[PATCH v13 04/18] drm: exynos: dsi: Switch to DSI panel or bridge find helper

[Jagan Teki]

On Tue, Feb 28, 2023 at 12:38 AM Marek Vasut <marex at denx.de> wrote:
>
> On 2/27/23 20:01, Jagan Teki wrote:
> > On Tue, Feb 28, 2023 at 12:25 AM Marek Vasut <marex at denx.de> wrote:
> >>
> >> On 2/27/23 12:39, Jagan Teki wrote:
> >>> drm_of_dsi_find_panel_or_bridge is capable of looking up the
> >>> downstream DSI bridge and panel and trying to add a panel bridge
> >>> if the panel is found.
> >>>
> >>> Replace explicit finding calls with drm_of_dsi_find_panel_or_bridge
> >>> followed with drmm_panel_bridge_add.
> >>>
> >>> Signed-off-by: Jagan Teki <jagan at amarulasolutions.com>
> >>> ---
> >>> Changes for v13, v12, v11:
> >>> - none
> >>> Changes for v10:
> >>> - new patch
> >>>
> >>>    drivers/gpu/drm/exynos/exynos_drm_dsi.c | 25 +++++++++++++------------
> >>>    1 file changed, 13 insertions(+), 12 deletions(-)
> >>>
> >>> diff --git a/drivers/gpu/drm/exynos/exynos_drm_dsi.c b/drivers/gpu/drm/exynos/exynos_drm_dsi.c
> >>> index df15501b1075..12a6dd987e8f 100644
> >>> --- a/drivers/gpu/drm/exynos/exynos_drm_dsi.c
> >>> +++ b/drivers/gpu/drm/exynos/exynos_drm_dsi.c
> >>> @@ -25,6 +25,7 @@
> >>>    #include <drm/drm_atomic_helper.h>
> >>>    #include <drm/drm_bridge.h>
> >>>    #include <drm/drm_mipi_dsi.h>
> >>> +#include <drm/drm_of.h>
> >>>    #include <drm/drm_panel.h>
> >>>    #include <drm/drm_print.h>
> >>>    #include <drm/drm_probe_helper.h>
> >>> @@ -1470,24 +1471,26 @@ static int exynos_dsi_host_attach(struct mipi_dsi_host *host,
> >>>        struct device *dev = dsi->dev;
> >>>        struct drm_encoder *encoder = &dsi->encoder;
> >>>        struct drm_device *drm = encoder->dev;
> >>> +     struct drm_bridge *bridge;
> >>>        struct drm_panel *panel;
> >>>        int ret;
> >>>
> >>> -     panel = of_drm_find_panel(device->dev.of_node);
> >>> -     if (!IS_ERR(panel)) {
> >>> -             dsi->out_bridge = devm_drm_panel_bridge_add(dev, panel);
> >>> -     } else {
> >>> -             dsi->out_bridge = of_drm_find_bridge(device->dev.of_node);
> >>> -             if (!dsi->out_bridge)
> >>> -                     dsi->out_bridge = ERR_PTR(-EINVAL);
> >>> -     }
> >>
> >> As far as I understand this from my conversation with Maxime (please put
> >> him on CC of V15), the change here should instead perform the panel look
> >> up NOT in exynos_dsi_host_attach() , but in exynos_dsi_bind() , i.e. in
> >> the component_ops .bind callback . Here is an example of correct
> >> implementation:
> >>
> >> https://cgit.freedesktop.org/drm-misc/tree/drivers/gpu/drm/vc4/vc4_dsi.c#n1805
> >
> > But, we don't have component_ops.bind for imx8m case, so where do we
> > want to place the panel hook?
> >
> > Exynos drm drivers are component-based but, imx8mm is not.
>
> In 14/18 patch, the same should be added to generic_dsim_register_host()
> , which is called from the driver .probe() callback, but that is OK.
>
> That's ^ is the iMX part.

Ohh. You mean, we need to find the panel hook separately in two places like
- bind for exynos
- probe for imx8mm

If so? how can I find the drm_device pointer in the probe?

Jagan.