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

[Cédric Le Goater]

On 7/18/24 11:44, Jamin Lin wrote:
> Hi Cedric,
>
> > Subject: Re: [PATCH v1 04/15] hw/i2c/aspeed: support discontinuous register
> > memory region of I2C bus
> >
> > 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 for your review and suggestion.
>
> Sorry, I am not very clearly understand your comments.
> Could you please describe it more detail?
> Thanks-Jamin

I don't think you need to introduce a gap size class attribute.

Setting :

    aic->reg_size = 0x100; /* size + gap */

in aspeed_2700_i2c_class_init() should be enough.

Thanks,

C.