Add flexcomm function selection unit tests.

Signed-off-by: Octavian Purdila <tavip@google.com>
---
 tests/qtest/flexcomm-test.c | 86 +++++++++++++++++++++++++++++++++++++
 tests/qtest/meson.build     |  1 +
 2 files changed, 87 insertions(+)
 create mode 100644 tests/qtest/flexcomm-test.c

diff --git a/tests/qtest/flexcomm-test.c b/tests/qtest/flexcomm-test.c
new file mode 100644
index 0000000000..2258633646
--- /dev/null
+++ b/tests/qtest/flexcomm-test.c
@@ -0,0 +1,86 @@
+/*
+ * Copyright (C) 2024 Google LLC
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/log.h"
+#include "qemu/module.h"
+#include "qemu/main-loop.h"
+#include "exec/memory.h"
+#include "hw/irq.h"
+#include "hw/qdev-properties.h"
+
+#include "hw/misc/flexcomm.h"
+#include "hw/arm/svd/flexcomm.h"
+#include "hw/arm/svd/rt500.h"
+#include "reg-utils.h"
+
+#define FLEXCOMM_BASE RT500_FLEXCOMM0_BASE
+
+static void select_test(gconstpointer data)
+{
+    static const struct {
+        int persel;
+        int func;
+    } persel_func_map[] = {
+        { FLEXCOMM_PERSEL_USART, FLEXCOMM_FUNC_USART },
+        { FLEXCOMM_PERSEL_SPI, FLEXCOMM_FUNC_SPI },
+        { FLEXCOMM_PERSEL_I2C, FLEXCOMM_FUNC_I2C },
+    };
+
+    g_assert(REG32_READ_FIELD(FLEXCOMM, PSELID, PERSEL) == 0);
+
+    /* no register access until a function is selected  */
+    readl_fail(FLEXCOMM_BASE);
+    writel_fail(FLEXCOMM_BASE, 0);
+
+    for (int i = 0; i < ARRAY_SIZE(persel_func_map); i++) {
+        int persel = persel_func_map[i].persel;
+
+        REG32_WRITE(FLEXCOMM, PSELID, persel);
+        g_assert_cmpuint(REG32_READ_FIELD(FLEXCOMM, PSELID, PERSEL), ==,
+                         persel);
+
+        /* test that we can access function registers */
+        writel(FLEXCOMM_BASE + 0x10, 0xabcd);
+        readl(FLEXCOMM_BASE + 0x10);
+    }
+
+    /* try to select something invalid */
+    REG32_WRITE(FLEXCOMM, PSELID, 7);
+    /* check for no function selected */
+    g_assert_cmpuint(REG32_READ_FIELD(FLEXCOMM, PSELID, PERSEL), ==, 0);
+
+    /* now select and lock USART */
+    REG32_WRITE(FLEXCOMM, PSELID,
+                FIELD_DP32(FLEXCOMM_PERSEL_USART, FLEXCOMM_PSELID, LOCK, 1));
+    g_assert_cmpuint(REG32_READ_FIELD(FLEXCOMM, PSELID, PERSEL), ==,
+                     FLEXCOMM_PERSEL_USART);
+    g_assert_cmpuint(REG32_READ_FIELD(FLEXCOMM, PSELID, LOCK), ==, 1);
+
+    /* try to change the selection to spi */
+    REG32_WRITE(FLEXCOMM, PSELID, FLEXCOMM_PERSEL_SPI);
+    /* it should still be locked USART */
+    g_assert_cmpuint(REG32_READ_FIELD(FLEXCOMM, PSELID, PERSEL), ==,
+                     FLEXCOMM_PERSEL_USART);
+    g_assert_cmpuint(REG32_READ_FIELD(FLEXCOMM, PSELID, LOCK), ==, 1);
+}
+
+int main(int argc, char **argv)
+{
+    int ret;
+
+    g_test_init(&argc, &argv, NULL);
+
+    qtest_add_data_func("/flexcomm/select", NULL, select_test);
+    qtest_start("-M rt595-evk");
+    ret = g_test_run();
+    qtest_end();
+
+    return ret;
+}
diff --git a/tests/qtest/meson.build b/tests/qtest/meson.build
index 12792948ff..9631b6c401 100644
--- a/tests/qtest/meson.build
+++ b/tests/qtest/meson.build
@@ -229,6 +229,7 @@ qtests_arm = \
   (config_all_devices.has_key('CONFIG_FSI_APB2OPB_ASPEED') ? ['aspeed_fsi-test'] : []) + \
   (config_all_devices.has_key('CONFIG_STM32L4X5_SOC') and
    config_all_devices.has_key('CONFIG_DM163')? ['dm163-test'] : []) + \
+  (config_all_devices.has_key('CONFIG_FLEXCOMM')? ['flexcomm-test'] : []) + \
   ['arm-cpu-features',
    'boot-serial-test']
 
-- 
2.46.0.295.g3b9ea8a38a-goog