add irq latency test code

Author: rcitach

examples/utest/testcases/pref/Kconfig

@@ -29,4 +29,9 @@ config UTEST_SYS_CONTEXT_SWITCH
     bool "system context switch test"
     default n
 
+config UTEST_SYS_IRQ_LATENCY
+    bool "system context switch test"
+    default n
+    depends on RT_USING_HWTIMER
+
 endmenu

examples/utest/testcases/pref/SConscript

@@ -8,6 +8,9 @@ CPPPATH = [cwd]
 if GetDepend(['UTEST_SYS_CONTEXT_SWITCH']):
     src += ['context_switch.c']
 
+if GetDepend(['UTEST_SYS_IRQ_LATENCY']):
+    src += ['irq_latency.c']
+
 group = DefineGroup('utestcases', src, depend = ['UTEST_SYS_PREF_TC'], CPPPATH = CPPPATH)
 
 Return('group')

examples/utest/testcases/pref/irq_latency.c

@@ -0,0 +1,119 @@
+/*
+ * Copyright (c) 2006-2025, RT-Thread Development Team
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2025-07-03     rcitach      test case for irq latency
+ */
+
+#include <rtthread.h>
+#include <rtdevice.h>
+#include <utest.h>
+#include <utest_assert.h>
+
+#define IRQ_LATENCY 1000
+
+static rt_device_t hw_dev = RT_NULL;
+static rt_sem_t test_sem = RT_NULL;
+static rt_hwtimerval_t timeout_s = {0};
+volatile static rt_bool_t complete = RT_FALSE;
+volatile static uint16_t irq_latency_count = 0;
+static rt_hwtimerval_t irq_time[IRQ_LATENCY];
+
+static rt_size_t get_timer_us(rt_hwtimerval_t *timeout_s)
+{
+    if (hw_dev)
+        return rt_device_read(hw_dev, 0, timeout_s, sizeof(rt_hwtimerval_t));
+    return 0;
+}
+
+static rt_err_t timer_callback(rt_device_t dev, rt_size_t size)
+{
+    get_timer_us(&irq_time[irq_latency_count]);
+    irq_latency_count++;
+    rt_device_control(hw_dev, HWTIMER_CTRL_STOP, RT_NULL);
+    if (irq_latency_count >= IRQ_LATENCY)
+    {
+        complete = RT_TRUE;
+        rt_sem_release(test_sem);
+        return RT_EOK;
+    }
+
+    rt_device_write(hw_dev, 0, &timeout_s, sizeof(rt_hwtimerval_t));
+    return RT_EOK;
+}
+
+void irq_latency_test(void)
+{
+    uint32_t total_time = 0;
+    timeout_s.sec = 0;
+    timeout_s.usec = 1000;
+    rt_device_write(hw_dev, 0, &timeout_s, sizeof(rt_hwtimerval_t));
+
+    rt_sem_take(test_sem, RT_WAITING_FOREVER);
+    for (int i = 0; i < IRQ_LATENCY; i++)
+    {
+        total_time += ((irq_time[i].sec - timeout_s.sec) * 1000000) + (irq_time[i].usec - timeout_s.usec);
+    }
+
+    LOG_I("Total time for %d interrupts: %u us", IRQ_LATENCY, total_time);
+    LOG_I("Average interrupt latency: %u us", total_time / IRQ_LATENCY);
+}
+
+static rt_err_t utest_tc_init(void)
+{
+    rt_hwtimer_mode_t mode = HWTIMER_MODE_PERIOD;
+
+    test_sem = rt_sem_create("irq_test", 0, RT_IPC_FLAG_FIFO);
+    if (test_sem == RT_NULL)
+    {
+        rt_kprintf("Failed to create semaphore\n");
+        return -RT_ERROR;
+    }
+
+    hw_dev = rt_device_find(UTEST_HWTIMER_DEV_NAME);
+    if (hw_dev == RT_NULL)
+    {
+        rt_kprintf("hwtimer sample run failed! can't find %s device!\n", UTEST_HWTIMER_DEV_NAME);
+        rt_sem_delete(test_sem);
+        return -RT_ERROR;
+    }
+
+    rt_err_t ret = rt_device_open(hw_dev, RT_DEVICE_OFLAG_RDWR);
+    if (ret != RT_EOK)
+    {
+        rt_kprintf("open %s device failed!\n", UTEST_HWTIMER_DEV_NAME);
+        rt_sem_delete(test_sem);
+        return ret;
+    }
+
+    rt_device_set_rx_indicate(hw_dev, timer_callback);
+    rt_device_control(hw_dev, HWTIMER_CTRL_MODE_SET, (void *)&mode);
+
+    return RT_EOK;
+}
+
+static rt_err_t utest_tc_cleanup(void)
+{
+    complete = RT_FALSE;
+    irq_latency_count = 0;
+    rt_memset(irq_time, 0, sizeof(irq_time));
+    if (test_sem)
+    {
+        rt_sem_delete(test_sem);
+        test_sem = RT_NULL;
+    }
+#ifdef USING_HWTIME_AS_TIME_REF
+    if (hw_dev) rt_device_close(hw_dev);
+#endif
+    return RT_EOK;
+}
+
+static void testcase(void)
+{
+    UTEST_UNIT_RUN(irq_latency_test);
+}
+
+UTEST_TC_EXPORT(testcase, "testcase.pref.irq_latency", utest_tc_init, utest_tc_cleanup, 10);