hw/arm: Add watchdog timer to Allwinner H40 and Bananapi board

Add watchdog timer support to Allwinner-H40 and Bananapi.
The watchdog timer is added as an overlay to the Timer
module memory map.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Strahinja Jankovic <strahinja.p.jankovic@gmail.com>
Message-id: 20240115182757.1095012-4-linux@roeck-us.net
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

docs/system/arm/bananapi_m2u.rst

@@ -25,6 +25,7 @@ The Banana Pi M2U machine supports the following devices:
  * SATA
  * TWI (I2C)
  * USB 2.0
+ * Hardware Watchdog
 
 Limitations
 """""""""""
@@ -33,7 +34,6 @@ Currently, Banana Pi M2U does *not* support the following features:
 
 - Graphical output via HDMI, GPU and/or the Display Engine
 - Audio output
-- Hardware Watchdog
 - Real Time Clock
 
 Also see the 'unimplemented' array in the Allwinner R40 SoC module

hw/arm/Kconfig

@@ -411,6 +411,7 @@ config ALLWINNER_R40
     select AHCI
     select ALLWINNER_SRAMC
     select ALLWINNER_A10_PIT
+    select ALLWINNER_WDT
     select AXP2XX_PMU
     select SERIAL
     select ARM_TIMER

hw/arm/allwinner-r40.c

@@ -53,6 +53,7 @@ const hwaddr allwinner_r40_memmap[] = {
     [AW_R40_DEV_OHCI2]      = 0x01c1c400,
     [AW_R40_DEV_CCU]        = 0x01c20000,
     [AW_R40_DEV_PIT]        = 0x01c20c00,
+    [AW_R40_DEV_WDT]        = 0x01c20c90,
     [AW_R40_DEV_UART0]      = 0x01c28000,
     [AW_R40_DEV_UART1]      = 0x01c28400,
     [AW_R40_DEV_UART2]      = 0x01c28800,
@@ -279,6 +280,8 @@ static void allwinner_r40_init(Object *obj)
     object_property_add_alias(obj, "clk1-freq", OBJECT(&s->timer),
                               "clk1-freq");
 
+    object_initialize_child(obj, "wdt", &s->wdt, TYPE_AW_WDT_SUN4I);
+
     object_initialize_child(obj, "ccu", &s->ccu, TYPE_AW_R40_CCU);
 
     for (int i = 0; i < AW_R40_NUM_MMCS; i++) {
@@ -545,6 +548,11 @@ static void allwinner_r40_realize(DeviceState *dev, Error **errp)
     sysbus_connect_irq(SYS_BUS_DEVICE(&s->emac), 0,
                        qdev_get_gpio_in(DEVICE(&s->gic), AW_R40_GIC_SPI_EMAC));
 
+    /* WDT */
+    sysbus_realize(SYS_BUS_DEVICE(&s->wdt), &error_fatal);
+    sysbus_mmio_map_overlap(SYS_BUS_DEVICE(&s->wdt), 0,
+                            allwinner_r40_memmap[AW_R40_DEV_WDT], 1);
+
     /* Unimplemented devices */
     for (unsigned i = 0; i < ARRAY_SIZE(r40_unimplemented); i++) {
         create_unimplemented_device(r40_unimplemented[i].device_name,

include/hw/arm/allwinner-r40.h

@@ -33,6 +33,7 @@
 #include "hw/net/allwinner-sun8i-emac.h"
 #include "hw/usb/hcd-ohci.h"
 #include "hw/usb/hcd-ehci.h"
+#include "hw/watchdog/allwinner-wdt.h"
 #include "target/arm/cpu.h"
 #include "sysemu/block-backend.h"
 
@@ -54,6 +55,7 @@ enum {
     AW_R40_DEV_OHCI2,
     AW_R40_DEV_CCU,
     AW_R40_DEV_PIT,
+    AW_R40_DEV_WDT,
     AW_R40_DEV_UART0,
     AW_R40_DEV_UART1,
     AW_R40_DEV_UART2,
@@ -114,6 +116,7 @@ struct AwR40State {
     const hwaddr *memmap;
     AwSRAMCState sramc;
     AwA10PITState timer;
+    AwWdtState wdt;
     AllwinnerAHCIState sata;
     AwSdHostState mmc[AW_R40_NUM_MMCS];
     EHCISysBusState ehci[AW_R40_NUM_USB];