[PATCH i-g-t 1/2] lib/igt_debugfs: added helper to enable/disable dark screen detection

[Kunal Joshi]

added helper function for dark screen detection

v2: Fix indentation (JP)
    Reduce complexity and redundancy (JP)

v3: Close fd (JP)
    Use ternary operator (JP)

v4: Added comments for functions (JP)

Cc: Juha-Pekka Heikkila <juhapekka.heikkila at gmail.com>
Cc: Nemesa Garg <nemesa.garg at intel.com>
Cc: Arun R Murthy <arun.r.murthy at intel.com>
Cc: Bhanuprakash Modem <bhanuprakash.modem at intel.com>
Signed-off-by: Kunal Joshi <kunal1.joshi at intel.com>
Reviewed-by: Juha-Pekka Heikkila <juhapekka.heikkila at gmail.com>
---
 lib/igt_debugfs.c | 39 +++++++++++++++++++++++++++++++++++++++
 lib/igt_debugfs.h |  2 ++
 2 files changed, 41 insertions(+)

diff --git a/lib/igt_debugfs.c b/lib/igt_debugfs.c
index a7b54bae5..323030b19 100644
--- a/lib/igt_debugfs.c
+++ b/lib/igt_debugfs.c
@@ -743,3 +743,42 @@ void __igt_debugfs_dump(int device, const char *filename, int level)
 	igt_log(IGT_LOG_DOMAIN, level, "%s:\n%s\n", filename, contents);
 	free(contents);
 }
+
+/**
+ * igt_is_dark_screen_supported:
+ * @drm_fd: fd of the device
+ * @pipe: display pipe
+ *
+ * Returns true if dark screen detection supported on platform
+ */
+bool igt_is_dark_screen_supported(int drm_fd, enum pipe pipe)
+{
+	char buf[256];
+	int dir;
+
+	dir = igt_debugfs_pipe_dir(drm_fd, pipe, O_DIRECTORY);
+	igt_require_fd(dir);
+	igt_debugfs_simple_read(dir, "i915_darkscreen_status", buf, sizeof(buf));
+	close(dir);
+	return (*buf == '0' || *buf == '1');
+}
+
+/**
+ * igt_set_dark_screen_detection:
+ * @drm_fd: fd of the device
+ * @pipe: display pipe
+ * @enable: bool to enable/disable dark screen detection
+ *
+ * Enable/Disable dark screen detection for given @pipe
+ */
+ssize_t igt_set_dark_screen_detection(int drm_fd, enum pipe pipe, bool enable)
+{
+	int dir;
+	int size;
+
+	dir = igt_debugfs_pipe_dir(drm_fd, pipe, O_DIRECTORY);
+	igt_require_fd(dir);
+	size = igt_sysfs_write(dir, "i915_darkscreen_status", enable ? "1" : "0", 1);
+	close(dir);
+	return size;
+}
diff --git a/lib/igt_debugfs.h b/lib/igt_debugfs.h
index 3e6194ade..68f25be59 100644
--- a/lib/igt_debugfs.h
+++ b/lib/igt_debugfs.h
@@ -77,6 +77,8 @@ void igt_hpd_storm_reset(int fd);
 bool igt_hpd_storm_detected(int fd);
 void igt_require_hpd_storm_ctl(int fd);
 bool igt_ignore_long_hpd(int fd, bool enable);
+bool igt_is_dark_screen_supported(int drm_fd, enum pipe pipe);
+ssize_t igt_set_dark_screen_detection(int drm_fd, enum pipe pipe, bool enable);
 
 /*
  * Drop caches
-- 
2.25.1