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-rw-r--r--drivers/gpu/drm/Makefile1
-rw-r--r--drivers/gpu/drm/drm_of.c67
-rw-r--r--include/drm/drm_crtc.h2
-rw-r--r--include/drm/drm_of.h18
4 files changed, 88 insertions, 0 deletions
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index dd2ba4269740..533d011eab3e 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -20,6 +20,7 @@ drm-$(CONFIG_COMPAT) += drm_ioc32.o
drm-$(CONFIG_DRM_GEM_CMA_HELPER) += drm_gem_cma_helper.o
drm-$(CONFIG_PCI) += ati_pcigart.o
drm-$(CONFIG_DRM_PANEL) += drm_panel.o
+drm-$(CONFIG_OF) += drm_of.o
drm-usb-y := drm_usb.o
diff --git a/drivers/gpu/drm/drm_of.c b/drivers/gpu/drm/drm_of.c
new file mode 100644
index 000000000000..16150a00c237
--- /dev/null
+++ b/drivers/gpu/drm/drm_of.c
@@ -0,0 +1,67 @@
+#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 = NULL;
+ uint32_t possible_crtcs = 0;
+
+ do {
+ ep = of_graph_get_next_endpoint(port, ep);
+ if (!ep)
+ break;
+
+ 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);
+ } while (1);
+
+ return possible_crtcs;
+}
+EXPORT_SYMBOL(drm_of_find_possible_crtcs);
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index 251b75e6bf7a..6a94909f1ca9 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -41,6 +41,7 @@ struct drm_framebuffer;
struct drm_object_properties;
struct drm_file;
struct drm_clip_rect;
+struct device_node;
#define DRM_MODE_OBJECT_CRTC 0xcccccccc
#define DRM_MODE_OBJECT_CONNECTOR 0xc0c0c0c0
@@ -314,6 +315,7 @@ struct drm_crtc_funcs {
*/
struct drm_crtc {
struct drm_device *dev;
+ struct device_node *port;
struct list_head head;
/**
diff --git a/include/drm/drm_of.h b/include/drm/drm_of.h
new file mode 100644
index 000000000000..2441f7112074
--- /dev/null
+++ b/include/drm/drm_of.h
@@ -0,0 +1,18 @@
+#ifndef __DRM_OF_H__
+#define __DRM_OF_H__
+
+struct drm_device;
+struct device_node;
+
+#ifdef CONFIG_OF
+extern uint32_t drm_of_find_possible_crtcs(struct drm_device *dev,
+ struct device_node *port);
+#else
+static inline uint32_t drm_of_find_possible_crtcs(struct drm_device *dev,
+ struct device_node *port)
+{
+ return 0;
+}
+#endif
+
+#endif /* __DRM_OF_H__ */