Re: [PATCH v3 2/4] drm/msm/dpu: support binding to the mdp5 devices

[Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>]

On 2/7/2024 11:56 AM, Dmitry Baryshkov wrote:
> On Wed, 7 Feb 2024 at 20:48, Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx> wrote:
> > On 1/5/2024 3:34 PM, Dmitry Baryshkov wrote:
> > > Existing MDP5 devices have slightly different bindings. The main
> > > register region is called `mdp_phys' instead of `mdp'. Also vbif
> > > register regions are a part of the parent, MDSS device. Add support for
> > > handling this binding differences.
> > >
> > > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
> > > ---
> > >    drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c | 98 ++++++++++++++++++++++++++-------
> > >    drivers/gpu/drm/msm/msm_drv.h           |  3 +
> > >    drivers/gpu/drm/msm/msm_io_utils.c      | 13 +++++
> > >    3 files changed, 93 insertions(+), 21 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
> > > index 723cc1d82143..aa9e0ad33ebb 100644
> > > --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
> > > +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
> > > @@ -1197,6 +1197,78 @@ static int dpu_kms_init(struct drm_device *ddev)
> > >        return 0;
> > >    }
> > >
> > > +static int dpu_kms_mmap_mdp5(struct dpu_kms *dpu_kms)
> > > +{
> > > +     struct platform_device *pdev = dpu_kms->pdev;
> > > +     struct platform_device *mdss_dev;
> > > +     int ret;
> > > +
> > > +     if (dpu_kms->pdev->dev.bus != &platform_bus_type)
> > > +             return -EINVAL;
> > > +
> >
> > !dev_is_platform() perhaps?
>
> looks good
>
> > But I would like to understand this check a bit more. Can you pls
> > explain for which case this check was added?
>
> It is necessary to be sure that we can perform to_platform_device() on
> the next line.

Got it but on the next line we are using to_platform_device on dpu's 
parent device. So shouldnt the check also be dpu_kms->pdev->dev.parent.bus?

