thermal/drivers/qcom-spmi-temp-alarm: Add support for GEN2 rev 2 PMIC peripherals

Add support for TEMP_ALARM GEN2 PMIC peripherals with digital major
revision 2.  This revision utilizes individual temp DAC registers
to set the threshold temperature for over-temperature stages 1 (warning),
2 (system shutdown), and 3 (emergency shutdown) instead of a single
register to specify a set of thresholds.

Co-developed-by: David Collins <david.collins@oss.qualcomm.com>
Signed-off-by: David Collins <david.collins@oss.qualcomm.com>
Signed-off-by: Anjelique Melendez <anjelique.melendez@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20250710224555.3047790-5-anjelique.melendez@oss.qualcomm.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Author: Anjelique Melendez

drivers/thermal/qcom/qcom-spmi-temp-alarm.c

@@ -26,6 +26,11 @@
 #define QPNP_TM_REG_SHUTDOWN_CTRL1	0x40
 #define QPNP_TM_REG_ALARM_CTRL		0x46
 
+/* TEMP_DAC_STGx registers are only present for TEMP_GEN2 v2.0 */
+#define QPNP_TM_REG_TEMP_DAC_STG1	0x47
+#define QPNP_TM_REG_TEMP_DAC_STG2	0x48
+#define QPNP_TM_REG_TEMP_DAC_STG3	0x49
+
 #define QPNP_TM_TYPE			0x09
 #define QPNP_TM_SUBTYPE_GEN1		0x08
 #define QPNP_TM_SUBTYPE_GEN2		0x09
@@ -71,6 +76,25 @@ static const long temp_map_gen2_v1[THRESH_COUNT][STAGE_COUNT] = {
 
 #define TEMP_STAGE_HYSTERESIS		2000
 
+/*
+ * For TEMP_GEN2 v2.0, TEMP_DAC_STG1/2/3 registers are used to set the threshold
+ * for each stage independently.
+ * TEMP_DAC_STG* = 0 --> 80 C
+ * Each 8 step increase in TEMP_DAC_STG* value corresponds to 5 C (5000 mC).
+ */
+#define TEMP_DAC_MIN			80000
+#define TEMP_DAC_SCALE_NUM		8
+#define TEMP_DAC_SCALE_DEN		5000
+
+#define TEMP_DAC_TEMP_TO_REG(temp) \
+	(((temp) - TEMP_DAC_MIN) * TEMP_DAC_SCALE_NUM / TEMP_DAC_SCALE_DEN)
+#define TEMP_DAC_REG_TO_TEMP(reg) \
+	(TEMP_DAC_MIN + (reg) * TEMP_DAC_SCALE_DEN / TEMP_DAC_SCALE_NUM)
+
+static const long temp_dac_max[STAGE_COUNT] = {
+	119375, 159375, 159375
+};
+
 /* Temperature in Milli Celsius reported during stage 0 if no ADC is present */
 #define DEFAULT_TEMP			37000
 
@@ -93,6 +117,7 @@ struct qpnp_tm_chip {
 	long				temp;
 	unsigned int			stage;
 	unsigned int			base;
+	unsigned int			ntrips;
 	/* protects .thresh, .stage and chip registers */
 	struct mutex			lock;
 	bool				initialized;
@@ -310,6 +335,54 @@ static const struct thermal_zone_device_ops qpnp_tm_sensor_ops = {
 	.set_trip_temp = qpnp_tm_set_trip_temp,
 };
 
+static int qpnp_tm_gen2_rev2_set_temp_thresh(struct qpnp_tm_chip *chip, unsigned int trip, int temp)
+{
+	int ret, temp_cfg;
+	u8 reg;
+
+	WARN_ON(!mutex_is_locked(&chip->lock));
+
+	if (trip >= STAGE_COUNT) {
+		dev_err(chip->dev, "invalid TEMP_DAC trip = %d\n", trip);
+		return -EINVAL;
+	} else if (temp < TEMP_DAC_MIN || temp > temp_dac_max[trip]) {
+		dev_err(chip->dev, "invalid TEMP_DAC temp = %d\n", temp);
+		return -EINVAL;
+	}
+
+	reg = TEMP_DAC_TEMP_TO_REG(temp);
+	temp_cfg = TEMP_DAC_REG_TO_TEMP(reg);
+
+	ret = qpnp_tm_write(chip, QPNP_TM_REG_TEMP_DAC_STG1 + trip, reg);
+	if (ret < 0) {
+		dev_err(chip->dev, "TEMP_DAC_STG write failed, ret=%d\n", ret);
+		return ret;
+	}
+
+	chip->temp_thresh_map[trip] = temp_cfg;
+
+	return 0;
+}
+
+static int qpnp_tm_gen2_rev2_set_trip_temp(struct thermal_zone_device *tz,
+					   const struct thermal_trip *trip, int temp)
+{
+	unsigned int trip_index = THERMAL_TRIP_PRIV_TO_INT(trip->priv);
+	struct qpnp_tm_chip *chip = thermal_zone_device_priv(tz);
+	int ret;
+
+	mutex_lock(&chip->lock);
+	ret = qpnp_tm_gen2_rev2_set_temp_thresh(chip, trip_index, temp);
+	mutex_unlock(&chip->lock);
+
+	return ret;
+}
+
+static const struct thermal_zone_device_ops qpnp_tm_gen2_rev2_sensor_ops = {
+	.get_temp = qpnp_tm_get_temp,
+	.set_trip_temp = qpnp_tm_gen2_rev2_set_trip_temp,
+};
+
 static irqreturn_t qpnp_tm_isr(int irq, void *data)
 {
 	struct qpnp_tm_chip *chip = data;
@@ -351,6 +424,60 @@ static int qpnp_tm_configure_trip_temp(struct qpnp_tm_chip *chip)
 	return ret;
 }
 
