[PATCH v2 5/6] hw/arm: Add the USART to the stm32l4x5 SoC

[Arnaud Minier <arnaud.minier@telecom-paris.fr>]

Add the USART to the SoC and connect it to the other implemented devices.

Signed-off-by: Arnaud Minier <arnaud.minier@telecom-paris.fr>
Signed-off-by: Inès Varhol <ines.varhol@telecom-paris.fr>
---
 docs/system/arm/b-l475e-iot01a.rst |  2 +-
 hw/arm/Kconfig                     |  1 +
 hw/arm/stm32l4x5_soc.c             | 82 +++++++++++++++++++++++++++---
 include/hw/arm/stm32l4x5_soc.h     | 13 +++++
 4 files changed, 91 insertions(+), 7 deletions(-)

diff --git a/docs/system/arm/b-l475e-iot01a.rst b/docs/system/arm/b-l475e-iot01a.rst
index 0afef8e4f4..a76c9976c5 100644
--- a/docs/system/arm/b-l475e-iot01a.rst
+++ b/docs/system/arm/b-l475e-iot01a.rst
@@ -19,13 +19,13 @@ Currently B-L475E-IOT01A machine's only supports the following devices:
 - STM32L4x5 SYSCFG (System configuration controller)
 - STM32L4x5 RCC (Reset and clock control)
 - STM32L4x5 GPIOs (General-purpose I/Os)
+- STM32L4x5 USARTs, UARTs and LPUART (Serial ports)
 
 Missing devices
 """""""""""""""
 
 The B-L475E-IOT01A does *not* support the following devices:
 
-- Serial ports (UART)
 - Analog to Digital Converter (ADC)
 - SPI controller
 - Timer controller (TIMER)
diff --git a/hw/arm/Kconfig b/hw/arm/Kconfig
index 893a7bff66..098d043375 100644
--- a/hw/arm/Kconfig
+++ b/hw/arm/Kconfig
@@ -477,6 +477,7 @@ config STM32L4X5_SOC
     select STM32L4X5_SYSCFG
     select STM32L4X5_RCC
     select STM32L4X5_GPIO
+    select STM32L4X5_USART
 
 config XLNX_ZYNQMP_ARM
     bool
diff --git a/hw/arm/stm32l4x5_soc.c b/hw/arm/stm32l4x5_soc.c
index 40e294f838..ae0868dcab 100644
--- a/hw/arm/stm32l4x5_soc.c
+++ b/hw/arm/stm32l4x5_soc.c
@@ -28,6 +28,7 @@
 #include "sysemu/sysemu.h"
 #include "hw/or-irq.h"
 #include "hw/arm/stm32l4x5_soc.h"
+#include "hw/char/stm32l4x5_usart.h"
 #include "hw/gpio/stm32l4x5_gpio.h"
 #include "hw/qdev-clock.h"
 #include "hw/misc/unimp.h"
@@ -116,6 +117,22 @@ static const struct {
     { 0x48001C00, 0x0000000F, 0x00000000, 0x00000000 },
 };
 
+static const hwaddr usart_addr[] = {
+    0x40013800, /* "USART1", 0x400 */
+    0x40004400, /* "USART2", 0x400 */
+    0x40004800, /* "USART3", 0x400 */
+};
+static const hwaddr uart_addr[] = {
+    0x40004C00, /* "UART4" , 0x400 */
+    0x40005000  /* "UART5" , 0x400 */
+};
+
+#define LPUART_BASE_ADDRESS 0x40008000
+
+static const int usart_irq[] = { 37, 38, 39 };
+static const int uart_irq[] = { 52, 53 };
+#define LPUART_IRQ 70
+
 static void stm32l4x5_soc_initfn(Object *obj)
 {
     Stm32l4x5SocState *s = STM32L4X5_SOC(obj);
@@ -132,6 +149,18 @@ static void stm32l4x5_soc_initfn(Object *obj)
         g_autofree char *name = g_strdup_printf("gpio%c", 'a' + i);
         object_initialize_child(obj, name, &s->gpio[i], TYPE_STM32L4X5_GPIO);
     }
+    
+    for (int i = 0; i < STM_NUM_USARTS; i++) {
+        object_initialize_child(obj, "usart[*]", &s->usart[i],
+                                TYPE_STM32L4X5_USART);
+    }
+
+    for (int i = 0; i < STM_NUM_UARTS; i++) {
+        object_initialize_child(obj, "uart[*]", &s->uart[i],
+                                TYPE_STM32L4X5_UART);
+    }
+    object_initialize_child(obj, "lpuart1", &s->lpuart,
+                            TYPE_STM32L4X5_LPUART);
 }
 
