src/cc1111: Turn off RC osc after xtal is running

There's no reason to keep running the RC oscillator after we switch to
the crystal, so turn it off.

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

1 files changed, 7 insertions, 0 deletions

diff --git a/src/cc1111/ao_timer.c b/src/cc1111/ao_timer.c
index 54af9605..75cc4ce8 100644
--- a/src/cc1111/ao_timer.c
+++ b/src/cc1111/ao_timer.c
@@ -95,6 +95,13 @@ ao_clock_init(void)
 	while (!(SLEEP & SLEEP_XOSC_STB))
 		;
 
+	/* Power down the unused HFRC oscillator */
+	SLEEP |= SLEEP_OSC_PD;
+
+	/* Wait for HFRC to power down */
+	while ((SLEEP & SLEEP_HFRC_STB) != 0)
+		;
+	
 	/* Crank up the timer tick and system clock speed */
 	CLKCON = ((CLKCON & ~(CLKCON_TICKSPD_MASK | CLKCON_CLKSPD_MASK)) |
 		  (CLKCON_TICKSPD_1 | CLKCON_CLKSPD_1));