+/* Configure TEMP_DAC registers based on DT thermal_zone trips */
+static int qpnp_tm_gen2_rev2_configure_trip_temps_cb(struct thermal_trip *trip, void *data)
+{
+	struct qpnp_tm_chip *chip = data;
+	int ret;
+
+	mutex_lock(&chip->lock);
+	trip->priv = THERMAL_INT_TO_TRIP_PRIV(chip->ntrips);
+	ret = qpnp_tm_gen2_rev2_set_temp_thresh(chip, chip->ntrips, trip->temperature);
+	chip->ntrips++;
+	mutex_unlock(&chip->lock);
+
+	return ret;
+}
+
+static int qpnp_tm_gen2_rev2_configure_trip_temps(struct qpnp_tm_chip *chip)
+{
+	int ret, i;
+
+	ret = thermal_zone_for_each_trip(chip->tz_dev,
+					 qpnp_tm_gen2_rev2_configure_trip_temps_cb, chip);
+	if (ret < 0)
+		return ret;
+
+	/* Verify that trips are strictly increasing. */
+	for (i = 1; i < STAGE_COUNT; i++) {
+		if (chip->temp_thresh_map[i] <= chip->temp_thresh_map[i - 1]) {
+			dev_err(chip->dev, "Threshold %d=%ld <= threshold %d=%ld\n",
+				i, chip->temp_thresh_map[i], i - 1,
+				chip->temp_thresh_map[i - 1]);
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+/* Read the hardware default TEMP_DAC stage threshold temperatures */
+static int qpnp_tm_gen2_rev2_sync_thresholds(struct qpnp_tm_chip *chip)
+{
+	int ret, i;
+	u8 reg = 0;
+
+	for (i = 0; i < STAGE_COUNT; i++) {
+		ret = qpnp_tm_read(chip, QPNP_TM_REG_TEMP_DAC_STG1 + i, &reg);
+		if (ret < 0)
+			return ret;
+
+		chip->temp_thresh_map[i] = TEMP_DAC_REG_TO_TEMP(reg);
+	}
+
+	return 0;
+}
+
 static const struct spmi_temp_alarm_data spmi_temp_alarm_data = {
 	.ops = &qpnp_tm_sensor_ops,
 	.temp_map = &temp_map_gen1,
@@ -375,6 +502,13 @@ static const struct spmi_temp_alarm_data spmi_temp_alarm_gen2_rev1_data = {
 	.get_temp_stage = qpnp_tm_gen2_get_temp_stage,
 };
 
+static const struct spmi_temp_alarm_data spmi_temp_alarm_gen2_rev2_data = {
+	.ops = &qpnp_tm_gen2_rev2_sensor_ops,
+	.sync_thresholds = qpnp_tm_gen2_rev2_sync_thresholds,
+	.configure_trip_temps = qpnp_tm_gen2_rev2_configure_trip_temps,
+	.get_temp_stage = qpnp_tm_gen2_get_temp_stage,
+};
+
 /*
  * This function initializes the internal temp value based on only the
  * current thermal stage and threshold.
@@ -491,8 +625,10 @@ static int qpnp_tm_probe(struct platform_device *pdev)
 		chip->data = &spmi_temp_alarm_data;
 	else if (subtype == QPNP_TM_SUBTYPE_GEN2 && dig_major == 0)
 		chip->data = &spmi_temp_alarm_gen2_data;
-	else if (subtype == QPNP_TM_SUBTYPE_GEN2 && dig_major >= 1)
+	else if (subtype == QPNP_TM_SUBTYPE_GEN2 && dig_major == 1)
 		chip->data = &spmi_temp_alarm_gen2_rev1_data;
+	else if (subtype == QPNP_TM_SUBTYPE_GEN2 && dig_major >= 2)
+		chip->data = &spmi_temp_alarm_gen2_rev2_data;
 	else
 		return -ENODEV;