| Message ID | 1489047306-31818-1-git-send-email-andy.tang@nxp.com (mailing list archive) |
|---|---|
| State | Changes Requested, archived |
| Headers | show |
On 09-03-17, 16:15, YuanTian Tang wrote: > From: Tang Yuantian <Yuantian.Tang@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.tang@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. > + 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 > + return PTR_ERR(pltclk); > + } > > - return sysfreq; > + return clk_get_rate(pltclk); > } > > static struct clk *cpu_to_clk(int cpu) > -- > 2.1.0.27.g96db324
Hi Viresh, > -----Original Message----- > From: Viresh Kumar [mailto:viresh.kumar@linaro.org] > Sent: Thursday, March 09, 2017 5:39 PM > To: Y.T. Tang > Cc: rjw@rjwysocki.net; linux-pm@vger.kernel.org; linux- > kernel@vger.kernel.org; linux-arm-kernel@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.Tang@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.tang@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
On 10-03-17, 01:44, Andy Tang wrote: > > 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. Looks like you misread my comment. Let me try again. Will it be fine to write get_bus_freq() this way? static u32 get_bus_freq(void) { struct clk *pltclk; /* get platform freq by its clock name */ pltclk = clk_get(NULL, "cg-pll0-div1"); if (IS_ERR(pltclk)) { pr_err("%s: can't get bus frequency %ld\n", __func__, PTR_ERR(pltclk)); return PTR_ERR(pltclk); } return clk_get_rate(pltclk); }
Hi Viresh, > -----Original Message----- > From: Viresh Kumar [mailto:viresh.kumar@linaro.org] > Sent: Friday, March 10, 2017 6:05 PM > To: Andy Tang > Cc: rjw@rjwysocki.net; linux-pm@vger.kernel.org; linux- > kernel@vger.kernel.org; linux-arm-kernel@lists.infradead.org > Subject: Re: [PATCH] cpufreq: qoriq: enhance bus frequency calculation > > On 10-03-17, 01:44, Andy Tang wrote: > > > 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. > > Looks like you misread my comment. Let me try again. Will it be fine to write > get_bus_freq() this way? > > static u32 get_bus_freq(void) > { > struct clk *pltclk; > > /* get platform freq by its clock name */ > pltclk = clk_get(NULL, "cg-pll0-div1"); > if (IS_ERR(pltclk)) { > pr_err("%s: can't get bus frequency %ld\n", > __func__, PTR_ERR(pltclk)); > return PTR_ERR(pltclk); > } > > return clk_get_rate(pltclk); > } > Yes, we can. But for some legacy powerpc-based socs, this may not work. powerpc-base socs are still using legacy clock driver. For compatibility sake, we better be compatible with old ones. It would break any compatibility this way. Regards, Yuantian > -- > viresh
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"); + if (IS_ERR(pltclk)) { + pr_err("%s: can't get bus frequency %ld\n", + __func__, PTR_ERR(pltclk)); + return PTR_ERR(pltclk); + } - return sysfreq; + return clk_get_rate(pltclk); } static struct clk *cpu_to_clk(int cpu)