/*
* convert_omap_sensor_temp_to_hotspot_temp() -Convert the temperature from the
* OMAP on-die temp sensor into OMAP hot spot temperature.
* This takes care of the existing temperature gradient between
* the OMAP hot spot and the on-die temp sensor.
* When PCB sensor is used, the temperature gradient is computed
* from PCB and averaged on-die sensor temperatures.
*
* @sensor_temp: Raw temperature reported by the OMAP die temp sensor
*
* Returns the calculated hot spot temperature for the zone calculation
*/
static signed int convert_omap_sensor_temp_to_hotspot_temp(int sensor_temp)
{
int absolute_delta;
if (pcb_sensor && (omap_gov->avg_is_valid == 1)) {
omap_gov->pcb_temp = thermal_request_temp(pcb_sensor);
if (omap_gov->pcb_temp < 0)
return sensor_temp + omap_gov->absolute_delta;
absolute_delta = (
((omap_gov->avg_cpu_sensor_temp - omap_gov->pcb_temp) *
OMAP_GRADIENT_SLOPE_WITH_PCB / 1000) +
OMAP_GRADIENT_CONST_WITH_PCB);
/* Ensure that this formula never returns negative value */
if (absolute_delta < 0)
absolute_delta = 0;
} else {
absolute_delta = ((sensor_temp * OMAP_GRADIENT_SLOPE / 1000) +
OMAP_GRADIENT_CONST);
}
omap_gov->absolute_delta = absolute_delta;
pr_debug("%s:sensor %d avg sensor %d pcb %d, delta %d hot spot %d\n",
__func__, sensor_temp, omap_gov->avg_cpu_sensor_temp,
omap_gov->pcb_temp, omap_gov->absolute_delta,
sensor_temp + absolute_delta);
return sensor_temp + absolute_delta;
}
static void decrease_mpu_freq_fn(struct work_struct *work)
{
struct omap_die_governor *omap_gov;
omap_gov = container_of(work, struct omap_die_governor,
decrease_mpu_freq_work.work);
omap_gov->sensor_temp = thermal_request_temp(omap_gov->temp_sensor);
thermal_sensor_set_temp(omap_gov->temp_sensor);
}
/*
* Make an average of the OMAP on-die temperature
* this is helpful to handle burst activity of OMAP when extrapolating
* the OMAP hot spot temperature from on-die sensor and PCB temperature
* Re-evaluate the temperature gradient between hot spot and on-die sensor
* (See absolute_delta) and reconfigure the thresholds if needed
*/
static void average_on_die_temperature(void)
{
int i;
int die_temp_lower = 0;
int die_temp_upper = 0;
int acc_temp;
if (omap_gov->temp_sensor == NULL)
return;
/* Read current temperature */
omap_gov->sensor_temp = thermal_request_temp(omap_gov->temp_sensor);
/* if on-die sensor does not report a correct value, then return */
if (omap_gov->sensor_temp == -EINVAL)
return;
/* Update historical buffer */
for (i = 1; i < AVERAGE_NUMBER; i++) {
cpu_sensor_temp_table[AVERAGE_NUMBER - i] =
cpu_sensor_temp_table[AVERAGE_NUMBER - i - 1];
}
cpu_sensor_temp_table[0] = omap_gov->sensor_temp;
if (cpu_sensor_temp_table[AVERAGE_NUMBER - 1] == 0)
omap_gov->avg_is_valid = 0;
else
omap_gov->avg_is_valid = 1;
/* Compute the new average value */
acc_temp = 0;
for (i = 0; i < AVERAGE_NUMBER; i++)
acc_temp += cpu_sensor_temp_table[i];
omap_gov->avg_cpu_sensor_temp =
(acc_temp / AVERAGE_NUMBER);
/*
* Reconfigure the current temperature thresholds according
* to the current PCB temperature
*/
convert_omap_sensor_temp_to_hotspot_temp(omap_gov->sensor_temp);
die_temp_lower = hotspot_temp_to_sensor_temp(
omap_gov->hotspot_temp_lower);
die_temp_upper = hotspot_temp_to_sensor_temp(
omap_gov->hotspot_temp_upper);
thermal_device_call(omap_gov->temp_sensor, set_temp_thresh,
die_temp_lower, die_temp_upper);
return;
}