From 10577f74c35bd395951d1b2382c8d821089b5745 Mon Sep 17 00:00:00 2001 From: Stephen Boyd Date: Fri, 18 Sep 2015 17:52:08 -0700 Subject: [PATCH 54/69] cpufreq-dt: Handle OPP voltage adjust events On some SoCs the Adaptive Voltage Scaling (AVS) technique is employed to optimize the operating voltage of a device. At a given frequency, the hardware monitors dynamic factors and either makes a suggestion for how much to adjust a voltage for the current frequency, or it automatically adjusts the voltage without software intervention. In the former case, an AVS driver will call dev_pm_opp_modify_voltage() and update the voltage for the particular OPP the CPUs are using. Add an OPP notifier to cpufreq-dt so that we can adjust the voltage of the CPU when AVS updates the OPP. Signed-off-by: Stephen Boyd Acked-by: Viresh Kumar Signed-off-by: Georgi Djakov --- drivers/cpufreq/cpufreq-dt.c | 68 ++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 65 insertions(+), 3 deletions(-) --- a/drivers/cpufreq/cpufreq-dt.c +++ b/drivers/cpufreq/cpufreq-dt.c @@ -27,6 +27,9 @@ struct private_data { struct opp_table *opp_table; struct device *cpu_dev; const char *reg_name; + struct notifier_block opp_nb; + struct mutex lock; + unsigned long opp_freq; bool have_static_opps; }; @@ -42,12 +45,15 @@ static int set_target(struct cpufreq_pol unsigned long freq = policy->freq_table[index].frequency; int ret; + mutex_lock(&priv->lock); ret = dev_pm_opp_set_rate(priv->cpu_dev, freq * 1000); if (!ret) { + priv->opp_freq = freq * 1000; arch_set_freq_scale(policy->related_cpus, freq, policy->cpuinfo.max_freq); } + mutex_unlock(&priv->lock); return ret; } @@ -90,6 +96,39 @@ node_put: return name; } +static int opp_notifier(struct notifier_block *nb, unsigned long event, + void *data) +{ + struct dev_pm_opp *opp = data; + struct private_data *priv = container_of(nb, struct private_data, + opp_nb); + struct device *cpu_dev = priv->cpu_dev; + struct regulator *cpu_reg; + unsigned long volt, freq; + int ret = 0; + + if (event == OPP_EVENT_ADJUST_VOLTAGE) { + cpu_reg = dev_pm_opp_get_regulator(cpu_dev); + if (IS_ERR(cpu_reg)) { + ret = PTR_ERR(cpu_reg); + goto out; + } + volt = dev_pm_opp_get_voltage(opp); + freq = dev_pm_opp_get_freq(opp); + + mutex_lock(&priv->lock); + if (freq == priv->opp_freq) { + ret = regulator_set_voltage_triplet(cpu_reg, volt, volt, volt); + } + mutex_unlock(&priv->lock); + if (ret) + dev_err(cpu_dev, "failed to scale voltage: %d\n", ret); + } + +out: + return notifier_from_errno(ret); +} + static int resources_available(void) { struct device *cpu_dev; @@ -246,10 +285,14 @@ static int cpufreq_init(struct cpufreq_p __func__, ret); } + mutex_init(&priv->lock); + priv->opp_nb.notifier_call = opp_notifier; + dev_pm_opp_register_notifier(cpu_dev, &priv->opp_nb); + ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table); if (ret) { dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret); - goto out_free_opp; + goto out_unregister_nb; } priv->cpu_dev = cpu_dev; @@ -281,6 +324,8 @@ static int cpufreq_init(struct cpufreq_p out_free_cpufreq_table: dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table); +out_unregister_nb: + dev_pm_opp_unregister_notifier(cpu_dev, &priv->opp_nb); out_free_opp: if (priv->have_static_opps) dev_pm_opp_of_cpumask_remove_table(policy->cpus);