From: Arnaud Minier <arnaud.minier@telecom-paris.fr>

Tests:
- the ability to change the sysclk of the device
- the ability to enable/disable/configure the PLLs
- if the clock multiplexers work
- the register flags and the generation of irqs

Signed-off-by: Arnaud Minier <arnaud.minier@telecom-paris.fr>
Signed-off-by: Inès Varhol <ines.varhol@telecom-paris.fr>
Acked-by: Thomas Huth <thuth@redhat.com>
Message-id: 20240303140643.81957-9-arnaud.minier@telecom-paris.fr
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
---
 tests/qtest/stm32l4x5_rcc-test.c | 189 +++++++++++++++++++++++++++++++
 tests/qtest/meson.build          |   3 +-
 2 files changed, 191 insertions(+), 1 deletion(-)
 create mode 100644 tests/qtest/stm32l4x5_rcc-test.c

diff --git a/tests/qtest/stm32l4x5_rcc-test.c b/tests/qtest/stm32l4x5_rcc-test.c
new file mode 100644
index 00000000000..d927c655d13
--- /dev/null
+++ b/tests/qtest/stm32l4x5_rcc-test.c
@@ -0,0 +1,189 @@
+/*
+ * QTest testcase for STM32L4x5_RCC
+ *
+ * Copyright (c) 2023 Arnaud Minier <arnaud.minier@telecom-paris.fr>
+ * Copyright (c) 2023 Inès Varhol <ines.varhol@telecom-paris.fr>
+ *
+ * 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 "hw/registerfields.h"
+#include "libqtest-single.h"
+#include "hw/misc/stm32l4x5_rcc_internals.h"
+
+#define RCC_BASE_ADDR 0x40021000
+#define NVIC_ISER 0xE000E100
+#define NVIC_ISPR 0xE000E200
+#define NVIC_ICPR 0xE000E280
+#define RCC_IRQ 5
+
+static void enable_nvic_irq(unsigned int n)
+{
+    writel(NVIC_ISER, 1 << n);
+}
+
+static void unpend_nvic_irq(unsigned int n)
+{
+    writel(NVIC_ICPR, 1 << n);
+}
+
+static bool check_nvic_pending(unsigned int n)
+{
+    return readl(NVIC_ISPR) & (1 << n);
+}
+
+static void rcc_writel(unsigned int offset, uint32_t value)
+{
+    writel(RCC_BASE_ADDR + offset, value);
+}
+
+static uint32_t rcc_readl(unsigned int offset)
+{
+    return readl(RCC_BASE_ADDR + offset);
+}
+
+static void test_init_msi(void)
+{
+    /* MSIRANGE can be set only when MSI is OFF or READY */
+    rcc_writel(A_CR, R_CR_MSION_MASK);
+    /* Wait until MSI is stable */
+    g_assert_true((rcc_readl(A_CR) & R_CR_MSIRDY_MASK) == R_CR_MSIRDY_MASK);
+    /* TODO find a way to test MSI value */
+}
+
+static void test_set_msi_as_sysclk(void)
+{
+    /* Clocking from MSI, in case MSI was not the default source */
+    rcc_writel(A_CFGR, 0);
+    /* Wait until MSI is selected and stable */
+    g_assert_true((rcc_readl(A_CFGR) & R_CFGR_SWS_MASK) == 0);
+}
+
+static void test_init_pll(void)
+{
+    uint32_t value;
+
+    /*
+     * Update PLL and set MSI as the source clock.
+     * PLLM = 1 --> 000
+     * PLLN = 40 --> 40
+     * PPLLR = 2 --> 00
+     * PLLDIV = unused, PLLP = unused (SAI3), PLLQ = unused (48M1)
+     * SRC = MSI --> 01
+     */
+    rcc_writel(A_PLLCFGR, R_PLLCFGR_PLLREN_MASK |
+            (40 << R_PLLCFGR_PLLN_SHIFT) |
+            (0b01 << R_PLLCFGR_PLLSRC_SHIFT));
+
+    /* PLL activation */
+    value = rcc_readl(A_CR);
+    rcc_writel(A_CR, value | R_CR_PLLON_MASK);
+
+    /* Waiting for PLL lock. */
+    g_assert_true((rcc_readl(A_CR) & R_CR_PLLRDY_MASK) == R_CR_PLLRDY_MASK);
+
+    /* Switches on the PLL clock source */
+    value = rcc_readl(A_CFGR);
+    rcc_writel(A_CFGR, (value & ~R_CFGR_SW_MASK) |
+        (0b11 << R_CFGR_SW_SHIFT));
+
+    /* Wait until SYSCLK is stable. */
+    g_assert_true((rcc_readl(A_CFGR) & R_CFGR_SWS_MASK) ==
+        (0b11 << R_CFGR_SWS_SHIFT));
+}
+
