Re: [PATCH v3 37/38] media: ti-vpe: cal: use frame desc to get vc and dt

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Tomi,

Thank you for the patch.

On Mon, May 24, 2021 at 02:09:08PM +0300, Tomi Valkeinen wrote:
> Use get_frame_desc() to get the frame desc from the connected source,
> and use the provided virtual channel and datatype instead of hardcoded
> ones.
> 
> get_frame_desc() works per stream, but as we don't support multiple
> streams yet, we will just always use stream 0.
> 
> If the source doesn't support get_frame_desc(), fall back to the
> previous method of always capturing virtual channel 0 and any datatype.
> 
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
> ---
>  drivers/media/platform/ti-vpe/cal-camerarx.c | 26 +++++++++++
>  drivers/media/platform/ti-vpe/cal.c          | 49 +++++++++++++++++++-
>  drivers/media/platform/ti-vpe/cal.h          |  3 ++
>  3 files changed, 76 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/platform/ti-vpe/cal-camerarx.c b/drivers/media/platform/ti-vpe/cal-camerarx.c
> index e3a4c20be1e6..cb6a37f47432 100644
> --- a/drivers/media/platform/ti-vpe/cal-camerarx.c
> +++ b/drivers/media/platform/ti-vpe/cal-camerarx.c
> @@ -583,6 +583,32 @@ static int cal_camerarx_parse_dt(struct cal_camerarx *phy)
>  	return ret;
>  }
>  
> +int cal_camerarx_get_remote_frame_desc(struct cal_camerarx *phy,
> +				       struct v4l2_mbus_frame_desc *fd)

Maybe s/fd/desc/ to avoid the confusion with file descriptor ?

> +{
> +	struct media_pad *pad;
> +	int ret;
> +
> +	if (!phy->source)
> +		return -ENODEV;

Would EPIPE (here and below) be a better error ? It will be returned to
userspace from VIDIOC_STREAMON(), which already uses EPIPE to indicate
that the links are not correctly set up.

> +
> +	pad = media_entity_remote_pad(&phy->pads[CAL_CAMERARX_PAD_SINK]);
> +	if (!pad)
> +		return -ENODEV;
> +
> +	ret = v4l2_subdev_call(phy->source, pad, get_frame_desc, pad->index,
> +			       fd);
> +	if (ret)
> +		return ret;
> +
> +	if (fd->type != V4L2_MBUS_FRAME_DESC_TYPE_CSI2) {
> +		dev_err(phy->cal->dev, "Frame desc do not describe CSI-2 link");

s/do not/does not/ and maybe s/desc/descriptor/

> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
>  /* ------------------------------------------------------------------
>   *	V4L2 Subdev Operations
>   * ------------------------------------------------------------------
> diff --git a/drivers/media/platform/ti-vpe/cal.c b/drivers/media/platform/ti-vpe/cal.c
> index fcc81024ae18..7975bb449acd 100644
> --- a/drivers/media/platform/ti-vpe/cal.c
> +++ b/drivers/media/platform/ti-vpe/cal.c
> @@ -469,10 +469,56 @@ static bool cal_ctx_wr_dma_stopped(struct cal_ctx *ctx)
>  	return stopped;
>  }
>  
> +static int
> +cal_get_remote_frame_desc_entry(struct cal_camerarx *phy, u32 stream,
> +				struct v4l2_mbus_frame_desc_entry *entry)
> +{
> +	struct v4l2_mbus_frame_desc fd;
> +	unsigned int i;
> +	int ret;
> +
> +	ret = cal_camerarx_get_remote_frame_desc(phy, &fd);
> +	if (ret) {
> +		if (ret != -ENOIOCTLCMD)
> +			dev_err(phy->cal->dev,
> +				"Failed to get remote frame desc: %d\n", ret);
> +		return ret;
> +	}
> +
> +	for (i = 0; i < fd.num_entries; i++) {
> +		if (stream == fd.entry[i].stream) {
> +			*entry = fd.entry[i];
> +			return 0;
> +		}
> +	}
> +

A dev_dbg() would be good here, in which case you could drop the
ctx_err() in cal_ctx_prepare() as all error paths will print a message.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> +	return -ENODEV;
> +}
> +
>  int cal_ctx_prepare(struct cal_ctx *ctx)
>  {
> +	struct v4l2_mbus_frame_desc_entry entry;
>  	int ret;
>  
> +	ret = cal_get_remote_frame_desc_entry(ctx->phy, ctx->stream, &entry);
> +
> +	if (ret == -ENOIOCTLCMD) {
> +		ctx->vc = 0;
> +		ctx->datatype = CAL_CSI2_CTX_DT_ANY;
> +	} else if (!ret) {
> +		ctx_dbg(2, ctx, "Framedesc: stream %u, len %u, vc %u, dt %#x\n",
> +		       entry.stream,
> +		       entry.length,
> +		       entry.bus.csi2.vc,
> +		       entry.bus.csi2.dt);

You can group multiple variables on the same line.

> +
> +		ctx->vc = entry.bus.csi2.vc;
> +		ctx->datatype = entry.bus.csi2.dt;
> +	} else {
> +		ctx_err(ctx, "Failed to get remote frame desc: %d\n", ret);
> +		return ret;
> +	}
> +
>  	ctx->use_pix_proc = !ctx->fmtinfo->meta;
>  
>  	if (ctx->use_pix_proc) {
> @@ -925,8 +971,7 @@ static struct cal_ctx *cal_ctx_create(struct cal_dev *cal, int inst)
>  	ctx->dma_ctx = inst;
>  	ctx->csi2_ctx = inst;
>  	ctx->cport = inst;
> -	ctx->vc = 0;
> -	ctx->datatype = CAL_CSI2_CTX_DT_ANY;
> +	ctx->stream = 0;
>  
>  	ret = cal_ctx_v4l2_init(ctx);
>  	if (ret)
> diff --git a/drivers/media/platform/ti-vpe/cal.h b/drivers/media/platform/ti-vpe/cal.h
> index 29b865d1a238..3aea444f8bf8 100644
> --- a/drivers/media/platform/ti-vpe/cal.h
> +++ b/drivers/media/platform/ti-vpe/cal.h
> @@ -245,6 +245,7 @@ struct cal_ctx {
>  	u8			pix_proc;
>  	u8			vc;
>  	u8			datatype;
> +	u32			stream;
>  
>  	bool			use_pix_proc;
>  };
> @@ -318,6 +319,8 @@ const struct cal_format_info *cal_format_by_code(u32 code);
>  
>  void cal_quickdump_regs(struct cal_dev *cal);
>  
> +int cal_camerarx_get_remote_frame_desc(struct cal_camerarx *phy,
> +				       struct v4l2_mbus_frame_desc *fd);
>  void cal_camerarx_disable(struct cal_camerarx *phy);
>  void cal_camerarx_i913_errata(struct cal_camerarx *phy);
>  struct cal_camerarx *cal_camerarx_create(struct cal_dev *cal,

-- 
Regards,

Laurent Pinchart