Hi Viresh, > -----Original Message----- > From: Viresh Kumar [mailto:viresh.ku...@linaro.org] > Sent: Thursday, March 09, 2017 5:39 PM > To: Y.T. Tang > Cc: r...@rjwysocki.net; linux...@vger.kernel.org; linux- > ker...@vger.kernel.org; linux-arm-ker...@lists.infradead.org; Y.T. Tang > Subject: Re: [PATCH] cpufreq: qoriq: enhance bus frequency calculation > > On 09-03-17, 16:15, YuanTian Tang wrote: > > From: Tang Yuantian <yuantian.t...@nxp.com> > > > > On some platforms, property device-type may be missed in soc node in > > dts which caused the bus-frequency can not be obtained correctly. > > > > This patch enhanced the bus-frequency calculation. When property > > device-type is missed in dts, bus-frequency will be obtained by > > looking up clock table to get platform clock and hence get its > > frequency. > > > > Signed-off-by: Tang Yuantian <yuantian.t...@nxp.com> > > --- > > drivers/cpufreq/qoriq-cpufreq.c | 24 +++++++++++++++++------- > > 1 file changed, 17 insertions(+), 7 deletions(-) > > > > diff --git a/drivers/cpufreq/qoriq-cpufreq.c > > b/drivers/cpufreq/qoriq-cpufreq.c index bfec1bc..0f22e40 100644 > > --- a/drivers/cpufreq/qoriq-cpufreq.c > > +++ b/drivers/cpufreq/qoriq-cpufreq.c > > @@ -52,17 +52,27 @@ static u32 get_bus_freq(void) { > > struct device_node *soc; > > u32 sysfreq; > > + struct clk *pltclk; > > + int ret; > > > > + /* get platform freq by searching bus-frequency property */ > > soc = of_find_node_by_type(NULL, "soc"); > > - if (!soc) > > - return 0; > > - > > - if (of_property_read_u32(soc, "bus-frequency", &sysfreq)) > > - sysfreq = 0; > > + if (soc) { > > + ret = of_property_read_u32(soc, "bus-frequency", &sysfreq); > > + of_node_put(soc); > > + if (!ret) > > + return sysfreq; > > + } > > > > - of_node_put(soc); > > + /* get platform freq by its clock name */ > > + pltclk = clk_get(NULL, "cg-pll0-div1"); > > Will this always work? If yes, then what about dropping the code parsing DT > completely ? That is, just rely on clk_get_rate() in all cases. > We put all the clock tree configuration in driver, not in dts. cg-pll0-div1 is hardcoded in driver since we don't depend on dts. We kind of don't have other choices but use the hardcode clock name here too.
> > + if (IS_ERR(pltclk)) { > > + pr_err("%s: can't get bus frequency %ld\n", > > + __func__, PTR_ERR(pltclk)); > > You need to properly align this. Try running checkpatch over this patch or: > > checkpatch --strict > I did check it with checkpatch script, but without --strict parameter. After applying --strict, script tell the alignment issue. :) Regards, Andy > > + return PTR_ERR(pltclk); > > + } > > > > - return sysfreq; > > + return clk_get_rate(pltclk); > > } > > > > static struct clk *cpu_to_clk(int cpu) > > -- > > 2.1.0.27.g96db324 > > -- > viresh