[PATCH v4 11/21] misc: altera_sysmgr: Add Altera System Manager driver

[Marek Vasut]

On 3/11/20 8:03 AM, Ang, Chee Hong wrote:
>> On 3/11/20 7:35 AM, Ang, Chee Hong wrote:
>> [...]
>>
>>>>>> Hmm, so you're just using misc_ops to still issue generic writes.
>>>>>> From the discussion with Marek in the last version, I would have
>>>>>> thought you wanted to create a higher level API instead of still
>>>>>> tunnelling
>>>> reads and writes?
>>>>
>>>> Any response to this?
>>> Sorry, I missed this one
>>> Actually I have created higher level API in ATF but I switch back to
>>> generic writes because the higher level API in ATF doesn't apply to Gen5/A10
>> platforms.
>>
>> ATF doesn't apply to Gen5/A10 either though ?
>>
>>> Here is what I will do in my revision in system manager driver:
>>> 1) drop misc_read/misc_write and use misc_ioctl instead in system
>>> manager
>>> 2) misc_ioctl() will support configuring EMAC/SDMMC
>>> 3) For SoC64 running at EL2 (non-secure), misc_iotctl() will invoke
>>> the ATF's 'high level' API
>>> 4) For Gen/A10 and SoC64 running at EL3 (secure), the driver just
>>> configure the EMAC/SDMMC registers in misc_iotcl() Is this better ?
>> Can't you configure everything in secure-mode and just not configure anything
>> anymore in non-secure mode ?
> Yes. I can move all these configurations to SPL(secure mode) and remove them from EMAC/SDMMC drivers.
> This will affect all platforms even Gen5/A10 even they don’t have the secure access problems.

Gen5/A10 are always in "secure" mode.

> All Gen5/A10/S10/Agilex share the same EMAC/SDMMC drivers.

Surely you can abstract this away somehow, e.g. with some function which
is compiled-out on Gen5/A10, while it's compiled-in on Agilex and tells
you whether you're in EL2/EL3 mode.

> For EMAC driver such as 'drivers/net/dwmac_socfpga.c', moving the PHY settings into SPL
> will leave this EMAC driver just asserting reset to EMAC controller and nothing else.
> EMAC node has to be enabled for SPL device tree as well for MAC PHY configuration.
> If you think it is OK to split the SDMMC clock and EMAC PHY configuration from SDMMC and EMAC drivers
> and put them in SPL, we can go this way.
> I can just drop the 'system manager' driver and all those high level APIs in ATF.

If this is only about clock/PHY configuration, can't the clock/PHY
driver for agilex just handle the EL2/EL3 stuff transparently ?
-- 
Best regards,
Marek Vasut