diff options
Diffstat (limited to 'src-avr/ao_timer.c')
| -rw-r--r-- | src-avr/ao_timer.c | 177 |
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 +} |