RE: [PATCH 2/5] aspeed: ast27x0: Map unimplemented devices in SoC memory

[Steven Lee]

Hi Cédric,

> -----Original Message-----
> From: Cédric Le Goater <clg@kaod.org>
> Sent: Friday, January 3, 2025 5:44 PM
> To: Steven Lee <steven_lee@aspeedtech.com>; Peter Maydell
> <peter.maydell@linaro.org>; Troy Lee <leetroy@gmail.com>; Jamin Lin
> <jamin_lin@aspeedtech.com>; Andrew Jeffery
> <andrew@codeconstruct.com.au>; Joel Stanley <joel@jms.id.au>; open
> list:ASPEED BMCs <qemu-arm@nongnu.org>; open list:All patches CC here
> <qemu-devel@nongnu.org>
> Cc: Troy Lee <troy_lee@aspeedtech.com>; Yunlin Tang
> <yunlin.tang@aspeedtech.com>
> Subject: Re: [PATCH 2/5] aspeed: ast27x0: Map unimplemented devices in SoC
> memory
> 
> On 1/3/25 09:14, Steven Lee wrote:
> > Hi Cédric,
> >
> >> -----Original Message-----
> >> From: Cédric Le Goater <clg@kaod.org>
> >> Sent: Friday, December 27, 2024 5:53 PM
> >> To: Steven Lee <steven_lee@aspeedtech.com>; Peter Maydell
> >> <peter.maydell@linaro.org>; Troy Lee <leetroy@gmail.com>; Jamin Lin
> >> <jamin_lin@aspeedtech.com>; Andrew Jeffery
> >> <andrew@codeconstruct.com.au>; Joel Stanley <joel@jms.id.au>; open
> >> list:ASPEED BMCs <qemu-arm@nongnu.org>; open list:All patches CC here
> >> <qemu-devel@nongnu.org>
> >> Cc: Troy Lee <troy_lee@aspeedtech.com>; Yunlin Tang
> >> <yunlin.tang@aspeedtech.com>
> >> Subject: Re: [PATCH 2/5] aspeed: ast27x0: Map unimplemented devices
> >> in SoC memory
> >>
> >> Hello,
> >>
> >> On 12/25/24 03:03, Steven Lee wrote:
> >>> Maps following unimplemented devices in SoC memory
> >>> - dpmcu
> >>> - iomem0
> >>> - iomem1
> >>> - ltpi
> >>> - io
> >>
> >> Could you please add a sentence about what these devices are ?
> >>
> >> Thanks,
> >>
> >> C.
> >>
> >
> > DPMCU stands for Display Port MCU controller.
> > Regarding LTPI, when the AST1700 is connected to the AST2700, AST1070
> LTPI controller's registers are mapped to 0x30000000.
> 
> Is the LTPI IP a device for communication between SoCs ?

Yes, it can be used to connect to AST1700. AST1700 is an I/O expander that 
supports the DC-SCM 2.1 LTPI protocol.  
It provides AST2700 with additional GPIO, UART, I3C, and other interfaces.

Thanks,
Steven

> 
> > Io, Iomem0 and Iomem1 include unimplemented controllers in the memory
> ranges 0x120000000 - 0x121000000 and 0x14000000 - 0x141000000.
> > For instance:
> > - USB hub at 0x12010000
> > - eSPI at 0x14C5000
> > - PWM at 0x140C0000
> >
> > I will include the description in the commit message.
> 
> yes please.
> 
> Thanks,
> 
> C.
> 
>