Re: [PATCH v7 02/10] drm: bridge: samsung-dsim: Lookup OF-graph or Child node devices
On Sun, Oct 16, 2022 at 3:18 AM Marek Vasut wrote:
>
> On 10/5/22 17:13, Jagan Teki wrote:
> > The child devices in MIPI DSI can be binding with OF-graph
> > and also via child nodes.
> >
> > The OF-graph interface represents the child devices via
> > remote and associated endpoint numbers like
> >
> > dsi {
> > compatible = "fsl,imx8mm-mipi-dsim";
> >
> > ports {
> > port@0 {
> >reg = <0>;
> >
> >dsi_in_lcdif: endpoint@0 {
> > reg = <0>;
> > remote-endpoint = <&lcdif_out_dsi>;
> >};
> > };
> >
> > port@1 {
> >reg = <1>;
> >
> >dsi_out_bridge: endpoint {
> > remote-endpoint = <&bridge_in_dsi>;
> >};
> > };
> > };
> >
> > The child node interface represents the child devices via
> > conventional child nodes on given DSI parent like
> >
> > dsi {
> > compatible = "samsung,exynos5433-mipi-dsi";
> >
> > ports {
> > port@0 {
> > reg = <0>;
> >
> > dsi_to_mic: endpoint {
> >remote-endpoint = <&mic_to_dsi>;
> > };
> > };
> > };
> >
> > panel@0 {
> > reg = <0>;
> > };
> > };
> >
> > As Samsung DSIM bridge is common DSI IP across all Exynos DSI
> > and NXP i.MX8M host controllers, this patch adds support to
> > lookup the child devices whether its bindings on the associated
> > host represent OF-graph or child node interfaces.
>
> This looks like a good candidate for common/helper code which can be
> reused by other similar drivers.
Tried that but unfortunately, it cannot hold to handle things in a generic way.
80253168dbfd ("drm: of: Lookup if child node has panel or bridge")
Jagan.
Re: [PATCH v7 02/10] drm: bridge: samsung-dsim: Lookup OF-graph or Child node devices
On 10/5/22 17:13, Jagan Teki wrote:
The child devices in MIPI DSI can be binding with OF-graph
and also via child nodes.
The OF-graph interface represents the child devices via
remote and associated endpoint numbers like
dsi {
compatible = "fsl,imx8mm-mipi-dsim";
ports {
port@0 {
reg = <0>;
dsi_in_lcdif: endpoint@0 {
reg = <0>;
remote-endpoint = <&lcdif_out_dsi>;
};
};
port@1 {
reg = <1>;
dsi_out_bridge: endpoint {
remote-endpoint = <&bridge_in_dsi>;
};
};
};
The child node interface represents the child devices via
conventional child nodes on given DSI parent like
dsi {
compatible = "samsung,exynos5433-mipi-dsi";
ports {
port@0 {
reg = <0>;
dsi_to_mic: endpoint {
remote-endpoint = <&mic_to_dsi>;
};
};
};
panel@0 {
reg = <0>;
};
};
As Samsung DSIM bridge is common DSI IP across all Exynos DSI
and NXP i.MX8M host controllers, this patch adds support to
lookup the child devices whether its bindings on the associated
host represent OF-graph or child node interfaces.
This looks like a good candidate for common/helper code which can be
reused by other similar drivers.
[PATCH v7 02/10] drm: bridge: samsung-dsim: Lookup OF-graph or Child node devices
The child devices in MIPI DSI can be binding with OF-graph
and also via child nodes.
The OF-graph interface represents the child devices via
remote and associated endpoint numbers like
dsi {
compatible = "fsl,imx8mm-mipi-dsim";
ports {
port@0 {
reg = <0>;
dsi_in_lcdif: endpoint@0 {
reg = <0>;
remote-endpoint = <&lcdif_out_dsi>;
};
};
port@1 {
reg = <1>;
dsi_out_bridge: endpoint {
remote-endpoint = <&bridge_in_dsi>;
};
};
};
The child node interface represents the child devices via
conventional child nodes on given DSI parent like
dsi {
compatible = "samsung,exynos5433-mipi-dsi";
ports {
port@0 {
reg = <0>;
dsi_to_mic: endpoint {
remote-endpoint = <&mic_to_dsi>;
};
};
};
panel@0 {
reg = <0>;
};
};
As Samsung DSIM bridge is common DSI IP across all Exynos DSI
and NXP i.MX8M host controllers, this patch adds support to
lookup the child devices whether its bindings on the associated
host represent OF-graph or child node interfaces.
v7, v6, v5, v4, v3:
* none
v2:
* new patch
Signed-off-by: Jagan Teki
---
drivers/gpu/drm/bridge/samsung-dsim.c | 38 +--
1 file changed, 36 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c
b/drivers/gpu/drm/bridge/samsung-dsim.c
index 07563d00a420..c34c6abac815 100644
--- a/drivers/gpu/drm/bridge/samsung-dsim.c
+++ b/drivers/gpu/drm/bridge/samsung-dsim.c
@@ -1356,18 +1356,52 @@ static int samsung_dsim_host_attach(struct
mipi_dsi_host *host,
struct samsung_dsim *dsi = host_to_dsi(host);
const struct samsung_dsim_plat_data *pdata = dsi->plat_data;
struct device *dev = dsi->dev;
+ struct device_node *np = dev->of_node;
+ struct device_node *remote;
struct drm_panel *panel;
int ret;
- panel = of_drm_find_panel(device->dev.of_node);
+ /**
+* Devices can also be child nodes when we also control that device
+* through the upstream device (ie, MIPI-DCS for a MIPI-DSI device).
+*
+* Lookup for a child node of the given parent that isn't either port
+* or ports.
+*/
+ for_each_available_child_of_node(np, remote) {
+ if (of_node_name_eq(remote, "port") ||
+ of_node_name_eq(remote, "ports"))
+ continue;
+
+ goto of_find_panel_or_bridge;
+ }
+
+ /*
+* of_graph_get_remote_node() produces a noisy error message if port
+* node isn't found and the absence of the port is a legit case here,
+* so at first we silently check whether graph presents in the
+* device-tree node.
+*/
+ if (!of_graph_is_present(np))
+ return -ENODEV;
+
+ remote = of_graph_get_remote_node(np, 1, 0);
+
+of_find_panel_or_bridge:
+ if (!remote)
+ return -ENODEV;
+
+ panel = of_drm_find_panel(remote);
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);
+ dsi->out_bridge = of_drm_find_bridge(remote);
if (!dsi->out_bridge)
dsi->out_bridge = ERR_PTR(-EINVAL);
}
+ of_node_put(remote);
+
if (IS_ERR(dsi->out_bridge)) {
ret = PTR_ERR(dsi->out_bridge);
DRM_DEV_ERROR(dev, "failed to find the bridge: %d\n", ret);
--
2.25.1
