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Groups > linux.kernel > #1483611
| From | Grygorii Strashko <grygorii.strashko@ti.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH 7/9] net: ethernet: ti: cpts: calc mult and shift from refclk freq |
| Date | 2016-09-14 22:10 +0200 |
| Message-ID | <shoFk-5qB-29@gated-at.bofh.it> (permalink) |
| References | <shi6S-1iq-7@gated-at.bofh.it> <shi6S-1iq-21@gated-at.bofh.it> <shjmi-1XX-43@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On 09/14/2016 05:22 PM, Richard Cochran wrote:
> On Wed, Sep 14, 2016 at 04:02:29PM +0300, Grygorii Strashko wrote:
>> @@ -35,6 +33,8 @@ Optional properties:
>> For example in dra72x-evm, pcf gpio has to be
>> driven low so that cpsw slave 0 and phy data
>> lines are connected via mux.
>> +- cpts_clock_mult : Numerator to convert input clock ticks into nanoseconds
>> +- cpts_clock_shift : Denominator to convert input clock ticks into nanoseconds
>
> You should explain to the reader how these will be calculated when the
> properties are missing.
Not sure how full should it be explained in bindings - I'll try.
>
>> diff --git a/drivers/net/ethernet/ti/cpts.c b/drivers/net/ethernet/ti/cpts.c
>> index ff8bb85..8046a21 100644
>> --- a/drivers/net/ethernet/ti/cpts.c
>> +++ b/drivers/net/ethernet/ti/cpts.c
>> @@ -418,18 +418,60 @@ void cpts_unregister(struct cpts *cpts)
>> clk_disable(cpts->refclk);
>> }
>>
>> +static void cpts_calc_mult_shift(struct cpts *cpts)
>> +{
>> + u64 maxsec;
>> + u32 freq;
>> + u32 mult;
>> + u32 shift;
>> + u64 ns;
>> + u64 frac;
>
> Why so many new lines? This isn't good style. Please combine
> variables of the same type into one line and sort the lists
> alphabetically.
Its matter of preferences :), but sure - I'll update.
>
>> + if (cpts->cc_mult || cpts->cc.shift)
>> + return;
>> +
>> + freq = clk_get_rate(cpts->refclk);
>> +
>> + /* Calc the maximum number of seconds which we can run before
>> + * wrapping around.
>> + */
>> + maxsec = cpts->cc.mask;
>> + do_div(maxsec, freq);
>> + if (!maxsec)
>> + maxsec = 1;
>> + else if (maxsec > 600 && cpts->cc.mask > UINT_MAX)
>> + maxsec = 600;
>> +
>> + clocks_calc_mult_shift(&mult, &shift, freq, NSEC_PER_SEC, maxsec);
>> +
>> + cpts->cc_mult = mult;
>> + cpts->cc.mult = mult;
>> + cpts->cc.shift = shift;
>> + /* Check calculations and inform if not precise */
>
> Contrary to this comment, you are not making any kind of judgment
> about whether the calculations are precise or not.
>
>> + frac = 0;
>> + ns = cyclecounter_cyc2ns(&cpts->cc, freq, cpts->cc.mask, &frac);
>> +
>> + dev_info(cpts->dev,
>> + "CPTS: ref_clk_freq:%u calc_mult:%u calc_shift:%u error:%lld nsec/sec\n",
>> + freq, cpts->cc_mult, cpts->cc.shift, (ns - NSEC_PER_SEC));
>> +}
>> +
>
Thanks for the review.