 static void stm32l4x5_soc_realize(DeviceState *dev_soc, Error **errp)
@@ -279,6 +308,53 @@ static void stm32l4x5_soc_realize(DeviceState *dev_soc, Error **errp)
     sysbus_mmio_map(busdev, 0, RCC_BASE_ADDRESS);
     sysbus_connect_irq(busdev, 0, qdev_get_gpio_in(armv7m, RCC_IRQ));
 
+    /* USART devices */
+    for (int i = 0; i < STM_NUM_USARTS; i++) {
+        dev = DEVICE(&(s->usart[i]));
+        qdev_prop_set_chr(dev, "chardev", serial_hd(i));
+        g_autofree char *name = g_strdup_printf("usart%d-out", i + 1);
+        qdev_connect_clock_in(dev, "clk",
+            qdev_get_clock_out(DEVICE(&(s->rcc)), name));
+        busdev = SYS_BUS_DEVICE(dev);
+        if (!sysbus_realize(busdev, errp)) {
+            return;
+        }
+        sysbus_mmio_map(busdev, 0, usart_addr[i]);
+        sysbus_connect_irq(busdev, 0, qdev_get_gpio_in(armv7m, usart_irq[i]));
+    }
+
+    /*
+     * TODO: Connect the USARTs, UARTs and LPUART to the EXTI once the EXTI
+     * can handle other gpio-in than the gpios. (e.g. Direct Lines for the usarts)
+     */
+
+    /* UART devices */
+    for (int i = 0; i < STM_NUM_UARTS; i++) {
+        dev = DEVICE(&(s->uart[i]));
+        qdev_prop_set_chr(dev, "chardev", serial_hd(STM_NUM_USARTS + i));
+        g_autofree char *name = g_strdup_printf("uart%d-out", STM_NUM_USARTS + i + 1);
+        qdev_connect_clock_in(dev, "clk",
+            qdev_get_clock_out(DEVICE(&(s->rcc)), name));
+        busdev = SYS_BUS_DEVICE(dev);
+        if (!sysbus_realize(busdev, errp)) {
+            return;
+        }
+        sysbus_mmio_map(busdev, 0, uart_addr[i]);
+        sysbus_connect_irq(busdev, 0, qdev_get_gpio_in(armv7m, uart_irq[i]));
+    }
+
+    /* LPUART device*/
+    dev = DEVICE(&(s->lpuart));
+    qdev_prop_set_chr(dev, "chardev", serial_hd(STM_NUM_USARTS + STM_NUM_UARTS));
+    qdev_connect_clock_in(dev, "clk",
+        qdev_get_clock_out(DEVICE(&(s->rcc)), "lpuart1-out"));
+    busdev = SYS_BUS_DEVICE(dev);
+    if (!sysbus_realize(busdev, errp)) {
+        return;
+    }
+    sysbus_mmio_map(busdev, 0, LPUART_BASE_ADDRESS);
+    sysbus_connect_irq(busdev, 0, qdev_get_gpio_in(armv7m, LPUART_IRQ));
+
     /* APB1 BUS */
     create_unimplemented_device("TIM2",      0x40000000, 0x400);
     create_unimplemented_device("TIM3",      0x40000400, 0x400);
@@ -294,10 +370,6 @@ static void stm32l4x5_soc_realize(DeviceState *dev_soc, Error **errp)
     create_unimplemented_device("SPI2",      0x40003800, 0x400);
     create_unimplemented_device("SPI3",      0x40003C00, 0x400);
     /* RESERVED:    0x40004000, 0x400 */
-    create_unimplemented_device("USART2",    0x40004400, 0x400);
-    create_unimplemented_device("USART3",    0x40004800, 0x400);
-    create_unimplemented_device("UART4",     0x40004C00, 0x400);
-    create_unimplemented_device("UART5",     0x40005000, 0x400);
     create_unimplemented_device("I2C1",      0x40005400, 0x400);
     create_unimplemented_device("I2C2",      0x40005800, 0x400);
     create_unimplemented_device("I2C3",      0x40005C00, 0x400);
@@ -308,7 +380,6 @@ static void stm32l4x5_soc_realize(DeviceState *dev_soc, Error **errp)
     create_unimplemented_device("DAC1",      0x40007400, 0x400);
     create_unimplemented_device("OPAMP",     0x40007800, 0x400);
     create_unimplemented_device("LPTIM1",    0x40007C00, 0x400);
-    create_unimplemented_device("LPUART1",   0x40008000, 0x400);
     /* RESERVED:    0x40008400, 0x400 */
     create_unimplemented_device("SWPMI1",    0x40008800, 0x400);
     /* RESERVED:    0x40008C00, 0x800 */
@@ -325,7 +396,6 @@ static void stm32l4x5_soc_realize(DeviceState *dev_soc, Error **errp)
     create_unimplemented_device("TIM1",      0x40012C00, 0x400);
     create_unimplemented_device("SPI1",      0x40013000, 0x400);
     create_unimplemented_device("TIM8",      0x40013400, 0x400);
-    create_unimplemented_device("USART1",    0x40013800, 0x400);
     /* RESERVED:    0x40013C00, 0x400 */
     create_unimplemented_device("TIM15",     0x40014000, 0x400);
     create_unimplemented_device("TIM16",     0x40014400, 0x400);
diff --git a/include/hw/arm/stm32l4x5_soc.h b/include/hw/arm/stm32l4x5_soc.h
index ee5f362405..a94ddbd19c 100644
--- a/include/hw/arm/stm32l4x5_soc.h
+++ b/include/hw/arm/stm32l4x5_soc.h
@@ -21,6 +21,12 @@
  * https://www.st.com/en/microcontrollers-microprocessors/stm32l4x5/documentation.html
  */
 
