Re: [PATCH 0/8] aspeed: I2C fixes, -drive removal (first step)

["Cédric Le Goater" <clg@kaod.org>]

On 2/15/23 11:45, Philippe Mathieu-Daudé wrote:
> On 14/2/23 18:18, Cédric Le Goater wrote:
>> Hello,
>>
>> This series starts with a first set of patches fixing I2C slave mode
>> in the Aspeed I2C controller, a test device and its associated test in
>> avocado.
>>
>> Follow some cleanups which allow the use of block devices instead of
>> drives. So that, instead of specifying :
>>
>>    -drive file=./flash-ast2600-evb,format=raw,if=mtd
>>    -drive file=./ast2600-evb.pnor,format=raw,if=mtd
>>    ...
>>
>> and guessing from the order which bus the device is attached to, we
>> can use :
>>
>>    -blockdev node-name=fmc0,driver=file,filename=./bmc.img
>>    -device mx66u51235f,bus=ssi.0,drive=fmc0
>>    -blockdev node-name=fmc1,driver=file,filename=./bmc-alt.img
>>    -device mx66u51235f,bus=ssi.0,drive=fmc1
>>    -blockdev node-name=pnor,driver=file,filename=./pnor
>>    -device mx66l1g45g,bus=ssi.1,drive=pnor
>>    ...
>>
>> It is not perfect, the CS index still depends on the order
> 
> Quick thoughts here:
> 
> TYPE_SSI_PERIPHERAL devices have one input SSI_GPIO_CS.
> 
> TYPE_SSI_BUS could have a "cs-num" property (how many
> CS line associated with this bus) and create an array of
> #cs-num output SSI_GPIO_CS.
> 
> TYPE_SSI_PERIPHERAL could have a "cs" (index) property;
> if set, upon ssi_peripheral_realize() when the device is
> plugged on the bus, the GPIO line is wired.

yes. I would like to check first the impact on migration compatibility.

Thanks,

C.

> So we could set the 'cs=' property from CLI:
> 
>    -blockdev node-name=fmc0,driver=file,filename=./bmc.img
>    -device mx66u51235f,bus=ssi.0,cs=1,drive=fmc0
>    -blockdev node-name=fmc1,driver=file,filename=./bmc-alt.img
>    -device mx66u51235f,bus=ssi.0,cs=0,drive=fmc1
> 
>> but it is
>> now possible to run a machine without -drive ...,if=mtd.
>>
>> This lacks the final patch enabling the '-nodefaults' option by not
>> creating the default devices if specified on the command line. It
>> needs some more evaluation of the possible undesired effects.
>> Thanks,
>>
>> C.
>