card: add open_modesetting_card()

Add open_modesetting_card() which iterates the DRM cards and returns the
first one that has crtcs and connectors.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

2 files changed, 23 insertions, 0 deletions

diff --git a/kms++/inc/kms++/card.h b/kms++/inc/kms++/card.h
index 72111f1..4b0d877 100644
--- a/kms++/inc/kms++/card.h
+++ b/kms++/inc/kms++/card.h
@@ -3,6 +3,7 @@
 #include <cstdint>
 #include <vector>
 #include <map>
+#include <memory>
 
 #include "decls.h"
 #include "pipeline.h"
@@ -13,6 +14,8 @@ class Card
 {
 	friend class Framebuffer;
 public:
+	static std::unique_ptr<Card> open_modesetting_card();
+
 	Card();
 	Card(const std::string& dev_path);
 	Card(const std::string& driver, uint32_t idx);
diff --git a/kms++/src/card.cpp b/kms++/src/card.cpp
index 4632f22..04750af 100644
--- a/kms++/src/card.cpp
+++ b/kms++/src/card.cpp
@@ -7,6 +7,7 @@
 #include <algorithm>
 #include <cerrno>
 #include <algorithm>
+#include <sys/stat.h>
 
 #include <xf86drm.h>
 #include <xf86drmMode.h>
@@ -18,6 +19,25 @@ using namespace std;
 namespace kms
 {
 
+unique_ptr<Card> Card::open_modesetting_card()
+{
+	for (uint32_t i = 0; ; ++i) {
+		string path = "/dev/dri/card" + to_string(i);
+
+		struct stat buffer;
+		if (stat(path.c_str(), &buffer))
+			break;
+
+		unique_ptr<Card> card = unique_ptr<Card>(new Card(path));
+
+		if (card->get_connectors().size() > 0 &&
+		    card->get_crtcs().size() > 0)
+			return card;
+	}
+
+	throw runtime_error("No modesetting DRM card found");
+}
+
 static int open_device_by_path(string path)
 {
 	int fd = open(path.c_str(), O_RDWR | O_CLOEXEC);