From ff74e83997de9c11096c6c54074f0e64bfaede0c Mon Sep 17 00:00:00 2001
From: Boram Park <boram1288.park@samsung.com>
Date: Mon, 21 Mar 2016 09:28:20 +0900
Subject: [PATCH] add tdm_helper_get_fd & tdm_helper_set_fd

Change-Id: I07027116cf37fd312eda56c49b271b2f36575c8f
---
 include/tdm_helper.h | 27 ++++++++++++++++++++++++++
 src/tdm.c            |  3 +++
 src/tdm_helper.c     | 53 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 83 insertions(+)

diff --git a/include/tdm_helper.h b/include/tdm_helper.h
index 86b6620..c329669 100644
--- a/include/tdm_helper.h
+++ b/include/tdm_helper.h
@@ -68,6 +68,33 @@ extern "C" {
 void
 tdm_helper_dump_buffer(tbm_surface_h buffer, const char *file);
 
+/**
+ * @brief Get a fd from the given enviroment variable.
+ * @details
+ * This function will dup the fd of the given enviroment variable. The Caller
+ * @b SHOULD close the fd.
+ * \n
+ * In DRM system, a drm-master-fd @b SHOULD be shared between TDM backend and
+ * TBM backend in display server side by using "TDM_DRM_MASTER_FD"
+ * and "TBM_DRM_MASTER_FD".
+ * @param[in] env The given enviroment variable
+ * @return fd if success. Otherwise, -1.
+ * @see #tdm_helper_set_fd()
+ */
+int tdm_helper_get_fd(const char *env);
+
+/**
+ * @brief Set the given fd to the give enviroment variable.
+ * @details
+ * In DRM system, a drm-master-fd @b SHOULD be shared between TDM backend and
+ * TBM backend in display server side by using "TDM_DRM_MASTER_FD"
+ * and "TBM_DRM_MASTER_FD".
+ * @param[in] env The given enviroment variable
+ * @param[in] fd The given fd
+ * @see #tdm_helper_get_fd()
+ */
+void tdm_helper_set_fd(const char *env, int fd);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/tdm.c b/src/tdm.c
index a7451f1..1a02ef1 100644
--- a/src/tdm.c
+++ b/src/tdm.c
@@ -40,6 +40,7 @@ SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #include "tdm.h"
 #include "tdm_backend.h"
 #include "tdm_private.h"
+#include "tdm_helper.h"
 
 static tdm_private_layer *
 _tdm_display_find_private_layer(tdm_private_output *private_output,
@@ -784,6 +785,8 @@ tdm_display_deinit(tdm_display *dpy)
 	_tdm_display_destroy_private_display(private_display);
 	_tdm_display_unload_module(private_display);
 
+	tdm_helper_set_fd("TDM_DRM_MASTER_FD", -1);
+
 	pthread_mutex_unlock(&private_display->lock);
 
 	pthread_mutex_destroy(&private_display->lock);
diff --git a/src/tdm_helper.c b/src/tdm_helper.c
index 7c47b6e..311ea6e 100644
--- a/src/tdm_helper.c
+++ b/src/tdm_helper.c
@@ -173,3 +173,56 @@ tdm_helper_dump_buffer(tbm_surface_h buffer, const char *file)
 
 	TDM_INFO("dump %s", file);
 }
+
+EXTERN int
+tdm_helper_get_fd(const char *env)
+{
+	const char *value;
+	int fd, newfd, flags, ret;
+
+	value = (const char*)getenv(env);
+	if (!value)
+		return -1;
+
+	ret = sscanf(value, "%d", &fd);
+	if (ret < 0) {
+		TDM_ERR("sscanf failed: %m");
+		return -1;
+	}
+
+	flags = fcntl(fd, F_GETFD);
+	if (flags == -1) {
+		TDM_ERR("fcntl failed: %m");
+		return -1;
+	}
+
+	newfd = dup(fd);
+	if (newfd < 0) {
+		TDM_ERR("dup failed: %m");
+		return -1;
+	}
+
+	TDM_INFO("%s: fd(%d) newfd(%d)", env, fd, newfd);
+
+	fcntl(newfd, F_SETFD, flags | FD_CLOEXEC);
+
+	return newfd;
+}
+
+EXTERN void
+tdm_helper_set_fd(const char *env, int fd)
+{
+	char buf[32];
+	int ret;
+
+	snprintf(buf, sizeof(buf), "%d", fd);
+
+	ret = setenv(env, (const char*)buf, 1);
+	if (ret) {
+		TDM_ERR("setenv failed: %m");
+		return;
+	}
+
+	if (fd >= 0)
+		TDM_INFO("%s: fd(%d)", env, fd);
+}
-- 
2.7.4