tests: Add a simple test of the CMSDK APB timer

Add a simple test of the CMSDK APB timer, since we're about to do
some refactoring of how it is clocked.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Luc Michel <luc@lmichel.fr>
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20210128114145.20536-4-peter.maydell@linaro.org
Message-id: 20210121190622.22000-4-peter.maydell@linaro.org

MAINTAINERS

@@ -581,6 +581,7 @@ F: include/hw/rtc/pl031.h
 F: include/hw/arm/primecell.h
 F: hw/timer/cmsdk-apb-timer.c
 F: include/hw/timer/cmsdk-apb-timer.h
+F: tests/qtest/cmsdk-apb-timer-test.c
 F: hw/timer/cmsdk-apb-dualtimer.c
 F: include/hw/timer/cmsdk-apb-dualtimer.h
 F: hw/char/cmsdk-apb-uart.c

tests/qtest/cmsdk-apb-timer-test.c

@@ -0,0 +1,75 @@
+/*
+ * QTest testcase for the CMSDK APB timer device
+ *
+ * Copyright (c) 2021 Linaro Limited
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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.
+ */
+
+#include "qemu/osdep.h"
+#include "libqtest-single.h"
+
+/* IoTKit/ARMSSE-200 timer0; driven at 25MHz in mps2-an385, so 40ns per tick */
+#define TIMER_BASE 0x40000000
+
+#define CTRL 0
+#define VALUE 4
+#define RELOAD 8
+#define INTSTATUS 0xc
+
+static void test_timer(void)
+{
+    g_assert_true(readl(TIMER_BASE + INTSTATUS) == 0);
+
+    /* Start timer: will fire after 40 * 1000 == 40000 ns */
+    writel(TIMER_BASE + RELOAD, 1000);
+    writel(TIMER_BASE + CTRL, 9);
+
+    /* Step to just past the 500th tick and check VALUE */
+    clock_step(40 * 500 + 1);
+    g_assert_cmpuint(readl(TIMER_BASE + INTSTATUS), ==, 0);
+    g_assert_cmpuint(readl(TIMER_BASE + VALUE), ==, 500);
+
+    /* Just past the 1000th tick: timer should have fired */
+    clock_step(40 * 500);
+    g_assert_cmpuint(readl(TIMER_BASE + INTSTATUS), ==, 1);
+    g_assert_cmpuint(readl(TIMER_BASE + VALUE), ==, 0);
+
+    /* VALUE reloads at the following tick */
+    clock_step(40);
+    g_assert_cmpuint(readl(TIMER_BASE + VALUE), ==, 1000);
+
+    /* Check write-1-to-clear behaviour of INTSTATUS */
+    writel(TIMER_BASE + INTSTATUS, 0);
+    g_assert_cmpuint(readl(TIMER_BASE + INTSTATUS), ==, 1);
+    writel(TIMER_BASE + INTSTATUS, 1);
+    g_assert_cmpuint(readl(TIMER_BASE + INTSTATUS), ==, 0);
+
+    /* Turn off the timer */
+    writel(TIMER_BASE + CTRL, 0);
+}
+
+int main(int argc, char **argv)
+{
+    int r;
+
+    g_test_init(&argc, &argv, NULL);
+
+    qtest_start("-machine mps2-an385");
+
+    qtest_add_func("/cmsdk-apb-timer/timer", test_timer);
+
+    r = g_test_run();
+
+    qtest_end();
+
+    return r;
+}

tests/qtest/meson.build

@@ -142,6 +142,7 @@ qtests_npcm7xx = \
    'npcm7xx_timer-test',
    'npcm7xx_watchdog_timer-test']
 qtests_arm = \
+  (config_all_devices.has_key('CONFIG_CMSDK_APB_TIMER') ? ['cmsdk-apb-timer-test'] : []) + \
   (config_all_devices.has_key('CONFIG_PFLASH_CFI02') ? ['pflash-cfi02-test'] : []) +         \
   (config_all_devices.has_key('CONFIG_NPCM7XX') ? qtests_npcm7xx : []) + \
   ['arm-cpu-features',