On 08/09/2016 03:58 PM, Minghsiu Tsai wrote:

This needs a 'depends on HAS_DMA' as well.

+	select VIDEOBUF2_DMA_CONTIG
+	select V4L2_MEM2MEM_DEV
+	select VIDEO_MEDIATEK_VPU
+	default n
+	---help---
+	    It is a v4l2 driver and present in Mediatek MT8173 SoCs.
+	    The driver supports for scaling and color space conversion.
+
+	    To compile this driver as a module, choose M here: the
+	    module will be called mtk-mdp.
+
 config VIDEO_MEDIATEK_VCODEC
 	tristate "Mediatek Video Codec driver"
 	depends on MTK_IOMMU || COMPILE_TEST

<snip>

+
+/*
+ * Return true if rectangle a is enclosed in rectangle b, or false otherwise.
+ */
+static bool mtk_mdp_m2m_is_rectangle_enclosed(struct v4l2_rect *a,
+					     struct v4l2_rect *b)
+{
+	if (a->left < b->left || a->top < b->top)
+		return false;
+
+	if (a->left + a->width > b->left + b->width)
+		return false;
+
+	if (a->top + a->height > b->top + b->height)
+		return false;
+
+	return true;
+}
+
+static int mtk_mdp_m2m_g_selection(struct file *file, void *fh,
+				   struct v4l2_selection *s)
+{
+	struct mtk_mdp_frame *frame;
+	struct mtk_mdp_ctx *ctx = fh_to_ctx(fh);
+
+	if ((s->type != V4L2_BUF_TYPE_VIDEO_CAPTURE) &&
+	    (s->type != V4L2_BUF_TYPE_VIDEO_OUTPUT)) {
+		mtk_mdp_dbg(1, "[%d] invalid type:%d", ctx->id, s->type);
+		return -EINVAL;
+	}
+
+	frame = mtk_mdp_ctx_get_frame(ctx, s->type);
+
+	switch (s->target) {
+	case V4L2_SEL_TGT_COMPOSE_DEFAULT:
+	case V4L2_SEL_TGT_COMPOSE_BOUNDS:
+	case V4L2_SEL_TGT_CROP_BOUNDS:
+	case V4L2_SEL_TGT_CROP_DEFAULT:
+		s->r.left = 0;
+		s->r.top = 0;
+		s->r.width = frame->width;
+		s->r.height = frame->height;
+		return 0;
+
+	case V4L2_SEL_TGT_COMPOSE:
+	case V4L2_SEL_TGT_CROP:
+		s->r.left = frame->crop.left;
+		s->r.top = frame->crop.top;
+		s->r.width = frame->crop.width;
+		s->r.height = frame->crop.height;
+		return 0;
+	}

This isn't right. For VIDEO_CAPTURE you support the COMPOSE targets, and for
the VIDEO_OUTPUT you support the CROP targets. Right now I can use e.g. TGT_CROP
with VIDEO_CAPTURE, which isn't correct.

s_selection has the same problem.

+
+	return -EINVAL;
+}
+
+static int mtk_mdp_check_scaler_ratio(struct mtk_mdp_variant *var, int src_w,
+				      int src_h, int dst_w, int dst_h, int rot)
+{
+	int tmp_w, tmp_h;
+
+	if (rot == 90 || rot == 270) {
+		tmp_w = dst_h;
+		tmp_h = dst_w;
+	} else {
+		tmp_w = dst_w;
+		tmp_h = dst_h;
+	}
+
+	if ((src_w / tmp_w) > var->h_scale_down_max ||
+	    (src_h / tmp_h) > var->v_scale_down_max ||
+	    (tmp_w / src_w) > var->h_scale_up_max ||
+	    (tmp_h / src_h) > var->v_scale_up_max)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int mtk_mdp_m2m_s_selection(struct file *file, void *fh,
+				   struct v4l2_selection *s)
+{
+	struct mtk_mdp_frame *frame;
+	struct mtk_mdp_ctx *ctx = fh_to_ctx(fh);
+	struct v4l2_crop cr;
+	struct mtk_mdp_variant *variant = ctx->mdp_dev->variant;
+	int ret;
+
+	cr.type = s->type;
+	cr.c = s->r;
+
+	if ((s->type != V4L2_BUF_TYPE_VIDEO_CAPTURE) &&
+	    (s->type != V4L2_BUF_TYPE_VIDEO_OUTPUT)) {
+		mtk_mdp_dbg(1, "[%d] invalid type:%d", ctx->id, s->type);
+		return -EINVAL;
+	}
+
+	ret = mtk_mdp_try_crop(ctx, &cr);

Please don't copy to a v4l2_crop. Just stick to v4l2_selection.
I would prefer not to see struct v4l2_crop in drivers.

