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Diffstat (limited to 'examples/stm32/l1/stm32l-discovery/button-irq-printf-lowpower/main.c')
-rw-r--r--examples/stm32/l1/stm32l-discovery/button-irq-printf-lowpower/main.c300
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diff --git a/examples/stm32/l1/stm32l-discovery/button-irq-printf-lowpower/main.c b/examples/stm32/l1/stm32l-discovery/button-irq-printf-lowpower/main.c
new file mode 100644
index 0000000..3f19319
--- /dev/null
+++ b/examples/stm32/l1/stm32l-discovery/button-irq-printf-lowpower/main.c
@@ -0,0 +1,300 @@
+/*
+ * This file is part of the libopencm3 project.
+ *
+ * Copyright (C) 2012 Karl Palsson <karlp@tweak.net.au>
+ *
+ * This library is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This library 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <errno.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <libopencm3/cm3/nvic.h>
+#include <libopencm3/cm3/scb.h>
+#include <libopencm3/stm32/dbgmcu.h>
+#include <libopencm3/stm32/gpio.h>
+#include <libopencm3/stm32/pwr.h>
+#include <libopencm3/stm32/exti.h>
+#include <libopencm3/stm32/timer.h>
+#include <libopencm3/stm32/usart.h>
+#include <libopencm3/stm32/rtc.h>
+#include <libopencm3/stm32/l1/rcc.h>
+#include <libopencm3/stm32/l1/flash.h>
+
+#include "syscfg.h"
+
+static volatile struct state_t state;
+
+__attribute__((always_inline)) static inline void __WFI(void)
+{
+ __asm volatile ("wfi");
+}
+
+void gpio_setup(void)
+{
+ /* green led for ticking, blue for button feedback */
+ gpio_mode_setup(LED_DISCO_GREEN_PORT, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, LED_DISCO_GREEN_PIN);
+ gpio_mode_setup(LED_DISCO_BLUE_PORT, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, LED_DISCO_BLUE_PIN);
+
+ /* Setup GPIO pins for USART2 transmit. */
+ gpio_mode_setup(GPIOA, GPIO_MODE_AF, GPIO_PUPD_NONE, GPIO2);
+
+ /* Setup USART2 TX pin as alternate function. */
+ gpio_set_af(GPIOA, GPIO_AF7, GPIO2);
+}
+
+void BUTTON_DISCO_USER_isr(void)
+{
+ exti_reset_request(BUTTON_DISCO_USER_EXTI);
+ state.pressed = true;
+ if (state.falling) {
+ state.falling = false;
+ exti_set_trigger(BUTTON_DISCO_USER_EXTI, EXTI_TRIGGER_RISING);
+ state.hold_time = TIM_CNT(TIMER_BUTTON_PRESS);
+ } else {
+ state.falling = true;
+ exti_set_trigger(BUTTON_DISCO_USER_EXTI, EXTI_TRIGGER_FALLING);
+ state.hold_time = TIM_CNT(TIMER_BUTTON_PRESS) = 0;
+ }
+}
+
+void setup_buttons(void)
+{
+ /* Enable EXTI0 interrupt. */
+ nvic_enable_irq(BUTTON_DISCO_USER_NVIC);
+
+ gpio_mode_setup(BUTTON_DISCO_USER_PORT, GPIO_MODE_INPUT, GPIO_PUPD_NONE, BUTTON_DISCO_USER_PIN);
+
+ /* Configure the EXTI subsystem. */
+ exti_select_source(BUTTON_DISCO_USER_EXTI, BUTTON_DISCO_USER_PORT);
+ state.falling = false;
+ exti_set_trigger(BUTTON_DISCO_USER_EXTI, EXTI_TRIGGER_RISING);
+ exti_enable_request(BUTTON_DISCO_USER_EXTI);
+}
+
+void usart_setup(void)
+{
+ usart_set_baudrate(USART_CONSOLE, 115200);
+ usart_set_databits(USART_CONSOLE, 8);
+ usart_set_stopbits(USART_CONSOLE, USART_STOPBITS_1);
+ usart_set_mode(USART_CONSOLE, USART_MODE_TX);
+ usart_set_parity(USART_CONSOLE, USART_PARITY_NONE);
+ usart_set_flow_control(USART_CONSOLE, USART_FLOWCONTROL_NONE);
+
+ /* Finally enable the USART. */
+ usart_enable(USART_CONSOLE);
+}
+
+/**
+ * Use USART_CONSOLE as a console.
