diff options
| author | Bdale Garbee <bdale@gag.com> | 2013-12-19 01:38:40 -0700 | 
|---|---|---|
| committer | Bdale Garbee <bdale@gag.com> | 2013-12-19 01:38:40 -0700 | 
| commit | 575bbaf976c5840fd0e308549c45a466fdec1352 (patch) | |
| tree | 11bfb498348bf7687bffc24699c4b1a998988ee4 /src/stm/ao_fast_timer.c | |
| parent | b825116df173b77e2cab217a7b76112c742f9279 (diff) | |
| parent | bc3610d8cecbfed40c62d4dcb93fc9a4d2a7c9e3 (diff) | |
Merge branch 'branch-1.3' into debian
Conflicts:
	ChangeLog
	altoslib/AltosRecordMM.java
	altosui/Makefile.am
	altosui/altos-windows.nsi.in
	configure.ac
	debian/changelog
	debian/control
	doc/Makefile
	doc/altusmetrum.xsl
	doc/release-notes-1.2.1.xsl
	doc/release-notes-1.2.xsl
Diffstat (limited to 'src/stm/ao_fast_timer.c')
| -rw-r--r-- | src/stm/ao_fast_timer.c | 120 | 
1 files changed, 120 insertions, 0 deletions
| diff --git a/src/stm/ao_fast_timer.c b/src/stm/ao_fast_timer.c new file mode 100644 index 00000000..d61b40c9 --- /dev/null +++ b/src/stm/ao_fast_timer.c @@ -0,0 +1,120 @@ +/* + * Copyright © 2013 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> +#include <ao_fast_timer.h> + +static void (*ao_fast_timer_callback[AO_FAST_TIMER_MAX])(void); +static uint8_t ao_fast_timer_count; +static uint8_t ao_fast_timer_users; + +static void +ao_fast_timer_enable(void) +{ +	stm_tim6.cr1 = ((0 << STM_TIM67_CR1_ARPE) | +			(0 << STM_TIM67_CR1_OPM) | +			(1 << STM_TIM67_CR1_URS) | +			(0 << STM_TIM67_CR1_UDIS) | +			(1 << STM_TIM67_CR1_CEN)); +} + +static void +ao_fast_timer_disable(void) +{ +	stm_tim6.cr1 = ((0 << STM_TIM67_CR1_ARPE) | +			(0 << STM_TIM67_CR1_OPM) | +			(1 << STM_TIM67_CR1_URS) | +			(0 << STM_TIM67_CR1_UDIS) | +			(0 << STM_TIM67_CR1_CEN)); +} + +void +ao_fast_timer_on(void (*callback)(void)) +{ +	ao_fast_timer_callback[ao_fast_timer_count] = callback; +	if (!ao_fast_timer_count++) +		ao_fast_timer_enable(); +} + +void +ao_fast_timer_off(void (*callback)(void)) +{ +	uint8_t	n; + +	for (n = 0; n < ao_fast_timer_count; n++) +		if (ao_fast_timer_callback[n] == callback) { +			for (; n < ao_fast_timer_count-1; n++) { +				ao_fast_timer_callback[n] = ao_fast_timer_callback[n+1]; +			} +			if (!--ao_fast_timer_count) +				ao_fast_timer_disable(); +			break; +		} +} + +void stm_tim6_isr(void) +{ +	uint8_t	i; +	if (stm_tim6.sr & (1 << STM_TIM67_SR_UIF)) { +		stm_tim6.sr = 0; + +		for (i = 0; i < ao_fast_timer_count; i++) +			(*ao_fast_timer_callback[i])(); +	} +} + +/* + * According to the STM clock-configuration, timers run + * twice as fast as the APB1 clock *if* the APB1 prescaler + * is greater than 1. + */ + +#if AO_APB1_PRESCALER > 1 +#define TIMER_23467_SCALER 2 +#else +#define TIMER_23467_SCALER 1 +#endif + +#define TIMER_10kHz	((AO_PCLK1 * TIMER_23467_SCALER) / 10000) + +void +ao_fast_timer_init(void) +{ +	if (!ao_fast_timer_users) { +		stm_nvic_set_enable(STM_ISR_TIM6_POS); +		stm_nvic_set_priority(STM_ISR_TIM6_POS, AO_STM_NVIC_CLOCK_PRIORITY); + +		/* Turn on timer 6 */ +		stm_rcc.apb1enr |= (1 << STM_RCC_APB1ENR_TIM6EN); + +		stm_tim6.psc = TIMER_10kHz; +		stm_tim6.arr = 9; +		stm_tim6.cnt = 0; + +		/* Enable update interrupt */ +		stm_tim6.dier = (1 << STM_TIM67_DIER_UIE); + +		/* Poke timer to reload values */ +		stm_tim6.egr |= (1 << STM_TIM67_EGR_UG); + +		stm_tim6.cr2 = (STM_TIM67_CR2_MMS_RESET << STM_TIM67_CR2_MMS); +		ao_fast_timer_disable(); +	} +	if (ao_fast_timer_users == AO_FAST_TIMER_MAX) +		ao_panic(AO_PANIC_FAST_TIMER); +	ao_fast_timer_users++; +} + | 
