tests/qtest: Check STM32L4x5 clock connections

For USART, GPIO and SYSCFG devices, check that clock frequency before
and after enabling the peripheral clock in RCC is correct.

Signed-off-by: Inès Varhol <ines.varhol@telecom-paris.fr>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Luc Michel <luc@lmichel.fr>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-id: 20241003081105.40836-4-ines.varhol@telecom-paris.fr
[PMM: Added missing qtest_quit() call]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

tests/qtest/stm32l4x5.h

@@ -0,0 +1,42 @@
+/*
+ * QTest testcase header for STM32L4X5 :
+ * used for consolidating common objects in stm32l4x5_*-test.c
+ *
+ * Copyright (c) 2024 Arnaud Minier <arnaud.minier@telecom-paris.fr>
+ * Copyright (c) 2024 Inès Varhol <ines.varhol@telecom-paris.fr>
+ *
+ * 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 "libqtest.h"
+
+/* copied from clock.h */
+#define CLOCK_PERIOD_1SEC (1000000000llu << 32)
+#define CLOCK_PERIOD_FROM_HZ(hz) (((hz) != 0) ? CLOCK_PERIOD_1SEC / (hz) : 0u)
+/*
+ * MSI (4 MHz) is used as system clock source after startup
+ * from Reset.
+ * AHB, APB1 and APB2 prescalers are set to 1 at reset.
+ */
+#define SYSCLK_PERIOD CLOCK_PERIOD_FROM_HZ(4000000)
+#define RCC_AHB2ENR 0x4002104C
+#define RCC_APB1ENR1 0x40021058
+#define RCC_APB1ENR2 0x4002105C
+#define RCC_APB2ENR 0x40021060
+
+
+static inline uint64_t get_clock_period(QTestState *qts, const char *path)
+{
+    uint64_t clock_period = 0;
+    QDict *r;
+
+    r = qtest_qmp(qts, "{ 'execute': 'qom-get', 'arguments':"
+        " { 'path': %s, 'property': 'qtest-clock-period'} }", path);
+    g_assert_false(qdict_haskey(r, "error"));
+    clock_period = qdict_get_int(r, "return");
+    qobject_unref(r);
+    return clock_period;
+}
+
+

tests/qtest/stm32l4x5_gpio-test.c

@@ -10,6 +10,7 @@
 
 #include "qemu/osdep.h"
 #include "libqtest-single.h"
+#include "stm32l4x5.h"
 
 #define GPIO_BASE_ADDR 0x48000000
 #define GPIO_SIZE      0x400
@@ -505,6 +506,26 @@ static void test_bsrr_brr(const void *data)
     gpio_writel(gpio, ODR, reset(gpio, ODR));
 }
 
+static void test_clock_enable(void)
+{
+    /*
+     * For each GPIO, enable its clock in RCC
+     * and check that its clock period changes to SYSCLK_PERIOD
+     */
+    unsigned int gpio_id;
+
+    for (uint32_t gpio = GPIO_A; gpio <= GPIO_H; gpio += GPIO_B - GPIO_A) {
+        gpio_id = get_gpio_id(gpio);
+        g_autofree char *path = g_strdup_printf("/machine/soc/gpio%c/clk",
+                                                gpio_id + 'a');
+        g_assert_cmpuint(get_clock_period(global_qtest, path), ==, 0);
+        /* Enable the gpio clock */
+        writel(RCC_AHB2ENR, readl(RCC_AHB2ENR) | (0x1 << gpio_id));
+        g_assert_cmpuint(get_clock_period(global_qtest, path), ==,
+                         SYSCLK_PERIOD);
+    }
+}
+
 int main(int argc, char **argv)
 {
     int ret;
@@ -556,6 +577,8 @@ int main(int argc, char **argv)
     qtest_add_data_func("stm32l4x5/gpio/test_bsrr_brr2",
                         test_data(GPIO_D, 0),
                         test_bsrr_brr);
+    qtest_add_func("stm32l4x5/gpio/test_clock_enable",
+                   test_clock_enable);
 
     qtest_start("-machine b-l475e-iot01a");
     ret = g_test_run();

tests/qtest/stm32l4x5_syscfg-test.c

@@ -10,6 +10,7 @@
 
 #include "qemu/osdep.h"
 #include "libqtest-single.h"
+#include "stm32l4x5.h"
 
