media: vivid: Improve timestamping

Simulate a more precise timestamp by calculating it based on the
current framerate.

Signed-off-by: Gabriel Francisco Mandaji <gfmandaji@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
[hverkuil-cisco@xs4all.nl: replaced division by 2 with bit shift]
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

diff --git a/drivers/media/platform/vivid/vivid-core.h b/drivers/media/platform/vivid/vivid-core.h
index a4ff854..6697c70 100644 (file)
--- a/drivers/media/platform/vivid/vivid-core.h
+++ b/drivers/media/platform/vivid/vivid-core.h
@@ -394,6 +394,9 @@ struct vivid_dev {
        /* thread for generating video capture stream */
        struct task_struct              *kthread_vid_cap;
        unsigned long                   jiffies_vid_cap;
+       u64                             cap_stream_start;
+       u64                             cap_frame_period;
+       u64                             cap_frame_eof_offset;
        u32                             cap_seq_offset;
        u32                             cap_seq_count;
        bool                            cap_seq_resync;

diff --git a/drivers/media/platform/vivid/vivid-kthread-cap.c b/drivers/media/platform/vivid/vivid-kthread-cap.c
index 46e46e3..f8006a3 100644 (file)
--- a/drivers/media/platform/vivid/vivid-kthread-cap.c
+++ b/drivers/media/platform/vivid/vivid-kthread-cap.c
@@ -425,12 +425,6 @@ static void vivid_fillbuff(struct vivid_dev *dev, struct vivid_buffer *buf)
                is_loop = true;
 
        buf->vb.sequence = dev->vid_cap_seq_count;
-       /*
-        * Take the timestamp now if the timestamp source is set to
-        * "Start of Exposure".
-        */
-       if (dev->tstamp_src_is_soe)
-               buf->vb.vb2_buf.timestamp = ktime_get_ns();
        if (dev->field_cap == V4L2_FIELD_ALTERNATE) {
                /*
                 * 60 Hz standards start with the bottom field, 50 Hz standards
@@ -554,14 +548,6 @@ static void vivid_fillbuff(struct vivid_dev *dev, struct vivid_buffer *buf)
                        }
                }
        }
-
-       /*
-        * If "End of Frame" is specified at the timestamp source, then take
-        * the timestamp now.
-        */
-       if (!dev->tstamp_src_is_soe)
-               buf->vb.vb2_buf.timestamp = ktime_get_ns();
-       buf->vb.vb2_buf.timestamp += dev->time_wrap_offset;
 }
 
 /*
@@ -667,10 +653,28 @@ static void vivid_overlay(struct vivid_dev *dev, struct vivid_buffer *buf)
        }
 }
 
+static void vivid_cap_update_frame_period(struct vivid_dev *dev)
+{
+       u64 f_period;
+
+       f_period = (u64)dev->timeperframe_vid_cap.numerator * 1000000000;
+       do_div(f_period, dev->timeperframe_vid_cap.denominator);
+       if (dev->field_cap == V4L2_FIELD_ALTERNATE)
+               f_period >>= 1;
+       /*
+        * If "End of Frame", then offset the exposure time by 0.9
+        * of the frame period.
+        */
+       dev->cap_frame_eof_offset = f_period * 9;
+       do_div(dev->cap_frame_eof_offset, 10);
+       dev->cap_frame_period = f_period;
+}
+
 static void vivid_thread_vid_cap_tick(struct vivid_dev *dev, int dropped_bufs)
 {
        struct vivid_buffer *vid_cap_buf = NULL;
        struct vivid_buffer *vbi_cap_buf = NULL;
+       u64 f_time = 0;
 
        dprintk(dev, 1, "Video Capture Thread Tick\n");
 
@@ -702,6 +706,11 @@ static void vivid_thread_vid_cap_tick(struct vivid_dev *dev, int dropped_bufs)
        if (!vid_cap_buf && !vbi_cap_buf)
                goto update_mv;
 
