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path: root/drivers/gpu/drm/sun4i
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Diffstat (limited to 'drivers/gpu/drm/sun4i')
-rw-r--r--drivers/gpu/drm/sun4i/sun4i_tcon.c22
1 files changed, 18 insertions, 4 deletions
diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
index 08747fc3ee71..264bcc43da11 100644
--- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
+++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
@@ -791,12 +791,14 @@ static int sun4i_tcon_init_regmap(struct device *dev,
*/
static struct sunxi_engine *
sun4i_tcon_find_engine_traverse(struct sun4i_drv *drv,
- struct device_node *node)
+ struct device_node *node,
+ u32 port_id)
{
struct device_node *port, *ep, *remote;
struct sunxi_engine *engine = ERR_PTR(-EINVAL);
+ u32 reg = 0;
- port = of_graph_get_port_by_id(node, 0);
+ port = of_graph_get_port_by_id(node, port_id);
if (!port)
return ERR_PTR(-EINVAL);
@@ -826,8 +828,20 @@ sun4i_tcon_find_engine_traverse(struct sun4i_drv *drv,
if (remote == engine->node)
goto out_put_remote;
+ /*
+ * According to device tree binding input ports have even id
+ * number and output ports have odd id. Since component with
+ * more than one input and one output (TCON TOP) exits, correct
+ * remote input id has to be calculated by subtracting 1 from
+ * remote output id. If this for some reason can't be done, 0
+ * is used as input port id.
+ */
+ port = of_graph_get_remote_port(ep);
+ if (!of_property_read_u32(port, "reg", &reg) && reg > 0)
+ reg -= 1;
+
/* keep looking through upstream ports */
- engine = sun4i_tcon_find_engine_traverse(drv, remote);
+ engine = sun4i_tcon_find_engine_traverse(drv, remote, reg);
out_put_remote:
of_node_put(remote);
@@ -950,7 +964,7 @@ static struct sunxi_engine *sun4i_tcon_find_engine(struct sun4i_drv *drv,
/* Fallback to old method by traversing input endpoints */
of_node_put(port);
- return sun4i_tcon_find_engine_traverse(drv, node);
+ return sun4i_tcon_find_engine_traverse(drv, node, 0);
}
static int sun4i_tcon_bind(struct device *dev, struct device *master,