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SubjectRe: [PATCH v2 2/2] drivers: clk: zynqmp: Update fraction clock check from custom type flags
Hi Stephan,

Thanks for the review.

> ------Original Message------
> From: Stephen Boyd <>
> Sent: Tuesday, May 26, 2020 6:08PM
> To: Jolly Shah <>, Arm <>,
Linux-clk <>, Michal Simek
<>, Mturquette <>, Olof
> Cc: Rajan Vaja <>,
<>, Tejas Patel <>,
Rajan Vaja <>, Jolly Shah <>
> Subject: Re: [PATCH v2 2/2] drivers: clk: zynqmp: Update fraction
clock check from custom type flags
> Quoting Jolly Shah (2020-03-12 14:31:39)
>> From: Tejas Patel <>
>> Older firmware version sets BIT(13) in clkflag to mark a
>> divider as fractional divider. Updated firmware version sets BIT(4)
>> in type flags to mark a divider as fractional divider since
>> BIT(13) is defined as CLK_DUTY_CYCLE_PARENT in the common clk
>> framework flags.
>> To support both old and new firmware version, consider BIT(13) from
>> clkflag and BIT(4) from type_flag to check if divider is fractional
>> or not.
>> To maintain compatibility BIT(13) of clkflag in firmware will not be
>> used in future for any purpose and will be marked as unused.
> Why are we mixing the firmware flags with the ccf flags? They shouldn't
> be the same. The firmware should have its own 'flag numberspace' that is
> distinct from the common clk framework's 'flag numberspace'. Please fix
> the code.

Yes firmware flags are using separate numberspace now. Firmware
maintains CCF and firmware specific flags separately but earlier
CLK_FRAC was mistakenly defined in ccf flagspace and hence handled here
for backward compatibility. Driver takes care of not registering same
with CCF. Let me know if I misunderstood.

Jolly Shah

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