# HG changeset patch
# User Mychaela Falconia <falcon@freecalypso.org>
# Date 1558817045 0
# Node ID 74610c4f10f7a7f3bac6c82963dab6c15a387e84
# Parent  3d73d4d3527f86f5c2460ad93b6f2c8313ae1805
target-utils: added 10 ms delay at the end of abb_power_off()

The deosmification of the ABB access code (replacement of osmo_delay_ms()
bogus delays with correctly-timed ones, which are significantly shorter)
had one annoying side effect: when executing the poweroff command from
any of the programs, one last '=' prompt character was being sent (and
received by the x86 host) as the Calypso board powers off.  With delays
being shorter now, the abb_power_off() function was returning and the
standalone program's main loop was printing its prompt before the Iota chip
fully executed the switch-off sequence!

I thought about inserting an endless tight loop at the end of the
abb_power_off() function, but the implemented solution of a 10 ms delay
is a little nicer IMO because if the DEVOFF operation doesn't happen for
some reason in a manual hacking scenario, there won't be an artificial
blocker in the form of a tight loop keeping us from further poking around.

diff -r 3d73d4d3527f -r 74610c4f10f7 target-utils/libbase/abbdrv.c
--- a/target-utils/libbase/abbdrv.c	Sat May 25 20:17:27 2019 +0000
+++ b/target-utils/libbase/abbdrv.c	Sat May 25 20:44:05 2019 +0000
@@ -102,4 +102,11 @@
 	abb_init();
 	serial_flush();
 	abb_reg_write(VRPCDEV, 0x01);
+	/*
+	 * TWL3025 datasheet seems to indicate that the time for the DEVOFF
+	 * command to take effect is 5 cycles of the 32.768 kHz clock.
+	 * We'll do an ARM-timed delay of 10 ms before returning from
+	 * this function.
+	 */
+	wait_ARM_cycles(13000 * 10);
 }