card: Add a method to retrieve the device minor

The device minor number is needed to access the debugfs directory
corresponding to the device. Make it available to users through a
get_minor() method on the Card object.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

2 files changed, 14 insertions, 0 deletions

diff --git a/kms++/inc/kms++/card.h b/kms++/inc/kms++/card.h
index 5c1cf7c..0a11747 100644
--- a/kms++/inc/kms++/card.h
+++ b/kms++/inc/kms++/card.h
@@ -35,6 +35,7 @@ public:
 	Card& operator=(const Card& other) = delete;
 
 	int fd() const { return m_fd; }
+	unsigned int dev_minor() const { return m_minor; }
 
 	void drop_master();
 
@@ -84,7 +85,9 @@ private:
 	std::vector<Framebuffer*> m_framebuffers;
 
 	int m_fd;
+	unsigned int m_minor;
 	bool m_is_master;
+	std::string m_device;
 
 	bool m_has_atomic;
 	bool m_has_universal_planes;
diff --git a/kms++/src/card.cpp b/kms++/src/card.cpp
index 527aca6..3a7ab70 100644
--- a/kms++/src/card.cpp
+++ b/kms++/src/card.cpp
@@ -9,6 +9,10 @@
 #include <algorithm>
 #include <glob.h>
 
+#include <sys/stat.h>
+#include <sys/sysmacros.h>
+#include <sys/types.h>
+
 #include <xf86drm.h>
 #include <xf86drmMode.h>
 
@@ -183,8 +187,15 @@ void Card::setup()
 	m_version.desc = string(ver->desc, ver->desc_len);
 	drmFreeVersion(ver);
 
+	struct stat stats;
 	int r;
 
+	r = fstat(m_fd, &stats);
+	if (r < 0)
+		throw invalid_argument("Can't stat device (" + string(strerror(errno)) + ")");
+
+	m_minor = minor(stats.st_dev);
+
 	r = drmSetMaster(m_fd);
 	m_is_master = r == 0;