[PATCH v3 2/3] thermal: qcom-spmi-temp-alarm: add support for GEN2 rev 2 PMIC peripherals

[David Collins]

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

Signed-off-by: David Collins <quic_collinsd@xxxxxxxxxxx>
---
 drivers/thermal/qcom/qcom-spmi-temp-alarm.c | 162 +++++++++++++++++++-
 1 file changed, 156 insertions(+), 6 deletions(-)

diff --git a/drivers/thermal/qcom/qcom-spmi-temp-alarm.c b/drivers/thermal/qcom/qcom-spmi-temp-alarm.c
index 895a2d7bff02..a8b288de6b52 100644
--- a/drivers/thermal/qcom/qcom-spmi-temp-alarm.c
+++ b/drivers/thermal/qcom/qcom-spmi-temp-alarm.c
@@ -26,6 +26,10 @@
 #define QPNP_TM_REG_STATUS		0x08
 #define QPNP_TM_REG_SHUTDOWN_CTRL1	0x40
 #define QPNP_TM_REG_ALARM_CTRL		0x46
+/* TEMP_DAC_* 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
@@ -67,6 +71,25 @@ 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
 
@@ -87,6 +110,9 @@ struct qpnp_tm_chip {
 
 	struct iio_channel		*adc;
 	const long			(*temp_map)[THRESH_COUNT][STAGE_COUNT];
+
+	bool				has_temp_dac;
+	long				temp_dac_map[STAGE_COUNT];
 };
 
 /* This array maps from GEN2 alarm state to GEN1 alarm stage */
@@ -120,6 +146,13 @@ static int qpnp_tm_write(struct qpnp_tm_chip *chip, u16 addr, u8 data)
  */
 static long qpnp_tm_decode_temp(struct qpnp_tm_chip *chip, unsigned int stage)
 {
+	if (chip->has_temp_dac) {
+		if (stage == 0 || stage > STAGE_COUNT)
+			return 0;
+
+		return chip->temp_dac_map[stage - 1];
+	}
+
 	if (!chip->temp_map || chip->thresh >= THRESH_COUNT || stage == 0 ||
 	    stage > STAGE_COUNT)
 		return 0;
@@ -221,6 +254,34 @@ static int qpnp_tm_get_temp(struct thermal_zone_device *tz, int *temp)
 	return 0;
 }
 
+static int qpnp_tm_set_temp_dac_thresh(struct qpnp_tm_chip *chip, int trip,
+				       int temp)
+{
+	int ret, temp_cfg;
+	u8 reg;
+
+	if (trip < 0 || 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_dac_map[trip] = temp_cfg;
+
+	return 0;
+}
+
 static int qpnp_tm_update_critical_trip_temp(struct qpnp_tm_chip *chip,
 					     int temp)
 {
@@ -308,6 +369,24 @@ static const struct thermal_zone_device_ops qpnp_tm_sensor_ops = {
 	.set_trip_temp = qpnp_tm_set_trip_temp,
 };
 
+static int qpnp_tm_set_temp_dac_trip_temp(struct thermal_zone_device *tz,
+					  int trip, int temp)
+{
+	struct qpnp_tm_chip *chip = tz->devdata;
+	int ret;
+
+	mutex_lock(&chip->lock);
+	ret = qpnp_tm_set_temp_dac_thresh(chip, trip, temp);
+	mutex_unlock(&chip->lock);
+
+	return ret;
+}
+
+static const struct thermal_zone_device_ops qpnp_tm_sensor_temp_dac_ops = {
+	.get_temp = qpnp_tm_get_temp,
+	.set_trip_temp = qpnp_tm_set_temp_dac_trip_temp,
+};
+
 static irqreturn_t qpnp_tm_isr(int irq, void *data)
 {
 	struct qpnp_tm_chip *chip = data;
@@ -340,6 +419,60 @@ static int qpnp_tm_get_critical_trip_temp(struct qpnp_tm_chip *chip)
 	return THERMAL_TEMP_INVALID;
 }
 