--
regards,
-grygorii
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[PATCH 0/9] net: ethernet: ti: cpts: update and fixes Grygorii Strashko <grygorii.strashko@ti.com> - 2016-09-14 15:10 +0200
[PATCH 8/9] net: ethernet: ti: cpts: fix overflow check period Grygorii Strashko <grygorii.strashko@ti.com> - 2016-09-14 15:10 +0200
Re: [PATCH 8/9] net: ethernet: ti: cpts: fix overflow check period Richard Cochran <richardcochran@gmail.com> - 2016-09-14 16:30 +0200
Re: [PATCH 8/9] net: ethernet: ti: cpts: fix overflow check period Richard Cochran <richardcochran@gmail.com> - 2016-09-14 22:10 +0200
Re: [PATCH 8/9] net: ethernet: ti: cpts: fix overflow check period Grygorii Strashko <grygorii.strashko@ti.com> - 2016-09-14 22:30 +0200
Re: [PATCH 8/9] net: ethernet: ti: cpts: fix overflow check period Richard Cochran <richardcochran@gmail.com> - 2016-09-14 22:50 +0200
Re: [PATCH 8/9] net: ethernet: ti: cpts: fix overflow check period Grygorii Strashko <grygorii.strashko@ti.com> - 2016-09-14 23:00 +0200
Re: [PATCH 8/9] net: ethernet: ti: cpts: fix overflow check period Grygorii Strashko <grygorii.strashko@ti.com> - 2016-09-14 22:10 +0200
[PATCH 7/9] net: ethernet: ti: cpts: calc mult and shift from refclk freq Grygorii Strashko <grygorii.strashko@ti.com> - 2016-09-14 15:10 +0200
Re: [PATCH 7/9] net: ethernet: ti: cpts: calc mult and shift from refclk freq Richard Cochran <richardcochran@gmail.com> - 2016-09-14 16:30 +0200
Re: [PATCH 7/9] net: ethernet: ti: cpts: calc mult and shift from refclk freq Grygorii Strashko <grygorii.strashko@ti.com> - 2016-09-14 22:10 +0200
Re: [PATCH 7/9] net: ethernet: ti: cpts: calc mult and shift from refclk freq Richard Cochran <richardcochran@gmail.com> - 2016-09-14 22:30 +0200
Re: [PATCH 7/9] net: ethernet: ti: cpts: calc mult and shift from refclk freq Grygorii Strashko <grygorii.strashko@ti.com> - 2016-09-14 23:00 +0200
Re: [PATCH 7/9] net: ethernet: ti: cpts: calc mult and shift from refclk freq Richard Cochran <richardcochran@gmail.com> - 2016-09-14 23:10 +0200
Re: [PATCH 7/9] net: ethernet: ti: cpts: calc mult and shift from refclk freq Grygorii Strashko <grygorii.strashko@ti.com> - 2016-09-14 23:20 +0200
Re: [PATCH 7/9] net: ethernet: ti: cpts: calc mult and shift from refclk freq Richard Cochran <richardcochran@gmail.com> - 2016-09-15 14:00 +0200
Re: [PATCH 7/9] net: ethernet: ti: cpts: calc mult and shift from refclk freq Richard Cochran <richardcochran@gmail.com> - 2016-09-15 16:00 +0200
[PATCH 1/9] net: ethernet: ti: exclude cpts from build when disabled Grygorii Strashko <grygorii.strashko@ti.com> - 2016-09-14 15:10 +0200
[PATCH 3/9] net: ethernet: ti: cpts: rework initialization/deinitialization Grygorii Strashko <grygorii.strashko@ti.com> - 2016-09-14 15:10 +0200
Re: [PATCH 3/9] net: ethernet: ti: cpts: rework initialization/deinitialization Richard Cochran <richardcochran@gmail.com> - 2016-09-14 16:00 +0200
Re: [PATCH 3/9] net: ethernet: ti: cpts: rework initialization/deinitialization Grygorii Strashko <grygorii.strashko@ti.com> - 2016-09-14 22:20 +0200
Re: [PATCH 3/9] net: ethernet: ti: cpts: rework initialization/deinitialization Grygorii Strashko <grygorii.strashko@ti.com> - 2016-09-14 22:40 +0200
Re: [PATCH 3/9] net: ethernet: ti: cpts: rework initialization/deinitialization Richard Cochran <richardcochran@gmail.com> - 2016-09-14 23:00 +0200
Re: [PATCH 3/9] net: ethernet: ti: cpts: rework initialization/deinitialization Grygorii Strashko <grygorii.strashko@ti.com> - 2016-09-14 23:00 +0200
Re: [PATCH 3/9] net: ethernet: ti: cpts: rework initialization/deinitialization Richard Cochran <richardcochran@gmail.com> - 2016-09-14 22:40 +0200
Re: [PATCH 3/9] net: ethernet: ti: cpts: rework initialization/deinitialization Richard Cochran <richardcochran@gmail.com> - 2016-09-15 10:20 +0200
[PATCH 5/9] net: ethernet: ti: cpts: add return value to tx and rx timestamp funcitons Grygorii Strashko <grygorii.strashko@ti.com> - 2016-09-14 15:10 +0200
Re: [PATCH 5/9] net: ethernet: ti: cpts: add return value to tx and rx timestamp funcitons Richard Cochran <richardcochran@gmail.com> - 2016-09-14 16:10 +0200
[PATCH 6/9] net: ethernet: ti: cpts: clean up event list if event pool is empty Grygorii Strashko <grygorii.strashko@ti.com> - 2016-09-14 15:10 +0200
Re: [PATCH 6/9] net: ethernet: ti: cpts: clean up event list if event pool is empty Richard Cochran <richardcochran@gmail.com> - 2016-09-14 16:20 +0200
Re: [PATCH 6/9] net: ethernet: ti: cpts: clean up event list if event pool is empty Grygorii Strashko <grygorii.strashko@ti.com> - 2016-09-14 22:00 +0200
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