drm: omapdrm: displays: Get panel source at connect time

The connector drivers need a handle to the source they are connected to
in order to control the source.

All drivers get that handle at probe time, resulting in probe deferral
when the source hasn't been probed yet. However they don't need the
handle until their connect handler is called.

Move retrieval of the source handle to the connect handler to avoid
probe deferrals.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

drivers/gpu/drm/omapdrm/displays/panel-tpo-td028ttec1.c

@@ -169,16 +169,25 @@ enum jbt_register {
 static int td028ttec1_panel_connect(struct omap_dss_device *dssdev)
 {
 	struct panel_drv_data *ddata = to_panel_data(dssdev);
-	struct omap_dss_device *in = ddata->in;
+	struct omap_dss_device *in;
 	int r;
 
 	if (omapdss_device_is_connected(dssdev))
 		return 0;
 
-	r = in->ops.dpi->connect(in, dssdev);
-	if (r)
-		return r;
+	in = omapdss_of_find_source_for_first_ep(dssdev->dev->of_node);
+	if (IS_ERR(in)) {
+		dev_err(dssdev->dev, "failed to find video source\n");
+		return PTR_ERR(in);
+	}
 
+	r = in->ops.dpi->connect(in, dssdev);
+	if (r) {
+		omap_dss_put_device(in);
+		return r;
+	}
+
+	ddata->in = in;
 	return 0;
 }
 
@@ -191,6 +200,9 @@ static void td028ttec1_panel_disconnect(struct omap_dss_device *dssdev)
 		return;
 
 	in->ops.dpi->disconnect(in, dssdev);
+
+	omap_dss_put_device(in);
+	ddata->in = NULL;
 }
 
 static int td028ttec1_panel_enable(struct omap_dss_device *dssdev)
@@ -362,23 +374,6 @@ static struct omap_dss_driver td028ttec1_ops = {
 	.check_timings	= td028ttec1_panel_check_timings,
 };
 
-static int td028ttec1_probe_of(struct spi_device *spi)
-{
-	struct device_node *node = spi->dev.of_node;
-	struct panel_drv_data *ddata = dev_get_drvdata(&spi->dev);
-	struct omap_dss_device *in;
-
-	in = omapdss_of_find_source_for_first_ep(node);
-	if (IS_ERR(in)) {
-		dev_err(&spi->dev, "failed to find video source\n");
-		return PTR_ERR(in);
-	}
-
-	ddata->in = in;
-
-	return 0;
-}
-
 static int td028ttec1_panel_probe(struct spi_device *spi)
 {
 	struct panel_drv_data *ddata;
@@ -404,10 +399,6 @@ static int td028ttec1_panel_probe(struct spi_device *spi)
 
 	ddata->spi_dev = spi;
 
-	r = td028ttec1_probe_of(spi);
-	if (r)
-		return r;
-
 	ddata->vm = td028ttec1_panel_vm;
 
 	dssdev = &ddata->dssdev;
@@ -420,21 +411,16 @@ static int td028ttec1_panel_probe(struct spi_device *spi)
 	r = omapdss_register_display(dssdev);
 	if (r) {
 		dev_err(&spi->dev, "Failed to register panel\n");
-		goto err_reg;
+		return r;
 	}
 
 	return 0;
-
-err_reg:
-	omap_dss_put_device(ddata->in);
-	return r;
 }
 
 static int td028ttec1_panel_remove(struct spi_device *spi)
 {
 	struct panel_drv_data *ddata = dev_get_drvdata(&spi->dev);
 	struct omap_dss_device *dssdev = &ddata->dssdev;
-	struct omap_dss_device *in = ddata->in;
 
 	dev_dbg(&ddata->spi_dev->dev, "%s\n", __func__);
 
@@ -443,8 +429,6 @@ static int td028ttec1_panel_remove(struct spi_device *spi)
 	td028ttec1_panel_disable(dssdev);
 	td028ttec1_panel_disconnect(dssdev);
 
-	omap_dss_put_device(in);
-
 	return 0;
 }