X-Git-Url: https://git.gag.com/?p=fw%2Faltos;a=blobdiff_plain;f=src%2Fcc1111%2Fao_timer.c;h=d681f51bb6689e224bbf2aa259f230a4fd182801;hp=54af9605b59bb997fa75b89508bb45e41f06e8d8;hb=feb0b5f8b28767197f87e5818812d6640c1f40e6;hpb=dcc51bb18985c24fa35bce0dd42ea3d847b960bf

diff --git a/src/cc1111/ao_timer.c b/src/cc1111/ao_timer.c
index 54af9605..d681f51b 100644
--- a/src/cc1111/ao_timer.c
+++ b/src/cc1111/ao_timer.c
@@ -83,18 +83,48 @@ ao_timer_init(void)
 	T1CTL = T1CTL_MODE_MODULO | T1CTL_DIV_8;
 }
 
+static void
+ao_clock_delay(void)
+{
+	uint16_t	i = 0;
+
+	while (--i)
+		ao_arch_nop();
+}
+
 /*
  * AltOS always cranks the clock to the max frequency
  */
 void
 ao_clock_init(void)
 {
+	/* Power up both oscillators */
+	SLEEP &= ~(SLEEP_OSC_PD);
+
+	/* Switch to the HFRC oscillator */
+	CLKCON = (CLKCON & ~CLKCON_OSC_MASK) | (CLKCON_OSC_RC);
+
+	/* Wait for the HFRC oscillator to be stable */
+	while (!(SLEEP & SLEEP_HFRC_STB))
+		;
+
+	/* Delay for 'a while' waiting for the crystal to
+	 * stabilize -- the XOSC_STB bit isn't reliable
+	 *
+	 *  http://www.ti.com/lit/er/swrz022c/swrz022c.pdf
+	 */
+
+	ao_clock_delay();
+
 	/* Switch system clock to crystal oscilator */
 	CLKCON = (CLKCON & ~CLKCON_OSC_MASK) | (CLKCON_OSC_XTAL);
 
-	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));