[Patch v2 4/6] drm/omap: Add virtual plane DT parsing support

[Benoit Parrot]

Virtual planes are used to extend display size capability for display
larger than 2048 pixels by splitting the frame buffer equally between
two physical video-pipelines.

Here we are adding DT support to parse 'plane' child nodes which
describe how logical planes are mapped to physical video-pipeline(s)
and which video-outputs they are available on.

Signed-off-by: Benoit Parrot <bparrot at ti.com>
---
 drivers/gpu/drm/omapdrm/dss/dispc.c   | 110 ++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/omapdrm/dss/omapdss.h |  11 ++++
 2 files changed, 121 insertions(+)

diff --git a/drivers/gpu/drm/omapdrm/dss/dispc.c b/drivers/gpu/drm/omapdrm/dss/dispc.c
index 35541d4441df..06a2e894175e 100644
--- a/drivers/gpu/drm/omapdrm/dss/dispc.c
+++ b/drivers/gpu/drm/omapdrm/dss/dispc.c
@@ -4360,6 +4360,115 @@ static u32 dispc_get_memory_bandwidth_limit(void)
 	return limit;
 }
 
+static struct device_node *dispc_of_get_plane_by_id(struct device_node *node,
+						    u32 id)
+{
+	struct device_node *plane;
+
+	for_each_child_of_node(node, plane) {
+		u32 plane_id = 0;
+
+		if (of_node_cmp(plane->name, "plane") != 0)
+			continue;
+		of_property_read_u32(plane, "reg", &plane_id);
+		if (id == plane_id)
+			return plane;
+	}
+
+	return NULL;
+}
+
+static int dispc_parse_dt_plane_data(struct dispc_plane_mappings *map)
+{
+	struct platform_device *pdev = dispc.pdev;
+	struct device_node *np = pdev->dev.of_node;
+	struct device_node *ep;
+	struct property *prop;
+	const __be32 *cur;
+	u32 v;
+	u32 num_ovls = dispc_get_num_ovls();
+	u32 hw_plane_mask = 0;
+	u32 num_planes;
+	int i, index;
+
+	if (!np)
+		return 0;
+
+	for (i = 0; i < num_ovls; i++) {
+		ep = dispc_of_get_plane_by_id(np, i);
+		if (!ep)
+			break;
+		if (!of_property_read_bool(ep, "video-pipelines")) {
+			dev_err(&pdev->dev,
+				"malformed plane node: video-pipelines missing.\n");
+			return -EINVAL;
+		}
+
+		index = 0;
+		of_property_for_each_u32(ep, "video-pipelines", prop, cur, v) {
+			if (v >= num_ovls) {
+				dev_err(&pdev->dev,
+					"video-pipelines property: '%d' out-of-range.\n",
+					v);
+				return -EINVAL;
+			}
+			if (hw_plane_mask & BIT_MASK(v)) {
+				dev_err(&pdev->dev,
+					"video-pipelines property: '%d' used more than once.\n",
+					v);
+				return -EINVAL;
+			}
+			hw_plane_mask |= BIT(v);
+
+			if (index == 0) {
+				map->plane[i].main_id = v;
+			} else if (index == 1) {
+				map->plane[i].aux_id = v;
+				map->plane[i].is_virtual = true;
+			} else if (index > 1) {
+				dev_err(&pdev->dev,
+					"video-pipelines property: more than 2 values specified.\n");
+				return -EINVAL;
+			}
+			index++;
+		}
+
+		of_property_for_each_u32(ep, "video-outputs", prop, cur, v) {
+			if (v >= dispc_get_num_mgrs()) {
+				dev_err(&pdev->dev,
+					"video-outputs property: '%d' out-of-range.\n",
+					v);
+				return -EINVAL;
+			}
+			map->plane[i].crtc_mask |= BIT(v);
+		}
+	}
+
+	num_planes = i;
+
+	if (num_planes) {
+		dev_dbg(&pdev->dev, "Plane definitions found from DT:");
+		for (i = 0; i < num_planes; i++) {
+			if (map->plane[i].is_virtual) {
+				dev_dbg(&pdev->dev,
+					"plane%d: virtual video-pipelines: %d, %d video-output mask: 0x%04x",
+					i, map->plane[i].main_id,
+					map->plane[i].aux_id,
+					map->plane[i].crtc_mask);
+			} else {
+				dev_dbg(&pdev->dev,
+					"plane%d: video-pipelines: %d video-output mask: 0x%04x",
+					i, map->plane[i].main_id,
+					map->plane[i].crtc_mask);
+			}
+		}
+	}
+
+	map->num_planes = num_planes;
+
+	return 0;
+}
+
 /*
  * Workaround for errata i734 in DSS dispc
  *  - LCD1 Gamma Correction Is Not Working When GFX Pipe Is Disabled
@@ -4552,6 +4661,7 @@ static const struct dispc_ops dispc_ops = {
 	.ovl_setup = dispc_ovl_setup,
 	.ovl_get_color_modes = dispc_ovl_get_color_modes,
 	.ovl_get_max_size = dispc_ovl_get_max_size,
+	.get_plane_mapping = dispc_parse_dt_plane_data,
 };
 
 /* DISPC HW IP initialisation */
diff --git a/drivers/gpu/drm/omapdrm/dss/omapdss.h b/drivers/gpu/drm/omapdrm/dss/omapdss.h
index c58c75292182..ad0f751ec047 100644
--- a/drivers/gpu/drm/omapdrm/dss/omapdss.h
+++ b/drivers/gpu/drm/omapdrm/dss/omapdss.h
@@ -637,6 +637,16 @@ void omapdss_set_is_initialized(bool set);
 struct device_node *dss_of_port_get_parent_device(struct device_node *port);
 u32 dss_of_port_get_port_number(struct device_node *port);
 
+struct dispc_plane_mappings {
+	struct {
+		u32 main_id;
+		u32 aux_id;
+		u32 crtc_mask;
+		bool is_virtual;
+	} plane[4];
+	u32 num_planes;
+};
+
 struct dss_mgr_ops {
 	int (*connect)(enum omap_channel channel,
 		struct omap_dss_device *dst);
@@ -720,6 +730,7 @@ struct dispc_ops {
 
 	const u32 *(*ovl_get_color_modes)(enum omap_plane_id plane);
 	void (*ovl_get_max_size)(u16 *width, u16 *height);
+	int (*get_plane_mapping)(struct dispc_plane_mappings *plane);
 };
 
 void dispc_set_ops(const struct dispc_ops *o);
-- 
2.9.0