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Date: Wed, 4 Mar 2015 15:45:40 +0530
From: Viresh Kumar <viresh.kumar@...aro.org>
To: "pi-cheng.chen" <pi-cheng.chen@...aro.org>
Cc: Matthias Brugger <matthias.bgg@...il.com>,
Rob Herring <robh+dt@...nel.org>,
"Rafael J. Wysocki" <rjw@...ysocki.net>,
Thomas Petazzoni <thomas.petazzoni@...e-electrons.com>,
Pawel Moll <pawel.moll@....com>,
Mark Rutland <mark.rutland@....com>,
Ian Campbell <ijc+devicetree@...lion.org.uk>,
Kumar Gala <galak@...eaurora.org>,
Catalin Marinas <catalin.marinas@....com>,
Will Deacon <will.deacon@....com>,
"Joe.C" <yingjoe.chen@...iatek.com>,
Eddie Huang <eddie.huang@...iatek.com>,
Howard Chen <ibanezchen@...il.com>,
Ashwin Chaugule <ashwin.chaugule@...aro.org>,
Mike Turquette <mturquette@...aro.org>, fan.chen@...iatek.com,
"devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
"linux-arm-kernel@...ts.infradead.org"
<linux-arm-kernel@...ts.infradead.org>,
Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
"linux-pm@...r.kernel.org" <linux-pm@...r.kernel.org>,
Linaro Kernel Mailman List <linaro-kernel@...ts.linaro.org>,
linux-mediatek@...ts.infradead.org
Subject: Re: [PATCH v2 1/4] cpufreq-dt: add clock domain and intermediate
frequency support
On 4 March 2015 at 14:19, pi-cheng.chen <pi-cheng.chen@...aro.org> wrote:
> In this patch, CPU clock/power domain information is added into the
> platform_data of cpufreq-dt so that cpufreq-dt driver could check with CPUs
> share clock/power. Also, intermediate frequency support is added in this
You should have separate patches for logically separate changes.
> version. Since the program flows of .target_index and .target_intermediate
> are quite similar, consolidate the flow as a new function to keep readibility.
>
> Signed-off-by: pi-cheng.chen <pi-cheng.chen@...aro.org>
> ---
> drivers/cpufreq/cpufreq-dt.c | 68 +++++++++++++++++++++++++++++++++++++++-----
> include/linux/cpufreq-dt.h | 7 +++++
> 2 files changed, 68 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/cpufreq/cpufreq-dt.c b/drivers/cpufreq/cpufreq-dt.c
> index bab67db..5948bdf 100644
> --- a/drivers/cpufreq/cpufreq-dt.c
> +++ b/drivers/cpufreq/cpufreq-dt.c
> @@ -34,25 +34,37 @@ struct private_data {
> struct regulator *cpu_reg;
> struct thermal_cooling_device *cdev;
> unsigned int voltage_tolerance; /* in percentage */
> + unsigned long intermediate_freq;
> };
>
> -static int set_target(struct cpufreq_policy *policy, unsigned int index)
> +static unsigned int get_intermediate(struct cpufreq_policy *policy,
> + unsigned int index)
> +{
> + struct private_data *priv = policy->driver_data;
> + struct cpufreq_frequency_table *freq_table;
> + unsigned long freq = clk_get_rate(policy->clk);
This will return current freq, which can also be fetched with
policy->cur.
> +
> + freq_table = cpufreq_frequency_get_table(policy->cpu);
instead, freq_table = policy->freq_table.
> +
Always add a comment over such decision making expressions, on
why you chose to return 0.
> + if (freq == priv->intermediate_freq ||
Looks fine, current freq == intermediate freq..
> + freq_table[index].frequency * 1000 == freq)
Absolutely wrong, current-freq == requested-freq.
Instead it should be:
freq_table[index].frequency * 1000 == priv->intermediate_freq.
