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 diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
  34 index 6bbf61f..3ae1795 100644
  35 --- a/drivers/thermal/thermal_core.c
  36 +++ b/drivers/thermal/thermal_core.c
  37 @@ -453,6 +453,45 @@ int thermal_zone_get_temp(struct thermal_zone_device *tz, int *temp)
  38  }
  39  EXPORT_SYMBOL_GPL(thermal_zone_get_temp);
  40
  41 +static void thermal_zone_set_trips(struct thermal_zone_device *tz)
  42 +{
  43 +       int low = -INT_MAX;
  44 +       int high = INT_MAX;
  45 +       int trip_temp, hysteresis;
  46 +       int temp = tz->temperature;
  47 +       int i;
  48 +
  49 +       if (!tz->ops->set_trips)
  50 +               return;
  51 +
  52 +       /* No need to change trip points */
  53 +       if (temp > tz->prev_low_trip && temp < tz->prev_high_trip)
  54 +               return;
  55 +
  56 +       for (i = 0; i < tz->trips; i++) {
  57 +               int trip_low;
  58 +
  59 +               tz->ops->get_trip_temp(tz, i, &trip_temp);
  60 +               tz->ops->get_trip_hyst(tz, i, &hysteresis);
  61 +
  62 +               trip_low = trip_temp - hysteresis;
  63 +
  64 +               if (trip_low < temp && trip_low > low)
  65 +                       low = trip_low;
  66 +
  67 +               if (trip_temp > temp && trip_temp < high)
  68 +                       high = trip_temp;
  69 +       }
  70 +
  71 +       tz->prev_low_trip = low;
  72 +       tz->prev_high_trip = high;
  73 +
  74 +       dev_dbg(&tz->device, "new temperature boundaries: %d < x < %d\n",
  75 +                       low, high);
  76 +
  77 +       tz->ops->set_trips(tz, low, high);
  78 +}
  79 +
  80  void thermal_zone_device_update(struct thermal_zone_device *tz)
  81  {
  82         int temp, ret, count;
  83 @@ -479,6 +518,8 @@ void thermal_zone_device_update(struct thermal_zone_device *tz)
  84         dev_dbg(&tz->device, "last_temperature=%d, current_temperature=%d\n",
  85                                 tz->last_temperature, tz->temperature);
  86
  87 +       thermal_zone_set_trips(tz);
  88 +
  89         for (count = 0; count < tz->trips; count++)
  90                 handle_thermal_trip(tz, count);
  91  }
  92 @@ -1494,6 +1535,8 @@ struct thermal_zone_device *thermal_zone_device_register(const char *type,
  93         tz->trips = trips;
  94         tz->passive_delay = passive_delay;
  95         tz->polling_delay = polling_delay;
  96 +       tz->prev_low_trip = INT_MAX;
  97 +       tz->prev_high_trip = -INT_MAX;
  98
  99         dev_set_name(&tz->device, "thermal_zone%d", tz->id);
 100         result = device_register(&tz->device);
 101 diff --git a/include/linux/thermal.h b/include/linux/thermal.h
 102 index 07bd5e8..aef6e13 100644
 103 --- a/include/linux/thermal.h
 104 +++ b/include/linux/thermal.h
 105 @@ -87,6 +87,7 @@ struct thermal_zone_device_ops {
 106         int (*unbind) (struct thermal_zone_device *,
 107                        struct thermal_cooling_device *);
 108         int (*get_temp) (struct thermal_zone_device *, int *);
 109 +       int (*set_trips) (struct thermal_zone_device *, int, int);
 110         int (*get_mode) (struct thermal_zone_device *,
 111                          enum thermal_device_mode *);
 112         int (*set_mode) (struct thermal_zone_device *,
 113 @@ -180,6 +181,8 @@ struct thermal_zone_device {
 114         int last_temperature;
 115         int emul_temperature;
 116         int passive;
 117 +       int prev_low_trip;
 118 +       int prev_high_trip;
 119         unsigned int forced_passive;
 120         const struct thermal_zone_device_ops *ops;
 121         const struct thermal_zone_params *tzp;
 122 --
 123 1.7.10.4
 124