[PATCH v5 1/3] thermal: qcom-spmi: Use PMIC thermal stage 2 for critical trip points

From: Matthias Kaehlcke
Date: Tue Jul 24 2018 - 19:47:08 EST

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 ÂC).
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 < 125ÂC
- the temperature of the critical trip point is > 140ÂC and no
ADC channel is configured (thus the OS is not notified when the critical
temperature is reached)

Suggested-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
Signed-off-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
---
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
@@ -23,6 +23,8 @@
#include <linux/regmap.h>
#include <linux/thermal.h>

+#include "thermal_core.h"
+
#define QPNP_TM_REG_TYPE 0x04
#define QPNP_TM_REG_SUBTYPE 0x05
#define QPNP_TM_REG_STATUS 0x08
@@ -37,9 +39,11 @@
#define STATUS_GEN2_STATE_MASK GENMASK(6, 4)
#define STATUS_GEN2_STATE_SHIFT 4

-#define SHUTDOWN_CTRL1_OVERRIDE_MASK GENMASK(7, 6)
+#define SHUTDOWN_CTRL1_OVERRIDE_S2 BIT(6)
#define SHUTDOWN_CTRL1_THRESHOLD_MASK GENMASK(1, 0)

+#define SHUTDOWN_CTRL1_RATE_25HZ BIT(3)
+
#define ALARM_CTRL_FORCE_ENABLE BIT(7)

/*
@@ -56,12 +60,17 @@
#define TEMP_THRESH_STEP 5000 /* Threshold step: 5 C */

#define THRESH_MIN 0
+#define THRESH_MAX 3
+
+#define STAGE2_THRESHOLD_MIN 125000 /* Stage 2 Threshold Min: 125 C */
+#define STAGE2_THRESHOLD_MAX 140000 /* Stage 2 Threshold Max: 140 C */

/* Temperature in Milli Celsius reported during stage 0 if no ADC is present */
#define DEFAULT_TEMP 37000

struct qpnp_tm_chip {
struct regmap *map;
+ struct device *dev;
struct thermal_zone_device *tz_dev;
unsigned int subtype;
long temp;
@@ -69,6 +78,10 @@ struct qpnp_tm_chip {
unsigned int stage;
unsigned int prev_stage;
unsigned int base;
+ /* protects .thresh, .stage and chip registers */
+ struct mutex lock;
+ bool initialized;
+
struct iio_channel *adc;
};

@@ -125,6 +138,8 @@ static int qpnp_tm_update_temp_no_adc(struct qpnp_tm_chip *chip)
unsigned int stage, stage_new, stage_old;
int ret;

+ WARN_ON(!mutex_is_locked(&chip->lock));
+
ret = qpnp_tm_get_temp_stage(chip);
if (ret < 0)
return ret;
@@ -163,8 +178,15 @@ static int qpnp_tm_get_temp(void *data, int *temp)
if (!temp)
return -EINVAL;

- if (!chip->adc) {
+ if (!chip->initialized) {
+ *temp = DEFAULT_TEMP;
+ return 0;
+ }
+
+ if (!chip->adc)) {
+ mutex_lock(&chip->lock);
ret = qpnp_tm_update_temp_no_adc(chip);
+ mutex_unlock(&chip->lock);
if (ret < 0)
return ret;
} else {
@@ -180,8 +202,77 @@ static int qpnp_tm_get_temp(void *data, int *temp)
return 0;
}

+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))
+ disable_s2_shutdown = true;
+ else
+ dev_warn(chip->dev,
+ "No ADC is configured and critical temperature is above the maximum stage 2 threshold of 140ÂC! Configuring stage 2 shutdown at 140ÂC.\n");
+ }
+
+skip:
+ reg |= chip->thresh;
+ if (disable_s2_shutdown)
+ reg |= SHUTDOWN_CTRL1_OVERRIDE_S2;
+
+ ret = qpnp_tm_write(chip, QPNP_TM_REG_SHUTDOWN_CTRL1, reg);
+ if (ret < 0)
+ return ret;
+
+ return ret;
+}
+
+static int qpnp_tm_set_trip_temp(void *data, int trip, int temp)
+{
+ struct qpnp_tm_chip *chip = data;
+ const struct thermal_trip *trip_points;
+ int ret;
+
+ trip_points = of_thermal_get_trip_points(chip->tz_dev);
+ if (!trip_points)
+ return -EINVAL;
+
+ if (trip_points[trip].type != THERMAL_TRIP_CRITICAL)
+ return 0;
+
+ mutex_lock(&chip->lock);
+ ret = qpnp_tm_update_critical_trip_temp(chip, temp);
+ mutex_unlock(&chip->lock);
+
+ return ret;
+}
+
static const struct thermal_zone_of_device_ops qpnp_tm_sensor_ops = {
.get_temp = qpnp_tm_get_temp,
+ .set_trip_temp = qpnp_tm_set_trip_temp,
};

static irqreturn_t qpnp_tm_isr(int irq, void *data)
@@ -193,6 +284,29 @@ static irqreturn_t qpnp_tm_isr(int irq, void *data)
return IRQ_HANDLED;
}