+/* Configure TEMP_DAC registers based on DT thermal_zone trips */
+static int qpnp_tm_temp_dac_update_trip_temps(struct qpnp_tm_chip *chip)
+{
+	const struct thermal_trip *trips;
+	int ret, ntrips, i;
+
+	ntrips = of_thermal_get_ntrips(chip->tz_dev);
+	/* Keep hardware defaults if no DT trips are defined. */
+	if (ntrips <= 0)
+		return 0;
+
+	trips = of_thermal_get_trip_points(chip->tz_dev);
+	if (!trips)
+		return -EINVAL;
+
+	for (i = 0; i < ntrips; i++) {
+		if (of_thermal_is_trip_valid(chip->tz_dev, i)) {
+			ret = qpnp_tm_set_temp_dac_thresh(chip, i,
+							  trips[i].temperature);
+			if (ret < 0)
+				return ret;
+		}
+	}
+
+	/* Verify that trips are strictly increasing. */
+	for (i = 1; i < STAGE_COUNT; i++) {
+		if (chip->temp_dac_map[i] <= chip->temp_dac_map[i - 1]) {
+			dev_err(chip->dev, "Threshold %d=%ld <= threshold %d=%ld\n",
+				i, chip->temp_dac_map[i], i - 1,
+				chip->temp_dac_map[i - 1]);
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+/* Read the hardware default TEMP_DAC stage threshold temperatures */
+static int qpnp_tm_temp_dac_init(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_dac_map[i] = TEMP_DAC_REG_TO_TEMP(reg);
+	}
+
+	return 0;
+}
+
 /*
  * This function initializes the internal temp value based on only the
  * current thermal stage and threshold. Setup threshold control and
@@ -372,10 +505,16 @@ static int qpnp_tm_init(struct qpnp_tm_chip *chip)
 	if (stage)
 		chip->temp = qpnp_tm_decode_temp(chip, stage);
 
-	crit_temp = qpnp_tm_get_critical_trip_temp(chip);
-	ret = qpnp_tm_update_critical_trip_temp(chip, crit_temp);
-	if (ret < 0)
-		goto out;
+	if (chip->has_temp_dac) {
+		ret = qpnp_tm_temp_dac_update_trip_temps(chip);
+		if (ret < 0)
+			goto out;
+	} else {
+		crit_temp = qpnp_tm_get_critical_trip_temp(chip);
+		ret = qpnp_tm_update_critical_trip_temp(chip, crit_temp);
+		if (ret < 0)
+			goto out;
+	}
 
 	/* Enable the thermal alarm PMIC module in always-on mode. */
 	reg = ALARM_CTRL_FORCE_ENABLE;
@@ -392,6 +531,7 @@ static int qpnp_tm_probe(struct platform_device *pdev)
 {
 	struct qpnp_tm_chip *chip;
 	struct device_node *node;
+	const struct thermal_zone_device_ops *ops;
 	u8 type, subtype, dig_major, dig_minor;
 	u32 res;
 	int ret, irq;
@@ -463,19 +603,29 @@ static int qpnp_tm_probe(struct platform_device *pdev)
 		return -ENODEV;
 	}
 
+	ops = &qpnp_tm_sensor_ops;
 	chip->subtype = subtype;
-	if (subtype == QPNP_TM_SUBTYPE_GEN2 && dig_major >= 1)
+	if (subtype == QPNP_TM_SUBTYPE_GEN2 && dig_major >= 2)
+		chip->has_temp_dac = true;
+	else if (subtype == QPNP_TM_SUBTYPE_GEN2 && dig_major >= 1)
 		chip->temp_map = &temp_map_gen2_v1;
 	else
 		chip->temp_map = &temp_map_gen1;
 
+	if (chip->has_temp_dac) {
+		ops = &qpnp_tm_sensor_temp_dac_ops;
+		ret = qpnp_tm_temp_dac_init(chip);
+		if (ret < 0)
+			return ret;
+	}
+
 	/*
 	 * 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_of_zone_register(
-		&pdev->dev, 0, chip, &qpnp_tm_sensor_ops);
+		&pdev->dev, 0, chip, ops);
 	if (IS_ERR(chip->tz_dev)) {
 		dev_err(&pdev->dev, "failed to register sensor\n");
 		return PTR_ERR(chip->tz_dev);
-- 
2.25.1