target/linux/mediatek/patches/0020-thermal-thermal-Add-support-for-hardware-tracked-tri.patch

   1 From 346632bc00fe71c269709702fecb474bb22e933e Mon Sep 17 00:00:00 2001
   2 From: Sascha Hauer <s.hauer@pengutronix.de>
   3 Date: Wed, 13 May 2015 10:52:39 +0200
   4 Subject: [PATCH 20/76] thermal: thermal: Add support for hardware-tracked
   5  trip points
   6
   7 This adds support for hardware-tracked trip points to the device tree
   8 thermal sensor framework.
   9
  10 The framework supports an arbitrary number of trip points. Whenever
  11 the current temperature is updated, the trip points immediately
  12 below and above the current temperature are found. A .set_trips
  13 callback is then called with the temperatures. If there is no trip
  14 point above or below the current temperature, the passed trip
  15 temperature will be -INT_MAX or INT_MAX respectively. In this callback,
  16 the driver should program the hardware such that it is notified
  17 when either of these trip points are triggered. When a trip point
  18 is triggered, the driver should call `thermal_zone_device_update'
  19 for the respective thermal zone. This will cause the trip points
  20 to be updated again.
  21
  22 If .set_trips is not implemented, the framework behaves as before.
  23
  24 This patch is based on an earlier version from Mikko Perttunen
  25 <mikko.perttunen@kapsi.fi>
  26
  27 Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
  28 ---
  29  drivers/thermal/thermal_core.c |   43 ++++++++++++++++++++++++++++++++++++++++
  30  include/linux/thermal.h        |    3 +++
  31  2 files changed, 46 insertions(+)
  32
  33 --- a/drivers/thermal/thermal_core.c
  34 +++ b/drivers/thermal/thermal_core.c
  35 @@ -456,6 +456,45 @@ int thermal_zone_get_temp(struct thermal
  36  }
  37  EXPORT_SYMBOL_GPL(thermal_zone_get_temp);
  38
  39 +static void thermal_zone_set_trips(struct thermal_zone_device *tz)
  40 +{
  41 +       int low = -INT_MAX;
  42 +       int high = INT_MAX;
  43 +       int trip_temp, hysteresis;
  44 +       int temp = tz->temperature;
  45 +       int i;
  46 +
  47 +       if (!tz->ops->set_trips)
  48 +               return;
  49 +
  50 +       /* No need to change trip points */
  51 +       if (temp > tz->prev_low_trip && temp < tz->prev_high_trip)
  52 +               return;
  53 +
  54 +       for (i = 0; i < tz->trips; i++) {
  55 +               int trip_low;
  56 +
  57 +               tz->ops->get_trip_temp(tz, i, &trip_temp);
  58 +               tz->ops->get_trip_hyst(tz, i, &hysteresis);
  59 +
  60 +               trip_low = trip_temp - hysteresis;
  61 +
  62 +               if (trip_low < temp && trip_low > low)
  63 +                       low = trip_low;
  64 +
  65 +               if (trip_temp > temp && trip_temp < high)
  66 +                       high = trip_temp;
  67 +       }
  68 +
  69 +       tz->prev_low_trip = low;
  70 +       tz->prev_high_trip = high;
  71 +
  72 +       dev_dbg(&tz->device, "new temperature boundaries: %d < x < %d\n",
  73 +                       low, high);
  74 +
  75 +       tz->ops->set_trips(tz, low, high);
  76 +}
  77 +
  78  void thermal_zone_device_update(struct thermal_zone_device *tz)
  79  {
  80         int temp, ret, count;
  81 @@ -489,6 +528,8 @@ void thermal_zone_device_update(struct t
  82                 dev_dbg(&tz->device, "last_temperature=%d, current_temperature=%d\n",
  83                         tz->last_temperature, tz->temperature);
  84
  85 +       thermal_zone_set_trips(tz);
  86 +
  87         for (count = 0; count < tz->trips; count++)
  88                 handle_thermal_trip(tz, count);
  89  }
  90 @@ -1522,6 +1563,8 @@ struct thermal_zone_device *thermal_zone
  91         tz->trips = trips;
  92         tz->passive_delay = passive_delay;
  93         tz->polling_delay = polling_delay;
  94 +       tz->prev_low_trip = INT_MAX;
  95 +       tz->prev_high_trip = -INT_MAX;
  96         /* A new thermal zone needs to be updated anyway. */
  97         atomic_set(&tz->need_update, 1);
  98
  99 --- a/include/linux/thermal.h
 100 +++ b/include/linux/thermal.h
 101 @@ -90,6 +90,7 @@ struct thermal_zone_device_ops {
 102         int (*unbind) (struct thermal_zone_device *,
 103                        struct thermal_cooling_device *);
 104         int (*get_temp) (struct thermal_zone_device *, int *);
 105 +       int (*set_trips) (struct thermal_zone_device *, int, int);
 106         int (*get_mode) (struct thermal_zone_device *,
 107                          enum thermal_device_mode *);
 108         int (*set_mode) (struct thermal_zone_device *,
 109 @@ -184,6 +185,8 @@ struct thermal_zone_device {
 110         int last_temperature;
 111         int emul_temperature;
 112         int passive;
 113 +       int prev_low_trip;
 114 +       int prev_high_trip;
 115         unsigned int forced_passive;
 116         atomic_t need_update;
 117         const struct thermal_zone_device_ops *ops;