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