thermal: export thermal_zone_parameters to sysfs

It's useful for tuning to be able to edit thermal_zone_parameters from
userspace.  Export them to the thermal_zone sysfs so that they can be
easily changed.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Javi Merino <javi.merino@arm.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>

diff --git a/Documentation/thermal/sysfs-api.txt b/Documentation/thermal/sysfs-api.txt
index fc7dfe10778be5ab99ba3469531ec6f4143c24c5..7d44d7f1a71bfdf2ff12beb662a2704312334738 100644 (file)
--- a/Documentation/thermal/sysfs-api.txt
+++ b/Documentation/thermal/sysfs-api.txt
@@ -184,6 +184,12 @@ Thermal zone device sys I/F, created once it's registered:
     |---trip_point_[0-*]_type: Trip point type
     |---trip_point_[0-*]_hyst: Hysteresis value for this trip point
     |---emul_temp:             Emulated temperature set node
+    |---sustainable_power:      Sustainable dissipatable power
+    |---k_po:                   Proportional term during temperature overshoot
+    |---k_pu:                   Proportional term during temperature undershoot
+    |---k_i:                    PID's integral term in the power allocator gov
+    |---k_d:                    PID's derivative term in the power allocator
+    |---integral_cutoff:        Offset above which errors are accumulated
 
 Thermal cooling device sys I/F, created once it's registered:
 /sys/class/thermal/cooling_device[0-*]:
@@ -307,6 +313,52 @@ emul_temp
          because userland can easily disable the thermal policy by simply
          flooding this sysfs node with low temperature values.
 
+sustainable_power
+       An estimate of the sustained power that can be dissipated by
+       the thermal zone. Used by the power allocator governor. For
+       more information see Documentation/thermal/power_allocator.txt
+       Unit: milliwatts
+       RW, Optional
+
+k_po
+       The proportional term of the power allocator governor's PID
+       controller during temperature overshoot. Temperature overshoot
+       is when the current temperature is above the "desired
+       temperature" trip point. For more information see
+       Documentation/thermal/power_allocator.txt
+       RW, Optional
+
+k_pu
+       The proportional term of the power allocator governor's PID
+       controller during temperature undershoot. Temperature undershoot
+       is when the current temperature is below the "desired
+       temperature" trip point. For more information see
+       Documentation/thermal/power_allocator.txt
+       RW, Optional
+
+k_i
+       The integral term of the power allocator governor's PID
+       controller. This term allows the PID controller to compensate
+       for long term drift. For more information see
+       Documentation/thermal/power_allocator.txt
+       RW, Optional
+
+k_d
+       The derivative term of the power allocator governor's PID
+       controller. For more information see
+       Documentation/thermal/power_allocator.txt
+       RW, Optional
+
+integral_cutoff
+       Temperature offset from the desired temperature trip point
+       above which the integral term of the power allocator
+       governor's PID controller starts accumulating errors. For
+       example, if integral_cutoff is 0, then the integral term only
+       accumulates error when temperature is above the desired
+       temperature trip point. For more information see
+       Documentation/thermal/power_allocator.txt
+       RW, Optional
+
 *****************************
 * Cooling device attributes *
 *****************************

diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index 78bb9aa9d4e402bd221b34797c84f172533bf879..962de1847cc08b40855df8c532e9f7e2d5ed0766 100644 (file)
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -875,6 +875,102 @@ emul_temp_store(struct device *dev, struct device_attribute *attr,
 static DEVICE_ATTR(emul_temp, S_IWUSR, NULL, emul_temp_store);
 #endif/*CONFIG_THERMAL_EMULATION*/
 
+static ssize_t
+sustainable_power_show(struct device *dev, struct device_attribute *devattr,
+                      char *buf)
+{
+       struct thermal_zone_device *tz = to_thermal_zone(dev);
+
+       if (tz->tzp)
+               return sprintf(buf, "%u\n", tz->tzp->sustainable_power);
+       else
+               return -EIO;
+}
+
+static ssize_t
+sustainable_power_store(struct device *dev, struct device_attribute *devattr,
+                       const char *buf, size_t count)
+{
+       struct thermal_zone_device *tz = to_thermal_zone(dev);
+       u32 sustainable_power;
+
+       if (!tz->tzp)
+               return -EIO;
+
+       if (kstrtou32(buf, 10, &sustainable_power))
+               return -EINVAL;
+
+       tz->tzp->sustainable_power = sustainable_power;
+
+       return count;
+}
+static DEVICE_ATTR(sustainable_power, S_IWUSR | S_IRUGO, sustainable_power_show,
+               sustainable_power_store);
+
+#define create_s32_tzp_attr(name)                                      \
+       static ssize_t                                                  \
+       name##_show(struct device *dev, struct device_attribute *devattr, \
+               char *buf)                                              \
+       {                                                               \
+       struct thermal_zone_device *tz = to_thermal_zone(dev);          \
+                                                                       \
+       if (tz->tzp)                                                    \
+               return sprintf(buf, "%u\n", tz->tzp->name);             \
+       else                                                            \
+               return -EIO;                                            \
+       }                                                               \
+                                                                       \
+       static ssize_t                                                  \
+       name##_store(struct device *dev, struct device_attribute *devattr, \
+               const char *buf, size_t count)                          \
+       {                                                               \
+               struct thermal_zone_device *tz = to_thermal_zone(dev);  \
+               s32 value;                                              \
+                                                                       \
+               if (!tz->tzp)                                           \
+                       return -EIO;                                    \
+                                                                       \
+               if (kstrtos32(buf, 10, &value))                         \
+                       return -EINVAL;                                 \
+                                                                       \
+               tz->tzp->name = value;                                  \
+                                                                       \
+               return count;                                           \
+       }                                                               \
+       static DEVICE_ATTR(name, S_IWUSR | S_IRUGO, name##_show, name##_store)
+
+create_s32_tzp_attr(k_po);
+create_s32_tzp_attr(k_pu);
+create_s32_tzp_attr(k_i);
+create_s32_tzp_attr(k_d);
+create_s32_tzp_attr(integral_cutoff);
+#undef create_s32_tzp_attr
+
+static struct device_attribute *dev_tzp_attrs[] = {
+       &dev_attr_sustainable_power,
+       &dev_attr_k_po,
+       &dev_attr_k_pu,
+       &dev_attr_k_i,
+       &dev_attr_k_d,
+       &dev_attr_integral_cutoff,
+};
+
+static int create_tzp_attrs(struct device *dev)
+{
+       int i;
+
+       for (i = 0; i < ARRAY_SIZE(dev_tzp_attrs); i++) {
+               int ret;
+               struct device_attribute *dev_attr = dev_tzp_attrs[i];
+
+               ret = device_create_file(dev, dev_attr);
+               if (ret)
+                       return ret;
+       }
+
+       return 0;
+}
+
 /**
  * power_actor_get_max_power() - get the maximum power that a cdev can consume
  * @cdev:      pointer to &thermal_cooling_device
@@ -1712,6 +1808,11 @@ struct thermal_zone_device *thermal_zone_device_register(const char *type,
        if (result)
                goto unregister;
 
+       /* Add thermal zone params */
+       result = create_tzp_attrs(&tz->device);
+       if (result)
+               goto unregister;
+
        /* Update 'this' zone's governor information */
        mutex_lock(&thermal_governor_lock);