+ * @param file
+ * @param ptr
+ * @param len
+ * @return
+ */
+int _write(int file, char *ptr, int len)
+{
+ int i;
+
+ if (file == STDOUT_FILENO || file == STDERR_FILENO) {
+ for (i = 0; i < len; i++) {
+ if (ptr[i] == '\n') {
+ usart_send_blocking(USART_CONSOLE, '\r');
+ }
+ usart_send_blocking(USART_CONSOLE, ptr[i]);
+ }
+ return i;
+ }
+ errno = EIO;
+ return -1;
+}
+
+/*
+ * Free running ms timer.
+ */
+void setup_button_press_timer(void)
+{
+ timer_reset(TIMER_BUTTON_PRESS);
+ timer_set_prescaler(TIMER_BUTTON_PRESS, 3999); // 4Mhz/1000hz - 1
+ timer_set_period(TIMER_BUTTON_PRESS, 0xffff);
+ timer_enable_counter(TIMER_BUTTON_PRESS);
+}
+
+int setup_rtc(void)
+{
+ /* turn on power block to enable unlocking */
+ rcc_peripheral_enable_clock(&RCC_APB1ENR, RCC_APB1ENR_PWREN);
+ pwr_disable_backup_domain_write_protect();
+
+ /* reset rtc */
+ RCC_CSR |= RCC_CSR_RTCRST;
+ RCC_CSR &= ~RCC_CSR_RTCRST;
+
+ /* We want to use the LSE fitted on the discovery board */
+ rcc_osc_on(LSE);
+ rcc_wait_for_osc_ready(LSE);
+
+ /* Select the LSE as rtc clock */
+ rcc_rtc_select_clock(RCC_CSR_RTCSEL_LSE);
+
+ /* ?! Stdperiph examples don't turn this on until _afterwards_ which
+ * simply doesn't work. It must be on at least to be able to configure it */
+ RCC_CSR |= RCC_CSR_RTCEN;
+
+ rtc_unlock();
+
+ /* enter init mode */
+ RTC_ISR |= RTC_ISR_INIT;
+ while ((RTC_ISR & RTC_ISR_INITF) == 0)
+ ;
+
+ /* set synch prescaler, using defaults for 1Hz out */
+ u32 sync = 255;
+ u32 async = 127;
+ rtc_set_prescaler(sync, async);
+
+ /* load time and date here if desired, and hour format */
+
+ /* exit init mode */
+ RTC_ISR &= ~(RTC_ISR_INIT);
+
+ /* and write protect again */
+ rtc_lock();
+
+ /* and finally enable the clock */
+ RCC_CSR |= RCC_CSR_RTCEN;
+
+ /* And wait for synchro.. */
+ rtc_wait_for_synchro();
+ return 0;
+}
+
+int setup_rtc_wakeup(int period)
+{
+ rtc_unlock();
+
+ /* ensure wakeup timer is off */
+ RTC_CR &= ~RTC_CR_WUTE;
+
+ /* Wait until we can write */
+ while ((RTC_ISR & RTC_ISR_WUTWF) == 0)
+ ;
+
+ RTC_WUTR = period - 1;
+
+ /* Use the 1Hz clock as source */
+ RTC_CR &= ~(RTC_CR_WUCLKSEL_MASK << RTC_CR_WUCLKSEL_SHIFT);
+ RTC_CR |= (RTC_CR_WUCLKSEL_SPRE << RTC_CR_WUCLKSEL_SHIFT);
+
+ /* Restart WakeUp unit */
+ RTC_CR |= RTC_CR_WUTE;
+
+ /* interrupt configuration */
+
