[PATCH v4 02/13] dt-bindings: Add bindings for peci-aspeed

On Thu, 2021-12-02 at 02:31 +0000, Billy Tsai wrote:

Hi Zev,

On 2021/12/2, 9:55 AM, "Zev Weiss" [off-list ref] wrote:

??? On Wed, Dec 01, 2021 at 02:38:04AM PST, Billy Tsai wrote:
??? >?? >Hi,
??? >?? >
??? >?? >On 2021/11/23, 10:10 PM, "openbmc on behalf of Iwona Winiarska"
<openbmc-bounces+billy_tsai=aspeedtech.com@lists.ozlabs.org?on behalf of
iwona.winiarska at intel.com> wrote:
??? >?? >
??? >?? >??? Add device tree bindings for the peci-aspeed controller driver.
??? >?? >
??? >?? >??? >?? +? aspeed,clock-divider:
??? >?? >??? >?? +??? description:
??? >?? >??? >?? +????? This value determines PECI controller internal clock
dividing
??? >?? >??? >?? +????? rate. The divider will be calculated as 2 raised to
the power of
??? >?? >??? >?? +????? the given value.
??? >?? >??? >?? +??? $ref: /schemas/types.yaml#/definitions/uint32
??? >?? >??? >?? +??? minimum: 0
??? >?? >??? >?? +??? maximum: 7
??? >?? >??? >?? +??? default: 0
??? >?? >??? >?? +
??? >?? >??? >?? +? aspeed,msg-timing:
??? >?? >??? >?? +??? description:
??? >?? >??? >?? +????? Message timing negotiation period. This value will
determine the period
??? >?? >??? >?? +????? of message timing negotiation to be issued by PECI
controller. The unit
??? >?? >??? >?? +????? of the programmed value is four times of PECI clock
period.
??? >?? >??? >?? +??? $ref: /schemas/types.yaml#/definitions/uint32
??? >?? >??? >?? +??? minimum: 0
??? >?? >??? >?? +??? maximum: 255
??? >?? >??? >?? +??? default: 1
??? >?? >??? >?? +
??? >?? >??? >?? +? aspeed,addr-timing:
??? >?? >??? >?? +??? description:
??? >?? >??? >?? +????? Address timing negotiation period. This value will
determine the period
??? >?? >??? >?? +????? of address timing negotiation to be issued by PECI
controller. The unit
??? >?? >??? >?? +????? of the programmed value is four times of PECI clock
period.
??? >?? >??? >?? +??? $ref: /schemas/types.yaml#/definitions/uint32
??? >?? >??? >?? +??? minimum: 0
??? >?? >??? >?? +??? maximum: 255
??? >?? >??? >?? +??? default: 1
??? >?? >I suggest deleting these three properties and replacing them with the
following
??? >?? >
??? >?? >aspeed,peci-bit-time:
??? >?? >??????? description:
??? >?? >????????? The bit time driven by PECI controller. The unit of the
value is Hz.
??? >?? >??? minimum: 2000
??? >?? >??? maximum: 1000000
??? >?? >
??? >?? >And the driver should use this property to caculate the appropriate
clock-divider,
??? >?? >msg-timing and addr-timing, instead of exposing hardware registers to
dts.
??? >?? >

??? >?? Or perhaps just 'bus-frequency' a la i2c-aspeed, gpio-aspeed-sgpio,
etc?

It's a good ideal for the consistency.

If we want to go with passing frequency - I would prefer to go with "clock-
frequency" and use clock framework for exposing it to peci-aspeed (as I
mentioned in reply to patch 05).

What do you think?

Thanks
-Iwona

Thanks

Best Regards,
Billy Tsai