[PATCH v2 1/4] gpu: drm: replace of_graph_get_next_endpoint()

[Kuninori Morimoto]

>From DT point of view, in general, drivers should be asking for a
specific port number because their function is fixed in the binding.

of_graph_get_next_endpoint() doesn't match to this concept.

Simply replace

        - of_graph_get_next_endpoint(xxx, NULL);
        + of_graph_get_endpoint_by_regs(xxx, 0, -1);

Link: https://lore.kernel.org/r/20240202174941.ga310089-r...@kernel.org
Signed-off-by: Kuninori Morimoto <kuninori.morimoto...@renesas.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart+rene...@ideasonboard.com>
---
 drivers/gpu/drm/drm_of.c                              | 4 +++-
 drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c | 2 +-
 drivers/gpu/drm/tiny/arcpgu.c                         | 2 +-
 3 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/drm_of.c b/drivers/gpu/drm/drm_of.c
index 177b600895d3..b6b2cade69ae 100644
--- a/drivers/gpu/drm/drm_of.c
+++ b/drivers/gpu/drm/drm_of.c
@@ -504,6 +504,8 @@ EXPORT_SYMBOL_GPL(drm_of_get_data_lanes_count_ep);
  * Gets parent DSI bus for a DSI device controlled through a bus other
  * than MIPI-DCS (SPI, I2C, etc.) using the Device Tree.
  *
+ * This function assumes that the device's port@0 is the DSI input.
+ *
  * Returns pointer to mipi_dsi_host if successful, -EINVAL if the
  * request is unsupported, -EPROBE_DEFER if the DSI host is found but
  * not available, or -ENODEV otherwise.
@@ -516,7 +518,7 @@ struct mipi_dsi_host *drm_of_get_dsi_bus(struct device *dev)
        /*
         * Get first endpoint child from device.
         */
-       endpoint = of_graph_get_next_endpoint(dev->of_node, NULL);
+       endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, -1);
        if (!endpoint)
                return ERR_PTR(-ENODEV);
 
diff --git a/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c 
b/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c
index 4618c892cdd6..e10e469aa7a6 100644
--- a/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c
+++ b/drivers/gpu/drm/panel/panel-raspberrypi-touchscreen.c
@@ -400,7 +400,7 @@ static int rpi_touchscreen_probe(struct i2c_client *i2c)
        rpi_touchscreen_i2c_write(ts, REG_POWERON, 0);
 
        /* Look up the DSI host.  It needs to probe before we do. */
-       endpoint = of_graph_get_next_endpoint(dev->of_node, NULL);
+       endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, -1);
        if (!endpoint)
                return -ENODEV;
 
diff --git a/drivers/gpu/drm/tiny/arcpgu.c b/drivers/gpu/drm/tiny/arcpgu.c
index 4f8f3172379e..8c29b719ea62 100644
--- a/drivers/gpu/drm/tiny/arcpgu.c
+++ b/drivers/gpu/drm/tiny/arcpgu.c
@@ -288,7 +288,7 @@ static int arcpgu_load(struct arcpgu_drm_private *arcpgu)
         * There is only one output port inside each device. It is linked with
         * encoder endpoint.
         */
-       endpoint_node = of_graph_get_next_endpoint(pdev->dev.of_node, NULL);
+       endpoint_node = of_graph_get_endpoint_by_regs(pdev->dev.of_node, 0, -1);
        if (endpoint_node) {
                encoder_node = of_graph_get_remote_port_parent(endpoint_node);
                of_node_put(endpoint_node);
-- 
2.25.1