stm32f0: stm32f1: buzzer: initial implementation

include/buzzer.h

@@ -0,0 +1,13 @@
+#pragma once
+
+#include <libopencm3/stm32/timer.h>
+
+struct buzzer {
+	uint32_t timer;
+	enum tim_oc_id channel;
+};
+
+void buzzer_init(struct buzzer *buzzer);
+void buzzer_enable(struct buzzer *buzzer);
+void buzzer_disable(struct buzzer *buzzer);
+void buzzer_set_freq(struct buzzer *buzzer, uint32_t freq);

source/platform/stm32f0/buzzer.c

@@ -0,0 +1,51 @@
+#include <libopencm3/stm32/gpio.h>
+#include <libopencm3/stm32/rcc.h>
+#include <libopencm3/stm32/timer.h>
+
+#include <buzzer.h>
+#include <macros.h>
+
+struct buzzer buzzers[] = {
+	{ TIM1, TIM_OC1 },
+	{ TIM2, TIM_OC2 },
+	{ TIM3, TIM_OC1 },
+	{ TIM14, TIM_OC1 },
+};
+
+size_t nbuzzers = count_of(buzzers);
+
+void buzzer_init(struct buzzer *buzzer)
+{
+	timer_reset(buzzer->timer);
+
+	timer_set_mode(buzzer->timer, TIM_CR1_CKD_CK_INT, TIM_CR1_CMS_EDGE, TIM_CR1_DIR_UP);
+
+	timer_set_prescaler(buzzer->timer, 48);
+	timer_set_repetition_counter(buzzer->timer, 0);
+	timer_enable_preload(buzzer->timer);
+	timer_enable_break_main_output(buzzer->timer);
+	timer_continuous_mode(buzzer->timer);
+
+	timer_disable_oc_output(buzzer->timer, buzzer->channel);
+	timer_set_oc_mode(buzzer->timer, buzzer->channel, TIM_OCM_PWM1);
+	timer_set_oc_value(buzzer->timer, buzzer->channel, 0);
+	timer_enable_oc_output(buzzer->timer, buzzer->channel);
+}
+
+void buzzer_enable(struct buzzer *buzzer)
+{
+	timer_enable_counter(buzzer->timer);
+}
+
+void buzzer_disable(struct buzzer *buzzer)
+{
+	timer_disable_counter(buzzer->timer);
+}
+
+void buzzer_set_freq(struct buzzer *buzzer, uint32_t freq)
+{
+	uint32_t period = 1000000 / freq;
+
+	timer_set_period(buzzer->timer, period);
+	timer_set_oc_value(buzzer->timer, buzzer->channel, period / 2);
+}

source/platform/stm32f1/buzzer.c

@@ -0,0 +1,49 @@
+#include <libopencm3/stm32/gpio.h>
+#include <libopencm3/stm32/rcc.h>
+#include <libopencm3/stm32/timer.h>
+
+#include <buzzer.h>
+#include <macros.h>
+
+struct buzzer buzzers[] = {
+	{ TIM2, TIM_OC3 },
+	{ TIM2, TIM_OC4 },
+};
+size_t nbuzzers = count_of(buzzers);
+
+void buzzer_init(struct buzzer *buzzer)
+{
+	timer_reset(buzzer->timer);
+
+	timer_set_mode(buzzer->timer, TIM_CR1_CKD_CK_INT, TIM_CR1_CMS_EDGE,
+		TIM_CR1_DIR_UP);
+
+	timer_set_prescaler(buzzer->timer, 72);
+	timer_set_repetition_counter(buzzer->timer, 0);
+	timer_enable_preload(buzzer->timer);
+	timer_enable_break_main_output(buzzer->timer);
+	timer_continuous_mode(buzzer->timer);
+
+	timer_disable_oc_output(buzzer->timer, buzzer->channel);
+	timer_set_oc_mode(buzzer->timer, buzzer->channel, TIM_OCM_PWM1);
+	timer_set_oc_value(buzzer->timer, buzzer->channel, 0);
+	timer_enable_oc_output(buzzer->timer, buzzer->channel);
+}
+
+void buzzer_enable(struct buzzer *buzzer)
+{
+	timer_enable_counter(buzzer->timer);
+}
+
+void buzzer_disable(struct buzzer *buzzer)
+{
+	timer_disable_counter(buzzer->timer);
+}
+
+void buzzer_set_freq(struct buzzer *buzzer, uint32_t freq)
+{
+	uint32_t period = 1000000 / freq;
+
+	timer_set_period(buzzer->timer, period);
+	timer_set_oc_value(buzzer->timer, buzzer->channel, period / 2);
+}