+static int qpnp_tm_get_critical_trip_temp(struct qpnp_tm_chip *chip)
+{
+ int ntrips;
+ const struct thermal_trip *trips;
+ int i;
+
+ ntrips = of_thermal_get_ntrips(chip->tz_dev);
+ if (ntrips <= 0)
+ return THERMAL_TEMP_INVALID;
+
+ trips = of_thermal_get_trip_points(chip->tz_dev);
+ if (!trips)
+ return THERMAL_TEMP_INVALID;
+
+ for (i = 0; i < ntrips; i++) {
+ if (of_thermal_is_trip_valid(chip->tz_dev, i) &&
+ (trips[i].type == THERMAL_TRIP_CRITICAL))
+ return trips[i].temperature;
+ }
+
+ return THERMAL_TEMP_INVALID;
+}
+
/*
* This function initializes the internal temp value based on only the
* current thermal stage and threshold. Setup threshold control and
@@ -203,17 +317,20 @@ static int qpnp_tm_init(struct qpnp_tm_chip *chip)
unsigned int stage;
int ret;
u8 reg = 0;
+ int crit_temp;
+
+ mutex_lock(&chip->lock);

ret = qpnp_tm_read(chip, QPNP_TM_REG_SHUTDOWN_CTRL1, &reg);
if (ret < 0)
- return ret;
+ goto out;

chip->thresh = reg & SHUTDOWN_CTRL1_THRESHOLD_MASK;
chip->temp = DEFAULT_TEMP;

ret = qpnp_tm_get_temp_stage(chip);
if (ret < 0)
- return ret;
+ goto out;
chip->stage = ret;

stage = chip->subtype == QPNP_TM_SUBTYPE_GEN1
@@ -224,21 +341,17 @@ static int qpnp_tm_init(struct qpnp_tm_chip *chip)
(stage - 1) * TEMP_STAGE_STEP +
TEMP_THRESH_MIN;

- /*
- * Set threshold and disable software override of stage 2 and 3
- * shutdowns.
- */
- chip->thresh = THRESH_MIN;
- reg &= ~(SHUTDOWN_CTRL1_OVERRIDE_MASK | SHUTDOWN_CTRL1_THRESHOLD_MASK);
- reg |= chip->thresh & SHUTDOWN_CTRL1_THRESHOLD_MASK;
- ret = qpnp_tm_write(chip, QPNP_TM_REG_SHUTDOWN_CTRL1, reg);
+ crit_temp = qpnp_tm_get_critical_trip_temp(chip);
+ ret = qpnp_tm_update_critical_trip_temp(chip, crit_temp);
if (ret < 0)
- return ret;
+ goto out;

/* Enable the thermal alarm PMIC module in always-on mode. */
reg = ALARM_CTRL_FORCE_ENABLE;
ret = qpnp_tm_write(chip, QPNP_TM_REG_ALARM_CTRL, reg);

+out:
+ mutex_unlock(&chip->lock);
return ret;
}

@@ -257,6 +370,9 @@ static int qpnp_tm_probe(struct platform_device *pdev)
return -ENOMEM;

dev_set_drvdata(&pdev->dev, chip);
+ chip->dev = &pdev->dev;
+
+ mutex_init(&chip->lock);

chip->map = dev_get_regmap(pdev->dev.parent, NULL);
if (!chip->map)
@@ -302,6 +418,18 @@ static int qpnp_tm_probe(struct platform_device *pdev)

chip->subtype = subtype;

+ /*
+ * Register the sensor before initializing the hardware to be able to
+ * read the trip points. get_temp() returns the default temperature
+ * before the hardware initialization is completed.
+ */
+ chip->tz_dev = devm_thermal_zone_of_sensor_register(&pdev->dev, 0, chip,
+ &qpnp_tm_sensor_ops);
+ if (IS_ERR(chip->tz_dev)) {
+ dev_err(&pdev->dev, "failed to register sensor\n");
+ return PTR_ERR(chip->tz_dev);
+ }
+
ret = qpnp_tm_init(chip);
if (ret < 0) {
dev_err(&pdev->dev, "init failed\n");
@@ -313,12 +441,7 @@ static int qpnp_tm_probe(struct platform_device *pdev)
if (ret < 0)
return ret;

- chip->tz_dev = devm_thermal_zone_of_sensor_register(&pdev->dev, 0, chip,
- &qpnp_tm_sensor_ops);
- if (IS_ERR(chip->tz_dev)) {
- dev_err(&pdev->dev, "failed to register sensor\n");
- return PTR_ERR(chip->tz_dev);
- }
+ chip->initialized = true;

return 0;
}
--
2.18.0.233.g985f88cf7e-goog