+       f_time = dev->cap_frame_period * dev->vid_cap_seq_count +
+                dev->cap_stream_start + dev->time_wrap_offset;
+       if (!dev->tstamp_src_is_soe)
+               f_time += dev->cap_frame_eof_offset;
+
        if (vid_cap_buf) {
                v4l2_ctrl_request_setup(vid_cap_buf->vb.vb2_buf.req_obj.req,
                                        &dev->ctrl_hdl_vid_cap);
@@ -721,9 +730,13 @@ static void vivid_thread_vid_cap_tick(struct vivid_dev *dev, int dropped_bufs)
                                VB2_BUF_STATE_ERROR : VB2_BUF_STATE_DONE);
                dprintk(dev, 2, "vid_cap buffer %d done\n",
                                vid_cap_buf->vb.vb2_buf.index);
+
+               vid_cap_buf->vb.vb2_buf.timestamp = f_time;
        }
 
        if (vbi_cap_buf) {
+               u64 vbi_period;
+
                v4l2_ctrl_request_setup(vbi_cap_buf->vb.vb2_buf.req_obj.req,
                                        &dev->ctrl_hdl_vbi_cap);
                if (dev->stream_sliced_vbi_cap)
@@ -736,6 +749,11 @@ static void vivid_thread_vid_cap_tick(struct vivid_dev *dev, int dropped_bufs)
                                VB2_BUF_STATE_ERROR : VB2_BUF_STATE_DONE);
                dprintk(dev, 2, "vbi_cap %d done\n",
                                vbi_cap_buf->vb.vb2_buf.index);
+
+               /* If capturing a VBI, offset by 0.05 */
+               vbi_period = dev->cap_frame_period * 5;
+               do_div(vbi_period, 100);
+               vbi_cap_buf->vb.vb2_buf.timestamp = f_time + vbi_period;
        }
        dev->dqbuf_error = false;
 
@@ -767,6 +785,8 @@ static int vivid_thread_vid_cap(void *data)
        dev->cap_seq_count = 0;
        dev->cap_seq_resync = false;
        dev->jiffies_vid_cap = jiffies;
+       dev->cap_stream_start = ktime_get_ns();
+       vivid_cap_update_frame_period(dev);
 
        for (;;) {
                try_to_freeze();
@@ -779,6 +799,9 @@ static int vivid_thread_vid_cap(void *data)
                        dev->jiffies_vid_cap = cur_jiffies;
                        dev->cap_seq_offset = dev->cap_seq_count + 1;
                        dev->cap_seq_count = 0;
+                       dev->cap_stream_start += dev->cap_frame_period *
+                                                dev->cap_seq_offset;
+                       vivid_cap_update_frame_period(dev);
                        dev->cap_seq_resync = false;
                }
                numerator = dev->timeperframe_vid_cap.numerator;

diff --git a/drivers/media/platform/vivid/vivid-vbi-cap.c b/drivers/media/platform/vivid/vivid-vbi-cap.c
index 903cebe..17aa4b0 100644 (file)
--- a/drivers/media/platform/vivid/vivid-vbi-cap.c
+++ b/drivers/media/platform/vivid/vivid-vbi-cap.c
@@ -95,8 +95,6 @@ void vivid_raw_vbi_cap_process(struct vivid_dev *dev, struct vivid_buffer *buf)
 
        if (!VIVID_INVALID_SIGNAL(dev->std_signal_mode))
                vivid_vbi_gen_raw(&dev->vbi_gen, &vbi, vbuf);
-
-       buf->vb.vb2_buf.timestamp = ktime_get_ns() + dev->time_wrap_offset;
 }
 
 
@@ -119,8 +117,6 @@ void vivid_sliced_vbi_cap_process(struct vivid_dev *dev,
                for (i = 0; i < 25; i++)
                        vbuf[i] = dev->vbi_gen.data[i];
        }
-
-       buf->vb.vb2_buf.timestamp = ktime_get_ns() + dev->time_wrap_offset;
 }
 
 static int vbi_cap_queue_setup(struct vb2_queue *vq,