> > > +     mdss_dev = to_platform_device(dpu_kms->pdev->dev.parent);
> > > +
> > > +     dpu_kms->mmio = msm_ioremap(pdev, "mdp_phys");
> > > +     if (IS_ERR(dpu_kms->mmio)) {
> > > +             ret = PTR_ERR(dpu_kms->mmio);
> > > +             DPU_ERROR("mdp register memory map failed: %d\n", ret);
> > > +             dpu_kms->mmio = NULL;
> > > +             return ret;
> > > +     }
> > > +     DRM_DEBUG("mapped dpu address space @%pK\n", dpu_kms->mmio);
> > > +
> > > +     dpu_kms->vbif[VBIF_RT] = msm_ioremap_mdss(mdss_dev,
> > > +                                               dpu_kms->pdev,
> > > +                                               "vbif_phys");
> > > +     if (IS_ERR(dpu_kms->vbif[VBIF_RT])) {
> > > +             ret = PTR_ERR(dpu_kms->vbif[VBIF_RT]);
> > > +             DPU_ERROR("vbif register memory map failed: %d\n", ret);
> > > +             dpu_kms->vbif[VBIF_RT] = NULL;
> > > +             return ret;
> > > +     }
> > > +
> > > +     dpu_kms->vbif[VBIF_NRT] = msm_ioremap_mdss(mdss_dev,
> > > +                                                dpu_kms->pdev,
> > > +                                                "vbif_nrt_phys");
> >
> > Do you think a "quiet" version would be better?
>
> Yep, why not.
>
> > > +     if (IS_ERR(dpu_kms->vbif[VBIF_NRT])) {
> > > +             dpu_kms->vbif[VBIF_NRT] = NULL;
> > > +             DPU_DEBUG("VBIF NRT is not defined");
> > > +     }
> > > +
> > > +     return 0;
> > > +}
> > > +
> > > +static int dpu_kms_mmap_dpu(struct dpu_kms *dpu_kms)
> > > +{
> > > +     struct platform_device *pdev = dpu_kms->pdev;
> > > +     int ret;
> > > +
> > > +     dpu_kms->mmio = msm_ioremap(pdev, "mdp");
> > > +     if (IS_ERR(dpu_kms->mmio)) {
> > > +             ret = PTR_ERR(dpu_kms->mmio);
> > > +             DPU_ERROR("mdp register memory map failed: %d\n", ret);
> > > +             dpu_kms->mmio = NULL;
> > > +             return ret;
> > > +     }
> > > +     DRM_DEBUG("mapped dpu address space @%pK\n", dpu_kms->mmio);
> > > +
> > > +     dpu_kms->vbif[VBIF_RT] = msm_ioremap(pdev, "vbif");
> > > +     if (IS_ERR(dpu_kms->vbif[VBIF_RT])) {
> > > +             ret = PTR_ERR(dpu_kms->vbif[VBIF_RT]);
> > > +             DPU_ERROR("vbif register memory map failed: %d\n", ret);
> > > +             dpu_kms->vbif[VBIF_RT] = NULL;
> > > +             return ret;
> > > +     }
> > > +
> > > +     dpu_kms->vbif[VBIF_NRT] = msm_ioremap_quiet(pdev, "vbif_nrt");
> > > +     if (IS_ERR(dpu_kms->vbif[VBIF_NRT])) {
> > > +             dpu_kms->vbif[VBIF_NRT] = NULL;
> > > +             DPU_DEBUG("VBIF NRT is not defined");
> > > +     }
> > > +
> > > +     return 0;
> > > +}
> > > +
> > >    static int dpu_dev_probe(struct platform_device *pdev)
> > >    {
> > >        struct device *dev = &pdev->dev;
> > > @@ -1230,28 +1302,12 @@ static int dpu_dev_probe(struct platform_device *pdev)
> > >
> > >        dpu_kms->base.irq = irq;
> > >
> > > -     dpu_kms->mmio = msm_ioremap(pdev, "mdp");
> > > -     if (IS_ERR(dpu_kms->mmio)) {
> > > -             ret = PTR_ERR(dpu_kms->mmio);
> > > -             DPU_ERROR("mdp register memory map failed: %d\n", ret);
> > > -             dpu_kms->mmio = NULL;
> > > -             return ret;
> > > -     }
> > > -     DRM_DEBUG("mapped dpu address space @%pK\n", dpu_kms->mmio);
> > > -
> > > -     dpu_kms->vbif[VBIF_RT] = msm_ioremap(pdev, "vbif");
> > > -     if (IS_ERR(dpu_kms->vbif[VBIF_RT])) {
> > > -             ret = PTR_ERR(dpu_kms->vbif[VBIF_RT]);
> > > -             DPU_ERROR("vbif register memory map failed: %d\n", ret);
> > > -             dpu_kms->vbif[VBIF_RT] = NULL;
> > > +     if (of_device_is_compatible(dpu_kms->pdev->dev.of_node, "qcom,mdp5"))
> > > +             ret = dpu_kms_mmap_mdp5(dpu_kms);
> > > +     else
> > > +             ret = dpu_kms_mmap_dpu(dpu_kms);
> > > +     if (ret)
> > >                return ret;
> > > -     }
> > > -
> > > -     dpu_kms->vbif[VBIF_NRT] = msm_ioremap_quiet(pdev, "vbif_nrt");
> > > -     if (IS_ERR(dpu_kms->vbif[VBIF_NRT])) {
> > > -             dpu_kms->vbif[VBIF_NRT] = NULL;
> > > -             DPU_DEBUG("VBIF NRT is not defined");
> > > -     }
> > >
> > >        ret = dpu_kms_parse_data_bus_icc_path(dpu_kms);
> > >        if (ret)
> > > diff --git a/drivers/gpu/drm/msm/msm_drv.h b/drivers/gpu/drm/msm/msm_drv.h
> > > index 16a7cbc0b7dd..01e783130054 100644
> > > --- a/drivers/gpu/drm/msm/msm_drv.h
> > > +++ b/drivers/gpu/drm/msm/msm_drv.h
> > > @@ -476,6 +476,9 @@ void __iomem *msm_ioremap(struct platform_device *pdev, const char *name);
> > >    void __iomem *msm_ioremap_size(struct platform_device *pdev, const char *name,
> > >                phys_addr_t *size);
> > >    void __iomem *msm_ioremap_quiet(struct platform_device *pdev, const char *name);
> > > +void __iomem *msm_ioremap_mdss(struct platform_device *mdss_pdev,
> > > +                            struct platform_device *dev,
> > > +                            const char *name);
> > >
> > >    struct icc_path *msm_icc_get(struct device *dev, const char *name);
> > >
> > > diff --git a/drivers/gpu/drm/msm/msm_io_utils.c b/drivers/gpu/drm/msm/msm_io_utils.c
> > > index 59d2788c4510..afedd61c3e28 100644
> > > --- a/drivers/gpu/drm/msm/msm_io_utils.c
> > > +++ b/drivers/gpu/drm/msm/msm_io_utils.c
> > > @@ -50,6 +50,19 @@ struct clk *msm_clk_get(struct platform_device *pdev, const char *name)
> > >        return clk;
> > >    }
> > >
> > > +void __iomem *msm_ioremap_mdss(struct platform_device *mdss_pdev,
> > > +                            struct platform_device *pdev,
> > > +                            const char *name)
> > > +{
> > > +     struct resource *res;
> > > +
> > > +     res = platform_get_resource_byname(mdss_pdev, IORESOURCE_MEM, name);
> > > +     if (!res)
> > > +             return ERR_PTR(-EINVAL);
> > > +
> > > +     return devm_ioremap_resource(&pdev->dev, res);
> > > +}
> > > +
> > >    static void __iomem *_msm_ioremap(struct platform_device *pdev, const char *name,
> > >                                  bool quiet, phys_addr_t *psize)
> > >    {