+	if (ret)
+		return ret;
+
+	if (s->flags & V4L2_SEL_FLAG_LE &&
+	    !mtk_mdp_m2m_is_rectangle_enclosed(&cr.c, &s->r))
+		return -ERANGE;
+
+	if (s->flags & V4L2_SEL_FLAG_GE &&
+	    !mtk_mdp_m2m_is_rectangle_enclosed(&s->r, &cr.c))
+		return -ERANGE;

As has been discussed for the encoder driver: just adjust the rectangle and
don't return ERANGE. Consider the flags as hints.

The V4L2 documentation is confusing, this will be addressed soon.

+
+	s->r = cr.c;
+
+	switch (s->target) {
+	case V4L2_SEL_TGT_COMPOSE_BOUNDS:
+	case V4L2_SEL_TGT_COMPOSE_DEFAULT:
+	case V4L2_SEL_TGT_COMPOSE:
+		frame = &ctx->s_frame;
+		break;
+
+	case V4L2_SEL_TGT_CROP_BOUNDS:
+	case V4L2_SEL_TGT_CROP:
+	case V4L2_SEL_TGT_CROP_DEFAULT:
+		frame = &ctx->d_frame;
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	/* Check to see if scaling ratio is within supported range */
+	if (mtk_mdp_ctx_state_is_set(ctx, MTK_MDP_DST_FMT | MTK_MDP_SRC_FMT)) {
+		if (V4L2_TYPE_IS_OUTPUT(s->type)) {
+			ret = mtk_mdp_check_scaler_ratio(variant, cr.c.width,
+				cr.c.height, ctx->d_frame.crop.width,
+				ctx->d_frame.crop.height,
+				ctx->ctrls.rotate->val);
+		} else {
+			ret = mtk_mdp_check_scaler_ratio(variant,
+				ctx->s_frame.crop.width,
+				ctx->s_frame.crop.height, cr.c.width,
+				cr.c.height, ctx->ctrls.rotate->val);
+		}
+
+		if (ret) {
+			dev_info(&ctx->mdp_dev->pdev->dev,
+				"Out of scaler range");
+			return -EINVAL;
+		}
+	}
+
+	frame->crop = cr.c;
+
+	return 0;
+}
+
+static const struct v4l2_ioctl_ops mtk_mdp_m2m_ioctl_ops = {
+	.vidioc_querycap		= mtk_mdp_m2m_querycap,
+	.vidioc_enum_fmt_vid_cap_mplane	= mtk_mdp_m2m_enum_fmt_mplane_vid_cap,
+	.vidioc_enum_fmt_vid_out_mplane	= mtk_mdp_m2m_enum_fmt_mplane_vid_out,
+	.vidioc_g_fmt_vid_cap_mplane	= mtk_mdp_m2m_g_fmt_mplane,
+	.vidioc_g_fmt_vid_out_mplane	= mtk_mdp_m2m_g_fmt_mplane,
+	.vidioc_try_fmt_vid_cap_mplane	= mtk_mdp_m2m_try_fmt_mplane,
+	.vidioc_try_fmt_vid_out_mplane	= mtk_mdp_m2m_try_fmt_mplane,
+	.vidioc_s_fmt_vid_cap_mplane	= mtk_mdp_m2m_s_fmt_mplane,
+	.vidioc_s_fmt_vid_out_mplane	= mtk_mdp_m2m_s_fmt_mplane,
+	.vidioc_reqbufs			= mtk_mdp_m2m_reqbufs,
+	.vidioc_create_bufs		= v4l2_m2m_ioctl_create_bufs,
+	.vidioc_expbuf			= v4l2_m2m_ioctl_expbuf,
+	.vidioc_subscribe_event		= v4l2_ctrl_subscribe_event,
+	.vidioc_unsubscribe_event	= v4l2_event_unsubscribe,
+	.vidioc_querybuf		= v4l2_m2m_ioctl_querybuf,
+	.vidioc_qbuf			= v4l2_m2m_ioctl_qbuf,
+	.vidioc_dqbuf			= v4l2_m2m_ioctl_dqbuf,
+	.vidioc_streamon		= mtk_mdp_m2m_streamon,
+	.vidioc_streamoff		= v4l2_m2m_ioctl_streamoff,
+	.vidioc_g_selection		= mtk_mdp_m2m_g_selection,
+	.vidioc_s_selection		= mtk_mdp_m2m_s_selection
+};
+
+static int mtk_mdp_m2m_queue_init(void *priv, struct vb2_queue *src_vq,
+				  struct vb2_queue *dst_vq)
+{
+	struct mtk_mdp_ctx *ctx = priv;
+	int ret;
+
+	memset(src_vq, 0, sizeof(*src_vq));
+	src_vq->type = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE;
+	src_vq->io_modes = VB2_MMAP | VB2_USERPTR | VB2_DMABUF;
+	src_vq->drv_priv = ctx;
+	src_vq->ops = &mtk_mdp_m2m_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->dev = &ctx->mdp_dev->pdev->dev;
+
+	ret = vb2_queue_init(src_vq);
+	if (ret)
+		return ret;
+
+	memset(dst_vq, 0, sizeof(*dst_vq));
+	dst_vq->type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
+	dst_vq->io_modes = VB2_MMAP | VB2_USERPTR | VB2_DMABUF;

