Re: [PATCH v1 04/15] hw/i2c/aspeed: support discontinuous register memory region of I2C bus

[Cédric Le Goater]

On 7/18/24 08:49, Jamin Lin wrote:
> It only support continuous register memory region for all I2C bus.
> However, the register address of all I2c bus are discontinuous
> for AST2700.
>
> Ex: the register address of I2C bus for ast2700 as following.
> 0x100 - 0x17F: Device 0
> 0x200 - 0x27F: Device 1
> 0x300 - 0x37F: Device 2
> 0x400 - 0x47F: Device 3
> 0x500 - 0x57F: Device 4
> 0x600 - 0x67F: Device 5
> 0x700 - 0x77F: Device 6
> 0x800 - 0x87F: Device 7
> 0x900 - 0x97F: Device 8
> 0xA00 - 0xA7F: Device 9
> 0xB00 - 0xB7F: Device 10
> 0xC00 - 0xC7F: Device 11
> 0xD00 - 0xD7F: Device 12
> 0xE00 - 0xE7F: Device 13
> 0xF00 – 0xF7F: Device 14
> 0x1000 – 0x107F: Device 15
>
> Introduce a new class attribute to make user set each I2C bus gap size.
> Update formula to create all I2C bus register memory regions.

I don't think this is necessary to model. Could we simply increase
tge register MMIO size for the AST2700 bus model and rely on the
memops to catch invalid register offsets ?


Thanks,

C.



> Signed-off-by: Jamin Lin <jamin_lin@aspeedtech.com>
> ---
>   hw/i2c/aspeed_i2c.c         | 3 ++-
>   include/hw/i2c/aspeed_i2c.h | 1 +
>   2 files changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/hw/i2c/aspeed_i2c.c b/hw/i2c/aspeed_i2c.c
> index 7d5a53c4c0..462ad78a13 100644
> --- a/hw/i2c/aspeed_i2c.c
> +++ b/hw/i2c/aspeed_i2c.c
> @@ -1011,6 +1011,7 @@ static void aspeed_i2c_realize(DeviceState *dev, Error 
> **errp)
>       SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
>       AspeedI2CState *s = ASPEED_I2C(dev);
>       AspeedI2CClass *aic = ASPEED_I2C_GET_CLASS(s);
> +    uint32_t reg_offset = aic->reg_size + aic->reg_gap_size;
>   
>       sysbus_init_irq(sbd, &s->irq);
>       memory_region_init_io(&s->iomem, OBJECT(s), &aspeed_i2c_ctrl_ops, s,
> @@ -1033,7 +1034,7 @@ static void aspeed_i2c_realize(DeviceState *dev, Error 
> **errp)
>               return;
>           }
>   
> -        memory_region_add_subregion(&s->iomem, aic->reg_size * (i + offset),
> +        memory_region_add_subregion(&s->iomem, reg_offset * (i + offset),
>                                       &s->busses[i].mr);
>       }
>   
> diff --git a/include/hw/i2c/aspeed_i2c.h b/include/hw/i2c/aspeed_i2c.h
> index 065b636d29..422ee0e298 100644
> --- a/include/hw/i2c/aspeed_i2c.h
> +++ b/include/hw/i2c/aspeed_i2c.h
> @@ -275,6 +275,7 @@ struct AspeedI2CClass {
>   
>       uint8_t num_busses;
>       uint8_t reg_size;
> +    uint32_t reg_gap_size;
>       uint8_t gap;
>       qemu_irq (*bus_get_irq)(AspeedI2CBus *);
>