[PATCH v6 2/5] dt-bindings: clock: Add AST2500/AST2600 HACE reset definition

Neal Liu neal_liu at aspeedtech.com
Thu Jun 30 00:12:45 PDT 2022


> On 6/29/2022 8:17 PM, Neal Liu wrote:
> [...]
> >> On 6/29/2022 2:44 AM, Neal Liu wrote:
> >>> Add HACE reset bit definition for AST2500/AST2600.
> >>>
> >>> Signed-off-by: Neal Liu <neal_liu at aspeedtech.com>
> >>> Signed-off-by: Johnny Huang <johnny_huang at aspeedtech.com>
> >>> ---
> >>>    include/dt-bindings/clock/aspeed-clock.h  | 1 +
> >>>    include/dt-bindings/clock/ast2600-clock.h | 1 +
> >>>    2 files changed, 2 insertions(+)
> >>>
> >>> diff --git a/include/dt-bindings/clock/aspeed-clock.h
> >>> b/include/dt-bindings/clock/aspeed-clock.h
> >>> index 9ff4f6e4558c..06d568382c77 100644
> >>> --- a/include/dt-bindings/clock/aspeed-clock.h
> >>> +++ b/include/dt-bindings/clock/aspeed-clock.h
> >>> @@ -52,5 +52,6 @@
> >>>    #define ASPEED_RESET_I2C		7
> >>>    #define ASPEED_RESET_AHB		8
> >>>    #define ASPEED_RESET_CRT1		9
> >>> +#define ASPEED_RESET_HACE		10
> >>
> >> NAK.
> >>
> >> I replied to older v5 of this patch, but this v6 also looks incorrect
> >> as per HW manual.
> >>
> >> https://lore.kernel.org/linux-arm-kernel/20220629032008.1579899-1-nea
> >> l_liu
> @aspeedtech.com/T/#m000bd3388b3e41117aa0eef10bf6f8a6a3a85cce
> >>
> >> For both AST2400 and AST2500:
> >> SCU04[10] = PECI.
> >>
> >> It will be best to refactor/split aspeed-clock.h into separate files.
> >
> > Hi, based on @Krzysztof mentioned, change these define is not allowed due
> to breaking ABI.
> > So another way is to define a new value(interface), and we can change
> driver's implementation.
> > I know this is not intuitive to hardware register's value, it also confused me at
> the first time.
> >
> >
> 
> This is not SW ABI issue. Each controller in the device-tree needs correct clock
> and reset paths. aspeed-clock.h is shared between g4 and
> g5 dtsi. Not sure how you picked bit 10 for HACE, it's for resetting PECI
> controller.
> 
> See drivers/clk/clk-aspeed.c, which BTW is duplicating same stuff.
>          [ASPEED_RESET_MIC]      = 18,
>          [ASPEED_RESET_PWM]      =  9,
>          [ASPEED_RESET_PECI]     = 10,
> 
> FWIW, the reset bit for HACE and MIC are interchanged for AST2400 and
> AST2500 (at least as per HW datasheet).
> 
> So this is really fixing what's apparently already broken.

Actually, "ASPEED_RESET_MIC" is just an index, the reset bit in SCU is bit 18 for both ast2400 and ast2500.
So we have to add the real reset bit in drivers/clk/clk-aspeed.c, which would be:
	[ASPEED_RESET_HACE] = 4,

I would send another patch for this change. I think it can be independent with these patch series.
So no need to combine them here.



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