Re: [PATCH v4 2/3] hw/riscv: add DesignWare APB timer to K230 board

On Thu, Aug 13, 2026 at 9:37 PM raoyi <[email protected]> wrote:
>
> Wire up the DesignWare APB timer to the K230 SoC with
> num-timers=6 and a 6.25 MHz clock. Connect timer IRQs
> to the PLIC. Remove the previous unimplemented timer stub.
>
> Signed-off-by: raoyi <[email protected]>
> ---
>  hw/riscv/Kconfig        |  1 +
>  hw/riscv/k230.c         | 33 ++++++++++++++++++++++++++++++---
>  include/hw/riscv/k230.h |  8 ++++++++
>  3 files changed, 39 insertions(+), 3 deletions(-)
>
> diff --git a/hw/riscv/Kconfig b/hw/riscv/Kconfig
> index de37c08cae..c2c01af6ee 100644
> --- a/hw/riscv/Kconfig
> +++ b/hw/riscv/Kconfig
> @@ -162,3 +162,4 @@ config K230
>      select SERIAL_MM
>      select UNIMP
>      select K230_WDT
> +    select DW_APB_TIMER
> diff --git a/hw/riscv/k230.c b/hw/riscv/k230.c
> index 656f28190c..78a05492ad 100644
> --- a/hw/riscv/k230.c
> +++ b/hw/riscv/k230.c
> @@ -24,6 +24,8 @@
>  #include "target/riscv/cpu.h"
>  #include "hw/core/loader.h"
>  #include "hw/core/sysbus.h"
> +#include "hw/core/clock.h"
> +#include "hw/core/qdev-clock.h"
>  #include "hw/riscv/k230.h"
>  #include "hw/riscv/boot.h"
>  #include "hw/riscv/machines-qom.h"
> @@ -37,6 +39,9 @@
>  #define K230_DIRECT_KERNEL_ADDR  0x8200000
>  #define K230_DIRECT_DTB_ADDR     0xa000000
>
> +#define K230_TIMER_NUM_CHANNELS 6
> +#define K230_TIMER_DEFAULT_FREQ 6250000

The TRM says the timer frequency is 50MHz. Where is this 6250000 coming from?

> +
>  static const MemMapEntry memmap[] = {
>      [K230_DEV_DDRC] =         { 0x00000000,  0x80000000 },
>      [K230_DEV_KPU_L2_CACHE] = { 0x80000000,  0x00200000 },
> @@ -110,6 +115,19 @@ static void k230_soc_init(Object *obj)
>      object_initialize_child(obj, "c908-cpu", cpu0, TYPE_RISCV_HART_ARRAY);
>      object_initialize_child(obj, "k230-wdt0", &s->wdt[0], TYPE_K230_WDT);
>      object_initialize_child(obj, "k230-wdt1", &s->wdt[1], TYPE_K230_WDT);
> +    object_initialize_child(obj, "dw-apb-timer", &s->timer,
> +                            TYPE_DW_APB_TIMER);
> +
> +    qdev_prop_set_uint32(DEVICE(&s->timer), "num-timers",
> +                         K230_TIMER_NUM_CHANNELS);
> +
> +    Clock *timer_clk = clock_new(OBJECT(s), "timer-clk");
> +    clock_set_hz(timer_clk, K230_TIMER_DEFAULT_FREQ);
> +    for (int i = 0; i < K230_TIMER_NUM_CHANNELS; i++) {
> +        g_autofree char *clock_name = g_strdup_printf("timer[%d]", i);
> +
> +        qdev_connect_clock_in(DEVICE(&s->timer), clock_name, timer_clk);
> +    }
>
>      qdev_prop_set_uint32(DEVICE(cpu0), "hartid-base", 0);
>      qdev_prop_set_string(DEVICE(cpu0), "cpu-type", TYPE_RISCV_CPU_THEAD_C908);
> @@ -191,6 +209,18 @@ static void k230_soc_realize(DeviceState *dev, Error **errp)
>          k230_create_uart(sys_mem, DEVICE(s->c908_plic), i);
>      }
>
> +    /* Timer */
> +    if (!sysbus_realize(SYS_BUS_DEVICE(&s->timer), errp)) {
> +        return;
> +    }
> +    sysbus_mmio_map(SYS_BUS_DEVICE(&s->timer), 0, memmap[K230_DEV_TIMER].base);
> +
> +    for (int i = 0; i < K230_TIMER_NUM_CHANNELS; i++) {
> +        sysbus_connect_irq(SYS_BUS_DEVICE(&s->timer), i,
> +                           qdev_get_gpio_in(DEVICE(s->c908_plic),
> +                                            K230_TIMER0_IRQ + i));
> +    }
> +
>      /* Watchdog */
>      for (int i = 0; i < 2; i++) {
>          if (!sysbus_realize(SYS_BUS_DEVICE(&s->wdt[i]), errp)) {
> @@ -283,9 +313,6 @@ static void k230_soc_realize(DeviceState *dev, Error **errp)
>      create_unimplemented_device("iomux", memmap[K230_DEV_IOMUX].base,
>                                  memmap[K230_DEV_IOMUX].size);
>
> -    create_unimplemented_device("timer", memmap[K230_DEV_TIMER].base,
> -                                memmap[K230_DEV_TIMER].size);
> -
>      create_unimplemented_device("wdt0", memmap[K230_DEV_WDT0].base,
>                                  memmap[K230_DEV_WDT0].size);
>
> diff --git a/include/hw/riscv/k230.h b/include/hw/riscv/k230.h
> index 592e1c26bf..42a36664eb 100644
> --- a/include/hw/riscv/k230.h
> +++ b/include/hw/riscv/k230.h
> @@ -18,6 +18,7 @@
>  #include "hw/core/boards.h"
>  #include "hw/riscv/riscv_hart.h"
>  #include "hw/watchdog/k230_wdt.h"
> +#include "hw/timer/dw-apb-timer.h"
>
>  #define C908_CPU_HARTID   (0)
>
> @@ -33,6 +34,7 @@ typedef struct K230SoCState {
>      RISCVHartArrayState c908_cpu; /* Small core */
>
>      K230WdtState wdt[2];
> +    DWAPBTimerState timer;
>      MemoryRegion sram;
>      MemoryRegion bootrom;
>
> @@ -127,6 +129,12 @@ enum {
>      K230_UART2_IRQ  = 18,
>      K230_UART3_IRQ  = 19,
>      K230_UART4_IRQ  = 20,
> +    K230_TIMER0_IRQ = 101,
> +    K230_TIMER1_IRQ = 102,
> +    K230_TIMER2_IRQ = 103,
> +    K230_TIMER3_IRQ = 104,
> +    K230_TIMER4_IRQ = 105,
> +    K230_TIMER5_IRQ = 106,
>      K230_WDT0_IRQ   = 107,
>      K230_WDT1_IRQ   = 108,
>  };
> --

Regards,
Bin