altos: Add fast-timer API. Use for quadrature and button drivers

This splits the fast-timer portion out of the debounce helper code and
shares that with the quadrature driver which now uses it directly.

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

4 files changed, 159 insertions, 187 deletions

diff --git a/src/stm/ao_debounce.c b/src/stm/ao_debounce.c
deleted file mode 100644
index 22cdf230..00000000
--- a/src/stm/ao_debounce.c
+++ /dev/null
@@ -1,187 +0,0 @@
-/*
- * 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_debounce.h>
-
-static uint8_t			ao_debounce_initialized;
-static uint8_t			ao_debounce_running;
-static struct ao_debounce	*ao_debounce;
-
-static void
-ao_debounce_on(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_debounce_off(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));
-}
-
-static void
-_ao_debounce_set(struct ao_debounce *debounce, uint8_t value)
-{
-	if (value != debounce->value) {
-		debounce->value = value;
-		debounce->_set(debounce, value);
-	}
-	_ao_debounce_stop(debounce);
-}
-
-/*
- * Get the current value, set the result when we've
- * reached the debounce count limit
- */
-static void
-_ao_debounce_check(struct ao_debounce *debounce)
-{
-	if (debounce->_get(debounce)) {
-		if (debounce->count < 0)
-			debounce->count = 0;
-		if (debounce->count < debounce->hold) {
-			if (++debounce->count == debounce->hold)
-				_ao_debounce_set(debounce, 1);
-		}
-	} else {
-		if (debounce->count > 0)
-			debounce->count = 0;
-		if (debounce->count > -debounce->hold) {
-			if (--debounce->count == -debounce->hold)
-				_ao_debounce_set(debounce, 0);
-		}
-	}
-}
-
-/*
- * Start monitoring one pin
- */
-void
-_ao_debounce_start(struct ao_debounce *debounce)
-{
-	if (debounce->running)
-		return;
-	debounce->running = 1;
-
-	/* Reset the counter */
-	debounce->count = 0;
-
-	/* Link into list */
-	debounce->next = ao_debounce;
-	ao_debounce = debounce;
-
-	/* Make sure the timer is running */
-	if (!ao_debounce_running++)
-		ao_debounce_on();
-
-	/* And go check the current value */
-	_ao_debounce_check(debounce);
-}
-
-/*
- * Stop monitoring one pin
- */
-void
-_ao_debounce_stop(struct ao_debounce *debounce)
-{
-	struct ao_debounce **prev;
-	if (!debounce->running)
-		return;
-
-	debounce->running = 0;
-
-	/* Unlink */
-	for (prev = &ao_debounce; (*prev); prev = &((*prev)->next)) {
-		if (*prev == debounce) {
-			*prev = debounce->next;
-			break;
-		}
-	}
-	debounce->next = NULL;
-
-	/* Turn off the timer if possible */
-	if (!--ao_debounce_running)
-		ao_debounce_off();
-}
-
-void stm_tim6_isr(void)
-{
-	struct ao_debounce	*debounce, *next;
-	if (stm_tim6.sr & (1 << STM_TIM67_SR_UIF)) {
-		stm_tim6.sr = 0;
-
-		/* Walk the current list, allowing the current
-		 * object to be removed from the list
-		 */
-		for (debounce = ao_debounce; debounce; debounce = next) {
-			next = debounce->next;
-			_ao_debounce_check(debounce);
-		}
-	}
-}
-
-/*
- * 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_100kHz	((AO_PCLK1 * TIMER_23467_SCALER) / 100000)
-
-void
-ao_debounce_init(void)
-{
-	if (ao_debounce_initialized)
-		return;
-	ao_debounce_initialized = 1;
-
-	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_100kHz;
-	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);
-
-	/* And turn it off (for now) */
-	ao_debounce_off();
-}
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++;
+}
+
diff --git a/src/stm/ao_fast_timer.h b/src/stm/ao_fast_timer.h
new file mode 100644
index 00000000..90fb3930
--- /dev/null
+++ b/src/stm/ao_fast_timer.h
@@ -0,0 +1,34 @@
+/*
+ * 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.
+ */
+
+#ifndef _AO_FAST_TIMER_H_
+#define _AO_FAST_TIMER_H_
+
+void
+ao_fast_timer_init(void);
+
+#ifndef AO_FAST_TIMER_MAX
+#define AO_FAST_TIMER_MAX	2
+#endif
+
+void
+ao_fast_timer_on(void (*callback)(void));
+
+void
+ao_fast_timer_off(void (*callback)(void));
+
+#endif /* _AO_FAST_TIMER_H_ */
diff --git a/src/stm/stm32l.h b/src/stm/stm32l.h
index 63bde0f8..1868468f 100644
--- a/src/stm/stm32l.h
+++ b/src/stm/stm32l.h
@@ -171,6 +171,11 @@ stm_gpio_get(struct stm_gpio *gpio, int pin) {
 	return (gpio->idr >> pin) & 1;
 }
 
+static inline uint16_t
+stm_gpio_get_all(struct stm_gpio *gpio) {
+	return gpio->idr;
+}
+
 extern struct stm_gpio stm_gpioa;
 extern struct stm_gpio stm_gpiob;
 extern struct stm_gpio stm_gpioc;