On Tue, Jul 24, 2018 at 04:46:34PM -0700, Matthias Kaehlcke wrote:
> There are three thermal stages defined in the PMIC:
>
> stage 1: warning
> stage 2: system should shut down
> stage 3: emergency shut down
>
> By default the PMIC assumes that the OS isn't doing anything and thus
> at stage 2 it does a partial PMIC shutdown and at stage 3 it kills
> all power. When switching between thermal stages the PMIC generates an
> interrupt which is handled by the driver. The partial PMIC shutdown at
> stage 2 can be disabled by software, which allows the OS to initiate a
> shutdown at stage 2 with a thermal zone configured accordingly.
>
> If a critical trip point is configured in the thermal zone the driver
> adjusts the stage 1-3 temperature thresholds to (closely) match the
> critical temperature with a stage 2 threshold (125/130/135/140 °C).
> If a suitable match is found the partial shutdown at stage 2 is
> disabled. If for some reason the system doesn't shutdown at stage 2
> the emergency shutdown at stage 3 kicks in.
>
> The partial shutdown at stage 2 remains enabled in these cases:
> - no critical trip point defined
> - the temperature of the critical trip point is < 125°C
> - the temperature of the critical trip point is > 140°C and no
> ADC channel is configured (thus the OS is not notified when the critical
> temperature is reached)
>
> Suggested-by: Douglas Anderson <[email protected]>
> Signed-off-by: Matthias Kaehlcke <[email protected]>
> ---
> Changes in v5:
> - patch added to the series
> ---
> drivers/thermal/qcom-spmi-temp-alarm.c | 161 ++++++++++++++++++++++---
> 1 file changed, 142 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/thermal/qcom-spmi-temp-alarm.c
> b/drivers/thermal/qcom-spmi-temp-alarm.c
> index ad4f3a8d6560..936e4dde4298 100644
> --- a/drivers/thermal/qcom-spmi-temp-alarm.c
> +++ b/drivers/thermal/qcom-spmi-temp-alarm.c
>
> ...
>
> +static int qpnp_tm_update_critical_trip_temp(struct qpnp_tm_chip *chip,
> + int temp)
> +{
> + u8 reg;
> + bool disable_s2_shutdown = false;
> + int ret;
> +
> + WARN_ON(!mutex_is_locked(&chip->lock));
> +
> + /*
> + * Default: S2 and S3 shutdown enabled, thresholds at
> + * 105C/125C/145C, monitoring at 25Hz
> + */
> + reg = SHUTDOWN_CTRL1_RATE_25HZ;
> +
> + if ((temp == THERMAL_TEMP_INVALID) ||
> + (temp < STAGE2_THRESHOLD_MIN)) {
> + chip->thresh = THRESH_MIN;
> + goto skip;
> + }
> +
> + if (temp <= STAGE2_THRESHOLD_MAX) {
> + chip->thresh = THRESH_MAX -
> + ((STAGE2_THRESHOLD_MAX - temp) /
> + TEMP_THRESH_STEP);
> + disable_s2_shutdown = true;
> + } else {
> + chip->thresh = THRESH_MAX;
> +
> + if (!IS_ERR(chip->adc))
Note to self: with commit 7a4ca51b7040 ("thermal/drivers/qcom-spmi:
Use devm_iio_channel_get") this should be 'if (chip->adc)'.
