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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