I wouldn't recommend setting VB2_USERPTR in combination with dma_contig.

That only works if the userptr points to physically contiguous memory,
unless there is an iommu that can fix things up.

+	dst_vq->drv_priv = ctx;
+	dst_vq->ops = &mtk_mdp_m2m_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->dev = &ctx->mdp_dev->pdev->dev;
+
+	return vb2_queue_init(dst_vq);
+}
+
+static int mtk_mdp_s_ctrl(struct v4l2_ctrl *ctrl)
+{
+	struct mtk_mdp_ctx *ctx = ctrl_to_ctx(ctrl);
+	struct mtk_mdp_dev *mdp = ctx->mdp_dev;
+	struct mtk_mdp_variant *variant = mdp->variant;
+	u32 state = MTK_MDP_DST_FMT | MTK_MDP_SRC_FMT;
+	int ret = 0;
+
+	if (ctrl->flags & V4L2_CTRL_FLAG_INACTIVE)
+		return 0;
+
+	switch (ctrl->id) {
+	case V4L2_CID_HFLIP:
+		ctx->hflip = ctrl->val;
+		break;
+	case V4L2_CID_VFLIP:
+		ctx->vflip = ctrl->val;
+		break;
+	case V4L2_CID_ROTATE:
+		if (mtk_mdp_ctx_state_is_set(ctx, state)) {
+			ret = mtk_mdp_check_scaler_ratio(variant,
+					ctx->s_frame.crop.width,
+					ctx->s_frame.crop.height,
+					ctx->d_frame.crop.width,
+					ctx->d_frame.crop.height,
+					ctx->ctrls.rotate->val);
+
+			if (ret)
+				return -EINVAL;
+		}
+
+		ctx->rotation = ctrl->val;
+		break;
+	case V4L2_CID_ALPHA_COMPONENT:
+		ctx->d_frame.alpha = ctrl->val;
+		break;
+	}
+
+	return 0;
+}
+
+static const struct v4l2_ctrl_ops mtk_mdp_ctrl_ops = {
+	.s_ctrl = mtk_mdp_s_ctrl,
+};
+
+static int mtk_mdp_ctrls_create(struct mtk_mdp_ctx *ctx)
+{
+	v4l2_ctrl_handler_init(&ctx->ctrl_handler, MTK_MDP_MAX_CTRL_NUM);
+
+	ctx->ctrls.rotate = v4l2_ctrl_new_std(&ctx->ctrl_handler,
+			&mtk_mdp_ctrl_ops, V4L2_CID_ROTATE, 0, 270, 90, 0);
+	ctx->ctrls.hflip = v4l2_ctrl_new_std(&ctx->ctrl_handler,
+					     &mtk_mdp_ctrl_ops,
+					     V4L2_CID_HFLIP,
+					     0, 1, 1, 0);
+	ctx->ctrls.vflip = v4l2_ctrl_new_std(&ctx->ctrl_handler,
+					     &mtk_mdp_ctrl_ops,
+					     V4L2_CID_VFLIP,
+					     0, 1, 1, 0);
+	ctx->ctrls.global_alpha = v4l2_ctrl_new_std(&ctx->ctrl_handler,
+						    &mtk_mdp_ctrl_ops,
+						    V4L2_CID_ALPHA_COMPONENT,
+						    0, 255, 1, 0);
+	ctx->ctrls_rdy = ctx->ctrl_handler.error == 0;
+
+	if (ctx->ctrl_handler.error) {
+		int err = ctx->ctrl_handler.error;
+
+		v4l2_ctrl_handler_free(&ctx->ctrl_handler);
+		dev_err(&ctx->mdp_dev->pdev->dev,
+			"Failed to create control handlers\n");
+		return err;
+	}
+
+	return 0;
+}
+
+static void mtk_mdp_set_default_params(struct mtk_mdp_ctx *ctx)
+{
+	struct mtk_mdp_dev *mdp = ctx->mdp_dev;
+	struct mtk_mdp_frame *frame;
+
+	frame = mtk_mdp_ctx_get_frame(ctx, V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE);
+	frame->fmt = mtk_mdp_find_fmt_by_index(0,
+					V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE);
+	frame->width = mdp->variant->pix_min->org_w;
+	frame->height = mdp->variant->pix_min->org_h;
+	frame->payload[0] = frame->width * frame->height;
+	frame->payload[1] = frame->payload[0] / 2;
+
+	frame = mtk_mdp_ctx_get_frame(ctx, V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE);
+	frame->fmt = mtk_mdp_find_fmt_by_index(0,
+					V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE);
+	frame->width = mdp->variant->pix_min->target_rot_dis_w;
+	frame->height = mdp->variant->pix_min->target_rot_dis_h;
+	frame->payload[0] = frame->width * frame->height;
+	frame->payload[1] = frame->payload[0] / 2;
+
+}
+
+static int mtk_mdp_m2m_open(struct file *file)
+{
+	struct mtk_mdp_dev *mdp = video_drvdata(file);
+	struct video_device *vfd = video_devdata(file);
+	struct mtk_mdp_ctx *ctx = NULL;
+	int ret;
+
+	if (mutex_lock_interruptible(&mdp->lock))
+		return -ERESTARTSYS;

