODE_M2M;
		else
			ctx->op_mode = DMA2D_MODE_M2M_FPC;
	}

	dma2d_config_out(dev, frm_cap,
			 vb2_dma_contig_plane_dma_addr(&dst->vb2_buf, 0));
	dma2d_config_common(dev, ctx->op_mode, frm_cap->width, frm_cap->height);

	dma2d_start(dev);
end:
	spin_unlock_irqrestore(&dev->ctrl_lock, flags);
}

static irqreturn_t dma2d_isr(int irq, void *prv)
{
	struct dma2d_dev *dev = prv;
	struct dma2d_ctx *ctx = dev->curr;
	struct vb2_v4l2_buffer *src, *dst;
	u32 s = dma2d_get_int(dev);

	dma2d_clear_int(dev);
	if (s & ISR_TCIF || s == 0) {
		clk_disable(dev->gate);

		WARN_ON(!ctx);

		src = v4l2_m2m_src_buf_remove(ctx->fh.m2m_ctx);
		dst = v4l2_m2m_dst_buf_remove(ctx->fh.m2m_ctx);

		WARN_ON(!dst);
		WARN_ON(!src);

		v4l2_m2m_buf_done(src, VB2_BUF_STATE_DONE);
		v4l2_m2m_buf_done(dst, VB2_BUF_STATE_DONE);
		v4l2_m2m_job_finish(dev->m2m_dev, ctx->fh.m2m_ctx);

		dev->curr = NULL;
	}

	return IRQ_HANDLED;
}

static const struct v4l2_file_operations dma2d_fops = {
	.owner		= THIS_MODULE,
	.open		= dma2d_open,
	.release	= dma2d_release,
	.poll		= v4l2_m2m_fop_poll,
	.unlocked_ioctl	= video_ioctl2,
	.mmap		= v4l2_m2m_fop_mmap,
#ifndef CONFIG_MMU
	.get_unmapped_area = v4l2_m2m_get_unmapped_area,
#endif
};

static const struct v4l2_ioctl_ops dma2d_ioctl_ops = {
	.vidioc_querycap	= vidioc_querycap,

	.vidioc_enum_fmt_vid_cap	= vidioc_enum_fmt,
	.vidioc_g_fmt_vid_cap		= vidioc_g_fmt,
	.vidioc_try_fmt_vid_cap		= vidioc_try_fmt,
	.vidioc_s_fmt_vid_cap		= vidioc_s_fmt,

	.vidioc_enum_fmt_vid_out	= vidioc_enum_fmt,
	.vidioc_g_fmt_vid_out		= vidioc_g_fmt,
	.vidioc_try_fmt_vid_out		= vidioc_try_fmt,
	.vidioc_s_fmt_vid_out		= vidioc_s_fmt,

	.vidioc_reqbufs			= v4l2_m2m_ioctl_reqbufs,
	.vidioc_querybuf		= v4l2_m2m_ioctl_querybuf,
	.vidioc_qbuf			= v4l2_m2m_ioctl_qbuf,
	.vidioc_dqbuf			= v4l2_m2m_ioctl_dqbuf,
	.vidioc_prepare_buf		= v4l2_m2m_ioctl_prepare_buf,
	.vidioc_create_bufs		= v4l2_m2m_ioctl_create_bufs,
	.vidioc_expbuf			= v4l2_m2m_ioctl_expbuf,

	.vidioc_streamon		= v4l2_m2m_ioctl_streamon,
	.vidioc_streamoff		= v4l2_m2m_ioctl_streamoff,

	.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
	.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
};

static const struct video_device dma2d_videodev = {
	.name		= DMA2D_NAME,
	.fops		= &dma2d_fops,
	.ioctl_ops	= &dma2d_ioctl_ops,
	.minor		= -1,
	.release	= video_device_release,
	.vfl_dir	= VFL_DIR_M2M,
};

static const struct v4l2_m2m_ops dma2d_m2m_ops = {
	.device_run	= device_run,
};

static const struct of_device_id stm32_dma2d_match[];

static int dma2d_probe(struct platform_device *pdev)
{
	struct dma2d_dev *dev;
	struct video_device *vfd;
	struct resource *res;
	int ret = 0;

	dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
	if (!dev)
		return -ENOMEM;

	spin_lock_init(&dev->ctrl_lock);
	mutex_init(&dev->mutex);
	atomic_set(&dev->num_inst, 0);

