hw/riscv: sifive_e: Support the watchdog timer of HiFive 1 rev b.

Create the AON device when we realize the sifive_e machine.
This patch only implemented the functionality of the watchdog timer,
not all the functionality of the AON device.

Signed-off-by: Tommy Wu <tommy.wu@sifive.com>
Reviewed-by: Frank Chang <frank.chang@sifive.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20230627141216.3962299-3-tommy.wu@sifive.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

hw/riscv/Kconfig

@@ -60,6 +60,7 @@ config SIFIVE_E
     select SIFIVE_PLIC
     select SIFIVE_UART
     select SIFIVE_E_PRCI
+    select SIFIVE_E_AON
     select UNIMP
 
 config SIFIVE_U

hw/riscv/sifive_e.c

@@ -45,6 +45,7 @@
 #include "hw/intc/riscv_aclint.h"
 #include "hw/intc/sifive_plic.h"
 #include "hw/misc/sifive_e_prci.h"
+#include "hw/misc/sifive_e_aon.h"
 #include "chardev/char.h"
 #include "sysemu/sysemu.h"
 
@@ -185,6 +186,8 @@ static void sifive_e_soc_init(Object *obj)
     object_property_set_int(OBJECT(&s->cpus), "resetvec", 0x1004, &error_abort);
     object_initialize_child(obj, "riscv.sifive.e.gpio0", &s->gpio,
                             TYPE_SIFIVE_GPIO);
+    object_initialize_child(obj, "riscv.sifive.e.aon", &s->aon,
+                            TYPE_SIFIVE_E_AON);
 }
 
 static void sifive_e_soc_realize(DeviceState *dev, Error **errp)
@@ -223,10 +226,17 @@ static void sifive_e_soc_realize(DeviceState *dev, Error **errp)
         RISCV_ACLINT_DEFAULT_MTIMER_SIZE, 0, ms->smp.cpus,
         RISCV_ACLINT_DEFAULT_MTIMECMP, RISCV_ACLINT_DEFAULT_MTIME,
         RISCV_ACLINT_DEFAULT_TIMEBASE_FREQ, false);
-    create_unimplemented_device("riscv.sifive.e.aon",
-        memmap[SIFIVE_E_DEV_AON].base, memmap[SIFIVE_E_DEV_AON].size);
     sifive_e_prci_create(memmap[SIFIVE_E_DEV_PRCI].base);
 
+    /* AON */
+
+    if (!sysbus_realize(SYS_BUS_DEVICE(&s->aon), errp)) {
+        return;
+    }
+
+    /* Map AON registers */
+    sysbus_mmio_map(SYS_BUS_DEVICE(&s->aon), 0, memmap[SIFIVE_E_DEV_AON].base);
+
     /* GPIO */
 
     if (!sysbus_realize(SYS_BUS_DEVICE(&s->gpio), errp)) {
@@ -245,6 +255,9 @@ static void sifive_e_soc_realize(DeviceState *dev, Error **errp)
                            qdev_get_gpio_in(DEVICE(s->plic),
                                             SIFIVE_E_GPIO0_IRQ0 + i));
     }
+    sysbus_connect_irq(SYS_BUS_DEVICE(&s->aon), 0,
+                       qdev_get_gpio_in(DEVICE(s->plic),
+                                        SIFIVE_E_AON_WDT_IRQ));
 
     sifive_uart_create(sys_mem, memmap[SIFIVE_E_DEV_UART0].base,
         serial_hd(0), qdev_get_gpio_in(DEVICE(s->plic), SIFIVE_E_UART0_IRQ));

include/hw/riscv/sifive_e.h

@@ -22,6 +22,7 @@
 #include "hw/riscv/riscv_hart.h"
 #include "hw/riscv/sifive_cpu.h"
 #include "hw/gpio/sifive_gpio.h"
+#include "hw/misc/sifive_e_aon.h"
 #include "hw/boards.h"
 
 #define TYPE_RISCV_E_SOC "riscv.sifive.e.soc"
@@ -35,6 +36,7 @@ typedef struct SiFiveESoCState {
     /*< public >*/
     RISCVHartArrayState cpus;
     DeviceState *plic;
+    SiFiveEAONState aon;
     SIFIVEGPIOState gpio;
     MemoryRegion xip_mem;
     MemoryRegion mask_rom;
@@ -76,6 +78,7 @@ enum {
 };
 
 enum {
+    SIFIVE_E_AON_WDT_IRQ  = 1,
     SIFIVE_E_UART0_IRQ    = 3,
     SIFIVE_E_UART1_IRQ    = 4,
     SIFIVE_E_GPIO0_IRQ0   = 8