Re: [PATCH v2 17/17] hw/arm/aspeed: Model AST1700 PWM block as unimplemented device

["Cédric Le Goater" <clg@kaod.org>]

On 11/5/25 04:58, Kane Chen wrote:
> From: Kane-Chen-AS <kane_chen@aspeedtech.com>
> 
> AST1700 includes an PWM block, but QEMU has no functional model for
> aspeed product yet. 

We could start with a dummy PWM model :

   https://github.com/legoater/qemu/commit/9d77c84b04c2d9ae5685b3ccb5c434873666ca78

Feel free to add to your series.

Thanks,

C.



Expose it as an unimplemented device so the
> address space is reserved and the missing functionality is explicit
> to users/guests.
> 
> Signed-off-by: Kane-Chen-AS <kane_chen@aspeedtech.com>
> ---
>   include/hw/misc/aspeed_ast1700.h |  1 +
>   hw/misc/aspeed_ast1700.c         | 16 ++++++++++++++++
>   2 files changed, 17 insertions(+)
> 
> diff --git a/include/hw/misc/aspeed_ast1700.h b/include/hw/misc/aspeed_ast1700.h
> index 8ada3a7775..9d432a7db0 100644
> --- a/include/hw/misc/aspeed_ast1700.h
> +++ b/include/hw/misc/aspeed_ast1700.h
> @@ -45,6 +45,7 @@ struct AspeedAST1700SoCState {
>   
>       UnimplementedDeviceState i3c;
>       UnimplementedDeviceState sgpiom;
> +    UnimplementedDeviceState pwm;
>   };
>   
>   #endif /* ASPEED_AST1700_H */
> diff --git a/hw/misc/aspeed_ast1700.c b/hw/misc/aspeed_ast1700.c
> index 66a5f21d27..3d9a920a7a 100644
> --- a/hw/misc/aspeed_ast1700.c
> +++ b/hw/misc/aspeed_ast1700.c
> @@ -20,9 +20,11 @@
>   #define AST1700_SOC_SRAM_SIZE        0x00040000
>   #define AST1700_SOC_I3C_SIZE         0x00010000
>   #define AST1700_SOC_SGPIOM_SIZE      0x00002000
> +#define AST1700_SOC_PWM_SIZE         0x00000200
>   
>   enum {
>       ASPEED_AST1700_DEV_SPI0,
> +    ASPEED_AST1700_DEV_PWM,
>       ASPEED_AST1700_DEV_SRAM,
>       ASPEED_AST1700_DEV_ADC,
>       ASPEED_AST1700_DEV_SCU,
> @@ -38,6 +40,7 @@ enum {
>   
>   static const hwaddr aspeed_ast1700_io_memmap[] = {
>       [ASPEED_AST1700_DEV_SPI0]      =  0x00030000,
> +    [ASPEED_AST1700_DEV_PWM]       =  0x000C0000,
>       [ASPEED_AST1700_DEV_SRAM]      =  0x00BC0000,
>       [ASPEED_AST1700_DEV_ADC]       =  0x00C00000,
>       [ASPEED_AST1700_DEV_SCU]       =  0x00C02000,
> @@ -174,6 +177,15 @@ static void aspeed_ast1700_realize(DeviceState *dev, Error **errp)
>                           sysbus_mmio_get_region(SYS_BUS_DEVICE(&s->sgpiom), 0),
>                           -1000);
>   
> +    /* PWM */
> +    qdev_prop_set_string(DEVICE(&s->pwm), "name", "ioexp-pwm");
> +    qdev_prop_set_uint64(DEVICE(&s->pwm), "size", AST1700_SOC_PWM_SIZE);
> +    sysbus_realize(SYS_BUS_DEVICE(&s->pwm), errp);
> +    memory_region_add_subregion_overlap(&s->iomem,
> +                        aspeed_ast1700_io_memmap[ASPEED_AST1700_DEV_PWM],
> +                        sysbus_mmio_get_region(SYS_BUS_DEVICE(&s->pwm), 0),
> +                        -1000);
> +
>       /* WDT */
>       for (i = 0; i < AST1700_WDT_NUM; i++) {
>           AspeedWDTClass *awc = ASPEED_WDT_GET_CLASS(&s->wdt[i]);
> @@ -241,6 +253,10 @@ static void aspeed_ast1700_instance_init(Object *obj)
>       object_initialize_child(obj, "ioexp-sgpiom[*]", &s->sgpiom,
>                               TYPE_UNIMPLEMENTED_DEVICE);
>   
> +    /* PWM */
> +    object_initialize_child(obj, "ioexp-pwm", &s->pwm,
> +                            TYPE_UNIMPLEMENTED_DEVICE);
> +
>       /* WDT */
>       for (i = 0; i < AST1700_WDT_NUM; i++) {
>           snprintf(typename, sizeof(typename), "aspeed.wdt-%s", socname);