altos-avr: Initial OS port to AVR

This is working with output to the serial line

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

1 files changed, 177 insertions, 0 deletions

diff --git a/src-avr/ao_timer.c b/src-avr/ao_timer.c
new file mode 100644
index 00000000..01bf8e0c
--- /dev/null
+++ b/src-avr/ao_timer.c
@@ -0,0 +1,177 @@
+/*
+ * Copyright © 2009 Keith Packard <keithp@keithp.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+#include "ao.h"
+
+static volatile __data uint16_t ao_tick_count;
+
+uint16_t ao_time(void) __critical
+{
+	return ao_tick_count;
+}
+
+static __xdata uint8_t ao_forever;
+
+void
+ao_delay(uint16_t ticks)
+{
+	ao_alarm(ticks);
+	ao_sleep(&ao_forever);
+}
+
+#define T1_CLOCK_DIVISOR	8	/* 24e6/8 = 3e6 */
+#define T1_SAMPLE_TIME		30000	/* 3e6/30000 = 100 */
+
+#if HAS_ADC
+volatile __data uint8_t	ao_adc_interval = 1;
+volatile __data uint8_t	ao_adc_count;
+#endif
+
+#ifdef AVR
+ISR(TIMER1_COMPA_vect)
+#else
+void ao_timer_isr(void) __interrupt(9)
+#endif
+{
+	++ao_tick_count;
+#if HAS_ADC
+	if (++ao_adc_count == ao_adc_interval) {
+		ao_adc_count = 0;
+		ao_adc_poll();
+	}
+#endif
+}
+
+#if HAS_ADC
+void
+ao_timer_set_adc_interval(uint8_t interval) __critical
+{
+	ao_adc_interval = interval;
+	ao_adc_count = 0;
+}
+#endif
+
+void
+ao_timer_init(void)
+{
+#ifdef AVR
+	TCCR1A = ((0 << WGM11) |	/* CTC mode, OCR1A */
+		  (0 << WGM10));	/* CTC mode, OCR1A */
+	TCCR1B = ((0 << ICNC1) |	/* no input capture noise canceler */
+		  (0 << ICES1) |	/* input capture on falling edge (don't care) */
+		  (0 << WGM13) |	/* CTC mode, OCR1A */
+		  (1 << WGM12) |	/* CTC mode, OCR1A */
+		  (3 << CS10));		/* clk/64 from prescaler */
+
+#if TEENSY
+	OCR1A = 2500;			/* 16MHz clock */
+#else
+	OCR1A = 1250;			/* 8MHz clock */
+#endif
+
+	TIMSK1 = (1 << OCIE1A);		/* Interrupt on compare match */
+#else
+	/* NOTE:  This uses a timer only present on cc1111 architecture. */
+
+	/* disable timer 1 */
+	T1CTL = 0;
+
+	/* set the sample rate */
+	T1CC0H = T1_SAMPLE_TIME >> 8;
+	T1CC0L = (uint8_t) T1_SAMPLE_TIME;
+
+	T1CCTL0 = T1CCTL_MODE_COMPARE;
+	T1CCTL1 = 0;
+	T1CCTL2 = 0;
+
+	/* clear timer value */
+	T1CNTL = 0;
+
+	/* enable overflow interrupt */
+	OVFIM = 1;
+	/* enable timer 1 interrupt */
+	T1IE = 1;
+
+	/* enable timer 1 in module mode, dividing by 8 */
+	T1CTL = T1CTL_MODE_MODULO | T1CTL_DIV_8;
+#endif
+}
+
+/*
+ * AltOS always cranks the clock to the max frequency
+ */
+void
+ao_clock_init(void)
+{
+#ifdef AVR
+	/* disable RC clock */
+	CLKSEL0 &= ~(1 << RCE);
+
+	/* Disable PLL */
+	PLLCSR &= ~(1 << PLLE);
+
+	/* Enable external clock */
+	CLKSEL0 |= (1 << EXTE);
+
+	/* wait for external clock to be ready */
+	while ((CLKSTA & (1 << EXTON)) == 0)
+		;
+
+	/* select external clock */
+	CLKSEL0 |= (1 << CLKS);
+
+	/* Disable the clock prescaler */
+	cli();
+	CLKPR = (1 << CLKPCE);
+	CLKPR = 0;
+	sei();
+
+	/* Set up the PLL to use the crystal */
+
+	/* Use primary system clock as PLL source */
+	PLLFRQ = ((0 << PINMUX) |	/* Use primary clock */
+		  (0 << PLLUSB) |	/* No divide by 2 for USB */
+		  (0 << PLLTM0) |	/* Disable high speed timer */
+		  (0x4 << PDIV0));	/* 48MHz PLL clock */
+
+	/* Set the frequency of the crystal */
+#if TEENSY
+	PLLCSR |= (1 << PINDIV);	/* For 16MHz crystal on Teensy board */
+#else
+	PLLCSR &= ~(1 << PINDIV);	/* For 8MHz crystal on TeleScience board */
+#endif
+
+	/* Enable the PLL */
+	PLLCSR |= (1 << PLLE);
+	while (!(PLLCSR & (1 << PLOCK)))
+		;
+#else
+	/* Switch system clock to crystal oscilator */
+	CLKCON = (CLKCON & ~CLKCON_OSC_MASK) | (CLKCON_OSC_XTAL);
+
+	while (!(SLEEP & SLEEP_XOSC_STB))
+		;
+
+	/* Crank up the timer tick and system clock speed */
+	CLKCON = ((CLKCON & ~(CLKCON_TICKSPD_MASK | CLKCON_CLKSPD_MASK)) |
+		  (CLKCON_TICKSPD_1 | CLKCON_CLKSPD_1));
+
+	while ((CLKCON & (CLKCON_TICKSPD_MASK|CLKCON_CLKSPD_MASK)) !=
+	       (CLKCON_TICKSPD_1 | CLKCON_CLKSPD_1))
+		;
+#endif
+}