Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / gpu / drm / drm_of.c

diff --git a/kernel/drivers/gpu/drm/drm_of.c b/kernel/drivers/gpu/drm/drm_of.c
new file mode 100644 (file)
index 0000000..aaa1307
--- /dev/null
+++ b/kernel/drivers/gpu/drm/drm_of.c
@@ -0,0 +1,63 @@
+#include <linux/export.h>
+#include <linux/list.h>
+#include <linux/of_graph.h>
+#include <drm/drmP.h>
+#include <drm/drm_crtc.h>
+#include <drm/drm_of.h>
+
+/**
+ * drm_crtc_port_mask - find the mask of a registered CRTC by port OF node
+ * @dev: DRM device
+ * @port: port OF node
+ *
+ * Given a port OF node, return the possible mask of the corresponding
+ * CRTC within a device's list of CRTCs.  Returns zero if not found.
+ */
+static uint32_t drm_crtc_port_mask(struct drm_device *dev,
+                                  struct device_node *port)
+{
+       unsigned int index = 0;
+       struct drm_crtc *tmp;
+
+       list_for_each_entry(tmp, &dev->mode_config.crtc_list, head) {
+               if (tmp->port == port)
+                       return 1 << index;
+
+               index++;
+       }
+
+       return 0;
+}
+
+/**
+ * drm_of_find_possible_crtcs - find the possible CRTCs for an encoder port
+ * @dev: DRM device
+ * @port: encoder port to scan for endpoints
+ *
+ * Scan all endpoints attached to a port, locate their attached CRTCs,
+ * and generate the DRM mask of CRTCs which may be attached to this
+ * encoder.
+ *
+ * See Documentation/devicetree/bindings/graph.txt for the bindings.
+ */
+uint32_t drm_of_find_possible_crtcs(struct drm_device *dev,
+                                   struct device_node *port)
+{
+       struct device_node *remote_port, *ep;
+       uint32_t possible_crtcs = 0;
+
+       for_each_endpoint_of_node(port, ep) {
+               remote_port = of_graph_get_remote_port(ep);
+               if (!remote_port) {
+                       of_node_put(ep);
+                       return 0;
+               }
+
+               possible_crtcs |= drm_crtc_port_mask(dev, remote_port);
+
+               of_node_put(remote_port);
+       }
+
+       return possible_crtcs;
+}
+EXPORT_SYMBOL(drm_of_find_possible_crtcs);