Hi Jai
On Thu, Jun 27, 2024 at 06:40:04PM GMT, Jai Luthra wrote:
> Use get_frame_desc() to get the frame desc from the connected source,
> and use the provided virtual channel instead of hardcoded one.
>
> 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.
>
> Co-developed-by: Pratyush Yadav <p.yadav@xxxxxx>
> Signed-off-by: Pratyush Yadav <p.yadav@xxxxxx>
> Signed-off-by: Jai Luthra <j-luthra@xxxxxx>
> ---
> .../media/platform/ti/j721e-csi2rx/j721e-csi2rx.c | 39 ++++++++++++++++++++++
> 1 file changed, 39 insertions(+)
>
> diff --git a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
> index b4b4bb69c88a..c0916ca1a6f8 100644
> --- a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
> +++ b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c
> @@ -29,6 +29,7 @@
> #define SHIM_DMACNTX_EN BIT(31)
> #define SHIM_DMACNTX_YUV422 GENMASK(27, 26)
> #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
> @@ -105,6 +106,8 @@ struct ti_csi2rx_ctx {
> struct media_pad pad;
> u32 sequence;
> u32 idx;
> + u32 vc;
> + u32 stream;
> };
>
> struct ti_csi2rx_dev {
> @@ -571,6 +574,7 @@ 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));
>
> @@ -844,6 +848,33 @@ static void ti_csi2rx_buffer_queue(struct vb2_buffer *vb)
> }
> }
>
> +static int ti_csi2rx_get_vc(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;
Would it be better to fail at bound() time if the remote subdev
doesn't support get_frame_desc ? you can use
if (!v4l2_subdev_has_op(subdev, pad, get_frame_desc)) {
> +
> + if (fd.type != V4L2_MBUS_FRAME_DESC_TYPE_CSI2)
> + return -EINVAL;
> +
> + for (i = 0; i < fd.num_entries; i++) {
for (unsigned int i
should num_entries be validated ?
> + if (ctx->stream == fd.entry[i].stream)
> + return fd.entry[i].bus.csi2.vc;
> + }
> +
> + return -ENODEV;
> +}
> +
> static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
> {
> struct ti_csi2rx_ctx *ctx = vb2_get_drv_priv(vq);
> @@ -864,6 +895,14 @@ static int ti_csi2rx_start_streaming(struct vb2_queue *vq, unsigned int count)
> if (ret)
> goto err;
>
> + ret = ti_csi2rx_get_vc(ctx);
> + if (ret == -ENOIOCTLCMD)
> + ctx->vc = 0;
Ah, so you fallback to 0 in case the subdev doesn't support
get_frame_desc. I'm not sure what would be better here maybe wait for
other's opinions as well.
Personally I would fail earlier to make sure subdev drivers are forced
to impement get_frame_desc
> + else if (ret < 0)
> + goto err;
> + else
> + ctx->vc = ret;
> +
> ti_csi2rx_setup_shim(ctx);
>
> ctx->sequence = 0;
>
> --
> 2.43.0
>
>
