bench_pm: Helper application for testing pm behavior

bench_pm/Makefile

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+APPLICATION = bench_pm
+BOARD ?= frdm-kw41z
+
+RIOTBASE ?= $(CURDIR)/../../RIOT
+QUIET ?= 1
+DEVELHELP ?= 1
+
+FEATURES_OPTIONAL = periph_rtt periph_gpio_irq
+
+# Disable auto_init to avoid starting any extra services
+DISABLE_MODULE += auto_init
+
+include $(RIOTBASE)/Makefile.include

bench_pm/README.md

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+Purpose
+=======
+
+This project is used to provide a baseline for the power consumption of the
+platform when no software is interfering with the low power modes. The
+application is designed to be used as a test subject for measuring power
+consumption and timing of low power modes.
+
+Hardware requirements
+=====================
+
+The data collection relies on external measurement equipment. An oscilloscope,
+or logic analyzer and a multimeter is required for any meaningful measurements.
+
+Test outputs
+============
+
+The test uses the board's LED0, LED1 pins as feedback from the application to
+the logic analyzer to signal when a low power mode is exited.
+The wake up request is triggered by UART RX activity, or a configurable GPIO pin.
+
+Set up
+======
+
+Connect the logic analyzer to trigger on the chosen GPIO wake pin (or UART RX
+pin, if not using the GPIO), connect the LED0 pin to the logic analyzer as well.
+
+The LED0 pin will be asserted immediately when control returns to the main thread.
+The LED1 pin is asserted by the ISR.
+
+Tested hardware
+===============
+
+The application is designed to run on the FRDM-KW41Z (or a custom R41Z board),
+but some care has been taken to allow building for different platforms without
+any major changes.
+
+Future work
+===========
+
+The logic analyzer requirement could be eliminated by creating a measurement
+application which can run on a different board for driving the test and taking
+measurements.

