[PATCH v9 1/2] drm/xe: Get GT clock to nanosecs

[Riana Tauro]

From: Aravind Iddamsetty <aravind.iddamsetty at linux.intel.com>

Helper to convert GT clock cycles to nanoseconds.

v2: Use DIV_ROUND_CLOSEST_ULL helper(Ashutosh)
v3: rename xe_gt_clock_interval_to_ns to xe_gt_clock_cycles_to_ns
v4: rebase
v5: add doc

Reviewed-by: Tejas Upadhyay <tejas.upadhyay at intel.com>
Reviewed-by: Ashutosh Dixit <ashutosh.dixit at intel.com>
Signed-off-by: Aravind Iddamsetty <aravind.iddamsetty at linux.intel.com>
Signed-off-by: Riana Tauro <riana.tauro at intel.com>
---
 drivers/gpu/drm/xe/xe_gt_clock.c | 13 +++++++++++++
 drivers/gpu/drm/xe/xe_gt_clock.h |  2 +-
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/xe/xe_gt_clock.c b/drivers/gpu/drm/xe/xe_gt_clock.c
index 86c2d62b4bdc..17bd8851ef3c 100644
--- a/drivers/gpu/drm/xe/xe_gt_clock.c
+++ b/drivers/gpu/drm/xe/xe_gt_clock.c
@@ -99,3 +99,16 @@ u64 xe_gt_clock_interval_to_ms(struct xe_gt *gt, u64 count)
 {
 	return div_u64_roundup(count * MSEC_PER_SEC, gt->info.reference_clock);
 }
+
+/**
+ * xe_gt_clock_cycles_to_ns - Convert sampled GT clock ticks to nsec
+ *
+ * @gt: GT instance
+ * @count: count of GT clock ticks
+ *
+ * Returns: time in nsec
+ */
+u64 xe_gt_clock_cycles_to_ns(const struct xe_gt *gt, u64 count)
+{
+	return DIV_ROUND_CLOSEST_ULL(count * NSEC_PER_SEC, gt->info.reference_clock);
+}
diff --git a/drivers/gpu/drm/xe/xe_gt_clock.h b/drivers/gpu/drm/xe/xe_gt_clock.h
index 3adeb7baaca4..2bbef839f19f 100644
--- a/drivers/gpu/drm/xe/xe_gt_clock.h
+++ b/drivers/gpu/drm/xe/xe_gt_clock.h
@@ -12,5 +12,5 @@ struct xe_gt;
 
 int xe_gt_clock_init(struct xe_gt *gt);
 u64 xe_gt_clock_interval_to_ms(struct xe_gt *gt, u64 count);
-
+u64 xe_gt_clock_cycles_to_ns(const struct xe_gt *gt, u64 count);
 #endif
-- 
2.40.0