+/*
+ * The STM32L4X5 is heavily inspired by the stm32f405 by Alistair Francis.
+ * The reference used is the STMicroElectronics RM0351 Reference manual
+ * for STM32L4x5 and STM32L4x6 advanced Arm ® -based 32-bit MCUs.
+ */
+
 #ifndef HW_ARM_STM32L4x5_SOC_H
 #define HW_ARM_STM32L4x5_SOC_H
 
@@ -31,6 +37,7 @@
 #include "hw/misc/stm32l4x5_exti.h"
 #include "hw/misc/stm32l4x5_rcc.h"
 #include "hw/gpio/stm32l4x5_gpio.h"
+#include "hw/char/stm32l4x5_usart.h"
 #include "qom/object.h"
 
 #define TYPE_STM32L4X5_SOC "stm32l4x5-soc"
@@ -41,6 +48,9 @@ OBJECT_DECLARE_TYPE(Stm32l4x5SocState, Stm32l4x5SocClass, STM32L4X5_SOC)
 
 #define NUM_EXTI_OR_GATES 4
 
+#define STM_NUM_USARTS 3
+#define STM_NUM_UARTS 2
+
 struct Stm32l4x5SocState {
     SysBusDevice parent_obj;
 
@@ -51,6 +61,9 @@ struct Stm32l4x5SocState {
     Stm32l4x5SyscfgState syscfg;
     Stm32l4x5RccState rcc;
     Stm32l4x5GpioState gpio[NUM_GPIOS];
+    Stm32l4x5UsartBaseState usart[STM_NUM_USARTS];
+    Stm32l4x5UsartBaseState uart[STM_NUM_UARTS];
+    Stm32l4x5UsartBaseState lpuart;
 
     MemoryRegion sram1;
     MemoryRegion sram2;
-- 
2.34.1