+ /* also, let's have an interrupt */
+ RTC_CR |= RTC_CR_WUTIE;
+
+ /* done with rtc registers, lock them again */
+ rtc_lock();
+
+
+ nvic_enable_irq(NVIC_RTC_WKUP_IRQ);
+
+ // EXTI configuration
+ /* Configure the EXTI subsystem. */
+ // not needed, this chooses ports exti_select_source(EXTI20, BUTTON_DISCO_USER_PORT);
+ exti_set_trigger(EXTI20, EXTI_TRIGGER_RISING);
+ exti_enable_request(EXTI20);
+ return 0;
+}
+
+void rtc_wkup_isr(void)
+{
+ /* clear flag, not write protected */
+ RTC_ISR &= ~(RTC_ISR_WUTF);
+ exti_reset_request(EXTI20);
+ state.rtc_ticked = true;
+}
+
+int process_state(volatile struct state_t *st)
+{
+ if (st->rtc_ticked) {
+ st->rtc_ticked = 0;
+ printf("Tick: %x\n", (unsigned int) RTC_TR);
+#if FULL_USER_EXPERIENCE
+ gpio_toggle(LED_DISCO_GREEN_PORT, LED_DISCO_GREEN_PIN);
+#else
+ gpio_clear(LED_DISCO_GREEN_PORT, LED_DISCO_GREEN_PIN);
+#endif
+ }
+ if (st->pressed) {
+ st->pressed = false;
+ if (st->falling) {
+ gpio_set(LED_DISCO_BLUE_PORT, LED_DISCO_BLUE_PIN);
+ printf("Pushed down!\n");
+ } else {
+ gpio_clear(LED_DISCO_BLUE_PORT, LED_DISCO_BLUE_PIN);
+ printf("held: %u ms\n", st->hold_time);
+ }
+ }
+ return 0;
+}
+
+void reset_clocks(void)
+{
+ /* 4MHz MSI raw range 2*/
+ clock_scale_t myclock_config = {
+ .hpre = RCC_CFGR_HPRE_SYSCLK_NODIV,
+ .ppre1 = RCC_CFGR_PPRE1_HCLK_NODIV,
+ .ppre2 = RCC_CFGR_PPRE2_HCLK_NODIV,
+ .voltage_scale = RANGE2,
+ .flash_config = FLASH_LATENCY_0WS,
+ .apb1_frequency = 4194000,
+ .apb2_frequency = 4194000,
+ .msi_range = RCC_ICSCR_MSIRANGE_4MHZ,
+ };
+ rcc_clock_setup_msi(&myclock_config);
+
+ /* buttons and uarts */
+ rcc_peripheral_enable_clock(&RCC_AHBENR, RCC_AHBENR_GPIOAEN);
+ /* user feedback leds */
+ rcc_peripheral_enable_clock(&RCC_AHBENR, RCC_AHBENR_GPIOBEN);
+ /* Enable clocks for USART2. */
+ rcc_peripheral_enable_clock(&RCC_APB1ENR, RCC_APB1ENR_USART2EN);
+ /* And a timers for button presses */
+ rcc_peripheral_enable_clock(&RCC_APB1ENR, RCC_APB1ENR_TIM7EN);
+}
+
+int main(void)
+{
+ reset_clocks();
+ gpio_setup();
+ usart_setup();
+ setup_buttons();
+ setup_button_press_timer();
+ printf("we're awake!\n");
+
+ setup_rtc();
+ setup_rtc_wakeup(1);
+
+ while (1) {
+ PWR_CR |= PWR_CR_LPSDSR;
+ pwr_set_stop_mode();
+ __WFI();
+ reset_clocks();
+ process_state(&state);
+ }
+
+ return 0;
+} \ No newline at end of file