Re: [PATCH v10 10/18] media: ti: j721e-csi2rx: add support for processing virtual channels

[Rishikesh Donadkar]

On 23/01/26 14:20, Tomi Valkeinen wrote:
> Hi,

Hi Tomi,

Thank you for the review !

> On 21/01/2026 15:54, Rishikesh Donadkar wrote:
> > From: Jai Luthra <j-luthra@xxxxxx>
> >
> > Use get_frame_desc() to get the frame desc from the connected source,
> > and use the provided virtual channel instead of VC 0.
> Not only VC, but also DT is handled here.


Thanks for pointing out, will update the commit message !

Rishikesh

> > 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.
> >
> > Reviewed-by: Yemike Abhilash Chandra <y-abhilashchandra@xxxxxx>
> > Co-developed-by: Pratyush Yadav <p.yadav@xxxxxx>
> > Signed-off-by: Pratyush Yadav <p.yadav@xxxxxx>
> > Signed-off-by: Jai Luthra <j-luthra@xxxxxx>
> > Signed-off-by: Rishikesh Donadkar <r-donadkar@xxxxxx>
> > ---
> >   .../platform/ti/j721e-csi2rx/j721e-csi2rx.c   | 50 ++++++++++++++++++-
> >   1 file changed, 49 insertions(+), 1 deletion(-)
> Reviewed-by: Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx>
>
>   Tomi
>
> > diff --git a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
> > index aa038d1badc07..81c86e2cc4a50 100644
> > --- a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
> > +++ b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
> > @@ -32,6 +32,7 @@
> >   #define SHIM_DMACNTX_YUV422		GENMASK(27, 26)
> >   #define SHIM_DMACNTX_DUAL_PCK_CFG	BIT(24)
> >   #define SHIM_DMACNTX_SIZE		GENMASK(21, 20)
> > +#define SHIM_DMACNTX_VC			GENMASK(9, 6)
> >   #define SHIM_DMACNTX_FMT		GENMASK(5, 0)
> >   #define SHIM_DMACNTX_YUV422_MODE_11	3
> >   #define SHIM_DMACNTX_SIZE_8		0
> > @@ -110,6 +111,9 @@ struct ti_csi2rx_ctx {
> >   	struct media_pad		pad;
> >   	u32				sequence;
> >   	u32				idx;
> > +	u32				vc;
> > +	u32				dt;
> > +	u32				stream;
> >   };
> >   
> >   struct ti_csi2rx_dev {
> > @@ -569,7 +573,7 @@ static void ti_csi2rx_setup_shim(struct ti_csi2rx_ctx *ctx)
> >   	ti_csi2rx_request_max_ppc(csi);
> >   
> >   	reg = SHIM_DMACNTX_EN;
> > -	reg |= FIELD_PREP(SHIM_DMACNTX_FMT, fmt->csi_dt);
> > +	reg |= FIELD_PREP(SHIM_DMACNTX_FMT, ctx->dt);
> >   
> >   	/*
> >   	 * The hardware assumes incoming YUV422 8-bit data on MIPI CSI2 bus
> > @@ -609,6 +613,7 @@ static void ti_csi2rx_setup_shim(struct ti_csi2rx_ctx *ctx)
> >   	}
> >   
> >   	reg |= FIELD_PREP(SHIM_DMACNTX_SIZE, fmt->size);
> > +	reg |= FIELD_PREP(SHIM_DMACNTX_VC, ctx->vc);
> >   
> >   	writel(reg, csi->shim + SHIM_DMACNTX(ctx->idx));
> >   
> > @@ -883,12 +888,46 @@ static void ti_csi2rx_buffer_queue(struct vb2_buffer *vb)
> >   	}
> >   }
> >   
> > +static int ti_csi2rx_get_vc_and_dt(struct ti_csi2rx_ctx *ctx)
> > +{
> > +	struct ti_csi2rx_dev *csi = ctx->csi;
> > +	struct v4l2_mbus_frame_desc fd;
> > +	struct media_pad *pad;
> > +	int ret, i;
> > +
> > +	pad = media_entity_remote_pad_unique(&csi->subdev.entity, MEDIA_PAD_FL_SOURCE);
> > +	if (!pad)
> > +		return -ENODEV;
> > +
> > +	ret = v4l2_subdev_call(csi->source, pad, get_frame_desc, pad->index, &fd);
> > +	if (ret)
> > +		return ret;
> > +
> > +	if (fd.type != V4L2_MBUS_FRAME_DESC_TYPE_CSI2)
> > +		return -EINVAL;
> > +
> > +	for (i = 0; i < fd.num_entries; i++) {
> > +		if (ctx->stream == fd.entry[i].stream) {
> > +			ctx->vc = fd.entry[i].bus.csi2.vc;
> > +			ctx->dt = fd.entry[i].bus.csi2.dt;
> > +			break;
> > +		}
> > +
> > +		/* Return error if no matching stream found */
> > +		if (i == fd.num_entries)
> > +			return -EINVAL;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> >   static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
> >   {
> >   	struct ti_csi2rx_ctx *ctx = vb2_get_drv_priv(vq);
> >   	struct ti_csi2rx_dev *csi = ctx->csi;
> >   	struct ti_csi2rx_dma *dma = &ctx->dma;
> >   	struct ti_csi2rx_buffer *buf;
> > +	const struct ti_csi2rx_fmt *fmt;
> >   	unsigned long flags;
> >   	int ret = 0;
> >   
> > @@ -903,6 +942,15 @@ static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
> >   	if (ret)
> >   		goto err;
> >   
> > +	ret = ti_csi2rx_get_vc_and_dt(ctx);
> > +	if (ret == -ENOIOCTLCMD) {
> > +		ctx->vc = 0;
> > +		fmt = find_format_by_fourcc(ctx->v_fmt.fmt.pix.pixelformat);
> > +		ctx->dt = fmt->csi_dt;
> > +	} else if (ret < 0) {
> > +		goto err;
> > +	}
> > +
> >   	ti_csi2rx_setup_shim(ctx);
> >   
> >   	ctx->sequence = 0;