Re: [PATCH 12/13] media: qcom: camss: Add sm8550 support

[Depeng Shao <quic_depengs@xxxxxxxxxxx>]

Hi Bryan,


On 7/10/2024 8:02 PM, Bryan O'Donoghue wrote:
> On 09/07/2024 17:06, Depeng Shao wrote:

> > diff --git a/drivers/media/platform/qcom/camss/camss-csid.c 
> > b/drivers/media/platform/qcom/camss/camss-csid.c
> > index 858db5d4ca75..90fba25db4c6 100644
> > --- a/drivers/media/platform/qcom/camss/camss-csid.c
> > +++ b/drivers/media/platform/qcom/camss/camss-csid.c
> > @@ -1013,6 +1013,7 @@ int msm_csid_subdev_init(struct camss *camss, 
> > struct csid_device *csid,
> >   {
> >       struct device *dev = camss->dev;
> >       struct platform_device *pdev = to_platform_device(dev);
> > +    struct resource *top_res;
> >       int i, j;
> >       int ret;
> > @@ -1040,6 +1041,26 @@ int msm_csid_subdev_init(struct camss *camss, 
> > struct csid_device *csid,
> >           else
> >               csid->base = 
> > csid->res->parent_dev_ops->get_base_address(camss, id)
> >                    + VFE_480_CSID_OFFSET;
> > +    } else if (camss->res->version == CAMSS_8550) {
> > +        /* for titan 780, CSID lite registers are inside the VFE lite 
> > region,
> > +         * between the VFE "top" and "bus" registers. this requires
> > +         * VFE to be initialized before CSID
> > +         */
> > +        if (csid_is_lite(csid))
> > +            csid->base =  
> > csid->res->parent_dev_ops->get_base_address(camss, id);
> > +        else {
> > +            csid->base = devm_platform_ioremap_resource_byname(pdev, 
> > res->reg[0]);
> > +            /* CSID "top" is a new function in Titan780.
> > +             * CSID can connect to VFE & SFE(Sensor Front End).
> > +             * This connection is ontrolled by CSID "top" registers.
> > +             * CSID "top" registers at only one region.
> > +             */
> > +            top_res = platform_get_resource_byname(pdev, 
> > IORESOURCE_MEM, res->reg[1]);
> > +            csid->top_base = ioremap(top_res->start, 
> > resource_size(top_res));
> > +        }
>
> If we just specify the csid lite regs in the dts, we don't need custom 
> code to get a pointer to them.

Yes, we can get the csid lite reg directly, will update this part.

> Similarly the csid->top_base = () should be generic not SoC specific, 
> i.e. we should be able to add in CSID 980 without adding any custom code 
> to camss-csid.c

csid lite doesn't have top reg block, but you are right, this can be 
generic, we can get csid->top_base if res->reg[1] isn't NULL.


> > diff --git a/drivers/media/platform/qcom/camss/camss-vfe.c 
> > b/drivers/media/platform/qcom/camss/camss-vfe.c
> > index 83c5a36d071f..479474c1cd95 100644
> > --- a/drivers/media/platform/qcom/camss/camss-vfe.c
> > +++ b/drivers/media/platform/qcom/camss/camss-vfe.c
> > @@ -338,6 +338,7 @@ static u32 vfe_src_pad_code(struct vfe_line *line, 
> > u32 sink_code,
> >       case CAMSS_845:
> >       case CAMSS_8250:
> >       case CAMSS_8280XP:
> > +    case CAMSS_8550:
> >           switch (sink_code) {
> >           case MEDIA_BUS_FMT_YUYV8_1X16:
> >           {
> > @@ -408,6 +409,10 @@ int vfe_reset(struct vfe_device *vfe)
> >       reinit_completion(&vfe->reset_complete);
> > +    /* The reset has been moved to csid in 8550 */
> > +    if (vfe->camss->res->version == CAMSS_8550)
> > +        return 0;
> > +
>
> Custom code for a specific SoC in camss.c camss-csid.c or camss-vfe.c 
> indicates to me we need to do more work elsewhere.
>
> This would do the same job for you.
>
> static void vfe_global_reset(struct vfe_device *vfe)
> {
>          /* VFE780 has no global reset, simply report a completion */
>          complete(&vfe->reset_complete);
> }
>
> const struct vfe_hw_ops vfe_ops_780 = {
>          .global_reset = vfe_global_reset,
>
> >       vfe->res->hw_ops->global_reset(vfe);
> >       time = wait_for_completion_timeout(&vfe->reset_complete

Sure, I will optimize this part.


Thanks,
Depeng