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White Rabbit Switch - Software
Commit 4d12719d authored by Adam Wujek's avatar Adam Wujek 💬
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userspace/libwr: update fan's speed only on changes 

Update fan's PWM only when there is a need to change fan's speed.
It should save some cpu cycles because of reduced number of i2c transers.
Signed-off-by: Adam Wujek's avatarAdam Wujek <adam.wujek@cern.ch>
parent 3c32109b
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Showing with 26 additions and 18 deletions
userspace/libwr/fan.c
View file @ 4d12719d
......@@ -165,12 +165,6 @@ static void tmp100_write_reg(int dev_addr, uint8_t reg_addr, uint8_t value)
i2c_write(&fpga_sensors_i2c, dev_addr, 2, data);
}
static float tmp100_read_temp(int dev_addr)
{
int temp = tmp100_read_reg(dev_addr, 0, 2);
return ((float)(temp >> 4)) / 16.0;
}
static int shw_init_i2c_sensors(void)
{
if (i2c_init_bus(&fpga_sensors_i2c) < 0) {
......@@ -259,29 +253,43 @@ int shw_init_fans(void)
*/
void shw_update_fans(struct hal_temp_sensors *sensors)
{
/* drive fan based on PLL temperature */
float t_cur = tmp100_read_temp(TEMP_SENSOR_ADDR_PLL);
float drive = pi_update(&fan_pi, t_cur - DESIRED_TEMPERATURE);
float t_cur;
float drive;
static float pwm_set_old = -1.0; /* anything different than 0, to force
write at the beginning */
static float pwm_set_new = 0;
//pr_info("t=%f,pwm=%f\n",t_cur , drive);
/* update sensor values */
sensors->fpga = tmp100_read_reg(TEMP_SENSOR_ADDR_FPGA, 0, 2);
sensors->pll = tmp100_read_reg(TEMP_SENSOR_ADDR_PLL, 0, 2);
sensors->psl = tmp100_read_reg(TEMP_SENSOR_ADDR_PSL, 0, 2);
sensors->psr = tmp100_read_reg(TEMP_SENSOR_ADDR_PSR, 0, 2);
/* drive fan based on PLL temperature */
t_cur = ((float)(sensors->pll >> 4)) / 16.0;
drive = pi_update(&fan_pi, t_cur - DESIRED_TEMPERATURE);
if (fan_hysteresis) {
if (t_cur < fan_hysteresis_t_disable) {
/* disable fans */
shw_pwm_speed(0xFF, 0);
pwm_set_new = 0;
}
if (t_cur > fan_hysteresis_t_enable) {
/* enable fans with given value */
shw_pwm_speed(0xFF,
((float) fan_hysteresis_pwm_val)/1000);
pwm_set_new = ((float) fan_hysteresis_pwm_val) / 1000;
}
/* pwm_set_new might be not updated. e.g. t_cur is between
* fan_hysteresis_t_disable and fan_hysteresis_t_enable */
} else {
/* use PI controller for FANs speeds */
shw_pwm_speed(0xFF, drive / 1000);
pwm_set_new = drive / 1000;
}
/* update sensor values */
sensors->fpga = tmp100_read_reg(TEMP_SENSOR_ADDR_FPGA, 0, 2);
sensors->pll = tmp100_read_reg(TEMP_SENSOR_ADDR_PLL, 0, 2);
sensors->psl = tmp100_read_reg(TEMP_SENSOR_ADDR_PSL, 0, 2);
sensors->psr = tmp100_read_reg(TEMP_SENSOR_ADDR_PSR, 0, 2);
/* Update PWM, only when there was a change */
if (pwm_set_new != pwm_set_old) {
shw_pwm_speed(0xFF, pwm_set_new);
pwm_set_old = pwm_set_new;
}
}
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