> + return 0;
> +
> + return priv->intermediate_freq;
> +}
> +
> +static int set_frequency(struct cpufreq_policy *policy, long freq_Hz)
> {
> struct dev_pm_opp *opp;
> - struct cpufreq_frequency_table *freq_table = policy->freq_table;
> struct clk *cpu_clk = policy->clk;
> struct private_data *priv = policy->driver_data;
> struct device *cpu_dev = priv->cpu_dev;
> struct regulator *cpu_reg = priv->cpu_reg;
> unsigned long volt = 0, volt_old = 0, tol = 0;
> unsigned int old_freq, new_freq;
> - long freq_Hz, freq_exact;
> + long freq_exact;
> int ret;
>
> - freq_Hz = clk_round_rate(cpu_clk, freq_table[index].frequency * 1000);
> - if (freq_Hz <= 0)
> - freq_Hz = freq_table[index].frequency * 1000;
> -
> freq_exact = freq_Hz;
> new_freq = freq_Hz / 1000;
> old_freq = clk_get_rate(cpu_clk) / 1000;
> @@ -112,6 +124,29 @@ static int set_target(struct cpufreq_policy *policy, unsigned int index)
> return ret;
> }
>
> +static int target_intermediate(struct cpufreq_policy *policy,
> + unsigned int index)
> +{
> + struct private_data *priv = policy->driver_data;
> + long freq_Hz;
> +
> + freq_Hz = priv->intermediate_freq;
> + return set_frequency(policy, freq_Hz);
Instead, return set_frequency(policy, priv->intermediate_freq);
> +}
> +
> +static int set_target(struct cpufreq_policy *policy, unsigned int index)
> +{
> + struct cpufreq_frequency_table *freq_table = policy->freq_table;
> + struct clk *cpu_clk = policy->clk;
> + long freq_Hz;
> +
> + freq_Hz = clk_round_rate(cpu_clk, freq_table[index].frequency * 1000);
Use policy->clk here directly instead of another local variable.
> + if (freq_Hz <= 0)
> + freq_Hz = freq_table[index].frequency * 1000;
Why shouldn't we call clk_round_rate() for intermediate freq as well ?
I think, it
should be called for it as well.. And so you can save intermediate_freq_index
instead of the freq..
> + return set_frequency(policy, freq_Hz);
> +}
> +
> static int allocate_resources(int cpu, struct device **cdev,
> struct regulator **creg, struct clk **cclk)
> {
> @@ -296,6 +331,23 @@ static int cpufreq_init(struct cpufreq_policy *policy)
> pd = cpufreq_get_driver_data();
> if (!pd || !pd->independent_clocks)
> cpumask_setall(policy->cpus);
> + else if (pd && !list_empty(&pd->domain_list)) {
> + struct list_head *domain_node;
> + struct cpufreq_cpu_domain *domain;
> +
> + list_for_each(domain_node, &pd->domain_list) {
> + domain = container_of(domain_node,
> + struct cpufreq_cpu_domain, node);
> + if (!cpumask_test_cpu(policy->cpu, &domain->cpus))
> + continue;
> +
> + if (domain->intermediate_freq)
> + priv->intermediate_freq =
> + domain->intermediate_freq;
> + cpumask_copy(policy->cpus, &domain->cpus);
> + break;
> + }
> + }
>
Do this in a separate patch.
> of_node_put(np);
>
> @@ -363,6 +415,8 @@ static struct cpufreq_driver dt_cpufreq_driver = {
> .verify = cpufreq_generic_frequency_table_verify,
> .target_index = set_target,
> .get = cpufreq_generic_get,
> + .get_intermediate = get_intermediate,
> + .target_intermediate = target_intermediate,
> .init = cpufreq_init,
> .exit = cpufreq_exit,
> .ready = cpufreq_ready,
> diff --git a/include/linux/cpufreq-dt.h b/include/linux/cpufreq-dt.h
> index 0414009..d6e2097 100644
> --- a/include/linux/cpufreq-dt.h
> +++ b/include/linux/cpufreq-dt.h
> @@ -10,6 +10,12 @@
> #ifndef __CPUFREQ_DT_H__
> #define __CPUFREQ_DT_H__
>
> +struct cpufreq_cpu_domain {
> + struct list_head node;
> + cpumask_t cpus;
> + unsigned long intermediate_freq;
This should come from DT instead of platform data.
> +};
This struct will die along with the below one as soon as my patches
on OPP bindings V2 get merged.
> struct cpufreq_dt_platform_data {
> /*
> * True when each CPU has its own clock to control its
> @@ -17,6 +23,7 @@ struct cpufreq_dt_platform_data {
> * clock.
> */
> bool independent_clocks;
> + struct list_head domain_list;
Also update the comment on how what these fields mean..
> };
>
> #endif /* __CPUFREQ_DT_H__ */
> --
> 1.9.1
>
--
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