[WIP] Change TPU offset on TS change or sync change

When TPU offset must be changed (assignment to different timeslot or handover
to a different cell), all tasks will be disabled until new TPU offset has been
applied. Currently scheduled tasks are finished before the new TPU offset is
applied.

On change of TPU offset, the TPU's interrupt may skip one frame when changing
backwards in time. Also it may generate two interrupts when changing
significantly forward in time. This is compensated by changing the GSM time.

Change-Id: If858484a9cf497e0f6e8d84593ab3637c2668869

1 files changed, 8 insertions, 12 deletions

diff --git a/src/target/firmware/layer1/tpu_window.c b/src/target/firmware/layer1/tpu_window.c
index f4e76c16..abdad956 100644
--- a/src/target/firmware/layer1/tpu_window.c
+++ b/src/target/firmware/layer1/tpu_window.c
@@ -67,30 +67,26 @@ static const uint16_t tx_burst_duration[_NUM_L1_TXWIN] = {
 	[L1_TXWIN_AB]	= L1_TX_AB_DURATION_Q,
 };
 
-
 static int _win_setup(__unused uint8_t p1, __unused uint8_t p2, __unused uint16_t p3)
 {
-	uint8_t tn;
-
-	rfch_get_params(&l1s.next_time, NULL, NULL, &tn);
-
-	l1s.tpu_offset = (5000 + l1s.tpu_offset + l1s.tpu_offset_correction) % 5000;
+	l1s.tpu_offset = (l1s.tpu_offset + l1s.tpu_offset_correction
+	                + l1s.tpu_offset_shift + L1_TDMA_LENGTH_Q
+			+ L1_TDMA_LENGTH_Q) % L1_TDMA_LENGTH_Q;
+	l1s.tpu_offset_changed = l1s.tpu_offset_correction
+	                       + l1s.tpu_offset_shift;
 	l1s.tpu_offset_correction = 0;
+	l1s.tpu_offset_shift = 0;
 
 	tpu_enq_at(4740);
-	tpu_enq_sync((5000 + l1s.tpu_offset + (L1_BURST_LENGTH_Q * tn)) % 5000);
+	tpu_enq_sync(l1s.tpu_offset);
 
 	return 0;
 }
 
 static int _win_cleanup(__unused uint8_t p1, __unused uint8_t p2, __unused uint16_t p3)
 {
-	uint8_t tn;
-
-	rfch_get_params(&l1s.next_time, NULL, NULL, &tn);
-
 	/* restore offset */
-	tpu_enq_offset((5000 + l1s.tpu_offset + (L1_BURST_LENGTH_Q * tn)) % 5000);
+	tpu_enq_offset(l1s.tpu_offset);
 
 	return 0;
 }