bench_pm/main.c

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+/*
+ * Copyright (C) 2017-2018 SKF AB
+ * Copyright (C) 2014 Freie Universität Berlin
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser General
+ * Public License v2.1. See the file LICENSE in the top level directory for more
+ * details.
+ */
+
+/**
+ * @ingroup tests
+ * @{
+ *
+ * @file
+ * @brief       Test for low power modes and wake up timings
+ *
+ * This test will switch to different low power modes and wait for wake events.
+ *
+ * @author      Joakim Nohlgård <[email protected]>
+ *
+ * @}
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+
+#include "cpu.h"
+#include "board.h"
+#include "periph_conf.h"
+#include "periph/rtt.h"
+#ifdef MODULE_PM_LAYERED
+#include "pm_layered.h"
+#endif
+#ifdef MODULE_PERIPH_GPIO_IRQ
+#include "periph/gpio.h"
+#endif
+#ifdef MODULE_PERIPH_LLWU
+/* Kinetis specific low leakage mode handling */
+#include "llwu.h"
+#endif
+
+#ifndef ENABLE_DEBUG
+/* Enabling debug prints will affect timing measurements */
+#define ENABLE_DEBUG        (0)
+#endif
+#include "debug.h"
+
+#if COMA_MODE
+/* For testing deepest low power modes without any interference */
+#undef MODULE_PERIPH_GPIO_IRQ
+#undef MODULE_PERIPH_RTT
+#undef MODULE_PERIPH_LLWU
+#undef LED0_ON
+#undef LED1_ON
+#endif
+
+#ifdef MODULE_PERIPH_RTT
+#define PRINT_RTT() (printf("RTT: %" PRIu32 "\n", rtt_get_counter()))
+#else
+#define PRINT_RTT()
+#endif
+
+#ifdef MODULE_PERIPH_GPIO_IRQ
+#ifndef GPIO_WAKE_PIN
+#ifdef BTN0_PIN
+#define GPIO_WAKE_PIN       BTN0_PIN
+#else
+#error Missing GPIO_WAKE_PIN configuration
+#endif /* BTN0_PIN */
+#endif /* GPIO_WAKE_PIN */
+#endif /* MODULE_PERIPH_GPIO_IRQ */
+
+#ifdef MODULE_PERIPH_LLWU
+/* Platform specific configuration for testing Kinetis low leakage wake up module (LLWU) */
+#ifndef LLWU_WAKE_PIN
+/* This macro should correspond to the pin used in the GPIO_WAKE_PIN macro */
+#if defined(BOARD_FRDM_KW41Z)
+#define LLWU_WAKE_PIN       LLWU_WAKEUP_PIN_PTC4
+#elif defined(BOARD_FRDM_K22F)
+#define LLWU_WAKE_PIN       LLWU_WAKEUP_PIN_PTC1
+#elif defined(BOARD_FRDM_K64F)
+#define LLWU_WAKE_PIN       LLWU_WAKEUP_PIN_PTC6
+#endif
+#endif /* LLWU_WAKE_PIN */
+#endif /* MODULE_PERIPH_LLWU */
+
+#ifndef TEST_PIN_ON
+#ifdef LED0_ON
+#define TEST_PIN_ON         LED0_ON
+#define TEST_PIN_OFF        LED0_OFF
+#else
+#define TEST_PIN_ON
+#define TEST_PIN_OFF
+#endif /* LED0_ON */
+#endif /* TEST_PIN_ON */
+
+#ifndef TEST_ISR_PIN_ON
+#ifdef LED1_ON
+#define TEST_ISR_PIN_ON     LED1_ON
+#define TEST_ISR_PIN_OFF    LED1_OFF
+#else
+#define TEST_ISR_PIN_ON
+#define TEST_ISR_PIN_OFF
+#endif /* LED1_ON */
+#endif /* TEST_ISR_PIN_ON */
+
+#ifdef MODULE_PERIPH_RTT
+#define TICKS_TO_WAIT       (10 * RTT_FREQUENCY)
+#endif /* MODULE_PERIPH_RTT */
+
+static volatile unsigned busy = 0;
+
+#ifdef MODULE_PERIPH_RTT
+static void cb_rtt(void *arg)
+{
+    (void)arg;
+    TEST_ISR_PIN_ON;
+    DEBUG("RTT IRQ\n");
+
+    busy = 0;
+}
+#endif /* MODULE_PERIPH_RTT */
+
+#ifdef MODULE_PERIPH_LLWU
+static void cb_llwu(void *arg)
+{
+    (void)arg;
+    TEST_ISR_PIN_ON;
+    DEBUG("llwu pin\n");
+
+    busy = 0;
+}
+#endif /* MODULE_PERIPH_LLWU */
+
+#ifdef MODULE_PERIPH_GPIO_IRQ
+static void cb_gpio(void *arg)
+{
+    (void)arg;
+    TEST_ISR_PIN_ON;
+    DEBUG("gpio pin\n");
+
+    busy = 0;
+}
+#endif /* MODULE_PERIPH_GPIO_IRQ */
+
+int main(void)
+{
+    TEST_PIN_ON;
+    puts("\nRIOT power consumption and wake timing test application");
+
+#ifdef MODULE_PERIPH_LLWU
+    /* Kinetis specific */
+    puts("Enable LLWU wake up from RTC");
+    llwu_wakeup_module_enable(LLWU_WAKEUP_MODULE_RTC_ALARM);
+    puts("Enable LLWU IRQ on PTC4 (SW4) falling");
+    gpio_init(GPIO_WAKE_PIN, GPIO_IN);
+    llwu_wakeup_pin_set(LLWU_WAKE_PIN, LLWU_WAKEUP_EDGE_FALLING, cb_llwu, NULL);
+#endif /* MODULE_PERIPH_LLWU */
+
+#ifdef MODULE_PERIPH_GPIO_IRQ
+    puts("Enable GPIO IRQ on PTC4 (SW4) falling");
+    int res = gpio_init_int(GPIO_WAKE_PIN, GPIO_IN_PU, GPIO_FALLING, cb_gpio, NULL);
+    if (res != 0) {
+        printf("!! gpio_init_int: %d\n", res);
+    }
+#endif /* MODULE_PERIPH_GPIO_IRQ */
+
+#ifdef MODULE_PERIPH_RTT
+    puts("Initializing the RTT driver");
+    rtt_init();
+#endif /* MODULE_PERIPH_RTT */
+
+#if ENABLE_CLKOUT
+    /* Kinetis specific, clock monitor via CLKOUT on pin PTB3 */
+    puts("Enable CLKOUT on PTB3");
+    PORTB->PCR[3] = PORT_PCR_MUX(4);
+    /* Select which clock to output */
+    SIM->SOPT2 = (SIM->SOPT2 & ~SIM_SOPT2_CLKOUTSEL_MASK) | SIM_SOPT2_CLKOUTSEL(2);
+    /* Use a logic analyzer or oscilloscope to look at the signal */
+#endif
+
+#if COMA_MODE
+    puts("Coma mode, going to pm_set(0), not coming back");
+    while (1) {
+        pm_set(0);
+        puts("woke up unexpectedly, going to pm_set(0)");
+    }
+#endif
+
+    while (1) {
+        PRINT_RTT();
+        puts("Busy spin");
+        {
+#ifdef MODULE_PERIPH_RTT
+            uint32_t rtt_target = rtt_get_counter() + TICKS_TO_WAIT;
+            rtt_target &= RTT_MAX_VALUE;
+            rtt_set_alarm(rtt_target, cb_rtt, 0);
+#endif /* MODULE_PERIPH_RTT */
+            busy = 1;
+            TEST_PIN_OFF;
+            TEST_ISR_PIN_OFF;
+            while (busy) {
+                __asm__ volatile ("" ::: "memory");
+            }
+            TEST_PIN_ON;
+            PRINT_RTT();
+        }
+#ifdef MODULE_PM_LAYERED
+        for (int k = PM_NUM_MODES; 0 <= k; --k) {
+#ifdef MODULE_PERIPH_RTT
+            uint32_t rtt_target = rtt_get_counter() + TICKS_TO_WAIT;
+            rtt_target &= RTT_MAX_VALUE;
+            rtt_set_alarm(rtt_target, cb_rtt, 0);
+#endif /* MODULE_PERIPH_RTT */
+            PRINT_RTT();
+            printf("pm_set(%d)\n", k);
+            TEST_PIN_OFF;
+            TEST_ISR_PIN_OFF;
+            pm_set((unsigned)k);
+            TEST_PIN_ON;
+            printf("wake from %d\n", k);
+        }
+#endif
+    }
+    return 0;
+}