 #define SYSCFG_BASE_ADDR 0x40010000
 #define SYSCFG_MEMRMP 0x00
@@ -26,7 +27,9 @@
 #define INVALID_ADDR 0x2C
 
 /* SoC forwards GPIOs to SysCfg */
-#define SYSCFG "/machine/soc"
+#define SOC "/machine/soc"
+#define SYSCFG "/machine/soc/syscfg"
+#define SYSCFG_CLK "/machine/soc/syscfg/clk"
 #define EXTI "/machine/soc/exti"
 
 static void syscfg_writel(unsigned int offset, uint32_t value)
@@ -41,7 +44,7 @@ static uint32_t syscfg_readl(unsigned int offset)
 
 static void syscfg_set_irq(int num, int level)
 {
-   qtest_set_irq_in(global_qtest, SYSCFG, NULL, num, level);
+   qtest_set_irq_in(global_qtest, SOC, NULL, num, level);
 }
 
 static void system_reset(void)
@@ -301,6 +304,17 @@ static void test_irq_gpio_multiplexer(void)
     syscfg_writel(SYSCFG_EXTICR1, 0x00000000);
 }
 
+static void test_clock_enable(void)
+{
+    g_assert_cmpuint(get_clock_period(global_qtest, SYSCFG_CLK), ==, 0);
+
+    /* Enable SYSCFG clock */
+    writel(RCC_APB2ENR, readl(RCC_APB2ENR) | (0x1 << 0));
+
+    g_assert_cmpuint(get_clock_period(global_qtest, SYSCFG_CLK), ==,
+                                       SYSCLK_PERIOD);
+}
+
 int main(int argc, char **argv)
 {
     int ret;
@@ -325,6 +339,8 @@ int main(int argc, char **argv)
                    test_irq_pin_multiplexer);
     qtest_add_func("stm32l4x5/syscfg/test_irq_gpio_multiplexer",
                    test_irq_gpio_multiplexer);
+    qtest_add_func("stm32l4x5/syscfg/test_clock_enable",
+                   test_clock_enable);
 
     qtest_start("-machine b-l475e-iot01a");
     ret = g_test_run();

tests/qtest/stm32l4x5_usart-test.c

@@ -12,6 +12,7 @@
 #include "libqtest.h"
 #include "hw/misc/stm32l4x5_rcc_internals.h"
 #include "hw/registerfields.h"
+#include "stm32l4x5.h"
 
 #define RCC_BASE_ADDR 0x40021000
 /* Use USART 1 ADDR, assume the others work the same */
@@ -331,6 +332,32 @@ static void test_ack(void)
     qtest_quit(qts);
 }
 
+static void check_clock(QTestState *qts, const char *path, uint32_t rcc_reg,
+                        uint32_t reg_offset)
+{
+    g_assert_cmpuint(get_clock_period(qts, path), ==, 0);
+    qtest_writel(qts, rcc_reg, qtest_readl(qts, rcc_reg) | (0x1 << reg_offset));
+    g_assert_cmpuint(get_clock_period(qts, path), ==, SYSCLK_PERIOD);
+}
+
+static void test_clock_enable(void)
+{
+    /*
+     * For each USART device, enable its clock in RCC
+     * and check that its clock frequency is SYSCLK_PERIOD
+     */
+    QTestState *qts = qtest_init("-M b-l475e-iot01a");
+
+    check_clock(qts, "machine/soc/usart[0]/clk", RCC_APB2ENR, 14);
+    check_clock(qts, "machine/soc/usart[1]/clk", RCC_APB1ENR1, 17);
+    check_clock(qts, "machine/soc/usart[2]/clk", RCC_APB1ENR1, 18);
+    check_clock(qts, "machine/soc/uart[0]/clk", RCC_APB1ENR1, 19);
+    check_clock(qts, "machine/soc/uart[1]/clk", RCC_APB1ENR1, 20);
+    check_clock(qts, "machine/soc/lpuart1/clk", RCC_APB1ENR2, 0);
+
+    qtest_quit(qts);
+}
+
 int main(int argc, char **argv)
 {
     int ret;
@@ -344,6 +371,7 @@ int main(int argc, char **argv)
     qtest_add_func("stm32l4x5/usart/receive_str", test_receive_str);
     qtest_add_func("stm32l4x5/usart/send_str", test_send_str);
     qtest_add_func("stm32l4x5/usart/ack", test_ack);
+    qtest_add_func("stm32l4x5/usart/clock_enable", test_clock_enable);
     ret = g_test_run();
 
     return ret;