[PATCH 2/8] [media] uvc_video: use ktime_t for timestamps

[Arnd Bergmann <arnd@arndb.de>]

uvc_video_get_ts() returns a 'struct timespec', but all its users
really want a nanoseconds variable anyway.

Changing the deprecated ktime_get_ts/ktime_get_real_ts to ktime_get
and ktime_get_real simplifies the code noticeably, while keeping
the resulting numbers unchanged.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/media/usb/uvc/uvc_video.c | 37 ++++++++++++-------------------------
 drivers/media/usb/uvc/uvcvideo.h  |  2 +-
 2 files changed, 13 insertions(+), 26 deletions(-)

diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
index d6bee37cd1b8..f7a919490b2b 100644
--- a/drivers/media/usb/uvc/uvc_video.c
+++ b/drivers/media/usb/uvc/uvc_video.c
@@ -369,12 +369,12 @@ static int uvc_commit_video(struct uvc_streaming *stream,
  * Clocks and timestamps
  */
 
-static inline void uvc_video_get_ts(struct timespec *ts)
+static inline ktime_t uvc_video_get_time(void)
 {
 	if (uvc_clock_param == CLOCK_MONOTONIC)
-		ktime_get_ts(ts);
+		return ktime_get();
 	else
-		ktime_get_real_ts(ts);
+		return ktime_get_real();
 }
 
 static void
@@ -386,7 +386,7 @@ uvc_video_clock_decode(struct uvc_streaming *stream, struct uvc_buffer *buf,
 	bool has_pts = false;
 	bool has_scr = false;
 	unsigned long flags;
-	struct timespec ts;
+	ktime_t time;
 	u16 host_sof;
 	u16 dev_sof;
 
@@ -436,7 +436,7 @@ uvc_video_clock_decode(struct uvc_streaming *stream, struct uvc_buffer *buf,
 	stream->clock.last_sof = dev_sof;
 
 	host_sof = usb_get_current_frame_number(stream->dev->udev);
-	uvc_video_get_ts(&ts);
+	time = uvc_video_get_time();
 
 	/* The UVC specification allows device implementations that can't obtain
 	 * the USB frame number to keep their own frame counters as long as they
@@ -473,7 +473,7 @@ uvc_video_clock_decode(struct uvc_streaming *stream, struct uvc_buffer *buf,
 	sample->dev_stc = get_unaligned_le32(&data[header_size - 6]);
 	sample->dev_sof = dev_sof;
 	sample->host_sof = host_sof;
-	sample->host_ts = ts;
+	sample->host_time = time;
 
 	/* Update the sliding window head and count. */
 	stream->clock.head = (stream->clock.head + 1) % stream->clock.size;
@@ -613,14 +613,12 @@ void uvc_video_clock_update(struct uvc_streaming *stream,
 	struct uvc_clock_sample *first;
 	struct uvc_clock_sample *last;
 	unsigned long flags;
-	struct timespec ts;
+	u64 timestamp;
 	u32 delta_stc;
 	u32 y1, y2;
 	u32 x1, x2;
 	u32 mean;
 	u32 sof;
-	u32 div;
-	u32 rem;
 	u64 y;
 
 	if (!uvc_hw_timestamps_param)
@@ -667,9 +665,8 @@ void uvc_video_clock_update(struct uvc_streaming *stream,
 	if (x1 == x2)
 		goto done;
 
-	ts = timespec_sub(last->host_ts, first->host_ts);
 	y1 = NSEC_PER_SEC;
-	y2 = (ts.tv_sec + 1) * NSEC_PER_SEC + ts.tv_nsec;
+	y2 = (u32)ktime_to_ns(ktime_sub(last->host_time, first->host_time)) + y1;
 
 	/* Interpolated and host SOF timestamps can wrap around at slightly
 	 * different times. Handle this by adding or removing 2048 to or from
@@ -686,24 +683,18 @@ void uvc_video_clock_update(struct uvc_streaming *stream,
 	  - (u64)y2 * (u64)x1;
 	y = div_u64(y, x2 - x1);
 
-	div = div_u64_rem(y, NSEC_PER_SEC, &rem);
-	ts.tv_sec = first->host_ts.tv_sec - 1 + div;
-	ts.tv_nsec = first->host_ts.tv_nsec + rem;
-	if (ts.tv_nsec >= NSEC_PER_SEC) {
-		ts.tv_sec++;
-		ts.tv_nsec -= NSEC_PER_SEC;
-	}
+	timestamp = ktime_to_ns(first->host_time) + y - y1;
 
 	uvc_trace(UVC_TRACE_CLOCK, "%s: SOF %u.%06llu y %llu ts %llu "
 		  "buf ts %llu (x1 %u/%u/%u x2 %u/%u/%u y1 %u y2 %u)\n",
 		  stream->dev->name,
 		  sof >> 16, div_u64(((u64)sof & 0xffff) * 1000000LLU, 65536),
-		  y, timespec_to_ns(&ts), vbuf->vb2_buf.timestamp,
+		  y, timestamp, vbuf->vb2_buf.timestamp,
 		  x1, first->host_sof, first->dev_sof,
 		  x2, last->host_sof, last->dev_sof, y1, y2);
 
 	/* Update the V4L2 buffer. */
-	vbuf->vb2_buf.timestamp = timespec_to_ns(&ts);
+	vbuf->vb2_buf.timestamp = timestamp;
 
 done:
 	spin_unlock_irqrestore(&clock->lock, flags);
@@ -1007,8 +998,6 @@ static int uvc_video_decode_start(struct uvc_streaming *stream,
 	 * when the EOF bit is set to force synchronisation on the next packet.
 	 */
 	if (buf->state != UVC_BUF_STATE_ACTIVE) {
-		struct timespec ts;
-
 		if (fid == stream->last_fid) {
 			uvc_trace(UVC_TRACE_FRAME, "Dropping payload (out of "
 				"sync).\n");
@@ -1018,11 +1007,9 @@ static int uvc_video_decode_start(struct uvc_streaming *stream,
 			return -ENODATA;
 		}
 
-		uvc_video_get_ts(&ts);
-
 		buf->buf.field = V4L2_FIELD_NONE;
 		buf->buf.sequence = stream->sequence;
-		buf->buf.vb2_buf.timestamp = timespec_to_ns(&ts);
+		buf->buf.vb2_buf.timestamp = uvc_video_get_time();
 
 		/* TODO: Handle PTS and SCR. */
 		buf->state = UVC_BUF_STATE_ACTIVE;
diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
index a2c190937067..d7797dfb6468 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -536,8 +536,8 @@ struct uvc_streaming {
 		struct uvc_clock_sample {
 			u32 dev_stc;
 			u16 dev_sof;
-			struct timespec host_ts;
 			u16 host_sof;
+			ktime_t host_time;
 		} *samples;
 
 		unsigned int head;
-- 
2.9.0