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	dev->regs = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(dev->regs))
		return PTR_ERR(dev->regs);

	dev->gate = clk_get(&pdev->dev, "dma2d");
	if (IS_ERR(dev->gate)) {
		dev_err(&pdev->dev, "failed to get dma2d clock gate\n");
		ret = -ENXIO;
		return ret;
	}

	ret = clk_prepare(dev->gate);
	if (ret) {
		dev_err(&pdev->dev, "failed to prepare dma2d clock gate\n");
		goto put_clk_gate;
	}

	ret = platform_get_irq(pdev, 0);
	if (ret < 0)
		goto unprep_clk_gate;

	dev->irq = ret;

	ret = devm_request_irq(&pdev->dev, dev->irq, dma2d_isr,
			       0, pdev->name, dev);
	if (ret) {
		dev_err(&pdev->dev, "failed to install IRQ\n");
		goto unprep_clk_gate;
	}

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

	vfd = video_device_alloc();
	if (!vfd) {
		v4l2_err(&dev->v4l2_dev, "Failed to allocate video device\n");
		ret = -ENOMEM;
		goto unreg_v4l2_dev;
	}

	*vfd = dma2d_videodev;
	vfd->lock = &dev->mutex;
	vfd->v4l2_dev = &dev->v4l2_dev;
	vfd->device_caps = V4L2_CAP_VIDEO_M2M | V4L2_CAP_STREAMING;

	platform_set_drvdata(pdev, dev);
	dev->m2m_dev = v4l2_m2m_init(&dma2d_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);
		goto rel_vdev;
	}

	ret = video_register_device(vfd, VFL_TYPE_VIDEO, 0);
	if (ret) {
		v4l2_err(&dev->v4l2_dev, "Failed to register video device\n");
		goto free_m2m;
	}

	video_set_drvdata(vfd, dev);
	dev->vfd = vfd;
	v4l2_info(&dev->v4l2_dev, "device registered as /dev/video%d\n",
		  vfd->num);
	return 0;

free_m2m:
	v4l2_m2m_release(dev->m2m_dev);
rel_vdev:
	video_device_release(vfd);
unreg_v4l2_dev:
	v4l2_device_unregister(&dev->v4l2_dev);
unprep_clk_gate:
	clk_unprepare(dev->gate);
put_clk_gate:
	clk_put(dev->gate);

	return ret;
}

static int dma2d_remove(struct platform_device *pdev)
{
	struct dma2d_dev *dev = platform_get_drvdata(pdev);

	v4l2_info(&dev->v4l2_dev, "Removing " DMA2D_NAME);
	v4l2_m2m_release(dev->m2m_dev);
	video_unregister_device(dev->vfd);
	v4l2_device_unregister(&dev->v4l2_dev);
	vb2_dma_contig_clear_max_seg_size(&pdev->dev);
	clk_unprepare(dev->gate);
	clk_put(dev->gate);

	return 0;
}

static const struct of_device_id stm32_dma2d_match[] = {
	{
		.compatible = "st,stm32-dma2d",
		.data = NULL,
	},
	{},
};
MODULE_DEVICE_TABLE(of, stm32_dma2d_match);

static struct platform_driver dma2d_pdrv = {
	.probe		= dma2d_probe,
	.remove		= dma2d_remove,
	.driver		= {
		.name = DMA2D_NAME,
		.of_match_table = stm32_dma2d_match,
	},
};

module_platform_driver(dma2d_pdrv);

MODULE_AUTHOR("Dillon Min <dillon.minfei@gmail.com>");
MODULE_DESCRIPTION("STM32 Chrom-Art Accelerator DMA2D driver");
MODULE_LICENSE("GPL");