target/linux/ipq806x/patches-4.19/0054-cpufreq-dt-Handle-OPP-voltage-adjust-events.patch

   1 From 10577f74c35bd395951d1b2382c8d821089b5745 Mon Sep 17 00:00:00 2001
   2 From: Stephen Boyd <sboyd@codeaurora.org>
   3 Date: Fri, 18 Sep 2015 17:52:08 -0700
   4 Subject: [PATCH 54/69] cpufreq-dt: Handle OPP voltage adjust events
   5
   6 On some SoCs the Adaptive Voltage Scaling (AVS) technique is
   7 employed to optimize the operating voltage of a device. At a
   8 given frequency, the hardware monitors dynamic factors and either
   9 makes a suggestion for how much to adjust a voltage for the
  10 current frequency, or it automatically adjusts the voltage
  11 without software intervention.
  12
  13 In the former case, an AVS driver will call
  14 dev_pm_opp_modify_voltage() and update the voltage for the
  15 particular OPP the CPUs are using. Add an OPP notifier to
  16 cpufreq-dt so that we can adjust the voltage of the CPU when AVS
  17 updates the OPP.
  18
  19 Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
  20 Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
  21 Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
  22 ---
  23  drivers/cpufreq/cpufreq-dt.c | 68 ++++++++++++++++++++++++++++++++++++++++++--
  24  1 file changed, 65 insertions(+), 3 deletions(-)
  25
  26 --- a/drivers/cpufreq/cpufreq-dt.c
  27 +++ b/drivers/cpufreq/cpufreq-dt.c
  28 @@ -32,6 +32,9 @@ struct private_data {
  29         struct device *cpu_dev;
  30         struct thermal_cooling_device *cdev;
  31         const char *reg_name;
  32 +       struct notifier_block opp_nb;
  33 +       struct mutex lock;
  34 +       unsigned long opp_freq;
  35         bool have_static_opps;
  36  };
  37
  38 @@ -47,12 +50,15 @@ static int set_target(struct cpufreq_pol
  39         unsigned long freq = policy->freq_table[index].frequency;
  40         int ret;
  41
  42 +       mutex_lock(&priv->lock);
  43         ret = dev_pm_opp_set_rate(priv->cpu_dev, freq * 1000);
  44
  45         if (!ret) {
  46 +               priv->opp_freq = freq * 1000;
  47                 arch_set_freq_scale(policy->related_cpus, freq,
  48                                     policy->cpuinfo.max_freq);
  49         }
  50 +       mutex_unlock(&priv->lock);
  51
  52         return ret;
  53  }
  54 @@ -95,6 +101,39 @@ node_put:
  55         return name;
  56  }
  57
  58 +static int opp_notifier(struct notifier_block *nb, unsigned long event,
  59 +                       void *data)
  60 +{
  61 +       struct dev_pm_opp *opp = data;
  62 +       struct private_data *priv = container_of(nb, struct private_data,
  63 +                                                opp_nb);
  64 +       struct device *cpu_dev = priv->cpu_dev;
  65 +       struct regulator *cpu_reg;
  66 +       unsigned long volt, freq;
  67 +       int ret = 0;
  68 +
  69 +       if (event == OPP_EVENT_ADJUST_VOLTAGE) {
  70 +               cpu_reg = dev_pm_opp_get_regulator(cpu_dev);
  71 +               if (IS_ERR(cpu_reg)) {
  72 +                       ret = PTR_ERR(cpu_reg);
  73 +                       goto out;
  74 +               }
  75 +               volt = dev_pm_opp_get_voltage(opp);
  76 +               freq = dev_pm_opp_get_freq(opp);
  77 +
  78 +               mutex_lock(&priv->lock);
  79 +               if (freq == priv->opp_freq) {
  80 +                       ret = regulator_set_voltage_triplet(cpu_reg, volt, volt, volt);
  81 +               }
  82 +               mutex_unlock(&priv->lock);
  83 +               if (ret)
  84 +                       dev_err(cpu_dev, "failed to scale voltage: %d\n", ret);
  85 +       }
  86 +
  87 +out:
  88 +       return notifier_from_errno(ret);
  89 +}
  90 +
  91  static int resources_available(void)
  92  {
  93         struct device *cpu_dev;
  94 @@ -161,6 +200,7 @@ static int cpufreq_init(struct cpufreq_p
  95         bool fallback = false;
  96         const char *name;
  97         int ret;
  98 +       struct srcu_notifier_head *opp_srcu_head;
  99
 100         cpu_dev = get_cpu_device(policy->cpu);
 101         if (!cpu_dev) {
 102 @@ -254,10 +294,13 @@ static int cpufreq_init(struct cpufreq_p
 103                                 __func__, ret);
 104         }
 105
 106 +       mutex_init(&priv->lock);
 107 +       dev_pm_opp_register_notifier(cpu_dev, &priv->opp_nb);
 108 +
 109         ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table);
 110         if (ret) {
 111                 dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret);
 112 -               goto out_free_opp;
 113 +               goto out_unregister_nb;
 114         }
 115
 116         priv->cpu_dev = cpu_dev;
 117 @@ -287,6 +330,8 @@ static int cpufreq_init(struct cpufreq_p
 118
 119  out_free_cpufreq_table:
 120         dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table);
 121 +out_unregister_nb:
 122 +       dev_pm_opp_unregister_notifier(cpu_dev, &priv->opp_nb);
 123  out_free_opp:
 124         if (priv->have_static_opps)
 125                 dev_pm_opp_of_cpumask_remove_table(policy->cpus);