drm/modes: Add drm_mode_hsync()
Signed-off-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
index 51f6772..6d81a02 100644
--- a/drivers/gpu/drm/drm_modes.c
+++ b/drivers/gpu/drm/drm_modes.c
@@ -553,6 +553,32 @@
}
EXPORT_SYMBOL(drm_mode_height);
+/** drm_mode_hsync - get the hsync of a mode
+ * @mode: mode
+ *
+ * LOCKING:
+ * None.
+ *
+ * Return @modes's hsync rate in kHz, rounded to the nearest int.
+ */
+int drm_mode_hsync(struct drm_display_mode *mode)
+{
+ unsigned int calc_val;
+
+ if (mode->hsync)
+ return mode->hsync;
+
+ if (mode->htotal < 0)
+ return 0;
+
+ calc_val = (mode->clock * 1000) / mode->htotal; /* hsync in Hz */
+ calc_val += 500; /* round to 1000Hz */
+ calc_val /= 1000; /* truncate to kHz */
+
+ return calc_val;
+}
+EXPORT_SYMBOL(drm_mode_hsync);
+
/**
* drm_mode_vrefresh - get the vrefresh of a mode
* @mode: mode
@@ -560,7 +586,7 @@
* LOCKING:
* None.
*
- * Return @mode's vrefresh rate or calculate it if necessary.
+ * Return @mode's vrefresh rate in Hz or calculate it if necessary.
*
* FIXME: why is this needed? shouldn't vrefresh be set already?
*