tests: Add a simple test of the CMSDK APB dual timer

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

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Luc Michel <luc@lmichel.fr>
Message-id: 20210128114145.20536-6-peter.maydell@linaro.org
Message-id: 20210121190622.22000-6-peter.maydell@linaro.org

1 files changed, 130 insertions, 0 deletions

diff --git a/tests/qtest/cmsdk-apb-dualtimer-test.c b/tests/qtest/cmsdk-apb-dualtimer-test.c
new file mode 100644
index 0000000000..ad6a758289
--- /dev/null
+++ b/tests/qtest/cmsdk-apb-dualtimer-test.c
@@ -0,0 +1,130 @@
+/*
+ * QTest testcase for the CMSDK APB dualtimer 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 dualtimer; driven at 25MHz in mps2-an385, so 40ns per tick */
+#define TIMER_BASE 0x40002000
+
+#define TIMER1LOAD 0
+#define TIMER1VALUE 4
+#define TIMER1CONTROL 8
+#define TIMER1INTCLR 0xc
+#define TIMER1RIS 0x10
+#define TIMER1MIS 0x14
+#define TIMER1BGLOAD 0x18
+
+#define TIMER2LOAD 0x20
+#define TIMER2VALUE 0x24
+#define TIMER2CONTROL 0x28
+#define TIMER2INTCLR 0x2c
+#define TIMER2RIS 0x30
+#define TIMER2MIS 0x34
+#define TIMER2BGLOAD 0x38
+
+#define CTRL_ENABLE (1 << 7)
+#define CTRL_PERIODIC (1 << 6)
+#define CTRL_INTEN (1 << 5)
+#define CTRL_PRESCALE_1 (0 << 2)
+#define CTRL_PRESCALE_16 (1 << 2)
+#define CTRL_PRESCALE_256 (2 << 2)
+#define CTRL_32BIT (1 << 1)
+#define CTRL_ONESHOT (1 << 0)
+
+static void test_dualtimer(void)
+{
+    g_assert_true(readl(TIMER_BASE + TIMER1RIS) == 0);
+
+    /* Start timer: will fire after 40000 ns */
+    writel(TIMER_BASE + TIMER1LOAD, 1000);
+    /* enable in free-running, wrapping, interrupt mode */
+    writel(TIMER_BASE + TIMER1CONTROL, CTRL_ENABLE | CTRL_INTEN);
+
+    /* Step to just past the 500th tick and check VALUE */
+    clock_step(500 * 40 + 1);
+    g_assert_cmpuint(readl(TIMER_BASE + TIMER1RIS), ==, 0);
+    g_assert_cmpuint(readl(TIMER_BASE + TIMER1VALUE), ==, 500);
+
+    /* Just past the 1000th tick: timer should have fired */
+    clock_step(500 * 40);
+    g_assert_cmpuint(readl(TIMER_BASE + TIMER1RIS), ==, 1);
+    g_assert_cmpuint(readl(TIMER_BASE + TIMER1VALUE), ==, 0);
+
+    /*
+     * We are in free-running wrapping 16-bit mode, so on the following
+     * tick VALUE should have wrapped round to 0xffff.
+     */
+    clock_step(40);
+    g_assert_cmpuint(readl(TIMER_BASE + TIMER1VALUE), ==, 0xffff);
+
+    /* Check that any write to INTCLR clears interrupt */
+    writel(TIMER_BASE + TIMER1INTCLR, 1);
+    g_assert_cmpuint(readl(TIMER_BASE + TIMER1RIS), ==, 0);
+
+    /* Turn off the timer */
+    writel(TIMER_BASE + TIMER1CONTROL, 0);
+}
+
+static void test_prescale(void)
+{
+    g_assert_true(readl(TIMER_BASE + TIMER2RIS) == 0);
+
+    /* Start timer: will fire after 40 * 256 * 1000 == 1024000 ns */
+    writel(TIMER_BASE + TIMER2LOAD, 1000);
+    /* enable in periodic, wrapping, interrupt mode, prescale 256 */
+    writel(TIMER_BASE + TIMER2CONTROL,
+           CTRL_ENABLE | CTRL_INTEN | CTRL_PERIODIC | CTRL_PRESCALE_256);
+
+    /* Step to just past the 500th tick and check VALUE */
+    clock_step(40 * 256 * 501);
+    g_assert_cmpuint(readl(TIMER_BASE + TIMER2RIS), ==, 0);
+    g_assert_cmpuint(readl(TIMER_BASE + TIMER2VALUE), ==, 500);
+
+    /* Just past the 1000th tick: timer should have fired */
+    clock_step(40 * 256 * 500);
+    g_assert_cmpuint(readl(TIMER_BASE + TIMER2RIS), ==, 1);
+    g_assert_cmpuint(readl(TIMER_BASE + TIMER2VALUE), ==, 0);
+
+    /* In periodic mode the tick VALUE now reloads */
+    clock_step(40 * 256);
+    g_assert_cmpuint(readl(TIMER_BASE + TIMER2VALUE), ==, 1000);
+
+    /* Check that any write to INTCLR clears interrupt */
+    writel(TIMER_BASE + TIMER2INTCLR, 1);
+    g_assert_cmpuint(readl(TIMER_BASE + TIMER2RIS), ==, 0);
+
+    /* Turn off the timer */
+    writel(TIMER_BASE + TIMER2CONTROL, 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-dualtimer/dualtimer", test_dualtimer);
+    qtest_add_func("/cmsdk-apb-dualtimer/prescale", test_prescale);
+
+    r = g_test_run();
+
+    qtest_end();
+
+    return r;
+}