This lock is taken very early. Move it down to where you really need the lock,
it can certainly be moved to after the kzalloc.

+
+	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+	if (!ctx) {
+		ret = -ENOMEM;
+		goto err_ctx_alloc;
+	}
+
+	mutex_init(&ctx->slock);
+	ctx->id = mdp->id_counter++;
+	v4l2_fh_init(&ctx->fh, vfd);
+	file->private_data = &ctx->fh;
+	ret = mtk_mdp_ctrls_create(ctx);
+	if (ret)
+		goto error_ctrls;
+
+	/* Use separate control handler per file handle */
+	ctx->fh.ctrl_handler = &ctx->ctrl_handler;
+	v4l2_fh_add(&ctx->fh);
+	INIT_LIST_HEAD(&ctx->list);
+
+	ctx->mdp_dev = mdp;
+	mtk_mdp_set_default_params(ctx);
+
+	INIT_WORK(&ctx->work, mtk_mdp_m2m_worker);
+	ctx->m2m_ctx = v4l2_m2m_ctx_init(mdp->m2m_dev, ctx,
+					 mtk_mdp_m2m_queue_init);
+	if (IS_ERR(ctx->m2m_ctx)) {
+		dev_err(&mdp->pdev->dev, "Failed to initialize m2m context");
+		ret = PTR_ERR(ctx->m2m_ctx);
+		goto error_m2m_ctx;
+	}
+	ctx->fh.m2m_ctx = ctx->m2m_ctx;
+	if (mdp->ctx_num++ == 0) {
+		ret = vpu_load_firmware(mdp->vpu_dev);
+		if (ret < 0) {
+			dev_err(&mdp->pdev->dev,
+				"vpu_load_firmware failed %d\n", ret);
+			goto err_load_vpu;
+		}
+
+		ret = mtk_mdp_vpu_register(mdp->pdev);
+		if (ret < 0) {
+			dev_err(&mdp->pdev->dev,
+				"mdp_vpu register failed %d\n", ret);
+			goto err_load_vpu;
+		}
+	}
+
+	list_add(&ctx->list, &mdp->ctx_list);
+	mutex_unlock(&mdp->lock);
+
+	mtk_mdp_dbg(0, "%s [%d]", dev_name(&mdp->pdev->dev), ctx->id);
+
+	return 0;
+
+err_load_vpu:
+	mdp->ctx_num--;
+	v4l2_m2m_ctx_release(ctx->m2m_ctx);
+error_m2m_ctx:
+	v4l2_ctrl_handler_free(&ctx->ctrl_handler);
+error_ctrls:
+	v4l2_fh_del(&ctx->fh);
+	v4l2_fh_exit(&ctx->fh);
+err_ctx_alloc:
+	kfree(ctx);
+	mutex_unlock(&mdp->lock);
+
+	return ret;
+}

<snip>