+static void test_activate_lse(void)
+{
+    /* LSE activation, no LSE Bypass */
+    rcc_writel(A_BDCR, R_BDCR_LSEDRV_MASK | R_BDCR_LSEON_MASK);
+    g_assert_true((rcc_readl(A_BDCR) & R_BDCR_LSERDY_MASK) == R_BDCR_LSERDY_MASK);
+}
+
+static void test_irq(void)
+{
+    enable_nvic_irq(RCC_IRQ);
+
+    rcc_writel(A_CIER, R_CIER_LSIRDYIE_MASK);
+    rcc_writel(A_CSR, R_CSR_LSION_MASK);
+    g_assert_true(check_nvic_pending(RCC_IRQ));
+    rcc_writel(A_CICR, R_CICR_LSIRDYC_MASK);
+    unpend_nvic_irq(RCC_IRQ);
+
+    rcc_writel(A_CIER, R_CIER_LSERDYIE_MASK);
+    rcc_writel(A_BDCR, R_BDCR_LSEON_MASK);
+    g_assert_true(check_nvic_pending(RCC_IRQ));
+    rcc_writel(A_CICR, R_CICR_LSERDYC_MASK);
+    unpend_nvic_irq(RCC_IRQ);
+
+    /*
+     * MSI has been enabled by previous tests,
+     * shouln't generate an interruption.
+     */
+    rcc_writel(A_CIER, R_CIER_MSIRDYIE_MASK);
+    rcc_writel(A_CR, R_CR_MSION_MASK);
+    g_assert_false(check_nvic_pending(RCC_IRQ));
+
+    rcc_writel(A_CIER, R_CIER_HSIRDYIE_MASK);
+    rcc_writel(A_CR, R_CR_HSION_MASK);
+    g_assert_true(check_nvic_pending(RCC_IRQ));
+    rcc_writel(A_CICR, R_CICR_HSIRDYC_MASK);
+    unpend_nvic_irq(RCC_IRQ);
+
+    rcc_writel(A_CIER, R_CIER_HSERDYIE_MASK);
+    rcc_writel(A_CR, R_CR_HSEON_MASK);
+    g_assert_true(check_nvic_pending(RCC_IRQ));
+    rcc_writel(A_CICR, R_CICR_HSERDYC_MASK);
+    unpend_nvic_irq(RCC_IRQ);
+
+    /*
+     * PLL has been enabled by previous tests,
+     * shouln't generate an interruption.
+     */
+    rcc_writel(A_CIER, R_CIER_PLLRDYIE_MASK);
+    rcc_writel(A_CR, R_CR_PLLON_MASK);
+    g_assert_false(check_nvic_pending(RCC_IRQ));
+
+    rcc_writel(A_CIER, R_CIER_PLLSAI1RDYIE_MASK);
+    rcc_writel(A_CR, R_CR_PLLSAI1ON_MASK);
+    g_assert_true(check_nvic_pending(RCC_IRQ));
+    rcc_writel(A_CICR, R_CICR_PLLSAI1RDYC_MASK);
+    unpend_nvic_irq(RCC_IRQ);
+
+    rcc_writel(A_CIER, R_CIER_PLLSAI2RDYIE_MASK);
+    rcc_writel(A_CR, R_CR_PLLSAI2ON_MASK);
+    g_assert_true(check_nvic_pending(RCC_IRQ));
+    rcc_writel(A_CICR, R_CICR_PLLSAI2RDYC_MASK);
+    unpend_nvic_irq(RCC_IRQ);
+}
+
+int main(int argc, char **argv)
+{
+    int ret;
+
+    g_test_init(&argc, &argv, NULL);
+    g_test_set_nonfatal_assertions();
+    /*
+     * These test separately that we can enable the plls, change the sysclk,
+     * and enable different devices.
+     * They are dependent on one another.
+     * We assume that all operations that would take some time to have an effect
+     * (e.g. changing the PLL frequency) are done instantaneously.
+     */
+    qtest_add_func("stm32l4x5/rcc/init_msi", test_init_msi);
+    qtest_add_func("stm32l4x5/rcc/set_msi_as_sysclk",
+        test_set_msi_as_sysclk);
+    qtest_add_func("stm32l4x5/rcc/activate_lse", test_activate_lse);
+    qtest_add_func("stm32l4x5/rcc/init_pll", test_init_pll);
+
+    qtest_add_func("stm32l4x5/rcc/irq", test_irq);
+
+    qtest_start("-machine b-l475e-iot01a");
+    ret = g_test_run();
+    qtest_end();
+
+    return ret;
+}
diff --git a/tests/qtest/meson.build b/tests/qtest/meson.build
index bdc8bba7a98..31b9f4ede47 100644
--- a/tests/qtest/meson.build
+++ b/tests/qtest/meson.build
@@ -203,7 +203,8 @@ qtests_aspeed = \
 
 qtests_stm32l4x5 = \
   ['stm32l4x5_exti-test',
-   'stm32l4x5_syscfg-test']
+   'stm32l4x5_syscfg-test',
+   'stm32l4x5_rcc-test']
 
 qtests_arm = \
   (config_all_devices.has_key('CONFIG_MPS2') ? ['sse-timer-test'] : []) + \
-- 
2.34.1