From: Keith Packard <keithp@keithp.com>
Date: Wed, 21 Sep 2011 18:39:24 +0000 (-0700)
Subject: altos: Pre-compute RDF packet len at compile time
X-Git-Tag: 1.0.9.1~13
X-Git-Url: https://git.gag.com/?p=fw%2Faltos;a=commitdiff_plain;h=c8a00bb9ccdf0d4257f037c2bf996ce5e6b0b0c0

altos: Pre-compute RDF packet len at compile time

Instead of computing the RDF packet len at run time, which takes a
pile of code space.

Signed-off-by: Keith Packard <keithp@keithp.com>
---

diff --git a/src/cc1111/ao_radio.c b/src/cc1111/ao_radio.c
index 00816b33..75f241d4 100644
--- a/src/cc1111/ao_radio.c
+++ b/src/cc1111/ao_radio.c
@@ -367,21 +367,9 @@ ao_radio_recv_abort(void)
 __xdata ao_radio_rdf_value = 0x55;
 
 void
-ao_radio_rdf(int ms)
+ao_radio_rdf(uint8_t pkt_len)
 {
 	uint8_t i;
-	uint8_t pkt_len;
-
-	/*
-	 * Compute the packet length as follows:
-	 *
-	 * 2000 bps (for a 1kHz tone)
-	 * so, for 'ms' milliseconds, we need
-	 * 2 * ms bits, or ms / 4 bytes
-	 */
-	if (ms > (255 * 4))
-		ms = 255 * 4;
-	pkt_len = ms >> 2;
 
 	ao_radio_abort = 0;
 	ao_radio_get(pkt_len);
diff --git a/src/core/ao.h b/src/core/ao.h
index 1d5769cb..c28c4549 100644
--- a/src/core/ao.h
+++ b/src/core/ao.h
@@ -1341,8 +1341,18 @@ ao_radio_recv(__xdata void *data, uint8_t size) __reentrant;
 void
 ao_radio_recv_abort(void);
 
+/*
+ * Compute the packet length as follows:
+ *
+ * 2000 bps (for a 1kHz tone)
+ * so, for 'ms' milliseconds, we need
+ * 2 * ms bits, or ms / 4 bytes
+ */
+
+#define AO_MS_TO_RDF_LEN(ms) ((ms) > 255 * 4 ? 255 : ((ms) >> 2))
+
 void
-ao_radio_rdf(int ms);
+ao_radio_rdf(uint8_t pkt_len);
 
 void
 ao_radio_rdf_abort(void);
diff --git a/src/core/ao_telemetry.c b/src/core/ao_telemetry.c
index de669ce1..c2707e7d 100644
--- a/src/core/ao_telemetry.c
+++ b/src/core/ao_telemetry.c
@@ -235,7 +235,7 @@ ao_telemetry(void)
 			    (int16_t) (ao_time() - ao_rdf_time) >= 0)
 			{
 				ao_rdf_time = ao_time() + AO_RDF_INTERVAL_TICKS;
-				ao_radio_rdf(AO_RDF_LENGTH_MS);
+				ao_radio_rdf(AO_MS_TO_RDF_LEN(AO_RDF_LENGTH_MS));
 			}
 #endif
 			time += ao_telemetry_interval;